外周血两种不同类型内皮祖细胞与颈动脉狭窄的关系

目的探讨外周血中早期内皮祖细胞和晚期内皮祖细胞数量和功能变化与颈动脉狭窄程度之间的关系。方法入组对象60例,根据全脑血管造影术分成颈动脉狭窄组40例(其中轻度狭窄组20例,中重度狭窄组20例),对照组20例。在全脑血管造影术中抽取患者股动脉血,采用密度梯度离心法分离外周血单个核细胞,分别培养至7天和21天鉴定为早期内皮祖细胞、晚期内皮祖细胞,计数细胞集落数量并分别用MTT比色法、改良的Boyden小室法和HFN培养板测定早期内皮祖细胞、晚期内皮祖细胞的增值、迁移、黏附功能。结果颈动脉狭窄组患者吸烟、高血压、甘油三酯、低密度脂蛋白明显高于对照组,高密度脂蛋白低于对照组(P<0.05);而年龄、性别、血糖、总胆固醇与对照组比较,差异无统计学意义(P>0.05)。与对照组比较,颈动脉狭窄组外周血早期内皮祖细胞、晚期内皮祖细胞数量及功能均下降(P<0.05),晚期内皮祖细胞数量与功能改变与颈动脉狭窄程度呈负相关(P<0.05)。结论颈动脉狭窄患者外周血晚期内皮祖细胞数量减少,功能受损,其数量与功能变化与颈动脉狭窄程度呈负相关。对于颈动脉狭窄患者,检测晚期内皮祖细胞数量及功能可间接预测颈动脉狭窄严重程度。     

内皮祖细胞与PI3K/Akt信号传导通路

内皮祖细胞作为内皮的前体细胞,主要来源于骨髓,在成人受损血管的修复、新生血管发生/生成中起重要作用.多种伴有血管内皮细胞损伤的疾病都可引起外周血循环、内皮祖细胞数量、功能的变化.因此,内皮祖细胞功能的研究,日益为人们所关注.研究显示PI3K/Akt信号传导通路在内皮祖细胞的动员、迁移、归巢、分化、抗凋亡上发挥重要作用.现主要就内皮祖细胞与PI3K/Akt信号传导通路关系作一综述.     

同型半胱氨酸对冠心病外周血内皮祖细胞的研究现状

同型半胱氨酸作为动脉粥样硬化的一个独立危险因素,影响冠心病外周血内皮祖细胞的数量和功能,导致内皮功能障碍。本文就高同型半胱氨酸血症对内皮祖细胞的影响及作用机制的研究进展进行了综述。     

冠心病患者内皮祖细胞变化与冠状动脉病变的相关性

目的观察冠心病患者外周血中提取的内皮祖细胞的细胞形态、数量、集落数与正常对照组的区别。并研究冠心病患者冠状动脉狭窄的不同范围和程度与内皮祖细胞数量变化的相关性。方法选择冠心病患者57例和对照组30例,从外周血获取单个核细胞,体外培养后进行细胞分析和计数。并分析冠状动脉狭窄的不同范围和程度,患者内皮祖细胞数量和成集落数量的区别,并进行相关分析。结果 (1)冠心病患者外周血内皮祖细胞数量(23.1±1.8比56.7±2.4)和细胞集落数(14.7±2.5比24.2±1.7)较对照组明显减少;(2)随着冠状动脉狭窄范围的扩大和狭窄程度的加重,内皮祖细胞的数量和活性明显下降。结论冠心病患者外周血内皮祖细胞的数量和成集落的数量明显降低;冠心病患者外周血内皮祖细胞的数量与冠状动脉病变的范围和狭窄程度呈负相关。     

增龄对内皮祖细胞数量和功能活性的影响及与血管内皮功能的关系

目的探讨增龄对人外周血内皮祖细胞数量和功能活性的影响及与血管内皮功能的关系。方法入选32例健康老年人作为实验组(老年组)和30例健康青年人为对照组(青年组)。抽取受试者外周静脉血20 ml,采用密度梯度离心法分离提取内皮祖细胞,采用流式细胞技术比较两组志愿者循环中内皮祖细胞数量。体外培养7 d后,分别检测两组志愿者内皮祖细胞体外迁移及黏附能力;通过裸鼠颈动脉拉脱模型,比较内皮祖细胞在体内皮损伤修复能力。检测两组志愿者血流介导的血管舒张功能(FMD)。结果与青年组相比,老年组外周血中内皮祖细胞数量明显下降(P0.01),体外迁移、黏附(P0.01)及在体再内皮化功能均明显受损。减少的在体再内皮化面积与下降的FMD之间呈正相关。结论增龄导致外周血中内皮祖细胞数量和功能活性受损与血管内皮功能下降密切相关,是动脉粥样硬化血管疾病发生发展的重要环节。     

运动与内皮祖细胞

内皮祖细胞可以分化成为血管内皮细胞,具有保护血管内皮,减少心血管疾病的发病率和死亡率的作用。无论是在健康人群中,还是在心血管疾病患者中,运动可以使外周血中内皮祖细胞的数量增多、功能改善,进而保护血管内皮。运动引起内皮祖细胞增加的机制尚不明确,血管内皮细胞生长因子和一氧化氮,可能在其中发挥作用。     

年龄对内皮祖细胞修复损伤血管内膜的影响

骨髓源性内皮祖细胞参与血管新生与血管修复过程,具有维持血管内膜功能的作用,但目前对影响内皮祖细胞功能的因素仍然了解不多。衰老是多细胞生物机体功能退变的过程,一般随着年龄的增长,体细胞逐渐出现自我更新能力的降低和功能紊乱。年龄与内皮祖细胞功能之间的关系尚不十分明确。现综述近年来国内外关于年龄与内皮祖细胞功能的研究成果,以期进一步了解年龄与内皮祖细胞功能的关系,为今后内皮祖细胞移植应用于冠心病临床治疗提供依据。     

基因转染内皮祖细胞治疗心血管病

人体外周血中内皮祖细胞的数量有限,基因转染能增强内皮祖细胞的增殖性以及功能。本文综述移植内皮祖细胞在治疗肢体缺血、防治冠心病、改善糖尿病患者的血管形成能力的作用。     

内皮祖细胞与冠心病

内皮祖细胞是内皮细胞的前体细胞,近年研究表明它在冠心病的发生、发展中扮演了重要角色。本文就冠心病患者内皮祖细胞数量、功能的改变及内皮祖细胞在冠心病的治疗应用等方面研究进展作一综述。     

自体内皮祖细胞移植修复兔动脉内皮损伤

目的观察不同数量的内皮祖细胞移植对内膜球囊损伤血管修复的影响。方法密度梯度离心法分离兔外周血单个核细胞,以EGM-2培养基培养7天,获得兔外周血内皮祖细胞。分高细胞数量移植组(5×105个细胞)和低细胞数量移植组(2×105个细胞),将相应数量的内皮祖细胞重悬于100μL生理盐水中移植至兔内膜球囊损伤血管局部,对照组仅注入100μL生理盐水。同时用CM-DiI标记内皮祖细胞移植,进行细胞示踪。4周后,处死动物,荧光显微镜下观察CM-DiI标记细胞的分布,并测量各组内膜损伤血管再生内皮覆盖率和新生内膜增生程度。结果荧光显微镜下发现荧光标记的内皮祖细胞分布在血管的中膜层、新生内膜层和内膜表面。内皮祖细胞移植可显著促进内膜损伤血管的再内皮化,以高细胞数量移植组为著,同时内皮祖细胞移植也大大减少了新生内膜的形成。结论内皮祖细胞移植可修复内膜球囊损伤血管,高细胞数量移植有更显著的效果。     

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.