用体表心电标测方法探讨复极离散及空间分布

目的　用体表心电标测时空图法探讨复极离散空间分布和临床价值。方法　采用体表心电标测时空图法及12导联心电图 ,分别测定 6 8例急性心肌梗死 (AMI)患者的QT间期及QT离散度 (QTd) ,并与 5 8例正常对照者进行对比。结果　 (1)在正常人及AMI患者时空图法测得QTd均大于 12导联心电图 ,两种方法均表明AMI后QTd增加。 (2 )正常人时空图分布 :T波呈单群、结束时间相对较一致 ;AMI后时空图分布发生明显变化 :梗死区对应体表部位T波结束延长 ,大致分 3型 ,部分患者可见零线垂直偏斜 ,ST T复极过程中分群现象 ,T波结束离散增大。 (3)AMI患者死亡及合并室性心律失常者时空图法测得QTd较无心律失常者增加、分布主要表现第Ⅰ、Ⅲ型 (18/ 2 1) ,12导联心电图未发现两组间差异。 (4 )时空图尚可展示相邻部位的复极离散和U波分布。结论　时空图法可直观反映QT间期空间分布及离散 ,并能有效鉴别U波 ,可能会成为QTd研究中一项有前途的方法     

急性心肌梗死QT间期测量的导联选择及QT离散度分析

目的探讨急性心肌梗死测定最大QT间期的导联选择及分析心肌梗死急性期QT离散度与恶性以律失常的相关性。方法研究41例急性心肌梗死患者发病一周内的常规12导联体表心电图,1.比较最大QT间期的所在导联;2.比较室速/室颤患者无室速/室颤的QT离散度。结果在常规12导联体表心电图上,最大QT间期导联在V1～V3;室速/室颤患者的QT离散度(83±25ms)显著大于无室速/室颤的QT离散度(65±20ms),P<0.01。结论在急性心肌梗死患者中进行QT间期测定和QT离散分析时,正确的选择应在胸前导联测量最大QT间期。而心肌梗死急性期QT离散度增加可作为恶性心律失常发生的危险信号。     

急性心肌梗死QT离散度变化及临床意义

1985年Campbell等发现不同导联间QT间期的差异有其规律性,提出了QT离散度(QT disper-sion)这个概念。1990年由Day等首先证实QT离散度具有重要临床价值。近年来许多研究表明,急性心肌梗死(AMI)患者体表心电图存在QT离散度(QTd)增大。心电图这种QT离散度增加反映了     

不同类型室性心律失常患者QTd与QTcd变化及其临床意义

<正> QT间期离散度(QTd)是指12导联心电图各导联间QT间期存在的差异.1985年由Campbell等报道QTd是心室复极时间的局部差异在体表心电图上的反映而非记录技术伪差所致.1990年由Day等首先证实QTd具有重要的临床价值.本文分析100例定性心律失常患者QTd与校正QT间期离散度(QTcd)值,旨在探讨其对恶性室性心律失常的预测价值.     

QT离散度预测AMI患者发生室颤的价值

室颤是急性心肌梗死（AMI）患者的主要死因。体表心电图不同导联间QT间期的变异,即QT离散度（QTd）可反映心室复极时间的局部差异,作为心肌各部位电活动稳定性的一项无创检查指标。本文通过对AMI患者和正常人QTd的对照分析,探讨QTd对心肌缺血性猝死的预测价值。     

QT离散度不能反映心肌复极的区域性差异

目的　探讨体表心电图上QT离散度 (QTd)是否可以反映区域性的心肌复极差异。方法　正常对照 (对照 )组和心肌梗死 (心梗 )组各有 12 0例 ,记录同步 12导联心电图 ,人工测量各导联QT间期 ,计算QTd。结果　与对照组相比 ,心梗组QTd明显增加 ,分别为 (5 6 3± 17 8)ms与 (10 0 9±5 4 3)ms,P <0 0 0 1;但两组之间存在很大交叉 ,无法确立参考值。最长QT和最短QT在两组的导联分布呈现一致趋势。心梗组全部 12导联QT间期均较对照组明显延长 ,平均QT间期分别为 (397 0± 4 6 8)ms与 (36 7 3± 2 2 8)ms ,P <0 0 0 1。不同梗死部位各亚组之间心电图各导联QT间期均值差异无显著性(P =0 6 36 ) ,未见到与梗死部位相关的区域性QT间期改变。结论　QTd增大常与QT间期延长同时出现 ,QTd增大从整体上反映了心肌复极异常 ,但是不能代表心肌复极的区域性差异。     

QT离散度

QT离散度(QTd)系指体表12导联心电图各导联QT间期存在的差异,这一现象早被人们发现,但未重视。直至1985年,Campbell等发现心电图导联间存在的QT间期差异是有规律性的,遂提出QT离散度这一概念。 概述 体表心电图与心肌细胞单相动作电位有着密切的关系。心电图的QT间期相当于动作电     

T环形态与QT离散度的关系研究

目的　探讨心向量图的T环形态与体表心电图出现QT离散度 (QTd)的关系。方法　使用中卫瑞德SCA Ⅱ型立体心电图仪 ,对确诊的陈旧心肌梗死患者和正常对照健康人各 10 0例进行 2 4条通道同步、实时、连续采样描记 12导联心电图、普通心向量图、9导联时间心向量图及连续心向量图检测 ,分析病例和对照组最大QT间期、最小QT间期在体表心电图各导联的分布特点以及在心向量图上T环的形态差异同QTd的关系。结果　 (1)病例和对照组从体表心电图测得的最大QT间期、最小QT间期几乎均集中在相同的导联 ;(2 )从心电向量额面 (F)、横面 (H)的T环形态来看 :病例组T环以圆小型比例大 (43% ) ,狭长型比例小 (16 % ) ,而对照组以狭长型为主 (6 8% ) ,圆小型最少 (4% )。综合分析发现狭长型T环所对应的体表QTd、校正QT离散度 (QTcd)最小 [(0 0 2 5± 0 0 0 9)s ,(0 0 2 5±0 0 0 9)s],圆小型T环所对应的体表QTd、QTcd最大 [(0 0 4 1± 0 0 17)s,(0 0 4 2± 0 0 18)s,P <0 0 1]。结论　QTd值的大小与额面和横面向量上T环的形态有关。最大QT间期、最小QT间期所集中的导联不会因梗死部位的出现而发生改变     

静脉溶栓治疗对急性心肌梗死患者QT间期离散度及室性心律失常的影响

目的　研究静脉溶栓心肌再灌注治疗对急性心肌梗死 (AMI)患者QT间期离散度(QTd)与校正的QT间期离散度 (QTcd)及室性心律失常 (VA)恶性程度的影响。方法　分别于入院时及溶栓治疗后 4周记录 15例溶栓成功及 17例溶栓未成功患者常规 12导联心电图 ,计算QTd及QTcd ,并行心电监测 ,记录住院期间发生的VA。结果　再通组 (15例 ) 4周后QTd与QTcd[(5 2 .9± 10 .4)ms、(5 8.7± 12 .3 )ms]与溶栓前QTd与QTcd比较 [(69.7± 15 .5 )ms ,(80 .5± 2 7.0 )ms]显著减小 (P <0 .0 5 )。 4周后再通组较溶栓失败冠脉未通组 (17例 )QTd与QTcd[(63 .7±15 .5 )ms ,(72 .3± 2 5 .4)ms]显著减小 (P <0 .0 5 )。再通组VA恶性程度与未通组比较有显著降低 ,死亡率亦降低。结论　早期静脉溶栓成功心肌再灌注治疗可以显著减小心肌梗死患者的QT间期离散度 ,并降低室性心律失常的恶性程度     

急性心肌梗死QT离散度的临床意义探讨

目的 观察急性心肌梗死(AMI)QT离散度(QTd)的变化与心律失常的关系以及有效的溶栓治疗对QTd的影响.方法 AMI病人42例与正常健康者50例进行对比,所有对象测量12导联心电图不同导联最长与最短的QT间期Qtmax和Qtmin,QTd=Qtmax-Qtmin,根据Bazett's公式,校正QT间期QTc=QT/(√RR),校正QT离散度(QTcd)=Qtcmax-Qtcmin.结果 AMI病人QTd、QTcd分别为(68.7±16.3)、(74.8±20.1)ms,对照组QTd(32.3±11.4)ms、QTcd(36.4±13.3)ms,P＜0.01,有心律失常组QTd(70.4±19.5)ms、QTcd (79.4±22.5)ms,无心律失常组QTd(54.4±16.3)ms、QTcd(63.2±20.1)ms,P＜0.01.溶栓有效者与无效者比较差异也有统计学意义(P＜0.05,表1).结论 有效的溶栓治疗可使QTd明显减小,减少危险性心律失常的发生,降低AMI患者病死率.QTd对预测AMI患者溶栓疗效以及早期危险性心律失常和预后具有重要价值.     

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.     

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.     

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.