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Biomedical subjects

D M Spitkovskiĭ

Publications and source records attributed to D M Spitkovskiĭ.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

[Difference in the protein composition of human leukocytes normally and in aneuploidy].

Using polyacrylamide gel electrophoresis an additional protein band was found in the leukocyte preparation obtained from patients with Down syndrome as compared with the cells of healthy donors. Impairments in gene expression, due to alteration in the ratio between content of histone genes and of nuclear DNA, were apparently responsible for qualitative alterations in the cell protein composition under conditions of aneuploidy as well as for the quantitative alterations, deviating from the principle of "gene dosage".

Adolescent↗
PubMedDate not supplied

[Effect of the structure of the cell nucleus chromatin on absorption of low-energy beta-radiation emitted from an incorporated source].

To study the energy absorption in cell nuclei the analysis was made of the level of registration of beta-particles, emitted by the incorporated tritium, using a liquid scintillation counter. It was shown that the treatment, modifying the chromatin structure, changed the number of beta-particles registered. The pattern of the spectral changes indicated that the effect observed was not the result of the quenching processes. The effect was absent when the source of a higher energy (14C) was used. The authors submit the conceptions concerning the mechanisms of the phenomenon observed which are confirmed by the theoretical studies.

Animals↗
PubMedDate not supplied

[Radiobiological constant in irradiation stimulation of cells for the subsequent adaptive response].

It was shown that the maximum adaptive response to damaging irradiation dose would be achieved after preirradiation when for latter the product of the dose by the dose rate (i. e. D*D/t) is equal to constant value. The radiobiological constant is the reciprocal of this product, i. e. k = t/D2 = tau/delta 2, where delta is an average dose received by the cell for single pass of ionizing particle through the cell sensitive volume with a given density. The triggering signal for the adaptive response program initiated by preirradiation is a certain reaction, which is completed for a time interval tau between two consistent acts of absorption. The radiobiological constant is determined by this time interval tau and by a dose delta. In human lymphocytes in the case of signal initiated by X-rays the value of tau is within the range of 1--5 s.

Adaptation, Biological↗