缺血预处理前加用益母草碱对大鼠心肌再灌注损伤的影响

目的：观察缺血预处理前加用益母草碱（Leonurine）对大鼠心肌再灌注损伤的影响并探讨其作用机制.方法：将SD大鼠随机分为4组,建立大鼠离体心脏左心作功模型,缺血期间均间断灌注心脏停搏液.结果：再灌注期,缺血预处理前加用益母草碱组心脏的左室收缩压（LVSP）、左室舒张末压（LVEDP）、左室内压上升最大速率（＋dp/dtmax）和左室内压下降最大速率（-dp/dtmax）恢复最佳,心肌组织丙二醛（malondialdehyde,MDA）含量低、超氧化物歧化酶（superoxide dismutase,SOD）活性高,能明显减轻心肌组织超微结构的损伤.结论：缺血预处理前加用益母草碱能强化缺血预处理对大鼠心肌再灌注的保护作用.     

吗啡对大鼠离体心脏再灌注损伤的保护作用

目的研究吗啡对大鼠离体心脏缺血再灌注损伤的保护作用及其机制。方法32只雄性wistar大鼠随机分为对照组,吗啡组,吗啡+纳络酮组,吗啡+格列本脲组,建立离体工作心脏模型。4℃St.ThomasⅡ停搏液诱导心脏停搏30min,观察缺血再灌注后吗啡对心排血量(CO)、左心室压力微分(±dp/dtmax)、左心室舒张压(LVDP)恢复率及乳酸脱氢酶(LDH)、肌酸激酶同工酶(CK-MB)、心肌超微结构的影响,并观察纳络酮和格列本脲对吗啡作用的影响。结果吗啡组CO、±dp/dtmax、LVDP的恢复率优于其他各组(P<0.05),LDH漏出明显低于其他组(P<0.05),心肌线粒体等超微结构损伤明显减轻;纳络酮和格列本脲可以完全阻断吗啡的心肌保护作用。结论吗啡可以减轻大鼠心肌的缺血再灌注损伤。吗啡是通过心脏局部的阿片受体及心肌细胞三磷腺苷(ATP)敏感性钾通道(KATP通道)介导产生心肌保护作用。     

不同缺血预处理对未成熟心肌细胞功能的影响

目的比较不同方法的缺血预处理对未成熟心肌细胞功能的影响。方法采用Langendorff离体心脏灌注模型。分为4组:缺血/再灌注(I/R)组,离体心脏灌注15min转为工作心15min后停灌45min,恢复灌注15min改为工作心30min;心脏缺血预处理(MIP)组:离体心脏灌注15min转为工作心15min后反复2次缺血5min/再灌注5min,然后重复I/R组缺血/再灌注方法;肾缺血预处理(RIP)组:反复三次阻断左肾动脉5min,放开5min,切取心脏,重复I/R组方法;双下肢缺血预处理(DLIP)组:反复3次捆扎双下肢5min,松开5min,切取心脏,重复I/R组方法。以血清肌酸激酶(CK)和乳酸脱氢酶(LDH)漏出率、心肌组织三磷腺苷(ATP)和丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、心肌细胞内Ca2+含量、心肌线粒体Ca2+-ATPase活性及其Ca2+含量、心肌线粒体合成三磷腺苷能力[ATP]m作为观察指标。结果MIP、RIP及DLIP组ATP含量、SOD活性、心肌线粒体Ca2+-ATPase活性、[ATP]m均高于I/R组(P<0.01),MDA含量、CK、LDH漏出率、心肌细胞内Ca2+含量、心肌线粒体Ca2+含量均低于I/R组(P<0.01)。结论肾缺血预处理、双下肢缺血预处理与心脏缺血预处理有同等的心肌细胞保护作用。     

血管紧张素Ⅱ预处理对体外大鼠缺血再灌注心肌的保护作用

目的 :研究血管紧张素Ⅱ (AngⅡ )预处理是否对缺血 /再灌注 (I/R)心肌有保护作用 ,其作用是否通过蛋白激酶C(proteinkinaseC ,PKC)及线粒体ATP依赖性钾通道 (KATP)而起作用。方法 :4 0只SD大鼠 ,随机分为 5组 (每组各 8只 ) :AngⅡ预处理组 (APC组 )、缬沙坦加AngⅡ预处理组 (VAPC组 )、PKC阻滞剂chelerythine加AngⅡ预处理组 (CLT组 )、线粒体KATP通道阻滞剂 5 Hydroxydecanoate加AngⅡ预处理组 (5 HD组 )和对照组(C组 )。应用Langendorff主动脉逆行灌流的体外大鼠I/R心脏模型 ,观察各组大鼠I/R后心肌细胞乳酸脱氢酶(LDH)及肌酸激酶 (CK)漏出率、心肌组织三磷酸腺苷 (ATP)含量及心功能指标 (LVSP与±dp/dtmax)。结果 :APC组CK、LDH漏出率较C组明显减少 (P <0 .0 1) ,心肌ATP含量较C组增加 (P <0 .0 1) ,心功能 (LVSP与±dp/dtmax)较C组改善。VAPC组、CLT组及 5 HD组上述各指标 (LDH、CK、ATP、LVSP及±dp/dtmax)分别与C组相应的各指标比较差异无统计学意义 (P >0 .0 5 )。结论 :AngⅡ预处理对I/R心肌有保护作用     

异氟烷预处理对离体大鼠心肌缺血再灌注损伤的影响

目的:采用Langendorff离体心脏灌注模型,研究异氟烷预处理对离体大鼠心肌缺血再灌注损伤的影响。方法:24只SD大鼠随机分为4组,每组6只,分别为缺血再灌注损伤组(IR组)、异氟烷预处理1组(IsoP 1组)、异氟烷预处理2组(IsoP 2组)和异氟烷预处理3组(IsoP 3组)。监测复灌后心功能恢复情况、冠脉流出液中磷酸肌酸激酶(CK)、乳酸脱氨酶(LDH)的释放量和心肌存活面积的变化。结果:复灌期间3组IsoP心脏各对应时间点的LVEDP均显著低于对照组(P<0.05~<0.01);再灌注30 min时IsoP各组LVDP的恢复均高于IR组(P<0.05),IsoP3组±dp／dtmax在再灌注30 min时的恢复百分比均高于IR组(P<0.05),IsoP1组+dp／dt max高于IR组(P<0.05);复灌后异氟烷预处理组各时间点的CK、LDH释放量均低于IR组(P<0.01);IsoP2组、IsoP1组和IsoP3组心肌存活面积百分比均高于IR组(P<0.01);预处理各组之间比较无显著性差异(P>0.05)。结论:IsoP对大鼠离体缺血再灌注心肌有保护作用,可以显著减轻心肌细胞的损伤,改善心功能,增加心肌存活面积。     

芍药苷预处理对大鼠离体缺血再灌注损伤心脏的保护作用

目的 观察芍药苷预处理对大鼠离体缺血再灌注损伤心脏的保护作用,探讨其可能机制.方法 建立Langendorff离体心脏灌注模型.随机将SD雄性大鼠分为6组,即空白对照(Con)组、单纯缺血再灌注(I/R)组、缺血预处理(IPC)组、不同浓度(15 mg/L,30 mg/L,60 mg/L)芍药苷预处理组(PF1PF3组).Chart5软件分析缺血前,再灌注后20 min、40 min心功能参数,包括:左心室收缩压(LVSP)、左心室内压变化最大速率(dp/dtmax)、心率(HR)、冠脉流出量(CF);收集灌注末心脏标本,制备心肌匀浆,检测超氧化物歧化酶(SOD)、丙二醛(MDA)、乳酸脱氢酶(LDH)、肌酸激酶(CK)值;电镜观察再灌注末心肌细胞超微结构并拍照.结果 IPC、PF预处理组在心功能恢复及心肌酶指标活力方面均优于I/R组(P<0.01);心肌超微结构损伤减轻.结论 芍药苷预处理对大鼠离体心脏能产生保护作用.     

褪黑激素对心肌缺血再灌注损伤的保护作用

目的 :探讨褪黑激素增补于停搏液中对缺血再灌注离体鼠心的保护作用。方法 :将 2 4只Wistar大鼠随机分为褪黑激素组 ,对照组。离体鼠心在改良的Langendorff Neely灌注模型上 30min预灌注 ,12 0min停搏 ,30min再灌注。缺血前及再灌注期间测定血流动力学指标 ,心肌酶 (CPK ,LDH)、心肌超氧化物歧化酶(SOD)、过氧化脂质 (LPO)含量。电镜观察心肌超微结构。结果 :再灌注后 ,褪黑激素组心功能、心肌超微结构的改善明显优于对照组 ;CPK ,LDH ,LPO含量显著低于对照组 (P <0 .0 1) ;SOD含量显著高于对照组 (P <0 .0 1)。结论 :褪黑激素增补于停搏液中可显著减轻心肌缺血再灌注损伤 ,具有良好的心肌保护作用     

高压氧预处理对缺血-再灌注诱导的糖尿病大鼠心功能的影响

目的 探讨高压氧预处理对糖尿病大鼠心功能的影响.方法 雄性Wistar大鼠30只,糖尿病造模成功后随机分为糖尿病对照组,糖尿病缺血-再灌注组,糖尿病高压氧预处理组,采用Langendorff离体心脏灌流方法,记录左室收缩压(LVSP)、左心室内压最大上升速率(+dp/dtmax)、左室舒张末压最大下降速率(-dp/dtmax);采用氯化三苯基四氮唑染色法检测心肌梗死面积.结果 与I/R组比较,高压氧预处理组LVSP、+dp/dtmax、-dp/dtmax显著增高(P＜0.05);心肌梗死面积显著降低(56.05% vs 40.30%).结论 高压氧预处理可改善糖尿病大鼠离体心脏的心功能,缩小心肌梗死面积.     

缺血预处理对体外循环中左心功能的恢复及心肌细胞膜流动性变化的影响

目的:观察缺血预处理(IPC)对体外循环(CPB)中心肌细胞膜流动性变化及心功能恢复的影响,评价IPC的心肌保护作用。方法:将72只健康家猫随机分为3组:单纯并行循环(CPB)组、缺血再灌注(IR)组和IPC组。监测CPB中猫左心室内压峰值(LVSP)、左心室等容收缩期压力升高最大速率(dp/dtmax)、左心室舒张期压力下降最大速率(dp/dtmin)等左心功能指标,并应用荧光偏振法测定心肌细胞膜的微黏度(η),以η的倒数表示心肌细胞膜脂流动性。结果:CPB组体外循环过程中左心功能各指标和心肌细胞膜微黏度均无明显变化;IR组主动脉阻断(ACC)期间η明显上升且于再灌注期间进一步升高,IPC组ACC期间η无明显变化,再灌注期间虽有所升高但明显低于IR组;心功能恢复阶段IPC组猫心LVSP、dp/dtmax和dp/dtmin均明显高于IR组。结论:IPC能够有效维持CPB中缺血再灌注心肌细胞膜脂的流动性,同时可改善左心功能的恢复。     

心肌缺血预处理和腺苷预处理对兔心肌缺血保护作用的比较

目的 :研究缺血预处理与“腺苷预处理 "对兔心收缩功能和心肌梗死范围的影响 ,探讨两种处理方法对再灌注损伤的可能有益作用。方法 :采用兔缺血再灌注模型 ,分别以缺血前短暂心肌缺血预处理 ,缺血前腺苷预处理和缺血前应用腺苷受体阻滞剂后行缺血预处理。采用 RM- 6 2 80多道生理纪录和分析处理系统处理心肌收缩功能指标 ,采用 Evans蓝 - TTC法测量心肌梗死范围。结果 :与对照组和腺苷受体拮抗剂组相比 ,缺血预处理组及腺苷预处理组心肌梗死范围均减少 （P<0 .0 1） ;左室内压峰值 （L VSP）恢复率和± dp/ dtmax恢复率均增高 （P<0 .0 5 ） ;心律失常发生率均降低。结论 :缺血预处理与腺苷预处理对缺血心脏具有相似的保护作用 ,可改善缺血 -再灌心脏收缩功能 ,缩小心肌梗死范围     

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.