OBJECTIVE: To investigate the meaning of the mutation screening, prevalence, inheritance and the intervention or the prevention for the specific drugs in 10 families with non-syndrome hearing loss in Yunnan Province, China. METHOD: To do a questionnaire about the cases of ten families with non-syndrome hearing loss and to draw a detailed matriarchal family tree detailed. Following that, the A1555G mutation-positive individuals were detected and confirmed using DNA extracting, PCR amplification and sequencing for family volunteer. RESULT: There are 96 members have attended the blood collection in these ten families. Thirty-six of them had the normal hearing and 60 of them had the sensory neural hearing loss. However, 4 out of those had no A1555G point mutation, and 92 had A1555G point mutation (95.8%). While 7 of those were Heterogeneity, the rest were all homogeneous mutation. There were also 73 patients who had amino glycoside antibiotic medication history. However all the rest cases had a history of amino glycoside antibiotic medication were not clear yet. CONCLUSION The proportion of patients with drug-induced deafness is high in Yunnan province and the mutation rate of mitochondrial DNA A1555G is also high. It is worthy to do DNA 12SrRNA A1555G mutation screening for drug intervention and prevention.
Adolescent ; Adult ; Aged ; Child ; China ; epidemiology ; DNA Mutational Analysis ; DNA, Mitochondrial ; genetics ; Deafness ; epidemiology ; genetics ; Female ; Humans ; Male ; Middle Aged ; Pedigree ; Point Mutation ; RNA, Ribosomal ; genetics ; Young Adult

OBJECTIVETo investigate the role of a potential diabetes-related mitochondrial region, which includes two previously reported mutations, 3243A-->G and 3316G-->A, in Chinese patients with adult-onset type 2 diabetes.

METHODSA total of 277 patients and 241 normal subjects were recruited for the study. Mitochondrial nt 3116 - 3353, which spans the 16S rRNA, tRNA(leu(UUR)) and the NADH dehydrogenase 1 gene, were detected using polymerase chain reaction (PCR), direct DNA sequencing, PCR-restriction fragment length polymorphism and allele-specific PCR. Variants were analyzed by two-tailed Fisher exact test. The function of the variants in 16S rRNA were predicted for minimal free energy secondary structures by RNA folding software mfold version 3.

RESULTSFour homoplasmic nucleotide substitutions were observed, 3200T-->C, 3206C-->T, 3290T-->C and 3316G-->A. Only the 3200T-->C mutation is present in the diabetic population and absent in the control population. No statistically significant associations were found between the other three variants and type 2 diabetes. The 3200T-->C and 3206C-->T nucleotide substitutions located in 16S rRNA are novel variants. The 3200T-->C caused a great alteration in the minimal free energy secondary structure model while the 3206C-->T altered normal 16S rRNA structure little.

CONCLUSIONSThe results suggest that the 3200T-->C mutation is linked to the development of type 2 diabetes, but that the other observed mutations are neutral. In contrast to the Japanese studies, the 3316G-->A does not appear to be related to type 2 diabetes.

Age of Onset ; Aged ; Alleles ; Base Sequence ; DNA Mutational Analysis ; DNA, Mitochondrial ; chemistry ; genetics ; Diabetes Mellitus, Type 2 ; genetics ; Humans ; Middle Aged ; Models, Molecular ; Nucleic Acid Conformation ; Point Mutation ; Polymerase Chain Reaction ; methods ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S ; chemistry ; genetics

Objective To investigate the distribution and expression changes of voltage-gated chloride channel CLC-2 and CLC-3 in rat models with lithium-pilocarpine-induced chronic epileptic,and discuss the significance of these changes in epileptic pathogenesis.Methods Eighty Wistar rats were randomly divided into status epilepticus(SE,n=60)and control(n=20)groups and rats in the SE group were assigned to 3 subgroups according to the different sacrificed times(24 h,14 d and 30 d).Rat models with chronic epileptic in the SE group were induced by lithium-pilocarpine.Immunohistochemistry was employed to observe the changes of voltage-gated chloride channel CLC-2 and CLC-3 in rat's hlppocampal formation different time points after seizure.The mRNA changes of chloride channel CLC-2 and CLC-3 at different time points after seizure were observed by RT-PCR.Results Compared with those in the control group,the quantity of CLC-2 immune positive neurons and the average optical density in the SE group decreased obviously 14 and 30 d after seizure;so was the mRNA expression of CLC-2(P<0.05).Compared with the control group,the SE group showed obviously increased quantity of CLC-3 immune positive neurons and optical density at each area of the hippocampus 24 h after seizure;so was the mRNA expression of CLC-3(P<0.05).Conclusion Seizures at chronic phase have relation with the decreased expressions of CLC-2.