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.     

缺血后处理对高血脂大鼠缺血/再灌注心肌的保护作用

目的 观察缺血后处理对高血脂大鼠缺血/再灌注（I/R）心肌的保护作用。方法 选择高血脂SD大鼠36只,随机分为3组,即假手术组、I/R组和缺血后处理组,每组12只。制备大鼠心肌I/R模型。I/R组:收紧结扎线缺血40 min,放松结扎线再灌注240 min。缺血后处理组:缺血40 min后,再灌注10 s,缺血10 s,连续3个循环,然后再灌注240 min。假手术组:开胸后穿线做套环,但不收紧结扎线。用全自动生化仪测定血清肌酸激酶（CK）的含量,黄嘌呤氧化酶法检测超氧化物岐化酶（SOD）的活性。采用硫代巴比妥酸法测定丙二醛（MDA）的含量,用伊文氏蓝-红四氮唑（TTC）染色法测定心肌梗死的范围。结果 ①血清CK活性的测定:再灌注结束后,缺血后处理组和I/R组的活性CK的活性明显高于假手术组［分别为（712.94±20.68）、（946.58±27.43） vs （232.12±18.26）U/L,P<0.05,1 U=16.67 nkat］,缺血后处理组明显低于I/R组(P<0.05)。②血清SOD和MDA的含量:缺血后处理组血清SOD 的含量高于对照组(P<0.05);MDA的含量明显低于对照组(P<0.05)。③心肌梗死范围:再灌注结束后,缺血后处理组和I/R组的心肌缺血区与左室面积的比率无明显差异。缺血后处理组的心肌坏死区与缺血区的比率显著低于I/R组［分别为(25.3±6.6）% vs （39.2±7.1）%,P<0.05］。结论 缺血后处理对高血脂大鼠I/R心肌具有保护作用。     

西维来司钠对大鼠脑缺血再灌注损伤的保护作用

目的 探讨西维来司钠(ONO-5046)对大鼠全脑缺血再灌注(I/R)损伤的保护作用及其机制.方法 SD大鼠随机分为假手术组、I/R组和I/R+ONO-5046组,I/R组和I/R+ONO-5046组根据再灌注时间的不同分为6、12、24、48 h四个亚组.采用四血管阻断法制备I/R模型,缺血15 min,I/R+ONO-5046组于再灌注时经股静脉持续给予 ONO-5046 2 mg·kg-1·h-1,假手术组和I/R组给予生理盐水.观察大鼠脑组织病理学变化,并检测中性粒细胞弹性蛋白酶(NE)、丙二醛 (MDA)含量及超氧化物歧化酶(SOD)、肿瘤坏死因子-α(TNF-α)活性.结果 I/R后,NE含量随再灌注时间延长而不断增强(P＜0.05或P＜0.01),TNF-α表达量也增加并于再灌注12 h达最高峰(P＜0.01).ONO-5046组显著降低缺血再灌注后脑组织NE、MDA含量,升高SOD活性以及减少TNF-α表达,明显改善脑组织病理形态.结论 ONO-5046对脑缺血-再灌注损伤有明显的保护作用,其机制可能与降低NE、MDA含量,升高SOD活性及下调TNF-α阳性表达细胞有关.     

N-乙酰半胱氨酸对大鼠肺缺血再灌注损伤的保护作用

目的探讨N-乙酰半胱氨酸(NAC)对大鼠在体肺缺血再灌注(I/R)损伤的保护作用。方法建立大鼠在体肺缺血再灌注模型,将30只SD大鼠随机分成假手术对照组,缺血再灌注组(I/R组)和N-乙酰半胱氨酸组(NAC组),NAC组缺血前1 h给予腹腔注射N-乙酰半胱氨酸200 mg/kg。再灌注2 h后摘取左肺,分别对各组进行以下检测:肺湿/干比(W/D)、超氧化物歧化酶(SOD)活力、髓过氧化物酶(MPO)活性、丙二醛(MDA)含量并进行病理学检查及肺组织损伤定量评价(IQA)。结果I/R组肺W/D和IQA显著高于假手术组(P0.01),NAC组上述指标明显降低(P0.01)。病理学结果显示三组动物肺组织结构基本正常,假手术组无充血;与NAC组比较,I/R组肺组织充血明显、白细胞浸润更严重及肺间质高度淤血水肿。I/R组MDA含量和MPO活性较假手术组明显升高(P0.01),SOD活性显著下降(P0.01)。NAC能明显减少MDA含量和降低MPO活性,提高SOD活性(P0.01)。结论N-乙酰半胱氨酸对肺缺血再灌注损伤具有保护作用,可能与其抗氧化作用和抑制中性粒细胞激活有关。     

腺苷与腺苷联合利多卡因对大鼠缺血再灌注损伤心肌的影响

目的观察腺苷和腺苷联合利多卡因预处理对SD大鼠心肌梗死面积及血清超氧化物歧化酶(SOD)和丙二醛(MDA)的影响,比较二者对缺血再灌注心肌的保护作用。方法 32只SD大鼠随机分为4组(每组8只),假手术组(C组):开胸只穿线不结扎血管,麻醉维持1 5 0 min;缺血再灌注组(I/R组):结扎3 0 min,再灌注2 h;腺苷组(AD组):缺血前股静脉缓慢输注腺苷3 0 5μg/(kg.min),持续30 min后再按I/R组操作;腺苷合利多卡因组(AL组):缺血前股静脉缓慢滴注腺苷和利多卡因305μg/(kg.min)和608μg/(kg.min),持续30 min后再按I/R组操作。实验结束后测定心肌梗死面积及血清SOD和MDA的水平。结果与I/R组比较,AD组及AL组心肌梗死范围均减小(P<0.05),血清SOD活性提高(P<0.05),MDA含量降低(P<0.05);与AD组相比,AL组心肌细胞梗死面积减小(P<0.05),血清SOD活性提高(P<0.05),MDA含量降低(P<0.05)。结论腺苷预处理可降低心肌梗死面积,提高血清SOD活性,降低MDA含量,有效保护缺血再灌注心肌,腺苷联合利多卡因的...     

延肾一号冲剂抗大鼠肾缺血再灌注氧化损伤的研究

目的 观察延肾一号冲剂对肾缺血再灌注(I/R)损伤大鼠肾组织活性氧(ROS)、丙二醛(MDA)含量及超氧化物歧化酶(SOD)、Ca2+-Mg2+ ATP酶活性的变化,探讨其抗肾I/R损伤的机制.方法 72只Wistar大鼠随机分为假手术组、对照组、治疗组,各24只.治疗组给予延肾一号冲剂,假手术组及对照组灌以相应量的生理盐水.分别检测缺血1 h、再灌注24、48 h时尿素氮、肌酐,ROS、MDA含量及SOD、Ca2+-Mg2+ ATP酶活性的变化.结果 再灌注24、48 h时治疗组、对照组与假手术组血清尿素氮(BUN)、肌酐(Cr)比较均有显著升高 (P＜0.01);再灌注24 h时对照组SOD、Ca2+-Mg2+ ATP酶活性与48 h时相比活性明显降低 (P＜0.05),再灌注24 h时治疗组与对照组相比SOD、Ca2+-Mg2+ ATP酶明显升高 (P＜0.05);再灌注24 h时,治疗组MDA、ROS则显著低于对照组 (P＜0.01) ,再灌注48 h时,治疗组与对照组相比仍有显著差异(P＜0.01).结论 氧化损伤是导致肾I/R损伤的重要原因;氧化损伤主要发生在I/R 24 h;延肾一号冲剂通过升高SOD、Ca2+-Mg2+ ATP酶的活性,减少MDA、ROS产生,减少其对肾脏的损伤作用.     

亚血红素对兔心肌缺血再灌注损伤的保护作用

目的 探讨亚血红素对兔心肌缺血再灌注(I/R)损伤的保护作用.方法 通过结扎兔冠状动脉前降支的方法 建立兔心肌I/R模型,随机分为缺血对照组、I/R组、亚血红素组、维生素C组,每组各10只.结扎冠状动脉60 min后,缺血对照组继续保持缺血状态,I/R、亚血红素、维生素C组恢复血流灌注,亚血红素组于再灌注同时经耳缘静脉给予亚血红素制剂(1 mg/kg),维生素C组于再灌注同时经耳缘静脉给予维生素C(5 mg/kg).4组动物分别于结扎前,结扎后15、30、60 min,缺血对照组结扎后90 min,I/R、亚血红素、维生素C组于再灌注后30 min,经颈静脉抽血3 ml,检测血清肌酸激酶(CK)、丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性.结果 各组于缺血后血清CK、MDA水平持续升高(P<0.01),I/R组恢复血流供应30 min后,二者水平仍继续上升,且明显高于缺血对照组继续保持缺血状态30 min后的水平(P<0.05),而在这个过程中SOD活性逐步下降(P<0.01).亚血红素组于再灌注30 min后CK升高水平明显低于缺血对照组(P<0.01),而MDA水平明显低于再灌注前(P<0.01),同时SOD水平明显回升,维生素C组类似变化不如亚血红素组显著(P<0.05).结论 亚血红素具有清除体内氧自由基,保护心肌细胞,减轻心肌I/R损伤的作用.     

褪黑素对缺血再灌注心律失常的作用

目的:探讨外源性褪黑素(M LT)对在体大鼠心脏缺血再灌注心律失常的作用。方法:34只大鼠随机分为对照组、缺血再灌注(I/R)组及缺血再灌注 褪黑素(I/R M LT)组,I/R组及I/R M LT组在体大鼠心脏左冠状动脉前降支完全阻断10 m in,再灌15 m in,监测记录室性心动过速、室颤的发生情况,并测定局部再灌注心肌中M DA(丙二醛)的含量和SOD(超氧化物歧化酶)的活性。结果:室性心动过速、室颤的发生率I/R M LT组明显低于I/R组(P<0.05);I/R组M DA的含量明显高于对照组及I/R M LT组(P<0.01),SOD活性明显低于对照组及I/R M LT组(P<0.01),I/R M LT组M DA含量及SOD活性与对照组无明显差异(P>0.05)。结论:褪黑素可抑制在体大鼠心脏缺血再灌注心律失常的发生,其作用机制可能与其作为自由基清除剂抗氧化作用有关。     

原花青素抗氧化应激效应对大鼠肢体缺血再灌注后肠黏膜的保护作用

目的:探究原花青素(proanthocyanidin,PC)抗氧化功能对大鼠肢体缺血再灌注(limb ischemia-reperfusion,LI/R)损伤后肠道的保护作用及可能的机制.方法:健康成年Sprague-Dawley♂大鼠21只,随机分为假手术组(n=7),缺血再灌注组(n=7),PC组(n=7);PC组给予PC 100 mg/(kg?d)预处理,其余两组灌胃等量色拉油,连续给药7 d.采用止血带捆绑大鼠左后肢复制缺血3 h后再灌注18 h大鼠LI/R模型,随后打开腹腔,分离腹主动脉取血离心,测定血清超氧化物歧化酶(superoxide dismutase,SOD)活力值和丙二醛(malondialdehyde,MDA)含量,取回肠组织进行苏木精-伊红(H E)染色,同时制备肠组织匀浆测定分泌型免疫球蛋白A(secretory immunoglobulin A,s Ig A)的含量.结果:与假手术组比较,LI/R后,血清SOD活力降低(P0.01),MDA含量增多(P0.01),大鼠肠黏膜损伤加重(P0.01),且肠组织中s Ig A含量明显减少(P0.01);与LI/R组相比,PC预处理后,大鼠血清SOD活力提高(P0.05),MDA的含量明显减少(P0.01),肠黏膜损伤减轻(P0.01),肠组织中s Ig A含量上升(P0.05).结论:PC可通过提高血清SOD活力,减少MDA含量,增加肠组织中s Ig A含量来减轻肠黏膜损伤,进而减轻LI/R后大鼠肠道损伤.     

CXC趋化因子受体3和其配体在大鼠肝脏缺血再灌注损伤中的表达

目的:探讨CXC趋化因子受体3(CXCR3)及其配体IP-10和Mig在大鼠肝脏缺血/再灌注(I/R)损伤中的表达及作用.方法:32只Wistar大鼠随机分成4组,每组8只.即假手术组,部分肝脏缺血再灌注6,12和24 h组.应用酶联免疫吸附实验(ELISA)法检测肝组织肿瘤坏死因子(TNF)-α水平.应用半定量聚合酶链式反应(RT-PCR)法测定肝组织CXCR3及其配体IP-10,Mig mRNA的表达.同时检测血清丙氨酸转氨酶(ALT)及天冬氨酸转氨酶(AST)的含量.结果:假手术组肝组织中CXCR3,IP-10,Mig mRNA低表达.缺血再灌注各组肝组织中CXCR3和IP-10 mRNA表达水平均明显高于假手术组(CXCR3:0.925±0.109,0.786±0.074,0.606±0.082 vs 0.125±0.028,均P<0.01;IP-10:0.863±0.091,0.680±0.075,0.543±0.284 vs 0.128±0.027,均P<0.01),6 h组高于12 h组(P<0.01),12h组与24h组无明显差别(P>0.05).Mig mRNA水平较假手术组相比,无显著差异(P>0.05).缺血再灌注各组TNF-α水平较假手术组明显升高(154.88±14-35 ng/L,258.88±13.73 ng/L,182.87±10.95 ng/L vs 23.63±4.00 ng/L,均P<0.01),再灌注12 h达高峰.结论:CXCR3及其配体IP-10在肝脏缺血再灌注早期表达上调,在缺血再灌注损伤中起重要的作用.     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

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.     

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.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

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.     

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.