驱虫剂氯氰菊酯异构体在戊烷体系中的分离

以高效液相色谱手性固定相法对顺式、反式、高效氯氰菊酯异构体进行了拆分，流动相为正戊烷，分别添加了不同比例的乙醇。实验结果显示，顺式、反式氯氰菊酯的两个对映体可以得到完全分离，分离度分别为2．48和2．28，高效氯氰菊酯的四个异构体也可得到较好的分离。     

异油酸异构体被瘤胃微生物氢化为顺式和反式C18∶1异构体过程研究

顺式和反式C18∶1异构体为反刍动物中脂肪酸转化的中间体,其产生的数量决定动物副产品品质的好坏;然而,顺式和反式C18∶1异构体的生成途径始终不清楚,并且其比例随日粮精粗比变化而变化。本研究旨在追踪异油酸的代谢途径,同位素标记的异油酸与瘤胃混合微生物在不同日粮下共同培养,瘤胃中的主要代谢产物为反式C18∶1,体外培养体系中接种饲喂粗料或精料日粮的山羊瘤胃液,并向该体系中添加[1-13 C]标记的反式-11C18∶1。培养0、5、24h后瘤胃液中富集的13 C脂肪酸通过气相色谱法分析检测,发现在硬脂酸和所有的顺式和反式的C18∶1中异构体均检测到13 C。95%标记13 C的异油酸与精料培养5h后饱和为硬脂酸,粗料为底物的培养体系中有78%的异油酸饱和为硬脂酸。结果表明,大多数异油酸被饱和为硬脂酸,部分被异构化为顺式和反式C18∶1异构体,尤其是饲喂粗料的反刍动物体内。     

HPLC法测定磷酸替米考星可溶性粉中替米考星含量的研究

建立了磷酸替米考星可溶性粉中替米考星含量的HPLC测定方法。采用高效液相色谱(HPLC)法,使用十八烷基硅烷键合硅胶为填充剂的色谱柱,以水∶乙腈∶磷酸二丁胺缓冲液∶四氢呋喃(805∶115∶25∶55)为流动相,流速1.0 mL/min,检测波长280 nm,柱温25℃。按外标法以峰面积计算含量。在此色谱条件下,替米考星顺式、反式异构体峰分离度良好,磷酸替米考星可溶性粉的线性范围为0.2~0.8 mg/mL(R 2=0.9998),平均回收率为97.96%,RSD<1.0%。本研究建立的方法分离效果好、精密度高、稳定性好,可作为磷酸替米考星可溶性粉的质量关键控制指标。     

HPLC法测定磷酸替米考星可溶性粉中有关物质的研究

建立HPLC法测定磷酸替米考星可溶性粉中的有关物质。采用C18柱(250 mm×4.6 mm, 5μm)色谱柱,以水-磷酸二丁胺溶液=975∶25为流动相A,以乙腈为流动相B,进行梯度洗脱,流速为1.1 mL/min,检测波长280 nm,进样量10μL。在拟定的色谱条件下,磷酸替米考星可溶性粉中反式异构体是两个不完全分开的峰,顺式异构体与顺-8差向异构体主色谱峰与相关的杂质完全分离,制剂中的辅料对主成分及有关物质测定无干扰;4家企业11批样品单个杂质与各杂质的和分别小于3.0%和9.0%。说明该方法可用于磷酸替米考星可溶性粉有关物质的质量控制。     

高效液相色谱法测定饲料中替米考星含量

本实验建立了测定饲料中替米考星含量的高效液相色谱(HPLC)检测方法。将2g饲料样品,经乙腈、乙腈-磷酸二氢钾缓冲液提取后过C18萃取柱净化、蒸干、流动相溶解后进行HPLC检测分析。流动相检测波长为290nm,流速1.0mL/min。结果表明:在1～500μg/mL的浓度范围内替米考星的峰面积(顺式和反式异构体的峰面积之和)与浓度呈良好的线性关系(r=1),平均回收率为81.4%以上,RSD小于6.1%,检测限为1μg/g。     

替米考星含量测定方法的改进研究

建立了高效液相色谱法测定替米考星原料及其制剂的中替米考星的含量。采用C18色谱柱（4.6mm×250mm，5μm），以10%三氟乙酸-乙腈（65-35）为流动相，流速1.0 mL/min，进样量10 μL，检测波长为280 nm，柱温30℃。结果表明，当替米考星浓度为0.01～2.0 mg/mL时，替米考星顺式峰和反式峰面积和与浓度线性关系良好（R2=0.9998），无杂质干扰，重复性、稳定性和精密度的相对标准偏差＜0.8%，检出限为0.8 μg/mL，替米考星顺式峰和反式峰的分离度符合规定，顺-8-差向异构体能够实现良好分离。该方法操作简便，准确度高，重复性好，提高了替米考星及其制剂质量控制的检测效率，为其质量标准的改进提供了依据。     

共轭亚麻酸的异构体-十八碳-顺8,反10,顺12-三烯酸中的反-10,顺-12二烯体并不具有降低体脂的特性

共轭亚麻酸(CLNA)是一组包含多种位置和构象的顺式和反式异构体。本试验旨在研究高脂肪日粮条件下,十八碳-顺8,反10,顺12-三烯酸作为CLNA的一种异构体在降低老鼠体脂和激活过氧化物酶体增殖物激活受体(PPARα和PPARγ)的潜能。研究结果表明,CLNA并不改变脂肪组织重量,也不影响脂蛋白酯酶、乙酰基辅酶A氧化酶和肉碱棕榈-Ⅰa的基因表达,但降低了PPARα和PPARγ的表达,且CLNA并不能够激活这些转录因子。因此,尽管十八碳三烯酸中存在二烯体反-10,顺-12,但它并不具有降低体脂的特性,有可能是因为第一个顺式双键位于第八碳原子上。而且不像CLNA的其他异构体,比如石榴油酸和α-桐酸,十八碳-顺8,反10,顺12-三烯酸并不能够激活PPARα和PPARγ。     

共轭亚油酸的免疫调节功能概述

共轭亚油酸(Conjugated Linoleic Acid,CLA)是亚油酸的位置异构体和结构异构体的总称,其共轭双键通常位于C9和C10位或C10和C12位,每个双键可以以顺式或反式构型存在.自1978年Pariza等[1]在研究烤牛肉过程中诱变剂的形成时发现共轭亚油酸具有抗癌特性后,在国内外相继报道了CLA的抗癌、抗动脉粥样硬化、降脂和增强免疫等生物学功能.在畜禽业上,许多实验证明CLA具有降低动物机体脂肪、促进蛋白质沉积、增强免疫力、改善畜禽肉品品质等营养生理作用.本文着重阐述CLA的的免疫调节作用.……     

雪糕中16种反式脂肪酸的测定

建立气相色谱测定雪糕中反式脂肪酸含量的方法.2.0 g雪糕样品中加入8 mL浓盐酸和10 mL无水乙醇进行前处理,经SP-2560毛细管色谱柱分离,气相色谱仪-氢火焰离子化检测器检测,面积归一化法计算组分含量.结果表明:在优化的色谱条件下,方法的检出限和定量限分别为0.012％和0.024％;实现了反式脂肪酸甲酯与顺式...     

β-胡萝卜素的营养

β -胡萝卜素 (β -Ｃ)是畜禽维生素Ａ的重要来源 ,主要分布于植物和细菌体内的光合作用器官中 ,动物体内不能合成 β -Ｃ(Ｈａｒｏｌｄ等 ,1 997)。自然界中的β -Ｃ有全反式 β -Ｃ、9-顺式 β -Ｃ、1 3-顺式 β -Ｃ和 1 5-顺式 β -Ｃ等几种异构体(Ｃｈａｎｄｌｅｒ和Ｓｃｈｗａｒｔｚ,1 987)。饲料或食物中的 β-Ｃ除了可以作为维生素Ａ源转化成维生素Ａ满足动物对维生素Ａ的需要外 ,还具有许多独特的营养生理功能。它是动物体内一种重要的生理性抗氧化剂 ,能有效地猝灭单线态氧 (1 Ｏ2 )、羟自由基 (ＨＯ- )、超氧根阴离子 (Ｏ- )等多…     

3-D Confocal Laser Scanning Microscopy used in Morphometric Analysis of Rat Purkinje Cell Dendritic Spines after Chronic Ethanol Consumption

A confocal laser scanning microscope (with a 543 nm laser) was used for imaging rat Purkinje cell dendritic spines at high 3-D resolution. In a nutritionally controlled study of the rat, 5 months of ethanol consumption was demonstrated to alter the spines of Purkinje cell dendrites in rat cerebellum. Intact spines showed significant elongation after ethanol exposure, whereas this neuromorphological alteration could not be detected in controls. Spine elongation could be regarded as compensative growth of spines in search of new synaptic contacts due to alcohol induced cell loss.     

The oral bioavailability of ibuprofen enantiomers in broiler chickens

Doses of racemic ibuprofen ranging from 5 to 20 mg/kg body weight were administered intravenously (i.v.) and orally to broiler chickens and plasma concentration-time profiles for both ibuprofen enantiomers were determined. The absorption of ibuprofen was evaluated after a bolus administration of a commercially available suspension into the crop and proventriculus, respectively. An enterohepatic circulation as described for other nonsteroidal anti-inflammatory drugs (NSAIDs) in other species could be suggested for both enantiomers after i.v. and oral administration. Significantly higher area under the curve (AUC) values for S(+)-ibuprofen compared with R(-)-ibuprofen were collected after crop and proventriculus administration. Several factors could be responsible for the significant differences in AUC values between both enantiomers.     

Pharmacokinetics of carprofen enantiomers in equine plasma and synovial fluid – a comparison with ketoprofen

Carprofen is a Non Steroidal Anti-Inflammatory Drug (NSAID) which is widely used for the treatment of musculoskeletal disorders in horses. The commercial preparation is a racemic mixture of two enantiomers (R and S carprofen). We used HPLC to measure plasma and synovial fluid R and S carprofen concentrations following a single intravenous (i.v.) dose, and computer modelling to determine the pharmacokinetic parameters of the enantiomers in these two body fluids. A comparison was made with results from an identical experiment using ketoprofen. The plasma elimination half lives of R and S carprofen were 20 and 16 times longer than those of R and S ketoprofen, and clearance was considerably slower for carprofen than ketoprofen. Plasma R carprofen concentrations were higher than S carprofen concentrations throughout the 48-h period. Ketoprofen was no longer detectable in synovial fluid after 5 h (S enantiomer) or 12 h (R enantiomer), whereas synovial fluid carprofen concentrations did not peak until 12 h and were still detectable at 48 h. Synovial fluid concentrations of both carprofen enantiomers were significantly lower than plasma concentrations, probably due to high plasma protein binding which could limit transfer through the synovial membrane. Our results indicate significant differences between carprofen and ketoprofen and between the two carprofen enantiomers.     

乙醇激活诱导小鼠孤雌胚的发育与核型分析

注射ｈＣＧ１８～１９ ｈ 后收集的小鼠卵母细胞, ８５ ％ 以上可为乙醇所激活, 产生均质单倍体、嵌合单倍体、１ 个原核的杂合二倍体和２ 个原核的杂合二倍体４ 种激活类型, 且它们的比率分别为８１－４ ％ 、１０－５ ％ 、４－６ ％ 和３－５ ％ 。单倍体胚胎体外培养后有少数可发育至囊胚期。单倍体孤雌胚在８ 细胞期开始出现二倍体核型, 从而形成单倍体胚胎、单倍体 二倍体嵌合胚和二倍体胚胎。孤雌胚的核型中还出现较高比率的非整倍体。     

A comparison between ethanol-induced chemical ablation and ivermectin plus prednizolone in the treatment of symptomatic esophageal spirocercosis in the dog: a prospective study on 14 natural cases

This study included a total of 14 dogs with spontaneous esophageal spirocercosis. Historical and clinical evidence of esophageal dysphagia, detection of parasitic ova in fecal samples and endoscopic documentation of esophageal nodules were the inclusion criteria. The animals were randomly assigned into two groups: group A (n = 6 ) dogs received two intranodular injections of absolute ethanol (96%) via a through-the-endoscope injector, at weekly intervals; group B (n = 8) dogs were put on ivermectin (600 microg/kg BW, subcutaneously, twice, 14 days apart) and oral prednisolone (0.5mg/kg BW, every 12h, for a total of 3 weeks, tapering the dose accordingly). Clinical and fecal examination as well as endoscopy, were performed on admission and at 20, 60 and 180 days from the beginning of the treatment. One group A dog responded poorly and died of pyothorax during the trial and another developed esophagitis due to accidental intraluminal ethanol infusion, only to experience an uneventful recovery. At different times during the 6-month follow-up period, there was a complete disappearance of the clinical signs in 4/6 group A dogs. However, full nodular regression was achieved only in one dog, and parasitic ova were still found in the feces of 4/6 dogs. At the same period of time in five group B dogs still available for evaluation, resolution of the clinical signs and complete nodular regression were seen in four and five animals, respectively, while negative fecal results were obtained in all dogs (8/8) of the same group 2 months from the beginning of the treatment. No significant difference was found between the groups, regarding the resolution of clinical signs, though group B dogs demonstrated a significantly higher rate of regression of esophageal nodules as well as negative fecal results, compared to group A dogs. The combination of ivermectin and prednizolone may be considered an effective treatment in the symptomatic and evidently asymptomatic esophageal spirocercosis of the dog.     

正交试验优选鸡血藤总黄酮提取工艺

为对鸡血藤总黄酮的提取工艺方法进行优化选择,以单因素考察为试验基础,选用四因素三水平的正交试验方案,对乙醇浓度、提取时间、提取温度、料液比四个因素对鸡血藤总黄酮提取率的影响进行了研究。结果表明:试验条件范围内鸡血藤总黄酮的最佳提取工艺为:乙醇提取液浓度60%、提取温度70℃、提取时间2.5 h、提取料液比1:20,此条件下鸡血藤总黄酮的提取率为34.90%。同时试验分析结果表明,四个影响因素中提取时间对提取率影响最大。综上,此提取工艺方法绿色、简单,可为鸡血藤在饲料添加剂中的应用提供参考。     

Enantiospecific pharmacokinetics of ketoprofen in plasma and synovial fluid of horses with acute synovitis

Pharmacokinetic parameters were established for enantiomers of the nonsteroidal anti-inflammatory drug (NSAID) ketoprofen (KTP) administered as the racemic mixture at a dose of 2.2 mg/kg and as separate enantiomers, each at a dose of 1.1 mg/kg to a group of six horses (five mares and one gelding). A four-period cross-over study in a LPS-induced model of acute synovitis was used. After administration of the racemic mixture S(+)KTP was the predominant enantiomer in plasma as well as in synovial fluid. Unidirectional inversion of R(-) to S(+)KTP was demonstrated but the inversion was less marked than previously reported. It is suggested that this reduction could be because of the influence of the inflammatory reaction on hepatic metabolism. The disposition of KTP enantiomers after administration of the racemic mixture was similar to those observed after administration of S(+) and R(-)KTP. The S(+) and R(-)KTP concentrations in synovial fluid were low and short lasting. After administration of R(-)KTP significant concentrations of the optical antipode were detected in synovial fluid.     

猪毛蒿醇提物最佳提取工艺条件研究

[目的]研究菊科植物猪毛蒿醇提物的最佳提取工艺条件。[方法]采用冷凝管回流提取法,以乙醇作为提取溶剂,以提取温度、乙醇浓度、料液比、提取时间为关键提取条件,采用四因素三水平设计正交试验,根据提取物得率确定猪毛蒿醇提物的最佳提取工艺。[结果]分析方差和极差R值表明,4个因素对猪毛蒿醇提物得率影响的主次顺序是：提取温度>乙醇浓度>提取时间>料液比;提取温度对提取物得率影响差异极显著（P<0.01）,是影响猪毛蒿乙醇提取效果的主要因素,乙醇浓度、料液比、提取时间对提取物得率影响差异不显著（P>0.05）,是影响提取效果的次要因素。确定猪毛蒿有效成分的醇提物最佳提取工艺条件是：乙醇浓度65%,料液比1∶7,提取温度75 ℃,提取时间3.0 h。[结论]在实验室条件下,确定了猪毛蒿醇提物的最佳提取工艺条件,为猪毛蒿提取物及其生物活性成分的进一步研发与应用提供了参考。     

Use of bacitracin in the prevention and treatment of experimentally-induced idiopathic colitis in horses.

Ten healthy ponies from a single herd were found by repeated fecal culture to be free of Salmonella species and Clostridium cadaveris. In a preliminary study, four ponies administered a single oral dose of 10 mg/kg lincomycin did not develop idiopathic colitis when the drug was administered alone. Four other ponies were administered 10 mg/kg lincomycin by stomach tube together with 0.45 L of colonic content from a horse with idiopathic colitis induced earlier by lincomycin alone. Two of the four ponies were treated with 25 g oral zinc bacitracin premix (110 g/kg active ingredient) 24 h later. Forty-two hours after inoculation the two untreated ponies had severe signs of idiopathic colitis and were euthanized. Postmortem findings were typical of idiopathic colitis. The two treated ponies had milder illness but the more severely affected was also euthanized; the other was retreated at 42 h with bacitracin pre-mix and again 12 h later. Its illness and diarrhea resolved over the next 24 h. Clostridium cadaveris was isolated in large numbers from the cecum of the euthanized ponies and their cecal content contained mouse lethal and guinea pig dermonecrotic, but not cytotoxic, activity. Enterotoxins of Clostridium perfringens and Clostridium difficile could not be demonstrated. No toxin could be demonstrated in culture supernatants of C. cadaveris or in supernatants of cecal contents treated with ethanol prior to culturing in anaerobically incubated broth. No Salmonella spp. were isolated. A further two ponies were administered 10 mg/kg lincomycin orally with 0.45 L colonic content from a horse with idiopathic colitis, as described.(ABSTRACT TRUNCATED AT 250 WORDS)     

The influence of cimetidine on the pharmacokinetics of the enantiomers of verapamil in the dog during multiple oral dosing

The disposition of intravenously (0.5 mg/kg) and orally (5 mg/kg) administered verapamil was studied in six dogs after 3 days' pre-treatment with verapamil alone (5 mg/kg, every 8 h) and during concomitant oral administration of cimetidine (16 mg/kg, every 8 h). Racemic verapamil and norverapamil, an active metabolite of verapamil, were measured by fluorescence high performance liquid chromatography using an achiral phenyl column. The isolated racemic verapamil was rechromatographed on an Ultron-OVM chiral column, which separated the two verapamil enantiomers. Cimetidine co-administration significantly reduced the systemic clearance of racemic verapamil as well as that of its enantiomers by 25–29%. The clearance of racemic verapamil administered orally as well as that of its enantiomers was also reduced by 28% during cimetidine coadministration. The decrease in verapamil metabolism by cimetidine appeared to be non-stereoselective. On the other hand, cimetidine co-administration had no significant effect on the apparent volume of distribution of racemic verapamil and its enantiomers or the plasma protein binding or the blood to plasma concentration ratio of racemic verapamil. In addition, the ratio of the area under the plasma concentration-time curve for norverapamil to that of verapamil was unaffected by cimetidine co-administration. These results suggest that cimetidine alters the disposition of verapamil by decreasing the hepatic blood flow rate and by inhibition of its first-pass metabolism.