Objective To establish a canine model of intervertebral disc extrusion by surgery and observe the histological and microcirculatory changes of the spinal cord , in order to accumulate data for studies on the pathology and mechanism of treatment for intervertebral disc extrusion .Methods Normal healthy adult dogs were divided randomly into two groups:normal control group and model group .To simulate the intervertebral disc extrusion caused by spinal cord compression, 6Fr double lumen catheter with ballon was inserted into the spinal cord T 12-T13 and filled with about 5 mL Iohexol after the exposure of spinal cord L 1 by hemilaminectomy .The spinal cord blood flow ( SCBF) at the L1 level before and after compression was measured by laser-Doppler flowmetry .Morphological changes of the compressed spinal cord at 14 days after compression was examined by histopathology .Results The ( Texas spinal cord injury score ) ( TSCIS) scores of the motor function of bilateral hind limbs were highly significantly decreased (P<0.01).The blood flow of spinal cord at the L1 level was significantly decreased (P<0.05) after compression than that before .Compared with the normal control group, the model group showed abnormal vacuolization in the white matter and the number of normal neurons in the ventral horn of gray matter was significantly lower ( P<0.01 ) .Conclusions Our findings demonstrate that canine models of intervertebral disc extrusion can be successfully established by balloon catheter compression , showing local impairment of microcirculation and histological changes in the spinal cord .This canine model may provide a useful model for evaluation of therapeutic effects of acupuncture and for mechanism studies .

Objective To establish an effective PCR assay for detection of Bartonella, and application of this assay in tree shrew .Methods Sequence of Bartonella was obtained from NCBI Genbank .Three pairs of primers were designed based on this sequence .One pair of primers was determined through amplifying the major strains in China .Sixty tree shrew blood samples were tested with this PCR assay .The positive amplified fragments were sequenced to verify the reliability of this method .Results A PCR method for detection of Bartonella is successfully established , with a high specificity and the sensitivity was of 2.0 ×10 -5 μg/mL.Among the tested 60 blood samples , 15 positive cases were detected.Sequencing of the samples confirmed a 25%infection rate of Bartonella in the tree shrews, well consistent with the amplification results , and verified the applicability of this detection method .Conclusion The establishment of this method provides the basis for detection of Bartonella in tree shrew.

The present situation , efficacy, problem and strategy of laboratory animal license management in Guangdong Province were reviewed in this article .The laboratory animal license management has been implemented for 10 years and showed good results .Now there are comprehensive management of quality , facilities, personnel, SOP, and unified item bank, and making standard of laboratory animals in Guangdong Province .The legislation of Guangdong laboratory animal management regulations is completed .Guangdong laboratory animal license is increased year by year .The distribution of industry and area is expanded .Through analysis of problems and search for strategy , Guangdong laboratory animal management will be further developed .

Objective To explore the use of integrated two methods in vitro in prediction of eye irritation caused by cosmetics.Method Chorioallantoic membrane vascular assay ( CAMVA), bovine corneal opacity and permeability (BCOP) and Draize rabbit eye irritation test were used to determine the predictive potential of eye irritation of 60 kinds of cosmetics.Results CAMVA method was able to distinguish 41 non-irritant samples and 18 irritant samples.BCOP method was able to predict 35 non-irritant samples , 21 mild-moderate irritant samples and 4 severe irritant samples . Combination of CAMVA and BCOP methods could obviously improve the identification ability of irritation , and the classification consistency with Draize rabbit eye irritation testing reached 98.3%.Conclusions The integrated test strategy combined BCOP with CAMVA can be used to appropriately predict ocular irritation of cosmetics , with a prediction range covering non-irritant to severe irritant samples .

Objective To establish a reverse transcription nested polymerase chain reaction ( RT-nPCR ) assay for detection of tree shrews orthoreovirus (TRV).Methods Three strains of TRV were respectively isolated from fresh feces of three tree shrews that came from the same field at different times .We designed and synthesized two pairs of MRV L1 gene nested primers and established the system of RT-nPCR.The TRV RNA was extracted and reversely transcribed to cDNA as a template for nested-PCR amplification.The developed RT-nPCR was optimized.The specificity and sensitivity were tested.Finally, the RT-nPCR was used to detect TRV in 25 tree shrew samples.Results Taking the genomic RNA of TRV as template, the RT-nPCR was able to amplify a specific fragment band targeting the L 1 gene, while there were no target bands in the normal cell control , ( Wa strain rotavirus , hepatitis A virus , and herpes simplex virus ) .The RNA of TRV was diluted by 1:10 to 1:109 .Each dilution sample was analyzed by the RT-nPCR.The minimum detectable concentration of RNA was 0.01 pg/μL.The results of RT-nPCR detection showed that 4 of the 15 tree shrews were TRV-positive in the survival group , and 10 of 10 tree shrews were TRV-positive in the death group . Conclusions The RT-nRCR assay established in this study is accurate , specific and sensitive .Therefore, it can be used for routine detection of TRV in quality assurance testing .

Objective To establish an indirect immunofluorescence assay for detection of murine norovirus ( MNV) .Methods Mouse leukaemic monocyte macrophage cell line RAW 264.7 cells were infected with MNV-1 and cultured for 36 hours to collect the virus and uninfected cells , and to make antigen glass slides .BALB/c mice were gavaged with MNV-1 (107 TCID50) and infected sera were collected as positive control .The serum was 1:10 diluted and used for measuring MNV antibody by immunofluorescence assay ( IFA ) .80 serum samples were tested using the two methods , IFA and ELISA, and the discrepant samples were validated by Western blotting .Results RAW264.7 cells were infected with MNV-1 for 36-48 h, showing an infection rate of 60% of the cells, and the cells infected for 36 h were preferred.IFA method was used to detect the serum with MNV-1 infection and showed that the antibody content was gradually increased at one week after infection , reaching a maximum antibody concentration at 4 weeks after infection , and maintained a stable level later .The mouse serum at four weeks after MNV-1infection was used as positive quality control . Among the 80 serum samples , 27 positive and 53 negative cases were detected by IFA method , and 32 positive and 48 negative cases were detected by ELISA .The five discrepant samples were verified by Western blotting , resulted in 3 positive and 2 negative cases . The coincidence rate of IFA was 96.0% and that of ELISA methods was 97.5%. Conclusions Basically, immunofluorescence assay can be used to detect the MNV-1 infection in mice, although false negative result may occur occasionally .IFA and ELISA detection can be selected as initial screening measures , and use Western blot assay to verify the discrepant samples .

Objective To improve the accuracy of detection through analyzing the phenotypes of P.pneumotropica isolates in laboratory animals in Beijing area .Methods 306 suspicious P.pneumotropica strains were identified by biochemical identification and 16S rDNA sequencing.Then, to obtain the phylogenetic relationships combined with colony characteristics on blood agar plates and biochemical characteristics of 53 biotypes .Results BD Phoenix 100 automated bacterial identification system and 16S rDNA sequencing identified P.pneumotropica positive rate of 306 isolates were 164/306 and 227/306, respectively.There were 140 phenotypes in 227 true-positive strains, of which 106 were biotype Heyl and 23 were biotype Jawetz .Conclusions In the samples of laboratory animals in Beijing area , P.pneumotropica infection mainly are of biotype Heyl , and less is of biotype Jawetz .The phenotypes are diverse and widely distributed .

Objective To study the toxicity of fosthiazate feeding for 90 days in rats, and to determine the maximal non-effective dose of fosthiazate , in order to provide the reference dose for safety in production and chronic toxicity experiment.Methods A total of 80 SD rats ( half female and half male ) were randomly divided into 4 groups, respectively:0.8 mg/kg· bw· d group, 4.0 mg/kg· bw· d group, 20.0 mg/kg· bw· d group, and normal control group .The rats were sacrificed to determine the indices including serum biochemical parameters , body weight , routine urine test and organ coefficients after the end of the experiment , and the results were statistically analyzed .Results In the high dose group, the body weight gain was slowed in male and female rats .The TG and CHE in the high dose group of male rats and the TP, ALB, CREA, GLU, and CHE in the high dose group of female rats were significantly lower than those of normal control group.The ALP in the high dose group of female rats was higher than that of the normal control group .The positive rates of BIL, SG, and PRO in both male and female rats had significant differences compared with those of normal control group.The organ coefficients of brain , lung, kidney, adrenal, and testis of male rats, and the organ coefficients of brain , lung, and kidney of female rats in the high dose group were significantly higher than those of the normal control group .The ovaries and uterus in the female rats of high dose group were significantly lower than those of normal control group ( P<0.05,P<0.01).Conclusions The oral dose of fosthiazate at 4.0 mg/kg· bw· d fed for 90 days and above cause toxic effects on rats , and its maximal non-effect dose of long-term intake of low-dose fosthiazate on rats is 4 mg/kg· bw· d.

Objective The aim of this study was to observe the anesthetic effect of xylazine hydrochloride Injection on Beagle dogs.Methods Anaesthetizing 30 healthy Beagles with xylazine hydrochloride injection, some physiological indexes of the dogs, such as body temperature (T), respiration (R), heart rate (P), and blood pressure (systolic pressure SBP, diastolic pressure DBP), were monitored.Results After using xylazine hydrochloride injection, the body temperature, respiration, heart rate, blood pressure, and peripheral vascular resistance were decreased in the Beagles.Conclusion Xylazine hydrochloride injection can keep a stable induction period, and has advantages including powerful and quick effect, simple method and operation, safe and insignificant toxicity and side effects,and has a better effect of anaesthesia.

Objective To understand the histological characteristics of the major endocrine organs of tree shrew , and provide a normal histological atlas of endocrine organs of tree shrew .Methods Ten artificially fed healthy tree shrews were killed and dissected after anesthesia .The thyroid, parathyroid, adrenal and pituitary glands were observed by gross inspection and samples were taken for routine histological examination with HE staining .Results ( 1 ) The thyroid gland was pale yellow, located on both sides of the 2-4 tracheal rings.The thyroid gland was plate-shaped, its surface was covered with a thin fibrous capsule . The thyroid parenchyma was divided into several lobules by stretched capsule membrane .Follicular and parafollicular cells were distributed in the lobules , and red colloid was present in follicular cavity.(2) Each side had one parathyroid , located on the cranial or the outer surface of the middle part of the thyroid gland, and was slightly covered by thyroid .The gland was round or oval , and its parenchyma was made up of the principal cells and eosinophil cells , and acinar structure appeared in the parenchyma .( 3 ) The adrenal glands were oval , yellow color, located in the renal hili , and linked to the kidneys .They were surrounded by a thin capsule .The parenchyma was divided into cortex and medulla .The cortex was divided into zona glomerulosa , zona fasciculata and zona reticularis from outside to inside.The zona glomerulosa was the thickest layer and the zona fasciculata was the thinnest .The medulla cells formed clumps or mesh, with central vein in the central part .(4) The pituitary gland was located in the sella turcica , with no recessus hypophysis .The pituitary gland was composed of the adenohypophysis and neurohypophysis .Its surface was covered with a connective tissue capsule .The pituitary gland was divided into distal part , middle part and pars tuberalis . neurohypophysis was made up of neural and pars infundibularis .Conclusions The histological atlas of endocrine organs in the tree shrew is established , which is close to that of the primate animals in the morphology , and provide histological evidence for the study of tree shrew endocrine organs and disorders , as well as the animal model of human diseases .