嗜麦芽寡养单胞菌L1基因克隆及其结构功能关系

目的：建立临床分离嗜麦芽寡养单胞菌L1酶的三维空间结构,并预测其活性基团。方法：PCR法扩增L1基因,通过克隆、测序、序列比对获得其基因序列和氨基酸残基;应用InsightⅡ软件构建L1酶的三维结构。结果：野生型L1酶的分子整体形状为“αβ／βα“丝带状”,活性中心由15个残基组成。结论：Asp74在酶活性中心外,但与酶活性中心的残基His105及His110之间存在相互作用,可能对酶活性产生影响。     

The faith of non-surveilled pancreatic cysts: a bicentric retrospective study

BackgroundIncidental discovery of pancreatic cystic neoplasms (PCLs) is a common and steadily increasing occurrence. The aim of this study was to investigate a cohort of patients presenting with incidentally detected PCLs which were not included in a surveillance protocol, and to compare their risk of malignant evolution with that of systematically surveilled lesions.Materials and methodsA population of PCLs which did not receive surveillance over a period >10 years (population A) was selected at the Medical University of Vienna. A group of “low risk” branch duct intraductal papillary mucinous neoplasm ≤15 mm in size upon diagnosis undergoing a regular follow-up of at least 5 years at the University of Verona was selected as control (population B). The incidence of pancreatic cancer (PC), cumulative risk of PC and disease-specific survival were compared.ResultsOverall, 376 patients with non-surveilled PCLs were included in study group A and compared to 299 patients in group B. This comparison resulted in similar incidence rates of PC (1.6% vs 1.7%, p = 0.938), a strong similarity in terms of disease-specific mortality rates (1.3% vs 0.3%, p = 0.171) and the 5- and 10-year cumulative risk of PC (? 1% and 2%, p = 0.589) and DSS (? 100% and 98%, p = 0.050).ConclusionThe “price to pay” for a negligence-based policy in the population of non-surveilled PCLs was reasonable, and the incidence of PC was comparable to that reported for a population of low-risk cysts enrolled to a standardized surveillance protocol.     

两种减压床垫对手术后患者压疮预防效果比较的随机对照试验

目的以随机对照试验设计研究两种减压床垫在手术后患者压疮预防中的效果,为临床优选减压床垫提供依据。方法2011年8月至2012年7月,选择4个省市中9个城市12所综合性医院的1074例手术后患者,按随机数字表法分组,其中观察组562例、对照组512例,术后分别给予每2h翻身1次+静态空气床垫和每2h翻身1次+动态空气床垫,观察并比较术后0~5d两组患者的Braden计分和医院内获得性压疮(hospital-acquired pressure ulcer,HAPU)的发生率及其分期。结果 1074例患者术后5d内共发生HAPU 11例(11处),HAPU的发生率为1.02%(11/1074),其中观察组HAPU的发生率为1.07%(6/562),对照组的发生率为0.98%(5/512),两组患者的Braden计分及HAPU的发生率差异均无统计学意义(均P0.05)。结论两种减压床垫应用于术后患者HAPU预防的效果接近,在缺乏电源时可优选静态空气床垫+定时翻身方案。     

Impact of simulated microgravity on microvascular endothelial cell apoptosis

Cardiovascular deconditioning is known to occur in astronauts exposed to microgravity. Endothelial dysfunction at microcirculatory sites might contribute to cardiovascular deconditioning induced by weightlessness. Recent studies have reported changes in the morphology and gene expression of endothelial cells exposed to conditions of simulated microgravity. The present study was aimed at examining the effects of microgravity on the apoptosis of microvascular endothelial cells and the mechanism underlying these effects. We simulated a microgravity environment and found that microgravity induced microvascular endothelial cell apoptosis and that this effect was correlated with the downregulation of the PI3K/Akt pathway, increased expression of NF-κB, and depolymerization of F-actin. These findings may provide important insights into the origin of the adverse physiological changes occurring due to exposure to microgravity conditions.     

过氧化脲漂白剂对釉质粘结强度的影响

目的：评价不同载体、不同浓度过氧化脲（Car bami de Per oxi de,CP）漂白剂对粘结釉质强度的影响。方法：60颗离体磨牙随机分为7组。1～6组颊舌面分别用以卡波姆（Carbopol）、聚乙烯吡咯烷酮（PVP）、泊洛沙姆（Pol oxamer）为增稠载体的含100g/L CP、200g/L CP的漂白剂在37℃、100%湿度条件下每天漂白8h,其中部分样本再浸入10%的抗坏血酸钠凝胶中3h,持续2周后即刻粘结树脂或延迟2周粘结。7组为对照组。准备界面为1mm×1mm的条形试件。通过微拉伸法测试釉质粘结强度,对不同类型的断面进行扫描电镜（scanni ng el ect i on mi croscope,SEM）观察。利用Spss11.0软件通过双因素方差分析（Two-way anal ysi s of var i ance）和SNK-q检验对其微拉伸粘结强度（iM cr ot ensi l e bond st r engt h,MTBS）进行统计分析。结果：各实验组2周漂白后即刻粘结,釉质粘结强度明显低于对照组（P〈0.05）;10%CP漂白同时抗氧化治疗或延迟粘结,釉质的粘结强度和对照组没有明显差异（P〉0.05）;20%CP漂白同时抗氧化治疗或延迟粘结,可明显提高釉质的粘结强度（P〈0.05）,但和对照组仍有显著差异（P〈0.05）。同种载体下,经10%CP漂白后的釉质粘结强度高于20%CP漂白组（P〈0.05）。同种浓度下,不同增稠载体组间的粘结强度没有显著差异（P〉0.05）。结论：漂白后即刻粘结,釉质的粘结强度随CP浓度的增高而下降;延迟2周粘结或抗氧化治疗可从一定程度上提高釉质的粘结强度,缩短漂白后粘结的时间;增稠载体对釉质的粘结强度没有显著影响。     

抗肾细胞癌异种化G250抗原基因疫苗的构建及真核表达

目的：构建含有人肾细胞癌特异性抗原G250主要T细胞表位区域、猴和鼠G250部分片段区域融合基因tG250的真核表达质粒,并在猴肾COS7细胞中表达。方法：通过基因合成和PCR技术构建人、猴和鼠G250区域融合基因tG250,将其插入含有人IgK链前导信号肽（sig）、人IgG-Fc和糖基磷脂酰肌醇（GPI）锚定信号肽融合基因序列的细胞膜锚定修饰真核表达载体pCI-FC-GPI中;将重组质粒pCI-Fe-tG250-GPI转染COS7细胞,流式细胞仪和免疫荧光检测其表达情况。结果：tG250融合基因经测序正确,PCR和酶切鉴定证明已成功连入真核表达载体pCl-Fc-tG250-GPI中;流式细胞仪和免疫荧光检测显示,重组质粒pCI-Fe-tG250-GPI在COS7细胞中得到很好的表达。结论：成功构建了重组质粒pCI-Fe-tG250-GPI,且在COS7细胞中可以有效表达,为以G250抗原为靶点基因疫苗的后续功能研究打下良好基础。     

Changes of p38 Mitogen-activated Protein Kinase and Apoptosis alter Spinal Cord Injury

There were very few studies about signal transduction of apoptosis of the spinal cord injury （SCI）. We applied spinal cord compression rats model （Nystrom＇s method） to study the changes of p38 mitogen-activated protein kinase （MAPK） and its relationship with apoptosis.     

HP培养滤液诱导下抑制bcl-2基因表达对SGC7901细胞端粒酶活性的影响

目的:探讨bcl-2表达与hTERT、端粒酶活性之间的调控关系,了解HP的致癌机制。方法:在HP培养滤液诱导前后,采用流式细胞仪检测bcl-2AODN抑制bcl-2基因之后人SGC7901细胞hTERT蛋白的表达。结果:对照组人SGC7901细胞24h、36h和48h表达hTERT蛋白的阳性细胞数和荧光指数显著低于经HP培养滤液诱导的SGC7901胃癌细胞组(P<0.05)。在HP滤液诱导下,抑制bcl-2基因的SGC7901胃癌细胞24h、36h和48h表达hTERT蛋白的阳性细胞数和荧光指数显著低于与SGC7901胃癌细胞(P<0.05),同时显著高于对照组(P<0.05)。结论:bcl-2基因正向调控hTERT蛋白表达,bcl-2表达上调可能是端粒酶活化的主要途径之一。端粒酶的激活不完全依赖于bcl-2途径,还存在其他的调控因素。HP感染不仅通过上调bcl-2的表达,还可以通过其他途径激活端粒酶,这可能是HP感染致癌的一条重要途径。     

Low skeletal muscle mass in cholangiocarcinoma treated by surgical resection. A meta-analysis

BackgroundTo date, the role of low skeletal muscle mass (LSMM) in cholangiocarcinoma (CC) is unclear. Our purpose was to analyze the influence of LSMM on survival in patients with CC treated by surgical resection.MethodsMEDLINE, Cochrane, and SCOPUS databases were screened for associations between LSMM and survival in CC up to June 2021. Overall, 16 studies met the inclusion criteria. The methodological quality of the involved studies was analyzed using the QUADAS instrument. The meta-analysis was undertaken using RevMan 5.4 software.ResultsThe prevalence of LSMM was 48.40%. LSMM was associated with lower overall survival (OS): HR = 2.44, 95%CI = (2.01–2.96) (simple regression); HR = 2.39, 95%CI = (1.83–3.13) (multiple regression).In extrahepatic CC, sarcopenic patients had lower OS, simple regression: HR = 2.11, 95%CI = (1.39–3.20); multiple regression: HR = 2.28, 95%CI = (1.41–3.70).In intrahepatic CC, LSMM predicted recurrence free survival: HR = 2.33, 95%CI = (1.93–2.81) (simple regression); HR = 2.23, 95%CI = (1.73–2.88) (multiple regression). LSMM predicted OS in intrahepatic CC, simple regression: HR = 2.69, 95%CI = (2.24–3.24); multiple regression: HR = 2.43, 95%CI = (1.73–3.41).ConclusionLSMM is a risk factor for OS in patients with CC treated by surgical resection. LSMM is a predictor of RFS in patients with intrahepatic CC.     

Age-adjusted incidence rates of synchronous liver metastases for stage IV colorectal cancer compared by sex,race, and age group

BackgroundReports on age-adjusted incidence rates of synchronous colorectal liver metastases (CRLM) among patients with stage IV colorectal cancer (CRC) are uncommon. This study presents in detail differences in CRLM incidence rates by sex, race, and age group.MethodsIncidence rates were obtained for adults diagnosed with Stage IV CRC in the years 2010–2015 using SEER. The ratio of CRLM incidence to stage IV CRC incidence was used to calculate the rate ratio.ResultsAverage age-adjusted CRLM incidence rate was 7.09 per 100,000 (95% CI, 6.93–7.26). CRLM incidence was higher at 8.68 (95% CI, 8.35–9.03) for males compared with 5.77 (95% CI, 5.64–5.90) for females. Highest incidence rate of 11.50 (95% CI, 10.43–11.76) was observed among Blacks. By age group the highest CRLM incidence was 24.42 (95% CI, 23.13–25.71) among adults age >75. The average rate ratio of CRLM to CRC incidence rate was 0.72 (95% CI, 0.71–0.73).ConclusionAge-adjusted incidence rates of synchronous CRLM are higher for men, Blacks, and older patients. The risk ratio indicates that 72% of stage IV CRC cases are at risk of synchronous CRLM, although CRLM risk appears to decline with age.