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.

OBJECTIVES: To estimate postmortem interval (PMI) by analyzing the protein changes in skeletal muscle tissues with the protein chip technology combined with multivariate analysis methods. METHODS: Rats were sacrificed for cervical dislocation and placed at 16 ℃. Water-soluble proteins in skeletal muscles were extracted at 10 time points (0 d, 1 d, 2 d, 3 d, 4 d, 5 d, 6 d, 7 d, 8 d and 9 d) after death. Protein expression profile data with relative molecular mass of 14 000-230 000 were obtained. Principal component analysis (PCA) and orthogonal partial least squares (OPLS) were used for data analysis. Fisher discriminant model and back propagation (BP) neural network model were constructed to classify and preliminarily estimate the PMI. In addition, the protein expression profiles data of human skeletal muscles at different time points after death were collected, and the relationship between them and PMI was analyzed by heat map and cluster analysis. RESULTS: The protein peak of rat skeletal muscle changed with PMI. The result of PCA combined with OPLS discriminant analysis showed statistical significance in groups with different time points (P<0.05) except 6 d, 7 d and 8 d after death. By Fisher discriminant analysis, the accuracy of internal cross-validation was 71.4% and the accuracy of external validation was 66.7%. The BP neural network model classification and preliminary estimation results showed the accuracy of internal cross-validation was 98.2%, and the accuracy of external validation was 95.8%. There was a significant difference in protein expression between 4 d and 25 h after death by the cluster analysis of the human skeletal muscle samples. CONCLUSIONS The protein chip technology can quickly, accurately and repeatedly obtain water-soluble protein expression profiles in rats' and human skeletal muscles with the relative molecular mass of 14 000-230 000 at different time points postmortem. The establishment of multiple PMI estimation models based on multivariate analysis can provide a new idea and method for PMI estimation.
Animals ; Humans ; Rats ; Multivariate Analysis ; Postmortem Changes ; Protein Array Analysis ; Technology

Improving the reproducibility of biomedical research results is a major challenge.Researchers reporting their research process transparently and accurately can help readers evaluate the reliability of the research results and further explore the experiment by repeating it or building upon its findings. The ARRIVE 2.0 guidelines, released in 2019 by the UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), provide a checklist applicable to any in vivo animal research report. These guidelines aim to improve the standardization of experimental design, implementation, and reporting, as well as the reliability, repeatability, and clinical translatability of animal experimental results. The use of ARRIVE 2.0 guidelines not only enriches the details of animal experimental research reports, ensuring that information on animal experimental results is fully evaluated and utilized, but also enables readers to understand the content expressed by the author accurately and clearly, promoting the transparency and integrity of the fundamental research review process. At present, the ARRIVE 2.0 guidelines have been widely adopted by international biomedical journals. This article is a Chinese translation based on the best practices of international journals following the ARRIVE 2.0 guidelines in international journals, specifically for the complete interpretation of the ARRIVE 2.0 guidelines published in the PLoS Biology journal in 2020 (original text can be found at https://arriveguidelines.org). The third part of the article includes the items 8-10 of ARRIVE 2.0 Essential 10, which covers "experimental animals" "experimental procedures" and "results". Its aim is to promote the full understanding and use of the ARRIVE 2.0 guidelines by domestic researchers, enhance the standardization of experimental animal research and reporting, and promote the high-quality development of experimental animal technology and comparative medicine research in China.

Objective To explore the value of CT images in distinguishing perihematomal edema in basal ganglia intracerebral hemorrhage with normal brain tissue,and its significance in assessing patients' conditions and prognoses.Methods CT images and clinical data of 120 patients with basal ganglia intracerebral hemorrhage admitted to our hospital from January 2017 to September 2018 were collected,and these 120 patients were randomly assigned to group of training data set (n=90) and group of test data set (n=30) at a ratio of 3∶l.The texture analysis software Mazda was used to preprocess the CT images and manually sketch the regions of interest (ROIs) to extract the texture parameters in patients from the group of training data set;Mazda software provides texture feature selection methods including mutual information (MI),Fisher coefficients (Fisher),classification error probability combined with average correlation coefficients (POE+ACC),and texture feature analysis including raw data analysis (RDA),principal component analysis (PCA),linear classification analysis (LDA) and nonlinear classification analysis (NDA);texture feature selection methods and texture feature analysis were grouped by pairs to establish different image omics labels;the error rate was used to evaluate the performance of different labels.Random forest model,support vector machine model and neural network model were built for texture parameters in patients from the group of test data set,and texture parameters extracted from patients from group of training data set were imported into these models;receiver operating characteristics curve was used to assess the performance of models.According to the maximum diameter of the hematomas,Glasgow coma scale (GCS) scores at admission,median of National Institute of Health Stroke Scale (NIHSS) scores 3 months after follow up,all patients were divided into two groups;Mazda software was used repeatedly for dimension reduction and establishment of different images omics labels;the sum of error rates from the two groups was taken as total error rate to evaluate the significance of different labels in predicting patients' conditions and prognoses.Results A total of 295 texture parameters were extracted from the ROIs of the best CT images of 90 patients from group of training data set,and 10 characteristic texture parameters were obtained by each of the three dimensionality reduction methods.Among all texture post-processing methods,the lowest error rate was 2.22％ for POE+ACC/NDA;AUCs were 0.87 (95％ CI:0.76-0.97),0.81 (95％ CI:0.72-0.93) and 0.76 (95％CI:0.67-0.89) for random forest model,support vector machine model and neural network model in the test dataset,respectively,which indicated that random forest model had the best forecast performance.The imaging omics labels established based on POE+ACC/NDA had the lowest total error rate for analysis of maximum diameter ofhematoma and GCS scores at admission (26.66％,23.33％);the imaging omics labels established based on Fishers coefficient method and NDA had the lowest total error rate(33.33％) for analysis of NIHSS scores at 3 months of follow up.Conclusion Radiomicmethod with proper model is of certain value in distinguishing erihematomal edema in basal ganglia intracerebral hemorrhage with normal brain tissue,and also has certain significance in evaluating the patienfs conditions and prognoses.

Objective To assess the effectiveness of osteoperiosteal decortication and extracortical bone-bridging in the treatment of atrophic humeral nonunions.Methods Nineteen patients with atrophic humeral nonuninon were treated by osteoperiosteal decortication and extracortical bone-bridging between March 2008 and April 2016.They were 12 men and 7 women,aged from 23 to 68 years (mean,36.6 years).The fracture was located at the left side in 10 cases and at the right side in 9.Before admission to our hospital,8 had received surgery once,6 twice and 5 thrice.The time from fracture to hospitalization ranged from 12 to 106 months (average,26.3 months).Shoulder function was evaluated by Neer scoring and elbow function by Mayo elbow performance score (MEPS) at final follow-ups.Results All incisions healed by first intention.Two cases reported transient radial nerve symptoms of numbness.All the 19 patients were followed up for 28.9 months on average (range,from 13 to 78 months).Radiographic examinations showed signs of bone remodeling,disappearance of fracture lines and formation of extracortical bone bridge at 6 to 8 weeks after operation.All of them achieved radiographic union within 10 to 46 weeks (16.8 weeks on average).The Neer scores averaged 82.5 (range,from 70 to 98),giving 12 excellent cases,5 good ones and 2 fair ones.The MEPS averaged 84.4 (range,from 70 to 96),giving 11 excellent cases,5 good ones and 3 fair ones.Conclusion Osteoperiosteal decortication and extracortical bone-bridging in treatment of atrophic humeral nonunions can effectively induce osteogenesis and increase stability of broken ends,promoting bone healing.

Air Pollution, Indoor ; analysis ; China ; Environmental Monitoring ; Humans ; Surveys and Questionnaires

Objective To explore the effect of traumatic brain injury on the fracture healing and its related mechanism by observing the expression of platelet-derived growth factors (PDGF) in serum and bone callus in rats with bone fracture and cerebral trauma.Methods One hundred and forty-four SD rats were randomized into 4 equal groups (n =36) which were subjected respectively to:no treatment (group N),traumatic brain injury (group TBI),bone fracture (group F) and bone fracture and cerebral trauma (group TBI + F).The animals were sacrificed at 3 days,1,2,3 and 4 weeks after modeling.In all the 4 groups,ELISA was used to detect the expression of PDGF in serum.In groups F and TBI + F,the callus growth was observed at the right tibial fracture site by X-ray,the callus growth and morphology were also observed by HE staining,the expression of PDGF in the callus tissue was measured by immunohistochemieal analysis,and the expression of PDGF mRNA in the callus tissue was measured by RT-PCR.Results X-ray showed that fracture healing was accelerated in group TBI + F compared with group F.The serum expression of PDGF in group TBI + F was significantly higher and the peak time was significantly earlier than in the other 3 groups (P ＜ 0.05).H-E staining showed that osteoblastic activity at the fracture ends in group TBI + F was stronger than in group F.Inmunohistochemica[staining showed that the expression of PDGF in the local callus was significantly higher at 3 days and 1 week in group TBI + F and the peak time was significantly earlier than in group F (P ＜ 0.05).RT-PCR showed that the expression of PDGF mRNA in the local callus was significantly higher at 3 days and 1 week in group TBI + F than in group F (P ＜0.05).Conclusions Traumatic brain injury can promote fracture healing in rats,which is probably related to increased expression of PDGF after cerebral trauma.

Objective To assess the effectiveness of pedicled iliac periosteal flap graft for treatment of old femoral neck fracture in adolescents.Methods Between June,2005 and December,2013,15 patients (15 hips) of old femoral neck fracture in adolescents treated with vascular pedicled iliac periosteal.There were 11 males and 4 females with an average age of 15.8(range 12 to 18) years.Based on the location of fracture,there was 5 cases of subcapital,8 cases of transcervical and 2 cases of basal.6 cases were treated with lower limb traction,3 cases with internal fixation and 6 just without any treatment.The average duration from injury to the second operation was 4.8 (range 1 to 19) months.There were 2 cases of femoral head necrosis after femoral neck fracture.Open reduction,pedicled iliac periosteal flap grafting and cannulate screw fixation were performed.Results All incisions healed by first intention.All patients were followed up 12 to 90 months (mean,46 months).The HHS was increased from (48.7 ± 8.3) pre-operation to (91.3 ± 6.1) at last followed-up,indicating a significant difference between before and after operation (P ＜ 0.01).One patient underwent total hip arthroplasty at 10 months after operation because of fracture nonunion and femoral head necrosis.Fracture healed successfully in 14 cases and the average time of fracture healing was 4 (range 3 to 6) months.Certain extent of remodelling and bulge of the head were observed in 2 cases of collapsed heads.Conclusion Pedicled iliac periosteal flap graft can provide good osteogenesis and vascular reconstruction for femoral head and promote fracture healing in treatment for old femoral neck fracture in adolescents.