传统结肠镜检查法的应用现状

自20世纪六十年代末结肠镜检査术问世以来,无论是其操作手法还是器械改革均得到飞速发展,并广泛应用于临床,使直视病灶、实现活检及治疗成为可能。虽然,结肠镜检查为结直肠疾病的诊断及治疗带来了巨大的帮助并成为结直肠癌诊断的金标准,但其局限性也日渐明显。作为一种侵入性操作,结肠镜检查无法避免的腹部疼痛、难以预知的并发症、无法保证的成功率以及可能存在的漏诊率限制了其临床应用不仅在一定程度上降低了患者的依从性,增加了操作的困难度,且使一部分具有操作指征的患者错失早期诊断及治疗的最佳时机。本文简要阐述了传统注气式结肠镜检查法的一般特点并总结了其应用现状,以期为今后传统注气式结肠镜检查法的合理化应用提供一定的参考依据。     

我国生物仿制药发展现状与策略研究

随着生物药专利失效期到来所带来的成本降低、药物可及性增加及巨大市场空间等因素影响,各大企业对生物仿制药的开发表现出浓厚的兴趣,纷纷涉足这一领域,然而由于生物仿制药的特殊性,开发及产业化困难重重。基于以上背景,首先分析了国内外生物医药行业宏观经济环境、行业政策环境、法律监管环境等外部环境,然后对当前生物仿制药开发存在的关键性技术共性问题进行了阐述。在此基础上对国内外主要生物仿制药企业现状进行分析,提出了我国与国外生物仿制药方面存在的主要差距。在上述分析的基础上,利用SWOT工具进行战略分析,指出我国生物仿制药应该执行的SO战略为主,SW战略为辅的策略。最后提出了一些参考建议。     

Confidence in ecological indicators: A framework for quantifying uncertainty components from monitoring data

The value of an ecological indicator is no better than the uncertainty associated with its estimate. Nevertheless, indicator uncertainty is seldom estimated, even though legislative frameworks such as the European Water Framework Directive stress that the confidence of an assessment should be quantified. We introduce a general framework for quantifying uncertainties associated with indicators employed to assess ecological status in waterbodies. The framework is illustrated with two examples: eelgrass shoot density and chlorophyll a in coastal ecosystems. Aquatic monitoring data vary over time and space; variations that can only partially be described using fixed parameters, and remaining variations are deemed random. These spatial and temporal variations can be partitioned into uncertainty components operating at different scales. Furthermore, different methods of sampling and analysis as well as people involved in the monitoring introduce additional uncertainty. We have outlined 18 different sources of variation that affect monitoring data to a varying degree and are relevant to consider when quantifying the uncertainty of an indicator calculated from monitoring data. However, in most cases it is not possible to estimate all relevant sources of uncertainty from monitoring data from a single ecosystem, and those uncertainty components that can be quantified will not be well determined due to the lack of replication at different levels of the random variations (e.g. number of stations, number of years, and number of people). For example, spatial variations cannot be determined from datasets with just one station. Therefore, we recommend that random variations are estimated from a larger dataset, by pooling observations from multiple ecosystems with similar characteristics. We also recommend accounting for predictable patterns in time and space using parametric approaches in order to reduce the magnitude of the unpredictable random components and reduce potential bias introduced by heterogeneous monitoring across time. We propose to use robust parameter estimates for both fixed and random variations, determined from a large pooled dataset and assumed common across the range of ecosystems, and estimate a limited subset of parameters from ecosystem-specific data. Partitioning the random variation onto multiple uncertainty components is important to obtain correct estimates of the ecological indicator variance, and the magnitude of the different components provide useful information for improving methods applied and design of monitoring programs. The proposed framework allows comparing different indicators based on their precision relative to the cost of monitoring.     

DNA计算机原理、现状及发展

DNA计算机是一种基于DNA生化反应 ,与传统计算机完全不同的新型生物计算机。本文概述了DNA计算机的原理、特点与现状。并对其发展进行展望     

Shrinking in a growing economy is not so puzzling after all

Bodenhorn, Guinnane, and Mroz (2017) argue that the diminution of heights during the Industrial Revolution and in the Antebellum U.S. is an artefact of the biased nature of the samples analyzed. We demonstrate that it would be an unfathomable coincidence if men and women all self-selected into scores of completely independent samples in such a way as to bias them in the identical direction. Instead, wWe show that BGM’s periodization is flawed and that their statistical models are misspecified, because they fail to consider the extent to which they introduce severe multicollinearity into their regressions. In addition, they fail to specify how they selected the samples they included in their analysis. In contrast, we argue that the economic transition from a predominantly agricultural to an increasingly industrial society was not a smooth process and lags in adjustment led to nutritional stresses. Height of a typical man in the U.S. decreased by 0.75 inches at a time when incomes were growing at a rate of 1.2% per annum. The developing human body of children and youth was sensitive enough to these nutritional stresses to register their effect better than monetary measures could. While nutritional status did decline during the Industrial Revolution in Europe and at the onset of modern economic in the U.S., by the second half of the 19^th century agricultural productivity caught up with the increased demand for foodstuffs and height reversals became a rarity. Thus, although markets adjusted, they did not do so instantaneously. Consequently, physical stature declined during this adjustment process although the wealthy were shielded from the increased price of nutrients. So, the divergence in average incomes and average heights at the threshold of the modern age is not so puzzling after all.     

Whole mitochondrial DNA variations in hippocampal surgical specimens and blood samples with high-throughput sequencing: A case of mesial temporal lobe epilepsy with hippocampal sclerosis

Introduction

Hippocampal sclerosis is the most common lesion in patients with mesial temporal lobe epilepsy. Recently, there has been growing evidence on the involvement of mitochondria also in sporadic forms of epilepsy. In addition, it has been increasingly argued that mitochondrial dysfunction has an important role in epileptogenesis and seizure generation in temporal lobe epilepsy. Although mtDNA polymorphisms have been identified as potential risk factors for neurological diseases, the link between homoplasmy and heteroplasmy within tissues is not clear. We investigated whether mitochondrial DNA (mtDNA) polymorphisms are involved in a case report of a patient with mesial temporal lobe epilepsy-hippocampal sclerosis (MTLE-HS).

Design

We report the whole genome mtDNA deep sequencing results and clinical features of a 36-year-old woman with MTLE-HS. We used pyrosequencing technology to sequence a whole mitochondrial genome isolated from six different regions of her brain and blood. To assess the possible role of mitochondrial DNA variations in affected tissues, we compared all specimens from different regions of the hippocampus and blood.

Results

In total, 35 homoplasmic and 18 heteroplasmic variations have been detected in 6 different regions of the hippocampus and in blood samples. While the samples did not display any difference in homoplasmic variations, it has been shown that hippocampus regions contain more heteroplasmic variations than blood. The number of heteroplasmic variations was highest in the CA2 region of the brain and accumulated in ND2, ND4 and ND5 genes. Also, dentate and subiculum regions of the hippocampus had similar heteroplasmic variation profiles.

Discussion

We present a new rare example of parallel mutation at 16223 position. Our case suggests that defects in mitochondrial function might be underlying the pathogenesis of seizures in temporal lobe epilepsy.     

姜黄素对癫痫大鼠认知功能障碍的预防作用及其可能机制

目的:探讨姜黄素(curcumin)对癫痫大鼠认知功能障碍的预防作用及其可能机制。方法:将30只成年雄性SD大鼠分为正常对照组、单纯致痫组(SE组)、姜黄素[60mg/(kg.d)]干预组(curcumin组)。采用Morris水迷宫方法检测大鼠学习记忆功能变化,并检测脑片水平的长时程增强(LTP)变化,处死大鼠后取脑组织并匀浆,测超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)、谷胱甘肽(GSH)、丙二醛(MDA)的水平。结果:(1)SE组大鼠寻找平台的潜伏期明显长于对照组,具有统计学意义(P<0.05),姜黄素组寻找平台的潜伏期相对于SE组显著缩短(P<0.05)。撤离平台后,SE组大鼠在平台所在象限的停留时间明显短于对照组(P<0.05),姜黄素治疗后大鼠在平台所在象限的停留时间较SE组显著延长(P<0.05)。(2)给予HFS刺激后各组兴奋性突出后电位(fEPSP)斜率较前明显增加,均可持续1h以上,与对照组比较SE组HFS刺激后fEPSP斜率明显减小(P<0.05),姜黄素可减轻SE所致的fEPSP斜率减小(P<0.05)。(3)SE组SOD、GSH-PX、GSH显著下降,MDA明显增高,姜黄素可逆转上述现象,有统计学意义(P<0.05)。结论:姜黄素可显著减轻癫痫持续状态所致的大鼠认知功能障碍,减轻海马区的氧化应激反应从而保护海马海马是其可能机制之一。     

维生素E对癫痫大鼠认知功能障碍的治疗作用及其可能机制

目的：探讨维生素E（VitE）对癫痫大鼠认知功能障碍的治疗作用及其可能机制。方法：将30只成年雄性SD大鼠随机分为健康对照组、单纯致痫组（SE组）、VitE[按体重100mg／（kg·d）]干预组（VitE组）。采用Morris水迷宫实验方法检测致癫后大鼠学习记忆功能变化,同时检测脑组织匀浆中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH—PX）、谷胱甘肽（GSH）、丙二醛（MDA）的水平。结果：（1）SE组大鼠寻找平台的潜伏期明显长于对照组,具有统计学意义（P〈0．05）,VitE组寻找平台的潜伏期相对于SE组显著缩短（P〈0．05）。撤离平台后,SE组大鼠在平台所在象限的停留时间明显短于对照组（P〈0．05）,VitE治疗后大鼠在平台所在象限的停留时间较SE组显著延长（P〈0．05）。（2）SE组SOD、GSH—PX、GSH显著下降,MDA明显增高,VitE干预组SOD、GSH．PX-GSH显著增高,而MDA明显下降,具有统计学意义（P〈0．05）。结论：VitE可改善癫痫持续状态后大鼠认知功能,其可能机制是通过减轻海马区的氧化应激反应减轻海马区的损伤,从而实现改善认知功能。     

维生素E 对癫痫大鼠认知功能障碍的治疗作用及其可能机制

目的:探讨维生素E(VitE)对癫痫大鼠认知功能障碍的治疗作用及其可能机制。方法:将30只成年雄性SD大鼠随机分为健康对照组、单纯致痫组(SE组)、VitE[按体重100mg/(kg.d)]干预组(VitE组)。采用Morris水迷宫实验方法检测致癫后大鼠学习记忆功能变化,同时检测脑组织匀浆中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)、谷胱甘肽(GSH)、丙二醛(MDA)的水平。结果:(1)SE组大鼠寻找平台的潜伏期明显长于对照组,具有统计学意义(P<0.05),VitE组寻找平台的潜伏期相对于SE组显著缩短(P<0.05)。撤离平台后,SE组大鼠在平台所在象限的停留时间明显短于对照组(P<0.05),VitE治疗后大鼠在平台所在象限的停留时间较SE组显著延长(P<0.05)。(2)SE组SOD、GSH-PX、GSH显著下降,MDA明显增高,VitE干预组SOD、GSH-PX、GSH显著增高,而MDA明显下降,具有统计学意义(P<0.05)。结论:VitE可改善癫痫持续状态后大鼠认知功能,其可能机制是通过减轻海马区的氧化应激反应减轻海马区的损伤,从而实现改善认知功能。