Mitochondrial DNA mutation associated with hypertension in tRNA(Ile) and tRNA(Gln) genes / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the relationship between mitochondrial DNA (mtDNA) mutations and hypertension.</p><p><b>METHODS</b>Clinical data of two pedigrees with maternally transmitted hypertension was collected. Whole mtDNA sequence was analyzed.</p><p><b>RESULTS</b>The family members on the maternal side presented with various levels of hypertension, with the onset age ranging from 44 to 55 years old. Analysis of the mtDNA sequence of the two families members showed all patients have carried a matrilineal 4329C> G mutation of the tRNA(Ile) and tRNA(Gln) genes. The same mutation was not found in 366 healthy controls. The 4329C site of mtDNA is highly conserved across species, and has been associated with the fidelity of amino acid accept arm of the tRNAs, as well as functionality and stability in the formation of tRNAs.</p><p><b>CONCLUSION</b>The 4329C> G point mutation in tRNA(Ile) and tRNA(Gln) probably has contributed to the pathogenesis of hypertension, possibly in association with other modifying factors.</p>

Study on Bartonella infection using molecular biological diagnostic techniques from China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To establish polymerase chain reaction (PCR) technique for the detection of specific genes related to species of genus Bartonella, and for diagnosing clinically suspected cat-scratch disease (CSD) case complicated with pneumonia on both lungs. The appearance of Bartonella infectious diseases calls for genus and species detection and tools for identification in order to make clinical diagnosis and carry on epidemiological studies.</p><p><b>METHODS</b>One pair of primer TIle.455p-TAla.885n was designed based on the fact that tRNA(Ile)-tRNA(Ala) intergenic spacer region in 16S-23S rRNA intergenic spacer (ITS) of genus Bartonella were high variable sequences flanked by completely conserved tRNA-encoding genes. 16S-23S rRNA was longer than that which had been described in other bacteria. Two published pairs of primers were used to directly detect the specific gene fragments of Bartonella species DNA extracts from human blood, followed by PCR product Sequencing and nucleotide base sequence analysis.</p><p><b>RESULTS</b>Amplification products of the three pairs of primers had the same predicted size of those in Bartonella spp. According to the different length of electrophoresis bank, the sample was identified as a species of genus Bartonella other than the positive control. Sequence analysis showed that the nuleotide sequence from the PCR product of primer TIle.455p-TAla.885n was identical to the Bartonella isolated from Yunnan in China.</p><p><b>CONCLUSIONS</b>PCR-based assay provided a simple and rapid means to detect pathogenic Bartonella species in humans and mammalian hosts as well as in arthropod vecters. This study suggested that this pathogenic Bartonella species existed in patients in northern and southern parts of China.</p>

mtDNA mutations in mouse tumors / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate variations of mtDNA in mouse tumors and to explore the relationship between mtDNA mutations and murine carcinogenesis.</p><p><b>METHODS</b>Variations of D-loop, ND3 and tRNAIle + Glu + Met gene fragments of mtDNA from six mouse tumor cell lines were analyzed by PCR-RFLP and PCR-SSCP techniques.</p><p><b>RESULTS</b>ND3 and tRNAIle + Glu + Met gene fragments of mtDNA from the tumors showed no variations at 27 endonuclease sites. The D-loop of mtDNA from Hca-F demonstrated an additional endonuclease site of Hinf I in contrast to the inbred mouse. Upon PCR-SSCP analysis, the D-loop of mtDNA was found to possess mutations in 4 of 6 tumors.</p><p><b>CONCLUSION</b>D-loop appears to be the hot spot for tumor mtDNA mutations, which may contribute to the carcinogenesis of murine tumors.</p>