血管生成抑制蛋白Vasohibin的研究进展

对血管新生的促进在缺血性疾病包括动脉粥样硬化的干预具有实际意义,血管新生的调节依赖于促进因子和抑制因子的作用。Vasohibin是新近发现的调节血管生成的内皮源性负反馈调节因子,对抑制血管生成起重要作用。血管新生(angiogenesis)是指从已有的血管长出新血管的过程,生理和病理状态均可有新生血管形成。前者如正常胚胎发育、生殖、伤口愈合;而后者则可见于肿瘤、增殖性视网膜疾病、类风湿性关节炎等。血管新生的调节出现异常,则会导致病     

肿瘤的血管新生与凋亡

肿瘤的生长是血管新生依赖性的。血管新生是由血管新生刺激因子和抑制因子之间平衡来调节。血管新生抑制剂可通过提高肿瘤细胞凋亡率来抑制肿瘤生长 ,提示血管新生与凋亡相关 ,凋亡受凋亡相关基因调控。凋亡相关基因与血管新生可能相关。     

p75 神经营养因子受体在心血管系统中的作用

p75神经营养因子受体属于神经营养因子的受体之一。越来越多的研究表明,p75NTR在心血管系统自主神经中发挥重要的作用,不仅促进交感神经的生长发育,还调节心脏神经递质的释放。p75NTR还抑制新生血管形成,具有一定的抗血管生成作用,且介导平滑肌细胞凋亡,加重血管粥样硬化损伤。p75NTR这些特性表明其抑制剂存在重要的治疗潜能,或许能够改善缺血所致的损伤,如冠心病、急性心肌梗死、周围血管病变等。     

色素上皮细胞衍生因子与糖尿病微血管病变

色素上皮细胞衍生因子（PEDF）是一种多功能糖蛋白,在人体中广泛存在,具有抑制新生血管、营养神经及抗肿瘤等多种功能,并能够同多种细胞因子发生相互作用。近年来研究表明,PEDF与糖尿病微血管病变关系密切。     

巨噬细胞移动抑制因子促进新生微血管生成

目的观察巨噬细胞移动抑制因子对体外培养的人血管内皮细胞增殖的作用,以及通过体内外血管生成实验证实巨噬细胞移动抑制因子促进新生微血管生成的作用。方法采用体外培养的人血管内皮细胞株EA-hy926为实验对象,通过四甲基偶氮唑盐比色法测定血管内皮细胞增殖;利用体外血管生成分析试剂盒量化分析巨噬细胞移动抑制因子在体外对新生微血管生成的作用;利用免疫组织化学染色法检测巨噬细胞移动抑制因子作用后基底膜类似物栓子中第Ⅷ因子相关抗原观察巨噬细胞移动抑制因子在小鼠体内对新生微血管生成的作用。结果巨噬细胞移动抑制因子可以促进体外培养的人血管内皮细胞增殖,促进体外培养的人血管内皮细胞在体外形成血管腔,在小鼠体内也能促进基底膜类似物栓子中新生微血管生成。结论巨噬细胞移动抑制因子有促进新生微血管生成的作用。     

血管内皮生长因子促进脑缺血后血管和神经发生

血管内皮生长因子是一种强有力的血管生成因子.近年来还发现其具有强大的促进神经再生能力,在治疗缺血性脑血管病中具有潜在价值.新生的血管内皮细胞可形成"血管龛",通过释放某些神经营养因子促进神经发生.同样,新生的神经细胞也可促进血管发生,二者之间存在"交叉对话",血管内皮生长因子在其中发挥着非常重要的媒介作用.文章对血管内皮生长因子促进脑缺血后血管和神经发生方面的研究做了综述.     

肿瘤的血管新生与凋亡

肿瘤的生长是血管新生依赖性的。血管新生是由血管新生刺激因子和抑制因子之间平衡来调节。血管新生抑制剂可通过提高肿瘤细胞凋亡率来抑制肿瘤生长，提示血管新生与调亡相关，凋亡受凋亡相关基因调控。凋亡相关基因与血管新生可能相关。     

新生血管性眼病的基因治疗现状

新生血管形成的基本过程包括血管内皮细胞（EC）激活、细胞外基质（ECM）降解、EC移行和增殖、管腔结构形成以及血管外膜形成.在新生血管的形成过程中,血管生成诱导因子和血管生成抑制因子共同作用,两者的平衡控制了血管的形成[1].如果这种平衡被改变,减少血管生成抑制因子或增加血管生成诱导因子的水平,都将促进新生血管的形成.很多细胞因子、细胞及ECM参与了新生血管的形成过程。     

心外膜脂肪因子促进血管新生的分子机制

心外膜脂肪组织是沉积在心脏尤其是冠状动脉周围的脂肪组织，可以表达多种脂肪因子参与动脉粥样硬化的发生与发展，最近这些脂肪因子已经被证实还可以引起冠状动脉粥样硬化斑块内的血管新生。这些新生血管在斑块内可能具有双重效应：一方面，新生血管具有很强的通透性，可以改善斑块局部缺氧状况；另一方面，新生血管可能促进斑块进展并导致其不稳定性增加。因此，通过研究脂肪因子致血管新生作用的机制，抑制斑块内的血管新生增强其稳定性可能成为未来治疗冠心病新的靶点。     

血管新生在糖尿病周围神经病变中的研究进展

糖尿病周围神经病变(DPN)是常见的糖尿病并发症, 其发生与神经微血管功能紊乱密切相关。有证据表明, DPN神经微血管病变的发生先于神经结构功能的改变。早期的神经微血管改变表现为基底膜增厚、内皮细胞增生及血液流变学异常等, 这些病变诱发了神经微循环障碍, 造成神经内缺血缺氧, 引起能量代谢障碍、山梨醇累积和氧化应激等效应导致DPN的发生发展。血管新生是组织恢复血液供应的重要方式, DPN的血管新生处于抑制状态, 周围神经组织无法通过正常的血管新生过程来恢复血液供应、修复受损神经。基于以上研究基础, 诱导血管新生促进神经血流恢复的方法被提出用于DPN的治疗。该文强调了微血管对周围神经的重要性, 论述了DPN的血管新生抑制现象及可能机制, 对目前治疗性血管新生在DPN中的研究进展作一梳理总结, 以期为后续研究及临床应用提供参考。     

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.     

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.     

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.     

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.