Chi Pui Pang

Capital Medical University, Beijing, Beijing Shi, China

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Publications (184)583.26 Total impact

  • Article: Topical Cyclosporine in the Treatment of Allergic Conjunctivitis: A Meta-analysis.
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    ABSTRACT: PURPOSE: To assess the efficacy and safety of topical cyclosporine versus placebo in the treatment of allergic conjunctivitis. DESIGN: Systematic review and meta-analysis. PARTICIPANTS: Seven qualified studies incorporating 306 eyes of 153 patients were analyzed. METHODS: Searches of randomized controlled trials were conducted in MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform. MAIN OUTCOME MEASURES: We assessed the methodologic quality of individual included trials and performed meta-analyses using the random effects model if P<0.1 in the test for heterogeneity, or otherwise used the fixed effect model. We assessed scores of composite signs and symptoms, reduction in steroid eye drop use in steroid-dependent patients, and safety outcomes (i.e., stinging or burning sensation). RESULTS: At 2 weeks of follow-up or longer, evidence suggests a statistically significant improvement in the composite signs (standardized mean difference [SMD], -1.21; 95% confidence interval [CI], -1.80 to -0.62; I(2) = 71%) and symptoms (SMD, -0.84; 95% CI, -1.51 to -0.16; I(2) = 80%) after topical cyclosporine treatment for allergic conjunctivitis regardless of the dosage of treatment. There was a significant reduction (mean difference, -61.16; 95% CI, -101.61 to -20.72; I(2) = 58%) in the use of steroid eye drops in patients with steroid-dependent allergic conjunctivitis. Stinging or burning sensation (odds ratio, 2.56; 95% CI, 0.19-35.06; I(2) = 73%) was common in both the cyclosporine and placebo groups. CONCLUSIONS: This systematic review and meta-analysis suggests topical cyclosporine could be an effective and safe treatment method for allergic conjunctivitis. Further randomized controlled trials with larger sample sizes and standardized outcome measurements, follow-up periods, and cyclosporine concentrations are warranted to determine the short- and long-term efficacy and safety and the minimal effective dosage of topical cyclosporine for allergic conjunctivitis. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
    Ophthalmology 06/2013; · 5.45 Impact Factor
  • Article: Directing Adult Human Periodontal Ligament-Derived Stem Cells to Retinal Fate.
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    ABSTRACT: PURPOSE. To investigate the retinal fate competence of human postnatal periodontal ligament (PDL)-derived stem cells (PDLSC) through a directed differentiation mimicking mammalian retinogenesis. METHODS. Human teeth were collected from healthy subjects under 35 years old. Primary PDLSC were isolated by collagenase digestion and cultivated. PDLSC at passage 3 were cultured in the induction media containing Noggin (antagonist of bone morphogenic protein) and Dkk-1 (antagonist of Wnt/β-catenin signaling). Gene expression of neural crest cells, retinal progenitors and retinal neurons, including photoreceptors, was revealed by RNA analyses, immunofluorescence and flow cytometry. The neuronal-like property of differentiated cells in response to excitatory glutamate was examined by fluo-4-acetoxymethyl calcium imaging assay. RESULTS. Primary human PDLSC stably expressed marker genes of neural crest (Notch1, BMP2, Slug, Snail, nestin and Tuj1), mesenchymal stem cell (CD44, CD90 and vimentin) and embryonic stem cell (c-Myc, Klf4, Nanog and SSEA4). Under low attachment culture, PDLSC generated neurospheres expressing nestin, p75/NGFR, Pax6 and Tuj1 (markers of neural progenitors). When neurospheres were plated on matrigel-coated surface, they exhibited rosette-like outgrowth. They expressed eye field transcription factors (Pax6, Rx, Lhx, Otx2). By flow cytometry, 94% of cells were Pax6nuclearRx+, indicative of retinal progenitors. At prolonged induction, they expressed photoreceptor markers (Nrl, rhodopsin and its kinase) and showed significant responsiveness to excitatory glutamate. CONCLUSION. Primary human PDLSC could be directed to retinal progenitors with a competence of photoreceptor differentiation. Human neural crest-derived PDL is readily accessible and can be an ample autologous source of undifferentiated cells for retinal cell regeneration.
    Investigative ophthalmology & visual science 05/2013; · 3.43 Impact Factor
  • Article: A genome-wide meta-analysis identifies two novel loci associated with high myopia in the Han Chinese population.
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    ABSTRACT: High myopia, highly prevalent in the Chinese population, is a leading cause of visual impairment worldwide. Genetic factors play a critical role in the development of this visual disorder. Genome-wide association studies in recent years have revealed several chromosomal regions that contribute to its progression. To identify additional genetic variants for high myopia susceptibility, we used a genome-wide meta-analysis to examine the associations between the disease and 286 031 single-nucleotide polymorphisms (SNPs) in a combined cohort of 665 cases and 960 controls. The most significant SNPs (n = 61) were genotyped in a replication cohort (850 cases and 1197 controls), and 14 SNPs were further tested through genotyping in two additional validation cohorts (combined 1278 cases and 2486 controls). As a result of this analysis, four SNPs reached genome-wide significance (P < 2.0 × 10-7). The most significantly associated SNP, rs2730260 [overall P = 8.95 × 10-14; odds ratio (95% CI) =1.33 (1.23-1.44)], is located in the VIPR2 gene, which is located in the MYP4 locus. The other three SNPs (rs7839488, rs4395927 and rs4455882) in the same linkage disequilibrium block are located in the SNTB1 gene, with -P values ranging from 1.13 × 10-8 to 2.13 × 10-11. The VIPR2 and SNTB1 genes are expressed in the retina and the retinal pigment epithelium and have been previously reported to have potential functions for the pathogenesis of myopia. Our results suggest that variants of the VIPR2 and SNTB1 genes increase susceptibility to high myopia in Han Chinese.
    Human Molecular Genetics 02/2013; · 7.64 Impact Factor
  • Article: Role of B lymphoma Mo-MLV insertion region 1 in the oncogenic behavior of retinoblastomas.
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    ABSTRACT: This study investigated the relationship between B lymphoma Mo-MLV insertion region 1 (BMI-1)-a polycomb protein for stem cell self-renewal and proliferation-and the clinicopathological parameters of human retinoblastomas, including differentiation status and retinal tissue invasion, as well as the effects of BMI-1 on retinoblastoma Y79 cells. Thirty-four archived human retinoblastoma samples were recruited for BMI-1 immunohistochemistry. The percentage of BMI-1-expressing cells was scored by independent pathologists and the data were correlated with the clinical features. Y79 cells were transfected to overexpress or specifically inhibit BMI-1 for cell proliferation, propidium iodide cell cycle and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis analyses, multicellular sphere formation assay, and gene expression study. BMI-1 was widely expressed in human retinoblastomas. Higher percentages of BMI-1-expressing cells were selectively limited to undifferentiated tumors and those tumors undergoing invasion to the optic nerve and choroid. However, there was no difference in BMI-1 expression in retinoblastoma retinas with or without tumor invasion. In Y79 cells, BMI-1 stimulated cell proliferation and suppressed apoptosis with reduced p14ARF and p16INK4 expression, along with upregulation of proliferating cell nuclear antigens cyclin D1 and D2. In contrast, silencing BMI-1 reversed these changes. It also upregulated CHX10 and Rx, but not other retinal development-related genes, including nestin and neurofilament M. Our work indicates that BMI-1 might render important oncogenic property of retinoblastomas and it could be a therapeutic target for the cancer treatment.
    Molecular vision 01/2013; 19:561-74. · 2.20 Impact Factor
  • Article: No association of age-related maculopathy susceptibility protein 2/HtrA serine peptidase 1 or complement factor H polymorphisms with early age-related maculopathy in a Chinese cohort.
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    ABSTRACT: Single nucleotide polymorphisms (SNPs) of age-related maculopathy susceptibility protein 2/HtrA serine peptidase 1 (ARMS2/HTRA1) and complement factor H (CFH) have been reported to be associated with age-related macular degeneration (AMD). The purpose of this study was to investigate the association of ARMS2/HTRA1 and CFH SNPs with early age-related maculopathy (ARM) in a Han Chinese cohort. The cohort consisted of 315 unrelated subjects, including 158 patients with early ARM and 157 recruited controls. Early ARM was diagnosed and graded according to the Age-Related Eye Disease Study criteria. Four SNPs in ARMS2/HTRA1 and six SNPs in CFH previously reported to be associated with AMD were genotyped using TaqMan genotyping assays. Logistic regression implemented with the R statistical language was used for association analysis. None of the ARMS2/HTRA1 and CFH SNPs showed any significant association with early ARM (all p>0.453), with the odds ratios ranging from 0.88 to 1.17. None of the SNPs were associated with unilateral or bilateral early ARM or any grade of early ARM (all p>0.249). The association of ARMS2/HTRA1 and CFH SNPs in early ARM was not detected in our cohort. The findings in the current study indicated that the effects of ARMS2/HTRA1 and CFH in early ARM could be much lower compared to those in AMD.
    Molecular vision 01/2013; 19:944-954. · 2.20 Impact Factor
  • Article: Diversified clinical presentations associated with a novel sal-like 4 gene mutation in a Chinese pedigree with Duane retraction syndrome.
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    ABSTRACT: To determine the underlying genetic cause of Duane retraction syndrome (DRS) in a non-consanguineous Chinese Han family. Detailed ophthalmic and physical examinations were performed on all members from a pedigree with DRS. All exons and their adjacent splicing junctions of the sal-like 4 (SALL4) gene were amplified with polymerase chain reaction and analyzed with direct sequencing in all the recruited family members and 200 unrelated control subjects. Clinical examination revealed a broad spectrum of phenotypes in the DRS family. Mutation analysis of SALL4 identified a novel heterozygous duplication mutation, c.1919dupT, which was completely cosegregated with the disease in the family and absent in controls. This mutation was predicted to cause a frameshift, introducing a premature stop codon, when translated, resulting in a truncated SALL4 protein, i.e., p.Met640IlefsX25. Bioinformatics analysis showed that the affected region of SALL4 shared a highly conserved sequence across different species. Diversified clinical manifestations were observed in the c.1919dupT carriers of the family. We identified a novel truncating mutation in the SALL4 gene that leads to diversified clinical features of DRS in a Chinese family. This mutation is predicted to result in a truncated SALL4 protein affecting two functional domains and cause disease development due to haploinsufficiency through nonsense-mediated mRNA decay.
    Molecular vision 01/2013; 19:986-994. · 2.20 Impact Factor
  • Article: Associations of the C2-CFB-RDBP-SKIV2L Locus with Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy.
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    ABSTRACT: PURPOSE: To investigate the associations of the C2-CFB-RDBP-SKIV2L region with neovascular age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV). DESIGN: Cross-sectional, case-control association study. PARTICIPANTS: A Chinese case-control group of 200 neovascular AMD patients, 233 PCV patients, and 275 control subjects. METHODS: An association analysis was performed of the C2-CFB-RDBP-SKIV2L locus with both neovascular AMD and PCV in a Chinese population using 19 haplotype-tagging single nucleotide polymorphisms (SNPs) and 6 previously reported SNPs across the C2-CFB-RDBP-SKIV2L region. All SNPs were genotyped using the TaqMan genotyping technology (TaqMan; Applied Biosystems [ABI], Foster City, CA). MAIN OUTCOME MEASURES: Allele and haplotype frequencies of the SNPs in the C2-CFB-RDBP-SKIV2L region. RESULTS: The SKIV2L SNPs rs429608 and rs453821 were significantly associated with neovascular AMD (P = 7.39×10(-5); odds ratio [OR], 0.22; 95% confidence interval [CI], 0.10-0.50; and P = 0.001; OR, 0.38; 95% CI, 0.21-0.70, respectively), whereas borderline associations were detected for C2 rs547154 (P = 0.002) and RDBP rs760070 (P = 0.003). Conditional haplotype analysis revealed that SKIV2L rs429608 could account fully for the global haplotype association identified in this region. The association of SKIV2L rs429608 with neovascular AMD remained significant after adjusting for CFH rs800292 and HTRA1 rs11200638. No individual SNP or haplotype was associated significantly with PCV. CONCLUSIONS: In this concurrent investigation of the associations of the entire C2-CFB-RDBP-SKIV2L region with neovascular AMD and PCV, the results suggested that SKIV2L is a likely causal gene for neovascular AMD, conferring a significant protective effect independent of CFH and HTRA1. These data do not support a significant role of this region in PCV, suggesting different molecular mechanisms between neovascular AMD and PCV. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
    Ophthalmology 12/2012; · 5.45 Impact Factor
  • Article: Quantification and Structure Elucidation of in vivo Bevacizumab modification in rabbit vitreous humor after intra-vitreal injection.
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    ABSTRACT: Off-label and intra-vitreal use of bevacizumab, a recombinant immunoglobulin against VEGF, has been practiced widely for ophthalmic treatments. However, longitudinal data of its intra-vitreal status is unavailable due to a lack of reliable methods for bevacizumab determination. Thus its pharmacokinetics and pharmacodynamics are uncertain. We developed and validated a high performance liquid chromatographic method to determine bevacizumab in vitreous humor and utilized a novel strategy to assess in vivo temporal binding changes by affinity chromatography. Mass spectrometry and tandem mass spectrometry detection were used for structural evaluation. The coefficient of variation (CV) for intra-batch imprecision varied from 0.5 - 14.3% and for inter-batch imprecision from 1.9 - 11.6%. The linearity was over 0.9982, lower limit of quantification 1.95 μg, recoveries over 95%, and accuracy between 91-111% over the range of 1.95 - 250 μg bevacizumab in 100 μl vitreous humor. Blank vitreous humor showed no interference peak. It was stable at room temperature for 5 hours. Bevacizumab elimination in the vitreous followed first order kinetic with half life as 5.7 days and elimination rate as 0.1221 day-1. Peptide mapping and tandem mass spectrometry revealed structural modifications of the in vivo bevacizumab mainly on the heavy chain in both variable and constant regions 7 days after intra-vitreal injection. Minor changes were also discovered on the light chain. Affinity chromatography showed significant affinity changes in samples 21 days after intra-vitreal injection. The changes were consistent with structural modifications as found in endothelial cells migration assays results. In conclusion, we have established a robust chromatographic method for determination of bevacizumab and strategies with affinity chromatography and molecular mass detection that revealed bevacizumab structural and possible functional changes in vitreous.
    Molecular Pharmaceutics 10/2012; · 4.78 Impact Factor
  • Article: Nicotine alters microRNA expression and hinders human adult stem cell regenerative potential.
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    ABSTRACT: Adult stem cells are critical for the healing process in regenerative medicine. However, cigarette smoking inhibits stem cell recruitment to tissues and delays the wound healing process. This study investigated the effect of nicotine, a major constituent in the cigarette smoke, on the regenerative potentials of human mesenchymal stem cells (MSC) and periodontal ligament-derived stem cells (PDLSC). The cell proliferation of 1.0 μM nicotine-treated MSC and PDLSC was significantly reduced when compared to the untreated control. Moreover, nicotine also retarded the locomotion of these adult stem cells. Furthermore, their osteogenic differentiation capabilities were reduced in the presence of nicotine as evidenced by gene expression (RUNX2, ALPL, BGLAP, COL1A1 and COL1A2), calcium deposition and alkaline phosphatase activity analyses. In addition, the microRNA profile of nicotine-treated PDLSC was altered; suggesting microRNAs might play an important role in the nicotine effects on stem cells. This study provided the possible mechanistic explanations on stem cell-associated healing delay in cigarette smoking.
    Stem cells and development 10/2012; · 4.15 Impact Factor
  • Article: Tracking retinal microgliosis in models of retinal ganglion cell damage.
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    ABSTRACT: Purpose. To investigate the longitudinal profiles of microgliosis after optic nerve injury induced by optic nerve crush and acute elevation of intraocular pressure (IOP). Methods. A confocal scanning laser ophthalmoscope was used to image the retinal microglia of the CX3CR1(GFP/+) transgenic mice in vivo at baseline, 3 days and then weekly for 4 weeks after optic nerve crush (n = 3), and after elevating the IOP to 110 mm Hg for 30 (n = 3) or 60 (n = 3) minutes. Results. After optic nerve crush, the density of microglia increased by 2.43 ± 0.19-fold at week 1 and then gradually declined with 2.04 ± 0.24-, 1.69 ± 0.25-, and 1.29 ± 0.11-fold increases at week 2, 3, and 4, respectively. Microgliosis followed a similar pattern after acute IOP elevation and the increase in microglia was associated with the duration of IOP elevation. There were 1.35 ± 0.17- and 2.03 ± 0.08-fold increases in microglia at week 1, and 1.15 ± 0.11- and 1.11 ± 0.10-fold increases at week 4, after 30 and 60 minutes of acute IOP elevation, respectively. The morphology of microglia changed from ramified to ameboid form in 1 week, and then returned to ramified form in the subsequent weeks. There was a significant negative association between the number of surviving retinal ganglion cells (RGCs) and the extent of microgliosis during the follow-up period (R(2) = 0.72, P = 0.004). Conclusions. Longitudinal in vivo imaging of the retinal microglia can provide an effective approach to study microgliosis and its association with RGC degeneration.
    Investigative ophthalmology & visual science 08/2012; 53(10):6254-62. · 3.43 Impact Factor
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    Article: In vitro amyloid aggregate forming ability of TGFBI mutants that cause corneal dystrophies.
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    ABSTRACT: We investigated the in vitro amyloid aggregation ability of TGFBI (transforming growth factor beta-induced) mutants causing corneal dystrophies (CDs). Peripheral blood samples were collected from 42 unrelated Chinese CD patients and 185 healthy subjects for mutation screening in all TGFBI coding exons and flanking introns. The expression vector pCMV6_TGFBI containing wild-type, Arg-124, or Arg-555 mutations was transfected to HEK293 cells. Cell-free media was incubated with amyloid-beta (Aβ) (1-40) peptides with or without a chemical osmolyte, trimethylamine N-oxide (TMAO), for different time intervals. After ultracentrifugation, protein aggregates were analyzed by denatured gel electrophoresis. The effect of TMAO on chemical and morphological properties of Aβ aggregation was examined. TGFBI sequencing analysis showed c.Arg124Cys in all 6 lattice CD patients, c.Arg555Glu in all 11 granular CD type 1 patients, and c.Arg124His in 22 of 25 granular CD type 2 patients. Double heterozygosity (c.307-308delCT and c.Arg124His) was detected in one GCD2 patient. After transfection, cell-free media containing Arg-124 TGFBIp led to Aβ aggregation within 12 hours, whereas wild-type and Arg-555 mutant displayed aggregation after 24 hours. Western blot and Congo red binding assays showed that TMAO dose-dependently suppressed Arg-124-induced Aβ aggregation. Transmission electron microscopy showed that TMAO reduced the fibrillar aggregates caused by Aβ and c.124R > H mutated TGFBIp. TGFBI sequence heterogeneity was observed in Chinese CD patients. TMAO reduced amyloid aggregation caused by Arg-124 mutants, which suggests a potential chemical-based treatment for CDs.
    Investigative ophthalmology & visual science 07/2012; 53(9):5890-8. · 3.43 Impact Factor
  • Article: Association of C2 and CFB polymorphisms with anterior uveitis.
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    ABSTRACT: Association of rs800292 (I62V) in the complement factor H (CFH) gene with anterior uveitis (AU) was identified in our previous study. We proceeded to investigate whether polymorphisms of two tightly linked genes in the complement pathway, complement component 2 (C2) and complement factor B (CFB), are associated with AU. Five single-nucleotide polymorphisms (SNPs), rs1048709, rs537160, rs4151657, rs2072633 in CFB, and rs3020644 in C2, were examined using genotyping assays in 98 Chinese AU patients and 291 unrelated controls. Adjustments and stratifications were given for sex, clinical manifestations, and HLA-B27 status. There were significant increases in the frequency of A allele and AA homozygosity for CFB-rs1048709 in AU patients compared with that of controls (P value after Bonferroni correction [P(corr)] = 2.67 × 10⁻⁴, P(corr) = 0.001, respectively). No association was found between AU and the other four SNPs after adjustment for multiple testing. Logistic regression analysis showed none of the 5 SNPs had significant interaction with sex. Stratified analyses showed that only rs1048709 was significantly associated with AU in HLA-B27-positive patients but not in HLA-B27-negative patients. No association was found in the 5 tested SNPs with clinical manifestations. A haplotype block across CFB (AATA) was significantly predisposed to AU with increased risk of 1.97 (P(corr) = 0.0005). Additive effect of CFB-rs1048709 and CFH-rs800292 was identified with an odds ratio of 7.48. Our results revealed an association between AU and CFB-rs1048709. The influence on AU might differ depending on HLA-B27 status. The joint effect in CFB and CFH strengthens the concept that the complement system plays an important role in the pathogenesis of AU.
    Investigative ophthalmology & visual science 06/2012; 53(8):4969-74. · 3.43 Impact Factor
  • Article: Long-term survival and axonal regeneration of retinal ganglion cells after optic nerve transection and a peripheral nerve graft.
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    ABSTRACT: To investigate the effect of autologous peripheral nerve grafting on retinal ganglion cell survival and axonal regeneration after an injury, the optic nerve of adult Sprague-Dawley rats was transected and grafted with an autologous peripheral nerve from the peroneal branch of the left sciatic nerve. The numbers of both surviving and axon-regenerating retinal ganglion cells were determined at different times after surgery. The majority of retinal ganglion cells were rapidly lost within 3 weeks, followed by a slow and protracted phase of cell loss until the end of the 6-month study. FluoroGold-labelled axon-regenerating retinal ganglion cells were first detected by 2 weeks, followed by a period of high axonal regeneration that peaked at 8 weeks and accounted for over 35% of the total surviving retinal ganglion cells. However, retinal ganglion cells with regenerated axons eventually died. Our data thus indicate that axonal regeneration in the autologous peripheral nerve graft is insufficient to sustain the long-term survival of axotomized retinal ganglion cells.
    Neuroreport 06/2012; 23(11):692-7. · 1.66 Impact Factor
  • Article: Differentiation of exudative age-related macular degeneration and polypoidal choroidal vasculopathy in the ARMS2/HTRA1 locus.
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    ABSTRACT: differentiate the associations of exudative age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) with the ARMS2/HTRA1 locus. The entire ARMS2 sequence was sequenced and HTRA1 rs11200638 genotyped in 568 unrelated Chinese individuals: 156 exudative AMD patients, 164 PCV patients, and 248 controls. A meta-analysis was performed to examine the effects of rs10490924 and rs11200638 at the ARMS2/HTRA1 locus in PCV. In total, 31 polymorphisms in ARMS2 were identified. Significant associations with both exudative AMD and PCV were observed in 11 of them and HTRA1 rs11200638, with different genotypic distributions between exudative AMD and PCV (P < 0.001). After adjusting for rs11200638, ARMS2 rs10490924 remained significantly associated with exudative AMD (P = 0.011), but not with PCV (P = 0.077). Meta-analysis showed consistent allelic associations of rs10490924 and rs11200638 with PCV in different study populations. There is a strong and consistent association of the ARMS2/HTRA1 locus with both exudative AMD and PCV, suggesting the two disorders share, at least partially, similar molecular mechanisms. Different effect sizes indicate the existence of additional genetic and environmental factors affecting them to different extents.
    Investigative ophthalmology & visual science 04/2012; 53(6):3175-82. · 3.43 Impact Factor
  • Article: Heterozygous familial hypercholesterolemia in Hong Kong Chinese. Study of 252 cases.
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    ABSTRACT: BACKGROUND: Earlier studies reported that Chinese subjects with heterozygous familial hypercholesterolemia (heFH) living in Mainland China or in Western countries had lower plasma low-density lipoprotein cholesterol (LDL-C) levels and lower prevalence of xanthomata or coronary heart disease (CHD) than Caucasians with heFH and a greater proportion went unrecognized. We characterized the features of Hong Kong Chinese with heFH identified by cascade screening. METHODS: Potential probands with primary hypercholesterolemia manifesting total cholesterol (TC) greater than 7.5mmol/L or LDL-C greater than 4.9mmol/L were selected from a lipid clinic in a public hospital in Hong Kong. After screening of 132 unrelated potential probands and their relatives, 252 subjects from 87 pedigrees were clinically diagnosed as heFH. RESULTS: In 252 heFH patients (mean age 37±17 years, 100 males), the plasma TC and LDL-C were 9.1±1.5mmol/L and 7.2±1.5mmol/L, respectively. In subjects aged ≥18years, the prevalence of xanthomata and corneal arcus was 40.6% and 81.2% in males, and 54.8% and 66.9% in females respectively. The overall incidence of CHD was 9.9% in males and 8.5% in females in patients aged over 18years with CHD history available. Multiple logistic regression analysis showed that advanced age and presence of xanthelasmata were significantly associated with increased risk of CHD. CONCLUSIONS: This study is the first to characterize the epidemiologic features of heFH in Hong Kong Chinese, which provides new population-specific information on this genetic disorder. This may presage how this condition will manifest in China in the near future.
    International journal of cardiology 03/2012; · 7.08 Impact Factor
  • Article: Interactive effects of ATOH7 and RFTN1 in association with adult-onset primary open-angle glaucoma.
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    ABSTRACT: Genome-wide association studies have shown association of the atonal homolog 7 (ATOH7) and raftlin lipid raft linker 1 (RFTN1) genes with glaucoma-related optic disc parameters. ATOH7 and RFTN1 sequence variations were investigated in patients with primary open-angle glaucoma (POAG) and their relationships with vertical cup-to-disc ratio (VCDR) and central corneal thickness (CCT) were determined. In 289 unrelated controls and 142 patients with adult-onset POAG, including 117 with high-tension glaucoma (HTG) and 25 with normal-tension glaucoma (NTG), the single exon of ATOH7 was sequenced by direct sequencing. Additional single-nucleotide polymorphisms (SNP) at upstream ATOH7 (rs1900004 and rs3858145) and an RFTN1 SNP (rs690037) were genotyped. Quantitative trait and disease associations were analyzed by linear and logistic regression respectively, controlling for sex and age. ATOH7 rs61854782 was associated with VCDR (P = 0.004) in controls and RFTN1 rs690037 was associated with CCT in combined POAG (HTG+NTG; P = 0.026). No coding mutation was detected in POAG, and no SNP was associated with POAG (P between 0.441 and 0.996). However, ATOH7 rs3858145 showed significant interaction with RFTN1 rs690037 in NTG and combined POAG (P = 0.026 and 0.013 respectively). ATOH7 rs3858145 GG combined with RFTN1 rs690037 TT conferred risk for glaucoma in HTG, NTG, and combined POAG (odds ratio = 2.11, 8.44, and 2.69, respectively). Coding mutations of ATOH7 were unlikely to be involved in POAG. But combination of ATOH7 and RFTN1 SNPs increased risk to POAG, indicating their diversified effects in the complex genetics of glaucoma.
    Investigative ophthalmology & visual science 02/2012; 53(2):779-85. · 3.43 Impact Factor
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    Article: A novel PAX6 deletion in a Chinese family with congenital aniridia.
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    ABSTRACT: To identify a disease-causing paired box 6 (PAX6) gene mutation in a Chinese family affected by autosomal dominant congenital aniridia. All participants in the study, including the aniridia family and 100 unrelated senile cataract controls, received a comprehensive ophthalmic examination. Genomic DNA was extracted from their whole blood. Mutation screen in all exons and their adjacent splicing junctions of PAX6 was performed by direct sequencing of polymerase chain reaction (PCR) products. PCR products of heterozygous mutation were further cloned into T-vectors and confirmed by sequencing. Multiple alignments were performed using ClustalX to compare PAX6 protein sequences among vertebrates. MicroRNA binding sites were predicted by TargetScan. A novel heterozygous PAX6 deletion c.1251_1353del103 (p.Pro418Serfs*87) affecting exon 14 and the 3'-untranslated-region (3'-UTR) was identified in the congenital aniridia family. The mutation was exclusively observed in all affected family members but not in any unaffected family member or unrelated control. Bioinformatics analysis showed that the deletion led to remarkable changes of the PAX6 protein, including a frameshift, changes of protein sequence, and a COOH-terminal extension. Multiple alignments showed that the affected region of PAX6 shared high sequence identity (100%) among its vertebrate orthologs. The COOH-terminal extension might also affect microRNA binding sites in the 3'-UTR as predicted by TargetScan. In the current study we reported a novel PAX6 deletion resulting in an abnormal PAX6 COOH-terminal extension in the Chinese family affected by aniridia. Our findings thus add to the mutation spectrum of PAX6.
    Molecular vision 01/2012; 18:989-95. · 2.20 Impact Factor
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    Article: Endophenotyping reveals differential phenotype-genotype correlations between myopia-associated polymorphisms and eye biometric parameters.
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    ABSTRACT: To investigate the association with ocular biometric parameters in myopia-associated single nucleotide polymorphisms (SNPs) of the gap junction protein delta 2 (GJD2), insulin-like growth factor-1 (IGF1) and hepatocyte growth factor (HGF) genes in two geographically different Chinese cohorts. In 814 unrelated Han Chinese individuals aged above 50 years including 362 inland residents and 432 island dwellers, comprehensive ophthalmic examinations were performed. Three SNPs, including GJD2 rs634990, IGF1 rs6214, and HGF rs3735520, were genotyped. Genetic association with ocular biometric parameters was analyzed in individual cohorts, using linear regression controlled for sex and age. Common associations shared by the two cohorts were revealed by meta-analysis. Meta-analysis showed that GJD2 rs634990 alone was not associated with any biometric parameters (adjusted p>0.645). The T allele of IGF1 rs6214 was specifically associated with thicker lens (β±SE=0.055±0.022, adjusted p=0.034). The A allele of HGF rs3735520 was associated with longer vitreous chamber depth (β±SE=0.143±0.060, adjusted p=0.050). Significant interaction between HGF rs3735520 and GJD2 rs634990 was found in association with axial length and vitreous chamber depth (adjusted p=0.003 and 0.033, respectively), and possibly with spherical error (adjusted p=0.056). Our endophenotyping analysis showed differential association between selected myopia-associated genes and ocular biometric parameters in our Chinese cohorts, which may underline substantial but diversified effects of these genes and their interaction on the development of eye structure and etiology of myopia.
    Molecular vision 01/2012; 18:765-78. · 2.20 Impact Factor
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    Article: Genetic associations in polypoidal choroidal vasculopathy: a systematic review and meta-analysis.
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    ABSTRACT: To investigate the genetic associations of polypoidal choroidal vasculopathy (PCV), the genetic difference between PCV and age-related macular degeneration (AMD), and the genotype-phenotype correlation of PCV. A systematic review and meta-analysis were performed. Published articles about genetic associations of PCV identified from a literature search were reviewed. The following data from individual studies were extracted and analyzed: 1) comparison of genetic polymorphisms between PCV and controls; 2) comparison of genetic polymorphisms between PCV and AMD; and 3) comparison of phenotypes between different genotype groups. A total of 33 articles fulfilled the inclusion criteria. With meta-analyses, variants in four genes were found to be significantly associated with PCV: LOC387715 rs10490924 (n=9, allelic odds ratio [OR]=2.27, p<0.00001), HTRA1 rs11200638 (n=4, OR=2.72, p<0.00001), CFH rs1061170 (n=4, OR=1.72, p<0.00001), CFH rs800292 (n=5, OR=2.10, p<0.00001), and C2 rs547154 (n=3, OR=0.56, p=0.01). LOC387715 rs10490924 was the only variant showing a significant difference between PCV and wet AMD (n=5, OR=0.66, p<0.00001). The risk genotypes of rs10490924 were associated with larger lesion size, greater chance of vitreous hemorrhage, and worse therapeutic response in PCV. LOC387715 rs10490924 was associated with PCV and its clinical manifestations, and showed a discrepant distribution between PCV and AMD. Variants in HTRA1, CFH, and C2 were also associated with PCV.
    Molecular vision 01/2012; 18:816-29. · 2.20 Impact Factor
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    Article: SNP rs1533428 at 2p16.3 as a marker for late-onset primary open-angle glaucoma.
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    ABSTRACT: To investigate the associations between gene variants in cholesterol 24S-hydroxylase (CYP46A1), LIM homeobox transcription factor 1-beta (LMX1B), plexin domain containing 2 (PLXDC2), toll-like receptor 4 (TLR4), transmembrane and tetratricopeptide repeat containing 2 (TMTC2), zona pellucida glycoprotein 4 (ZP4), chromosome 2p16.3, and primary open-angle glaucoma (POAG). We studied 462 POAG patients and 577 controls from three cohorts (Hong Kong, Shantou, and Beijing, China). Twelve single-nucleotide polymorphisms (SNPs) were genotyped in the Hong Kong cohort using TaqMan genotyping assay. Significant associations were validated in the Shantou and Beijing cohorts. Association of POAG with TLR4 rs7037117, in a recessive model, was identified in the Hong Kong and Shantou cohorts (both southern Chinese, p(rec)=0.0019) but not the Beijing cohort (northern Chinese). rs1533428 at chromosome 2p16.3 showed a consistent trend of age-specific association in all three cohorts. Genotypes TT + CT conferred a 2.16 fold of significantly increased risk to late-onset POAG (p(dom)=0.00025), but no significant risk to POAG of younger ages of onset in the combined cohort. A joint effect was found between rs7037117 and rs1533428, with carriers of both higher-risk genotypes having a 4.53 fold of increased disease risk (p=0.00028). Our study reveals discrepant association patterns of 12 candidate SNPs in 7 genes/loci with POAG in Chinese, provides positive replications for POAG markers rs1533428 at 2p16.3 and TLR4 rs7037117, and suggests that rs1533428 is a putative risk variant for late-onset POAG. The identification of an age-specific association between rs1533428 and late-onset POAG highlights a new genotype-phenotype association in POAG. Further studies are warranted to confirm the age-specific association.
    Molecular vision 01/2012; 18:1629-39. · 2.20 Impact Factor

Institutions

  • 2013
    • Capital Medical University
      Beijing, Beijing Shi, China
  • 1998–2013
    • The Chinese University of Hong Kong
      • • Department of Ophthalmology and Visual Sciences
      • • Department of Chemical Pathology
      Hong Kong, Hong Kong
  • 2007–2012
    • Shantou University
      Shantou, Guangdong Sheng, China
  • 2008
    • Government of the People's Republic of China
      Beijing, Beijing Shi, China
  • 2006
    • Zhejiang University
      • School of Medicine
      Hangzhou, Zhejiang Sheng, China