[GJB2 gene mutation in deaf patients].

OBJECTIVE: To detect the GJB2 gene mutation in patients with autosomal-recessive deafness, and analyze the relationship between clinical phenotype and gene mutation. METHODS: Forty-two patients were examined clinically by pure tone audiometry, acoustic impedance and auditory brainstem response. The complete coding region of the GJB2 gene was amplified by polymerase chain reaction (PCR) and the PCR products were subjected to automatic DNA sequencing. RESULTS: Two cases had homozygous mutation of 235delC. One of them had sensorineural hearing loss while the other had mixed hearing loss. Heterozygous mutation of 176del16bp was detected in a pair of twins who had mixed hearing loss. The 109G to A, 79G to A and 341A to G mutations were observed in both the patients and the controls. CONCLUSION: Homozygous 235delC mutation is one of the pathogeni c mutations which could occur in patients with mixed hearing loss. The heterozygous 176del16bp mutation combined with environmental factor may cause hearing loss. The 109G to A, 79G to A and 341A to G variants were considered to be polymorphisms of the GJB2 gene.

[The relationship between the effect of amlodipine on carotid intimal-medial thickness and angiotensin converting enzyme genotypes in elderly hypertensive patients].

OBJECTIVE: To investigate the association between the anti-atherosclerotic effects of amlodipine and angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism in elderly essential hypertensive (EH) patients. METHODS: A total of 220 EH patients were treated with amlodipine (2.5 - 10 mg, once daily) for twelve months and complete data were obtained from 208 patients with genotypes of II (n = 90), ID (n = 91) and DD (n = 27). The indices of carotid arterial were compared before and post amlodipine treatment in patients with identical genotype and among different ACE genotypes and each genotype post therapy. RESULTS: The carotid mean intimal-medial thickness (MIMT) was slightly decreased in EH patients with ID and DD genotypes and significantly decreased in EH patients with II genotype (0.96 +/- 0.12 vs. 0.92 +/- 0.13, P < 0.01) compared to pre-treatment values. The decreased degree of MIMT (DeltaMIMT) in II genotype was significantly higher in II genotype than those in ID or DD genotype (0.05 +/- 0.03 vs. 0.01 +/- 0.02, 0.01 +/- 0.03 respectively, P < 0.01). The post treatment plaque score (PS) in patients with II genotype was significantly reduced (4.85 +/- 2.51 vs. 3.90 +/- 2.36, P < 0.05). Multivariate linear regression analysis showed the baseline SBP, the decreased degree of SBP (DeltaSBP) and the II genotype were the major factors affecting the DeltaMIMT. CONCLUSION: Hypertensive patients carrying II genotype ACE genotype are the best responders for the anti-atherosclerotic effects of amlodipine.

[Effects of bu yang huan wu decoction on astrocytes after cerebral ischemia and reperfusion].

OBJECTIVE: To study the effects of Bu Yang Huan Wu Decoction on astrocytes after cerebral ischemia and reperfusion. METHOD: Cerebral ischemia model in gerbils was produced by ligating bilateral common carotid artery. The dynamic expressin of GFAP were determined by immunochemistry after cerebyal ischemia for 15 min followed by reperfusion for 24 hours and 48 hours. RESULT: GFAP positive reactions reached a peak after cerebral ischemia for 15 min followed by reperfusion for 24 hours. Bu Yang Huan Wu Decoction decreased the expression. GFAP positive reactions decreased after cerebral ischemia for 15 min followed by reperfusion for 48 hours, Bu Yang Huan Wu Decoction increased the expression. CONCLUSION: The regulation of Bu Yang Huan Wu Decoction on astrocytes after cerebral ischemia and reperfusion may be related to repairing process after cerebral ischemia.

Mitochondrial DNA polymorphisms in Gelao ethnic group residing in Southwest China.

Gelao ethnic group, an aboriginal population residing in southwest China, has undergone a long and complex evolutionary process. To investigate the genetic structure of this ancient ethnic group, mitochondrial DNA (mtDNA) polymorphisms of 102 Gelao individuals were collected and analyzed in this study. With the aid of the information extracted from control-region hypervariable segments (HVSs) I and II as well as some necessary coding-region segments, phylogenetic status of all mtDNAs under study were determined by means of classifying into various defined haplogroups. The southern-prevalent haplogroups B, R9, and M7 account for 45.1% of the gene pool, whereas northern-prevalent haplogroups A, D, G, N9, and M8 consist of 39.2%. Haplogroup distribution indicates that the Gelao bears signatures of southern populations and possesses some regional characters. In the PC map, Gelao clusters together with populations with Bai-Yue tribe origin as well as the local Han and the Miao. The results demonstrate the complexity of Gelao population and the data can well supplement the China mtDNA database.

Analysis of mitochondrial DNA polymorphisms in Guangdong Han Chinese.

Previous investigations on Chinese mitochondrial DNA (mtDNA) variation revealed that the matrilineal gene pool of southern Han Chinese is rather complex, with much higher genetic diversity and more basal/ancient lineages than the northern Hans. The extreme case is Guangdong Han populations, among which pronounced (matrilineal) differentiation has been observed, indicative of complex demography of the region. To get more insights into the maternal makeup of southern Han Chinese, mtDNA variation of a total of 106 individuals sampled from Dongguan, Guangdong Province, China, was analyzed in this study. With the aid of the information from control-region hypervariable segments I and II (HVS-I and -II) as well as some necessary coding-region segments, the phylogenetic status of all mtDNAs under examination were determined according to the reconstructed East Asian mtDNA tree. In this way, the mtDNAs have been classified into various haplogroups or sub-haplogroups. The southern-prevalent haplogroups, such as R9 (20.8%), B (17.9%), M7b (14.2%), show relatively high distribution frequencies in Dongguan Hans; whereas the frequencies of Northern-prevalent haplogroups (with the exception of D) are quite low: C (1.9%), G2 (1.9%) and Z (1.9%), indicating the southern-origin of Dongguan Hans.