青海四种土蝗(直翅目:斑翅蝗科)染色体核型分析

用常规染色体制片方法研究了青海高山草地的四种土蝗：黄胫异痂蝗（Bryodemella bolderei holdereri Krauss,)、白边痂蝗（Bryodema luctuosum luctuosun Stoll)，黄胫小车蝗（Oedaleus infernalis Sauss）、亚洲小车蝗（Oedaleu asiatisc B.-Bienko）的染色体数目和核型。四种土蝗染色体数目均为，（2n♂）＝23＝27＝22＋XO；全部染色体都为近端着丝点类型；四种土蝗染色体的核型公式均为K(2n,♂）＝23＝23T＝4L＋14M＋4S＋XO。结果表明，斑翅蝗科3属间的蝗虫主要区别为常染色体和性染色体相对长度有明显差异，小车蝗属内2种间区别主要为常染色体相对长度的差异。     

东亚飞蝗染色体C带和银染带型分析

本研究采用改进后的悬浮滴片法制备东亚飞蝗(Locusta migratoria manilensis)雄性染色体标本,进行东亚飞蝗核型、C带和银染显带分析.东亚飞蝗雄性核型为2N-22+XO(↑),染色体组式为4L+4M+4S+XO.C带显示东亚飞蝗染色体全部为端着丝粒,第2对染色体有端带;东亚飞蝗的银染核仁组织区位于...     

3份长穗偃麦草种质的体细胞核型分析

采用根尖压片法,对不同国家来源的3份长穗偃麦草(Elytrigia elongata)种质材料的体细胞染色体核型进行分析,旨在为其细胞学特性和系统演化的研究奠定科学基础.结果表明:来源于中国新疆的EE001细胞染色体相对长度组成为1L+ 17M2+ 15M1+ 2S,核型公式为K(2n)=10X=70=50m+ 16sm+ 4st;来源于德国的EE014细胞染色体相对长度组成为3L+ 14M2 +13M1 +5S,核型公式为K(2n)=10X=70=48m+20sm+2st;来源于葡萄牙的EE020细胞染色体相对长度组成为5L+ 11M2 +15M1 +4S,核型公式为K(2n)=10X=70=38m+ 22sm+ 8st+2t.3份长穗偃麦草种质的体细胞染色体核型均为“2B”类型.     

热研4号王草和桂闽引象草的核型分析

采用常规压片法,对热研4号王草(Pennisetum purpureum×P.americanum cv.Reyan No.4)和桂闽引象草(P.purpureumcv.Guiminyin)的染色体数目和核型进行分析,以期为狼尾草属种质资源多样性保护利用和遗传育种研究提供理论依据。结果表明,两者染色体基数均为x=7。其中,热研4号王草为三倍体,有21条染色体,核型公式2n=3x=21=21m(3SAT),染色体相对组成I.R.L=9S+3M1+3M2+6L,3条染色体含有随体;桂闽引象草为四倍体,有28条染色体,核型公式2n=4x=28=18m(2SAT)+10sm(2SAT),染色体相对组成I.R.L=10S+6M1+4M2+8L,4条染色体含有随体。热研4号王草和桂闽引象草核型不对称系数分别为60.15%和62.19%,属于1B型和1C型,其核型都属于比较原始的类型。     

毛稃偃麦草染色体核型分析

采用根尖压片法对毛稃偃麦草的细胞染色体进行核型分析。结果表明毛稃偃麦草（Elytri-gia alatavica）染色体数目为2n=42,染色体相对长度组成为12L＋4M2＋14M1＋12S,核型公式K（2n）=6 X=42=36m＋6sm（2sat）,属于＂1B＂类型。其中,3对为近中着丝粒染色体,且带有1对随体,其...     

经营田鼠染色体核型与G带分析

采用骨髓法制备经营田鼠染色体标本片,并对其染色体核型和G带进行分析。结果表明,经营田鼠体细胞染色体数为2n=38,雄性染色体核型由18对常染色体和1对异配型性染色体XY组成,雌性为18对常染色体和1对同配型性染色体XX组成。1～9号为端着丝粒（t）染色体（包括Y染色体）,10号为近端着丝粒（st）染色体,11～18号为中央着丝粒（m）染色体（包括X色体）。19对染色体共分布有370条G带（雄性365条）,其中深带190条,浅带180条。因此,经营田鼠的染色体数目、G带具有明显种的特征,与其他鼠类不同。     

中国不同地区罂粟的核型比较

为揭示不同地区生境条件下的罂粟生态型的染色体核型变化,利用普通压片法对来自中国5个省(市)的10份罂粟材料染色体数与核型进行了分析。结果表明,不同地区来源的罂粟材料可分为白花1号和白花2号2个生态型,染色体倍性均为二倍体,染色体数目为2n=2x=22条,染色体相对长度组成(IRL)为2L+3M2+5M1+1S;白花1号的核型公式是K(2n) =2x=22=18sm+4st,平均核型不对称系数(Ask)为72.04%,核型分类标准属于4A型;白花2号的核型公式是K(2n)=2x=22=16sm+6st,平均核型不对称系数为73.00%,核型分类标准属于4B型;不同地区的白花1号和白花2号的核型均为极不对称型,但核型发生了多样性变化。     

日本血蜱的二倍体与三倍体核型

以日本血蜱卵早期胚细胞为材料,气干法制片,Giemsa染色制备染色体标本,首次证明:日本血蜱的有丝分裂核型为2n=22(20 XY)和2n=22(20 XX);性别决定属于XY—XX遗传系统;并发现三倍体(3n=33)。雌性核型中含1对X-染色体,雄性核型含1条X-和1条Y-性染色体。X-染色体最长,占单倍体总长度的20.8±1.8％,Y-染色体次长,约为X-染色体长之68.7％,明显长于其余10对常染色体。据本实验结果,与前人报道的该雄蜱减数分裂含21条染色体进行讨论。     

中间偃麦草和长穗偃麦草染色体核型分析

选用从国外引进的中间偃麦草(Elytrigia intermedia)和长穗偃麦草(E.elongata)种子为材料,采用根尖压片法进行细胞染色体核型分析。结果表明,中间偃麦草染色体数目为2n=6x=42,染色体相对长度组成为：10L+10M2+12M1+10S,核型公式为：K(2n)=6x=42=34m+8sm,属于“2B”类型。长穗偃麦草染色体数目为2n=10x=70,染色体相对长度组成为:10L+22M2+30M1+8S,核型公式为：K(2n)=10x=70=38m+22sm+8st+2t,属于“2B”类型。本研究结果可以为中间偃麦草和长穗偃麦草的细胞学特性和遗传机制的研究提供理论依据。     

黄花苜蓿和紫花苜蓿分子核型比较

黄花苜蓿(Medicago falcata L. 2n=32)是一种重要的野生豆科牧草,由于其突出的抗逆特性,被认为是用来进行苜蓿改良的优异遗传资源。本研究利用染色体荧光原位杂交技术(FISH),以不同荧光物标记的3种重复序列(5S rDNA,45S rDNA和C₀t-1 DNA),对黄花苜蓿和和紫花苜蓿(Medicago sativa L. 2n=32)染色体进行了FISH分析和分子核型比较,以期在染色体水平上揭示二者之间的亲缘关系。结果表明:利用上述重复序列可以较好的将苜蓿32条染色体区分为16对特征不同的染色体。黄花苜蓿和紫花苜蓿绝大多数染色体FISH杂交特征表现一致或高度相似性,分子核型无显著区别,因此二者间在遗传上具有高度的相似性。     

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