高同型半胱氨酸血症兔模型动脉粥样硬化的形成

为评价兔高同型半胱氨酸血症模型的建立及其对动脉粥样硬化形成的影响，采用含1%蛋氨酸饮食饲养新西兰大白兔，并与高脂模型和正常组比较，动态分析各组血清中同型半胱氨酸的变化及动脉粥样硬化形成的情况。结果发现，给予1%蛋氨酸负荷，4周即可观察到明显的高同型半胱氨酸血症发生;8周时可见明显的血管狭窄和动脉粥样硬化斑块形成等变化。结果提示，采用新西兰大白兔给予1%蛋氨酸饮食负荷是一种较为可靠的造高同型半胱氨酸血症模型的方法；高同型半胱氨酸血症是动脉粥样硬化形成的一个独立危险因素。     

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。     

高同型半胱氨酸血症对内皮细胞炎症反应的促发作用及其干预性研究

目的本研究试图了解辛伐他汀对同型半胱氨酸诱导的内皮细胞炎症反应的抑制作用及其分子机制。方法同型半胱氨酸、辛伐他汀或两者联合处理人脐静脉内皮细胞不同时间点后,用核转录因子κB P65检测系统和凝胶电泳迁移率实验法检测κB P65核转录因子的活性,蛋白质印迹技术分析相关蛋白的表达。结果在高浓度同型半胱氨酸(3mmol/L)刺激下,人脐静脉内皮细胞中核转录因子κB的活化高峰出现在作用30min和6h时;且伴有IκBα短暂快速的磷酸化及IκKα和IκKβ蛋白水平升高(P<0.05)。高浓度同型半胱氨酸(3mmol/L)刺激24h后人脐静脉内皮细胞分泌基质金属蛋白酶2、基质金属蛋白酶9及白细胞介素1β显著增加。而辛伐他汀能显著抑制核转录因子κB活化及其继发的基质金属蛋白酶2、基质金属蛋白酶9及白细胞介素1β升高。结论同型半胱氨酸能引起人脐静脉内皮细胞炎症因子的表达与释放,这些生物学效应是通过核转录因子κB信号通路来实现的;辛伐他汀能显著抑制上述效应。     

兔腹主动脉血管弹性的超声及实验研究

目的应用高分辨率超声检测动脉硬化兔模型腹主动脉弹性，探讨其与高脂血症、血浆同型半胱氨酸的关系。方法雄性新西兰大白兔24只，高胆固醇组12只、高蛋氨酸组12只。应用ATL HD15000彩色多普勒超声检测仪检测以上2组免腹主动脉弹性，并进行病理学检查（光镜和电镜）、血脂（胆固醇、低密度脂蛋白胆固醇）及血浆同型半胱氨酸水平的测定。结果①实验第4周末2组生化指标均有不同程度增高：高胆固醇组血脂水平明显升高（P〈0．05），高蛋氨酸组血浆同型半胱氨酸水平明显升高（P〈0．05）。②8周末高胆固醇组和高蛋氨酸组腹主动脉弹性减低（P〈0．05）。结论高脂血症与高同型半胱氨酸均是引起动脉硬化的危险因素，分别与动脉硬化呈正相关，胆固醇浓度与同型半胱氨酸浓度无显著相关；动脉弹性的变化发生于动脉内膜-中层增厚之前。     

同型半胱氨酸对KKAy鼠心肌病变的影响

目的　观察高同型半胱氨酸血症对糖尿病小鼠心脏的影响 ,以及补充叶酸对心肌病变的作用。方法　 2 4只KKAy小鼠随机分三组 ,分别喂养高热量饮食 (KA组 )、高蛋氨酸饮食 (KB组 )以及高蛋氨酸加叶酸和维生素B12饮食 (KC组 )。测定各组血浆同型半胱氨酸、叶酸和维生素B12水平 ,并观察心肌病理改变。结果　饲养 16周后发现 ,高蛋氨酸饮食组血浆同型半胱氨酸明显增高 (2 9.33± 16 .85对 5 .33± 2 .0 3,P <0 .0 0 1) ,且心肌间质纤维化、钙化、小动脉管壁增厚和透明变性等病变加重 ,经叶酸和维生素B12治疗后血浆同型半胱氨酸降至正常 (4 .0 4± 1.81) ,且心肌病变减轻。结论　同型半胱氨酸可以加重糖尿病鼠的心肌病变 ,叶酸和维生素B12可以有效减缓这一病变进程。     

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...     

叶酸、维生素B12对高同型半胱氨酸血症大鼠ICAM-1及VCAM-1表达的影响

目的观察叶酸、维生素B12对高同型半胱氨酸血症(hyperhomecysteinemia,Hhcy)大鼠主动脉壁细胞间黏附分子-1(ICAM-1)及血管细胞黏附分子-1(VCAM-1)表达的影响。方法 24只雄性SD大鼠随机分为三组:空白对照组、Hhcy模型组、叶酸、维生素B12干预组。8 w后检测血浆同型半胱氨酸(Hcy)水平,观察主动脉壁形态学变化并检测胸主动脉血管壁ICAM-1及VCAM-1的表达。结果 Hhcy模型组大鼠的血浆Hcy水平明显高于空白对照组(P<0.01),主动脉壁ICAM-1及VCAM-1表达较空白对照组明显上调(P<0.01)。Hhcy模型组血浆Hcy水平明显高于叶酸、维生素B12干预组(P<0.01),主动脉壁ICAM-1及VCAM-1的表达较空白对照组明显上调(P<0.01)。结论高蛋氨酸饮食可诱发Hhcy,主动脉壁ICAM-1及VCAM-1表达上调。叶酸、维生素B12可以下调血浆Hcy水平及主动脉壁ICAM-1及VCAM-1的表达,对Hhcy致AS具有明显预防作用。     

三萜醇酮对高同型半胱氨酸血症致兔动脉粥样硬化的影响

目的探讨三萜醇酮类化合物对高同型半胱氨酸血症（HHcy）所致兔动脉粥样硬化（As）的影响。方法用皮下注射DL-蛋氨酸法建立动物模型，三萜醇酮大、小剂量组同时灌胃给药。实验前、后分别取血检测血浆总同型半胱氨酸（tHey）。12w后处死动物，检测血脂、超敏C-反应蛋白（hs—CRP）。用免疫组织化学方法检测主动脉组织内核因子-κB（NF—κB）的表达。结果三萜醇酮大、小剂量组兔tHey、血脂、hs—CRP、NF—κB光密度值明显低于模型组（P〈0.05）；大剂量三萜醇酮优于小剂量（P〈0.05）。结论三萜醇酮可以抑制HHcy诱导的AS的发生发展，其作用可能是通过降低tHey、抑制NF—κB的激活和降低hs—CRP的生成而实现。     

高同型半胱氨酸血症与胰岛素抵抗及糖尿病慢性并发症

同型半胱氨酸是蛋氨酸代谢的中间产物,它的生理作用是维持体内含硫氨基酸的平衡。近年来的研究显示,血浆同型半胱氨酸水平的升高与血管疾病有关。糖尿病的慢性并发症主要是血管病变,但其血管病变的机制至今尚未完全阐明。血浆胰岛素水平可能会通过影响同型半胱氨酸代谢而导致血管病变。高同型半胱氨酸血症与糖尿病大血管病变的发生有关,与微血管病变亦可能有一定关系。可能是通过影响血管内皮细胞的结构和功能,影响血管平滑肌和血凝系统而导致血管病变的产生,并加速其发展。     

卡托普利对同型半胱氨酸硫内酯损伤血管内皮功能的保护作用

目的探讨卡托普利对同型半胱氨酸硫内酯所致在体大鼠血管内皮功能损伤的保护作用及其机制。方法采用同型半胱氨酸硫内酯(50mg/kg)灌胃8周的方法造成大鼠的血管内皮损伤模型,治疗组同时给予卡托普利(10、20、40mg/kg)进行灌胃。检测血管内皮依赖性舒张反应、血中对氧磷酶1、血管紧张素转化酶活性,血管组织内皮细胞核因子κB活性;肝组织中对氧磷酶1mRNA表达水平。结果同型半胱氨酸硫内酯显著抑制大鼠胸主动脉的内皮依赖性舒张反应,导致大鼠血清对氧磷酶1活性的降低,肝组织对氧磷酶1mRNA表达下调;同型半胱氨酸硫内酯同时激活血管内皮细胞核因子κB活性;卡托普利呈剂量依赖性地改善同型半胱氨酸硫内酯损伤的大鼠胸主动脉的内皮依赖性舒张反应,抑制血管内皮细胞核因子κB活性;同时降低血清中血管紧张素转化酶活性、维持对氧磷酶1活性、促进对氧磷酶1mRNA的表达。结论卡托普利对同型半胱氨酸硫内酯所致大鼠血管内皮功能损伤具有保护作用。     

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.