内源性腺苷在心脏缺血/再灌注损伤中的作用

目的研究心脏缺血预适应对心脏缺血/再灌注(I/R)损伤的保护机制。方法建立在体家兔心脏I/R模型,测定心肌腺苷含量,CK、LDH漏出率及心肌梗死面积,并观察心肌的组织切片和超微结构,以观察缺血预适应对I/R心肌损伤的保护效应。结果缺血预适应组心功能恢复明显好于对照组(P<0.01),CK、LDH漏出率及心肌梗死面积均低于对照组(P<0.01),同时伴有心肌组织腺苷含量增高(P<0.01)。结论缺血预适应对I/R损伤具有保护作用,腺苷可能介导这种保护效应。     

山莨菪碱对小型猪缺血-再灌注血管内皮相关因子的影响

目的:探讨冠状动脉内注射山莨菪碱对小型猪缺血-再灌注血管内皮功能相关因子的影响。方法:12头小型猪,随机分为0.9%氯化钠组(6头)和山莨菪碱组(6头),球囊闭塞冠状动脉前降支(LAD)造成心肌缺血,撤除球囊恢复冠状动脉灌注,同时冠状动脉内注射药物,分别在冠状动脉闭塞前、冠状动脉再灌注5、30、60、120、180min抽取血标本,测定血管内皮相关因子[一氧化氮(NO)、内皮素(ET-1)]等的变化。结果:小型猪缺血再灌注后,0.9%氯化钠组:NO降低,ET-1、丙二醛(MDA)、血小板聚集率(PagT)及血管性假性血友病因子(vWF)抗原升高(P<0.05),且在120min变化最大;山莨菪碱组:NO降低,ET-1、MDA、PagT及vWF抗原等升高(P<0.05),但升高的峰值变化与0.9%氯化钠组相比,幅度均明显减小,2组相比差异有统计学意义(P<0.05)。结论:小型猪在缺血-再灌注开始即出现血管内皮相关因子变化,在灌注开始后90~120min达高峰;冠状动脉内注射山莨菪碱可抑制NO降低、ET-1等升高的幅度,从而减轻血管内皮的缺血-再灌注损伤。     

参麦注射液对兔心肌缺血再灌注内皮功能的影响

目的 :观察兔心肌缺血再灌注 (I/R)损伤中内皮功能改变 ,参麦注射液 (SMI)对其影响及作用机制。方法 :检测假手术对照组、心肌I/R模型组及心肌I/R加SMI治疗组 ,不同时期血中一氧化氮代谢产物 (NOP)和内皮素 (ET)含量及心肌组织NOP、ET、总超氧化物歧化酶 (T SOD)和丙二醛 (MDA)含量 ,并电镜观察心肌超微结构。结果 :I/R模型组与假手术对照组比较缺血 4 0min、再灌注 4 0min血清NOP明显降低 ,血浆ET显著增高 ;再灌注 4 0min后心肌组织NOP、T SOD明显降低 ,ET、MDA明显增高 ,心肌超微结构发生异常改变。而I/R加SMI治疗组与I/R模型组比较上述改变减轻。结论 :心肌I/R导致血管内皮功能紊乱 ;SMI能够改善I/R时的内皮功能 ,减轻心肌I/R损伤     

尤瑞克林对兔心肌缺血再灌注损伤保护作用的实验研究

目的观察尤瑞克林对兔心肌缺血再灌注损伤的保护作用,并探讨其作用机制。方法新西兰大白兔48只,随机均分成假手术组(Sham组)、缺血再灌注组(I/R组)、尤瑞克林治疗组(Y组)。术中观察心电图变化,测定各组不同时间点血清中肌酸激酶同工酶(CK-MB)、肌钙蛋白I(cTnI)、白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、内皮素-1(ET-1)和一氧化氮(NO)的含量;再灌注结束后I/R组、Y组各取8只兔心肌组织,进行相应染色后通过光学显微镜观察形态学变化,电境观察超微结构变化。结果与I/R组相比,Y组的CK-MB、cTnI、IL-6、TNF-α、ET-1水平明显降低(P均<0.05),NO生成增加(P均<0.05);心肌组织形态学及超微结构损伤明显减轻。结论尤瑞克林对兔缺血再灌注损伤心肌具有明显保护作用,并能明显减轻心肌细胞和组织的损伤,其作用机制可能与其抗炎、保护血管内皮功能有关。     

心痛贴对急性心肌梗死犬氧化应激、心肌代谢和超微结构的影响

目的 观察心痛贴(XTT)对犬急性心肌梗死的保护作用机制.方法 30只犬随机分成5组:假手术组、模型组、XTT小剂量组、大剂量组、阳性药对照组.结扎犬冠状动脉左前降支(LAD)复制急性心肌梗死模型,将XTT贴于犬左前胸近腋窝部位,测定给药后6 h血清超氧化物歧化酶(SOD)、脂质过氧化物(LPO)、游离脂肪酸(FFA)、氧化氮(NO)含量变化,透射电镜观察心肌细胞超微结构改变.结果 XTT能降低血清FFA及LPO含量,提高NO含量和SOD活性(P<0.05、0.01),可改善心肌梗死后心肌细胞超微结构.结论 XTT可改善心肌细胞超微结构,对缺血心肌具有明显保护作用,与其增强抗氧化酶活性,减少脂质过氧化反应,纠正心肌FFA代谢紊乱,提高NO水平有关.     

双羟基黄酮醇防治心肌梗死后再灌注损伤的实验研究

目的评价双羟基黄酮醇(DiOHF)对缺血再灌注(I/R)损伤心肌释放的氧自由基(OFR)的清除作用和对心肌再灌注损伤的保护效果。方法山羊随机分为4组(n=8):对照组(CON)、缺血预适应组(IPC)、DiOHF治疗组(2 mg/kg,iv)和赋形剂治疗组(VEH)。心肌I/R通过阻断第二对角支分叉以后的左前降支1 h和复通3 h来实现。结果用10-8~10-4mol/L的DiOHF在体外孵育VEH组的I/R损伤心肌具有浓度依赖地抑制OFR释放的效应,来自DiOHF组的I/R损伤心肌释放OFR的能力也显著下降。心肌梗死面积在DiOHF组[(47±6)%]和IPC组[(44±4)%]分别较VEH组的[(74±3)%]与CON组[(76±5)%]有明显的缩小。与VEH组相比,DiOHF组显著减少了心肌酶的释放和中性粒细胞在缺血区心肌的浸润。结论DiOHF在山羊心肌梗死模型中显著减少了I/R损伤心肌OFR的释放,缩减了心肌梗死面积和中性粒细胞浸润的程度,且DiOHF对I/R损伤心肌的保护效果与缺血预适应具有可比性。     

清开灵注射液对大鼠心肌缺血再灌注损伤的保护作用

目的探讨清开灵(QKL)注射液对大鼠实验性缺血/再灌注(I/R)损伤的保护作用及机制。方法 Wistar大鼠40只,随机分为假手术组、模型组、清开灵注射液高剂量组(QKL 40 mg/kg)、清开灵注射液低剂量组(QKL 20 mg/kg),每组10只。结扎大鼠冠状动脉左前降支40 min、再灌120 min制备心肌I/R损伤模型。检测QKL对I/R损伤大鼠血清中LDH、CK、AST、SOD、MDA、NO含量的影响;同时以TTC染色检测心肌梗死面积变化。结果与模型组比较,QKL高剂量组及QKL低剂量组大鼠血清中LDH、CK、AST含量明显降低(P<0.05),SOD活性明显升高(P<0.01),MDA及NO含量降低(P<0.01)。QKL高剂量组及QKL低剂量组心肌梗死面积明显低于模型组(P<0.05)。免疫组化法检测结果显示,QKL高剂量组及QKL低剂量组心肌细胞iNOS表达量低于模型组(P<0.05)。结论 QKL可能通过抑制iNOS,对大鼠心肌I/R损伤具有保护作用。     

磷酸肌酸对大鼠缺血再灌注损伤心肌线粒体MDA、SOD和Ca2+表达的影响

目的 探讨磷酸肌酸(PCr)对缺血再灌注(I/R)损伤心肌线粒体的影响.方法 采用大鼠左冠状动脉前降支结扎法建立大鼠I/R模型.60只雄性大鼠随机分为缺血再灌注(I/R)损伤组、假手术组、PCr组,假手术组只剖胸不结扎冠状动脉,余两组制作I/R模型,PCr组结扎前45 min经股静脉注射PCr 4 mg/kg,假手术组和I/R组分别静脉注射相应体积的生理盐水,在缺血45 min及2 h时测定I/R区心肌丙二醛(MDA)、超氧化物歧化物(SOD)及总Ca2+浓度.结果 与假手术组比较I/R损伤组MDA、总钙显著增高(P＜0.05),SOD显著降低(P＜0.01);与I/R损伤组比较,PCr组MDA含量及总钙水平显著降低(P<0.05),SOD显著增高(P＜0.01).结论 PCr对心肌I/R损伤有保护作用.     

氨基胍对大鼠骨骼肌缺血再灌注肺损伤一氧化氮合酶表达的影响

目的观察骨骼肌缺血再灌注(I/R)肺损伤诱导型一氧化氮合酶(iNOS)及一氧化氮(NO)变化情况,探讨氨基胍(AG)及NO在骨骼肌I/R肺损伤中的作用机制。方法将24只雄性Wistar大鼠随机分为四组,对照组,仅进行常规麻醉,不阻断后肢血流;缺血组,即缺血4 h无再灌注组;I/R组,即缺血4 h后再灌注6 h;I/R+AG治疗组,即缺血4 h后继续再灌注6 h,并于再灌注开始时经尾静脉注射AG(150 mg/kg)。检测血清中乳酸脱氢酶(LDH)、NO含量、肺组织中丙二醛(MDA)含量及iNOS基因在肺组织中的表达情况。结果 iNOS表达对照组不明显;在缺血、IR组呈上升趋势;I/R+AG组表达下调;与对照组比较,其余三组差异显著(P0.05);I/R+AG组与对照组比较差异显著(P0.05)。LDH、NO、MDA含量:缺血、I/R组逐渐升高(P0.05);I/R+AG组相应下降,与I/R组比较差异显著(P0.05)。结论在骨骼肌I/R后肺组织中iNOS、血清中的NO均明显升高,AG可明显抑制iNOS表达上调,降低NO、LDH、MDA含量,通过抑制iNOS降低NO含量,减少肺损伤。     

鬼针草总黄酮对心肌缺血再灌注大鼠的保护作用

目的研究鬼针草总黄酮(TFB)对缺血再灌注大鼠心肌的保护作用,并探讨其作用机制。方法将雄性Wistar大鼠50只随机分为5组:假手术组(SH组)、心肌缺血再灌注模型组(I/R组)、TFB低、中、高剂量组(TFBL组、TFBM组、TFBH组),每组10只。TFB各组分别给予鬼针草总黄酮灌胃,剂量分别为40、80、160 mg/kg,1次/d,连续给药14 d;除SH组外,其他各组结扎冠状动脉左前降支,使心肌缺血30 min,再灌注120 min。ELISA法测定血清乳酸脱氢酶(LDH)、肌酸激酶(CK)、肿瘤坏死因子(TNF)-α和白细胞介素(IL)-8含量,测定心肌组织丙二醛(MDA)含量和过氧化物酶(SOD)活力,氯化三苯基四氮唑红(TTC)染色法测定心肌梗死面积,透射电镜观察心肌超微结构。结果与I/R组相比,TFB各组均能降低心肌组织MDA含量并提高SOD活力,减小心肌梗死面积,改善心肌超微结构;TFBM、TFBH组能有效降低血清中LDH、CK、TNF-α和IL-8的释放量。结论 TFB预处理可减轻缺血再灌注心肌损伤,可能与其抗炎和抗自由基作用有关。     

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.