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A bioluminescent derivative of Bacillus subtilis containing a plasmid encoding a luxAB fusion under control of a vegetative promoter and gives bioluminescence upon addition of an exogenous long-chain aldehyde has been used as test organism. Its spore populations have been produced and their heat- and radiation survival curves established. Heat-sensitization effect of pre-irradiation of spores was proven not only by colony counting but also with differential scanning calorimetry. Under a linearly programmed temperature increase, the heat destruction of spores surviving 2.5 kGy gamma irradiation resulted in at a few centigrade lower temperature than that of untreated spores. Heat denaturation endotherms in the DSC-thermogram of irradiated spores were shifted to lower temperatures as well. Comparative turbidimetric, luminometric and phase-contrast microscopic studies of untreated, heat-treated and irradiated spore populations showed that the kinetics of germination and the light emission during germination of radiation-inactivated spores were the same as those of untreated spores, revealing that the pre-formed luciferase enzyme packaged into the spores during sporulation remained intact after an irradiation dose causing 90% decrease in number of colony forming spores. Therefore, in contrast to heat-treated spores, the initial bioluminescence reading upon germination of irradiated spores does not reflect the viable count of their population.

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Left atrial (LA) distension has been demonstrated to be linked with aortic stiffness in different patient populations. Three-dimensional (3D) speckle-tracking echocardiography (STE) seems to be a promising tool for volumetric and functional evaluation of the LA. The aim of the present study was to determine whether correlations exist between 3DSTE-derived LA volume-based and strain parameters characterizing all phasic functions of the LA and echocardiographic aortic elastic properties in healthy subjects. The study included 19 healthy volunteers (mean age: 37.9 ± 11.4 years, 11 men) who had undergone complete two-dimensional (2D) Doppler transthoracic echocardiography extended with the assessment of aortic elastic properties and 3DSTE. Results: None of LA volumes correlated with echocardiographic aortic elastic properties. Active atrial stroke volume correlated with aortic stiffness index (ASI, r = 0.45, p = 0.05). None of other volume-based functional properties signifcantly correlated with aortic stiffness parameters. Global peak 3D strain correlated with aortic strain (r = ‒0.46, p = 0.05). global radial pre-atrial contraction strain correlated with ASI (r = ‒0.49, p = 0.04) and AS (r = ‒0.50, p = 0.04). Conclusions: Correlations exist between 3DSTE-derived LA functional parameters and eschocardiographic aortic elastic properties in healthy subjects.

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In Hungary, ECG is a keystone of routine athletic screening. Its signifcance is based on simplicity, quickness and high informative value as well as the fact that appearance of pathological ECG signs can precede the formation of structural heart diseases. During screening of healthy athletes, we studied the incidence of athletic ECG changes and pathological ECG abnormalities. Methods: We performed detailed analysis of 12-lead ECG recordings of asymptomatic elite, non-elite and master athletes and controls. Results: 227 athletes (male: 180, age: 27.2±8.7 years) and 89 controls (male: 57, age: 28.1±6.8 years) were examined. Benign ECG signs: sinus bradycardia, early repolarization and isolated Voltage criteria of left ventricular hypertrophy were common and more often in athletes compared to controls. Potentially pathological ECG signs: ST- (6.6% vs. 1.1%, p < 0.05) and T-wave (15.0% vs. 5.6%, p < 0.05) changes and signs of pathological left ventricular hypertrophy (5.3% vs. 0%, p < 0.05) occurred more frequently in athletes compared to controls. Conclusions: Signs of pathological left ventricular hypertrophy and repolarization abnormalities are more often in athletes. No structural heart disease could be verifed in the background of the disorders. However, athletes having pathological ECG should be kept under tight cardiology control. Exact defnition and widespread knowledge of pathological ECG changes is essential in early recognition of high risk athletes.

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