正交设计法优化淫羊藿多糖的提取工艺

为了优选淫羊藿多糖的最佳提取工艺条件,通过单因素试验和正交试验,以料水比、提取时间、提取温度和提取次数为考察目标,以多糖提取率为评价指标,优选最佳提取工艺。结果表明,淫羊藿多糖最佳提取工艺为料水比为1∶25,提取时间2h,提取次数为3次,提取温度为90℃。多糖醇沉浓度为700mL/L。该工艺为淫羊藿多糖的提取奠定了基础,并为进一步的工业化生产提供了科学依据。     

响应曲面法优化淫羊藿黄酮提取工艺

在单因素试验基础上,采用响应面法的(Box-Benhnken)组合设计原理,对淫羊藿总黄酮的提取工艺参数进行优化。淫羊藿总黄酮的最佳提取工艺条件为:提取时间1.73 h、水料比31∶1(mL/g),温度67.5℃、乙醇浓度79%,淫藿黄酮类化合物的平均提取率为2.054%,比理论预测值高0.08%。     

响应面法对磷酸化淫羊藿多糖制备工艺的研究

采用混合磷酸盐法制备磷酸化淫羊藿多糖,再以磷酸化淫羊藿多糖磷酸根含量为考察指标,通过响应面法对工艺的提取参数进行优化,研究了修饰条件中反应温度(A)、反应时间(B)和反应p H值(C)3个因素对磷酸化多糖磷酸根含量的影响,建立了回归模型,验证了其有效性,并分析了主效应和因素交互作用。结果表明:反应温度、反应时间和反应p H值对磷酸化淫羊藿多糖磷酸根含量的影响显著,并且两两因素间存在一定的交互作用;影响磷酸化淫羊藿多糖的工艺因素按主次顺序排列为:反应温度反应时间反应p H值;磷酸化淫羊藿多糖的最佳工艺为:三聚磷酸钠与三偏磷酸钠比例为5∶2,反应温度97℃,反应时间2.8 h,反应p H 8.7,在此条件下,磷酸化淫羊藿多糖磷酸根含量为(6.012±0.021)%。     

淫羊藿多糖醇沉工艺优化及其对巨噬细胞释放NO的影响

旨在优化淫羊藿多糖醇沉条件并研究不同浓度乙醇醇沉的淫羊藿多糖对巨噬细胞释放NO的影响。采用乙醇沉淀法从淫羊藿多糖提取物中获得淫羊藿多糖,在单因素试验基础上,选择浓缩比、乙醇浓度、乙醇体积倍数、醇沉时间为自变量,采用L9(34)的正交试验设计,优化淫羊藿多糖最佳醇沉条件。用浓度为400、500、600、700、800mL/L乙醇醇沉的淫羊藿多糖,采用体外培养法,测定淫羊藿多糖对巨噬细胞释放NO的影响。结果表明,淫羊藿多糖最佳醇沉条件为浓缩比为1∶2,乙醇浓度为800mL/L,乙醇体积倍数为4倍,醇沉时间为12h;每个乙醇浓度醇沉的淫羊藿多糖均具有良好的活性,500mL/L乙醇醇沉的多糖活性最好。结果显示,淫羊藿多糖对巨噬细胞具有良好的刺激作用。     

酶解法提取山豆根多糖的工艺优化

为建立高得率的山豆根多糖提取工艺,试验以山豆根为原料,采用木瓜蛋白酶酶解法提取多糖。通过单因素试验和正交试验研究最佳提取工艺,采用苯酚-硫酸比色法测定多糖含量。结果表明:4个因素对山豆根多糖提取率的影响依次为酶浓度酶解温度酶解时间酶解pH值。山豆根多糖最佳提取工艺条件为酶浓度2%、酶解温度55℃、酶解时间3 h、酶解pH值5,山豆根粗多糖含量为88.48%,多糖的提取率为5.11%,明显高于水提醇沉法提取的粗多糖得率(3.54%)。该方法简便、成本低、提取率高,适用于山豆根多糖的提取。     

淫羊藿多糖提取工艺的优化及对小鼠细胞免疫功能的影响

淫羊藿为小檗科淫羊属植物,是传统的补肾助阳中药.现代药理试验结果表明,淫羊藿能增加心脑血管流量,促进造血功能、免疫功能及骨代谢,具有抗衰老、抗肿瘤的功效.多糖是淫羊藿发挥免疫调节作用的有效成分之一,试验在传统水提醇沉法的基础上运用超声波法提取淫羊藿多糖,通过正交设计优化并建立淫羊藿多糖的最佳提取工艺,并进行小鼠腹腔巨噬细胞吞噬试验和淋巴细胞转化试验,以探讨淫羊藿多糖对小鼠细胞免疫功能的影响.     

蜗牛酶辅助提取马勃多糖的工艺研究

本试验以马勃多糖得率为评价指标,通过研究提取温度、时间、酶用量、p H对多糖提取率的影响,以单因素试验和正交试验设计优选最佳提取工艺条件。结果表明:蜗牛酶辅助提取马勃多糖的最佳提取工艺条件为提取温度35℃、提取时间120 min、酶用量5.0%、p H 6.0。在此条件下,马勃多糖得率为0.908%。与传统水提法相比,多糖得率提高了158.01%。由此可见,蜗牛酶辅助提取具有得率高、提取时间短、条件温和等优点。     

红甜菜多糖提取及纯化工艺研究

试验旨在探究不同提取方法对红甜菜多糖的提取效果。试验以红甜菜为原料，分别采用水提醇沉法和超声辅助水提法，在单因素试验基础上进行正交设计优化其提取工艺，探究液料比、提取温度、提取时间对红甜菜多糖提取率的影响。利用Sevag试剂、活性炭和石油醚依次对粗多糖进行纯化。结果表明，采用水提醇沉法时，在液料比90 mL/g、提取温度70℃、提取时间1.5 h的条件下，红甜菜多糖得率最高，提取率达2.33%；采用超声波辅助水提法的最佳提取工艺为液料比40 mL/g、提取温度40℃、提取时间30 min。在此条件下，提取率为6.85%。超声波辅助水提法提取红甜菜多糖中蛋白质去除率、色素去除率、脂肪去除率分别为29.73%、3.88%、2.76%。研究表明，超声波辅助水提法所用提取溶剂少、耗时短、所需温度低、提取率高，更适用于红甜菜多糖的提取。     

响应面法优化紫穗槐叶多糖提取工艺及其抗氧化活性分析

试验以紫穗槐叶为原料，采用超声辅助酶解法提取紫穗槐叶多糖。以多糖得率为指标，通过单因素试验确定纤维素酶浓度、酶作用时间和反应温度的取值范围。利用响应面试验优化超声辅助酶解法提取紫穗槐叶多糖的工艺条件。结果显示，紫穗槐叶多糖的最佳提取条件为纤维素酶浓度5%、酶作用时间2 h、反应温度50℃，多糖的实际提取率为8.31%，与理论模拟值8.40%接近，建立的模型真实可靠。抗氧化试验表明，紫穗槐叶多糖对DPPH自由基和羟基自由基均有较强的清除能力，最大清除率分别为83.79%和99.18%。紫穗槐叶多糖对脂质氧化也具有较强的抑制能力，对β-胡萝卜素-亚油酸氧化体系的抑制能力约为2, 6-二叔丁基对甲酚（BHT）的83%。研究表明，响应面法优化紫穗槐叶多糖提取工艺稳定可行，且紫穗槐叶多糖具有较强的抗氧化活性，具有较高的应用价值。     

虎尾草多糖提取工艺优化及其抗氧化研究

为确定虎尾草多糖的超声协同蜗牛酶辅助提取工艺及其对油脂的抗氧化活性，以虎尾草为原料、多糖提取率为指标，设计超声协同蜗牛酶辅助提取虎尾草多糖工艺的单因素试验；在确定单因素的最佳取值范围后，利用响应面法进行优化，确定了最佳的提取工艺，进一步采用红外光谱（FTIR）对多糖的结构进行分析；最后探讨了虎尾草多糖对油脂的抗氧化活性。结果表明：虎尾草多糖的最佳提取工艺为：超声温度52℃、酶用量1.4%，超声时间41 min和pH 5.1，得到虎尾草多糖提取率为85.12 mg/g，与多糖最大提取率预测值的相对误差为0.83%，说明该回归方程误差小，准确性好。红外光谱表明：所提取的物质具有多糖的基本特征。油脂抗氧化表明：虎尾草多糖对植物油脂和动物油脂均表现出一定的脂质抗氧化作用，其用量与油脂的过氧化值呈现出负向的量效关系，说明虎尾草多糖可作为提高油脂产品货架期的添加剂。     

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