白细胞介素-1α对仔猪睾丸间质细胞睾酮分泌的影响

用体外培养的仔猪睾丸间质细胞，研究了白细胞介素－１α（ＩＬ－１α）对间质细胞睾酮分泌的影响。结果，ＩＬ－１α能抑制ｈＣＧ诱导的间质细胞分泌睾酮，其睾酮产生量随ＩＬ－１α剂量的增加及作用时间的延长而下降；用２０Ｕ／ｍＬ和５０Ｕ／ｍＬ的ＩＬ－１α作用４８ｈ，可分别抑制６０％及６５％的睾酮分泌量；但无ｈＣＧ诱导时，５０Ｕ／ｍＬ的ＩＬ－１α可使间质细胞基础睾酮的生成量增加１倍。提示睾丸内ＩＬ－１α可能通过多种途径调节间质细胞睾酮的产生。     

白细胞介素—1与不育

在造成人和动物不育的诸多因素中，免疫因素较为突出，ＩＬ－１是介导机体免疫功能的主要细胞因子，在感染，发热，肿瘤，组织修复等病理过程中，浓度特异性升高，促进分泌免疫活性淋巴因子，发挥重要的作用。同时它还是一种生殖关联性蛋白，与两种受体及受体拮抗剂组成ＩＬ－１作用系统，广泛存在于垂体，子宫，睾丸，卵巢等生殖器官。体内外研究表明，正常和异常状态下，ＩＬ－１对促性腺激素的调控，配子的产生，受精，早期胚胎的     

维生素E对奶牛免疫功能的影响

将１２头奶牛随机分为两组，实验组于分娩前４周开始到产后８周，每日口服维生素Ｅ３０００ＩＵ／头，并于预产前１周一次性注射维生素Ｅ５０００ＩＵ。实验结果，对照组奶牛产后血液中性粒细胞产生的超氧化物阴离子（ＳＡ）相对含量较产前降低了约１倍（Ｐ＜０．０５），血液巨噬细胞产生的ＩＬ－１和ＭＨＣⅡ类抗原分别减少了１５％和３５％（Ｐ＜０．０５）。表明奶牛产后早期血液巨噬细胞、中性粒细胞的免疫功能均受到抑制。而实验组奶牛产后与产前相比，中性粒细胞产生ＳＡ、巨噬细胞产生ＩＬ－１和ＭＨＣⅡ类抗原表达的水平均无差异。据此推断，在奶牛产后早期维生素Ｅ可防止血液中性粒细胞和巨噬细胞功能的抑制。     

对小白鼠经不同途径注射抗原后脾单个核细胞的细胞因子IL—1βIL—2？…

应用ＲＴ－ＰＣＲ结合激光密度扫描定量分析方法，观察了不同途径免疫小白鼠的脾单个核细胞的细胞因子ＩＬ－１β，ＩＬ－２和ＩＦＮ－γ的ｍＲＮＡ动态表达水平。结果显示，穴位免疫组细胞因子ＩＬ－１β和ＩＬ－２的ｍＲＮＡ表达峰值和持续时间均大于非穴位免疫对照组。穴位免疫组与对照组比较，ＩＦＮ－γ的ｍＲＮＡ表达水平无统计学差异。这一结果在ｍＲＮＡ水平上证明经后海穴途径免疫可增强机体的免疫功能。提示在穴位免疫激活     

白纤维介素—1α调节仔猪睾丸间质细胞睾酮分泌的机制

本实验利用体外培养的２－３周龄仔猪睾丸间质细胞，研究了ＩＬ－１α调节间质细胞睾酮分泌的机制。结果表明，ＩＬ－１α能抑制ｈＣＧ刺激间质细胞分泌睾酮，其睾酮产生量随ＩＬ－１α剂量增大（０－１０μ／ｍｌ）及刺激时间延长（０－４８ｈ）而下降。     

鸡马立克氏病免疫抑制机理的研究

用马立克氏病强毒（ｖＭＤＶ）感染１日龄健康ＡＡ雏鸡，在感染后５、２５、４５日检测其胸腺、脾脏Ｔ细胞白细胞介素２（ＩＬ－２）诱生活性、ＩＬ－２受体（ＩＬ－２Ｒ）表达及Ｔ细胞增殖功能，胸腺、法氏囊、脾脏、盲肠、扁桃体、肺支气管粘膜淋巴组织及哈德尔腺中α－萘酚酯酶阳性Ｔ细胞、酸性磷酸酶阳性Ｔ细胞、抗体生成细胞数量，外周血液中Ｔ细胞数量、ＩｇＧ、ＩｇＭ、ＩｇＡ含量及泪液、气管液、肠液、胆汁中ＩｇＡ．ＩｇＧ、ＩｇＭ含量的动态变化。揭示了感染鸡细胞因子ＩＬ－２的免疫调节发生障碍，中枢与外周免疫器官的细胞免疫和体液免疫功能呈现抑制，呼吸道与消化道的局部免疫防御功能明显降低。     

中国流行株ＨＩＶ—1gag—gp120与ＩＬ／ＩＬ—６共表达核酸疫苗质粒的构建和

以pcDNA3.１( ）为载体，构建了中国流行株ＨＩＶ－1gag-gp1２０嵌合基因的核酸疫苗质粒；并以pIRES1neo为载体，构建了gap-gp120与ＩＬ－２／ＩＬ－６共表达的２种核酸疫苗质粒。将核酸疫苗质粒在体外转染ＢＨＫ－２１细胞，ＥＬＩＳＡ方法检测到３种核酸疫苗质粒均表达了目的ＨＩＶ－１结构蛋白。将核酸疫苗质粒免疫小鼠，免疫学指标检测结果表明，在本实验条件下，未能检测到含有gap-gp120的核酸疫苗质粒免疫鼠的细胞免疫和体液免疫功能的明显改变；而与ＩＬ－２／ＩＬ６共表达的２种核酸疫苗质粒使免疫鼠ＣＤ^ 4、ＣＤ^ 8T细胞数量明显升高，ＣonA和ＬＰＳ诱导的细胞增殖能力显著增强，ＣＴＬ活性明显提高，表明ＩＬ－２和ＩＬ－６有效地发挥了免疫佐剂作用。     

鸡IL-2基因的克隆及序列测定

应用逆转录多聚酶链反应（ＲＴ－ＰＣＲ）技术，参照Ｓｕｎｄｉｃｋ发表的鸡白细胞介素２（ＩＬ－２）ｃＤＮＡ基因序列，利用在行设计合成的１对引物，从ＣｏｎＡ活化的５周龄ＨＷＬ－ＳＰＦ鸡脾细胞中，扩增出长４４５ｂｐ的鸡ＩＬ－２ｃＤＮＡ基因，以ＰＵＣ１１９为载体，克隆了扩增片段，经酶切鉴定及ＤＮＡ序列测定，确认为鸡ＩＬ－２基因，该序列与Ｓｕｎｄｉｃｋ报道的结果一致。对氨基酸的比较发现，鸡ＩＬ－２与牛ＩＬ－２     

鸡马立克氏病免疫抑制机理的研究

用马立克氏病强毒感染１日龄健康ＡＡ雏鸡，在感染后５、２５、４５日检测其胸腺、脾脏Ｔ细胞白细胞介素２（ＩＬ－２）诱生活性、ＩＬ－２受体（ＩＬ－２Ｒ）表达及Ｔ细胞增殖功能，胸腺、法氏囊、脾脏、盲肠、扁桃体、肺支气管粘膜淋织及哈德尔腺中ａ－萘酚酯酶阳性Ｔ细胞、酸性磷酸酶阳性Ｔ细胞、抗性成细胞数量，外周血液中Ｔ细胞数量、ＩｇＧ，ＩｇＭ，ＩｇＡ含量及泪液，气管液，肠液，胆汁中ＩｇＡ，ＩｇＧ，ＩｇＭ含量的动态     

后海穴对小鼠脾淋巴细胞产生IL—2活性的影响

本文采用Ｃ５７ＢＬ／６Ｊ小鼠胸腺＾３Ｈ－ＴｄＲ掺入法，观察了后海穴对小鼠脾淋巴细胞产季了ＩＬ－２活性的影响。结果表明，针刺后海穴，后海穴注射８３０１多糖，腹腔注射８３０１多糖均能增高脾淋巴细胞产生ＩＬ－２的能力。后海穴注糖量，注糖次数，均比腹腔少，而对ＩＬ－２活性的影响却二者无显著差异，从而间接地证实了后海穴有正向增强小鼠脾淋巴细胞产生ＩＬ－２的能力。     

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.     

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.     

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.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Evaluation of the Microbiological Status of Milk and Various Structures in Mammary Glands from Naturally Infected Dairy Cows

A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.     

Development and survival of free-living stages of gastrointestinal nematodes of sheep and goats on pasture in the Nigerian derived savanna

Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L₃) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L₃ developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.