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Biomedical subjects

S G Vorsanova

Publications and source records attributed to S G Vorsanova.

At least 55 records · Page 3Linked to original sources
PubMed1981

[DNA replication in cultured amniotic fluid cells].

A correlation was studied between replication and characteristics of the synthesis of DNA cells in amniotic fluid under in-vitro cultivation. Radioautography of DNA molecules was used to show that in the primary cultures of epithelium- and fibroblast-like cells of amniotic fluid, DNA replication proceeds at a lower rate as compared to that in diploid cells of the fetus skin. The DNA replication rate in the passaged cells of amniotic fluid does not differ from that seen in controls. The cultivated fibroblasts obtained from amniotic fluid of the fetus with anencephalia manifested a significant increase in the DNA replication rate. The size and number of the replication units do not differ as shown by the examination of all cell types. The data obtained suggest a correlation between the diminution of the DNA molecule replication rate and the decreased growth tendency under in-vitro cultivation of human amniotic fluid cells. The reasons are discussed which are likely to provoke the decreased rate of the replication fork movement in the primary cell cultures of human amniotic fluid.

Amniotic Fluid↗
PubMed1979

[Method of culturing amniotic fluid cells].

The influence of pregnancy term and the concentration of cell suspension, introduced into culture, on the growth of amniotic fluid cells have been studied on 29 specimens. Optimum term of amniotic fluid cells sampling for the best growth was 17 weeks of pregnancy. It is recommended to take into account the concentration of cell suspension in the amniotic fluid before introducing the cells into the culture depending on pregnancy terms.

Amniotic Fluid↗
PubMed1978

Human embryonic prealbumin as a marker for tumours and fibroblasts.

Embryonic prealbumin (E.P.A.) was demonstrated by agar immunodiffusion in 122 out of 505 homogenates of various tumours and in 7 out of 20 serum samples from patients with connective-tissue tumours. Analogous antigen was found in human embryonic and adult cultured fibroblasts. This newly identified antigen is probably actively secreted by fibroblasts into the circulation of patients with tumours.

Adult↗
PubMed1978

[Stationary populations of genetically different homonuclear strains of human cells].

Morphological and cytophysiological indices of cells and cellular populations were studied during this stationary phase. In difference from normal cell strains which displayed a definite complex of ontogenetic changes, cells of the strains with chromosomal and gene mutations showed individual differences apparently caused by disturbed differentiation and by expression of features characteristic of malignant cells.

Cell Line↗
PubMed1977

[Dynamics of changes in anomalous human cells during prolonged cultivation in the stationary phase. Trisomy 7 cells].

Ontogenetic changes of normal diploid cells and cells with chromosomal aberration (strain LHC-162; 47, XY, +7) were studied in prolonged cultivation in stationary phase. Cultivated cells were human found to possess their specific type of ontogenetic changes for each culture; the dynamics of these changes depended on the density of cellular population. Two morphologically different cellular subpopulations differing by the degree of cell nucleus heterochromatinization (normal strains) and three different cellular subpopulations in the aberrant strain (47, XY, +7) were discovered in studying the cell nucleus.

Cells, Cultured↗
PubMed1977

[Dynamics of changes in a population of human fibroblasts after long-term cultivation in the stationary phase].

Defined and repeated alterations in human fibroblasts were discovered under continuous cultivation in the stationary phase. In the normal diploid fibroblast population, two cell subpopulations were distinguished by the heterochromatinization degree of the nucleus. While in the stationary phase, the number of cells with a parahaploid number of large chromocenters, regularly arranged in the nucleus, is seen increasing. It is supposed that the death of the normal diploid fibroblast culture occurs primarily at the expence of cells with heterochromatinized nuclei. Examination of strains with trisomy (47, XY, +7) and of a strain taken from a patient with pigmented xeroderma has shown that the process of nucleus heterochromatinization and its dynamics are substrains. A possibility is discussed of gene or chromosome mutation influences on the well-regulated nuclear heterochromatinization process and on the cell population structure alteration.

Cells, Cultured↗
PubMed1975

[Dynamics of changes in human cells with chromosome and genetic mutations in prolonged cultivation in a stationary phase. Report 1. Study of cells in xeroderma pigmentosum].

Ontogenetic changes of normal diploid cells and cells with genetic mutations (LHC-484 from a patient with xeroderma pigmentosum) have been studied under prolonged cultivation in a stationary phase. While investigating the dynamics of complex changes in certain cell properties and cell populations it was found that the cultivated human cells possess a particular pattern of ontogenetic changes for every culture and the dynamics of these changes depends upon the density of the cell population. Two cell subpopulations different in the degree of nucleus heterochromotinization have been discovered.

Cells, Cultured↗
PubMed1975

[Characteristics of human embryonal hepatocytes cultivated in vitro].

A simple and reproducible method for cultivation of human embryo (7--12-week) hepatocytes in a monolayer is presented. The culture showed the capacity for limited growth, displayed a viability for 4 to 6 weeks without being subcultured, and retained some specific characteristics: synthesis of serum protein (albumin and alpha-fetoprotein), a significant amount of glycogen, a high activity of monaminooxidase, and a characteristics response to a high concentration of glucocorticoids. These properties are useful as markers for genetic experiments or for selection.

Cells, Cultured↗
PubMedDate not supplied

Analysis of alphoid DNA variation and kinetochore size in human chromosome 21: evidence against pathological significance of alphoid satellite DNA diminutions.

Centromeric alpha satellite DNA sequences are linked to the kinetochore CENP-B proteins and therefore may be involved in the centromeric function. The high heterogeneity of size of the alphoid blocks raises the question of whether small amount of alphoid DNA or "deletion" of this block may have a pathological significance in the human centromere. In the present study, we analysed the correlation between size variations of alphoid DNA and kinetochore sizes in human chromosome 21 by molecular cytogenetic and immunochemical techniques. FISH analyses of alpha satellite DNA sizes in chromosome 21 homologues correlated well with the variation of their physical size as determined by pulsed field gel electrophoresis (PFGE). By contrast, the immunostaining study of the same homologous chromosomes with antikinetochore antibodies suggested that there is no positive correlation between the alpha satellite DNA block and kinetochore sizes. FISH analysis of chromosome 21-specific alphoid DNA and immunostaining of kinetochore extended interphase chromatin fibers indicate that centromeric kinetochore-specific proteins bind to restricted areas of centromeric DNA arrays. Thus, probably, restricted regions of centromeric DNA play an important role in kinetochore formation, centromeric function and abnormal chromosome segregation leading to non-disjunction.

Cell Line↗
PubMedDate not supplied

16q subtelomeric deletion in proband with congenital malformations and mental retardation.

We present a female child with mild mental retardation and congenital malformations. After fluorescence in situ hybridization (FISH) we found only abnormal karyotype in all cells. We used rapid FISH and original DNA probes--PAC62.10.1 and PAC20.19.N, specific for segments of chromosome 16q24. Karyotype of proband 46,XX.ish del(16)(q24.2:) (PAC20.19.N,PAC62.10.1-). Parent karyotypes are normal. This case may suggest the presence of clinical picture 16q- with defined clinical polymorphism at small telomeric loss, and also its necessary of the use of molecular-cytogenetic techniques in genetic departments.

Adolescent↗
PubMedDate not supplied

Two new cases of the Christchurch (Ch1) chromosome 21: evidence for clinical consequences of de novo deletion 21P-.

We performed an investigation of two unrelated cases with extremal variants of chromosome 21 without visible materials of the short arms (Christchurch or Ch1 chromosome). In the first case chromosome 21p- was initially detected during routine cytogenetic amniocentesis. Chromosomal variant was inherited from phenotypically normal father to phenotypically normal fetus (phenotypically normal boy after the birth). The second case of chromosome 21p- was detected in 7 years old boy, referred to cytogenetic analysis due to mental retardation and mild congenital malformation, including prenatal hypoplasia, microcephaly, low-set dysplastic ears, short nose, micrognatia, short neck. Molecular characterization of 21p-variant chromosomes was performed by the use of FISH with DNA probes specific to the short arm and centromeric region of chromosome 21 (telomeric, beta-satellite, ribosomal, classical satellite and alphoid DNA probes). Chromosomes 21p-hybridized positively only with telomeric DNA at both chromosomal ends and alphoid DNA probes at centromeric region of the first patient. In second case (de novo deletion of 21p), the Ch1 was associated with clinical phenotype and loss of telomeric and subtelomeric DNA in the p-arm of chromosome 21. Therefore, the complete absent of the short arm of chromosome 21 may be considered as abnormal. We propose that de novo deletion 21p- could have negative consequences due to absence of large portion of chromosomal DNA from the p-arm (telomeric, satellite or ribosomal DNAs) and following imbalance in organization and functioning of genome.

Amniocentesis↗
PubMedDate not supplied

[A case of deletion of the short arm of the chromosome 21 (21p-) (christchurch chromosome) discovered prenatally:clinical and cytogenetic data].

Results of cytogenetic research of placental villi and amniotic fluid cells culture of the 22-weeks-old fetus with multiple congenital malformations (MCM) are presented. The absence of the short arm in one of the homologue of the chromosome 21 was revealed. Cytogenetic analysis of the fetus father's blood lymphocytes determined the similar chromosome. Further research of the father's karyotype made by FISH-method using specific DNA samples had discovered the absence of subtelomeric parts in the short arm of the chromosome 21 that might be considered as a deletion. It was suggested that the effect of position and interaction of genes could play a key role in appearing of MCM in the fetus in the case when the 21p-chromosome was transferred to it from the healthy parents.

Abnormalities, Multiple↗
PubMedDate not supplied

[X chromosome inactivation pattern in elderly women over 70 years of age].

In the present study we have analyzed X chromosome inactivation patterns in 40 women aged from 74 to 85 years (mean age 78 years). The control group was 36 women (mean age 30 years). The most common AR-assay was used to determine X-inactivation patterns (the study of methylation patterns of HpaII site in human androgen receptor gene (HUMARA) by quantative PCR). The age dependence of X-inactivation was not observed. We have detected skewed X-inactivation in three women among 40 (7.5%) elderly women comparing to two women among 36 (5.5%) women from control group. The difference was not found to be statistically significant. We made a suggestion that higher incidence of skewed X-inactivation in elderly women revealed by previous studies could occur due to some experimental ambiguities as heterogeneity of the group studied; inclusion of women having relatives with genetic abnormalities associated with skewed X-inactivation patterns; the difference of X chromosome inactivation skewing determination. We conclude that present study does not show X chromosome inactivation to be age dependent.

Adolescent↗
PubMedDate not supplied

[Molecular cytogenetic study of Robertsonian translocation 13;14 and Down syndrome in a 3-year-old infant].

We describe here a rare case of Robertsonian translocation 13;14 of maternal origin combined with regular trisomy 21 (46,XX,der(13;14)(q10;q10)mat,+21) with Down syndrome phenotype. Molecular cytogenetic studies allowed us to determine the maternal origin of additional chromosome 21 and the non-disjunction of chromosome 21 to occur in meiosis I. On the basis of data obtained we discuss the possible involvement of structural alterations of chromosomes 13 and 14 in the chromosome 21 non-disjunction.

Child, Preschool↗
PubMedDate not supplied

Non-disjunction of chromosome 21, alphoid DNA variation, and sociogenetic features of Down syndrome.

The analysis of non-disjunction of chromosome 21 and alphoid DNA variation by using cytogenetic and molecular cytogenetic techniques (quantitative fluorescence in situ hybridization) in 74 nuclear families was performed. The establishment of possible correlation between alphoid DNA variation, parental age, environmental effects, and non-disjunction of chromosome 21 was made. The efficiency of techniques applied was found to be 92% (68 from 74 cases). Maternal non-disjunction wasfound in 58 cases (86%) and paternal non-disjunction - in 7 cases (10%). Post-zygotic mitotic non-disjunction was determined in 2 cases (3%) and one case was associated with Robertsonian translocation 46,XX,der(21;21)(q10;q10), +21. Maternal meiosis I errors were found in 43 cases (64%) and maternal meiosis II errors--in 15 cases (22%). Paternal meiosis I errors occurred in 2 cases (3%) and paternal meiosis I errors--in 5 cases (7%). The lack of the correlation between alphoid DNA variation and non-disjunction of chromosome 21 was established. Sociogenetic analysis revealed the association of intensive drug therapy of infectious diseases during the periconceptual period and maternal meiotic non-disjunction of chromosome 21. The correlation between non-disjunction of chromosome 21 and increased parental age as well as exposure to irradiation, alcohol, tobacco, mutagenic substances was not found. The possible relevance of data obtained to the subsequent studies of chromosome 21 non-disjunction is discussed.

Chromosomes, Human, Pair 21↗
PubMedDate not supplied

Pericentric inversion inv(7)(p11q21.1): report on two cases and genotype-phenotype correlations.

We report on two unrelated cases of pericentric inversion 46,XY,inv(7)(p11q21.1) associated with distinct pattern of malformation including mental retardation, development delay, ectrodactyly, facial dismorphism, high arched palate. Additionally, one case was found to be characterized by mesodermal dysplasia. Cytogenetic analysis of the families indicated that one case was a paternally inherited inversion whereas another case was a maternally inherited one. Molecular cytogenetic studies have shown paternal inversion to have a breakpoint within centromeric heterochromatin being the cause of alphoid DNA loss. Maternal inversion was also associated with a breakpoint within centromeric heterochromatin as well as inverted euchromatic chromosome region flanked by two disrupted alphoid DNA blocks. Basing on molecular cytogenetic data we hypothesize the differences of clinical manifestations to be produced by a position effect due to localization of breakpoints within variable centromeric heterochromatin and, alternatively, due to differences in the location breakpoints, disrupteding different genes within region 7q21-q22. Our results reconfirm previous linkage analyses suggested 7q21-q22 as a locus of ectrodactily and propose inv (7)(p11q21.1) as a cause of recognizable pattern of malformations or a new chromosomal syndrome.

Adolescent↗