Calreticulin, a potential vascular regulatory protein, reduces intimal hyperplasia after arterial injury

Both thrombotic and inflammatory responses to arterial injury have been implicated in atherosclerotic plaque growth. Calreticulin is a ubiquitous calcium-binding protein with antithrombotic activity and, in addition, is associated with leukocyte activation. We are investigating calreticulin as a potential vascular regulatory protein. The development of intimal hyperplasia was studied at sites of balloon injury in iliofemoral arteries from 91 rats. Calreticulin was infused directly into the artery immediately before balloon injury, and plaque growth was then assessed at 4 weeks' follow-up. Parallel studies of the effects of each calreticulin domain as well as a related calcium-binding protein, calsequestrin, were examined. The effects of calreticulin on platelet activation, clot formation, and mononuclear cell migration were also studied. When infused before balloon injury in rat iliofemoral arteries, calreticulin, or its high-capacity Ca(2+)-binding C domain, significantly reduces plaque development, whereas calsequestrin, a related calcium-binding protein that lacks the multifunctional nature of calreticulin, does not decrease plaque area (saline: 0.037 +/- 0.007 mm2, calsequestrin: 0.042 +/- 0.021 mm2, calreticulin: 0.003 +/- 0.002 mm2, n = 46, P < .04). The N domain and more specifically the P domain, a low-capacity, high-affinity calcium-binding domain in calreticulin, do not reduce intimal hyperplasia (N + P domain: 0.038 +/- 0.012 mm2, C domain: 0.003 +/- 0.002 mm2, n = 45 rats, P < .0001). Calreticulin reduces macrophage and T cell staining in the arterial wall after injury but has no direct effect on monocyte migration in vitro (percent medial area staining positive for macrophage 24 hours after injury (N + P: 4.06 +/- 1.42, calreticulin: 0.273 +/- 0.02; n = 26, P < .009). Calreticulin does, however, reduce platelet-dependent whole blood clotting time, in vitro (baseline: 78.23 +/- 2.04 seconds, calreticulin: 113.5 +/- 1.95 seconds; n = 5, P < .002). We conclude that calreticulin significantly reduces intimal hyperplasia after arterial injury, potentially acting as a vascular regulatory protein.     

Durability and generalizability of persistence training.

40 male and 40 female college students experienced either partial reinforcement (persistence training) or continuous reinforcement on either of 2 instrumental tasks (finger shuttle or button press) as therapy for failure-induced depression and subsequently were exposed to protracted failure (extinction). Following this initial extinction phase all Ss received continuous reinforcement on a common instrumental task (button press) as therapy and then encountered extinction (consecutive failure trials) for a 2nd time. Results show that increased persistence occasioned by partial-reinforcement therapy was able to survive interpolated periods of extinction and continuous reinforcement; that is, durable persistence training effects were shown. Furthermore, persistence training effects were shown to be generalizable (the persistence advantage associated with partial-reinforcement therapy transferred across topographically different responses), but the generalization process was not a complete one. The results are discussed within the frameworks of frustration theory and alternative cognitive theories. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spectrum of Cyanide Toxicity and Allocation in <Emphasis Type="Italic">Heliconius erato</Emphasis> and <Emphasis Type="Italic">Passiflora</Emphasis> Host Plants

The larvae of three races of Heliconius erato were fed various species of Passiflora containing varying levels of cyanoglucosides. The mortality rate of larvae and pupae rose when larvae were fed species of Passiflora capable of releasing larger quantities of cyanide. When larvae were fed species of Passiflora with these properties, the resulting adult butterflies also released higher levels of cyanide. This may serve as a defense mechanism. The compounds responsible for the release of cyanide were not evenly distributed throughout the adult butterfly’s body. The thorax contained the highest concentration of cyanogenic substances, followed by the head, wings, and abdomen. The younger tissues of Passiflora plants had higher levels of cyanide-releasing compounds than stems and mature leaves. Cyanogenic glycoside distribution within the plants is consistent with optimal allocation theory. The levels of cyanide-releasing substances in plants varied depending on the season.     

基于虚拟仪器的原油管道泄漏监测系统

近年来我国原油泄漏事故频仍,造成巨大经济损失和环境污染,所以需要一个能够及时发现并精确定位的监测系统。我们使用ational Instruments公司的虚拟仪器开发平台LabVIEW和数据采集卡,不间断采集压力、流量、温度等参数,监视管道运行状况,并利用电话线路构成通信网络,建立了一个实时性较好的监测系统。对于突发的原油泄漏,我们综合运用了包括小波分析在内的多种信号处理方法,能够及时准确地定位泄漏点。本系统已经成功地应用于胜利油田和华东输油管理局等集输管网和长输管线,取得了可观的经济效益。     

Chronic cadmium exposure alters cocaine self-administration in adult male rats.

Adult male rats (Rattus norvegicus) were exposed to a water supply in the home cage containing 100 ppm cadmium chloride and sodium saccharin (.65% wt/vol; cadmium group) or water containing only the saccharin amendment (group control). On Day 65 of exposure, animals from each group received jugular catheter implants and were subsequently trained over the course of 15 daily 2-hr sessions to self-administer a .25 mg/kg/infusion of cocaine HCl under a fixed ratio 1 schedule. Immediately following acquisition training, the full dose-effect function was determined for all animals by using cocaine doses of .03, .06, .125, .25, .50, and 1.0 mg/kg. Cadmium-exposed animals executed more active (cocaine) lever responses during acquisition training but were not different from controls in depressing a pharmacologically inactive lever. For dose-effect testing, cadmium exposed animals exhibited greater self-administration than controls at the higher doses of cocaine, and there was evidence that the cocaine dose that produced maximum responding was higher in cadmium-exposed than control animals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dietary lead increases ethanol consumption in the rat.

When 36 male Sprague-Dawley rats fed either a diet containing 500 parts per million Pb (as lead acetate) or an unadulterated control diet for 50 days were offered a 15% ethanol (ETOH) solution in a nonchoice (1-bottle) test situation, Pb-diet Ss consumed greater amounts of the ETOH solution than did controls. In a subsequent choice (3-bottle, 2-fluid) test situation offering a nonpreferred ETOH solution or tap water as alternatives, Pb-diet Ss again ingested greater amounts of the ETOH solution. Findings are discussed in terms of possible Pb-induced increases in emotionality and the potential stress-reduction properties of ETOH. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)