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Biomedical subjects

G I Laziuk

Publications and source records attributed to G I Laziuk.

At least 19 recordsLinked to original sources

[Incidence of developmental defects in human embryos in the territory of Byelarus after the accident at the Chernobyl nuclear power station].

The incidence of developmental abnormalities (DA) among 5 to 12-week human embryos collected in Minsk during abortions before the Chernobyl' accident was compared to that in Minsk, Mogilev, and southeastern districts of Gomel' and Mogilev regions before and after the accident. The incidence of DA among human embryos from the most radionuclide-contaminated rural regions of Byelarus exceeds that of the control group and of the urban population after the Chernobyl' accident by a factor of 1.5-2. The mutagenic effect of irradiation is the most probable cause of the increased DA frequency. These data suggest that recording of DA in embryos obtained by medical abortions is a new promising approach to the monitoring of genetic consequences of irradiation in human populations.

Abnormalities, Radiation-Induced↗

[Pathomorphologic verification of the prenatal diagnosis of developmental defects in trimester II fetuses].

153 foetuses were studied obtained after the artificial abortion for genetical indications. The scheme of the material investigation is given. Isolated, systemic and multiple defects were found in 39.0, 12.1 and 48.9%, respectively, and the contribution of the syndrome forms in the multiple developmental disturbances was 60.9%. The interruption of the pregnancy in 2% of cases was assessed as unfounded: as a consequence of hyperdiagnosis and in cases of treatable defects. The frequency of the discrepancy between prenatal and pathology diagnoses was 31.8% including hyperdiagnosis of the defect (1.3%), nosological disagreement (13.3%), the lack of diagnosis of the additional defects detectable during II trimester by present ultrasound methods (17.2%). The efficacy of the work of the prenatal diagnostic centre is, according to the authors, the number of justified interruptions of pregnancy (98% in this study).

Abnormalities, Multiple↗

[The contribution of genetic factors to perinatal pathology and infant mortality].

The authors consider the contribution made by genetic factors to perinatal and infant mortality on the basis of many-year studies performed in the Minsk Teratology Center and analysis of the data available in the literature. In 1972-1984 there was an increase in the incidence of congenital malformations among deceased children. Genetic factors predispose to at least 7-8% postimplantation embryonal and fetal elimination. Perinatal and neonatal mortality is caused by congenital malformations in 19.1 and 37% of cases, respectively. A genetic analysis has indicated that 23.2% of them are induced by genic, chromosomal, and genomic mutations and 51.0% are caused multifactorially. The prevention of genetically determined perinatal mortality is most effective in implementing the screening programs for detection of heterozygous carriage along with subsequent prospective examination and prenatal diagnosis.

Anemia, Hemolytic, Congenital↗

[The prospective directions of research in teratology].

Unsolved problems of modern teratology are discussed. The monitoring of the congenital malformation incidence is one of the variants of evaluation and control of the mutation pressing in the population. The investigation of human foetuses obtained in artificial abortions may be very helpful in this respect. The investigation of the phenotypical manifestations of malformations in the human prenatal ontogenesis and the use of the results for the creation of notion on the malformation morphogenesis seems to be perspective. The definition of the tissue dysplasias and their classification (dystopia, dyssynchronia, hamartomas) are given. The issue of the tissue malformations during the postnatal development is not similar. They may be asymptomatic, or to disturb the function of the organ concerned, or to predispose to chronic inflammation or neoplastic growth.

Congenital Abnormalities↗

[Aplasia of the radius and mechanisms of deformity of the arm].

A complex study (roentgenographic, arteriographic, anatomic, anthrometric and microscopic) of 16 upper extremities of stillborn and deceased infants with aplasia and hypoplasia of the radius has been carried out. The etiologic factors of the defect were chromosomal and monogenic mutations and multifactor causes. It has been demonstrated that: 1) in cases of reduction of the radius the structure of the arteries, nerves and muscles in destroyed mostly in the radial border of the forearm and hand; 2) the severity of the changes in the anatomic depends on the type of the defect; 3) the pathomorphologic manifestations of the forms of the defect characterized by the same severity are mostly similar. The mechanisms of deformations of the hand in aplasia (hypoplasia of the radius) are discussed.

Arteriovenous Malformations↗

[The main etiologic groups of congenital developmental defects and the problems of diagnosis and thanatogenesis].

The proportion of congenital developmental defects (CDD) in children decreased in perinatal or early age is increasing. According to national and foreign data this figure is in the range of 21-41%. The etiologic structure of CDD for the last 5 years (1980-1984) basing on the data from the Minsk Teratologic Center has not practically changed. As in the previous 5 years, 50.8% of CDD belong to multifactorial ones, 14.3% are due to single gene mutations (8.4% of them are inherited according to dominant type and 5.9%--according to recessive type). Chromosome and gene mutations caused 7.9% of CDD. About 2% of CDD are induced by the effect of environmental factors on the embryo (less frequently on the fetus). Etiology of 25.1% of CDD is not clear.

Congenital Abnormalities↗

[Pathological anatomy of monogenic syndromes of multiple congenital developmental defects].

Morphological study, with no selection, is performed of 1106 stillborns and children died before one year of age with congenital malformations (CM), 536 (46.9 +/- 1.5%) among them having multiple CM. Syndrome diagnosis is made in 44.1 +/- 2.1% cases: in 26.9 +/- 1.9% among them these were syndromes of chromosomal and in 17.9 +/- 1.7% syndromes of non-chromosomal etiology. Monogenic hereditary forms among non-chromosomal syndromes were in 42.1 +/- 4.8%. Comparative analysis of frequency and types of CM of various systems in monogenic and chromosomal syndromes and unclassified CM showed that the monogenic syndromes by their phenotypic manifestations are close to the chromosomal syndromes. The uniformity of alterations of certain morphological structures in these syndromes appear to be the consequence of common ways of realisation of both mutant genes in monogenic syndromes and their imbalance in chromosomal syndromes.

Abnormalities, Multiple↗

[Importance of the diagnosis of congenital developmental defects in the practice of pathologists].

Composite studies of 1286 stillborns and infants with congenital malformations (CMF) dying at the age under 1 year conducted in the Teratological Center of Minsk showed that in specialized therapeutic institutions the causes of CMF could be established in at least 70% of the cases. In the infant autopsy materials, 12% of CMF were associated with chromosome pathology, 17% with single gene mutations, over 40% had multifactor determinants and 2.7% were due to teratogenic effects.

Abnormalities, Drug-Induced↗

[Bowen-Conrad syndrome].

An observation of multiple malformation defects (Bowen-Conradi syndrome) is presented. The main morphological manifestations included: marked prenatal hypoplasia, facial dysplasias, microgeny, clinodactylia of little fingers, hypospadia, cryptorchism, changes in the central nervous system. All the patients with this syndrome die within the first year of life. The disease is inherited by the autosome-recessive type.

Abnormalities, Multiple↗

[Pathologic anatomy of the Wolf-Hirschhorn syndrome (partial monosomy 4p--)].

An analysis of phenotypic manifestations of Wolf-Hirschhorn syndrome from the 60 cases most thoroughly described in the literature and 3 own observations was done. Most characteristic malformations of this syndrome were shown to include coracoid nose and hypertelorism, coloboma of the eyes, hypospadia, aplasia, hypoplasia and polycystosis of the kidneys, dystopia and dysplasia of the cerebellar gyri, shortening of H2 field of the Ammon's horn with imparied orientation of its neurons, sacral sinus, and retarded bone maturation.

Abnormalities, Multiple↗

[Multiple developmental defects. The Neu-Povýsilová syndrome].

An observation of Neu-Povýsilová lethal syndrome of multiple congenital malformations and data on 6 cases of this syndrome described in the literature are presented. The main morphological manifestations of the syndrome include markedly manifest prenatal hypoplasia, defects of the CNS and the extremities. The presumed type of heredity is autosomal-recessive.

Abnormalities, Multiple↗

[Genetic syndromes of multiple congenital developmental defects].

Analysis of developmental defects in 615 children who had died in hospitals in Minsk during the 5-year period (1971--1975)showed that in 274 children defects were multiple. This number includes 78 children with chromosomal diseases and 37 children with genic syndromes of multiple congenital malformations (MCM). The total number of genic syndromes of MCM is extremely great, at present over 250 of them are known. Analysis of the available literature and the authors' own findings made it possible to develop criteria of morphological diagnosis of genic syndromes of MCM with due account for different diagnostic significance of various defects. Genealogical studies and estimation of population incidence of individual malformations are also necessary for diagnosis of genic syndromes of MCM and identification of new syndromes. An etiological classification of MCM and that of genic syndromes of MCM are considered on the basis of isolation of similar clinical forms, which are of important for differential diagnosis.

Abnormalities, Multiple↗