金银花中微波辅助提取绿原酸工艺条件研究

以金银花为原料,采用微波法辅助提取金银花中的绿原酸,研究浸提时间、乙醇浓度、料液比、提取温度、pH值对金银花中绿原酸提取率的影响。采用正交试验优化提取工艺,结果表明:浸提时间30min、乙醇浓度75%、料液比1∶30、提取温度65℃、pH值为7时金银花中绿原酸的提取率达5.068mg/g。     

金银花中绿原酸的微波辅助提取工艺条件研究

文章采用微波法辅助提取金银花中的绿原酸,以金银花为原料,研究可能影响到金银花中绿原酸提取率的因素。包括微波条件控制中的微波功率、微波温度、微波时间;提取绿原酸过程中的乙醇浓度、料液比、提取温度、浸提时间、pH等因素。文章旨在对通过微波法辅助提取金银花中绿原酸提取工艺条件中的可能因素进行研究,以期为金银花中绿原酸的工业化微波辅助提取提供参考。     

金银花中绿原酸提取工艺的研究

以金银花为原料,采用乙醇为提取剂,提取了金银花中的绿原酸。通过正交试验优化了金银花中绿原酸的提取工艺,结果表明最佳工艺条件是：浸提温度为60℃,料液比为1：25,乙醇浓度为60%,浸提时间为45min,pH为7。在此条件下,绿原酸的得率为5.117mg/g。     

“青大1号”紫花苜蓿叶蛋白提取条件优化

为了开发新的食用蛋白质资源,本试验以“青大1号”紫花苜蓿新品系青干草为原料,采用酸化加热法配合加盐法提取叶蛋白.单因素试验设计,分别考察料水比、加盐量、絮凝时间、pH、预浸时间、絮凝温度6个因素对粗蛋白质提取率的影响,并以单因素试验结果为依据,采用四因素（料水比、加盐量、絮凝时间、pH）三水平L9（34）正交试验设计进行提取工艺优化.试验结果表明：影响粗蛋白质提取率的因素,从大到小依次为料液比、絮凝时间、pH、加盐量.当絮凝温度为70℃、料液比为1∶10、加盐量1％、絮凝时间5min、pH为4时是叶蛋白提取的最优提取条件.     

响应面法优化钝裂银莲花花色素提取工艺

以钝裂银莲花(Anemone obtusiloba)的萼片为提取材料,选取料液质量浓度、pH、提取时间、提取温度4个因素,以钝裂银莲花花色素提取液的吸光值为响应面,对钝裂银莲花花色素的提取条件进行优化,用四舍五入法确定了钝裂银莲花花色素提取的最佳工艺为:料液质量浓度70g·mL~(-1),pH 3.8,提取温度61℃,提取时间87min,在此条件下,钝裂银莲花花色素提取液的吸光值可达最佳,为0.154 5。     

响应面分析法优化党参总黄酮提取工艺研究

研究响应面分析法优化党参中黄酮的提取工艺。在乙醇浓度、料液比、提取时间和提取温度4个单因素实验基础上,通过响应面法优化党参中黄酮的提取条件。结果表明,党参黄酮的最佳提取工艺条件为：提取时间68 min,提取温度85℃,乙醇浓度90%,料液比1∶40（g.mL-1）。在此条件下黄酮提取率的实测值为0.839%,理论值为0.834%,两者的相对误差为0.60%,说明采用响应面法优化得到的提取条件切实可行。     

应用响应面试验设计优化酶法提取桑叶中1-脱氧野尻霉素的工艺条件

桑叶中富含的1-脱氧野尻霉素(1-deoxynojirimycin,DNJ)为一种哌啶类生物碱,是α-葡萄糖苷酶的强抑制剂,具有降低餐后血糖、抑制肿瘤转移和抗病毒等作用。应用纤维素酶法提取桑叶中的DNJ,在单因素试验考察纤维素酶的质量浓度、提取液p H值、提取温度、提取时间、料液质量浓度等5个因素对桑叶DNJ提取率影响的基础上,通过响应面法进一步优化得到的最佳提取工艺条件为:提取温度60℃,提取液p H值3.8,料液质量浓度0.017 0 g/m L,纤维素酶质量浓度3.4 mg/m L,提取时间1.0 h。用高效液相色谱测定在此优化工艺条件下桑叶DNJ的提取率为0.095 0%。与传统的水、酸提取桑叶DNJ的方法相比,采用该优化的酶法提取工艺条件桑叶DNJ的提取率显著提高(P0.01),比盐酸提取法提高了20.3%。     

正交试验法优选红金银花中绿原酸提取工艺的研究

为优化红金银花中绿原酸的提取工艺,本研究采用正交试验法设计对红金银花中绿原酸的提取工艺进行优化,考察了不同的提取工艺对金银花中绿原酸提取率的影响。结果显示,正交试验优选出红金银花中绿原酸的提取工艺的最佳条件,即提取时乙醇的用量为药材的10倍,乙醇浓度为75%,提取次数为2次,提取时间为2h。表明研究试验结果可靠,以优化的工艺所得金银花中绿原酸提取率高,有利于大生产。     

恩拉霉素预混剂含量测定方法的改进

对《进口兽药质量标准》中收载的恩拉霉素预混剂的含量测定方法进行了适当的改进，将pH4．0的醋酸盐缓冲液改为pH7．8的磷酸盐缓冲液，将贮备液浓度由1000单位／mL降低为200单位／mL，提取时间延长至2—3h，优化了检测条件，能充分提取样品中的恩拉霉素，使检测数据更准确可靠。     

超声波辅助提取金银花绿原酸的工艺优化

河南封丘金银花种植区是中国最大的金银花产地之一,其金银花产量大、品质优。金银花枝叶及花常因营养丰富和药效价值而被添加到饲料中,具有抗病、增产的效果。为了优化超声波辅助提取金银花中绿原酸的提取工艺,本研究将金银花烘干粉碎之后,按一定的液料比加溶剂浸润,经超声、抽滤、浓缩等处理,借助高效液相色谱检测绿原酸含量。从液料比、乙醇浓度、超声波处理温度等方面通过单因素和正交设计优化,为金银花中绿原酸的提取提供了一定的参考。     

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