牛磺熊去氧胆酸的合成进展

牛磺熊去氧胆酸是由熊去氧胆酸的羧基和牛磺酸的氨基之间缩水而形成的结合型胆汁酸。主要介绍了目前四种牛磺熊去氧胆酸合成方法,并对四种方法的优缺点进行了全面的评价,从而为牛磺熊去氧胆酸的合理开发和利用提供思路。     

三株梭菌通过生物转化形成熊去氧胆酸的研究

用改进的薄层层析法定量测定了三株厌氧梭菌——产气荚膜梭菌(Clostridium perfr-ingens)HS-10、丁酸梭菌(C.butyrium)DL-20和LQ-29形成熊去氧胆酸(UDCA)的生物转化能力,并用正交法确定了HS-10菌株的最佳转化条件。发现该菌株在含O．2mmol／L鹅去氧胆酸(CDCA)的RCM培养基中培养6-48小时内,UDCA转化率均在80％以上。而且,当CDCA的浓度高达0．8-1．0 mmol／L时,其转化率仍在70％以上。此外,还初步发现未加任何营养成分的豆腐废水也可作为良好的转化培养基。本文是这两种菌能单独将CDCA 转化为UDCA的首次报道。     

薄层色谱法定量测定血清中游离胆固醇

讨论了应用硅胶G-CMCNa薄层色谱分离测定血清中游离胆固醇的实验条件。采用石油醚-乙酸乙脂-冰醋酸(80∶20∶1)为展开体系,硫酸香草醛为显色剂,在选定的测定条件下,胆固醇含量与峰面积在80ng—700ng范围内线性良好。板内,板间变异系数分别为2.4％和7.4％,平均回收率为101.6％。该方法准确,快速,经实验观察和临床应用获得较好结果。     

薄层荧光扫描法测定花生茎中白藜芦醇的含量

本文采用薄层荧光扫描法测定花生茎中白藜芦醇含量,以氯仿-乙酸乙酯-甲酸(8∶2∶0.35)为展开剂,狭缝尺寸为3 mm×0.45 mm,在335 nm处进行扫描测定。结果表明:白藜芦醇在46.4~104.4 ng范围内线性关系良好,回归方程为:Y=7.446X 2890.328相关系数R为0.9970。该法简便,快速,精密度高,平均回收率为103.46%,相对标准偏差为0.66%(n=3)。     

顶空气相色谱法测定熊去氧胆酸中3种有机溶剂残留量

目的:建立顶空气相色谱法同时测定熊去氧胆酸原料药中3种有机溶剂残留量的方法。方法:用0.25 mol·L-1的氢氧化钠溶液溶解样品,采用顶空进样-气相色谱法,应用FID检测器,在DB-WAX毛细管色谱柱(30.0 m×320μm×1.0μm)上程序升温(起始温度70℃,保持5分钟,再以15℃·min-1的升温速率升至180℃,保持5分钟),载气为氮气,进样口温度200℃,检测器温度230℃。结果:待测组分均能得到有效分离,各组分在所考察的浓度范围内线性关系良好,r=0.9976~0.9996,平均回收率为91.00%~99.09%。结论:本方法可准确测定熊去氧胆酸原料药中丙酮、乙醇及N,N-二甲基甲酰胺的残留量,操作简便、准确度和灵敏度高,可达到有效控制其质量的目的。     

牛磺熊去氧胆酸抑制两种病毒的研究

熊胆汁是自古就被用于消炎祛火的重要中药。牛磺熊去氧胆酸(tauroursodeoxycholic acid,TUDCA)为熊胆汁的主要成分,人胆汁中也有低水平的存在。为了探究TUDCA对儿童手足口病重要病原体柯萨奇病毒A16型(coxsackievirus A16,CVA16)是否有抑制作用,在病毒感染不同阶段加入TUDCA处理,通过MTT法、流式细胞术等技术检测CVA16感染的细胞存活率以及TUDCA对人横纹肌肉瘤细胞(rhabdomyosarcoma cell,RD)内吞效率的影响。结果发现,TUDCA在病毒吸附进入阶段抑制CVA16感染细胞,但不影响宿主细胞的内吞活性。研究还发现TUDCA能在病毒入侵阶段抑制水泡口炎疱疹病毒(vesicular stomatitis virus,VSV)的感染,这提示TUDCA的抗病毒作用不具有特异性。本研究发现了TUDCA抑制CVA16和VSV病毒感染这一新用途,为抗手足口病和口炎疱疹药物的研发提供了新的思路和方案。     

鹅去氧胆酸对多囊卵巢综合征大鼠内分泌状态及胰岛功能的影响CSCD

目的 探索鹅去氧胆酸（CDCA）对多囊卵巢综合征（PCOS）大鼠内分泌功能及胰岛功能的影响,为进一步完善PCOS的临床治疗提供基础。方法 选取30只SPF级SD大鼠为研究对象,分为对照组（5只）和模型组（25只）,模型组大鼠使用来曲唑—羧甲基纤维素钠混悬液灌胃构建大鼠PCOS模型,造模成功后将模型组大鼠分为PCOS组和PCOS+CDCA组。PCOS组继续予以来曲唑—羧甲基纤维素钠混悬液灌胃,PCOS+CDCA组在PCOS组基础上予以0.3 mL 0.25%鹅去氧胆酸钠灌胃。并在饲养第21天及饲养第42天,采用HE染色观察模型组大鼠的卵巢形态;获取大鼠的尾静脉血,检测其血清睾丸素水平、空腹血糖、空腹胰岛素及炎症因子水平,计算胰岛素抵抗指数的稳态模型评估（HOMA-IR）和β细胞功能的稳态模型评估（HOMA-β）指数;收集模型组大鼠的粪便分析肠道菌群中大肠埃希菌、变形杆菌、链球菌及革兰阳性杆菌的占比。采用Spearman相关性分析评估模型组大鼠肠道菌群与其卵巢囊性卵泡数量、血清睾丸素、HOMA-IR、HOMA-β、肿瘤坏死因子-α(TNF-α)及白介素-6(IL-6)的相关性。结果 模型组大鼠的囊性卵泡数量、血清睾丸素、HOMA-IR水平均显著高于对照组,HOMA-β水平显著低于对照组（均P<0.05）,血清炎症因子水平显著高于对照组（均P<0.05）。PCOS组大鼠的血清睾丸素、HOMA-IR及炎症因子水平显著高于PCOS+CDCA组大鼠,而HOMA-β水平显著低于PCOS+CDCA组大鼠（均P<0.05）。PCOS组大鼠肠道大肠埃希菌比例呈显著上升趋势,而变形杆菌、链球菌及革兰阳性杆菌比例呈显著下降趋势（均P<0.05）。在CDCA的作用下,PCOS+CDCA组大鼠肠道大肠埃希菌比例升高趋势显著减缓,变形杆菌、链球菌及革兰阳性杆菌比例下降趋势显著减缓（均P<0.05）;干预后PCOS+CDCA组大鼠的肠道大肠埃希菌占比显著低于PCOS组大鼠,而变形杆菌、链球菌及革兰阳性杆菌比例均显著高于PCOS组大鼠（均P<0.05）。PCOS组大鼠中,大肠埃希菌占比与囊性卵泡数量、血清睾丸素、HOMA-IR、TNF-α、IL-6均呈正相关,HOMA-β呈负相关（均P<0.05）;变形杆菌、链球菌及革兰阳性杆菌的占比与囊性卵泡数量、血清睾丸素、HOMA-IR、TNF-α、IL-6均呈负相关,与HOMA-β呈正相关（均P<0.05）。在PCOS+CDCA组大鼠中,大肠埃希菌占比与囊性卵泡数量、TNF-α均呈正相关（均P<0.05）,变形杆菌占比与血清睾丸素呈负相关（P<0.05）。结论 CDCA可以在一定程度上缓解PCOS大鼠的内分泌紊乱、胰岛素抵抗及机体炎症水平,而这些疾病状态的改变与肠道菌群的调节具有显著的相关性。     

薄层色谱-荧光分光光度法测定淫羊藿药材中淫羊藿苷的含量

目的 :建立了薄层色谱 荧光分光光度法测定淫羊藿药材中淫羊藿苷的含量。方法 :用 70 %乙醇水浴回流提取 ,用醋酸丁酯 甲酸 水 (1.3∶1∶1)在 10℃以下放置后的上层溶液为展开剂 ,展开 ,分离淫羊藿苷 ,在Ex=4 30nm ,Em=4 80nm条件下测定荧光强度。结果 :线性范围为 0 .8～ 4 .8μg ,相关系数r =0 .9973,平均回收率 97.4 8%。结论 :此法简单、灵敏、准确 ,重现性好。     

The Enzymic and Chemical Synthesis of Ursodeoxycholic and Chenodeoxycholic Acid from Cholic Acid

Three approaches to the synthesis of ursodeoxycholic acid (UDC) from cholic acid have been investigated: (i) oxidation of cholic acid to 3α,7α-dihydroxy-12 keto-5β-cholanoic acid (12K-CDC) with Clostridium group P 12α-hydroxysteroid dehydrogenase (HSDH), isomerization of 12K-CDC to 3α, 7β-dihydroxy-12 keto-5β-cholanoic acid (12K-UDC) with Clostridium absonum 7α- and 7β-HSDH and reduction of 12K-UDC by Wolff-Kishner to UDC; (ii) isomerization of cholic acid to ursocholic acid (UC) by C. absonum 7α- and 7β-HSDH, oxidation of UC to 12K-UDC with Clostridium group P 12α-HSDH and Wolff-Kishner reduction of 12K-UDC to UDC; (iii) oxidation of cholic acid to 12K-CDC by Clostridium group P 12α-HSDH, Wolff-Kishner reduction of 12K-CDC to chenodeoxycholic acid (CDC) and isomerization of CDC to UDC using whole cell cultures of C. absonum. In the first two approaches (using cell free systems) the yields of desired product were relatively low primarily due to the formation of various side products. The third method proved the most successful giving an overall yield of 37% (UDC) whose structure was verified by mass spectroscopy of the methyl ester.     

薄层层析指导下的嗜碱放线菌菌株YIMGQ-14次生代谢产物研究

在微生物资源的开发研究过程中,利用TLC方法,配合TLC数据库的检索,对嗜碱放线菌菌株YIMGQ14的次生代谢产物进行了研究。并从中分离纯化出两个具有生物活性的专利化合物“Umycin C”和“Umycin B”。结果证明：相对于常规的生物活性筛选,TLC法在微生物次生代谢产物研究中具有快速、简便、经济的特点,适合于小量常规筛选的目的。通过进一步对相关的TLC数据库进行构建和补充,将能极大地改善该方法的使用效率。     

Immunoprecipitation Assay of Alpha-fetoprotein Synthesis by Cultured Mouse Hepatoma Cells Treated with Estrogens and Glucocorticords

This investigation was to study the biosynthesis of ³H-labeled alpha-fetoprotein (AFP) by cultured mouse hepatoma (HEPA-2) cells. Both the function and regulation of this oncodevelopmental gene are unknown. However, evidence indicates that mechanisms controlling the expression of AFP involve aspects of both normal embryonic development and neoplastic transformation. The secretion of AFP was analyzed during different phases of the growth cycle to provide information on AFP production using standard culture conditions. The highest rate of secretion occurred during the stationary phase, followed by the late logarithmic and early logarithmic phases of growth, respectively. The production of AFP was then determined following the addition of glucocorticords and estrogens in an attempt to understand hormonal factors that may be involved. Studies utilizing estradiol-17β indicated that the secretion of AFP did not appear to be sensitive to this steroid even though sucrose density gradient analysis of HEPA-2 cytosol, for estrogenic receptors, revealed competitive binding moieties in the 8S and 4S regions of the gradient. In contrast, the secretion of the total complement of proteins, including AFP, was significantly stimulated by the glucocorticords, dexamethasone and corticosterone. Analysis of HEPA-2 cytosol for glucocorticord receptors revealed binding components in the 7S and 3–4S regions of the gradient. The ³H-dexamethasone binding appeared to be stereospecific since nonlabeled dexamethasone, but not nonlabeled estradiol-17β, effectively displaced the bound radioactivity. The glucocorticoid-binding component in HEPA-2 therefore displayed characteristics reported for glucocorticord receptors in normal liver and other hepatomas.     

HPLC快速测定氨基酸口服液中的L—色氨酸

本文用ＨＰＬＣ直接测定Ｌ—色氨酸,简便快速,波长２８０ｎｍ,线性良好（ｒ＝０．９９９９）,平均回收率：１００．０１％,ｎ＝４,ｃｖ＝０．６０％。     

Glutamic Acid Decarboxylase and γ-Aminobutyric Acid in Huntington''s Disease Fibroblasts and Other Cultured Cells, Determined by a [3H]Muscimol Radioreceptor Assay

A sensitive and reproducible [3H]muscimol radioreceptor assay was developed for measuring low levels of both glutamic acid decarboxylase activity and gamma-aminobutyric acid. By using this technique, endogenous gamma-aminobutyric acid and glutamic acid decarboxylase activity were detected in two rat neuroblastomas, B35 and B50, a human medulloblastoma cell line, TE671, and cultured human skin fibroblasts. Glutamic acid decarboxylase activities and gamma-aminobutyric acid levels were compared for human skin fibroblasts obtained from patients with Huntington's disease and their controls in a well-controlled, blind study. However, no significant difference was found to either measure between Huntington and control cells. Glutamic acid decarboxylase activity was relatively low in all cell types examined except for the TE671 cells, which had more than four times the activity found in the other cells. This human medulloblastoma cell line appears to be a good model for studying gamma-aminobutyric acid metabolism and the control of glutamic acid decarboxylase expression.     

Ascorbic Acid Uptake by a High-Affinity Sodium-Dependent Mechanism in Cultured Rat Astrocytes

Ascorbic acid (vitamin C) is synthesized in rodent liver, circulates in the blood, and is concentrated in the brain. Experiments were performed to characterize the mechanism of ascorbate uptake by rat cerebral astrocytes in primary culture. Astroglial uptake of L-[14C]ascorbate was observed to be both saturable and stereoselective. In addition, uptake was dependent on both the incubation temperature and the concentration of Na+ because it was largely inhibited by cooling to 4 degrees C, by treatment with ouabain to increase intracellular Na+, and by the substitution of K+, Li+, or N-methyl-D-glucamine for extracellular Na+. The affinity for ascorbate was relatively high in cells incubated with a physiological concentration of extracellular Na+, because the apparent Km was 32 microM in 138 mM Na+. However, the affinity for ascorbate was significantly decreased when the extracellular Na+ concentration was lowered. Treatment of astrocytes with dibutyryl cyclic AMP induced stellation and increased the maximum rate of ascorbate uptake by 53%. We conclude that astrocytes possess a stereoselective, high-affinity, and Na+-dependent uptake system for ascorbate. This system may regulate the cerebral ascorbate concentration and consequently modulate neuronal function.     

Superoxide Dismutase Activity During Dimethylhydrazine Colon Carcinogenesis and the Effects of Cholic Acid and Indole

Copper, zinc superoxide dismutase (Cu, ZnSOD) and manganese superoxide dismutase (MnSOD) activities were measured in mouse large intestinal mucosa during dimethylhydrazine (DMH) carcinogenesis. Mice were divided into five groups. Group A was subcutaneously injected with DMH (20mg/kg) weekly and fed with a diet containing 0.2% cholic acid (C) and 0.8% indole (I). Group B was injected with DMH and given indole feeding. Group C was treated with DMH injection and cholic acid feeding. Group D was given DMH injection alone. Group E was an age-matched control group given 0.9% NaCl injection. The experiment last 21 weeks. The Cu, ZnSOD activity of intestinal mucosa in group A animals began to increase significantly at the 7th week of the experiment. In groups B, C and D, however, this enzyme was not elevated statistically until the 16th week, and then each of these groups kept an increased Cu, ZnSOD level the rest of the experimental period. MnSOD activity was elevated statistically in group C animals at the 7th week. The enzyme activity in group A and D animals increased at the 9th week, but the enzyme activity did not increase statistically until the 11th week in group B. After the 16th week of the experiment the increased activity of MnSOD in all experimental groups returned to the level of the control group. Large intestinal cancer tissues had increased Cu, ZnSOD activity and decreased MnSOD activity.     

Superoxide Dismutase Activity During Dimethylhydrazine Colon Carcinogenesis and the Effects of Cholic Acid and Indole

Copper, zinc superoxide dismutase (Cu, ZnSOD) and manganese superoxide dismutase (MnSOD) activities were measured in mouse large intestinal mucosa during dimethylhydrazine (DMH) carcinogenesis. Mice were divided into five groups. Group A was subcutaneously injected with DMH (20mg/kg) weekly and fed with a diet containing 0.2% cholic acid (C) and 0.8% indole (I). Group B was injected with DMH and given indole feeding. Group C was treated with DMH injection and cholic acid feeding. Group D was given DMH injection alone. Group E was an age-matched control group given 0.9% NaCl injection. The experiment last 21 weeks. The Cu, ZnSOD activity of intestinal mucosa in group A animals began to increase significantly at the 7th week of the experiment. In groups B, C and D, however, this enzyme was not elevated statistically until the 16th week, and then each of these groups kept an increased Cu, ZnSOD level the rest of the experimental period. MnSOD activity was elevated statistically in group C animals at the 7th week. The enzyme activity in group A and D animals increased at the 9th week, but the enzyme activity did not increase statistically until the 11th week in group B. After the 16th week of the experiment the increased activity of MnSOD in all experimental groups returned to the level of the control group. Large intestinal cancer tissues had increased Cu, ZnSOD activity and decreased MnSOD activity.     

一种新的以影像为基础的细胞增殖和细胞毒性检测方法

3-(4,5-二甲基-2-噻唑)-2,5-二苯基溴化四唑盐)（MTT）比色法是传统上检测细胞增殖和细胞毒性的常用方法.
CloneSelectTM成像系统是一种以影像为基础的用于分析细胞生长的可视检测系统.本研究采用人结直肠癌HCT116细胞系,运用CloneSelect成像系统和MTT方法分别检测药物阿的平的细胞毒性,并采用Bland Altman作图法比较两种实验方法获得的pEC50值,分析两种研究方法获得的结果的一致性. 结果表明,CloneSelectTM成像系统和MTT法获得的pEC50值具有较好的一致性.与MTT方法相比,基于影像的CloneSelectTM成像分析技术检测快速、无损伤且结果更准确,获取资料不损伤细胞,允许后续其它时间点或动力学检测. 研究提示,这种新的以影像为基础的检测技术可以替代MTT方法,用于分析不同药物的抗细胞增殖活性.     

Fluorometric Assay of Potential Change of Bombyx mori Midgut Brush Border Membrane Induced by δ-Endotoxin from Bacillus thuringiensis

Bacillus thuringiensis δ-endotoxin, CryIA(a), increased ion permeability of brush border membrane vesicles isolated from midgut epithelia of Bombyx mori larvae. This ion permeability change was measured with a potential-sensitive fluorescent dye, 3,3′-dipropylthiadicarbocyanine iodide. This effect was observed at concentrations of the toxin that correspond to normal effective doses in vivo. CryIA(b) and heat-treat CryIA(a) did not show this effect. CryIA(a) did not show this effect on rat renal brush border membranes. The effects depended on the toxin dose in saturable manner. These suggest that this assay system reflects the mode of action of δ-endotoxin in vivo. The toxin increased various ion permeabilities, suggesting that δ-endotoxin forms non-selective cation pores on brush border membranes.