抵抗素参与血管内皮细胞功能障碍的研究进展

抵抗素是脂肪细胞分泌的一种多肽类激素,早有研究证明抵抗素通过影响胰岛素信号转导参与了胰岛素抵抗,与2型糖尿病的发生发展密切相关.越来越多研究表明抵抗素可以促进肿瘤坏死因子α、白细胞介素6等炎症标志物的表达,诱导血管炎症反应的发生,从而损伤血管内皮细胞并影响其功能.内皮细胞功能异常又是动脉粥样硬化及糖尿病血管并发症病理过程的始动环节,提示抵抗素可能在心血管疾病的发生发展中起重要作用.本文就有关抵抗素参与血管内皮细胞功能障碍的研究进展作一综述.     

抵抗素、脂联素对原代培养的脐静脉内皮细胞分泌NO、ET-1、TGF-β1的影响

目的观察抵抗素、脂联素对原代培养的脐静脉内皮细胞（HUVECs）分泌一氧化氮（NO）、内皮素1（ET-1）和转化生长因子艮（TGF—β1）的影响。方法用含不同浓度抵抗素（10、50、100ng／ml）、抗抵抗素抗体加高浓度抵抗素（100ng／ml）、脂联素（10μg／ml）加高浓度抵抗素的无血清RPMI 1640液培养HUVECs24、48h，取上清液测定NO、ET-1和TGF-β1水平。结果抵抗素呈剂量依赖性促进HUVECs分泌ET-1和TGF-β1（P〈0．01，〈0．05），对NO无明显影响（P〉0．05）。生理剂量的脂联素能增加NO释放（P〈0．05），对高浓度抵抗素引起的ET-1分泌无明显抑制作用，对高浓度抵抗素引起的TGF-β1分泌有部分抑制作用（P〈0．05）。结论抵抗素能刺激血管内皮细胞过度分泌ET-1和TGF-β1导致血管内皮细胞功能紊乱，加速糖尿病（DM）血管病变的发生发展。脂联素在DM血管病变的发生发展中起保护作用。     

人抵抗素对脂肪细胞摄取葡萄糖的影响及其机制研究

构建人抵抗素基因表达载体转染细胞,研究其对脂肪细胞摄取葡萄糖、细胞增殖及分化的影响.结果 表明,人抵抗素通过促进前脂肪细胞增殖和抑制脂肪细胞分化来降低葡萄糖摄取.二甲双胍能拈抗人抵抗素对成脂的抑制作用.     

抵抗素对动脉硬化和心脏疾病的影响

抵抗素是脂肪细胞分泌的一种多肽类激素。越来越多研究表明抵抗素可以促进C反应蛋白,肿瘤坏死因子α、白细胞介素6等炎症标志物的表达,诱导血管炎症反应的发生,从而损伤血管内皮细胞以及平滑肌细胞并影响其功能。本文就抵抗素与动脉粥样硬化及心血管疾病相互关系的研究现状做一综述。     

脂联素与抵抗素对动脉粥样硬化的作用及其与血管紧张素受体拮抗剂关系

<正>大部分脂肪因子通过自分泌和旁分泌途径促进血管局部和远端炎性反应,然而同样有脂肪细胞的脂联素却具有相反作用〔1〕。脂联素血症是动脉粥样硬化(AS)发展的独立危险因子。抵抗素最初被认为是联系肥胖、胰岛素抵抗和2型糖尿病的新型脂肪因子,然而最近研究表明抵抗素可以作用于血管内皮细胞及平滑肌细胞从而影响其功能,促进AS的发生与发展〔2〕。而脂联素与抵抗素在对AS的作用中都部分性地通过核     

血清抵抗素与充血性心力衰竭的相关性探讨

血清抵抗素是一种脂肪组织分泌的“脂肪细胞因子”, 它是一种富含半胱氨酸的生物活性肽,通过自分泌,旁分泌和内分泌效应,影响机体多种功能, 如能量平衡、免疫、胰岛素敏感性、新生血管生成、血压、脂代谢和凝血等,所有这些都与心血管病的发生有关[1,2]. 近年来研究发现在啮齿动物中抵抗素与胰岛素抵抗有关,血浆抵抗素水平与炎症的标记相关,可促进内皮细胞活化及平滑肌细胞增殖,并且可预兆人的冠状动脉硬化[3,5]. 本研究旨在探讨血清抵抗素水平是否与心力衰竭的恶化有关, 是否可以用来预测心力衰竭患者的不良临床预后.     

抵抗素对原代培养的脐静脉内皮细胞分泌ET-1、TGF-β1的影响

目的观察抵抗素对原代培养的脐静脉内皮细胞（HUVECs）产生内皮素-1（ET-1）和转化生长后子-β1（TGF-β1）的影响。方法分别用含不同浓度抵抗素、抗抵抗素IgG加高浓度抵抗素、脂联素加高浓度抵抗番的无血清RPMI 1640液培养HUVECs 48h，用放射免疫法测定其上清液中的ET-1水平，用ELISA法测定爿TGF-β1水平。结果抵抗素呈剂量依赖性促进HUVECs分泌ET-1（P〈0.01）和TGF-β1（P〈0．05）。抗抵抗京IgG能够完全抑制高浓度抵抗索引起的ET-1和TGF-β1分泌（P〉0．05）。生理剂量的脂联素对高浓度抵抗素引起的ET-1的分泌无明显抑制作用（P〉0．05），对高浓度抵抗素引起的TGF-β1：分泌有部分抑制作用（P〈0．05）。结论抵抗素导致血管内皮细胞功能紊乱。促发糖尿病血管病变。而脂联素在糖尿病血管病变中起保护作用。     

抵抗素与脑卒中危险因素的相关研究

抵抗素(resistin)是近年发现的一种脂肪组织特异分泌的多肽类激素,又称脂肪组织特异分泌因子(adipose tissue-specific secretory factor),它与胰岛素抵抗、肥胖及2型糖尿病均有一定的联系.目前对于抵抗素的研究大部分集中在肥胖及糖尿病方面,对于脑卒中方面的研究极为有限.根据目前的研究报道,本文简要综述了抵抗素基因的结构及其多态性、抵抗素基因的表达及表达的调控,以及抵抗素与肥胖、糖尿病、动脉硬化、血管内皮素等因素之间的关联.因其皆为脑卒中的危险因素,从而间接指出抵抗素与脑卒中的关系密切.     

抵抗素的研究进展

抵抗素是存在于血浆中的富含半胱氨酸的分泌性蛋白。新近研究表明,抵抗素可作用于脂肪、肝脏、骨骼肌等胰岛素靶器官,通过影响胰岛素信号转导途径及代谢相关酶的转录影响糖、脂代谢,参与机体的能量调节。人抵抗素主要在外周血单核细胞中表达。抵抗素可作用于血管内皮细胞及平滑肌细胞影响其功能。临床研究显示,抵抗素与多个炎症标志相关,与动脉粥样硬化的病变范围关系密切,提示抵抗素可能在动脉粥样硬化的发病机制中发挥作用。     

抵抗素与炎症、动脉粥样硬化研究进展

抵抗素最初被认为是联系肥胖与胰岛素抵抗、2型糖尿病的脂肪细胞因子。然而近年来研究发现其在人体主要与炎症有关,抵抗素不仅促进炎症的发生,而且炎症因子也可影响抵抗素的表达。动脉粥样硬化是一种慢性亚临床性炎症,大量的研究表明抵抗素与动脉粥样硬化相关。抵抗素通过局部和全身炎症作用诱导内皮功能失调、巨噬细胞的脂质沉积以及平滑肌增殖迁移,从而促进动脉粥样硬化的发生发展。     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.