Molecular weight and quaternary structure of ribulose bisphosphate carboxylase from the cyanobacterium,Synechococcus sp.

Inhibition of photosynthetic growth of Rhodopseudomonas capsulata by metronidazole was dependent on the nitrogen supply in culture solutions. Cultures fixing dinitrogen were more susceptible to inhibition by low concentrations than those supplied with NH ₄ ⁺ . Light-dependent C₂H₂ reduction and H₂ production by washed cells were inhibited by 80% and 60% respectively by 1 mM metronidazole. When this compound was first reduced with H₂-palladised asbestos prior to assay, it only partially restricted C₂H₂ reduction in washed cells (33%) compared with unreduced inhibitor (68%). Metronidazole was without effect on other metabolic functions. Thus, even at 40 mM it did not inhibit either (a) dark or light respiration in cells grown under photo- and chemo-heterotrophic conditions; (b) H₂-dependent photoreduction of ¹⁴CO₂; (c) -glutamyltransferase activity of glutamine synthetase in cell-free extracts (25 mM inhibitor).Metronidazole (1 mM) completely inhibited C₂H₂ reduction by washed cells of Azotobacter vinelandii. The dithionite-dependent C₂H₂ reduction of a partially purified nitrogenase was only partially inhibited (30%) by 1 mM metronidazole.     

Alkaline and acid phosphatase in the intestines of rats infected with a virulent strain of Entamoeba histolytica and treated with emetine and Flagyl

The distribution patterns of alkaline phosphatase (EC 3.1.3.1) and acid phosphatase (EC 3.1.3.2) in the intestine of rats inoculated intracaecally with a virulent strain of Entamoeba histolytica and treated with emetine hydrochloride and metronidazole (Flagyl) were studied. The caecum and the large intestine showed a highly significant increase in alkaline phosphatase activity after amoebic inoculation, and the enhanced activity was lowered by emetine and Flagyl treatment. There was no significant increase in acid phosphatase activity either in the caecum and the large intestine or in the small intestine (ileocaecal end). Intracaecal inoculation of bacterial associates alone from E. histolytica cultures did not produce any significant change in the level of these enzymes in the intestine.     

Helicobacter pylori disulphide reductases: role in metronidazole reduction

Disulphide reductases play an important role in maintaining intracellular redox potential. Three disulphide reductase activities were identified in Helicobacter pylori, which used dithiobis-2-nitrobenzoic acid, glutathione or l-cystine and ferredoxin as substrates. The kinetic parameters of these activities were determined and it was demonstrated that the reductase activities were inhibited by the presence of metronidazole. Substrate competition experiments served to show inhibition of metronidazole reduction by dithiobis-2-nitrobenzoic acid, glutathione and ferredoxin in lysates from metronidazole susceptible and resistant matched pairs of strains. The study demonstrated that the activities of three disulphide reductases were modulated by the presence of metronidazole, and that metronidazole reduction was inhibited by the presence of disulphide reductase substrates.     

双唑泰泡腾片与乳酸杆菌活菌胶囊联合治疗细菌性阴道病的临床疗效分析

本文旨在探讨双唑泰泡腾片与乳酸杆菌活菌胶囊联合治疗细菌性阴道病的临床疗效.将100例就诊于江苏省中西医结合医院妇产科的细菌性阴道病患者随机平均分为两组:治疗组给予阴道内放置双唑泰泡腾片与乳酸杆菌活菌胶囊联合治疗;对照组单用阴道内放置双唑泰泡腾片.药物剂量、治疗时间相同.结果显示,治疗组细菌性阴道病48例(失访2例),3...     

定君生联合甲硝唑治疗滴虫性阴道病的临床疗效观察

目的 通过定君生联合甲硝唑以及单独用药治疗滴虫性阴道病的临床疗效观察,探讨联合用药对滴虫性阴道病的疗效.方法 选择诊断明确的滴虫性阴道病患者150例,随机分为3组,试验组采用甲硝唑联合定君生的治疗,对照组Ⅰ采用定君生单独用药,对照组Ⅱ采用甲硝唑治疗,观察治疗后的症状、体征、滴虫和阴道的pH的变化.结果 3组患者有效率差异有统计学意义(P＜0.05),起效时间和复发率差异有统计学意义(P＜0.01).结论 定君生联合甲硝唑治疗滴虫性阴道病,疗效好,有利于快速恢复阴道的微生物环境的平衡,降低复发率.     

Diazepam-Loaded Solid Lipid Nanoparticles: Design and Characterization

The aim of the present study was to investigate the feasibility of the inclusion of a water-insoluble drug (diazepam, DZ) into solid lipid nanoparticles (SLNs), which offer combined advantages of rapid onset and prolonged release of the drug. This work also describes a new approach to prepare suppositories containing DZ-loaded SLN dispersions, as potential drug carrier for the rectal route. Modified high-shear homogenization and ultrasound techniques were employed to prepare SLNs. The effect of incorporation of different concentrations of Compritol® ATO 888 or Imwitor® 900K and Poloxamer 188 or Tween 80 was investigated. Results showed that varying the type or concentration of lipid matrix or surfactant had a noticeable influence on the entrapment efficiencies, particle size, and release profiles of prepared SLNs. Differential scanning calorimetry and X-ray diffraction measurements showed that the majority of SLNs possessed less ordered arrangements of crystals than the corresponding bulk lipids, which was favorable for increasing the drug loading capacity. Transmission electron microscopy and laser diffractometry studies revealed that the prepared nanoparticles were round and homogeneous and 60% of the formulations were less than 500 nm. Additionally, SLN formulations showed significant (P?in vitro release of DZ from the suppositories prepared using DZ-loaded SLN dispersions (equivalent to 2 mg DZ) was significantly (P?相似文献   

Simultaneous quantification of amoxycillin and metronidazole in plasma using high-performance liquid chromatography with photodiode array detection

A simple, robust HPLC method was developed to measure simultaneously the plasma concentrations of amoxycillin and metronidazole in order to assess their disposition in the eradication of Helicobacter pylori. Plasma samples were protein precipitated, pH adjusted and the supernatant injected onto the HPLC system which used a C₁₈ column, paired-ion aqueous mobile phase and photodiode array detection of amoxycillin at 230 nm and metronidazole at 313 nm. Intra- and inter-day precision and inaccuracy were less than 10% for concentrations between 5 and 20 mg/l. The limit of quantification was 1 mg/l. Samples were stable on the HPLC injector for 48 h at room temperature and multiple freeze–thaw cycles led to no decomposition.     

Quantification of metronidazole in small-volume biological samples using narrow-bore high-performance liquid chromatography

A rapid, selective and sensitive HPLC assay has been developed for the routine analysis of metronidazole in small volumes of rat plasma, gastric aspirate and gastric tissue. The extraction procedure involves liquid–liquid extraction and a protein precipitation step. A microbore Hypersil ODS 3 μm (150×2.1 mm I.D.) column was used with a mobile phase consisting of acetonitrile–aqueous 0.05 M potassium phosphate buffer (pH 7) containing 0.1% triethylamine (10:90). The column temperature was at 25°C and the detection was by UV absorbance at 317 nm. The limit of detection was 0.015 μg ml⁻¹ for gastric juice aspirate and plasma and 0.010 μg g⁻¹ for gastric tissue (equivalent to 0.75 ng on-column). The method was linear up to a concentration of 200 μg ml⁻¹ for plasma and gastric juice aspirate and up to 40 μg g⁻¹ for tissue, with inter- and intra-day relative standard deviations less than 14%. The measured recovery was at least 78% in all sample matrices. The method proved robust and reliable when applied to the measurement of metronidazole in rat plasma, gastric juice aspirate and gastric tissue for pharmacokinetic studies in individual rats.     

Analysis of the rdxA gene in high-level metronidazole-resistant clinical isolates confirms a limited use of rdxA mutations as a marker for prediction of metronidazole resistance in Helicobacter pylori

Metronidazole (Mtz) resistance in the gastric pathogen Helicobacter pylori is closely associated with inactivation of the nitroreductase gene rdxA. In order to identify respective mutations for diagnostic purposes we analyzed the rdxA gene in a collection of high-level Mtz-resistant clinical H. pylori isolates. Size alterations in the rdxA gene region were found in only two out of 45 and one out of 40 isolates showing lower-level (minimal inhibitory concentrations (MICs) 32-192 microg ml(-1)) and high-level (MIC>/=256 microg ml(-1)) Mtz resistance, respectively. Point mutations that interrupt the rdxA reading frame were detected in two out of eight high-level resistant isolates (MICs>/=256 microg ml(-1)). Most remarkably, the rdxA gene sequence was found to be identical in four out of five high-level Mtz-resistant and -susceptible paired H. pylori isolates from the same patients each. Taken together, these results demonstrate that although some isolates carry classical resistance-associated rdxA mutations, as described earlier, the use of rdxA mutations as a marker for prediction of Mtz resistance is limited.     

乳酸菌阴道胶囊联合甲硝唑栓对妊娠晚期BV患者阴道乳酸菌及妊娠结局的影响

目的 探讨乳酸菌阴道胶囊联合甲硝唑栓对妊娠晚期细菌性阴道病（BV）患者阴道乳酸菌数量及妊娠结局的影响。方法 选取产科门诊治疗的妊娠晚期BV妇女110例,随机分为观察组和对照组各55例。观察组予以乳酸菌阴道胶囊（1粒/晨,1次/d）联合甲硝唑栓（1粒/晚,1次/d）阴道给药,对照组予以单纯甲硝唑栓阴道给药治疗,用法与用量同观察组,两组疗程均为10 d。治疗结束后1周复诊观察阴道乳酸菌数量,并比较其临床疗效、妊娠结局及阴道假丝酵母菌病（VVC）的发生率。结果 1周后复诊,观察组患者阴道乳酸菌数量多于对照组（χ2=24.44,P0.05）。观察组和对照组分别诱发VVC 2例（3.64%）和8例（14.55 %）,观察组VVC发生率低于对照组（χ2=3.96,P<0.05）。结论 妊娠晚期BV患者予以乳酸菌阴道胶囊和甲硝唑栓联合治疗的疗效确切,能增加阴道乳酸菌数量,纠正阴道菌群紊乱,减少VVC的发生率,从而减少早产发生率,改善妊娠结局。