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Biomedical subjects

P Synek

Publications and source records attributed to P Synek.

At least 19 recordsLinked to original sources
PubMed1991

[The past and the present of cardiac glycosides. III. Pharmacokinetics].

The molecular structure is one of the keypoints that govern both the extent of extracardiac action of cardiac glycosides and their different kinetics. The apolar, fat soluble digitoxin is very well absorbed from the intestine, its onset of action is slow, binds to a high degree to albumin and undergoes enterohepatic recirculation which accounts for a long elimination half time and stability of plasmatic levels. Digitoxin is largely excreted via gastrointestinal tract. The absorption of digoxin is less reliable, onset of action occurs earlier and the binding to albumin is considerably less than that of digitoxin. The drawback, however small, of digoxin lies in a lower stability of plasma levels and prevailing renal excretion. The molecule of strophatin is highly polar, its absorption from the intestine negligible and can be administered only intravenously. The onset of action is prompt, elimination half time short and about half the injected amount is excreted extrarenally.

Cardiac Glycosides↗
PubMed1989

[The past and present of cardiac glycosides. II. Structure, physical and chemical properties. Pharmacodynamics].

An outline is presented on the physical and chemical properties and structure of the most important cardiac glycosides, i.e. digoxin, digitoxin and g-strophanthin. The overall effects of cardiac glycosides on the cardiovascular system not only are a composite of changes in the force of ventricular contraction and heart rate but also result from effects on the autonomic nervous system and on vascular smooth muscle. Furthermore reflex adjustments to the initial hemodynamic changes caused by the drug are also important. In the normal heart and circulation cardiac glycosides increase inotropy and decrease the chronotropy and dromotropy of the heart. They increase the peripheral vascular resistance and venous tone. Cardiac output remains unchanged or decreases slightly owing to increased peripheral vascular resistance and slowed heart rate. In patients with compromised cardiac inotropy the effects of the glycosides on the heart is essentially the same as in normal subjects, however by suppressing the enhanced sympathetic activity the negative chronotropic and dromotropic effects are more prominent. Peripheral vascular resistance is lowered, cardiac output and venous capacity are increased.

Cardiac Glycosides↗
PubMed1983

The lymphocytic reaction to blood donation in the peripheral blood of healthy blood donors.

This study was undertaken to provide more information on the lymphocytic reaction to blood loss in the peripheral blood of healthy blood donors. Number of lymphocytes as well as lymphocytic nucleolar coefficient and number of lymphocytes classified according to the presence of functionally dominant nucleoli in their nuclei were studied 10 minutes, 2 and 24 hours, 2, 4, 6, and 8 weeks after blood donation. In general, the number of these cells increased rapidly after blood donation reaching maximal values of 2-24 hours, then it slowly returned to the original values after 4-8 weeks depending on the functionally dominant nucleolar type in their nuclei. According to the presented results the lymphocytic reaction may also differ in new and repeated blood donors as well as in various seasons of the year. In contrast, no differences were observed between male and female blood donors after the first blood donation in one and the same season of the year. The values of the lymphocytic nucleolar coefficient increased after blood donation and were usually different in new and repeated blood donors. Some differences of the nucleolar coefficient were also found in various seasons of the year before as well as after blood donation.

Blood Donors↗
PubMed1976

Hydrophilized polyethylene catheters.

Complications arising in the application of polyethylene catheters in surgery may be reduced by their surface hydrophilization. This study describes a combination of chemical transformation and coating with a hydrophilic gel. Modified catheters were tolerated well by the patients and in contrast with the original catheters, they did not lead to the formation of thrombi or phlebitis.

Adsorption↗