Biomedical subjects

A A Krivonos

Publications and source records attributed to A A Krivonos.

3 recordsLinked to original sources

PubMed1993

[ATP-dependent structural changes in chromatin].

Incubation (1 hour, 37 degrees C) of nuclei and chromatin from guinea pig spleen (but not from thymus or the liver) resulted in a proteolysis of H1 and H2A histones and accumulation of specific hydrolytic products. Sodium dodecyl sulfate gel electrophoresis revealed a decline in H1 and H2A and the appearance of new protein bands under histone H10 and between H2A and H4. ATP (10 mM) (but not cAMP or PPi) added to the incubation mixture prevented the H1 and H2A digestion and accumulation of the aforementioned products. The ATP, which protects the histones in the nucleus and chromatin from proteinases, promoted the cleavage of cytosolic low molecular weight proteins. The mechanisms of ATP-dependent chromatin structural rearrangements determining the resistance of nuclear proteins to proteolysis are discussed.

Adenosine Triphosphate↗

PubMed1991

[A rapid method of preparing the (H3-H4-H2A-H2b)(2) histone octamer in large quantities].

A simple and fast method for isolation of large amounts of the histone octamer (H2A-H2B-H3-H4)2 is proposed. This method is based on chromatin adsorption by hydroxyapatite with subsequent extraction of the histone octamer with 50 mM sodium-phosphate buffer containing 4 M NaCl pH 8.0. It was shown that the properties of the histone octamer isolated by this extractive procedure are identical with those of the histone octamer obtained by elution on a Sephadex G-100 column. The histone tetramer (H3-H4)2 and dimer (H2A-H2B) were obtained after gel filtration on Sephadex G-100 in 50 mM sodium-acetate (pH 5.6).

Animals↗

PubMedDate not supplied

[Diagnosis of fatigue in flight personnel based on cardiodynamic data].

By Doppler cardiography systolic acid diastolic time time intervals and cardiac contractility were measured in 22 pilots during interflight periods. Certain cardiodynamic parameters showed significant differences in the pilots as compared to 24 nonpilots. It is indicated that these parameters should be regularly monitored between flights in order to prevent fatigue of the flight personnel, to detect early developments of cardiac insufficiency, and maintain pilot longevity.

Aerospace Medicine↗