RAPD与形态学对片形吸虫种类鉴别的比较研究

通过形态学特征观察与随机扩增多态DNA（RAPD）技术，对国内外8株片形吸虫（Fasciola)作比较鉴别。形态典型的6株肝片形吸虫（F.hepatica)和1株大片形吸虫（F.gigantica)两种方法结果。南京的1株不典型虫种（F.sp)，其形态特征类似日本中间种／印度片形吸虫（F.indica),RAPD检测则与大片形吸虫聚类，差异仅0．255，亲缘于大片形吸虫，是一株形态不典型的大片形吸虫。比较表明，形态学方法能简单易行正确地判定典型片形吸虫，但难以识别中间种或亲缘种；RAPD技术则从分子遗传变异水平上鉴别虫种，有利于对中间种或亲缘种的识别及新种的发现，两者具有相互不可替代的相辅相成作用。     

片形吸虫Cold-SSCP鉴别方法的建立

以采自我国不同地区的片形吸虫虫体为研究对象，PCR扩增出核糖体DNA (rDNA)的第一内转录间隔区(ITS-1)序列，然后采用非同位素的单链构象多态性(Cold-SSCP)方法分析PCR产物，对不同地区片形吸虫进行分子鉴定。所有样品经Cold-SSCP分析显示2种带型。样品测序及序列分析结果表明，第1种为肝片形吸虫带型，另1种为大片形吸虫带型。本研究建立了区分大片形吸虫和肝片形吸虫的Cold SSCP方法，可用于这2种吸虫的分子流行病学调查，从而为片形吸虫分子生物学的进一步研究奠定了基础。     

分子分类结合形态学观察鉴定重庆地区片形吸虫种类

目的明确重庆地区片形吸虫的种类,并为重庆地区片形吸虫的分类研究提供科学的参考依据。方法在对重庆地区黄牛、水牛肝脏上寄生的片形吸虫形态结构进行观察后,根据片形吸虫第一内转录间隔区(ITS-1)和第二内转录间隔区(ITS-2)基因设计特异性引物,运用多聚酶链式反应(PCR)技术,以法国肝片吸虫gDNA为对照,对所采样品gDNA用大片吸虫和肝片吸虫的ITS-1和ITS-2特异性引物进行扩增。结果形态学鉴定均为“不规则”片形吸虫,电泳结果显示均分别扩增出特异性ITS-1和ITS-2条带。结论综合形态学和PCR鉴定结果,初步认为重庆地区存在着大片吸虫和肝片吸虫的“中间型”。     

青海省藏羊片形吸虫观察及鉴定

为了明确青海省藏羊体内一种片形属吸虫的种类,并为青海省藏羊体内片形吸虫的分类研究提供科学的参考依据,采用形态学方法对青海省部分地区藏羊片形属吸虫进行了形态学观察及鉴定,对肩部特征不明显虫体进行了扫描电镜观察以及对体长、体宽测量并计算体长与体宽的比值。结果发现肩部特征不明显的虫体的体长范围在1.80~3.40 cm,体宽范围在0.70~1.20 cm,比值范围为2.38~3。扫描电镜观察虫体结构符合肝片吸虫的形态学特点。综合结果分析,初步鉴定青海省藏羊体内的片形属吸虫为肝片吸虫(Fasciola hepatica)。     

肝片形吸虫与巨片形吸虫的DNA和氨基酸含量的分析

本文对肝片形吸虫和巨片形吸虫进行了组织化学探讨。结果表明：肝片形吸虫和巨片形吸虫的ＤＮＡ含量不同，二者比值为２：３，且所含１７种氨基酸种类相同，含量却不相同，某些氨基酸含量差别很大。     

黄牛源Fh/Fg杂合型片形吸虫的鉴定

为弄清黄牛感染的片形吸虫种类,首先对来自河南济源市一肉牛屠宰场黄牛肝脏上的片形吸虫进行形态学观察,然后基于核糖体ITS1、ITS2区域和线粒体nad1、cox1基因序列进行分子鉴定。ITS1和ITS2序列分析结果显示,济源黄牛源片形吸虫分离株JY003和JY004为Fh/Fg杂合型片形吸虫。基于nad1和cox1基因序列,JY003和JY004与大片形吸虫的相似性高于肝片形吸虫,其中nad1序列与大片形吸虫中国云南、日本和韩国分离株的相似性高达100%。在基于nad1和cox1基因的进化树上,分离株均与大片形吸虫参考株处于同一分支。结果表明,首次从河南黄牛体内鉴定出Fh/Fg杂合型片形吸虫,为动物和人的片形吸虫病防控提供重要的基础数据。     

肝片形吸虫和巨片形吸虫同工酶的分析

同工酶与基因和遗传有着密切的关系，生物种类的不同可表现为某些同工防的数量和种类的变化。因此，它可作为一项生化指标，研究生物的分化情况。本文对人畜共患的两种片吸虫的同工配进行研究，发现二者的某些同工酶存在明显差异。1．材料与方法1．1材料来源成虫采自福州市屠宰场宰杀的黄牛和山羊的胆囊和胆管中，分别选出典型的肝片形吸虫和巨片形吸虫的成虫。本研究所使用的试剂均系分析纯。1．2匀浆制各：将典型的肝片形吸虫和巨片形吸虫的成虫分别用生理盐水洗3次，成虫用pH74的缓冲液在冰水浴中研磨5分钟，高速离心（1200转／分）10分…     

片形吸虫第一内转录间隔区DNA多态性的研究

以不同地区的片形吸虫虫株为研究对象，经PCR扩增出了ITS-1部分基因片段，采用单链构象多态性(SSCP)方法，并结合序列分析研究了不同地区片形吸虫ITS-1 DNA的多态性。不同地区的样品经SSCP分析，显示3种带型，第1种为大片形吸虫的带型，第2种为肝片形吸虫的带型，第3种为2种带形的混合带型。广西区样品和大部分贵州省样品属于大片形吸虫带型；四川省、黑龙江省和部分贵州省样品为混合带型；南京市和甘肃省样品为肝片形吸虫带型或混合带型。测序结果表明，根据ITS-1基因的序列变异位点可区分2种片形吸虫；表现为混合带型的样品在变异位点具有多态性。本研究结果显示，ITS-1片段可作为遗传标记用以区分大片形吸虫和肝片形吸虫，同时也证实，在我国除了这2种片形吸虫外，还可能存在着“中间型”的片形吸虫。     

两种片形吸虫感染家兔的试验比较

用大片形吸虫和肝片形吸虫感染家兔以便选择大片形吸虫对动物的最佳感染量，及明确号肝片形吸虫和大片形吸虫的生物学和对动物宿主的致病力的差别。结果显示肝片形吸虫虫体在兔体内发育成熟的时间早于大片形吸虫．感染成活率更高，对动物的病理损害明显比感染大片形吸虫兔的病变要轻。本试验证实这两种片形吸虫除了形态学的差异外，在对动物致病力、病理损害等万面确实存在差别。     

酶切图谱及序列分析虫体ITS2鉴别中国的片形吸虫

提取我国广西、四川、黑龙江、甘肃等地及法国的片形吸虫的总DNA，用PCR扩增完整的ITS－2。对得到的PCR产物用限制性内切酶Hsp 92Ⅱ，RcaI进行酶切和RFLP技术分析。并对ITS－2PCR产物进行双向测序。以便确定国内片形吸虫种内及种间ITS－2的特点和序列变异的水平。结果显示：广西、四川、黑龙江、法国等地的样品通过PCR均扩增到约550bp的ITS－2目标片段。Hsp92 Ⅱ,Rcal可区别不同种的片形吸虫。对PCR产物的序列分析结果表明片形吸虫ITS－2全长均为362bp，同种内ITS－2序列无变异，不同种间ITS－2序列存在5－6个碱基差异，变异率约为2.8%。对各地区片形吸虫ITS－2的PCR－RFLP分析与对PCR产物的DNA序列分析一致证明，来自四川的样品和法国样品同属肝片形吸虫F.hepatica；广西样品属大片形吸虫F.gigantica；黑龙江的样品为中间型片形吸虫。本研究首次从分子水平上证实我国除有肝片形吸虫、大片形吸虫外，还存在中间型的片形吸虫。     

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.     

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 -