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Ong JWJ, Tan KS, Lee JJX, Seet JE, Choi HW, Ler SG, Gunaratne J, Narasaraju T, Sham LT, Patzel V, Chow VT. Differential effects of microRNAs miR-21, miR-99 and miR-145 on lung regeneration and inflammation during recovery from influenza pneumonia. J Med Virol 2023; 95:e29286. [PMID: 38087452 DOI: 10.1002/jmv.29286] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 10/10/2023] [Accepted: 11/18/2023] [Indexed: 12/18/2023]
Abstract
In a mouse model of influenza pneumonia, we previously documented that proliferating alveolar type II (AT2) cells are the major stem cells involved in early lung recovery. Profiling of microRNAs revealed significant dysregulation of specific ones, including miR-21 and miR-99a. Moreover, miR-145 is known to exhibit antagonism to miR-21. This follow-up study investigated the roles of microRNAs miR-21, miR-99a, and miR-145 in the murine pulmonary regenerative process and inflammation during influenza pneumonia. Inhibition of miR-21 resulted in severe morbidity, and in significantly decreased proliferating AT2 cells due to impaired transition from innate to adaptive immune responses. Knockdown of miR-99a culminated in moderate morbidity, with a significant increase in proliferating AT2 cells that may be linked to PTEN downregulation. In contrast, miR-145 antagonism did not impact morbidity nor the proliferating AT2 cell population, and was associated with downregulation of TNF-alpha, IL1-beta, YM1, and LY6G. Hence, a complex interplay exists between expression of specific miRNAs, lung regeneration, and inflammation during recovery from influenza pneumonia. Inhibition of miR-21 and miR-99a (but not miR-145) can lead to deleterious cellular and molecular effects on pulmonary repair and inflammatory processes during influenza pneumonia.
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Affiliation(s)
- Joe Wee Jian Ong
- Infectious Diseases Translational Research Program, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Kai Sen Tan
- Infectious Diseases Translational Research Program, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | - Ju Ee Seet
- Department of Pathology, National University of Singapore, Singapore
| | - Hyung Won Choi
- Department of Medicine, National University of Singapore, Singapore
| | | | | | - Teluguakula Narasaraju
- Adichunchanagiri Institute of Medical Sciences, Adichunchanagiri University, Karnataka, India
| | - Lok-To Sham
- Infectious Diseases Translational Research Program, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Volker Patzel
- Infectious Diseases Translational Research Program, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - Vincent T Chow
- Infectious Diseases Translational Research Program, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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2
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Tran TL, Tsai I, Choi HW. Solitary Metastasis to the Breast From Thigh Myxoid Liposarcoma. Cureus 2023; 15:e45559. [PMID: 37868406 PMCID: PMC10586712 DOI: 10.7759/cureus.45559] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2023] [Indexed: 10/24/2023] Open
Abstract
Metastasis to the breast from non-mammary malignancies are rare and suggestive of advanced disease. Accurate and prompt diagnosis of breast metastasis can provide important prognostic information and guide treatment planning. Interestingly, in contrast to primary breast malignancies, non-mammary metastatic breast lesions often have benign-appearing imaging characteristics. Knowing a patient's clinical history and having prior breast imaging studies for comparison is important for making accurate assessments and appropriate recommendations. Imaging-guided biopsy is often indicated for definitive tissue diagnosis. We report a rare case of solitary metastasis to the breast from thigh myxoid liposarcoma.
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Affiliation(s)
- Thuy-Linh Tran
- School of Medicine, University of California, Irvine, Orange, USA
| | - Irene Tsai
- Department of Radiological Sciences, University of California, Irvine, Orange, USA
| | - Hyung Won Choi
- Department of Radiological Sciences, University of California, Irvine, Orange, USA
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3
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Ma X, Cheung YF, Lyu H, Choi HW. Heterogeneous integration of a GaN-based photonic integrated circuit with an Si-based transimpedance amplifier. Opt Lett 2023; 48:1124-1127. [PMID: 36857229 DOI: 10.1364/ol.481935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/23/2023] [Indexed: 06/18/2023]
Abstract
The heterogeneous integration of a GaN-based photonic integrated circuit (PIC) and an Si-based transimpedance amplifier (TIA) is demonstrated in this work. The monolithic GaN PIC, fabricated from a GaN-on-Si light-emitting diode (LED) wafer, comprises LEDs whose optical outputs are coupled to photodetectors (PD) through suspended waveguides. The PIC chip is mounted onto a printed circuit board together with a TIA chip and two filter chip capacitors, occupying a compact footprint. The components are interconnected directly using wire-bonds to minimize signal delays and attenuation. The integrated system achieves rise and fall times of 2.21 and 2.10 ns, respectively, a transmission delay of 3.54 ns, and a bandwidth exceeding 390 MHz. Transmission of a pseudorandom binary sequence-3 (PRBS-3) signal across the integrated system is also demonstrated at the data transmission rate of 280 Mbit/s with a clearly resolved open eye diagram.
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4
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Shahrouki P, Chan TL, Choi HW, Chau AH, Chow L. Spontaneous Angiolipoma in Autologous Flap Reconstruction. Cureus 2022; 14:e31582. [DOI: 10.7759/cureus.31582] [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] [Accepted: 11/04/2022] [Indexed: 11/18/2022] Open
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5
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Murakami W, Won Choi H, Joines MM, Hoyt A, Doepke L, McCann KE, Salamon N, Sayre J, Lee-Felker S. Quantitative Predictors of Response to Neoadjuvant Chemotherapy on Dynamic Contrast-enhanced 3T Breast MRI. J Breast Imaging 2022; 4:168-176. [PMID: 38422427 DOI: 10.1093/jbi/wbab095] [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: 03/23/2021] [Indexed: 03/02/2024]
Abstract
OBJECTIVE To assess whether changes in quantitative parameters on breast MRI better predict pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) in breast cancer than change in volume. METHODS This IRB-approved retrospective study included women with newly diagnosed breast cancer who underwent 3T MRI before and during NAC from January 2013 to December 2019 and underwent surgery at our institution. Clinical data such as age, histologic diagnosis and grade, biomarker status, clinical stage, maximum index cancer dimension and volume, and surgical pathology (presence or absence of in-breast pCR) were collected. Quantitative parameters were calculated using software. Correlations between clinical features and MRI quantitative measures in pCR and non-pCR groups were assessed using univariate and multivariate logistic regression. RESULTS A total of 182 women with a mean age of 52 years (range, 26-79 years) and 187 cancers were included. Approximately 45% (85/182) of women had pCR at surgery. Stepwise multivariate regression analysis showed statistical significance for changes in quantitative parameters (increase in time to peak and decreases in peak enhancement, wash out, and Kep [efflux rate constant]) for predicting pCR. These variables in combination predicted pCR with 81.2% accuracy and an area under the curve (AUC) of 0.878. The AUCs of change in index cancer volume and maximum dimension were 0.767 and 0.613, respectively. CONCLUSION Absolute changes in quantitative MRI parameters between pre-NAC MRI and intra-NAC MRI could help predict pCR with excellent accuracy, which was greater than changes in index cancer volume and maximum dimension.
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Affiliation(s)
- Wakana Murakami
- University of California at Los Angeles David Geffen School of Medicine, Department of Radiological Sciences, Los Angeles, CA, USA
- Showa University Graduate School of Medicine, Department of Radiology, Shinagawa-ku, Tokyo, Japan
| | - Hyung Won Choi
- University of California at Los Angeles David Geffen School of Medicine, Department of Radiological Sciences, Los Angeles, CA, USA
| | - Melissa M Joines
- University of California at Los Angeles David Geffen School of Medicine, Department of Radiological Sciences, Los Angeles, CA, USA
| | - Anne Hoyt
- University of California at Los Angeles David Geffen School of Medicine, Department of Radiological Sciences, Los Angeles, CA, USA
| | - Laura Doepke
- University of California at Los Angeles David Geffen School of Medicine, Department of Radiological Sciences, Los Angeles, CA, USA
| | - Kelly E McCann
- University of California at Los Angeles David Geffen School of Medicine, Department of Medicine, Los Angeles, CA, USA
| | - Noriko Salamon
- University of California at Los Angeles David Geffen School of Medicine, Department of Radiological Sciences, Los Angeles, CA, USA
| | - James Sayre
- University of California at Los Angeles Fielding School of Public Health, Department of Biostatistics, Los Angeles, CA, USA
| | - Stephanie Lee-Felker
- University of California at Los Angeles David Geffen School of Medicine, Department of Radiological Sciences, Los Angeles, CA, USA
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Zi H, Fu WY, Tabataba-Vakili F, Kim-Chauveau H, Frayssinet E, De Mierry P, Damilano B, Duboz JY, Boucaud P, Semond F, Choi HW. Whispering-gallery mode InGaN microdisks on GaN substrates. Opt Express 2021; 29:21280-21289. [PMID: 34265918 DOI: 10.1364/oe.427727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 06/08/2021] [Indexed: 06/13/2023]
Abstract
Microdisks fabricated with III-nitride materials grown on GaN substrates are demonstrated, taking advantage of the high material quality of homoepitaxial films and advanced micro-fabrication processes. The epitaxial structure consists of InGaN/GaN multi-quantum wells (MQWs) sandwiched between AlGaN/GaN and InAlN/GaN superlattices as cladding layers for optical confinement. Due to lattice-matched growth with low dislocations, an internal quantum efficiency of ∼40% is attained, while the sidewalls of the etched 8 µm-diameter microdisks patterned by microsphere lithography are optically smooth to promote the formation of whispering-gallery modes (WGMs) within the circular optical cavities. Optically pumped lasing with low threshold of ∼5.2 mJ/cm2 and quality (Q) factor of ∼3000 at the dominant lasing wavelength of 436.8 nm has been observed. The microdisks also support electroluminescent operation, demonstrating WGMs consistent with the photoluminescence spectra and with finite-difference time-domain (FDTD) simulations.
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7
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Sock Hwee T, Koh HWL, Chua JY, Yang XX, Ong CC, Teo L, Choi HW, Pilbrow AP, Pickering JW, Troughton RW, Doughty RN, Richards AM, Chan MY. P5719Plasma proteomics identify plaque-related proteins that predict long-term recurrent coronary events in patients with acute coronary syndrome. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz746.0660] [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: 11/12/2022] Open
Abstract
Abstract
Background
Coronary plaque burden and composition drive recurrent ischaemic events in coronary artery disease.
Purpose
We first investigated the association between plasma proteins and coronary plaque characteristics in a cohort of asymptomatic individuals with low-intermediate Framingham Risk Score. Plaque-related proteins were further evaluated in a second cohort of patients with acute coronary syndrome (ACS) to determine their prognostic value for predicting future myocardial infarction (MI).
Methods
We profiled 1305 plasma proteins using an aptamer-based array (SOMAscan) in asymptomatic individuals who had undergone 384-slice coronary computed tomography angiography. Plaques were categorized by composition as calcified or non-calcified. First, we identified proteins that were different (based on multiple testing adjusted p-values: q-value <0.05) between 250 ACS patients who suffered a recurrent MI event on follow-up compared with another 250 ACS patients who remained event-free using Mann-Whitney U test. Next, protein candidates that also correlated (Pearson's p<0.05) with specific categories of plaque composition were evaluated using a cox proportional hazards model to determine the risk of recurrent MI, adjusting for potential confounders in the second cohort.
Results
A total of 65 and 120 plasma proteins were significantly associated with calcified and non-calcified plaques respectively in the asymptomatic cohort (N=79). Of these 185 proteins, 23 proteins were differentially expressed (DE) between ACS patients with and without recurrent MI events (median follow-up 1811 days). The top three up-and down-regulated proteins in the recurrent MI group were macrophage-capping protein, trefoil factor 3 and cystatin-SN (median FC 1.22, 1.17 and 1.17; q-value 4.34x10–6, 2.18x10–4, 3.17x10–3 respectively) and fibroblast growth factor 20, lymphotoxin a2/b1 and vascular endothelial growth factor receptor 2 (median FC 0.92, 0.94 and −0.090; q-value 1.31x10–3, 9.45x10–3 and 3.90x10–3) respectively. The quartiles of these protein concentrations were also associated with risk of recurrent MI, (log-rank test p-value range from 2.71x10–7 to 0.04). Of the DE proteins, the adjusted hazards ratio (HR) of cystatin-SN in the highest quartile (Q4) was 1.44 times that of the first quartile (Q1) (adjusted HR: 1.44, 95% CI: 0.93–2.2) and higher plasma concentration of cystatin-SN was associated with increasing risk of recurrent MI events (Trend test p=0.004). On the other hand, the highest quartile of fibroblast growth factor 20 was associated with 44% reduction in risks of recurrent MI adjusted HR: 0.56, 95% CI of HR: 0.35–0.87), with significant trend test (p=0.0096).
Conclusions
Large-scale plasma proteomics identified novel plaque-related proteins predictive of recurrent coronary events in patients with ACS. Further studies may help unravel the biological underpinnings of these circulating proteins and their potential as novel prognostic biomarkers.
Acknowledgement/Funding
This work was supported by grant NMRC/CSA-INV/0001/2016 from the National Medical Research Council, Singapore.
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Affiliation(s)
- T Sock Hwee
- National University of Singapore, Singapore, Singapore
| | - H W L Koh
- National University of Singapore, Singapore, Singapore
| | - J Y Chua
- National University Heart Centre, Singapore, Singapore
| | - X X Yang
- National University of Singapore, Singapore, Singapore
| | - C C Ong
- National University Heart Centre, Singapore, Singapore
| | - L Teo
- National University Heart Centre, Singapore, Singapore
| | - H W Choi
- National University of Singapore, Singapore, Singapore
| | - A P Pilbrow
- University of Otago Christchurch, Christchurch, New Zealand
| | - J W Pickering
- University of Otago Christchurch, Christchurch, New Zealand
| | - R W Troughton
- University of Otago Christchurch, Christchurch, New Zealand
| | - R N Doughty
- The University of Auckland, Department of Medicine, Auckland, New Zealand
| | - A M Richards
- National University of Singapore, Singapore, Singapore
| | - M Y Chan
- National University of Singapore, Singapore, Singapore
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Tan KS, Andiappan AK, Lee B, Yan Y, Liu J, Tang SA, Lum J, He TT, Ong YK, Thong M, Lim HF, Choi HW, Rotzschke O, Chow VT, Wang DY. RNA Sequencing of H3N2 Influenza Virus-Infected Human Nasal Epithelial Cells from Multiple Subjects Reveals Molecular Pathways Associated with Tissue Injury and Complications. Cells 2019; 8:cells8090986. [PMID: 31461941 PMCID: PMC6770044 DOI: 10.3390/cells8090986] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [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: 07/05/2019] [Revised: 08/15/2019] [Accepted: 08/23/2019] [Indexed: 12/15/2022] Open
Abstract
The human nasal epithelium is the primary site of exposure to influenza virus, the initiator of host responses to influenza and the resultant pathologies. Influenza virus may cause serious respiratory infection resulting in major complications, as well as severe impairment of the airways. Here, we elucidated the global transcriptomic changes during H3N2 infection of human nasal epithelial cells from multiple individuals. Using RNA sequencing, we characterized the differentially-expressed genes and pathways associated with changes occurring at the nasal epithelium following infection. We used in vitro differentiated human nasal epithelial cell culture model derived from seven different donors who had no concurrent history of viral infections. Statistical analysis highlighted strong transcriptomic signatures significantly associated with 24 and 48 h after infection, but not at the earlier 8-h time point. In particular, we found that the influenza infection induced in the nasal epithelium early and altered responses in interferon gamma signaling, B-cell signaling, apoptosis, necrosis, smooth muscle proliferation, and metabolic alterations. These molecular events initiated at the infected nasal epithelium may potentially adversely impact the airway, and thus the genes we identified could serve as potential diagnostic biomarkers or therapeutic targets for influenza infection and associated disease management.
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Affiliation(s)
- Kai Sen Tan
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | | | - Bernett Lee
- Singapore Immunology Network (SIgN), A*STAR, Singapore 138648, Singapore
| | - Yan Yan
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Center for Interventional Medicine, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai 519000, China
| | - Jing Liu
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - See Aik Tang
- Singapore Immunology Network (SIgN), A*STAR, Singapore 138648, Singapore
| | - Josephine Lum
- Singapore Immunology Network (SIgN), A*STAR, Singapore 138648, Singapore
| | - Ting Ting He
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - Yew Kwang Ong
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - Mark Thong
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - Hui Fang Lim
- Division of Respiratory and Critical Care Medicine, National University Hospital, Singapore 119074, Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Hyung Won Choi
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
- Institute of Molecular and Cell Biology, A*STAR, Singapore 138673, Singapore
| | - Olaf Rotzschke
- Singapore Immunology Network (SIgN), A*STAR, Singapore 138648, Singapore
| | - Vincent T Chow
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore.
| | - De Yun Wang
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore.
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Park Y, Li KH, Fu WY, Cheung YF, Choi HW. Packaging of InGaN stripe-shaped light-emitting diodes. Appl Opt 2018; 57:2452-2458. [PMID: 29714220 DOI: 10.1364/ao.57.002452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 02/26/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate the fabrication of InGaN/GaN stripe-shaped light-emitting diodes (LEDs) in flip-chip packaging (FC-LED) and vertically mounted packaging (VM-LED). Compared to conventionally packaged LEDs, these packaging schemes enhance light output and emission divergence in ways favorable for general lighting applications. The FC-LED can sustain efficiency at high current operations due to effective heat sinking, while the VM-LED excels at light extraction efficiency due to the exposure of two large emission surfaces. Together with the properties of low luminous exitance and emission uniformity, the stripe-shaped LEDs are ideal for the assembly of luminaires. An LED light tube comprising a continuous linear array of 10 stripe-shaped LED chips has been assembled. The optical performance of the light tube is compared to another light tube assembled with conventional square-shaped LED chips (with and without external diffuser) by confocal microscopy. It is found that emission uniformity of the stripe-shaped LED tube is significantly improved, with a threefold increase in illumination area, without efficiency loss associated with diffusers.
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10
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Tan KS, Ong HH, Yan Y, Liu J, Li C, Ong YK, Thong KT, Choi HW, Wang DY, Chow VT. In Vitro Model of Fully Differentiated Human Nasal Epithelial Cells Infected With Rhinovirus Reveals Epithelium-Initiated Immune Responses. J Infect Dis 2018; 217:906-915. [PMID: 29228279 DOI: 10.1093/infdis/jix640] [Citation(s) in RCA: 40] [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] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 12/07/2017] [Indexed: 12/19/2022] Open
Abstract
Human rhinoviruses (HRVs) are the commonest cause of the common cold. While HRV is less pathogenic than other respiratory viruses, it is frequently associated with exacerbation of chronic respiratory diseases such as rhinosinusitis and asthma. Nasal epithelial cells are the first sites of viral contact, immune initiation, and airway interconnectivity, but there are limited studies on HRV infection of nasal epithelial cells. Hence, we established a model of HRV infection of in vitro-differentiated human nasal epithelial cells (hNECs) derived from multiple individuals. Through HRV infection of hNECs, we found that HRV mainly targeted ciliated cells and preferentially induced type I and III interferon antiviral pathways. Quantitative polymerase chain reaction analysis of inflammatory genes suggested predominant type 1 immunity signaling and recruitment, with secreted CXCL9, IP-10, CXCL11, and RANTES as likely initiators of airway inflammatory responses. Additionally, we further explored HRV bidirectional release from the hNECs and identified 11 associated genes. Other HRV interactions were also identified through a systematic comparison with influenza A virus infection of hNECs. Overall, this in vitro hNEC HRV infection model provides a platform for repeatable and controlled studies of different individuals, thus providing novel insights into the roles of human nasal epithelium in HRV interaction and immune initiation.
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Affiliation(s)
- Kai Sen Tan
- Department of Otolaryngology, Yong Loo Lin School of Medicine, Singapore
| | - Hsiao Hui Ong
- Department of Otolaryngology, Yong Loo Lin School of Medicine, Singapore
| | - Yan Yan
- Department of Otolaryngology, Yong Loo Lin School of Medicine, Singapore
| | - Jing Liu
- Department of Otolaryngology, Yong Loo Lin School of Medicine, Singapore
| | - Chunwei Li
- Department of Otolaryngology, Yong Loo Lin School of Medicine, Singapore
| | - Yew Kwang Ong
- Department of Otolaryngology, Yong Loo Lin School of Medicine, Singapore
| | - Kim Thye Thong
- Department of Otolaryngology, Yong Loo Lin School of Medicine, Singapore
| | - Hyung Won Choi
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - De-Yun Wang
- Department of Otolaryngology, Yong Loo Lin School of Medicine, Singapore
| | - Vincent T Chow
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore
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11
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Park YS, Lee SH, Lim CK, Choi HW, An JH, Park CW, Lee HS, Lee JS, Seo JT. Paternal age as an independent factor does not affect embryo quality and pregnancy outcomes of testicular sperm extraction-intracytoplasmic sperm injection in azoospermia. Andrologia 2017; 50. [PMID: 28703337 DOI: 10.1111/and.12864] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/27/2017] [Indexed: 12/25/2022] Open
Abstract
This study was performed to evaluate the independent influence of paternal age affecting embryo development and pregnancy using testicular sperm extraction (TESE)-intracytoplasmic sperm injection (ICSI) in obstructive azoospermia (OA) and nonobstructive azoospermia (NOA). Paternal patients were divided into the following groups: ≤30 years, 31-35 years, 36-40 years, 41-45 years and ≥46 years. There were no differences in the rates of fertilisation or embryo quality according to paternal and maternal age. However, clinical pregnancy and implantation rates were significantly lower between those ≥46 years of paternal age compared with other age groups. Fertilisation rate was higher in the OA than the NOA, while embryo quality, pregnancy and delivery results were similar. Clinical pregnancy and implantation rates were significantly lower for patients ≥46 years of paternal age compared with younger age groups. In conclusion, fertilisation using TESE in azoospermia was not affected by the independent influence of paternal age; however, as maternal age increased concomitantly with paternal age, rates of pregnancy and delivery differed between those with paternal age <41 years and ≥46 years. Therefore, paternal age ≥46 years old should be considered when applying TESE-ICSI in cases of azoospermia, and patients should be advised of the associated low pregnancy rates.
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Affiliation(s)
- Y S Park
- Laboratory of Reproductive Medicine, Cheil General Hospital & Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea
| | - S H Lee
- Laboratory of Reproductive Medicine, Cheil General Hospital & Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea.,Division of Developmental Biology and Physiology, School of Biosciences and Chemistry, Sungshin Women's University, Seoul, Korea
| | - C K Lim
- Laboratory of Reproductive Medicine, Cheil General Hospital & Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea
| | - H W Choi
- Laboratory of Reproductive Medicine, Cheil General Hospital & Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea
| | - J H An
- Laboratory of Reproductive Medicine, Cheil General Hospital & Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea
| | - C W Park
- Department of Obstetrics and Gynecology, Cheil General Hospital & Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea
| | - H S Lee
- Department of Urology, Cheil General Hospital & Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea
| | - J S Lee
- Department of Urology, Cheil General Hospital & Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea
| | - J T Seo
- Department of Urology, Cheil General Hospital & Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea
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Bachus KJ, Mats L, Choi HW, Gibson GTT, Oleschuk RD. Fabrication of Patterned Superhydrophobic/Hydrophilic Substrates by Laser Micromachining for Small Volume Deposition and Droplet-Based Fluorescence. ACS Appl Mater Interfaces 2017; 9:7629-7636. [PMID: 28169515 DOI: 10.1021/acsami.6b16363] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The deposition of nanoliter and subnanoliter volumes is important in chemical and biochemical droplet-based microfluidic systems. There are several techniques that have been established for the deposition/generation of small volumes including the use of surfaces with patterned differences in wettability. Many such methods require complex and time-consuming lithographic techniques. Here, we present a facile method for the fabrication of superhydrophobic surfaces with patterned hydrophilic regions by laser micromachining. A comprehensive study of fabrication parameters (laser machining speed, laser power, and patch size) on the material, patch wettability, and droplet volume is presented. Patch sizes as small as 100 μm diameter and as large as 1500 μm diameter were investigated, and volumes as low as 400 pL were observed. As an example application of such patterned materials and the deposition of small volumes, halide salts were preconcentrated on the hydrophilic patches, and their fluorescence quenching constants were rapidly calculated using a 3D-printed device coupled to a fluorescence spectrometer.
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Affiliation(s)
- K J Bachus
- Department of Chemistry, Queen's University , Kingston, Ontario K7L 3N6, Canada
| | - L Mats
- Department of Chemistry, Queen's University , Kingston, Ontario K7L 3N6, Canada
| | - H W Choi
- Department of Chemistry, Queen's University , Kingston, Ontario K7L 3N6, Canada
| | - G T T Gibson
- CMC Microsystems , Innovation Park, Kingston, Ontario K7L 0E9, Canada
| | - R D Oleschuk
- Department of Chemistry, Queen's University , Kingston, Ontario K7L 3N6, Canada
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13
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Liu JJ, Ghosh S, Kovalik JP, Ching J, Choi HW, Tavintharan S, Ong CN, Sum CF, Summers SA, Tai ES, Lim SC. Profiling of Plasma Metabolites Suggests Altered Mitochondrial Fuel Usage and Remodeling of Sphingolipid Metabolism in Individuals With Type 2 Diabetes and Kidney Disease. Kidney Int Rep 2016; 2:470-480. [PMID: 29142974 PMCID: PMC5678636 DOI: 10.1016/j.ekir.2016.12.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 12/06/2016] [Accepted: 12/08/2016] [Indexed: 12/11/2022] Open
Abstract
Introduction Pathophysiology of diabetic kidney disease (DKD) is incompletely understood. We aim to elucidate metabolic abnormalities associated with DKD in type 2 diabetes mellitus (T2DM) by targeted plasma metabolomics. Methods A total of 126 T2DM participants with early DKD (urinary albumin-to-creatinine ratio [ACR] 30−299 mg/g and eGFR ≥ 60 ml/min/1.73 m2), 154 overt DKD (ACR ≥ 300 mg/g or eGFR < 60 ml/min/1.73 m2), and 129 non-DKD T2DM controls (ACR < 30 mg/g and eGFR ≥ 60 ml/min/1.73 m2) were included in discovery study. Findings were subsequently validated in 149 T2DM with macroalbuminuria (ACR ≥ 300 mg/g) and 149 matched non-DKD T2DM controls. Plasma amino acid, acylcarnitine, Krebs cycle organic acid, and sphingolipids/ceramide levels were quantified by liquid chromatography−mass spectrometry and gas chromatography−mass spectrometry. Results Of 123 metabolites included in the data analysis, 24 differed significantly between DKD and controls in the same direction in both discovery and validation subpopulations. A number of short acylcarnitines including their dicarboxylic derivatives (C2−C6) were elevated in DKD, suggesting abnormalities in fatty acids and amino acids metabolic pathways. Five phosphatidylcholines were lower whereas 4 metabolites in the sphingomyelin−ceramide subfamily were higher in DKD. Principal component regression revealed that long-chain ceramides were independently associated with ACR but not eGFR. Conversely, essential amino acids catabolism and short dicarboxylacylcarnitine accumulation were associated with eGFR but not ACR. Discussion DKD is associated with altered fuel substrate use and remodeling of sphingolipid metabolism in T2DM with DKD. Associations of albuminuria and impaired filtration function with distinct metabolomic signatures suggest different pathophysiology underlying these 2 manifestations of DKD.
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Affiliation(s)
- Jian-Jun Liu
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore
| | | | | | | | - Hyung Won Choi
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | | | - Choon Nam Ong
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | | | | | - E Shyong Tai
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Su Chi Lim
- Diabetes Centre, Khoo Teck Puat Hospital, Singapore
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14
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Lu Y, Wang Y, Ong CN, Subramaniam T, Choi HW, Yuan JM, Koh WP, Pan A. Metabolic signatures and risk of type 2 diabetes in a Chinese population: an untargeted metabolomics study using both LC-MS and GC-MS. Diabetologia 2016; 59:2349-2359. [PMID: 27514531 DOI: 10.1007/s00125-016-4069-2] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 07/13/2016] [Indexed: 12/31/2022]
Abstract
AIMS/HYPOTHESIS Metabolomics has provided new insight into diabetes risk assessment. In this study we characterised the human serum metabolic profiles of participants in the Singapore Chinese Health Study cohort to identify metabolic signatures associated with an increased risk of type 2 diabetes. METHODS In this nested case-control study, baseline serum metabolite profiles were measured using LC-MS and GC-MS during a 6-year follow-up of 197 individuals with type 2 diabetes but without a history of cardiovascular disease or cancer before diabetes diagnosis, and 197 healthy controls matched by age, sex and date of blood collection. RESULTS A total of 51 differential metabolites were identified between cases and controls. Of these, 35 were significantly associated with diabetes risk in the multivariate analysis after false discovery rate adjustment, such as increased branched-chain amino acids (leucine, isoleucine and valine), non-esterified fatty acids (palmitic acid, stearic acid, oleic acid and linoleic acid) and lysophosphatidylinositol (LPI) species (16:1, 18:1, 18:2, 20:3, 20:4 and 22:6). A combination of six metabolites including proline, glycerol, aminomalonic acid, LPI (16:1), 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid and urea showed the potential to predict type 2 diabetes in at-risk individuals with high baseline HbA1c levels (≥6.5% [47.5 mmol/mol]) with an AUC of 0.935. Combined lysophosphatidylglycerol (LPG) (12:0) and LPI (16:1) also showed the potential to predict type 2 diabetes in individuals with normal baseline HbA1c levels (<6.5% [47.5 mmol/mol]; AUC = 0.781). CONCLUSIONS/INTERPRETATION Our findings show that branched-chain amino acids and NEFA are potent predictors of diabetes development in Chinese adults. Our results also indicate the potential of lysophospholipids for predicting diabetes.
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Affiliation(s)
- Yonghai Lu
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Republic of Singapore
| | - Yeli Wang
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Republic of Singapore
| | - Choon-Nam Ong
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Republic of Singapore
- NUS Environmental Research Institute, National University of Singapore, Singapore, Republic of Singapore
| | - Tavintharan Subramaniam
- Department of General Medicine, Diabetes Centre, Khoo Teck Puat Hospital, Singapore, Republic of Singapore
| | - Hyung Won Choi
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Republic of Singapore
| | - Jian-Min Yuan
- Division of Cancer Control and Population Sciences, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, USA
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Woon-Puay Koh
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Republic of Singapore.
- Office of Clinical Sciences, Duke-NUS Medical School, 8 College Road Level 4, Singapore, 169857, Republic of Singapore.
| | - An Pan
- Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Rd, Wuhan, 430030, Hubei, People's Republic of China.
- Ministry of Education Key Laboratory of Environment and Health, and State Key Laboratory of Environmental Health (incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.
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15
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Abstract
The majority of a GaN light-emitting diode (LED) is released from its sapphire substrate through selective-area laser lift-off to form a freely suspended light emitter. By virtue of being suspended in air without supporting substrates, the ultrathin crystalline and crack-free film possesses flexibility and bendability. The free-standing LEDs benefit from significant relaxation of strain, evident from red-shifting of the E2(high) phonon frequencies as measured by Raman spectroscopy toward those of strain-free free-standing GaN substrates. The phonon frequencies remain invariant upon bending of the film; this indicates that the properties of the flexible device will not be dependent on the bending curvatures. The observation of pronounced spectral blue-shifts from the photoluminescence (PL) spectrum from the flexible regions further confirms the occurrence of strain relaxation in the quantum wells. Being free-standing and thus lacking a direct heat-sinking pathway, emissions from the different regions of the suspended film can be affected by thermal effects to different extents, which are investigated by long-wave infrared thermometry. Heat accumulation is determined to be most severe at the far end of the flexible stripe at higher currents, leading to reduced efficiencies and electroluminescence (EL) spectral red-shifts. Based on this architecture, a monolithic 3 × 4 dot-matrix microdisplay prototype is demonstrated, comprising three adjacent flexible stripe emitters with four individually addressable pixels on each stripe. This proof-of-concept demonstration opens up new opportunities for GaN optoelectronics for a wide range of flexible display and visual applications.
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Affiliation(s)
- Y F Cheung
- Department of Electrical and Electronic Engineering, The University of Hong Kong , Pokfulam Road, Hong Kong
| | - K H Li
- Department of Electrical and Electronic Engineering, The University of Hong Kong , Pokfulam Road, Hong Kong
| | - H W Choi
- Department of Electrical and Electronic Engineering, The University of Hong Kong , Pokfulam Road, Hong Kong
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Stebbings KA, Choi HW, Ravindra A, Caspary DM, Turner JG, Llano DA. Ageing-related changes in GABAergic inhibition in mouse auditory cortex, measured using in vitro flavoprotein autofluorescence imaging. J Physiol 2015; 594:207-21. [PMID: 26503482 DOI: 10.1113/jp271221] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 10/18/2015] [Indexed: 12/24/2022] Open
Abstract
KEY POINTS Ageing is associated with hearing loss and changes in GABAergic signalling in the auditory system. We tested whether GABAergic signalling in an isolated forebrain preparation also showed ageing-related changes. A novel approach was used, whereby population imaging was coupled to quantitative pharmacological sensitivity. Sensitivity to GABAA blockade was inversely associated with age and cortical thickness, but hearing loss did not independently contribute to the change in GABAA ergic sensitivity. Redox states in the auditory cortex of young and aged animals were similar, suggesting that the differences in GABAA ergic sensitivity are unlikely to be due to differences in slice health. To examine ageing-related changes in the earliest stages of auditory cortical processing, population auditory cortical responses to thalamic afferent stimulation were studied in brain slices obtained from young and aged CBA/CAj mice (up to 28 months of age). Cortical responses were measured using flavoprotein autofluorescence imaging, and ageing-related changes in inhibition were assessed by measuring the sensitivity of these responses to blockade of GABAA receptors using bath-applied SR95531. The maximum auditory cortical response to afferent stimulation was not different between young and aged animals under control conditions, but responses to afferent stimulation in aged animals showed a significantly lower sensitivity to GABA blockade with SR95531. Cortical thickness, but not hearing loss, improved the prediction of all imaging variables when combined with age, particularly sensitivity to GABA blockade for the maximum response. To determine if the observed differences between slices from young and aged animals were due to differences in slice health, the redox state in the auditory cortex was assessed by measuring the FAD+/NADH ratio using fluorescence imaging. We found that this ratio is highly sensitive to known redox stressors such as H2 O2 and NaCN; however, no difference was found between young and aged animals. By using a new approach to quantitatively assess pharmacological sensitivity of population-level cortical responses to afferent stimulation, these data demonstrate that auditory cortical inhibition diminishes with ageing. Furthermore, these data establish a significant relationship between cortical thickness and GABAergic sensitivity, which had not previously been observed in an animal model of ageing.
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Affiliation(s)
- K A Stebbings
- Neuroscience Program, University of Illinois at Urbana-Champaign, IL, USA
| | - H W Choi
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, IL, USA
| | - A Ravindra
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, IL, USA
| | - D M Caspary
- Department of Pharmacology, Southern Illinois University College of Medicine, IL, USA
| | - J G Turner
- Department of Pharmacology, Southern Illinois University College of Medicine, IL, USA.,Department of Psychology, Illinois College, IL, USA
| | - D A Llano
- Neuroscience Program, University of Illinois at Urbana-Champaign, IL, USA.,Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, IL, USA
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17
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Shah L, Choi HW, Berrang-Ford L, Henostroza G, Krapp F, Zamudio C, Heymann SJ, Kaufman JS, Ciampi A, Seas C, Gotuzzo E, Brewer TF. Geographic predictors of primary multidrug-resistant tuberculosis cases in an endemic area of Lima, Peru. Int J Tuberc Lung Dis 2015; 18:1307-14. [PMID: 25299862 DOI: 10.5588/ijtld.14.0011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Peru reports among the highest multidrug-resistant tuberculosis (MDR-TB) rates in the Americas, with a growing proportion in previously untreated tuberculosis (TB) cases. The identification of clusters of primary MDR-TB compared with drug-susceptible TB (DS-TB) could help prioritize interventions. OBJECTIVE To examine the clustering of primary MDR-TB case residences and their proximity to high-risk locations in San Juan de Lurigancho District, Lima, Peru. DESIGN Enrolled primary MDR-TB and primary DS-TB cases were interviewed and their primary residence was recorded using handheld Global Positioning System devices. Kuldorff's spatial scan statistic was used for cluster detection (SaTScan(TM), v. 9.1.1). Identified clusters were visualized in Quantum Geographic Information Systems software (v1.8.0). The following cluster centers were tested: a health centre with the highest TB and MDR-TB rates (Clinic X), a hospital and two prisons. Using regression analyses, we examined predictors of primary MDR-TB cases. RESULTS A statistically significant cluster of primary MDR-TB cases was identified within a 2.29 km radius around Clinic X. Proximity to Clinic X remained a significant predictor of primary MDR-TB in adjusted regression analyses. CONCLUSION We identified a hotspot of primary MDR-TB cases around Clinic X in a TB-endemic area. Causes of this clustering require investigation; targeted interventions for this high-risk area should be considered.
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Affiliation(s)
- L Shah
- Department of Epidemiology, Biostatistics & Occupational Health, McGill University, Montreal, Quebec, Canada
| | - H W Choi
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - L Berrang-Ford
- Department of Geography, McGill University, Montreal, Quebec, Canada
| | - G Henostroza
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - F Krapp
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - C Zamudio
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - S J Heymann
- Department of Epidemiology, Jonathan and Karin Fielding School of Public Health, University of California, Los Angeles, USA
| | - J S Kaufman
- Department of Epidemiology, Biostatistics & Occupational Health, McGill University, Montreal, Quebec, Canada
| | - A Ciampi
- Department of Epidemiology, Biostatistics & Occupational Health, McGill University, Montreal, Quebec, Canada
| | - C Seas
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - E Gotuzzo
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - T F Brewer
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA
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18
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Li KH, Cheung YF, Choi HW. Whispering gallery mode lasing in optically isolated III-nitride nanorings. Opt Lett 2015; 40:2564-2567. [PMID: 26030558 DOI: 10.1364/ol.40.002564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
III-nitride nanorings fabricated from a combination of hybrid-nanosphere-lithography and laser lift-off processes is demonstrated. Being formed on an interfacial metallic layer optically coupling between the optical ring and its substrate is eliminated, maximizing optical confinement of whispering gallery resonant mode within the ring cavity. The tapered cross-sectional profile also promotes coupling of emitted light into resonant modes. Optically pumped lasing with a dominant peak at 421.5 nm is observed at room temperature, with threshold energy density of ∼6.5 mJ/cm2. Etch-induced sidewall roughness causes scattering of light at the interface to diminish confinement, and is also responsible for the mode-splitting effect according to finite-difference time-domain simulations.
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19
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Cheung WS, Cheung YF, Chen HT, Hui RSY, Waffenschmidt E, Choi HW. InGaN light-emitting diode stripes with reduced luminous exitance. Opt Express 2015; 23:15021-15028. [PMID: 26072858 DOI: 10.1364/oe.23.015021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
InGaN light-emitting diodes of stripe geometries have been demonstrated. The elongated geometry facilitates light spreading in the longitudinal direction. The chips are further shaped by laser-micromachining to have partially-inclined sidewalls. The light extraction efficiencies of such 3D chip geometries are enhanced by ~12% (~8% according to ray-trace simulations), leading to a reduction of junction temperatures. The effective emission area is also increased four times compared to a cubic chip. The stripe LEDs are thus more efficient emitters with reduced luminous exitance, making them more suitable for a wide range of lighting applications.
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20
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Li L, Chong HC, Ng SY, Kwok KW, Teo Z, Tan EHP, Choo CC, Seet JE, Choi HW, Buist ML, Chow VTK, Tan NS. Angiopoietin-like 4 Increases Pulmonary Tissue Leakiness and Damage during Influenza Pneumonia. Cell Rep 2015; 10:654-663. [PMID: 25660016 PMCID: PMC7185373 DOI: 10.1016/j.celrep.2015.01.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [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: 07/11/2014] [Revised: 11/27/2014] [Accepted: 12/31/2014] [Indexed: 01/09/2023] Open
Abstract
Excessive host inflammatory responses negatively impact disease outcomes in respiratory infection. Host-pathogen interactions during the infective phase of influenza are well studied, but little is known about the host's response during the repair stage. Here, we show that influenza infection stimulated the expression of angiopoietin-like 4 (ANGPTL4) via a direct IL6-STAT3-mediated mechanism. ANGPTL4 enhanced pulmonary tissue leakiness and exacerbated inflammation-induced lung damage. Treatment of infected mice with neutralizing anti-ANGPTL4 antibodies significantly accelerated lung recovery and improved lung tissue integrity. ANGPTL4-deficient mice also showed reduced lung damage and recovered faster from influenza infection when compared to their wild-type counterparts. Retrospective examination of human lung biopsy specimens from infection-induced pneumonia with tissue damage showed elevated expression of ANGPTL4 when compared to normal lung samples. These observations underscore the important role that ANGPTL4 plays in lung infection and damage and may facilitate future therapeutic strategies for the treatment of influenza pneumonia.
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Affiliation(s)
- Liang Li
- School of Biological Sciences, College of Science, Nanyang Technological University, Singapore 637551, Singapore; Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Han Chung Chong
- School of Biological Sciences, College of Science, Nanyang Technological University, Singapore 637551, Singapore
| | - Say Yong Ng
- School of Biological Sciences, College of Science, Nanyang Technological University, Singapore 637551, Singapore
| | - Ka Wai Kwok
- School of Biological Sciences, College of Science, Nanyang Technological University, Singapore 637551, Singapore
| | - Ziqiang Teo
- School of Biological Sciences, College of Science, Nanyang Technological University, Singapore 637551, Singapore
| | - Eddie Han Pin Tan
- School of Biological Sciences, College of Science, Nanyang Technological University, Singapore 637551, Singapore
| | - Chee Chong Choo
- Institute of Molecular and Cell Biology, A(∗)STAR, Singapore 138673, Singapore
| | - Ju Ee Seet
- Department of Pathology, National University Hospital, Singapore 119074, Singapore
| | - Hyung Won Choi
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore 117549, Singapore
| | - Martin Lindsay Buist
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Vincent Tak Kwong Chow
- Host and Pathogen Interactivity Laboratory, Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
| | - Nguan Soon Tan
- School of Biological Sciences, College of Science, Nanyang Technological University, Singapore 637551, Singapore; Institute of Molecular and Cell Biology, A(∗)STAR, Singapore 138673, Singapore.
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21
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Zhang X, Cheung YF, Zhang Y, Choi HW. Whispering-gallery mode lasing from optically free-standing InGaN microdisks. Opt Lett 2014; 39:5614-5617. [PMID: 25360941 DOI: 10.1364/ol.39.005614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Optically pumped multi-mode whispering-gallery mode (WGM) lasing has been observed in optically free-standing InGaN/GaN quantum well microdisks at room temperature. The ∼6.6 μm optically isolated microdisks are patterned by microsphere lithography on GaN thin-films prepared by laser lift-off of the sapphire substrate, enabling superior optical confinement. The modes are determined to be of second order according to simulations. The lasing threshold is found to be ∼9.06 mJ/cm2, with a quality factor Q of ∼770 evaluated from the dominant mode at λ=430.2 nm, and a free space range (FSR) of 3.17 to 2.16 nm, which is mode-dependent.
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22
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Choi HW, Lee KH, Hur NH, Lim HB. Cerium oxide-deposited mesoporous silica nanoparticles for the determination of carcinoembryonic antigen in serum using inductively coupled plasma-mass spectrometry. Anal Chim Acta 2014; 847:10-5. [PMID: 25261895 DOI: 10.1016/j.aca.2014.08.041] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 08/13/2014] [Accepted: 08/14/2014] [Indexed: 12/31/2022]
Abstract
CeO2-deposited mesoporous silica nanoparticles were synthesized as a probe to determine carcinoembryonic antigen (CEA) in serum by inductively coupled plasma-mass spectrometry (ICP-MS). The prepared mesoporous nanoparticles were modified and tagged to the target for sandwich-type immunoassay. Fe3O4 magnetic nanoparticles (MNPs) were also synthesized and immobilized with antibody to extract the target biomarker. The calibration curve of the synthesized CeO2-deposited silica nanoparticles, which was plotted by the signal ratio of (140)Ce/(57)Fe measured by ICP-MS vs. the concentration of CEA, showed excellent linearity and sensitivity owing to the signal amplification and low spectral interference. Under optimal conditions, the sandwich-type analytical method was applied to determine CEA in serum spiked in the range of 0.001-5 ng mL(-1) and showed a limit of detection of 0.36 ng mL(-1). Since the deposited CeO2 in the mesoporous silica layer can be substituted by other metal compounds, various kinds of metal-deposited nanoparticles can be prepared as probe materials for multiplex detection in bioanalysis.
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Affiliation(s)
- H W Choi
- Department of Chemistry, NSBI, Dankook University, 126 Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do 448-701, South Korea
| | - K H Lee
- Department of Chemistry, Sogang University, Shinsu-dong, Mapo-gu, Seoul, South Korea
| | - N H Hur
- Department of Chemistry, Sogang University, Shinsu-dong, Mapo-gu, Seoul, South Korea
| | - H B Lim
- Department of Chemistry, NSBI, Dankook University, 126 Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do 448-701, South Korea.
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Choi HW, Miele K, Dowdy D, Shah M. Cost-effectiveness of Xpert® MTB/RIF for diagnosing pulmonary tuberculosis in the United States. Int J Tuberc Lung Dis 2014; 17:1328-35. [PMID: 24025386 DOI: 10.5588/ijtld.13.0095] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Conventional approaches to tuberculosis (TB) diagnosis and resistance testing are slow. The Xpert® MTB/RIF assay is an emerging molecular diagnostic assay for rapid TB diagnosis, offering results within 2 hours. However, the cost-effectiveness of implementing Xpert in settings with low TB prevalence, such as the United States, is unknown. OBJECTIVE We evaluated the cost-effectiveness of incorporating Xpert into TB diagnostic algorithms in the United States compared to existing diagnostics. DESIGN A decision-analysis model compared current TB diagnostic algorithms in the United States to algorithms incorporating Xpert. Primary outcomes were the costs and quality-adjusted life years (QALYs) accrued with each strategy; cost-effectiveness was represented using incremental cost-effectiveness ratios (ICER). RESULTS Xpert testing of a single sputum sample from TB suspects is expected to result in lower total health care costs per patient (US2673) compared to diagnostic algorithms using only sputum microscopy and culture (US2728) and improved health outcomes (6.32 QALYs gained per 1000 TB suspects). Compared to existing molecular assays, implementation of Xpert in the United States would be considered highly cost-effective (ICER US39992 per QALY gained). CONCLUSION TB diagnostic algorithms incorporating Xpert in the United States are highly cost-effective.
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Affiliation(s)
- H W Choi
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Ramaswamy RS, Choi HW, Mouser HC, Narsinh KH, McCammack KC, Treesit T, Kinney TB. Role of interventional radiology in the management of acute gastrointestinal bleeding. World J Radiol 2014; 6:82-92. [PMID: 24778770 PMCID: PMC4000612 DOI: 10.4329/wjr.v6.i4.82] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 02/20/2014] [Accepted: 03/12/2014] [Indexed: 02/06/2023] Open
Abstract
Acute gastrointestinal bleeding (GIB) can lead to significant morbidity and mortality without appropriate treatment. There are numerous causes of acute GIB including but not limited to infection, vascular anomalies, inflammatory diseases, trauma, and malignancy. The diagnostic and therapeutic approach of GIB depends on its location, severity, and etiology. The role of interventional radiology becomes vital in patients whose GIB remains resistant to medical and endoscopic treatment. Radiology offers diagnostic imaging studies and endovascular therapeutic interventions that can be performed promptly and effectively with successful outcomes. Computed tomography angiography and nuclear scintigraphy can localize the source of bleeding and provide essential information for the interventional radiologist to guide therapeutic management with endovascular angiography and transcatheter embolization. This review article provides insight into the essential role of Interventional Radiology in the management of acute GIB.
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25
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Oh JY, Kang MS, Yoon H, Choi HW, An BK, Shin EG, Kim YJ, Kim MJ, Kwon JH, Kwon YK. The embryo lethality of Escherichia coli isolates and its relationship to the presence of virulence-associated genes. Poult Sci 2012; 91:370-5. [PMID: 22252350 DOI: 10.3382/ps.2011-01807] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aims of this study were to determine if the chicken embryo lethality assay and the presence of 9 virulence-associated genes of Escherichia coli were correlated and to discover which virulence genes contributed most to embryo lethality. We examined 58 E. coli strains isolated from visceral organs of chickens with colibacillosis for the presence of 9 virulence genes (fimC, tsh, fyuA, irp2, iucD, cvi/cva, iss, astA, and vat) by PCR. The gene FimC (type I fimbriae) was detected with the highest prevalence in 93.1% of the isolates, followed by iucD (67.24%), iss (58.62%), tsh (34.48%), cvi/cva (34.48%), fyuA (32.76%), astA (31.0%), irp2 (27.59%), and vat (17.24%). The embryo mortality ranged from 5 to 100%; however, most of the isolates were moderately or highly virulent. High positive correlations were observed between the presence of virulence genes and chicken embryo lethality. In addition, presence of the iucD (aerobactin) gene was the trait that best contributed to embryo mortality by using the multivariate model. These results suggest that expression frequency of these 9 virulence genes is associated with embryo mortality, and the gene that best predicted embryo mortality was iucD.
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Affiliation(s)
- J Y Oh
- Animal, Plant and Fisheries Quarantine and Inspection Agency, Anyang, Kyunggi, Korea
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26
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Abstract
An ordered hexagonal closed-packed nanopillar array is fabricated on GaN. A metal coating is then applied to encapsulate the pillars for promoting optical confinement within the cylindrical cavity. Room-temperature lasing at 373 nm is observed under pulsed excitation, at a lasing threshold of 0.42 MW/cm2. With pillar diameters of around 980 nm, the number of modes overlapping the emission spectrum is reduced, giving rise to single-mode whispering gallery stimulated emission. Finite-difference time-domain simulations are carried out for the prediction of resonant frequencies and electric field patterns corresponding to the resonant modes.
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Affiliation(s)
- K H Li
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China
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27
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Abstract
Blue GaN light emitting diodes (LEDs) in the shape of cuboids and circular disks have been fabricated by laser micromachining. The proposed circular geometry serves to enhance overall light extraction on a macro-scale and to improve uniformity of the emission pattern due to the rotational symmetry of the chip. Analysis of the chip shaping effect is carried out by ray-tracing simulations and further supported with mathematical modeling using ideal LED models, and subsequently verified with fabricated devices. In comparison, a 10% improvement in overall emission was observed for circular LEDs over the regular cuboids, consistent with simulations and calculations. The measured emission pattern from the circular LED confirms the axial symmetry of the emission beam.
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Affiliation(s)
- X H Wang
- Semiconductor Display and Lighting Laboratory, Department of Electrical and Electronic Engineering The University of Hong Kong, Pokfulam Road, Hong Kong
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28
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Abstract
A new design for a polychromatic light-emitting diode (LED) is proposed and demonstrated. LED chips of the primary colors are physically stacked on top of each other. Light emitted from each layer of the stack passes through each other, and thus is mixed naturally without additional optics. As a color-tunable device, a wide range of colors can be generated, making it suitable for display purposes. As a phosphor-free white light LED, luminous efficacy of 30 lm/watt was achieved.
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Affiliation(s)
- K N Hui
- Department of Electrical and Electronic Engineering, Semiconductor Display and Lighting Laboratory, The University of Hong Kong, Hong Kong
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Hui KN, Fu WY, Ng WN, Leung CH, Lai PT, Wong KKY, Choi HW. Polychromatic light-emitting diodes with a fluorescent nanosphere opal coating. Nanotechnology 2008; 19:355203. [PMID: 21828836 DOI: 10.1088/0957-4484/19/35/355203] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A hexagonally close-packed array consisting of fluorescent nanospheres was coated onto short-wavelength GaN light-emitting diodes to demonstrate polychromatic white light emission. The spherical particles self-assemble into ordered three-dimensional opal structures, performing the role of color conversion to generate a polychromatic spectrum with smooth and uniform emission patterns. Different ratios of green and orange-red fluorescent nanospheres were mixed and coated onto high-extraction-efficiency micro-LEDs. Four devices with different shades of white emission were demonstrated. Device A, with a high content of orange-red nanospheres, offers the highest CRI value of 80, whereas device C with a well-balanced ratio of green and orange-red nanospheres exhibits color characteristics closest to ideal white with CIE coordinate at (0.34, 0.34). At 20 mA driving current, the luminous efficacy of the devices A, B, C, and D are 40.5 lm W(-1), 57.7 lm W(-1), 63.1 lm W(-1), and 67.2 lm W(-1) respectively, while the correlated color temperatures (CCTs) of the corresponding devices are 3587, 4778, 5271, and 13 000 K.
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Affiliation(s)
- K N Hui
- Department of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong
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30
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Abstract
Instead of using conventional electron lithography, a two-dimensional photonic crystal consisting of a hexagonal array of triangular air-holes was created on the surface of a GaN LED substrate using microsphere lithography. The microspheres self-assemble into a single-layered hexagonal-close-packed array acting as an etch mask. A significant enhancement in photoluminescence intensity was recorded from the PhC LED structure. A twofold increase in electroluminescence was observed from the PhC LED compared to an as-grown LED with identical geometry. Besides geometrical factors due to surface roughening, the dispersive nature of PhCs and diffractive properties of the PhC as a grating contribute to the enhancement of light extraction from the LED.
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Affiliation(s)
- W N Ng
- Department of Electrical and Electronic Engineering, University of Hong Kong, Pokfulam road, Hong Kong
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31
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Abstract
An innovative spectral conversion scheme for light emitting diodes using fluorescent microspheres has been demonstrated. An optimally mixed proportion of green and red fluorescent microspheres were coated onto a high-extraction-efficiency GaN micro-LED with emission centred at 470 nm. The microspheres self-assemble into ordered hexagonally arrays, forming regular and uniform coating layers. Devices with cool and warm white emission were achieved. The bluish-white LED has a luminous efficacy of 27.3 lm/W (at 20 mA) with CIE coordinates of (0.26, 0.28) and 8500K CCT, while the yellowish-white LED has a luminous efficacy of 26.67 lm/W (at 20 mA) with CIE coordinates of (0.36, 0.43) and 13000K CCT.
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Affiliation(s)
- K N Hui
- Department of Electrical and Electronic Engineering, University of Hong Kong
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32
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Yamamoto T, Choi HW, Ryan RO. Apolipoprotein E isoform-specific binding to the low-density lipoprotein receptor. Anal Biochem 2007; 372:222-6. [PMID: 17923100 DOI: 10.1016/j.ab.2007.09.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 09/01/2007] [Accepted: 09/05/2007] [Indexed: 10/22/2022]
Abstract
Apolipoprotein E (apoE) is a ligand for members of the low-density lipoprotein receptor (LDLR) family and functions in plasma cholesterol homeostasis. A fluorescence-based assay has been employed in molecular studies of receptor-ligand interactions. Competition experiments revealed isoform-specific differences in binding of lipid-associated apoE N terminal (NT) domain to a recombinant soluble LDLR (sLDLR). In a similar manner, lipid--associated-but not lipid-free--full-length apoE3 showed binding activity to sLDLR. The molecular chaperone, receptor-associated protein, inhibited apoE3-NT-phospholipid complex binding to sLDLR. Kinetic studies of apoE3-NT-phospholipid complex interaction with sLDLR revealed time-dependent effects of apoE-NT isoform binding to sLDLR. The results reveal a discerning method for study of the molecular basis of ligand interactions that likely influence receptor function in maintenance of whole body cholesterol homeostasis.
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Affiliation(s)
- Taichi Yamamoto
- Center for Prevention of Obesity, Diabetes, and Cardiovascular Disease, Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA
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33
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Choi HW, Farson DF, Bovatsek J, Arai A, Ashkenasi D. Direct-write patterning of indium-tin-oxide film by high pulse repetition frequency femtosecond laser ablation. Appl Opt 2007; 46:5792-9. [PMID: 17700755 DOI: 10.1364/ao.46.005792] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Ablation of indium oxide doped with tin oxide (ITO) from glass substrates is described. Laser pulse energy and focus spot size were varied in single-pulse, single-spot ablation tests and for ablation of linear features with scanned multiple pulses. The single-pulse ablation threshold of ITO was smaller than that of the glass substrate so the entire thickness of ITO could be removed in a single pulse or with overlying multiple pulses without the possibility of substrate ablation. Linear features could be created at much higher scanning speeds using a high repetition frequency (100 kHz) Yb fiber amplified laser as compared to a lower repetition frequency (2 kHz) laser. An analysis showed that incubation effects lowered ITO ablation thresholds when pulse frequency was high relative to scanning speed, contributing to large feasible scanning speeds for high pulse frequency lasers.
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Affiliation(s)
- H W Choi
- Laboratory for Multiscale Processing & Characterization, Ohio State University, Columbus 43221, USA
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34
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Choi HW, Barakat AI. Modulation of ATP/ADP concentration at the endothelial surface by shear stress: effect of flow disturbance. Conf Proc IEEE Eng Med Biol Soc 2007; 2004:5065-8. [PMID: 17271456 DOI: 10.1109/iembs.2004.1404400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The adenine nucleotides ATP and ADP modulate the release of endothelial-derived relaxing factors and hence play an important role in flow-mediated arterial vasoregulation. Adenine nucleotide concentration at the endothelial cell (EC) surface within an artery is determined by a balance of convective-diffusive delivery of blood-borne nucleotides to the EC surface, hydrolysis of these nucleotides at the cell surface, and flow-induced ATP release from ECs. Previous numerical simulations in a parallel plate flow chamber had demonstrated that flow-induced ATP release has a profound effect on nucleotide concentration under both steady and pulsatile flow conditions. In the present study, we have extended this analysis to probe the impact of disturbed flow downstream of a backward facing step on adenine nucleotide concentration at the EC surface. The results have demonstrated that over a wide range of applied wall shear stress, the ATP concentration at the EC surface drops abruptly within the disturbed flow zone due to increased nucleotide residence time within this region. The concentration is intricately sensitive to the kinetics of flow-induced ATP release, and this sensitivity is more pronounced at lower levels of wall shear stress.
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Affiliation(s)
- H W Choi
- Department of Mechanical & Aeronautical Engineering, California University, Davis, CA, USA
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35
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Abstract
The frequency-dependent electrical data of the bismuth germanate silicate (BGSO) glasses have been discussed in the framework of the electric modulus representation and the power-law conductivity. The activation energies of the mean electric relaxation time and the direct current (dc) conductivity obtained by the complex modulus analysis show that the BGSO glasses satisfy the Barton, Nakajima, and Namikawa (BNN) relation. The proper relation between the exponent of the power-law conductivity and the stretched exponential of the modulus representation is shown. The temperature- and frequency-dependent characteristics of non-Debye behavior are discussed. The scaling properties of both the modulus M*(omega) and the alternating current (ac) conductivity sigma(omega) are examined.
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Affiliation(s)
- Y H Rim
- School of Liberal Arts, Semyung University, Chechon, Chungbuk 390-711, Korea
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36
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Girkin JM, Gu E, Griffin C, Choi HW, Dawson MD, McConnell G. Use of confocal and multiphoton microscopy for the evaluation of micro-optical components and emitters. Microsc Res Tech 2004; 64:293-6. [PMID: 15481047 DOI: 10.1002/jemt.20085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We report on the application of confocal and multiphoton microscopic techniques for the evaluation of the latest generation of micro optical components. The optical emitting characteristics of arrays of matrix addressable GaN micrometer-sized light emitting diodes (micro-LEDs) have been measured using a commercial confocal microscope utilising the LEDs' own emission along with reflection confocal microscopy to determine the surface structure. Multiphoton induced luminescence from the 10-20-micron diameter emitters has also been used to examine the structure of the device and we compare this with electrically induced emission. In related work, the optical properties of micro lens arrays (10-100-micron diameter) fabricated in SiC, Sapphire, and Diamond have been determined using transmission confocal microscopy. Such optical microscopy techniques offer a simple, non-destructive method to determine the structure and performance of such novel devices.
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Affiliation(s)
- J M Girkin
- Institute of Photonics, Wolfson Centre, University of Strathclyde, Glasgow, G4 0NW, United Kingdom.
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37
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Choi HW, Lemaux PG, Cho MJ. Long-term stability of transgene expression driven by barley endosperm-specific hordein promoters in transgenic barley. Plant Cell Rep 2003; 21:1108-1120. [PMID: 12836006 DOI: 10.1007/s00299-003-0630-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2002] [Revised: 02/27/2003] [Accepted: 03/02/2003] [Indexed: 05/24/2023]
Abstract
In order to evaluate the long-term stability of transgene expression driven by the B(1)- and D-hordein promoters in transgenic barley ( Hordeum vulgare L., 2 n=2 x=14), we analyzed plants from 15 independent transgenic barley lines [6 for uidA and 9 for sgfp(S65T)] produced via microprojectile bombardment of immature embryos; 4 were diploid and 11 were tetraploid. The expression and inheritance of transgenes were determined by analysis of functional transgene expression, polymerase chain reaction and fluorescence in situ hybridization (FISH). Ability to express transgenes driven by either B(1)- or D-hordein promoter was inherited in T(4) and later generations: T(4) (2 lines), T(5) (8 lines), T(6) (3 lines), T(8) (1 line) and T(9) (1 line). Homozygous transgenic plants were obtained from 12 lines [5 for uidA and 7 for sgfp(S65T)]; the remaining lines are currently being analyzed. The application of the FISH technique for physical mapping of chromosomes was useful for early screening of homozygous plants by examining for presence of the transgene. For example, one line expressing uidA, and shown to have doublet fluorescence signals on a pair of homologous chromosomes was confirmed as a homozygous line by its segregation ratio; additionally this line showed stable inheritance of the transgene to T(9) progeny. The expression of transgenes in most lines (14 out of 15 lines) driven by hordein promoters was stably transmitted to T(4) or later generations, although there was a skewed segregation pattern (1:1) from the T(1) generation onward in the remaining line. In contrast, transgene silencing or transgene loss under the control of the maize ubiquitin promoter was observed in progeny of only 6 out of 15 lines.
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Affiliation(s)
- H W Choi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
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38
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Cho MJ, Choi HW, Okamoto D, Zhang S, Lemaux PG. Expression of green fluorescent protein and its inheritance in transgenic oat plants generated from shoot meristematic cultures. Plant Cell Rep 2003; 21:467-474. [PMID: 12789450 DOI: 10.1007/s00299-002-0542-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2002] [Revised: 09/13/2002] [Accepted: 09/13/2002] [Indexed: 05/24/2023]
Abstract
The expression of green fluorescent protein (GFP) and its inheritance were studied in transgenic oat ( Avena sativa L.) plants transformed with a synthetic green fluorescent protein gene [sgfp(S65T)] driven by a rice actin promoter. In vitro shoot meristematic cultures (SMCs) induced from shoot apices of germinating mature seeds of a commercial oat cultivar, Garry, were used as a transformation target. Proliferating SMCs were bombarded with a mixture of plasmids containing the sgfp(S65T) gene and one of three selectable marker genes, phosphinothricin acetyltransferase (bar), hygromycin phosphotransferase (hpt) and neomycin phosphotransferase (nptII). Cultures were selected with bialaphos, hygromycin B and geneticin (G418), respectively, to identify transgenic tissues. From 289 individual explants bombarded with the sgfp(S65T) gene and one of the three selectable marker genes, 23 independent transgenic events were obtained, giving a 8.0% transformation frequency. All 23 transgenic events were regenerable, and 64% produced fertile plants. Strong GFP expression driven by the rice actin promoter was observed in a variety of tissues of the T(0) plants and their progeny in 13 out of 23 independent transgenic lines. Stable GFP expression was observed in T(2) progeny from five independent GFP-expressing lines tested, and homozygous plants from two lines were obtained. Transgene silencing was observed in T(0) plants and their progeny of some transgenic lines.
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Affiliation(s)
- M-J Cho
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
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39
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Choi HW, Lemaux PG, Cho MJ. Use of fluorescence in situ hybridization for gross mapping of transgenes and screening for homozygous plants in transgenic barley ( Hordeum vulgare L.). Theor Appl Genet 2002; 106:92-100. [PMID: 12582875 DOI: 10.1007/s00122-002-0997-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2001] [Accepted: 04/18/2002] [Indexed: 05/24/2023]
Abstract
Introduced transgenes, uidA, sgfp (S65T) and/or bar, were localized using fluorescence in situ hybridization (FISH) on metaphase chromosomes of transgenic barley produced by microparticle bombardment of immature embryos. Of the 19 independent transgenic lines (eight diploid and 11 tetraploid), nine had uidA and ten had s gfp (S65T). All lines tested had three or more copies of the transgenes and 18 out of 19 lines had visibly different integration sites. At a gross level, it appeared that no preferential integration sites of foreign DNA among chromosomes were present in the lines tested; however, a distal preference for transgene integration was observed within the chromosome. In diploid T0 plants that gave a 3:1 segregation ratio of transgene expression in the T1, only single integration sites were detected on one of the homologous chromosomes. Homozygous diploid plants had doublet signals on a pair of homologous chromosomes. All tetraploid T0 plants that gave a 3:1 segregation ratio in the T1 generation had only a single integration site on one of the homologous chromosomes. In contrast, the single tetraploid T0 plant with a 35:1 segregation ratio in the T1 generation had doublet signals on a pair of homologous chromosomes. In the one tetraploid T0 line, which had a homozygote-like segregation ratio (45:0), there were doublet signals at two loci on separate chromosomes. We conclude that the application of FISH for analysis of transgenic plants is useful for the gross localization of transgene(s) and for early screening of homozygous plants.
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Affiliation(s)
- H W Choi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
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40
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Kwon TH, Kim MS, Choi HW, Joo CH, Cho MY, Lee BL. A masquerade-like serine proteinase homologue is necessary for phenoloxidase activity in the coleopteran insect, Holotrichia diomphalia larvae. Eur J Biochem 2000; 267:6188-96. [PMID: 11012672 DOI: 10.1046/j.1432-1327.2000.01695.x] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Previously, we reported the molecular cloning of cDNA for the prophenoloxidase activating factor-I (PPAF-I) that encoded a member of the serine proteinase group with a disulfide-knotted motif at the N-terminus and a trypsin-like catalytic domain at the C-terminus [Lee, S.Y., Cho, M.Y., Hyun, J.H., Lee, K.M., Homma, K.I., Natori, S. , Kawabata, S.I., Iwanaga, S. & Lee, B.L. (1998) Eur. J. Biochem. 257, 615-621]. PPAF-I is directly involved in the activation of pro-phenoloxidase (pro-PO) by limited proteolysis and the overall structure is highly similar to that of Drosophila easter serine protease, an essential serine protease zymogen for pattern formation in normal embryonic development. Here, we report purification and molecular cloning of cDNA for another 45-kDa novel PPAF from the hemocyte lysate of Holotrichia diomphalia larvae. The gene encodes a serine proteinase homologue consisting of 415 amino-acid residues with a molecular mass of 45 256 Da. The overall structure of the 45-kDa protein is similar to that of masquerade, a serine proteinase homologue expressed during embryogenesis, larval, and pupal development in Drosophila melanogaster. The 45-kDa protein contained a trypsin-like serine proteinase domain at the C-terminus, except for the substitution of Ser of the active site triad to Gly and had a disulfide-knotted domain at the N-terminus. A highly similar 45-kDa serine proteinase homologue was also cloned from the larval cDNA library of another coleopteran, Tenebrio molitor. By in vitro reconstitution experiments, we found that the purified 45-kDa serine proteinase homologue, the purified active PPAF-I and the purified pro-PO were necessary for expressing phenoloxidase activity in the Holotrichia pro-PO system. However, incubation of pro-PO with either PPAF-I or 45-kDa protein, no phenoloxidase activity was observed. Interestingly, when the 45-kDa protein was incubated with PPAF-I and pro-PO in the absence, but not in the presence of Ca2+, the 45-kDa protein was cleaved to a 35-kDa protein. RNA blot hybridization revealed that expression of the 45-kDa protein was increased in the Holotrichia hemolymph after Escherichia coli challenge.
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Affiliation(s)
- T H Kwon
- College of Pharmacy, Pusan National University, Jangjeon Dong, Kumjeong Ku, Pusan, Korea
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41
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Lee KM, Lee KY, Choi HW, Cho MY, Kwon TH, Kawabata S, Lee BL. Activated phenoloxidase from Tenebrio molitor larvae enhances the synthesis of melanin by using a vitellogenin-like protein in the presence of dopamine. Eur J Biochem 2000; 267:3695-703. [PMID: 10848987 DOI: 10.1046/j.1432-1327.2000.01402.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
One of the biological functions of activated phenoloxidase in arthropods is the synthesis of melanin around invaded foreign materials. However, little is known about how activated phenoloxidase synthesizes melanin at the molecular level. Even though it has been suggested that the quinone derivatives generated by activated phenoloxidase might use endogenous protein components for melanin synthesis in arthropods, there is no report of protein components engaged in melanin synthesis induced by activated phenoloxidase. In this study, to isolate and characterize proteins involved in melanin synthesis, we prepared in vitro prophenoloxidase activating solution (designated G-100 solution), specifically showing phenoloxidase activity in the presence of Ca2+ and beta-1, 3-glucan, from the hemolymph of larvae of the coleopteran Tenebrio molitor by using a Sephadex G-100 column. When G-100 solution was incubated with dopamine to induce melanin synthesis in the presence of Ca2+ and beta-1,3-glucan, four types of protein (160 kDa, prophenoloxidase, phenoloxidase and 45 kDa) disappeared from SDS/PAGE under reducing conditions. Under identical conditions, but including phenylthiourea as a phenoloxidase inhibitor added to the G-100 solution, three of these proteins (160 kDa, phenoloxidase and 45 kDa) did not disappear. To characterize these melanization-engaging proteins, we first purified the 160-kDa melanization-engaging protein to homogeneity and raised a polyclonal antibody against it. Analysis of the cDNA revealed that it consisted of 1439 amino-acid residues and showed partial homology with Caenorhabditis elegans vitellogenin precursor-6 (19.7%). Western blot analysis showed that it disappeared when active phenoloxidase induced melanin synthesis. Furthermore, when the purified 160-kDa melanization-engaging protein was added to a G-100 solution deficient in it, melanin synthesis was enhanced compared with the same solution without the protein. These data support the conclusion that the 160-kDa vitellogenin-like protein is involved in arthropod melanin synthesis.
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Affiliation(s)
- K M Lee
- College of Pharmacy, Pusan National University, Korea
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42
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Abstract
In Plasmodium vivax and Plasmodium ovale malaria, some of the liver stage parasites remain dormant. The activation of these dormant forms (called hypnozoite) can give rise to relapse weeks, months or years after the initial infection. To prevent relapses, a course of primaquine may be given as terminal prophylaxis to patients. Different strains of Plasmodium vivax vary in their sensitivity to primaquine and, recently, cases of relapse of Plasmodium vivax after this standard primaquine therapy were reported from various countries. We reported a case of primaquine resistant malaria which initially was thought to be relapsed caused by loss of terminal prophylaxis.
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Affiliation(s)
- D J Na
- Department of Internal Medicine, Sun General Hospital, Dae Jeon, Korea
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Cho MY, Choi HW, Moon GY, Kim MH, Kwon TH, Homma K, Natori S, Lee BL. An 86 kDa diapause protein 1-like protein is a component of early-staged encapsulation-relating proteins in coleopteran insect, Tenebrio molitor larvae. FEBS Lett 1999; 451:303-7. [PMID: 10371210 DOI: 10.1016/s0014-5793(99)00608-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [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: 10/18/2022]
Abstract
Recently, we reported two novel early-staged encapsulation-relating proteins (56 kDa and 48 kDa ERPs) isolated from the hemolymph of coleopteran insect, Tenebrio molitor larvae [Cho et al. (1999) Eur. J. Biochem. (in press)]. Here, a cDNA clone for another early-staged encapsulation-relating protein (86 kDa) was isolated. We found that the 86 kDa protein shows high homology with insect diapause protein 1. The 86 kDa protein was localized in the fat body and hemolymph, but not hemocyte lysate. A significant level of 86 kDa protein was detected in pre-pupae stage, but it decreased rapidly at late larvae and pupae, and no protein was found in embryo, early larvae and adult stages. This diapause protein 1-like protein is likely to be a component of early-staged encapsulation-relating proteins in the insect cellular defense reaction.
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Affiliation(s)
- M Y Cho
- College of Pharmacy, Pusan National University, South Korea
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44
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Yang XX, Choi HW, Yang SF, Li N. A UV-light activated cinnamic acid isomer regulates plant growth and gravitropism via an ethylene receptor-independent pathway. Aust J Plant Physiol 1999; 26:325-35. [PMID: 11542914 DOI: 10.1071/pp99007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Naturally occurring cinnamic acids (CA) exist in both trans- and cis-isoforms. UV-light irradiation of trans-CA is able to produce cis-CA. cis-CA was found to possess auxin-like activity before. In contrast, the vapor of cis-CA induced an epinastic response in tomato plants just as ethylene does. Given the existence of a double bond in and the gaseous nature of cis-CA, we suspected that cis-CA might also function as an ethylene-like compound. To distinguish between these possibilities, we selected an ethylene perception-deficient tomato plant, Never-ripe (Nr), and an ethylene biosynthesis-deficient tomato plant, A11. Not only did the vapor of cis-CA fail to trigger A11 tomato fruit ripening but it also delayed the ripening of banana fruit. Moreover, the vapor of cis-CA induced epinasty and the 'triple response' in both the wild type and Nr tomato plants, indicating that the vapor of cis-CA does not act via an ethylene receptor-dependent pathway. Furthermore, the vapor of cis-CA inhibited the negative gravitropic response of stems of both etiolated Nr seedlings and young plants, whereas ethylene had little effect on the negative gravitropism of the Nr plants. These results support the conclusion that the action sites of the vapor of cis-CA and ethylene are fundamentally different.
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Affiliation(s)
- X X Yang
- Department of Biology, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR
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45
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LaTrenta GS, Choi HW, Ward RF, Hoffman L, Neidich JA. Complete nasal agenesis with bilateral microphthalmia and unilateral duplication of the thumb. Plast Reconstr Surg 1995; 95:1101-4. [PMID: 7732122 DOI: 10.1097/00006534-199505000-00024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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: 01/26/2023]
Abstract
Complete nasal aplasia is an extremely rare clinical entity and most infants are stillborn when this is associated with holoprosencephaly. A viable 3-year-old infant born with frontonasal arrest without holoprosencephaly is presented. The child's main complaint was lack of a nasal airway, which made eating extremely difficult. A method for craniofacial reconstruction of the nasopharynx is presented.
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Affiliation(s)
- G S LaTrenta
- Division of Plastic and Reconstructive Surgery, New York Hospital-Cornell Medical Center, New York, N.Y., USA
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Choi HW, Breman JG, Teutsch SM, Liu S, Hightower AW, Sexton JD. The effectiveness of insecticide-impregnated bed nets in reducing cases of malaria infection: a meta-analysis of published results. Am J Trop Med Hyg 1995; 52:377-82. [PMID: 7771600 DOI: 10.4269/ajtmh.1995.52.377] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.0] [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: 01/27/2023] Open
Abstract
The use of insecticide-impregnated bed nets to minimize human-vector contact may reduce the incidence of malaria. Consequently, several field trials have evaluated their effectiveness as a malaria prevention strategy. A meta-analysis of published reports of field trials that measured the incidence of infections was performed to provide a measure of the effectiveness of insecticide-treated bed nets in preventing clinical malaria. Subsetted analyses were performed on the 10 field trials to calculate pooled incidence rate ratios of infection among the study groups. For the studies comparing insecticide-impregnated bed nets with untreated bed nets, the summary incidence rate ratio for acquiring malarial infections was 0.757 (95% confidence interval [CI] = 0.612-0.938), representing a reduction of 24%. For the studies comparing permethrin-impregnated bed nets with controls without bed nets, the summary incidence rate ratio was 0.497 (95% CI = 0.417-0.592) (Rothman-Boice heterogeneity statistics = 17.27 [P = 0.004] and 23.55 [P = 0.0003], respectively). These data suggest that insecticide-impregnated bed nets are effective in preventing malaria, decreasing the incidence rate ratio by approximately 50% in field trials performed to date.
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Affiliation(s)
- H W Choi
- Epidemiology Program Office, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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Abstract
Subsequent to 22 hr of deprivation of water, 40 male rats were given daily access to water and a sweetened ethanol solution for 2 hr each day for 24 days. Twenty of the rats had this opportunity to take fluids during the light-phase of the circadian cycle while the other twenty were given it during the dark. Prior to the 24 days, some rats (half of each group) were implanted subcutaneously with osmotic pumps giving them constant infusions of morphine (0.6 mg/kg/hr). Across daily sessions, all rats gradually increased their intakes of ethanol with the greatest increases among those having morphine and taking fluids during the light-phase. The rats which drank during the dark gained more weight than the others and the most marked gains in weight were by those receiving no morphine. The data support the conclusion that some general disruption resulting from the schedule of presentation of fluids during the day qualifies as a setting condition for heightened intake of ethanol.
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Affiliation(s)
- H W Choi
- Department of Psychology, Rensselaer Polytechnic Institute, Troy, NY 12180-3590
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