Kai Ma

Capital Medical University, Peping, Beijing, China

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Publications (10)6.86 Total impact

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    ABSTRACT: Objective To identify the possible association between C(-106)T polymorphism of the aldose reductase (ALR) gene and diabetic retinopathy (DR) in a cohort of Chinese patients with type 2 diabetes mellitus (T2DM).Methods From November 2009 to September 2010, patients with T2DM were recruited and assigned to DR group or diabetic without retinopathy (DWR) group according to the duration of diabetes and the grading of 7-field fundus color photographs of both eyes. Genotypes of the C(-106)T polymorphism (rs759853) in ALR gene were analyzed using the MassARRAY genotyping system and an association study was performed.Results A total of 268 T2DM patients (129 in the DR group and 139 in the DWR group) were included in this study. No statistically significant differences were observed between the 2 groups in the age of diabetes onset (P=0.10) and gender (P=0.78). The success rate of genotyping for the study subjects was 99.6% (267/268), with one case of failure in the DR group. The frequencies of the T allele in the C(-106)T polymorphism were 16.0% (41/256) in the DR group and 19.4% (54/278) in the DWR group (P=0.36). There was no significant difference in the C(-106)T genotypes between the 2 groups (P=0.40). Compared with the wild-type genotype, odds ratio (OR) for the risk of DR was 0.7 (95% CI, 0.38-1.3) for the heterozygous CT genotype and 0.76 (95% CI, 0.18-3.25) for the homozygous TT genotype. The risk of DR was positively associated with microalbuminuria (OR=4.61; 95% CI, 2.34-9.05) and insulin therapy (OR=3.43; 95% CI, 1.94-6.09).Conclusions Microalbuminuria and insulin therapy are associated with the risk of DR in Chinese patients with T2DM. C(-106)T polymorphism of the ALR gene may not be significantly associated with DR in Chinese patients with T2DM.
    Chinese Medical Sciences Journal 03/2014; 29(1):1-6.
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    ABSTRACT: Objective To identify the possible association between C(-106)T polymorphism of the aldose reductase (ALR) gene and diabetic retinopathy (DR) in a cohort of Chinese patients with type 2 diabetes mellitus (T2DM). Methods From November 2009 to September 2010, patients with T2DM were recruited and assigned to DR group or diabetic without retinopathy (DWR) group according to the duration of diabetes and the grading of 7-field fundus color photographs of both eyes. Genotypes of the C(-106)T polymorphism (rs759853) in ALR gene were analyzed using the MassARRAY genotyping system and an association study was performed. Results A total of 268 T2DM patients (129 in the DR group and 139 in the DWR group) were included in this study. No statistically significant differences were observed between the 2 groups in the age of diabetes onset (P=0.10) and gender (P=0.78). The success rate of genotyping for the study subjects was 99.6% (267/268), with one case of failure in the DR group. The frequencies of the T allele in the C(-106)T polymorphism were 16.0% (41/256) in the DR group and 19.4% (54/278) in the DWR group (P=0.36). There was no significant difference in the C(-106)T genotypes between the 2 groups (P=0.40). Compared with the wild-type genotype, odds ratio (OR) for the risk of DR was 0.7 (95% CI, 0.38-1.3) for the heterozygous CT genotype and 0.76 (95% CI, 0.18-3.25) for the homozygous TT genotype. The risk of DR was positively associated with microalbuminuria (OR=4.61; 95% CI, 2.34-9.05) and insulin therapy (OR=3.43; 95% CI, 1.94-6.09). Conclusions Microalbuminuria and insulin therapy are associated with the risk of DR in Chinese patients with T2DM. C(-106)T polymorphism of the ALR gene may not be significantly associated with DR in Chinese patients with T2DM.
    Chinese Medical Sciences Journal 01/2014; 29(1):1–6.
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    ABSTRACT: To investigate the association of diabetic self-management with the risk of diabetic retinopathy (DR) in patients with type 2 diabetes mellitus. Cross-sectional study. Recruited patients with type 2 diabetes mellitus in the Desheng community of urban Beijing between November 2009 and May 2011. All patients were surveyed using a standardized questionnaire and underwent detailed ophthalmic examination. Patients were classified into DR group or diabetic without retinopathy (DWR) group according to the grading of fundus color photographs using the Early Treatment of Diabetic Retinopathy Study (ETDRS) standard grading protocol. In the DR group, proliferative diabetic retinopathy (PDR) was further defined. The overall levels of diabetes self-management in the study population were assessed and compared for the differences between DR and DWR, PDR and NPDR groups. One thousand one hundred patients with type 2 diabetes mellitus were recruited. The prevalence of DR was 32.1% (353/1100) in the study population. Sixty-three percent (652/1035) of patients had glycated hemoglobin (HbA1c) level less than 7.0%. The majority of patients (85.4%, 916/1072) conducted a diet control, 77.3% (827/1070) exercised, 56.0% (609/1088) monitored blood glucose regularly, 56.8% (416/733) detected HbA1c more than once every six months, 71.7% (762/1062) had ophthalmologic examination after the diagnosis of diabetes mellitus, and 47.9% (525/1097) had mydriatic check-up. Increased risk of DR was associated with longer duration of diabetes (more than 10 years) (OR = 3.90, 95% CI:2.97-5.51, P < 0.05), higher HbA1c level of ≥ 7.0% (OR = 3.23, 95% CI:2.44-4.28, P < 0.05), insulin therapy (OR = 4.82, 95% CI:3.55-6.57, P < 0.05), male gender (OR = 1.41, 95% CI:1.08-1.84, P < 0.05), lower level of education (OR = 1.90, 95% CI:1.39-2.62, P < 0.05), lower monthly income (OR = 1.46, 95% CI:1.12-1.91, P < 0.05), lower obedience to diet control (OR = 1.72, 95% CI:1.22-2.43, P < 0.05), no exercise (OR = 1.42, 95% CI:1.04-1.94, P < 0.05), change of therapeutic protocol during the last five years (OR = 1.78, 95% CI:1.32-2.41, P < 0.05), and family history of diabetes (OR = 1.35, 95% CI:1.01-1.78, P < 0.05). Increased risk of PDR was associated with the diagnosis age of diabetes (OR = 0.92, 95% CI:0.89-0.95, P < 0.05), longer duration of diabetes (more than 10 years) (OR = 4.54, 95% CI:1.95-12.32, P < 0.05), and insulin therapy (OR = 4.85, 95% CI:2.34-10.90, P < 0.05). In the multifactor logistic regression model, male gender (OR = 2.21, 95% CI:1.57-3.11, P < 0.05), lower level of education (OR = 1.98, 95% CI:1.33-2.94, P < 0.05), lower monthly income (OR = 1.66, 95% CI:1.15-2.39, P < 0.05) ,longer duration of diabetes (more than 10 years) (OR = 2.46, 95% CI:1.77-3.41, P < 0.05) ,HbA1c ≥ 7.0% (OR = 2.24, 95% CI:1.64-3.07, P < 0.05) and insulin therapy (OR = 3.38, 95% CI:2.38-4.8, P < 0.05) were associated with higher risk of DR. The diagnosis age of diabetes (OR = 0.94, 95% CI:0.91-0.98, P < 0.05) and insulin therapy (OR = 3.49, 95% CI:1.47-8.27, P < 0.05) were associated with PDR. Higher risk of DR is associated with longer duration of diabetes,insulin therapy, higher HbA1c level, male gender, and lower level of education, whereas higher risk of DR is also associated with lower obedience to diet control and less exercise, which suggest that lower level of diabetic self-management increased the risk of DR.
    [Zhonghua yan ke za zhi] Chinese journal of ophthalmology 06/2013; 49(6):500-506.
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    ABSTRACT: To investigate the association between angiotensin converting enzyme (ACE) gene locus rs1799752 insertion/deletion (I/D) polymorphism and diabetic retinopathy (DR) in type 2 diabetes mellitus. Case-control study. Type 2 diabetes patients were recruited and assigned into DR group, which included proliferative diabetic retinopathy (PDR) group or diabetes without retinopathy (DWR) group. Volunteers without diabetes from the same community were recruited as the control group. PCR and agarose gel electrophoresis methods were adopted to determine the rs1799752 I/D polymorphism genotypes of the ACE gene. The frequency of genotypes and alleles was compared among the various groups. Four hundred and twelve diabetes patients: (207 subjects of DR, including 53 subjects of PDR and 205 subjects of DWR) and 97 non-diabetic control subjects were included in the study. The frequencies of the I and D alleles of ACE rs1799752 polymorphism were 54.1% and 45.9%, respectively, in the DR group, 52.8% and 47.2% in the PDR group, and 48.0% and 52.0% in the DWR group. There were no statistical differences between DR and DWR groups (χ(2) = 3.02, P > 0.05) or between PDR and DWR groups (χ(2) = 0.77, P > 0.05). Moreover, there were no statistical differences in the distribution of the ACE genotypes between DR group (II 25.1%, ID 58.0%, DD 16.9%) and DWR group (II 22.0%, ID 52.2%, DD 25.9%) (χ(2) = 4.92, P > 0.05) or between PDR group (II 20.7%, ID 64.2%, DD 15.1%) and DWR group (χ(2) = 3.19, P > 0.05). No statistical differences were found in the frequencies of the I and D alleles, and the distributions of I/D genotypes between diabetic group and the control group (χ(2) = 0.25, 4.98; P > 0.05). In the multiple regressions model including clinical factors such as the age of onset of diabetes, urinary albumin, insulin usage, creatinine, glycated hemoglobin, fast glucose, and the use of ACE inhibitor, no association was found between ACE gene polymorphism and DR (OR = 0.80, 95%CI: 0.59 - 1.09) or PDR (OR = 1.23, 95%CI: 0.78 - 1.93). There is no association between ACE rs1799752 gene insertion/deletion (I/D) polymorphism and DR in patients with type 2 diabetes mellitus.
    [Zhonghua yan ke za zhi] Chinese journal of ophthalmology 01/2013; 49(1):52-7.
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    ABSTRACT: To identify the disease-causing mutation in a family of Leber hereditary optic neuropathy (LHON). Clinical data and family information were collected. Peripheral venous blood was drawn from patients and family members who agreed to donate the blood samples. Genomic DNA was extracted from blood leukocytes. Three primary mitochondrial DNA (mtDNA) mutations, G3460A, G11778A, and T14484C were screened using a method of polymerase chain reaction (PCR) followed by direct sequencing. This 3-generation family had 14 members. Seven family members were affected, including 5 female patients and 2 male patients. Pedigree analysis showed maternal inheritance. Mutation analysis in 4 affected and 3 unaffected family members showed G11778A mutation in all 4 affected and 2 of the 3 unaffected individuals. G11778A mutation in mtDNA is the disease-causing mutation in this family of LHON. For the mutation carriers, early intervention may prevent or delay the onset of the disease.
    [Zhonghua yan ke za zhi] Chinese journal of ophthalmology 12/2011; 47(12):1080-3.
  • Xiu-fen Yang, Jun Xu, Kai Ma
    Chinese Medical Sciences Journal 09/2011; 26(3):194-6.
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    ABSTRACT: To investigate whether single nucleotide polymorphisms (SNPs) in the vascular endothelial growth factor (VEGF) gene are associated with diabetic retinopathy (DR) in a cohort of Chinese patients with type 2 diabetes mellitus (T2DM). A total of 268 patients with T2DM (129 with DR and 139 without DR) were recruited and enrolled in the study. Patients with T2DM were assigned to a DR group or a diabetic-without-retinopathy group, based on the duration of diabetes and grading of fundus images. Genotypes of eight SNPs in the VEGF gene (rs699947, rs833061, rs13207351, rs2010963, rs833069, rs2146323, rs3025021, and rs3025039) were analyzed using a mass-array genotyping system, and an association study was performed. After adjusting for covariates, a significant association of DR was observed with the homozygous genotype of the minor allele for promoter SNPs rs699947 (odds ratio (OR)=3.54, 95% confidence interval (CI): 1.12-11.19), rs833061 (OR=3.72, 95% CI: 1.17-11.85) and rs13207351 (OR=3.76, 95% CI: 1.21-11.71). A significant association of DR was also observed with haplotype ACA, as defined by minor alleles of promoter SNPs rs699947, rs833061, and rs13207351 (OR=1.52, 95% CI: 1.03-2.24), and haplotype GAA, as defined by SNPs rs2010963, rs833069, and rs2146323 (OR=1.62, 95% CI: 1.08-2.41). Our data suggest that polymorphisms in the promoter region of the VEGF gene increase the risk of DR in Chinese patients with T2DM.
    Molecular vision 01/2011; 17:3088-96. · 1.99 Impact Factor
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    ABSTRACT: We identified a large Chinese family with X-linked juvenile retinoschisis. The purpose of this study was to report the clinical findings of the family and to identify the genetic mutation by screening the retinoschisis 1 (RS1) gene. Family history was collected and all family members underwent routine ophthalmic examination. Venous blood was collected from family members and genomic DNA was extracted. The exons of RS1 were screened by PCR followed by direct sequencing and/or restriction enzyme digestion. The pedigree of interest was a four-generation family with 52 family members, including seven affected individuals. The proband was a 5-year-old boy showing highly elevated bullous retinoschisis with moderate vitreous hemorrhage in both eyes. Vitrectomy was performed in the left eye of the proband. Five affected males showed large peripheral retinoschisis in both eyes, either involving the macula or combined with foveal stellate cystic change. One of the affected family members showed only a foveal stellate cystic change in both eyes without periphery retinoschisis. Visual acuity of affected individuals ranged from hand motion to 0.4. The R213W mutation in exon 6 of RS1 was identified in all affected individuals, predicting an amino acid substitution of arginine to tryptophan at codon 213. Our data show that the R213W mutation in RS1 causes various severities of retinoschisis in a large Chinese family, providing further evidence for X-linked juvenile retinoschisis phenotypic variability.
    Molecular vision 01/2010; 16:1593-600. · 1.99 Impact Factor
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    ABSTRACT: A Chinese family with autosomal dominant central areolar choroidal dystrophy (CACD) was identified. The purpose of this study was to collect the clinical findings from the family and to identify the genetic entity by linkage analysis. Forty-three individuals from 3 generations of the family underwent ophthalmologic examinations, including best-corrected visual acuity, examination of the anterior segments, and inspection of the ocular fundus after pharmacologic mydriasis. Affected family members further underwent color vision test, color fundus photography, fluorescein angiography, automated perimetry, and electroretinography. The family was followed up for 30 months. Peripheral venous blood or buccal swabs were collected from each family member and genomic DNA was extracted. Linkage analysis was performed for candidate genes or loci using microsatellite markers. Seven family members in 3 continuous generations were diagnosed as having autosomal dominant CACD. The family showed progressive development of the disease, affecting both male and female. Age of onset of visual disturbances varied between 11 and 50 years. Phenotypic variability among affected individuals was apparent and ranged from relatively normal-appearing fundus with mild parafoveal pigment mottling to geographic atrophy of the macula. Fluorescein angiography showed hyperfluorescent parafoveal changes in early stage or well-demarcated area of chorioretinal atrophy with enhanced visibility of the residual underlying choroidal vessels in the late stage. Peripheral retina and visual fields were normal in affected individuals. Electroretinogram showed normal or mild reduction in the photopic amplitude. Eight candidate genes (STGD4, RCD1, peripherin/RDS, GUCA1A, RIMS1, UNC119, GUCY2D, and AIPL1) and two genetic loci (4p15.2 - 16.3, and 17p13) were excluded to be responsible for the disease by linkage analysis. The clinical findings of this Chinese family with CACD shared similarities with previously reported families of other ethnicities. Linkage analysis excluded the known genes and genetic loci, indicating genetic heterogeneity of the disease.
    Chinese medical journal 11/2009; 122(22):2686-90. · 0.90 Impact Factor
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    ABSTRACT: Variants in complement factor H (CFH), the hypothetical LOC387715, and the high-temperature requirement A-1 (HTRA1) genes have been reported to be associated with age-related macular degeneration (AMD). The purpose of this study was to investigate the association of reported common single-nucleotide polymorphisms (SNPs) in CFH, LOC387715, and HTRA1 with exudative AMD in a northern Chinese population. A cohort of 121 unrelated patients with exudative AMD and 132 control subjects were enrolled in this study. Genomic DNA was extracted from blood leukocytes. Genotyping for SNPs rs1061170:T>C in CFH (Y402H), rs10490924:G>T in LOC387715 (A69S), and rs11200638:G>A in the promoter of HTRA1 was performed using a polymerase chain reaction (PCR) method followed by allele-specific restriction enzyme digestion and direct sequencing. The Y402H variant in CFH was not associated with exudative AMD in our study population. Frequencies of Y402H was 10.3% in AMD cases and 8.0% in controls (p=0.353). Significant associations were detected for exudative AMD with SNPs rs10490924:G>T in LOC387715 (A69S), and rs11200638:G>A in the promoter of HTRA1. The risk T-allele frequency of rs10490924 in LOC387715 was 64.9% in cases versus 43.2% in controls (p<0.001). The odds ratio for risk of AMD was 1.56 (95% CI; 0.80-3.03) for the GT genotype and 5.45 (95% CI; 2.59-11.49) for the TT genotype. The A allele frequency of rs11200638 in the HTRA1 promoter was 67.8% in cases versus 42.4% in controls (p<0.001). The odds ratio was 2.75 (95% CI; 1.34-5.64) for the GA genotype and 7.90 (95% CI; 3.61-17.26) for the AA genotype. An odds ratio of 7.94 (95% CI; 3.49-18.04) was obtained for carriers with both TT genotype in LOC387715 and AA genotype in the HTRA1 promoter. Our data suggest that the LOC387715 and HTRA1 polymorphisms are associated with a higher risk of exudative AMD in northern Chinese. We found no association of CFH Y402H with exudative AMD. The low frequency of CFH Y402H variant was further confirmed in this study population.
    Molecular vision 02/2008; 14:1373-81. · 1.99 Impact Factor