Extraction,Purification and Activity Analysis of Lipopolysaccharides from Escherichia coli Isolated from Swine

In order to obtain higher purity and high yield of LPS isolated from Escherichia coli, and evaluate its virulence,excrement of diarrhea piglet was collected as pathological samples, of which, some strains of Escherichia coli were isolated and identified. And furthermore, a strain of Escherichia coli was acquired by 16S rDNA identification. The LPS from this strain of Escherichia coli was isolated with the hot-phenol water method and purified by DNaseⅠ, RNaseA, proteinase K treatment and alcohol precipitation. The polysaccharide, protein and nucleic acid content of purified LPS were detected by phenol-sulfuric acid method, Bradford method and UV points spectrophotometric method. And its bioactivity and acute median lethal dose was determinated by tachypleus amebocyte lysate (TAL) method and acute toxicity experiment method, respectively. The results showed that a strain of highly pathogenic Escherichia coli was successfully isolated. The average yield of purified LPS was 3.74%, the proportion of the polysaccharide was 13.40%, the protein was 0.48%, and the nucleic acid was 0.06%. SDS-PAGE electrophoresis and silver stain showed that the bands were mainly concentrated in the range of 14 to 160 ku. The LAL bioactivity of the prepared LPS was 1.21×10⁷ EU/mg, LD₅₀ of the mouse abdominal cavity was 31.86 mg/kg. The results revealed that the diarrhea piglets in the farm was caused by pathogenic Escherichia coli,purified LPS from this strain of Escherichia coli had the advantages of higher purity, high yield and strong virulence, which would provide theoretical data for clinical prevention and treatment of diarrhea piglets.     

Prevalences of feline leukaemia virus and feline immunodeficiency virus infections in cats in Sydney

Objective To determine prevalences of feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) infections in ‘healthy’ cats that, through acute misadventure or other circumstance, were presented to veterinary practitioners. Prevalences of FeLV and FIV in this population were compared to those in a population of predominantly sick cats. Design and procedures Serum specimens were obtained over a 2-year period from 200 cats oldeer than 1 year of age presented to veterinary clinics for routine procedures, including cat fight injuries or abscesses, vehicular trauma, neutering, dental scaling, vaccination, grooming or boarding. An additional 894 sera were obtained over approximately the same period from specimens submitted by veterinarians to a private clinical pathology laboratory, mainly from sick cats suspected of having immune dysfunction, but including some sera from healthy cats being screened prior to FeLV vaccination. FIV antibody and FeLV antigen were detected in samples using commercial enzyme immunoassays. Results Amongst 200 ‘healthy’ cats, the prevalence of FeLV infection was 0 to 2%, and the prevalence of FIV was 6.5 to 7.5%, depending on the stringency of the criteria used to define positivity. FIV infection was significantly more prevalent in cats which resided in an inner city environment (P = 0.013). Of the 894 serum specimens submitted to the laboratory by practitioners, 11/761 (1.4%) were FeLV positive, while 148/711 (20.8%) were FIV positive. The prevalence of FIV was significantly higher in these predominantly ‘sick’ cats than in cats seen for routine veterinary procedures (P < 0.00001), while there was no difference in the prevalence of FeLV (P = 0.75) Conclusions The prevalence of FeLV and FIV in healthy cats may have been substantially overestimated in some previous Australian surveys. FeLV infection would appear to be a rare cause of disease in Australian cats. The higher prevalence of FIV positivity in sick as opposed to healthy cats infers that FIV infection contributes to the development of disease.     

急性心肌梗死患者冠状动脉支架植入术的近期疗效观察

目的 :观察急性心肌梗死患者冠状动脉支架植入术的近期疗效。方法 :4 8例急性心肌梗死 (AMI)患者 ,胸痛发作至介入治疗时间 (4 .1± 3.1)h,行急诊冠状动脉造影 ,证实冠状动脉闭塞 ,仅对梗死相关血管行支架植入。结果 :全组 4 8例术后即刻血管再通恢复心肌梗死溶栓试验为 3级者 4 3例 (93.7% )、2级者 5例 ,1例术中死于继发性心室颤动。4 8例中在梗死相关血管开通后出现心室颤动 10例 (2 0 .1% ) ,1例术后 2周后因再次心肌梗死死亡。植入术后存活的 4 6例术后随访 (8.2± 3.6 )月 ,无 1例再发生心脏事件。结论 :急性心肌梗死行冠状动脉支架术能成功挽救频死的心肌 ,能有效降低病死率。     

Production and related variables in bovine leukaemia virus-infected cows

A newly developed milk dot blot test was used to detect anti-bovine leukaemia virus (BLV) antibody in milk samples from 2079 lactating adult cows from among 61 herds. The milk dot blot test was highly repeatable; the concordance rate, compared with the agar gel immunodiffusion test performed on serum, was 83.5%. All herds contained BLV-positive cows; the prevalence rate was 36%. BLV-positive cows tended to come from larger herds and were older and more often later in lactation. Fourteen production and related variables (herd size, age, days open, days in milk, milk somatic cell count, milk, fat, and protein produced in the current lactation, projected production of milk, fat, and protein, and breed class average deviations for milk, fat, and protein) were compared between BLV-positive and BLV-negative cows. Although somatic cell count, milk produced, and projected production of milk and protein were related significantly to BLV status using simple tests of association, once the variables herd size, age and days in milk were controlled, these differences were removed. Further analyses using logistic (outcome: individual cow BLV status) and least-squares regression (outcome:herd proportion of BLV-positive cows) failed to show an association between any of the measured production or related variables and BLV-positivity. We concluded that the effect of BLV on production and related variables in dairy cows was below the sensitivity of our analytical techniques or was non-existent.Abbreviations ABCA herd average breed class average for milk, fat, and protein production - AVGAGE average age of the herd - ADIM herd average for days in milk - AGID agar gel immunodiffusion - AVGSCC herd average milk somatic cell count - BCA breed class average, a milk, fat and protein production index calculated by comparing a cow's actual 305-day lactation production to the corresponding BCA standard for the same breed, age, and month of calving - BLV bovine leukaemia virus - CALVINT calving interval - COWAGE cow age - DBCA breed class average deviation for milk, fat, and protein production, the difference between an individual cow's BCA and the herd average - DIM days in milk - HS herd size corresponding to the number of lactating cows in a herd - LACT actual amount of milk, fat, and protein produced in a cow's lactation - ODHIC Ontario Dairy Herd Improvement Corporation - PCTPOS percentage of herd that is BLV-positive - PROJ projected 305-day production for milk, fat, and protein by fitting to a standard lactation curve adjusted for days in milk and age at calving - RHBCA rolling herd average for breed class average for milk, fat, and protein production, the average for all cows that completed a lactation (cows must have completed a 305-day lactation) during the previous 12 months - SCC milk somatic cell count     

Acute Hepatic Necrosis And Liver Failure Associated With Benzodiazepine Therapy In Six Cats, 1986–1995.

A retrospective analysis was conducted of all feline necropsies performed during a nine year period to identify cases of sever, acute, centrilobular (periacinar), hepatic necrosis (ACHN). After exclusion of cats with anemia, a series of seven cases of ACHN was identified. In addition, two similar cases were identified from tissue submitted for histopathology following, and eight had bile duct hyperplasia. Seven of the nine cats received diazepam prior to dath, and one received zolazepam. Of the seven cats that received diazepam, five were healthy prior to treatment and received oral diazepam for the treatment of inappropriate urination, intercat aggression, or skin disease. Two cats which received diazepam exhibited other clinical signs: one had chronic vomiting, and the other received diazepam after biochemical evidence of hepatocellular necrosis was present. Onset of clinical sings in cats receiving oral diazepam occurred 7–13 days following the initiation of treatment. Clinical signs and clinical biochemical analysis were compatible with severe hepatocellular necrosis and acute liver failure. All cats had lesions in other organs: five had pancreatic disease, five had cardiac disease, and five had renal disease. All cats died, or were euthanized, within 4 dyas of the onset of clinical signs and 2 days after presentation to a veterinarian. Fatal, acute, centrilobular hepatic necrosis appears to be a serious adverse reaction to diazepam therapy in certain cats.     

乳源康的急性毒性和抗炎活性研究

研究了治疗奶牛乳房炎新型中草药制剂—乳源康注射液的急性毒性和抗炎活性,用不同剂量的乳源康注射液分别进行了小白鼠灌胃和腹腔注射的急性毒性试验,结果显示灌胃时制剂的 LD50为 36.80 g/kg,其 95 %可信限为 32.12~41.47 g/kg;腹腔注射时其制剂的 LD50:13.85 g/kg,95 %可信限为 12.76~14.94 g/kg,表明乳源康注射液实际无毒;用小鼠耳廓肿胀法,观察了乳源康和氢化可的松的抗炎活性试验,结果表明乳源康对二甲苯所致小鼠急性耳廓肿胀有明显抑制作用(P<0.05),其抗炎药效和氢化可的松的相同。     

桑蚕雄蛾酒的急性毒性和应激能力的试验

桑蚕雄蛾与药食两用的中药配制成的桑蚕雄蛾酒，经小鼠的急性毒性试验和应激能力（包括缺氧试验、高温试验和游泳试验）试验表明：桑蚕雄蛾酒的安全性极高；应激能力的提高与对照相比，均达到显著水平（Ｐ＜０．０５）     

镉-菲复合污染对蚯蚓急性毒性效应的研究

采用人工土壤法,研究重金属镉、多环芳烃菲对安德爱胜蚓(Eisenia andrei)的单一与复合急性毒性效应。单一毒性试验结果表明,菲的毒性大于镉毒性;14 d时镉、菲的半数致死浓度(LC50)分别为788.71 mg.kg-1、42.51 mg.kg-1。复合毒性试验结果表明,镉在各浓度下与菲复合,对蚯蚓的毒性都产生拮抗作用,且随镉浓度升高其降低菲毒性的程度降低,说明复合污染物的组成及各污染物的不同浓度组合是决定混合物毒性的重要因素。     

几种金属离子对萼花臂尾轮虫的急性毒性试验

萼花臂尾轮虫是鱼苗最适口的优质饵料之一，也是生态研究的主要对象之一。其适应力强、生长快、繁殖迅速、培养成本低，极易在生产实践中推广应用。并可作为水环境监测的指示生物。通过对萼花臂尾轮虫的24h标准化急性毒性试验，证明了Zn^2 、Pb^2 、Cu^2 、Cd^2 对萼花臂尾轮虫具有急性毒害作用。     

东菱克栓酶与蝮蛇抗栓酶治疗急性动脉硬化性脑梗塞的疗效比较

目的：观察东菱克栓酶（ＤＦ－５２１）与蝮蛇抗栓酶（Ｓｖａｔｅ）对急性动脉粥样硬化性血栓性脑梗塞（ＡＡＣＩ）的疗效比较。方法：经ＣＴ或ＭＲＩ确诊的ＡＡＣＩ７８例随机分为２组即ＤＦ－５２１组４８例和Ｓｖａｔｅ组３０例。结果：总有效率：ＤＦ－５２１组为８９．６％，Ｓｖａｔｅ组为７６．６％（Ｐ〉０．０５）；两组的显效率分别为７０．８％、３６．７％（Ｐ〈０．０１）。结论：ＤＦ－５２１的疗效明显优于Ｓｖａｔｅ