Physiologie (Bucarest)最新文献

Silent myocardial ischemia is undoubtedly the second most prevalent cardiovascular disease after arterial hypertension. Considering its statistical and social importance, the authors, while admitting the less specific coronary character of this entity, do not agree with its being omitted from the last classification of coronary disease (1979), in which especially/angina pectoris and myocardial infarction are emphasized. In the present paper, which opens up an investigation into initially silent ischemia carried out on a great number of cases, the authors discuss the preliminary observations derived from a ten-year (1976-1986) follow up of 56 cases of initially asymptomatic electrocardiographic ischemia with an electric localization suggesting specific coronary territories. It results that the incidence of an unfavourable evolution (myocardial infarction, angina pectoris, onset of arrhythmias or conduction defects) is somewhat higher in males than in females, but not up to 3-4 times as stated in most populational studies on myocardial infarction. The electrocardiographic and clinical improvements are, however, definitely more frequent (4 times) in women than in men (p less than 0.002). Of the 56 cases studied, 26.6% worsened, 23.2% improved, and 21.5% presented no change along the 10 years of follow up (the others showed electrocardiographic evolutions without a clinical expression, while 2 died from a noncardiac cause.

Exposure of rats to an environment of +40 degrees C that increases central (rectal) temperature to about 40 degrees C, importantly decrease the number of thrombocytes, the blood coagulation (the Quick time and Howel time) and euglobulin lysis time (ELT). In order to search for the mechanism responsible for coagulability and fibrinolysis we studied the relations of these changes with the sympatheticoadrenergic system and with the adrenal hormonal secretion. Some parameters were thus explored after adrenalectomy and under the influence of a beta-blocking agent, Eraldin. Adrenalectomy moderately reduced these decreasing effects, excepting the ELT. Eraldin has a contrary effect. Adrenalectomy acts by suppressing the corticoid reaction and by diminishing the catecholamineones. Since Eraldin influences coagulation and fibrinolysis in an opposite sense than adrenalectomy, it may be concluded that catecholamines do moderate the effect of heating, inhibiting and not stimulating circulation, as assumed. On the contrary, corticoids (gluco- or mineralo-) contribute to the effect, influencing coagulation in hyperthermia. Both influences are slight, not determinant. Supplementary explorations revealed that repeated daily exposure for 1-2 or 3 weeks, simply in the cages in which hyperthermia was subsequently produced, decreased also the number of thrombocites, the QT and the ELT, especially the last one. The HT was less influenced. It results that these exposures, produced effects similar with hyperthermia. Heating rats after these daily repeated exposures does not influence these already changed parameters.

Coagulation and fibrinolysis were studied in rats exposed to hypokinesia (HK) obtained by including rats (for 1, 2 and 3 weeks) in small cages designed to limit their movements, permitting only spontaneous feeding (a method widely used for mimicking space flight conditions). The number of thrombocytes, the Quick time, the Howell time and the euglobulinlysis time (ELT) decreased after 1 and 2 weeks of HK; however, after 3 weeks, the parameters of coagulation approached normal control levels, while ELT was still significantly under the control values. An increased blood level of corticosterone in animals subjected to HK suggested that changes observed in the blood coagulation could be linked with it. After exposing rats to heat, similar changes were noticed, i.e. thrombocytopenia and an increase in the speed of coagulation and fibrinolysis. When hyperthermia was induced in hypokinetic animals (after 1 and 2 weeks of HK), the association of exposure to HLK and heat was not followed by a cumulative response.

Acute effects of l-carnitine (vials of 1 g endovenous) were recorded in a group of elite athletes (17 swimmers) by a prospective double-blind placebo-controlled trial and cross over. Significant changes were registered after l-carnitine injection, compared to placebo, for FFA, triglycerides, lactic acid after exercise, evoked muscular potential, 90 to 120 minutes after injection. The authors explain these changes by the increase of free carnitine, which permits a larger quantity of FFA to enter the mitochondria and to be more extensively used as energy source.

The pre-Hilbert space of normal and pathological states of a living organism is built and a set of functions of medical interest are defined on it. Thus we put in mathematical terms the pathological of a state, the drug, the treatment, the length and the therapeutical effect of a treatment and the therapeutical efficiency of a drug.

An easy to use, for a physiologist, BASIC program based on a previous published theory (Iacobaş & Iacobaş 1985, 1987) is presented. The user should introduce the mean values, the allowed fluctuations and the experimentally determined values (at certain time moments) of the parameters which are satisfactorily describing the living system. The computer will then determine the corresponding values of the dimensionless parameters, will compute the pathological for every experimentally studied state and will build the pre-Hilbert space of normal and pathological states of the system. On request, the computer could present on the display the graph for each parameter (natural or dimensionless) and could fit the experimental data with some analytical functions giving their coefficients and the fitting standard errors. The computer could also make predictions (on request) concerning the evolution of the system in any realistic time interval.

The advantages and shortcomings of various exercise tests applied to rats are discussed. Special attention is devoted to two procedures used by our team: swimming till exhaustion in thermoindifferent water and treadmill run with recording of maximal run distance and duration. Contributions obtained in three research areas (changes of the exercise performance after treatment with various substances, modifications of biochemical and physiological parameters following exercise, endocrine, neuromotor and systemic features of training) are summarized, differences between running and swimming effects are underlined and experimental and practical prospects of these tests are outlined.