Abstract:The DNA of Mycobacterium tuberculosis is amplified by polymerase chain reaction and we get a specific 158 bp DNA fragment of Mycobacterium tuberculosis.The DNA of Mycobacterium bovis is also amplified,but other thirteen mycobacteria are not.The DNA fragment is recovered and used as a DNA probe,It can hybridizes with DNA of Mycobacterium tuberculosis and Mycobacterium bovis,but not with the DNA of Staphylococcus aureus,Bacillus pyocyaneus and other mycobacteria.This result suggests that the Mycobacterium tuberculosis and Mycobacterium bovis can be detected by PCR and the amplified 158bp DNA fragment can be utilized as a molecular probe. This probe can examine the Mycobacterium tuberculosis and Mycobacterium bovis and distinguish them from other mycobacteria.

Abstract:A specific,sensitive and simple radioligand binding assay for apoCⅢ-binding sites of hepatic plasma membranes has been established by separation of B/F with PEG.Addition of increasing concentration of ¹²⁵Ⅰ-labeled apoCⅢ to human hepatic plasma membranes revealed saturation binding to membranes with a K_d of 0.31μmol/L(3.1×10^-7mol/L) and binding maximum of 1.74μg/mg of membrane protein.In displacement studies using unlabeled apoCⅢ and isolated lipoproteins HDL,LDL and VLDL,only apoCⅢ and VLDL effectively competed with ¹²⁵Ⅰ-apoCⅢ for membrane binding sites. The binding of ¹²⁵Ⅰ-apoC l to human liver plasma membranes was Ca²⁺-independent and was abolished when plasma membranes were treated with trypsin. The characteristics of apoC Ⅲ-binding sites of mouse liver plasma membranes was similar to that of human liver plasma membranes with an exception of binding maximum of 1.52μg/mg of membrane protein.

Abstract:Comparisons of the nucleotide sequences and amino acid sequences were made among various hepadnaviruses,and the relative evolutional distances were calculated.From the comparison,it was shown that DHBV,HBV,GSHV and WHV are derived from a common ancestor,and the three mammalian hepatitis B viruses are more homologous to each other than they are to DHBV,indicating that DHBV starts to evolve on its own earlier than the three other viruses,as do birds compared with mammals.Based on these findings it was proposed that viruses evolved in a fashion parallel to the species they infect. From the calculated relative evolutional distances, it was suggested that WHV and GSHV can be categorized in a way similar to the subgroups of HBV.