儿童迁延性腹泻患者肠道菌群和肠黏膜屏障功能的 变化以及双歧杆菌三联活菌散的干预作用

目的探讨儿童迁延性腹泻患者肠道菌群和肠黏膜屏障功能的变化以及双歧杆菌三联活菌散的干预作用。方法选取儿科就诊迁延性腹泻患儿40例为观察组,予以双歧杆菌三联活菌散1.0g/次,3次/d,溶解于温水中口服,连用8周,检测观察组患儿治疗前后肠道菌群数量及肠黏膜屏障指标的变化。另选择同期在我院体检的正常儿童30例为对照组。结果观察组患儿治疗前双歧杆菌、乳杆菌的数量及B/E比值明显少于对照组,而大肠埃希菌数量明显多于对照组(P0.05)。治疗8周后,观察组患儿双歧杆菌、乳杆菌的数量及B/E比值较治疗前明显上升,大肠埃希菌数量较治疗前明显下降(P0.05);观察组患儿治疗前血清D-乳酸、PCT和DAO水平明显高于对照组(P0.05)。治疗8周后,血清D-乳酸、PCT和DAO水平较治疗前明显下降(P0.05)。结论儿童迁延性腹泻患者存在肠道菌群紊乱,引起肠黏膜屏障功能受损,肠黏膜的通透性异常。双歧杆菌三联活菌散治疗儿童迁延性腹泻患者可纠正肠道菌群紊乱,保护肠黏膜屏障功能,降低其通透性,达到治疗腹泻的目的。     

双歧杆菌三联活菌胶囊对胆囊切除术后腹泻患者肠道菌群及sIgA水平的影响

目的探讨双歧杆菌三联活菌胶囊对胆囊切除术后腹泻患者肠道菌群及sIgA水平的影响。方法选取胆囊切除术后腹泻患者68例,分为观察组和对照组。两组患者均予以低脂饮食和止泻药等常规治疗。观察组患者予以口服双歧杆菌三联活菌胶囊420 mg,3次/d,连用4周。对照组除不口服双歧三联活菌肠溶胶囊外余治疗基本同观察组。观察两组患者治疗前后肠道菌群和sIgA水平的变化,并比较其临床疗效。结果治疗4周后,观察组患者双歧杆菌和乳酸杆菌数量较前明显上升,肠杆菌和肠球菌较前明显减少（P〈0.05）,而对照组治疗前后肠道菌群数量均无明显变化（P〉0.05）;两组患者肠道sIgA水平较前明显上升（P〈0.05或P〈0.01）,且观察组上升值明显大于对照组（P〈0.05）;同时观察组患者临床总有效率明显高于对照组（χ2=5.31,P〈0.05）。结论双歧杆菌三联活菌胶囊治疗胆囊切除术后腹泻的疗效确切,能调节患者肠道菌群失调,从而重建肠道微生态平衡,提高肠道免疫力,改善和保护肠道功能。     

双歧三联活菌胶囊对结直肠癌术后炎症反应及 肠道微生态的影响

目的探讨围手术期补充双歧三联活菌胶囊对结直肠癌术后炎症反应及肠道微生态的影响。方法选取拟行结直肠癌根治术的患者70例,随机分为观察组和对照组。两组患者均予以根治性结直肠癌术,对照组术前予以常规禁食、传统肠道准备,术后予以围手术期常规治疗,并予以等氮量等热量的营养支持。观察组在对照组基础上术前5d加用双歧三联活菌胶囊630mg/次,3次/d,温水口服,替代术前肠道抗生素的使用,术后24h继续使用双歧三联活菌胶囊至术后1周,剂量和方法同术前。评估两组患者入院时及术后1周肠道菌群(双歧杆菌、乳杆菌、大肠埃希菌和粪肠球菌)数量和血清炎症因子[超敏C反应蛋白(hs-CRP)和肿瘤坏死因子-α(TNF-α)]水平的变化,并比较感染并发症的发生率。结果术后1周,观察组双歧杆菌、乳杆菌和肠球菌数量较入院时均有不同程度的上升(P0.05),大肠埃希菌数量变化不明显(P0.05);对照组双歧杆菌、乳杆菌和肠球菌数量较入院时均有不同程度的下降(P0.05),大肠埃希菌数量较入院时有不同程度上升(P0.05)。术后1周,观察组双歧杆菌、乳杆菌和肠球菌数量较对照组更多,大肠埃希菌数量较对照组更少(P0.05)。同时两组血清hs-CRP和TNF-α水平均较入院时均有不同程度的上升(P0.05或P0.01),其上升幅度观察组低于对照组(P0.05)。在感染并发症发生率上观察组较对照组更低(χ~2=4.20,P0.05)。结论围手术期补充双歧三联活菌胶囊不仅能纠正结直肠癌患者术后肠道微生态失调,提高肠道内乳杆菌和双歧杆菌的数量,重建肠道菌群平衡,还能有效减轻患者术后炎症反应,减少术后感染并发症的发生。     

酪酸梭菌活菌片联合多烯磷脂酰胆碱对 酒精性肝病患者肠道菌群及炎症因子的影响

目的探讨酪酸梭菌活菌片联合多烯磷脂酰胆碱对酒精性肝病(ALD)患者肠道菌群及炎症因子的影响。方法选取2015年1月至2018年1月进行治疗的ALD患者80例,随机分为观察组和对照组。两组患者均予以严格戒酒、高蛋白高热量低脂饮食、维生素及门冬氨酸钾镁等常规治疗。观察组患者在此基础上加用酪酸梭菌活菌片(0.7g/次,3次/d,口服)和多烯磷脂酰胆碱胶囊(456mg/次,3次/d,口服)联合治疗8周。对照组患者在常规治疗基础上单纯加用多烯磷脂酰胆碱片治疗,其剂量、用法及疗程与观察组相同。观察并比较治疗前后患者肝功能指标、肠道菌群数量及炎症因子的变化。结果治疗8周后,两组患者血清ALT、AST和TBiL水平均较治疗前显著下降(P0.05),且观察组下降幅度较对照组更大(P0.05)。两组患者肠道双歧杆菌和乳杆菌数量较治疗前明显上升,大肠埃希菌数量较治疗前明显下降(P0.05),且观察组变化幅度较对照组更大(P0.05)。两组患者血清IL-6和TNF-α水平较治疗前明显下降(P0.05),且观察组下降幅度较对照组更大(P0.05)。结论酪酸梭菌活菌片联合多烯磷脂酰胆碱能有效改善ALD患者肝功能指标,促进肝功能恢复,其作用机制可能与其能纠正肠道菌群失调,促进有益菌的繁殖,同时下调血清炎症因子水平,抑制肝内炎症反应密切相关。     

双歧杆菌三联活菌胶囊对动脉粥样硬化患者 血脂、颈动脉斑块和肠道菌群的影响

目的探讨双歧杆菌三联活菌胶囊辅助治疗颈动脉粥样硬化患者及其对患者血脂、颈动脉斑块和肠道菌群的影响。方法选择2017年1月至2017年10月在我院门诊治疗的颈动脉粥样硬化患者84例,随机分为观察组和对照组各42例。对照组患者均予以瑞舒伐他汀(10mg/次,1次/d)+肠溶阿司匹林片(100mg/次,1次/d)口服治疗,并根据病情酌情给予降压、降糖等治疗。观察组患者在对照组基础上加用双歧杆菌三联活菌胶囊630mg/次,3次/d,温水口服。两组患者疗程均为6个月。观察两组患者治疗前后血脂指标[总胆固醇(TC)、甘油三脂(TG)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)]水平、颈动脉斑块指标[颈动脉斑块内-中膜厚度(IMT)及斑块面积)及肠道菌群数量(双歧杆菌、乳杆菌和大肠埃希菌)的变化。结果治疗6个月后,两组患者TC、TG和LDL-C水平较治疗前均明显下降,HDL-C水平较治疗前均有明显上升(P0.05),且观察组变化幅度较对照组更明显(P0.05);两组患者颈动脉IMT及斑块面积较治疗前均明显下降(P0.05),且观察组下降幅度幅度较对照组更明显(P0.05);两组患者肠道双歧杆菌和乳杆菌数量较治疗前明显上升,大肠埃希菌数量较治疗前明显下降(P0.05或P0.01),且观察组变化幅度幅度较对照组更明显(P0.05)。结论双歧杆菌三联活菌胶囊对颈动脉粥样硬化患者具有良好的协同降脂作用,并能延缓和逆转颈动脉粥样硬化,降低IMT及斑块面积。其作用机制可能与其能纠正肠道菌群紊乱,增加肠道有益菌数量,减少致病菌数量密切相关。     

溃疡性结肠炎患者肠道菌群和肠黏膜屏障的变化及益生菌的干预作用

目的探讨溃疡性结肠炎(UC)患者肠道菌群和肠黏膜屏障的变化及益生菌的干预作用。方法选取2014年1月-2017年12月内科门诊就诊活动期UC患者50例为观察组,予以双歧杆菌三联活菌胶囊2粒/次(210mg/粒),饭后30min温水送服,2次/d,连用8周。检测观察组治疗前与治疗后肠道菌群数量及肠黏膜屏障指标的变化。另选择同期肠镜检查未见肠道病变的正常成人30例为对照组。结果观察组患者治疗前双歧杆菌和乳杆菌的数量明显少于对照组,而大肠杆菌数量明显多于对照组(Ps0.05)。治疗8周后,观察组患者双歧杆菌和乳杆菌的数量较治疗前明显上升(Ps0.05),但仍明显低于对照组(Ps0.05);而大肠杆菌数量较前明显下降(Ps0.05),但仍明显高于对照组(Ps0.05)。同时观察组患者治疗前血清ET、D-乳酸和PCT水平明显高于对照组(Ps0.05)。治疗8周后,血清ET、D-乳酸和PCT水平较治疗前明显下降(Ps0.05),但仍明显高于对照组(Ps0.05)。结论双歧杆菌三联活菌胶囊治疗活动性UC能纠正患者肠道菌群紊乱,修复肠黏膜屏障。     

妊娠期糖尿病患者肠道菌群及炎症因子的变化

目的探讨妊娠期糖尿病患者肠道菌群及炎症因子的变化。方法选择38例在丽水市中医院就诊的妊娠期糖尿病患者为观察组,选择同期就诊的正常孕妇50例为对照组,两组患者均检测肠道双歧杆菌、乳酸杆菌、拟杆菌含量,比较菌群失调发生率,同时检测并比较炎症因子IL-2、IL-6水平,探讨两组患者的肠道菌群及炎症因子的差异。结果观察组双歧杆菌、乳酸杆菌、拟杆菌的数量均少于对照组(t_双=2.41,t_乳=2.27,t_拟=2.14,P均0.05);观察组肠道菌群失调发生率高于对照组(χ~2=6.29,P0.05);观察组IL-2水平较对照组低,IL-6水平较对照组高(t_(IL-2)=3.74,t_(IL-6)=3.21,P均0.01)。结论妊娠期糖尿病患者容易出现肠道菌群失调,影响患者的免疫功能,应及早进行干预治疗。     

双歧三联活菌胶囊对胆囊切除术后腹泻患者血清D-乳酸及肠道菌群的影响

目的探讨双歧三联活菌胶囊对胆囊切除术后腹泻(PCD)患者血清D-乳酸及肠道菌群的影响。方法选取80例PCD患者,随机分为观察组(n=40)和对照组(n=40)。两组均予以低脂饮食和止泻药等常规治疗。观察组加用双歧三联活菌胶囊420mg/次,3次/d,连用6周,温开水或温牛奶送服。检测两组治疗前后血清D-乳酸水平及肠道菌群数量变化,并比较其临床疗效及不良反应。结果观察组与对照组分别失访2例(5.0%)和4例(10.0%),两组失访率比较差异无统计学意义(P0.05)。治疗6周后,两组血清D-乳酸指标较治疗前均明显下降(对照组治疗前后比较,P0.05;观察组治疗前后比较,P0.01),观察组下降幅度较对照组更明显(P0.05);同时观察组双歧杆菌和乳酸杆菌数量增加,肠杆菌和肠球菌数量下降(P0.05),而对照组肠道菌群数量变化差异无统计学意义(P0.05);同时观察组其总有效率(92.11%)较对照组(72.22%)高(χ2=5.05,P0.05)。结论双歧三联活菌胶囊治疗PCD具有确切疗效,能降低血清D-乳酸指标,纠正并调节患者肠道微生态紊乱,重建肠道微生态平衡,改善其肠道功能。     

原发性肝癌患者肠道菌群变化与内毒素和炎性因子水平的关系

目的探讨原发性肝癌患者肠道菌群变化及其与内毒素、炎性因子水平的相关性。方法选取2018年2月至2019年10月我院收治的80例原发性肝癌患者为观察组,另选同时期80例健康体检者为对照组。观察两组对象肠道菌群情况,同时检测两组对象血清内毒素和白细胞介素6(IL-6)、白细胞介素1(IL-1)及肿瘤坏死因子α(TNF-α)水平。采用Pearson检验进行相关性分析。结果观察组患者肠道双歧杆菌、乳杆菌和拟杆菌数量低于对照组;而肠杆菌和酵母菌数量高于对照组(均P0.05)。观察组患者血清内毒素、IL-6、IL-1、TNF-α水平均高于对照组(均P0.05)。Pearson相关性分析显示,肠道双歧杆菌、乳杆菌和拟杆菌数量与血清内毒素和IL-6、IL-1、TNF-α水平呈负相关,肠道肠杆菌和酵母菌数量与内毒素和IL-6、IL-1、TNF-α水平呈正相关(均P0.05)。结论原发性肝癌患者肠道菌群紊乱与内毒素和炎症因子水平具有相关性,肠道菌群失衡可能是促进该病病情发展的原因之一。     

双歧杆菌三联活菌胶囊对非酒精性脂肪性肝炎患者血清内毒素和炎症因子的影响

目的探讨双歧杆菌三联活菌胶囊对非酒精性脂肪性肝炎患者血清内毒素和炎症因子的影响。方法将84例非酒精性脂肪性肝炎患者随机分为对照组和观察组。两组患者均予以常规保肝治疗,观察组患者加用双歧杆菌三联活菌胶囊420mg,2次／d,连用4周。对照组除不使用双歧杆菌三联活菌胶囊外,余治疗同观察组。观察两组患者治疗前后肝功能、血清内毒素、白介素（IL）-6和肿瘤坏死因子（TNF）-α水平的变化。结果治疗4周后,两组患者ALT、AST和GGT水平较前均明显下降（P〈0．05或P〈0．01）,且观察组下降幅度比对照组更明显（P〈0．05）;同时两组患者血清内毒素、IL-6和TNF-＆水平均较前明显下降（P〈0．05或P〈0．01）,且观察组下降幅度比对照组更明显（P〈0．05）。结论双歧杆菌三联活菌胶囊对非酒精性脂肪性肝炎具有良好辅助治疗作用,能降低血清内毒素、IL-6和TNF—α水平,减轻肠源性内毒素血症,抑制肝细胞炎症及免疫损伤,改善肝功能指标。     

壳聚糖酶的克隆表达与壳寡糖的制备分析

目的:克隆壳聚糖酶基因于大肠杆菌中实现高表达,制备壳寡糖。方法:以枯草芽孢杆菌总DNA为模板扩增壳聚糖酶基因(CSN),克隆至载体pET23a(+)上,转化菌株BL21(DE3)。重组子经0.5 mmol/L IPTG诱导后,SDS-PAGE和质谱检测与鉴定重组酶。酶纯化后水解壳聚糖,薄层色谱分析其水解产物。结果:质谱证明壳聚糖酶(31.5kDa)成功表达,表达量占菌体总蛋白的45%左右。纯化后重组酶浓度为900 mg/L,纯度95%、回收率85%,酶活力为10 000 U/mg。壳聚糖降解产物为壳二糖至壳四糖。结论:原核表达载体pET23a(+)-CSN构建正确,壳聚糖酶表达量与活性高,适用于水解壳聚糖制备壳寡糖。     

国内外蝗害治理技术现状与展望

本文首先概述了国内外蝗虫发生与为害的态势,总结了现阶段我国蝗虫发生与为害的主要特点:即农田飞蝗暴发频繁而且严重,草原土蝗的发生时常造成严重的经济损失,而且侵入城市干扰市民生活,我国与周边国家之间蝗虫过境迁移频繁,使用化学农药污染环境和农产品;分析了国内外蝗虫防治对策与技术的发展现状,重点介绍了应急防治和可持续治理对策、...     

Coiled-coil nanomechanics and uncoiling and unfolding of the superhelix and alpha-helices of myosin

The nanomechanical properties of the coiled-coils of myosin are fundamentally important in understanding muscle assembly and contraction. Force spectra of single molecules of double-headed myosin, single-headed myosin, and coiled-coil tail fragments were acquired with an atomic force microscope and displayed characteristic triphasic force-distance responses to stretch: a rise phase (R) and a plateau phase (P) and an exponential phase (E). The R and P phases arise mainly from the stretching of the coiled-coils, with the hinge region being the main contributor to the rise phase at low force. Only the E phase was analyzable by the worm-like chain model of polymer elasticity. Restrained molecular mechanics simulations on an existing x-ray structure of scallop S2 yielded force spectra with either two or three phases, depending on the mode of stretch. It revealed that coiled-coil chains separate completely near the end of the P phase and the stretching of the unfolded chains gives rise to the E phase. Extensive conformational searching yielded a P phase force near 40 pN that agreed well with the experimental value. We suggest that the flexible and elastic S2 region, particularly the hinge region, may undergo force-induced unfolding and extend reversibly during actomyosin powerstroke.     

放牧对牧草光合作用、呼吸作用和氮、碳吸收与转运的影响

研究放牧对草地植物生理活动的影响,对于揭示草地放牧演替的生理机制有重要意义.大量研究表明,家畜放牧对牧草光合作用、呼吸作用以及C和N吸收与转运的影响,可以分为生理伤害和生理恢复2个阶段.放牧通过改变草地冠层结构影响牧草光合作用,净光合作用速率短期内迅速下降,随着叶面积指数增加又逐渐上升,呼吸作用有相似的变化趋势.牧草放牧后再生长所需的C和N最初主要来自根系和留茬中的贮藏物质,此后随着牧草生长恢复逐渐由同化作用供给,C代谢与土壤N水平负相关.放牧后牧草生理活动变化与牧草遗传特性、种间竞争、家畜放牧特征、非生物环境等因素密切相关.     

Kinetics and thermodynamics of peroxidase- and laccase-catalyzed oxidation of N-substituted phenothiazines and phenoxazines

N -substituted phenothiazines (PTs) and phenoxazines (POs) catalyzed by fungal Coprinus cinereus peroxidase and Polyporus pinsitus laccase were investigated at pH 4–10. In the case of peroxidase, an apparent bimolecular rate constant (expressed as k _cat/K _m) varied from 1 ×10⁷M⁻¹s⁻¹to 2.6×10⁸M⁻¹s⁻¹ at pH 7.0. The constants for PO oxidation were higher in comparison to PT. pH dependence revealed two or three ionizable groups with pK _a values of 4.9–5.7 and 7.7–9.7 that significantly affected the activity of peroxidase. Single-turnover experiments showed that the limiting step of PT oxidation was reduction of compound II and second-order rate constants were obtained which were consistent with the constants at steady-state conditions. Laccase-catalyzed PT and PO oxidation rates were lower; apparent bimolecular rate constants varied from 1.8×10⁵M⁻¹s⁻¹ to 2.0×10⁷M⁻¹s⁻¹ at pH 5.3. PO constants were higher in comparison to PT, as was the case with peroxidase. The dependence of the apparent bimolecular constants of compound II or copper type 1 reduction, in the case of peroxidase or laccase, respectively, was analyzed in the framework of the Marcus outer-sphere electron-transfer theory. Peroxidase-catalyzed reactions with PT, as well as PO, fitted the same hyperbolic dependence with a maximal oxidation rate of 1.6×10⁸M⁻¹s⁻¹ and a reorganization energy of 0.30 eV. The respective parameters for laccase were 5.0×10⁷M⁻¹s⁻¹ and 0.29 eV. Received: 20 September 1999 / Accepted: 24 February 2000     

Synthesis of hapten and conjugates of coumestrol and development of immunoassay

3-O-Carboxymethylcoumestrol was prepared as the hapten for immunoassay by a partial alkylation of coumestrol with ethyl chloroacetate in acetone alkalized with potassium carbonate. 3-O-Ethoxycarbonylmethylcoumestrol was separated by column chromatography and finally was hydrolyzed with formic acid. 1H and 13C NMR data (APT, COSY, HMQC, and HMBC) revealed that the reaction was regioselective, as 3-O-ethoxycarboxymethylcoumestrol was the only monosubstituted derivative. The hapten was then conjugated to bovine serum albumin and used for immunization of rabbits. A radioimmunoassay (RIA) system was established based on the polyclonal antiserum and a 125I-labeled hapten-tyrosine methyl ester conjugate as the radioligand. Parameters of the RIA: sensitivity: 12 pg per tube, 50% intercept: 140 pg per tube, working range: 20-4000 pg per tube. The cross-reactivity of a panel isoflavonoid and lignan phytoestrogens was either negligible (e.g. formononetin 0.07%; biochanin A 0.06%) or not detectable at all. The major immunoreactive peak in HPLC fractions from an alfalfa extract had the same retention time as coumestrol standard and represented 94.8% of the signal. The remaining 5.2% of immunoreactivity was distributed between five minor peaks. We conclude that after the validation for particular matrices, the method will be a useful tool for analysis of coumestrol, especially in low volume and low concentration samples.     

白术同源四倍体的诱导和鉴定及其与二倍体过氧化物酶的比较

以白术（Atractylodes macrooephala Koidz.）二倍体组培苗为材料,对其四倍体诱导方法进行研究,共获得45个白术同源四倍体株系,为优良株系的选育提供了材料。此外,还分析比较了其中8个白术四倍体株系与二倍体的过氧化物酶同工酶（POD）的酶谱差异,发现四倍体各株系过氧化物酶同工酶谱比二倍体的均多了Rf0.310的谱带,且总过氧化物酶比活力也发生了很大改变,对探讨白术四倍体优良株系的生理生化机理具有一定的参考价值。