Compression of the rostral ventrolateral medulla oblongata (RVLM) by an abnormally located artery is regarded as one possible cause of arterial hypertension. There exists a limited set of data suggesting that increased sympathetic activity in patients with RVLM compression may lead to arterial hypertension. Accordingly, we decided to assess the sympathetic activity in patients with severe arterial hy pertension and to investigate any correlation with the presence of RVLM compression. Sixty-four patients with severe arterial hypertension were enrolled in our study. Sympathetic activity was evaluated using 24-hour urinary norepinephrine as measured by high-pressure liquid chromatography with electrochemical detection. The presence of RVLM compression was assessed with magnetic resonance imaging. Neurovascular compression of the RVLM was identified in 40 patients, 27 of whom presented left-sided compression. Twenty-four hour urinary norepinephrine averaged 263.6± 135.9 nmol in patients with neurovascular compression - 255.6±137.3 nmol in those with left-sided compression and 251.6±138.5 nmol in patients without RVLM compression. We did not identify any increase in urinary norepinephrine in patients with severe arterial hypertension and neurovascular compression of the RVLM. Our results do not support the hypothesis that neurovascular compression of RVLM may exhibit a sympathetically mediated increase in blood pressure., M. Solař ... [et al.]., and Obsahuje seznam literatury
Pulse dye densitometry (PDD) enables the evaluation of hemodynamic state as well as liver function. A repeated examination, even after a short pause (or under stress condition), enables to follow safely the dynamics of liver pathology. From presented parameters we have evaluated as reliable the C5-clearance, an expression of equilibrium state in the two compartment liver system. Furthermore, T-index expresses ratio of C5 value to cardiac output, it is a sensitive indicator of the blood pole, i.e. sinusoidal uptake, which is in very good correlation with staging of hepatopathies. The isolated h constant in correlation to T-index is valuable For functional grading. The Japanese automatic analyzer of indocyanine green (ICG) dilution and elimination curves, after incorporation of a two compartment mathematical mode l, becomes more useful for complex hepatological diagnostics. Non-invasive PDD is becoming of uppermost importance to clinic al interest, yielding comparable results as other complicated and invasive examinations and may be, therefore, repeated in short time intervals for different indications with minimal stress of examined patient., J. A. Tichý ... [et al.]., and Obsahuje seznam literatury
Our present focus on the hypoxic immature heart is driven by clinical urgency: cyanotic congenital cardiac malformations remain the single largest cause of mortality from congenital defects and ischemic heart disease is no more the disease of the fifth and older decades but its origin as well as risk factors are present already during early ontogeny. Moreover, the number of adult patients operated for cyanotic congenital heart disease during infancy steadily increases. This group approaches the age of the rising risk of serious cardiovascular diseases, particularly ischemic heart disease. Experimental results have clearly shown that the immature heart is significantly more tolerant to oxygen deficiency than the adult myocardium. However, the mechanisms of this difference have not yet been satisfactorily clarified; they are likely the result of developmental changes in cardiac energy metabolism, including mitochondrial function. The high resistance of the newborn heart cannot be further increased by ischemic preconditioning or adaptation to chronic hypoxia; these protective mechanisms appear only with decreasing tolerance during development. Resistance of the adult myocardium to acute oxygen deprivation may be significantly influenced by perinatal hypoxia. These results suggest that the developmental approach offers new possibilities in the studies of pathogenesis, prevention and therapy of critical cardiovascular diseases., B. Ošťádal ... [et al.]., and Obsahuje seznam literatury