不同月龄鼠急性心肌梗死后心室重构和心脏破裂的观察

目的 探讨老龄对小鼠急性心肌梗死(AMI)后心室重构心脏破裂的影响. 方法 老龄和低龄C57BL/6小鼠,随机分为假手术组、心肌梗死组.建立AMI模型后,观察心脏破裂发生率,并于AMI后第7天行超声和血流动力学检查;应用酶谱法、病理染色及免疫组化方法 ,分别于AMI后第3、7天检测基质金属蛋白酶-2、-9(MMP-2、MMP-9)活性表达,炎性细胞浸润程度,心肌间质胶原含量(CVF)和类型的变化. 结果 AMI后老龄组心脏破裂率高于低龄组(38.0%与16.0%,X2=6.139,P＜0.05);第7天时,较低龄组出现明显的梗死区扩张、左心室重构、心功能障碍及血流动力学变化(t=5.754,P＜0.05).与低龄组比较,老龄AMI组AMI后第3天炎性细胞浸润程度、MMP-9表达明显增加(P＜0.05).与低龄组比较,老龄组心肌间质胶原含量、Ⅲ型胶原表达增加(P＜0.05). 结论 老龄是小鼠AMI后心脏破裂的高危因素,其原因可能与AMI早期炎性细胞浸润程度增加、MMP-9、Ⅲ型胶原过度表达和早期左心室重构恶化有关.     

核因子-κB抑制剂对老龄小鼠急性心肌梗死后心脏破裂和心室重构的影响及机制研究

目的:探讨核因子(NF)-κB抑制剂二硫代氨基甲酸吡咯烷(PDTC)对老龄小鼠急性心肌梗死(AMI)后心脏破裂、心室重构的影响及机制研究.方法:18个月龄雄性C57/BL小鼠212只结扎左冠状动脉建立AMI模型,分为两组(每组106只):AMI+PDTC组术后每日腹腔注射PDTC 120 mg/(kg·d),AMI组每日注射同等剂量生理盐水.观察1周内心脏破裂率及心脏超声改变.再将AMI后3天、7天、14天不同时间行p65、肿瘤坏死因子-α mRNA表达,基质金属蛋白酶-9、2活性及心肌间质胶原含量测定.结果:与AMI组相比,AMI+PDTC组心脏破裂率降低(35.3%比15.6%),差异有统计学意义(P<0.05).与AMI组相比AMI+PDTC组舒张末期内径、左心室舒张末期外径降低,舒张期前壁厚度、收缩期前壁厚度、左心室重量增加,左心室短轴缩短率升高,差异均有统计学意义(P均<0.05),AMI后3天及7天AMI+PDTC组基质金属蛋白酶-9表达较AMI组同时间点降低(P均=0.000),AMI后3天及14天时AMI+PDTC组基质金属蛋白酶-2表达较AMI组同时间点降低(P均=0.000).AMI后7天和14天肿瘤坏死因子-α mRNA表达在AMI+PDTC组较AMI组同时间点降低(P=0.000),差异均有统计学意义.AMI后3天和7天AMI+PDTC组较AMI组心肌间质胶原容积分数降低(P值均为0.000),差异有统计学意义.结论:NF-κB抑制剂PDTC可降低老龄小鼠AMI后心脏破裂率,改善心室重构,可能是通过抑制肿瘤坏死因子-α及基质金属蛋白酶-9表达,降低胶原降解并抑制胶原合成的结果.     

急性心肌梗死并发心脏破裂19例分析

目的 :探讨急性心肌梗死 (AMI)伴心脏破裂的临床特征、早期诊断及防治措施。方法 :对 AMI院内死亡的 112例患者中经心包穿刺或超声证实为心脏破裂者 19例 ,进行回顾性分析。结果 :年龄≥ 6 0岁者占 89.5 % ,女性发生率多于男性 (P <0 .0 5 ) ,首次发生梗死者 94.7% ,梗死累及广泛前壁者 89.5 % ,心脏破裂时 78.9%患者处于应激状态 ,所有患者均发生在 AMI第 1周内。心脏破裂 6 8.4%的患者表现为心跳骤停、电 -机械分离 ,其余表现为突然血压下降伴心包填塞或心力衰竭。结论 :AMI早期对老年、女性、首次发生的、特别是广泛前壁心肌梗死 ,应积极处理 ,避免增加心脏负担 ,防止心脏破裂。对疑有心脏破裂者 ,尽早行心包穿刺、超声检查 ,争取手术治疗     

急性心肌梗死并发心脏破裂42例临床分析

目的　探讨急性心肌梗死 (AMI)并发心脏破裂的临床特征 ,早期诊断及提出预防措施。方法　分析了院内死亡的 AMI并发心脏破裂病例 42例临床资料。结果　女性发病率多于男性 (P<0 .0 1)。所有心脏破裂均发生于第一周 ,首次发生 AMI者占 92 .9% ,全部为透壁性 AMI,6h后溶栓者心脏破裂发生率高于 6h内溶栓者 (P<0 .0 5 )。结论　 AMI并发心脏破裂应预防为主 ,早期发现早治疗。     

急性心肌梗死患者合并心脏破裂的分析

目的:观察急性心肌梗死(AMI)患者发生心脏破裂的特点。方法:连续入选2004年1月至2006年2月收入我院心内科监护室(CCU)确诊为AMI患者共1324例,经超声心动图证实心脏破裂18例。结果:前壁梗死509例,下壁梗死528例,非ST段抬高心肌梗死287例。发生心脏破裂18例(1.36%),其中游离壁破裂9例,室间隔穿孔9例。13例发病72h内破裂,5例在发病4～7d破裂。男性8例(8/973,0.82%),女性10例(10/351,2.85%),女性明显高于男性(P=0.005)。发生心脏破裂患者年龄[(72.6±8.2)岁]明显高于无破裂者[(63.3±12.2)岁,P=0.000]。成功再灌注治疗者心脏破裂发生率(5/575,0.87%)明显少于无再灌注者(13/749,1.74%,P=0.041)。所有合并心脏破裂者全部死亡。前壁梗死合并心脏破裂的发生明显多于下壁和非ST段抬高心肌梗死(2.16%,1.32%,0%,P=0.041)。结论:AMI合并心脏破裂的发生率为1.36%,其预后极差。女性、高龄、前壁梗死患者易于发生心脏破裂。成功再灌注治疗减少心脏破裂的发生。     

急性心肌梗塞并发心脏破裂的诊断与治疗

心脏破裂是急性心肌梗塞(AMI)早期的重要并发症和主要死亡原因之一。根据国内报道,心脏破裂在AMI尸检中占18.6～30.6%,在AMI住院患者的各种死因中占35.1%。心脏破裂主     

老龄小鼠心肌梗死后wnt信号通路表达的变化及与心脏破裂的关系

目的 研究老龄鼠心肌梗死后wnt信号通路的变化,探讨老龄小鼠冠状动脉结扎后心脏破裂率高和左室重构重的可能机制.方法 选择3个月(低龄)和18个月(老龄)雄性C57/BL小鼠各116只,其中每组70只结扎左冠状动脉建立急性心肌梗死(AMI)模型,10只为假手术组,7 d时进行心脏超声及血液动力学检测,比较心脏破裂率和左室重构程度;36只按AMI后时间分AMI后3、7、14 d三组(每组12只),用Western blot法检测左室心肌和梗死区dvl-1,β-联蛋白(β-catenin)和缝隙连接膜通道蛋白43(connexin 43)的表达.结果 老龄组小鼠AMI后1周心脏破裂的发生率明显高于低龄组(36.7%比16.7%,P<0.05).老龄组心室腔扩大和收缩功能障碍更为明显,AMI后左心室dvl-1和β-catenin表达高于假手术组(P<0.05),AMI 3 d时梗死区dvl-1及β-catenin表达明显低于低龄鼠(P<0.05),AMI后connexin 43表达明显低于假手术组(P<0.05).老龄组梗死区connexin 43表达在AMI 3及14 d时低于低龄组(P<0.05),7 d时高于低龄组(P<0.05).结论 老龄小鼠AMI后心脏wnt信号通路未能被及时激活,这可能是导致老龄鼠心脏破裂率更高和左室重构更重的机制之一.     

急性心肌梗死并发心脏破裂危险因素分析

目的分析急性心肌梗死(AMI)并发心脏破裂的临床特点、危险因素及预后,并探讨临床防治措施。方法回顾性收集AMI患者1561例,其中发生心脏破裂患者21例为心脏破裂组,随机选取未发生心脏破裂的AMI患者105例为对照组,采集2组患者临床资料及治疗方案,分析AMI并发心脏破裂的危险因素。结果与对照组比较,心脏破裂组年龄、入院心率、女性、肌钙蛋白、N末端B型钠尿肽前体、尿素明显升高(P<0.05,P<0.01),急诊PCI、血红蛋白、红细胞计数、使用β受体阻滞剂及血管紧张素转换酶抑制剂(ACEI)/血管紧张素受体阻滞剂(ARB)比例明显降低,差异有统计学意义[42.86%vs 72.38%,P=0.011;(119.33±19.37)g/L vs (139.29±17.65)g/L,P=0.001;(4.13±0.62)×10^12/L vs (4.60±0.69)×10^12/L,P=0.010;47.62%vs 73.33%,P=0.020;23.81%vs 52.38%,P=0.017]。结论女性、高龄、再灌注时间延迟、入院心率快、高NT-ProBNP、高肌钙蛋白、低血红蛋白、低红细胞计数是AMI患者心脏破裂的危险因素,早期的再灌注治疗、ACEI/ARB、β受体阻滞剂的使用是预防AMI后发生心脏破裂的重要措施。     

急性心肌梗塞心室重构及治疗对策

急性心肌梗塞(AMI)后的心室重构是一个不断进展的过程,最终导致心力衰竭。它与AMI早期心脏破裂、室壁瘤形成等严重并发症有关,是影响AMI近、晚期预后的主要原因。有效地防止心室重构是心肌梗塞(MI)治疗的重要目的之一,也是目前研究的热点。     

急性心肌梗死伴与不伴心脏破裂临床病理分析

目的探讨急性心肌梗死(AMI)心脏破裂的原因、好发部位及与冠状动脉狭窄的关系。方法AMI死亡并行尸体解剖检查63例,其中AMI伴心脏破裂18例,不伴心脏破裂45例。结果AMI伴心脏破裂组高血压、溶栓治疗及首次心肌梗死发生率明显升高(P<0．05),而性别、梗死后心绞痛、心源性休克、心肌酶谱峰值、梗死面积与心脏破裂无明显关系(P>0．05)。心脏破裂多发生在AMI后3d内,第1天占33．3％,多见于前壁、心尖部及下壁。尸体解剖示破裂处心肌变薄伴出血,梗死相关血管多为高度狭窄。结论高血压、溶栓治疗及首次心肌梗死均为心脏破裂的危险因素。AMI的超急性期是心脏破裂的高发期。前降支及右冠状动脉高度狭窄导致心脏破裂增加。     

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.     

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.     

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.     

Variabilité des concentrations plasmatiques de l’angiotensinogène et risque d’hypertension artérielle chez le rat transgénique

Aim

Genetic polymorphisms of the human angiotensinogen gene are frequent and may induce up to 30% increase of plasma angiotensinogen concentrations with a blood pressure increase of up to 5 mmHg. Their role for the pathogenesis of human arterial hypertension remains unclear. High plasma angiotensinogen levels could increase the sensitivity to other blood pressure stressors.

Methods

Male transgenic rats with a 9-fold increase of plasma angiotensinogen concentrations and male non-transgenic rats aged 10 weeks were treated or not with NG-Nitro-L-arginine-methyl ester for 3 weeks in their drinking water (n = 3/group). Systolic blood pressure and body weight were measured at baseline and at the end of the study when left ventricular weight and ventricular expression of angiotensin I-converting enzyme and procollagen Iα1 were determined (polymerase chain reaction).

Results

At baseline, transgenic rats had +18 mmHg higher bood pressure and –8% lower body weight compared to non-transgenic rats (P < 0.05) without significant changes for the vehicle groups throughout the study (P > 0.05). NG-Nitro-L-arginine-methyl ester increased blood pressure, left ventricular weight and left ventricular weight indexed for body weight by +41%, +17.6% and +18.6% (P < 0.05) in transgenic and +25%, +5.3% and +6.7% (P > 0.05) in non-transgenic rats compared to untreated animals, respectively. Cardiac gene expression showed no differences between groups (P > 0.05).

Conclusion

Increased plasma angiotensinogen levels may sensitize to additional blood pressure stressors. Our preliminary results point towards an independent role of angiotensinogen in the pathogenesis of human hypertension and associated end-organ damage.