头孢地尼与其他6种β-内酰胺类的体外抗菌活性研究

目的　比较头孢地尼与头孢克肟、头孢克洛、头孢呋辛、头孢拉定、头孢氨苄、阿莫西林对临床常见致病菌的体外抗菌活性。方法　采用琼脂平板稀释法测定最低抑菌浓度 (MIC)。结果　头孢地尼对金黄色葡萄球菌、表皮葡萄球菌的敏感率分别为 73 3%、90 % ,抗菌活性显著强于头孢克肟 ;对肺炎克雷伯氏菌的活性与头孢克肟相似 ,强于受试第一代、二代头孢菌素 ;对大肠埃希氏菌活性强于其他 6种抗生素 ;对变形菌活性与头孢克肟相似。阴沟肠杆菌、柠檬酸杆菌属对受试药物耐药性均较高 ,其中头孢地尼和头孢克肟的敏感率 40 %左右 ,较其他 5种抗生素为强。结论　头孢地尼对大部分革兰氏阳性及革兰氏阴性菌具有较强的抗菌活性。     

头孢地尼与其他6种抗菌药物的体外抗菌活性研究

目的对比研究头孢地尼(CFDN)与头孢克肟(CFIX)、头孢克罗(CCL)、头孢呋辛(CXM)、头孢拉定(CED)、头孢氨苄(CEX)、阿莫西林(AMXL)对临床常见致病菌的体外抗菌活性.方法采用琼脂平板稀释法测定最低抑菌浓度(MIC).结果头孢地尼对金黄色葡萄球菌、表皮葡萄球菌的敏感率分别为73.3%和90%,抗菌活性显著强于头孢克肟.对肺炎克雷伯菌与头孢克肟相似,强于受试第一代、第二代头孢菌素;对大肠埃希菌强于其他6种抗生素;对变形杆菌与头孢克肟相似;阴沟枸橼酸杆菌属、肠杆菌对受试药物耐药性均较高,其中头孢地尼和头孢克肟的敏感率40%左右,较其他5种抗生素为强.结论头孢地尼对大部分G+及G-菌具有较强的抗菌活性.     

头孢吡肟对576株临床常见病原菌的抗菌活性分析

目的:了解头孢吡肟对临床常见病原菌的体外抗菌活性。方法:采用K-B法对576株临床分离菌进行头孢吡肟等15种常用抗生素的药物敏感性试验。结果:对头孢吡肟的耐药率方面,576株的总耐药率为43·8%;耐甲氧西林葡萄球菌(MRS)与甲氧西林敏感的葡萄球菌(MSS)比较具有极显著性差异(P<0·01);大肠埃希菌和肺炎克雷伯菌中产超广谱β-内酰胺酶(ESBLs)与非产ESBLs菌比较具有极显著性差异(P<0·01);阴沟杆菌与铜绿假单胞菌对头孢吡肟的耐药率均低于第2代和第3代头孢菌素。结论:头孢吡肟对MSS和ESBLs阴性菌均有较好的抗菌活性,当病原菌及药敏情况不明时,可作为院内感染菌的经验性用药。     

头孢硫脒等6种抗菌药物对革兰阳性球菌体外抗菌活性研究

目的对比研究头孢硫脒(CTM)、头孢唑啉(CEZ)、头孢呋辛(CXM)、头孢曲松(CTRX)、苯唑西林(OXL)、万古霉素(VCM)对99株临床分离G+球菌的体外抗菌活性.方法采用琼脂平板稀释法测定最低抑菌浓度(MIC).结果CTM对金黄色葡萄球菌的敏感率为97.06%,强于CTRX;CTM对表皮葡萄球菌的敏感率为91.67%,强于CTRX和OXL,对甲氧西林耐药的葡萄球菌(MRS)的抗菌作用明显优于CEZ、CXM、CTRX;CTM对粪肠球菌的抗菌活性与万古毒素相仿,强于CEX、CXM、CTRX、OXL.结论头孢硫脒对葡萄球菌和粪肠球菌具有很强的体外抗菌活性.     

头孢吡肟对儿科常见G-杆菌体外抗菌活性的研究

目的:评价头孢吡肟对儿科常见革兰阴性杆菌的体外抗菌活性。方法:采用ATBG鄄5药敏分析仪测定头孢吡肟对革兰阴性杆菌的敏感性,并与头孢他啶、头孢噻肟、阿莫西林+克拉维酸、哌拉西林+他唑巴坦作对比研究。结果:总敏感率依次为哌拉西林+他唑巴坦73.3%、阿莫西林+克拉维酸62.6%、头孢吡肟61.8%、头孢他啶58.8%、头孢噻肟51.3%。头孢吡肟对鲍曼不动杆菌、大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌的敏感率分别为82.4%、70.3%、65.6%、27.3%,与头孢他啶、头孢噻肟、阿莫西林+克拉维酸、哌拉西林+他唑巴坦比较,无显著差异(P>0.05);对铜绿假单胞菌敏感率31.3%,明显低于头孢他啶、哌拉西林+他唑巴坦(χ2=4.50,P<0.05)。结论:头孢吡肟对鲍曼不动杆菌、大肠埃希菌、肺炎克雷伯菌均有强大的体外抗菌活性,对铜绿假单胞菌的体外抗菌活性不如头孢他啶、哌拉西林+他唑巴坦。     

4种头孢菌素对社区呼吸道感染分离菌的体外抗菌活性

目的研究头孢菌素的体外抗菌活性。方法从未接受抗菌药物治疗或48h接受有效抗菌药物治疗的呼吸道感染病人中分离致病菌,采用纸片法测定细菌敏感试验结果及采用琼脂平板二倍稀释法测定最低抑菌浓度(MIC)。结果本项研究共分离出致病菌160株,常见病原菌为:克雷伯菌(42)、嗜血杆菌(30)、葡萄球菌(30)、肺炎链球菌(9)、阴沟肠杆菌(7)和大肠埃希菌 (14)。对于流感嗜血杆菌和肺炎链球菌头孢呋辛和头孢他啶的敏感性为100％;对于甲氧西林敏感的金黄色葡萄球菌(MSSA)头孢唑林钠的敏感性最高,为100％,其次为头孢呋辛94％、头孢他啶61％,其MIC值的结果显示同样的结果;对于革兰阴性杆菌,第三代头孢菌素最强,依次为第二代、一代头孢菌素,在本次实验中一代头孢菌素对于克雷伯菌、大肠埃希菌有较好的抗菌活性。结论针对不同来源的病人,合理选择不同的头孢菌素。     

4种β-内酰胺类抗生素对临床分离致病菌的体外抗菌活性

目的 对比研究头孢呋辛、头孢克洛、头孢噻肟和阿莫西林等4种β-内酰胺类抗生素对随机选取的临床分离致病菌的体外抗菌活性。方法 随机收集2006-2007年解放军总医院微生物科和空军总医院感染控制科分离的部分临床致病菌，采用琼脂平板稀释法测定最低抑菌浓度（MIC）。结果 头孢呋辛对金葡菌、表葡菌的敏感率分别为45％和83．33％，抗菌活性显著强于头孢克洛，对肺炎克雷伯菌、大肠埃希菌、阴沟肠杆菌及不动杆菌的敏感率分别为38．10％、30．77％、0、0，高于阿莫西林，弱于头孢噻肟。结论 第二代头孢菌素目前对大部分革兰阳性菌仍具有较强的抗菌活性，但对革兰阴性菌的抗菌活性明显弱于第三代头孢菌素。     

4种-内酰胺类抗生素对临床分离致病菌的体外抗菌活性

目的对比研究头孢呋辛、头孢克洛、头孢噻肟和阿莫西林等4种β-内酰胺类抗生素对随机选取的临床分离致病菌的体外抗菌活性。方法随机收集2006～2007年解放军总医院微生物科和空军总医院感染控制科分离的部分临床致病菌,采用琼脂平板稀释法测定最低抑菌浓度(MIC)。结果头孢呋辛对金葡菌、表葡菌的敏感率分别为45%和83.33%,抗菌活性显著强于头孢克洛,对肺炎克雷伯菌、大肠埃希菌、阴沟肠杆菌及不动杆菌的敏感率分别为38.10%、30.77%、0、0,高于阿莫西林,弱于头孢噻肟。结论第二代头孢菌素目前对大部分革兰阳性菌仍具有较强的抗菌活性,但对革兰阴性菌的抗菌活性明显弱于第三代头孢菌素。     

69株革兰阳性球菌对抗菌药物的体外敏感度测定

目的了解抗菌药物对临床常见革兰阳性球菌的体外抗菌活性。方法采用K B法对临床分离得到的69株革兰阳性球菌进行药物敏感性测定。结果革兰阳性球菌对万古霉素的敏感率为100.0%，表皮葡萄球菌对头孢硫脒的敏感率为89.7%，对头孢唑林为84.4%;金黄色葡萄球菌对头孢硫脒的敏感率为95.0%，对头孢唑林为93.5%。肠球菌对头孢硫脒和头孢唑林的敏感率均为50%。结论头孢硫脒对革兰阳性球菌的抗菌活性优于头孢唑林、红霉素、阿奇霉素，仅次于万古霉素。头孢硫脒与头孢唑林对肠球菌的抗菌活性基本相同。     

大肠埃希菌和肺炎克雷伯菌对头孢美唑耐药性监测

目的评价头孢美唑对大肠埃希菌和肺炎克雷伯菌体外抗菌活性及其对产β内酰胺酶（ESBLs）菌株的作用情况,为临床合理用药提供参考。方法收集住院患者各类标本中分离出的大肠埃希菌和肺炎克雷伯菌共203株,对其进行药物敏感试验及ESBLs测定。结果203株大肠埃希菌和肺炎克雷伯菌中产ESBLs株124株（占61%）,头孢美唑对大肠埃希菌和肺炎克雷伯菌产ESBLs株的耐药率高于亚胺培南、美罗培南及哌拉西林/他唑巴坦,但低于二、三、四代头孢菌素及头孢哌酮/舒巴坦。结论头孢美唑对大肠埃希菌和肺炎克雷伯菌产ESBLs株仍保持较高的抗菌活性（80%以上）,对于产ES-BLs的大肠埃希菌和肺炎克雷伯菌引起的感染仍可根据病情选用头孢美唑。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.