高效液相色谱法测定磺胺氯达嗪钠含量

建立高效液相色谱(HPLC)法测定磺胺氯达嗪钠的含量。色谱柱为Agilent ZORBAX Eclipse Plus C18柱(150mm×1.6mm,5μm),流动相为0.1%磷酸溶液-甲醇(85∶15),流速为1.0mL/min,柱温为25℃,检测波长为270nm。磺胺氯达嗪钠对照品质量浓度在40～200μg/mL范围内与峰面积呈良好的线性关系,线性回归方程A=23.34C-10.58,r=0.9999(n=5);平均回收率为99.7%,RSD=0.32%(n=5)。HPLC法快速、简便,专属性强,重现性好,准确度高,可用于磺胺氯达嗪钠原粉的含量测定。     

双波长分光光度法检测二甲氧苄啶的含量

采用双波长等吸收分光光度法测定复方磺胺氯吡嗪钠制剂中二甲氧苄啶(DVD)的含量。DVD浓度在9～27μg·mL~(-1)范围内具有良好的线性关系(r=0.999 8)，平均回收率为99.3％(n=5)，RSD为0.43％。     

复方伊维菌素片含量测定方法的探讨

采用HPLC法及紫外-可见分光光度法分别测定复方伊维菌素片中伊维菌素及阿苯达唑的含量，以控制该制剂的质量。用十八烷基键合硅胶柱分离伊维菌素，以甲醇-水(85：15)为流动相，检测波长245nm；用紫外-可见分光光度法在295nm波长处测定阿苯达唑的含量。结果表明，用HPLC法测定本品中伊维菌素的含量时，伊维菌素能与阿苯达唑完全分离，平均回收率为99．56％，RSD=1．27(n=5)；用紫外-可见分光光度法测定本品中阿苯达唑的含量，伊维菌素对测定无干扰，平均回收率为99．14％，RSD=0．48(n：4)。本法简便、快速，可用于该产品的质量控制。     

双波长紫外分光光度法测定酒石酸泰乐菌素-盐酸多西环素可溶性粉的含量

建立了双波长紫外分光光度法同时测定酒石酸泰乐菌素-盐酸多西环素可溶性粉中酒石酸泰乐菌素和盐酸多西环素含量的检测方法。结果显示，吸收度与浓度呈良好线性关系。酒石酸泰乐菌素的平均回收率为99．90％，RSD为0．42％n=5）；盐酸多西环素的平均回收率为100．07％，RSD为0．74％（n=5）。     

测定复方磺胺氯吡嗪钠可溶性粉含量HPLC法的验证

为了验证同时测定复方磺胺氯吡嗪钠可溶性粉中磺胺氯吡嗪钠和甲氧苄啶含量的HPLC法,试验以Agilent C18柱为色谱柱,0.1%磷酸溶液(三乙胺调节pH值至4.0)-乙腈(80∶20)为流动相,流速为1.0 mL/min,检测波长为271 nm,柱温为35℃的条件建立了同时检测复方磺胺氨氯吡嗪钠可溶性粉有效成分含量的HPLC法,并进行方法的方法学验证试验,对样品含量进行实测。结果表明:磺胺氯吡嗪钠在30.1～61.9μg/mL,甲氧苄啶在6.1～194.3μg/mL范围内,浓度与其相应峰面积呈良好线性关系,R~2分别为1.000和0.999 9。精密度试验RSD分别为0.04%和0.08%。重复性试验RSD分别为0.29%和0.09%。稳定性试验RSD分别为0.31%和0.18%。平均加样回收率分别为99.4%和98.8%。样品中实测磺胺氯吡嗪钠和甲氧苄啶的平均含量分别为102.16%和102.68%。说明建立的测定复方制剂中磺胺氯吡嗪钠和甲氧苄啶含量的方法简单快速、重现性好、准确度高。     

HPLC法测定复方多聚甲醛粉中水杨酸和苯甲酸

建立了HPLC法测定复方多聚甲醛粉中水杨酸和苯甲酸的方法。采用AgilentZORBAXEclipseXDB-C18色谱柱（4．6mm×250mm,5μm）,以0．05mol／L磷酸二氢钾溶液（pH6．0）-甲醇（90：10）为流动相,流速1．0mL／min,检测波长230nm,柱温40cC,进样量10μL,以外标法定量。水杨酸和苯甲酸在1．0～50μg／mL范围内均线性关系良好,相关系数r均为0．9999,平均回收率分别为99．06％～99．69％（RSD=0．09％～0．63％）和99．12％～99．73％（RSD=0．16％～0．48％）,n=3。本方法简便、准确,可快速测定复方多聚甲醛粉中水杨酸和苯甲酸的含量,为产品质量控制提供了依据。     

强力恩诺沙星可溶性粉中有效成分含量的检测

采用双波长等吸收分光光度法同时测定强力恩诺沙星可溶性粉中恩诺沙星和硫酸小檗碱的含量。线性范围恩诺沙星2～10(μg／m1)，γ=0．99999；硫酸小檗碱8～16(μg／m1)，γ=0．9995；平均回收率为：恩诺沙星99．4％(n=5)，RSD为0．21%；硫酸小檗碱99．5％(n=5)，RSD为0．26％。     

紫外分光光度法测定氟苯尼考制剂的含量

采用紫外分光光度法测定氟苯尼孝预混剂、注射液的含量，结果表明在50－400μg/ml的浓度范围内，吸收度与浓度呈良好线性关系，预混剂平均回收率99．6％，RSD＝0．44％；注射液平均回收率99．9％，RSD＝0．54％。并与电位法进行对照，结果基本一致，本法具有简便、快速、准确、重现性好等优点，可用于氟苯尼考制剂含量的快速测定。     

高效液相色谱法测定复方阿莫西林舒巴坦钠纳米乳含量

[目的]建立了高效液相色谱（HPIC）法测定复方阿莫西林舒巴坦钠纳米乳含量的分析方法。[方法]采用HPLC法测定复方阿莫西林舒巴坦钠纳米乳含量。色谱柱为DiamondC18柱（250mmx4．6mm,5um）。流动相为磷酸盐缓冲液-乙腈-水,检测波长为220nm。[结果]阿莫西林在40～400μg／mL的范围内．线性关系良好（r=0．9990）,回收率为99．9％,RsD为0．52％。舒巴坦钠在20～200μg／mL的范围内．线性关系良好（r=：0．9998）,回收率为99．9％,RSD为0．66％。[结论]该方法为控制复方阿莫西林舒巴坦钠纳米乳质量提供了可靠韵审罟奔新青津     

复方磺胺甲噁唑片有效成分含量测定方法的研究

采用转换曲线分光光度法可同时测定复方磺胺甲唑片中磺胺甲唑和甲氧苄啶的含量。在276～288nm范围中,上述2者的平均回收率分别为99．84％和100．39％,CV分别为0．39％和0．76％。     

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.     

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