动物病理学实验教学改革与探索

通过对传统教育方式的改革,提高了学生分析问题、解决问题的能力,培养了多元思维能力和创新意识,学生对学习产生了浓厚的兴趣。

动物病理解剖实验课程创新教育探索与实践

创新精神与能力培养是高等教育承担的基本职责。动物病理解剖实验课程是动物医学类专业的必修基础课程,对动物医学类临床工作具有重要的指导意义。笔者在对国内动物病理学解剖实验课程存在问题进行分析的基础上,结合教学实践活动,在创新教育的方面进行了探索与实践,取得了较好的教学效果。

水产动物病理学实验课的教学问题及探讨

水产动物病理学实验课是水产动物医学新专业中的专业核心课水产动物病理学的配套课程。本课程通过观察动物病理剖检标本和病理组织学切片标本,以求提高病理诊断实际操作能力的一门实验课程。作为上海海洋大学第一届该课的授课老师,本文作者在备课和授课的过程对此课程授课中存在的问题进行思考、归纳和总结,以期为今后该课程及相关课程的开展提供经验,并为进一步改进教学效果提供帮助。

动物病理学实验教学研究与实践

动物病理学是兽医学一门重要的理论与实践学科,是联系基础学科与临床学科的桥梁。该文主要探讨如何在动物病理实验教学中激发、引导、培养学生的创新性思维和实践能力。

动物病理解剖学实验教学新模式实践研究

通过对动物病理解剖学实验教学内容、教学方法、实验操作、实验效果等方面评价进行探索改进,以提高学生学习积极性和实验操作能力为目标,拓展学生自主探究知识及提升科研逻辑的实验思维,使学生更好地掌握动物疾病病因、机制、病理变化,从而能够深层次了解引起病变的本质,为进一步强化动物病理学实验教学改革奠定基础。

动物病理实验室管理与体会

动物病理实验室是进行兽医临床诊断、实验教学和科研的主要实验室,在动物病理实验室的管理中,实行实验室的管理制度,重视危害因素对动物病理检测人员健康的影响,稳定动物病理人员的工作心态,从而保证病理实验顺利开展。

信息化背景下病理动物实验教学改革新思路

病理动物实验是病理教学的重要组成部分,主要利用人为操作在适宜动物身上复制特定的疾病模型,通过这种疾病模型的复制和模拟,学生不但可以锻炼动手能力,还能够更好地理解疾病的发生发展过程。但是在实际教学过程中,由于师资、场地以及经费等多方面因素制约,病理动物实验开展困难重重。本文通过分析现阶段护理职业教育中病理动物实验开展现状,探讨可能存在的问题,探索如何应用信息技术和手段调整教学设计思路,以更好地适应当前护理职业教育需求,提高教学效果和效率。

基于《水生动物病理学实验》授课经验浅谈安全意识与培养

结合水生动物病理学实验课授课经验,从实验器材、液体、操作和管理四个方面,分享实验过程中可能存在的安全隐患。在安全中谈收获和进步。

兽医病理学检测领域CNAS认可能力范围表述浅析

现阶段,由于兽医病理学检测认可能力范围表述存在一定差异,中国合格评定国家认可委员会(China National Accreditation Service for Conformity Assessment,CNAS)认可实验室在兽医病理学检测领域扩项申报过程及评审员评审过程中出现了不规范、不统一的情况,使很多从事实验动物病理学检测及科研工作的实验室无法获得相关资质。本文通过对兽医病理学检测领域CNAS认可能力范围表述存在问题进行分析,对比英国、美国、加拿大、新西兰、新加坡等国外实验室兽医病理学能力范围表述,以及CNAS和其他ISO/IEC 17025认可机构的医学病理学实验室检测能力范围表述,并结合我国兽医病理学实验室认可实践情况,提出了针对兽医病理学检测领域能力范围表述的建议,期望进一步统一和规范我国兽医病理学检测领域的认可能力范围表述,以提升我国认可制度的规范性。

Microcirculation disturbance affects rats with acute severe pancreatitis following lung injury

AIM: To study the effects of microcirculation disturbance(MD) on rats with acute severe pancreatitis (ASP).METHODS: We developed ASP rat models, and anatomized separately after 1, 3, 5, 7, and 9 h. We took out blood and did hemorrheologic examination and erythrocyte osmotic fragility test, checked up the water content, capillary permeability, and genetic expression of intercellular adhesion molecule-1 (ICAM-1) in lung tissues, examined the apoptosis degree of blood vessel endothelium while we tested related gene expression of Bax and Bcl-2in lung tissues. We did the same examination in control group.RESULTS: The viscosity of total blood and plasma, the hematocrit, and the erythrocyte osmotic fragility were all increased. Fibrinogen was decreased. The water content in lung tissues and capillary permeability were increased.Apoptosis degree of blood vessel endothelium was increased too. ICAM-1 genetic expression moved up after1 h and reached its peak value after 9 h.CONCLUSION: MD plays an important role in ASP following acute lung injury (ALI). The functional damage of blood vessel endothelium, the apoptosis of capillary vessel endothelium, WBC edging-concentration and the increasing of erythrocyte fragility are the main reasons of ALI.

Anti-hepatoma effect of arsenic trioxide on experimental liver cancer induced by 2-acetamidofluorene in rats

AIM： To study the anti-hepatoma efficiency of arsenic trioxide （As2O3） in the treatment of experimental rat hepatocellular carcinoma （HCC） induced by 2-acetamidofluorene （2-FAA） and to elucidate the possible mechanisms. METHODS： SD rats （2 mo old） had been fed with 2-FAA for 8 wk to induce HCC, and then they were treated with As2O3 or matrine. On d 29, the rats were killed and the liver was weighed and liver tumors were counted. The histological changes of liver tissue were observed under microscope, and the cellular dynamic parameters were studied by flow cytometry. Immunohistochemistry （two-step method） was used to observe the expression of vascular endothelial growth factor （VEGF） and micro-vessel density （MVD） on consecutive sections. The pathological parameters were also analyzed, the levels of serum aspartate aminotransferase （AST）, alanine aminotransferase （ALT）, total bilirubin （TBi）, and direct bilirubin （DBi）. RESULTS： The number of liver tumors decreased significantly in groups treated with As2O3, especially in medium-dose （1 mg/kg） group （t = 2.80, P〈0.01）. As2O3 caused HCC cell death via apoptosis; necrosis was seen and apoptosis was common when the dose was 1 mg/kg. Proliferation index decreased sharply in medium-dose （1 mg/kg） group （7.87±4.11 vs24.46±6.49, t= 2087, P〈0.01）, but not in 0.2 mg/kg group. However, S-phase fraction decreased dramatically in both groups, it reached the bottom level only when the dose was i mg/kg compared with control （0.40±0.13 vs3.01±0.51, t= 2.97, P〈0.01）, and it was obviously accompanied with accumulation of cells in G0/G1 （G0/G1 restriction）. The expressions of VEGF and MVD in medium-dose （1 mg/kg） group were significantly lower than normal saline group （0.63±0.74 vs2.44±0.88, P〈0.05; 15.75±3.99 vs47.44±13.41, t= 2.80, P〈0.01）. Compared with normal saline group, mediumand low-dose groups As203 and matrine lowered the levels of ALT in serum （61.46±9.46, 63.75±20.40, 61.18±13.00 vs 108.98±29.86, t= 2.14, P〈0.05）, but had no effect onthe level of serum AST, TBi, and DBi. CONCLUSION： As203 had inhibitory effect on growth of experimental HCC in rats induced by 2-FAA, but had no obvious effect on normal hepatic cells. The mechanisms may involve decrease of cell division, accumulation of cells in G0/G1 phase, apoptosis of tumor cells, and inhibitory effect on angiogenesis through blocking VEGF.

Resveratrol prolongs allograft survival after liver transplantation in rats

AIM： To study the immuno-modulatory effect of resveratrol （RES） on allograft rejection after liver transplantation in rats. METHODS： Male Sprague-Dawley （SD） rats were selected as donors and male Wistar rats as recipients for a rejection model. The recipients were divided into four groups after orthotopic liver transplantation （OLTx）. In the RES A, B, and C groups, RES was given intra-peritoneally once a day （25, 50, and 100 mg/kg, respectively） after OLTx, whereas in the control group, vehicle buffer was given intra-peritoneally once a day. The survival time, serum chemistry, production of cytokines, activation of transcription factor NF-kB, and histopathologic findings were then compared among these groups. RESULTS： The mean survival time after OLTx in the RES C group was significantly longer than that in the control group （16.7＋-1.2 d ,vs9.3＋-0.6 d, P〈0.01）. On the 7th posttransplant day the serum albumin level significantly improved in the RES C group, the serum total bile acid and alanine aminotransferase （ALT） levels were significantly lower in the RES C group, the serum IL-2 and INF-y levels were significantly lower in the RES C group, and the activation of transcription factor NF-kB in peripheral blood T lymphocytes was significantly suppressed in the RES A, B, and C groups in comparison to those in the control group. On the 7^th post-transplant day, a histological examination revealed apparent difference in the severity of rejection between the RES C group and control group. CONCLUSION： RES has an immuno-suppressive property as well as protective effect on hepatocytes under allograft rejection. It might serve as a novel agent for reducing the severity of hepatic allograft rejection in rats.

Effect of hypercholesterolemia on experimental colonic anastomotic wound healing in rats

AIM： To evaluate the mechanical and biochemical parameters of colonic anastomotic healing in hypercholesterolemic rats. METHODS： Sixty rats were divided into two groups of 30 each according to their dietary regimens. The test group was fed with a high cholesterol-containing diet for two months while the control group had standard diet. These two groups were further divided into three subgroups consisting of ten rats each. After hypercholesterolemia was established, left colon resection and anastomosis were performed in both groups and samples from liver and abdominal aorta were taken to evaluate the systemic effects of hypercholesterolemia. Anastomotic wound healing, blow-out pressures and tissue hydroxyproline levels were evaluated. RESULTS： The test group had a significant weight gain in two months. Microscopic examination of the abdominal aorta revealed no atherosderotic change in none of the groups, but liver tissue specimens showed significant steatosis in the test group. Tissue hydroxyproline levels and anastomotic blow-out pressures were significantly lower in the test group than in the controls. CONCLUSION： Hypercholesterolemia not only increases hydroxyproline levels and blow-out pressures but also worsens anastomotic wound healing.

Effect of indomethacin on electrical field stimulation-induced contractions of isolated transverse and longitudinal rat gastric fundus strips

AIM: To study the effects of indomethacin on the isolated transverse and longitudinal rat gastric fundus strips.METHODS: The strips were suspended in an organ bath containing oxygenated Krebs solution, and contractile responses to electrical field stimulation were recorded on a physiograph in an isotonic manner after administration of cumulative concentrations of indomethacin. The effects of indomethacin on the strips pretreated with KATP channel modulators, diazoxide and glybenclamide were studied.RESULTS: Treatment of the transverse strips with indomethacin resulted in a concentration-dependent inhibitory response. In longitudinal strips, biphasic responses were seen, which included a stimulatory response at low concentrations of indomethacin, followed by an inhibitory response at higher concentrations.Diazoxide pre-treatment inhibited the stimulatory response of longitudinal strips. Glybenclamide pre-treatment not only blocked inhibitory effect of the low concentrations of indomethacin on transverse strips, but also increased the amplitude of contractions. Moreover, the drug decreased the amplitude of contractions in longitudinal strips.CONCLUSION: Responses of the isolated longitudinal and transverse rat gastric fundus strips to indomethacin are not similar, and are influenced by KATP channel modulators.

Changes of CD8+CD28-T regulatory cells in rat model of colitis induced by 2,4-dinitrofluorobenzene

AIM:To determine the changes of CD8+ T subsets especially CD8+CD28-T regulatory cells in rat model of experimental colitis induced by 2,4-dinitrofluorobenzene (DNFB). METHODS:The rat model of experimental colitis was induced by enema with DNFB.Ten days later,colonic intraepithelial and splenic lymphooltes were isolated from colitis animals (n=16) and controls (n=8).The proportion of CD8+ T cells,CD8+CD28+ T cells and CD8+CD28-T regulatory cells were determined by flow cytometry. RESULTS:The model of experimental colitis was successfully established by DNFB that was demonstrated by bloody diarrhea,weight loss and colonic histopathology.The proportion of CD8+ T cells in either splenic or colonic intraepithelial lymphocytes was not significantly different between colitis animals and controls (spleen:34.6±7.24 % vs 33.5±9.41%, colon:14.0±8.93 % vs 18.0±4.06 %,P>0.05).But CD8+CD28- T regulatory cells from colitis animals were significantly more than those from controls (spleen:11.3±2.26 % vs 5.64±1.01%, colon:6.50±5.37 % vs 1.07±0.65 %,P<0.05).In contrast, CD8+CD28+ T cells from colitis animals were less than those from controls (spleen:23.3±6.14 % vs 27.8±9.70 %,P=0.06; colon:7.52±4.18 % vs 16.9±4.07 %,P<0.05).The proportion of CD8+CD28-T regulatory cells in splenic and colon intraepithelial CD8+ T cells from colitis animals was higher than that from controls (spleen:33.3±5.49 % vs 18.4±7.26 %, colon:46.0±14.3 % vs6.10±3.72 %,P<0.005). CONCLUSION:Experimental colitis of rats can be induced by DNFB with simplicity and good reproducibility.The proportion of CD8+CD28-T regulatory cells in rats with experimental colitis is increased,which may be associated with the pathogenesis of colitis.

A Correlative Study of CT, MR and Pathology in Rabbit Liver after Embolization by a China-Formulated Lipiodol Emulsion

OBJECTIVE To explore the MR characteristics following lipiodol retention in rabbit liver and to evaluate the sensitivity of CT （CT value 〉400 HU） and MR in displaying the hepatic degeneration and necrosis following embolization. METHODS Thirty-two rabbits were randomly divided into 3 groups. In the control group （n=8）, 2 ml of normal saline was injected into the right branch of the portal vein. In the first experimental group（n= 12）, 4 ml of lipiodol emulsion was injected into the main portal vein. In the second experimental group （n= 12）, 2 ml of lipiodol emulsion was injected into the right branch of the portal vein. CT and MR images were obtained before and after surgery in each group. The histopathologic condition was determined for all liver tissue specimens. RESULTS In the control group, CT and MR did not show any significant changes in the livers after surgery. After the operations in the experimental groups, the regional CT attenuation was 601±101 HU in the largest slice, which had no abnormal signals on T1Wl and T2Wl. In the first group, histologic examinations showed there were concentrated lipiodol droplets around the portal areas. In the second group, serious degeneration and necrosis in the right hepatic lobe occurred in 9 rabbits. T1Wl displayed homogenous or non-homogenous low signals and T2Wl mainly displayed a high signal. However, these pathologic changes did not appear on CT scanning due to high attenuation of the lipiodol. CONCLUSION There were no remarkable hepatic changes on MR in rabbits following good retention of the formulated lipiodol emulsion mixture of lipiodol and urografin（CT value 〉 400 HU）. MR displayed serious degeneration and necrosis of the liver following embolization.

THE DEVELOPMENT OF MONOCLONAL ANTIBODY AGAINST rhTNF AND ITS CURATIVE EFFECTSON E.Coli INFECTED MICE

Fifteen hybridoma cell lines producing monoclonal antiboclies (McAb) against recombinant human tu-mor necrosis factor a (rhTNFa) have been established by fusing SP 2/0 cells with spleen cells from aBALB/c mouse immunized with rhTNFa. Following J M Davis’s Works, semi-solid medium was usedfor initial cloning. Five of them were studied further. Their main chromosome- numbers range were 96 to105, all of them were IgG1 subclass. The affinities of these McAbs were estimated to be 1. 25 ×108 mol/L, 1. 12×108 mol/L, 2. 34×108 mol/L, 8. 55 × 107 mol/L, 1. 04×108 mol/L, respectively.Two groups of mice challenging with E Coli (107 organisms), one group treated with 2mg/kg anti-TNF monoclonal antibody, the other did not. There was a higher survival rate in treated group, the serumTNF level was significantly lower too, and the untreated mice had severe pathologic changes in vlscera.

Expression and effect of Caspase-3 in neurons after tractive spinal cord injury in rats

Objective: To investigate Caspase-3 expression and its role in neuronal apoptosis.Methods: The T13-L2 spinal cord of rats was injured by traction after the amplitude of P1-N1 wave, monitored by a cortical somatosensory evoked potential (CSEP) monitor, decreased to seventy percent of that before operation. Then rats were killed in 6 h, 1 d, 4 d, 7 d, 14 d and 21 d respectively after operation. Flow cytometer terminal deoxynucleotldyl transferease-mediated biotinylated deoxynuridine triphosphate nick end labeling (TUNEL), Caspase-3 activity assay and immunohistochemical method were applied to investigate Caspase-3 expression in the spinal cord tissue and to study neuronal apoptosis in rats. Results: After spinal cord injury, apoptotic cells detected by flow cytometry and TUNEL-positive cells were significantly more, and positive immunohistochemical staining of Caspase-3 and Caspase-3 activity were significantly higher in Group injury than in Groups control and laminectomy, respectively (P> 0.05, P> 0.01). Similar trend of changes was noticed in apoptotic cells, TUNEL-positive cells and positive immunohistochemical staining of Caspase-3, all of which reached their respective peak 7 days after operation. Caspase-3 activity reached its peak, however, 4 days postoperatively. Conclusions: Increased expression and activity of Caspase-3 protein in neurons after tractive spinal cord injury is the biochemical signal of early spinal cell apoptosis. It is of great significance for understanding the mechanism of spinal cord injury.

Pathological study of rabbits' femoral arteries subjected to gunshot wounds combining with seawater immersion

Objective: To investigate pathological characteristics of gunshot wounds concomitant seawater immersion in rabbits’ femoral arteries. Methods: Thirty rabbits were divided randomly into 3 groups: simple gunshot-wound group (Group I, n=10), gunshot wound with seawater immersion for 30 mins (Group II, n=10), and 60 mins group (Group III, n=10). Femoral arteries were impacted by (0.38 g) steel spheres fired with a (7.62 mm) rifle. After being wounded, rabbits in Groups II and III were immersed in seawater for 30 or 60 mins, but those in Group I were not. At 2, 4, 6, 8, 12 hours following injury, a 40 mm segment of the artery on each side of the gunshot point were excised and observed by light and electron microscopy. Results: The patterns of arterial injuries were mainly contusion and transection. Completely transected artery was classified as primary-wound-tract area, contused area and shocked area. Compared with those in Group I, the primary-wound-tract and contused areas in Group II manifested obvious swelling in the arterial wall especially at the outside 2/3 of the media. Vacuolar structures were often seen in smooth muscle cells of the media. Intercellular space among the smooth muscle cells were filled with homogeneous acidophilic substances. Deep rugae among endothelial cells flattened or rugal folds lost their longitudinal orientation, and marked fibrin and platelet deposition were noticed. No significant difference was detected between Group II and III. The pathological changes in the shocked area were similar in 3 groups. Conclusions: For gunshot wounds concomitant seawater immersion in rabbits’ femoral arteries, there was a marked swelling of cells and intercellular space in primary-wound-tract area and contusion area. The influence of these pathological changes on surgical reparation deservers further study.