A new aspect of in vitro antimicrobial leukocyte- and platelet-rich plasma activity based on flow cytometry assessment

The current literature suggests that the antibacterial effect of leukocyte- and platelet-rich plasma (L-PRP) is directly related to platelet and leukocyte concentrations. The aim of this study was twofold: first, to evaluate the antimicrobial effect of L-PRP against selected bacterial strains in vitro, and second, to correlate this effect with leukocyte and platelet content in the final concentration. Blood was collected from 20 healthy males, and L-PRP, acellular plasma (AP), and autologous thrombin were consecutively prepared. Flow cytometry analysis of the blood, L-PRP, and AP was performed. The L-PRP gel, liquid L-PRP, and thrombin samples were tested in vitro for their antibacterial properties against seven selected bacterial strains using the Kirby–Bauer disk-diffusion method. There was notable antimicrobial activity against selected bacterial strains. No statistically significant correlations between antimicrobial activities and the platelet concentration in L-PRP were observed. Statistically significant positive correlations between selected leukocyte subtypes and antimicrobial activity were noted. A negative correlation was found between elevated monocyte count and antimicrobial activity of L-PRP against one bacterial strain studied. L-PRP possesses antimicrobial activity and can be potentially useful in the fight against certain postoperative infections. The bactericidal effect of L-PRP is caused by leukocytes, and there exists a relationship among selected leukocyte subtypes and L-PRP antimicrobial activity.     

Phenotypic and genetic features of enteropathogenic Escherichia coli isolates from diarrheal children in the Ribeirão Preto metropolitan area,São Paulo State,Brazil

This study was designed to characterize a collection of 60 enteropathogenic Escherichia coli (EPEC) isolates from diarrheic feces of patients in the Ribeirão Preto metropolitan area regarding different phenotypic and molecular features. We examined antibiotic resistance profiles, occurrence of virulence factors‐encoding genes, intimin subtypes and the correlation of serotypes among typical (tEPEC) and atypical (aEPEC) EPEC isolates. The results demonstrated that atypical EPEC was more heterogeneous than typical EPEC concerning the characteristics investigated and 45.2% do not belong to classical EPEC serogroups. Intimin subtype β was the most frequent among the EPEC isolates (46.7%), being detected in both tEPEC and aEPEC. The majority of aEPEC isolates presented localized adherence‐like (LAL) pattern to HEp‐2 cells, although aEPEC isolates displaying diffuse adherence (DA) or non‐adherent were also detected. High prevalence of antimicrobial resistance was found for ampicillin, cephalothin, sulfonamide and tetracycline. In general, tEPEC isolates were more resistant to the antimicrobials tested than aEPEC isolates.     

铜绿假单胞菌噬菌体PaP3生物学特性的研究

目的测定铜绿假单胞菌噬菌体PaP3的最佳感染复数、一步生长曲线和吸附K值及交叉吸附K值等基本生物学特性。方法按照感染复数（MOI）分别为0．0001、0．001、0．01、0．1、1和10加入噬菌体纯培养液和宿主菌，充分裂解细菌后，测定噬菌体滴度；以MOI=10的比例加入噬菌体及宿主菌，进行一步生长实验；纯化PaP3颗粒，免疫家兔，获得抗血清，通过中和反应实验测定PaP3和其抗血清之间的吸附反应常数K值。同时，利用抗血清交叉中和试验确定本室分离的三株噬菌体之间的血清学关系。结果当MOI=0．001时PaP3感染其宿主菌产生的子代噬菌体滴度最高；根据一步生长实验结果绘制一步生长曲线；通过血清交叉中和反应得出不同的吸附常数。结论PaP3最佳感染复数为0．001，感染宿主菌的潜伏期是20min，爆发期是60min，平均爆发量约为31，其抗血清反应的吸附常数K值为262。     

三环形回肠贮袋-肛管吻合术在全结肠切除术中的应用

目的探讨全结肠切除后三环形回肠贮袋-肛管吻合加选择性截流术的价值。方法1994年9月至2004年9月对18例全结肠切除患者应用三环形回肠贮袋加选择性截流术,其中家族性大肠腺瘤性息肉病14例,溃疡性结肠炎4例。结果18例获12月～5年随访,无手术死亡。术后发生并发症3例(16.7%),贮袋阴道瘘、早期炎性肠梗阻、切口感染各1例,均治愈。术后平均排便频率:术后2周内4.9次/d,1个月3.8次/d,6个月3.1次/d,1年1.8次/d。至6个月时都能控制干便,其中控制正常者15例(83.3%),控制欠佳者3例(16.7%),无大便失禁。但稀便控制能力较差,至1年时仍有1例(5.6%)患者稀便失禁。无一例须插管排空。结论全结肠切除后三环形回肠贮袋肛管吻合加选择性截流术操作简单,手术并发症少,术后排便功能好,是家族性大肠腺瘤性息肉病和严重溃疡性结肠炎全结肠切除后较为合适的消化道重建方式。     

钛对大肠杆菌生长影响的实验研究

以草酸钛钾溶液为受试物，用无菌操作法在不同浓度试验水样及不含钛的对照水样中加入大肠杆菌稀释液1ml（含菌300个），观察6小时和1－7天的细菌生长情况。结果各受试组与对照组比较，10.0mg／L和1．0mg／L组接触6小时至7天大肠杆菌生长均有明显的抑制作用；0．1mg／L组接触6－24小时显示抑制作用，但第4天开始菌落减少的速度比对照组缓慢。提示钛对大肠杆菌的生长有抑制作用，其作用阈浓度为1．0mg／L，阈下浓度为0，1mg／L。     

Antibacterial activities of the leaf extracts of Eugenia uniflora Linn. (Synonym Stenocalyx michelli Linn.) Myrtaceae

The aqueous, organic, and volatile oil extracts of leaves of Eugenia uniflora Linn. Family Myrtaceae were investigated for antibacterial properties using agar dilution techniques. The aqueous extract was the most active against the organisms compared to the organic and volatile oil extracts. The extracts were found to inhibit Gram positive Staphylococcus aureus and Bacillus subtilis and Gram negative Escherichia coli and Shigella dysentcriae. Pseudomonas aeruginosa, Klebsiella pneumoniac, and Salmonella typhi were not inhibited.     

用头孢西丁三相试验检测大肠埃希菌及肺炎克雷伯菌的质粒AmpC酶

目的：检测质粒介导的持续高产AmpC酶在大肠埃希菌及肺炎克雷伯菌中的携带率，为临床治疗提供指导。方法：采用头孢西丁纸片药敏试验（K-B法）作AmpC酶的初筛试验，头孢西丁三相试验间接法作AmpC酶的确证试验。结果：在检测的86株菌中，有9株菌K-B法初筛结果为阳性。在这9株菌中经头孢西丁三相试验确证有5株产AmpC酶，阳性率为5.8%。其中大肠埃希菌3株，肺炎克雷伯菌2株。结论：头孢西丁K-B法筛选试验结合头孢西丁三相试验可准确检出质粒介导的AmpC酶，可用于临床常规检测。     

幽门螺杆菌ureB基因表达产物的反应原性

目的：克隆幽门螺杆菌ureB基因，并进行表达，验证表物的反应原性。方法：应用PCR技术从技术临床分离株中扩增出ureB基因，克隆入载体pGEM-7zf( ）进行测序，进一步转到友大肠杆菌表达载体pBV220进行诱导表达，以Western blot实验验证重组蛋白的反应原性。结果：测序后经同源性比较，证实扩增后得到的片断确为ureB基因，并原核表达出可被抗Hp抗体识别的非融合重组蛋白。结论：获得了有反应原性的重组ureB蛋白。     

人离体骨肉瘤组织血管噬菌体肽库筛选模型的建立及其意义

目的建立人离体骨肉瘤血管亲和筛选模型。方法(1)建立模型。术前对患肢局部行数字减影造影检查,标记肿瘤固有动脉大致走行,术后小心修剪,并连接类似于Langendorff的灌流装置,监控模型血管内的pH值、温度、氧分压等;(2)对噬菌体十二肽库进行筛选。结果28例骨肉瘤离体标本均建模成功,可直接用于灌流实验,并筛选出具有较高特异性的亲和短肽(基序为RLTR),各项指标显示离体骨肉瘤较好模拟了人体内的环境。结论建立人离体骨肉瘤血管亲和筛选模型是可行的,可直接用于对噬菌体随机肽库的亲和筛选,为骨肉瘤的靶向化疗提供参考。