Objective To study the changes of antioxidant on ZCLA Mongolian gerbils' sera within different growth period.Methods The gerbils at the age of 1 month,3 months and 24 months were used in the experiment,with each 16(half male and half female),and the sera were collected for determining the MDA,SOD and GSH-Px.Results At the age of 3 months,MDA was the lowest,but GSH-Px was the highest,while the SOD was ascending with growing.Conclusion The changes of GSH-Px showed the direct relation to MDA,while the changes of the SOD was irrespective to the changes of MDA.

Objective To investigate the method to isolate and culture hepatic stellate cells ( HSCs) for studying the cellular mechanisms of hepatic frbrosis.Methods HSCs were isolated by nycodenz density gradient centrifugation after the hepatocytes obtained from adult male gebils were digested with pronase, collagenase and DNase, infused via portal vein.The cell viability was determined by trypan blue exclusion test.The purity of HSCs was identified by detectingα-SMA, desmin immunohistochemical staining.Results The yield rate of HSCs was 0.5~1 ×107 per gerbil liver, and the cell viability was more than 90%.The percentage ofα-SMA-positive cells was more than 75%after 3 days primary culture and almost 100% cells were α-SMA and desmin positive in passage culture.Conclusion The successful protocol of primary culture of Mongolian gerbil HSC provide a technical support for research of relevant liver diseases and drug development in the future.

Objective To investigate the numbers of corpus luteum and ovarian follicles and compare the levels of serum prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol (E2 ) in different phases of estrus cycle in female gerbils .Methods Consecutively taking vaginal smears of the gerbils and directly examined under light microscope to distinguish the four phases of the estrus cycle .Hematoxylin and eosin staining was used to histological examination of the gerbil ovaries , and to detect the levels of serum PRL , LH, FSH and E2 by ELISA assay during estrus cycle .Results The proportion of cornified vaginal exfolliated cells could be the basis to distinguish four phases respectively:proestrus, oestrus, metoestrus, and dioestrus.Moreover, there were no significant differences between the numbers of ovarian follicles in different phases of estrus cycle .The numbers of corpus luteum in preoestrus were significantly lower than that in the other phases of estrus cycle ( P <0.05 ) .The levels of serum PRL and LH were increasing constantly from preoestrus to dioestrus , and both reached a peak at dioestrus ( P<0.05 ) .The levels of serum FSH and E2 both peaked at preoestrus , and were significantly higher than those at oestrus , metoestrus and dioestrus ( P<0.05).Conclusions There are no significant differences between the numbers of ovarian follicles in different phases of estrus cycle .Gonadotropin , prolactin and estradiol paly important roles in the regulation of estrous cycle .The phases during which surges of FSH and E 2 occur in Mongolian gerbils are similar to those of rats and mice , while the PRL and LH are different .Our findings provide further reference to the study of reproductive physiology of Mongolian gerbils .

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 .

Objective To establish a real-time quantitative PCR ( qPCR) method for detection of Streptobacillus moniliformis, which can be used to rapidly detect this pathogen in laboratory animals .Method According to the S. moniliformis sequences published in NCBI , we designed specific primers and MGB probe .The specificity, sensitivity and stability of this method were evaluated using 24 standard reference strains .Total of 823 respiratory specimens of animals including mice, rats, guinea pigs, hamsters, rabbits, Mongolian gerbils and tree shrews , were detected by this established Taqman MGB qPCR method .Results We had successfully established the S.moniliformis Taqman MGB qPCR method . S.moniliformis was not detected in the samples of mice , rats, guinea pigs, hamsters and rabbits.The positive rate of S. moniliformis was 1.5% ( 1/65 ) and 61.7% ( 37/60 ) in conventional Mongolian Gerbils and tree shrews , respectively . Conclusions Our developed qPCR method can be used to effectively detect S.moniliformis in laboratory animals .Moreover , its accuracy and sensitivity are better than the national standard method .This study laid the foundations for optimizing the quality inspection system of laboratory animals .

Objective To establish a fluorescence quantitative Taqman-PCR method for rapid and accurate detection of mouse poxvirus.Methods After sequence alignment and comparison, ERPV_027 gene was selected as the primer and probe design gene.Furthermore, the specificity, sensitivity, stability and reproducibility of these primers and probes were detected.Results The detection limitation of this method was 68 copies/μL.Data showed that this method has high specificity, which specifically amplifies mouse poxvirus, with no amplification signal of mouse hepatitis virus, Sendai virus, Salmonella and some other viruses and bacteria.This method also showed good stability and reproducibility. Conclusions This study has successfully established a fluorescence quantitative Taqman-PCR method for detection of mouse poxvirus, with high specificity, sensitivity, good stability and reproducibility, and a broad application potential.

Objective:To analyze the drug-resistant gene loci of Mycoplasma pneumoniae (MP) using metagenomic next-generation sequencing (mNGS). Methods:From November 2022 to October 2023, 697 clinical samples (including sputum, alveolar lavage fluid and blood) of 686 children with Mycoplasma pneumoniae positive detected by mNGS were retrospectively analyzed. Samples were divided into intensive care unit (ICU) group and non-ICU group, Chi-square test was used to compare groups, and Mann-Kendall trend test was used to analyze the change trend of the detection rate of drug resistance gene loci over time. Results:Of the 697 samples, 164 were from the ICU group and 533 were from the non-ICU group. The detection rate of Mycoplasma pneumoniae resistance gene was 44.3% (309/697), and all detected drug-resistant gene loci of MP were A2063G. The detection rate of Mycoplasma pneumoniae in ICU group was 50.0% (82/164), and the detection rates of Mycoplasma pneumoniae resistance gene loci in sputum, alveolus lavage fluid and blood samples were 75.0% (18/24) and 48.4% (62/128), respectively. The detection rate in sputum was higher than alveolus lavage fluid samples ( χ2=5.72, P=0.017). The detection rate of Mycoplasma pneumoniae in non-ICU group was 42.6% (227/533), the detection rate of Mycoplasma pneumoniae resistance gene loci in sputum and alveolar lavage fluid was 40.0% (16/40), 44.3% (201/454), and no detection rate in blood samples (0/12). There was no significant difference in the detection rate of alveolar lavage fluid and sputum ( χ2=0.27, P=0.602). From November 2022 to October 2023, the detection rate of submitted samples showed an increasing trend month by month (overall: Z=3.99, ICU inspection group: Z=2.93, non-ICU group: Z=3.01, all P<0.01). Among the bacteria commonly detected with Mycoplasma pneumoniae, Streptococcus pneumoniae accounted for the highest proportion, the detection rate was 15.5% (108/697), and Epstein-Barr virus accounted for the highest proportion of 17.6% (123/697). Conclusions:From November 2022 to October 2023, the detection rate of Mycoplasma pneumoniae drug resistance gene loci showed an increasing trend. The detection rate of drug resistance gene loci in sputum samples of ICU group was higher than alveolus lavage fluid. No new drug resistance site were detected.