雏鸭感染鸭肝炎病毒后血液中SOD活性和丙二醛含量的变化

用不同毒力株鸭肝炎病毒人工感染雏鸭 ,测定雏鸭血浆中超氧化物歧化酶 (SOD)的活性和丙二醛 (MDA)的含量 ,研究SOD和MDA在鸭病毒性肝炎的发病过程中的作用。结果表明 ,雏鸭感染中毒株和强毒株鸭肝炎病毒后 3d ,血浆中SOD的活性 (中毒株组为 (6 3.72± 8.88)和强毒株组为 (75 .90± 8.41)显著低于对照组 (94.79± 6 .5 9) (P <0 .0 5 ) ;而强毒株组血浆MDA含量 (13.6 2± 2 .0 8)则在感染后 1d就显著高于对照组 (7.6 9± 0 .2 6 ) (P <0 .0 5 ) ,中毒株组雏鸭血浆MDA含量 (14.90± 1.6 5 )在感染后 3d极显著高于对照组 (7.70± 0 .6 6 ) (P <0 .0 1) ,而弱毒株组雏鸭血浆MDA含量与对照组比较则无明显差异。     

雏鸭感染鸭肝炎病毒后血液中GSH—Px活性的变化

用不同毒力株鸭肝炎病毒人工感染雏鸭,测定雏鸭血浆中谷胱甘肽过氧化物酶(GSH-Px)的活性。结果表明,雏鸭感染不同毒力株鸭肝炎病毒后,血浆中GSH-Px的活性下降,其中弱毒株组在感染后5d的GSH-Px活性(53.44±2.30)显著低于对照组(60.70±2.00)(P<0.05)。     

自由基在鸭病毒性肝炎发病过程中的作用

用不同毒力的鸭肝炎病毒株人工感染雏鸭,建立了鸭病毒性肝炎病理模型.于感染后1、3、5、7 d剖杀雏鸭,采集血液和肝脏样品,测定血浆和肝组织中的一氧化氮(NO)、超氧化物歧化酶(SOD)和丙二醛(MDA),研究了自由基在鸭病毒性肝炎发病过程中的作用.结果表明雏鸭感染不同毒力株鸭肝炎病毒后1 d,血浆NO含量开始上升,3 d显著或极显著高于对照组,并持续至试验结束;肝组织NO含量在感染后1 d便显著升高.不同毒力株感染组雏鸭血浆和肝组织中SOD活性在感染后1 d便低于或显著低于对照组,而不同毒力株感染组雏鸭血浆和肝组织中的MDA却高于或显著高于时照组.提示,雏鸭感染鸭肝炎病毒后产生的自由基在鸭病毒性肝炎的发病过程中起重要作用.     

自由基在鸭病毒性肝炎发病过程中的作用

用不同毒力的鸭肝炎病毒株人工感染雏鸭，建立了鸭病毒性肝炎病理模型。于感染后1、3、5、7d剖杀雏鸭，采集血液和肝脏样品，测定血浆和肝组织中的一氧化氮(NO)、超氧化物歧化酶(SOD)和丙二醛(MDA)，研究了自由基在鸭病毒性肝炎发病过程中的作用。结果表明：雏鸭感染不同毒力株鸭肝炎病毒后1d，血浆NO含量开始上升，3d显著或极显著高于对照组，并持续至试验结束；肝组织NO含量在感染后1d便显著升高。不同毒力株感染组雏鸭血浆和肝组织中SOD活性在感染后1d便低于或显著低于对照组，而不同毒力株感染组雏鸭血浆和肝组织中的MDA却高于或显著高于对照组。提示，雏鸭感染鸭肝灸病毒后产生的自由基在鸭病毒性肝炎的发病过程中起重要作用。     

不同毒力鸭肝炎病毒对雏鸭肝脏抗氧化功能的影响

用不同毒力株鸭肝炎病毒感染雏鸭复制病理模型 ,研究雏鸭感染病毒性肝炎后肝脏抗氧化功能的变化。将 16 0只刚出壳的北京鸭 ,经 1周适应性饲养后 ,随机均分为对照组、弱毒株组、中毒株组和强毒株组。在攻毒组的每只雏鸭背部分别肌肉注射 0 .3m L弱毒株、中毒株和强毒株的稀释液。攻毒后 1、3、5、7d剖杀雏鸭 ,采集其肝组织 ,测定鸭肝组织中过氧化氢酶 (CAT)、谷胱甘肽过氧化物酶 (GSH- Px)及超氧化物歧化酶 (SOD)的含量。结果表明 ,中毒组和强毒组的 CAT含量在攻毒后 1d便显著或极显著低于对照组 ,但弱毒株组在攻毒后的 5 d才显著低于对照组。攻毒后1d,雏鸭肝组织中 SOD含量开始下降 ,3d后显著或极显著低于对照组。攻毒后 5 d,各攻毒组雏鸭肝组织中的 GSH-Px的含量亦显著降低。这些抗氧化酶含量的降低 ,说明感染鸭肝炎病毒后雏鸭清除自由基的能力下降 ,自由基参与了鸭病毒性肝炎的发病过程。     

感染新型鸭肝炎病毒雏鸭的SOD活性和MDA含量变化

用新型鸭肝炎病毒人工感染雏鸭，对感染雏鸭血液、肝、脑中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量进行了检测。结果显示：血清和肝组织中MDA含量在感染后第24 h极显著高于对照组(P＜0．01)，脑组织中MDA含量无显著变化。血清中SOD活性第24h极显著高于对照组(P＜0．01)，第96h极显著低于对照组(P％0．01)；肝组织SOD活性于感染后第24h显著低于对照组(P＜0．05)；脑组织中SOD活性无显著变化。提示：自由基参与了新型鸭肝炎的发生、发展过程。     

鸭肝炎病毒对雏鸭肝组织中MDA和GSH-PX的影响

对雏鸭分别感染弱毒株、中毒株、强毒株肝炎病毒后，在ld、3d、5d、7d分别测定对照组和实验组肝组织中丙二醛(MDA)的含量和谷胱甘肽过氧化物酶(GSH—Px)的活性。结果表明，雏鸭感染鸭肝炎病毒(DHV)后肝组织中MDA含量和GSH—Px活性发生明显变化，其中，实验组在5d时MDA含量显著增多，而GSH—Px的活性明显降低。结果提示，自由基参与了鸭病毒性肝炎(DVH)发生发展的致病过程，在DHV诱导的细胞凋亡过程中自由基可能起关键作用。     

雏鸭感染鸭肝炎病毒后血液中一氧化氮和一氧化氮合酶的变化

用不同毒力株鸭肝炎病毒人工感染雏鸭，测定雏鸭血浆一氧化氮（NO）和一氧化氮合酶（NOS）的含量，研究NO在鸭病毒性肝炎发病过程中的作用。结果表明：雏鸭感染不同毒力株鸭肝炎病毒后第1天血浆一氧化氮和一氧化氮合酶含量就开始上升，第3天显著或极显著高于对照组，并持续至实验结束。揭示一氧化氮同雏鸭病毒性肝炎的发生发展过程有关。     

鸭病毒性肝炎对雏鸭外周血淋巴细胞转化及ANAE阳性率的影响

从广东部分地区采集鸭病毒性肝炎病毒 ,经半数致死量测定确定病毒毒力。取 1d无DHN病史、没有注射过DVH疫苗的健康仙湖三号鸭 2 0 0只 ,经 1周适应饲养后 ,随机分为对照组 (C组 ) ,弱毒株组 (S组 ) ,中毒株组 (M组 )以及强毒株组 (H组 ) 4个组 ,每组 5 0只。试验组背部肌肉分别注射 0 .3mL弱毒株、中毒株、强毒株的稀释液 ,对照组背部分点注射等量稀释液 ,隔离饲养。在攻毒后 1,3,5 ,7d采血 ,分别用形态学方法和酸性 -α-醋酸萘酯酶染色法 (ANAE)测定鸭外周血淋巴细胞转化率及ANAE阳性率。结果表明 :在整个试验期内 ,中毒组和强毒组的淋巴细胞转化率显著 (或极显著 )下降 (P <0 .0 5或P <0 .0 1) ,弱毒组仅在攻毒后 5d ,淋巴细胞转化率显著下降 (P <0 .0 5 ) ,其它时间与对照组相比没有显著差异 ;这些变化与病毒毒力有关 ;试验组在 3,5 ,7d测定时 ,与对照组相比 ,淋巴细胞转化升高 ,差异显著或极显著 (P <0 .0 5或P <0 .0 1) ,这些变化与病毒毒力无关。提示鸭病毒性肝炎病毒能抑制淋巴细胞的转化 ,这种抑制作用与毒力有关 ;攻毒组ANAE阳性率升高 ,不受病毒毒力强弱的影响。这些结果的不一致性 ,说明机体受到抗原侵袭时 ,免疫系统各组感受性发生的先后次序是不一致的     

DVH引发雏鸭血清及肝脏中NOS活性变化的研究

用鸭肝炎病毒人工感染雏鸭,于感染后3、12、36、48、72、96、144、168h和192h剖杀感染组和对照组雏鸭各5只,测定其血清和肝脏中一氧化氮合酶(NOS)的活性。结果表明,雏鸭感染鸭肝炎病毒后,血清和肝脏中NOS的活性升高,在感染48h时显著高于对照组,表明鸭肝炎病毒导致的肝损伤与NO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