Renewal of the membrane complex of Schistosoma mansoni is closely associated with lipid metabolism

Metabolic pathways leading to lipid biosynthesis in four different developmental stages of Schistosoma mansoni were explored and quantified by incubation in the presence of labeled precursors in a chemically defined medium. At the schistosomulum stage and in male, female, or paired worms, glycerol and oleate incorporation into neutral lipids, mainly in the form of triacylglycerols, was greater than into phospholipids, whereas in 11-and 15-day-old worms, synthesis mainly led to phospholipids. Incorporation into phospholipids was recovered largely in phosphatidylcholine, and distribution into other phospholipids depended on the developmental stage. Incorporation of choline and ethanolamine into their respective phospholipids represented up to 15% of the parasitic phospholipid content. The formation of phosphatidylcholine by phosphatidylethanolamine methylation occurred mainly in the immature parasitic stages. Inositol incorporation was also measurable, whereas [14C]serine incorporation was low or undetectable. Addition of 1-palmitoyl-2-[14C]oleyl phosphatidylcholine revealed a very high uptake of this phospholipid by the immature stages but further metabolism was not detectable. In contrast, adult S. mansoni were completely unable to take up or absorb this exogenous phospholipid. The most striking aspect of this study was the relatively high metabolic activity in 11-day-old worms and the lower but sustained activity on day 15 and at the schistosomulum stage. By comparison, biosynthetic activity in adult S. mansoni, on which research studies have been focused until now, was very low. We also discuss the participation of lipid metabolism in the constant renewal of the membrane complex which is essential to parasitism by S. mansoni.     

Formation of Regular Hole Pattern in Polymer Films

Ordered macroporous materials recently have attracted much attention. A method that utilizes the condensation of monodisperse water droplets on a polymer solution is proposed for the preparation of honeycomb microporous films. Our results show that it is a general method that can be used for patterning a wide range of polymers. The presence of water vapor and polymer is necessary for the formation of regular holes in films. The formation of hexagonal packing instead of other kinds of packing takes place because the hexagonal packing has the lowest free energy. The formation mechanisms of regular hole pattern and imperfections in the hexagonal packing are proposed.

Hexagonal hole structures in a PMMA film.     

Polyamines in Trichomonas vaginalis

Trichomonas vaginalis was grown in a modified Bushby's medium and putrescine, spermidine and spermine levels were determined in extracts from 24- and 48-h cultures and also in the culture media. All three polyamines were present in T. vaginalis extracts; the putrescine level and putrescine/spermidine ratio were much higher than those reported for other protozoa or for mammalian tissues. There were no significant differences between 24-h and 48-h amine levels per mg protein in these extracts, but amine levels per cell were higher at 24 than at 48 h. The spent culture media had a much higher putrescine content than corresponding uninoculated media and it was concluded that T. vaginalis secreted putrescine into the culture medium.     

The SLC14 gene family of urea transporters

Carrier-mediated urea transport allows rapid urea movement across the cell membrane, which is particularly important in the process of urinary concentration and for rapid urea equilibrium in non-renal tissues. Urea transporters mediate passive urea uptake that is inhibited by phloretin and urea analogues. Facilitated urea transporters are divided into two classes: (1) the renal tubular/testicular type of urea transporter, UT-A1 to -A5, encoded by alternative splicing of the SLC14A2 gene, and (2) the erythrocyte urea transporter UT-B1 encoded by the SLC14A1 gene. The primary structure of urea transporters is unique, consisting of two extended, hydrophobic, membrane-spanning domains and an extracellular glycosylated-connecting loop. UT-A1 is the result of a gene duplication of this two-halves-structure, and the duplicated portions are linked together by a large intracellular hydrophilic loop, carrying several putative protein kinase A (PKA) and -C (PKC) phosphorylation sites. UT-A1 is located in the apical membrane of the kidney inner medullary collecting duct cells, where it is stimulated acutely by cAMP-mediated phosphorylation in response to the antidiuretic hormone vasopressin. Vasopressin also up-regulates UT-A2 mRNA/protein expression in the descending thin limb of the loops of Henle. UT-A1 and UT-A2 are regulated independently and respond differently to changes in dietary protein content. UT-A3 and UT-A4 are located in the rat kidney medulla and UT-A5 in the mouse testis. The widely expressed UT-B participates in urea recycling in the descending vasa recta, as demonstrated by a relatively mild "urea-selective" urinary concentrating defect in transgenic UT-B null mice and individuals with the Jk_null blood group.     

复方延胡索颗粒的制备、质控与初步戒毒作用的研究

目的：研究复方延胡索颗粒的制备、质量控制方法、观察该制剂对吗啡依赖鼠的治疗作用。方法：选用黄芪、延胡索、甘草、远志、酸枣仁、石菖蒲、芸香等七种中药组方制备复方延胡索颗粒,以有效部位部性物碱及有效成分四氢帕马丁的含量作为制备方法的筛选指标及复方延胡索颗粒制的质控指标。总生物碱的含量用非水电位滴定法测定,四氢帕马丁的含量以单波长反射锯齿式薄层扫描外标两点法测定,以该中药制剂治疗吗啡依赖性大鼠自然戒断模型体质量变化百分率作为初步戒毒作用的观察指标。结果：四氢帕马丁在1－6μg范围内线性关系良好（r=0.9992)其仪器精密度、同板精密度良好（RSD＜3．0％）,且在显色后0．5－6h内结果稳定,制剂的加样回收率约为975,复方延胡索颗粒中剂量组（0．6g/kg)和高剂量组（1．2g/kg)对吗啡依赖鼠的体质量下降可产生显治疗作用（P＜0．05,P＜0．01）。结论：本制剂一定剂量可有效控制吗啡身体依赖性大鼠戒断后的体质量下降,对吸毒可能有促进康复的作用。     

A contribution to a new test method for dandruff-inhibiting and “keratolytic” action of drugs

Summary Free cholesterol in lipids from the scalp and hair is predominantly a constituent of epidermal lipids. Therefore, a reduction in cholesterol content induced by a drug indicates a reduction in cell turnover in the epidermis. As, according to the literature, increased cell turnover in the epidermis results in formation of dandruff, a reduction in the proportion of cholesterol should indicate inhibition of the formation of dandruff. Conversely, an increase in free cholesterol should generally indicate a keratolytic effect. So unequivocal an interpretation has not so far been possible in persons with dandruff, as it was not known whether free cholesterol was increased or decreased. In addition, this interpretation was not possible after use of antimicrobial substances, as in vitro investigations had failed to exclude microbial esterification of cholesterol on the scalp. The present investigation has shown that correlation of free cholesterol level with cell turnover is permissible in patients with dandruff, even if antimicrobial drugs are being tested.     

神农心脑康胶囊的研制及临床应用

目的：研究神农心脑康胶囊的制备和质量标准，观察临床治疗冠心病心绞痛的治疗效果。方法：用薄层色谱鉴别麝香、银杏、川芎、淫羊藿的成分，单盲临床观察40例冠心病心绞痛的患者并确定其临床治疗冠心病心绞痛的疗效标准。结果：薄层扫描法可用于鉴别其主药；经临床观察冠心病心绞痛患者，其总有效率达87．5％。结论：制备工艺合理，所得制剂质量可控，治疗冠心病心绞痛疗效显著，且无任何不良反应。     

骨疏灵胶囊的质量标准研究

目的：研究骨疏灵胶囊的质量控制标准。方法：采用薄层色谱法对制剂中的补骨脂、女贞子进行定性鉴别；并利用高效液相色谱法对制剂中的淫羊藿苷进行定量分析，以CH3CN-H2O(30：70)为流动相，流速1．0mL／min，色谱柱为C18柱，检测波长为270nm。结果：补骨脂与女贞子的薄层色谱鉴别专属性强，阴性对照无干扰；淫羊藿苷在0.0968～0.4840μgg范围内线性关系良好(r=0．9999)，平均回收率为97．27％(RSD=1．88％，n=5)。结论：该方法可为骨疏灵胶囊的质量评价提供科学依据。     

薄层扫描法测定妇炎泰胶囊中延胡索乙素的含量

目的建立妇炎泰胶囊中延胡索乙素的含量测定方法。方法采用薄层扫描法测定妇炎泰胶囊中延胡索乙素的含量,以正己烷-氯仿-甲醇(7∶3∶0.5)为展开剂,双波长反射法锯齿扫描,λS=275nm,λR=370nm,狭缝1.2×1.2mm,SX=3。结果线性范围为0.2～1.0μg,r=0.9992,平均回收率为96.7%,RSD为1.92%。结论该方法准确,重现性好,可用于该制剂的质量控制。     

酸克糖颗粒的质量标准研究

目的：建立酸克糖颗粒的质量控制方法。方法：采用薄层色谱法鉴别其所含山茱萸、白芍，薄层扫描法测定其熊果酸的含量。结果：薄层色谱法鉴别专属性强、重现性好。熊果酸的含量测定线性范围为0．24～1．20μg，回归方程Y=7186．3 X-1356.4，相关系数r=0.9972；加样回收率为100．5％，RSD=2．4％(n=5)。结论：方法操作简便、可行，可用于酸克糖颗粒的质量控制。