Peptidomics and genomics analysis of novel antimicrobial peptides from the frog, Rana nigrovittata

Much attention has been paid on amphibian peptides for their wide-ranging pharmacological properties, clinical potential, and gene-encoded origin. More than 300 antimicrobial peptides (AMPs) from amphibians have been studied. Peptidomics and genomics analysis combined with functional test including microorganism killing, histamine-releasing, and mast cell degranulation was used to investigate antimicrobial peptide diversity. Thirty-four novel AMPs from skin secretions of Rana nigrovittata were identified in current work, and they belong to 9 families, including 6 novel families. Other three families are classified into rugosin, gaegurin, and temporin family of amphibian AMP, respectively. These AMPs share highly conserved preproregions including signal peptides and spacer acidic peptides, while greatly diversified on mature peptides structures. In this work, peptidomics combined with genomics analysis was confirmed to be an effective way to identify amphibian AMPs, especially novel families. Some AMPs reported here will provide leading molecules for designing novel antimicrobial agents. (C) 2009 Elsevier Inc. All rights reserved

氟代柠檬酸对体外培养的神经胶质瘤细胞G422增殖的抑制效应

为研究氟代柠檬酸(Fluorocitrate)对体外培养的神经胶质瘤细胞生长的影响,采用MTT法研究不同的氟代柠檬酸浓度(0.0025mmol/L,0.005mmol/L,0.01 mmol/L,0.025mmol/L和0.1 mmol/L)和作用时间(36h,48h和60h)对神经胶质瘤细胞G422增殖的影响.结果发现:(1)氟代柠檬酸可抑制G422细胞的增殖,并且其抑制作用随氟代柠檬睃浓度的增加而增强;(2)高浓度(0.01 mmol/L,0.025 mmol/L和0.1 mmol/L)氟代柠檬酸对G422细胞的增殖抑制作用随作用时问的延长而增强:(3)低浓度(0.0025mmol/L和0.005mmol/L)氟代柠檬酸对G422细胞的增殖抑制作用不随作用时间的延长而改变.实验表明,氟代柠檬酸能够抑制神经胶质瘤细胞的增殖,其抑制能力随氟代柠檬酸浓度的增加和作用时间的延长而加强.

Delta EEG Activity in Left Orbitofrontal Cortex in Rats Related to Food Reward and Craving

眶额叶皮质与中脑边缘多巴胺奖赏系统有着复杂的相互纤维联系.先前的研究探讨了药物成瘾过程中眶额叶皮质的脑电活动.在本实验中,将探讨食物奖赏和渴求过程中该皮质的脑电活动.实验采用了两个环境:对照环境和食物刺激相关的环境.首先,训练大鼠在食物刺激相关的环境中吃巧克力花生豆,而后在该环境中设置两种不同的刺激方式:能看到和闻到但不能吃到(渴求实验),或者仍旧可以吃到巧克力花生豆(奖赏实验):同时进行左侧眶额叶皮质的脑电记录.结果发现,在食物刺激相关的环境中大鼠Delta频段(2-4Hz)的脑电活动与食物刺激显著相关,此外,与在对照环境中相比,其相对功率在食物渴求时下降而在食物奖赏时升高.本实验表明,食物相关的奖励可以改变大鼠眶额叶皮质的脑电活动,而且,Delta频段的脑电活动能够作为监测该奖励的一个指标.

Morphine and propranolol co-administration impair consolidation of Y-maze spatial recognition memory

In the present study, the interaction between morphine and the beta-adrenergic receptor antagonist, propranolol (PROP), in memory consolidation was investigated in a two-trial recognition Y-maze task. Four sets of Y-maze experiments were carried out in mi

Distracters Impair and Create Working Memory-Related Neuronal Activity in the Prefrontal Cortex

The prefrontal cortex (PFC) has a central role in working memory (WM). Resistance to distraction is considered a fundamental feature of WM and PFC neuronal activity. However, although unexpected stimuli often disrupt our work, little is known about the un

Pentylenetetrazole-induced status epilepticus following training does not impair expression of morphine-induced conditioned place preference

Learning and memory play an important role in morphine addiction. Status epilepticus (SE) can impair the spatial and emotional learning and memory. However, little is known about the effects of SE on morphine-induced conditioned place preference (CPP). Th

Bibliometric analysis of nicotine research in China during the period of 1991 to 2007

With the widespread exposure of people to nicotine through recreational use of tobacco products, research into nicotine has attracted increasing attention. Tobacco smoking is by far the most important cause of lung cancer. As the world's largest producer and consumer of tobacco products, China bears a large proportion of the global burden of smoking-related disease; therefore, information on nicotine publications should be collected to formulate future research policy. In the present study, we investigated nicotine-related research articles published by Chinese authors that were indexed in the Science Citation Index (SCI) from 1991 to 2007. An indicator "citations per publication" (CPP) was used in the study to evaluate the impact of journals, articles, and institutes. The quantity of publications has increased at a quicker pace than the worldwide trend. Article visibility, measured as the frequency of being cited, also increased during the period. However, the overall quality of articles, based on the impact factor of journals publishing those articles, dropped behind the worldwide average level. There has been an increase in international collaboration, mainly with researchers in the USA. The average CPP of international co-authorship articles was higher than that of single country publications. Besides the USA, nicotine research in China will benefit from more collaboration with Taiwan, England, and Germany. Some 110 of 264 articles were published by a single institute, and the top six institutes were compared from various angles. Seventy-two subject categories were covered, and trends (in terms of both quantity and quality) of nicotine research in China were compared with worldwide trends. In addition, analysis of keywords in both nicotine and lung cancer research fields was applied to indicate research interests. Mutual cooperation among multiple disciplines needs further strengthening.

High negative ion production yield in 30 keV F2+ + adenine (C5H5N5) collisions

In collisions between slow F2+ ions (30 keV) and molecular targets, adenine, scattered particle production yields have been measured directly by simultaneous detection of neutrals, positive and negative ions. The relative cross-section for a negative ion formation channel was measured to be 1%. Despite a slight decrease compared to a larger target, the fullerene C-60, the measured negative ion formation cross section is still at least one order of magnitude larger than the yield in ion-atom interactions.