纳米细菌与冠心病

最近新发现的纳米细菌是目前已知的最小的细菌,其直径为几十至几百纳米.与其它细菌不同,它们是一种生长繁殖缓慢,能通过普通滤菌器(0.2um),吴有生物矿化作用和一定抗辐射能力,革兰氏染色阴性的球形细菌.它们最特殊的生物学特性是可以在生理状态的钙、磷浓度下分泌主要由羟磷石灰碳酸盐构成的保护性外壳.因此,它们被认为与机体内病理性钙化密切相关.近年来研究发现,它们可能是冠心病的一种感染性致病源.抗纳米细菌治疗的临床实验显示在冠心病患者中具有一定疗效.     

论知情同意的中国本土化--中国文化视野中的知情同意走向

知情同意原产于西方,移植到中国后被"家文化"、"功利论"、"简单化"等中华传统文化彻底改造过以后,浓缩成了手术前一味要求病人家属或单位领导签字的行为模式,远离了知情同意的主旨,但曾一度非理性地普遍流行.现在,又出现了一种照搬欧美知情同意的倾向,在一线医务人员中引发了诸多困惑和不满.在实施知情同意时,离开中华文化语境,或者在本土化中化掉其本质的做法,都是不可行的.正确的取向只能是立足于中国当代医学实践,以正在形成中的中国现代文化去整合西方知情同意的本质、理念和规范,构建成一套适合中国国情的知情同意机制.     

冠状动脉介入治疗的合理应用

近年来我国的冠心病介入治疗迅速发展,但有许多问题必须引起注意。本文讨论了我国目前冠脉介入治疗存在的问题;如何正确选择冠心病介入治疗、冠状动脉搭桥和药物治疗;重视冠脉介入手术病人的综合治疗等问题。     

从循证医学看目前冠心病的药物治疗

为使冠心病患者尽可能达到最优化的药物治疗,结合最近几年出现的大型临床研究,分析了不同冠心病患者应采取的合理药物治疗措施及可能带来的益处,并针对我国现状,提出了相应的解决方案。     

急性应激与风险倾向：兴奋易感性的调节作用

为探索应激对决策的作用机理及其个体差异,减少工程作业中因应激导致的决策失误,本研究采用特里尔社会应激测试和气球模拟风险任务考察应激反应与应激下风险倾向的关系,并探索兴奋易感性在其中的调节作用。研究结果表明,应激下个体的皮质醇反应越大,行为越冒险。且这一作用受到兴奋易感性的调节：兴奋易感性较高的个体,应激下皮质醇反应越大,行为越冒险;而兴奋易感性较低的个体,其皮质醇变化不能预测风险倾向。该发现提示了兴奋易感性在应激影响中的重要作用,也为高压岗位的人员选拔提供了科学启示。     

Is the heart preadapted to hypoxia? Evidence from fractal dynamics of heartbeat interval fluctuations at high altitude (5,050 m)

The dynamics of heartbeat interval time series over large time scales were studied by a modifed random walk analysis introduced recently asDetrended Fluctuation Analysis. In this analysis, the intrinsic fractal long-range power-law correlation properties of beat-to-beat fluctuations generated by the dynamical system (i.e., cardiac rhythm generator), after decomposition from extrinsic uncorrelated sources, can be quantified by the scaling exponent (α) which, in healthy subjects, for time scales of ∼10⁴ beats is ∼1.0. The effects of chronic hypoxia were determined from serial heartbeat interval time series of digitized twenty-four-hour ambulatory ECGs recorded in nine healthy subjects (mean age thirty-four years old) at sea level and during a sojourn at 5,050 m for thirty-four days (Ev-K2-CNR Pyramid Laboratory, Sagarmatha National Park, Nepal). The group averaged α exponent (±SD) was 0.99±0.04 (range 0.93–1.04). Longitudinal assessment of α in individual subjects did not reveal any effect of exposure to chronic high altitude hypoxia. The finding of α∼1 indicating scale-invariant long-range power-law correlations (1/f noise) of heartbeat fluctuations would reflect a genuinely self-similar fractal process that typically generates fluctuations on a wide range of time scales. Lack of a characteristic time scale along with the absence of any effect from exposure to chronic hypoxia on scaling properties suggests that the neuroautonomic cardiac control system is preadapted to hypoxia which helps prevent excessive mode-locking (error tolerance) that would restrict its functional responsiveness (plasticity) to hypoxic or other physiological stimuli. Editorial Note: A philosopher is, by definition, a lover of wisdom. In the following article, Dr. Dimitrov, as a philosopher, examines the principles that underlie being and thinking as performed by the structures of the brain. He reports his thoughts in a “virtual context.” Virtual, a word enjoying great popularity today, is derived from the Latin word for man; it describes manliness and implies apparent, but not actual, power. In his analysis of how information is dealt with by the human being, the author uses theoretical physics and mathematics that may seem arcane to some readers. A major aspect of his thesis declares that the effective performance of information systems relies not on the structures involved, but on the way they interact.     

Electrocortical signs of arousal in response to darkness and the assessment of type A behavior in professional drivers with and without cardiovascular disease

Background and Aims  In night driving, the fatal accident rate is about four times that in daytime. There is a lack of published studies of the effect of darkness on electrocortical responses in professional drivers (PD). Aim: Assessing relations between electroencephalographic (EEG) reactions to enforced darkness reminiscent of night driving, and untoward behavioral response patterns, notably Type A behavior. Methods  PD: 13 with ischemic heart disease, 12 hypertensives (HTN), 10 borderline hypertensives and 34 normotensives, and 23 non-PD controls. Five minutes of electroencephalographic recording with eyes closed, and subsequently 3 minutes exposure to darkness. EEG parameters were: alpha abundance, amplitude and frequent. Type A behavior (TAB) was assessed by observation and by questionnaire. Results  Alpha abundance diminished significantly for darkness compared to spontaneous recording for all groups. No between-group differences were found for EEG. There were no significant differences in EEG between drivers with IHD or HTN taking versus not taking centrally active β-blockers. Drivers with IHD were the only group to show significant increase in dominant α frequency at darkness. The IHD group also had the highest TAB questionnaire scores and the heaviest exposure to professional driving. Type A scores were significantly correlated with dominantt alpha frequency during darkness. Low availability of attachment and special driving hazards best predicted TAB scores in driven. There was a significance between group difference with respect to Symbolic Aversiveness at the work place comparing each driver group with the non-PD control group. Conclusions  Exposure to darkness reminiscent of night driving can elicit central arousal, in conflict with circadian rhythm, and in combination with other driving hazards which contribute to symbolic aversiveness, the essence of driving. And low availability of social attachment could contribute to sustained, and in turn to the development of Type A behavior in professional drivers.     

Legal and Ethical Considerations in Allowing Parental Exemptions From Newborn Critical Congenital Heart Disease (CCHD) Screening

Critical congenital heart disease (CCHD) screening is rapidly becoming the standard of care in the United States after being added to the Recommended Uniform Screening Panel (RUSP) in 2011. Newborn screens typically do not require affirmative parental consent. In fact, most states allow parents to exempt their baby from receiving the required screen on the basis of religious or personally held beliefs. There are many ethical considerations implicated with allowing parents to exempt their child from newborn screening for CCHD. Considerations include the treatment of religious exemptions in our current legal system, as well as medical and ethical principles in relation to the rights of infants. Although there are significant benefits to screening newborns for CCHD, when a parent refuses for religious or personal beliefs, in the case of CCHD screening, the parental decision should stand.     

Illness perceptions or recurrence risk perceptions: What comes first? A longitudinal cross-lagged examination among cardiac patients

Objectives: Previous research suggested that illness perceptions provide the basis for illness risk perceptions through an inductive reasoning process. This study aimed to assess the direction of relationships between illness and recurrence risk perceptions over time, among cardiac patients.

Design: A longitudinal study was conducted among 138 patients undergoing coronary angioplasty. Self-report questionnaires measured perceived recurrence risk and illness perceptions one day and one month after catheterisation.

Results: Cross-lagged Panel Model Analyses revealed that higher perceptions of timeline, consequences and emotional representations of illness at hospitalisation were associated with higher recurrence risk perceptions one month later. Perceived personal control was the only illness perception with bi-directional associations: higher perceived personal control at hospitalisation was associated with higher recurrence risk perceptions one month later; and higher recurrence risk perceptions at hospitalisation was associated with lower personal control one month later.

Conclusions: The findings suggest that the associations between recurrence risk and illness perceptions can only partly be explained by inductive reasoning. Halo effects and defensive processes are suggested as complementary explanations for the observed associations between risk and illness perceptions.