鸡球虫病药物防治现状及防控对策分析

正鸡球虫病是临床上十分常见的一种体内寄生虫疾病,该种疾病的致病源为艾美耳属的各种球虫。鸡球虫病主要危害鸡的肠道组织,虫体寄生在肠道粘膜上,对肠道黏膜造成损伤,临床上会导致患病鸡出现严重的腹泻,排泄物中常常夹杂大量肠黏膜和血液。鸡群感染寄生虫后鸡饲料利用率下降,成本支出增加,生长发育迟缓,即便是能够恢复健康,部分鸡恢复健康后,停止生长发育,成为僵鸡,使得鸡群的淘汰率进一步升高。为此,就需要我们高度重视鸡球虫病的诊断和防治,科学     

胃肠道黏液层中Akkermansia muciniphila的定殖研究及其与宿主的相互作用

动物胃肠道中定植着数量巨大的肠道微生物,影响宿主动物的代谢和发育。肠道微生物在营养物质交换、信息传递和抵抗病原微生物入侵方面均发挥着重要的作用。依据定植部位,可以分成黏液层微生物和肠腔内微生物,Akkermansia muciniphila偏好地定植于肠道黏液层,对机体活动影响广泛。在肠道中,Akkermansia muciniphila可以特异地降解黏蛋白和低聚糖,分别产生短链脂肪酸和丙酸,在为宿主提供能量的同时也促进了自身的定植。而与此同时,机体黏蛋白的降解会促使宿主补偿产生更多的黏蛋白,进而降低宿主蛋白的沉积。Akkermansia muciniphila的定植还可减缓脂肪沉积,延缓糖尿病。在肠道微生态系统中,该菌群并没有严重的致病性,适宜丰度的Akkermansia muciniphila定植可以促进宿主免疫系统的发育,进而促进肠道健康。随着更多科学研究的展开,胃肠道微生物在机体中的重要性得到呈现。作为目前国内外的研究热点,Akkermansia muciniphila在机体肠道内的作用机制尚未完全明确。本文从Akkermansia muciniphila的定植环境、生理特性、对机体营养代谢的影响、与代谢性疾病及机体免疫相互作用等方面进行了综述,Akkermansia muciniphila为很有潜力的生物标记,应用于营养状态、代谢性疾病、免疫甚至癌症的评估和检测。     

犬的几种寄生虫与驱虫方法

<正>犬在生长过程中,常常因吃奶舔毛、舔地面等感染寄生虫,还有犬经胎盘感染。这给寄生虫检测合格的犬带来严重危害,影响犬的生长发育,同时配合其病原体的入侵创造了条件。一、主要寄生虫蛔虫是幼犬最普遍感染的寄生虫,米色,似橡皮筋样,寄生在肠道内,吸收已消化的养分。这种寄生虫大多数是从母体垂直传染来的。绦虫的虫体像扁扁的面条,有片     

河南省鹌鹑肠道寄生虫感染情况调查

为了解鹌鹑肠道寄生虫感染情况,采用饱和蔗糖溶液漂浮法对河南省12个鹌鹑养殖场共711份粪便样品进行检查。结果表明,在鹌鹑体内发现4种肠道寄生虫,寄生虫总感染率达99.2%,其中8个养殖场的寄生虫感染率均为100%。球虫为主要感染虫种,感染率为99.2%,隐孢子虫、圆线虫和蛔虫感染率分别为6.0%、16.0%和1.1%;2～3种寄生虫混合感染率为20.1%。分析表明,鹌鹑肠道寄生虫感染较为严重,应加强其寄生虫病的防治工作。     

腔内苏氨酸浓度急剧变化影响仔猪肠黏膜蛋白和黏蛋白合成

肠黏膜蛋白的合成对饲粮苏氨酸添加量敏感,这表明消化道对苏氨酸的需要可能在整个机体需要中占重要比例。试验采用连续灌注的消化道环模型及腔内灌注剂量技术,选择6头仔猪,研究苏氨酸在不同腔内对肠黏膜蛋白和黏蛋白合成所产生的急剧影响。将完全氨基酸混合物连续灌注到分离的环中、持续120min,其中含30min的3H-苯丙氨酸灌注量,该氨基酸混合物中苏氨酸含量为0、21或56mg·^-1,苏氨酸在整个机体中的需要率为28mg·g^-1。通过分析3H一掺入苯丙氨酸测定总黏膜蛋白和黏蛋白的片段合成率。与灌注苏氨酸含量为0、21mg·g^-1混合物的环相比,灌注苏氨酸含量为56mg·g。混合物的环中,总黏膜蛋白合成片段速率高（P〈0．05）,三者分别为42±9％·d^-1,53±6％·d^-1,66±4％·d^-1。灌注苏氨酸含量为0、21、56mg·g^-1混合物的环间,黏蛋白合成片段速率差异显著（P〈0．05）,三者分别为323±72％·d^-1,347±49％·d^-1,414±31％·d^-1。除此之外,蛋白水解产物中总脯氨酸和苏氨酸浓度随着腔内苏氨酸浓度的升高而显著升高（P〈0．05）,表明含苏氨酸和脯氨酸丰富的蛋白质增加。黏膜蛋白和黏蛋白新生合成对腔内苏氨酸浓度极其敏感,这证实了供应到消化道蛋白质代谢的饲粮氨基酸的重要性。     

长白山林区中国林蛙体内寄生虫感染情况调查

通过解剖镜检分析了长白山地区中国林蛙寄生虫的感染情况.结果表明：长白山林区中国林蛙寄生虫为线虫3种（Rhabdia bufonis、Cosmocercella sp、Oswaldocru sp）、吸虫3种（Rowsbiella tineri、Pelystoma integerimrn、Pelystoma ocellatrm）,分别隶属5科5属;其主要感染肺线虫Rhabdia bufonis和肠道寄生虫Oswaldocru sp,感染率和感染强度分别为56.66%、4.87和67.33%、9.25;不同种类寄生虫在长白山林区林蛙体内分布有一定规律,不同种类寄生在适宜自身的生态环境中,表现出寄生部位及感染寄生虫的专一性;长白山林区林蛙寄生虫的感染率和强度随年龄增加而增大,不同地点中国林蛙的寄生虫感染率及感染强度普遍较高,不同地点不同种类寄生虫的感染率及强度存在差异;雌、雄林蛙体内寄生虫感染情况差异不显著（P〉0.05）.     

重庆市部分种羊场山羊肠道寄生虫感染情况调查

调查了重庆市山羊肠道寄生虫感染情况,采用卢戈氏碘液染色法、离心沉淀法、饱和蔗糖溶液漂浮法对重庆市武陵山区和三峡库区6个种羊场共301份粪样进行了检测.结果检出肠道寄生虫7种(类),总感染率为98.67%,以球虫、阿米巴、圆线虫为主要感染虫种,感染率分别为94.68%,63.12%,41.86%,其中球虫每克粪便中所含卵囊数(OPG)值最高为28 200,圆线虫每克粪便中所含虫卵数(EPG)值最高为7 800;贾第虫、鞭虫、莫尼茨绦虫、矛形双腔吸虫感染率分别为23.59%,3.32%,2.66%,1.66%.总混合感染率为86.71%,主要为2和3种寄生虫混合感染.球虫、圆线虫、阿米巴的场感染率为100%;贾第虫场感染率为83.33%;绦虫的场感染率为66.67%;鞭虫的场感染率为50%;吸虫的场感染率为33.33%.结果表明重庆山羊肠道寄生虫感染较普遍,应加强综合防治措施.     

965名医科大学生肠道线虫感染的调查分析

近年来,全国已逐步实施人体寄生虫感染分布调查方案,在全国城乡广泛地开展人体寄生虫感染的抽查。为了了解大学生肠道寄生虫感染的现状,我们于1985年始在我院大学生中结合人体寄生虫实验课中的粪便检查,开展线虫感染的调查,结果如下。     

猪消化道寄生虫病防治

猪消化道寄生虫病是养猪生产过程中的常见病,其中以蛔虫、姜片吸虫、棘头虫和结节虫最为常见;寄生虫可造成肠道堵塞和黏膜损伤,感染猪很容易发生继发感染,长期受寄生虫病困扰的猪会表现营养不良,同时还会对公共卫生安全造成影响;养殖场可通过改善养殖卫生条件,定期驱虫及消灭中间宿主的方法来预防本病发生。     

天津地区警犬肠道寄生虫调查

肠道寄生虫病是影响警犬健康的一类常见疾病,不但给警犬基地带来沉重的经济负担,还会严重影响警犬从业人员的工作和健康。通过调查天津地区警犬基地犬肠道寄生虫病的流行情况,有利于预防警犬肠道寄生虫病,从而保障警犬的健康,减少寄生虫对警犬从业人员的威胁,对保障警犬正常工作具有重要意义。本文采用水洗沉淀法、饱和盐水浮聚法,对240只警犬粪便进行了取样检查,调查天津地区警犬基地警犬肠道寄生虫感染情况。结果表明:在天津地区警犬肠道中共检出犬弓首蛔虫、犬狮蛔虫、犬等孢球虫、犬复孔绦虫、犬钩虫5种寄生虫,其中犬弓首蛔虫检出率最高,达到15.42%;犬狮蛔虫为7.92%;犬等孢球虫为6.25%;犬复孔绦虫为4.58%;犬钩虫为4.17%。生活在不同警犬基地警犬的肠道寄生虫感染率也有所不同。通过对不同品种的警犬粪便进行采样检查,马里努阿犬肠道寄生虫感染率最高,达到43.48%,其他品种警犬肠道寄生虫感染率相差不大。警犬肠道寄生虫感染情况在不同季节有明显差异,夏季和秋季感染率高于春季和冬季。     

Bladder-surface glycosaminoglycans: an efficient mechanism of environmental adaptation

The transitional epithelium of the urinary bladder secretes and binds to its surface a glycosaminoglycan than inhibits the adherence of bacteria. Synthetic sulfonated glycosaminoglycans instilled intraluminally into bladders whose natural mucin layer has been removed are as effective as the natural mucin in preventing bacterial adherence. It also appears that adherence of calcium and protein is reduced in the presence of both the natural mucin layer and the synthetic sulfonated glycosaminoglycan sodium pentosanpolysulfate, suggesting that the antiadherence activity of both natural and synthetic surface glycosaminoglycans in the bladder extends to the molecular and ionic levels.     

Natural antibiotic function of a human gastric mucin against Helicobacter pylori infection

Helicobacter pylori infects the stomachs of nearly a half the human population, yet most infected individuals remain asymptomatic, which suggests that there is a host defense against this bacterium. Because H. pylori is rarely found in deeper portions of the gastric mucosa, where O-glycans are expressed that have terminal alpha1,4-linked N-acetylglucosamine, we tested whether these O-glycans might affect H. pylori growth. Here, we report that these O-glycans have antimicrobial activity against H. pylori, inhibiting its biosynthesis of cholesteryl-alpha-D-glucopyranoside, a major cell wall component. Thus, the unique O-glycans in gastric mucin appeared to function as a natural antibiotic, protecting the host from H. pylori infection.     

2种胃膜素制备方法的比较

[目的]比较分析制备胃膜素的2种方法，优化制备方法，为工业化规模生产提供试验依据。[方法]以猪胃黏膜为材料，采用单产工艺和联产工艺提取胃膜素，比较分析2种制备方法所得胃膜素的性状、得率、总氮含量和还原性物质含量的差异。[结果]2种方法提取的胃膜素在黏度、酸度、干燥失重和炽灼残渣等方面差异不大，总氮含量和还原性物质含量也无明显差异，均符合国家标准。单产工艺胃膜素得率较高，平均达3．5％，联产工艺得率偏低，仅有1．7％，但联产工艺可以得到副产品胃蛋白酶。[结论]单产工艺的得率高于联产工艺，联产工艺可以同时得到副产品。     

Human T cell leukemia viruses use a receptor determined by human chromosome 17

Human T cell leukemia viruses (HTLV-I and HTLV-II) can infect many cell types in vitro. HTLV-I and HTLV-II use the same cell surface receptor, as shown by interference with syncytium formation and with infection by vesicular stomatitis virus (VSV) pseudotypes bearing the HTLV envelope glycoproteins. Human-mouse somatic cell hybrids were used to determine which human chromosome was required to confer susceptibility to VSV(HTLV) infection. The only human chromosome common to all susceptible cell hybrids was chromosome 17, and the receptor gene was localized to 17cen-qter. Antibodies to surface antigens known to be determined by genes on 17q did not block the HTLV receptor.     

Envelope-constrained neutralization-sensitive HIV-1 after heterosexual transmission

Heterosexual transmission accounts for the majority of human immunodeficiency virus-1 (HIV-1) infections worldwide, yet the viral properties that determine transmission fitness or outgrowth have not been elucidated. Here we show, for eight heterosexual transmission pairs, that recipient viruses were monophyletic, encoding compact, glycan-restricted envelope glycoproteins. These viruses were also uniquely sensitive to neutralization by antibody from the transmitting partner. Thus, the exposure of neutralizing epitopes, which are lost in chronic infection because of immune escape, appears to be favored in the newly infected host. This reveals characteristics of the envelope glycoprotein that influence HIV-1 transmission and may have implications for vaccine design.     

Synthetic peptide immunoassay distinguishes HIV type 1 and HIV type 2 infections

Efforts to solve the epidemiologic puzzle of AIDS in Africa are complicated by the presence of multiple human retroviruses. Simple serologic tests that unambiguously distinguish among infections by these retroviruses are essential. To that end, a partially conserved immunoreactive epitope was identified in the transmembrane glycoproteins of human immunodeficiency viruses (HIV) types 1 and 2. Synthetic peptides derived from these conserved domains were used in sensitive and specific immunoassays that detect antibodies in sera from patients infected with HIV-1 or HIV-2. By making single amino acid substitutions in the HIV-1 peptide, it was possible to demonstrate HIV-1 strain-specific antibody responses to this epitope. Such custom-designed peptides synthesized from this domain are likely to detect newly discovered HIV types, define infection with specific HIV strains, and allow detection of group-common antibodies.     

Identification of the fusion peptide of primate immunodeficiency viruses

Membrane fusion induced by the envelope glycoproteins of human and simian immunodeficiency viruses (HIV and SIVmac) is a necessary step for the infection of CD4 cells and for the formation of syncytia after infection. Identification of the region in these molecules that mediates the fusion events is important for understanding and possibly interfering with HIV/SIVmac infection and pathogenesis. Amino acid substitutions were made in the 15 NH2-terminal residues of the SIVmac gp32 transmembrane glycoprotein, and the mutants were expressed in recombinant vaccinia viruses, which were then used to infect CD4-expressing T cell lines. Mutations that increased the overall hydrophobicity of the gp32 NH2-terminus increased the ability of the viral envelope to induce syncytia formation, whereas introduction of polar or charged amino acids in the same region abolished the fusogenic function of the viral envelope. Hydrophobicity in the NH2-terminal region of gp32 may therefore be an important correlate of viral virulence in vivo and could perhaps be exploited to generate a more effective animal model for the study of acquired immunodeficiency syndrome.     

Glycosylation and the immune system

Almost all of the key molecules involved in the innate and adaptive immune response are glycoproteins. In the cellular immune system, specific glycoforms are involved in the folding, quality control, and assembly of peptide-loaded major histocompatibility complex (MHC) antigens and the T cell receptor complex. Although some glycopeptide antigens are presented by the MHC, the generation of peptide antigens from glycoproteins may require enzymatic removal of sugars before the protein can be cleaved. Oligosaccharides attached to glycoproteins in the junction between T cells and antigen-presenting cells help to orient binding faces, provide protease protection, and restrict nonspecific lateral protein-protein interactions. In the humoral immune system, all of the immunoglobulins and most of the complement components are glycosylated. Although a major function for sugars is to contribute to the stability of the proteins to which they are attached, specific glycoforms are involved in recognition events. For example, in rheumatoid arthritis, an autoimmune disease, agalactosylated glycoforms of aggregated immunoglobulin G may induce association with the mannose-binding lectin and contribute to the pathology.     

鱿鱼MUCIN型糖蛋白抗疲劳作用试验研究

为评价鱿鱼M UCIN型糖蛋白的抗疲劳作用,分别以不同剂量的鱿鱼M UCIN型糖蛋白经口给予昆明小鼠连续灌胃4周,研究鱿鱼MUCIN型糖蛋白对小鼠负重力竭游泳时间,肝糖原（LC）、血糖（GLU）、血乳酸（LD）含量和血乳酸脱氢酶（LDH）活性等反映疲劳的生化指标的影响。结果表明,与对照组相比,中、高剂量组能明显延长小鼠力竭游泳时间;增加运动后小鼠LC的储备量和GLU含量,增强LDH的活性,降低LD的含量,减少乳酸在肌肉及血液中的堆积,延缓疲劳的发生。说明鱿鱼M UCIN型糖蛋白对小鼠具有较好的抗疲劳作用。     

Role of EDEM in the release of misfolded glycoproteins from the calnexin cycle

The mechanisms that determine how folding attempts are interrupted to target folding-incompetent proteins for endoplasmic reticulum-associated degradation (ERAD) are poorly defined. Here the alpha-mannosidase I-like protein EDEM was shown to extract misfolded glycoproteins, but not glycoproteins undergoing productive folding, from the calnexin cycle. EDEM overexpression resulted in faster release of folding-incompetent proteins from the calnexin cycle and earlier onset of degradation, whereas EDEM down-regulation prolonged folding attempts and delayed ERAD. Up-regulation of EDEM during ER stress may promote cell recovery by clearing the calnexin cycle and by accelerating ERAD of terminally misfolded polypeptides.