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Biomedical subjects

J Zakrzewski

Publications and source records attributed to J Zakrzewski.

At least 19 recordsLinked to original sources
PubMed2001

Driven Rydberg atoms reveal quartic level repulsion.

The dynamics of Rydberg states of a hydrogen atom subjected simultaneously to uniform static electric field and two microwave fields with commensurate frequencies is considered in the range of small field amplitudes. In the certain range of the parameters of the system the classical secular motion of the electronic ellipse reveals chaotic behavior. Quantum mechanically, when the fine structure of the atom is taken into account, the energy level statistics obey predictions appropriate for the symplectic Gaussian random matrix ensemble.

Journal Article↗
PubMed1997

Pharmacokinetics of intragastrically administered digoxin in rabbits with experimental bile duct obstruction.

A change in the functioning of the liver as a result of experimental cholestasis could result in a change in the biotransformation of drugs. The aim of this study was to evaluate the effect of extrahepatic cholestasis on the pharmacokinetics of digoxin. The investigation was performed on male rabbits randomly divided into two groups: sham-operated and animals with bile-duct ligation. Digoxin (0.02 mg kg-1) was administered intragastrically as a single dose. Biomedical and anatomo-pathological tests and pharmacokinetic assays were performed before the operation and on the 6th day after surgery. A significant increase in area under the serum concentration-time curve and in mean residence time, a decrease in total body clearance, a reduction in the volume of distribution and increases in maximum concentration and the time to reach maximum concentration were observed in animals with the bile-duct ligation. These results suggest reduced elimination of digoxin in animals with obstructive cholestasis.

Administration, Oral↗
PubMed1994

Effect of experimental hyperlipidemia on the pharmacokinetics of digoxin.

The study was carried out on 18 male rabbits randomaly ascribed into two groups: control one on standard diet and experimental one on high-fat diet for 2 months. Pharmacokinetic assays were performed in all animals after 2 months of the experiment. Blood was sampled within 24 hours after intragastrical administration of digoxin at a dose 0.02 mg/kg. The two compartment open model for extravascular administration was used for calculations. Marked increase in plasma drug concentration, as well as decrease in total clearance were noted. The study revealed the influence of experimental hyperlipidemia on digoxin pharmacokinetics leading to a slower drug elimination.

Animals↗
PubMed1993

[On the etiology of systemic ozena].

The paper presents an outline of the function of the mucous membrane of the nose and the pharynx as well as the pathological changes in the mucous membrane of patients with ozena. It offers a feasible explanation why systemic ozena connected dysfunction (deficiency of iron, proteins and vitamins) is manifested mainly in the mucous membrane of the nose and pharynx. The author also discusses other possible etiologies of the disease regarding the systemic theory of ozena. An attempt has been undertaken to find out why ozena is almost absent, in the well-developed regions and why it commonly occurs in underdeveloped countries where the everyday diet is poor in iron, proteins and vitamins.

Developing Countries↗