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Biomedical subjects

M Petrova

Publications and source records attributed to M Petrova.

30 records · Page 2Linked to original sources
PubMed1984

[Age-related characteristics of hemoglobin and erythrocytes in 7- to 17-year-old pupils].

A total of 1100 students, aged from 7 to 17 (50 boys and 50 girls from each age group) were covered wigh the study. The following indices were studied: hemoglobin concentration in blood and erythrocyte count. The results reveal that the average values of hemoglobin and erythrocytes in the boys and girls, aged from 7 to 17, are similar and gradually grow with age. Considerably higher values were found in the boys within the age period 14-17. Our results of hemoglobin of the students, aged 7-17, are lower then those of the foreign authors. The same lower values were established (according to literature data) about the adult population in our country, necessitating additional studies and elucidation of that fact.

Adolescent↗
PubMed1979

[Age characteristics and circadian biorhythm of the leukocytes in schoolchildren].

The leucocyte counts were determined three times daily at 6 hours' interval in 480 children from 7 to 14 years of age (30 boys and 30 girls of each age group). The results showed that there exist no age or sex differences in the leucocyte counts in school-children. There was essential increase in the leucocyte counts in boys and girls from morning to evening. These data should be taken into consideration, when results of repeated determinations throughout the the day in clinical practice, sport medicine and research work are to be interpretted.

Adolescent↗
PubMed1976

[Seasonal changes in the makeup of the red blood of healthy children].

Hemoglobin and red blood count are studied in a series of 240 children, aged 7 to 10 years (30 boys and 30 girls each in the various age groups), during the autumn, winter and spring. The research is performed in boarding-school conditions where all the children are subjected to identicad living conditions, The results point to the fact that both hemoglobin and erythrocyte indicators of the boys and girls in the ages covered by the study show a tendency to an autumn-winter increase and spring reduction. The incidence of anemias does not rise during the spring season. No sex-related difference is established in the indicators under study.

Age Factors↗
PubMed1975

Partial degradation of transfer RNAs by different preparations of snake venom exonuclease.

The degradation of yeast tRNASer with eight different exonuclease preparations from four snake venoms was investigated. The reaction products were separated on polyacrylamide gels containing 7 M urea. Patterns of sharp bands were obtained which were more or less similar. Two tRNA fragments were characterized by oligonucleotide analyses, one of which was tRNA degraded by the exonuclease up to the beginning of the T-phi-C-stem. The other one was generated by the additional loss of several nucleotides from the 5'-terminus. The formation of the latter fragment was very probably caused by an endonuclease activity in the exonuclease. The endonuclease contaminant, which was found in all preparations, was further investigated by experiments with modified tRNAs whose 3'-terminus should be resistant to exonuclease (tRNASer-A, tRNASerOX-red). With 3'-AMP as substrate no phosphatase activity was found under the conditions of tRNA degradation. Not only in tRNASer, but also in yeast tRNATyr and tRNAAla as well as in fragments of tRNASer and tRNAPhe, the degradation by exonuclease was inhibited at the beginning of the T-phi-C-stem. The finding of such a retardation site in addition to the general retardation of exonuclease digestion after removal of the C-C-A sequence may indicate that retardation at certain elements of secondary structure is a more general feature of degradations by this enzyme.

Animals↗