Breeding and microbiological quality control of germ-free pigs / 中国实验动物学报

The industry of germ-free animals has been a hot spot in research along with the rapid development of studies on the relationship between microbiota and host diseases. Because it is pathogen?free, and the high degree of simi?larity in anatomy, physiology, pathogenesis to humans, germ?free pig is considered a clinical relevant model to be widely used in life science research. Based on the current state of research of germ?free pig cultivation at home and abroad and the experimental studies carried out in our laboratory as well, this article gives a simple discussion on germ?free technique of domestic pigs.

Isolating technologies development and used in gnotobiology / 中国比较医学杂志

To introduce germfree isolating technologies used in gnotobiology , and to compare the differences with in Cleaning Rooms, Restrictive Access Barrier Systems (RABS) and Isolators.To expect the development of isolators , and to describe the uses of isolators in gnotobioly .

Avaliação de indicadores biológicos na validação de processos de esterilização de isoladores por peróxidos de hidrogênio / Assessment of biological indicators in the validation of isolator decontamination with hydrogen peroxide

Os isoladores permitem a aplicação de descontaminação por gases, resultando em ambiente estéril. Esta característica, adicionada a possibilidade de não interferência humana no processo, torna o emprego dos isoladores consideravelmente vantajosa quando comparada com a performance dos processos em salas limpas convencionais. A descontaminação empregando peróxido de hidrogênio é vantajosa em relação a outros métodos disponíveis uma vez que é de fácil remoção após aplicação; sendo água e oxigênio seus produtos de degradação, apresenta boa compatibilidade com materiais usualmente empregados nas áreas produtivas; e seu custo é relativamente baixo. O propósito deste estudo foi demonstrar que o Geobacillus stearothermophilus (ATCC 12980) é o microrganismo mais resistente quando comparado com microrganismos isolados presentes em áreas produtivas, assim como avaliar o melhor material a servir de suporte durante a validação do processo de descontaminação das superfícies internas do isolador e externas de materiais presentes. Bacillus sp., Micrococcus luteus, Corynebacterium sp., Staphylococcus sp. e Penicilium sp. foram os microrganismos que apresentaram maior incidência na área produtiva. Aço inoxidável é o material mais adequado a ser usado como suporte para o emprego do peróxido de hidrogênio, por ser inerte e o principal componente dos isoladores e por não demonstrar incompatibilidade com o agente esterilizante. Os resultados obtidos nesta etapa do estudo demonstraram que o Geobacillus stearothermophilus é o microrganismo mais resistente para ser utilizado na avaliação da eficácia do peróxido de hidrogênio quando comparado com aqueles microrganismos encontrados na flora normal. Adicionalmente, o melhor suporte é o aço inoxidável, significando que os indicadores biológicos comercialmente disponíveis neste material são a melhor opção para este propósito.

Isolators allow decontamination gases to be employed to create a sterile processing environment. This feature, added to the potential removal of human interference in the process, makes the use of isolators rather advantageous, compared to performing aseptic processes in conventional clean rooms. Decontamination with vaporized hydrogen peroxide (VHP) offers several advantages over other available methods, as it decomposes to water and oxygen and is thus easy to remove after use, is highly compatible with materials usually employed in production areas and it is relatively cheap. The aims of this study were to prove that Geobacillus stearothermophilus (ATCC 12980) is more resistant than microorganisms isolated from the normal production area flora and to determine the best material to serve as a support during validation of the decontamination of the inner surfaces of isolators and outer surfaces of materials inside them. Bacillus sp., Micrococcus luteus, Corynebacterium, Staphylococcus sp. and Penicillium sp. were the microorganisms of highest incidence among those identified in the production area. Stainless steel is the best material to be used as a support for the VHP treatment of specimens, as it is inert and the main component of isolators and showed no incompatibility with this sterilizing agent. The results obtained in this phase of the experiment proved that Geobacillus stearothermophilus is the most resistant microorganism with which to challenge the effectiveness of hydrogen peroxide, when tested against species of the normal flora. Secondly, the best support material is stainless steel, showing that the commercial bioindicators available on the market with this support material are scientifically proved to be the best choice for this purpose.

Diagnosis of Central Venous Catheter-Related Sepsis Using Differential Quantitative Blood Cultures / 대한임상병리학회지

BACKGROUND: When central venous catheter (CVC) related sepsis is suspected based on clinical symptoms, removal of catheter is both diagnostic and therapeutic, but this approach leads to wastage of many sterile lines. Therefore, a reliable method to diagnose or exclude CVC sepsis without catheter removal is desirable. We performed differential quantitative blood cultures for the diagnosis of CVC related sepsis, in catheterized patients who had previous positive blood cultures. METHODS: Differential quantitative blood cultures were performed by collecting the blood specimens simultaneously via catheter and peripheral vein in 1.5 mL Isolator tubes (Wampole, USA). Sixty-three samples from 61 catheterized patients were taken and the colony counts from catheter blood samples were compared with those from peripheral samples. RESULTS: In 17 samples (27%), the colony counts from catheter blood samples were 5-fold higher than those from peripheral samples (the C/P ratio, > OR =5), suggesting CVC related sepsis; in 7 samples the C/P ratio was below 5, suggesting that sepsis was not CVC related. Of 35 samples (56%) in which no organisms were cultured, 2 samples were diagnosed as CVC related sepsis by the catheter tip culture. In 19 cases with proven CVC related sepsis, Candida spp. (n=8) and Gram-negative rods (n=7) were the predominant causative organisms and 16 cases (84%) were improved after catheter removal. CONCLUSIONS: This data show that quantitative blood culture method using Isolator may be very useful for diagnosing CVC related sepsis, especially in patients with positive blood cultures.

Development of a magnetorheological vibration isolator / 医疗卫生装备

Since vibration highly influences the performance of vehicles, the effective improvment of vibration isolation has a great significance for enhancing the economy, balance, stability and reliability of vehicles. Based on the variable viscosity properties of magnetorheological(MR) fluids with the variation of a external magnetic flied resulted from adjustable and controllable electric current, a magnetorheological vibration isolator is developed. Through experiment and application, it is proved that the magnetorheological vibration isolator can highly increase vibration isolation efficiency.

The study on optimization of inner environment of a negative pressure isolator for transportation of infectious disease patient / 医疗卫生装备

Objective Study and determine the suitable negative pressure condition for a negative pressure isolator. Method The filter efficiency, pressure, capabilities of inner environment and physiological parameters of the user were tested in different negative pressure conditions. Results The different negative pressure conditions influence above mentioned capabilities of the isolator considerably except for the filter efficiency Conclusion Under the conditions of -30Pa～-50Pa,those are optimized the capabilities of inner environment and physiological parameters of the user.