Abstract:Objective To study the effect of repeated rectal exposure of low-dose simian immunodeficiency virus on the systemic cellular immunity in monkeys. Methods Eight 3- to 4-year old rhesus macaques (Macaca mulatta) (male:female 1:1) were used in this study. The monkeys were inoculated with 10 TCID₅₀ SIVmac239 virus through rectum twice a week for consecutive 6 weeks to establish a multiple rectal exposure model of SIVmac239 virus infection. Then, plasma viral load, CD4⁺ T cell count, T cell subsets and IFN-γ secretion of the experiment monkeys were determined. Results Low-dose SIVmac239 virus induced some changes in the immune system through the rectal mucosa, but didn't induce typical infection. Repeated rectal mucosal low-dose virus exposure can activate the cellular immune system. Conclusions This study defines the effect of repeated low-dose simian immunodeficiency virus exposure on the systemic cellular immunity, and provided basic information for HIV-1 vaccine research.

Abstract:Objective In order to establish a rhesus monkey model of p53 gene silencing, firstly we screened and determined the effective silencing targets of p53 gene at the cellular level in rhesus monkey.Methods The expression of p53 gene was detected in COS-7 cells (derived from the kidney of the African Green Monkey, Cercopithecus aethiops).Three small hairpin RNA (shRNA) sequences targeting rhesus monkey p53 gene were designed, analysed by bioinformatics, and inserted into lentivirus-based gene silencing constructs FUGW-TDT. The plasmids of p53-RNAi and control vector were transfected into the COS-7 cells, respectively.The suppression of p53 mRNA was detected by real-time PCR, and the changes of p53 protein expression were detected by Western blot assay. Results p53 gene expression was detected in COS-7 cells.Bioinformatics analysis showed that three gene-silencing sequences were screened which lied in the open reading frame (ORF) region and targeted 238-258bp, 681-701bp, 169-189bp of the rhesus monkey p53 mRNA.At 48 hrs after transfection of the three silencing constructs, p53 mRNA was suppressed by(87.17±4.03)%, (72.62±4.11)% and(76.22±0.98)%, and p53 protein was suppressed by (84.44±2.18)%, (71.04±1.18)% and (74.17±0.95)%, respectively. Conclusions We obtained three effective target sequences showing high efficiency in p53silencing, which can be used in further studies on gene silencing in rhesus monkey.

Abstract:Objective To explore the differences in immune responses between Cricetulus barabensis and their albino mutant infected with Trichinella spiralis. Methods The physiological parameters of blood, expression levels of IL-2 protein and IL-6 gene in the spleen were analyzed. Results The level of immune cells and cytokines of Cricetulus barabensis was higher than that in the albino mutant. Conclusions Cricetulus barabensis is a suitable model animal for research on long-term latent infection such as infection with Trichinella spiralis.

Abstract:Objective To explore the reproductive toxicity of 2,4-D butylate to the testis in male mice.Methods Forty-eight ICR male mice were randomly divided into four groups: the control group, and three 2,4-D butylate experimental groups (10, 20, 40 mg/kg), 12 mice in each group. 2,4-D butylate was intragastrically administered once a day and six days per week for five weeks. At the end of the exposure, the activities of total antioxidant capacity (T-AOC), Na⁺ K⁺ -ATPase, Ca⁺⁺ Mg⁺⁺-ATPase, lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) in testis homogenate were measured by spectrophotometry. Results The activity of T-AOC was gradually decreased with the increase of doses, with a significant difference between the high dose group and other groups. The activities of LDH in the moderate and high dose groups were significantly lower than those of the low dose group and control group, and there was a significant difference between the high dose group and moderate dose group. The activities of SDH in the testis was gradually decreased with the increase of the 2,4-D butylate dose, showing significant differences between the high dose group and the moderate dose and control groups, and between the high and moderate dose groups and the low dose group. The activities of Na⁺K⁺-ATPase in the moderate and high dose groups were significantly lower than that of the control and low dose group. The activities of Ca⁺⁺Mg⁺⁺-ATPase was significantly lower in the experimental groups than that in the control group. Conclusion Exposure to 2,4-D butylate has certain toxic effect on the testicular tissue in male mice.

Abstract:Objective To explore the application value of ultra-high frequency ultrasound in detection of femoral artery stenosis in rabbits. Methods Twenty-four healthy male New Zealand white rabbits (body weight 2.5-3.0 kg) were randomly divided into three groups, 8 rabbits in each group. Preparation of femoral atherosclerosis model: the rabbits were fed with high fat diet for 4 weeks, 8 weeks and 12 weeks after femoral artery balloon injury, respectively. The changes of cholesterol level were observed. We used ultra-high frequency ultrasonic probe to observe the femoral artery, to assess the diameter stenosis rate and peak systolic velocity (SPV) at the symptomatic side, and the histological areal stenosis was evaluated. Results 1. The blood cholesterol levels were increased after fed high cholesterol diet, with a significant difference among the groups (P<0.001); 2. There was a stenosis to a different degree in the modeling artery after fed high cholesterol diet for 4 wks, 8 wks, and 12 wks, and the stenosis degree was increased gradually. At 12 w, the degree of stenosis was higher than that at 4 w and 8 w, respectively, showing statistical significance (P<0.001). At the symptomatic side, the peak systolic flow velocity was increased, and it was higher at 12 w than that at 4w and 8 w, respectively. 3. With the extension of time, the arterial stenosis rate was increased along with the time course (P<0.05). Conclusions 1. High fat diet combined with balloon injury can cause varying degrees of rabbit femoral artery stenosis; 2. Ultrahigh frequency ultrasound can clearly show different degrees of rabbit femoral artery stenosis, and can be used for detecting the lesions in animal models of peripheral vascular diseases.

Abstract:Objective To observe the effect of a Uyghur medicine Munziq Balgam on the mouse model of psoriasis. Methods 130 healthy Kunming mice were used in this study. The mouse model of psoriasis was established by applying 5% propranol hydrochloride emulsion to the mouse ear. The tail and ear skin histology was examined using HE staining, and the serum levels of IL-10, IL-17, IL-23 were measured with ELISA. Results The mice of Munziq Balgam treated groups (2, 4, 8 g/kg) did not show obvious abnormalities of general condition and body weight changes (P>0.05). The 8 g/kg Munziq Balgam treated group showed decreased thymus index (P<0.05). The 2, 4, and 8 g/kg Munziq Balgam treated groups showed no significant changes of the serum levels of IL-10, IL-17, and IL-23 (P>0.05). The 2, 4, and 8 g/kg Munziq Balgam treated groups showed promoted formation of epidermis granular layer in the mouse tail skin and improved histology of the ear skin. Conclusions The Uygur medicine Munziq Balgam shows therapeutic effect on experimental mouse models of psoriasis.

Abstract:Objective To investigate the infection status of Toxoplasma gondii in different colonies of tree shrews and then provide the basis for parasitological monitoring. Methods Each of the forty blood samples were randomly collected from three tree shrews colonies: wild origin, domesticated and first generation, respectively. Both indirect hemagglutination test (IHA) and PCR assay were used to detect the Toxoplasma gondii. Results No positive sample of Toxoplasma gondii was detected from either IHA or PCR results. The results from IHA and PCR assays were in coincidence with each other. Conclusions According to the survey none of the tree shrews from the three groups is infected with Toxoplasma gondii. More samples or infection experiments are needed to determine whether tree shrews can be infected with Toxoplasma gondii.

Abstract: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.

Abstract: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.

Abstract:Objective To accumulate operating experience and background data for housing mice in individually ventilated cages (IVC). Methods 5 weeks old Balb/c male mice(n=80) were allocated to 8 groups(n=10), which then housed in 5 or 10 per cage in 3 IVC systems(30,50 and 70 air changes/h, respectively) and one open-top cages(OTC) shelf for 8 weeks. Body weight was assessed at the initial date and every week. By the end of the experiment, necropsy was done and organs were separated and weighed. Excel and SPSS software statistics was made to draw the growth curve, and comparative analysis of body weight and organ coefficients was performed between the groups. Results 1.The growth curves of 5-mice per cage were better than that of 10-mice per cage. 2.In the IVC groups, the curves trend and fluency of 50 air changes/h were more similar to that of 5-mice housed OTC group. 3. The previously mentioned differences were statistically not significant (P>0.05). 4. In the liver coefficients, there was a statistically significant difference between the 10-mice housed OTC group and 5-mice housed IVC group with 30 air changes/h(P<0.05), there wasn`t any other significant statistically difference with the organ coefficients between groups(P>0.05). Conclusions Based on the results of this study, the air change frequency on 50 times per hour and keeping 5 Balb/c mice per cage is recommended as the best condition for mouse housing in IVC.

Abstract:The cause of dilated cardiomyopthy (DCM) has not been elucidated yet. The poor prognosis and lack of specific and effective treatment became a serious health problem. Therefore to establish animal models of DCM to study the pathogenesis and treatment is necessary and urgent. At present the molding method of DCM mainly includes drug induction, immunological induction and molecular biology, etc. This article reviews the mature and commonly used establishing methods and mechanism of DCM models.

Abstract:Microglia are the inherent macrophages and immune surveillance cells in the central nervous system (CNS) and compose the first guard of immune defense in CNS. The activation of microglia is one of the pathological features of many CNS diseases and acts as an important role during the multiple sclerosis (MS) process. MS is a CNS disease characterized by neuroinflammatory infiltration, demyelination and axonal damage. Accumulation of activated microglia at the injury site has been observed in brains of MS patients and experimental animals with complicated mechanisms. Microglia have both detrimental and beneficial roles. For instance, microglia have been shown to recruit and reactivate T cells in the CNS and release many detrimental molecules such as proteases, inflammatory cytokines, and free radicals. Conversely, they have also been observed to aid in axonal regeneration and remyelination as well as assist in the clearance of inhibitory myelin debris. In addition, microglia have been shown to release a variety of neurotrophic factors. Cuprizone[oxalic acid bis(cyclohexylidene hydrazide)] is a well-known copper-chelating agent. Cuprizone ingestion in mice induces a highly reproducible demyelination of distinct brain regions. Discussion on the detrimental and beneficial aspects of microglia in cuprizone animal models will serve to better understand the development of MS and find out new therapeutic targets. This review will further our understanding of the dichotomous roles of microglia in cuprizone-induced demyelination in animal models of multiple sclerosis.

Abstract:Acute hepatic failure (AHF) is a severe liver disease associated with a variety of clinical symptoms. AHF is difficult to treat and with a high mortality rate. Therefore, it is necessary to establish animal models of AHF for the investigation of therapy. In this article, the preparation methods of AHF animal models are reviewed which are applicable to different types of animals.

Abstract:Guinea pig as a commonly used laboratory animal is widely used in various fields of biomedical research. The stability of genetic quality directly affects its development and application. Genetic testing is designed to confirm the genetic characteristics of each strain, to verify whether there are genetic mutations and other genetic contamination, to ensure that the test object meets the requirements of this strain. Along with the emerge of biochemical and molecular marker technology, a more convenient and reliable means is provided for research of genetic homozygosity, genetic type detection and genetic quality monitoring of guinea pigs. In this paper, the application and research progress of biochemical, cytological and molecular markers in studies of guinea pig diversity will be summarized, and provide some help for genetic testing guinea pig.

Abstract:It is very important to establish and execute the all-sided experimental animal quality monitoring in order to guarantee human health, animal health and welfare as well as the authenticity, validity, and repeatability of the experimental research results. Setting corresponding sentinel animals in the experiment can effectively monitor the quality of experimental animals. This article gives a general review of the selection of sentinel rats in the microbiological quality monitoring of the experiment animals, contact form and time between the sentinel rats and the rats being monitored, the placement of sentinel rats, and the number of rat cages being monitored by each cage of sentinel rats, as well as the test quantity, test frequency and the project.

Abstract:Animal models are highly valuable systems that have been extensively used to elucidate human disease pathogenesis and to find therapeutic ways to treat human diseases. Since non-human primates are close to humans,monkeys are important model species in exploring the mechanisms and treatment of human neurodegenerative diseases, neuropsychiatric disorders, cognitive function, and neural circuits. However, due to the lack of embryonic stem cell lines in large animals, the traditional gene targeting technology is difficult to establish primate animal models of human diseases. CRISPR/Cas9, as a recently developed tool for genome modifications, has been successfully used to target genomic loci in mouse, rat, monkey, and other species. Here, we discuss the utilization of CRISPR/Cas9 technology in establishing monkey models for studying human neurodegenerative diseases.

Abstract:Because of its unique advantages, zebrafish has been more and more widely used in drug screening and safety assessment, environmental protection, developmental biology and other fields. But the standardization of environments, feed, and water environment of zebrafish are prominent problems and weakness which hindered their application. This paper probes into the standardization of environment and feed of zebrafish in Zhejiang, in order to promote its standardization construction.