AIM: To know the variations of the cytochrome b gene in cancer tissue, paracarinoma tissue and normal tissue and to inquire into the relationship between mutations of mitochondrial genome and carcinogenesis. METHODS: Cellular total DNA was extracted.The cytochrome b genes of three tissues were amplifyed with polymerase chain reaction(PCR). PCR products were analysed by DNA auto-sequencing method. RESULTS: The cytochrome b gene of cancer tissue had the C to G mutation at nt 14931, the C to G mutation at nt 15004 and the T to C mutation at nt15435,respectively. The cytochrome b gene of paracarinoma tissue had the A to C mutation at nt 15436. The cytochrome b gene of normal tissue had not mutation. CONCLUSION: Mitochondrial DNA mutations could be the endogenous factors that induce nuclear genome mutation. It could promoto carcinogenesis. The paracarinoma tissue was abnormal in DNA molecular level.

Many people affected by fragile X syndrome (FXS) and autism spectrum disorders have sensory processing deficits, such as hypersensitivity to auditory, tactile, and visual stimuli. Like FXS in humans, loss of Fmr1 in rodents also cause sensory, behavioral, and cognitive deficits. However, the neural mechanisms underlying sensory impairment, especially vision impairment, remain unclear. It remains elusive whether the visual processing deficits originate from corrupted inputs, impaired perception in the primary sensory cortex, or altered integration in the higher cortex, and there is no effective treatment. In this study, we used a genetic knockout mouse model (Fmr1^KO), in vivo imaging, and behavioral measurements to show that the loss of Fmr1 impaired signal processing in the primary visual cortex (V1). Specifically, Fmr1^KO mice showed enhanced responses to low-intensity stimuli but normal responses to high-intensity stimuli. This abnormality was accompanied by enhancements in local network connectivity in V1 microcircuits and increased dendritic complexity of V1 neurons. These effects were ameliorated by the acute application of GABA_A receptor activators, which enhanced the activity of inhibitory neurons, or by reintroducing Fmr1 gene expression in knockout V1 neurons in both juvenile and young-adult mice. Overall, V1 plays an important role in the visual abnormalities of Fmr1^KO mice and it could be possible to rescue the sensory disturbances in developed FXS and autism patients.
Animals ; Disease Models, Animal ; Fragile X Mental Retardation Protein/metabolism* ; Fragile X Syndrome/metabolism* ; Humans ; Mice ; Mice, Knockout ; Neurons/metabolism*