正交试验优化猪苓多糖的超声提取工艺

为了优化猪苓多糖超声提取工艺,试验采用4因素3水平的试验设计确定最佳提取工艺条件,并比较不同产地猪苓中多糖的含量。结果表明：在超声功率为200 W,猪苓粒度为300目、提取时间为40 min、料液比为1∶40、提取温度为60℃条件下,提取效果最好,稳定可行;用此工艺条件提取,陕西省产的猪苓中多糖含量最高,吉林省产的最低;与传统提取法比较,超声提取法能显著提高猪苓多糖的提取率。     

正交试验优化猪苓多糖的超声提取工艺

为了优化猪苓多糖超声提取工艺,试验采用4因素3水平的试验设计确定最佳提取工艺条件,并比较不同产地猪苓中多糖的含量。结果表明:在超声功率为200 W,猪苓粒度为300目、提取时间为40 min、料液比为1∶40、提取温度为60℃条件下,提取效果最好,稳定可行;用此工艺条件提取,陕西省产的猪苓中多糖含量最高,吉林省产的最低;与传统提取法比较,超声提取法能显著提高猪苓多糖的提取率。     

响应面优化米糠多糖的超声波辅助提取工艺研究

为研究超声波时间、超声波温度、超声波功率及料液比对米糠多糖提取率的影响,本研究在单因素试验基础上,以米糠多糖提取率为响应值,采用Box-Behnken中心组合进行三因素三水平试验设计优化米糠多糖的超声波提取工艺。结果表明,最优工艺条件为超声波时间74 min、超声波温度82℃、料液比1∶26(g/mL)、超声波功率250 W,此条件下米糠多糖的提取率为1.4197%。超声波提取法稳定性好,回收率高。     

北五味子多酚提取工艺的研究

为了得到北五味子多酚提取工艺的最佳条件,试验以北五味子为原料,采用超声波法和正交试验法提取北五味子多酚。以多酚提取率为指标,研究了超声温度、超声时间、超声功率、料液比4个因素对北五味子多酚提取率的影响。结果表明:在超声温度60℃,超声时间8 min,超声功率600 W、料液比1∶18条件下,北五味子多酚的提取率最高,为5.62%。     

猴头菇菌渣中多糖提取工艺的优化及其体外抗氧化活性研究

试验旨在使用超声法优化猴头菇菌渣多糖的提取工艺。试验研究了4个不同影响因素(液料比、超声波功率、超声时间和超声次数)对猴头菇菌渣多糖提取率的影响,利用正交分析法优化生产工艺参数,考察在最优工艺参数条件下猴头菇菌渣多糖的提取率,并检测其体外抗氧化活性。结果显示,影响猴头菇菌渣多糖提取率各因素的排序为液料比>超声次数>超声波功率>超声时间;提取工艺最优参数组合为液料比15 mL/g、超声波功率350 W、超声时间15 min、超声次数2次。在此工艺条件下,猴头菇菌渣多糖提取率为8.85%。体外抗氧化试验表明,猴头菇菌渣多糖对DPPH自由基、超氧阴离子自由基和ABTS⁺自由基的清除率分别为88.03%、67.42%和97.83%,具有一定的抗氧化能力。研究表明,试验结果可为猴头菇菌渣多糖的生产工艺优化及饲喂利用价值开发提供参考。     

正交试验法优选荷叶中总黄酮超声提取工艺

目的：优选荷叶中总黄酮超声提取工艺。方法：采用正交试验法,以荷叶中芦丁提取率为考核指标。考察乙醇浓度、超声提取时间、超声功率和料液比对荷叶总黄酮提取率的影响。结果：荷叶总黄酮超声提取的最佳工艺是：乙醇浓度为60%、超声时间40 min、超声功率为250 W、料液比1∶20。结论：此工艺操作简便、稳定性较好,可用于荷叶总黄酮的提取。     

急弯棘豆总黄酮超声波辅助提取工艺研究

为了探索超声波辅助提取急弯棘豆黄酮的最佳工艺条件,试验以急弯棘豆黄酮的含量为考察指标,通过单因素和正交实验设计试验研究提取超声功率、温度、时间、乙醇浓度、料液比对急弯棘豆黄酮提取率的影响,筛选出最佳提取工艺。结果表明,影响急弯棘豆超声辅助提取的主要因素依次为超声功率、温度、超声时间和料液比。超声波辅助提取弯棘豆黄酮最佳提取工艺条件:乙醇浓度在60%,超声时间为45min,超声波功率为800 W,温度45℃,料液比为1∶10。最高提取率为1.97%。     

正交优化超声波辅助提取米糠多糖的工艺研究

研究了超声波时间、超声波温度、超声波功率及料液比对米糠多糖提取率的影响。在单因素的基础上,以米糠多糖提取率为指标,采用正交试验设计优化了米糠多糖的超声波提取工艺。最优工艺条件为：超声波时间75min,超声波温度80℃,料液比1：25g/mL、超声波功率250W,此条件下米糠多糖的提取率为1.4061%。     

超声辅助紫萼玉簪根多糖提取工艺及抑菌研究

为了筛选紫萼玉簪根多糖的最佳提取条件,并研究紫萼玉簪根多糖抑菌活性,试验采用超声辅助法提取多糖,用硫酸苯酚法测定多糖含量,在料液比、超声次数、超声功率单因素试验的基础上,采用Box-Behnken响应面设计法建立数学模型,以确定最佳提取工艺;并测定紫萼玉簪根多糖对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌的最小抑菌浓度(MIC)。结果表明:紫萼玉簪根多糖在超声辅助提取中最佳提取工艺为超声功率390 W(52%),料液比1∶93,超声次数128次(6 min 40 s),多糖得率为23.6%,与理论值相差0.2百分点;紫萼玉簪根多糖对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌的MIC分别为18.75 mg/mL、37.5 mg/mL、75 mg/mL。     

竹叶黄酮的超声提取工艺研究

以水作为提取剂,采用超声提取竹叶黄酮,并对提取工艺进行优化,实验探究超声时间、超声温度、超声功率、料液比等因素对提取效果的影响,在此基础上,通过正交优化了竹叶黄酮的提取工艺,所得的最佳工艺参数为:超声时间60min,料液比1∶17g/mL,超声温度60℃,超声功率200W,此条件下竹叶黄酮的提取率达4.692%。超声提取竹叶黄酮用作饲料添加剂高效安全,可进一步工业化推广。     

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