滋养血管在动脉粥样硬化形成中的作用

滋养血管(VV)在拉丁语中的意思是"血管的血管",是由一些微小血管构成的网状结构,包绕在大中血管壁的中外层,为宿主血管管壁提供氧气和营养物质并排出代谢废物。早在100多年前就有学者发现VV与动脉粥样硬化(AS)之间存在着密切关系,但随着AS研究热点的不断更换,VV的研究未能全面开展。近年来随着血管外膜结构与功能的深入研究以及显微CT和超声血管造影成像等技术在科研领域的应用,人们对VV的认识也越来越多,现就其在AS形成过程中的作用作     

动脉三级淋巴组织与动脉粥样硬化关系的研究进展

学者们对动脉血管的研究常聚焦在血管内膜动脉粥样硬化(As)斑块的形成,而很少关注血管外膜的免疫反应及其对疾病病程的影响。前期研究发现,老龄的ApoE－/－小鼠动脉外膜出现免疫细胞的有序集聚,形成类似淋巴结的异位淋巴组织,称之为动脉三级淋巴组织(ATLO),其形成对内膜As具有明显的调控作用。ATLO的发现及研究为As的研究指明了新的方向,并为其他疾病状况下三级淋巴组织(TLO)的研究提供了很好的范例。因此,阐明TLO的特点及形成机制对As的防治具有重要的意义,并为其在其他疾病中的临床运用提供坚实的基础。     

脉络学说为指导,基于外膜滋养血管探讨动脉粥样硬化发病机制

<正>动脉粥样硬化(AS)是严重危害人类健康的多种心血管疾病(CVD)的病理基础,发病机制非常复杂,包括炎症、氧化应激、免疫与缺氧等多种机制。既往研究往往认为血管内皮功能障碍是AS发生的始动因素,关于血管外膜的潜在作用往往被忽视。近年研究证实在AS早期,外膜就已经出现病变,甚至先于大血管内皮功能障碍。所以,AS不仅存在"由内向外"内膜-中膜-外膜的发病机制,"由外向内"外膜-中膜-内膜的发病途径     

去除外膜对血管内膜增殖及反应性的影响

目的:观察去血管外膜后兔颈动脉血管内膜增殖及血管反应性改变的情况。方法:在体去除兔颈动脉外膜,于术后0周及1周时取出动脉作组织学检查,血管张力测试,免疫组织化学染色,用RT-PCR法测定返原型辅酶Ⅱ氧化酶P22亚单位(NADPH Oxidase P22Phox)信使核糖核酸(mRNA)。结果:(1)外膜去除方法对血管内皮及中层平滑肌无明显损伤;(2)外膜去除后血管内膜增生,增生成分为血管平滑肌细胞;(3)与完整外膜血管比较,去外膜血管对去甲肾上腺素(NE)的收缩反应在术后即刻及1周均减弱(P<0.05),对乙酰胆碱(Ach)的舒张反应在术后即刻增强(P<0.05);(4)与完整外膜血管比较,去外膜血管NADPH Oxidase P22Phox在1周时表达增高(P<0.05)。结论:外膜去除可致兔颈动脉内膜增生,同时引起血管舒缩反应性发生改变。     

血管外膜成纤维细胞在动脉粥样硬化及PCI后再狭窄中的作用

血管外膜是动脉粥样硬化(AS)和经皮冠状动脉介入治疗(PCI)后再狭窄等血管重构疾病的"积极参与者"。血管外膜不仅发挥简单的支持血管、提供营养物质的作用,越来越多的研究表明,外膜还主动参与了AS和PCI后再狭窄的病理过程。作为血管外膜最重要的组成部分,外膜成纤维细胞(AF)通过活化、增殖、迁移,分泌细胞因子和细胞外基质导致血管外膜和内膜的增厚和管腔狭窄。另外,AF活化后还通过参与一氧化氮的调节、氧化应激和炎症反应等促进AS和PCI后再狭窄的形成。     

NADPH氧化酶与Rho/Rho-激酶激活在外膜介导的血管重塑中的作用

目的　探讨NADPH氧化酶与Rho/Rho 激酶在外膜介导的血管重塑中的作用。方法在体去除兔颈动脉外膜 ,于术后即刻、1周及 2周取出颈动脉。用图像分析系统测定内膜及中层面积 ;应用多道生理仪测血管反应性 ;原位杂交及RT PCR检测mRNA表达。结果　 (1)血管外膜去除后内膜增生 ,2周时内膜增生较 1周时更为明显。对照侧无内膜增生。 (2 )与对照侧比较 ,去外膜侧血管在术后即刻、1周对去甲肾上腺素的收缩反应减弱 (P <0 0 5)。 (3 )与对照侧比较 ,去外膜侧NADPH氧化酶P2 2PhoxmRNA表达在 1周时增高 (P <0 0 5)。 (4)与对照侧比较 ,去外膜侧Rho 激酶mRNA表达在 2周时增高 (P <0 0 5)。结论　外膜去除后血管内膜增生 ,血管舒缩功能改变 ,其发生机制与NADPH氧化酶及Rho 激酶激活有关     

阿托伐他汀对自发性高血压大鼠去外膜颈动脉内膜增生的影响

目的研究阿托伐他汀对自发性高血压大鼠颈动脉外膜去除后血管内膜增生的影响。方法24只13周龄雄性自发性高血压大鼠去除右侧颈动脉外膜后,随机分为自发性高血压组、阿托伐他汀组和缬沙坦组,每组8只;8只同周龄雄性WKY大鼠作为正常对照组。机械和化学法去除大鼠右侧颈动脉外膜,左侧作假手术对照。4周后,放射免疫法测定血浆及双侧颈动脉血管紧张素Ⅱ浓度,取双侧颈动脉制成光镜标本,病理图像分析系统测定颈动脉管腔横截面积、内弹力层围绕面积、外弹力层围绕面积,评价内膜和中膜增生程度。逆转录聚合酶链反应检测颈动脉血管紧张素转化酶2 mRNA表达,免疫组织化学法检测血管紧张素转换酶2蛋白表达。结果自发性高血压大鼠对照组去外膜侧和外膜完整侧血管内膜增生较正常对照组明显(P<0.01),中膜面积显著增大(P<0.05或P<0.01),去外膜侧内膜增生较外膜完整侧显著(P<0.05);阿托伐他汀组较自发性高血压组内膜增生显著降低(P<0.01)。与外膜完整侧比较,去外膜侧颈动脉血管紧张素Ⅱ浓度显著增高(P<0.01),血管紧张素转化酶2mRNA和蛋白表达明显减弱(P<0.01);与自发性高血压组比较,阿托伐他汀组颈动脉血管紧张素Ⅱ浓度显著降低(P<0.01),血浆血管紧张素Ⅱ浓度、血管紧张素转化酶2 mRNA和蛋白表达显著升高(P<0.01)。结论阿托伐他汀可显著抑制自发性高血压大鼠颈动脉去外膜后血管内膜增生,其机制可能是通过上调血管局部血管紧张素转化酶2而实现的。     

高血压大鼠主动脉一氧化氮合成途径的变化

目的观察高血压大鼠主动脉内膜、中膜和外膜一氧化氮合成途径的改变,并探讨其可能的病理生理意义.方法 Wistar大鼠缩窄腹主动脉复制高血压模型,动物随机分为对假手术组和高血压组.取大鼠主动脉,分离血管内膜、中膜和外膜.分别测定其亚硝酸盐(NO2--)生成量、一氧化氮合酶(NOS)活性及L-精氨酸(L-Arg)转运,免疫组化染色检测诱导型一氧化氮合酶(iNOS)的分布.结果与假手术组相比,高血压大鼠血浆中一氧化氮代谢产物(NOx)高26.2%(P<0.05);主动脉NO2--生成低65.8%(P<0.01),中膜及外膜孵育液的NO2--生成量分别高59.6%和123.6%(均P<0.01);主动脉内膜NOS活性低59.3% (P<0.01),中膜和外膜NOS活性分别高62.6%和118.7%(均P<0.01);血管内膜L-Arg转运率低62.5%(P<0.01),中膜和外膜L-Arg转运率分别高53.7%和99.8%(均P<0.01).iNOS免疫组化染色显示,高血压大鼠血管中膜和外膜尤其是外膜iNOS阳性染色明显增强.结论高血压大鼠血管壁一氧化氮合成与代谢发生改变,血管内膜L-Arg/NOS/NO途径受抑,而中膜和外膜尤其是外膜的L-Arg/NOS/NO系统的活性增强,血管生成的NO增多.提示血管中膜和外膜源NO增多在高血压时可能具有一定的代偿作用.     

外膜滋养血管新生的病理机制

<正>外膜是集成血管壁功能的主要监管机构,可以充当生物"中央处理器",外膜分布有多种细胞能够发挥强效免疫调节作用,包括成纤维细胞、巨噬细胞、树突状细胞、祖细胞、滋养血管以及肾上腺素能神经。成纤维细胞的激活能够促进巨噬细胞、树突状细胞、祖细胞作用的发挥,创建一个持久的炎症反应的微环境,引起滋养血管的新生〔1〕。由于研究血管滋养管的适合方法有限,观察动脉壁上微血管新生的病理生理环境也知之甚少。本文就今年来关于外膜滋养血管(VV)新生的生理、病理     

血管外膜剥离致内膜增生病变的动物模型

目的建立颈动脉外膜剥离引起内膜增生的动物模型,为研究血管外膜在动脉粥样硬化发生中的作用奠定基础。方法2g/L的Ⅱ型胶原酶消化颈动脉外膜后,眼科镊钝性剥离外膜,HE染色明确外膜剥离效果;免疫组织化学染色观察外膜剥离对内膜的影响。结果酶化学消化 眼科镊钝性剥离可有效剥离血管外膜;外膜剥离2周后可见相应内膜处出现增生性病变,病变成分为分泌型平滑肌细胞;而外膜保留侧正常。结论胶原酶消化 眼科镊钝性剥离的方法可有效剥离血管外膜,促进血管内膜增生性病变形成。     

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.