胞外黏质物在心血管材料表面细菌生物膜形成中的作用

目的 通过体外试验观察、预处理的涤纶材料表面细菌生物膜（BF）形成的影响，为临床以生物材料为中心的感染（BCI）提供有益的思路。方法 用生物膜形成阳性的表皮葡萄球菌RP62A和生物膜形成阴性的表皮葡萄球菌M7，在普通液体培养基及其调整浓度后的培养基中，对以血浆预处理和未处理的涤纶材料进行体外动态生物膜形成试验，用激光共聚焦显微镜（CLSM）测定生物膜厚度，用环境扫描电子显微镜（SEM）直接观察涤纶材料上细菌生物膜形成的情况。结果 RP62A与M7在两组材料表面形成BF差异有显著性（P〈0．05）；RP62A在不同处理材料表面BF形成有显著区别（P〈0．05）；培养基调整组与培养基正常组生物膜厚度比较差异有显著性（P〈0．05）。结论 细菌生物膜在生物材料表面形成是动态的过程，其高峰期在24～30h；血浆预处理生物材料和培养基调整组能增加胞外黏质物（ESS）的分泌和促进细菌生物膜形成；ESS在生物材料表面细菌生物膜形成中起重要作用，阻断ESS产生及其作用必将为临床治疗以生物材料为中心的感染提供帮助。

黏质物在凝固酶阴性葡萄球菌生物膜耐药机制中的作用

目的了解湘雅医院临床分离凝固酶阴性葡萄球菌(CNS)药物敏感性,初步探讨细菌生物膜的耐药机制及黏质物在其中的作用。方法临床分离的158株CNS,纸片扩散法检测其对抗菌药物的敏感性;比色法测定其黏质物量;提取黏质物并以聚丙烯酰胺凝胶电泳分析;微量肉汤稀释法测定提取的黏质物对万古霉素、庆大霉素、利福平最小抑菌浓度(MIC)的影响。结果CNS对青霉素、红霉素、复方新诺明的耐药率高,对氨苄西林/舒巴坦和利福平较敏感,未发现耐万古霉素的菌株;158株CNS除1株外均产黏质物,高/低产黏质物组菌株的产黏质物量差异有统计学意义(P<0.05),而纸片扩散法测定的耐药率P>0.05;20 mg/ml的黏质物可增加万古霉素、庆大霉素MIC,对利福平无影响;提取的黏质物为糖胺聚糖,其与硫酸软骨素的迁移率相近。结论CNS在一定条件下普遍产黏质物,进而形成生物膜,黏质物可因分子筛效应或干扰抗菌药物活性而增加万古霉素、庆大霉素的MIC,致使含生物膜的CNS耐药性增高。

表皮葡萄球菌icaA和icaD基因表达及其与黏质物形成的关系

目的了解临床分离的表皮葡萄球菌所携带的icaA和icaD操纵子表达情况及其与黏质物形成之间的关系。方法收集ICU临床分离的表皮葡萄球菌62株,采用刚果红法检测其黏质物形成,PCR法检测icaA、icaD基因表达,卡方检验法进行统计学处理。结果 62株表皮葡萄球菌中产黏质物菌株有26株(41.9%);产黏质物菌株中icaA、icaD基因表达阳性的菌株分别为22株(84.6%)和19株(73.1%),icaA、icaD基因表达均为阳性有17株(65.4%),明显高于非产黏质物菌株(P<0.01);icaA、icaD基因表达均阴性为2株(7.7%),明显低于非产黏质物菌株(P<0.01)。结论 icaA、icaD基因表达对表皮葡萄球菌的黏质物产生具有重要影响,但并不是其唯一的影响因素。

RNAⅢ抑制肽体外抑制葡萄球菌胞外黏质物产生的作用分析

目的探究RNAⅢ抑制肽(RIP)体外抑制葡萄球菌胞外黏质物产生的作用。方法分别将表皮葡萄球菌ATCC35984、表皮葡萄球菌ATCC10228加入2支试管,做生物被膜形成实验,观察不同菌株的生物被膜形成情况;设不同因素交叉成组,表皮葡萄球菌ATCC35984设为因素A1,表皮葡萄球菌ATCC12228设为因素A2;正常空白培养基设为因素B1,加入RIP的培养基设为因素B2,两两组合分别A1B1组、A2B1组、A1B2组和A2B2组,将各组试管封口,在37℃、170 rm条件下摇晃培养,用酶标仪在550 nm波长下检测不同时间的光密度(OD)值。结果胞外黏质物观察结果显示,表皮葡萄球菌ATCC12228黏着能力较低,未形成明显的生物被膜,而表皮葡萄球菌ATCC35984则明显产生生物被膜并大量附着在试管壁上;A1B1组在24 h内产生大量的胞外黏质物,但A2B1组则未出现明显的胞外黏质物,但A1B2组与A1B1组比较,胞外黏质物产生明显减少,组间对比差异有统计学意义(P<0.05)。结论不同表皮葡萄球菌产生胞外黏质物的能力有所差异,表皮葡萄球菌ATCC35984能够在6～24 h内产生大量的胞外黏质物,RIP能够有效抑制胞外黏质物的产生。

黏质物脱除工艺优化及其提高亚麻籽提油率的效果

为了提高水酶法提取亚麻籽油的提油率,该文探究了亚麻籽表面黏质物的存在对水酶法提取亚麻籽油提油率的影响,并对热水浸提法脱除亚麻籽黏质物的工艺进行优化。结果表明,水酶法提取亚麻籽油的提油率随亚麻籽表面黏质物的减少而升高,未脱黏亚麻籽的提油率为69.20%±1.51%,渣相含油量为26.00%±1.24%。经100℃浸提脱黏后,黏质物的脱除率为94.69%±1.94%,此时亚麻籽的提油率可达84.26%±0.63%,渣相含油量降低至10.45%±0.89%。对热水浸提脱除黏质物的工艺(浸提温度、浸提时间、体系p H值、料水比以及浸提次数)进行了单因素优化,发现在浸提温度85℃、p H值3、料水比1:7 g/m L、浸提2次,每次浸提60 min的条件下,黏质物的脱除效果最好,脱除率为97.88%±0.69%,脱黏后亚麻籽的提油率可达84.47%±0.53%,亚麻籽油和蛋白质的损失率分别为0.70%±0.16%和10.78%±0.41%,且浸提脱黏过程对水酶法提取亚麻籽油的品质(酸值和过氧化值)无显著影响。此外,浸提脱黏过程还可有效去除亚麻籽中的抗营养因子生氰糖苷,使生氰糖苷的含量由浸提前的(242.6±0.8)mg/kg显著降低到浸提后的(7.1±0.6)mg/kg。该研究提供了一种简单高效的热水浸提脱黏工艺,显著提高了后续水酶法提取亚麻籽油的提油率,同时也有利于亚麻籽多糖的回收和亚麻籽粕的进一步利用,为亚麻籽资源的综合利用提供有益参考。

凝固酶阴性葡萄球菌胞外黏质物检测及临床意义的探讨

实验室用定量法,在一定时期内,对获自不同临床标本的194株凝固酶阴性葡萄球菌(CNS)进行了胞外黏质物(ESS)检测,结果表明,ESS总阳性检出率47%,其中以血液、前列腺液和尿液分离株较高,分别为64%、62%和53%;不同种类的CNS、ESS阳性检出率不同,其中101株表皮葡萄球菌有80株(72%)为产ESS株,明显高于其他CNS;药敏试验提示,ESS阳性的CNS对抗菌药物的耐药性有增强趋势。研究认为,对临床分离的CNS进行ESS检测,可为临床提供菌株毒力强弱以及治疗用药的参考依据。特别在当前环境下,更具有一定的临床实用价值。

Effect of Short Chain Alcohols upon Viscosity of TTAB Solution

The effect of ethanol （C2H5OH）, propanol （C3H7OH）, and butanol （C4H9OH） upon the viscosity of tetradecyltrimethylammonium bromide （TTAB） solution in the presence or absence of KBr at 30℃was investigated, where the surfactant concentration CS is kept constant. In the absence of KBr, the relative viscosity ηr of TTAB solution increases linearly with the alcohol concentration CA, indicating that the alcohols do not promote micelle formation of TTAB. In the presence of KBr, ηr linearly decreases with CA for C2H5OH, but it exhibits a maximum with increasing CA for C3H7OH or C4H9OH. The facts reveal that C2H5OH or C4H9OH promotes the micelle formation of TTAB. A possible explanation is that the hydrophobicity of the mieellar interior is enhanced by KBr, so that C2H5OH or C4H9OH can dissolve in micelle and promotes micelle formation. In the presence of KCl, which is less efficient in promoting the micelle formation of cationic surfactant, both C3H7OH and C4H9OH have only a slight effect on the micelle formation. In contrast, due to the hydrophilicity, C2H5OH cannot dissolve in micelles in the presence of KBr or KCl.

Protein and non-protein sulfhydryls and disulfides in gastric mucosa and liver after gastrotoxic chemicals and sucralfate: Possible new targets of pharmacologic agents

AIM： To investigate the role of major non-protein and protein sulfhydryls and disulfides in chemically induced gastric hemorrhagic mucosal lesions （HML） and the mechanism of gastroprotective effect of sucralfate.METHODS： Rats were given 1 mL of 75% ethanol, 25%NaCl, 0.6 mol/L HCI, 0.2 mol/L NaOH or 1% ammonia solutions intragastrically （i.g.） and sacrificed 1, 3, 6 or 12 min later. Total （reduced and oxidized） glutathione （GSH ＋ GSSG）, glutathione disulfide （GSSG）, protein free sulfhydryls （PSH）, protein-glutathione mixed disulfides （PSSG） and protein cystine disulfides （PSSP） were measured in gastric mucosa and liver.RESULTS： Reduced glutathione （GSH） was depleted in the gastric mucosa after ethanol, HCI or NaCl exposure,while oxidized glutathione （GSSG） concentrations increased, except by HCI and NaOH exposure. Decreased levels of PSH after exposure to ethanol were observed,NaCl or NaOH while the total protein disulfides were increased. Ratios of reduced to oxidized glutathione or sulfhydrils to disulfides were decreased by all chemicals.No changes in thiol homeostasis were detected in the liver after i.g. abbreviation should be spelled out the first time here administration of ethanol. Sucralfate increased the concentrations of GSH and PSH and prevented the ethanol-induced changes in gastric mucosal thiol concentrations.CONCLUSION： Our modified methods are now suitable for direct measurements of major protein and nonprotein thiols/disulfides in the gastric mucosa or liver.A common element in the pathogenesis of chemically induced HML and in the mechanism of gastroprotective drugs seems to be the decreased ratios of reduced and oxidized glutathione as well as protein sulfhydryls and disulfides.

Effects of Wei Chang An pill(胃肠安丸) on enzyme activity and levels of vasoactive peptide and substance P in the small intestine of rats with compound diarrhea

OBJECTIVE:To investigate the regulatory effects of Wei Chang An Pill(WCAP) on enzyme activity and gastrointestinal hormones in the small intestine of rats with compound diarrhea.METHODS:Forty Wistar rats were randomly divided into a control,diarrhea model,and WCAP high,medium,and low dose groups.The control group was not treated,and the model group was administered intragastric distilled water.The WCAP groups were given WCAP suspension,80,60 or 40 mg · kg-1 · d-1,for 4 days.Stool properties were observed.After the experiment,thymus and spleen indices were measured,and the activities of lactate dehydrogenase(LDH),malate dehydrogenase(MDH),and disaccharidase(lactase) in the small intestinal mucous membrane,and levels of substance P(SP) and vasoactive peptide(VIP) in the colon were determined.RESULTS:Compared with the control group,thymus and spleen indices were significantly decreased,LDH,MDH,and disaccharidase activity in the small intestine was decreased,and SP and VIP levels in the colon were significantly increased inthe diarrhea model group.Compared with the model group,thymus and spleen indices were significantly increased,and LDH,MDH,and disaccharidase activity in the small intestine and SP and VIP levels in the colon were significantly decreased in theWCAP medium dose group.CONCLUSION:The diarrhea model rats exhibited pathological changes including atrophy of the thymus and spleen,decreased enzyme activity in the small intestine,and gastrointestinal hormone disturbance.WCAP can increase the activity of intestinal digestive enzymes and regulate gastrointestinal hormones,thereby relieving diarrhea.