α-MSH在体温调节中作用及其机理的研究进展

α MSH是从多种属哺乳动物脑组织中分离出来的 1 3肽。它在动物体温调节中发挥重要的负调节作用。无论静脉注射还是脑室内给α MSH均可使发热动物降温 ,但不参与正常的体温调节。本文从以下几方面对其解热作用机理进行了综述 :①α MSH发挥解热作用的部位主要是脑内隔区 ;②α MSH的退热活性是主要由其COOH 端序列Lys Pro Val(α MSH1 1 -1 3 )起作用的 ;③MC3 R和MC4 R可能是参与α MSH体温调节的主要受体 ;④关于其解热机制的几种假说。这些研究为我们进一步开发新的解热药物提供了帮助     

血小板在免疫网络中调节作用的研究进展

健康人中血小板相对于红细胞是含量第二丰富的细胞,每升1.0×1011～3.0×1011个.血小板在机体内起着重要的促凝血作用.以前认为尽管血小板可作为免疫损害的靶子,它的生成也受许多免疫因子的调节,但血小板本身不参与免疫反应.     

内质网应激在低氧性肺动脉高压中作用的研究进展

低氧性肺动脉高压(HPH)是长期低氧导致的血管持续性收缩和血管不可逆重塑的严重肺部并发症。低氧可干扰内质网腔内蛋白质折叠过程,激活内质网应激(ERS)。ERS作为细胞应激的核心反应,与HPH的发生发展关系密切。     

Regulation of IL-18 expression by CRH in mouse microglial cells

Corticotropin releasing hormone (CRH) is a major regulator of the stress response. This study examined whether CRH regulates interleukin-18 expression on microglia, BV2. Our data show that CRH enhanced IL-18 expression and significantly induced the secretion of functional IL-18 protein. Furthermore, CRH induced IL-18 production could be blocked by N-acetyl-L-cystein (NAC), which suggests that reactive oxygen intermediates (ROI) may be involved in regulating IL-18. Indeed, it was also found that CRH increased the generation of ROI. Taken together, these results indicate that CRH is an important mediator that regulates IL-18 expression in the brain during stress.     

Fever and Behavioural Temperature Regulation in the Frog Rana esculenta

The skin and colonic temperatures were recorded in frogs (Rana esculenta) which had selected a suitable microenvironment in a box filled with 2–3 cm water. The water temperatures ranged from 0°C to + 40°C. Such measurements were performed before and after intraperitoneal injections of killed pathogenic bacteria (M. xenopi and M. ranae), killed non-pathogenic bacteria (M. aquae II) and 0.9% sterile saline, intraperitoneal injections of blood plasma from frogs pre-injected with killed M. ranae, injections of PGE, into the brain. The injections of pathogenic bacterial endotoxin caused, after latencies of 5–120 min, higher preferred water temperatures, which produced an average maximum colonic temperature increase of 6.5°C ± 1.0°C (S.E.) (p< 0.001). The non-pathogenic bacteria and sterile saline caused no temperature change. Monophasic hyperthermia of shorter latency was caused by injections of blood plasma from frogs pre-injected with M. ranae. Monophasic hyperthermia of the shortest latency was observed after diencephalic injections of PGE₁. Based on their similarity we suggest that ectothermic and endothermic fever have a common phylogenetic origin.     

Fetal undernutrition induces overexpression of CRH mRNA and CRH protein in hypothalamus and increases CRH and corticosterone in plasma during postnatal life in the rat

Prenatal undernutrition induces a variety of cardiovascular alterations in mammals when adults, including hypertension and hypercortisolism, which are thought to be caused by decreased glucocorticoid feedback control of the hypothalamus–pituitary–adrenal (HPA) axis programmed during fetal life. Hypothalamic CRH seems to be involved in blood pressure elevation of spontaneously hypertensive rats and in primary hypertension of humans, but the influence of prenatal undernutrition on CRH expression has deserved little attention. Here, we studied the expression of both CRH mRNA and CRH protein in the hypothalamus of neonatal and juvenile offspring of rats undernourished during fetal life, as well as the plasma levels of CRH and corticosterone. Prenatal undernutrition of pups was induced by submitting pregnant rats to diet restriction (10 g daily of 21% protein standard laboratory diet). Pups born from dams with free access to the standard laboratory diet served as controls. At day 2 of postnatal age, undernourished pups showed lower body and brain weights, but higher plasma CRH and corticosterone than normal pups. At day 40 of age, brain weight was significantly decreased in the undernourished rats, while plasma corticosterone, plasma CRH and systolic pressure were significantly increased in these animals. At days 2 and 40 of postnatal age, increased CRH mRNA expression and CRH concentration were found in the hypothalamus of undernourished rats. Results indicate that, in the rat, prenatal undernutrition led to fetal programming of CRH overexpression, a neuropeptide serving as activating signal to the HPA axis and/or to extrahypothalamic brain regions concerned with cardiovascular regulation.     

Daxx的转录抑制及激活调控功能

Daxx定位细胞核PODs,可在转录调控中行使转录抑制或转录激活双重功能.Daxx通过转位、化学修饰、染色体调节、直接与转录因子或转录相关蛋白相互作用等多种方式发挥转录调控作用.其中,Daxx通过转位,转录后化学修饰,染色体调节,与转录因子或转录相关蛋白相互作用行使转录抑制功能,但相关研究表明Daxx同样可通过与相关因...     

Pituitary CRH receptor blockade reduces waking in the rat

We have previously hypothesized that corticotropin-releasing hormone (CRH) is involved in the regulation of physiological waking. Central administration of CRH receptor antagonists reduces spontaneous waking in the rat. Some of the responses to central administration of CRH receptor antagonists may be mediated by mechanisms involving the hypothalamic-pituitary-adrenal axis, either by direct actions on the hypothalamus or by actions at the level of the pituitary due to leakage of the antagonists from the cerebrospinal fluid to blood. To further clarify the role of the hypothalamic-pituitary-adrenal axis as a mediator of responses to CRH receptor blockade, we administered intravenously into freely behaving rats in their home recording cages two specific CRH receptor antagonists, astressin or alpha-helical CRH, and determined subsequent changes in waking and sleep. Our results indicate that both antagonists reduce spontaneous waking, but with different time courses. Astressin, a potent antagonist of pituitary CRH receptors, reduces waking during postinjection hours 9-10, whereas high doses of alpha-helical CRH reduce waking only during the first postinjection hour. These results indicate that some effects of CRH on sleep-wake behavior may be meditated by pituitary CRH receptors.     

糖尿病肾病研究进展

糖尿病肾病是目前糖尿病最为常见的并发症,一旦发病,则机体代谢变得毫无规律,极大地影响了人体正常机能。基于此本文凭借对糖尿病肾病的发病机制进行深入探析,最终总结出了下述结论:其发病机制主要受制于若干因素的影响,常见的有如下几种:糖代谢紊乱、肾脏血流改变,细胞因子表达异常,遗传因素以及氧化应激等。深入探究其发病机制,有助于确定最佳的根治方法。     

登革出血热皮疹的病理及超微结构研究

通过３例登革出血热皮疹处皮肤病理切片检查，对皮疹的发生、消退，病理改变，病变处血管等超微结构进行观察。结果显示登革出血热皮疹的主要病理改变为真皮上层血管内皮细胞的变性，致使红、白细胞外溢，推论内皮细胞的病变与病毒感染相关，并为出血的基本机理。     

Comparison between the central effects of CRH and AVP in steers

In cattle, the in vivo effects of centrally administered corticotropin-releasing hormone (CRH) or arginine vasopressin (AVP) from the perspective of stress regulation have not been fully elucidated. We compared behavioral, adrenocorticotropic, and autonomic nervous responses to intracerebroventricularly infused bCRH or AVP in steers. Intracerebroventricular infusions of both bCRH and AVP (0.2, 2, 10 and 20 nmol/500 mul/30 min) evoked a dose-related increase in plasma concentrations of ACTH and cortisol. At 10 nmol, the AUC response of cortisol concentration to bCRH tended to be higher than that in response to AVP (p=0.075). There were significant differences among treatments in the total number of head shaking (Friedman's test, chi2=22.79, p=0.004), upright posture (chi2=16.80, p=0.032), head rubbing (chi2=23.93, p=0.002), tongue playing (chi2=27.18, p=6.58E(-4)), and bleating (chi2=26.84, p=7.54E(-4)). AVP 10 and 20 nmol treatments induced more head shaking and tongue playing than vehicle treatment (Nemenyi multiple comparisons: p<0.1). Ten nmol (32.8+/-40.2 times) and 20 nmol (34.8+/-19.9 times) of bCRH induced bleating, but no dosage of AVP induced bleating. These findings indicate that both bCRH and AVP could activate HPA axis in steers when infused intracerebroventricularly and that bCRH was more potent to stimulate HPA axis than AVP. As for the effects on behavioral function, high dosages of both peptides induced stereotyped behaviors and the types of stereotyped behaviors induced were different between bCRH and AVP.     

Chronic Q Fever in the Netherlands 5 Years after the Start of the Q Fever Epidemic: Results from the Dutch Chronic Q Fever Database

Coxiella burnetii causes Q fever, a zoonosis, which has acute and chronic manifestations. From 2007 to 2010, the Netherlands experienced a large Q fever outbreak, which has offered a unique opportunity to analyze chronic Q fever cases. In an observational cohort study, baseline characteristics and clinical characteristics, as well as mortality, of patients with proven, probable, or possible chronic Q fever in the Netherlands, were analyzed. In total, 284 chronic Q fever patients were identified, of which 151 (53.7%) had proven, 64 (22.5%) probable, and 69 (24.3%) possible chronic Q fever. Among proven and probable chronic Q fever patients, vascular infection focus (56.7%) was more prevalent than endocarditis (34.9%). An acute Q fever episode was recalled by 27.0% of the patients. The all-cause mortality rate was 19.1%, while the chronic Q fever-related mortality rate was 13.0%, with mortality rates of 9.3% among endocarditis patients and 18% among patients with a vascular focus of infection. Increasing age (P = 0.004 and 0.010), proven chronic Q fever (P = 0.020 and 0.002), vascular chronic Q fever (P = 0.024 and 0.005), acute presentation with chronic Q fever (P = 0.002 and P < 0.001), and surgical treatment of chronic Q fever (P = 0.025 and P < 0.001) were significantly associated with all-cause mortality and chronic Q fever-related mortality, respectively.