[An analysis of human marker chromosomes originating from chromosome 21 by using in situ hybridization].

Four cases of patients with additional marker chromosomes are described. The clinical, cytogenetic and molecular cytogenetic methods have been used for investigation. The identification of marker chromosomes was made by using in situ hybridization and the collection of chromosome-specific DNA probes.

[A review of the data from cytogenetic and molecular cytogenetic research on human supernumerary minichromosomes].

The literature about the nature of marker chromosomes (mini-chromosomes of unknown origin) in patients with mental retardation, hereditary defects of development as well as in healthy individuals is reviewed. The advantage of the use of modern molecular methods of research for the analysis of nature and origin of additional mini-chromosomes is demonstrated.

[Limited genetic monitoring in Kiev in relation to the accident at the Chernobyl Atomic Electric Power Station].

Frequency of innate developmental defects, perinatal death rate, spontaneous and induced abortions were statistically studied on the basis of primary medical information from archives of two largest maternity hospitals of Kiev for the period between 1969 and 1989. Significant variations in the chosen characters in different years were found, unidirectional changes in time being absent. No increase in the number of innate defects and frequency of spontaneous abortions after 1986 was found.

[The restriction fragment length polymorphism of the DNA loci of human chromosome 7].

The results of comparative RFLP analysis in some DNA loci of chromosome 7 in the populations of different Ukrainian regions are presented. Significant differences in RFLP-genotype distributions among regional populations are found. The role of different genetical processes which take place in the populations of different regions of the Ukraine is under discussion.

[Aneuploidy in man (facts and hypotheses)].

Mechanisms of the human aneuploidy formation are discussed proceeding from the review of the published data obtained by Soviet and foreign authors. It is supposed that hereditary determination of this process plays a main role as compared with new genomic mutations resulting from the induction by ecological factors. Microstructural rearrangements and nonhomologous recombination in nondisjunction of chromosomes during cell division are considered parallel with mosaicism as one of possible reasons of genetic predisposition.

[The importance of medical genetics study for the early diagnosis of mucoviscidosis].

The method of specific DNA amplification was used to study the polymorphism of the length of restriction fragment in the system CS-7 and KM-19 locus D7S23 in the family C. It is shown that cohesion of alleles A2 and B2 with mutation of mucoviscidosis and presence of a mucoviscidosis gene occurred in a healthy sibling. The family C, is prospective for prenatal diagnosis of mucoviscidosis by the method of specific DNA amplification in the system KM-19 restrictase Pst-1 and CS-7-Hinf-6-1.

[Unusual cases of the inheritance of Down's syndrome].

Three unusual cases of Down's syndrome inheritance are presented which permit supposing that microstructural chromosome aberrations in parents may induce not only a structural imbalance of chromosomal material in progeny, but also a numerical imbalance.

[C-polymorphism of chromosomes 1, 9, 16 and Y in newborn infants of various gestational ages].

Comparative evaluation of absolute C-segment lengths of chromosomes 1, 9, 16 and Y in new-born children of different gestational age has revealed no significant differences in their value between individuals with unfinished intrauterine development and those born in time.

[Virus-induced mutagenesis and various aspects of genetic engineering in humans].

The author's own data and those available in literature concerning the mutagenic action of viruses and recombinant DNA molecules on mammalian cells permit drawing attention to the possible hazards of genetic engineering which might affect the genome of mammals, including a man.

[Role of the oncogene in the mutagenic activity of bovine adenovirus type 3].

The mutagenic and carcinogenic effect of two EcoRI-fragments of bovine adenovirus type 3 (BAV-3) DNA inserted into pBR325 has been studied. The C fragment (located between 3,6 and 19,7 map units) contains the viral oncogene, the C fragment (between 44,3 and 63,7 map units) displays no transforming activity. It has been established that oncogene BAV-3 statistically true increases the yield of mutants resistant to 6-mercaptopurine (6MP) in Chinese hamster cells.

[TPA enhancement of the mutagenic and transforming action of bovine adenovirus type 3 on cultured mouse cells].

The cultured 10TI/2C3H mouse cells were infected with bovine adenovirus 3(BAV-3) and treated by TPA. This combined treatment induced ouabain-resistant mutants 19 to 26 times more often than action of only BAV-3. BAV-3- and TPA-treated cells were implanted to syngenic mice.

[Induction of mutations in mammalian cells by the action of live vaccinal strains of poliomyelitis virus].

The attenuated strains' poliomyelitis virus induces mutagenesis in human and Chinese hamster cultured cells. The mutagenic action of the poliovirus is detected at chromosome and gene levels and directly depends on the multiplicity of cell infection. Possibilities for developing nonmutagenic antivirus vaccines are discussed.

[Malignant transformation of mouse cultured cells using bovine adenovirus type 3 and modification of this process by MNNG].

It is shown that tumour transformation of cultured mouse cells 10T1/2C3H depends on the time after the infection with virus BAV-3. The maximal number of tumours was observed 3 weeks after infection, then the frequency of tumours was reduced. MNNG modified virus-induced tumour cell transformation differently depending on the time between cell infection and treatment with the chemical agent.

[Origin of marker chromosomes in a continuous human cell line].

The karyotypes of L-41 cells (subline J-96) and those of cell strains obtained from RH strain in the course of multiple passages and mycoplasm infection were studied using the GTG technique. All the RH strains contained chromosomes with bands similar to Hela and other cell strains well-adapted to permanent growth in the tissue culture. The origin of marker chromosomes was studied.

[Characteristics of structural chromosome aberrations induced by type 1 adenovirus in human and Chinese hamster cells in vitro].

Adenovirus multiplies in both studied cultures. In the Chinese hamster cells infection is of slowed down, cyclic character. In this case a short subcultivation of cells infected with the virus and the study of the damage distribution in groups of chromosomes are possible.