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Ng DS, Yip BHK, Young AL, Yip WWK, Lam NM, Li KK, Ko ST, Chan WH, Aryasit O, Sikder S, Ferris JD, Pang CP, Tham CC. Cost-effectiveness of virtual reality and wet laboratory cataract surgery simulation. Medicine (Baltimore) 2023; 102:e35067. [PMID: 37800761 PMCID: PMC10552957 DOI: 10.1097/md.0000000000035067] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 08/14/2023] [Indexed: 10/07/2023] Open
Abstract
PURPOSE To evaluate the cost-effectiveness of phacoemulsification simulation training in virtual reality simulator and wet laboratory on operating theater performance. METHODS Residents were randomized to a combination of virtual reality and wet laboratory phacoemulsification or wet laboratory phacoemulsification. A reference control group consisted of trainees who had wet laboratory training without phacoemulsification. All trainees were assessed on operating theater performance in 3 sequential cataract patients. International Council of Ophthalmology Surgical Competency Assessment Rubric-phacoemulsification (ICO OSCAR phaco) scores by 2 masked independent graders and cost data were used to determine the incremental cost-effectiveness ratio (ICER). A decision model was constructed to indicate the most cost-effective simulation training strategy based on the willingness to pay (WTP) per ICO OSCAR phaco score gained. RESULTS Twenty-two trainees who performed phacoemulsification in 66 patients were analyzed. Trainees who had additional virtual reality simulation achieved higher mean ICO OSCAR phaco scores compared with trainees who had wet laboratory phacoemulsification and control (49.5 ± standard deviation [SD] 9.8 vs 39.0 ± 15.8 vs 32.5 ± 12.1, P < .001). Compared with the control group, ICER per ICO OSCAR phaco of wet laboratory phacoemulsification was $13,473 for capital cost and $2209 for recurring cost. Compared with wet laboratory phacoemulsification, ICER per ICO OSCAR phaco of additional virtual reality simulator training was US $23,778 for capital cost and $1879 for recurring cost. The threshold WTP values per ICO OSCAR phaco score for combined virtual reality simulator and wet laboratory phacoemulsification to be most cost-effective was $22,500 for capital cost and $1850 for recurring cost. CONCLUSIONS Combining virtual reality simulator with wet laboratory phacoemulsification training is effective for skills transfer in the operating theater. Despite of the high capital cost of virtual reality simulator, its relatively low recurring cost is more favorable toward cost-effectiveness.
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Affiliation(s)
- Danny S. Ng
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Eye Hospital, Hong Kong, China
- Hong Kong Baptist Hospital, Hong Kong, China
| | - Benjamin H. K. Yip
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Alvin L. Young
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Prince of Wales Hospital, Hong Kong, China
| | - Wilson W. K. Yip
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Prince of Wales Hospital, Hong Kong, China
| | - Nai M. Lam
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Eye Hospital, Hong Kong, China
| | - Kenneth K. Li
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- United Christian Hospital, Hong Kong, China
| | - Simon T. Ko
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Pamela Youde Nethersole Eastern Hospital, Hong Kong, China
| | | | | | - Shameema Sikder
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD
| | - John D. Ferris
- Ophthalmology, Gloucestershire Hospitals, National Health Service Foundation Trust, Cheltenham, United Kingdom
| | - Chi P. Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Clement C. Tham
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Eye Hospital, Hong Kong, China
- Prince of Wales Hospital, Hong Kong, China
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Chan PP, Lee VWY, Yam JCS, Brelén ME, Chu WK, Wan KH, Chen LJ, Tham CC, Pang CP. Flipped Classroom Case Learning vs Traditional Lecture-Based Learning in Medical School Ophthalmology Education: A Randomized Trial. Acad Med 2023; 98:1053-1061. [PMID: 37067959 DOI: 10.1097/acm.0000000000005238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
PURPOSE To address the problem of teaching noncore specialties, for which there is often limited teaching time and low student engagement, a flipped classroom case learning (FCCL) module was designed and implemented in a compulsory 5-day ophthalmology rotation for undergraduate medical students. The module consisted of a flipped classroom, online gamified clinical cases, and case-based learning. METHOD Final-year medical students in a 5-day ophthalmology rotation were randomized to the FCCL or a traditional lecture-based (TLB) module. The outcomes of subjective assessments (student-rated anonymous Likert scale questionnaire, scale 1 to 5, and course and teaching evaluation, scale 1 to 6) and objective assessments (end-of-rotation and post-MBChB multiple-choice questions, scale 0 to 60) were compared between the 2 groups. RESULTS Between May 2021 and June 2022, 216 students (108 in each group) completed the study. Compared with the TLB students, the students in the FCCL group rated various aspects of the course statistically significantly higher, including feeling more enthusiastic and engaged by the course and more encouraged to ask questions and participate in discussions (all P < .001). They also gave higher ratings for the instructional methods, course assignments, course outcomes, and course workload ( P < .001). They gave higher course and teaching evaluation scores to the tutors (5.7 ± 0.6 vs 5.0 ± 1.0, P < .001). The FCCL group scored higher than the TLB group on the end-of-rotation multiple-choice questions (53.6 ± 3.1 vs 51.8 ± 2.8, P < .001). When 32 FCCL students and 36 TLB students were reassessed approximately 20 weeks after the rotation, the FCCL group scored higher (40.3 ± 9.1) than the TLB group (34.3 ± 10.9, P = .018). CONCLUSIONS Applying the FCCL module in ophthalmology teaching enhanced medical students' satisfaction, examination performance, and knowledge retention. A similar model may be suitable for other specialties.
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Affiliation(s)
- Poemen P Chan
- P.P. Chan is assistant professor, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Vivian W Y Lee
- V.W.Y. Lee is associate professor, Centre for Learning Enhancement And Research, The Chinese University of Hong Kong, Hong Kong, China
| | - Jason C S Yam
- J.C.S. Yam is associate professor, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Marten E Brelén
- M.E. Brelén is associate professor, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Wai Kit Chu
- W.K. Chu is research assistant professor, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Kelvin H Wan
- K.H. Wan was assistant professor, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China, at the time of writing
| | - Li J Chen
- L.J. Chen is professor, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Clement C Tham
- C.C. Tham is S.H. Ho Professor of Ophthalmology and Visual Sciences and chairman, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Chi P Pang
- C.P. Pang is S.H. Ho Research Professor of Visual Science, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
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Peng Y, Bui CH, Zhang XJ, Chen JS, Tham CC, Chu WK, Chen LJ, Pang CP, Yam JC. The role of EZH2 in ocular diseases: a narrative review. Epigenomics 2023; 15:557-570. [PMID: 37458071 DOI: 10.2217/epi-2023-0147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023] Open
Abstract
EZH2, acting as a catalytic subunit of PRC2 to catalyze lysine 27 in histone H3, induces the suppression of gene expression. EZH2 can regulate cell proliferation and differentiation of retinal progenitors, which are required for physiological retinal development. Meanwhile, an abnormal level of EZH2 has been observed in ocular tumors and other pathological tissues. This review summarizes the current knowledge on EZH2 in retinal development and ocular diseases, including inherited retinal diseases, ocular tumors, corneal injury, cataract, glaucoma, diabetic retinopathy and age-related retinal degeneration. We highlight the potential of targeting EZH2 as a precision therapeutic target in ocular diseases.
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Affiliation(s)
- Yu Peng
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, 999077, Hong Kong
| | - Christine Ht Bui
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, 999077, Hong Kong
| | - Xiu J Zhang
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, 999077, Hong Kong
| | - Jian S Chen
- Aier School of Ophthalmology, Central South University, Changsha, Hunan Province, 410000, China
- Aier Eye Institute, Changsha, Hunan Province, 410000, China
- Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, Guangdong Province, 510000, China
| | - Clement C Tham
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, 999077, Hong Kong
- Hong Kong Eye Hospital, Kowloon, 999077, Hong Kong
- Department of Ophthalmology & Visual Sciences, Prince of Wales Hospital, 999077, Hong Kong
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, 999077, Hong Kong
| | - Wai K Chu
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, 999077, Hong Kong
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, 999077, Hong Kong
| | - Li J Chen
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, 999077, Hong Kong
- Department of Ophthalmology & Visual Sciences, Prince of Wales Hospital, 999077, Hong Kong
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, 999077, Hong Kong
| | - Chi P Pang
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, 999077, Hong Kong
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, 999077, Hong Kong
| | - Jason C Yam
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, 999077, Hong Kong
- Hong Kong Eye Hospital, Kowloon, 999077, Hong Kong
- Department of Ophthalmology, Hong Kong Children's Hospital, 999077, Hong Kong
- Department of Ophthalmology & Visual Sciences, Prince of Wales Hospital, 999077, Hong Kong
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, 999077, Hong Kong
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Tsang HW, Chua GT, To KKW, Wong JSC, Tu W, Kwok JSY, Wong WHS, Wang X, Zhang Y, Rosa Duque JS, Chan GCF, Chu WK, Pang CP, Tam PKH, Lau YL, Wong ICK, Leung WH, Yuen KY, Kwan MYW, Ip P. Assessment of SARS-CoV-2 Immunity in Convalescent Children and Adolescents. Front Immunol 2021; 12:797919. [PMID: 34975908 PMCID: PMC8718543 DOI: 10.3389/fimmu.2021.797919] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 12/02/2021] [Indexed: 01/08/2023] Open
Abstract
Persistence of protective immunity for SARS-CoV-2 is important against reinfection. Knowledge on SARS-CoV-2 immunity in pediatric patients is currently lacking. We opted to assess the SARS-CoV-2 adaptive immunity in recovered children and adolescents, addressing the pediatrics specific immunity towards COVID-19. Two independent assays were performed to investigate humoral and cellular immunological memory in pediatric convalescent COVID-19 patients. Specifically, RBD IgG, CD4+, and CD8+ T cell responses were identified and quantified in recovered children and adolescents. SARS-CoV-2-specific RBD IgG detected in recovered patients had a half-life of 121.6 days and estimated duration of 7.9 months compared with baseline levels in controls. The specific T cell response was shown to be independent of days after diagnosis. Both CD4+ and CD8+ T cells showed robust responses not only to spike (S) peptides (a main target of vaccine platforms) but were also similarly activated when stimulated by membrane (M) and nuclear (N) peptides. Importantly, we found the differences in the adaptive responses were correlated with the age of the recovered patients. The CD4+ T cell response to SARS-CoV-2 S peptide in children aged <12 years correlated with higher SARS-CoV-2 RBD IgG levels, suggesting the importance of a T cell-dependent humoral response in younger children under 12 years. Both cellular and humoral immunity against SARS-CoV-2 infections can be induced in pediatric patients. Our important findings provide fundamental knowledge on the immune memory responses to SARS-CoV-2 in recovered pediatric patients.
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Affiliation(s)
- Hing Wai Tsang
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Gilbert T. Chua
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Kelvin K. W. To
- State Key Laboratory for Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Joshua S. C. Wong
- Department of Paediatrics and Adolescent Medicine, Prince Margaret Hospital, Hospital Authority, Hong Kong, Hong Kong SAR, China
| | - Wenwei Tu
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Janette S. Y. Kwok
- Department of Pathology, Queen Mary Hospital, Hospital Authority, Hong Kong, Hong Kong SAR, China
| | - Wilfred H. S. Wong
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Xiwei Wang
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Yanmei Zhang
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Jaime S. Rosa Duque
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Godfrey C. F. Chan
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Wai Kit Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - CP Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Paul K. H. Tam
- Department of Surgery and Dr. Li Dak Sam Research Centre, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
- Faculty of Medicine, Macau University of Science and Technology, Macau, Macau SAR, China
| | - Yu Lung Lau
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Ian C. K. Wong
- Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - WH Leung
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Kwok-Yung Yuen
- State Key Laboratory for Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Mike Y. W. Kwan
- Department of Paediatrics and Adolescent Medicine, Prince Margaret Hospital, Hospital Authority, Hong Kong, Hong Kong SAR, China
- *Correspondence: Mike Y. W. Kwan, ; Patrick Ip,
| | - Patrick Ip
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
- *Correspondence: Mike Y. W. Kwan, ; Patrick Ip,
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Alqawasmeh OAM, Zhao M, Chan CPS, Leung MBW, Chow KC, Agarwal N, Mak JSM, Wang CC, Pang CP, Li TC, Chu WK, Chan DYL. Green tea extract as a cryoprotectant additive to preserve the motility and DNA integrity of human spermatozoa. Asian J Androl 2021; 23:150-156. [PMID: 33154201 PMCID: PMC7991818 DOI: 10.4103/aja.aja_58_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 07/19/2020] [Indexed: 01/06/2023] Open
Abstract
Cryopreservation impairs sperm quality and functions, including motility and DNA integrity. Antioxidant additives in sperm freezing media have previously brought improvements in postthawed sperm quality. Green tea extract (GTE) is widely considered as an excellent antioxidant, and its beneficial role has been proven in other human cells. This study aims to evaluate the GTE as a potential additive in cryopreservation media of human spermatozoa. In part one, the semen of 20 normozoospermic men was used to optimize the concentration of GTE that maintains sperm motility and DNA integrity against oxidative stress, induced by hydrogen peroxide (H2O2). Spermatozoa were treated with GTE at different concentrations before incubation with H2O2. In part two, the semen of 45 patients was cryopreserved with or without 1.0 ng ml-1 GTE. After 2 weeks, the semen was thawed, and the effect on sperm motility and DNA fragmentation was observed. Our data showed that GTE significantly protected sperm motility and DNA integrity against oxidative stress induced by H2O2when added at a final concentration of 1.0 ng ml-1. We found that the addition of 1.0 ng ml-1 GTE to cryopreservation media significantly increased sperm motility and DNA integrity (both P < 0.05). More interestingly, patients with high sperm DNA damage benefited similarly from the GTE supplementation. However, there was no significant change in the reactive oxygen species (ROS) level. In conclusion, supplementing sperm freezing media with GTE has a significant protective effect on human sperm motility and DNA integrity, which may be of clinical interest.
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Affiliation(s)
- Odai AM Alqawasmeh
- Assisted Reproductive Technology Unit, Department of Obstetrics and Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Mingpeng Zhao
- Assisted Reproductive Technology Unit, Department of Obstetrics and Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Carol PS Chan
- Assisted Reproductive Technology Unit, Department of Obstetrics and Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Maran BW Leung
- Assisted Reproductive Technology Unit, Department of Obstetrics and Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Ki C Chow
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Nikunj Agarwal
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Jennifer SM Mak
- Assisted Reproductive Technology Unit, Department of Obstetrics and Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Chi C Wang
- Assisted Reproductive Technology Unit, Department of Obstetrics and Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Chi P Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Tin C Li
- Assisted Reproductive Technology Unit, Department of Obstetrics and Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Wai K Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - David YL Chan
- Assisted Reproductive Technology Unit, Department of Obstetrics and Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
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Wong ES, Zhang XJ, Yuan N, Li J, Pang CP, Chen L, Tham CC, Cheung CY, Yam JC. Association of Optical Coherence Tomography Angiography Metrics With Detection of Impaired Macular Microvasculature and Decreased Vision in Amblyopic Eyes: The Hong Kong Children Eye Study. JAMA Ophthalmol 2021; 138:858-865. [PMID: 32584368 DOI: 10.1001/jamaophthalmol.2020.2220] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Importance Microvascular abnormalities in amblyopia are becoming evident with high-resolution imaging, such as optical coherence tomography angiography (OCT-A); however, to our knowledge, the clinical significance and use of these findings are unknown. Objective To assess changes in quantitative OCT-A metrics in amblyopic eyes and explore their association with visual acuity in children. Design, Setting, and Participants This population-based nested case-control study included children aged 6 to 8 years who were consecutively recruited between January 2016 and July 2017 from the population-based Hong Kong Children Eye Study (HKCES) at the Chinese University of Hong Kong Eye Centre. All participants underwent OCT-A with a swept-source OCT and detailed ophthalmic investigations. Macular microvasculature of the superficial capillary plexus was quantified by a customized automated image analysis program. A multivariable linear regression was conducted to evaluate the differences in OCT-A metrics between amblyopic and nonamblyopic eyes after adjustment for all known confounders. Data analysis was conducted from September to November 2018. Main Outcomes and Measures Differences in OCT-A metric (foveal avascular zone [FAZ]) area, FAZ circularity, vessel density, vessel diameter index, and fractal dimension between amblyopic and nonamblyopic eyes. Results There were 30 participants with amblyopia (mean [SD] age, 7.57 [1.2] years; 16 girls [53.3%]) and 1045 controls (mean [SD] age, 7.65 [1.0] years; 580 girls [55.5%]) in this cohort. Compared with control eyes, amblyopic eyes had decreased FAZ circularity (-0.058; 95% CI, -0.096 to -0.021, P = .002), decreased fractal dimension (-0.014; 95% CI, -0.024 to -0.003; P = .01), and increased vessel diameter index (0.002; 95% CI, 0.002 to 0.003; P < .001). A difference was not identified between FAZ area and vessel density. LogMAR visual acuity was associated with FAZ circularity (sβ, -0.133; P < .001) and vessel diameter index (sβ, 0.097; P = .001) but not with vessel density nor FAZ area. Conclusions and Relevance The results of this population-based study in children supports the presence of macular microvascular abnormalities in amblyopic eyes. Such changes as measured by OCT-A metrics are associated with visual acuity, inferring retinal involvement in the development of amblyopia and suggesting a potential role of quantitative OCT-A metrics in the diagnosis and recognition of amblyopia.
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Affiliation(s)
- Emily S Wong
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.,Hong Kong Eye Hospital, Kowloon, Hong Kong
| | - Xiu-Juan Zhang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Nan Yuan
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Jian Li
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.,Zhejiang University School of Medicine, Department of Ophthalmology, Affiliated Hangzhou First People's Hospital, Hangzhou, China
| | - C P Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Lijia Chen
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.,Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Sha Tin, Hong Kong
| | - Clement C Tham
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.,Hong Kong Eye Hospital, Kowloon, Hong Kong.,Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Sha Tin, Hong Kong
| | - Carol Y Cheung
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Jason C Yam
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.,Hong Kong Eye Hospital, Kowloon, Hong Kong.,Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Sha Tin, Hong Kong
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7
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Liu TT, Ye FC, Pang CP, Yong TQ, Tang WD, Xiao J, Shang CH, Lu ZJ. Isolation and identification of bioactive substance 1-hydroxyphenazine from Pseudomonas aeruginosa and its antimicrobial activity. Lett Appl Microbiol 2020; 71:303-310. [PMID: 32449160 DOI: 10.1111/lam.13332] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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: 01/21/2020] [Revised: 04/05/2020] [Accepted: 05/18/2020] [Indexed: 12/20/2022]
Abstract
A strain named as Pseudomonas aeruginosa 2016NX1, which could produce phenazine and cereusitin, was isolated from the root of Millettia specisoa. Phenazines were extracted, isolated and purified by chloroform, thin-layer chromatography, column chromatography and high-performance liquid chromatography. Then the purified materials were identified by analysis of nuclear magnetic resonance. The major yellow component is 1-hydroxyphenazine and the minor blue component is cereusitin A. The tests of antimicrobial activity of yellow component showed that the growth of several common plant pathogenic fungi and bacteria (such as Cochliobolus miyabeanus, Diaporthe citri, Salmonella sp., Klebsiella oxytoca) could be strongly inhibited. This study suggested that Pseudomonas aeruginosa strain 2016NX1 had a significant potential for biological control of phytopathogenic fungi. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, one bioactive substance from Pseudomonas aeruginosa 2016NX1 was identified and its antimicrobial activity was verified. This study demonstrated that one bioactive substance from P. aeruginosa can strongly inhibit the growth of plant pathogenic fungi and bacteria. This study suggested that P. aeruginosa strain 2016NX1 has a significant potential for biological control of phytopathogenic fungi.
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Affiliation(s)
- T T Liu
- College of Life Science, Guangxi Normal University, Guilin, Guangxi, China.,Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, Guangxi, China
| | - F C Ye
- College of Life Science, Guangxi Normal University, Guilin, Guangxi, China.,Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, Guangxi, China
| | - C P Pang
- College of Life Science, Guangxi Normal University, Guilin, Guangxi, China.,Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, Guangxi, China
| | - T Q Yong
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application and Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, Guangdong, China
| | - W D Tang
- College of Life Science, Guangxi Normal University, Guilin, Guangxi, China.,Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, Guangxi, China
| | - J Xiao
- College of Life Science, Guangxi Normal University, Guilin, Guangxi, China.,Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, Guangxi, China
| | - C H Shang
- College of Life Science, Guangxi Normal University, Guilin, Guangxi, China.,Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, Guangxi, China
| | - Z J Lu
- College of Life Science, Guangxi Normal University, Guilin, Guangxi, China.,Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, Guangxi, China
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Chen LJ, Pang CP, Tham CCY, Leung CKS. Genetic prediction models for primary open-angle glaucoma: translational research. Hong Kong Med J 2019; 25 Suppl 9:12-16. [PMID: 31889028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023] Open
Affiliation(s)
- L J Chen
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong
| | - C P Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong
| | - C C Y Tham
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong
| | - C K S Leung
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong
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Chen LJ, Pang CP, Tham CCY, Leung CKS. Exome sequencing to reveal presymptomatic genetic markers for primary open angle glaucoma. Hong Kong Med J 2019; 25 Suppl 5:39-43. [PMID: 31416987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023] Open
Affiliation(s)
- L J Chen
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong
| | - C P Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong
| | - C C Y Tham
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong
| | - C K S Leung
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong
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Abstract
Cataract is the leading cause of reversible blindness and visual impairment globally. Blindness from cataract is more common in populations with low socioeconomic status and in developing countries than in developed countries. The only treatment for cataract is surgery. Phacoemulsification is the gold standard for cataract surgery in the developed world, whereas manual small incision cataract surgery is used frequently in developing countries. In general, the outcomes of surgery are good and complications, such as endophthalmitis, often can be prevented or have good ouctomes if properly managed. Femtosecond laser-assisted cataract surgery, an advanced technology, can automate several steps; initial data show no superiority of this approach over current techniques, but the results of many large clinical trials are pending. The greatest challenge remains the growing 'backlog' of patients with cataract blindness in the developing world because of lack of access to affordable surgery. Efforts aimed at training additional cataract surgeons in these countries do not keep pace with the increasing demand associated with ageing population demographics. In the absence of strategie that can prevent or delay cataract formation, it is important to focus efforts and resources on developing models for efficient delivery of cataract surgical services in underserved regions. For an illustrated summary of this Primer, visit: http://go.nature.com/eQkKll.
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Affiliation(s)
- Dennis Lam
- State Key Laboratory of Ophthalmology, and Zhongshan Ophthalmic Center, Sun Yat-Sen University, 54 South Xianlie Road, Guangzhou 510060, China.,C-MER (Shenzhen), Dennis Lam Eye Hospital, Shenzhen, China
| | | | - Vineet Ratra
- C-MER (Shenzhen), Dennis Lam Eye Hospital, Shenzhen, China
| | - Yizhi Liu
- State Key Laboratory of Ophthalmology, and Zhongshan Ophthalmic Center, Sun Yat-Sen University, 54 South Xianlie Road, Guangzhou 510060, China
| | - Paul Mitchell
- Department of Ophthalmology, Centre for Vision Research, Westmead Hospital, University of Sydney, Sydney, Australia
| | - Jonathan King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | | | - Jost Jonas
- Department of Ophthalmology, Ruprecht-Karls-University, Heidelberg, Germany
| | - Chi P Pang
- Department of Ophthalmology &Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - David F Chang
- Department of Ophthalmology, University of California, San Francisco, California, USA
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Liang XY, Chen LJ, Ng TK, Tuo J, Gao JL, Tam POS, Lai TYY, Chan CC, Pang CP. FPR1 interacts with CFH, HTRA1 and smoking in exudative age-related macular degeneration and polypoidal choroidal vasculopathy. Eye (Lond) 2014; 28:1502-10. [PMID: 25277308 PMCID: PMC4268466 DOI: 10.1038/eye.2014.226] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 08/12/2014] [Indexed: 12/31/2022] Open
Abstract
PURPOSE To determine the genetic association of an inflammation-related gene, formyl peptide receptor 1 (FPR1), in exudative age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV). METHODS The coding region of FPR1 gene was sequenced in 554 unrelated Chinese individuals: 155 exudative AMD patients, 179 PCV patients, and 220 controls. Interactions and combined effects of FPR1 with complement factor H (CFH), high temperature requirement factor A1 (HTRA1), and smoking were also investigated. RESULTS A total of 28 polymorphisms in FPR1 were identified. Single nucleotide polymorphisms (SNP) rs78488639 increased the risk to exudative AMD (P=0.043) and PCV (P=0.016), whereas SNP rs867229 decreased the risk to exudative AMD (P=0.0026), but not PCV. Homozygous G allele of rs1042229 was associated with exudative AMD (P=0.0394, odds ratio (OR)=2.27, 95% confident interval: 1.08-4.74), but not with PCV. Exudative AMD, but not PCV, was associated with the heterozygous genotypes of rs2070746 (P=0.019, OR=0.57) and rs867229 (P=0.0082, OR=0.54). Significantly, interactions were identified among FPR1 rs78488639, CFH rs800292, and HTRA1 rs11200638 in both exudative AMD and PCV. Combined heterozygous risk alleles of CFH rs800292 GA and FPR1 rs78488639 CA were posed to PCV (P=2.22 × 10(-4), OR=10.47), but not exudative AMD. Furthermore, FPR1 rs78488639 CA combining with HTRA1 rs11200638 and smoking was also predisposed risks to exudative AMD and PCV. CONCLUSION FPR1 is associated with exudative AMD and PCV in a Hong Kong Chinese cohort. FPR1 rs78488639 interacted with CFH rs800292, HTRA1 rs11200638, and smoking, enhancing risk to exudative AMD and PCV.
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Affiliation(s)
- X Y Liang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong
| | - L J Chen
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong
| | - T K Ng
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong
| | - J Tuo
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - J-L Gao
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - P O S Tam
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong
| | - T Y Y Lai
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong
| | - C-C Chan
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - C P Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong
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12
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Chen JH, Qiu J, Chen H, Pang CP, Zhang M. Rapid and cost-effective molecular diagnosis using exome sequencing of one proband with autosomal dominant congenital cataract. Eye (Lond) 2014; 28:1511-6. [PMID: 25301372 DOI: 10.1038/eye.2014.158] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 03/02/2014] [Indexed: 12/27/2022] Open
Abstract
PURPOSE Due to high genetic heterogeneity, to exclude known mutations and map novel mutations in autosomal dominant congenital cataract (ADCC) using conventional candidate gene screening requires laborious laboratory work. We attempted to use a cost-effective exome sequencing strategy to identify disease-causing mutations in an ADCC pedigree. METHODS An ADCC pedigree affected by nuclear cataract and 200 unrelated senile cataract controls were recruited and given comprehensive ophthalmic examination. Whole exome of the proband of the family was captured by the Illumina TruSeq Exome Enrichment Kit, followed by sequencing using Illumina HiSeq 2000 sequencer. Validation was performed by direct sequencing. RESULTS The whole exome, including all exons of known ADCC disease-causing genes, was screened for possible disease-causing mutations. A recurrent missense mutation c.773C>T (p.S258F) in exon 2 of the gap junction protein alpha 8 gene (GJA8) was identified in the proband with nuclear cataract. The result was confirmed by direct sequencing. The mutation showed complete co-segregation with the disease phenotype in the family but was not observed in unrelated unaffected controls. CONCLUSION By successfully sequencing whole exome of only one proband and identifying a GJA8 mutation in one ADCC pedigree, the current study demonstrated that exome sequencing could serve as a rapid, robust, and cost-effective approach in clinical diagnosis and disease-causing gene discovery for ADCC.
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Affiliation(s)
- J-H Chen
- 1] Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China [2] Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China
| | - J Qiu
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - H Chen
- 1] Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China [2] Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China
| | - C P Pang
- 1] Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China [2] Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China
| | - M Zhang
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
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13
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Lv W, Chen J, Chen W, Hou P, Pang CP, Chen H. Multimodal retinal imaging in a Chinese kindred with familial amyloid polyneuropathy secondary to transthyretin Ile107Met mutation. Eye (Lond) 2014; 28:452-8. [PMID: 24480837 DOI: 10.1038/eye.2014.10] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 12/10/2013] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE To investigate the ocular phenotype and gene mutation of a Chinese pedigree with familial amyloid polyneuropathy (FAP) and vitreous amyloidosis. METHODS A Chinese pedigree with familial amyloid polyneuropathy and vitreous amyloidosis was recruited. Combined phacoemulsification, vitrectomy and intraocular lens implantation were performed on the right eye of the index patient. Ophthalmic investigations were performed before and after surgery. The DNA from the pedigree was sequenced for the transthyretin (TTR) gene. RESULTS After vitrectomy, the best-corrected visual acuity of the patient improved from counting finger to 20/20. Red-free confocal ophthalmoscopy demonstrated perifoveal ring and several perivessel white sheaths. Optical coherence tomography (OCT) revealed cotton wool like reflections on the vitreoretinal interface. Electroretinogram and autofluorescence was normal. Amyloid was present in the vitreous specimen. A substitution of T to G at nucleotide 381 in exon 4 of TTR DNA (Ile107Met) was found. This mutation co-segregated with phenotype in the pedigree and was not detected in 200 controls. CONCLUSIONS TTR Ile107Met mutation is associated with vitreous amyloidosis and FAP. OCT and red-free imaging are helpful in identifying amyloid deposits in the retina.
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Affiliation(s)
- W Lv
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - J Chen
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - W Chen
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - P Hou
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - C P Pang
- 1] Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China [2] Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China
| | - H Chen
- 1] Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China [2] Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China
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Wang CC, Fung KP, Fok TF, Lau TK, Pang CP, Chu KO, Shum ASW, Lam CWK, Chan MHM, Ho CS, Lau CM, Ting TL, Mak TCW. Melamine toxicity in rat foetuses and infants. Hong Kong Med J 2013; 19 Suppl 8:20-22. [PMID: 24473523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Affiliation(s)
- C C Wang
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong
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15
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Zhang X, Lai TYY, Chiang SWY, Tam POS, Liu DTL, Chan CKM, Pang CP, Zhao C, Chen LJ. Contribution of SNRNP200 sequence variations to retinitis pigmentosa. Eye (Lond) 2013; 27:1204-13. [PMID: 23887765 DOI: 10.1038/eye.2013.137] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 05/21/2013] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Mutations in the SNRNP200 gene have been reported to cause autosomal dominant retinitis pigmentosa (adRP). In this study, we evaluate the mutation profile of SNRNP200 in a cohort of southern Chinese RP patients. METHODS Twenty adRP patients from 11 families and 165 index patients with non-syndromic RP with mixed inheritance patterns were screened for mutations in the mutation hotspots of SNRNP200. These included exons 12-16, 22-32, and 38-45, which covered the two helicase ATP-binding domains in DEAD-box and two sec-63 domains. The targeted regions were amplified by polymerase chain reaction and analyzed by direct DNA sequencing, followed by in silico analyses. RESULTS Totally 26 variants were identified, 18 of which were novel. Three non-synonymous variants (p.C502R, p.R1779H and p.I698V) were found exclusively in patients. Two of them, p.C502R and p.R1779H, were each identified in one simplex RP patient, whereas p.I698V occurred in one patient with unknown inheritance pattern. All three residues are highly conserved in SNRNP200 orthologs. Nevertheless, only p.C502R and p.R1779H were predicted to affect protein function by in silico analyses, suggesting these two variants are likely to be disease-causing mutations. Notably, all mutations previously identified in other study populations were not detected in this study. CONCLUSIONS Our results reveal a distinct mutation profile of the SNRNP200 gene in a southern Chinese cohort of RP patients. The identification of two novel candidate mutations in two respective patients affirmed that SNRNP200 contributes to a proportion of overall RP.
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Affiliation(s)
- X Zhang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
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16
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Lu Y, Vitart V, Burdon KP, Khor CC, Bykhovskaya Y, Mirshahi A, Hewitt AW, Koehn D, Hysi PG, Ramdas WD, Zeller T, Vithana EN, Cornes BK, Tay WT, Tai ES, Cheng CY, Liu J, Foo JN, Saw SM, Thorleifsson G, Stefansson K, Dimasi DP, Mills RA, Mountain J, Ang W, Hoehn R, Verhoeven VJM, Grus F, Wolfs R, Castagne R, Lackner KJ, Springelkamp H, Yang J, Jonasson F, Leung DYL, Chen LJ, Tham CCY, Rudan I, Vatavuk Z, Hayward C, Gibson J, Cree AJ, MacLeod A, Ennis S, Polasek O, Campbell H, Wilson JF, Viswanathan AC, Fleck B, Li X, Siscovick D, Taylor KD, Rotter JI, Yazar S, Ulmer M, Li J, Yaspan BL, Ozel AB, Richards JE, Moroi SE, Haines JL, Kang JH, Pasquale LR, Allingham RR, Ashley-Koch A, Mitchell P, Wang JJ, Wright AF, Pennell C, Spector TD, Young TL, Klaver CCW, Martin NG, Montgomery GW, Anderson MG, Aung T, Willoughby CE, Wiggs JL, Pang CP, Thorsteinsdottir U, Lotery AJ, Hammond CJ, van Duijn CM, Hauser MA, Rabinowitz YS, Pfeiffer N, Mackey DA, Craig JE, Macgregor S, Wong TY. Genome-wide association analyses identify multiple loci associated with central corneal thickness and keratoconus. Nat Genet 2013; 45:155-63. [PMID: 23291589 DOI: 10.1038/ng.2506] [Citation(s) in RCA: 210] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 11/29/2012] [Indexed: 12/13/2022]
Abstract
Central corneal thickness (CCT) is associated with eye conditions including keratoconus and glaucoma. We performed a meta-analysis on >20,000 individuals in European and Asian populations that identified 16 new loci associated with CCT at genome-wide significance (P < 5 × 10(-8)). We further showed that 2 CCT-associated loci, FOXO1 and FNDC3B, conferred relatively large risks for keratoconus in 2 cohorts with 874 cases and 6,085 controls (rs2721051 near FOXO1 had odds ratio (OR) = 1.62, 95% confidence interval (CI) = 1.4-1.88, P = 2.7 × 10(-10), and rs4894535 in FNDC3B had OR = 1.47, 95% CI = 1.29-1.68, P = 4.9 × 10(-9)). FNDC3B was also associated with primary open-angle glaucoma (P = 5.6 × 10(-4); tested in 3 cohorts with 2,979 cases and 7,399 controls). Further analyses implicate the collagen and extracellular matrix pathways in the regulation of CCT.
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Affiliation(s)
- Yi Lu
- Queensland Institute of Medical Research, Statistical Genetics, Herston, Brisbane, Queensland, Australia
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Henstridge DC, Bruce CR, Pang CP, Lancaster GI, Allen TL, Estevez E, Gardner T, Weir JM, Meikle PJ, Lam KSL, Xu A, Fujii N, Goodyear LJ, Febbraio MA. Skeletal muscle-specific overproduction of constitutively activated c-Jun N-terminal kinase (JNK) induces insulin resistance in mice. Diabetologia 2012; 55:2769-2778. [PMID: 22832498 PMCID: PMC3590919 DOI: 10.1007/s00125-012-2652-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [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: 04/04/2012] [Accepted: 06/18/2012] [Indexed: 01/24/2023]
Abstract
AIMS/HYPOTHESIS Although skeletal muscle insulin resistance has been associated with activation of c-Jun N-terminal kinase (JNK), whether increased JNK activity causes insulin resistance in this organ is not clear. In this study we examined the metabolic consequences of isolated JNK phosphorylation in muscle tissue. METHODS Plasmids containing genes encoding a wild-type JNK1 (WT-JNK) or a JNK1/JNKK2 fusion protein (rendering JNK constitutively active; CA-Jnk) were electroporated into one tibialis anterior (TA) muscle of C57Bl/6 mice, with the contralateral TA injected with an empty vector (CON) to serve as a within-animal control. RESULTS Overproduction of WT-JNK resulted in a modest (~25%) increase in phosphorylation (Thr(183)/Tyr(185)) of JNK, but no differences were observed in Ser(307) phosphorylation of insulin receptor substrate 1 (IRS-1) or total IRS-1 protein, nor in insulin-stimulated glucose clearance into the TA muscle when comparing WT-JNK with CON. By contrast, overexpression of CA-Jnk, which markedly increased the phosphorylation of CA-JNK, also increased serine phosphorylation of IRS-1, markedly decreased total IRS-1 protein, and decreased insulin-stimulated phosphorylation of the insulin receptor (Tyr(1361)) and phosphorylation of Akt at (Ser(473) and Thr(308)) compared with CON. Moreover, overexpression of CA-Jnk decreased insulin-stimulated glucose clearance into the TA muscle compared with CON and these effects were observed without changes in intramuscular lipid species. CONCLUSIONS/INTERPRETATION Constitutive activation of JNK in skeletal muscle impairs insulin signalling at the level of IRS-1 and Akt, a process which results in the disruption of normal glucose clearance into the muscle.
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Affiliation(s)
- D C Henstridge
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, VIC, 3004, Australia
| | - C R Bruce
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, VIC, 3004, Australia
- Department of Physiology, Monash University, Clayton, VIC, Australia
| | - C P Pang
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, VIC, 3004, Australia
| | - G I Lancaster
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, VIC, 3004, Australia
| | - T L Allen
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, VIC, 3004, Australia
| | - E Estevez
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, VIC, 3004, Australia
| | - T Gardner
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, VIC, 3004, Australia
| | - J M Weir
- Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - P J Meikle
- Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - K S L Lam
- Department of Medicine and Research Center for Heart, Brain, Hormones, and Healthy Aging, University of Hong Kong, Hong Kong, SAR, People's Republic of China
| | - A Xu
- Department of Medicine and Research Center for Heart, Brain, Hormones, and Healthy Aging, University of Hong Kong, Hong Kong, SAR, People's Republic of China
| | - N Fujii
- Department of Health Promotion Science, Tokyo Metropolitan University, Hachioji, Tokyo, Japan
| | | | - M A Febbraio
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, VIC, 3004, Australia.
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Pong JCF, Chu CY, Chu KO, Poon TCW, Ngai SM, Pang CP, Wang CC. Identification of hemopexin in tear film. Anal Biochem 2010; 404:82-5. [PMID: 20450875 DOI: 10.1016/j.ab.2010.04.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Accepted: 04/29/2010] [Indexed: 10/19/2022]
Abstract
Human tear fluid is a complex mixture of aqueous lipids, proteins, enzymes, and other biochemical and cellular elements. By conventional comparative proteomic approaches, we investigated the proteome in human tear fluid and compared the tear protein profile of normal control subjects with that of patients suffering from the ocular inflammatory disease vernal keratoconjunctivitis (VKC). Collected tear samples were directed to two-dimensional polyacrylamide gel electrophoresis protein separation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry peptide identification. Six differentially expressed proteins-interleukin 4, phospholipase A2, albumin, lactoferrin, hemopexin, and lipocalin-were displayed. Hemopexin had not been reported previously in tear film. Enzyme-linked immunosorbent assay confirmed that hemopexin concentrations were significantly higher in VKC tear samples and increased with disease stages. The results implied clinical interest of hemopexin in the tear proteome and eye diseases.
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Affiliation(s)
- Jeffrey C F Pong
- Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong
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Wong AL, Leung CKS, Weinreb RN, Cheng AKC, Cheung CYL, Lam PTH, Pang CP, Lam DSC. Quantitative assessment of lens opacities with anterior segment optical coherence tomography. Br J Ophthalmol 2008; 93:61-5. [DOI: 10.1136/bjo.2008.137653] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Lau CSL, Choy KW, Fan DSP, Yu CBO, Wong CY, Lam DSC, Pang CP. Prenatal screening for retinoblastoma in Hong Kong. Hong Kong Med J 2008; 14:391-394. [PMID: 18840911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
We report the first use in Hong Kong of molecular techniques to screen prenatally for retinoblastoma and review 17 cases of retinoblastoma seen at the Hong Kong Eye Hospital from 2001 to 2006. A pregnant couple whose first child had retinoblastoma requested prenatal screening for retinoblastoma during their second pregnancy in 2000. Whole RB1 coding gene sequencing was performed on peripheral blood cells taken from family members and cultured amniocytes collected from the foetus during the 14th week of gestation. No RB1 gene mutations were found in the amniocyte samples and at birth the baby had no evidence of ocular tumours. During 5 years of follow-up the child remained healthy with intact visual function. Prenatal diagnosis of retinoblastoma alleviates parental stress and improves the perinatal care of affected family members.
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Affiliation(s)
- Charles S L Lau
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
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Abstract
PURPOSE To study the molecular pathogenesis of a Chinese family with coronary form of cataract. METHODS One Chinese three-generation family with inherited coronary cataract phenotype was recruited. Five affected and seven unaffected family members attended our study. Genome-wide linkage analysis was applied to map the disease loci, and two candidate genes from a locus on chromosome 1 and a locus on chromosome 22 were sequenced for mutation identification. Software at the Expasy proteomics server was utilized to predict the mutation effect on proteins. RESULTS Whole genome linkage analysis indicated some regions on chromosome 1, 10, and 22, with LOD score values greater than 1. Within these loci, the GJA8 and CRYBB2 genes, located in the two loci with the highest LOD score of 1.51 on chromosomes 1 and 22, respectively, were sequenced. A novel mutation c.92C>G in exon 2 of CRYBB2 causing S31W was identified in all five patients. It was not found in 95 unrelated controls. This missense sequence alteration likely enhanced the local solubility. Around the mutation site, a lipocalin signature motif was predicted by ScanProsite. CONCLUSIONS A novel disease-causing mutation S31W in CRYBB2 was identified in a Chinese cataract family. It is the first reported mutation for coronary cataract. Functional characterization should be carried out to evaluate the biological effects of this mutant.
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Affiliation(s)
- D Lou
- Department of Ophthalmology, The First Affiliated Hospital, Medical College, Zhejiang University, Hangzhou, People's Republic of China
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Huang Y, Cen LP, Luo JM, Wang N, Zhang MZ, van Rooijen N, Pang CP, Cui Q. Differential roles of phosphatidylinositol 3-kinase/akt pathway in retinal ganglion cell survival in rats with or without acute ocular hypertension. Neuroscience 2008; 153:214-25. [PMID: 18358617 DOI: 10.1016/j.neuroscience.2008.02.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 02/04/2008] [Accepted: 02/05/2008] [Indexed: 11/30/2022]
Abstract
Intraocular pressure (IOP) elevation has often been used as an experimental model to study mechanisms underlying retinal ganglion cell (RGC) death associated with ocular ischemic injury and glaucoma. The aim of the present study, using both in vitro and in vivo approaches, was to investigate the role of phosphatidylinositol 3-kinase (PI3K)/akt pathway in RGC viability in normal rats and rats following transient IOP elevation. For in vivo studies, pathway inhibitors were administered intravitreally on days 3, 9, and 15 post-2-h IOP elevation at 110 mm Hg. Toward the end of the 3-week examination period, the fluorescent dye Fluorogold was used to retrogradely label surviving RGCs. In order to examine the role of macrophages that were recruited into the eye following the pathway inhibition, clodronate liposomes were used to deplete phagocytic cells in the eye. PI3K/akt pathway activity and location in the retina were examined using Western blot and immunohistochemistry, respectively. Here we showed that PI3K/akt inhibitors 2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride (LY294002) and KY12420 at low concentrations (2 microM or 20 microM) did not influence RGC survival but caused RGC loss at high concentration (200 muM) in retinal explants derived from intact rats. In contrast, both LY294002 and KY12420 at 20 microM led to RGC loss in retinal explants derived from IOP-elevated eyes. A detrimental action of phagocytic cells on RGC survival was also seen in these retinas. In vivo results confirmed the detrimental actions of PI3K/akt inhibition and macrophages on RGC survival in IOP-elevated, but not intact eyes even with high concentration of LY294002. Low level of PI3K/akt activity was detected in the ganglion cell layer (GCL) in intact retina. Acute IOP elevation activated PI3K/akt pathway in the inner nuclear layer and GCL including RGCs. This study thus demonstrates that PI3K/akt pathway mediates RGC survival after IOP elevation but not under normal condition.
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Affiliation(s)
- Y Huang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, 147K Argyle Street, Kowloon, Hong Kong, People's Republic of China
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Vithana EN, Morgan PE, Ramprasad V, Tan DTH, Yong VHK, Venkataraman D, Venkatraman A, Yam GHF, Nagasamy S, Law RWK, Rajagopal R, Pang CP, Kumaramanickevel G, Casey JR, Aung T. SLC4A11 mutations in Fuchs endothelial corneal dystrophy. Hum Mol Genet 2007; 17:656-66. [PMID: 18024964 DOI: 10.1093/hmg/ddm337] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The endothelial (posterior) corneal dystrophies, which result from primary endothelial dysfunction, include Fuchs endothelial corneal dystrophy (FECD), posterior polymorphous corneal dystrophy (PPCD) and congenital hereditary endothelial dystrophy (CHED). Mutations in SLC4A11 gene have been recently identified in patients with recessive CHED (CHED2). In this study, we show that heterozygous mutations in the SLC4A11 gene also cause late-onset FECD. Four heterozygous mutations [three missense mutations (E399K, G709E and T754M) and one deletion mutation (c.99-100delTC)] absent in ethnically matched controls were identified in a screen of 89 FECD patients. Missense mutations involved amino acid residues showing high interspecies conservation, indicating that mutations at these sites would be deleterious. Accordingly, immunoblot analysis, biochemical assay of cell surface localization and confocal immunolocalization showed that missense proteins encoded by the mutants were defective in localization to the cell surface. Our data suggests that SLC4A11 haploinsufficiency and gradual accumulation of the aberrant misfolded protein may play a role in FECD pathology and that reduced levels of SLC4A11 influence the long-term viability of the neural crest derived corneal endothelial cells.
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Affiliation(s)
- Eranga N Vithana
- Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore 168751, Singapore.
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Abstract
AIMS More than 20 mutations associated with retinitis pigmentosa (RP) have been identified in the retinitis pigmentosa 1 (RP1) gene, all of them leading to the production of a truncated protein without 50-70% of the C-terminal of the RP1 protein. RP1 was recently found to be a microtubule-associated protein (MAP) and responsible for the organisation of the photoreceptor outer segment. The N-terminal doublecortin (DCX) domain of RP1 is essential for its function. But how the C-terminal of the protein affects its function is still not known. This study aims to get a better understanding of the RP1 gene by mutation screening on RP patients. METHODS Peripheral blood was taken from 72 RP patients. Together with 101 RP patients and 190 control subjects previously reported, mutation screening was performed by polymerase chain reaction (PCR) and direct sequencing. Statistical analysis was performed using SPSS. RESULTS Two novel missense sequence changes, D984G and C727W, and one novel variant, 6492T>G, at the 3' untranslated region were found. They were not found in 190 control subjects. D984G causes RP. It creates two possible N-myristoylation sites according to PROSITE. C727W does not segregate with RP in the family. It abolishes an N-myristoylation site. R872H, a previously reported polymorphism, was predominantly present in control subjects (P=0.001). CONCLUSIONS Our results suggest that disruption of the C-terminal of RP1 may be associated with the development of RP, and the possible involvement of the RP1 polypeptide downstream of its DCX domain in normal RP1 function.
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Affiliation(s)
- S W Y Chiang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
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Abd El-Aziz MM, El-Ashry MF, Chan WM, Chong KL, Barragan I, Antiñolo G, Pang CP, Bhattacharya SS. A novel genetic study of Chinese families with autosomal recessive retinitis pigmentosa. Ann Hum Genet 2006; 71:281-94. [PMID: 17156103 DOI: 10.1111/j.1469-1809.2006.00333.x] [Citation(s) in RCA: 10] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Autosomal recessive retinitis pigmentosa (arRP) is the commonest form of RP worldwide. To date 22 loci have been implicated in the pathogenesis of this disease; however none of these loci independently account for a significant proportion of recessive RP. Linkage studies of arRP in consanguineous families have been mainly based on homozygosity mapping, but this strategy cannot be applied in the case of non-consanguineous families. Therefore, we implemented a systematic approach for identifying the disease locus in three non-consanguineous Chinese families with arRP. Initially, linkage analysis using SNPs/microsatellite markers or mutation screening of known arRP genes excluded all loci/genes except RP25 on chromosome 6. Subsequently a whole genome scan for the three families using the 10K GeneChip Mapping Array was performed, in order to identify the possible disease locus. To the best of our knowledge this is the first report on the utilisation of the 10K GeneChip to study linkage in non-consanguineous Chinese arRP. This analysis indicates that the studied families are probably linked to the RP25 locus, a well defined arRP locus in other populations. The identification of another ethnic group linked to RP25 is highly suggestive that this represents a major locus for arRP.
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Affiliation(s)
- M M Abd El-Aziz
- Department of Molecular Genetics, Institute of Ophthalmology, London EC1V 9EL, UK.
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Chu KO, Wang CC, Chu CY, Choy KW, Pang CP, Rogers MS. Uptake and distribution of catechins in fetal organs following in utero exposure in rats. Hum Reprod 2006; 22:280-7. [PMID: 16959805 DOI: 10.1093/humrep/del353] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Although catechins are known to be powerful antioxidants, no reports have shown their transport to fetal organs. We investigated the distribution of catechins in fetal rat organs after maternal exposure to green tea extract (GTE). METHODS GTE (550 mg/kg) or water was fed orally to pregnant dams at 15.5 days of gestation, the dams were sacrificed and fetal organs were dissected 0, 0.5, 1, 2, 3, 5, and 8 h later. Catechins and catechin gallates were determined by high-performance liquid chromatography (HPLC) after solid-phase extraction. RESULTS In the GTE-treated group, catechins were detected in most of the fetal organs studied, including the brain, eyes, heart, lungs, kidneys and liver but not in the control group. The first peak times (T(max)) were about 0.5-1 h. The maximum concentrations (C(max)) of catechins in the fetal eye were about 2-10 times higher than in the other organs, ranging from 249 pmol/g for epicatechin (EC) to 831 pmol/g for epigallocatechin gallate (EGCG). Catechin gallates were generally more readily taken up by fetal organs than catechins. EGCG had the highest level of uptake according to area under the curve (AUC) plots and the highest C(max) in all organs. CONCLUSIONS Various fetal organs had low but significant levels of catechins after GTE intake by the dams, and organ levels were found to be related to catechin structure. EGCG could be a potential candidate for antioxidant supplementation of the fetus in utero.
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Affiliation(s)
- K O Chu
- Department of Obstetrics and Gynaecology, The Chinese Univerity of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong
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Hui M, Kwok AKH, Pang CP, Cheung SW, Lam DSC, Chan RCY. An in vitro study on the compatibility and concentrations of combinations of vancomycin, amikacin, and dexamethasone in human vitreous. Eye (Lond) 2006; 21:643-8. [PMID: 16531970 DOI: 10.1038/sj.eye.6702321] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To investigate the precipitation process of a mixture of vancomycin, amikacin, and dexamethasone by equilibrium dialysis and its subsequent effect on the levels of available-free antibiotics and steroid. METHODS Concentrations of amikacin, vancomycin, and dexamethasone in an equilibrium dialysis chamber were measured during the equilibrium process by high-performance liquid chromatography and fluorescence polarisation immunoassay. Vitreous were used as the medium of dialysis, with the three medications prepared in normal saline (NS) and balanced salt solution plus (BSS Plus) separately. RESULTS Amikacin showed no measurable loss in NS or BSS Plus, either alone or when mixed with vancomycin or dexamethasone. Vancomycin showed minimal loss in BSS Plus, either alone or when mixed with amikacin or dexamethasone. Dexamethasone showed a median loss of 16 and 15% when incubated alone in NS and BSS Plus, respectively, at 48 h. When mixed with vancomycin or amikacin in BSS Plus, it showed a median loss of 13 and 12%, respectively, at 48 h. There was no statistically significant difference in the loss of dexamethasone under various conditions. In equilibrium dialysis in vitreous, amikacin, vancomycin, and dexamethasone reached equilibrium within 24 h and with no loss up to 192 h. There was no difference observed when the medications were prepared in NS or BSS Plus. CONCLUSIONS Both amikacin and vancomycin did not show precipitation or decrease in concentration in NS or BSS Plus. Dexamethasone showed relatively small percentage loss. As a result, treatment of endophthalmitis with vancomycin and amikacin combination is preferred.
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Affiliation(s)
- M Hui
- Department of Microbiology, The Chinese University of Hong Kong, The Prince of Wales Hospital, Hong Kong.
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Choy KW, Wang CC, Ogura A, Lau TK, Rogers MS, Ikeo K, Gojobori T, Tang LY, Lam DSC, Chung TKH, Pang CP. Molecular characterization of the developmental gene in eyes: through data-mining on integrated transcriptome databases. Clin Biochem 2006; 39:224-30. [PMID: 16427038 DOI: 10.1016/j.clinbiochem.2005.12.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2005] [Revised: 11/03/2005] [Accepted: 12/13/2005] [Indexed: 11/17/2022]
Abstract
OBJECTIVES Our aim was to utilize publicly available and proprietary sources to discover candidate genes important for ocular development. DESIGN AND METHODS The collated information on our 5092 non-redundant clusters was grouped and functional annotation was conducted using gene ontology (FatiGO) for categorizing them with respect to molecular function. The web-based viewer technological platform (H-InvDB) was employed for transcription analyses of in-house high quality fetal eye Expressed Sequence Tags (ESTs). Eye-specific ESTs were also analyzed across species by using EMBEST. RESULTS According to adult eye cDNA libraries, nucleic acid binding and cell structure/cytoskeletal protein genes were the most abundant among the ESTs of fetal eyes. Using cDNA assembly in H-InvDB, 20 (80%) of the 25 most commonly expressed genes in the human eye are also expressed in extraocular tissues. The crystalline gamma S gene is highly expressed in the eye, but not in other tissues. We used EMBEST to compare human fetal eye and octopus eye ESTs and the expression similarity was low (1.6%). This indicated that our fetal eye library contains genes necessary for the developmental process and biological function of the eye, which may not be expressed in the fully developed octopus eyes. The human fetal eye cDNA library also contained highly abundant eye tissue genes, including alphaA-crystallin, eukaryotic translation elongation factor 1 alpha 1 (EEF1A1), bestrophin (VMD2), cystatin C, and transforming growth factor, beta-induced (BIGH3). CONCLUSIONS Our annotated EST set provides a valuable resource for gene discovery and functional genomic analysis. This display will help to appreciate the strengths and weaknesses of the different technological platforms, so that in future studies the maximum amount of beneficial information can be derived from the appropriate use of each method.
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Affiliation(s)
- K W Choy
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong.
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Choy KW, Wang CC, Ogura A, Lau TK, Rogers MS, Ikeo K, Gojobori T, Lam DSC, Pang CP. Genomic annotation of 15,809 ESTs identified from pooled early gestation human eyes. Physiol Genomics 2005; 25:9-15. [PMID: 16368877 DOI: 10.1152/physiolgenomics.00121.2005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To complement cDNA libraries from the human eye at early gestation and to discover candidate genes associated with early ocular development, we used freshly dissected human eyeballs from week 9-14 of gestation to construct the early human fetal eye cDNA library. A total of 15,809 clones were isolated and sequenced from the unamplified and unnormalized library. We screened 11,246 good-quality ESTs, leading to the identification of 5,534 nonredundant clusters. Among them, 4,010 (72%) genes matched in the human protein database (Ensembl). The remaining 28% (1,524) corresponded to potentially novel or previously unidentified ESTs. We used BLASTX to compare our EST data with eight organisms and found common expression of a high portion of genes: Caenorhabditis briggsae (26%), Caenorhabditis elegans (27%), Anopheles gambiae (37%), Drosophila melanogaster (32%), Danio rerio (42%), Fugu rubripes (49%), Rattus norvegicusvalitus (52%), and Mus musculus (59%). Nevertheless, 48% (2,680 of 5,534) of the genes expressed in the early developing eye were not shared with current NEIBank human eye cDNA data. In addition, eight known retinal disease genes existed in our ESTs. Among them, six (COL11A1, BBS5, PDE6B, OAT, VMD2, and PGK1) were conserved among the genomes of other organisms, indicating that our annotated EST set provides not only a valuable resource for gene discovery and functional genomic analysis but also for phylogenetic analysis. Our foremost early gestation human eye cDNA library could provide detailed comparisons across species to identify physiological functions of genes and to elucidate evolutionary mechanisms.
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Affiliation(s)
- K W Choy
- Department of Ophthalmology, Chinese University of Hong Kong, Hong Kong
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Xia Y, Baum L, Pang CP, Siest G, Visvikis S. Cardiovascular risk-associated allele frequencies for 15 genes in healthy elderly French and Chinese. Clin Chem Lab Med 2005; 43:817-22. [PMID: 16201890 DOI: 10.1515/cclm.2005.137] [Citation(s) in RCA: 6] [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: 11/15/2022]
Abstract
In order to investigate possible ethnic differences in genetic and environmental determinants, we investigated several cardiovascular disease-associated genetic variations in successful ageing populations of France (Nancy) and China (Hong Kong). Allelic frequencies of these genetic variations were compared between healthy elderly Chinese (n=103) and French populations (n=100). A multi-locus assay was used to genotype 15 genes for 29 biallelic sites, genes implicated in lipid and homocysteine metabolism, thrombosis, leukocyte adhesion, and blood pressure regulation. For most of the candidate markers within lipid metabolism genes, the less frequent alleles were more common in the Chinese population compared with the French population, while the less frequent alleles of the majority of the other markers were detected only or more commonly in the French population. In conclusion, polymorphisms in 13 genes exhibited statistically significant differences in allelic frequencies between the two populations. Since the two populations were selected as examples of successful ageing, we could hypothesise that genetic factors that could play a role in a successful ageing process may be different between the two populations.
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Affiliation(s)
- Yongjing Xia
- INSERM U525, Université Henri Poincaré Nancy I, Nancy, France
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31
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Wang DY, Chan WM, Tam POS, Chiang SWY, Lam DSC, Chong KKL, Pang CP. Genetic markers for retinitis pigmentosa. Hong Kong Med J 2005; 11:281-8. [PMID: 16085945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
OBJECTIVE To review recent advances in the molecular genetics of retinitis pigmentosa with emphasis on the development of genetic markers that aids diagnosis and prognosis. DATA SOURCES AND EXTRACTION Literature search of MEDLINE from 1988 to 2005 using the following key words: 'retinitis pigmentosa', 'rhodopsin', 'RP1', 'RPGR', and 'genetic counseling'. References of two genes--RHO and RP1--causing retinitis pigmentosa in the Chinese population were reviewed. STUDY SELECTION Literature and data related to genetic markers for retinitis pigmentosa. DATA SYNTHESIS The genetics of retinitis pigmentosa is complex. It can be sporadic or familial, with heterogeneous transmission modes. Retinitis pigmentosa is associated with nearly 40 chromosomal loci, where 32 candidate genes have been identified. A large number of mutations are known to cause retinitis pigmentosa. But no single mutation alone accounts for more than 10% of unrelated retinitis pigmentosa patients. Genetic tests for retinitis pigmentosa require screening for a consort of mutations in a large number of genes. High throughput screening technology such as denaturing high performance liquid chromatography and automated DNA sequencing should make such tests feasible. CONCLUSIONS Rapid developments in the understanding of the genetics of retinitis pigmentosa have helped to establish genetic tests of clinical value. The complex mode of inheritance nonetheless makes genetic counselling difficult, even in the presence of positive genetic screening results.
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Affiliation(s)
- D Y Wang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, 147K Argyle Street, Hong Kong
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Wang DY, Chan WM, Tam POS, Baum L, Lam DSC, Chong KKL, Fan BJ, Pang CP. Gene mutations in retinitis pigmentosa and their clinical implications. Clin Chim Acta 2005; 351:5-16. [PMID: 15563868 DOI: 10.1016/j.cccn.2004.08.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [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: 05/12/2004] [Revised: 08/23/2004] [Accepted: 08/24/2004] [Indexed: 11/30/2022]
Abstract
Retinitis pigmentosa (RP) is a group of inherited progressive retinal diseases affecting about 1 in 3500 people worldwide. So far, there is no prevention or cure, with permanent visual loss or even blindness the ultimate consequence usually after midlife. The genetics of RP are complex. It can be sporadic, autosomal dominant, autosomal recessive, or X-linked. Thirty-two genes are known to be associated with RP, sometimes the same gene gets involved in different inheritance traits. Some RP cases have a digenic cause. About 60% RP cases still have no known genetic cause. A large number of mutations cause RP, and they can be deletions, insertions, or substitutions that cause missense mutations or truncations. The RHO, RP1, and RPGR genes contribute the greatest number of known mutations causative of RP. But there is no single mutation that alone accounts for more than 10% of unrelated patients. Genetic testing for RP therefore requires screening for a group of genes. High-throughput and automated sequence detection technologies are essential. Due to the complexity in phenotype and genetics, and the fact that RP is untreatable, genetic testing for presymptomatic diagnosis of RP is controversial. Meanwhile, new genes are still to be identified, mostly by family linkage and sib-pair analysis. Research on gene therapy for RP requires information on gene mutations causative of RP.
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Affiliation(s)
- D Y Wang
- Department of Ophthalmology and Visual Sciences, Hong Kong Eye Hospital, The Chinese University of Hong Kong, 147K Argyle Street, Kowloon, Hong Kong, China
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Kwok AKH, Yeung CK, Lai TYY, Chan KP, Pang CP. Effects of trypan blue on cell viability and gene expression in human retinal pigment epithelial cells. Br J Ophthalmol 2004; 88:1590-4. [PMID: 15548818 PMCID: PMC1772415 DOI: 10.1136/bjo.2004.044537] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To evaluate the effects of trypan blue on cell viability and gene expression in human retinal pigment epithelial (RPE) cells. METHODS Three concentrations (0.06 mg/ml, 0.6 mg/ml, and 4 mg/ml) of trypan blue were applied to human ARPE19 cells for 1 minute. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RPE cells were sampled daily for 6 consecutive days to assess the effects of trypan blue on cell viability. The effects of trypan blue on the expression of apoptosis related and cell cycle arrest gene expressions including c-fos, c-jun, p53, and p21 were performed using reverse transcription-polymerase chain reaction and immunostaining. RESULTS The MTT assay showed a concentration dependent suppression effect of trypan blue on cell viability, with higher reduction in the 0.6 mg/ml and 4 mg/ml trypan blue treated groups. No significant change in the expression of c-fos and c-jun was found with all three concentrations of trypan blue. An increase in p53 expression was found in the 4 mg/ml trypan blue treated group at 10-30 minutes after trypan blue application. Immunostaining showed a mild, albeit insignificant, increase of p53 expression in the RPE cells. No significant increase in p21 expression was observed in the 0.06 mg/ml trypan blue treated group but there were significant increases in p21 expression in both the 0.6 mg/ml (p = 0.032) and the 4 mg/ml (p = 0.025) treated groups. CONCLUSIONS Trypan blue may lead to toxicity on cultured RPE cells as indicated by the reduction in cell viability and changes in the expression of apoptosis related and cell cycle arrest genes at higher concentrations. The application of 0.06 mg/ml trypan blue for 1 minute appeared to have no significant effect on cultured RPE.
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Affiliation(s)
- A K H Kwok
- Department of Ophthalmology, Hong Kong Sanatorium and Hospital, 2 Village Road, Happy Valley, Hong Kong.
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Kwok T, Cheng G, Lai WK, Poon P, Woo J, Pang CP. Use of fasting urinary methylmalonic acid to screen for metabolic vitamin B12 deficiency in older persons. Nutrition 2004; 20:764-8. [PMID: 15325684 DOI: 10.1016/j.nut.2004.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVES We sought to determine the cutoffs of fasting urinary methylmalonic acid (MMA) indicating elevated and mildly elevated serum MMA concentrations in older persons. METHODS We studied 113 female Chinese vegetarians older than 55 y with normal renal function. Fasting serum samples were obtained for measurement of vitamin B12, MMA, and folate and tests of renal function. A fasting urine sample was collected for MMA measurement by the stable-isotope dilution method. The correlation between serum and urinary MMA levels was examined. The optimal cutoffs of urinary MMA for predicting elevated and mildly elevated serum MMA were estimated by use of receiver operating characteristic curves. RESULTS Fasting urinary and serum MMA levels were linearly correlated. Pearson's correlation coefficient was 0.94. The cutoff of fasting urinary MMA of 2 microM/mM of creatinine had a sensitivity of 79%, a specificity of 85%, and a positive predictive value of 93% for elevated serum MMA (> 0.4 microM/L). A cutoff of 1.5 microM/mM of creatinine had a sensitivity of 86%, a specificity of 85%, and a positive predictive value of 95% for mildly elevated serum MMA (> 0.3 microM/L). Both cutoffs had high positive predictive values for subnormal vitamin B12 concentrations. CONCLUSION Overnight fasting urinary MMA concentrations have a strong linear relation to serum MMA in older vegetarians without renal impairment. Urinary MMA is potentially useful as a screening tool for metabolic vitamin B12 deficiency in older persons.
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Affiliation(s)
- T Kwok
- Department of Medicine and Therapeutics, Shatin, Hong Kong, Peoples' Republic of China.
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Wong FCS, Pang CP, Tang SK, Tung SY, Leung TW, Sze WK, Cheung KB. Treatment results of endometrial carcinoma with positive peritoneal washing, adnexal involvement and serosal involvement. Clin Oncol (R Coll Radiol) 2004; 16:350-5. [PMID: 15341439 DOI: 10.1016/j.clon.2004.03.009] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
AIMS To review the treatment results of patients with endometrial carcinoma having positive peritoneal washing (PPW), adnexal involvement, uterine serosal involvement, or all three. MATERIALS AND METHODS The treatment records of patients who had undergone primary surgery for endometrial cancer without distant metastasis during 1990--2001 at the Department of Clinical Oncology, Tuen Mun Hospital, Hong Kong, were reviewed. Thirty-five patients were found to have involvement of positive PPW, adnexal involvement, uterine serosal involvement, or all three. Seven (20%) of them had gross or microscopic lymph-node metastasis. Thirty-three (94.3%) patients received adjuvant radiotherapy (28 whole-pelvic irradiation [WPI]; five abdominal radiotherapy [WART]). Two patients with solitary ovarian metastasis received chemotherapy, and one with isolated PPW also received adjuvant hormonal therapy. The median follow-up was 50.4 months (range 2.4-151.2 months). Multivariate analysis was carried out using the Cox regression proportional hazards model. RESULTS Among the 28 patients with clinical or pathological node-negative disease (International Federation of Gynecology and Obstetrics [FIGO] stage IIIA), only two patients with solitary ovarian metastases developed recurrence. The 5-year actuarial disease-free survival (DFS) rates for the whole group and patients without lymph-node involvement were 77.9% and 91.7%, respectively. Five out of the seven patients with lymph-node involvement developed recurrences. Univariate analysis showed that lymph-node involvement (P < 0.0001) and high-grade disease (P = 0.011) were the significant poor prognostic factors. Multivariate analysis showed that lymph-node involvement was the only significant poor prognostic factor to predict poor 5-year DFS (P = 0.0001). Only one patient (3.7%) who had received WART developed grade 4 toxicity. CONCLUSIONS This study showed that good treatment results could be obtained from patients with stage IIIA endometrial carcinoma without clinical or pathological lymph-node involvement after adjuvant radiotherapy, with acceptable late side-effects. The relative prognostic importance of individual IIIA involvement and the optimal adjuvant treatment remain to be determined.
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Affiliation(s)
- F C S Wong
- Department of Clinical Oncology, Tuen Mun Hospital, Hong Kong (Special Administrative Region), People's Republic of China.
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Hui M, Kwok AKH, Pang CP, Cheung SW, Chan RCY, Lam DSC, Cheng AFB. An in vitro study on the compatibility and precipitation of a combination of ciprofloxacin and vancomycin in human vitreous. Br J Ophthalmol 2004; 88:218-22. [PMID: 14736778 PMCID: PMC1771976 DOI: 10.1136/bjo.2003.017947] [Citation(s) in RCA: 25] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To investigate the precipitation process of a mixture of vancomycin and ciprofloxacin by equilibrium dialysis and its subsequent effect on the level of available free antibiotics. METHODS Concentrations of vancomycin and ciprofloxacin in an equilibrium dialysis chamber were measured during the equilibrium process by high performance liquid chromatography and fluorescence polarisation immunoassay. Normal saline (NS), balanced salt solution plus (BSS Plus), and vitreous were used separately as the medium of dialysis. RESULTS Precipitation of ciprofloxacin occurred on incubation at 37 degrees C. It formed precipitate on its own or when mixed with vancomycin in all the three media of NS, BSS Plus, and vitreous. There was more precipitation at higher initial ciprofloxacin concentrations; at 25.0 mg/l about 75% free drug in BSS Plus was lost after 72 hours. The extent of precipitation was similar in both NS and BSS Plus. In the dialysis chambers, 20 mg/l ciprofloxacin dialysed against 125 mg/l vancomycin was reduced to a concentration about 5.0 mg/l after 168 hours. Precipitation of vancomycin was negligible. Ciprofloxacin precipitated in vitreous at body temperature, irrespective of the presence of vancomycin. Even after precipitation, the resultant concentration of ciprofloxacin was still higher than the MIC(90) of the drug against most Gram negative organisms. CONCLUSIONS Based on this in vitro study, ciprofloxacin precipitated in vitreous at body temperature, irrespective of the presence of vancomycin or the medium for intravitreal injection. The resultant amount of ciprofloxacin was still higher than the MIC(90) of the drug against most Gram negative organisms after precipitation. The authors suggest ciprofloxacin in place of ceftazidime when used in combination with vancomycin for treatment of infective endophthalmitis.
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Affiliation(s)
- M Hui
- Department of Microbiology, The Chinese University of Hong Kong, Hong Kong, ROC
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Liauw L, Chung YN, Tsoi CW, Pang CP, Cheung KB. Laparoscopy for the treatment of women with endometrial cancer. Hong Kong Med J 2003; 9:108-12. [PMID: 12668821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
OBJECTIVE To evaluate the use of a laparoscopic approach for the management of endometrial cancer. DESIGN Retrospective study. SETTING Regional hospital, Hong Kong. SUBJECTS AND METHODS Individual medical records of patients with preoperative histological diagnosis of endometrial carcinoma from January 2000 to December 2001 were reviewed and the data analysed. MAIN OUTCOME MEASURES Success of laparoscopic-assisted surgical staging, intra-operative and postoperative morbidity, and length of hospital stay. RESULTS Laparoscopic surgery was successful for 93.3% (28 of 30) patients. Two patients were converted to laparotomy. The mean operating time was 102 minutes (standard deviation, 16 minutes) and the mean operative blood loss was 280 mL (standard deviation, 137 mL). The mean hospital stay was 5 days (standard deviation, 2.3 days). The intra-operative and postoperative complication rate was 16.7%, including vaginal tear, injury to the inferior epigastric vessel, lymphocyst, and pulmonary embolism. CONCLUSION This study illustrated that a laparoscopic approach is feasible for endometrial cancer surgery and may be considered as the primary treatment modality in skilled hands. This approach should be offered to women with endometrial cancer without contraindications for laparoscopic surgery if experienced endoscopic surgeons are available. Prophylaxis for venous thromboembolism and the use of retroperitoneal drainage may be helpful in decreasing the perioperative morbidity.
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Affiliation(s)
- L Liauw
- Department of Obstetrics and Gynaecology, Tuen Mun Hospital, Tsing Chung Koon Road, Tuen Mun, Hong Kong
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Kwok T, Cheng G, Woo J, Lai WK, Pang CP. Independent effect of vitamin B12 deficiency on hematological status in older Chinese vegetarian women. Am J Hematol 2002; 70:186-90. [PMID: 12111763 DOI: 10.1002/ajh.10134] [Citation(s) in RCA: 25] [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: 11/11/2022]
Abstract
We have examined the independent effect of vitamin B(12) deficiency on hematological indices in older Chinese vegetarian women using a cross-sectional study design: 119 women older than 55 years who had been vegetarian for more than 3 years were studied. Fasting blood samples were taken for complete blood count, serum iron, total serum iron binding capacity, serum iron saturation, serum vitamin B(12), serum folate, serum methylmalonic acid levels (MMA), and renal function test. Subjects with iron deficiency (iron saturation <15%) and those with serum creatinine >150 mmol/L were excluded. The prevalence of definite vitamin B(12) deficiency (vitamin B(12) level < 150 pmol/L and MMA >or= 0.4 micromol/L) was 42%. Another 32.8% had possible vitamin B(12) deficiency (either criterion). The prevalence of iron deficiency was 10%. After exclusions, 96 subjects were further analyzed. Vitamin B(12) deficiency defined by serum vitamin B(12) and MMA was associated with a decrease in hemoglobin concentrations by up to 0.9 g/dL, but it was not associated with an increase in mean corpuscular volume (MCV). Serum MMA but not vitamin B(12) levels correlated inversely with hemoglobin and platelet counts and positively with MCV, after adjustment of confounding factors. However, the percentage of subjects with anemia did not increase significantly until serum MMA became >1.0 micromol/L. In conclusion, vitamin B(12) deficiency was associated with a significant decrease in hemoglobin concentration. However, anemia associated with vitamin B(12) deficiency was seldom macrocytic. We recommend that older vegetarians should be given vitamin B(12) supplements routinely.
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Affiliation(s)
- T Kwok
- Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin.
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Affiliation(s)
- Y F Leung
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Kowloon
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Khoo US, Chan KYK, Cheung ANY, Xue WC, Shen DH, Fung KY, Ngan HYS, Choy KW, Pang CP, Poon CSP, Poon AYA, Ozcelik H. Recurrent BRCA1 and BRCA2 germline mutations in ovarian cancer: a founder mutation of BRCA1 identified in the Chinese population. Hum Mutat 2002; 19:307-8. [PMID: 11857749 DOI: 10.1002/humu.9015] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Previous mutational analysis for BRCA gene mutations in sporadic ovarian cancer occurring in Chinese patients in Hong Kong identified six germline BRCA1 mutations and one germline BRCA2 mutation, six of which were novel (Khoo et al., 2000). Knowledge of BRCA gene mutations in the Chinese population is relatively scant. In this study, we focussed on whether any of these mutations could be recurrent in our Chinese population, making use of archival paraffin embedded tissue. A consecutive series of 214 ovarian cancer cases, half of Southern Chinese origin from Hong Kong whilst the other half of Northern Chinese origin from Beijing were used for the study. We identified one further novel mutation, 1081delG, in BRCA1. This was found to occur in two unrelated individuals with shared haplotype as revealed by allelotype analysis, thus demonstrating founder effect. Two other recurrent mutations were also identified, the 2371-2372delTG mutation in BRCA1 and the 3337C>T mutation in BRCA2 recurring in two and three unrelated individuals respectively, giving an overall prevalence 4.7% of recurrent BRCA mutations in ovarian cancer in the Southern Chinese population. Most importantly, all our recurrent mutation carriers were identified from Southern Chinese patients from Hong Kong whilst such mutations were absent in samples from the Northern Chinese. Our findings indicate possible heterogeneity in the BRCA genotype between Northern and Southern Chinese. The identification of a founder mutation and two recurrent mutations moreover, has important implications towards screening strategies for breast and ovarian cancer among Chinese of southern ancestral origin who are now dispersed throughout the world.
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Affiliation(s)
- Ui-Soon Khoo
- Department of Pathology, Queen Mary Hospital, The University of Hong Kong, Hong Kong
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Rao SK, Fan DSP, Pang CP, Li WWY, Ng JSK, Good WV, Lam DSC. Bilateral congenital corneal keloids and anterior segment mesenchymal dysgenesis in a case of Rubinstein-Taybi syndrome. Cornea 2002; 21:126-30. [PMID: 11805525 DOI: 10.1097/00003226-200201000-00028] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To report the unusual association of bilateral corneal keloids and anterior segment mesenchymal dysgenesis in a child with Rubinstein-Taybi syndrome. METHODS Case report of a 2-year-old boy. RESULTS Excision of the epicorneal mass in the right eye was followed by recurrence of the lesion. Multiple penetrating keratoplasties were unsuccessful in reconstructing the anterior segment because of recurrent corneal epithelial breakdown, suggesting limbal stem cell insufficiency. Histopathology and electron microscopy of the excised mass lesion showed features typical of a corneal keloid: thickened keratinized epithelium, absent Bowman's layer, and fibrovascular hyperplasia, with haphazard orientation of the collagen lamellae. Ultrasound biomicroscopy and intraoperative findings suggested a diagnosis of Peter anomaly, but genetic analysis did not show a PAX6 mutation. CONCLUSION The findings in our patient add to the spectrum of ocular changes described in Rubinstein-Taybi syndrome and confirm earlier reports of poor ocular prognosis in corneal keloids and Rubinstein-Taybi syndrome.
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Affiliation(s)
- Srinivas K Rao
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin
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Khaw KS, Wang CC, Ngan Kee WD, Pang CP, Rogers MS. Effects of high inspired oxygen fraction during elective caesarean section under spinal anaesthesia on maternal and fetal oxygenation and lipid peroxidation. Br J Anaesth 2002; 88:18-23. [PMID: 11883375 DOI: 10.1093/bja/88.1.18] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.0] [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: 11/12/2022] Open
Abstract
BACKGROUND Oxygen supplementation is given routinely to parturients undergoing Caesarean section under regional anaesthesia. While the aim is to improve fetal oxygenation, inspiring a high oxygen fraction (FIO2) can also increase free radical activity and lipid peroxidation in both the mother and baby. In this prospective, randomized, double-blind study, we investigated the effect of high inspired oxygen fraction (FIO2) on maternal and fetal oxygenation and oxygen free radical activity in parturients having Caesarean section under spinal anaesthesia. METHODS Forty-four healthy parturients were randomized to breathe either 21% (air group) or 60% oxygen (oxygen group) intraoperatively via a ventimask. Maternal arterial blood was collected at 5-min intervals from baseline until delivery, and umbilical arterial and venous blood was collected at delivery. We measured blood gases and the products of lipid peroxidation (8-isoprostane, malondialdehyde (MDA), hydroperoxide (OHP)) and purine metabolites. RESULTS At delivery, the oxygen group had greater maternal arterial PO2 [mean 30.0 (SD 6.3) vs 14.2 (1.9) kPa; mean difference 15.8 kPa, 95% confidence interval 12.9-18.7 kPa, P<0.001] and greater umbilical venous PO2 [4.8 (1.0) vs 4.0 (1.4) kPa; mean difference 0.8 kPa, 95% confidence interval 0.0-1.5 kPa, P=0.04] compared with the air group. Maternal and umbilical plasma concentrations of lipid peroxides (8-isoprostane, MDA, OHP) were greater in the oxygen group than in the air group (P<0.05). CONCLUSIONS We conclude that breathing high FIO2 modestly increased fetal oxygenation but caused a concomitant increase in oxygen free radical activity in both mother and fetus.
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Affiliation(s)
- K S Khaw
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, China
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Affiliation(s)
- Y F Leung
- Dept of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, 3/F, 147K Argyle Street, Kowloon, Hong Kong
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Pang CP, Fan DS, Keung JW, Baum L, Tang NL, Lau JW, Lam DS. Congenital hypertrophy of the retinal pigment epithelium and APC mutations in Chinese with familial adenomatous polyposis. Ophthalmologica 2001; 215:408-11. [PMID: 11741105 DOI: 10.1159/000050898] [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: 11/19/2022]
Abstract
Mutations in the adenomatous polyposis coli gene (APC) often cause both congenital hypertrophy of the retinal pigment epithelium (CHRPE) and familial adenomatous polyposis (FAP). To investigate the relationship between APC mutations, CHRPE and FAP, all FAP patients at the Prince of Wales Hospital, Hong Kong, were asked to participate in a study. Ten Chinese patients from 6 kindreds and their family members volunteered, along with 12 healthy control subjects selected among hospital visitors and staff. All were examined for dilated fundus by indirect ophthalmoscopy. Mutations in APC coding exons were detected by sequencing. In one FAP patient, a novel A insertion at codon 1023 was detected. Three previously reported mutations were detected in 6 FAP patients: a deletion of ACAAA at codon 1061, and 2 truncating point substitutions at codons 216 and 283. In 3 FAP patients, no APC mutation was found, suggesting that mutations in APC coding regions are not the sole cause of FAP or CHRPE. A total of 64 CHRPE lesions were found in FAP patients and some relatives with and without APC mutations. Contrary to most reports, APC mutations before exon 9 did cause CHRPE lesions, albeit relatively few.
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Affiliation(s)
- C P Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, China.
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Affiliation(s)
- Y F Leung
- Dept of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, 3/F, 147K Argyle Street, Kowloon, Hong Kong
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Tang NL, Choy KW, Pang CP, Yeo W, Johnson PJ. Prevalence of breast cancer predisposition gene mutations in Chinese women and guidelines for genetic testing. Clin Chim Acta 2001; 313:179-85. [PMID: 11694257 DOI: 10.1016/s0009-8981(01)00671-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Breast cancer is the most common cancer among Caucasian females. On average, 1 in 12 women will have breast cancer during their lifetime. There is a marked difference in breast cancer incidence in Chinese. In Hong Kong women, the lifetime risk is 1 in 29. BRCA1 and BRCA2 are high-penetrant cancer predisposition genes, but the prevalence and nature of mutations in these genes appear to be ethnic-specific. It is not clear if the differences in cancer incidence between Caucasians and Chinese are due to genetic or environmental factors. METHODS In our investigation of BRCA1 mutations among Chinese female patients in Hong Kong, BRCA1 mutations were found in 3.8% (CI: 1.3-8.8%) of 130 breast cancer patients. The prevalence was higher in a separate group of 56 early onset patients, aged<45 years, (8%, CI: 2.2-19.2). Most of the mutations were different from those reported in Caucasians. A deletion 589delCT was found in three unrelated patients, which may represent a common mutation. Similar prevalence of mutations was reported in Taiwan and Singapore Chinese. Other low-penetrant cancer predisposition genes may be important in the pathogenesis of the majority of breast cancers. CONCLUSIONS Although the epidemiology of breast cancer is different between Caucasians and Chinese, the prevalence of mutations in the high-penetrant cancer-predisposition gene of BRCA1 is comparable. It may indicate that the role of genetic contribution to breast cancer may be similar in the two ethnic groups and the difference in epidemiology may be contributed more heavily by environmental factors.
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Affiliation(s)
- N L Tang
- Department of Chemical Pathology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, SAR, Hong Kong, China.
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48
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Abstract
The Cambridge Healthtech Institute's Microarrays and Microchips conference was held in Tokyo, Japan, 4-5 June 2001.
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Affiliation(s)
- Y F Leung
- Dept of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, 3/F, 147K Argyle Street, Hong Kong, China
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49
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Abstract
BACKGROUND At least 1 million people worldwide have retinitis pigmentosa (RP), making it relatively common among the inherited forms of blindness. Mutations in many genes may cause RP. The most common known mutation, Pro347Leu in rhodopsin, is found in no more than about 1% of unrelated patients, implying the impracticality of a diagnostic test which would screen only for a few, common mutation sites. CONCLUSIONS Ongoing discovery and study of RP genes makes it feasible to consider a molecular diagnostic test which would screen coding regions of all known RP genes by a mutation detection method such as conformation-sensitive gel electrophoresis followed by sequencing. The parallel development of RP genetic knowledge and treatments such as gene therapy will make such tests both possible and necessary.
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Affiliation(s)
- K Y Yeung
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
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Abstract
AIM To determine the pattern of rhodopsin mutations in Chinese retinitis pigmentosa (RP) patients. METHODS The rhodopsin gene was examined in 101 RP patients and 190 controls from Hong Kong. RESULTS Three coding changes were identified: Pro347Leu, Ala299Ser, and 5211delC. Each protein sequence alteration was found in one patient. Ala299Ser also existed in two controls. CONCLUSION The C-terminal nonsense mutation may cause mis-sorting of rhodopsin protein. The finding of controls with Ala299Ser suggests this is only the third missense alteration reported that does not cause RP. The expected frequency of rhodopsin mutations in RP is <7% (2/101=2.0%, 95% confidence interval: 0.2%-7.0%).
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Affiliation(s)
- W M Chan
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
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