Detailed analysis of the plasma extracellular vesicle proteome after separation from lipoproteins

The isolation of extracellular vesicles (EVs) from blood is of great importance to understand the biological role of circulating EVs and to develop EVs as biomarkers of disease. Due to the concurrent presence of lipoprotein particles, however, blood is one of the most difficult body fluids to isolate EVs from. The aim of this study was to develop a robust method to isolate and characterise EVs from blood with minimal contamination by plasma proteins and lipoprotein particles. Plasma and serum were collected from healthy subjects, and EVs were isolated by size-exclusion chromatography (SEC), with most particles being present in fractions 8–12, while the bulk of the plasma proteins was present in fractions 11–28. Vesicle markers peaked in fractions 7–11; however, the same fractions also contained lipoprotein particles. The purity of EVs was improved by combining a density cushion with SEC to further separate lipoprotein particles from the vesicles, which reduced the contamination of lipoprotein particles by 100-fold. Using this novel isolation procedure, a total of 1187 proteins were identified in plasma EVs by mass spectrometry, of which several proteins are known as EV-associated proteins but have hitherto not been identified in the previous proteomic studies of plasma EVs. This study shows that SEC alone is unable to completely separate plasma EVs from lipoprotein particles. However, combining SEC with a density cushion significantly improved the separation of EVs from lipoproteins and allowed for a detailed analysis of the proteome of plasma EVs, thus making blood a viable source for EV biomarker discovery.     

The effects of beta-endorphin on arginine-8-vasopressin and oxytocin levels in rat brain areas

Measurements were made of the effects of intracerebroventricular treatment with beta-endorphin (BE; 100 ng) on the arginine-8-vasopressin (AVP) and oxytocin contents of rat hypothalamic and limbic brain areas (hippocampus, amygdala and septum). The hormone concentrations were determined by radioimmunoassay. The administration of BE resulted in a significant reduction of the AVP level in the amygdala in a naloxone-reversible manner. Naloxone (Nal) administered subcutaneously significantly increased the AVP content in the septum. The results revealed that BE and Nal had regionally specific effects on the activity of the vasopressinergic system but not on that of the oxytocinergic system in the brain.     

Reception and discovery: the nature of Johann Wilhelm Ritter’s invisible rays

Ultraviolet radiation is generally considered to have been discovered by Johann Wilhelm Ritter in 1801. In this article, we study the reception of Ritter’s experiment during the first decade after the event—Ritter’s remaining lifetime. Drawing on the attributional model of discovery, we are interested in whether the German physicists and chemists granted Ritter’s observation the status of a discovery and, if so, of what. Two things are remarkable concerning the early reception, and both have to do more with neglect than with (positive) reception. Firstly, Ritter’s observation was sometimes accepted as a fact but, with the exception of C. J. B. Karsten’s theory of invisible light, it played almost no role in the lively debate about the nature of heat and light. We argue that it was the prevalent discourse based on the metaphysics of Stoffe that prevented a broader reception of Ritter’s invisible rays, not the fact that Ritter himself made his findings a part of his Naturphilosophie. Secondly, with the exception of C. E. Wünsch’s experiments on the visual spectrum, there was no experimental examination of the experiment. We argue that theorizing about ontological systems was more common than experimenting, because, given its social and institutional situation, this was the appropriate way of contributing to physics. Consequently, it was less clear in 1810 than in 1801 what, if anything, had been discovered by Ritter.     

Cr2O3／SiC（M,Y）—Al2O3系稳定的低粘度高固相含量悬浮体的制备

研究了复相 Cr2 O3 / Si C(M,Y) - Al2 O3 系稳定的高固相含量的低粘度悬浮体的流变特性 ,找出了影响流变性的主要因素。在碱性条件下 ,用实验室合成的 PMAA- NH4和 CM作为复合分散剂以及引入有机单体制备出固相含量高达 6 3(vol) % ,粘度为 2 35 m Pa.s的 Cr2 O3 /Si C(M,Y) - Al2 O3 悬浮体。     

Twisting the Dollar? On the Consistency of Short‐Run and Long‐Run Exchange Rate Expectations

We examine consistency properties of the exchange rate expectation formation process of short‐run and long‐run forecasts in the dollar/euro and yen/dollar market. Applying nonlinear consistency restrictions we show that in a simple expectation formation structure short‐run forecasts are indeed inconsistent with long‐run predictions. Moreover, we establish a ‘twist’ in the dollar/euro expectation formation process, i.e. market participants expect bandwagon effects in the short run, while they have stabilizing expectations in their long‐run forecasts. Applying a panel probit analysis we find that this twisting behavior is more likely to occur in periods of excess exchange rate volatility. Copyright © 2011 John Wiley & Sons, Ltd.     

Sick building syndrome,perceived odors,sensation of air dryness and indoor environment in Urumqi,China

In order to evaluate the perceived home indoor air quality, as well as sick building syndrome （SBS） in areas with typical arid continental climate such as Urumqi, northwest of China, a cross-sectional study including 4,260 parents of children （1-8 years） was performed by a ques- tionnaire survey in winter season in 2011. The sensation of air dryness （weekly/sometimes） in the last 3 months had the highest proportion of reports by more than half of the parents （57.4 %）, followed by perceived stuffy odor （40.6 %）, unpleasant odor （27.0 %）, tobacco smoke odor （25.5 %）, sensation of humid air （17.9 %）, pungent odor （11.7 %） and moldy odor （9.5 %）, respectively. The prevalence of SBS symptoms in the same time period was 40.4 % for general symptom, 47.7 % for mucosal symptom and 9.5 % for skin symptom, respectively. There were significant associations between perceived odors/sensation of air dryness and SBS symptoms （ORs range 1.39-1.42）. Additionally, the OR values increased with an increase of the OH score （P 〈 0.05）. Dampness, the presence of cockroaches and mosquitoes/flies, prenatal exposure to decoration and close to traffic were all risk factors of SBS symptoms. However, frequently putting bedding to sun- shine was potentially a protective factor. In conclusion, adults＇ perceptions of odors and sensation of air dryness are related to SBS symptoms and home environmental factors in Urumqi, China.     

Increasing prevalence of asthma and allergy in Beijing pre-school children: Is exclusive breastfeeding for more than 6 months protective?

This study evaluated the prevalence and risk factors for asthma, allergy and related symptoms; and breastfeeding patterns and durations for 5479 Beijing children aged 3–6. Parents of children in randomly selected kindergartens wrote responses to a questionnaire used previously. The study aimed to evaluate trends in the prevalence of asthma and related illnesses, and to determine whether “more” breastfeeding, defined as exclusive, > 6 months, was associated with reduced prevalence. Asthma has increased in this age group between 1990 and 2011, with the steepest increase in the last 2–3 years. Of the total, 14.2% (779) children were breastfed exclusively for > 6 months. The efficacy of “more” breastfeeding was tested in a subset with two strong risk factors, positive family history (for asthma and/or allergy) and male gender. “More” breastfeeding was found to be significantly protective (aOR 0.42, P < 0.05) for this subset against Doctor-diagnosed asthma (D-asthma). Protection that did not reach statistical significance was also found for this subset against Wheeze ever, Cough at night, Rhinitis ever, Doctor-diagnosed rhinitis (D-rhinitis) and Eczema. The greatest protective effects were found for girls with no family history of asthma or allergy, reaching statistical significance for Wheeze ever (aOR 0.48, P < 0.01), Cough at night (aOR 0.47, P < 0.01), D-asthma (aOR 0.14, P < 0.01) and Rhinitis ever (aOR 0.67, P < 0.05). “More” breastfeeding was not consistently associated with either a protective or risk effect for Eczema.     

不同聚合态胰岛素的晶体学研究:重组突变体B9(Ser→Asp)人胰岛素的系列结晶及其初步晶体学研究

用基因工程方法制备的B9(Ser→Asp)人胰岛素突变体是一种速效胰岛素.报道这一突变体的晶体生长,初步晶体学分析及衍射数据收集与处理.在不同的晶体生长条件下,分别得到了正交、四方、三方3种晶型的晶体.突变分子在不同晶型的晶体中以不同聚合方式存在,其构建单位分别是二体和六体.通过对这3种不同晶型的晶体结构解析和比较研究,将对此突变体的速效特性的结构基础以及胰岛素在不同条件下的自聚合特征有更深入的了解.