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Biomedical subjects

A F Zakharov

Publications and source records attributed to A F Zakharov.

6 recordsLinked to original sources
PubMed1979

[Sister chromatid exchanges in bromine incorporation into DNA cytosine nucleotides. III. 5-bromodeoxycytidine as a DNA thymine precursor. The characteristics of the exchanges].

Cell movement through the mitotic cycle and sister chromatid exchanges (SCE) were studied in human blood lymphocytes cultured in the presence of 5-bromodeoxycytidine (BrdC, 0.05 mM) plus thymidine (dT 0.4, 0.8, and 1.0 mM). In controls, lymphocytes were cultivated in the presence of 5-bromodeoxyuridine (BrdU, 0.05 mM) and deoxycytidine (0.1 mM), or BrdC alone. All nucleosides were added to the cultures 28 hours prior to fixation and were maintained in the medium for 16 hours. As determined from percentage of metaphases of 1st to 3rd divisions, BrdC did not release from thymidine block. This fact leads us to conclude that BrdC in contrast to deoxycytidine does not serve as a cytosine precursor. No significant differences in the frequency of SCE and their distribution among chromosomes were found between cultures treated with BrdC and with BrdU.

Bromine↗
PubMed1975

Nature of the longitudinal differential staining of metaphase chromosomes.

Patterns of differential longitudinal spiralization of chromosomes induced by the addition of 5-bromodexyuridine (200 mug/ml) for 5-7 h before fixation of the cells were compared with the differential staining of normally spiralized chromosomes with giemsa stain in chromosomes of lymphocytes in human blood cultures. The patterns of differentiation of both types were found to coincide for all chromosomes of the normal karyotype; areas of incomplete spiralization corresponded to areas staining intensively with giemsa stain. The significance of these results in connection with the mechanisms of differential staining of metaphasechromosomes is discussed.

Bromodeoxyuridine↗
PubMed1975

[Linear differentiation of the human Y-chromosome].

During the final 5.5th to 7th hr of the cycle in presence of BUdR, the human Y-chromosome was delayed in its mitotic condensation in the distal part of the long arm. This part was not homogeneous by the degree of the delay. The unevenly condensed Y-chromosome stained with quinacrine was brightly fluorescent in its stretched part. The fluorescence seemed to correlate with the degree of stretching. The distal part of the long arm was heavily labeled with H3-deoxycytidine thus demonstrating presence of late replicating DNA with GC-base pairs.

Adult↗
PubMed1975

[Dependence of heterochromatin differential staining on the time of its reduplication and the degree of condensation].

A comparison of the chromosomes banding pattern after G-and C-staining with the time of DNA reduplication and the degree of chromosome condensation, was carried out using Chinese hamster metaphase chromosomes. Chromosome condensation was studied under 5-bromodeoxyuridine and 5-bromodeoxycytidine treatment. All the chromosomal segments stained with C-technique are also stainable with G-technique, while only some G-positive segments are capable to be C-bands. C-bands are heterochromatic segments characterized by extremely late replication and great delay in condensation under the analog action, while G-bands are segments with earlier labelling and irregular decondensation. The data obtained suggest a close correlation between the capability of chromosomal region of G- and C- staining and the degree of its heterochromatinization.

Aneuploidy↗