Thermal Injury Protocol to Study Healing, With and Without Infection, in Guinea Pig (Cavia porcellus) Model / Protocolo de Lesión Térmica, para Estudio de Cicatrización, en Modelo Animal Cobayo (Cavia porcellus)

SUMMARY: Experimental healing studies in humans are complex and difficult to replicate in vitro. Hence, animal models are needed to study the different stages involved. The guinea pig (Cavia porcellus) is a model close to human physiology, including the lack of vitamin C synthesis, a precursor of collagen fibers for healing. The thermal injury in this animal makes it possible to study all the stages of healing, taking few days to show tissue repair in the processes with and without localized infection. The aim of this work was to systematize an experimental guinea pig (Cavia porcellus) animal model protocol for studies on healing with and without localized infection.

Los estudios experimentales de cicatrización en humanos son complejos, difícilmente replicables in vitro, por lo que se hace necesarias modelos animales que permitan el estudio de las distintas etapas que ella implica. El cobayo (Cavia porcellus) resulta ser un modelo cercano a la fisiología humana, incluyendo la falta síntesis de vitamina C precursora de fibras colágenas para la cicatrización. La lesión térmica en este animal, permite estudiar todas las etapas de la cicatrización, mostrando pocos días en la reparación tisular, tanto en proceso con y sin infección localizada. El objetivo de este trabajo fue sistematizar un protocolo de modelo animal experimental en cobayo (Cavia porcellus) para estudios de cicatrización con y sin infección localizada.

Combination of Merocel sponge with Lipopolysaccharide to establish rat rhinosinusitis model

Abstract Objective The study aimed to investigate the feasibility of establishing rhinosinusitis model in rats combinated with Lipopolysaccharide (LPS) and merocel sponge. Methods SD (Sprague Dawley) rats that underwent nasal obstruction using Merocel sponge packing, rats with LPS instillation alone, and rats with both nasal obstruction and LPS instillation were used to establish rat models of rhinosinusitis. After the models were established, the nasal symptoms of rats were recorded, the histopathological examination and Transmission Electron Microscopy (TME) of the sinus tissue were performed and the levels of Tumor Necrosis Factor-α (TNF-α), Interleukin-6 (IL-6) in the blood were also analyzed. The expressions of Aquaporin-5 (AQP5), Occludin, Toll-Like Receptor-4 (TLR4), Medullary differentiation factor 88 (MyD88) and phosphorylated (p)-p65 protein were detected by Western blot to evaluate the effect and mechanism of the experimental models. Results We found that compared with the control group and LPS group, the sinusitis symptom scores in the Merocel sponge combined with LPS group were significantly increased; the respiratory epithelia of the maxillary sinus were degenerated, cilia were detached, and even inflammatory cell infiltration occurred; the levels of TNF-α and IL-6 were increased; the expression of AQP5 and Occludin protein was decreased; and the expressions of TLR4, MyD88, and p-p65 protein were increased. Conclusion For the first time, we successfully established a rat rhinosinusitis model using Merocel sponge with LPS and explored the possible mechanism of LPS action.

Moringa oleifera seeds attenuate benzene-induced alterations in lipid peroxidation and antioxidant enzymes in liver and kidney tissues of Wistar rats

Benzene is a notorious toxicant that is responsible for a host of diseases including leukemia. Its concentration in the environment is increasing day-by-day due to excessive automobile use, accelerated industrial activities and cigarette smoke. The awareness on the harmful effects of benzene on health is limited and no antidote has been reported yet. In this study, an attempt has been made to find out a suitable remedy to overcome benzene toxicity in a living organism from a natural source with the seeds of the plant Moringa oleifera (MO). Thirty six Wistar rats were considered for the study and divided into six groups (n=6). While group I remained as control with normal animals, those in groups II – VI received benzene by oral route (800 mg/kg body weight) for 28 consecutive days. On day 29, the benzene-treated animals in groups III – VI received respectively the standard drug ascorbic acid (AA, 25 mg/kg body weight) and MO (50, 100 and 200 mg/kg body weight) for the following 7 days. Group II rats that received only benzene served as negative control without any treatment. On day 36, all the animals were sacrificed and vital organs liver and kidney were removed for studying lipid peroxidation (LPO) and antioxidant markers [Superoxide dismutase (SOD), Total reduced glutathione (TRG), Glutathione peroxidase (GPx) and Catalase (CAT)] in addition to histopathological changes in the tissues. The results of the study revealed that significant changes occurred in the above parameters due to benzene dosing to animals were reverted to near normal values on MO administration in the liver and kidney tissues as compared to untreated animals, suggesting MO’s pro-active role in attenuating benzene toxicity.

Meta-analysis of Ac-SDKP inhibition of Pulmonary fibrosis in animal models / 中华劳动卫生职业病杂志

Objective: To systematically study the anti-fibrotic effect of N-acetyl-seryl-as partyl-lysyl-proline (Ac-SDKP) on pulmonary fibrosis. Methods: In May 2021, a computer search was performed on CNKI, Wanfang Knowledge Service Platform, VIP.com, China Biomedical Literature Database, Pubmed, OVID and other databases. The retrieval time was from January 2008 to May 2021. Randomized controlled experiments on the inhibition of pulmonary fibrosis by Ac-SDKP were screened. The control group was the pulmonary fibrosis model group and the experimental group was the Ac-SDKP treatment group. The quality of the literature was assessed using the syrcle risk of bias assessment tool, and data were extracted. Data analysis was Performed using revman 5.4 software. Results: 18 papers were included, with a total of 428 animal models. The results of meta analysis showed that the contents of α-smooth muscle actin (α-SMA), type I collagen, type Ⅲ collagen, transforming growth factor-β (TGF-β) and Nodule area in the exPerimental group were lower than those in the control grouP. [SMD=-2.44, 95%CI (-3.71--1.17), P=0.000][SMD=-5.36, 95%CI (-7.13--3.59), P=0.000] [SMD=-3.07, 95%CI (-4.13--2.02), P<0.000][SMD=-2.88, 95%CI (-3.63--2.14), P=0.000] [SMD=-1.80, 95%CI (-2.42--1.18), P=0.000], the content of hydroxy proline in the experimental group was higher than that in the control group [SMD=7.62, 95%CI (4.90-10.33), P=0.000], all indexes included in the literature were statistically significant. Conclusion: Ac-SDKP has obvious inhibitory effect on the process of pulmonary fibrosis, and may become a new clinical drug for the treatment of pulmonary fibrosis.

Animal experimental study on the effects of different levels of amputation on cardiovascular system / 生物医学工程学杂志

Vascular injury resulting from lower limb amputation leads to the redistribution of blood flow and changes in vascular terminal resistance, which can affect the cardiovascular system. However, there was no clear understanding of how different amputation levels affect the cardiovascular system in animal experiments. Therefore, this study established two animal models of above-knee amputation (AKA) and below-knee amputation (BKA) to explore the effects of different amputation levels on the cardiovascular system through blood and histopathological examinations. The results showed that amputation caused pathological changes in the cardiovascular system of animals, including endothelial injury, inflammation, and angiosclerosis. The degree of cardiovascular injury was higher in the AKA group than in the BKA group. This study sheds light on the internal mechanisms of amputation's impact on the cardiovascular system. Based on the amputation level of patients, the findings recommend more comprehensive and targeted monitoring after surgery and necessary interventions to prevent cardiovascular diseases.

Fitting Degrees of Cathartic Colon Animal Models with Disease Characteristics of Western Medicine and Syndrome Characteristics of Traditional Chinese Medicine / 中国实验方剂学杂志

Cathartic colon （CC） is a common and refractory digestive system disease， with the pathogenesis not fully clarified. The effective therapies other than laxatives and surgery remain to be developed for CC. Therefore， establishing the CC animal models that fit the disease characteristics of western medicine and syndrome characteristics of traditional Chinese medicine （TCM） is an important link to promote the research on this disease. The fitting degree of animal models with the latest Chinese and western medical diagnostic criteria is an indicator to assess the effectiveness of the animal models in simulating the disease characteristics of western medicine and syndrome characteristics of TCM. The literature review showed that the model animals， drugs and their dosage forms， doses， administration methods， and modeling period of CC varied in different studies， and the available CC animal models presented different fitting degrees with the disease characteristics of western medicine and syndrome characteristics of TCM. Rats were the preferred animals for the modeling of CC. Rhei Radix et Rhizoma preparations were commonly used for model inducing， which， however， may cause water electrolyte disorders， decreased immunity， and even death of animals at the late stage of modeling. The animals were modeled by gradually increasing the starting dose， while the starting dose and increasing dose varied. The maintenance dose was determined based on 50% of the animals having loose stools， and the end for a cycle was determined as the time when loose stools disappeared in 80% of animals. The modeling always lasted for 2-3 cycles， approximately 2-4 months. The CC models established with Rhei Radix et Rhizoma granules and rhein had high fitting degrees with the disease and syndrome characteristics. In addition， the CC animal models of TCM syndromes were still in the exploration stage. There were only the animal models of four TCM syndromes： liver depression and spleen deficiency， both Qi and Yin deficiency， Qi stagnation and blood stasis， and spleen and kidney deficiency. Efforts should be made to establish the animal models that meet the characteristics of disease of western medicine and syndromes of TCM， so as to facilitate the research on CC mechanism and drug development.

Research progress on non-clinical safety evaluation of SARS-CoV-2 vaccine / 中国生物制品学杂志

@#The Coronavirus Disease 2019(COVID-19) pandemic is having a dramatic impact on human health,lives,and the global economy. The development of a safe and efficacious vaccine is the most effective intervention to protect the population from the disease and limit the spread of the virus. Based on the current guidelines and research progress of severe acute respiratory symptom coronavirus 2(SARS-CoV-2) vaccines in various countries,this review summarized the research progress on non-clinical safety evaluation of SARS-CoV-2 vaccines by referring to the guidelines and relevant literatures over the world,in order to provide a reference for non-clinical research of SARS-CoV-2 vaccines.

Advances in the establishment and evaluation of animal models of secondary lymphedema / 中华显微外科杂志

Secondary lymphedema is a chronic progressive disease caused by the obstruction of lymphatic reflux, which leads to a series of secondary affection. There is no cure at present. Exploring the pathogenesis and treatment of lymphedema is based on animal models that mimic the pathophysiology of chronic lymphedema in humans. Currently, there are many known animal models of lymphedema, such as the limb lymphedema model of mice, dogs and other animals, and the rabbit ear lymphedema model. But most of them cannot induce the persistent and stable lymphedema temporarily, which lead to a deadlock in the related research progress. Therefore, it is necessary to improve and even create new animal models of lymphedema. This paper summarises the progress of relevant literature and provides references for further improving the establishment of a lymphedema animal model. It also summarise existing methods for evaluating lymphedema or lymphatic vessel function to provide an evaluation tool for modified or new animal models.

Establishment of a hyperuricemia rat model by stimulation of high temperature-humidity environment / 中华内分泌代谢杂志

Objective:To establish a hyperuricemia rat model through the high temperature-humidity treatment, and monitor its vital signs and biochemical indicator characteristics, as well as observe the changes of renal histomorphology and ultrastructure.Methods:Male SD rats were randomly divided into control(CON) group, potassium oxonate(PO) group and high temperature-humidity(HTH) group, 6 rats each. The experiment lasted for 6 consecutive weeks. Rats from PO group was given 250 mg/kg PO by gavage every day. The rats from HTH group were treated with a special thermostatic incubator for one hour each day after gavaging 250 mg/kg PO. Serum uric acid, creatinine and other indicators were detected every 2 weeks. After 6 weeks, the kidney tissues were collected. The morphological changes and urate crystal deposition of kidney tissues were observed by hematoxylin-eosin staining, Masson′s trichrome staining and gomori staining, while the ultramicrostructural changes of kidney were observed by transmission electron microscope.Results:Two weeks after the experiment, the average serum uric acid values of PO group and HTH group increased significantly, HTH group was higher than PO and CON groups[(133.9±17.8), (107.6±12.4), and (85.7±4.1) μmol/L, P=0.001]. And after 6 weeks, the HTH group was still higher than the other two groups[(115.1±27.8), (82.7±13.9), and (72.9±17.8) μmol/L, P=0.008). The average serum creatinine in HTH group was slightly higher than that in PO group and CON group at 6 weeks[(46.2±4.7), (38.1±6.0), and (28.3±6.3) μmol/L, P=0.001]. Light microscope showed partial renal tubular dilatation in PO group, but renal tubular epithelial cells swelling and inflammatory cells infiltration were more significant in HTH group. The ultrastructural changes such as glomerular podocyte swelling were found in HTH group by transmission electron microscope. Conclusion:In this study, we had successfully established a hyperuricemia rat model by simulating the high temperature-humidity environment combined with potassium oxyzinate after 2 weeks of experiment. After 6 weeks of modeling, it was found that the high temperature-humidity induced rat models possessed a relatively higher and stabler serum uric acid level than that of the traditional chemical medicine induced rats. The method can be applied to the research of pathogenesis and pharmacotherapy of hyperuricemia caused by high temperature-humidity environment.

Effects of methyl methanesulfonate and UV sensitive gene clone 81 on hepatocellular carcinoma cells / 中华肝胆外科杂志

Objective:To detect the expression of methyl methanesulfonate and UV sensitive gene clone 81 (Mus81) in hepatocellular carcinoma(HCC) and to observe the effects of Mus81 on the migration, invasion and metastatic ability of human HCC cells.Methods:Thirty-two tissue specimens were selected from HCC tissues and corresponding paraneoplastic tissues of patients with HCC who underwent surgical resection in Guangzhou Red Cross Hospital Affiliated to Jinan University from January 2020 to June 2021. The expression levels of Mus81 in 32 HCC specimens, 374 HCC samples from the cancer genome atlas database, human normal liver cell line HL-7702 and human HCC cell lines JHH-7, Huh-7 and Hep3B were analyzed. Mus81 knockdown in JHH-7, Huh-7 and overexpressed in Hep3B HCC cell lines were constructed, and the effects of Mus81 on HCC cells were observed by scratch assay, Transwell migration and invasion assay and tail vein injection transfer assay in nude mice.Results:The expression of Mus81 was higher in HCC tissues or cell lines than which in paraneoplastic tissues or normal hepatocyte lines (all P<0.05). The migration rate, metastatic and invasive cell numbers of Mus81-knockdown Huh-7 HCC cells were 22.24%±2.16%, 49.04±5.62, 3.81±1.08, the negative control group were 26.89%±1.15%, 86.81±4.79, 19.78±3.30, and the differences between the two groups were statistically significant ( t=4.24, 26.59, 23.92, all P<0.01). The migration rate, metastatic and invasive cell numbers of Mus81-overexpressed Hep3B HCC cells were 80.57%±5.12%, 18.74±8.07, 33.81±8.44, which were significantly higher than those of the empty vector group 64.17%±7.20%, 10.96±5.32, 3.04±1.13, and the differences were statistically significant ( t=4.15, 4.18, 18.78, all P<0.01). Tail vein transfer experiments in nude mice showed that the total fluorescence expression, weight of metastatic tumors, and the metastatic rates in kidney, vertebral column, neck, axilla and subcutis in nude mice injected with Mus81-knockdown JHH-7 cells were significantly lower than those in the control group (all P<0.05). Conclusion:Mus81 gene expression is upregulated in HCC and promotes the migration, invasion and metastatic ability of HCC cells, suggesting that Mus81 may be a potential therapeutic target for HCC.

Experimental study on the value of enhanced MRI in evaluating the permeability of pancreatic ductal adenocarcinoma / 中华放射学杂志

Objective:To investigate the value of enhanced MRI in evaluating the tissue permeability of pancreatic ductal adenocarcinoma (PDAC) animal model.Methods:The experimental animals were 27 female C57BL/6 mice. The mice were divided into 3 groups with 9 mice in each group by random number method. Murine pancreatic adenocarcinoma (Panc02) and embryonic fibroblasts (NIH/3T3) were implanted subcutaneously at the ratio of 2∶1 and 1∶1 to establish PDAC models with different tissue permeability, which were low fibroblast group and high fibroblast group, respectively, and simple Panc02 implantation model was control group. The positive expression rate of α-smooth muscle actin (α-SMA), the positive expression rate of fibroblast activating protein (FAP), the coverage rate of collagen fibers, number of blood vessels and the long/short diameter of tissue vessels were quantitatively evaluated by tissue staining, and the tissue permeation efficiency was quantified by the average optical density (AOD) of tissue sections stained by Evans blue (EB). Enhanced MRI was performed on mice, and the enhancement degree and the enhancement rate of 20 min were obtained. One-way ANOVA was used to compare the overall differences of tumor histological indexes and MRI enhancement parameters in each group, and the correlation between the indexes was analyzed by Pearson correlation analysis. Multiple linear stepwise regression analysis was conducted with 20 min enhancement rate as dependent variable, while α-SMA positive expression rate, collagen fiber coverage rate and vascular long/short diameter as independent variables.Results:There were significant differences in AOD value, α-SMA positive expression rate, FAP positive expression rate, collagen fiber coverage rate, vascular long/short diameter, 20 min enhancement degree and 20 min enhancement rate among the three groups ( P<0.001), but there was no significant difference in the number of blood vessels ( P=0.650). The AOD value was negatively correlated with the positive expression rate of α-SMA, the coverage rate of collagen fibers and the long/short diameter of blood vessels in PDAC model, respectively ( r=-0.888, P=0.001; r=-0.813, P=0.008; r=-0.915, P<0.001). The 20 min enhancement degree was positively correlated with AOD value ( r=0.954, P<0.001). The positive expression rate of α-SMA, collagen fiber coverage and vascular long/short diameter were negatively correlated with 20 min enhancement rate ( r=-0.901, P<0.001; r=-0.837, P=0.005; r=-0.880, P=0.002). The results of multiple linear stepwise regression analysis showed that the positive expression rate of α-SMA was an important influencing factor for the 20 min enhancement rate (R 2=0.813, P=0.001). Conclusions:The increase of fibroblast implantation ratio significantly decreased the permeation efficiency of tumor tissue. The positive expression rate of α-SMA, the coverage rate of collagen fibers and the long/short diameter of blood vessels were negatively correlated with the permeation efficiency of tumor tissue. The 20 min enhancement degree was positively correlated with tissue permeation efficiency.

Preliminary study of shear wave dispersion imaging in the evaluation of hepatic acute graft-versus-host disease / 中华超声影像学杂志

Objective:To investigate the feasibility of using shear wave dispersion (SWD) imaging in evaluating acute graft-versus-host disease (aGVHD) of the liver.Methods:A total of 42 Wistar rats were used as receptors and 10 Fischer 344 rats were used as donors for bone marrow transplantation to establish aGVHD models. Six rats were randomly selected every week for clinical observation and scoring. Then, ultrasonic SWD was performed to obtain shear wave speed (SWS) and shear wave dispersion slope (SWDS). Then, the histological characteristics were used as a reference standard, and the rats were divided into two groups: the group without aGVHD (nGVHD group) and the group with aGVHD. The differences in the clinical score and SWD values between the two groups were compared, the meaningful indexes were screened by binary Logistic regression analysis, and the joint prediction parameters were obtained. The ROC curve was plotted and the diagnostic efficiency was compared. The correlations between SWS, SWDS, clinical score and pathological grade were analyzed.Results:Clinical score, SWS, and SWDS in aGVHD group were higher than those in the nGVHD group (all P<0.05). The correlation between SWDS and pathological grade ( r=0.774, P<0.001) was higher than those between SWS, clinical score and pathological grade ( r=0.579, P=0.005; r=0.452, P=0.034). Logistic regression showed that SWDS was a significant indicator. In addition, the AUC values determined by SWDS and predictive parameters were (0.859, 0.886), which were significantly higher than the AUC of the clinical score (0.760, P<0.05). Conclusions:SWD imaging technology may become a promising method to evaluate hepatic aGVHD.

The expression of miR-876-3p based on a rat model of bronchopulmonary dysplasia induced by hyperoxia / 中国小儿急救医学

Objective:To establish a neonatal rat bronchopulmonary dysplasia(BPD) model induced by hyperoxia, to detect the expression of miR-876-3p in the lung tissue, and to analyze the role of miR-876-3p in the occurrence and development of BPD, so as to provide a theoretical basis for the pathogenesis, prevention and treatment of BPD.Methods:Eighty newborn SD rats were randomly divided into hyperoxia group(FiO 2 60%) and air group(FiO 2 21%). Lung tissue samples were taken on the 1st, 7th, 14th and 21st day after birth, the pathological changes of lung tissue were observed.Quantitative real-time PCR technique was used to detect the expression level of miR-876-3p. Results:Within 21 days after birth, with the prolongation of hyperoxia exposure time, the general growth of rats in hyperoxia group were lower than those in air group[14 d: (35.46±1.62) g vs.(37.08±1.25) g; 21 d: (51.92±1.83) g vs.(58.87±2.43) g]( P<0.05). On the 14th and 21st day after birth, the radial alveolar counts in lung tissue of rats in hyperoxia group were significantly reduced compared with those in air group( P<0.05). On the 7th, 14th and 21st day after birth, the alveolar septal thickness of rats in air group were lower than those in hyperoxia group( P<0.05). The expression level of miR-876-3p in hyperoxia group decreased gradually and was significantly lower on the 7th, 14th and 21st day compared with air group at the same time points[7 d: (14.97±1.13) vs.(16.64±0.89); 14 d: (11.92±0.71) vs.(16.85±0.79); 21 d: (11.39±0.79) vs.(17.52±1.17)], and the differences were all statistically significant( P all<0.01). Conclusion:In this study, a new BPD model of neonatal rats can be induced by hyperoxia and the expression level of miR-876-3p in this model is decreased.The differential expression level of miR-876-3p may play a role in the occurrence and development of BPD.

Establishment of a mouse model of acute systemic cold injury induced by hypothermia / 中华急诊医学杂志

Objective:To establish an animal model of acute systemic cold injury in mice.Methods:There were 98 C57BL/6 mice, half male and half female, with body weight of 22-27 g and age of 10 weeks. The mice were randomly divided into 7 groups ( n=14) according to the changes of anal temperature in cold environment, namely, group A (38.5 ± 1) ℃, group B (35 ± 1) ℃, group C (30 ± 1) ℃, group D (25 ± 1) ℃, group E (20 ± 1) ℃, group F (15 ± 1) ℃, and group G (10 ± 1) ℃, among which, group A was the blank control group, and the rest groups were the experimental group. The mice in the blank control group were placed in the normal environment (20 ± 5) ℃, and the mice in the experimental group were placed in the low temperature artificial climate box at - 20℃. The anal temperature of the mice was measured intermittently (as the core temperature), and the time required for the core temperature of the mice to drop to groups B, C, D, E, F and G was recorded. The righting reflex was used to evaluate the consciousness state, the action ability and the general state of each organ of mice were observed, and the blood routine and HE staining of each organ were detected. Results:The lower the core temperature of the experimental group, the longer the time required. The consciousness state, action ability, general state of organs, blood routine, and HE staining of organs in groups B, C, and D were basically the same as those in group A, and there was no acute systemic cold injury. Therefore, the blood routine, general observation of organs, and HE staining of organs in groups B, C, and D were no longer displayed compared with those in group A. Compared with group A, mice in group E began to suffer from disturbance of consciousness and action ability. With the decrease of core body temperature, the damage was aggravated, and mice in group G died. Compared with group A, the indices of blood routine test (WBC, RBC, HGB, PLT) of mice in group E began to decrease, and the univariate variance calculation showed that only WBC changes had statistical significance ( P<0.05). Compared with groups A and E, the indices of blood routine test (WBC, RBC, HGB, PLT) of mice in group F were further reduced, and the changes of each index in univariate variance calculation were statistically significant ( P<0.05). The general observation results showed that compared with group A, the lung, liver and spleen surfaces of mice in group E began to darken, and compared with groups A and E, the lung, liver, spleen, kidney and heart of mice in group F were further deepened and darkened, with irregular edges. HE staining results of various organs showed that compared with group A, the mice in group E began to have partial alveolar structure destruction and a small amount of inflammatory cell infiltration, the central vein of the liver was slightly congested, and the red and white pulp of the spleen were indistinct. Compared with groups A and E, the pathological structure damage of the lung, liver, spleen, kidney, heart and brain tissues of the mice in group F was further aggravated. Conclusions:Detection of consciousness state, action ability, general state of organs, blood routine and HE staining indices of organs in mice under low temperature can simulate the progress of clinical acute cold injury, and the animal model of acute systemic cold injury was successfully prepared.

Short-Term Changes of Graft Viscosity after Anterior Cruciate Ligament Reconstruction / 医用生物力学

Objective To study the short-term variation patterns of graft viscosity after anterior cruciate ligament reconstruction (ACLR) surgery. Methods Six male New Zealand rabbits were selected. The ACLR animal model of unilateral knee was made with Achilles tendon as the graft. The experimental rabbits were euthanized 15 days after ACLR surgery, with removal of the graft, healthy anterior cruciate ligament (ACL) and Achilles tendon. The cross-sectional area and viscosity coefficient of the graft were measured, and the creep experiments were carried out under equilibrium conditions of 0.1 MPa and 1 MPa, respectively. The viscosity coefficent was calculated. Variation patterns of graft viscosity were summarize. The grafts were compared with healthy ACL. Results The cross-sectional area of the graft increased slowly within 15 days after ACLR surgery. The viscosity of ACL and graft changed nonlinearly. The viscosity coefficient was quite different under different stresses. The viscosity coefficient of the graft decreased with the time after ACLR surgery, which was more obviously under the condition of low stress. Conclusions The results are helpful to guide the implementation of early postoperative rehabilitation plan after ACLR surgery .

An improved 4-vessel intermittent occlusion method for establishing rat models of global cerebral ischemia-reperfusion injury / 南方医科大学学报

OBJECTIVE@#To improve the classical 4-vessel occlusion (4VO) model established by Pulsinelli and Brierley.@*METHODS@#Thirty-two male SD rats were randomized into sham operation group, I4VO-Con10 group, I4VO-Int10 group and I4VO-Int15 group. The sham surgery group underwent exposure of the bilateral vertebral arteries and carotid arteries without occlusion to block blood flow. The I4VO-Con10 group experienced continuous ischemia by occluding the bilateral vertebral arteries and carotid arteries for 10 minutes followed by reperfusion for 24 hours. The I4VO-Int10 and I4VO-Int15 groups were subjected to intermittent ischemia. The I4VO- Int10 group underwent 5 minutes of ischemia, followed by 5 minutes of reperfusion and another 5 minutes of ischemia, and then reperfusion for 24 hours. The I4VO-Int15 group experienced 5 minutes of ischemia followed by two cycles of 5 minutes of reperfusion and 5 minutes of ischemia, and then reperfusion for 24 hours. The regional cerebral blood flow (rCBF) was monitored with laser Doppler scanning, and survival of the rats was observed. HE staining was used to observe hippocampal pathologies to determine the optimal method for modeling. Another 48 rats were randomized into 6 groups, including a sham operation group and 5 model groups established using the optimal method. The 5 I4VO model groups were further divided based on the reperfusion time points (1, 3, 7, 14, and 28 days) into I4VO-D1, I4VO-D3, I4VO-D7, I4VO- D14, and I4VO- D28 groups. Body weight changes and survival of the rats were recorded. HE staining was used to observe morphological changes in the hippocampal, retinal and optic tract tissues. The Y-maze test and light/dark box test were used to evaluate cognitive and visual functions of the rats in I4VO-D28 group.@*RESULTS@#Occlusion for 5 min for 3 times at the interval of 5 min was the optimal method for 4VO modeling. In the latter 48 rats, the body weight was significantly lower than that of the sham-operated rats at 1, 3, 7, 14 and 28 days after modeling without significant difference in survival rate among the groups. The rats with intermittent vessel occlusion exhibited progressive deterioration of hippocampal neuronal injury and neuronal loss. Cognitive impairment was observed in the rats in I4VO-D28 group, but no obvious ischemic injury of the retina or the optic tract was detected.@*CONCLUSION@#The improved 4VO model can successfully mimic the main pathological processes of global cerebral ischemia-reperfusion injury without causing visual impairment in rats.

The nonsynaptic plasticity in Parkinson's disease: Insights from an animal model

Abstract Background The 6-OHDA nigro-striatal lesion model has already been related to disorders in the excitability and synchronicity of neural networks and variation in the expression of transmembrane proteins that control intra and extracellular ionic concentrations, such as cation-chloride cotransporters (NKCC1 and KCC2) and Na+/K+-ATPase and, also, to the glial proliferation after injury. All these non-synaptic mechanisms have already been related to neuronal injury and hyper-synchronism processes. Objective The main objective of this study is to verify whether mechanisms not directly related to synaptic neurotransmission could be involved in the modulation of nigrostriatal pathways. Methods Male Wistar rats, 3 months old, were submitted to a unilateral injection of 24 µg of 6-OHDA, in the striatum (n= 8). The animals in the Control group (n= 8) were submitted to the same protocol, with the replacement of 6-OHDA by 0.9% saline. The analysis by optical densitometry was performed to quantify the immunoreactivity intensity of GFAP, NKCC1, KCC2, Na+/K+-ATPase, TH and Cx36. Results The 6-OHDA induced lesions in the striatum, were not followed by changes in the expression cation-chloride cotransporters and Na+/K+-ATPase, but with astrocytic reactivity in the lesioned and adjacent regions of the nigrostriatal. Moreover, the dopaminergic degeneration caused by 6-OHDA is followed by changes in the expression of connexin-36. Conclusions The use of the GJ blockers directly along the nigrostriatal pathways to control PD motor symptoms is conjectured. Electrophysiology of the striatum and the substantia nigra, to verify changes in neuronal synchronism, comparing brain slices of control animals and experimental models of PD, is needed.

The myocardial capillary network is altered in congenital diaphragmatic hernia in the fetal rabbit model

Congenital diaphragmatic hernia (CDH) is associated with thoracic compression of the lungs and heart caused by the herniated abdominal content, leading to cardiac modifications including pressure and vascular changes. Our aim was to investigate the experimental immunoexpression of the capillary proliferation, activation, and density of Ki-67, VEGFR2, and lectin in the myocardium after surgical creation of a diaphragmatic defect. Pregnant New Zealand rabbits were operated on the 25th gestational day in order to create left-sided CDH (LCDH, n=9), right-sided CDH (RCDH, n=9), and Control (n=9), for a total of 27 fetuses in 19 pregnant rabbits. Five days after the procedure, animals were sacrificed, and histology and immunohistochemistry studies of the harvested hearts were performed. Total body weight and heart weight were not significantly different among groups (P=0.702 and 0.165, respectively). VEGFR2 expression was increased in both ventricles in the RCDH group (P<0.0001), and Ki-67 immunoexpression was increased in the left ventricle in the LCDH group compared to Control and RCDH groups (P<0.0001). In contrast, capillary density was reduced in the left ventricle in the LCDH compared to the Control and RCDH groups (P=0.002). Left and right ventricles responded differently to CDH in this model depending on the laterality of the diaphragmatic defect. This surgical model of diaphragmatic hernia was associated with different expression patterns of capillary proliferation, activation, and density in the myocardium of the ventricles of newborn rabbits.

Application of Rat Model of Neurotic Erectile Dysfunction in Experiment / 中国医学科学院学报

Erectile dysfunction (ED) refers to the persistent inability to achieve and/or maintain a sufficient erection of the penis to obtain a satisfactory sexual life,which affects the quality of life of the patients and their sexual partners.To decipher the pathophysiological mechanism of ED,researchers have established a variety of animal models and achieved a series of progress.The cavernous nerve (CN) of rodents,anatomically similar to that of humans,is cost-effective,thick,and easy to be identified,which has gradually become the mainstream of animal models.In this paper,we reviewed the modeling methods of the neurological ED caused by bilateral CN injury in rats in recent years,summarized the model evaluation indicators,and discussed the application and progress of ED models in basic experimental research.

Research progress and application of rodents model construction of peri-implantitis / 口腔医学

@#With the increasing popularity of dental implants, prevalence of peri-implantitishas also been increasing in recent years. However, a deeper understanding of the pathogenesis of peri-implantitis is still lacking. Animal models are a good bridge for studying the pathogenesis of clinical diseases. Animals such as mini-pigs, canines, non-human primates and rodents are used to construct animal models of peri-implantitis. Among them, rodents are easy to obtain and feed, and have a wide range of applications for research. In this review, we summarize the construction of rodent modelswithperi-implantitis as well as the research progress and applications.