脑活素治疗新生大鼠缺血缺氧性脑病机理的研究

7日龄Wister大鼠结扎左侧颈总动脉后吸入氧氮混合气体（8％O2和92％N2）2h,制成缺血缺氧性脑病动物模型,测定大鼠脑组织中丙二醛（MDA）的含量和超氧化物歧化酶（SOD）的活性。结果显示,缺血缺氧后6h,缺血缺氧组MDA含量显著升高,24h达到高峰,以后逐渐下降,96h与对照组比较无统计学差异;缺血缺氧脑活素治疗组MDA含量于缺血缺氧后6h已经显著下降,72h与对照组比较无统计学差异。缺血缺氧组SOD活力值在缺血缺氧后6h已经下降,24h降到最低点,以后逐渐回升,96h与对照组比较无统计学差异;缺血缺氧脑活素治疗组SOD活力值在缺血缺氧后6h明显提高,于缺血缺氧后96h与对照组比较无统计学差异。结果提示,缺血缺氧引起新生大鼠脑组织的氧化-抗氧化系统失衡,氧自由基大量产生,参与了新生大鼠缺血缺氧性脑病脑损伤过程;脑活素能够抑制氧自由基的生成,提高SOD的活力值,对缺血缺氧性脑病具有神经保护作用。     

Effects of nitric oxide on hepatic encephalopathy in cirrhotic rats induced by LPS

AIM: To investigate the effects of nitric oxide (NO) on hepatic encephalopathy in cirrhotic rats induced by LPS. METHODS: The cirrhotic model of rats was established by complex pathogeny. Since the end of the 8 th week, the rats were intragastrically-infused with 0.9% salt, L-arginine(L-arg) and LNNA respectively for 2 weeks.The hepatic encephalopathy in cirrhotic rats were induced by 3 mg/kg LPS (ip) 4 hours before the rats were sacrificed. RESULTS: The normal behaviors and electroencephalograph were appeared in L-arg group. LNNA group showed hepatic encephalopathy. The content of NO₂^-/NO₃^- of brain tissue was markedly higher in L-arg group than LNNA group(P<0.05), but the content of histamine in brain tissue was lower in L-arg group than LNNA group(P<0.05). There was a negative correlation between the content of histamine in brain tissue and the content of NO₂^-/NO₃^- of brain tissue. CONCLUSION: NO can prevent hepatic encephalopathy in cirrhotic rats induced by LPS.     

检测猪流行性腹泻病毒的R-PCR方法的建立

根据猪流行性腹泻病毒 (PEDV)的N基因自行设计和合成了一对可扩增长度为 641bp目的片段的引物 ,成功地建立了检测的猪流行性腹泻病毒的RT PCR方法。对猪轮状病毒 (PRV)、猪传染性胃肠炎病毒 (TGEV)的RT PCR检测结果均呈阴性。对PEDV JS株的RT PCR产物的序列分析表明 ,与CV777株的同源性为 97 3 %。     

Establishment and Application of a Multiplex RT-PCR Assay for Detection of PEDV,TGEV and PRoV

In this study,a multiplex RT-PCR assay was established to differentially detect porcine epidemic diarrhea virus (PEDV),porcine transmissible gastroenteritis virus (TGEV) and porcine rotavirus (PRoV) after optimization of the reaction conditions.Three pairs of primers PEDV-N,TGEV-M and PRoV-VP6 were designed for specifically amplifying PEDV N gene,TGEV M gene and PRoV VP6 gene,respectively.The assay could specifically amplify PEDV,TGEV and PRoV,but not classical swine fever virus (CSFV),porcine foot and mouth disease virus (FMDV),pseudorabies virus (PRV),porcine parvovirus (PPV) and porcine circovirus type 2 (PCV2).The detection limits of PEDV,TGEV and PRoV standard recombinant plasmids were 1.41×10³,1.41×10² and 1.41×10³ copies/μL,respectively.The repeated reaction under the same conditions obtained uniform results.The assay was used to detect a total number of 190 clinical samples,of which 42 (22.11%) samples were positive for PEDV,58 (30.53%) samples for TGEV and 34 (17.89%) samples for PRoV,and there were mixed infection among these viruses.The results indicated that this multiplex RT-PCR assay had the advantages of sensitivity,specificity and repeatability and provided a useful tool for differential detection and epidemiological investigation of PEDV,TGEV and PRoV.     

Canine transmissible venereal tumour: a review

Canine transmissible venereal tumour (CTVT) is a contagious venereal tumour of dogs, commonly observed in dogs that are in close contact with one another, or in stray and wild dogs that exhibit unrestrained sexual activity. CTVT represents a unique, naturally transmissible, contagious tumour, where the mutated tumour cell itself is the causative agent and perpetuates as a parasitic allograft in the host. Clinical history, signalment and cytological features are often obvious for establishing a diagnosis though biopsy and histological examination may be needed in atypical cases. Most cases are curable with three intravenous injections of vincristine sulphate at weekly intervals. The role of stray and wild dogs makes the disease difficult to control and necessitates sustained animal birth control in stray dogs along with prompt therapy of the affected dogs. This review captures the manifold developments in different areas embracing this fascinating tumour, including its biology, diagnosis and therapeutic alternatives.     

Experimental transmission of encephalopathy and retinopathy induced by nodavirus to sea bream, Sparus aurata L., using different infection models

The transmission of viral encephalopathy and retinopathy (VER) was investigated in juvenile sea bream, Sparus aurata L. Two different infection routes [intraperitoneal (i.p.) and intramuscular injection (i.m.)] were tested at two different temperatures (20 and 26 °C) using sea bream of mean weight 0.7, 2 and 4 g, as well as an immersion challenge performed at 26 °C with sea bream of 0.7 g. Successful transmission of the disease was only achieved by i.m. injection. Mortalities of 100% occurred in sea bream of 0.7 g at day 15 post-infection and 47% in sea bream of both 2 and 4 g at day 30 post-infection in all the experimental infections at 26 °C. No mortalities were ever observed with infections at 20 °C. When mortalities were observed, the virus was detected by immunoperoxidase staining in the SSN-1 cell line inoculated with tissues from infected fish. Histological examination of both normal and infected fish showed a vacuolization in the bipolar and granular layers of the retina of the infected sea bream. This is the first experimentally induced transmission of VER in sea bream. Differences were observed at the time of disease onset depending on water temperature, the route of infection and the age of the juvenile fish.     

Protective immunity of sevenband grouper, Epinephelus septemfasciatus Thunberg, against experimental viral nervous necrosis

This paper describes the protective immune responses of sevenband grouper, Epinephelus septemfasciatus Thunberg, immunized with live piscine nodavirus, the causative agent of viral nervous necrosis (VNN), or the Escherichia coli – expressed recombinant coat protein. Nodavirus-neutralizing antibodies were detected at titres ranging from 1:158 to 1:1257 in serum of sevenband grouper which survived intramuscular injection with the virus, by a cell culture assay system. The virus-neutralizing ability of immune serum was also confirmed by injecting virus previously treated with serum into fish. This indicates establishment of acquired immunity in survivors and thus explains why survivors from natural infection are resistant to recurrence of the disease. Young sevenband grouper were immunized twice by intramuscular injections with the recombinant coat protein. Immunized fish produced neutralizing antibodies at high titres for at least 110 days and showed significantly lower mortalities in virus challenge tests. These results suggest the potential for vaccination against VNN in sevenband grouper, which is susceptible to piscine nodavirus at all life-stages.     

Comparative pathogenicity study of ten different betanodavirus strains in experimentally infected European sea bass,Dicentrarchus labrax (L.)

Viral encephalopathy and retinopathy (VER), otherwise known as viral nervous necrosis (VNN), is a severe pathological condition caused by RNA viruses belonging to the Nodaviridae family, genus Betanodavirus. The disease, described in more than 50 fish species worldwide, is considered as the most serious viral threat affecting marine farmed species in the Mediterranean region, thus representing one of the bottlenecks for further development of the aquaculture industry. To date, four different genotypes have been identified, namely red‐spotted grouper nervous necrosis virus (RGNNV), striped jack nervous necrosis virus (SJNNV), tiger puffer nervous necrosis virus and barfin flounder nervous necrosis virus, with the RGNNV genotype appearing as the most widespread in the Mediterranean region, although SJNNV‐type strains and reassortant viruses have also been reported. The existence of these genetically different strains could be the reason for the differences in mortality observed in the field. However, very little experimental data are available on the pathogenicity of these viruses in farmed fish. Therefore, in this study, the pathogenicity of 10 isolates has been assessed with an in vivo trial. The investigation was conducted using the European sea bass, the first target fish species for the disease in the Mediterranean basin. Naive fish were challenged by immersion and clinical signs and mortality were recorded for 68 days; furthermore, samples collected at selected time points were analysed to evaluate the development of the infection. Finally, survivors were weighed to estimate the growth reduction. The statistically supported results obtained in this study demonstrated different pathogenicity patterns, underlined the potential risk represented by different strains in the transmission of the infection to highly susceptible species and highlighted the indirect damage caused by a clinical outbreak of VER/VNN.