Nuclear receptors,the superfamily of ligand-activated transcription factors,play crucial role in the regulation of gene expression of the lipid metabolism,and are involved in many metabolic diseases,such as cholesterol gallstone disease.Recently many domestic and foreign researches on the role of nuclear receptors in the lipid metabolism,help to further elucidate the biomolecular pathogenesis of cholesterol gallstone disease and other diseases associated with the lipid metabolism.

Objective To establish a real-time fluorescent quantitative PCR ( FQ-PCR ) method for detection of murine norovirus ( MNV) in laboratory mouse and provide the basis for establishment of a standard detection method for MNV.Methods Specific primers were designed and MNV DNA standards were prepared according to the MNV genome sequences published on NCBI .The specificity, sensitivity, repeatability and stability of the established Q-PCR method were tested.The established Q-PCR method was applied to detect 766 mouse caecum content samples to explore preliminarily the infection status of laboratory mice in Beijing .Results No cross reaction showed in human norovirus and feline calicivirus with the established Q-PCR method.The sensitivity was up to 10 copies/μL.The coefficient of variation ( CV) of intra-assay and inter-assay was less than 2%.There were 301 positive cases detected in the 766 samples of laboratory mice.Conclusions The established FQ-PCR method is accurate and effective with high specificity , sensitivity and repeatabiliy in the quantitative detetion of nucleic acid , and can be applied to rapidly and quantitatively screen MNV in laboratory mice .

Objective To diagnosis tumor transplanted nude mice Strongyloidiasis .Methods Postmortem microscopic examination of the tumor transplanted nude mice detected Strongyloides stercoralis for morphological identification and double polymerase chain reaction ( PCR ) assay for molecular diagnosis of Strongyloides stercoralis infection in tumor transplanted nude mice .Results Presence of numerous S .stercoralis in autopsy in tumor transplanted nude mice samples preliminary determined the diagnosis of strongyloidiasis .Confirmed diagnosis of Strongyloides stercoralis infection by double PCR detection of specific DNA in tumor transplanted nude mice samples .Conclusion The most important clue to prevent such serious consequences is early diagnosis .Tumor transplanted recipients and donors should be screened for parasitic infections including strongyloidiasis .To the authors ’ knowledge , this study is the first extensive report on diagnosis tumor transplanted nude mice Strongyloidiasis .

Adenosine monophosphate-activated protein kinase (AMPK) activation also can inhibit the synthesis of cholesterol and fat.Recent studies have shown that activation of AMPK can also inhibit the synthesis of bile acid and promote bile salt export pump' s generation.All of those illustrated that AMPK played an important role in regulating bile acid metabolism.This article will summarize the AMPK activation pathway,bile acid metabolism,AMPK activity in bile acid synthesis and transfer,and so on.

Objective Giardia lamblia is an important pathogen of zoonosis giardiasis , it poses a potential threat to the quality of SPF (specific pathogen-free) laboratory animals cannot be ignored.The aim of this study is to establish the method of rapid diagnosis of Giardia lamblia, and analyze the test results of 516 batches form 17 manufactures.Methods Direct microscopy, Giemsa-fast staining and multiplex polymerase chain reaction (multiplex PCR) were applied to detect Giardia lamblia.Results Numerous of Giardia lamblia trophozoites and cysts were detected in SPF laboratory animals by using direct microscopy and Giemsa-fast staining, and multiplex PCR were performed to identify 18S rDNA,β-giardin, TPI and GDH genes of DNA extracted from these trophozoites and cysts identified Giardia lamblia.Direct microscopy, Giemsa-fast staining, and multiplex PCR methods can be used to detect Giardia lamblia.Of the 2562 SPF laboratory animals studied, 22.9%(586/2562) were positive for Giardia lamblia.Conclusions Direct microscopy , Giemsa-fast staining , and multiplex PCR were effective techniques with high sensitivity and specificity for rapid diagnosis of Giardia lambliain.It is not satisfactory that the results of Giardia lamblia examination in 516 batches form 17 manufactures failed to meet the requirements 100%.

Objective To establish an effective PCR assay for leptospirosis detection , and applicate the assay in tree shrew, mongolian gerbil and gray hamster .Methods Sequence of leptospira was obtained from the NCBI Genbank , and primers were designed based on the sequences .The positive amplified fragments were sequenced to verify the reliability of the method.The samples from tree shrew, mongolian gerbils and hamsters were tested using this PCR method .Results The PCR method for detection of leptospirosis was successfully established .The positive rate of Leptospira was 8.33% in 60 samples of conventional tree shrews , 100% in 104 samples of the conventional Mongolian gerbils , and 0% in 60 samples of clean gray hamsters.Conclusions The establishment of this PCR assay is useful in the detection of leptospirosis in tree shrew, mongolian gerbil and gray hamster .The results of our investigation of leptospira infection levels of the three new experimental animals may promote their application in biomedical research .

Objective To study the immunoreaction of the recombinant proteins encoded by the fragments of ORF2 ( second open reading frames) gene of hepatitis E virus ( HEV). Methods The aimed sequence from the full-length ORF2 in clone PEH2 , which was derived from a Chinese strain of HEV,was amplified and cloned it into vector pcDNAS. 1 which was then transfected to 293 cell. Results The ORF2 protein was present in the soluble fractions of the cell lysate. The expressed protein of HEV ORF2 in 293 cells by using a plasmid pcDNA3. 1-based system showed positive on immunoblots probed against antibodies raised in BALB/c mice. Conclusion The experimental results laid a foundation for developing diagnostic reagent to detect HEV by using the expressed products of ORF2 protein.

Objective To test the potency of hepatitis B vaccine in China. Methods Two inbred strains(DBA/1 and BALB/c) and two NIH closes-colonies of mice were typed in the H-2 region by microcy-totoxicity method and PCR. Groups of mice of the tested strains were immunized with the same hepatitis B vaccine, the titre of anti-HBsAg antibody was analyzed by microplate, and the ED50 was then estimated by Karder method for each strain. Results Significant differences were found between potency estimates de-rived from assays using different strains of mice. Conclusion It is likely that the variation of immune re-sponse to hepatitis B vaccine in mice is correlative with the H-2 haplotype. In some special case, the bet-erozygosity in H-2 region found in NIH stock could influence the accuracy in such testing even a reference preparation of hepatitis B vaccine was used. Base on our experiment, to select an appropriate NIH stocks with the H-2q haplotype for potency testing of hepatitis B vaccine in China.

0.05). Cross-reactivity was seen in 1 case of clonorchiasis sinensis by both the methods. Conclusion Microwave ELISA has the advantages of high sensitivity, specificity and rapidity.

To investigate the prevalence and the antibiotic resistance of bacteria isolated from 25 miniature pigs. 45 bacterial strains were isolated, which were identified by biochemical assays, amplification of 16S rRNA genes by PCR and sequence analysis, and were evaluated for resistance to 30 antibiotics. The identification results showed that these bacteria belonged to Campylobacter (Campylobacter jejuni), Helicobacterium (Helicobacter pylori), Klebsiella (Klebsiella pneumoniae), Escherichia (Escherichia coli, Escherichia fergusonii), Pseudomonas (Pseudomonas aeruginosa), Stenotrophomonas (Stenotrophomonas maltophilia), Staphylococcus (Staphylococcus aureus, Staphylococcus haemolyticus, Staphylococcus simulans), Streptococcus (Streptococcus pneumoniae, Streptococcus suis, Streptococcus vestibularis, Streptococcus mitis, Gemella measles, Aerococcus viridans) and Bacillus (Bacillus subtilis, Bacillus licheniformis, Bacillus alvei, Bacterium megaterium). These bacteria were all susceptible to aztreonam and cephalothin. However, the resistence to furazolidone was found. Microbial population carried by miniature pigs in China had characters of diversity. Results of this study provided scientifical accordance for the microorganism monitoring of miniature pigs in China.