枇杷花茶水提物的镇咳、抗炎与抗氧化作用研究

采用小鼠氨水致咳法研究枇杷花茶水提物镇咳效果,以二甲苯致小鼠耳肿胀法研究其抗炎效果,并从枇杷花茶的还原能力及对超氧阴离子和羟自由基的清除作用分析枇杷花茶水提物的抗氧化效果。结果表明,枇杷花茶的水提物高剂量组(3000 mg·kg-1)、低剂量组(700 mg·kg-1)均有镇咳抗炎效果,水提物的浓度越高,效果越好。各浓度枇杷花茶水提物均表现出一定的还原能力,对于羟基自由基和超氧阴离子都有一定的清除效果。其中,20 mg·mL-1水提物还原效果最好(吸光值0.903),超过0.2 mg·mL-1抗坏血酸(吸光值0.814);10 mg·mL-1的水提物对超氧阴离子的清除率为47.32%;20 mg·mL-1水提物对于羟基自由基的清除效果非常明显,清除率为91.62%。枇杷花茶水提物镇咳、抗炎、抗氧化效果明显。     

基因功能研究方法的新进展

随着生命科学的发展,研究领域的不断开拓,越来越多的未知新基因和基因的新功能被科学家们发现,研究这些未知新基因的功能和已知基因的新功能成为了极其重要的一项内容。本文对基因功能研究的最新方法进行了介绍。     

Nonparametric Tests for Interval‐Censored Failure Time Data

This paper discusses two sample nonparametric comparison of survival functions when only interval‐censored failure time data are available. The problem considered often occurs in, for example, biological and medical studies such as medical follow‐up studies and clinical trials. For the problem, we present and study several nonparametric test procedures that include methods based on both absolute and squared survival differences as well as simple survival differences. The presented tests provide alternatives to existing methods, most of which are rank‐based tests and not sensitive to nonproportional or nonmonotone alternatives. Simulation studies are performed to evaluate and compare the proposed methods with existing methods and suggest that the proposed tests work well for nonmonotone alternatives as well as monotone alternatives. An illustrative example is presented.     

Flavonoids and cognitive function: a review of human randomized controlled trial studies and recommendations for future studies

Evidence in support of the neuroprotective effects of flavonoids has increased significantly in recent years, although to date much of this evidence has emerged from animal rather than human studies. Nonetheless, with a view to making recommendations for future good practice, we review 15 existing human dietary intervention studies that have examined the effects of particular types of flavonoid on cognitive performance. The studies employed a total of 55 different cognitive tests covering a broad range of cognitive domains. Most studies incorporated at least one measure of executive function/working memory, with nine reporting significant improvements in performance as a function of flavonoid supplementation compared to a control group. However, some domains were overlooked completely (e.g. implicit memory, prospective memory), and for the most part there was little consistency in terms of the particular cognitive tests used making across study comparisons difficult. Furthermore, there was some confusion concerning what aspects of cognitive function particular tests were actually measuring. Overall, while initial results are encouraging, future studies need to pay careful attention when selecting cognitive measures, especially in terms of ensuring that tasks are actually sensitive enough to detect treatment effects.     

Haemodynamics using transthoracic echocardiography in healthy pregnant and non-pregnant baboons (Papio hamadryas)

Background To determine systolic and diastolic function using transthoracic echocardiography in the baboon (Papio hamadryas). Methods Transthoracic echocardiography was performed in eight non‐pregnant female and six pregnant baboons according to American Society of Echocardiography recommendations. Results Haemodynamic measurements were obtained from fourteen baboons. Compared to non‐pregnant baboons, pregnant baboons demonstrated: (mean ± SD, pregnant vs. healthy) increased cardiac output (1615 ± 121 ml/minutes vs. 1317 ± 134 ml/minutes P = 0.001) due to an increased heart rate [120 ± 11 beats per minute (BPM) vs. 105 ± 6 BPM P = 0.018]. The inter‐observer and intra‐observer variability (mean difference ± SD) for the left ventricular outflow tract diameter was 0.05 ± 0.07 cm and 0.01 ± 0.03 cm respectively. There was minimal impact to the animal’s daily activities. Conclusions Transthoracic echocardiography was applicable and reproducible for the assessment of haemodynamics in baboons thus enabling translation of animal results to human studies.     

Quantifying protein function specificity in the gene ontology

Quantitative or numerical metrics of protein function specificity made possible by the Gene Ontology are useful in that they enable development of distance or similarity measures between protein functions. Here we describe how to calculate four measures of function specificity for GO terms: 1) number of ancestor terms; 2) number of offspring terms; 3) proportion of terms; and 4) Information Content (IC). We discuss the relationship between the metrics and the strengths and weaknesses of each.     

Enamel microstructure and molar wear in the greater galago,Otolemur crassicaudatus (mammalia,primates)

This study describes the molar enamel microstructure of the greater galago, based on SEM study of four individuals. Galago molar enamel consists primarily of radially oriented Pattern 1 prisms. However, the most superficial enamel is characterized by regions of poorly developed prisms or nonprismatic enamel, and Pattern 3 prisms can be found at depths intermediate and deep to the enamel surface. Orientations of prism long axes relative to wear surfaces differ among functionally distinct regions (cuspal facets, Phase I/II facets, and crushing basins). Consequently, orientations of enamel crystallites relative to these surfaces also differ. Because crystallites are the structural unit involved in enamel abrasion, these differences in orientation may have important effects on molar wear patterns. Crystallite orientations differ most between cuspal facets and Phase I/II facet surfaces. Cuspal facets are characterized by near surface-parallel interprismatic and surface-oblique prismatic crystallites. Previous experimental studies suggest that this arrangement is most resistant to wear when surface-normal (compressive) loads predominate. In contrast, prismatic and interprismatic crystallites intercept Phase I/II facet surfaces obliquely, an arrangement expected to resist abrasion when surface-parallel (shearing) loads predominate. Superficial enamel is preserved at most basin surfaces, indicating that these regions are subject to comparatively little abrasive wear. These results support the hypothesis that galago occlusal enamel is organized so as to resist abrasion of different functional regions, a property that may prove important in maintaining functional efficiency. However, this largely reflects constraints of occlusal topography on a microstructure typical of many mammals and thus does not appear to represent a structural innovation. © 1993 Wiley-Liss, Inc.     

Systematic analysis of residual density suggests that a major limitation in well‐refined X‐ray structures of proteins is the omission of ordered solvent

In the residual electron density map of a fully refined X‐ray protein model, there should be no peaks arising from modeling errors or missing atoms. Any residual peaks that do occur should be contributed by random residual intensity differences between the model and the data. If the model is incomplete (i.e., some atoms are missing), there will be more positive peaks than negative ones. On the other hand, if the model includes inappropriately located atoms, there will be an excess of negative peaks. In this study, random residual peaks are quantified using the probability density function P(x), which is defined as the probability for a peak having peak height between x and x + dx. It is found that P(x) is single‐exponential and symmetric for both positive and negative peaks. Thus, P(x) can be used to discriminate residual peaks contributed by random noise in complete models from residual peaks being attributable to modeling errors in incomplete models. For a number of representative structures in the PDB it is found that P(x) has far more large (greater than 5 sigma) positive peaks than large negative peaks. This excess of large positive peaks suggests that the main defect in these refined structures is the omission of ordered water molecules.     

Stress and psychophysiological dysregulation in patients with fibromyalgia syndrome

Fibromyalgia syndrome (FMS) is a prevalent musculoskeletal pain disorder characterized by diffuse pain and associated psychophysiological symptoms. Despite extensive research in the past 3 decades, the etiology and pathophysiology of FMS and effective treatment approaches are yet to be delineated. Recently, it has been suggested that FMS may be related to hypofunctional stress systems, particularly in the autonomic nervous system (ANS) and the hypothalamic-pituitary-adrenal (HPA) axis. Studies have demonstrated that patients with FMS exhibit lowered sympathoadrenal reactivity to stress. These findings seem to be consistent with the large volume of research indicating the inverse relationship between pain sensitivity and sympathetic reactivity. In this paper, we discuss the role of stress in the pain experience in general, stress in patients with FMS, and review the studies evaluating the ANS and HPA functions in response to various stressors.     

A sequence-coupled vector-projection model for predicting the specificity of GalNAc-transferase.

The specificity of GalNAc-transferase is consistent with the existence of an extended site composed of nine subsites, denoted by R4, R3, R2, R1, R0, R1', R2', R3', and R4', where the acceptor at R0 is either Ser or Thr to which the reducing monosaccharide is being anchored. To predict whether a peptide will react with the enzyme to form a Ser- or Thr-conjugated glycopeptide, a new method has been proposed based on the vector-projection approach as well as the sequence-coupled principle. By incorporating the sequence-coupled effect among the subsites, the interaction mechanism among subsites during glycosylation can be reflected and, by using the vector projection approach, arbitrary assignment for insufficient experimental data can be avoided. The very high ratio of correct predictions versus total predictions for the data in both the training and the testing sets indicates that the method is self-consistent and efficient. It provides a rapid means for predicting O-glycosylation and designing effective inhibitors of GalNAc-transferase, which might be useful for targeting drugs to specific sites in the body and for enzyme replacement therapy for the treatment of genetic disorders.     

Survival and hazard functions for progressive diseases using saddlepoint approximations

Saddlepoint approximations for the computation of survival and hazard functions are introduced in the context of parametric survival analysis. Although these approximations are computationally fast, accurate, and relatively straightforward to implement, their use in survival analysis has been lacking. We approximate survival functions using the Lugannani and Rice saddlepoint approximation to the distribution function or by numerically integrating the saddlepoint density approximation. The hazard function is approximated using the saddlepoint density and distribution functions. The approximations are especially useful for consideration of survival and hazard functions for waiting times in complicated models. Examples include total or partial waiting times for a disease that progresses through various stages (convolutions of distributions).     

甲亢性肝损害116例临床分析

目的探讨甲状腺功能亢进症（甲亢）肝损害的临床特点。方法收集228例甲亢患者的临床资料,分为肝损害组及无肝损害组,对两组患者的年龄、性别、甲亢病程、肝功能及甲状腺功能等指标进行分析比较。结果 228例甲亢患者中发生肝损害116例,发生率为50.72%。甲亢患者的性别与甲亢性肝损害的发生率无相关性;而年龄越大甲亢性肝损害发生率越高,病程越长甲亢性肝损害发生率也越高。甲亢性肝损害患者甲状腺功能指标TT4、FT3明显高于甲亢肝功能正常的患者,差异有统计学意义（P〈0.05）;肝功能测定以ALT、ALP升高多见。结论甲亢性肝损害的发病率较高,病情的严重程度与年龄、病程、甲状腺激素水平有密切关系;建议临床医生对初诊及复诊甲亢患者进行肝功能常规测定,以便合理选用治疗方案,使甲亢性肝损害得以及早治疗。     

蛭弧菌BDG-9质粒不稳定性研究

本文建立了研究难于单独连续培养的专性蛭孤菌质粒稳定性的方法体系。应用此方法体系发现并证明了在传蛭孤菌ＢＤＧ－９中所含的质粒ｐＳＴⅠ存在着独特的质粒缺失现象,当蛭弧菌ＢＤＧ－９单独培养时,在通常决定质粒稳定性的复制功能和分配功能都正常的情况之下,随着细胞的传代,质粒ｐＳＴⅠ逐渐丢失,蛭弧菌的生长繁殖也逐渐停止,表明质粒ｐＳＴⅠ的存在对ＢＤＧ－９细胞单独生长有重要作用。     

A method for assessing recovery of fine motor function of the hand in a rhesus monkey model of cortical injury: an adaptation of the Fugl–Meyer Scale and Eshkol–Wachman Movement Notation

Motor dysfunction of the upper extremity can result from stroke, cortical injury and neurological diseases and causes significant disruption of activities of daily living. While some spontaneous recovery in terms of compensatory movements does occur after injury to cortical motor areas, full recovery is rare. The distinction between complete recovery and compensatory recovery is important as the development of compensatory movements in the upper extremity may not translate into full functional use in human patients. However, current animal models of stroke do not distinguish full recovery from compensatory recovery. We have developed a Non-Human Primate Grasp Assessment Scale (GRAS) to quantify the precise recovery of composite movement, individual digit action, and finger-thumb pinch in our rhesus monkey model of cortical injury. To date, we have applied this GRAS scale to assess the recovery of fine motor function of the hand in young control and cell-therapy treated monkeys with cortical injury confined to the hand representation in the dominant primary motor cortex. We have demonstrated that with this scale we can detect and quantify significant impairments in fine motor function of the hand, the development of compensatory function during recovery and finally a return to full fine motor function of the hand in monkeys treated with a cell therapy.     

机器人辅助妇科手术术中气腹对患者肝肾功能影响的初步临床研究

目的:研究机器人辅助妇科手术中气腹对术者肝肾功能的影响。方法:择期开腹妇科手术和机器人辅助妇科手术患者各20例,18-65岁,体重指数18-30,美国麻醉医师协会分级1-2级。手术均在全身麻醉下进行。采用丙泊酚(1.5-2 mg/kg)和芬太尼(2-4μg/kg)进行全麻诱导。麻醉维持采用七氟烷和瑞芬太尼。术中维持Narcotrend指数于40-60。分别于手术开始前和结束后30 min抽取静脉血,测定血谷丙转氨酶、谷草转氨酶、尿素氮和肌酐水平并分析其变化。结果:与开腹手术相比,机器人辅助妇科手术气腹后血谷丙转氨酶、谷草转氨酶、尿素氮和肌酐的升高更为明显(P均0.05)。结论:机器人辅助妇科手术中长时间气腹可能引起肝肾功能的异常。     

正加速度应激致心脑损伤的动物实验研究综述

正加速度（ positive acceleration ,＋Gz）作用下机体的心脑功能防护是航空航天医学领域重点关注的课题。＋Gz作用致机体心脑等重要生命脏器损伤的特点和机制有待深入研究。本文就国内外有关＋Gz作用致实验动物心脑损伤及其机制的研究文献进行综述。