Advances in viral encephalitis:Viral transmission,host immunity,and experimental animal models

Viral infections have led to many public health crises and pandemics in the last few centuries.Neurotropic virus infection-induced viral encephalitis(VE),especially the symptomatic inflammation of the meninges and brain parenchyma,has attracted growing attention due to its high mortality and disability rates.Understanding the infectious routes of neurotropic viruses and the mechanism underlying the host immune response is critical to reduce viral spread and improve antiviral therapy outcomes.In this review,we summarize the common categories of neurotropic viruses,viral transmission routes in the body,host immune responses,and experimental animal models used for VE study to gain a deeper understanding of recent progress in the pathogenic and immunological mechanisms under neurotropic viral infection.This review should provide valuable resources and perspectives on how to cope with pandemic infections.

Standardization of experimental animals temporal bone sections

Preparation of the temporal bone for light microscopy is an important step in histological studies of the inner ear. Due to the complexity of structures of the inner ear, it is difficult to measure or compare structures of interest without a commonly accepted standardized measure of temporal bone sections. Therefore, standardization of temporal bone sections is very important for histological assessment of sensory hair cells and peripheral ganglion neurons in the cochlear and vestibular systems. The standardized temporal bone sectioning is oriented to a plane parallel to the outer and internal auditory canals. Sections are collected from the epitympanum to the hypotympanum to reveal layers in the order of the crista ampullaris of the superior and lateral semicircular canals, macula utriculi and macula sacculi, superior vestibular ganglion neurons, macula of saccule and inferior vestibular ganglion neurons, cochlear modiolus, endolymphatic duct and endolymphatic sac, and finally the crista ampullaris of the posterior semicircular canal. Moreover, technical details of preparing for temporal bone sectioning including fixation, decalcification, whole temporal bone staining, embedding penetration, and embedding orientation are also discussed.

Effects of mesenchymal stem cell on dopaminergic neurons,motor and memory functions in animal models of Parkinson's disease:a systematic review and meta-analysis

Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse the disease itself.Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson’s disease.Mesenchymal stem cells are considered a promising option due to fewer ethical concerns,a lower risk of immune rejection,and a lower risk of teratogenicity.We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function,memory,and preservation of dopamine rgic neurons in a Parkinson’s disease animal model.We searched bibliographic databases(PubMed/MEDLINE,Embase,CENTRAL,Scopus,and Web of Science)to identify articles and included only pee r-reviewed in vivo interve ntional animal studies published in any language through J une 28,2023.The study utilized the random-effect model to estimate the 95%confidence intervals(CI)of the standard mean differences(SMD)between the treatment and control groups.We use the systematic review center for laboratory animal expe rimentation’s risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment.A total of 33studies with data from 840 Parkinson’s disease model animals were included in the meta-analysis.Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test.Among the stem cell types,the bone marrow MSCs with neurotrophic factor group showed la rgest effect size(SMD[95%CI]=-6.21[-9.50 to-2.93],P=0.0001,I^(2)=0.0%).The stem cell treatment group had significantly more tyrosine hydroxylase positive dopamine rgic neurons in the striatum([95%CI]=1.04[0.59 to 1.49],P=0.0001,I^(2)=65.1%)and substantia nigra(SMD[95%CI]=1.38[0.89 to 1.87],P=0.0001,I^(2)=75.3%),indicating a protective effect on dopaminergic neurons.Subgroup analysis of the amphetamine-induced rotation test showed a significant reduction only in the intracranial-striatum route(SMD[95%CI]=-2.59[-3.25 to-1.94],P=0.0001,I^(2)=74.4%).The memory test showed significant improvement only in the intravenous route(SMD[95%CI]=4.80[1.84 to 7.76],P=0.027,I^(2)=79.6%).Mesenchymal stem cells have been shown to positively impact motor function and memory function and protect dopaminergic neurons in preclinical models of Parkinson’s disease.Further research is required to determine the optimal stem cell types,modifications,transplanted cell numbe rs,and delivery methods for these protocols.

Exploration of the Characteristics of Animal Supply and Demand in University Experimental Teaching Pratice

The supply and demand of laboratory animals for teaching in colleges and universities has its own internal characteristics.To grasp the supply and demand characteristics of laboratory animals for teaching is of vital importance to the planning,supply and use of teaching animals,the realization of teaching objectives and the completion of teaching tasks.Based on the supply of teaching experimental animals and the work of animal experimental teaching in our university in recent years,this paper expounds the inherent characteristics and practice of supply and demand of teaching experimental animals.

Experimental Studies on immune－Complex in Situ Type Glomerulonephritis in Rabbits Treated with Mai－Luo－Tong and Natural Indig

By injection of C-BSA. immune-complex in situ type glomerulonephritis was duplicated in rabbits and treated with Mai-Luo-Tong and natural Indigo.The resuts showed that proteinuria in the treated groups M and Q was decreased.The difference between group M and control group is statistically significant (P<0.05). Under light and electron microscope.although glomerular basement membrane was irregularly thickened and subepithelial dense electron deposited in the treated group, but microthromhus. erythrocytes and platelets aggregation and leukocytes impaction were not seen within glomerular capillaries. Also in groups C,Q,M, mesenteric cell count was 99. 40±18.53,92.87±17. 89,66. 55±7.75 respectively,the M.Q groups are compared with group C, the result is of statistical significance(P<0.05)and there is no apparent glomerular fibrosis in the treated groups.

Animal modeling in bone research—Should we follow the White Rabbit?

Animal models are live subjects applied to translational research.They provide insights into human diseases and enhance biomedical knowledge.Livestock development has favored the pace of human social development over millennia.Today's society is more aware of animal welfare than past generations.The general public has marked objections to animal research and many species are falling into disuse.The search for an ideal methodology to replace animal use is on,but animal modeling still holds great importance to human health.Bone research,in particular,has unmet requirements that in vitro technologies cannot fully address.Standardizing novel models remains necessary and rabbits are gaining in popularity as potential bone models.Our aim here is to provide a broad overview of animal modeling and its ethical implications,followed by a narrower focus on bone research and the role rabbits are playing in the current scenario.

Diversified Teaching Methods in Nursing:Using Animal Experimentation to Promote Core Professional Competencies in Basic Nursing Training

Objective： The aim of this project was to train highly professional and specialized nursing students from medical colleges to adapt to bedside clinical care by exploring and discussing various methods of injection and IV infusion in animal experimentation to hone the core professional nursing competencies. Methods： Two classes from the 2012 senior graduating nursing class were randomly selected by a computer to conduct the diversified practical teaching methods based on animal experimentation. A hospital environment was simulated by requiring students to perform different types of injections and practical IV infusion techniques. A comprehensive evaluation of the core professional competencies, as well as other integrated competencies, was conducted to determine the effectiveness of the teaching methods. Results： Two-sampled, pairwise u-tests were performed between the scores of the experimental （nursing class 2） and control （nursing class 1） groups. These findings showed that the overall test scores were significantly higher in the experimental group compared to the control group and that the average P-values for the competencies in various categories were 〈0.01, which indicated statistically significant results. Conclusions： Based on the data from this project, diversified teaching methods for basic nursing training founded on animal experimentation can help nursing students perfect their core professional competencies and improve their overall professional standing. The introduction of animal experimentation requires further verification, and an increased acknowledgement of its benefits through the widespread dissemination of this information.

Preparation of Filling Porous Osteoconduction Materials and Its Animal Experiment Study

Titanium rods were processed into implant samples with cavity and groove in which was filled with HAP/β-TCP porous osteoconduction composite materials in order to increase the mechanical stability of the implant in vivo.The phase compositions of the composite was characterized by X-ray diffraction （XRD） and scanning electron microscopy（SEM）.Histological evaluation showed that the biogradable composite could enhanced the ability of new bone formation.The composite can conduct new bone tissue growing into the cavities gradually after implanted into animal,and then achieve mechanical fixation.The filling biogradable compound exhibited excellent biocompatibility,which combined with the new bone tissues tightly without inflammation and loosing.

Alteration of Nitric Oxide Synthase in Experimental Spinal Cord Injury in Rats

In order to detect the role of NO to the secondary damage following spinal cord injury (SCI). NOS in the injury site (T\-8) were studied using a rat SCI model induced by Allens weight drop method (10 g2.5 cm). The results suggested that activities of NOS significantly increased in 10 min\, 1\,2\,4\,8 h. The results indicated that NO was related to SCI. The rise of NO following SCI might lead to secondary spinal cord damage.\;

An Experimental Study on Somatostatin Receptors in the Brains of Hepatic Encephaiopathy Rats

The present study was undertaken to evaluate the effect of somatostatin (SS) receptor,a brain-gut peptide receptor which is capable of inhibiting central neurons, on the pathogenesis of hepatic encephalopathy (HE).By means of radioligand binding assay, SS receptors in crude synaptosomal membrane of rat brains were investigated in a rat model of HE induced by partial hepatectomy following carbon tetrachloride intoxication and in controls. Binding to SS receptor was studied using125 I-SS as radiolgand Scatchard analysis of binding data was linear, yielding a dissociation constant (Kd) of 3.99 ±0.22 nmol/L and a maximal binding capacity (Bmax) of 238± 14.2 fmol/mg of protein in HE rats.Only increased Bmax values were observed (P< 0.005),while the Kd values were statistically unchanged (P>0.50),in HE rats as compared with those in controls.The results suggest that the changes of SS receptors in brains play a significant role in the pathogenesis of HE.The mechanism of HE induced by the alterations of SS receptors in the brains was discussed in this paper.

A New Model of Experimental Cerebral Infarction in New Zealand White Rabbits

To develop an easy, reproducible experimental model of cerebral infarction(CI)without craniotomy in New Zealand white rabbits,a silicone rubber cylinder embedded in a nylon suture was delivered to the middle cerebral arteries through the internal carotid artery in anesthetized animals.Rabbits were sacrificed 0.5-5 h after embolization.CI size and location were ascertained by the tripheny1-2H-tetrazoliuni chloride(TTC)staining method;cerebral blood flow(CBF)was measured prior to and after embolization.Pco2,temperature and blood pressure were monitored and kept constant.CI occurred in all rabbits after 4 h of ischemia,in 50% after 3 h and only in 33% after 2.5 h.CI did not occur within less than 2.5 h of ischemia.No correlation was found between size and location of CI and occlusion time.CBF was maximally reduced in the right MCA territory but was also reduced in both anterior cerebral arteries and left MCA territories.This model is technically easy and the retrievable embolus allows the study of reperfusion by pulling on the nylon suture.It is suitable for studying chemical and molecular changes of the ischemic cells and/or for studying neuroimage changes after ischemic stroke.

Complete Achilles Tenotomy:A New Improved Experimental Surgical Technique in Rats

Rupture of the Achilles tendon is one of the most frequent tendon injuries in humans. However, there is no standard surgical technique thus far to reproduce complete rupture of this tendon in rats. Surgical procedures were performed in Wistar rats under light microscopy, with posterior longitudinal incision and preservation of the plantaris tendon. The animals were sacrificed on 2nd and 8th postoperative week and we used hematoxilin and eosin, picrosirius-red and Weigert’s resorcin-fuchsin to observe general tendon healing. The mean operative time was one minute and 24 seconds. Histological studies showed cellular proliferation and fibrillogenesis at two weeks, with decreased amounts of cellularity and elastic fibers at the 8th week, besides changes in structural organization of collagen fibers. The complete Achilles tenotomy in rats, was improved under light microscopy and sparing the plantaris tendon. This surgical technique was simple and quick, showed signs of normal healing process, could be easily reproducible, and triggered translational researches in this area.

Experimental study of tibial transverse bone transfer on wound healing of diabetic rabbit leg ulcer

Objective To investigate the efficacy and mechanism of tibial transverse bone transfer in the treatment of lower limb ulcer wounds in diabetic rabbits.Methods Animal models of diabetic foot lower extremity ischemia were made,and grouped Animal models of diabetic foot lower extremity ischemia were made,and grouped control studies were designed to evaluate the time of wound healing and the expression level of vascular endothelial growth factor(VEGF),platelet derived growth factor(PDGF),and epidermal cell growth factor(EGF)in the wound during the same period of time.Results In animal experiments,transverse tibial bone transfer can shorten the healing time of diabetic ulcer and increase the expression of wound growth factor(VEGF,PDGF,EGF).Conclusion In animal experiments,diabetes can inhibit the expression of growth factors(VEGF,PDGF,EGF)in ulcer wounds,and tibial transverse bone transfer can promote wound healing.The mechanism may be related to the increased expression of VEGF,PDGF and EGF in the wound surface.

Fundus photography,fundus fluorescein angiography,and optical coherence tomography of healthy cynomolgus monkey,New Zealand rabbit,Sprague Dawley rat,and BALB/c mouse retinas

Background:A variety of experimental animal models are used in basic ophthalmological research to elucidate physiological mechanisms of vision and disease pathogenesis.The choice of animal model is based on the measurability of specific parameters or structures,the applicability of clinical measurement technologies,and the similarity to human eye function.Studies of eye pathology usually compare optical parameters between a healthy and altered state,so accurate baseline assessments are critical,but few reports have comprehensively examined the normal anatomical structures and physiological functions in these models.Methods:Three cynomolgus monkeys,six New Zealand rabbits,ten Sprague Dawley(SD)rats,and BALB/c mice were examined by fundus photography(FP),fundus fluorescein angiography(FFA),and optical coherence tomography(OCT).Results:Most retinal structures of cynomolgus monkey were anatomically similar to the corresponding human structures as revealed by FP,FFA,and OCT.New Zealand rabbits have large eyeballs,but they have large optic disc and myelinated retinal nerve fibers in their retinas,and the growth pattern of retinal vessels were also different to the human retinas.Unlike monkeys and rabbits,the retinal vessels of SD rats and BALB/c mice were widely distributed and clear.The OCT performance of them were similar with human beings except the macular.Conclusions:Monkey is a good model to study changes in retinal structure associated with fundus disease,rabbits are not suitable for studies on retinal vessel diseases and optic nerve diseases,and rats and mice are good models for retinal vascular diseases.These measures will help guide the choice of model and measurement technology and reduce the number of experimental animals required.

Study on prescription medication mode and mechanism of traditional Chinese medicine in the treatment of noncritical COVID-19 based on data mining

Background:As of 2023,coronavirus disease 2019(COVID-19)is still spreading globally.Therefore,we aim to integrate non-critical COVID-19 high-frequency and high-targeting Chinese medicines to provide a reference for clinical prescriptions to improve COVID-19-related symptoms.Materials and methods:The information on non-critical COVID-19 high-frequency Chinese medicines in the diagnosis and treatment of COVID-19 was obtained by the TCM inheritance support platform.Using network pharmacology and molecular docking technology,high-targeting Chinese medicines with good docking activity with COVID-19 receptors angiotensin-converting enzyme-II(ACE2),3CLpro and tyrosine-protein kinase receptor UFO(AXL)were obtained.A new prescription for non-critical COVID-19 was established by integrating high-frequency and high-targeting Chinese medicines.Rats with acute lung injury induced by lipopolysaccharide were used as the experimental model.The histopathological changes in the lungs of rats in each group were observed by hematoxylin-eosin staining.The lung coefficient of rats was measured.The levels of IL-6,TNF-α,and IL-1βin serum were detected by enzyme-linked immunosorbent assay.The mRNA and protein levels of ACE2 and AXL in lung tissue were detected by real-time quantitative polymerase chain reaction and western blot.Results:Through data mining,it was found that there were 39 high-frequency traditional Chinese medicines for non-critical COVID-19 in the diagnosis and treatment guidelines.According to network pharmacology and molecular docking,30 highly targeted traditional Chinese drugs for COVID-19 were found.The new prescriptions for non-critical COVID-19 were comprehensively obtained,including Glycyrrhizae Radix,Ephedra Herba,Amygdalus Communis Vas,Gypsum Fibrosum,Descurainiae Semen,Atractylodes Lancea,Scutellariae Radix,Amomum Tsao-Ko Crevostet,Forsythiae Fructus,Pogostemon cablin,Magnolia Officinalis.Compared with the LPS-induced lung injury model group,the medium dose of the new prescription group had significantly alleviated pathological changes in lung tissue,decreased lung coefficient,decreased contents of IL-6,TNF-αand IL-1β,and increased mRNA and protein expression of ACE2 and AXL(P<0.05).Conclusion:Based on data mining,network pharmacology and molecular docking technology,the new prescription for non-critical COVID-19 established by this method has an anti-inflammatory effect on rats with acute lung injury induced by lipopolysaccharide and can provide a reference for clinicians to alleviate the symptoms related to non-critical COVID-19.

Regulation of Quan Du Zhong capsule on VEGF/bFGF and expression of Bcl‑2/Bax and Caspase‑3 protein in the repairing process of canine femoral head necrosis

Objective:To explore the repair and treatment effect of Quan Du Zhong capsule on necrosis of femoral head in dogs.Methods:Totally 12 beagles were randomly divided into normal group,model group,Quan Du Zhong capsule group and Xianlinggubao capsule group,with three in each group.In addition to the normal group,the other groups established the femoral head necrosis model by liquid nitrogen alternative freezing.The normal group and the model group did not have any intervention during the modeling period,and the Quan Du Zhong group began to receive the Quan Du Zhong by gavage on the day of modeling;Xianlinggubao capsule group was given Xianlinggubao capsule by gavage once a day for 12 consecutive weeks on the day of modeling.The levels of VEGF and bFGF in the blood vessels of each group at the 12th week were compared,and the ratios of BMD,BS/BV,BV/TV,Tb.Th,Tb.N were measured by Micro CT,and the expressions of Bcl-2,Bax,Caspase-3 proteins were detected by immune reaction.Results:1.Compared with the normal group,the level of serum VEGF and bFGF in the model group decreased after 12 weeks of modeling(P<0.05);Compared with the model group,the levels of serum VEGF and bFGF water in the Xianlinggubao capsule group and the Quan Du Zhong capsule group increased on average at the 12th week of modeling,with statistical difference(P<0.05).The level of the Quan Du Zhong capsule group was the highest,followed by the Xianlinggubao capsule group.2.Compared with the normal group,BMD,BS/BV,BV/TV,Tb.Th and Tb.N in the model group were lower,and Tb.SP were higher,the results were statistically significant(P<0.05).Compared with the model group,the BMD,BV/TV,Tb.Th and Tb.N of Xianlinggubao capsule group and the total eucommia capsule group increased,while the BS/BV and Tb.SP decreased(P<0.05).3.The Quan Du Zhong capsule group and Xianlinggubao capsule group could significantly increase the expression of bcl-2 protein in the femoral head of dogs,which was significantly different from the model group(P<0.05).The expression of bax protein in the femoral head of dogs in the Quan Du Zhong capsule group and the Xianlinggubao capsule group was significantly reduced compared with the model group(P<0.05).The expression of caspase-3 protein in the femoral head of dogs was significantly reduced in the Quan Du Zhong capsule group and Xianlinggubao capsule group,which was significantly different from the model group(P<0.05).Conclusion:Quan Du Zhong capsule can increase the expression of VEGF and bFGF in serum,increase the expression of bcl-2,inhibit the expression of bax,and reduce the expression of caspase-3,which plays a synergistic role in the treatment of avascular necrosis of the femoral head,and has potential targets.

Establishment of Bacterial Lobular Pneumonia Model in Mice

In this study cortisol and cyclophosphamide were injected into abdominal cavities of mice to keep them in an immunosuppressive state. Then the pathogen Klebsiella pneumoniae was given to infect the lungs and the experimental modcl of lobular pneumonia in the mice was thus established successfully.The experimental animal model has typical pathologic manifestation and good replication and can be used to to study the effect of drugs.

High-dose dietary zinc promotes prostate intraepithelial neoplasia in a murine tumor induction mode

To evaluate the role of high-dose dietary zinc in the process of prostate malignancy,60 Sprague-Dawley rats were randomly divided into four groups：tumor induction with carcinogen and hormone （group 1）,oral zinc administration without tumor induction （group 2）,oral zinc administration with tumor induction （group 3） and a control without zinc administration or tumor induction （group 4）. Zinc was supplied orally in the form of zinc sulfate heptahydrate dissolved in drinking water to groups 2 and 3 for 20 weeks. Although the serum level of zinc measured at 20 weeks was maintained similarly in each group （P = 0.082）,intraprostatic zinc concentrations were statistically different. Group 1 prostates contained the least amount of zinc in both the dorsolateral and ventral lobes at levels of 36.3 and 4.8 μg g^-1,respectively. However,in group 3,zinc levels increased in both lobes to 59.3 and 12.1 μg g^-1,respectively,comparable with that of group 4 （54.5±14.6 and 14.1±2.4 μg g^-1）. In spite of these increases in zinc concentration,the prevalence of prostate intraepithelial neoplasm was rather increased in group 3 （53.3% and 46.7%） compared with group 1 （33.3% and 33.3%） in both dorsolateral and ventral prostate lobes. Although prostate intraepithelial neoplasm did not develop in any prostate in group 4,zinc administration did induce prostate intraepithelial neoplasm in group 2 （46.7% and 40.0%）. Thus,although high dietary zinc increased intraprostatic zinc concentrations,it promoted,instead of preventing,prostate intraepithelial neoplasm in a murine prostate malignancy induction model.

Improved Cardiac Contractility of Human Recombinant Growth Hormone on the Congestive Heart Failure of Pig

The enhanced cardiac contractility effect of human recombinant growth hormone (hr-GH) on the congestive heart failure (CHF) was studied on the pig. To build a pig model of congestive heart failure, a temporary artificial cardiac pacemaker was implanted in the pig’s body and paced at 220 beats to 240 beats per minute for 1 week. After the model of congestive heart failure was successfully set up, the frequency of the pacemaker was changed to 150 beats to 180 beats per minute to maintain the CHF model stable. Pigs were divided into three groups: The hr-GH group in which 0.5 mg/kg per day of hr-GH was administrated intramuscularly for 15 days, the injection control group in which an equal amount of physiological saline was injected intramuscularly, and a normal control group. The left ventricular diastolic end pressure was (10.60±2.41) mmHg in the hr-GH group, but (19.00±3.81) mmHg in the saline control group (P<0.01); Cardiac output was (1.86±0.13) L/min in the hr-GH group, but (1.56±0.18) L/min in the saline control group (P<0.05); Peripheral vascular resistance was (56.88±7.51) mmHg·(L/min) -1 in the hr-GH group, whereas (70.30±11.59) mmHg·(L/min) -1 in the saline control group (P<0.05); +dp/dt max was (2900±316.23) and (2280±286.36) in the hr-HG group and the saline control group respectively (P<0.05). The results show that hr-GH enhances myocardial contractility of CHF, and the CHF model built by a temporary artificial cardiac pacemaker at a high rate of stimulation is reasonable and applicable.