大鼠心肌梗死后心力衰竭模型的建立和评估

目的建立大鼠心肌梗死后心力衰竭（心衰）模型,并进行评估,以提高存活率和成功率。方法分批对160只大鼠行冠状动脉左前降支结扎手术,同时设48只假手术组,计算死亡率。在4周时行血流动力学检查,检测心率（HR）、左心室舒张末压（LVEDP）、计算左室压力最大上升速率（+dp/dtm ax）和左室压力最大下降速率（-dp/dtm ax）。结果4周时模型组心率、+dp/dtm ax和-dp/dtm ax绝对值均低于假手术组（分别为P<0.05,P<0.01,P<0.01）,LVEDP则高于假术组（P<0.01）。随着手术大鼠例数的增多,存活率得到提高（P<0.05）。结论心梗后4周形成心衰模型,通过采取必要的措施,可以提高动物生存率。     

容量超负荷心力衰竭大鼠模型的制备及心脏功能的超声评价

目的：改进容量超负荷大鼠模型制备的方法并探讨超声心动图观察大鼠容量超负荷心力衰竭模型心功能状况的准确性与可靠性。方法采用大鼠腹主动脉下腔静脉造瘘方法建立容量超负荷心力衰竭模型,同时设置对照组,造瘘组40只,对照组20只,应用心脏彩色超声诊断仪动态检测大鼠左室舒张末内径（LVEDD）、左室收缩末内径（LVESD）、左房内径（LAD）及左室射血分数（LVEF）等指标,颈动脉插管测定两组大鼠颈动脉血压（CABP）、左心室收缩末期压力（LVSP）和舒张末期压力（LVDP）,以及反映左心室收缩功能指标的±dp/dtmax值,以评价两组间血流动力学改变;并于术后12周比较两组大鼠心脏质量及心脏重体重比（心体比）。结果造模术后8周,造瘘组大鼠超声心动图表现为左室心腔扩大呈球形,与假手术组比较,射血分数和短轴缩短率明显降低[LVEF：（61.31±3.07）%vs.（77.20±2.41）%;短轴缩短率：（30.37±2.39）%vs.（41.08±2.13）%],左室重量指数增加[（2.85±0.41） vs.（1.59±0.15）],心体比升高[（5.89±0.56） vs.（2.99±0.21）],差异均有统计学意义（P均＜0.01）;造模术后12周,造瘘组大鼠LVDP[（12.53±22.63）mmHg vs.（2.27±1.77）mmHg]和-dp/dtmax[（-3.78±2.14） vs.（-5.80±2.26）]较假手术组升高,LVSP[（108.88±34.39）mmHg vs.（126.48±19.44）mmHg]和＋dp/dtmax[（4.89±2.93） vs.（6.92±1.65）]较假手术组降低（P＜0.05）。结论大鼠超声心动图可较好地动态评价腹主动脉下腔静脉瘘方法建立的容量超负荷心力衰竭模型的心脏形态和心功能状态。     

右室流出道间隔部起搏的血流动力学观测

目的比较右室流出道间隔部（RVS）与右室心尖部（RVA）起搏对血流动力学的影响。方法选择具备起搏器植入指征的患者30例,随机分为RVA组与RVS组,采用超声心动图检测左室射血分数（LVEF）、每搏量（SV）、左室短轴缩短率（FS）、心脏指数（CI）,对比观察术前、术后3,6个月差异。并比较术前与术后心电图QRS波宽度。结果两组患者均顺利完成手术。两组QRS波时限均较自身心律时延长,差异有统计学意义（P<0.01）,RVA组起搏QRS时限显著长于RVS组[（158±15）msvs（132±15）ms,P<0.01];RVA组术后3个月随访LVEF,SV,FS,CI较术前均显著降低,均有统计学意义[（59±3）%vs（51±3）%,（79±15）mlvs（71±16）ml,（0.36±0.11）vs（0.31±0.09）,（2.5±0.4）L/（min·m2）vs（2.1±0.4）L/（min.m2）,均P<0.05];RVS组术后3,6个月随访LVEF,SV,FS,CI与术前无显著性差异,RVS组3,6个月随访LVEF,SV,FS,CI均显著高于同期RVA组,均有统计学意义（均P<0.05）。结论RVS起搏尽可能的保证了心室激动和收缩同步性,实现了比RVA起搏较为良好的血流动力学状态。     

快速右心室起搏心力衰竭犬模型的建立

目的应用改进的快速右心室起搏的方法制备慢性心力衰竭犬模型,分析模型相应的临床和血流动力学及病理变化。方法选择比格犬12只,随机分为起搏组(7只)和对照组(5只),起搏组采用230 ppm的频率快速右心室起搏4周,之后改用180 ppm的频率维持右心室起搏4周。对照组正常喂养不处理,4周后测量相应指标。起搏组起搏前、起搏1、8周后,分别行心脏超声、血流动力学检测,之后处死取心脏做病理切片检查。结果与对照组和同组起搏前比较,起搏组犬起搏4、8周后,出现慢性心力衰竭的相应临床表现;超声心动图示各心腔内径均变大,左心室射血分数明显下降,左心导管示左心室舒张末压力增加,左心室收缩末压力及左心室内压最大上升及下降速率降低,差异有统计学意义(P<0.05,P<0.01)。结论经过改进的快速右心室起搏方法,可以产生相对稳定的慢性心力衰竭犬模型。     

缬草单萜氧化物预处理对供心保存的实验研究

目的观察缬草单萜氧化物（VMO）预处理对供心保存效果的影响,并探讨其机制。方法随机将兔分为5组:对照组（Con组）;缺血预处理组（IP组）;VMO预处理组（VMO组）;格列苯脲加VMO预处理组（G li+VMO组）;格列苯脲组（G li组）。各预处理组均在Langendorff灌注模型下行预处理,随后停搏,4℃保存180 m in,最后行再灌注。观察低温保存后的左室压力变化最大速率（±dp/dtm ax）、心肌磷酸肌酸激酶（CK-MB）释放量、心肌ATP含量和能荷（EC）。结果①与Con组比较,IP组+dp/dtm ax增加29.9%、-dp/dtm ax增加29.9%,CK-MB降低25.1%,ATP提高76.1%、EC提高27.9%;VMO组+dp/dtm ax增加25.1%、-dp/dtm ax增加25.3%,CK-MB降低20.7%,ATP提高72.8%、EC提高20.9%;②G li+VMO组和G li组分别与Con组比较,±dp/dtm ax,CK-MB,ATP和EC均无显著差异（P>0.05）;③G li+VMO组与VMO组比较,±dp/dtm ax,CK-MB,ATP和EC差异显著（P<0.05或P<0.01）。结论VMO预处理供心可以发挥和缺血预处理类似的心脏保护作用。开放KATP通道可能是VMO发挥药物预处理作用的重要机制之一。     

亚硝酰氢对心力衰竭大鼠心脏有保护作用

【摘要】目的 探讨亚硝酰氢对心力衰竭大鼠心脏是否有保护作用。方法 选取50只雄性Wistar大鼠，从中随机抽取42只采用结扎左冠状动脉前降支方法制作心肌梗死后心力衰竭模型，剩余8只作为假手术组（sham组，n=8），术后3天手术组大鼠存活17只，随机分为心力衰竭对照组（HF组，n=8）、亚硝酰氢治疗组（HNO组，n=9），术后第3天开始给予HNO组大鼠腹腔注射亚硝酰氢供体Angeli’s salt，HF组及sham组均给予等量生理盐水，4周后用ELISA法检测大鼠外周血N末端B型利钠肽（NT-ProBNP）水平，超声心动图检测大鼠心功能，左心压力导管检测大鼠血流动力学改变，最后处死大鼠计算心体指数。结果 术后4周HNO治疗组大鼠与HF组相比，NT-ProBNP、左心室舒张末压（LVEDP）明显降低[385.65±43.50vs496.13±52.80pg/mL，P<0.01、17.49±2.04vs21.19±1.91mmHg，P<0.05]，左心室射血分数（LVEF）、左心室短轴收缩率（LVFS）、左心室内压力最大上升速率（ dp/dt）、左心室内压力最大下降速率（-dp/dt）明显增加[（52.88±5.46）%vs（39.71±3.64）%，P<0.01、（23.75±3.11）%vs（16.57±1.72）%，P<0.01、3029.13±634.12vs2347.43±451.38mmHg/s，P<0.05、2896.50±642.66vs2169.29±433.17mmHg/s，P<0.05]，心体指数（HW/BW）、左心室舒张末容积（LVEDd）、左心室收缩压（LVSP）无明显差异[2.97±0.17vs2.98±0.16g/kg，7.19±0.87vs7.66±0.84mm，131.38±9.47vs130.57±11.46mmHg，均为 P>0.05]。结论 亚硝酰氢可以增加心力衰竭大鼠心脏功能，改善血流动力学，降低外周血NT-ProBNP水平，对心力衰竭大鼠心脏起保护作用。     

心脏再同步化治疗对缺血性心力衰竭犬的疗效及心肌钙通道电流的影响

目的研究心脏再同步化治疗(CRT)对失同步化缺血性心力衰竭犬的疗效及钙离子通道电流(ICa)的影响。方法取西北犬行左束支射频消融术和冠状动脉前降支结扎术建立失同步化缺血性心力衰竭模型(n=14)。随机选取7只造模成功犬行CRT治疗,作为CRT组。另7只造模成功犬作为失同步化组。取5只正常犬作为对照组。CRT后6周(其它两组于相应时间点)检测心电图学、超声心动图及血流动力学指标,上述指标检测完毕后,分离左室侧壁和前壁心肌细胞,用全细胞膜片钳法检测ICa。结果与对照组相比较,失同步化组的RR间期缩短(420±55 ms vs 598±98 ms,P<0.05),QTc间期延长(433±46 ms vs 378±32 ms,P<0.05),QRS波时限延长(100±23 ms vs 53±8 ms,P<0.05),失同步化指数(DI)升高(80±22 ms vs 28±6 ms,P<0.05)。与失同步化组比较,CRT组QRS波时限缩短(73±11 ms vs 100±23 ms,P<0.05),降低了DI(32±24 ms vs 80±22 ms,P<0.05),缩短了QTc间期(392±36 ms vs 433±46 ms,P<0.05)。对照组左室前壁和侧壁的ICa密度峰值无差别(-4.7±0.3pA/pF vs-4.5±0.3 pA/pF,P>0.05)。失同步化组侧壁ICa电流密度低于前壁(-3.8±0.2 pA/pF vs-5.2±0.3 pA/pF,P<0.01)。CRT组侧壁和前壁的电流密度无差别(-4.5±0.2 pA/pF vs-4.5±0.3 pA/pF,P>0.05)。结论 CRT能部分地逆转失同步化缺血性心力衰竭的电重构与机械重构。     

右室心尖部起搏对心脏功能正常患者左室收缩同步性及功能的影响

目的应用超声心动图组织多普勒技术评价右室心尖部起搏对左室收缩同步性及心脏功能的影响,探讨起搏诱发的心室不同步收缩对于心脏功能的影响机制。方法65例置入双腔起搏器的病窦综合征患者分别在心室节律全部为起搏节律或室上性节律状态下行常规及组织多普勒超声心动图检查,测量左室收缩功能及收缩同步性指标。结果右室完全起搏模式下左室收缩功能下降(射血分数:0.58±0.07 vs 0.61±0.01,P<0.001),左室6节段收缩期平均速度下降(4.0±1.5cm/s vs 4.7±1.6cm/s,P<0.001),心室收缩同步性下降(12节段达峰时间标准差:37.5±12.5ms vs 23.7±10.2ms,P<0.001),心室同步性恶化程度与收缩功能恶化中度相关(r=0.37,P<0.05)。结论右室心尖部起搏可致左室收缩不同步及左室功能降低。     

乙酰胆碱诱发犬急性心房颤动模型的研究

目的 :研究乙酰胆碱 （ACh）诱发犬急性心房颤动模型的效果及机制。方法 :取 10条健康杂种犬 ,给予持续静注 ACh及心房快速起搏 ,测定房颤持续时间 ,根据房颤持续时间逐渐增加药量 ,直至通过心房快速起搏可以诱发出持续性房颤 （≥ 3m in）为止。给药前及给药后测定心率 ,校正窦房结恢复时间 ,心房有效不应期 ,给药前后及房颤发生后测定左室内压及左室内压最大上升、下降速率 （± dp/ dtmax）。结果 :在给予 ACh前 ,通过心房快速起搏均未能诱发出持续性房颤 ,随着 ACh量的逐渐增加 ,诱发出房颤的时间逐渐延长 ,当增加到一定量 （18± 8μg· kg- 1·min- 1 ）之后 ,10只犬均可以通过心房快速起搏诱发出持续性房颤 ,有 1只犬不需诱发即可出现 ,其持续时间为 34 4± 173s。测定犬心率明显减慢 （15 7± 2 5 vs138± 2 0· m in- 1 ,P<0 .0 1） ,校正窦房结恢复时间延长 （4 4± 13vs81±2 4ms,P<0 .0 1） ,心房有效不应期明显缩短 （80± 16 vs 6 0± 13m s,P<0 .0 1） ,使用 ACh后左室内压及其最大上升、下降速率差异不显著 （140± 2 9vs 12 9± 15 m m Hg· s- 1 ,P>0 .0 5 ;2 75 2± 876 vs 2 434± 5 31mm Hg· s- 1 ;-3115± 10 6 7vs- 2 70 7± 714m m Hg· s- 1 ,P>0 .0 5 ） ,房颤发生后则明显降低 (12 9± 15 v     

超声心动图评价双心室起搏作用的临床研究

双心室起搏是近来用于改善原发性扩张型心肌病病人的血流动力学的一种新疗法。该文旨在评价其对慢性心力衰竭、低射血分数和心室间及心室内传导阻滞病人的超声心动图参数的影响,并探讨双心室起搏对左、右心室间传导延迟以及对左、右心室功能的作用。     

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.     

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.