对产超广谱β-内酰胺酶细菌的检测和耐药性分析

目的 :了解临床病人标本中产超广谱 β-内酰胺酶 (ESBLs)细菌的检出率及耐药情况 ,以指导临床合理使用抗生素。方法 :用NCCLS规定的表型确证试验进行ESBLs的检测。结果 :ESBLs的总阳性率为 19.9% ,大肠埃希菌为 18. 1% ,肺炎克雷伯菌为 2 2 . 7%。产ESBLs菌对 8种抗生素的耐药率与不产ESBLs菌相比有显著差异 (P <0 0 5 ) ,对 3种抗生素 (亚胺培南、头孢哌酮 /舒巴坦、哌拉西林 /他唑巴坦 )的耐药率与不产ESBLs菌相比无显著差异。结论 :临床实验室应加强对ESBLs的检测 ,治疗产ESBLs菌引起的感染 ,应选用头霉素、碳青霉烯类及含酶抑制剂的复合抗生素。     

多聚酶链反应检测细菌DNA对大鼠空、回肠吻合口瘘的早期诊断价值

目的:探讨PCR检测大鼠外周血及腹水中细菌DNA对空肠-空肠、回肠-回肠吻合口瘘的早期诊断价值。方法:健康Wistar雌性大鼠50只，随机分成5组，每组10只：A组为假手术组;B组为空肠-空肠吻合组;C组为空肠吻合口瘘组;D组为回肠-回肠吻合组;E组为回肠吻合口瘘组。采集手术前后外周血及术后腹水，抽提DNA, 比较lacZ基因和16SrRNA基因的PCR阳性率，并观察各组的病理学情况。结果:（1）C，E组术后外周血lacZ基因PCR阳性率与B，D组无显著性差异（P>0.05）;C，E组术后外周血16SrRNA基因PCR阳性率显著高于B，D组（P<0.05）。（2）C，E组腹水lacZ基因和16SrRNA基因PCR阳性率均显著高于B，D组（P<0.05）。（3）C，E组腹水lacZ基因阳性率显著高于外周血（P<0.05）;C，E组腹水16SrRNA基因阳性率与外周血无显著性差异（P>0.05）。结论:（1）PCR检测术后外周血16SrRNA基因对空、回肠吻合口瘘的早期诊断有一定意义;（2）检测术后腹水lacZ基因和16SrRNA基因对空肠-空肠、回肠-回肠吻合口瘘的早期诊断也有一定意义。     

Effect of early and late antibiotic treatment in experimental acute pancreatitis in rats

Background The clinical course in acute necrotizing pancreatitis is mainly determined by bacterial infection of pancreatic and peripancreatic necrosis. The effect of two antibiotic regimens for early and late treatment was investigated in the taurocholate model of necrotizing pancreatitis in the rat. Materials and methods Seventy male Wistar rats were divided into five pancreatitis groups (12 animals each) and a sham-operated group (10 animals). Pancreatitis was induced by intraductal infusion of 3% taurocholate under sterile conditions. Animals received two different antibiotic regimes (20 mg/kg imipenem or 20 mg/kg ciprofloxacin plus 20 mg/kg metronidazole) early at 2, 12, 20, and 28 h after induction of pancreatitis or late at 16 and 24 h after induction of pancreatitis or no antibiotics (control). Animals were examined after 30 h for pancreatic and extrapancreatic infection. Results Early and late antibiotic treatment with both regimes could significantly reduce pancreatic infection from 58 to 8–25%. However, extrapancreatic infection was only reduced by early antibiotic therapy. While quinolones also reduced bacterial counts in small and large bowel, imipenem did not. Conclusions In our animal model of necrotizing pancreatitis, early and late treatment with ciprofloxacin/metronidazole and imipenem reduce bacterial infection of the pancreas. Extrapancreatic infection, however, is reduced significantly only by early antibiotic treatment. The effectivity of early antibiotic treatment in the clinical setting should be subject to further investigation with improved study design and sufficient patient numbers.     

国产与进口头孢他啶治疗小儿细菌性下呼吸道感染的成本-效果分析

目的对国产与进口头孢他啶治疗小儿细菌性下呼吸道感染进行成本—效果分析。方法对我院2008年10月-2009年10月间患小儿细菌性下呼吸道感染且单用头孢他啶治疗的住院患者136例进行回顾性分析,根据药品不同产地将其分为A、B两组,A组给与头孢他啶（国产）60mg/（kg·d）,分2次静脉滴注;B组给与头孢他啶（进口）60mg/（kg·d）,分2次静脉滴注,两组疗程均为7d,分别计算两组病人治疗后的细菌清除率、不良反应发生率,两组的治疗有效率和总成本,计算成本-效果比。结果疗程结束后A、B两组的药物治疗成本分别为：A组236.4元、B组982.5元,组间比较存在显著性差异（P〈0.05）;治疗有效率分别为：91.30%、94.03%;A、B两组的细菌清除率分别为：86.36%、90.70%;两组不良反应发生率分别为：5.80%、2.99%,组间比较差异均无显著性（P〈0.05）;两组成本-效果比分别为：2.59、10.45。结论国产头孢他啶的成本-效果比优于进口头孢他啶,为较佳的治疗方案。     

Endotoxin transfer through dialysis membranes: small- versus large-pore membranes.

In this in-vivo study, dialysate and serum endotoxin was evaluated before and after haemodialysis with small-pore (PS400) and large-pore (PS600) polysulphone dialysers, and before and after haemodiafiltration with the PS600 filter. The source of the endotoxin was the presence in dialysate of Pseudomonads at a concentration of 10(3)-10(4) CFU/ml. Endotoxin was measured by a modified chromogenic limulus amoebocyte lysate (LAL) assay. In spite of dialysate endotoxin concentrations greater than 100 pg/ml, no changes in pre- versus posttreatment LAL reactivity were observed in PS400 dialysis and PS600 haemodiafiltration. In contrast, PS600 haemodialysis was related to an increase in serum LAL reactivity from 1.3 +/- 1.5 to 3.8 +/- 2.0 pg/ml (n = 15, P less than 0.01), and five patients (33.3%) showed a post-dialysis value in excess of 5 pg/ml. Our data are consistent with the absence of in-vivo endotoxin transfer during haemodialysis with small-pore dialyser membranes, and during haemodiafiltration with membranes with larger pores. An increase in LAL reactivity during haemodialysis with membranes with larger pores is, however, present, presumably due to the occurrence of backdiffusion/filtration with that specific strategy.     

杀菌性通透性增强蛋白对失血性休克的保护作用及其机理

分别在失血和复苏开始即刻ｉｖ杀菌性／通透性增强蛋白（ＢＰＩ）１．５和３．５ｍｇｋｇ－１，观察ＢＰＩ对大鼠失血性休克转归的影响．结果显示，ＢＰＩ治疗能明显改善失血性休克大鼠肝肾功能，提高休克动物存活率（ＢＰＩ组８１％ｖｓ休克对照组４４％，Ｐ＜０．０５），ＢＰＩ组大鼠复苏后与休克前的血浆内毒素（０．２０±０．０４ｖｓ０．２４±０．０５ｋＵＬ－１）水平无明显变化，血浆肿瘤坏死因子α和白介素６水平较休克前明显升高，但均显著低于休克对照组．提示ＢＰＩ对失血性休克大鼠具有一定的保护作用，其机理可能与ＢＰＩ拮抗休克时内源性内毒素活性，抑制细胞因子反应有关．     

Splanchnic ischaemia and its role in multiple organ failure

Multiple organ failure remains the leading cause of death in the intensive care unit. Increasing numbers of investigators have focused their attention on the role of gastrointestinal tract in the pathogenesis of this syndrome. Their data indicate that inadequate gut perfusion leads to a measurable imbalance between oxygen delivery and the needs of the tissues, i.e., ischaemia. Gut ischaemia of sufficient duration impairs gastrointestinal tract barrier function, facilitating the passage of enteric bacterial endotoxin into the circulation. It has been hypothesized that production of tumor necrosis factor α, and other biologic mediators by endotoxin–stimulated macrophages, triggers a generalized and uncontrolled inflammatory response that ultimately leads to multiple organ failure.
Preliminary evidence suggests that survival can be improved significantly if gut ischaemia is promptly identifed and aggressively treated by administration of fluids and inotropic drugs, using gastric intramucosal pH as the therapeutic endpoint. Future studies are needed to determine whether additional treatment modalities can improve outcome once the inflammatory response has fully developed.     

Human monocyte interactions with non-enzymatically glycated collagen

Summary We have previously shown that receptors for advanced glycation end products are expressed on activated human monocytes. We now report that activated human monocytes exhibit increased adhesion to non-enzymatically glycated collagen substrates (+32%±1, p<0.001), and the increased adhesion can be competitively inhibited with non-enzymatically glycated albumin. Non-activated monocytes, which do not express receptors for advanced glycation end products, exhibit decreased adhesion (-16%±1, p<0.001). Similar results were observed with substrates of fibronectin and endothelial cell matrix proteins. As the presence of glycation adducts on collagen interferes with the normal binding of monocytes/macrophages, one possible role for advanced glycation adduct receptors on activated monocytes is to counterbalance such decreased adherence. Overcompensation for long periods of time may lead to pathological changes. Additionally, such receptors may play a role in monocyte-mediated remodelling of glycated matrix proteins, as we have observed increased degradation of nonenzymatically glycated collagen substrates by activated human monocytes at 2 h (+52%±11, p=0.01), 3 h(+49% ±10, p=0.01), and 4 h (+36%±6, p<0.01) after adding activated monocytes to ¹²⁵I-labelled substrates.     

Cerebrospinal fluid-filtration reduces TNF alpha in bacterial meningitis-CSF

A 37 year old male was admitted with the diagnosis of bacterial meningitis. Pneumococci were seen in the Gram stain of the cerebrospinal fluid. The clinical condition did not suggest severely raised intracranial pressure, there were no localizing signs and symptoms. CSF was turpid, with 20.100/3/mm³, mainly polymorphonuclear cells. Tumor necrosis factor alpha in CSp was greatly increased with 813 pg/ml. Parallel to the application of intravenous Penicillin G a CSF filtration was carried out. Within 214 h 225 ml CSF were filtrated through a Pall-filter, using a bidirectional pump. Cell count dropped to 720/3 cells/mm³, TNF-alpha to 39 pg/ml. The clinical course was uneventful, on day 12 the patient could be discharged without sequelae. CSF filtration may be a highly effective method to reduce from the CSF pathogenetically important cytokines, such as TNF-alpha, being responsible for intrathecal/meningeal inflammatory processes and triggered by cell-wall components of bacteria, e.g. pneumococci.     

Use of the microorganism Bacillus stearothermophilus as a model to evaluate toxicity of the lipophilic environmental pollutant endosulfan

Microorganisms are very powerful tools for the supply of information about the toxic effects of lipophilic compounds, since an impairment of cell growth usually occurs as a result of perturbations related, in most cases, with the partition of toxicants in membranes. The thermophilic eubacterium Bacillus stearothermophilus has been used as a model system to identify α- and β-endosulfan interactions with the membrane possibly related with the insecticide toxicity. Two approaches have been pursued: (a) bacterial growth is followed and the effects of endosulfan isomers determined; (b) biophysical studies with the fluorescent fluidity probe 1,6-diphenyl-1,3,5-hexatriene (DPH) were performed to assess the effects of α- and β-endosulfan on the organization of the membrane lipid bilayer. The effects on growth were quantitatively evaluated by determination of growth parameters, namely the lag phase, the specific growth rate and the cell density reached by cultures in the stationary phase. Growth inhibition by α and β-endosulfan dependent on the concentration is diminished or removed by the addition of 2.5 m Ca²⁺ to bacterial cultures. Fluorescence DPH polarization consistently showed opposite effects of Ca²⁺ and α- and β-endosulfan on the physical state of bacterial polar lipid dispersions.