水牛伊氏锥虫人工感染抗体规律及其广西地区自然感染状况的初步调查

通过实验感染,研究伊氏锥虫在水牛体内抗体及虫体消长的规律.ELISA检测结果表明,水牛感染伊氏锥虫后第6 d检出抗体,而且在2个多月的监测时间里,抗体都维持在较高水平(OD450nm>0.3),因此可利用ELISA方法对水牛感染伊氏锥虫进行早期诊断和监测;水牛感染伊氏锥虫后,即出现一个2～3周左右的虫血症峰期,然后虫血症峰期迅速下降,在虫血症峰期下降后1个多月的监测时间里,虫血症维持在一个很低的水平(≤1条虫体/视野),水牛感染伊氏锥虫后这种峰期短无明显症状、虫血症水平低的现象,给临床诊断和血液镜检虫体造成了一定的困难.对广西部分地区79份血清样品水牛检测的结果表明,伊氏锥虫抗体阳性率达到29.1%,说明广西各地水牛感染伊氏锥虫的现象普遍存在,而且感染率比较高,为了保证本地区水牛产业的健康发展,有必要对水牛伊氏锥虫感染进行有效的监测.     

检测伊氏锥虫循环抗原的McAb-RPHA试验

用一株抗伊氏锥虫、马媾疫锥虫和布氏锥虫共同抗原(与泰氏锥虫等抗原无交叉反应)的单克隆抗体建立了检测伊氏锥虫循环抗原(TcA)的反向间接血凝试验。用以检测人工感染兔,于感染后8～10天TcA转阴;如不治疗直至观察期结束持续阳性;治疗后一周即转阴。用以检测疫区36份虫血症阳性水牛血清,25份阳性(69.44％);16份虫血症阴性、IHA阳性水牛血清,3份阳性;25份虫血症和IHA阴性水牛血清,全部阴性。     

克隆伊氏锥虫对安锥赛抗药性的培育

为了深入观察伊氏锥虫对安锥赛抗药性的形成,将伊氏锥虫浙江水牛株克隆,克隆繁殖后的虫体一部分作为原种对照组,即C01组;一部分虫体连续经环磷酰胺免疫抑制的小鼠,再用安锥赛亚治疗剂量治疗该小鼠,使其伊氏锥虫对安锥赛产生7个不同程度的抗药性组,即C1～C7组;另一部分虫体也连续经环磷酰胺免疫抑制的小鼠,作为伴随C7的同步繁殖组,即不用药物的C02组.结果C01、C02、C1～C7组所用安锥赛剂量依次为0、0、6、16、40、80、196、406、638mg/kg,它们经小鼠传代数依次为0、28、1、3、6、9、15、22、28代.用体外生长繁殖抑制法测得它们的ICs0值依次为0.015 50、0.016 87、0.082 60、0.102 37、1.409 29、1.922 90、9.923 30、23.563 00、43.84000.结果表明,安锥赛亚治疗剂量与伊氏锥虫抗药性的IC50值呈曲线关系,从C1到C4的IC50值上升较缓慢,从C4后的ICs0值上升较快,并且几乎呈直线上升;伊氏锥虫所经小鼠的代数与它们的IC50值的关系呈抛物线型,从C1到C4的ICs0值上升很慢,C4以后的IC50值上升很快.用体内试验测试C01～C4组的CD100值,每个组感染35只小鼠,每只小鼠接种1.0×104条锥虫,其中30只小鼠分为安锥赛的3个剂量治疗小组,另5只小鼠为不治疗对照组.结果C01组和C1组的CD100值分别为7.0、13.0 mg/kg,这表明C1组只经1代免疫抑制小鼠,注射安锥赛剂量3×2 mg/kg,就使该组伊氏锥虫对安锥赛的抗药性提高了6 mg/kg,并且它们的IC50值C1是C01的6.6倍.C2、C3和C4组由于抗药性程度过高均不能治愈,因此尚未测到它们的CD100值.这些结果表明,伊氏锥虫经免疫抑制小鼠对安锥赛产生抗药性的速度是非常快的.     

伊氏锥虫体外培养株的建立及其HGPRT活性测定

用带虫培养法和带虫传代法建立了伊氏锥虫体外培养株，无论有、无饲养细胞，虫体均能快速增殖。培养７０ｄ以上，虫体仍保持原有生物学特性，对小鼠有感染性，活力旺盛，在体外能连续培养传代。虫数最高达２．４８×１０６／ｍＬ，群体增倍时间为８．８６～１０．８ｈ。液氮保存、复苏后的虫体可在饲养细胞上立即增殖。培养中发现由巨噬细胞转化的巨核母细胞对虫体生长有促进作用，经胰酶消化能与虫体一道连续传代。通过ＨＡＴ选择性培养液测定，伊氏锥虫对氨基喋呤不敏感，试验组虫体与对照一样生长良好，证明伊氏锥虫具有次黄嘌呤鸟嘌呤磷酸核糖转化酶（ＨＧＰＲＴ）     

伊氏锥虫病引起水牛群发性流产病例

本市桐城镇索溪村的索溪与乌岐两自然村有水牛29头（公3头，母14头，小牛12头），于1995年6～8月10头怀孕母牛有7头发生流产。笔者进行逐户调查，并采了病牛血，取20ml注射于健康的，无感染推虫的成年长毛兔体内。接种后饲养3天，采兔耳静脉血，作生理盐水压滴镜检，查到伊氏锥虫。确诊该村流产母牛不患伊氏锥虫病引起。（一）发病原因分析：该自然村，背山面海，草源丰富，草质好，适合养牛。近年由于水牛价高，销路好，富裕人家搞买卖水牛生意，从外地买回带犊母水牛，待小牛饲养至周岁时卖掉而获利；或买回怀孕母水牛，饲养至产犊，再母…     

新书《人体寄生虫学彩色图谱》征订启事

咪唑苯脲为军兽医大学1985年新合成的抗巴贝西虫病新药。张咏梅等于1990年试用于人工感染伊氏锥虫病小白鼠及水牛，按kg体重3mg肌注，连用两天为一疗程，治疗6头水牛，全部治愈。对人工感染锥虫病猪也有很好疗效。为此。我们于1990年2～3月间在江宁县进行了现场推广试用。     

12株中国伊氏锥虫对苏拉明的药敏试验

用体外培养生长抑制试验检测了中国伊氏锥虫安徽水牛株（AHB）、广东阳江水牛株（GDB1）、广东水牛株（GDB2）、广东马株（GDH）、广西骡株（GXM）、湖北骡株（HBM）、湖南水牛株（HNB）、江苏高邮水牛株（JSB1）、江苏盱眙水牛株（JSB2）、新疆骆驼株（XJCA）、云南水牛株（YNB）、浙江水牛株（ZJB）对苏拉明的敏感性。它们的50％生长抑制浓度（IC50）依次为0．114、0．041、0．120、0．1490．752、0．252、0．171、0．127、0．339、0．094、0．106、0．118ng/L。结果显示，不同虫株的伊氏锥虫对苏拉明的敏感性明显不同，提示中国伊氏锥虫不同虫株存在抗药性差异。在12株伊氏锥虫中，GXM株对苏拉明的抗药性水平明显高于其他株。小鼠体内治疗试验显示，GXM株以10mg/kg剂量苏拉明治疗无效，在临床上表现出一定的抗药性，而GDB1株以10mg/kg剂量苏拉明治疗则全部治愈。由此可见，体外药敏试验结果与体内治疗结果一致。这一结果提示，多数中国伊氏锥虫株对苏拉明的敏感性偏低，少数虫株已表现出一定的抗药性。     

人血清中伊氏锥虫溶虫活性因子的鉴定

将伊氏锥虫在体外与人血清一起培养，虫体出现渐进性水肿，由蝌蚪形变成环形，最后崩解。将人血清注入感染鼠体内，可以清除体内虫体，使感染鼠得到保护。人血清对接种１０３个锥虫感染鼠的最小保护剂量为０．２ｍＬ，感染后５ｄ注入人血清，血中虫体数量逐日下降，至第１０天全部消失。对体外伊氏锥虫不同变异株，人血清均有同样的溶虫效果。经ＤＥＡＥ层析和ＳｅｐｈａｄｅｘＧ－２００过滤后，人血清中只有富ＩｇＭ的Ｆ－１有溶虫活性，而富ＩｇＧ的Ｆ－２和富ＨＤＬ的Ｆ－３均无溶虫活性，表明人血清对伊氏锥虫的溶虫活性与ＩｇＭ类天然抗体有关。另外，去补体的人血清体外溶虫活性明显减弱，而体内保护仍然有效。     

伊氏锥虫在小鼠体内抗原变异规律及免疫保护试验

为了探索伊氏锥虫抗原的变异规律及其用于免疫预防的可能性，首先对伊氏锥虫安微株单虫克隆2个早期变异体ShTatl.1、ShTat1.2采用蛋白酶抑制剂TLCK处理，分离纯化这2种变异体的VSG，用ShTat1.1 VSG免疫KM小鼠，ShTat1.1锥虫攻击免疫鼠后6d分离锥虫，经间接免疫荧光试验（IFT）和班点酶标记试验（Dot-EIA)鉴定为ShTat1.2，说明同一克隆锥虫感染兔，小鼠第1次发生抗原变异后产生的变异体相同。依据这一规律，设计了免疫预防保护试验，试验小鼠分3组：一组为未免疫对照组，一组为ShTat1.1VSG单一抗原免疫组，另一组为ShTat1.1 VSG,ShTat1.2 VSG混合免疫抗原免疫组，各组均以ShTat1.1锥虫攻击，结果ShTat1.1 VSG ShTat1.2VSG免疫组小鼠全部获得保护，单用ShTat1.1 VSG免疫组小鼠和未免疫小鼠血中全部出虫、死亡，前者比后者出虫时间、存活时间延长。提示运用伊氏锥虫抗原变异这一规律设计的这种复合抗原，能激发宿主克服虫体抗原变异对免疫保护的干扰。     

水牛伊氏锥虫间接ELISA检测方法的建立

利用伊氏锥虫的优势变异型虫体作为可溶性抗原,通过试验研究和条件优化,建立了一种水牛伊氏锥虫间接ELISA方法.测试结果表明,该法灵敏度高,特异性强,对实验感染样本的检测获得了较好的效果,为一种有效的ELIAS方法,为广西水牛伊氏锥虫病的诊断奠定了技术基础.     

The efficacy and pharmacokinetics of long-term low-level intraruminal administration of tricalbendazole in buffalo with induced fasciolosis

A study was conducted on the pharmacokinetics and therapeutic efficacy of triclabendazole at three low dose rates of 0.5, 1.0 and 1.5 mg/kg body weight in buffaloes experimentally infected with Fasciola gigantica. The pharmacokinetics were compared with the effects of a single intraruminal dose at 24.0 mg/kg body weight in uninfected buffaloes. At all three dose rates, an equilibrium between the absorption of triclabendazole and the disposition of its metabolites was observed by days 3 and 4 and remained almost unchanged thereafter. Continuous daily dosing at 1.5 mg/kg body weight proved to be efficacious against liver fluke infection in buffaloes.Abbreviations TCBZ triclabendazole - p.i. post-infection - HPLC high-performance liquid chromatography - TCBZ-SO triclabendazole sulphoxide - TCBZ-SO2 triclabendazole sulphone - C _max peak concentration in plasma - T _max time to reach C _max - AUC area under the concentration-time curve - t _1/2 elimination half-life - epg eggs per gram     

Comparative toxicology of monensin sodium in laboratory animals

The toxicology of monensin has been studied in several laboratory animal species. There was considerable species variation in acute oral LD50 values. The consistent signs of acute toxicity were: anorexia, hypoactivity, skeletal muscle weakness, ataxia, diarrhea, decreased weight gain and delayed deaths. The 3-mo study in rats fed diets containing 0, 50, 150 or 500 ppm monensin resulted in no effects at the lowest dose level, slight reduction of body weight gain in the middle-dose group and severe depression in body weight gain, skeletal and cardiac lesions, and deaths in the highest dose group. The 3-mo study in dogs given daily oral doses of 0, 5, 15 or 50 mg/kg monensin resulted in no effects at the lowest dose level. Dogs in the 15 and 50 mg/kg groups developed, during test wk 1 to 4, anorexia, weakness, ataxia, labored respiration, body weight loss, increased serum muscle enzyme values, severe skeletal muscle degeneration and necrosis with less severe heart lesions and deaths. Mice fed diets containing 0, 37.5, 75, 150 or 300 ppm monensin for 3 mo had reduced body weight gain in all test groups but no other physical signs. Serum creatine phosphokinase (CPK) values were increased in mice in the two highest dose groups and minimal heart lesions were found in the highest dose group. Dogs given daily oral doses of 0, 1.25, 2.5, 5 or 7.5 mg/kg monensin for 1 yr survived with no evidence of toxicity in the two lowest dose groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pharmacological and toxicological study of turimycin]

Turimycin is characterised by low acute toxicity. Mean lethal doses for mouse and rat are 750 mg/kg body weight for intraperitoneal application of something in excess of 3,000 mg/kg for oral administration. The blood pressure of anaesthetised cats may be reduced by amounts depending on intravenous Turimycin doses (between 10 and 50 mg/kg). The hypotensive effect of Turimycin is attributable to its negative inotropic effect on the heart and its spasmolytic action on the unstriated muscles. Reversible reduction of urine and ion excretion of rat following intraperitoneal application of 50 mg/kg body weight of Turimycin is interpreted as a consequence of such action upon blood pressure. A preliminary study was conducted into dogs which had orally received daily Turimycin doses of 50 or 125 mg/kg body weight over twelve months. No substance-depending functional or morphological damage was recorded.     

Prednisone treatment alters the serum amylase and lipase activities in normal dogs without causing pancreatitis.

In order to test the hypothesis that treatment with glucocorticoids causes pancreatitis in dogs, 18 mongrel dogs were divided into three groups of six individuals, each group receiving prednisone at different doses orally or intramuscularly for two weeks. Two groups consisting of six dogs each served as controls. Treatment for two weeks with oral prednisone at 1.2 mg/kg body weight or at 4 mg/kg body weight daily decreased the serum amylase activities, but increased the serum lipase activities. Postmortem examinations revealed microscopic evidence of mild pancreatitis in only one dog given prednisone, that clinically appeared normal. It was concluded that daily doses of 4 mg prednisone/kg body weight or less given orally or intramuscularly for two weeks do not cause pancreatitis in dogs.     

Productivity effects of bovine mange and control with ivermectin

A randomised block design study was conducted to evaluate the effects of mange on cattle. Twenty-four Simmentaler Fleckvieh bulls were formed into eight replicates of three bulls based on Day -56 body weight (288-414 kg). Within replicates bulls were randomly allocated to groups G1: uninfested control, G2: infested control or G3: infested, treated with 0.2mg ivermectin/kg (1% ivermectin injection; IVOMEC, Merial) on Day 0. The G2 and G3 bulls were infested with Sarcoptes/Chorioptes mites on Days -56 and -49. Feed consumption was recorded daily throughout the study (Days -56 to 56). Body weights were measured and serum samples collected. Mites were counted at bi-weekly intervals from Day -14 on. The carcasses of the bulls and the leather produced from their hides were evaluated. Differences between variables were declared significant if P相似文献   

12月龄生长母水牛绝食代谢的研究

用传统开路式牛用呼吸面具对12月龄母水牛绝食产热(FHP)进行研究。结果表明:①12月龄母水牛FHP为334.03KJ/KgW0.75·d;每天排出内源尿氮(EUN)为31.06g;代谢体重每天排出EUN为0.53g;蛋白分解产热占总产热量为17.99%;EUN与FHP比值为1.60mg/KJ。②12月龄母水牛维持净能需要:NEm=400.84KJ/W0.75d。     

Blood concentrations of 2,3-butanedione monoxime and some blood biochemical changes inbubalus bubalis after intramuscular administration of this cholinesterase reactivator

The blood levels of cholinesterase reactivator 2,3-butanedione monoxime were determined in buffalo calves following single intramuscular doses of 20 and 50 mg/kg body weight. Blood cholinesterases and other enzymatic activities were monitored at various times. The drug was rapidly absorbed with half-life of 0.09–0.12 h. The peak 2,3-butanedione monoxime blood concentrations of 24.7±0.3 and 38.9±1.7 ug/ml occurred at 10 min after 20 and 50 mg/kg doses, respectively. The elimination half-life varied between 3.05±0.12 and 3.80±0.19 h. Lack of adverse effect of 2,3-butanedione monoxime on blood cholinesterases and other enzymes indicated that intramuscular doses as high as 50 mg/kg may be safely employed in buffaloes.     

Effect of dose and route of application on the action of decamethrin against cattle grubs

The efficacy of pour-on or orally administered decamethrin against bovine hypodermosis was investigated on naturally infested yearlings. Treatment at dose rates of 1, 2 or 10 mg per kg body weight were ineffective, but the highest dose had a long-term lethal effect on warbles. The severe side effects which followed the high dose suggest that this drug is unsatisfactory for systemic grub control. Investigations on the dynamics of circulating anti-Hypoderma antibodies in the post-treatment period showed that there is some sub-lethal activity of decamethrin on the larval physiology even at the lowest doses.     

不同饲喂方式对育肥水牛胴体特征和肉品质的影响

文章旨在研究不同饲喂方式对育肥水牛生长性能、胴体特征、肉品质及抗氧化的影响.试验将36头平均初始体重为(207.67±12.81)kg的水牛随机分为4组,每组3个重复,每个重复3头.处理1组和处理2组水牛采用放牧的形式,即分别在象草及象草与柱花草间作的牧场放牧,处理3组和处理4组饲喂浓缩饲料的同时补充2％和4％的象草,...     

Exposure of growing and adult captive cheetahs (Acinonyx jubatus) to dietary isoflavones: twenty years later

Dietary isoflavones are associated with oestrogenic and anti‐oestrogenic effects, and have been linked to infertility in cheetahs. This study aimed to determine the isoflavone content of commercially prepared diets consumed by captive cheetahs. Sixteen international zoological facilities provided diets, and the isoflavone content of each diet was determined by acid hydrolysis and HPLC quantification. Proximate nutritional composition was also determined. Over half the diets analysed contained detectable concentrations of isoflavones, whereby total isoflavone content ranged from 1.75–183 mg/kg dry matter. The zoo‐specific diets were calculated to deliver a median isoflavone dose of 0.07 mg/kg body weight (BW) and a maximum of 1.95 mg/kg BW to captive cheetahs. On a metabolic body weight basis this equates to a maximum of 4.90–5.43 mg/kg^0.75. Some diets prepared for hand‐rearing neonatal cheetahs could expose neonates to doses of up to 4.24 mg/kg BW (or 4.24–6.33 mg/kg^0.75 for cubs under 3 months of age). Only one of six zoo‐specific diets was found to deliver isoflavones in doses shown to possess biological activity in other species. Therefore, on average, dietary isoflavones were not found in commercially prepared diets consumed by captive cheetahs in concentrations predicted to cause physiological changes. However, a small proportion of these diets, including hand‐rearing formulas, contained elevated isoflavones concentrations which may influence cheetah fertility, behaviour or other physiological parameters.