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Lee CH, Wu MZ, Lui DTW, Fong CHY, Ren QW, Yu SY, Yuen MMA, Chow WS, Huang JY, Xu A, Yiu KH, Lam KSL. Prospective associations of circulating thrombospondin-2 level with heart failure hospitalization, left ventricular remodeling and diastolic function in type 2 diabetes. Cardiovasc Diabetol 2022; 21:231. [PMID: 36335340 PMCID: PMC9637303 DOI: 10.1186/s12933-022-01646-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 09/23/2022] [Indexed: 11/06/2022] Open
Abstract
Background Circulating thrombospondin-2 (TSP2) levels were associated with the development of heart failure (HF) in recent studies. However, these studies included only a minority of patients with type 2 diabetes, which is associated with an increased HF risk. As hyperglycemia induces TSP2 expression and its tissue expression increases in type 2 diabetes, we investigated the prospective association of circulating TSP2 with incident HF hospitalization (HHF), and its associations with longitudinal changes of echocardiographic parameters in type 2 diabetes. Methods Baseline serum TSP2 levels were measured in 4949 patients with type 2 diabetes to determine its association with incident HHF using multivariable Cox regression analysis. In the echocardiographic study, baseline serum TSP2 levels were measured in another 146 patients with type 2 diabetes but without cardiovascular diseases who underwent detailed transthoracic echocardiography at baseline and after 1 year. Results Over a median follow-up of 7.8 years, 330 of 4949 patients (6.7%) developed incident HHF. Baseline serum TSP2 levels were independently associated with the development of HHF (HR 1.31, 95%CI 1.06–1.62, p = 0.014) after adjustments for baseline conventional cardiovascular risk factors, atrial fibrillation, estimated glomerular filtration rate, albuminuria and high-sensitivity C-reactive protein level, use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, loop-diuretics, aspirin, insulin, metformin and sodium-glucose co-transporter 2 inhibitors. Moreover, baseline serum TSP2 levels were independently associated with increase in average E/e’ and left atrial volume index (p = 0.04 and < 0.01, respectively). Conclusion Serum TSP2 levels were independently associated with both incident HHF and deterioration in diastolic function in type 2 diabetes. Trial registration Not Applicable Supplementary information The online version contains supplementary material available at 10.1186/s12933-022-01646-x.
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Lui DTW, Lee CH, Chow WS, Lee ACH, Tam AR, Cheung CYY, Fong CHY, Kwok STM, Law CY, To KKW, Lam CW, Tan KCB, Woo YC, Hung IFN, Lam KSL. Development of a prediction score (ThyroCOVID) for identifying abnormal thyroid function in COVID-19 patients. J Endocrinol Invest 2022; 45:2149-2156. [PMID: 35831586 PMCID: PMC9281239 DOI: 10.1007/s40618-022-01854-y] [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] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 06/27/2022] [Indexed: 11/10/2022]
Abstract
PURPOSE Thyroid dysfunction in COVID-19 carries clinical and prognostic implications. In this study, we developed a prediction score (ThyroCOVID) for abnormal thyroid function (TFT) on admission amongst COVID-19 patients. METHODS Consecutive COVID-19 patients admitted to Queen Mary Hospital were prospectively recruited during July 2020-May 2021. Thyroid-stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) were measured on admission. Multivariable logistic regression analysis was performed to identify independent determinants of abnormal TFTs. ThyroCOVID was developed based on a clinical model with the lowest Akaike information criteria. RESULTS Five hundred and forty six COVID-19 patients were recruited (median age 50 years, 45.4% men, 72.9% mild disease on admission). 84 patients (15.4%) had abnormal TFTs on admission. Patients with abnormal TFTs were more likely to be older, have more comorbidities, symptomatic, have worse COVID-19 severity, higher SARS-CoV-2 viral loads and more adverse profile of acute-phase reactants, haematological and biochemical parameters. ThyroCOVID consisted of five parameters: symptoms (malaise), comorbidities (ischaemic heart disease/congestive heart failure) and laboratory parameters (lymphocyte count, C-reactive protein, and SARS-CoV-2 cycle threshold values). It was able to identify abnormal TFT on admission with an AUROC of 0.73 (95% CI 0.67-0.79). The optimal cut-off of 0.15 had a sensitivity of 75.0%, specificity of 65.2%, negative predictive value of 93.5% and positive predictive value of 28.1% in identifying abnormal TFTs on admission amongst COVID-19 patients. CONCLUSION ThyroCOVID, a prediction score to identify COVID-19 patients at risk of having abnormal TFT on admission, was developed based on a cohort of predominantly non-severe COVID-19 patients.
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Affiliation(s)
- D. T. W. Lui
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - C. H. Lee
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - W. S. Chow
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - A. C. H. Lee
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - A. R. Tam
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - C. Y. Y. Cheung
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - C. H. Y. Fong
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - S. T. M. Kwok
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - C. Y. Law
- Division of Chemical Pathology, Queen Mary Hospital, Hong Kong, China
| | - K. K. W. To
- Department of Microbiology, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - C. W. Lam
- Department of Pathology, The University of Hong Kong, Hong Kong, China
| | - K. C. B. Tan
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - Y. C. Woo
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - I. F. N. Hung
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - K. S. L. Lam
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
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Lui DTW, Lee CH, Chau VWK, Fong CHY, Yeung KMY, Lam JKY, Lee ACH, Chow WS, Tan KCB, Woo YC, Lam KSL. Potential role of fibroblast growth factor 21 in the deterioration of bone quality in impaired glucose tolerance. J Endocrinol Invest 2021; 44:523-530. [PMID: 32602078 DOI: 10.1007/s40618-020-01337-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 06/14/2020] [Indexed: 12/23/2022]
Abstract
PURPOSE Findings on trabecular bone score (TBS), an index of bone quality, have been reported in prediabetes defined by impaired fasting glucose or HbA1c. Here, we assessed the bone mineral density (BMD) and TBS in prediabetes individuals with impaired glucose tolerance (IGT), and investigated the association of these bone parameters with serum levels of fibroblast growth factor 21 (FGF21), a hormone implicated in bone metabolism and with higher levels in IGT. METHODS Chinese postmenopausal women aged 55-80 years, without diabetes, were recruited from the Hong Kong Cardiovascular Risk Factor Prevalence Study in 2016-2018. Normal glucose tolerance (NGT) was defined by fasting glucose < 5.6 mmol/L and 2-h plasma glucose (2hG) < 7.8 mmol/L, and IGT by 2hG 7.8-11 mmol/L. Serum levels of FGF21 and other bone metabolism regulators were measured. Insulin sensitivity was assessed by the Matsuda index. Independent determinants of TBS were evaluated using multivariable stepwise linear regression. RESULTS 173 individuals with NGT and 73 with IGT were included. TBS was lower in those with IGT compared to those with NGT, while BMD was comparable. Individuals with IGT had significantly higher serum FGF21 levels, which in turn showed an independent inverse relationship with TBS, attenuated after inclusion of the Matsuda index. Serum FGF21 levels, however, did not correlate with BMD. CONCLUSION Among Chinese postmenopausal women, bone quality was worse in IGT, despite comparable bone density. FGF21 levels showed a significant independent inverse relationship with TBS, partly attributed to insulin resistance. Whether FGF21 contributes to the impaired bone quality in IGT remains speculative.
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Affiliation(s)
- D T W Lui
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
| | - C H Lee
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
| | - V W K Chau
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
| | - C H Y Fong
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
| | - K M Y Yeung
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
| | - J K Y Lam
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
| | - A C H Lee
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
| | - W S Chow
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
| | - K C B Tan
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
| | - Y C Woo
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China.
| | - K S L Lam
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China.
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Lui DTW, Lee CH, Chan YH, Chow WS, Fong CHY, Siu DCW, Tse HF, Woo YC, Lam KSL. HbA1c variability, in addition to mean HbA1c, predicts incident hip fractures in Chinese people with type 2 diabetes. Osteoporos Int 2020; 31:1955-1964. [PMID: 32385660 DOI: 10.1007/s00198-020-05395-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 03/17/2020] [Indexed: 12/28/2022]
Abstract
UNLABELLED Type 2 diabetes is associated with an increased risk of hip fractures. We hypothesize that long-term glycemic variability predicts incident hip fractures. We demonstrated that HbA1c variability predicted incident hip fractures independent of mean HbA1c, suggesting the potential benefits of minimizing glycemic variability in addition to optimizing mean glycemia for bone health. INTRODUCTION Type 2 diabetes is associated with an increased risk of hip fractures, and a linear relationship between HbA1c levels and hip fracture incidence has been observed. We hypothesize that HbA1c variability also predicts incident hip fractures in type 2 diabetes. METHODS Chinese individuals with type 2 diabetes aged ≥ 60 years were identified from electronic health records in Hong Kong between 2008 and 2012 and observed for incident hip fractures. Hip fracture was defined by the International Classification of Diseases (Ninth Revision) code 820. HbA1c variability was determined using standard deviation, adjusted standard deviation, and coefficient of variation of HbA1c measurements in the 5 years preceding the entry date. Multivariable Cox regression analysis was used to evaluate associations between HbA1c variability and incident hip fractures. RESULTS A total of 83,282 participants were included. Their mean age was 71.3 ± 7.5 years, duration of diabetes 11.7 ± 7.7 years, baseline HbA1c 56.6 ± 13.5 mmol/mol (7.33 ± 1.23%), and median follow-up 6.8 years. All indices of HbA1c variability were significant independent predictors of incident hip fractures, with an adjusted hazard ratio of up to 1.29 (all p < 0.001), and remained to be independent predictors across groups of different intensity of glycemic control. Mean HbA1c ≥ 64 mmol/mol (8.0%) was associated with a 25% increase in incident hip fractures compared with mean HbA1c < 53 mmol/mol (7.0%). CONCLUSION HbA1c variability is an independent positive predictor of hip fracture in type 2 diabetes, across the spectrum of varying degree of glycemic control, while a high HbA1c is also not advisable from the perspective of bone health.
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Affiliation(s)
- D T W Lui
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China
| | - C H Lee
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong SAR, China
| | - Y H Chan
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China
| | - W S Chow
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China
| | - C H Y Fong
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China
| | - D C W Siu
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China
| | - H F Tse
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China
| | - Y C Woo
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China.
| | - K S L Lam
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China.
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong SAR, China.
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Chau ACM, Cheung EYW, Chan KH, Chow WS, Shea YF, Chiu PKC, Mak HKF. Impaired cerebral blood flow in type 2 diabetes mellitus - A comparative study with subjective cognitive decline, vascular dementia and Alzheimer's disease subjects. Neuroimage Clin 2020; 27:102302. [PMID: 32521474 PMCID: PMC7284123 DOI: 10.1016/j.nicl.2020.102302] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [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: 04/23/2020] [Revised: 04/27/2020] [Accepted: 05/25/2020] [Indexed: 12/21/2022]
Abstract
CBF impairment is found in T2DM and SCD individuals, which might suggest a preclinical stage of dementia. Comparing to HC, lower CBF in T2DM was due to higher rate of multiple cerebrovascular risk factors. Unlike T2DM, CBF reduction in AD and VD was due to amyloid deposition and microangiopathy respectively. Significant negative correlation between adjusted CBF and HbA1c in all cortical regions in healthy control and T2DM.
The link between non-demented type 2 diabetes mellitus (T2DM) and different types of cognitive impairment is controversial. By controlling for co-morbidities such as cerebral macrovascular and microvascular changes, cerebral atrophy, amyloid burden, hypertension or hyperlipidemia, the current study investigated the cerebral blood flow of T2DM individuals as compared to cognitively impaired subjects recruited from a memory clinic. 15 healthy control (71.8 ± 6.1 years), 18 T2DM (62.5 ± 3.7 years), as well as 8 Subjective Cognitive Decline (69.5 ± 7.5 years), 12 Vascular Dementia (79.3 ± 4.2 years) and 17 Alzheimer’s Disease (75.1 ± 8.2 years) underwent multi-parametric MRI brain scanning. Subjects with T2DM and from the memory clinic also had 18-F Flutametamol PET-CT scanning to look for any amyloid burden. Pseudocontinuous Arterial Spin Labeling (PCASL), MR Angiography Head, 3D FLAIR and 3D T1-weighted sequences were used to quantify cerebral blood flow, cerebrovascular changes, white matter hyperintensities and brain atrophy respectively. Vascular risk factors were retrieved from the medical records. The 37 subjects from memory clinic were classified into subjective cognitive decline (SCD), vascular dementia (VD) and Alzheimer’s disease (AD) subgroups by a multi-disciplinary panel consisting of a neuroradiologist, and 2 geriatricians. Absolute cortical CBF in our cohort of T2DM, SCD, VD and AD was significantly decreased (p < 0.01) as compared to healthy controls (HC) in both whole brain and eight paired brain regions, after age, normalized grey matter volume and gender adjustment and Bonferroni correction. Subgroup analysis between T2DM, SCD, VD, and AD revealed that CBF of T2DM was not significantly different from AD, VD or SCD. By controlling for co-morbidities, impaired cortical CBF in T2DM was not related to microangiopathy or amyloid deposition, but to the interaction of triple risk factors (such as diabetes mellitus, hypertension, and hyperlipidemia). There was statistically significant negative correlation (p ≤ 0.05) between adjusted CBF and HbA1c in all brain regions of T2DM and HC (with partial correlation ranging from −0.30 to −0.46). Taken together, altered cerebral blood flow in T2DM might be related to disruption of cerebrovascular autoregulation related to vascular risk factors, and such oligemia occurred before clinical manifestation due to altered glycemic control.
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Affiliation(s)
- Anson C M Chau
- The University of Hong Kong (Shenzhen) Teaching Hospital Limited, The University of Hong Kong, Pokfulam Road, Hong Kong.
| | - Eva Y W Cheung
- Department of Diagnostic Radiology, LKS Faculty of Medicine, The University of Hong Kong, K406, Queen Mary Hospital, Pokfulam Road, Hong Kong
| | - K H Chan
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, 405B, Professorial Block, Queen Mary Hospital, Pokfulam Road, Hong Kong.
| | - W S Chow
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, 405B, Professorial Block, Queen Mary Hospital, Pokfulam Road, Hong Kong.
| | - Y F Shea
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, 405B, Professorial Block, Queen Mary Hospital, Pokfulam Road, Hong Kong
| | - Patrick K C Chiu
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, 405B, Professorial Block, Queen Mary Hospital, Pokfulam Road, Hong Kong
| | - Henry K F Mak
- Department of Diagnostic Radiology, LKS Faculty of Medicine, The University of Hong Kong, K406, Queen Mary Hospital, Pokfulam Road, Hong Kong; State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong; Alzheimer's Disease Research Network, The University of Hong Kong, Hong Kong.
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Koo HC, Kaur S, Chan KQ, Soh WH, Ang YL, Chow WS, Hew MK, Wong SY, Yap MP. Whole-grain intake and its inverse relationships with fatty acids intake among multiethnic Malaysian schoolchildren. J Hum Nutr Diet 2020; 33:670-677. [PMID: 32250007 DOI: 10.1111/jhn.12753] [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] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Little is known about the relationship of whole-grain intake with dietary fatty acids intake. The present study aimed to assess the whole-grain intake and its relationships with dietary fatty acids intake among multiethnic schoolchildren in Kuala Lumpur, Malaysia. METHODS This cross-sectional study was conducted among 392 schoolchildren aged 9-11 years, cluster sampled from five randomly selected schools in Kuala Lumpur. Whole-grain and fatty acids intakes were assessed by 3-day, 24-h diet recalls. All whole-grain foods were considered irrespective of the amount of whole grain they contained. RESULTS In total, 55.6% (n = 218) were whole-grain consumers. Mean (SD) daily intake of whole grain in the total sample was 5.13 (9.75) g day-1 . In the whole-grain consumer's only sample, mean (SD) intakes reached 9.23 (11.55) g day-1 . Significant inverse associations were found between whole-grain intake and saturated fatty acid (SAFA) intake (r = -0.357; P < 0.001), monosaturated fatty acid (MUFA) (r = -0.373; P < 0.001) and polyunsaturated fatty acid (PUFA) (r = -0.307; P < 0.001) intake. Furthermore, whole-grain intake was a significant predictor of SAFA (β = -0.077; P = 0.004), MUFA (β = -0.112; P = <0.001) and PUFA (β = -0.202; P = <0.001) intakes, after controlling for sex, age and ethnicity. CONCLUSIONS Whole-grain intake in Malaysia was well below recommendations. Schoolchildren who consumed higher whole grain tend to reduce fat intake; however, it would also reduce the SAFA, MUFA and PUFA intakes. Future collaboration may be conducted between industry, government and universities to promote unsaturated fatty acids-rich foods and whole-grain food, although not to promote processed whole-grain foods with a high sugar and salt content.
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Affiliation(s)
- H C Koo
- Faculty of Applied Sciences, Tunku Abdul Rahman University College, Kuala Lumpur, Malaysia
| | - S Kaur
- Faculty of Applied Sciences, UCSI University, Kuala Lumpur, Malaysia
| | - K Q Chan
- Faculty of Applied Sciences, Tunku Abdul Rahman University College, Kuala Lumpur, Malaysia
| | - W H Soh
- Faculty of Applied Sciences, Tunku Abdul Rahman University College, Kuala Lumpur, Malaysia
| | - Y L Ang
- Faculty of Applied Sciences, Tunku Abdul Rahman University College, Kuala Lumpur, Malaysia
| | - W S Chow
- Faculty of Applied Sciences, Tunku Abdul Rahman University College, Kuala Lumpur, Malaysia
| | - M K Hew
- Faculty of Applied Sciences, Tunku Abdul Rahman University College, Kuala Lumpur, Malaysia
| | - S Y Wong
- Faculty of Applied Sciences, Tunku Abdul Rahman University College, Kuala Lumpur, Malaysia
| | - M P Yap
- Faculty of Applied Sciences, Tunku Abdul Rahman University College, Kuala Lumpur, Malaysia
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Tan K, Chow WS, Leung J, Ho A, Ozaki R, Kam G, Li J, Choi CH, Tsang MW, Chan N, Lee KK, Chan KW. Clinical considerations when adding a sodium-glucose co-transporter-2 inhibitor to insulin therapy in patients with diabetes mellitus. Hong Kong Med J 2019; 25:312-319. [PMID: 31416990 DOI: 10.12809/hkmj197802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- K Tan
- Department of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - W S Chow
- Department of Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
| | - J Leung
- Department of Integrated Medical Service, Ruttonjee and Tang Shiu Kin Hospitals, Hong Kong
| | - A Ho
- Department of Medicine and Geriatrics, Tuen Mun Hospital, Tuen Mun, Hong Kong
| | - R Ozaki
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - G Kam
- Department of Medicine and Geriatrics, United Christian Hospital, Kwun Tong, Hong Kong
| | - J Li
- Department of Medicine, Yan Chai Hospital, Tsuen Wan, Hong Kong
| | - C H Choi
- Department of Medicine, Queen Elizabeth Hospital, Jordan, Hong Kong
| | - M W Tsang
- Specialist in Endocrinology, Private Practice
| | - N Chan
- Specialist in Endocrinology, Private Practice
| | - K K Lee
- Department of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - K W Chan
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Laichikok, Hong Kong
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Yao H, Zhang Y, Yi X, Zhang X, Fan D, Chow WS, Zhang W. Diaheliotropic leaf movement enhances leaf photosynthetic capacity and photosynthetic light and nitrogen use efficiency via optimising nitrogen partitioning among photosynthetic components in cotton (Gossypium hirsutum L.). Plant Biol (Stuttg) 2018; 20:213-222. [PMID: 29222927 DOI: 10.1111/plb.12678] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [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: 09/28/2017] [Accepted: 12/01/2017] [Indexed: 06/07/2023]
Abstract
Phototropic leaf movement of plants is an effective mechanism for adapting to light conditions. Light is the major driver of plant photosynthesis. Leaf N is also an important limiting factor on leaf photosynthetic potential. Cotton (Gossypium hirsutum L.) exhibits diaheliotropic leaf movement. Here, we compared the long-term photosynthetic acclimation of fixed leaves (restrained) and free leaves (allowed free movement) in cotton. The fixed leaves and free leaves were used for determination of PAR, leaf chlorophyll concentration, leaf N content and leaf gas exchange. The measurements were conducted under clear sky conditions at 0, 7, 15 and 30 days after treatment (DAT). The results showed that leaf N allocation and partitioning among different components of the photosynthetic apparatus were significantly affected by diaheliotropic leaf movement. Diaheliotropic leaf movement significantly increased light interception per unit leaf area, which in turn affected leaf mass per area (LMA), leaf N content (NA ) and leaf N allocation to photosynthesis (NP ). In addition, cotton leaves optimised leaf N allocation to the photosynthetic apparatus by adjusting leaf mass per area and NA in response to optimal light interception. In the presence of diaheliotropic leaf movement, cotton leaves optimised their structural tissue and photosynthetic characteristics, such as LMA, NA and leaf N allocation to photosynthesis, so that leaf photosynthetic capacity was maximised to improve the photosynthetic use efficiency of light and N under high light conditions.
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Affiliation(s)
- H Yao
- The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Corps, Shihezi University, Shihezi, Xinjiang, China
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, Australia
| | - Y Zhang
- The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Corps, Shihezi University, Shihezi, Xinjiang, China
| | - X Yi
- The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Corps, Shihezi University, Shihezi, Xinjiang, China
| | - X Zhang
- The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Corps, Shihezi University, Shihezi, Xinjiang, China
| | - D Fan
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, Australia
| | - W S Chow
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, Australia
| | - W Zhang
- The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Corps, Shihezi University, Shihezi, Xinjiang, China
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Lee CH, Shih AZL, Woo YC, Fong CHY, Yuen MMA, Chow WS, Lam KSL. Which creatinine-based estimated glomerular filtration rate equation best predicts all-cause mortality in Chinese subjects with type 2 diabetes? Diabetes Res Clin Pract 2017; 126:25-29. [PMID: 28189951 DOI: 10.1016/j.diabres.2017.01.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 01/20/2017] [Indexed: 11/19/2022]
Abstract
AIM In Chinese, ethnicity-based and/or diabetes specific modifications of the Modification of Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations have been developed for determining estimated glomerular filtrate rate (eGFR). This study aimed to compare the performance of five different creatinine-based eGFR equations in predicting all-cause mortality among Chinese subjects with type 2 diabetes (T2DM). METHODS A total of 6739 Chinese subjects with T2DM were included. Their eGFR was calculated using the MDRD, CKD-EPI, their respective modified equations for Chinese, and the diabetes specific CKD-EPI Chinese T2DM equations. Multiple Cox regression analysis was used to evaluate the associations of eGFR with all-cause mortality. C-statistics, net reclassification index (NRI) and integrated discrimination index (IDI) were applied to assess the discrimination and reclassification of each eGFR equation in predicting mortality outcome. RESULTS Over a follow-up of 5.7years, the incidence of all-cause mortality was 12.9% (N=867). The CKD-EPI equation discriminated all-cause mortality better than the MDRD equation (C-statistics: 0.714 vs. 0.689, p<0.0001), and Chinese modification of their respective equations did not improve discrimination. Among the five eGFR equations evaluated, the CKD-EPI Chinese T2DM equation provided the best discrimination in predicting all-cause mortality among Chinese subjects with T2DM, and was the only equation providing a significantly positive NRI and IDI relative to the CKD-EPI equation. CONCLUSIONS Among Chinese subjects with T2DM, our findings suggested that the CKD-EPI Chinese T2DM equation best predicted all-cause mortality, and relative to the CKD-EPI equation, conferred improved discrimination and reclassification.
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Affiliation(s)
- C H Lee
- Department of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region; Research Centre of Heart, Brain, Hormone and Healthy Aging, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region
| | - A Z L Shih
- Department of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Y C Woo
- Department of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - C H Y Fong
- Department of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - M M A Yuen
- Department of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - W S Chow
- Department of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region.
| | - K S L Lam
- Department of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region; Research Centre of Heart, Brain, Hormone and Healthy Aging, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region; State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region.
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Lee CH, Cheung CYY, Chow WS, Woo YC, Yeung CY, Lang BHH, Fong CHY, Kwok KHM, Chen SPL, Mak CM, Tan KCB, Lam KSL. Genetics of Apparently Sporadic Pheochromocytoma and Paraganglioma in a Chinese Population. Horm Metab Res 2015; 47:833-8. [PMID: 26267327 DOI: 10.1055/s-0035-1555955] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Identification of germline mutation in patients with apparently sporadic pheochromocytomas and paragangliomas is crucial. Clinical indicators, which include young age, bilateral or multifocal, extra-adrenal, malignant, or recurrent tumors, predict the likelihood of harboring germline mutation in Caucasian subjects. However, data on the prevalence of germline mutation, as well as the applicability of these clinical indicators in Chinese, are lacking. We conducted a cross-sectional study at a single endocrine tertiary referral center in Hong Kong. Subjects with pheochromocytomas and paragangliomas were evaluated for the presence of germline mutations involving 10 susceptibility genes, which included NF1, RET, VHL, SDHA, SDHB, SDHC, SDHD, TMEM 127, MAX, and FH genes. Clinical indicators were assessed for their association with the presence of germline mutations. Germline mutations, 2 being novel, were found in 24.4% of the 41 Chinese subjects recruited and 11.4% among those with apparently sporadic presentation. The increasing number of the afore-mentioned clinical indicators significantly correlated with the likelihood of harboring germline mutation in one of the 10 susceptibility genes. (r=0.757, p=0.026). The presence of 2 or more clinical indicators should prompt genetic testing for germline mutations in Chinese subjects. In conclusion, our study confirmed that a significant proportion of Chinese subjects with apparently sporadic pheochromocytoma and paraganglioma harbored germline mutations and these clinical indicators identified from Caucasians series were also applicable in Chinese subjects. This information will be of clinical relevance in the design of appropriate genetic screening strategies in Chinese populations.
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Affiliation(s)
- C H Lee
- Department of Medicine, Queen Mary Hospital, Hong Kong SAR, China
| | - C Y Y Cheung
- Department of Medicine, Queen Mary Hospital, Hong Kong SAR, China
| | - W S Chow
- Department of Medicine, Queen Mary Hospital, Hong Kong SAR, China
| | - Y C Woo
- Department of Medicine, Queen Mary Hospital, Hong Kong SAR, China
| | - C Y Yeung
- Department of Medicine, Queen Mary Hospital, Hong Kong SAR, China
| | - B H H Lang
- Department of Surgery, Queen Mary Hospital, Hong Kong SAR, China
| | - C H Y Fong
- Department of Medicine, Queen Mary Hospital, Hong Kong SAR, China
| | - K H M Kwok
- Department of Medicine, Queen Mary Hospital, Hong Kong SAR, China
| | - S P L Chen
- Kowloon West Cluster Laboratory Genetic Service, Department of Pathology, Princess Margaret Hospital, Hong Kong SAR, China
| | - C M Mak
- Kowloon West Cluster Laboratory Genetic Service, Department of Pathology, Princess Margaret Hospital, Hong Kong SAR, China
| | - K C B Tan
- Department of Medicine, Queen Mary Hospital, Hong Kong SAR, China
| | - K S L Lam
- Department of Medicine, Queen Mary Hospital, Hong Kong SAR, China
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Lee CH, Hui EYL, Woo YC, Yeung CY, Chow WS, Yuen MMA, Fong CHY, Xu A, Lam KSL. Circulating fibroblast growth factor 21 levels predict progressive kidney disease in subjects with type 2 diabetes and normoalbuminuria. J Clin Endocrinol Metab 2015; 100:1368-75. [PMID: 25625802 DOI: 10.1210/jc.2014-3465] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND Elevated fibroblast growth factor 21 (FGF21) levels have been suggested, from cross-sectional studies, as an indicator of subclinical diabetic nephropathy. We investigated whether serum FGF21 was predictive of the development of diabetic nephropathy. METHOD Baseline serum FGF21 levels were measured in 1136 Chinese type 2 diabetic subjects recruited from the Hong Kong West Diabetes Registry. The role of serum FGF21 in predicting decline in estimated glomerular filtration rate (eGFR) over a median follow-up of 4 years was analyzed using Cox regression analysis. RESULTS At baseline, serum FGF21 levels increased progressively with eGFR category (P for trend <.001). Among 1071 subjects with baseline eGFR ≥ 30 mL/min/1.73 m(2), serum FGF21 levels were significantly higher in those with eGFR decline during follow-up (n = 171) than those without decline (n = 900) (P < .001). In multivariable Cox regression analysis, baseline serum FGF21 was independently associated with eGFR decline (hazard ratio, 1.21; 95% confidence interval [CI], 1.01-1.43; P = .036), even after adjustment for baseline eGFR. In a subgroup of 559 subjects with baseline eGFR ≥ 60 mL/min/1.73 m(2) and normoalbuminuria, serum FGF21 level remained an independent predictor of eGFR decline (hazard ratio, 1.36; 95% CI, 1.06-1.76; P = .016). Integrated discrimination improvement (IDI) suggested that the inclusion of baseline serum FGF21 significantly improved the prediction of eGFR decline (IDI, 1%; 95% CI, 0.1-3.0; P = .013) in this subgroup, but not in the initial cohort involving all subjects. CONCLUSIONS Elevated serum FGF21 levels may be a useful biomarker for predicting kidney disease progression, especially in the early stages of diabetic nephropathy.
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Affiliation(s)
- C H Lee
- Department of Medicine (C.H.L., E.Y.L.H., Y.C.W., C.Y.Y., W.S.C., M.M.A.Y., C.H.Y.F. A.X., K.S.L.L.), Queen Mary Hospital, Hong Kong SAR; Research Centre of Heart, Brain, Hormone and Healthy Aging (E.Y.L.H., A.X., K.S.L.L.), The University of Hong Kong, Pokfulam, Hong Kong SAR; and State Key Laboratory of Pharmaceutical Biotechnology (A.X., K.S.L.L.), The University of Hong Kong, Pokfulam, Hong Kong SAR
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Li ZJ, Fan DY, Chen FQ, Yuan QY, Chow WS, Xie ZQ. Physiological integration enhanced the tolerance of Cynodon dactylon to flooding. Plant Biol (Stuttg) 2015; 17:459-465. [PMID: 25557716 DOI: 10.1111/plb.12254] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [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: 07/18/2014] [Accepted: 09/01/2014] [Indexed: 06/04/2023]
Abstract
Many flooding-tolerant species are clonal plants; however, the effects of physiological integration on plant responses to flooding have received limited attention. We hypothesise that flooding can trigger changes in metabolism of carbohydrates and ROS (reactive oxygen species) in clonal plants, and that physiological integration can ameliorate the adverse effects of stress, subsequently restoring the growth of flooded ramets. In the present study, we conducted a factorial experiment combining flooding to apical ramets and stolon severing (preventing physiological integration) between apical and basal ramets of Cynodon dactylon, which is a stoloniferous perennial grass with considerable flooding tolerance. Flooding-induced responses including decreased root biomass, accumulation of soluble sugar and starch, as well as increased activity of superoxide dismutase (SOD) and ascorbate peroxidase (APX) in apical ramets. Physiological integration relieved growth inhibition, carbohydrate accumulation and induction of antioxidant enzyme activity in stressed ramets, as expected, without any observable cost in unstressed ramets. We speculate that relief of flooding stress in clonal plants may rely on oxidising power and electron acceptors transferred between ramets through physiological integration.
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Affiliation(s)
- Z J Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
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Chow WS, Ng K, Mohd Ishak ZA, Hashim H, Mohd Noor SNF. Human Gingival Fibroblasts Cell Viability of Poly(Lactic Acid) Powder Reinforced PMMA/Hydroxyapatite Biocomposites. INT J POLYM MATER PO 2014. [DOI: 10.1080/00914037.2014.936590] [Citation(s) in RCA: 2] [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: 10/24/2022]
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Lam JKY, Lam KSL, Chow WS, Tan KCB. A middle-aged man with increasing body fat. Clin Obes 2014; 4:237-40. [PMID: 25826795 DOI: 10.1111/cob.12061] [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] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/16/2014] [Indexed: 11/26/2022]
Abstract
A 51-year-old man was referred for evaluation of gradual increase in body fat over bilateral arms, chest and abdomen for 6 months. He was a non-smoker and he drank at least four bottles of beer daily since the age of 18. There was no significant past medical history or any family history of obesity or endocrine diseases. Physical examination showed localized large bulk of fat over the neck, both arms and mammary regions, abdomen, and back (Figs and ). The lower limbs and buttock were relatively spared. There was telangiectasia over the face and chest wall, but no palmar erythema nor finger clubbing. The liver span was normal, and the spleen tip was palpated 2 cm below the costal margin. Examination of the cardiovascular, respiratory and neurological system was normal. [Figure: see text] [Figure: see text] Blood tests showed thrombocytopenia (platelet 140 × 10(9) L(-1) [normal: 170-380 × 10(9) L(-1) ]) and liver function derangement (bilirubin 27 μmol L(-1) , ALP 298 U L(-1) , ALT 127 U L(-1) , AST 165 U L(-1) , GGT 1353 U L(-1) , albumin 33 g L(-1) and globulin 42 g L(-1) ). His clotting profile and renal functions were normal. His hepatitis B surface antigen was positive, but his HBV DNA was <60 copies per mL. Fasting glucose was 5.0 mmol L(-1) . HbA1c was 5.6%. His lipid profile was satisfactory with total cholesterol of 2.9 mmol L(-1) , triglycerides 1.0 mmol L(-1) , HDL-C 1.37 mmol L(-1) and LDL-C 1.1 mmol L(-1) . Ultrasound of the abdomen showed normal-sized liver with coarsened liver parenchymal echogenicity. The spleen was enlarged to 14 cm. This middle-aged man suffered from multiple symmetric lipomatosis and alcoholic liver disease. Dual-energy X-ray showed 1746 gm (40.1%), 1498 gm (32.8%) and 8322 gm (26.8%) fat over the left arm, right arm and trunk, respectively. The legs were unaffected with 1703 gm (19.4%) and 1627 gm (17.7%) fat over the left and right sides, respectively. The patient was advised to stop drinking and he declined surgical treatment.
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Affiliation(s)
- J K Y Lam
- Department of Medicine, Queen Mary Hospital, Hong Kong
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Tham WL, Mohd Ishak ZA, Chow WS. Mechanical and Thermal Properties Enhancement of Poly(Lactic Acid)/Halloysite Nanocomposites by Maleic-Anhydride Functionalized Rubber. J MACROMOL SCI B 2014. [DOI: 10.1080/00222348.2013.839314] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Zulfli NHM, Bakar AA, Chow WS. Mechanical and thermal properties improvement of nano calcium carbonate-filled epoxy/glass fiber composite laminates. HIGH PERFORM POLYM 2013. [DOI: 10.1177/0954008313507961] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In this work, the influence of precipitated nano calcium carbonate (PNCC) on the mechanical and thermal properties of epoxy/glass fiber (GF) laminates was studied. The mechanical properties of the epoxy/GF/PNCC composites were characterized by flexural and impact tests. The fracture toughness of the epoxy hybrid composites was evaluated by the principle of linear elastic fracture mechanics via single-edge notched bending tests. The thermal properties of the epoxy hybrid composites were studied using dynamic mechanical analyzer (DMA) and thermogravimetric analyzer (TGA). The flexural properties, impact strength, and fracture toughness of the epoxy/GF laminates were increased profoundly in the presence of PNCC. Additionally, from the DMA and TGA results, it was found that the storage modulus and thermal decomposition temperature of the epoxy/GF increased remarkably with the addition of PNCC.
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Affiliation(s)
- N. H. Mohd Zulfli
- School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, Penang, Malaysia
| | - A. Abu Bakar
- School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, Penang, Malaysia
| | - W. S. Chow
- School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, Penang, Malaysia
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Abstract
Photosynthesis, the natural process that yields food, fuel and fibre, spans physical and biological sciences, spatially from atomic scales to the global and temporally from electronic transitions to the evolutionary time frame. Photosynthesis is highly efficient in its primary energy capture, but much less so in terms of conversion to crop yield. The natural photosynthetic system provides fertile ground for exploring and dissecting partial processes that may be mimicked inartificial systems for human needs, perhaps with improved efficiency. Future developments are limited only by the imagination.
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Affiliation(s)
- W S Chow
- Photobioenergetics Group, Research School of Biological Sciences, Institute of Advanced Studies, Australian National University, GPO Box 475, Canberra, ACT 2601 Australia
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Phua YJ, Chow WS, Mohd Ishak ZA. Reactive processing of maleic anhydride-grafted poly(butylene succinate) and the compatibilizing effect on poly(butylene succinate) nanocomposites. EXPRESS POLYM LETT 2013. [DOI: 10.3144/expresspolymlett.2013.31] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Li JY, Chow WS, Igelnik B, Pao YH. Comments on "Stochastic choice of basis functions in adaptive function approximation and the functional-link net" [and reply]. ACTA ACUST UNITED AC 2012; 8:452-4. [PMID: 18255650 DOI: 10.1109/72.557702] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This paper includes some comments and amendments of the above-mentioned paper by Igelnik et al. (1995). Subsequently, Theorem 1 in the above-mentioned paper has been revised. The significant change of the original theorem is the space of the thresholds in the hidden layer. The revised theorem says that the thresholds of hidden b(0), should be -w(0).y(0)-u(0), where w(0)=alphaw;(0); w;(0)=(w; (01), ..., y(0d)), and u(0 ) be independent and uniformly distributed in V(d)=[0; Omega]x[-Omega; Omega](d-1), I(d), and [-2dOmega, 2dOmega], respectively. In reply, Igelnik et al. acknowledge that a factor of two was omitted in the statement of a trigonometric identity. However, the validity of the essential point of Theorem 1 is unaltered.
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Affiliation(s)
- J Y Li
- Dept. of Electron. Eng., City Univ. of Hong Kong, Kowloon
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Chow WS, Leu YY, Mohd Ishak ZA. Effects of SEBS-g-MAH on the properties of injection moulded poly(lactic acid)/nano-calcium carbonate composites. EXPRESS POLYM LETT 2012. [DOI: 10.3144/expresspolymlett.2012.53] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Leu YY, Mohd Ishak ZA, Chow WS. Mechanical, thermal, and morphological properties of injection molded poly(lactic acid)/SEBS-g-MAH/organo-montmorillonite nanocomposites. J Appl Polym Sci 2011. [DOI: 10.1002/app.35084] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Phua YJ, Chow WS, Mohd Ishak ZA. Mechanical properties and structure development in poly(butylene succinate)/organo-montmorillonite nanocomposites under uniaxial cold rolling. EXPRESS POLYM LETT 2011. [DOI: 10.3144/expresspolymlett.2011.11] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Tham WL, Chow WS, Ishak ZAM. The effect of 3-(trimethoxysilyl) propyl methacrylate on the mechanical, thermal, and morphological properties of poly(methyl methacrylate)/hydroxyapatite composites. J Appl Polym Sci 2010. [DOI: 10.1002/app.32111] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Tham WL, Chow WS, Mohd Ishak ZA. Simulated body fluid and water absorption effects on poly(methyl methacrylate)/hydroxyapatite denture base composites. EXPRESS POLYM LETT 2010. [DOI: 10.3144/expresspolymlett.2010.66] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Chow WS, Neoh SS. Dynamic mechanical, thermal, and morphological properties of silane-treated montmorillonite reinforced polycarbonate nanocomposites. J Appl Polym Sci 2009. [DOI: 10.1002/app.30977] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Tam X, Shiu S, Chow WS, Wong Y, Betteridge J, Tan K. Abstract: P1203 ATORVASTATIN INDUCES THE EXPRESSION OF SOLUBLE RECEPTOR FOR ADVANCED GLYCATION END PRODUCTS. ATHEROSCLEROSIS SUPP 2009. [DOI: 10.1016/s1567-5688(09)70310-1] [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: 10/20/2022]
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Chow WS, Tham WL. Effects of antistatic agent on the mechanical, morphological and antistatic properties of polypropylene/organo-montmorillonite nanocomposites. EXPRESS POLYM LETT 2009. [DOI: 10.3144/expresspolymlett.2009.15] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Yeung DCY, Xu A, Tso AWK, Chow WS, Wat NMS, Fong CHY, Tam S, Sham PC, Lam KSL. Circulating levels of adipocyte and epidermal fatty acid-binding proteins in relation to nephropathy staging and macrovascular complications in type 2 diabetic patients. Diabetes Care 2009; 32:132-4. [PMID: 18931100 PMCID: PMC2606847 DOI: 10.2337/dc08-1333] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To investigate the relationships of serum adipocyte fatty acid-binding protein (A-FABP) and epidermal fatty acid-binding protein (E-FABP) with renal dysfunction and macrovascular complications in type 2 diabetic patients. RESEARCH DESIGN AND METHODS The associations of serum A-FABP and E-FABP with markers of renal function, nephropathy staging, and macrovascular complications were examined in 237 type 2 diabetic patients. RESULTS Serum A-FABP and E-FABP correlated significantly with serum creatinine, mean albumin excretion rate, and glomerular filtration rate (all P < 0.001) and were independently associated with diabetic nephropathy staging (P = 0.001 and P < 0.05, respectively). Circulating levels of both types of FABP were increased (P < 0.01) in subjects with macrovascular complications. Serum A-FABP was independently associated with macrovascular complications (odds ratio 2.92 [95% CI 1.42-6.01]; P = 0.004). CONCLUSIONS Serum A-FABP and E-FABP might be novel serum biomarkers for evaluating the progression of nephropathy and its cardiovascular risk in type 2 diabetic patients.
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Affiliation(s)
- Dennis C Y Yeung
- Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China
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Chan AOO, Chow WS, Lam KF, Hsu A, Hung I, Chan P, But D, Seto WK, Lam KSL. The effect of intragastric balloon placement on weight loss and type 2 diabetes control. Aliment Pharmacol Ther 2008; 28:162-4; author reply 164-5. [PMID: 18532946 DOI: 10.1111/j.1365-2036.2008.03687.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Chow WS, Yap YP. Optimization of process variables on flexural properties of epoxy/organo-montmorillonite nanocomposite by response surface methodology. EXPRESS POLYM LETT 2008. [DOI: 10.3144/expresspolymlett.2008.2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Kusmono, Mohd Ishak ZA, Chow WS, Takeichi T, Rochmadi. Enhancement of properties of PA6/PP nanocomposites via organic modification and compatibilization. EXPRESS POLYM LETT 2008. [DOI: 10.3144/expresspolymlett.2008.78] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Tan KCB, Chow WS, Tso AWK, Xu A, Tse HF, Hoo RLC, Betteridge DJ, Lam KSL. Thiazolidinedione increases serum soluble receptor for advanced glycation end-products in type 2 diabetes. Diabetologia 2007; 50:1819-1825. [PMID: 17639302 DOI: 10.1007/s00125-007-0759-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Accepted: 06/06/2007] [Indexed: 10/23/2022]
Abstract
AIMS/HYPOTHESIS Interfering with the activation of receptor for AGE (RAGE) by using a soluble form of the AGE receptor (sRAGE) prevents or ameliorates the vascular complications of diabetes in experimental studies. Relatively little is known about factors that influence endogenous circulating sRAGE in humans. We investigated the impact of improving glycaemic control on serum total sRAGE and endogenous secretory RAGE (esRAGE), a splice variant of sRAGE, and compared the effect of rosiglitazone with that of sulfonylurea. METHODS A randomised, open-label, parallel group study was performed with 64 participants randomised to receive add-on therapy with either rosiglitazone or sulfonylurea. Serum total sRAGE and esRAGE and metabolic parameters were measured before and after 6 months of treatment. RESULTS At 6 months, both rosiglitazone and sulfonylurea resulted in a significant reduction in HbA(1c), fasting glucose and AGE. However, significant increases in total sRAGE and esRAGE were only seen in the rosiglitazone group. As a result, serum esRAGE was higher in the rosiglitazone group than in the sulfonylurea group at 6 months (p < 0.01), whereas the differences in sRAGE between the two groups did not reach statistical significance. Stepwise linear regression analysis showed that treatment modality made a greater contribution than the changes in HbA(1c) to the subsequent changes in esRAGE levels at 6 months. CONCLUSIONS/INTERPRETATION Treating type 2 diabetic patients with thiazolidinedione can increase circulating levels of esRAGE and sRAGE. Whether modulation of circulating sRAGE has a beneficial effect on diabetic complications will have to be evaluated in long-term prospective studies.
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Affiliation(s)
- K C B Tan
- Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong SAR, People's Republic of China.
- Research Centre of Heart, Brain, Hormone and Healthy Aging, University of Hong Kong, Hong Kong SAR, People's Republic of China.
| | - W S Chow
- Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong SAR, People's Republic of China
| | - A W K Tso
- Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong SAR, People's Republic of China
| | - A Xu
- Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong SAR, People's Republic of China
- Research Centre of Heart, Brain, Hormone and Healthy Aging, University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - H F Tse
- Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong SAR, People's Republic of China
- Research Centre of Heart, Brain, Hormone and Healthy Aging, University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - R L C Hoo
- Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong SAR, People's Republic of China
| | - D J Betteridge
- Department of Medicine, Royal Free and University College London Medical School, London, UK
| | - K S L Lam
- Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong SAR, People's Republic of China
- Research Centre of Heart, Brain, Hormone and Healthy Aging, University of Hong Kong, Hong Kong SAR, People's Republic of China
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Chow WS, Mohd Ishak ZA. Mechanical, morphological and rheological properties of polyamide 6/organo-montmorillonite nanocomposites. EXPRESS POLYM LETT 2007. [DOI: 10.3144/expresspolymlett.2007.14] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Tan KCB, Shiu SWM, Chow WS, Leng L, Bucala R, Betteridge DJ. Association between serum levels of soluble receptor for advanced glycation end products and circulating advanced glycation end products in type 2 diabetes. Diabetologia 2006; 49:2756-62. [PMID: 16969649 DOI: 10.1007/s00125-006-0394-1] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2006] [Accepted: 07/06/2006] [Indexed: 01/11/2023]
Abstract
AIMS/HYPOTHESIS Activation of the receptor for advanced glycation end products (RAGE, also known as AGE-specific receptor [AGER]) has been implicated in the development of diabetic vascular complications. Blockade of RAGE using a soluble form of the receptor (sRAGE) suppressed vascular hyperpermeability and atherosclerosis in animal models. Since little is known about the regulation of endogenous sRAGE levels, we determined whether serum sRAGE is influenced by circulating AGEs and the severity of nephropathy in type 2 diabetic patients. MATERIALS AND METHODS We recruited 150 healthy control and 318 diabetic subjects. Diabetic subjects were subdivided into those with proteinuria, microalbuminuria or normoalbuminuria. Serum sRAGE was assayed by ELISA and serum AGEs by competitive ELISA using a polyclonal rabbit antiserum raised against AGE-RNase. RESULTS Diabetic subjects had higher sRAGE (1,029.5 pg/ml [766.1-1,423.0] interquartile range vs 1,002.6 [726.5-1,345.3], p<0.05) and AGEs (4.07+/-1.13, SD, unit/ml vs 3.39+/-1.05, p<0.01) than controls. Proteinuric subjects had the highest sRAGE levels and there was a significant trend between the severity of nephropathy and sRAGE (p=0.01). In diabetic subjects, serum log(sRAGE) correlated with AGEs (r=0.27, p<0.001), log(plasma creatinine) (r=0.31, p<0.001), log(urine AER) (r=0.24, p<0.01) and log(triglycerides) (r=0.15, p<0.01). On stepwise linear regression analysis, AGEs and creatinine levels were the main independent determinants of sRAGE concentration. CONCLUSIONS/INTERPRETATION Serum sRAGE levels and circulating AGEs are associated with the severity of nephropathy in type 2 diabetic patients. Prospective studies are required to determine whether endogenous sRAGE potentially influences the development of diabetic vascular complications.
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Affiliation(s)
- K C B Tan
- Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong SAR, People's Republic of China.
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Chow WS, Ishak ZAM, Karger-Kocsis J. Atomic force microscopy study on blend morphology and clay dispersion in polyamide-6/polypropylene/organoclay systems. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/polb.20408] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Chow WS, Abu Bakar A, Mohd Ishak ZA. Water absorption and hygrothermal aging study on organomontmorillonite reinforced polyamide 6/polypropylene nanocomposites. J Appl Polym Sci 2005. [DOI: 10.1002/app.22172] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Adiponectin may have an antiatherogenic effect by reducing endothelial activation. We hypothesized that plasma adiponectin levels were correlated with endothelial function. Plasma adiponectin level was determined by an in-house RIA assay using a rabbit polyclonal antibody in 73 type 2 diabetic patients and 73 controls. Endothelium-dependent and independent vasodilation of the brachial artery was measured by high-resolution vascular ultrasound. Plasma adiponectin level was lower in diabetic patients than in controls (4.73 +/- 1.96 vs. 7.69 +/- 2.80 microg/ml, respectively; P < 0.001), and they also had impaired endothelium-dependent (5.6 +/- 3.6 vs. 8.6 +/- 4.5%, respectively; P < 0.001) and -independent vasodilation (13.3 +/- 4.9 vs. 16.5 +/- 5.6%, respectively; P < 0.001). Plasma adiponectin correlated with endothelium-dependent vasodilation in controls (P = 0.02) and diabetic patients (P = 0.04). On general linear-model univariate analysis, brachial artery diameter, the presence of diabetes, plasma adiponectin, and high-density lipoprotein were significant independent determinants of endothelium-dependent vasodilation. In vitro experiments showed that endothelial cells expressed adiponectin receptors, and adiponectin increased nitric oxide production in human aortic endothelial cells. In conclusion, low plasma adiponectin level is associated with impaired endothelium-dependent vasodilation, and the association is independent of diabetes mellitus. Adiponectin may act as a link between adipose tissue and the vasculature.
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Affiliation(s)
- K C B Tan
- Department of Medicine, University of Hong Kong.
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Au WY, Tsang J, Cheng TS, Chow WS, Woo YC, Ma SK, Tam S. Cough mixture abuse as a novel cause of megaloblastic anaemia and peripheral neuropathy. Br J Haematol 2004; 123:956-8. [PMID: 14632792 DOI: 10.1046/j.1365-2141.2003.04694.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
Cucumber leaf discs were illuminated at room-temperature with far-red light to photo-oxidise P700, the chlorophyll dimer in Photosystem (PS) I. The post-illumination kinetics of P700(+) re-reduction were studied in the presence of inhibitors or cofactors of photosynthetic electron transport. The re-reduction kinetics of P700(+) were well fitted as the sum of three exponentials, each with its amplitude and rate coefficient, and an initial flux (at the instant of turning off far-red light) given as the product of the two. Each initial flux is assumed equal to a steady state flux during far-red illumination. The fast phase of re-reduction, with rate coefficient k (1) approximately 10 s(-1), was completely abolished by a saturating concentration of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU); it is attributed to electron flow to P700(+) from PS II, which was stimulated to some extent by far-red light. The intermediate phase, with rate coefficient k (1) approximately 1 s(-1), was only partly diminished by methyl viologen (MV) which diverts electron flow to oxygen. The intermediate phase is attributed to electron donation from reduced ferredoxin to the intersystem pool; reduced ferredoxin could be formed: (1) directly by electron donation on the acceptor of PS I; and/or (2) indirectly by stromal reductants, in line with only a partial inhibition of the intermediate phase by MV. Duroquinol enhanced the intermediate phase in the presence of DCMU, presumably through its interaction with thylakoid membrane components leading to the partial reduction of plastoquinone. The slow phase of P700(+) re-reduction, with rate coefficient k (1) approximately 0.1 s(-1), was unaffected by DCMU and only slightly affected by MV; it could be associated with electron donation to either: (1) the intersystem chain by stromal reductants catalysed by NAD(P)H dehydrogenase slowly; or (2) plastocyanin/P700(+) by ascorbate diffusing across the thylakoid membrane to the lumen. It is concluded that a post-illumination analysis of the fluxes to P700(+) can be used to probe the pathways of electron flow to PS I in steady state illumination.
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Affiliation(s)
- W S Chow
- Photobioenergetics Group, Research School of Biological Sciences, Australian National University, PO Box 475, Canberra, ACT, 2601, Australia
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Yap AUJ, Chung SM, Chow WS, Tsai KT, Lim CT. Fracture resistance of compomer and composite restoratives. Oper Dent 2004; 29:29-34. [PMID: 14753329] [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: 04/28/2023]
Abstract
This study evaluated and compared the fracture toughness of compomers and composites. Three compomer (Compoglass F [CG], Vivadent; F2000 [FT], 3M-ESPE; Dyract Posterior [DP], Dentsply) and three composite (Tetric Ceram [TC], Vivadent; Z250 [ZT], 3M-ESPE; Esthet X [EX], Dentsply) restoratives were selected for the study. Single-edged notched specimens (25 x 2 x 2 mm) were fabricated according to manufacturers' instructions and conditioned in distilled water at 37 degrees C for one week prior to testing. Seven specimens were made for each material. The specimens were loaded to failure using an Instron microtester with a crosshead speed of 0.5 mm/minute. Data were subjected to ANOVA/Scheffe's test and Independent Samples T-test at significance level 0.05. The mean fracture toughness (K(IC)) ranged from 0.97 to 1.23 MPam 1/2 for compomers and 1.75 to 1.92 MPam 1/2 for composites. The fracture toughness of compomers was significantly lower than their composite counterparts. No significant difference in K(IC) values was observed among the different composites. When the compomers were compared, FT had significantly higher fracture toughness than DP and CG. In view of their poorer resistance to crack propagation, compomers are not recommended for use in stress-bearing areas.
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Affiliation(s)
- Adrian U J Yap
- Department of Restorative Dentistry, Faculty of Dentistry, National University of Singapore, Republic of Singapore.
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Chow WS, Ishak ZAM, Ishiaku US, Karger-Kocsis J, Apostolov AA. The effect of organoclay on the mechanical properties and morphology of injection-molded polyamide 6/polypropylene nanocomposites. J Appl Polym Sci 2003. [DOI: 10.1002/app.13244] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Given the unique problem of the extremely high potential of the oxidant P(+)(680) that is required to oxidize water to oxygen, the photoinactivation of photosystem II in vivo is inevitable, despite many photoprotective strategies. There is, however, a robustness of photosystem II, which depends partly on the highly dynamic compositional and structural heterogeneity of the cycle between functional and non-functional photosystem II complexes in response to light level. This coordinated regulation involves photon usage (energy utilization in photochemistry) and excess energy dissipation as heat, photoprotection by many molecular strategies, photoinactivation followed by photon damage and ultimately the D1 protein dynamics involved in the photosystem II repair cycle. Compelling, though indirect evidence suggests that the radical pair P(+)(680)Pheo(-) in functional PSII should be protected from oxygen. By analogy to the tentative oxygen channel of cytochrome c oxidase, oxygen may be liberated from the two water molecules bound to the catalytic site of the Mn cluster, via a specific pathway to the membrane surface. The function of the proposed oxygen pathway is to prevent O(2) from having direct access to P(+)(680)Pheo(-) and prevent the generation of singlet oxygen via the triplet-P(680) state in functional photosytem IIs. Only when the, as yet unidentified, potential trigger with a fateful first oxidative step destroys oxygen evolution, will the ensuing cascade of structural perturbations of photosystem II destroy the proposed oxygen, water and proton pathways. Then oxygen has direct access to P(+)(680)Pheo(-), singlet oxygen will be produced and may successively oxidize specific amino acids of the phosphorylated D1 protein of photosystem II dimers that are confined to appressed granal domains, thereby targeting D1 protein for eventual degradation and replacement in non-appressed thylakoid domains.
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Affiliation(s)
- Jan M Anderson
- Photobioenergetics, Research School of Biological Sciences, Australian National University, GPO Box 475, Canberra ACT 2601, Australia.
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