Linkage analysis of candidate genes and gene-gene interactions in chinese hypertensive sib pairs.
(41/13273)
Previous studies of hypertension in humans and experimental animal models have identified a number of candidate genes that have since been implicated as possibly contributing to essential hypertension. Among them are the genes encoding angiotensinogen, renin, the beta- and gamma-subunits of the epithelial sodium channel (beta/gamma-ENaC), alpha-adducin, and kallikrein (KLK). To examine the role of possible contribution of these genes in ethnic Chinese, as well as the epistatic interaction among them, we studied a large cohort of hypertensive sib pairs from China. DNA samples from 310 concordant affected sibling pairs with hypertension were tested for linkage with the use of excess allele-sharing algorithms based on genotyping with highly informative GT-repeat microsatellite markers localized in the immediate vicinity of the genes encoding angiotensinogen, renin, beta- and gamma-ENaC, alpha-adducin, and KLK. Affected sib pair analysis conducted according to 3 different methods (Statistical Analysis for Genetic Epidemiology [S.A.G.E. ]/SIBPAL, MAPMAKER/SIBS, and affected pedigree member [APM] methods) revealed no evidence for linkage of any of these genes to primary hypertension in the population studied. Moreover, 2-locus sib pair linkage analyses to test for gene-gene interactions among each possible pair of candidate genes failed to yield any statistically significant results. Our findings provide no support for a significant contribution of the angiotensinogen, renin, beta/gamma-ENaC, alpha-adducin, or KLK genes, alone or in concert, to the pathogenesis of essential hypertension among Chinese. Our results emphasize the possible role of ethnic differences for complex disease genetics, as well as the need for large, well-characterized investigations. (+info)
Clinical epidemiologic characteristics of 430 cases of gallbladder cancer.
(42/13273)
OBJECTIVE: To make clear the incidence, clinical characteristics and possible regional difference of gallbladder cancer in China. METHODS: A total of 430 cases of gallbladder cancer from 28 hospitals between 1986-1996 were reviewed, according to a standard protocol called "the clinical epidemiological list of gallbladder cancer". RESULTS: The incidence of gallbladder cancer was higher in the females than in the males. There was significant difference in the incidence between the north and south of China, and between the mountain area and flatlands. Gallbladder cancer accounted for 1.6% of bile tract disease in the same period. Gallstones were found in about 50% of the cases of gallbladder cancer. The clinical symptoms included abdominal pain, ictus, etc. The major pathohistologic type was adenocarcinoma, and 58% of tumors were localized in the whole gallbladder. Metastasis occurred mainly along the biliary tract or directly to the bed of gallbladder and liver. Ultrasonography and CT were useful to diagnosis. The positive imaging diagnostic rate was higher in 1991-1996 than in 1986-1990 P < 0.05) [corrected]. The rate of operative resection was 100% for stage I and II disease, 75% for stage III and IV, and significantly lower for stage V (P < 0.05). The 3-year survival rate in patients with stage I or II disease was significantly higher than that in those with terminal cancer (P < 0.05). CONCLUSIONS: There is specific populational, time and regional difference in the distribution of gallbladder cancer. Ultrasonography and CT are the most important diagnostic methods. Early diagnosis and early radical resection are the key to increasing the 5-year survival rate. (+info)
Genetic heterogeneity for familial hypertrophic cardiomyopathy in Chinese: analysis of six Chinese kindreds.
(43/13273)
OBJECTIVE: Familial hypertrophic cardiomyopathy (FHCM) is a primary myocardial disease characterized by unexplained ventricular hypertrophy. The application of the techniques of reverse genetics has identified at least five chromosomal loci as the major causes for FHCM in diverse ethnic populations, suggesting substantial genetic heterogeneity for FHCM. Recently, the defective gene loci of two Chinese families with FHCM have been mapped to chromosome 11 and 14q1, respectively. For further understanding of the molecular basis of FHCM in Chinese, we analyzed the linkage between four other Chinese kindreds and DNA markers from chromosome 14q1. METHODS: Six unrelated Chinese families with FHCM, including two previously reported, were studied. Totally 90 family members were included for analysis. DNA from 80 individuals was extracted and polymerase chain reactions were performed using the primers designed according to the sequences derived from the alpha and beta myosin heavy chain gene. Totally four polymorphisms were studied, including three polymorphic microsatellite sequences and one single strand conformation polymorphism. Genetic linkage analysis were performed using the Linkage program. RESULTS: In the six studied families, 39 of the 90 family members were found to be affected diagnosed either by echocardiography or by clinical evaluation. The pattern of inheritance in all six studied families was most consistent with an autosomal dominant trait with a high degree of penetrance. Genetic linkage analysis using polymorphisms on the alpha and beta MHC genes showed a combined maximal lod score of 6.2 for trinucleotide repeat polymorphism AMHC-I 15 at theta = 0.00 for three studied families without recombination. Exclusion of linkage to the chromosome 14q1 location was noted in two of three other families with the maximal lod score of -2 or less. CONCLUSIONS: These results provide further evidence that FHCM in Chinese is genetically heterogeneous. Chromosome 14q1 locus, probably the beta myosin heavy chain gene, is important as the molecular basis for FHCM in Chinese. (+info)
Alveolar echinococcosis in China.
(44/13273)
DATA SOURCES: All reference data originated from related Chinese- or English-language literature in Chinese journals. STUDY SELECTION: Twenty-three original articles published in 1992-1996 were selected according to the stated purpose and 9 of them were written by myself. DATA EXTRACTION: The present paper dealt with 5 subtopics, i.e. epidemiology, parasitology, pathology, diagnosis, treatment and prognosis. RESULTS: Five hundred and eighty-four patients with alveolar echinococcosis (AE) have been reported from 7 provinces or autonomous regions. Human infection rate was 19.2% or 2.8%, and the morbidity was 2.4%-5.0%. The intermediate hosts of Echinococcus multilocularis included 7 species of rodents and 3 species of livestocks, and the final hosts of that were fox, dog or wolf. Diagnosis of AE was chiefly based on imaging examination (ultrasound and CT) and immunological test. The operative resection rate for liver AE was only 10.5% (27/258). Albendazole was a certain remedy for the chemotherapy of AE, and TCM "Xiao-Bao" pill may be a hopeful drug. CONCLUSIONS: In the past 30 years, a lot of work concerning basic and clinical studies has been done in China and some achievements have been achieved. However, some important problems such as how to conduct further research on molecular biology, how to make early diagnosis, how to improve the chemotherapeutic effect, and how to control the prevalence of AE, need to be studied more deeply in the 21st century. (+info)
Trinucleotide repeat expansion of spinocerebellar ataxia (SCA1) found in a Chinese family.
(45/13273)
OBJECTIVE: To investigate the gene mutation and the ratio of the spinocerebellar ataxia type 1 (SCA1) in Chinese patients with autosomal dominant spinocerebellar ataxia (ADSCA). METHOD: The family material and DNA samples were collected from thirteen families with ADSCA. To determine the characteristics of the CAG trinucleotide repeats in SCA1 gene, the PCR products of the Rep1 and Rep2 primers were analyzed, and the bands with CAG repeat expansion were cloned by PCR2. 1 vector and sequenced. RESULTS: One family was found to have an expanded CAG repeat in the 13 families with ADSCA. The clinically affected individual was heterozygous with one disease allele being 55 CAG repeats, whereas the mean size of the CAG repeats on 104 chromosomes generated from unrelated control Chinese individuals is 29.3 (ranging from 18 to 34). CONCLUSIONS: The frequency of the SCA1 mutation is about 7% in the 13 Chinese families with ADSCA, suggesting that this type of genetic defect is not the main cause involved in the pathogenesis of ADSCA in China. Since the mutation has also been found in Caucasian, Japanese, Malaysian, and Bangladeshi kindreds, it is suggested that this genetic defect may well have multiple origins in different ethnic groups. (+info)
HLA-DQA1, -DQB1 polymorphism distribution in Chinese women with pregnancy induced hypertension in Shanghai area.
(46/13273)
OBJECTIVE: To explore the association of human leukocyte antigen (HLA) with pregnancy induced hypertension (PIH). METHODS: We oligotyped HLA-DQA1, -DQB1 locus of 30 Chinese PIH families and 14 control families in Shanghai area by polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO) hybridization method (probes labeled by nonradioactive technique). RESULTS: Compared with the control group, the allelic frequency of HLA-DQB1 * 0502 was significantly higher in PIH couples, and the sharing of HLA-DQA1 increased in PIH couples as well. No difference was found in HLA-DQA1 allelic frequencies or HLA-DQB1 sharing between the two groups. Analysis of neither HLA-DQA1 nor HLA-DQB1 allelic frequencies in PIH patients and PIH mother-and-fetuses showed positive result. CONCLUSION: HLA-DQB1 * 0502 may be a marker of susceptibility to PIH. DQB1 * 0502 itself or some gene(s) located in HLA class II region and in linkage disequilibrium with 0502 affect maternal T cell immunity during pregnancy. The increase of compatibility in HLA-D region causes the production of blocking antibody to decrease. (+info)
N-ras mutations in 43 Chinese cases of acute myeloid leukemia.
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OBJECTIVE: To detect 3 kinds of N-ras mutations in Chinese patients with acute myeloid leukemia (AML). METHODS: In vitro DNA amplification followed by oligonucleotide dot analysis were used to study N-ras gene mutations in 43 cases of acute myeloid leukemia (AML). 25 healthy people were used as controls. Patients were selected in the Beijing district and consisted of 19 males and 24 females. The average age was 37. The controls were healthy individuals with the average age of 36.5 from the same region. 3 oligonucleotide probes were artificially synthesized to detect mutations in codon 12 and 13 of N-ras. RESULTS: Five out of 43 AML samples have been found contain G-->A mutation in codon 12.2 have G-->T mutation in codon 12. One has G-->A mutation in codon 13. The mutation rate was 18.6%. None of the controls presented these mutations. The frequency of mutation of N-ras in the AML samples showed statistical differences with that of the controls. CONCLUSION: Analysis of the results suggests the N-ras mutations may have some relationship with the etiology of acute myeloid leukemia. (+info)
The epidemiology study of hyperuricemia and gout in a community population of Huangpu District in Shanghai.
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OBJECTIVE: To investigate the prevalence of hyperuricemia and gout in a community population of Huangpu District in Shanghai. METHODS: In the target community, 2037 dwellers were interviewed with relevan questionnares from house to house. According to even house number 1017 blood samples were taken for serum uric acid (SUA) levels measured with the uricase-peroxidase enzymatic method. RESULTS: The prevalence of hyperuricemia was 14.2% in men (SUA > 70 mg/L, 62 cases), 7.1% in women (SUA > 60 mg/L, 41 cases), 10.1% in both sexes. Seven gout patients were all men. The prevalence of gout in 2037 dwellers in Huangpu District was 0.77% in men and 0.34% in both sexes. CONCLUSIONS: The mean SUA level in each age group in this survey was much higher than that of a previous study 1 carried out in Shanghai, Beijing and Guangzhou in 1980 (P < 0.05). And the prevalence of hyperuricemia was increased rapidly (in men: from 1.4% in the survey of 1980 to 14.2% in our survey; in women: from 1.3% in the survey of 1980 to 7.1% in our survey). Compared with Idonesia data in 1992, the prevalence of hyperuricemia and gout in our survey was lower than that in Indonesia (P < 0.05), which suggests that racial and genetic predispositions are key causative factors. (+info)