烧伤感染后血清补体 C3 IL-10的变化

目的：探究机体烧伤感染后免疫因子的水平变化。方法选取2013年4月至2014年2月我院收治的200例烧伤患者,分别于烧伤后第3、7、14天检测观察外周血补体C3、IL‐10水平并进行比较。结果随着时间的推移,患者创面感染率升高;烧伤后患者补体C3和IL‐10的水平均呈现先上升后下降的变化;感染患者体内的补体C3水平均高于未感染患者;烧伤后脓毒血症患者机体补体C3和IL‐10水平均高于单独创面感染患者。结论烧伤后感染可影响患者血清补体C3和 IL‐10水平的改变,可通过对相应免疫因子水平的调节进行治疗以维持患者体内免疫反应平衡,防止感染加重。     

白及须根醇提物抗胃溃疡作用研究

目的研究白及须根醇提物抗大鼠乙醇急性胃溃疡的活性及其作用机理。方法实验设正常组、模型组、阳性对照组、白及须根醇提物低、中、高剂量组,用无水乙醇诱导大鼠胃溃疡模型。初次采用扫描仪扫描大鼠胃溃疡情况。ELISA检测血清中IL-1β、TNF-α、IL-10等因子的水平,初步分析其作用机理。结果白及须根醇提物可以减小溃疡面积;ELISA数据显示,血清中IL-1β、TNF-α、IL-10等因子与模型组相比均有显著性变化。结论白及须根醇提物具有显著抗胃溃疡作用,须根醇提物组分可通过降低IL-1β等因子和提高IL-10、VEGF等因子的水平发挥抗胃溃疡作用。     

小儿先天性心脏病介入治疗麻醉处理临床观察

目的探讨小儿先天性心脏病介入治疗的麻醉处理.方法确诊动脉导管未闭(343例)、房间隔缺损(428例)、室间隔缺损(229例)择期行介入封堵术10岁以下患儿,随机分为氯胺酮复合咪达唑仑组及氯胺酮复合丙泊酚组.结果2组患儿术中不同时点平均动脉压、心率、呼吸频率、血氧饱和度与麻醉前比较差异无统计学意义(P＞0.05),组间术中不良反应、术中并发症差异无统计学意义(P＞0.05),所有患儿均保留自主呼吸,顺利完成先心病介入治疗.结论氯胺酮复合咪达唑仑或氯胺酮复合丙泊酚的麻醉方法应用于先天性心脏病封堵术麻醉满意,并发症少,安全有效,麻醉苏醒快,无明显临床区别.     

Direct sequencing of SARS-coronavirus S and N genes from clinical specimens shows limited variation

Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) emerged, in November 2002, as a novel agent causing severe respiratory illness. To study sequence variation in the SARS-CoV genome, we determined the nucleic acid sequence of the S and N genes directly from clinical specimens from 10 patients--1 specimen with no matched SARS-CoV isolate, from 2 patients; multiple specimens from 3 patients; and matched clinical-specimen/cell-culture-isolate pairs from 6 patients. We identified 3 nucleotide substitutions that were most likely due to natural variation and 2 substitutions that arose after cell-culture passage of the virus. These data demonstrate the overall stability of the S and N genes of SARS-CoV over 3 months during which a minimum of 4 generations for transmission events occurred. These findings are a part of the expanding investigation of the evolution of how this virus adapts to a new host.     

连续性肾脏替代治疗的临床应用进展

连续性肾脏替代治疗(CRRT),也称之为连续性血液净化(CBP),是通过弥散和(或)对流、吸附机制、缓慢、连续地进行溶质交换和水分清除的血液净化疗法的统称。CRRT作为一种新技术,在重症急性肾功能衰竭,系统性炎症反应综合征(SIRS),急性呼吸窘迫综合征(ARDS),多器官功能障碍综合征(MODS),重症急性胰腺炎和中毒等危重病的救治中已经和正在发挥其独特的优势,是抢救危重病患者的重要治疗措施之一,是近年来重症监护病房(ICU)治疗中最重要的进展之一。其地位与机械通气和全胃肠外营养(TPN)同样重要[1]。1概述CRRT最早由Kramer等提出应用…     

Progressive nature of paroxysmal atrial fibrillation. Observations from a 14-year follow-up study.

BACKGROUND: Atrial fibrillation (AF) is believed to occur first as paroxysmal, then be gradually perpetuated, and finally become chronic as the end result. However, this presumed clinical course has not been well confirmed. METHODS AND RESULTS: The clinical course of recurrent paroxysmal AF (PAF) from its onset was examined in 171 patients (mean follow-up period: 14.1+/-8.1 years). This study population consisted of patients with no structural heart disease (n=88), ischemic heart disease (n=28), dilated or hypertrophic cardiomyopathy (n=17), valvular heart disease (n=35) or other cardiac diseases. The mean age at the onset of AF was 58.3 +/-11.8 years old. During the mean follow-up period of 14.1 years, PAF eventually developed into its chronic form in 132 patients under conventional antiarrhythmic therapy (77.2%, 5.5% of patients per year). The independent factors for early development into chronic AF were aging (hazard ratio (HR) 1.27 per 10 years, 95% confidence interval (CI) 1.06-1.47)), dilated left atrium (HR 1.39 per 10 mm, 95% CI 1.11-1.69), myocardial infarction (HR 2.33, 95% CI 1.13-4.81), and valvular diseases (HR 2.29, 95% CI 1.22-4.30). CONCLUSIONS: The present long-term observations definitely and quantitatively revealed the progressive nature of PAF.     

A genetic method for dating ancient genomes provides a direct estimate of human generation interval in the last 45,000 years

The study of human evolution has been revolutionized by inferences from ancient DNA analyses. Key to these studies is the reliable estimation of the age of ancient specimens. High-resolution age estimates can often be obtained using radiocarbon dating, and, while precise and powerful, this method has some biases, making it of interest to directly use genetic data to infer a date for samples that have been sequenced. Here, we report a genetic method that uses the recombination clock. The idea is that an ancient genome has evolved less than the genomes of present-day individuals and thus has experienced fewer recombination events since the common ancestor. To implement this idea, we take advantage of the insight that all non-Africans have a common heritage of Neanderthal gene flow into their ancestors. Thus, we can estimate the date since Neanderthal admixture for present-day and ancient samples simultaneously and use the difference as a direct estimate of the ancient specimen’s age. We apply our method to date five Upper Paleolithic Eurasian genomes with radiocarbon dates between 12,000 and 45,000 y ago and show an excellent correlation of the genetic and ¹⁴C dates. By considering the slope of the correlation between the genetic dates, which are in units of generations, and the ¹⁴C dates, which are in units of years, we infer that the mean generation interval in humans over this period has been 26–30 y. Extensions of this methodology that use older shared events may be applicable for dating beyond the radiocarbon frontier.Ancient DNA analyses have transformed research into human evolutionary history, making it possible to directly observe genetic variation patterns that existed in the past, instead of having to infer them retrospectively (1). To interpret findings from an ancient specimen, it is important to have an accurate estimate of its age. The current gold standard is radiocarbon dating, which is applicable for estimating dates for samples up to 50,000 y old (2). This method is based on the principle that, when a living organism dies, the existing ¹⁴C starts decaying to ¹⁴N with a half-life of ∼5,730 y (3). By measuring the ratio of ¹⁴C to ¹²C in the sample and assuming that the starting ratio of carbon isotopes is the same everywhere in the biosphere, the age of the sample is inferred. A complication is that carbon isotope ratios vary among carbon reservoirs (e.g., marine, freshwater, atmosphere) and over time. Thus, ¹⁴C dates must be converted to calendar years using calibration curves based on other sources, including annual tree rings (dendrochronology) or uranium-series dating of coral (2). Such calibrations, however, may not fully capture the variation in atmospheric carbon. In addition, contamination of a sample by modern carbon, introduced during burial or by handling afterwards, can make a sample seem younger than it actually is (2). The problem is particularly acute for samples that antedate 30,000 y ago because they retain very little original ¹⁴C.Here, we describe a genetic approach for dating ancient samples, applicable in cases where DNA sequence data are available, as is becoming increasingly common (1). This method relies on the insight that an ancient genome has experienced fewer generations of evolution compared with the genomes of its living (i.e., extant) relatives. Because recombination occurs at an approximately constant rate per generation, the accumulated number of recombination events provides a molecular clock for the time elapsed or, in the case of an ancient sample, the number of missing generations since it ceased to evolve. This idea is referred to as “branch shortening” and estimates of missing evolution can be translated into absolute time in years by using an estimate of the mean age of reproduction (generation interval) or an independent calibration point such as human–ape divergence time.Branch shortening has been used in studies of population history, for inferring mutation rates, and for establishing time scales for phylogenic trees in humans and other species (4, 5). It was first applied for dating ancient samples on a genome-wide scale by Meyer et al. (6), who used the mutation clock (instead of the recombination clock as proposed here) to estimate the age of the Denisova finger bone, which is probably older than 50,000 y, and has not been successfully radiocarbon dated (6). Specifically, the authors compared the divergence between the Denisova and extant humans and calibrated the branch shortening relative to human–chimpanzee (HC) divergence time. The use of ape divergence time for calibration, however, relies on estimates of mutation rate that are uncertain (7). In particular, recent pedigree studies have yielded a yearly mutation rate that is approximately twofold lower than the one obtained from phylogenetic methods (7). In addition, comparison with HC divergence relies on branch-shortening estimates that are small relative to the total divergence of millions of years, so that even very low error rates in allele detection can bias estimates. These issues lead to substantial uncertainty in estimated age of the ancient samples, making this approach impractical for dating specimens that are tens of thousands of years old, a time period that encompasses the vast majority of ancient human samples sequenced to date.Given the challenges associated with the use of the mutation clock, here we explore the possibility of using a molecular clock based on the accumulation of crossover events (the recombination clock), which is measured with high precision in humans (8). In addition, instead of using a distant outgroup, such as chimpanzees, we rely on a more recent shared event that has affected both extant and ancient modern humans and is therefore a more reliable fixed point on which to base the dating. Previous studies have documented that most non-Africans derive 1–4% ancestry from Neanderthals from an admixture event that occurred ∼37,000–86,000 y before present (yBP) (9, 10), with some analyses proposing a second event (around the same time) into the ancestors of East Asians (11, 12). Because the vast majority of ancient samples sequenced to date were discovered in Eurasia (with estimated ages of ∼2,000–45,000 yBP), postdate the Neanderthal admixture, and show evidence of Neanderthal ancestry, we used the Neanderthal gene flow as the shared event.The idea of our method is to estimate the date of Neanderthal gene flow separately for the extant and ancient genomes. Because the ancient sample is closer in time to the shared Neanderthal admixture event, we expect that the inferred dates of Neanderthal admixture will be more recent in ancient genomes (by an amount that is directly determined by the sample’s age) compared with the dates in the extant genomes. The difference in the dates thus provides an estimate of the amount of missing evolution: that is, the age of the ancient sample. An illustration of the idea is shown in SI Appendix, Fig. S1. An assumption in our approach is that the Neanderthal admixture into the ancestors of modern humans occurred approximately at the same time and that the same interbreeding events contributed to the ancestry of all of the non-African samples being compared. Deviations from this model could lead to incorrect age estimates. Our method is not applicable for dating genomes that do not have substantial Neanderthal ancestry, such as sub-Saharan African genomes.To date the Neanderthal admixture event, we used the insight that gene flow between genetically distinct populations, such as Neanderthals and modern humans, introduces blocks of archaic ancestry into the modern human background that break down at an approximately constant rate per generation as crossovers occur (13–15). Thus, by jointly modeling the decay of Neanderthal ancestry and recombination rates across the genome, we can estimate the date of Neanderthal gene flow, measured in units of generations. Similar ideas have been used to estimate the time of admixture events between contemporary human populations (14–16), as well as between Eurasians and Neanderthals (9, 17). An important feature of our method is that it is expected to give more precise results for samples that are older because these samples are closer in time to the Neanderthal introgression event, thus it is easier to accurately estimate the time of the admixture event for them. Thus, unlike ¹⁴C dating, the genetic approach becomes more reliable with age and, in that regard, complements ¹⁴C dating.     

泽泻配方颗粒中23-乙酰泽泻醇B的含量测定

目的调查国内6个厂家的泽泻配方颗粒中23-乙酰泽泻醇B的含量。方法采用高效液相色谱法测定,选用Sun FireTM-C18(250 mm×4.6 mm)色谱柱,流动相以乙腈-水等梯度洗脱,流速:1.0 m L/min,检测波长为208 nm,柱温:30℃。结果 6个厂家的23-乙酰泽泻醇B分别为:0.175 6、2.074 9、0.220 1、0.438 6、0.112 5、0.190 7 mg/g。结论 6个厂家的泽泻配方颗粒中23-乙酰泽泻醇B的含量差异显著。     

急诊医护人员遭受工作场所身体暴力事件后真实体验的质性研究

目的:总结急诊科医护人员遭受工作场所身体暴力事件后的真实体验,分析身体暴力事件对其造成的影响,以期引起相关部门的重视。方法:采用质性研究中传统的扎根理论研究方法,选择广州市3家三级甲等医院10例遭受过急诊科身体暴力事件的医护人员,进行半结构式访谈,遵循Colaizzi七步法,分析访谈内容。结果:遭受急诊科身体暴力事件的医护人员存在以委屈感、愤怒感、无助感、恐惧感、厌倦感为主的负面情绪,存在安全、心理辅导、被尊重、普及规章流程及法律知识、获得医院社会支持五个方面的需求。结论:医疗机构及社会相关部门应重视急诊科医护人员遭受身体暴力事件的情况,建立完善的遭受身体暴力事件后的支持系统,减少其负面情绪并满足其多种需求。