Wnt5a介导Wnt/Ca2+通路对BCG诱导牛原代肺泡上皮细胞自噬的调控作用

旨在探讨体外分离培养牛肺泡上皮细胞（bovine alveolar epithelial cells,BAECs）的方法及Wnt5a对牛结核分枝杆菌卡介苗（bacille Calmette-Guérin,BCG）感染BAECs细胞自噬的调控机制。试验选用酶联合消化法和机械刮刷法分离细胞,差速贴壁法纯化BAECs,免疫荧光染色检测上皮细胞标志物角蛋白14（cytokeratin 14,CK14）和角蛋白5（cytokeratin 5,CK5）的表达;BCG感染BAECs,并用Box-5抑制Wnt5a的表达,Western blot和免疫荧光染色检测自噬相关蛋白及非经典Wnt信号通路相关蛋白的表达。结果表明,采用酶联合消化法和机械刮刷法能够成功分离纯度较高的BAECs,细胞经CK14和CK5鉴定为阳性;BCG感染BAECs促进Wnt5a表达,增加细胞自噬,Box-5预处理下调BCG诱导的细胞自噬相关蛋白LC3II、P62、Atg7及Atg5的表达,且抑制非经典Wnt/Ca²⁺信号通路相关蛋白Wnt5a、CaMKII及NFAT的表达。综上,试验成功建立BAECs分离培养方法,BCG感染增加BAECs内Wnt5a表达和细胞自噬,抑制Wnt5a下调BCG诱导的BAECs细胞自噬,且Wnt5a是通过非经典Wnt/Ca²⁺信号通路调控BCG诱导的BAECs细胞自噬。     

Hepatic abscesses in cats: 14 cases (1985-2002)

In this retrospective study, we describe 14 cats diagnosed with hepatic abscesses. The objective of the study was to report the clinical signs, physical examination findings, clinicopathologic findings, and outcomes in affected cats. These findings were then compared with those previously reported in dogs and humans. Clinical signs were vague and included anorexia, lethargy, and weight loss. Only 23% of cats had fever, whereas 31% were hypothermic. Increases in serum activities of alanine aminotransferase and alkaline phosphatase were found in 45 and 18%, respectively, of the 11 cats that had laboratory work performed. Abdominal ultrasound examinations were performed in 7 cats, and abnormalities were found in 71% of them. Four cats had solitary abscesses, all of which were located in the right liver lobes. The other 10 cats had multifocal small abscesses or microabscesses, and all of these cats had clinical signs suggestive of sepsis. Cytologic evaluation of samples obtained by abdominocentesis indicated septic inflammation in 67% of cats in which peritoneal fluid was analyzed. Hepatic abscess cultures yielded polymicrobial growth in 66% of the cats: Escherichia coli was the most commonly cultured organism. Overall mortality rate was 79%. All survivors underwent exploratory laparotomy for partial hepatectomy to resect the abscess followed by medical management. Hepatic abscesses should be considered in cats with signs consistent with sepsis. More routine use of ultrasonography may aid in earlier diagnosis of hepatic abscesses, potentially improving prognosis and outcome.     

An oculo-cerebellar syndrome caused by congenital bovine viral diarrhoea virus-infection

An epizootic characterized by birth of calves severly ataxic and blind were encountered in 3 herds 7–8 months after outbreaks of bovine virus diarrhoea. Serological and virological investigations indicated introduction of bovine viral diarrhoea virus (BVDV) into previously virus-free herds, followed by transplacental virus infection of the fetuses of cows in the first trimester. Clinical, pathological, serological, and microbiological examinations were performed on 10 calves. Pathological findings included microcephaly and cerebellar hypoplasia, ocular malformations, and thymic hypoplasia. BVDV was isolated from tissue and blood of 7 calves, and 4 calves, 1 of which had not received colostrum, had virus-specific neutralizing antibodies.This is the first report on natural occurrence of congenital bovine infection with BVDV among Danish cattle herds resulting in abortion and birth of calves with severe debilitating congenital anomalies. It draws attention to the importance of this virus for bovines of all age groups.     

牛体细胞核移植技术

对牛体细胞核移植技术中核供体细胞周期同期化处理，电融合条件及去核方法等进行了研究。结果表明，血清－饥饿组（细胞周期同期化处理组）的移核重构胚细胞融合率（83．3％），卵裂率（70％）和囊胚发育率（33．8％）与血清－选择组对应指标间无显著性差异（82．3％，69．2％，32．4％，P＞0．05）；但上述2组分别极显著高于血清－随机组（64．8％，33．8％，4．35％，P＜0．01），试验确立了场强1.025kV/cm，脉冲宽度50μs，连续2次脉冲为最佳电融合条件。摸索出的点击去核法，对卵母细胞进行去核，去核成功率达90％，极显著高地吸引法的68．3％（P＜0．01）；其囊胚发育率为34．1％，显著高于吸引法的18．0％（P＜0．05），与挤压法（20．9％）相比差异不显著（P＞0．05），移植重构胚胎移植后，产2头成活的体细胞克隆牛。     

牛病毒性腹泻病毒致病机制研究进展

牛病毒性腹泻（bovine viral diarrhea,BVD）和黏膜病（mucosal disease,MD）均是由牛病毒性腹泻病毒（bovine viral diarrhea virus,BVDV）感染引发的传染病,严重威胁世界养牛业的发展。文章概述了BVDV分型及其分子生物学特征,并从急性感染、经胎盘或子宫感染、持续性感染和黏膜病4个方面总结了近期国内外BVDV致病机制的研究进展。根据序列保守性及是否致细胞病变可将BVDV分为两种基因型和两种生物型,其中,新发现的"HoBi"株归类为瘟病毒属。BVDV基因进化很快,基因组编码4种结构蛋白和8种非结构蛋白,编码蛋白在病毒的复制、翻译及在宿主致病过程中发挥重要作用。BVDV致病机制复杂,急性感染会造成病毒血症、繁殖障碍、免疫抑制等,急性感染牛发生腹泻的原因与BVDV感染胃肠道的肌层、黏膜下层并干扰肠道神经的正常功能相关,非致细胞病变型（NCP）BVDV是造成急性感染的病因。胚胎感染BVDV取决于病毒首次侵袭时胎儿在子宫内的生长阶段。NCP型BVDV具有抑制胎儿体内产生Ⅰ型干扰素的能力,致使该病毒在宿主中得以生存并形成持续性感染牛,当持续性感染牛再次感染与NCP型BVDV高度同源的致细胞病变型（CP）毒株时直接诱发黏膜病。两种生物型的产生是发生持续性感染和黏膜病的重要因素,NCP型可向CP型BVDV进行转化。本综述有助于发现控制BVD-MD传播的新途径,为消灭该病和新型疫苗的研制提供参考。     

GMP玻璃化冷冻未成熟牛卵母细胞核成熟及冷冻损伤试验

本试验通过荧光染色的方法建立了未成熟牛卵母细胞在体外培养过程中第1次减数分裂的各个阶段的参考判定图谱;根据这个标准来观察毛细玻璃管(GMP)玻璃化冷冻对卵母细胞核成熟和冷冻损伤的影响。结果表明,从屠宰场废弃的卵巢表面卵泡内抽取的COCs,70%处于生发泡期,12.5%生发泡开始破裂,7.5%已开始浓缩,这说明从屠宰场获得的COCs有较高的异质性;卵母细胞在成熟培养22h时收获排出第一极体的卵母细胞,可得到丰度较高的极体-胞质染色体对称、紧密相邻的成熟卵母细胞;GMP玻璃化冷冻损伤主要有2种表现形式,首先,直接影响膜结构的完整性,包括细胞膜和核膜,这可从退化的细胞比例看出(8～24h,有21.9%～27.2%的细胞处于该阶段),其次,影响CONDENSED向MⅠ期的过渡,这可从处于CONDENSED卵母细胞的比例看出(8～24h,有24.1%～34.3%的细胞处于该阶段)。     

p38介导β-羟丁酸对原代培养犊牛肝细胞凋亡的影响

本试验旨在探讨β-羟丁酸（BHBA）对体外原代培养犊牛肝细胞凋亡的影响以及p38MAPK在其中的调控作用。选择培养72h的肝细胞,添加不同浓度的BHBA（0、0．6、1．2、2．4mmol／L）,培养9h,每个浓度3个重复。另外选取细胞,p38MAPK抑制剂SB203580（10pmol／L）预处理1h后,添加BHBA,使其终浓度为2．4retool／L;PI／An—nexinV—FITC双染,运用荧光显微镜观察肝细胞凋亡情况;ELISA法检测p38的活性;实时荧光定量PCR方法检测p38、Caspase-3、Caspase9、bcl2基因的mRNA表达水平。结果表明,与对照组相比,1．2和2．4mmol／I—BHBA组的肝细胞凋亡明显增加;p38酶活性明显升高;p38、caspase-3和caspase-9基因mRNA表达水平均显著增加（P〈0．01）。bcl2基因mRNA表达水平显著降低（P〈0．05）;添加p38抑制剂后,caspase-3和caspase-9基因mRNA表达水平显著降低（P〈0．01）,bcl-2基因mRNA表达水平显著增加（P〈O．05）。高浓度的BHBA可以诱导体外原代培养犊牛肝细胞凋亡,p38在BHBA诱导的细胞凋亡中发挥重要作用。     

一株A型副鸡嗜血杆菌的分离鉴定

从山东省某蛋鸡场发病鸡群中分离到一株细菌,经培养特性观察、生化试验、V因子生长试验、致病性试验和PCR试验,证实分离菌为一株致病性副鸡嗜血杆菌,血清型鉴定该菌为A型。药物敏感性试验表明分离菌对头孢噻肟、头孢曲松、丁胺卡那霉素高度敏感,对硫酸新霉素、强力霉素中度敏感,对磺胺间甲氧嘧啶钠、环丙沙星、庆大霉素耐药。     

干扰MSTN的牛骨骼肌卫星细胞实时荧光定量PCR内参基因的筛选

为了筛选在牛骨骼肌卫星细胞（MSCs）分化前后稳定表达以及不受MSTN基因表达影响的内参基因,试验以野生组（WT）、转染干扰MSTN组（si-MSTN）和对照组（NC-MSTN）的牛MSCs作为样品,选取HMBS、B2M、GAPDH、TUBB、SDHA、18S rRNA、ACTB、RPL4、PPIA、HPRT1和YWHAZ作为候选内参基因,采用实时荧光定量PCR技术Ct值分析法对各候选内参基因的相对表达进行测定,首先利用3个独立评价软件geNorm、NormFinder和BestKeeper分别对各候选内参基因在野生组牛MSCs增殖期（GM）和分化第3天（DM3）细胞中的表达稳定性进行评价,筛选出前5个表达相对稳定的候选内参基因;然后以此为基础,利用相同的方法分析MSTN干扰组和对照组增殖期和分化第3天的细胞中上述5个内参基因的表达水平和稳定性。geNorm、NormFinder分析结果均显示,HMBS、B2M、TUBB、GAPDH和ACTB在牛MSCs分化前后表达较稳定,BestKeeper分析显示ACTB和TUBB相关系数（r）排序靠前,GAPDH、HMBS和B2M排序不是很高,但是GAPDH的SD值最小,因此选择这5个候选内参基因做后续试验;在牛MSCs MSTN干扰组和对照组增殖期和分化第3天,geNorm、NormFinder软件分析结果显示,上述5个候选内参基因中GAPDH、TUBB和B2M表达最稳定,BestKeeper分析显示TUBB相关系数排名不是最高,但其SD值最小,综合以上分析,选择TUBB作为牛MSCs干扰组和对照组增殖期和分化第3天最适内参基因。研究结果可为以后进行牛MSCs在不同生长时期以及MSTN表达被调控后基因的表达分析提供参考。     

传染性支气管炎病毒的鉴定

试验采用鸡胚接种和气管环培养相结合的方法,对IBV毒株进行培养鉴定,IBV经鸡胚传一代后再上鸡胚气管环培养可引起气管环纤毛运动停止,应用此法可以快速地进行IBV检测。