【摘要】 目的 探討老老年患者留置尿管內壁細菌生物被膜形成情況及其對導管相關感染(CRI)的影響。〖HTH〗方法〖HTSS〗 分析2007年2月—2009年10月住院的175例留置尿管患者,均為男性,年齡75~96歲,平均86歲。不同留置時間(7~15 d 53例、16~30 d 49例、31~45 d 44例、gt;45 d 29例)的尿管,于拔出尿管后運用超聲震蕩使尿管內表面生物被膜完全脫落,梯度稀釋后進行生物被膜活菌計數,細菌的培養分類及構成比分析；采用掃描電鏡觀察尿管內壁細菌生物被膜形成的情況；觀察尿管留置時間與生物被膜CRI的關系。結果 隨著尿管留置時間的延長,尿管內表面生物被膜活菌計數呈指數趨勢增長,CRI發生率有升高趨勢,各置管時段組間尿管內表面生物被膜活菌計數及CRI發生率比較差異均有統計學意義(Plt;0.05)。掃描電鏡見生物被膜的形成隨時間的延長而明顯增多。結論 細菌生物被膜形成是老老年患者留置尿管相關性尿路感染的重要致病因素,尿管留置時間越長,尿管生物被膜感染的危險性及幾率越高。更換尿管或縮短留置時間仍是防止尿管生物被膜感染的主要方法。
Objective To investigate the influence of hypoxic preconditioning on pulmonary structure of rats exposed to simulated high altitude hypoxia and to explore the role of hypoxia inducible factor-1α（HIF-1α）.Methods Fifty-six Wistar rats were randomly divided into 7 groups(n=8 in each group),ie,a normal control group(N group)，an acute hypoxic control group(H0 group)，an acute hypoxic group(H1 group)，a 3 000 m hypoxic preconditioning group(C3.0 group)，a 3 000 m hypoxic preconditioning + acute hypoxic group (C3.1 group)，a 5 000 m hypoxic preconditioning group(C5.0 group)，and a 5 000 m hypoxic preconditioning + acute hypoxic group(C5.1 group).After treated with hypoxic preconditioning，the animals were exposed to simulated altitude of 6 000 m for 24 hours.Then the protein and mRNA expression of HIF-1α in lung of N，H0，C3.0 and C5.0 groups were assessed by Western blot and RT-PCR，respectively.The lung structure in N，H1，C3.1 and C5.1 groups was observed by light microscope and electron microscope.Results Pulmonary interstitial edema was apparently observed in H1 group，while significantly relieved in two hypoxic preconditioning groups.HIF-1α protein was not detected in rat lungs by Western blot analysis.Compared to N group，the levels of HIF-1α mRNA significantly increased in C3.0 group and C5.0 group(both Plt;0.01).Conclusions Hypoxic preconditioning can relieve hypoxic pulmonary interstitial edema and increase HIF-1α mRNA expression in rat lungs.HIF-1 may be involved in the process of hypoxic preconditioning in rat lungs.