China National Accreditation Service for Conformity Assessment (CNAS) laboratory animal institutions accreditation is an important system for the management of laboratory animals in China. It is a third-party evaluation on Chinese characteristics dedicated to ensuring the quality and welfare of laboratory animals in China. The American Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC) certification provides global services about animal welfare evaluation and ethical certification, which are important for management and use of laboratory animals. This study compared and analyzed the nature of CNAS and AAALAC, the nature of CNAS accreditation and AAALAC certification, the evaluation principles, required documents, the evaluation process, the management of reviewers, and the acceptance of results, and discussed the differences and characteristics of the two evaluation systems for laboratory animal institutions.

TD disinfectant has been employed in hospital and used to clean and disinfect vegeta-bles and fruits. It is harmless to both men and animals. The possibility of TD disinfectant to be used in laboratory animal facilities was studied. The results showed that TD could be used for the disinfection of animal cages，air，ceiling and walls of animal rooms at the con-centration of 0.5% （W/V） ； 1% TD was available for the disinfection of the floor and cage racks；The disinfection effect of 0. 5% TD was similar to those of 5% lysol and 0.1% bro-mogeramine. These results suggest that TD disinfectant can be employed for the disinfec-tion of laboratory animal facilities.

With the development of innovative medicine discovery, various kinds of immunodeficiency mice or severe combined immunodeficiency mice were more widely used in each research institutes. The newly raised problem is that the barrier environment and animal populations of more animal research facilities were contaminated by Corynebacterium bovis (C. bovis). At present, the  C. bovis has not been enrolled into SPF laboratory animal-microbiologic standards in China, although this opportunistic pathogen has great threat to immunodeficiency animals. As rapid spread contamination and extremely difficult elimination of C. bovis, it is an extensive disaster to immunodeficiency animal facilities, and there were no appropriate prevention and elimination solutions in the past. In this paper, based on the research progress and the experience of two animal research facilities in past six years, the feasible strategies to prevent and eliminate C. bovis from barrier facilities were proposed.

Ultrasonic-B was used for the diagnosis of early pregnancy in Rhesus monkey, 23 cases at 18-30 days of gestation were confirmed in 22 with one suspected,15 cases at 31-60 days of gestation were all confirmed by the diagnosis. In early pregnancy monkeys,a region of even and strong echogram and single gestational sac（GS） may be seen in their uteri. Most of the GS were round or oval in shape and the size increased with the length of the gestational period. With the advance of the gestation,fetus and heartthrob of the embryo may be seen. The size of the uterus in normal monkey during breeding season was less than 28mm in length and 22mm in width, no strong echogram region was found in the uterus.

Male Clean SD rats were divided into two groups, and raised in conventional facility (open air,group 1 , n=54) or in a room utilizing laminar air flow with filtration (clean air, group 2, n=50). To induce immunosuppression the rats were given cortisone acetate (25mg×2/week，sc)for 12 weeks, then the lung impression smears and bronchoalveolar lavage fluid sediment smears stained with Giemsa stain and lung sections stained with Gro-cott-Gomori silver stain were prepared to find Pneiunocystis carinii (PC) organism. Bacteria and fungi were also checked. The results showed that the incidence of induced Pnenmocystis carinii pneumonia (PCP) in group 2 (28%, 14/50) was higher then that in group 1 (0% ,0/54, P＜0.001),and that the incidence of bacterial pneumonia in group 2(62%) was lower than that in group 1 (89% , P＜0.01). The results suggested that the air quality of breeding room could affect the incidence of PCP induced by immunosuppressive agents in rat.

The accreditation for laboratory animal institutions of China National Accreditation Service for Conformity Assessment (CNAS) is a third-party evaluation program that is in line with international practices and China's national conditions, it is complementary to the national laboratory animal license system, and is an important system for the management of laboratory animal institutions. This paper introduces the origin, development, status quo, problems, and challenges of CNAS laboratory animal accreditation, and proposes countermeasures and suggestions for improving the accreditation system of laboratory animal institutions.

The descent of testicles and reproduction of Meriones meridianus jei and Cricetulus migratorius in breeding rooms were observed in four conditions ：under the artificial illumination with a regime of D8 : L16 at temperature 15～20℃ or 10～14℃，and utilizing the sun-shine with a regime of Dll. 5～15 : L12. 5～9 at two temperatures mentioned above. The results showed that both M. meridianus and C. migratorius belong to the rodents of long sunshine type. With the lighting regime D8 : L16,raising temperature could lead the testes to descend,and the copulations were effective by more than 43d and 21d’s stimulating (15～20℃) in M. meridianus jei and C. migratorius respectively. With the lighting regime Dll. 5～15 : L12. 5～9，raising temperature could stimulate the testes to descend in C. migratorius that could also take part in reproduction by more than 60d’s stimulating (1.5～20℃) »but not in M. meridianus jei.

Object Studing the feasibility of saving mice embryos in vapour nitrogen transport jar in short time. Method we used in vitro fertilization to get the 2-cell embryos of C57BL/6J, B6D2F1, DBA/2, B10A，these embryos were vitrificated in liquid nitrogen，then transferred to vapour nitrogen jar. About 14 days later，these embryos were transferred to liquid nitrogen again for some time. Last, these embryos were post-thawed and transferred to psudopregnant mice. Result The rate of the post-thawmg of the embryos from C57BL/6J，B6D2F1, DBA/2, B10A were 69.70%, 77.27%, 77.59%, 72.64%, and the control groups (embryos vitrificated in liquid nitrogen only) were 97.00%、84.38%、 75.00%、71.43% respectively, there was no difference in the two groups ( P＜0.05). When transferred to psudopregnant, there were no difference in C57BL/6J, B6D2F1, DBA/2 in tne rate of birth. But for B10A，the difference was significant( P＜0.01). Conclution The vapour nitrogen transport jar is suitable to cryopreserve and transport mice embryos in short time.

Objective To evaluate the biocompatibility which include blood、muscle and genotoxicity of coronary stents in rabbits. Methods Cased on ISO 10993-10，the assessments of biocompatibility were identified by experiment of the blood compatibility, genetic toxicity test and local reactions of muscle embedding test. Results 1. Coronary stents had no effects on the coagulation system of the rabbits 2. The histopathology and clinical anatomical observation of the local muscle were normal and no chromosome aberration . 3.The package remained sterile and no leakage were found. Conclusion 1. In rabbits coronary stents had no effects on the coagulation system，no local irritative reaction and genotoxicity as well. 2.The package remained no leakage and the efficacy of the package in blockage of bacteria appeared to be very effective.

Specific pathogen free KM mice were obtained from Cesarean section. Random mating system （rotational mating） was established to produce and maintain the mice in the barrier system. The growth rate and reproductive performance and genetic profiles were measured and detected in the fifth and tenth generation of the random mating groups. The results were compared with those of the chance mating group,and was verified that the random system mating method is an important measure for the maintenance of out bred colonies.

The Reconstruction program for the ventilation system in laboratory animal rooms was reported. The indoor inlet and outlet were installed with medium - efficacy filter and rough filter respectively. The fresh air was supplied by the original ventilation system. The indoor fresh air mixed with the circulating air was cooled or heated by the window air condition machines,and then pumped through tubular filter into the animal room. The reconstructed animal rooms reached the requirements of clean semi - barrier system with low cost and energy consuming.