Toll样受体3介导呼吸道合胞病毒感染人肺上皮细胞的炎性反应及其信号转导通路

目的:观察呼吸道合胞病毒感染肺上皮细胞A549后Toll样受体3表达的变化,探讨Toll样受体3介导呼吸道合胞病毒感染肺上皮细胞的炎性反应及其介导的信号转导通路。方法:实验于2006-05/12在安徽医科大学基础医学院分子生物学实验室完成。用呼吸道合胞病毒感染体外培养的A549细胞,于感染后4,8,16,24h收集细胞和细胞培养上清。用Trizol提取细胞总RNA,RT-PCR法检测TOLL样受体3mRNA、肿瘤坏死因子αmRNA表达的变化;提取细胞总蛋白和核蛋白,免疫印迹法分别检测TOLL样受体3蛋白、核内活性核因子κB的变化;用ELISA检测细胞培养上清肿瘤坏死因子α的表达。以未感染病毒的细胞为正常对照组。结果:①呼吸道合胞病毒感染A549细胞后,Toll样受体3和肿瘤坏死因子α的mRNA和蛋白的表达量均升高且有时间依赖性,Toll样受体3mRNA24h表达量是基础表达量的5倍多,肿瘤坏死因子αmRNA24h表达量是基础表达量的3倍多。②A549细胞中核内活性核因子κB有基础表达,经由呼吸道合胞病毒感染,核内活性核因子κB随感染时间的延长升高;同时呼吸道合胞病毒感染能促进Toll样受体3蛋白的表达,高于正常对照组(P<0.01)。③呼吸道合胞病毒感染能促进A549细胞分泌肿瘤坏死因子α,感染24h分泌达到高峰。结论:呼吸道合胞病毒感染A549细胞后上调Toll样受体3表达,其诱导的炎性反应与Toll样受体3介导的信号转导途径有关。     

Ⅳ型胶原黏附法分选表皮干细胞

目的:评估Ⅳ型胶原黏附法分选表皮干细胞的分选效果及对细胞生物学特性的影响。方法:实验于2004-11/2005-05在中山大学附属第一医院外科实验室完成。选取中山大学附属第一医院外科门诊包皮环切手术患者的皮肤标本5份(患者知情同意),进行表皮细胞的分离培养。取培养的二三代表皮细胞,消化后加入铺有100mg/LⅣ型胶原的培养瓶中分选。取分选细胞悬液于培养箱中过夜培养,第2天取出爬片,磷酸缓冲液冲洗3min×2次,去除残留培养液,4%多聚甲醛室温下固定10min,磷酸缓冲液冲洗3min×2次,以含0.1%Triton-100的3%山羊血清封闭、透膜20min,滴加稀释好的角蛋白K19/β1整合素抗体进行双标,4℃过夜孵育,磷酸缓冲液冲洗3min×2次,加入配置好的双标用二抗,37℃下孵育20min,磷酸缓冲液冲洗3min×2次,加入5mg/L的Hochest33258,标记细胞核,37℃下孵育5min,磷酸缓冲液冲洗3min×2次,滴加含40%甘油的碳酸氢钠缓冲液,盖玻片封片,以上步骤均在暗室中操作,同时以磷酸缓冲液代替一抗作为阴性对照。激光共聚焦显微镜下观察,拍照。同时表达角蛋白K19、β1整合素认为是表皮干细胞。分别取分选前及筛选后细胞各4×106个,检测表皮干细胞(α6briCD71dim细胞)、短暂扩增细胞(α6briCD71bri细胞)及终末分化细胞(α6dim细胞)的百分率及分选前后的细胞周期。结果:①分选后细胞体积小,均匀一致,核浆比例大,免疫荧光检测同时表达K19、β1整合素。②与分选前细胞比较,分选后细胞中表皮干细胞α6briCD71dim细胞、短暂扩增细胞α6briCD71bri细胞的百分率明显增高,差异显著[(9.41±0.31)%,(38.74±1.09)%;(43.66±1.12)%,(48.92±2.49)%,P<0.01]。③与分选前细胞比较,分选后细胞G0/G1期所占比例明显增高,差异显著[(80.80±1.69)%,(94.37±1.32)%,P<0.01]。提示分选后细胞处于相对静止状态的表皮干细胞所占比例高。结论:Ⅳ型胶原黏附分选出的细胞含有高纯度的表皮干细胞,此分选方法对细胞活力无明显影响。能够为组织工程皮肤构建提供理想的种子细胞。     

改进色差计探头解决前牙唇面形态测量边缘漏光

目的:通过改进色差计探头解决测量前牙冠表面颜色时边缘漏光问题。方法:实验于2005-09/2006-01在第二军医大学长海医院口腔实验室完成。随机抽取临床常用复合树脂牙(Heraeus-Kulzer Shanghai,China)L/A468型21色中切牙、侧切牙、尖牙,各8付。试验材料由上海齿科材料厂提供。分别用改进前后的色差计测量涂有红色涂料的前牙唇面颈、中、切部色度值,计算所测色度值与红色涂料实际色度值之间的色差值,进行两组色差之间的对比分析,色差公式为ΔEab*=｛(ΔL#)2 (Δa*)2 (Δb*)2｝1/2。结果:未经改进的色差计探头测得的上颌中切牙、侧切牙中部颜色的色差值小于颈部和切部(分别为2.28±2.79,3.88±1.17,3.41±1.94;2.24±1.36,3.31±1.99,3.89±1.29,P<0.05),测得的尖牙中部色差值远小于其颈部、切部的色差值(分别为4.73±2.89,8.35±1.86,11.07±2.46,P<0.01),大于中切牙、侧切牙各部分的色差值(P<0.05)。改进后的色差计探头与未改进的相比较,测得的上述色差值均明显变小(P<0.05),其中,中切牙、侧切牙的颈部、中部和切部的色差值均<2,而尖牙中部的色差值为2.85±1.19,颈部色差值3.71±1.24,色差均<4,切部色差值仍然偏大(8.51±2.68)。结论:改进后的色差计探头可以解决部分凹凸程度较小的牙冠表面边缘漏光问题,使测色结果更加准确可靠,但对尖牙切部的屏蔽效果不佳。     

Guideline implementation results in a decrease of pressure ulcer incidence in critically ill patients

OBJECTIVE: To describe the short-term and long-term effects of a hospital-wide pressure ulcer prevention and treatment guideline on both the incidence and the time to the onset of pressure ulcers in critically ill patients. DESIGN: Prospective cohort study. SETTING: Adult intensive care department of a university medical center. PATIENTS: Critically ill patients (n = 399). INTERVENTIONS: A guideline for pressure ulcer care was implemented on all intensive care units. The attention of nurses for timely transfer to a specific pressure-reducing device was an important part of this guideline. MEASUREMENTS AND MAIN RESULTS: Patient characteristics, demographics, pressure ulcer risk profile at admission, daily pressure ulcer grading, and type of mattress were determined to describe the short-term and long-term effects 3 and 12 months after the implementation. The incidence density of pressure ulcers grade II-IV decreased from 54 per 1000 patient days at baseline to 32 per 1000 days (p = .001) 12 months after the implementation. The median pressure ulcer-free time increased from 12 days to 19 days (hazard rate ratio, 0.58; p = .02). After adjustment for differences in risk factors in a Cox proportional hazard model, the number of preventive transfers to special mattresses was the strongest indicator for the decreased risk of pressure ulcers (hazard rate ratio, 0.22; p < .001). The number needed to treat to prevent one pressure ulcer during the first 9 days was six. CONCLUSIONS: The implementation of a guideline for pressure ulcer care resulted in a significant and sustained decrease in the development of grade II-IV pressure ulcers in critically ill patients. Timely transfer to a specific mattress (i.e., transfer before the occurrence of a pressure ulcer) was the main indicator for a decrease in pressure ulcer development.     

Transfusion transmission of retroviruses: human T-lymphotropic virus types I and II compared with human immunodeficiency virus type 1

BACKGROUND: The incidence of transfusion transmission of human T- lymphotropic virus type I (HTLV-I) and HTLV type II (HTLV-II) has not been compared directly or to that of human immunodeficiency virus type 1 (HIV-1). The effects of refrigerator storage of the blood component on infectivity of the viruses needs definition. STUDY DESIGN AND METHODS: The circumstances influencing the transmission of HTLV-I, HTLV- II, and HIV-1 via blood of donors whose sera were stored in a repository and who were retrospectively documented as having been infected at blood donation were examined. Confirmation and typing of anti-HTLV positivity in donors and recipients used polymerase chain reaction, supplemented by specific peptide testing. RESULTS: Overall, 27 percent (26/95) of the recipients of blood components from anti-HTLV- I- and -II-positive donors became infected (9 with HTLV-I and 17 with HTLV-II). No recipients of acellular blood components became infected with HTLV-I or -II. There was no probable transmission by components stored > 10 days. The rates of transmission for both viruses were similar: 0 to 5 days' storage, 17 (74%) of 23; 6 to 10 days, 8 (44%) of 18; and 11 to 14, 0 (0%) of 10 (trend, p = 0.0002). In comparison, 89 percent (112/126) of the recipients of anti-HIV-1-positive blood were infected regardless of component type, and no effect on transmission occurred with storage for < 26 days. CONCLUSION: Transfusion- transmitted HTLV-I and -II are similar. The data suggest that a donor's lymphocytes become noninfectious when they lose the ability to be activated or to proliferate.     

Donor ductal anomaly is not a contraindication to right liver lobe donation

BackgroundData of living-donor liver transplantation (LDLT) suggested that donor ductal anomaly may contribute to postoperative biliary complications in recipients and in donors. This retrospective study aimed to determine if the occurrence of postoperative biliary stricture in donors or recipients in right-lobe LDLT (RLDLT) is related to donor biliary anatomy type.MethodsWe analyzed our RLDLT recipients’ clinical data and those of their graft donors. The recipients were divided into 2 groups: with and without postoperative biliary stricture. The 2 groups were compared. The primary endpoints were donor biliary anatomy type and postoperative biliary complication incidence; the secondary endpoints were 1-, 3- and 5-year graft and patient survival rates.ResultsTotally 127 patients were included in the study; 25 (19.7%) of them developed biliary anastomotic stricture. In these 25 patients, 16 had type A biliary anatomy, 3 had type B, 2 had type C, 3 had type D, and 1 had type E. In the 127 donors, 96 (75.6%) had type A biliary anatomy, 13 (10.2%) had type B, 6 (4.7%) had type C, 10 (7.9%) had type D, and 2 (1.6%) had type E. Biliary stricture was seen in 2 donors, who had type A biliary anatomy. None of the recipients or donors developed bile leakage. No association between the occurrence of postoperative biliary stricture and donor biliary anatomy type was found (P = 0.527).ConclusionsThe incidence of biliary stricture in donors or recipients after RLDLT was not related to donor biliary anatomy type. As postoperative complications were similar in whatever type of donor bile duct anatomy, donor ductal anomaly should not be considered a contraindication to donation of right liver lobe.     

Hydrophilic coating aids radial sheath withdrawal and reduces patient discomfort following transradial coronary intervention: a randomized double-blind comparison of coated and uncoated sheaths.

Radial artery spasm may cause severe discomfort during radial artery sheath removal. A hydrophilic-coated sheath may reduce the force required to remove a radial sheath. This force may be quantified using an automatic pullback device (APD). The objective of this study was to assess if a hydrophilic coating reduces the required force and discomfort associated with removal of a radial sheath following transradial coronary intervention. Ninety patients undergoing percutaneous coronary intervention via the radial artery were randomly assigned to two groups receiving either coated or uncoated introducer sheaths. Radifocus Introducer II (Terumo) 25 cm, 6 Fr radial sheaths and sheaths that were identical apart from the presence of the coating were used in all patients. The APD was used for sheath removal at the end of the procedure. Three patients (7%) in the coated group experienced discomfort during automatic sheath removal, compared to 12 patients (27%) in the uncoated group (P = 0.02). The maximum pullback force (MPF) was significantly lower in the coated compared to the uncoated group (0.24 +/- 0.31 vs. 0.44 +/- 0.33 kg; P = 0.003). Similarly, the mean pullback force was significantly lower in the coated group (0.14 +/- 0.23 vs. 0.32 +/- 0.24 kg; P < 0.001). Only one patient (2%) in each group had an MPF greater than 1.0 kg together with clinical evidence of radial artery spasm. Removal of the coated Terumo Radifocus sheath requires less force than an identical uncoated sheath. The coated sheath was also associated with less discomfort for the patient.     

Recombinant factor VIIa improves clot formation but not fibrolytic potential in patients with cirrhosis and during liver transplantation

Cirrhosis is associated with a bleeding tendency, which is particularly pronounced during orthotopic liver transplantation (OLT). A novel approach to treating the bleeding diathesis of patients with cirrhosis is administration of recombinant factor VIIa (rFVIIa). This study examined whether the efficacy of rFVIIa in cirrhosis might be explained in part by enhanced down-regulation of fibrinolysis by thrombin-activatable fibrinolysis inhibitor (TAFI). Addition of therapeutic or supratherapeutic doses of rFVIIa to plasma of 12 patients with stable cirrhosis did not result in a prolongation of clot lysis time, though clotting times were significantly reduced. Also, clot lysis assays of plasma samples taken during and after OLT, which was performed with or without a single bolus dose of rFVIIa, did not show any effect of rFVIIa on plasma fibrinolytic potential. In conclusion, this study shows no evidence for an antifibrinolytic effect of rFVIIa in cirrhotic patients or in patients undergoing OLT.     

Acoustical Properties of Individual Liposome-Loaded Microbubbles

A comparison between phospholipid-coated microbubbles with and without liposomes attached to the microbubble surface was performed using the ultra-high-speed imaging camera (Brandaris 128). We investigated 73 liposome-loaded microbubbles (loaded microbubbles) and 41 microbubbles without liposome loading (unloaded microbubbles) with a diameter ranging from 3–10 μm at frequencies ranging from 0.6–3.8 MHz and acoustic pressures ranging from 5–100 kPa. The experimental data showed nearly the same shell elasticity for the loaded and unloaded bubbles, but the shell viscosity was higher for loaded bubbles compared with unloaded bubbles. For loaded bubbles, a higher pressure threshold for the bubble vibrations was noticed. In addition, an “expansion-only” behavior was observed for up to 69% of the investigated loaded bubbles, which mostly occurred at low acoustic pressures (≤30 kPa). Finally, fluorescence imaging showed heterogeneity of liposome distributions of the loaded bubbles.     

Costs and benefits of rapid screening of methicillin-resistant Staphylococcus aureus carriage in intensive care units: a prospective multicenter study

Introduction

Pre-emptive isolation of suspected methicillin-resistant Staphylococcus aureus (MRSA) carriers is a cornerstone of successful MRSA control policies. Implementation of such strategies is hampered when using conventional cultures with diagnostic delays of three to five days, as many non-carriers remain unnecessarily isolated. Rapid diagnostic testing (RDT) reduces the amount of unnecessary isolation days, but costs and benefits have not been accurately determined in intensive care units (ICUs).

Methods

Embedded in a multi-center hospital-wide study in 12 Dutch hospitals we quantified cost per isolation day avoided using RDT for MRSA, added to conventional cultures, in ICUs. BD GeneOhm™ MRSA PCR (IDI) and Xpert MRSA (GeneXpert) were subsequently used during 17 and 14 months, and their test characteristics were calculated with conventional culture results as reference. We calculated the number of pre-emptive isolation days avoided and incremental costs of adding RDT.

Results

A total of 163 patients at risk for MRSA carriage were screened and MRSA prevalence was 3.1% (n = 5). Duration of isolation was 27.6 and 21.4 hours with IDI and GeneXpert, respectively, and would have been 96.0 hours when based on conventional cultures. The negative predictive value was 100% for both tests. Numbers of isolation days were reduced by 44.3% with PCR-based screening at the additional costs of €327.84 (IDI) and €252.14 (GeneXpert) per patient screened. Costs per isolation day avoided were €136.04 (IDI) and €121.76 (GeneXpert).

Conclusions

In a low endemic setting for MRSA, RDT safely reduced the number of unnecessary isolation days on ICUs by 44%, at the costs of €121.76 to €136.04 per isolation day avoided.