呼吸道感染病原菌分析

目的 了解老年人院内呼吸道感染与非老年人呼吸道感染病原菌分布情况。方法 回顾性调查１９９８年１月至１２月老年人院内呼吸道感染（老年组）的２８５份痰标本和同时期非老年人呼吸道感染（非老年组,含门诊和住院）的１１９２份痰标本的培养情况。结果 老年组阳性率为８９．１％（２５４／２８５）,其中２２份标本为混合感染,共检出病原菌２７６株,以非发酵菌占绝对优势（９７．８％）;非老年组阳性率为４０．３％（４８０／１１９２）,病原菌无明显集中趋势,非发酵菌２８．３％,肠杆菌科２３．８％,革兰阳性菌２５．０％,真菌２２．９％。结论 老年组阳性率明显高于非老年组（Ｘ＾２＝２１９．６,Ｐ〈０．００５）,病原菌以非发酵菌为主,非老年组病原菌各科细菌所占比例无明显差异,引起呼吸道感染的病原菌主要为条件致病菌。     

医院病原菌的分布及耐药趋势的调查分析

通过对我院１９９４年６月至１９９５年１２月间门诊及住院患者送检的２１６５例阳性标本分析中发现,病原菌感染以呼吸道及肺部感染为最多见,其次为尿路感染和创伤感染。感染菌以革兰氏阴性杆菌为主。病原菌检出率最多的顺序是：大肠埃希氏菌、肠球菌、金黄色葡萄球菌、铜绿假单胞菌、表皮葡萄球菌、变形杆菌、鲍曼氏不动杆菌、肺炎克雷伯氏菌、白色念珠菌等。而引起呼吸道感染的病原菌依次为：鲍曼氏不动杆菌（２７．９７％）、肺炎克雷伯氏菌（２５．６％）、铜绿假单胞菌（１３．５６％）、白色念珠菌（１３．２０％）、金黄色葡萄球菌（１１．２％）、大肠埃希氏菌（７．１％）等。药敏实验结果显示：革兰氏阴性杆菌（简称Ｇ－ｂ）对丁胺卡那和头孢呋新敏感率呈上升趋势（Ｐ＜５％）,头孢三嗪、青霉素、红霉素敏感率稳定,其余七种抗生素敏感率呈下降趋势。革兰氏阳性球菌中（简称Ｇ＋ｃ）首选药为去甲万古霉素,丁胺卡那敏感率稳定,头孢呋新敏感率呈上升趋势,其余抗生素敏感率呈下降趋势（Ｐ＜５％）。     

62例变形杆菌医院内感染的调查分析

本文对我院１９８８年１月至１９９５年２月间６２例变形杆菌医院内感染进行了调查分析,结果显示,内科占６７．８％、外科１７．７％、五官科０．０８％、儿科０．０２％、妇产科０．０２％,以普通变形杆菌感染率最高占４６．７％,奇异变形杆菌３２．２％、摩根变形杆菌１４．５％,雷极氏０．０５％,并分析了导致变形杆菌感染的条件,提出了如何治疗,预防变形杆菌的医院内感染。     

1168例医院感染患者病原菌的调查及其影响因素的探讨

医院感染发病率较高且易于引起医患纠纷。为了解影响医院感染的主要因素及其主要病原体,对陕西省宝鸡市第二人民医院2002—2007年1168例医院感染患者进行了病原菌分离、鉴定及分析,同时对患者基础疾病及感染部位与医院感染的关系进行了探讨。实验结果表明,在临床各科室中,ICU患者医院感染比例（40．6％）最高（P〈0．01）,其次为烧伤科（13．3％）、泌尿外科（10．6％）和血液科患者（8．2％）（P〈0．05）。下呼吸道是最为常见的感染部位（33．9％,P〈0．01）,其次为泌尿道、胃肠道、手术切口、烧伤创面和血液（10．3％～14．7％,P〈0．05）。1168例医院感染患者标本中,病原菌总阳性率为67．3％（786／1168）。786株病原菌中,革兰阴性菌所占58．7％、革兰阳性菌占26．4％、真菌占14．9％。所分离的革兰阴性菌中,以铜绿假单胞菌（16．9％）、克雷伯菌（15．2％）和大肠埃希菌（11．7％）最为常见。所分离的革兰阳性菌中,以金黄色葡萄球菌（9．3％）和表皮葡萄球菌（7．2％）最为常见。     

慢性阻塞性肺疾病急性加重患者下呼吸道病原菌分析

目的了解慢性阻塞性肺疾病急性加重患者（AECOPD）下呼吸道感染病原菌的特点及耐药情况,为临床合理选择抗菌药物提供借鉴。方法取诸暨市人民医院2005年1月至2009年12月住院的273例AECOPD患者的下呼吸道痰标本及纤支镜刷取分泌物进行培养、鉴定、药敏,并对结果进行分析。结果273例AECOPD患者中有225例患者分离到病原菌,分离病原菌282株。病原菌中革兰阴性杆菌最多,占46．8％,依次为铜绿假单胞菌、肺炎克雷伯菌、鲍曼不动杆菌等;革兰阳性球菌占18．4％,以金黄色葡萄球菌最多,肠球菌、肺炎链球菌次之;真菌占20．9％;流感嗜血杆菌占13．8％。药敏结果显示阴性杆菌对美罗培意敏感率最好,其次为亚胺培南、哌拉西林．他唑巴坦。结论AECOPD患者下呼吸道病原菌以革兰阴性杆菌为主,耐药现象明显,流感嗜血杆菌已经成为AECOPD患者重要的致病菌之一。     

用纤维支气管镜检查236例肺部感染者的病原学分析

本文报告了２３６例支气管肺部感染者,用纤支镜双塞保护法采样,病原菌培养结果。总阳性率７４．６％。共分离到２２种２９１株病原菌。球茵占１６．７％、肠杆菌科占１１．７％、非发酵菌占３７．１％,厌氧菌占２２．３％、真菌占１２．７％,３９．２％的病例为复合菌感染。还报告了８种带见病原菌对２８种抗生素的敏感试验结果。对近年肺部感染的病原菌谱型变化及复合菌感染等进行了讨论。     

用Hela229细胞培养法研究呼吸道肺炎衣原体感染

本文用Ｈｅｌａ２２９细胞培养与单克隆抗体免疫荧光法对９４０例咽拭子及２２４例纤支镜取材标本进行肺炎衣原体分离鉴定。结果正常组、上呼吸道感染组、下呼吸道感染组、肺部肿瘤组的咽拭子标本分离率分别为０％（０／２４８）,２．１３％（１０／４６８）,２．１％（３／１４６）,１．２８％（１／７８）。上呼吸道感染组和下呼吸道感染组的分离率均高于正常组和肺部肿瘤组。前二组与正常组的差异有显著性意义（Ｐ＜０．０５）,与肿瘤组的差异无显著性意义（Ｐ＞０．０５）。下呼吸道感染组、肺部肿瘤组的纤支镜取材分离率分别为１０．９６％（     

蛇腐皮病的病原特性及其防治方法的研究

目的：对广西驯养珍稀蛇类腐皮病病原菌的特性进行研究,并对疾病有效的防治措施进行探索。方法：对蛇类腐皮病的5种主要病原菌进行药敏感试验,小白鼠接种试验、本动物回归试验,常用消毒剂的体外杀菌试验,以及对蛇场采场的综合性防治措施。结果：药敏试验表明：除绿脓杆菌外,其它蛇类腐皮病病原菌均对头孢唑啉有高度的敏感,对丁胺卡那霉素,10株菌均有不同程度的敏感,小白鼠接种试验表明：接种后24h内,变形杆菌、绿脓杆菌和腐败假单胞杆菌对小白鼠致死率为100％（各为4／4）,雷极普鲁威登斯菌致死率为25％（1／4）,金黄色葡萄球菌致死率为0％（0／4）;本动物回归试验表明：5种主要病原菌在皮肤创口接种后20天内,均可诱发腐皮病,从皮肤化脓灶及尾血均分别分离到接种菌;常用消毒剂体外抑菌试验表明,百毒杀、来苏儿、新洁尔灭对10株细菌的杀菌率均在99．9％以上,特别是百毒杀低浓度下杀菌效果尤为明显;蛇场采取综合性防治措施后,蛇腐皮病发病率由20％减少到10％以下,死亡率由10％减少到5％以下。结论：本研究的结果证明,蛇腐皮病的主要病原是变形杆菌、绿脓杆菌、腐败假单胞菌、协极普鲁威登斯菌、金黄色葡萄球菌;5种病原菌的抗药性均比较强,仅对丁胺卡那霉素、头孢唑啉有广泛的敏感性,丁胺卡那霉素、头孢唑啉为治疗蛇腐皮病的首选药物。百毒杀、来苏儿、新洁尔可作为防治蛇腐皮病的消毒剂。此外还需要采用取综合性措施才能有效地控制蛇腐皮病的发生及危害。     

神经外科颅内出血患者下呼吸道感染病原菌的耐药性监测

目的了解神经外科重症监护室（NICU）颅内出血患者下呼吸道感染病原菌的种类及耐药情况,为临床合理用药提供依据。方法对2010年1月至2011年1月颅内出血的患者,其下呼吸道感染病原菌的种类及耐药性进行回顾性分析。结果分离出的374例病原菌中以革兰阴性杆菌为主,占81．8％,革兰阳性球菌占4．0％,真菌占14．2％。分离率较高的细菌依次为鲍曼不动杆菌、铜绿假单胞菌、肺炎克雷伯菌、嗜麦芽窄食单胞菌、金黄色葡萄球菌。其中,产超广谱β-内酰胺酶（ESBLs）的肺炎克雷伯菌的检出率为50．0％;耐甲氧西林金黄色葡萄球菌（MRSA）的检出率为73．3％。鲍曼不动杆菌和铜绿假单胞菌对丁胺卡那、妥布霉素、多粘菌素B有较好的敏感性;而金黄色葡萄球菌对复方新诺明、呋喃妥因、万古霉素耐药率较低。结论NICU颅内出血患者下呼吸道感染以多重耐药的革兰阴性杆菌为主,临床应根据药敏结果合理用药,控制和减少感染的发生。     

呼吸道感染与甲型链球菌的相关性研究

目的：探讨呼吸道感染与甲型链球菌的相关性。方法 对呼吸道感染患者和健康对照组口腔咽后壁取样进行分析。结果 健康对照组中甲型链球菌检出率（５０％）明显高于呼吸道感染病人组（２５．７５％）,且各疾病组甲型链球菌检出率均有显著性差异（Ｐ＜０．０５）,如肺内感染１６．６７％,支气管炎１７．２４％,具有显著性差异（Ｐ＞０．０５）,但肺炎患者甲型链球菌检出率５３．８５％与健康人相比无显著性差异（Ｐ＞０．０５）     

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、...     

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     

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.     

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。     

Effect of soil salinity and water stresses on growth and content of nitrogen,chloride and phosphate of wheat and triticale

Summary Three wheats and one triticale were grown, up to flowering stage, in pots on calcareous soil adjusted to a range of salinities (S₁=3.5, S₂=6, S₃=8.5, and S₄=11 mmhos/cm, 20°C, soilpaste extract) by adding solution consisting of 3∶2∶1 of Na-, Ca- and Mg chlorides in chemical equivalent amounts. Moisture in the pots was kept at 100% (W₁), 40% (W₂) and 20% (W₃) of the available water. The vegetative growth, nitrogen and phosphate were affected by S and W treatments, chloride was affected only by S. The interaction S×W affected only dry weight. Varietal effect was observed between wheat as a group and triticale. Multiple quadratic regression equations of these properties on salinity and water revealed that the higher the available water the wider the range of tolerable salinity. Triticale was relatively more tolerant to water stress. Salinity increases Cl and decreases N, whereas water stress enhances N accumulation to a certain extent. However, in triticale at S₃ and S₄ the effect of water stress on N was overshadowed by the excessive salinity. This did not occur for the wheat (Florence). P trends were described. R² for P was low (0.7435–0.3603) which made interpretations rather difficult.     

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.