用免疫抑制小鼠快速培育抗苏拉明伊氏锥虫

将伊氏锥虫克隆ＪＧｍｃ５用环磷酰胺处理的免疫抑制小鼠频繁地连续传代，并予以亚治疗剂量的苏拉明治疗，连续传代１４次，历时８８日，即获得对苏拉明具有高水平抗药性的伊氏锥虫群体。在用免疫活性正常的健康小鼠测定抗药性时，此抗苏拉明锥虫群体仍保持高水平的抗药性，ＣＤ１００＞４００ｍｇ／ｋｇ。在以体外药敏试验测定时，其ＩＣ５０为１２３．２μｇ／ｍｌ。实验结果表明，宿主免疫系统的损害，在实验条件下，可导致伊氏锥虫迅速产生抗药性。在野外条件下，机体免疫系统的损害对锥虫抗药性的产生可能也起一定作用。     

体外培育抗苏拉灭伊氏锥虫克隆

将３个苏拉灭敏感的伊氏锥虫原种的克隆连续培养于改良Ｂａｌｔｚ无细胞培养系统中，通过逐步提高培养基中苏拉灭的含量，培育了３个抗苏拉灭的伊氏锥虫克隆─ＪＧｃ１－１６０、ＪＸ－１ｃ１－１６０和ＺＪｃ１－１４０。它们体外药敏试验的ＩＣ５０依次为３５８．５、４１２．３和２４６．４μｇ／ｍＬ，是各自亲本克隆的１２９２．５、１８７４．１和１７６０．ｏ倍；小鼠治疗试验的ＣＤ１００，对免疫功能正常小鼠依次为８０、１２０和３０ｍｇ／ｋｇ，为各自亲本克隆的５．３、８．０和３．０倍，对免疫抑制小鼠为２５０、３００和１００ｍｇ／ｋｇ，分别是相应免疫正常小鼠的３．１、２．５和３．３倍。试验结果表明，抗锥虫药治疗剂量不足和宿主免疫功能不全是导致产生抗药虫株的重要因素，各自既可单独发挥作用，又可相互协同。本文报道了体外培育伊氏锥虫抗药虫株的方法，这一方法对研究锥虫抗药性具有重要作用。     

鬼臼酰肼哌啶腙氮氧自由基抗肿瘤作用的实验观察

鬼臼酰肼哌啶氮氧自由基对体外培养的人红白血病Ｋ５６２细胞及小鼠Ｌ１２１０细胞，用小孔板法在１００．０，５０．０，２５．０，１０．０μｇ／ｍｌ终浓度剂量２４ｈ后，残留率分别为３９．４５％，５８．４３％，７２．３３％，８１．２４％及３４．５５％，５０．３７％，７６．５８％，８０．６４％，对小鼠移植肿瘤Ｈｃｓ用８０ｍｇ／ｋｇ剂量，瘤重抑制率为４０．１３％；用４０．１３％。     

海南霉素的遗传毒性研究及其致癌性预测：1.海南霉素的体外致突…

海南霉素是我国研制成功的第一个聚醚类抗生素，它具有良好的抗球虫作用。本文从遗传毒理学试验的生物学意义方面考虑，选择了２种体外致突变试验方法，对海南霉素的遗传毒性作了研究。１．体外哺乳动物细胞（ＣＨＬ）染色体畸变试验。根据海南霉素的细胞毒性试验结果，设立以下剂量组①６－１８ｈ方案：１．６４、８．２０和１６．４０μｇ／ｍｌ；②２４－０和４８－０ｈ方案：０．０９５、０．１９９和０．９５０μｇ／ｍｌ。同时     

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）     

浇泼剂对小鼠皮肤组织结构的影响

给小白鼠背部按一定剂量浇泼阿维菌素浇泼剂及倍硫磷浇泼剂，于８ｈ、２４ｈ、３５ｈ将用药小鼠处死，背部（用药部位）取材，分别进行光学显微镜及透射电子显微镜观察。结果，阿维菌素浇泼剂按０．００４ｍｌ／１０ｇ浇泼，约有２０％的表皮上皮细胞角化及脱落，而按０．１ｍｌ／１０ｇ浇泼，约有４０％的表皮上皮细胞完全角化及脱落、坏死，真皮胶原纤维减少、疏松、染色较浅泼有充血和出血现象；毛囊外根鞘上皮细胞浆内出现大量空泡、间质细胞内质网有轻度的扩张。倍硫磷浇泼剂按０．０４１３ｍｌ／１０ｇ浇泼，可见上皮细胞轻度角化、真皮胶原纤维淡染、疏松并有空泡变性及散在的红细胞；毛囊外根鞘及内根鞘细胞浆内有大量空泡、间质中胶原纤维染色不均。按０．１ｍｌ／１０ｇ背部浇泼透皮吸收促进剂，经不同时间取材进行光镜及电镜观察，未发现明显的组织结构变化。     

黄花棘豆生物碱胚胎发育毒性的体外实验研究

应用大鼠全胚胎培养（ＷＥＣ）方法，观察了黄化棘豆主要有毒成分－生物碱对体外胚胎生长发育、形态分化的影响，首先用醇类溶剂提取法从黄花棘豆中提取生物碱，薄板层析鉴定于少有４种生物碱成分。在选定０．１％ＤＭＳＯ为该生物碱溶剂的基础上，分别在含有２５、５０、１００和２００μｇ／ｍｌ生物碱的大鼠血清中培养９．５ｄ胚胎４８ｈ，结果在５０μｇ／ｍｌ以上可影响胚胎生长发育和器官分化，颅臂长、体节数、蛋白质含量及１     

伊氏锥虫多因素致弱苗免疫机理的研究——补体在体液免疫和细胞免疫中的作用实验

用我室研制的伊氏锥虫多因素致弱苗免疫马血清中的补体，观察其灭活前后对体液免疫和细胞免疫的作用。结果：灭活补体的免疫血清，在体外试验，对锥虫形态活力不认异常；巨噬细胞对用灭活补体的免疫血清处理的锥虫吞噬率仅达８％；在体内试验，锥虫对小白鼠具有致病力，潜伏期为３～５ｄ，存活期为８～１６ｄ。未灭活补体的免疫血清，可使锥虫形态异常，活力减退、停止；用未被灭活补体的免疫马血清处理的锥虫，注射小白鼠可健活６０～７０ｄ，巨噬细胞对未用灭活补体的免疫马血清处理的锥虫吞噬率高达９１％。生物试验表明：被吞噬的锥虫均无感染力。从而看出补体在本虫苗的体液免疫和细胞免疫方面具有极为重要的意义。     

海南霉素的遗传毒性研究及其致癌性预测 1．海南霉素的体外致突变性研究

海南霉素是我国研制成功的第一个聚醚类抗生素，它具有良好的抗球虫作用。本文从遗传毒理学试验的生物学意义方面考虑，选择了２种体外致突变试验方法，对海南霉素的遗传毒性作了研究。１．体外哺乳动物细胞（ＣＨＬ）染色体畸变试验。根据海南霉素的细胞毒性试验结果，设立以下剂量组①６～１８ｈ方案：１．６４、８．２０和１６．４０μｇ／ｍｌ；②２４～Ｏ和４８～０ｈ方案：０．０９５、０．１９０和０．９５０μｇ／ｍｌ。同时设溶剂和阳性对照。试验结果经Ｘ２检验为阴性。２．体外哺乳动物细胞（ＣＨＬ）姊妹染色单体交换试验，根据海南霉素的细胞毒性试验结果，设立以下剂量组：０．２、２．０、２０．０和３３．０μｇ／ｍ１。同时设溶剂和阳性对照。试验结果经ｔ检验为阴性。     

鸡传染性法氏囊病蜂灭活苗的田间免疫试验

用６批ＩＢＤ蜂胶灭活苗按０．５ｍｌ的剂量分别在７日龄１８－２０日龄免疫健康雏鸡，免疫后２８ｄ抗体阳转率为９８．３％，于免疫后４０ｄ对３批疫苗免疫的雏鸡用强毒攻击，保护率为１００％。以１．０ｍｌ的剂量于胸部皮下接种１８０－２００日龄产蛋鸡，免疫后２１ｄ卵黄抗体琼扩效价全部达１：６４以上。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

Changes in proportion of canine urinary calculi composed of calcium oxalate or struvite in specimens analyzed from 1981 through 2001

The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.