Low surface tension calcium hydroxide solution is an effective antiseptic

The antimicrobial effects of a saturated calcium hydroxide solution, and in combination with 10% and 20% detergent, were evaluated on Streptococcus faecalis. Strepto-coccus sanguis, Streptococcus mutans, Streptococcus salivarius, Neisseria sp., diphlheroid, Staphylococcus aureus, Lactobacillus sp., Staphylococcus epidermidis, Bacillus suhtilis and Candida albicans. The saturated calcium hydroxide solution was effective against only four of the 11 microorganisms studied over a 60-min exposure time. The calcium hydroxide solutions con-taining detergent killed all 11 test organisms over a 30-min exposure time. This difference was statistically significant (P<0.01). No statistically significant difference in antimicrobial action was found between the 10% and 20% detergent calcium hydroxide solutions (F>0.01). However, the low surface tension (46.5 × 10^?3 Nm^?1) and high pH (10.8) of the calcium hydroxide solution with 20% detergent establish it as the more effective solution.     

Oral mucosal desquamation caused by two toothpaste detergents in an experimental model

Sodium lauryl sulfate (SLS), the most widely used detergent in toothpastes, has been reported to cause adverse effects on oral soft tissues. This double-blind cross-over study describes the oral mucosal effects of SLS-containing toothpastes and pastes containing a zwitterionic detergent, cocoamidopropyl-betaine (CAPB) in an experimental model in 28 healthy females. Seven toothpastes, differing only in detergent concentration and/or type, were used: SLS (0.5, 1.0, 1.5%), CAPB (0.64, 1.27, 1.90%) and a placebo. Each participant applied 1 cm of assigned test toothpaste via a cap splint to the teeth and the mucosa of the upper jaw. The splints were used twice daily for 2 min during a period of 4 d, after which the participants were examined for oral desquamation. No other oral hygiene was allowed during the test periods. Ten days brushing with a detergent-free toothpaste was performed between each test period. Forty-five desquamative reactions were observed in 21 of 27 subjects (one was excluded) during the trial. Forty-two reactions were recorded during the SLS periods and the remaining three during the CAPB periods. The detergent-free toothpaste did not result in oral desquamation. SLS in toothpastes significantly increased the incidence of desquamation of the oral mucosa compared with toothpastes containing the detergent CAPB. The model used is not directly relevant to normal toothbrushing with toothpaste, but indicates that sensitive patients may contract mucosal irritation through SLS in toothpastes. Less toxic detergents, e.g. CAPB, are desirable in oral hygiene products.     

TD清洗消毒剂对口腔科器械消毒效果探讨

通过实验室和口腔科临床观察表明:TD清洗消毒剂(氯化磷酸三钠)对金黄色葡萄球菌、绿脓杆菌和枯草杆菌黑色变种的平均杀菌率为100.0％,对口腔科器械消毒无菌率为100％,对被HBsAg阳性血清污染的器械浸泡30分钟转阴率为98.1％。其消毒效果优于新洁尔灭,与戊二醛相同。在口腔科使用两年,未见金属器械有锈斑生成。     

Differential activation of hepatitis B DNA polymerase by detergent and salt

Three patterns of activity were evident when the differential activation of the DNA polymerase associated with serum Dane particles by nonionic detergent and salt was investigated. The patterns were obtained by plotting the increase in enzyme activity mediated by the detergent Nonidet P-40 (NP-40) in increasing concentrations of KCl compared to the activity observed in the absence of detergent. The pattern of differential activity of hepatitis B (HB) DNA polymerase in detergent and salt was altered by subjecting the HBAg preparations to shearing forces. Hepatitis B DNA polymerase activity was stable even in NP-40 concentrations as high as 10%. In addition to hepatitis B DNA polymerase, DNA polymerase activated by calf thymus DNA was found in pellets containing Dane particles. The latter DNA polymerase activity was also activated by NP-40 and was not decreased by DNAse; this DNA polymerase coprecipitated with hepatitis B antigen (HBAg) upon addition of anti-HBs. However, the DNA polymerase activated by calf thymus DNA was inhibited by 0.4 M KCl. Electron microscopic observations of serum Dane particles in 0.4 M KCl showed no alterations of morphology of these particles when compared to particles in low-salt buffer. The data indicated that KCl activated HB DNA polymerase by a different mechanism from that of shear or NP-40, which removed the surface antigen coat from the Dane particles.     

鲁沃夫清洗液在内镜清洗中的应用

目的观察鲁沃夫(Ruhof)多酶清洗液在内镜中的应用效果。方法对使用后的内镜80例次采用卫生部规定的四槽法进行多酶清洗液清洗,观察清洗后镜身表面附着物、喷嘴堵塞、内镜表面清洁度的变化。结果Ruhof多酶清洗液清洗后,镜身表面附着物、喷嘴堵塞、表面清洁度评价值显著下降,清洗前后差值比较差异有统计学意义(P<0.01)。结论Ruhof多酶清洗液是一种理想的内镜清洗剂,能有效清洗,减少医源性交叉感染的发生。     

流动注射在线萃取法测定饮用水中阴离子合成洗涤剂

目的：探讨使用流动注射在线萃取法测定饮用水中阴离子合成洗涤剂含量的方法。方法利用阴离子合成洗涤剂中的主要成分可与碱性亚甲基蓝形成离子对络合物的原理,采用QC8500型流动注射仪对水中阴离子合成洗涤剂含量进行定量分析。本研究分别对方法的检出限、精确度、准确度进行了测定,并对饮用水样品进行检测,最后将检测结果与国家标准方法所得结果进行了比较。结果方法线性范围为0.025~1.00 mg/L,相关系数r值为0.9996,相对标准偏差为2.04%~4.35%,最低检出限为5.2μg/L,回收率为95.5%~105.3%。结论使用流动注射在线萃取法测定饮用水中阴离子合成洗涤剂,方便、快捷、稳定、准确、灵敏度高,符合阴离子合成洗涤剂的检测要求。     

Translocation t(5;12)(q31-q33;p12-p13): a non-random translocation associated with a myeloid disorder with eosinophilia

SUMMARY. To investigate the clinical significance of determination of plasma tissue factor (TF) antigen, we have developed a highly sensitive enzyme-linked immunosorbent assay (ELISA) for plasma TF, using two different monoclonal antibodies against TF apoprotein, 6B4 (catching antibody) and 5G9 (detecting antibody), and tetramethyl benzidine/H₂O₂ as substrates. Titration curves of recombinant human TF in buffer containing Triton X-100 were linear within the range from 50 to 2000pg/ml. The total assay time was 3h. Ultracentrifugation and immunoblot analysis indicated that human plasma and urine contained 50 000 g sedimentable and non-sedimentable forms of TF, both of which were detected by our ELISA method.
Plasma and urine concentrations of TF in healthy subjects and patients with various diseases were measured by the ELISA method. In healthy subjects, plasma and urinary TF levels were found to be 149± 72pg/ml (n = 30) and 175±60pg TF/urine creatinine mg (n = 95). respectively. TF was increased in plasma of patients with disseminated intravascular coagulation (DIC), thrombotic thrombocytopenic purpura, vasculitis associated with collagen diseases, diabetic microangiopathy and chronic renal failure receiving haemodialysis, but not in the plasma of endotoxaemic patients without DIC. The plasma TF/serum creatinine ratio did not show a positive correlation. Measurement of TF antigen in plasma may be useful for evaluating the endothelial damage and cell destruction in TF-containing tissues.     

Dynamics of a bacterial multidrug ABC transporter in the inward- and outward-facing conformations

The study of membrane proteins remains a challenging task, and approaches to unravel their dynamics are scarce. Here, we applied hydrogen/deuterium exchange (HDX) coupled to mass spectrometry to probe the motions of a bacterial multidrug ATP-binding cassette (ABC) transporter, BmrA, in the inward-facing (resting state) and outward-facing (ATP-bound) conformations. Trypsin digestion and global or local HDX support the transition between inward- and outward-facing conformations during the catalytic cycle of BmrA. However, in the resting state, peptides from the two intracellular domains, especially ICD2, show a much faster HDX than in the closed state. This shows that these two subdomains are very flexible in this conformation. Additionally, molecular dynamics simulations suggest a large fluctuation of the Cα positions from ICD2 residues in the inward-facing conformation of a related transporter, MsbA. These results highlight the unexpected flexibility of ABC exporters in the resting state and underline the power of HDX coupled to mass spectrometry to explore conformational changes and dynamics of large membrane proteins.     

Impact of solvent/detergent treatment of plasma on transfusion-relevant bacteria

Background A solvent/detergent (S/D) treatment in a medical device has been developed for pathogen reduction of plasma for transfusion. Impact of S/D on bacterial growth and on the capacity of complement to kill bacteria has been investigated in this study. Study design and methods A pool of apheresis plasma from four donors was spiked with eight transfusion‐relevant bacteria. Plasma was treated with 1% tri(n‐butyl) phosphate and 1% Triton X‐45 at 31°C for 90 min and then extracted by oil at 31°C for 70 min. Decomplemented plasma and Phosphate Buffer Saline were used as controls. Bacterial count was determined in samples taken immediately after spiking, or after S/D and oil treatment. Similar experiments were conducted using three individual recovered plasma donations. Bacteria growth inhibition tests were performed using discs soaked with plasma samples whether containing the S/D agents or not. Results The mean reduction factors of Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae due to complement during S/D treatment were >8·75, 4·71, and 4·18 log in pooled plasma and >7·42, 2·24 and >6·08 log in individual plasmas, respectively. Bacillus cereus and Bacillus subtilis were inactivated by S/D (>7·04 and 1·60 log in pooled, and >6·06 and 2·39 in individual plasmas, respectively). Staphylococcus aureus, Staphylococcus epidermidis and Enterobacter cloacae did not multiply during S/D treatment of plasma. Growth inhibition tests revealed an inhibition of three Gram‐negative bacteria by complement and all Gram‐positive by S/D. Conclusion The S/D treatment of plasma does not alter the bactericidal activity of complement, and inactivates some Gram‐positive bacteria.     

健乐牌洗消片杀菌性能的研究

研制的健乐牌洗消片以二氯异氰尿酸钠为主成分,对细菌繁殖体与芽胞有良好杀灭作用。用于餐具消毒,以含500ppm有效氯溶液作用1～2分钟即可。其杀菌作用可被有机物减弱,但所试pH与水质硬度对之无影响。浓度与温度升高,或作用时间延长有利于其杀菌作用。