白细胞介素-2的研究进展及在兽医中的应用

白细胞介素-2（interleukin，IL-2）是由淋巴细胞产生的一类重要的细胞因子，它具有显著的免疫增强作用，不仅能促进T细胞增殖分化和B细胞分泌抗体，而且能增强NK细胞的杀伤力和诱导LAK细胞增生，还可与其它细胞因子如IFN-γ、TNF等一起发挥免疫功能，因而在疾病的治疗和预防上发挥着重要作用。     

鸡白细胞介素-2分子生物学和疾病防治应用研究进展

鸡白细胞介素-2(IL-2)是由激活的T细胞分泌产生的糖蛋白,具有显著的免疫增强作用,不仅在T细胞、B细胞的生长与分化和NK细胞的激活等方面发挥重要作用,而且与其他细胞因子一起发挥免疫功能,是一种能影响机体免疫反应各个方面的调节因子。文章综述了鸡白细胞介素-2分子生物学和疾病防治应用研究进展。     

白细胞介素-12在免疫学上应用的研究进展

白细胞介素12(IL-12)又名NK细胞刺激因子和CTL成熟因子,是80年代末发现的具有免疫调节功能的生物活性物质.     

蒙药特润舒都乐对模型小鼠脾脏NK细胞活性的影响

目的:观察和探讨蒙药特润舒都乐对小鼠脾脏NK细胞杀伤活性的影响,了解该蒙药的生物学活性.方法:采用皮下给药的体内实验及3 H-TdR掺入抑制法检测小鼠脾脏NK细胞活性.结果:蒙药特润舒都乐能显着提高小鼠脾脏NK细胞杀伤活性,且呈剂量依赖性,其高、中、低剂量(50,25,10mg/L)各组的NK活性分别为64.39±16.53、46.21±13.28、36.09±12.26,与空白对照及阴性对照均有显着性差异(P<0.05).结论:蒙药特润舒都乐能提高NK细胞活性,并有剂量依赖性.     

免疫系统组成及其功能

免疫系统是由免疫器官、免疫细胞和免疫因子组成的。①免疫器官:免疫细胞生成、成熟或集中分布的场所,包括骨髓、胸腺、脾、淋巴结等。②免疫细胞:参与免疫应答或与免疫应答有关的细胞,主要包括淋巴细胞系(T细胞、B细胞、K细胞、NK细胞等)、粒细胞系(噬中性粒细胞、噬酸性粒细胞、噬碱性粒细胞)、单核细胞系(巨噬细胞、肥大细胞)。③免疫因子:由免     

禽干扰素基因工程表达技术研究进展

干扰素是一组具有多种功能的活性蛋白(主要是糖蛋白),是一种由单核细胞和淋巴细胞产生的细胞因子。根据干扰素产生的来源和结构不同可分为α干扰素、β干扰素和γ干扰素三类。研究发现干扰素通过细胞表面受体作用使细胞产生抗病毒蛋白,从而抑制病毒的复制,同时它还可增强自然杀伤细胞(NK细胞)、巨噬细胞和T淋巴细胞的活力,从而起到免疫调节作用,并增强抗病毒能力。由于干扰素几乎能抵抗所有病毒引起的感染,加     

姜黄素对雏鸡T淋巴细胞转化功能的影响

将60羽健康雏鸡随机分成3组,试验Ⅰ组注射姜黄素溶液0.5mL/只,试验Ⅱ组注射姜黄素溶液1mL/只,对照组注射生理盐水1 mL/只。30日龄时取脾脏组织制备淋巴细胞和NK细胞,以MTT法测定淋巴细胞、LDH测定法测定NK细胞活性。结果显示,一定浓度的姜黄素溶液能提高雏鸡T淋巴细胞转化率及NK细胞活性,且在一定范围内呈剂量依赖关系。     

白细胞介素-2的研究进展及其在畜禽业中的应用前景

白细胞介素-2(IL-2)是T细胞和自然杀伤性细胞(NK细胞)产生的糖蛋白。在机体的免疫应答中起重要作用。Morgan等人首先报道的名称是T细胞生长因子(TCGF),1979年在第二届细胞因子研究会上定名为IL-2。IL-2的其它名称包括T细胞替代因子(TRF)、T细胞促分裂因子(TMF)、淋巴细胞条件培     

4种因素对NK细胞杀伤活性的影响

为了探讨效应细胞与靶细胞的比例(效靶比)、孵育时间、显色时间以及小牛血清浓度对NK细胞杀伤活性的影响,采用乳酸脱氢酶释放法来测定不同因素对NK细胞杀伤活性的影响,结果表明,最佳效靶比和孵育时间分别为50∶1和2 h。在最优效靶比及孵育时间的基础上,显色0.5 h,小牛血清浓度为50 mL/L时NK细胞活性最高,证明4种因素对NK细胞杀伤活性均有不同程序的影响。     

不同感染剂量MDRV对番鸭免疫反应和细胞毒性作用的影响

用不同剂量番鸭呼肠孤病毒(MDRV MW9710株)感染8日龄番鸭后,通过检测血液中淋巴细胞对ConA、LPS的反应和NK细胞、细胞毒T细胞(CTL)的细胞毒性作用,探讨MDRV感染对番鸭免疫细胞功能和细胞毒性作用的影响。结果显示,不同感染剂量MDRV均会抑制番鸭血液淋巴细胞对ConA、LPS的增殖反应,降低NK细胞和CTL细胞的杀伤活性,且影响程度与剂量相关;同时感染番鸭生长缓慢,脾脏肿大,胸腺和法氏囊缩小。上述结果表明,MDRV感染能导致番鸭免疫抑制,且细胞免疫抑制程度与感染病毒量有关。     

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.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

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

Tropical Animal Health and Production -     

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.     

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.     

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