Effects of bile salt and phospholipid hydrophobicity on lithogenicity of human gallbladder bile

Abstract Increased biliary bile salt and phospholipid hydrophobicity may promote nucleation of cholesterol crystals and gallstone formation. We therefore compared bile salt composition (determined by gas-liquid chromatography) in patients with cholesterol ( n = 35) and pigment ( n = 16) gallstones (group A). Bile salt composition and cumulative bile salt hydrophobicity index were not different between both stone types. Hydrophobicity index or % of individual bile salts did not correlate with cholesterol saturation index or nucleation time. In an additional 21 cholesterol stone patients (group B) biliary bile salt and phospholipid hydrophobicity as determined by high-pressure liquid chromatography did not correlate with cholesterol saturation index or nucleation time. In both group A and group B, cholesterol stone patients with cholesterol crystals in their fresh biles had a higher % deoxycholic acid, a lower % cholic acid and a higher bile salt hydrophobicity index than crystal-negative patients. This study indicates the need for further research on the role of bile salt hydrophobicity in the pathogenesis of gallstones.     

AFM观察囊泡融合法形成支撑磷脂膜的微观形成过程

目的利用原子力显微镜（AFM）观察支撑磷脂膜的微观形成过程。方法冰浴超声法制备磷脂脂质体溶液,囊泡融合法形成人工磷脂双分子层,用AFM进行观察。结果利用AFM观察到磷脂膜的微观形成过程为：脂质体囊泡吸附一脂质体囊泡之间发生黏着,一脂双层之间形成接触点一磷脂囊泡破裂一形成磷脂分子层一磷脂分子层间流动进行融合形成大片磷脂膜。结论AFM可观察磷脂膜的微观形成过程,进而为细胞膜和膜蛋白的功能研究提供基础。     

Leishmaniasis: vaccine candidates and perspectives

Leishmania is a protozoan parasite and a causative agent of the various clinical forms of leishmaniasis. High cost, resistance and toxic side effects of traditional drugs entail identification and development of therapeutic alternatives. The sound understanding of parasite biology is key for identifying novel drug targets, that can induce the cell mediated immunity (mainly CD4+ and CD8+ IFN-gamma mediated responses) polarized towards a Th1 response. These aspects are important in designing a new vaccine along with the consideration of the candidates with respect to their ability to raise memory response in order to improve the vaccine performance. This review is an effort to identify molecules according to their homology with the host and their ability to be used as potent vaccine candidates.     

Studies on the viability and membrane integrity of human spermatozoa treated with essential oil of Trachyspermum ammi (L.) Sprague ex Turrill fruit

The present study aimed at investigating the effects of essential oil of Trachyspermum ammi fruits, an oil-bearing plant of Apiaceae family, on human sperm viability and membrane integrity. Chemical compositions of the oil were analysed by GC-MS. Thirty compounds representing 91.39% of the total oil were identified. The viability and membrane integrity of human spermatozoa were assessed using minimum effective dose (MED) concentration (125 μg ml(-1)) of the oil. Sperm treated with essential oil showed a significant decrease (P < 0.05) in viability assessed by eosin-nigrosin and fluorescence dual staining. Moreover, the treated sperm also showed a significant loss (P < 0.05) of functional mitochondria and antioxidant enzyme, catalase (EC 1.11.1.6, CAT), when compared to control. The cholesterol:phospholipid ratio was also increased (P < 0.05) in treated sperm when compared to control, which is an indicator of loss of binding ability of human spermatozoa to the zona pellucida. The scanning electron microscopic studies demonstrated the loss of membrane integrity in essential oil-treated human spermatozoa, which showed vacuolation, swelling of acrosomal cap, detachment of head portion and tail coiling. Present observations indicate the spermicidal property of essential oil of T. ammi fruits, which could be helpful to develop medicinal preparations as a male contraceptive.     

偏头痛患者血浆溶血磷脂酸及其极性相似总磷脂水平的研究

目的 探讨发作期偏头痛患者血浆溶血磷脂酸(LPA)、溶血磷脂酸极性相似总磷脂(AP)的水平.方法 测定30例偏头痛发作期患者(偏头痛组)与30例健康对照者(对照组)血浆LPA和AP的水平.结果 偏头痛组血浆LPA水平[(4.0±2.7)μmol/L]高于对照组[(2.6±2.3)μmol/L](P<0.05);偏头痛组血浆AP水平[(5.8±2.8)μmol/L]高于对照组[(4.2±2.4)μmol/L](P<0.05).结论 偏头痛发作期患者存在脑组织缺血和血小板活化,易于发生血栓形成,可能是其容易发生缺血性脑卒中的原因之一.     

Engineered peptides for the development of actively tumor targeted liposomal carriers of doxorubicin

Chemotherapy is still the treatment of choice for many types of cancer; but its effectiveness is hampered by dose limiting toxicity. Properly designed delivery systems can overcome this shortcoming by reducing the non-specific distribution and toxicity of chemotherapeutics in healthy organs and at the same time increasing drug concentrations at tumor tissue. In this study, we developed stealth liposomal formulations of doxorubicin (DOX) having a novel stable engineered peptide ligand, namely p18-4, that binds specifically to breast cancer cell line MDA-MB-435 on its surface. The coupling of p18-4 to liposomes was carried out through conventional, post insertion and post conjugation techniques and prepared liposomes were characterized for their size and level of peptide modification. The p18-4 decorated liposomal DOX formulations were then evaluated for their cellular uptake as well as cytotoxicity against the human breast cancer MDA-MB-435 cells. In this context, the effect of coupling technique on the uptake and cytotoxicity of p18-4 liposomal DOX in MDA-MB-435 cells was evaluated. The conventional and post conjugation methods of peptide incorporation were found to be more reliable for the preparation of p18-4 decorated liposomes for active DOX targeting to MDA-MB-435 cells. p18-4 decoration of liposomes by these methods did not have a notable effect on the size of prepared liposomes and DOX release, but increased the uptake and cytotoxicity of encapsulated DOX in MDA-MB-435 cells. The results show a potential for p18-4 decorated liposomes prepared by conventional and post conjugation method for tumor targeted delivery of DOX in breast tumor models.     

GABA-receptor stimulation enhances norepinephrine-induced polyphosphoinositide metabolism in rat hippocampal slices

The effect of gamma-aminobutyric acid (GABA)receptor stimulation on norepinephrine (NE)-induced metabolism of polyphosphoinositides (PIPs) was studied in rat hippocampal slices. Inositol phosphates (IPs), PIPs, and phosphatidic acid were measured. NE induced formation of IPs and phosphatidic acid in a dose-dependent manner with an EC50 of 4.5 microM. GABA, 3-aminopropanesulphonic acid (3APS) and muscimol did not affect PIPs breakdown, but they strongly increased (greater than 100%) PIPs metabolism induced by 1 microM NE. Their action was antagonized by bicuculline (10 microM). We discuss the implications of these findings in hippocampal neurotransmission.     

黄芩苷及其磷脂复合物药效学对比研究——在体鼻黏膜吸收及不同给药途径抗大鼠脑水肿和神经功能损伤对比

目的:对比研究黄芩苷及其磷脂复合物的大鼠在体鼻黏膜吸收情况,并比较黄芩苷磷脂复合物经舌下静脉及鼻腔给药之不同给药途径对脑缺血损伤致大鼠脑水肿和神经功能损伤的影响。方法:通过大鼠在体鼻黏膜吸收试验比较黄芩苷及其磷脂复合物经鼻吸收的差异,采用紫外分光光度法测定0～120 min黄芩苷累计吸收量,并计算其吸收速率常数;采用线栓法制备大鼠大脑中动脉缺血再灌注损伤模型,观察经舌下静脉给药(给药剂量以黄芩苷计为7.5 mg.kg-1)及经鼻给药(给药剂量以黄芩苷计为7.5 mg·kg-1)后黄芩苷磷脂复合物不同给药途径对脑水肿和神经功能评分的防治效果。结果:黄芩苷磷脂复合物大鼠鼻黏膜吸收速率明显大于黄芩苷,其吸收速率常数分别为[(12.2±2.04)×10-3·min-1,(9.60±1.34)×10-3·min-1],且经鼻给药防治脑缺血损伤致大鼠脑水肿和神经功能损伤的效果优于舌下静脉给药,其神经功能评分结果分别为(1.66±0.68)分和(1.78±0.78)分;脑组织含水量分别为(79.10±0.65)%和(79.48±0.76)%。结论:黄芩苷制备成磷脂复合物后体内吸收及药效优于黄芩苷,且经鼻给药优于舌下静脉给药。     

Effect of diisopropanolamine upon choline uptake and phospholipid synthesis in Chinese hamster ovary cells.

Aminoalcohols differ in mammalian toxicity at least in part based upon their ability to alter the metabolism of phospholipids and to cause depletion of the essential nutrient choline in animals. This study examined the incorporation of diisopropanolamine (DIPA) into phospholipids (PLs) and effects of DIPA upon choline uptake and phospholipid synthesis in Chinese hamster ovary (CHO) cells. Results were compared to those of a related secondary alcohol amine, diethanolamine (DEA), whose systemic toxicity is closely associated with its metabolic incorporation into PLs and depletion of choline pools. DIPA caused a dose-related inhibition of (3)H-choline uptake by CHO cells that was approximately 3-4 fold less potent, based upon an IC50, than that reported for DEA. DIPA, in contrast to DEA, did not cause changes in the synthesis rates of (33)P-phosphatidylethanolamine, (33)P-phosphatidylcholine or (33)P-sphingomyelin at either non-toxic or moderately toxic concentrations. Only approximately 0.004%, of administered (14)C-DIPA was metabolically incorporated into PLs, over 30-fold less than the incorporation of (14)C-DEA under similar conditions. Overall, these data and previous pharmacokinetic and toxicity data obtained in vivo suggests that DIPA is distinct from DEA and lacks significant choline and PL metabolism related toxicity in animals.     

药用豆磷脂的HPLC法测定

本文报告了用HPLC法对药用豆磷脂进行定性定量分析。作者选用硅胶为固定相,以正己烷-异芮醇-醋酸盐缓冲液(pH5.8)(7.5:8:1)为流动相,紫外检测波长206nm,使得磷脂酰胆碱(PC),磷脂酰乙醇胺(PE),溶血磷脂酰胆碱(LPC),磷脂酰肌醇(PI)和磷脂酸(PA)获得满意分离,并对主成分PC进行了含量测定,平均回收率为99.8%,方法的变异系数为0.8%.