同型半胱氨酸对球囊损伤大鼠颈动脉原癌基因表达及新生内膜增生的影响

目的观察高蛋氨酸饮食诱导的高同型半胱氨酸(Hcy)血症对大鼠颈动脉球囊损伤后血管组织原癌基因c-fos及c-jun mRNA表达及新生内膜增生的影响,探讨Hcy在血管球囊损伤后新生内膜过度增生中的作用及可能机制.方法采用RT-PCR方法检测血管组织c-fos及c-jun mRNA表达情况,并做半定量分析.采用光镜和计算机图像分析定量方法观察高Hcy血症对大鼠颈动脉内皮损伤后新生内膜增生的影响.结果低蛋氨酸组和高蛋氨酸组c-fos及c-jun mRNA的表达[分别为(1.40±0.21)、(1.43±0.25)及(1.68±0.27)、(1.71±0.30)]均高于对照组[分别为(1.10±0.15)、(1.00±0.13),P<0.05和0.01)],高蛋氨酸组也明显高于低蛋氨酸组(P<0.05).与对照组比较,低蛋氨酸组、高蛋氨酸组的新生内膜增生明显,计算机图像定量分析表明血管损伤后14 d,低和高蛋氨酸组新生内膜增生面积和内∕中膜面积比率比对照组分别增加87%、98%和97%、109%(均为P<0.01), 管腔面积在低、高蛋氨酸组比对照组分别减少45%、55%(P<0.05).结论 (1)高Hcy血症能使球囊损伤后颈动脉新生内膜增生恶化,预示高Hcy血症可能是血管内皮球囊损伤后再狭窄的一个独立危险因素;(2)Hcy能上调血管内皮损伤后动脉组织原癌基因c-fos及c-jun mRNA的表达,且呈浓度依赖性,这可能是其促使血管内皮损伤后新生内膜过度增生的机制之一.     

过量服用蛋氨酸所致高同型半胱氨酸血症对缺血性血管新生的抑制作用

高同型半胱氨酸血症是引起动脉粥样硬化的一种独立危险因素。过量服用蛋氨酸会导致血清中同型半胱氨酸浓度增高、内皮功能受损、血管舒缩功能减弱。本研究使用过量服用蛋氨酸导致高同型半胱氨酸血症大鼠，与对照组比较，观察缺血下肢血管新生的情况，判断高同型半胱氨酸血症对缺血性血管新生的影响。将36只雄性Sprague-Dawley大鼠分为两组：对照组和高同型半胱氨酸血症组。对照组始终给予自来水；高同型半胱氨酸血症组则给予含有0．5％蛋氨酸的饮水。两组动物分别按上述方法给予不同饮水2周后，手术切除左侧股动、静脉，观察缺血28d内缺血区域血管新生和侧枝血管形成的情况。过量服用蛋氨酸导致的高同型半胱氨酸血症减弱了大鼠下肢慢性缺血性血管新生和侧枝血管的建立，这可能与高同型半胱氨酸血症减弱内皮源性一氧化氮生物活性有关。     

高同型半胱氨酸血症致血管炎症作用

目的 探讨高同型半胱氨酸血症是否引发兔主动脉的血管炎症反应。方法 20只雄性新西兰兔随机分成对照组（正常饮食）和蛋氨酸组（高蛋氨酸饮食），每组各10只，12周后测定血浆同型半胱氨酸。观察主动脉病理变化，酶联免疫吸附法检测白细胞介素8蛋白水平，免疫组织化学检测血管核因子κB的表达和活化。结果 高蛋氨酸饮食显著增加血浆同型半胱氨酸水平，蛋氨酸组主动脉切片发现内皮细胞脱落，局部内膜增厚；白细胞介素8分泌增加；主动脉内皮细胞核因子κB表达增强。结论 高同型半胱氨酸血症可以导致血管炎症反应。而炎症反应是高同型丰胱氨酸血症加速动脉粥样硬化潜在的分子机制之一。     

高同型半胱氨酸血症大鼠冠状动脉内皮细胞单核细胞趋化蛋白1的表达

目的观察高同型半胱氨酸血症对大鼠冠状动脉内皮细胞表达单核细胞趋化蛋白1的影响,以明了冠状动脉粥样硬化性心脏病的发病机制。方法24只大鼠随机分成正常饮食对照组、高蛋氨酸饮食组、高蛋氨酸 叶酸饮食组、高半胱氨酸饮食组。每组6只,分别给予普通饲料;普通饲料加1.7%蛋氨酸;普通饲料加1.7%蛋氨酸和0.006%叶酸;普通饲料加1.2%半胱氨酸。饲养6周,采用高效液相色谱荧光检测法测定血浆总同型半胱氨酸浓度,免疫组织化学染色法检测大鼠冠状动脉左主干和左前降支内皮细胞单核细胞趋化蛋白1的表达。结果喂以高蛋氨酸饲料6周,可诱导大鼠高同型半胱氨酸血症。与正常饮食对照组比较,高蛋氨酸饮食组大鼠血浆总同型半胱氨酸浓度显著升高(P<0.01),冠状动脉内皮单核细胞趋化蛋白1的表达水平明显增强;高蛋氨酸 叶酸饮食组大鼠血浆总同型半胱氨酸水平较高蛋氨酸饮食组显著降低(P<0.01),其冠状动脉内皮单核细胞趋化蛋白1的表达水平也降低;高半胱氨酸饮食组大鼠血浆总同型半胱氨酸浓度,以及冠状动脉内皮单核细胞趋化蛋白1的表达水平与正常饮食对照组比较差异无显著性。结论高同型半胱氨酸血症促进了大鼠冠状动脉内皮细胞表达单核细胞趋化蛋白1,在冠状动脉粥样硬化性心脏病的发生和发展中起着重要的作用。     

4,5,7-三羟异黄酮减轻高同型半胱氨酸血症导致的血管内皮损伤

目的观察植物雌激素4,5,7-三羟异黄酮(GST)对同型半胱氨酸(Hcy)诱导的血管内皮损伤的保护作用。方法健康成年雌性Wistar大鼠随机分成4组:对照组;2.5%蛋氨酸饮食组;卵巢去势+2.5%蛋氨酸饮食组;卵巢去势+2.5%蛋氨酸饮食+GST治疗组,每组8只。给予大鼠高蛋氨酸(2.5%)饮食来复制高同型半胱氨酸血症(HHcy)模型,卵巢去势+2.5%蛋氨酸饮食组和卵巢去势+2.5%蛋氨酸饮食+GST治疗组大鼠施行卵巢去势手术,GST以2.5 mg/(kg.d)剂量灌胃给药。治疗12周以后,颈总动脉采血,检测血浆中雌二醇和Hcy的水平。分离大鼠胸主动脉环,检测血管环对苯肾上腺素(PE),乙酰胆碱(Ach)和硝普钠(SNP)的反应性以评价血管功能;HE染色观察胸主动脉壁形态学的改变。体外培养内皮细胞株Eahy926,观察GST体外干预对Hcy诱导内皮细胞损伤的作用。结果高蛋氨酸饮食能够导致大鼠血浆Hcy水平显著升高,出现明显血管内皮功能和形态损伤,卵巢去势进一步加重了血浆Hcy水平的升高和血管内皮损伤。GST治疗12周能够明显减轻去卵巢HHcy大鼠的血管内皮的功能和形态损伤,而且能够降低血浆中Hcy水平;G...     

p38和丝裂原活化蛋白激酶磷酸酶1在内膜损伤后血管平滑肌细胞表型转化过程中的表达变化

目的观察动脉内膜损伤后血管平滑肌细胞表型转化和p38及丝裂原活化蛋白激酶磷酸酶1表达的动态变化。方法分别用免疫组织化学、免疫印迹和逆转录聚合酶链反应方法检测假损伤组和损伤后不同时间点血管壁中增殖细胞核抗原、平滑肌α肌动蛋白、p38蛋白和丝裂原活化蛋白激酶磷酸酶1蛋白及其mRNA的表达。结果假损伤组血管中膜平滑肌细胞及内皮细胞增殖细胞核抗原为阴性表达;损伤后5~14天,新生内膜阳性细胞率逐渐增加,28天后开始逐渐减少,且新生内膜阳性率均略高于中膜。假损伤组血管中膜平滑肌α肌动蛋白表达为阳性,内皮为阴性;中膜阳性面积于损伤后1天开始减少,3天最为明显,5天后开始逐渐增加,且新生内膜阳性表达略低于中膜。假损伤组血管中膜p38呈阴性或弱阳性着色;损伤后1~35天呈持续高表达,新生内膜阳性表达高于中膜。p38表达变化与增殖细胞核抗原表达变化呈正相关。假损伤组血管中膜丝裂原活化蛋白激酶磷酸酶1呈弱阳性或阳性表达;损伤后1天即开始下降,14~28天稍有回升,至35天仍未回到假损伤组水平,且新生内膜阳性面积稍低于中膜。其表达变化与增殖细胞核抗原表达变化呈负相关。结论内膜损伤后血管平滑肌细胞增殖能力与其表型转化密切相关,p38和丝裂原活化蛋白激酶磷酸酶1参与了损伤后血管平滑肌细胞表型转化的信号转导及调节。     

大鼠高同型半胱氨酸血症对心脏超微结构的影响

目的研究高同型半胱氨酸血症(Hcy)对大鼠心脏超微结构的影响。方法采用雄性Wister大白鼠50只为研究对象,给予正常饮食10只作为对照,给予1%蛋氨酸(高蛋氨酸)饮食20只复制高Hcy血症模型;给予1%蛋氨酸、1%胆固醇、10%猪油(高脂高蛋氨酸)饮食20只复制高脂高Hcy复合模型作为阳性对照。分别在实验的第8周、20周处死动物取心脏,透射电镜检测组织学改变。结果检测血清中t Hcy(血同型半胱氨酸)、胆固醇(CHO)、低密度脂蛋白胆固醇(LDL-CHO)、高密度脂蛋白胆固醇(HDLCHO)、甘油三脂(TG),证实模型复制成功。透射电镜下观察到心肌超微结构改变。结论血症持续时间越长病变越严重,同一时间点,高脂高Hcy复合组病变重于高Hcy组。     

高同型半胱氨酸血症与冠心病

同型半胱氨酸是蛋氨酸和半胱氨酸代谢过程中一个重要的中间产物。研究发现血液中同型半胱氨酸增高，即高同型半胱氨酸血症，能够导致血管内皮损害，促进低密度脂蛋白的氧化、血小板集聚及血管平滑肌细胞增殖，从而促发动脉粥样硬化的发生。人们已经逐渐认识到它是引起心脑血管意外的独立危险因素。近年来，高同型半胱氨酸血症与冠心病，尤其是急性冠状动脉综合征的研究越来越多，然而，结果并非完全一致。遗传和环境两方面的因素共同决定了血浆同型半胱氨酸的水平，补充B族维生素可以降低血浆同型半胱氨酸的水平。     

高同型半胱氨酸血症:心脑血管疾病的独立危险因子

同型半胱氨酸是蛋氨酸和半胱氨酸代谢过程中一个重要的中间产物。由同型半胱氨酸的代谢异常导致的高同型半胱氨酸血症已被许多研究证实是心脑血管疾病发病的独立危险因子,其致病机理尚不十分明确,可能与氧化机制造成的内皮损伤和功能失调,破坏体内凝血纤溶平衡,刺激血管平滑肌细胞增殖和影响脂质代谢等方面有关。     

丹参对Hhcy兔动脉粥样硬化干预作用的实验研究

目的探讨丹参对高同型半胱氨酸血症（Hhcy）兔动脉粥样硬化的干预作用。方法采用高L-蛋氨酸饮食方法建立兔Hhcy血症模型,用丹参13服液灌胃,以正常家兔做对照,分别与实验0W、4W、8W检测各组血清同型半胱氨酸（Hcy）丙二醛（MDA）、总胆固醇（TC）、甘油三酯（TG）含量和超氧化物歧化酶（SOD）活力,并血管超声和组织学观察腹主动脉血管病理变化。结果蛋氨酸组第4W、8W时血清Hcy、MDA、TC、TG、含量显著高于同期正常对照组（P〈0．01,P〈0．05）,而SOD活力则明显降低（P〈0．01）;丹参组含量显著高于对照组;随着用药时间的延长,丹参干预组血浆Hey含量呈下降趋势,MDA、TC、TG、含量显著低于蛋氨酸组,而SOD比蛋氨酸组显著增高（P〈0．01）。血管超声和病理学观察,蛋氨酸组、腹主动脉内膜明显增厚、血管平滑肌细胞增生,弹力纤维断裂、排列紊乱、有斑块形成;丹参组血管内膜较光滑、组织结构排列整齐无斑块,与正常组比较无明显差异。结论丹参具有拮抗Hcy诱导的损伤效应,干预Hhcy导致的血管损害,有延缓或阻止动脉粥样硬化形成的作用。     

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.