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Objective To compare and analyze the genetic structure of NIH mice bred in Unites A and B, using microsatellite technology.Methods Thirty SPF 8-week old outbred NIH mice (half male and half female) of each population were randomly chosen from the Units A and B, respectively.PCR amplification and STR scan were performed to determine the genetic characteristics of two outbred populations using microsatellite loci, and the population genetic structure was analyzed with statistical software Popgene 1.32.Results In the NIH mouse population form the Unit A, 74 alleles were obtained, with an average heterozygosity of 0.3108 and polymorphism information content of 0.2637.In the NIH mouse population from the Unit B, 76 alleles were obtained, with an average heterozygosity of 0.3257 and polymorphism information content of 0.2777.The inter-population comparison showed that genetic differentiation coefficient Fst was 0.3932, the genetic identity was 0.3971, and the genetic distance was 0.9235.The population difference was significant.Conclusions There is serious genetic differentiation between the two NIH mice populations,resulting in the formation of two different closed populations.
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Objective To establish a mouse model of systemic C. albicans infection by oral inoculation of the pathogen and observe the proliferation and distribution of C. albicans in vivo tissues. Methods Male ICR mice(n=46) were used as the experiment group(n=40) and blank group (n=6). Cotton swabs with C. albicans were used to infect the mice (7 × 106 CFU/mL), and the blank group with saline. The mice of the experiment group were randomly divided into two groups:model group A for clinical assessment (n=20) and model group B for tissue fungal burden detection (n=20). Clinical score, survival and autopsy were carried out among the model group A. Five mice were randomly killed from the model group B at 3 d, 5 d and7 d after infection, respectively ( blank group killed 2 mice each time) . Microbial load tablet method was used to detect the tissue fungal burdens in different tissues, meanwhile samples of tongue, esophagus, stomach, liver, kidney, lung of infected mice were taken for pathological examination. Results White spot appeared on the surface of tongue since 3 d postinfection and increased with time and finally caused death. The mortality reached over 50% at 5 d. C. albicans was not only detected from the tongue (87?5%), stomach (87?5%), liver (54?5%), kidney (50?5%), lung (20%) and heart (4%), but also was microscopically seen mycelia proliferation in the tongue, stomach, liver, and kidney , yet not seen in the control group, showing that C. albicans caused disseminated systemic infection through mucosal infection in mice. Conclusions C. albicans can induce opportunistic systemic infection by breakthrough the mucosal immune barrier, so as to increase the infection to death.
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Objective To assess the potential of whole blood IFN-γassay for diagnosing mycobacterium in rhesus macaques.Methods Firstly, basic serum IFN-γconcentrations of TST-negative and -positive rhesus macaques were detected.Then, heparinized whole blood from TST-negative and-positive rhesus macaques was incubated with PBS and 200 IU bovine-PPD ( tuberculin purified protein derivative ) for about 24 h, respectively.The supernatant plasma were harvested and used to determine the concentrations of IFN-γ.The results of plasma IFN-γconcentrations and stimulation index ( SI) were used to analyze the diagnostic potential of the whole blood IFN-γassay.Results The basic serum concentrations of IFN-γfor the TST-positive monkeys were significantly higher than that of the TST-negative macaques, showing a high coefficient of variation.There was no significant effect on the production of IFN-γin the TST-negative macaques.While significantly elevation of IFN-γconcentrations was found in stimulated plasma of TST-positive macaques (P<0.01).The SI of TST-positive macaques was significantly higher than the TST-negative ones.ROC curve analysis revealed that IFN-γconcentrations and SI could be used as evaluation index of whole blood IFN-γassay.Conclusions Based on a small sample experiment we have demonstrated that whole blood IFN-γassay may be one possible auxiliary diagnostic method for tuberculin skin test.
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Objective To screen strains of minipigs sensitive to highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) for evaluation of HP-PRRS live vaccine.Methods Lantang pigs, Juema, Bama and Wuzhishan ( white) minipigs were inoculated with virulent strain NVDC-JXA1 of PRRSV, and local binary hybrid pigs were used as control.The animals were continuously observed for 5 weeks on mental status, appetite, survival, etc.after inoculation of virus.The dead pigs were autopsied and the lung tissue samples were collected for detecting virus by RT-PCR.By the end of the experiment, serum of survival animals were collected for detecting PRRSV antibody by ELISA assay.Result The animals showed depression, anorexia, and other clinical signs and death in each group after inoculation.Meanwhile, the testing results were all positive in the RT-PCR and ELISA detection.Bama and Wuzhishan ( white) minipigs were the most sensitive to virulent strain NVDC-JXA1 of PRRSV regarding mortality rate.Conclusions Bama and Wuzhishan ( white) minipigs are sensitive to HP-PRRSV, and can be used for the inspection of HP-PRRS live vaccine.
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Objective To assess the changes of humidity and ammonia concentration in rat and mouse individually ventilated cages (IVC) based on macroenvironmental humidity and air ventilation changes .Methods Three kinds of rat and mouse IVC in barrier facilities were set as research objective .The changes of micronvironmental humidity and ammonia concentration at 40 times/h and 60 times /h air changes were detected continuously for a 7-days-cycle relative to low (40%), moderate (50%), and high (60%) macroenvironmental humidity.Results Mouse and rat IVC with 40 times /h air changes under low macroenvironmental humidity condition , mouse IVC with 40 times/h and rat IVC with 60 times/h air changes under moderate macroenvironmental humidity condition , mouse IVC with 60 times /h air changes under high macroenvironmental humidity condition , basically meet the GB14925-2010 requirements.While under macroenvironmental high humidity condition, the microenvironments of rat and mouse IVC with 60 times/h air changes could not satisfy the requirements.Conclusions The environmental humidity and ventilation frequency are the key index of IVC microenvironment.Only on the basis of external environment conditions to set up reasonable IVC ventilation frequency in order to better maintain the IVC microenvironment so that to achieve the goal of effective management .
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Aim To observe the change of amyloid, acetylcholine transferase and glial fibrillary acidic protein expression in Macaca Rhesus hippocampal after infused the Aβ_(1-42) and thiorphan and explore the possibility of the establishment of Macaca Rhsus AD model in brain.Method The Rhesus monkeys were anesthetized (im), the skull was exposed by a midline scalp incision, and oriented craniotomy was performed on left side by dental drill.First, neprilysin in cerebral cortex and basal nucleus was consumed by infusion thiorphan. Then cerebral cortex and basal nucleus were slowly infused with fibrilla Aβ_(1-42). Finally, the cannula for thiorphan infusion was implanted into the basal nucleus.Miniosmotic pump (Alzet MODEL 2ML4,) was subcutaneously fixed by bio gel 454 on the calvaria (Loctite Co. Ltd,USA) according to the manufacturer's instructions.After 50 days' survival, animals were deep anesthetized with ketamine and sacrificed. The pathological changes were observed by HE staining and immunostaining in monkey brains.Result Neuronal loss and a proliferation of microglia were detected in hippocampal formation by HE staining.Immuno-staining showed Aβ_(1-42),ChAT and GFAP positive cells density were 0.59±0.05,0.21±0.04 and 0.19±0.04 separately.Compared with control group, the density in experimental groups showed distinct difference in statistic analysis (P<0.01).Conclusion The same pathological change was detected in the thioaphan and Aβ_(1-42) infusion in Macaca Rhesus hippocampal formation as what was found in AD patients.
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Objective To test our hypothesis that sensitivity to avian influenza A(H5N1)virus varies among mouse strain backgrounds, we compared the pathogenicity of H5N1 viral infection in 5 mouse strains. Methods Onehundred-fifty mice from 2 inbred strains(BALB/c and C57BL/6), and 3 outbred stocks(ICR, NIH Swiss, and KM Swiss)were used. Thirty mice of each strain were subjected to an infected group(20 mice), in which mice were inoculated with 0. 1 mL(104.875 TCID50)of A/Goose/Guangdong/NH/2003(H5N1)virus intra-nasally; ten control mice received noninfectious allantoic fluid. Clinical signs were assessed daily for 14 days post-infection. Necropsy was performed on mice that died during the experiment and those euthanized at end of study. Tissue samples were collected for viral isolation and pathological analysis. Results H5N1 virus infection can cause respiratory illness in all 5 strains with severe or minor acute respiratory distress symptoms, but with different mortality rates: 70% in BALB/c; 50% in ICR; 40% in NIH Swiss; 25% in C57BL/6; and 10% in KM Swiss mice. Necrotizing interstitial pneumonia was found in all cases of death. The virus was isolated from the lungs of all infected dead mice. Conclusion A/Goose/Guangdong/NH/2003 (H5N1)virus can infect all mouse strains used in this study, and can cause clinical symptoms and pathological changes similar to those found in humans infected with HSN1 viruses. However, the pathogenicity of H5N1 viral infection varies significantly between the different mouse strains. Thus, in future study of H5N1 virus infections the mouse strain most relevant to their particular research purpose should be selected as animal model.
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Objective To measure the organ weight and body weight of outbred Wuzhishan mini-pigs (WZSP), and calculate the organ coefficient and the linear and multiple linear regression equations between body weight and major organ weights. Methods 30 common WZSP (16 males and 14 females) were chosen,the body weight and 7 organ weights were determined, and the organ coefficients were calculated. The organ coefficients between males and females were compared. The correlation and regression analysis was performed using the SAS software. Results The coefficient of heart had remarkably significant difference between males and females (P<0.05).The linear analysis showed that there were apparent linear correlations between body weight and all the organ weights except for the stomach of males and the lung of females.The weights of liver and kidney showed great influence on the body weight of males, while the body weight of females relied on the weights of heart, liver and kidney greatly. Conclusion Differences of organ coefficients are not significant between males and females,and there are linear relationships between body weight and some major organ weights.