RESUMO
Mutations in the mitochondrial DNA have been certified to be one of the most important causes of maternally inherited sensorineural hearing loss. Among these, mitochondrial 12S rRNA1555A>G, 1494C>T and other mutations are associated with both nonsyndromic and drug induced hearing loss caused by aminoglycosides. Individuals carrying 1555A>G or 1494C>T mutation have a variety of clinical manifestations, which implies that the 1555A>G or 1494C>T mutation is a chief factor underlying the development of deafness but insufficient to produce the clinical phenotype. Therefore other modifier factors, such as aminoglycosides, mitochondrial haplotypes, secondary mutation or nuclear modifier genes, may play an important role in the phenotypic expression of the deafness-associated mitochondrial 12S rRNA1555A>G or 1494C>T mutation. In this review, the modifier factors for the phenotypic expression of deafness-associated mitochondrial 12S rRNA1555A>G or 1494C>T mutations were summarized and proposed the pathogenesis of maternally inherited deafness.
RESUMO
With the doses of Spirulina compound tablet (FST) 1.5g?kg 1 ,3g?kg 1 by ig administration to normal rats,alloxan (ALX) induced diabetic rats and hyperlipidemic model rats respectively for 14 days ,then the fast blood glucose(FBG) and the serum lipids were detected.The results showed that FST could decrease the FBG and the serum TC,TG,LDL C,increase HDL C in normal and in diabetic rats.(But FST 1.5g?kg 1 had no significant effect on TG,HDL C in normal rats).In addition,it was found that FST could remarkably decrease the level of serum TC,TG, and LDL C,as well as increase HDL C in hyperlipidemic model rats.It is suggested that FST not only significantly decrease the FBG and the lipids contents both in normal and in diabetic rats,but also remarkably decrease the serum lipids level in hyperlipidemic model rats. [WT5HZ]