Bases of surgical treatment of bilateral suppurative processes in the lungs

In dogs subjected to gravitational overloadings (+Gx) according to a special training schedule the wall structure of the main arteries (carotid, humeral, femoral and aorta) was studied by histological methods. The amount of catecholamines (adrenaline and noradrenaline) in the venous blood plasma and in the adrenal tissue was the index of the sympathoadrenal system condition. It was demonstrated that in trained animals the tolerance threshold to continuously increasing overloadings (+Gx) rose. It was accompanied by an elevated amount of catecholamines in blood and the adrenals In the walls of the main arteries studied a moderate hyperelastosis and a slight collagenization of the adventitia was noted. All parts of the microcirculatory bed were moderately dilated, which favoured a better blood outflow. The data obtained demonstrate adaptational changes, which can be interpreted as indices of training and reliability of the organism.     

Teratogenic and embryotoxic activity of several 2,4-diaminopyrimidine derivatives

The degree of teratogenic and embryotoxic effects is dependent not only on the period of gestation and the agent dosage but also on the chemical structure of its molecule. In the series of derivatives of 2,4-diamino-5-phenylpyrimidine with different length of the alkul radical in the 6 position the preparation with ethyl group has the greatest injuring effect. Thus, the structural distinctions in the molecules of pharmacological agents are responsible for the selective toxicity of drugs in relation to mammalian embryos.     

The cytogenetic disorders in the people who took part in the cleanup of the sequelae at the Chernobyl Atomic Electric Power Station and who lived continuously in areas with an unfavorable ecological situation

Cytogenetic disturbances are manifested now in persons who liquidated aftereffects of the Chernobyl disaster. The character and course of the disturbances depend on the ecological conditions of the region where liquidators live at present. Examination of a group of liquidators with nerve-psychopathologic disorders and accompanying somatic pathology has revealed the presence of cytogenetic disturbances, mainly of the chromosome aberration type. At the same time, in persons who live under conditions of high environment pollution with ejections of industrial enterprises, the number of chromatid aberrations increases, which may be a result of action of chemical mutagens. A tight correlation is revealed between the level of cytogenetic disorders in lymphocytes and expressivity of the secondary immunodeficiency. Elimination of lymphocytes with unstable chromosome aberration is delayed when ecological pollution of the biosphere reaches the high level.     

Clinical trials comparing two treatment policies: which aspects of the treatment policies make a difference?

We discuss pragmatic clinical trials with survival endpoints in which subjects commonly change treatment during follow-up. Suppose that an intention-to-treat (ITT) analysis shows a significant difference between the randomized groups. We may want to ask questions about the reason for such a difference in outcome between randomized groups: for example, was the difference due to different policies for change to a third more beneficial regime? We address such questions using the semi-parametric accelerated life models of Robins, which exploit the randomization assumption fully and avoid direct comparisons of possibly differently selected subgroups. No assumption is made about the relationship of treatment actually prescribed to prognosis. A sensitivity analysis, using a range of plausible values for the causal effect of a covariate, estimates the contrasts between randomized groups that would have been observed if the covariate had universally been 0. The main technical problem is in dealing with censoring, for the method requires different degrees of recensoring for different values of the causal effect, and this can lead to estimates of low precision. The methods are applied to a randomized comparison of two anti-hypertensive treatments in which approximately half the subjects changed treatment during follow-up. Various time-dependent covariates, representing patterns of side-effects and treatments, are used in the model. We find that the observed difference in cardiovascular deaths between the randomized groups cannot be explained in this way by their different covariate patterns.     

The surgical treatment of hepatic echinococcosis and of its biliary complications

The authors report the experience of 47 patients submitted to surgery for hepatic hydatidosis. Results from different therapeutic procedures are then compared. Finally, possible biliary complications of the hepatic echinococcosis and their surgical treatment are discussed.     

Effect of the vascular endothelium on norepinephrine-induced contractions in uterine radial arteries from the nonpregnant and pregnant human uterus

OBJECTIVE: Our purpose was to investigate the role of the endothelium in the human uterine arterial response to norepinephrine in the nonpregnant and pregnant states. STUDY DESIGN: Tissue was obtained from six pregnant and six nonpregnant women undergoing cesarean section or hysterectomy. Uterine radial arteries were isolated and subjected to norepinephrine dose-response curves with and without intact endothelium. RESULTS: Responses were obtained over a dose range of 10(-8) to 10(-4) norepinephrine. Initially there was no difference between vessels from pregnant and nonpregnant patients, but removal of the endothelium significantly increased the response in vessels from pregnant women. Addition of nitro-L-arginine methyl ester when the endothelium was intact did not alter the dose-response curves. CONCLUSIONS: In pregnancy human uterine radial arteries are more sensitive to norepinephrine than during the nonpregnant state. This increase is countered by an endothelium-derived relaxing factor. The factor is unlikely to be nitric oxide.     

Effect of dietary selenium on the progression of heart failure in the ageing spontaneously hypertensive rat

Oxidative stress has been directly implicated in hypertension and myocardial remodelling, two pathologies fundamental to the development of chronic heart failure. Selenium (Se) can act directly and indirectly as an antioxidant and a lowered Se status leads to a higher risk of cardiovascular disease. This study examined the role of Se on the development of hypertension and subsequent progression to chronic heart failure in spontaneously hypertensive rats (SHR). Three dietary groups were studied: (i) Se‐free; (ii) normal Se (50 μg Se/kg food); and (iii) high Se (1000 μg Se/kg food). Systolic blood pressure and echocardiography were used to detect cardiac changes in vivo. At study end, cardiac tissues were assayed for glutathione peroxidase activity, thioredoxin reductase activity, and protein carbonyls. The major finding of this study was the high heart failure‐related mortality rate in SHRs fed an Se‐free diet (70%). Normal and high levels of dietary Se resulted in higher survival rates of 78 and 100%, respectively. Furthermore, high dietary Se was clearly associated with lower levels of cardiac oxidative damage and increased antioxidant expression, as well as a reduction in disease severity and mortality in the SHR.     

Analysis of the energy efficiency of solar aided biomass gasification for pure hydrogen production

This paper presents a simulative analysis of the energy efficiency of solar aided biomass gasification for pure hydrogen production. Solar heat has been considered as available at 250 °C in three gasification processes: i) gasification reactor followed by two water gas shift reactors and a pressure swing adsorber; ii) gasification reactor followed by an integrated membrane water gas shift reactor; iii) supercritical gasification reactor followed by two flash separators and a pressure swing adsorber.