三黄连散的亚慢性毒性试验研究

探讨大鼠长期口服三黄连散的亚慢性毒性作用。将80只大鼠随机分为空白对照组、三黄连散低(2.5 g/kg·BW)、中(5.0 g/kg·BW)和高剂量组(10.0 g/kg·BW),每组20只,雌雄各半,采用混饲给药的方式连续给药30 d,每日观察临床表现,记录体重和饲料消耗量,停药后继续观察7 d。分别于给药后30 d和停药后7 d进行血液常规指标、血液生化指标和脏器解剖学、病理学检查。结果显示,给药期间和停药后,各试验组大鼠未出现中毒和死亡情况,临床症状、解剖学检查等均无异常变化,脏器指数、组织病理学检查结果均无异常;血液常规指标、血液生化指标结果表明该药物无毒副作用,仅见高剂量组大鼠的体重和饲料消耗量显著低于空白对照组(P0.05)。结果表明,三黄连散给大鼠连续饲喂30 d未见明显毒性反应。     

穿琥宁注射液对大鼠的长期毒性试验

将SD大鼠随机分为4个组,3个剂量组分别按75.7、15.14、7.57mg/kg通过腹腔注射法对大鼠给药,对照组给予同体积生理盐水,连续观察28d,记录大鼠毒副反应情况。停药后继续观察2周,测试大鼠体重、血液学指标、血液生化学指标、脏器指数。结果表明,各剂量组大鼠与对照组比较,给药期与恢复期的体重增长、血液学指标、血清生化指标、脏器指数均无显著性差异(P0.05)。试验结果表明,穿琥宁注射液连续给药28d,大鼠无不良反应,停药14d后亦未出现迟发性不良反应。     

人参叶口服液对大鼠的亚慢性毒性试验

将Wistar大鼠随机分为4组,3个剂量组(以人参皂苷计)分别按40、80、160 mg/kg体重给大鼠灌胃,对照组给予同体积生理盐水,1次/d,连续28 d,记录大鼠毒副反应.停药后继续观察14 d,测试大鼠体重、血液学指标、血液生化学指标、脏器指数.结果表明,各剂量组大鼠与对照组比较,给药期与恢复期的体重增长,血液...     

仔泻康口服液的急性毒性和亚慢性毒性试验研究

试验旨在通过小鼠急性毒性试验和大鼠亚慢性毒性试验对仔泻康口服液进行安全性评价,为临床安全用药提供理论依据。在急性毒性试验中,采用最大给药剂量对36只昆明小鼠进行灌胃给药。在亚慢性毒性试验中,将80只大鼠,随机均分成高、中、低剂量组和对照组,高、中、低剂量组分别按24、12和6g/kg体重灌胃给药,对照组给予等体积生理盐水,连续给药30d,停药后称量大鼠体重、检测血常规指标、血液生化指标、计算脏器指数并观察组织病理变化等。结果显示,在急性毒性试验中,各剂量组均无小鼠死亡,无法计算LD50,最大耐受量试验也无死亡情况;在亚慢性毒性试验中,该口服液对大鼠生长发育没有影响;经剖检,仅高剂量组可见中央静脉远端的肝细胞有不同程度的肿大,但未见坏死和炎性反应,其他各剂量组的实质器官均未发现异常变化;各剂量组血液学指标、血液生化指标和脏器指数均在正常范围内,与对照组相比均无显著差异(P0.05)。结果表明,根据外源化学物急性毒性分级(WHO)标准,该制剂属于无毒物质,安全性较高,在合理剂量下,临床使用仔泻康口服液是安全的。     

肿节风三清颗粒安全性试验研究

试验旨在考察肿节风三清颗粒的急性毒性、亚慢性毒性和靶动物安全性,为临床安全用药提供理论依据。急性毒性试验中,一次性给小鼠灌胃给药,未测出LD50,故采用24h内多次给药的方式测定最大耐受量。亚慢性毒性试验中,大鼠以低、中、高(5、10、20g/kg体重)3个不同剂量灌胃给药,每天1次,连用35d,并设生理盐水对照组;在给药期间观察大鼠的临床体征和体重变化,35d称重并测定血常规和血液生化指标,取脏器观察病理组织学变化。靶动物安全性试验,按临床推荐剂量的1、3、5倍剂量饮水投服肿节风三清颗粒,连续5d,观察试验鸡的临床体征并按期称重,测定血常规和血液生化指标。结果显示,急性毒性试验各剂量组小鼠均无死亡,无法测出LD50,最大耐受量为75g/kg体重(以颗粒计)。亚慢性毒性试验中,给药组大鼠的临床体征、体重、血常规、血液生化指标与空白对照组大鼠相比均无显著差异(P0.05),组织病理学观察发现实质器官无异常病变。靶动物安全性试验中,各用药组鸡的增重、饲料转化率、血常规和血液生化指标与空白对照组相比差异均不显著(P0.05)。结果表明,肿节风三清颗粒无急性毒性和亚慢性毒性作用,靶动物临床用药在5倍推荐剂量内安全。     

枸杞子对小鼠生长及部分血液生化指标的影响

笔者通过试验观察饮水中添加不同剂量枸杞子水煎液对小鼠生长及部分血液生化指标的影响。取小鼠40只,随机均分为4组,分别为对照组(饮用自来水)、枸杞子水煎液低剂量组(10 g/kg)、枸杞子水煎液中剂量组(20 g/kg)和枸杞子水煎液高剂量组(40 g/kg),每日按体重加药1次,24 h内饮完,连续给药28 d。最后1次给药后30 min,称重,摘眼球取血,测定部分血液生化指标。结果表明,与对照组比较,口服枸杞子水煎液各剂量组小鼠第2、3、4周末增重速度明显减小(P0.01);血清中谷草转氨酶低、中剂量组显著降低(P0.05);尿素低、中、高剂量组显著降低(P0.05);总胆红素高剂量组显著升高(P0.05)。     

芪参口服液的毒理学研究

为评价芪参口服液临床用药的安全性,根据毒理学评价程序和方法对其进行了急性毒性试验和长期毒性试验。在急性毒性试验中,将40只昆明小鼠按体重随机分为2组,采用最大给药量法测定小鼠口服芪参口服液的最大耐受剂量;在长期毒性试验中,将80只Wistar大鼠按体重随机分为4组,3个剂量组分别按3.75、7.5、15 g/kg体重给大鼠灌胃,对照组给予同体积生理盐水,1次/d,连续4周。记录每日饮水量、饲料采食量及每周体重,检测给药4周及停药2周血液生化指标、血常规、脏器系数和组织病理学变化。试验结果显示,小鼠口服芪参口服液的最大耐受剂量为生药量40 g/kg,此剂量相当于临床日用量的40倍。部分给药组采食量和饮水量与对照组相比出现显著(P＜0.05)或极显著(P＜0.01)变化,但对平均周增重无显著性影响(P＞0.05);血常规的部分指标出现显著(P＜0.05)或极显著变化(P＜0.01),但停药2周后,所有指标与相应的对照组相比无显著性差异(P＞0.05);给药组血液生化和脏器系数的各项指标与对照组相比,无显著性变化(P＞0.05)。病理组织学检查无明显差异。试验结果表明,在本次试验条件下,该口服液安全无毒。     

三黄连合剂亚慢性毒性试验

为考察三黄连合剂对动物的安全性,采用大鼠进行长期毒性试验。设三黄连合剂20 g/kg、10 g/kg、5 g/kg剂量组及空白对照组。连续给药30 d,观察给药期间和停药后7 d大鼠的临床表现,于停药后第1天(试验第31天)和停药后7 d(试验第38天)分别进行腹主动脉采血,用于血常规指标和血清生化指标检测,同时剖检并采集大鼠实质性脏器计算脏器指数及制作石蜡组织切片。结果显示,三黄连合剂高、中、低剂量组与对照组相比除个别指标外,其余指标差异均无统计学差异(P0.05),且未见与药物有关的病理变化。结果表明三黄连合剂安全性好。     

常山总碱的亚急性毒性试验

为评价常山总碱的安全性和今后系统研究其药理作用以及为临床安全用药提供试验依据,在小鼠急性毒性试验的基础上,进行亚急性毒性试验。80只大鼠随机分成常山总碱高、中、低剂量组和空白对照组,药物组按照大鼠体质量6.50,3.25,1.63g/kg的剂量灌胃给药,连续给药14d,所有大鼠于给药后分2次（7,14d）扑杀。结果表明,常山总碱低、中剂量组大鼠的体质量、脏器系数、血液学指标、血液生化指标、组织病理学变化等各项指标与对照组比较均无显著性差异（P〉0.05）;高剂量组对上述部分指标有一定影响,需要进一步研究。本试验结果提示,常山总碱的毒性很低,临床用药较为安全。     

仔泻康口服液的急性毒性和亚慢性毒性试验研究

试验旨在通过小鼠急性毒性试验和大鼠亚慢性毒性试验对仔泻康口服液进行安全性评价,为临床安全用药提供理论依据。在急性毒性试验中,采用最大给药剂量对36只昆明小鼠进行灌胃给药。在亚慢性毒性试验中,将80只大鼠,随机均分成高、中、低剂量组和对照组,高、中、低剂量组分别按24、12和6 g/kg体重灌胃给药,对照组给予等体积生理盐水,连续给药30 d,停药后称量大鼠体重、检测血常规指标、血液生化指标、计算脏器指数并观察组织病理变化等。结果显示,在急性毒性试验中,各剂量组均无小鼠死亡,无法计算LD₅₀,最大耐受量试验也无死亡情况;在亚慢性毒性试验中,该口服液对大鼠生长发育没有影响;经剖检,仅高剂量组可见中央静脉远端的肝细胞有不同程度的肿大,但未见坏死和炎性反应,其他各剂量组的实质器官均未发现异常变化;各剂量组血液学指标、血液生化指标和脏器指数均在正常范围内,与对照组相比均无显著差异（P>0.05）。结果表明,根据外源化学物急性毒性分级（WHO）标准,该制剂属于无毒物质,安全性较高,在合理剂量下,临床使用仔泻康口服液是安全的。     

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.     

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.     

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     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

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

Tropical Animal Health and Production -