The effect of medetomidine on the regional cerebral blood flow in dogs measured using Technetium-99m-Ethyl Cysteinate Dimer SPECT

Sedatives and anaesthetics are known to cause changes in the regional cerebral blood flow. In dogs intramuscular sedation with medetomidine, a potent sedative frequently used in veterinary medicine, is sometimes indicated prior to intravenous injection of ^99mTechnetium-Ethyl Cysteinate Dimer (^99mTc-ECD) in brain perfusion studies using Single Photon Emission Computed Tomography (SPECT). Based on the knowledge of the distribution of alpha₂-receptors in the brain, we hypothesized altered regional brain perfusion in dogs receiving medetomidine prior to ^99mTc-ECD. Two conditions were compared in 10 dogs; tracer injection before and after intramuscular sedation with medetomidine. In our study, medetomidine caused a significantly higher tracer uptake in all brain regions. Semi-quantification of brain perfusion rendered a lower perfusion index in the subcortical region and an imbalance between left and right cortical perfusion induced by medetomidine. This study shows that caution is needed when quantifying the brain perfusion indices under medetomidine sedation.     

Effect of Fu-Sheng powder on NPY and its mRNA in brain of rats with hyperlipidemia after cerebral ischemia and reperfusion

AIM:To observe the changes in neuropeptide Y(NPY) and the effect of Fu-Sheng powder(FSP) on NPY in the rat brain in a steady cerebral ischemia and reperfusion(I/R) model. METHODS: The models of rat brain injury were established by repeated cerebral I/R in rats with hyperlipidemia. Radioimmunoassay was performed to determine the level of NPY, while NPY mRNA expression was observed by in situ hybridization. RESULTS: After 1 day of I/R, compared with control group, the content of NPY in the model animals were significantly increased by 51.86% (P＜0.01) and lasting 7 days after I/R, and the expression of NPY mRNA was greatly increased. FSP treatment decreased the contents of NPY (P＜0.05,P＜0.01) and its mRNA expression. CONCLUTION: There were obvious imbalances of NPY in the rat brain after cerebral I/R and the FSP might antagonize ischemia injury of brain through modulating NPY, which may be one of the mechanisms underlying FSP treatment for cerebral vascular diseases.     

鳜脑组织细胞系的建立及其病毒敏感性研究

鱼类细胞是开展鱼类病毒分离鉴定、功能基因分析以及生物制品制备等研究的重要物质基础。鳜(Siniperca chuatsi)是深受养殖者和消费者欢迎的养殖品种。随着鳜鱼养殖产量的逐年增加,其病害问题尤其是病毒病问题也日趋严重,但是,可用于鳜鱼病毒分离和基因功能分析的鳜细胞系缺乏。本研究采用组织块消化法,对来源鳜脑组织的细胞进行原代培养,建立了鳜脑组织细胞系,命名为MFB。MFB细胞在28℃含10%胎牛血清的L-15中已稳定传代超过70次,第25代鳜脑组织细胞的染色体众数为56。采用免疫荧光细胞化学技术(β-tubulin和Neu-N)鉴定MFB细胞的神经元纯度,结果显示,培养的MFB细胞为神经元类细胞。病毒敏感性实验结果显示,鳜蛙虹彩病毒(MFRaIV)、大口黑鲈蛙虹彩病毒(LMBRaIV)和大鲵虹彩病毒(GSIV)均可在MFB细胞中产生典型细胞病变效应,病毒滴度分别为108.68±0.12、108.36±0.15、1010.15±1.85 TCID50/mL。使用脂质体Lipofectamine®2000将pEGFP-N1转入MFB细胞,转染效率可达20%。本研究建立的鳜脑组织细胞系不仅对多种蛙虹彩病毒敏感,而且转染质粒效率较高,为鳜病毒性病原的分离及基因功能研究奠定了前期基础。     

Applicability of a rapid chromatographic immunoassay for analysis of the distribution of PrPBSE in confirmed BSE cases

The Prionics-Check PrioSTRIP is a rapid chromatographic immunoassay for bovine spongiform encephalopathy (BSE) approved by the European Union in 2004. In this study, the PrioSTRIP was used to analyse PrP(BSE) in 16 different brain areas of nine confirmed BSE cases. The levels of PrP(BSE) in the different brain areas were plotted to give the brain PrP(BSE) distribution curve (BPDC) and compared with the BPDC obtained previously by Western blotting and enzyme-linked immunosorbent assay (ELISA) methods on the same samples. The distribution of PrP(BSE) in different areas of the brain was similar, irrespective of the test applied, indicating that each test could be used for the characterisation of BSE cases.     

Effect of BNP- mediated cAMP-PKA signaling pathway on bFGF expression in rats with spleen-qi deficiency syndrome

AIM: To explore the changes and the mechanism of heart functions in the rats with spleen-qi deficiency syndrome. METHODS: The rats were randomly divided into blank control group and spleen-qi deficiency model group. The changes of cardiac functions in the rats were determined by ultrasonic imaging with a high-resolution in vivo imaging system. HE staining was used to observe the pathological changes. The protein expression of brain natriuretic peptide (BNP) in the myocardium was assessed by Western blotting. The contents of BNP and cAMP in the serum and myocardium were measured by ELISA. The mRNA expression of basic fibroblast growth factor (bFGF) and protein kinase A (PKA) was detected by real-time PCR. RESULTS: Compared with blank control group, the myocardial cells in the model group had different degrees of necrosis and degeneration. Stroke volume and ejection fraction were decreased. The contents of cAMP and BNP in the serum and myocardium were increased in model group. The protein expression of BNP and the mRNA expression of bFGF and PKA were also increased.CONCLUSION: Spleen-qi deficiency syndrome causes heart function decline in rats. The expression of BNP, cAMP, PKA and bFGF is all increased.     

Upregulative effect of CGRP on expression of CREB and phospho-CREB protein during focal cerebral ischemia/reperfusion in rat parietal cortex

AIM: To investigate the effect of calcitonin gene related peptide (CGRP) on the expression of cyclic AMP response element binding protein (CREB) and phosphorylated-CREB in rat parietal cortex during focal cerebral ischemia/reperfusion (I/R).METHODS: Focal cerebral ischemia/reperfusion model was induced by occlusion of the right middle cerebral artery using the intraluminal suture method. The expressions of CREB and phospho-CREB in the parietal cortex in different groups (sham group, focal cerebral ischemia/reperfusion group and CGRP group) were detected with immunohistochemistry and Western blotting, and the positive products were analyzed by image analysis system.RESULTS: There was definite expression of CREB in right parietal cortex in sham group, while it was lesser in I/R group than that in sham group, but it became more in CGRP group than that in I/R group (P<0.05). Phospho-CREB was barely detected in right parietal cortex in sham group and it became more in I/R group than that in sham group. The expression of phospho-CREB increased in CGRP group than that in I/R group of the right parietal cortex (P<0.05).CONCLUSION: CGRP upregulates the expression of CREB and phospho-CREB in the ischemic neurons of the parietal cortex during focal cerebral ischemia/reperfusion and CREB probably involves in the mechanism of protective role of CGRP to ischemic neurons.     

Changes of BAEP,NO contents and Na+-K+ATPase activities in brain tissues in rats with hyperbilirubinemia

AIM: To explore the roles of brain-stem auditory evoked potential (BAEP) in early monitoring the hearing loss and brain damages in hyperbilirubinemia and nitric oxide(NO) in the pathogenesis of bilirubin-induced hearing loss and brain damages. METHODS: Different doses of bilirubin solution (30 mg/kg, 60 mg/kg, 90 mg/kg, 120 mg/kg and 150 mg/kg) were injected into the abdominal cavity of 15-day old SD rats to make the animal model of hyperbilirubinemia. The serum concentrations of bilirubin were detected by a micro-gauge. The bilirubin concentrations in the brain tissues were examined via a diazo method. The Na+-K+ATPase activities in the brain tissues were analyzed by rooting phosphorus. The NO contents in the brain tissues were assayed via the method of nitrate reductase. BAEP were recorded with an evoked potential recorder. RESULTS: After making the ejection, parts of the rats in the high dosage groups (120 mg/kg and 150 mg/kg) showed the abnormal neuro-behaviors. After 6 hours of the ejection, the bilirubin concentrations in serum and in brain tissues, and NO contents in the brain tissues were increased significantly. The Na+-K+ATPase activities in the brain tissues were decreased obviously, and the PL and IPL of BAEP were prolonged significantly in all the experimental rats except the ones in low dosage group (30 mg/kg). The changes of them were closely related to the dose of injected bilirubin. CONCLUSION: The PL and IPL of BAEP are the objective and sensitive indexes for early monitoring the hearing loss and brain damages in hyperbilirubinemia. NO may plays a certain role in the pathogenesis of bilirubin induced hearing loss and brain damages.