Cats, owing to their physiological and immunological similarities with humans, have become increasingly valuable as model animals in virology research, drug development, and vaccine evaluation. They are irreplaceable in studies of feline immunodeficiency virus, feline coronavirus, and other related pathogens. However, cats are temperamentally sensitive, exhibit strong stress responses, and possess well-developed nervous systems as well as sharp claws and teeth. Consequently, the biosafety risks associated with infectious experiments using cats in animal biosafety level 2 laboratory (ABSL-2) are significantly higher than those encountered with conventional rodents. Drawing on long-term ABSL-2 operational experience, this article systematically reviews the entire workflow of infectious experiments in laboratory cats — from animal selection, pre-entry preparation, reception and quarantine, housing management, to infectious experimental procedures and incident response — identifying and addressing critical risk points at each stage. For strain selection, SPF-grade shorthair cats with defined genetic backgrounds and docile temperaments are recommended; sex and age should be scientifically matched to experimental objectives. During pre-entry preparation, emphasis is placed on dual-credential personnel management, health surveillance, standardized disinfection of environments and cages, feed and water standards, and robust record-keeping. During reception and quarantine, standardized protocols are established for transport control, appearance inspection, isolation quarantine, pathogen exclusion, and positive-reinforcement training. During infectious experimentation, a "three-fixed" husbandry principle is clearly implemented: dedicated caretakers, fixed feeding/cleaning times, and fixed cage positions. Disinfectant selection, autoclaving of waste, and daily veterinary rounds are rigorously enforced. Operational risk control includes detailed measures for graded personal protection, animal anesthesia and restraint, zoned operation within biosafety cabinets, and disposal of experimental waste. Contingency plans are formulated to address animal death, escape, personnel exposure, and spills of infectious materials. This study provides a reproducible and scalable technical pathway and operational standard for conducting infectious experiments in laboratory cats in ABSL-2 laboratories, offering a reference for other facilities undertaking similar work.

ObjectiveTo prepare rabbit anti-porcine inhibin polypeptide-keyhole limpet hemocyanin(KLH) conjugated polyclonal antibody and evaluate its effect on superovulation in C57BL/6J mice. MethodsNew Zealand white rabbits were immunized with a synthesized porcine inhibin polypeptide conjugated with KLH to produce anti-inhibin serum (AIS, i.e., inhibin polyclonal antibody). Female C57BL/6J mice received intraperitoneal injections of purified AIS in combination with pregnant mare serum gonadotropin (PMSG), followed by human chorionic gonadotropin (hCG) after 48 hours to induce superovulation. Oocytes obtained from superovulation were collected and counted 15 hours post-hCG administration, and the number of 2-cell embryos was assessed 24 hours after in vitro fertilization. ResultsAIS prepared by immunizing New Zealand White rabbits with KLH-conjugated porcine inhibin polypeptide was subjected to titer determination by indirect ELISA, showing titers reaching 1∶ 512 000. SDS-polyacrylamide gel electrophoresis analysis of ammonium sulfate-purified AIS revealed distinct 50 kDa and 25 kDa bands corresponding to the theoretical molecular weights of IgG antibody heavy and light chains, confirming successful production of porcine inhibin polyclonal antibody. Compared with conventional superovulation methods, AIS diluted 10-fold combined with PMSG significantly increased the number of oocytes obtained from superovulation in mice (P<0.05) by approximately 1.5-fold. ConclusionPorcine inhibin polyclonal antibody, as an improved superovulation reagent, can improve superovulation efficiency in C57BL/6J mice, and shows promising prospects for future applications.

ObjectiveTo observe the spontaneous testicular tumors in interferon receptor-deficient mice (AG129) and provide a basis for further research using this mouse strain. MethodsThe AG129 mouse population was bred in an SPF barrier environment and reproduced normally. Among the 3-week-old weaned mice, we found that one male mouse had an abnormally enlarged testis, while none of the other mice in the same litter exhibited a similar condition. The spontaneous testicular tumor in this mouse was continuously monitored. The mouse was euthanized and dissected at 9 weeks of age. The gross morphology of the tumor was observed, and the tissue was then embedded in paraffin and sectioned for hematoxylin and eosin (HE) staining. ResultsAfter several weeks of observation, the tumor tissue gradually increased in size as the mice aged. Upon dissection, the tumor tissue was encapsulated in a smooth capsule. After opening the capsule, the tumor tissue was irregular in shape, with some areas being hard and others soft. The results of HE staining showed that the tumor tissue developed from tissues derived from multiple germ layers, with nerve tissue, bone tissue, muscle tissue, and adipose tissue inside, exhibiting an irregular morphological structure. ConclusionBased on the tumor development, gross morphological structure, and the HE staining results of the pathological sections, the tumor in this mouse was preliminarily diagnosed as an immature teratoma.

Objective To analyze Pseudomonas aeruginosa (PA) infection and drug resistance in the elderly with respiratory tract infection, so as to provide a basis for the control of nosocomial infection and rational use of antibiotics. Methods The samples from elderly inpatients with respiratory tract infection were collected between March 2020 and March 2022. PA infection/colonization were investigated, and the drug resistance of pathogens was determined according to CLSI criteria (2019 version). Results There were 123 strains of PA isolated from the sputum and bronchoscopy lavage fluid of elderly patients with respiratory tract infection. The main departments with positive PA detection were respiratory department, ICU ward and neurology department. The difference of PA detection in different years was not statistically significant (P>0.05). The proportion of nosocomial infection in 2021 was lower than that in 2020 (44.44% vs 63.33%, c2=4.410, P=0.036). The resistance rate of 123 isolated PA strains to piperacillin was >90.00%, and they were resistant to ceftazidime, cefotaxime, cefepime, aztreonam and gentamicin to varying degrees. There was no significant difference in resistance rate of PA to antibiotics in different years (P>0.05). In the 123 strains of pathogens, there were 17 strains (13.82%) of carbapenem-resistant PA, and their resistance to common antibiotics was significantly higher than that of carbapenem-sensitive PA (P<0.05). Conclusion The main pathogen of nosocomial infection is PA, and the proportion of nosocomial infection shows a downward trend. The detection rate of carbapenem-resistant PA is high. In clinical treatment, targeted antibiotics can be applied.

Objective To evaluate the Effect of dexmedetomidine on the stress reaction for awake nasotra-cheal intubation in patients with maxillofacial tumor. Methods Forty patients,which are ASA physical status Ⅰor Ⅱ,aged 20 ~ 62 yr ,BMI < 25 and scheduled for radical operation for maxillofacial tuomr ,were randomly divided into 2 groups (n = 20 each)using a random number table:dexmedetomidine groups(group D)and mid-azolam group(group M). MAP ,HR ,SpO2 were recorded ,and the rate of respiratory depression ,the degree of tolerance and matching and the memory to intubation were recorded. Results Compared with the baseline value at T0,MAP and HR at T1-2 and HR at T3 were increased in group M. HR were increased at T1 in group D(P<0.05). Compared with group M,MAP and HR at T1-2 and HR at T3 were decresed in group D(P<0.05). The rate of respi-ratory depression in group D was decreased compared with group M ,and the degree of tolerance and matching to intubation was better in group D. Conclusion dexmedetomidine can inhibit the stress reaction caused by nasotra-cheal intubation in patients with maxillofacial tuomr ,and improve the degree of comfort and security in the process of intubation.