1
|
John M, Zinyandu T, Rosenblum J, Shashidharan S, Chai P, Shaw F. Neonatal Heart Transplantation in the United States: Trends and Outcomes. J Heart Lung Transplant 2023. [DOI: 10.1016/j.healun.2023.02.1704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
|
2
|
Teoh SE, Tan EWX, Teo YN, Basker G, Teo YH, Chai P, Wong RCC, Yip JWL, Kuntjoro I, Lim YH, Poh KK, Yeo TC, Kong WKF, Sia CH. Effects of medical therapy, transcatheter intervention, and surgery on outcomes of patients with functional mitral regurgitation: a systematic review and network meta-analysis. Eur Heart J 2023. [DOI: 10.1093/eurheartj/ehac779.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Ching-Hui Sia was supported by the National University of Singapore Yong Loo Lin School of Medicine's Junior Academic Fellowship Scheme.
Background
Functional mitral regurgitation (FMR) is the most common valvular heart disease worldwide. Despite recent major trials, the relative efficacy between medical therapy, transcatheter intervention, and surgery for the treatment of FMR remains poorly understood.
Purpose
We performed a systematic review and network meta-analysis of all published randomised controlled trials (RCTs) and observational studies to compare the efficacy between medical therapy, transcatheter intervention, and surgery on the clinical outcomes of patients with FMR.
Methods
Four electronic databases (PubMed, EMBASE, SCOPUS, and the Cochrane Library) were searched from inception to March 13, 2022, for studies reporting clinical outcomes in patients with FMR and comparing the efficacy between either medical therapy, transcatheter intervention, or surgery. Frequentist network meta-analysis models were utilised to summarise the studies. This study was registered in the International Prospective Register of Systematic Reviews.
Results
10 articles were included in the analysis, comprising a combined cohort of 1,981 patients. Network meta-analysis demonstrated that compared to medical therapy, transcatheter intervention achieved a lower relative risk in the composites of all-cause mortality (risk ratio [RR]: 0.43; 95% confidence interval [CI] 0.22-0.82) and mitral regurgitation (MR) severity grade ≥3+ (RR: 0.06; 95% CI 0.01-0.42). Compared to surgery, transcatheter intervention achieved a lower relative risk in the composites of cardiovascular death (RR: 0.36; 95% CI 0.17-0.75) and MR severity grade ≥3+ (RR: 0.25; 95% CI 0.09-0.70) and higher relative risk in the composite of heart failure hospitalisation (RR: 2.94; 95% CI 1.26-6.82). Compared to medical therapy, surgery achieved a higher relative risk in the composite of cardiovascular death (RR: 2.54; 95% CI 1.18-5.47) and lower relative risks in the composites of all-cause mortality (RR: 0.56; 95% CI 0.34-0.91) and heart failure hospitalisation (RR: 0.28; 95% CI 0.13-0.61).
Conclusion
Medical therapy, transcatheter intervention, and surgery in patients with FMR displayed differing effects on the various clinical outcomes. Further head-to-head trials are required to better understand the optimal treatment modality in this population.
Collapse
Affiliation(s)
- S E Teoh
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - E W X Tan
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - Y N Teo
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - G Basker
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - Y H Teo
- National University of Singapore, Department of Medicine , Singapore , Singapore
| | - P Chai
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - R C C Wong
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - J W L Yip
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - I Kuntjoro
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - Y H Lim
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - K K Poh
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - T C Yeo
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - W K F Kong
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - C H Sia
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| |
Collapse
|
3
|
Low CHX, Ong JSP, Li TYW, Ho JSY, Sharma VK, Tan BYQ, Seow SC, Yeo LLL, Yeo TC, Chai P, Chan MYY, Sia CH. Sex-based comparisons of clinical characteristics and outcomes of patients with embolic stroke of undetermined source with implantable loop recorders. Eur Heart J 2023. [DOI: 10.1093/eurheartj/ehac779.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: None.
Introduction
Embolic strokes of undetermined source (ESUS) constitute a significant proportion of all ischemic strokes, but sex-based comparisons of clinical characteristics and outcomes of ESUS patients have not been well explored. As such, we aimed to examine how sex influences outcomes of ESUS patients.
Methods
Retrospective cohort study performed on consecutive ESUS patients with an implanted ILR between December 2013 to September 2021. We obtained information on the patients’ characteristics, treatments, and outcomes from the electronic medical records. Cox regression was used to investigate whether sex was independently associated with outcomes.
Results
There were 176 patients included in this study. The mean duration of follow-up was 1254 ± 724 days. Mean age was 60.8 ± 12.0 and 47 (26.7%) of patients were female. On univariable Cox regression analysis for subsequent atrial fibrillation (AF) on implantable loop recorder (ILR), patients with subsequent AF on ILR were more likely to be female (HR 2.19, 95% CI 1.04–4.63, p = 0.040), older (HR 1.07, 95% CI 1.03–1.12, p = 0.001), have a lower glomerular filtration rate (eGFR) (HR 0.98, 95% CI 0.97– 0.99, p = 0.004), and have previous percutaneous coronary intervention (PCI) (HR 2.60, 95% CI 1.05–6.46, p = 0.039). On multivariable Cox regression, after adjustment for age, eGFR and previous PCI status, female sex remained independently associated with the development of subsequent AF on ILR. Female sex was not associated with other outcomes including mortality, subsequent acute myocardial infarction, stroke/transient ischemic attack and heart failure.
Conclusions
In this cohort of ESUS patients with ILR implantation, female sex was independently associated with a higher risk of development of AF on ILR. However, female sex was not a predictor of mortality, subsequent acute myocardial infarction, stroke/transient ischemic attack and heart failure.
Collapse
Affiliation(s)
- C H X Low
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - J S P Ong
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - T Y W Li
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - J S Y Ho
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - V K Sharma
- National University Hospital, Division of Neurology, Department of Medicine , Singapore , Singapore
| | - B Y Q Tan
- National University Hospital, Division of Neurology, Department of Medicine , Singapore , Singapore
| | - S C Seow
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - L L L Yeo
- National University Hospital, Division of Neurology, Department of Medicine , Singapore , Singapore
| | - T C Yeo
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - P Chai
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - M Y Y Chan
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - C H Sia
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| |
Collapse
|
4
|
Teo YN, Basker G, Teoh SE, Tan EWX, Teo YH, Chai P, Wong RCC, Yip JWL, Kuntjoro I, Lim Y, Poh KK, Yeo TC, Kong WKF, Sia CH. Natural history of functional mitral regurgitation: a systematic review and individual patient data meta-analysis. Eur Heart J 2023. [DOI: 10.1093/eurheartj/ehac779.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Ching-Hui Sia was supported by the National University of Singapore Yong Loo Lin School of Medicine's Junior Academic Fellowship Scheme.
Background
Functional mitral regurgitation (FMR) precipitates a vicious cycle of left ventricular volume overload and remodelling, leading to perpetual worsening of FMR and left ventricular dysfunction, with a resultant poor prognosis. However, there is a lack of conclusive data on the natural progression of FMR in patients who do not undergo valvular intervention.
Purpose
We performed a one-stage meta-analysis on reconstructed individual patient data (IPD) to elucidate the natural history of FMR.
Methods
Four databases (PubMed, Embase, Scopus, Cochrane) were searched for randomised controlled trials or cohorts, published from inception to March 13, 2022, reporting clinical outcomes in patients with FMR not receiving valvular intervention. IPD meta-analysis, as the gold standard approach for evidence synthesis, was performed with reconstructed IPD obtained from the survival curves reported in the included studies. Pooled survival estimates were derived. Quality assessment of included studies was conducted using the Cochrane risk-of-bias tool and Newcastle Ottawa Scale. This study was registered on the International Prospective Register of Systematic Reviews.
Results
A total of five studies were included, comprising a total cohort of 691 patients with FMR who did not undergo valvular intervention. The mean age of the cohort was 72.4 years (95% CI 67.6 to 77.1) and the proportion of males was 61.1% (95% CI 43.8 to 76.0). All-cause mortality was analysed over a follow-up duration of five years, while hospitalisation for heart failure, cardiovascular death, and the composite of all-cause mortality and hospitalisation for heart failure were analysed over a follow-up duration of three years. The probability of survival of patients with FMR without intervention was 79.4% (95% CI 76.2 to 82.3), 50.9% (95% CI 46.6 to 55.1), and 39.6% (95% CI 33.1 to 46.0) at one, three, and five years respectively. The probability of survival free from the composite of all-cause mortality and hospitalisation for heart failure was 51.3% (95% CI 46.8 to 55.6) and 12.0% (95% CI 8.9 to 15.7) at one year and three years respectively. The probability of survival free from hospitalisation for heart failure was 58.3% (95% CI 54.0 to 62.3) and 19.7% (95% CI 16.0 to 23.7) at one and three years respectively. The probability of survival free from cardiovascular death was 75.4% (95% CI 68.9 to 80.8) and 45.6% (95% CI 29.1 to 60.7) at one and three years respectively. All included studies were of low to moderate risk of bias.
Conclusion
FMR in the absence of valvular intervention is associated with poor survival and cardiovascular outcomes. Further research should focus on the role of interventions to mitigate its poor prognosis.
Collapse
Affiliation(s)
- Y N Teo
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - G Basker
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - S E Teoh
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - E W X Tan
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - Y H Teo
- National University of Singapore, Department of Medicine , Singapore , Singapore
| | - P Chai
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - R C C Wong
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - J W L Yip
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - I Kuntjoro
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - Y Lim
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - K K Poh
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - T C Yeo
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - W K F Kong
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - C H Sia
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| |
Collapse
|
5
|
Chong B, Jayabaskaran J, Ruban J, Goh R, Chin YH, Kong G, Ng CH, Foo R, Chai P, Kong W, Poh KK, Chan MY, Mehta A, Dimitriadis GK, Chew NWS. Effects of epicardial adipose tissue volume and thickness assessed by computed tomography and echocardiography on cardiovascular and cerebrovascular outcomes: a systematic review and meta-analysis. Eur Heart J 2023. [DOI: 10.1093/eurheartj/ehac779.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: None.
Background
Epicardial adipose tissue (EAT) has garnered attention as a potential imaging biomarker for the risk stratification of cardiovascular diseases (CVD). However, the prognostic utility of EAT due to inter-ethnic differences and imaging modality (computed tomography (CT) or transthoracic echocardiography (TTE)) remains undetermined.
Purpose
To evaluate the effect of EAT volume and thickness on cardiovascular and cerebrovascular outcomes. We also aim to compare the prognostic utility between CT volumetric and TTE thickness quantification; and provide consolidated data on the heterogeneity in EAT measurements across different ethnic groups.
Methods
Medline and Embase databases were searched from inception till 16 May 2022 for studies that measured EAT volume or thickness of adult patients at baseline and reported follow-up data on outcomes of interest. Outcomes included MACE, all-cause mortality, cardiac death, myocardial infarction (MI), coronary revascularisation, atrial fibrillation (AF), and stroke. Statistical analyses were conducted on Review Manager 5.4.1 to obtain unadjusted and adjusted hazard ratios (HR) and odds ratios (OR) with the results presented on forest plots.
Results
Twenty-nine studies comprising 19709 patients were included in our analysis. Increased EAT thickness and volume were associated with higher risks of MACE (adjusted HR [aHR] 1.46, 95%CI 1.25–1.71, p<0.001), cardiac death (OR 2.53, 95%CI 1.17–5.44, p=0.020), MI (OR 2.63, 95%CI 1.39–4.96, p=0.003), coronary revascularisation (OR 2.99, 95%CI 1.64–5.44, p<0.001), AF (aOR 4.04, 95%CI 3.06–5.32, p<0.001), and stroke (HR 1.02, 95%CI 1.01–1.03, p<0.001). CT-volumetric quantification of EAT conferred a larger MACE risk (aHR 1.79, 95%CI 1.47–2.17, p<0.001) compared to TTE thickness quantification (aHR 1.20, 95%CI 1.09–1.32, p<0.001). Studies originating from North America (HR 1.91, 95%CI 1.26–2.89, p=0.002) and Asia (HR 1.60, 95%CI 1.09–2.36, p=0.020) demonstrated a significantly higher risk of MACE with increased EAT thickness and volume. However, this significance was not seen in European studies (HR 1.48, 95%CI 0.99–2.20, p=0.060). Subgroup differences were also noted across the studies’ countries of origin when analysing the association of EAT and MI (p=0.020). European studies reported a higher magnitude of MI risk associated with higher EAT thickness and volume (OR 5.28, 95%CI 2.34–11.95, p<0.001) as compared to Asian studies (OR 1.75, 95%CI 1.05–2.92, p=0.030). No differences were noted across other outcomes in the subgroup comparisons by geographical region and between CT and TTE quantification of EAT.
Conclusion
The utility of EAT as an imaging biomarker for predicting and prognosticating CVD is promising. Future efforts to harmonise the EAT parameter thresholds, based on the type of imaging modality and the target population’s ethnic characteristics, will be the next important step before including EAT in CVD prediction models.
Collapse
Affiliation(s)
- B Chong
- National University of Singapore , Singapore , Singapore
| | - J Jayabaskaran
- National University of Singapore , Singapore , Singapore
| | - J Ruban
- National University of Singapore , Singapore , Singapore
| | - R Goh
- National University of Singapore , Singapore , Singapore
| | - Y H Chin
- National University of Singapore , Singapore , Singapore
| | - G Kong
- National University of Singapore , Singapore , Singapore
| | - C H Ng
- National University of Singapore , Singapore , Singapore
| | - R Foo
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - P Chai
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - W Kong
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - K K Poh
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - M Y Chan
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - A Mehta
- VCU Health Pauley Heart Center, Division of Cardiology , Richmond , United States of America
| | - G K Dimitriadis
- King's College Hospital NHS Foundation Trust, Department of Endocrinology , London , United Kingdom of Great Britain & Northern Ireland
| | - N W S Chew
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| |
Collapse
|
6
|
Chai P, Wu Z, Wu L, Wang H, Fu C, Huang W. An Operando Study of H 2O-Enhanced Low-Temperature CO Oxidation on Pt(111) under Near Ambient Pressure Conditions. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peng Chai
- Hefei National Research Center for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Zongfang Wu
- Hefei National Research Center for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Longxia Wu
- Hefei National Research Center for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Haocheng Wang
- Hefei National Research Center for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Cong Fu
- Hefei National Research Center for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Weixin Huang
- Hefei National Research Center for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian 116023, P. R. China
| |
Collapse
|
7
|
Goh FQ, Sim JJL, Ling RR, Neo VSQ, Ng EST, Leow AST, Tan BYQ, Kong WKF, Sharma VK, Poh KK, Wong RC, Yeo LLL, Chai P, Yeo TC, Sia CH. Clinical characteristics, echocardiographic features and long-term outcomes of patients with ischaemic versus non-ischaemic left ventricular thrombus. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Left ventricular thrombus (LVT) may develop in patients following myocardial infarction (MI), as well as in ischaemic and non-ischaemic cardiomyopathies, and may result in acute ischaemic stroke. Smaller studies comparing LVT associated with ischaemic and non-ischaemic aetiologies only reported 1-year outcomes or focused on specific subpopulations. We aimed to compare the clinical and echocardiographic characteristics and longer-term outcomes in a large population of patients with ischaemic versus non-ischaemic LVT.
Methods
This was a retrospective study of 552 consecutive patients with echocardiographically-identified LVT from March 2011 to January 2021 at a tertiary centre. Ischaemic LVT included LVT associated with MI and ischaemic cardiomyopathy. Non-ischaemic LVT included cases without evidence of ischaemia. Echocardiographic images were interpreted by trained cardiologists. We studied thrombus resolution as well as 5-year rates of ischaemic stroke and all-cause mortality.
Results
Of the 552 patients, mean age was 59.9 years and 84.4% were male. 492 patients had ischaemic LVT and 60 patients had non-ischaemic LVT. Ischaemic LVT was associated with older age (60.4 versus 55.3 years), male sex (86.8% versus 65.0%), smoking (49.2% versus 25.0%) and hyperlipidaemia (54.3% versus 28.3%). Left ventricular ejection fraction (LVEF) was lower in non-ischaemic LVT (28.9% versus 31.9%). LVEF ≤35% was associated with increased mortality in ischaemic LVT (HR 2.11, 95% CI 1.32–3.38). Rates of thrombus resolution, stroke and all-cause mortality were similar in the 2 groups. Anticoagulation was associated with a lower risk of stroke in ischaemic LVT (HR 0.32, 95% CI 0.16–0.66) and lower mortality in both ischaemic (HR 0.44, 95% CI 0.26–0.72) and non-ischaemic LVT (HR 0.14, 95% CI 0.03–0.61).
Conclusion
Patients with ischaemic LVT were more often older, male, smokers and had cardiovascular co-morbidities compared to those with non-ischaemic LVT. Thrombus resolution, stroke and all-cause mortality rates were similar in both groups. Anticoagulation was associated with lower mortality but this needs to be investigated in future prospective studies.
Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): CHS was supported by the National University of Singapore Yong Loo Lin School of Medicine's Junior Academic Faculty Scheme
Collapse
Affiliation(s)
- F Q Goh
- National University Hospital , Singapore , Singapore
| | - J J L Sim
- National University of Singapore, Department of Medicine, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - R R Ling
- National University of Singapore, Department of Medicine, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - V S Q Neo
- National University of Singapore, Department of Medicine, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - E S T Ng
- National University of Singapore, Department of Medicine, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - A S T Leow
- National University Hospital , Singapore , Singapore
| | - B Y Q Tan
- National University Hospital, Division of Neurology, Department of Medicine , Singapore , Singapore
| | - W K F Kong
- National University Heart Centre , Singapore , Singapore
| | - V K Sharma
- National University Hospital, Division of Neurology, Department of Medicine , Singapore , Singapore
| | - K K Poh
- National University Heart Centre , Singapore , Singapore
| | - R C Wong
- National University Heart Centre , Singapore , Singapore
| | - L L L Yeo
- National University Hospital, Division of Neurology, Department of Medicine , Singapore , Singapore
| | - P Chai
- National University Heart Centre , Singapore , Singapore
| | - T C Yeo
- National University Heart Centre , Singapore , Singapore
| | - C H Sia
- National University Heart Centre , Singapore , Singapore
| |
Collapse
|
8
|
Zeng Y, Cai Y, Chai P, Mao Y, Chen Y, Wang L, Zeng K, Zhan Z, Xie Y, Li C, Zhan H, Zhao L, Chen X, Zhu X, Liu Y, Chen M, Song Y, Zhou A. Optimization of cancer immunotherapy through pyroptosis: A pyroptosis-related signature predicts survival benefit and potential synergy for immunotherapy in glioma. Front Immunol 2022; 13:961933. [PMID: 35990696 PMCID: PMC9382657 DOI: 10.3389/fimmu.2022.961933] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 07/11/2022] [Indexed: 12/03/2022] Open
Abstract
Background Pyroptosis is a critical type of programmed cell death that is strongly associated with the regulation of tumor and immune cell functions. However, the role of pyroptosis in tumor progression and remodeling of the tumor microenvironment in gliomas has not been extensively studied. Thus, in this study, we aimed to establish a comprehensive pyroptosis-related signature and uncover its potential clinical application in gliomas. Methods The TCGA glioma cohort was obtained and divided into training and internal validation cohorts, while the CGGA glioma cohort was used as an external validation cohort. Unsupervised consensus clustering was performed to identify pyroptosis-related expression patterns. A Cox regression analysis was performed to establish a pyroptosis-related risk signature. Real-time quantitative PCR was performed to analyze the expression of signature genes in glioma tissues. Immune infiltration was analyzed and validated by immunohistochemical staining. The expression patterns of signature genes in different cell types were analyzed using single-cell RNA sequencing data. Finally, therapeutic responses to chemotherapy, immunotherapy, and potential small-molecule inhibitors were investigated. Results Patients with glioma were stratified into clusters 1 and 2 based on the expression patterns of pyroptosis-related genes. Cluster 2 showed a longer overall (P<0.001) and progression-free survival time (P<0.001) than Cluster 1. CD8+ T cell enrichment was observed in Cluster 1. A pyroptosis-related risk signature (PRRS) was then established. The high PRRS group showed a significantly poorer prognosis than the low PRRS group in the training cohort (P<0.001), with validation in the internal and external validation cohorts. Immunohistochemical staining demonstrated that CD8+ T cells were enriched in high PRRS glioma tissues. PRRS genes also showed cell-specific expression in tumor and immune cells. Moreover, the high PRRS risk group showed higher temozolomide sensitivity and increased response to anti-PD1 treatment in a glioblastoma immunotherapy cohort. Finally, Bcl-2 inhibitors were screened as candidates for adjunct immunotherapy of gliomas. Conclusion The pyroptosis-related signature established in this study can be used to reliably predict clinical outcomes and immunotherapy responses in glioma patients. The correlation between the pyroptosis signature and the tumor immune microenvironment may be used to further guide the sensitization of glioma patients to immunotherapy.
Collapse
Affiliation(s)
- Yu Zeng
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Yonghua Cai
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Peng Chai
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yangqi Mao
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yanwen Chen
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Li Wang
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Kunlin Zeng
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Ziling Zhan
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Yuxin Xie
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Cuiying Li
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Hongchao Zhan
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Liqian Zhao
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xiaoxia Chen
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Xiaoxia Zhu
- Department of Radiation Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Yu Liu
- Department of Neurosurgery, Shanghai Children’s Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Ming Chen
- Department of Neurosurgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Aidong Zhou, ; Ye Song, ; Ming Chen,
| | - Ye Song
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
- Department of Neurosurgery, Ganzhou People’s Hospital, Ganzhou, China
- *Correspondence: Aidong Zhou, ; Ye Song, ; Ming Chen,
| | - Aidong Zhou
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
- Department of Radiation Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- Guangdong Province Key Laboratory of Molecular Tumor Pathology, Southern Medical University, Guangzhou, China
- *Correspondence: Aidong Zhou, ; Ye Song, ; Ming Chen,
| |
Collapse
|
9
|
Luo Y, Rao Y, Gu X, Chai P, Yang Y, Lin J, Xu X, Jia R, Xu S. Novel MSH6 mutation predicted metastasis in eyelid and periocular squamous cell carcinoma. J Eur Acad Dermatol Venereol 2022; 36:2331-2342. [PMID: 35855666 DOI: 10.1111/jdv.18454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 06/03/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Our previous research revealed the relative local aggressiveness of eyelid and periocular squamous cell carcinoma (EPSCC), but its distinct genetic characteristics involved remain unknown. OBJECTIVES We conducted this study based on next-generation sequencing to identify the genetic distinctiveness of EPSCC and damaging mutations for possible etiology and poor prognosis. METHODS We performed sequencing using a 556-gene panel (smartonco) in 48 EPSCCs. Cox hazards model was applied to explore mutated genes that increase risk of metastasis and death. Pathogenesis of the mutations was predicted by sequence alignment algorithms. RESULTS The most commonly mutated genes were KMT2C (N=17, 35%), LRP1B (N=14, 29%), KMT2D (N=12, 25%), PTCH1(N=10, 21%) and TP53(N=10, 21%). DNA mismatch repair (MMR) genes (42%) like MSH6(19%) and MLH3(12%) were among the most frequently mutated genes. Cell cycle regulators including TP53(21%) and CDKN2A (10%) were less frequently mutated than in other squamous cell carcinomas (SCCs). Ultra violet exposure, MMR deficiency and aging were the main etiology. Of note, KMT2C has a deleterious mutation hotspot. Patients burdened with MSH6 mutation has a higher risk of overall metastasis (P=0.045, HR=5.165) and nodal metastasis (P=0.022, HR=14.038). Moreover, a hotspot mutation MSH6E52A brought an even higher risk of nodal metastasis (P=0.011, HR=18.745). CONCLUSIONS EPSCCs displayed a unique mutation profile from cutaneous SCCs and mucosal SCCs. We have identified novel damaging mutations in epigenetic regulators like KMT2C boosted early onset of EPSCCs in addition to UVR, aging or MMR deficiency. And malfunction of MMR genes worsened prognosis.
Collapse
Affiliation(s)
- Y Luo
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - Y Rao
- Department of pathology, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China
| | - X Gu
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - P Chai
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - Y Yang
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - J Lin
- Department of pathology, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China
| | - X Xu
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - R Jia
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| | - S Xu
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China
| |
Collapse
|
10
|
Wang C, Leng S, Tan R, Chai P, Fam J, Teo L, Chin C, Ong C, Baskaran L, Keng F, Low A, Chan M, Wong A, Chua T, Tan S, Lim S, Zhong L. 517 Computed Tomography Coronary Angiography Based Morphological Index Predicts Coronary Ischemia. J Cardiovasc Comput Tomogr 2022. [DOI: 10.1016/j.jcct.2022.06.128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
11
|
Cai Y, Li K, Lin J, Liang X, Xu W, Zhan Z, Xue S, Zeng Y, Chai P, Mao Y, Song Z, Han L, Song Y, Zhang X, Wang H. Lighting a Fire: Gasdermin-Mediated Pyroptosis Remodels the Glioma Microenvironment and Promotes Immune Checkpoint Blockade Response. Front Immunol 2022; 13:910490. [PMID: 35784306 PMCID: PMC9249059 DOI: 10.3389/fimmu.2022.910490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/11/2022] [Indexed: 12/02/2022] Open
Abstract
Pyroptosis is a proinflammatory programmed cell death pathway mediated by gasdermins. Exploring the role of pyroptosis can provide new insights into tumor malignancy. The most recent studies on pyroptosis have focused on tumor cells. However, the effects of pyroptosis on the tumor microenvironment (TME), immunotherapeutic responses, and efficacy have been neglected, especially in case of glioma. In this study, four independent glioma cohorts comprising 1,339 samples and a pan-cancer cohort comprising 10,535 tumor samples were analyzed. The relationships among pyroptosis status, prognosis, microenvironment cellular components, and clinical and biological phenotypes were investigated through the identification of pyroptosis subtypes, construction of a gasdermin-related prognostic index (GPI), and evaluation of immunological characteristics in glioma. The Genomics of Drug Sensitivity in Cancer database and “pRRophetic” package in R were used to estimate temozolomide (TMZ) sensitivity. The “Submap” package and external immunotherapy cohorts were used to investigate and confirm the role of GPI in response to and efficacy of immunotherapy in glioma. Finally, potential small-molecule compounds related to GPI were identified using the connectivity map database and mode-of-action analysis. We identified three different pyroptosis subtypes: cluster 1 (C1) characterized by a higher GPI, while cluster 2 (C2) and cluster 3 (C3) characterized by a lower GPI. The high GPI of C1 was associated with glioma progression and worse prognoses, whereas the low GPI of subtype C2 and C3 was associated with better prognoses. However, patients with high GPIs were found to be more sensitive to TMZ and immune checkpoint blockade than those with low GPIs. Furthermore, gasdermin D may be a principal potential biomarker and play key roles in pyroptosis-inducible therapy combined with immunotherapy in glioma. This study provides a clinical, biological, and molecular landscape of pyroptosis and suggests that pyroptosis of glioma cells may perform the dual function of promoting both tumorigenesis and antitumor immunity.
Collapse
Affiliation(s)
- Yonghua Cai
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Ke Li
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jie Lin
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xianqiu Liang
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Wei Xu
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zhengming Zhan
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Shuaishuai Xue
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yu Zeng
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Peng Chai
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yangqi Mao
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zibin Song
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Lei Han
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Ye Song
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
- Department of Neurosurgery, Ganzhou People’s Hospital, Ganzhou, China
- *Correspondence: Hai Wang, ; Xian Zhang, ; Ye Song,
| | - Xian Zhang
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
- *Correspondence: Hai Wang, ; Xian Zhang, ; Ye Song,
| | - Hai Wang
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
- *Correspondence: Hai Wang, ; Xian Zhang, ; Ye Song,
| |
Collapse
|
12
|
Thamlikitkul L, Chai P, Nadal CB, Roy R, Sun XM, MacFarlane M, Keun H, Seckl M, Pardo O. Abstract 3037: RSK4 inhibition promotes pseudo-hypoxic metabolic responses in lung adenocarcinoma. Cancer Res 2022. [DOI: 10.1158/1538-7445.am2022-3037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: RSK4 is a member of the p90 Ribosomal S6 kinase family that promotes metastasis and chemoresistance in non-small cell lung cancer and its inhibition improves therapeutic outcome in in vivo and ex vivo models. Here, we show that RSK4 inhibition activates HIF-1alpha and also impacts glucose and glutamine metabolism in lung adenocarcinoma cells.
Methods: RSK4 was downregulated in lung adenocarcinoma cells by RNA interference or CRISPR/Cas9 technology. Glycolytic rate assay and mitochondrial stress test were performed using the Seahorse XFe96 analyzer. ATP levels were determined by the CellTiter Glo assay. Intracellular metabolites were profiled by untargeted mass spectrometry and U-13C glutamine labelling. 3D spheroids viability was assessed by CellTiter Glo 3D assay with or without glycolysis inhibition using 2-deoxy-D-glucose (2DG) or glutaminase inhibition using 6-Diazo-5-oxo-L-norleucine (DON). Protein expression was determined by Western blotting.
Results: RSK4 downregulation enhanced glycolysis, oxidative phosphorylation, and ATP production in A549 cells. The RSK4-silenced cells showed increased lactate production and glutamine consumption via reductive carboxylation. This sensitized RSK4-silenced cells to 2DG and DON treatments. Mechanistically, RSK4 knockdown upregulates HIF-1alpha in normoxia through decreased activation of PHD2, an enzymes that targets HIF-1alpha for degradation. Stabilization of HIF-1alpha resulted in increased transcription of HK2, the rate limiting enzyme of glycolysis, and GLS1, which hydrolyzes glutamine.
Conclusion: RSK4 knockdown promotes a pseudo-hypoxic phenotype in lung adenocarcinoma cells characterized by increased glycolysis and enhanced glutamine utilization via reductive carboxylation. Targeting these changes potentiates the effects of RSK4 inhibition and may represent new therapeutic opportunities for this tumor type.
Citation Format: Lucksamon Thamlikitkul, Peng Chai, Cristina Balcells Nadal, Rajat Roy, Xiao-Ming Sun, Marion MacFarlane, Hector Keun, Michael Seckl, Olivier Pardo. RSK4 inhibition promotes pseudo-hypoxic metabolic responses in lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3037.
Collapse
Affiliation(s)
| | - Peng Chai
- 2Imperial College London, London, United Kingdom
| | | | - Rajat Roy
- 2Imperial College London, London, United Kingdom
| | - Xiao-Ming Sun
- 3MRC Toxicology Unit, Cambridge University, Cambridge, United Kingdom
| | - Marion MacFarlane
- 3MRC Toxicology Unit, Cambridge University, Cambridge, United Kingdom
| | - Hector Keun
- 2Imperial College London, London, United Kingdom
| | | | | |
Collapse
|
13
|
Chai P, Jin Y, Sun G, Ding L, Wu L, Wang H, Fu C, Wu Z, Huang W. A near-ambient pressure flow reactor coupled with polarization-modulation infrared reflection absorption spectroscopy for operando studies of heterogeneous catalytic reactions over model catalysts. Rev Sci Instrum 2022; 93:054105. [PMID: 35649779 DOI: 10.1063/5.0081102] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/28/2022] [Indexed: 06/15/2023]
Abstract
The model catalyst approach is often used for fundamental investigations of complex heterogeneous catalysis, in which operando characterizations are critical. A flow reactor is usually adopted for gas-solid heterogeneous catalytic reactions. Herein, we report a home-designed near-ambient pressure (NAP) flow reactor coupled with polarization-modulation infrared reflection absorption spectroscopy (PM-IRAS) and an online quadrupole mass spectrometer for operando studies of heterogeneous catalytic reactions over model catalysts. A unique gas supply system is designed and manufactured to enable a stable gas inlet to the NAP flow reactor at pressures up to ∼100 mbar. An ultrahigh vacuum chamber equipped with the facilities for x-ray photoelectron spectroscopy, low-energy electron diffraction, thermal desorption spectroscopy, E-beam evaporation source, and ion sputtering gun is connected to the NAP flow reactor via a gate valve for preparations and routine characterizations of model catalysts. The functions of the system are demonstrated by in situ PM-IRAS characterization of CO adsorption on Pt(111) and operando characterizations of CO oxidation on Pt(111) under NAP conditions.
Collapse
Affiliation(s)
- Peng Chai
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Yuekang Jin
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Guanghui Sun
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Liangbing Ding
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Longxia Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Haocheng Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Cong Fu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Zongfang Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Weixin Huang
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| |
Collapse
|
14
|
Wu L, Wu Z, Wang Z, Xu H, Chai P, Huang W. In Situ Generated Ti 3+-Mediated Photocatalytic Methanol Decomposition to Carbon Monoxide and Hydrogen on a Rutile TiO 2(100) Surface. J Phys Chem Lett 2022; 13:2614-2618. [PMID: 35293745 DOI: 10.1021/acs.jpclett.1c04198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Photocatalysis of methanol on the TiO2 surface is a prototype of photocatalytic reactions. Here, we unveil a synergistic effect of photoexcited electrons and holes on converting methanol to CO and H2 on a rutile TiO2(100) surface. Upon Hg light irradiation, photoexcited holes oxidize methoxy species at the 5-fold coordinated Ti4+ sites sequentially to formaldehyde and formate intermediates, while photoexcited electrons reduce the associated Ti4+ sites to Ti3+ sites. The formate intermediates selectively decompose to CO and H2 mediated by the Ti3+ sites at elevated temperatures. These results greatly enrich methanol photochemistry on the TiO2 surface and point to a surface structure engineering strategy of oxide photocatalysts for photocatalytic direct methanol decomposition to CO and H2.
Collapse
Affiliation(s)
- Longxia Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Zongfang Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Zhengming Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Hong Xu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- State Key Laboratory of Fire Science, University of Science of Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Peng Chai
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Weixin Huang
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian, Liaoning 116023, People's Republic of China
| |
Collapse
|
15
|
Cai Y, Liang X, Zhan Z, Zeng Y, Lin J, Xu A, Xue S, Xu W, Chai P, Mao Y, Song Z, Han L, Xiao J, Song Y, Zhang X. A Ferroptosis-Related Gene Prognostic Index to Predict Temozolomide Sensitivity and Immune Checkpoint Inhibitor Response for Glioma. Front Cell Dev Biol 2022; 9:812422. [PMID: 35174170 PMCID: PMC8842730 DOI: 10.3389/fcell.2021.812422] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 12/30/2021] [Indexed: 12/20/2022] Open
Abstract
Background: Gliomas are highly lethal brain tumors. Despite multimodality therapy with surgery, radiotherapy, chemotherapy, and immunotherapy, glioma prognosis remains poor. Ferroptosis is a crucial tumor suppressor mechanism that has been proven to be effective in anticancer therapy. However, the implications of ferroptosis on the clinical prognosis, chemotherapy, and immune checkpoint inhibitor (ICI) therapy for patients with glioma still need elucidation. Methods: Consensus clustering revealed two distinct ferroptosis-related subtypes based on the Cancer Genome Atlas (TCGA) glioma dataset (n = 663). Subsequently, the ferroptosis-related gene prognostic index (FRGPI) was constructed by weighted gene co-expression network analysis (WGCNA) and “stepAIC” algorithms and validated with the Chinese Glioma Genome Atlas (CGGA) dataset (n = 404). Subsequently, the correlation among clinical, molecular, and immune features and FRGPI was analyzed. Next, the temozolomide sensitivity and ICI response for glioma were predicted using the “pRRophetic” and “TIDE” algorithms, respectively. Finally, candidate small molecular drugs were defined using the connectivity map database based on FRGPI. Results: The FRGPI was established based on the HMOX1, TFRC, JUN, and SOCS1 genes. The distribution of FRGPI varied significantly among the different ferroptosis-related subtypes. Patients with high FRGPI had a worse overall prognosis than patients with low FRGPI, consistent with the results in the CGGA dataset. The final results showed that high FRGPI was characterized by more aggressive phenotypes, high PD-L1 expression, high tumor mutational burden score, and enhanced temozolomide sensitivity; low FRGPI was associated with less aggressive phenotypes, high microsatellite instability score, and stronger response to immune checkpoint blockade. In addition, the infiltration of memory resting CD4+ T cells, regulatory T cells, M1 macrophages, M2 macrophages, and neutrophils was positively correlated with FRGPI. In contrast, plasma B cells and naïve CD4+ T cells were negatively correlated. A total of 15 potential small molecule compounds (such as depactin, physostigmine, and phenacetin) were identified. Conclusion: FRGPI is a promising gene panel for predicting the prognosis, immune characteristics, temozolomide sensitivity, and ICI response in patients with glioma.
Collapse
Affiliation(s)
- Yonghua Cai
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xianqiu Liang
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zhengming Zhan
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yu Zeng
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jie Lin
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Anqi Xu
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Shuaishuai Xue
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Wei Xu
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Peng Chai
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yangqi Mao
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zibin Song
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Lei Han
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jianqi Xiao
- Department of Neurosurgery, The First Hospital of Qiqihar City, Qiqihar, China
- *Correspondence: Xian Zhang, ; Ye Song, ; Jianqi Xiao,
| | - Ye Song
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
- Department of Neurosurgery, Ganzhou People’s Hospital, Ganzhou, China
- *Correspondence: Xian Zhang, ; Ye Song, ; Jianqi Xiao,
| | - Xian Zhang
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
- *Correspondence: Xian Zhang, ; Ye Song, ; Jianqi Xiao,
| |
Collapse
|
16
|
Xiong W, Gu XK, Zhang Z, Chai P, Zang Y, Yu Z, Li D, Zhang H, Liu Z, Huang W. Author Correction: Fine cubic Cu 2O nanocrystals as highly selective catalyst for propylene epoxidation with molecular oxygen. Nat Commun 2021; 12:6429. [PMID: 34728611 PMCID: PMC8563758 DOI: 10.1038/s41467-021-26712-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Wei Xiong
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes and Department of Chemical Physics, University of Science and Technology of China, 230026, Hefei, People's Republic of China
| | - Xiang-Kui Gu
- School of Power and Mechanical Engineering, Wuhan University, 430072, Wuhan, People's Republic of China
| | - Zhenhua Zhang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces, Institute of Physical Chemistry, Zhejiang Normal University, 321004, Jinhua, People's Republic of China
| | - Peng Chai
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes and Department of Chemical Physics, University of Science and Technology of China, 230026, Hefei, People's Republic of China
| | - Yijing Zang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, People's Republic of China
| | - Zongyou Yu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes and Department of Chemical Physics, University of Science and Technology of China, 230026, Hefei, People's Republic of China
| | - Dan Li
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes and Department of Chemical Physics, University of Science and Technology of China, 230026, Hefei, People's Republic of China
| | - Hui Zhang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, People's Republic of China
| | - Zhi Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, People's Republic of China.,School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, People's Republic of China
| | - Weixin Huang
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes and Department of Chemical Physics, University of Science and Technology of China, 230026, Hefei, People's Republic of China. .,Dalian National Laboratory for Clean Energy, 116023, Dalian, People's Republic of China.
| |
Collapse
|
17
|
Xiong W, Gu XK, Zhang Z, Chai P, Zang Y, Yu Z, Li D, Zhang H, Liu Z, Huang W. Fine cubic Cu 2O nanocrystals as highly selective catalyst for propylene epoxidation with molecular oxygen. Nat Commun 2021; 12:5921. [PMID: 34635649 PMCID: PMC8505410 DOI: 10.1038/s41467-021-26257-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 09/21/2021] [Indexed: 11/24/2022] Open
Abstract
Propylene epoxidation with O2 to propylene oxide is a very valuable reaction but remains as a long-standing challenge due to unavailable efficient catalysts with high selectivity. Herein, we successfully explore 27 nm-sized cubic Cu2O nanocrystals enclosed with {100} faces and {110} edges as a highly selective catalyst for propylene epoxidation with O2, which acquires propylene oxide selectivity of more than 80% at 90–110 °C. Propylene epoxidation with weakly-adsorbed O2 species at the {110} edge sites exhibits a low barrier and is the dominant reaction occurring at low reaction temperatures, leading to the high propylene oxide selectivity. Such a weakly-adsorbed O2 species is not stable at high reaction temperatures, and the surface lattice oxygen species becomes the active oxygen species to participate in propylene epoxidation to propylene oxide and propylene partial oxidation to acrolein at the {110} edge sites and propylene combustion to CO2 at the {100} face sites, which all exhibit high barriers and result in decreased propylene oxide selectivity. Direct propylene epoxidation with O2 to form propylene oxide (PO) selectively is a challenge. Here, the authors explore 27 nm-sized cubic Cu2O nanocrystals as thermocatalysts for this reaction which facilitate PO production with high selectivity, >80%, at moderate temperatures of 90–110 °C.
Collapse
Affiliation(s)
- Wei Xiong
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes and Department of Chemical Physics, University of Science and Technology of China, 230026, Hefei, People's Republic of China
| | - Xiang-Kui Gu
- School of Power and Mechanical Engineering, Wuhan University, 430072, Wuhan, People's Republic of China
| | - Zhenhua Zhang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces, Institute of Physical Chemistry, Zhejiang Normal University, 321004, Jinhua, People's Republic of China
| | - Peng Chai
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes and Department of Chemical Physics, University of Science and Technology of China, 230026, Hefei, People's Republic of China
| | - Yijing Zang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, People's Republic of China
| | - Zongyou Yu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes and Department of Chemical Physics, University of Science and Technology of China, 230026, Hefei, People's Republic of China
| | - Dan Li
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes and Department of Chemical Physics, University of Science and Technology of China, 230026, Hefei, People's Republic of China
| | - Hui Zhang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, People's Republic of China
| | - Zhi Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, People's Republic of China.,School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, People's Republic of China
| | - Weixin Huang
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes and Department of Chemical Physics, University of Science and Technology of China, 230026, Hefei, People's Republic of China. .,Dalian National Laboratory for Clean Energy, 116023, Dalian, People's Republic of China.
| |
Collapse
|
18
|
Sun G, Wang F, Jin Y, Chen X, Chai P, Wu L, Teng BT, Huang W. Oxidative Coupling of Methanol with Molecularly Adsorbed Oxygen on Au Surface to Methyl Formate. J Phys Chem Lett 2021; 12:6941-6945. [PMID: 34282915 DOI: 10.1021/acs.jpclett.1c01564] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Supported Au catalysts efficiently catalyze the oxidative coupling of methanol with O2 to methyl formate, in which the atomic O species (O(a)) formed via O2 dissociation on the Au surface has been considered as the active oxygen species. Herein we report for the first time that the oxidative coupling of methanol can occur facilely with molecularly adsorbed O2 species (O2(a)) on a Au(997) surface at temperatures as low as around 125 K, while that with O(a) occurs at around 175 K. Both experimental and theoretical calculation results demonstrate a novel reaction mechanism of oxidative coupling of CH3OH with O2(a) via a dioxymethylene (H2COO) intermediate, resulting in the production of both HCOOCH3 and HCOOCH3. These results reveal the unique reactivity of molecularly adsorbed O2 species on Au surfaces for low-temperature oxidation reactions.
Collapse
Affiliation(s)
- Guanghui Sun
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Fang Wang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, P. R. China
| | - Yuekang Jin
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Xuanye Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Peng Chai
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Longxia Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Bo-Tao Teng
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, P. R. China
- Tianjin Key Laboratory of Brine Chemical Engineering and Resource Eco-utilization, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Weixin Huang
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
- Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Dalian 116023, P. R. China
| |
Collapse
|
19
|
Abstract
This study aimed to detect the expression of Wnt-induced secreted protein-1 (WISP-1) in renal fibrosis (RF) and to clarify the underlying mechanism. An in vivo mousee model of unilateral ureteral obstruction (UUO) and in vitro model of fibrosis on renal tubular epithelial NRK52E cells after transforming growth factor-β1 (TGF-β1) stimulation were used. Quantitative real-time PCR (qRT-PCR), Western blot (WB), and immunohistochemistry were used to detect WISP-1 and fibrosis markers, including the expression of fibronectin (FN), collagen I (Col I), collagen IV (Col IV), and α-smooth muscle actin (α-SMA). In vitro experiments showed that the expression of WISP-1 and fibrosis markers FN, Col I, Col IV, and α-SMA in rat renal tubular epithelial cells were significantly higher than that in the control group after 48 h of TGF-β1 stimulation. In vivo experiments showed that the expressions of WISP-1 and fibrosis markers FN, Col I, Col IV, and α-SMA in the obstructed kidney of UUO animal models were significantly increased in mRNA and protein levels compared to normal mice. This study showed that WISP-1 may be an essential cytokine that promotes renal fibrosis, being involved in the development of renal fibrosis.
Collapse
Affiliation(s)
- Y Zhou
- Department of Nephrology, General Hospital of Ningxia Medical University, Yinchuan, China
| | - P Chai
- Department of Ultrasonic, General Hospital of Ningxia Medical University, Yinchuan, China
| | - J Wang
- Department of Nephrology, General Hospital of Ningxia Medical University, Yinchuan, China
| | - L Li
- Department of Nephrology, General Hospital of Ningxia Medical University, Yinchuan, China
| | - M H Chen
- Department of Nephrology, General Hospital of Ningxia Medical University, Yinchuan, China
| |
Collapse
|
20
|
Liang CR, Ong CC, Chai P, Teo LLS. Comparison of radiation dose, contrast enhancement and image quality of prospective ECG-Gated CT coronary angiography: Single versus dual source CT. Radiography (Lond) 2021; 27:831-839. [PMID: 33581989 DOI: 10.1016/j.radi.2021.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 01/09/2021] [Accepted: 01/13/2021] [Indexed: 10/22/2022]
Abstract
INTRODUCTION The updated National Institute of Clinical Excellence (NICE) guidelines of 2017 state that new generation cardiac CT scanners (Aquilion ONE, Brilliance iCT, Discovery CT750 HD and Somatom Definition Flash) are recommended as an option for first-line imaging of the coronary arteries in people with suspected stable coronary artery disease (with an estimated likelihood of coronary artery disease of 10-29%) in whom imaging with earlier generation CT scanners is difficult. New generation cardiac CT scanners are also recommended as an option for first-line evaluation of disease progression, to establish need for revascularisation in people with known coronary artery disease in whom imaging with earlier generation CT scanners is difficult. CT scanning might not be necessary in situations in which immediate revascularisation is being considered. The European Society of Cardiology 2019 clinical practice guidelines recommend non-invasive functional imaging for myocardial ischaemia or coronary CT angiography (CTA) as the initial test to diagnose CAD in symptomatic patients in whom obstructive CAD cannot be excluded by clinical assessment alone. Given increased computed tomography coronary angiogram (CTCA) utilisation, radiation dose, contrast enhancement and image quality of prospective ECG-gated CTCA between 256-slice single-source and 192x2-slice dual-source CT scanners were retrospectively evaluated. METHODS Prospectively gated CTCA data from 63 patients on a 256-slice CT (group A) and 71 patients on a 192x2-slice dual source CT (group B) from January to December 2016 were retrospectively evaluated respectively. Scanner-reported dose length product values were used with a conversion factor (k = 0.014 mSv/mGy x cm) to estimate effective dose. Contrast enhancement was assessed with mean CT attenuation at selected regions of interest on axial coronary images. Image quality of the coronary arteries was assessed by a 4-point grading score (1 = non-diagnostic, 4 = excellent image quality). RESULTS The radiation doses in group B were significantly lower than group A (3.68 + 2.13 mSv versus 4.81 + 1.56 mSv, p < 0.001). There were no significant differences in contrast enhancement in the left coronary artery, proximal right coronary artery and left ventricular wall for both groups. Vessel image quality scores for group B were higher than group A (right coronary artery (RCA): 3.2 + 0.7 versus 2.4 + 0.7, p < 0.001; left anterior descending (LAD) artery: 3.0 + 0.8 vs 2.5 + 0.6, p < 0.001; left circumflex (LCx) artery: 3.3 + 0.7 vs 2.6 + 0.6, p < 0.001). Coronary artery contour scores for group B were significantly higher than group A (RCA: 3.2 + 0.8 versus 2.3 + 0.7, p < 0.001; LAD: 3.0 + 0.7 versus 2.4 + 0.6, p < 0.001; LCx: 3.3 + 0.6 versus 2.5 + 0.6, p < 0.001). CONCLUSION Prospective ECG-gated CTCA performed on 192x2-slice CT results in better image quality and lower radiation dose than 256-slice CT. There were no significant differences in contrast enhancement in left main coronary artery (LMCA), proximal RCA and left ventricular wall in both groups. IMPLICATIONS FOR PRACTICE In institutions with both 256-slice and 192x2-slice CT scanners, we recommend that CTCAs be preferentially performed using the 192x2-slice CT scanner.
Collapse
Affiliation(s)
- C R Liang
- Department of Diagnostic Imaging, National University Hospital, Singapore
| | - C C Ong
- Department of Diagnostic Imaging, National University Hospital, Singapore
| | - P Chai
- Department of Diagnostic Imaging, National University Hospital, Singapore
| | - L L S Teo
- Department of Diagnostic Imaging, National University Hospital, Singapore.
| |
Collapse
|
21
|
Kavoosi M, O’Reilly TE, Kavoosi M, Chai P, Engel C, Korz W, Gallen CC, Lester RM. Safety, Tolerability, Pharmacokinetics, and Concentration-QTc Analysis of Tetrodotoxin: A Randomized, Dose Escalation Study in Healthy Adults. Toxins (Basel) 2020; 12:toxins12080511. [PMID: 32784930 PMCID: PMC7472037 DOI: 10.3390/toxins12080511] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/05/2020] [Accepted: 08/05/2020] [Indexed: 12/19/2022] Open
Abstract
Tetrodotoxin (TTX) is a highly specific voltage-gated sodium channel (VGSC) blocker in clinical evaluation as a peripheral-acting analgesic for chronic pain. This study presents the first published results of the safety including cardiac liability of TTX at therapeutic-relevant concentrations in twenty-five healthy adults. Randomized, double-blind, placebo-, and positive- (moxifloxacin) controlled study evaluated single ascending doses of 15 µg, 30 µg, and 45 µg TTX over 3 periods with a 7-day washout between each period. Subcutaneous injections of TTX were readily absorbed, reaching maximum plasma concentration (Cmax) within 1.5 h. Both extent of exposure (AUC) and Cmax increased in proportion to dose. No QT prolongation was identified by concentration-QTc analysis and the upper bounds of the two-sided 90% confidence interval of predicted maximum baseline and placebo corrected QTcF (ΔΔQTcF) value did not exceed 10 ms for all tetrodotoxin doses, thereby meeting the criteria of a negative QT study. Safety assessments showed no clinically relevant changes with values similar between all groups and no subject withdrawing due to adverse events. Paresthesia, oral-paresthesia, headache, dizziness, nausea, and myalgia were the most common TEAEs (overall occurrence ≥5%) in the TTX treatment groups. TTX doses investigated in this study are safe, well-tolerated, and lack proarrhythmic proclivity.
Collapse
Affiliation(s)
- Mojgan Kavoosi
- WEX Pharmaceuticals Inc., Vancouver, BC V6E-4A6, Canada; (M.K.); (W.K.); (C.C.G.)
- Correspondence:
| | | | - Mehran Kavoosi
- WEX Pharmaceuticals Inc., Vancouver, BC V6E-4A6, Canada; (M.K.); (W.K.); (C.C.G.)
| | - Peng Chai
- Celerion Inc., Lincoln, NE 68502, USA;
| | | | - Walter Korz
- WEX Pharmaceuticals Inc., Vancouver, BC V6E-4A6, Canada; (M.K.); (W.K.); (C.C.G.)
| | | | | |
Collapse
|
22
|
Wu L, Wang Z, Xiong F, Sun G, Chai P, Zhang Z, Xu H, Fu C, Huang W. Surface chemistry and photochemistry of small molecules on rutile TiO 2(001) and TiO 2(011)-(2 × 1) surfaces: The crucial roles of defects. J Chem Phys 2020; 152:044702. [PMID: 32007048 DOI: 10.1063/1.5135945] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Surface chemistry and photochemistry of small molecules on the rutile TiO2(001) and TiO2(011)-(2 × 1) surfaces were studied by low energy electron diffraction, thermal desorption spectroscopy, and x-ray photoelectron spectroscopy. It was found that the TiO2(001) surface mainly exhibits the defects of Ti interstitials in the near-surface region, while the TiO2(011)-(2 × 1) surface mainly exhibits the defects of double-oxygen vacancies. The defect structures of TiO2 surfaces strongly affect their adsorption and thermal/photodesorption behaviors. On the TiO2(001) surface, CH3OH and H2O dissociatively adsorb at the surface Ti sites near Ti interstitials; O2 molecularly adsorbs at the surface Ti sites adjacent to Ti interstitials, forming photoactive O2 species that undergoes a hole-mediated photodesorption process; CO adsorbs at the nearest surface Ti sites close to the Ti interstitials, but CO2 does not, and the resulting CO species is photoactive; and both CO and CO2 species adsorbed at the normal Ti4+ sites are photoinactive. On the TiO2(011)-(2 × 1) surface, O2 adsorbs only at the double-oxygen vacancy sites, and the resulting O2 species dissociates to form two oxygen atoms to refill in the oxygen vacancies upon heating; CO2 adsorbs at the double-oxygen vacancy sites, but CO does not, and the resulting CO2 species is photoactive; and both CO and CO2 species adsorbed at the surface Ti4+ sites are photoinactive. These results broaden the fundamental understandings of the chemistry and photochemistry of TiO2 surfaces, and the established structure-reactivity relation of small molecules on TiO2 surfaces is useful in probing complex structures of TiO2 powder catalysts.
Collapse
Affiliation(s)
- Longxia Wu
- Hefei National Laboratory for Physical Sciences at Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, CAS Key Laboratory of Materials for Energy Conversion, Department of Chemical Physics, University of Science and Technology of China, Jinzhai Road 96, Hefei 230026, China
| | - Zhengming Wang
- Hefei National Laboratory for Physical Sciences at Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, CAS Key Laboratory of Materials for Energy Conversion, Department of Chemical Physics, University of Science and Technology of China, Jinzhai Road 96, Hefei 230026, China
| | - Feng Xiong
- Hefei National Laboratory for Physical Sciences at Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, CAS Key Laboratory of Materials for Energy Conversion, Department of Chemical Physics, University of Science and Technology of China, Jinzhai Road 96, Hefei 230026, China
| | - Guanghui Sun
- Hefei National Laboratory for Physical Sciences at Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, CAS Key Laboratory of Materials for Energy Conversion, Department of Chemical Physics, University of Science and Technology of China, Jinzhai Road 96, Hefei 230026, China
| | - Peng Chai
- Hefei National Laboratory for Physical Sciences at Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, CAS Key Laboratory of Materials for Energy Conversion, Department of Chemical Physics, University of Science and Technology of China, Jinzhai Road 96, Hefei 230026, China
| | - Zhen Zhang
- Hefei National Laboratory for Physical Sciences at Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, CAS Key Laboratory of Materials for Energy Conversion, Department of Chemical Physics, University of Science and Technology of China, Jinzhai Road 96, Hefei 230026, China
| | - Hong Xu
- Hefei National Laboratory for Physical Sciences at Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, CAS Key Laboratory of Materials for Energy Conversion, Department of Chemical Physics, University of Science and Technology of China, Jinzhai Road 96, Hefei 230026, China
| | - Cong Fu
- Hefei National Laboratory for Physical Sciences at Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, CAS Key Laboratory of Materials for Energy Conversion, Department of Chemical Physics, University of Science and Technology of China, Jinzhai Road 96, Hefei 230026, China
| | - Weixin Huang
- Hefei National Laboratory for Physical Sciences at Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, CAS Key Laboratory of Materials for Energy Conversion, Department of Chemical Physics, University of Science and Technology of China, Jinzhai Road 96, Hefei 230026, China
| |
Collapse
|
23
|
Chai P, Li S, Li Y, Liang L, Yin X. Mechanical Behavior Investigation of 4H-SiC Single Crystal at the Micro-Nano Scale. Micromachines (Basel) 2020; 11:mi11010102. [PMID: 31963606 PMCID: PMC7019960 DOI: 10.3390/mi11010102] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/07/2020] [Accepted: 01/15/2020] [Indexed: 11/17/2022]
Abstract
In this paper, theoretical models of the critical indentation depth and critical force on brittle materials using cleavage strength and contact theory are proposed. A Berkovich indenter is adopted for nanoindentation tests on a 4H-SiC single crystal sample to evaluate its mechanical behaviors. The stages of brittle material deformation (elastic, plastic, and brittle) can be characterized by the load versus indentation depth curves through the nanoindentation test. The curve of the elastic deformation stage follows the Hertz contact theory, and plastic deformation occurs at an indentation depth of up to 10 nm. The mechanism of 4H-SiC single crystal cracking is discussed, and the critical indentation depth and critical force for the plastic–brittle transition are obtained through the occurrence of the pop-in point. This shows that the theoretical results have good coherence with the test results. Both the values of the elastic modulus and hardness decrease as the crack length increases. In order to obtain more accurate mechanical property values in the nanoindentation test for brittle materials such as SiC, GaN, and sapphire, an appropriate load that avoids surface cracks should be adopted.
Collapse
Affiliation(s)
| | | | - Yan Li
- Correspondence: (S.L.); (Y.L.)
| | | | | |
Collapse
|
24
|
Chai P, Li S, Li Y. Modeling and Experiment of the Critical Depth of Cut at the Ductile-Brittle Transition for a 4H-SiC Single Crystal. Micromachines (Basel) 2019; 10:mi10060382. [PMID: 31181650 PMCID: PMC6631271 DOI: 10.3390/mi10060382] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 05/22/2019] [Accepted: 06/05/2019] [Indexed: 11/16/2022]
Abstract
In this paper, a theoretical model of the critical depth of cut of nanoscratching on a 4H-SiC single crystal with a Berkovich indenter is proposed, and a series of scratch tests in a nanomechanical test system was performed. Through nanoindentation experimentation on fused quartz, the Berkovich indenter nose radius was indirectly confirmed using least squares. The range of critical depths of cut at the ductile-brittle transition was obtained by SEM observation, and the size of cracks was amplified with increasing scratching depth. The theoretical result of the critical depth of cut at the ductile-brittle transition for a 4H-SiC single crystal is 91.7 nm, which is close to the first obvious pop-in point of the relation curve between tangential force and lateral displacement. Repeated experimental results show good consistency and good agreement with other references.
Collapse
Affiliation(s)
- Peng Chai
- School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, No. 5 South Jinhua Road, Xi'an 710048, Shaanxi, China.
| | - Shujuan Li
- School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, No. 5 South Jinhua Road, Xi'an 710048, Shaanxi, China.
| | - Yan Li
- School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, No. 5 South Jinhua Road, Xi'an 710048, Shaanxi, China.
| |
Collapse
|
25
|
Omar A, Hey M, Chai P, Wong M. An evaluation of grams prediction as an adjunctive reportable element on the Sysmex Uf-5000 for cases of bacteria. Clin Chim Acta 2019. [DOI: 10.1016/j.cca.2019.03.993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
26
|
O'Connor M, Lorts A, Mascio C, Sutcliffe D, Davies R, Law S, Chai P, Rosenthal D, Maeda K, Nandi D, McConnell P, Morales D. Real World Data from the ACTION Quality Improvement Network - Preliminary Experience with a Magnetically Levitated Ventricular Assist Device in US Pediatric Centers. J Heart Lung Transplant 2019. [DOI: 10.1016/j.healun.2019.01.438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
27
|
Chai P, Dong S, Chai L, Chen S, Flaishman M, Ma H. Cytokinin-induced parthenocarpy of San Pedro type fig (Ficus carica L.) main crop: explained by phytohormone assay and transcriptomic network comparison. Plant Mol Biol 2019; 99:329-346. [PMID: 30656555 DOI: 10.1007/s11103-019-00820-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 01/02/2019] [Indexed: 05/15/2023]
Abstract
CPPU-induced San Pedro type fig main crop parthenocarpy exhibited constantly increasing IAA content and more significantly enriched KEGG pathways in the receptacle than in female flowers. N-(2-chloro-4-pyridyl)-N-phenylurea (CPPU) was applied to San Pedro fig (Ficus carica L.) main crop to induce parthenocarpy; the optimal effect was obtained with 25 mg L-1 application to syconia when female flowers were at anthesis. To elucidate the key expression changes in parthenocarpy conversion, significant changes in phytohormone level and transcriptome of fig female flowers and receptacles were monitored. HPLC-MS revealed increased IAA content in female flowers and receptacle 2, 4 and 10 days after treatment (DAT), decreased zeatin level in the receptacle 2, 4 and 10 DAT, decreased GA3 content 2 and 4 DAT, and increased GA3 content 10 DAT. ABA level increased 2 and 4 DAT, and decreased 10 DAT. CPPU-treated syconia released more ethylene than the control except 2 DAT. RNA-Seq and bioinformatics analysis revealed notably more differentially expressed KEGG pathways in the receptacle than in female flowers. In the phytohormone gene network, GA-biosynthesis genes GA20ox and GA3ox were upregulated, along with GA signal-transduction genes GID1 and GID2, and IAA-signaling genes AUX/IAA and GH3. ABA-biosynthesis gene NCED and signaling genes PP2C and ABF were downregulated 10 DAT. One ACO gene showed consistent upregulation in both female flowers and receptacle after CPPU treatment, and more than a dozen of ERFs demonstrated opposing changes in expression. Our results revealed early-stage spatiotemporal phytohormone and transcriptomic responses in CPPU-induced San Pedro fig main crop parthenocarpy, which could be valuable for further understanding the nature of the parthenocarpy of different fig types.
Collapse
Affiliation(s)
- Peng Chai
- College of Horticulture, China Agricultural University, Beijing, People's Republic of China
| | - Sujuan Dong
- College of Horticulture, China Agricultural University, Beijing, People's Republic of China
| | - Lijuan Chai
- College of Horticulture, China Agricultural University, Beijing, People's Republic of China
| | - Shangwu Chen
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China
| | - Moshe Flaishman
- Department of Fruit Tree Sciences, Agricultural Research Organization, The Volcani Center, Bet-Dagan, Israel
| | - Huiqin Ma
- College of Horticulture, China Agricultural University, Beijing, People's Republic of China.
| |
Collapse
|
28
|
Xiong F, Wang Z, Wu Z, Sun G, Xu H, Chai P, Huang W. Direct evidence for hydrated protons as the active species in artificial photocatalytic water reduction into hydrogen. Sci China Chem 2019. [DOI: 10.1007/s11426-018-9377-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
29
|
Chai L, Chai P, Chen S, Flaishman MA, Ma H. Transcriptome analysis unravels spatiotemporal modulation of phytohormone-pathway expression underlying gibberellin-induced parthenocarpic fruit set in San Pedro-type fig (Ficus carica L.). BMC Plant Biol 2018; 18:100. [PMID: 29859043 PMCID: PMC5984833 DOI: 10.1186/s12870-018-1318-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 05/24/2018] [Indexed: 05/15/2023]
Abstract
BACKGROUND Gibberellin (GA) treatments can induce parthenocarpy in the main crop of San Pedro-type figs, the native non-parthenocarpic fruit, however, the underlying mechanism is still largely unclear. RESULTS In our study, GA3 was applied to San Pedro-type fig main crop at anthesis. Sharply increased GA3 content was detected in both female flowers and receptacle, along with significantly decreased indole-3-acetic acid (IAA), zeatin and abscisic acid (ABA) levels in female flowers, and increased zeatin peak intensity and earlier ABA peak in receptacles. Transcriptome comparison between control and treatment groups identified more differentially expressed genes (DEGs) in receptacles than in female flowers 2 and 4 days after treatment (DAT); 10 DAT, the number of DEGs became similar in the two tissues. Synchronized changing trends of phytohormone-associated DEGs were observed in female flowers and receptacles with fruit development. Modulation of ethylene and GA signaling and auxin metabolism by exogenous GA3 occurred mainly 2 DAT, whereas changes in auxin, cytokinin and ABA signaling occurred mainly 10 DAT. Auxin-, ethylene- and ABA-metabolism and response pathways were largely regulated in the two tissues, mostly 2 and 10 DAT. The major components altering fig phytohormone metabolic and response patterns included downregulated GA2ox, BAS1, NCED and ACO, and upregulated ABA 8'-h and AUX/IAA. CONCLUSIONS Thus GA-induced parthenocarpy in fig is co-modulated by the female flowers and receptacle, and repression of ABA and ethylene biosynthesis and GA catabolism might be the main forces deflecting abscission and producing fig parthenocarpy.
Collapse
Affiliation(s)
- Lijuan Chai
- College of Horticulture, China Agricultural University, Beijing, People’s Republic of China
| | - Peng Chai
- College of Horticulture, China Agricultural University, Beijing, People’s Republic of China
| | - Shangwu Chen
- College of Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, People’s Republic of China
| | - Moshe A. Flaishman
- Department of Fruit Tree Sciences, Agricultural Research Organization, Volcani Center, Bet-Dagan, Israel
| | - Huiqin Ma
- College of Horticulture, China Agricultural University, Beijing, People’s Republic of China
| |
Collapse
|
30
|
Yang MJ, Zhang ZM, Wang YJ, Li DW, Zhou W, Tang HH, Liu YT, Chai P, Shuai L, Huang XC, Liu SQ, Zhu ML, Jiang XP, Zhang YW, Li T, Ma B, Sun SF, Sun LY, Wang Q, Lu ZR, Zhang T, Wei L. An instrument for measuring scintillators efficiently based on silicon photomultipliers. Rev Sci Instrum 2016; 87:113308. [PMID: 27910308 DOI: 10.1063/1.4968563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An instrument used for measuring multiple scintillators' light output and energy resolution was developed. The instrument consisted of a light sensor array which was composed of 64 discrete SiPMs (Silicon Photomultipliers), a corresponding individual channel readout electronics system, and a data processing algorithm. A Teflon grid and a large interval between adjacent SiPMs were employed to eliminate the optical cross talk among scintillators. The scintillators' light output was obtained by comparing with a reference sample with known light output. Given the SiPM temperature dependency and the difference among each SiPM, a temperature offset correction algorithm and a non-uniformity correction algorithm were added to the instrument. A positioning algorithm, based on nine points, was designed to evaluate the performance of a scintillator array. Tests were performed to evaluate the instrument's performance. The uniformity of 64 channels for light output measurement was better than 98%, the stability was better than 98% when temperature varied from 15 °C to 40 °C, and the nonlinearity under 511 keV was better than 2%. This instrument was capable of selecting scintillators and evaluating the packaging technology of scintillator arrays with high efficiency and accuracy.
Collapse
Affiliation(s)
- M J Yang
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Z M Zhang
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Y J Wang
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - D W Li
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - W Zhou
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - H H Tang
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Y T Liu
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - P Chai
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - L Shuai
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - X C Huang
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - S Q Liu
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - M L Zhu
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - X P Jiang
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Y W Zhang
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - T Li
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - B Ma
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - S F Sun
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - L Y Sun
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Q Wang
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Z R Lu
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - T Zhang
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - L Wei
- Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
31
|
Jia Y, Pan H, Meng H, Liu H, Wang Z, Li X, Zhu L, Chai P, Gong C. Synthesis of Ni3N/SiO2 nanocomposites and investigation of their intrinsic static and dynamic magnetic properties. RSC Adv 2015. [DOI: 10.1039/c4ra13694b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Ni3N/SiO2 nanocomposites were prepared via nitriding of a Ni/SiO2 nanocomposite precursor in flowing ammonia.
Collapse
Affiliation(s)
- Yongshuai Jia
- Key Laboratory for Special Functional Materials of the Ministry of Education
- Henan University
- Kaifeng 475004
- China
| | - Haoshuai Pan
- Key Laboratory for Special Functional Materials of the Ministry of Education
- Henan University
- Kaifeng 475004
- China
| | - Hongjie Meng
- Key Laboratory for Special Functional Materials of the Ministry of Education
- Henan University
- Kaifeng 475004
- China
| | - Haojie Liu
- Key Laboratory for Special Functional Materials of the Ministry of Education
- Henan University
- Kaifeng 475004
- China
| | - Zeqian Wang
- College of Chemistry and Chemical Engineering
- Henan University
- Kaifeng 475004
- China
| | - Xiao Li
- College of Chemistry and Chemical Engineering
- Henan University
- Kaifeng 475004
- China
| | - Longlong Zhu
- College of Chemistry and Chemical Engineering
- Henan University
- Kaifeng 475004
- China
| | - Peng Chai
- College of Chemistry and Chemical Engineering
- Henan University
- Kaifeng 475004
- China
| | - Chunhong Gong
- College of Chemistry and Chemical Engineering
- Henan University
- Kaifeng 475004
- China
| |
Collapse
|
32
|
Feng P, Yang K, Xu Z, Wang Z, Fan L, Qin L, Zhu S, Shang C, Chai P, Yuan Z, Hu L. Growth and lipid accumulation characteristics of Scenedesmus obliquus in semi-continuous cultivation outdoors for biodiesel feedstock production. Bioresour Technol 2014; 173:406-414. [PMID: 25444884 DOI: 10.1016/j.biortech.2014.09.123] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 09/22/2014] [Accepted: 09/23/2014] [Indexed: 06/04/2023]
Abstract
In an effort to identify suitable microalgal species for biodiesel production, seven species were isolated from various habitats and their growth characteristics were compared. The results demonstrated that a green alga Scenedesmus obliquus could grow more rapidly and synthesize more lipids than other six microalgal strains. S. obliquus grew well both indoors and outdoors, and reached higher μmax indoors than that outdoors. However, the cells achieved higher dry weight (4.36 g L(-1)), lipid content (49.6%) and productivity (183 mg L(-1) day(-1)) outdoors than in indoor cultures. During the 61 days semi-continuous cultivation outdoors, high biomass productivities (450-550 mg L(-1) day(-1)) and μmax (1.05-1.44 day(-1)) were obtained. The cells could also achieve high lipid productivities (151-193 mg L(-1) day(-1)). These results indicated that S. obliquus was promising for lipids production in semi-continuous cultivation outdoors.
Collapse
Affiliation(s)
- Pingzhong Feng
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Kang Yang
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Zhongbin Xu
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Zhongming Wang
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Lu Fan
- Microalgae Laboratory, School of Resource & Environmental Engineering, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei University of Technology, Wuhan 430068, China
| | - Lei Qin
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Shunni Zhu
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Changhua Shang
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Peng Chai
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Zhenhong Yuan
- Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China.
| | - Lei Hu
- Jiangsu Key Laboratory for Biomass-based Energy and Enzyme Technology, Huaiyin Normal University, Huaian 223300, China
| |
Collapse
|
33
|
Poh KK, Lee LC, Shen L, Chong E, Tan YL, Chai P, Yeo TC, Wood MJ. Left ventricular fluid dynamics in heart failure: echocardiographic measurement and utilities of vortex formation time. Eur Heart J Cardiovasc Imaging 2011; 13:385-93. [DOI: 10.1093/ejechocard/jer288] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
34
|
Lim KC, Chai P, Teo LS. Incidental cardiac abnormalities on non-electrocardiogram-gated multi-detector computed tomography imaging of the thorax and abdomen. Singapore Med J 2011; 52:906-913. [PMID: 22159935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Little attention is usually paid to the heart on non-electrocardiogram (ECG)-gated multi-detector computed tomography (MDCT) imaging of the thorax and abdomen. The current MDCT systems have fast scanning capabilities that render non-ECG-gated images with reduced cardiac motion artefacts due to greater temporal and spatial resolution. This has allowed for better evaluation of the cardiac structures. We present a pictorial review of incidental cardiac abnormalities found on MDCT imaging of the thorax and abdomen performed in our institution. We systematically describe abnormalities involving the pericardium, myocardium, cardiac valves, cardiac chambers, coronary artery and congenital heart disease. Some of these images have echocardiograph and magnetic resonance imaging correlation. The purpose of this pictorial essay is to draw attention to cardiac abnormalities found incidentally on non-ECG-gated MDCT imaging of the thorax and abdomen, which may or may not be related to the patient's symptoms.
Collapse
Affiliation(s)
- K C Lim
- Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074.
| | | | | |
Collapse
|
35
|
Alsaif HS, Venkatesh SK, Chai P, Cheah WK, Teo LLS. Unusual case of unrepaired omphalocoele and uncorrected tetralogy of Fallot in a young adult. Singapore Med J 2011; 52:e213-e216. [PMID: 22009411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
An omphalocoele is a congenital defect that affects the development of the abdominal wall in the umbilical region, resulting in a hernial-type sac of variable size. The condition is usually diagnosed prenatally and corrected in early infancy to prevent rupture of the covering membranes, which carries a high mortality and morbidity rate. Tetralogy of Fallot is the most common cyanotic congenital heart defect during infancy that is associated with this condition. Most patients experience cyanosis at birth and die in childhood if there is no surgical intervention. Overall, it is uncommon for untreated patients with both omphalocoele and tetralogy of Fallot to survive into adulthood. We report the rare case of a 17-year-old young adult with untreated omphalocoele and uncorrected tetralogy of Fallot.
Collapse
Affiliation(s)
- H S Alsaif
- Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074
| | | | | | | | | |
Collapse
|
36
|
Chen YH, Chen MH, Wang G, Chen WX, Yang SC, Chai P. [Effects of slopes on nitrogen transport along with runoff from sloping plots on a lateritic red soil amended with sewage sludge]. Huan Jing Ke Xue 2010; 31:2423-2430. [PMID: 21229756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The effects of different slopes on nitrogen transport along with runoff from sloping plots amended with sewage sludge on a lateritic red soil were studied under simulated rainfall conditions. When the sludge was broadcasted and mixed with surface soils (BM), the MTN (total nitrogen of mixing sample), STN (total nitrogen of settled sample), TPN (total particulate nitrogen), TSN (total suspended nitrogen), TDN (total dissolved nitrogen) and NH4(+) -N concentrations and nitrogen loss amounts in runoff of all treatments were highest at 1 day or 18 days after application. The highest concentrations and the loss amounts of MTN and STN in the slope runoff for the BM treatment increased with slope degree, showing increasing pollution risks to the surface waters. The STN concentration and loss amounts from the 25 degrees plots were 126.1 mg x L(-1) and 1788.6 mg x m(-2), respectively, being 4.6 times and 5.8 times of the corresponding values from the 10 degrees plots, respectively. Then the concentrations and the loss amounts of nitrogen (except NO3(-) -N) from the BM plots diminished rapidly first and then tended to be stable with dwindling differences between the slopes. The loss of MTN and STN in early runoff (1 day and 18 days) accounted for 68.6% -73.4% and 62.3% -66.7% of the cumulative loss amounts during the experimental period for all the broadcasted treatments. Runoff loss coefficients of MTN increased in the order of 20 degrees > 25 degrees > 15 degrees > 10 degrees. Nitrogen was largely lost in dissolved species while large portion of NH4(+) -N was lost with particulates.
Collapse
Affiliation(s)
- Yan-Hui Chen
- Department of Resources and Environmental Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | | | | | | | | | | |
Collapse
|
37
|
Zhang J, Chong E, Chai P, Poh KK. Contrasting fatty involvement of the right ventricle: lipoma versus lipomatous hypertrophy. Singapore Med J 2009; 50:e342-e345. [PMID: 19907871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report two rare cases of right ventricular lipomatous involvement, and discuss their contrasting diagnostic images and clinical manifestations. Case 1 is a 21-year-old Malay man who presented with recurrent syncope. Transthoracic echocardiography showed a homogeneous discrete mass attached to the right ventricular septum, occupying the right ventricular outflow tract. Cardiac magnetic resonance (MR) imaging showed features consistent with intracardiac lipoma, which was confirmed on histology, upon surgical resection. Case 2, a 73-year-old Caucasian woman, was found to have incidental lipomatous infiltration of the right ventricle on echocardiography and MR imaging. In contrast to the well-defined right ventricular lipoma seen in the first case, lipomatous involvement was manifested as a diffuse homogeneous thickening of the right ventricular free wall. Multimodality imaging allows for a complementary and detailed characterisation of lipomatous masses involving the ventricular septum.
Collapse
Affiliation(s)
- J Zhang
- Cardiac Department, National University Heart Centre Singapore, Yong Loo Lin School of Medicine, National University of Singapore, 5 Lower Kent Ridge Rd, Singapore
| | | | | | | |
Collapse
|
38
|
Chong E, Poh KK, Shen L, Chai P, Tan HC. Diabetic patients with normal baseline renal function are at increased risk of developing contrast-induced nephropathy post-percutaneous coronary intervention. Singapore Med J 2009; 50:250-254. [PMID: 19352566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
INTRODUCTION We hypothesised that diabetic patients with normal baseline renal impairment who do not receive prophylaxis before percutaneous coronary intervention (PCI) are at an increased risk of developing contrast-induced nephropathy (CIN). METHODS We conducted a cohort study involving 839 patients who underwent PCI between 2004 and 2006, and divided them into three groups: Group A (304 diabetics with normal baseline serum creatinine [Cr] of less than 1.5 mg/dL); Group B (465 non-diabetics with normal Cr); Group C (70 patients with impaired baseline renal function with Cr more than or equal to 1.5 mg/dL). CIN prophylaxis, including oral N-acetylcysteine and saline hydration, were administered only to Group C patients. RESULTS The median age for Groups A, B and C was 58, 56 and 64 years, respectively. The prevalence of hypertension in Groups A, B and C was 76.3, 56 and 85.7 percent, respectively. Baseline demographics were comparable among the three groups with regard to gender, left ventricular systolic function and contrast volume use. Incidences of CIN in Groups A, B and C were 8.9 percent, 4.3 percent and 4.5 percent, respectively (p-value is 0.042). The incidence of CIN in diabetic patients with a normal baseline Cr who did not receive prophylaxis (Group A) was significantly higher than in the other two groups (p-value is less than 0.001). CONCLUSION Our findings suggest that diabetic patients, despite having a normal baseline Cr, are at an increased risk of developing CIN post-PCI. Routine prophylaxis in this cohort may be beneficial.
Collapse
Affiliation(s)
- E Chong
- Cardiology Department, Alexandra Hospital, 378 Alexandra Road, Singapore 159964. ericchong80@hotmailcom
| | | | | | | | | |
Collapse
|
39
|
Chong E, Poh KK, Shen L, Yeh IB, Chai P. Infective endocarditis secondary to intravenous Subutex abuse. Singapore Med J 2009; 50:34-42. [PMID: 19224082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
INTRODUCTION Subutex (buprenophine) was approved by the Health Science Authority of Singapore for heroin detoxification in 2002. The number of heroin addicts has decreased in Singapore since the introduction of Subutex. However, Subutex abuse and its associated complications became arising medical problems. We report the management of a series of infective endocarditis cases secondary to Subutex abuse. METHODS We identified 12 cases of infective endocarditis in former heroin addicts treated with Subutex from August 2005 to April 2006. All patients were interviewed by the research coordinator and prospectively followed-up for two years. RESULTS The treatment period of Subutex endocarditis was often prolonged with a mean hospitalisation stay of 48 days, with 3.8 days in the intensive care unit. Multiple medical complications were noted. Staphylococcus aureus septicaemia accounted for 92 percent of cases. Mortality rate was 42 percent. Failure rate of medical therapy alone was common. 25 percent underwent open heart valve surgery. All patients were subsidised. Mean hospitalisation expenses was S$31,218. CONCLUSION Subutex endocarditis causes significant morbidity and mortality. It imposes a heavy medical and financial burden to the patient and society. Multidisciplinary treatment involving cardiologists, infectious disease physicians, psychiatrists, surgeons, medical counsellors and social workers is required to manage these patients.
Collapse
Affiliation(s)
- E Chong
- National University Heart Centre, Cardiac Department, National University Hospital, Singapore.
| | | | | | | | | |
Collapse
|
40
|
Meng J, Wang Z, Lu M, Liu X, Chai P, Liu Y, Zhou X. Preparation of ferritesMFe2O4(M= Co, Ni) nanoporous ribbons structure and their magnetic properties. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308083736] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
41
|
Chai P. Field observations and feeding experiments on the responses of rufous-tailed jacamars (Galbula ruficauda) to free-flying butterflies in a tropical rainforest. Biol J Linn Soc Lond 2008. [DOI: 10.1111/j.1095-8312.1986.tb01772.x] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
42
|
|
43
|
Omar AR, Suppiah N, Chai P, Chan YH, Seow YH, Quek LL, Poh KK, Tan HC. Efficacy of community-based multidisciplinary disease management of chronic heart failure. Singapore Med J 2007; 48:528-31. [PMID: 17538751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
INTRODUCTION A multidisciplinary disease management (DM) programme in chronic heart failure (CHF) improves clinical outcome. The efficacy of such a programme in a heterogeneous Asian community is not well established. Therefore, we undertook the evaluation of the efficacy of the multidisciplinary community-based DM CHF programme. METHODS This was a prospective study involving 154 patients (54 percent male) with a primary diagnosis of CHF, New York Heart Association functional class III/IV CHF, with left ventricular ejection fraction (LVEF) less than 40 percent. The mean age was 65 +/- 12 years and mean LVEF was 27 +/- 9 percent. We evaluated CHF hospitalisation, quality of life, activity status and quality of care (percentage of patients who received ACE inhibitors/angiotensin receptor blockers (ARB) and beta blockers after a period of six months. RESULTS At six months, there was improvement in the quality of life and activity status (p < 0.001). ACE inhibitors/ARB were maintained in 97 percent of the patients and there was an increased usage of beta blockers (p-value equals 0.001). The rate of CHF hospitalisation was reduced by 68 percent (p-value is less than 0.001) and there was no mortality. CONCLUSION The multidisciplinary DM of CHF in a heterogeneous Asian community showed significant improvement in quality of life, quality of care and reduction in CHF hospitalisation.
Collapse
Affiliation(s)
- A R Omar
- Department of Cardiology, National University Hospital, Singapore.
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Abstract
SUMMARY
Hummingbirds evolved during a period of decline in atmospheric oxygen concentration and currently encounter varying levels of oxygen availability along their elevational distribution. We tested the hypothesis that inspiration of hyperoxic gas increases hummingbird hovering performance when birds are simultaneously challenged aerodynamically. We measured the maximum duration of hovering flight while simultaneously monitoring the rate of oxygen consumption of ruby-throated hummingbirds (Archilochus colubris) in low-density heliox that was either normoxic (21% O2) or hyperoxic (35% O2). As air density decreased below 0.85kgm−3, hummingbirds hovered significantly longer in hyperoxia than in normoxia, but the air density at which the birds could no longer sustain hovering flight was independent of oxygen concentration. At low air densities in hyperoxia flight trials, hummingbirds appeared to increase their rate of oxygen consumption relative to flight sequences at equivalent densities in normoxia trials, but these differences were not significant. We tested the hypothesis that hummingbirds can discriminate between environments that differ in oxygen concentration. In another density-reduction experiment, hummingbirds were allowed to choose between artificial feeders infused with either normoxic or hyperoxic gases. The hypothesis was not supported because birds failed to associate oxygen concentration with a particular feeder independently of air density. Supplemental oxygen thus yields increased hovering duration at intermediate air densities, but the minimum density at which birds can fly is limited exclusively by aerodynamic considerations.
Collapse
Affiliation(s)
- D L Altshuler
- Section of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA.
| | | | | |
Collapse
|
45
|
Lau CL, Daggett WC, Yeatman MF, Chai P, Lin SS, Lodge AJ, Chen EP, Diamond LE, Byrne GW, Logan JS, Parker W, Platt JL, Davis RD. The role of antibodies in dysfunction of pig-to-baboon pulmonary transplants. J Thorac Cardiovasc Surg 2000; 120:29-38. [PMID: 10884652 DOI: 10.1067/mtc.2000.106841] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Pulmonary transplantation has become the preferred treatment for end-stage lung disease, but application of the procedure is limited because of a paucity of donors. One way to solve donor limitations is to use animal organs as a donor source or xenotransplantation. The current barrier to pulmonary xenotransplantation is the rapid failure of the pulmonary xenograft. Although antibodies are known to play a role in heart and kidney xenograft rejection, their involvement in lung dysfunction is less defined. This project was designed to define the role of antibodies in pulmonary graft rejection in a pig-to-baboon model. METHODS Orthotopic transgenic swine left lung transplants were performed in baboons depleted of antibodies by one of three techniques before transplantation: (1) ex vivo swine kidney perfusion, (2) total immunoglobulin-depleting column perfusion, and (3) ex vivo swine lung perfusion. Results were compared with those of transgenic swine lung transplants in unmodified baboons. RESULTS All three techniques of antibody removal resulted in depletion of xenoreactive antibodies. Only pretransplantation lung perfusion improved pulmonary xenograft function compared with lung transplantation in unmodified baboons. CONCLUSIONS The pathogenesis of pulmonary injury in a swine-to-primate transplant model is different from that in renal and cardiac xenografts. Depletion of antibodies alone does not have a beneficial effect and may actually be detrimental.
Collapse
Affiliation(s)
- C L Lau
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
|
47
|
Chai P, Altshuler DL, Stephens DB, Dillon ME. Maximal horizontal flight performance of hummingbirds: effects of body mass and molt. Physiol Biochem Zool 1999; 72:145-55. [PMID: 10068617 DOI: 10.1086/316652] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Hovering and fast forward flapping represent two strenuous types of flight that differ in aerodynamic power requirement. Maximal capabilities of ruby-throated hummingbirds (Archilochus colubris) in hovering and forward flight were compared under varying body mass and wing area. The capability to hover in low-density gas mixtures was adversely affected by body mass, whereas the capability to fly in a wind tunnel did not show any adverse mass effect. Molting birds that lost primary flight feathers and reduced wing area also displayed mass loss and loss of aerodynamic power and flight speed. This suggests that maximal flight speed is insensitive to short-term perturbations of body mass but that molting is stressful and reduces the birds' speed and capacity for chase and escape. Hummingbirds' flight behavior in confined space was also investigated. Birds reduced their speeds flying through a narrow tube to approximately one-fifth of that in the wind tunnel and did not display differences under varying body mass and wing area. Hence, performance in the flight tube was submaximal and did not correlate with performance variation in the wind tunnel. For ruby-throated hummingbirds, both maximal mass-specific aerodynamic power derived from hovering performance in low-density air media and maximal flight velocity measured in the wind tunnel were invariant with body mass.
Collapse
Affiliation(s)
- P Chai
- Department of Zoology, University of Texas, Austin, Texas 78712-1064.
| | | | | | | |
Collapse
|
48
|
Thumboo J, Fong KY, Chng HH, Koh ET, Chia HP, Leong KH, Koh WH, Howe HS, Leong KP, Wong MH, Chew SM, Chai P, Goh LH, Goon TJ, Lau TC, Lim WS, Pek WY, Tong KL, Yang WL, Feng PH, Boey ML. The effects of ethnicity on disease patterns in 472 Orientals with systemic lupus erythematosus. J Rheumatol Suppl 1998; 25:1299-304. [PMID: 9676760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE To determine the effects of ethnicity on disease manifestations in Oriental patients with systemic lupus erythematosus (SLE) and to describe the risk of developing renal or central nervous system (CNS) involvement with time. METHODS A retrospective study of 472 patients with SLE seen at the only Rheumatology Unit in Singapore. The effect of ethnicity on selected disease manifestations at diagnosis was assessed after adjusting for demographic variables using multiple logistic regression. The probability of developing selected disease manifestations with time was determined using the Kaplan-Meier product limit method. RESULTS At diagnosis, Malays had a higher risk of renal or CNS involvement than Chinese (OR 2.26, 95% CI 1.21 to 4.21, and OR 3.07, 95% CI 1.01 to 9.34, respectively), and Indians a lower risk of malar rash and a higher risk of oral ulcers than Chinese (OR 0.30, 95% CI 0.13 to 0.68, and OR 2.90, 95% CI 1.45 to 7.34, respectively). The prevalence of renal or CNS involvement in the entire cohort increased with time, reaching 75.6% (95% CI 66.1% to 85.0%) and 16.7% (95% CI 11.7% to 21.6%), respectively, after 18 years of disease. CONCLUSION Ethnicity influenced disease manifestations at diagnosis in this cohort of Oriental patients with SLE. Renal or CNS involvement developed in previously unaffected patients up to 18 years after diagnosis, highlighting the need for continued vigilance in patients with lupus.
Collapse
Affiliation(s)
- J Thumboo
- Department of Rheumatology and Immunology, Tan Tock Seng Hospital, National University of Singapore, Singapore
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Abstract
As the smallest homeotherms, hummingbirds suffer from low thermal inertia and high heat loss. Flapping flight is energetically expensive, and convective cooling due to wing and air movements could further exacerbate energy drain. Energy conservation during flight is thus profoundly important for hummingbirds. The present study demonstrates that heat produced by flight activity can contribute to thermoregulatory requirements in hovering hummingbirds. The rate of oxygen consumption, as an indicator of metabolic cost, was measured during hover-feeding and compared with that during perch-feeding. In hover-feeding, oxygen consumption increased only moderately between 35 and 5 degreesC in contrast to the sharp increase during perch-feeding over the same temperature range. This result suggests that heat produced by contraction of the flight muscles substituted for regulatory thermogenesis to accommodate for heat loss during exposure to low temperature. With declining air temperatures, the mechanical power requirements of hovering decreased slightly, but metabolic costs increased moderately. As a result, the mechanical efficiency of the muscle in converting metabolic power to mechanical power was reduced. Changes in wingbeat kinematics also accompanied the reduction in muscle efficiency. Wingbeat frequency increased but stroke amplitude decreased when hovering in the cold, suggesting thermoregulatory roles for the flight muscles. Hovering hummingbirds modulated their wingbeat frequency within a narrow range, reflecting the physical constraints of tuning to a natural resonant frequency with an elastic restoring force. We hypothesize that, by forcing the resonant system of the wings and thorax to oscillate at different frequencies, muscle contraction in the cold generates more heat at the expense of mechanical efficiency. This mechanism of modulating the efficiency of muscle contraction and heat production allows flying hummingbirds to achieve energy conservation at low air temperatures.
Collapse
|
50
|
Koh WH, Seah A, Chai P. Clinical presentation and disease associations of gout: a hospital-based study of 100 patients in Singapore. Ann Acad Med Singap 1998; 27:7-10. [PMID: 9588267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The aim of this retrospective study was to characterise the clinical presentation and disease associations of Oriental patients with gout seen in our hospital over a six-month period. One hundred patients comprising of 77 males and 23 females [89% Chinese, 7% Malays, 2% Indians and 2% others; mean age was 50.9 years (range 18 to 82 years), mean age at onset of disease was 43.7 years (range 16 to 78 years)] were studied. The disease was familial in 18% and 44% of patients had a history of alcohol ingestion. Co-morbid conditions included hypertension (36%), hyperlipidaemia (25%), renal failure (17%), ischaemic heart disease (13%), diabetes mellitus (4%), systemic lupus erythematosus (3%), psoriasis (2%) and ankylosing spondylitis (1%). The majority of patients (68%) had at least one associated disease. At the onset of disease, the joints commonly involved were the ankles (39%) and knees (27%) whilst the first metatarsophalangeal (MTP) joint was affected in only 26% of cases. Polyarticular onset was uncommon (n = 6). The precipitating factors reported by the patients included food (n = 23), alcohol (n = 12), drugs (n = 4), trauma (n = 3) and surgery (n = 2). Eleven patients had a history of renal calculi and 15% had tophaceous gout. Majority of patients (71%) had been treated with urate-lowering drugs (allopurinol). We concluded that gout in Singapore predominantly affects middle-aged men who often have an accompanying illness.
Collapse
Affiliation(s)
- W H Koh
- Department of Rheumatology and Immunology, Tan Tock Seng Hospital, Singapore
| | | | | |
Collapse
|