Effects of a Peracetic Acid Disinfection Protocol on the Biocompatibility and Biomechanical Properties of Human Patellar Tendon Allografts

Patellar tendon allografts, retrieved from cadaveric human donors, are widely used for replacement of damaged cruciate ligaments. In common with other tissue allografts originating from cadaveric donors, there are concerns regarding the potential for disease transmission from the donor to the recipient. Additionally, retrieval and subsequent processing protocols expose the graft to the risk of environmental contamination. For these reasons, disinfection or sterilisation protocols are necessary for these grafts before they are used clinically. A high-level disinfection protocol, utilising peracetic acid (PAA), has been developed and investigated for its effects on the biocompatibility and biomechanics of the patellar tendon allografts. PAA disinfection did not render the grafts either cytotoxic or liable to provoke an inflammatory response as assessed in vitro . However, the protocol was shown to increase the size of gaps between the tendon fibres in the matrix and render the grafts more susceptible to digestion with collagenase. Biomechanical studies of the tendons showed that PAA treatment had no effect on the ultimate tensile stress or Young's modulus of the tendons, and that ultimate strain was significantly higher in PAA treated tendons.     

Application of HACCP to identify hygiene risks in the home

Hygiene related health hazards in the home include ingestion of microorganisms or toxins, inhalation of toxins, allergens or microorganisms and infections through the skin. Bacteria, fungi and viruses may all be involved. For any particular family these hazards translate into different risks ranging from mild irritations to serious health threats. These will require different responses in terms of hygiene practice and hygiene product use. The consumer needs help to identify which hazards in his/her home pose a high risk and which are insignificant. Risk analysis techniques especially HACCP (Hazard analysis—critical control point) have been proven as effective tools in controlling hazards in the food industry. We have applied HACCP principles to a risk analysis of a typical home. We conclude that further studies are warranted and to focus on particular groups (e.g. families with infants, pensioners). Such information could be valuable in drawing up hygiene codes of practice and for forming the basis of educational material aimed at different target groups.     

屏障环境的门禁控制系统的设计与应用

实验动物屏障环境设施在动态运行时是一个封闭的系统,进入的人、动物、饲料、空气、垫料及用品均须进行严格的微生物控制。传递仓、渡槽、风淋室和缓冲间设备上的控制环节缺少必要的门禁自动化控制设备,在日常工作上极容易造成违章操作和失误,该门禁系统可控制设备的开关门程序和时间,并可启动消毒设备,实现门禁控制和消毒灭菌的目的。     

Dichloroacetate- and trichloroacetate-induced phagocytic activation and production of oxidative stress in the hepatic tissues of mice after acute exposure

Dichoroacetate (DCA) and trichloroacetate (TCA) are by-products formed during chlorination of the drinking water and were found to be hepatotoxic and hepatocarcinogenic in rodents. In this study, the abilities of the compounds to induce oxidative stress and phagocytic activation have been studied in B6C3F1 mice. Groups of mice were administered 300 mg/kg of either DCA or TCA, p.o, and were sacrificed after 6 or 12 h. Peritoneal lavage cells (PLCs) were isolated and assayed for superoxide anion (SA) production, and hepatic tissues were assayed for the production of SA, lipid peroxidation (LP), and DNA-single strand breaks (SSBs). TCA resulted in significant production of SA in the PLCs, and in the production of SA, LP, and DNA-SSBs in the hepatic tissues, 12 h after dosing, as compared with the control. DCA administration, on the other hand, resulted in significant increases in the productions of LP and DNA-SSBs in the hepatic tissues at both time points, and in SA production in PLCs and hepatic tissues, 6 h after dosing. However, DCA-induced increases in SA production in PLC and hepatic tissues declined at the 12-h time point, reaching control level in the hepatic tissues. These results may implicate the contribution of phagocytic activation to the induction of oxidative stress in the hepatic tissues and also the role of SA production in the induction of LP and/or DNA damage in those tissues, in response to the compounds. The results also suggest studying the involvement of these mechanisms in the long-term hepatotoxicity/hepatocarcinogencity of the compounds.     

花梨木组织培养外植体消毒方法初步探讨

针对在花梨木(Dalbergia odofifera T. Chen)组织培养过程中外植体的有效消毒方法进行研究。外植体消毒主要以2年生以上实生苗的茎段为材料,开展了茎段外植体次氯酸钠(5%,10%,15%)和升汞(0.05%,0.1%,0.2%)3个浓度水平的消毒试验。在此基础上,开展了外植体消毒的时间试验,次氯酸钠消毒时间为10 min、20 min、30 min,升汞消毒时间为5 min、10 min、15 min。结果表明：茎段外植体采用10%浓度的次氯酸钠消毒效果较好,最佳消毒方式75%的酒精浸泡2 min,10%次氯酸钠消毒20 min,该方法污染率最低、存活力最高。     

The use of bacteriophages of Bacteroides fragilis as indicators of the efficiency of virucidal products

The potential use of bacteriophage B40-8 of Bacteroides fragilis for the evaluation of the virucidal activity of antiseptics or disinfectants was investigated. The antiviral activity of two antiseptics and two disinfectants was evaluated according to a standard guideline. The effect of the virucidal agents was assessed on (i) viruses usually spread by direct contact with surfaces with contaminated secretions, i.e. herpes virus 1 and 2, and vaccinia virus, and (ii) viruses transmitted by the fecal-oral route, i.e. hepatitis A virus, poliovirus, adenovirus and rotavirus. The survival of B40-8 always equalled or exceeded that of the animal viruses tested. Our data suggest the use of bacteriophage B40-8 to complement the information furnished by some standardized methods in ascertaining the antiviral activity of virucidal preparations.     

Modulation by ellagic acid of DCA-induced developmental toxicity in the zebrafish (Danio rerio)

The ability of ellagic acid (EA) to modulate dichloroacetic acid (DCA)-induced developmental toxicity and oxidative damage was examined in zebrafish embryos. Embryos were exposed to 20 mM EA administered concomitantly with 32 mM DCA at 4 hours postfertilization (hpf) and 20 h later. Embryos were observed through 144 hpf for developmental malformations, and production of superoxide anion (SA) and nitric oxide (NO) was determined in embryonic homogenates. DCA was shown to produce developmental abnormalities and significant levels of SA and NO in zebrafish embryos. EA exposure alleviated the developmental malformations observed in treated embryos and decreased the levels of SA and NO in those same embryos. Less than 10% of DCA + EA exposed embryos showed developmental malformations compared to 100% of embryos treated with DCA alone. Animals in this group that developed malformations were shown to have fewer defects than those treated with DCA only. Taken together, the results confirm the involvement of oxidative stress in the developmental toxicity of DCA in zebrafish embryos, and suggest possible protection against those effects with the use of antioxidants.     

Comparison of assays for Cryptosporidium parvum oocysts viability after chemical disinfection

Abstract In vitro excystation, vital dyes (4', 6-diamidino-2-phenylindole (DAPI) and propidium iodide (PI)), and infeictivity in neonatal CD-1 mice were used to assess the viability of Cryptosporidium parvum oocysts after chemical disinfection. In vitro excystation and DAPI/PI staining provided similar estimates of viability in bench-scale experiments, but both of these methods significantly overestimated the viability when compared with infectivity (Pr ≤ 0.01). Infectivity was the most reliable measure of the viability of C. parvum oocysts following chemical disinfection.     

The combined effects of various disinfectants against poliovirus 1 in a municipal wastewater effluent

Abstract The effects of the combination of any two of the following disinfectants: chlorine, chlorine dioxide, ozone and peracetic acid were investigated using poliovirus 1 as a model virus in a municipal sewage effluent. It was noted that the efficacy of chlorine was enhanced in the presence of either chlorine dioxide, ozone or peracetic acid. Maximum enhancement was achieved when peracetic acid was present with either chlorine or ozone and less enhancement was noted when the peracetic acid was added before chlorine dioxide. Similar results were noted when hydrochloric acid was used instead of peracetic acid. It may be concluded that the application of any two of the disinfectants studied were rarely synergistic but merely additive or complementary (i.e., one disinfectant provides the other with a medium in which it functions better).     

Reliability of using urinary and blood trichloroacetic acid as a biomarker of exposure to chlorinated drinking water disinfection byproducts

This study was designed to analyse the reliability of using urinary and blood trichloroacetic acid (TCAA) as a biomarker of exposure. A total of 46 healthy women consumed supplied TCAA-containing tap water for 15 days and provided urine and blood samples for TCAA measurements. The findings revealed that the reliability of measurements was excellent by using measures of TCAA ingestion, blood concentration and urinary excretion (intraclass correlation coefficients (ICC)?>?0.75, p??0.95, p?相似文献