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Biomedical subjects

M Gaál

Publications and source records attributed to M Gaál.

At least 37 records · Page 2Linked to original sources
PubMed1982

[Cytogenetic background of male infertility].

An account is given of cytogenetic causes of male infertility, on the basis of literature and the authors' own observations. Impairment of sexual differentiation was found to be one of the causes of infertility. The functional mechanisms of the Y-chromosome and H-Y antigen are discussed, in that context. The structural changes in the Y-chromosome were found to provide a possibility of gene labelling and to offer an explanation of the genetic processes underlying various types of infertility. An analysis was made also of male fertility accompanied by aberrations of the other chromosomes. The point is made that in the pathogenesis of male infertility decisive importance should be attributed to chromosomal aberrations, above all to deviations of sexual chromosomes. Thorough cytogenetic examination is absolutely essential unless another causative factor has been clearly established.

Chromosome Aberrations↗
PubMed1982

Ultrastructure of the fibrous tissue of the streak gonads.

The ultrastructure of the streak gonad was studied in 12 cases. Under the electron microscope the streak gonad displays fibroblasts, collagen fibres with the usual periodicity of 64-65 nm, and capillaries. The ultrastructure of the fibrous tissue of the streaks was similar in each patient regardless of the associated chromosome complements, and indistinguishable from that of polycystic and normal ovaries. The finding might suggest that the fibrosis in the streak gonad might be the result and not the cause of the early degeneration of the gonad.

Adolescent↗
PubMed1981

Cytogenetic investigation of six patients with X isochromosomes, i(Xq), and of two subjects with isodicentric X chromosomes, idic (Xq).

The detailed cytogenetic study of six Xq isochromosomes, i(Xq), and two isodicentric Xq chromosomes revealed that both their banding and their inactivation patterns differ as a result of differences in their mechanisms of origin. The arms of Xq isochromosomes may be expected to be mirror images in respect of their morphologic pattern and DNA replication sequence only in dicentric Xq isochromosomes.

Azure Stains↗
PubMed1980

Body measurements of patients with streak gonads and their bearing upon the karyotype.

Anthropometric and cytogenetic investigations were carried out in 32 patients with streak gonads. The physique of the patients was delineated according to their chromosomal complements. For the possible localization of the determinants of the X chromosome for the physique the following conclusions were drawn. 1. For normal height both the short and the long arm of the X chromosome are essential. 2. The short arm of the X chromosome contains determinants that, if deleted, result in a high weight-to-height ration, i.e., proportionally heavier weight. The weight-to-height ratio is also shifted to the left in deleted Xq cases, but to a lesser extent. 3. Determinants are present in both the short and the long arms of the X chromosomes, which are involved in the proportional development of the ratio of the limbs to trunk. In all deleted-X cases the limbs were shorter. 4. Duplication of the long arm of the X chromosome does not compensate for loss of the short arm.

Adolescent↗
PubMed1980

Lymph vessel defects in patients with ovarian dysgenesis.

Lymphangiography of the lower extremities was performed in 21 patients with ovarian dysgenesis. Seventeen subjects turned out to have hypoplastic superficial lymph vessels of the lower limbs. Aplasia of the lymphatics of the legs occurred in four instances. Hypoplastic lymph pathways were also observed in the pelvis and in the retroperitoneal space. Although the impairment of the lymphatic channels occurred in all cases of ovarian dysgenesis, it appears that it is more severe in patients with streak gonads. There was no correlation between the lymphatic defect and the karyotype. Patients with and without lymphedema had similar lymphatic defects. Our findings suggest that hypoplasia of the superficial lymph vessels of the lower limbs is a common abnormality in patients with ovarian dysgenesis irrespective of their chromosomal complements. The hypothesis that lymphedema in ovarian dysgenesis is mainly attributable to hypoplasia of the lymphatic channels is supported by this study. However, it appears that other factor(s) may also play a role in the pathogenesis of the lymphedema, since, despite lymphatic hypoplasia, lymphedema does not develop in all instances.

Adolescent↗
PubMed1980

[Use and importance of photometric scanning to gonadal dysgenesis in concomitance with structural aberrations of the X-chromosome (author's transl)].

A photometric scanning method has been developed by the authors for high-accuracy identification of structural aberrations of chromosomes. By testing structural aberrations of gonosomes, the authors found that the scanning technique was highly suitable not only for band presentation, but also for complementary aberration assessment and, consequently, for genetic localisation and mapping of chromosomes in clinical practice.

Adolescent↗
PubMed1978

46,XY pure gonadal dysgenesis with non-fluorescent Y chromosome.

A 46,XY karyotype with a non-fluorescent Y chromosome was found in an infantile girl aged 16 with primary amenorrhea. Identification of the Y chromosome was made by different staining techniques and a photometric scanning method. The histology of the streak gonad also indicated the Y character of the chromosome. The authors' interpretation is a 46,XY pure gonadal dysgenesis with a non-fluorescent Y chromosome.

Adolescent↗
PubMed1977

Nonmosaic 46,X,r(Y) karyotype with female phenotype.

A nonmosaic case of ring Y chromosome is described. The patient is phenotypically female and has streak gonads. The histologic examination revealed dysgenetic seminiferous tubules in the streaks and epididymislike tubules besides them. The possibilities of the development of the phenotype and the streaks are discussed.

Adult↗
PubMed1977

X inactivation pattern in an unbalanced X-autosome translocation with gonadal dysgenesis.

An unbalanced X-autosome translocation was observed in a patient with primary amenorrhea, Turner phenotype and bilateral streak gonads. The karyotype of the proposita was 45,X,-X,+der(6),t(X;6). Autoradiography and BUDR pretreatment revealed differential inactivation of the X chromosomes. Sex chromatin pattern was in good agreement with the types of the X inactivation. Our finding brings out some further questions regarding inactivation of the human X chromosome and the human X chromosome and the related phenotypical changes.

Adult↗
PubMed1977

[Placental vascular changes in maternal diabetes mellitus].

Uniform pathological changes characteristic for the diabetes mellitus in the placenta were not revealed. In 63 per cent of the 22 cases morphological changes in the small- and middle vessels were observed. The most severe pathological changes were seen in the media in form of concentric fibrosis. It caused narrowing of the lumen, although the intima remained undamaged. It was not possible to detect a correlation between the severity of damage to the placentar vessels and groups described by White.

Blood Vessels↗
PubMed1976

Chromosome studies in ovarian hypoplasia.

Six phenotypic female patients characterized by an average stature, infantile body constitution, underdeveloped external and internal reproductive organs and secondary sex characteristics and amenorrhoea are described. In each of them laparotomy and histological study disclosed ovarian hypoplasia. The karyotype was 46,XX in all patients except one. However, the metaphase analysis extending over a greater than usual number of cells revealed an autosomal ring (15) in 5 to 26% of cells. The patients also showed phenotype signs of D chromosome anomalies. The authors agree with the previously suggested autosomal gene effect in sex differentiation.

Adolescent↗
PubMed1975

[The so-called pure gonadal dysgenesis (author's transl)].

4 cases of pure gonadal dysgenesis are reported, their phenotype, karyotype and the histology of the rudimentary gonads are described. There were 3 cases with a 46/XY-karyotype and 1 case with a 46/XX/45/X-karotype. In the 2 cases with a 46/XY-karyotype gonadal dysgenesis, a gonadoblastoma was found. It is therefore recommended that the rudimentary gonads should be removed in cases of pure gonadal dysgenesis of the XY-type.

Adolescent↗
PubMed1975

Clinical and morphological studies in streptozotocin diabetic pregnant rats.

Diabetes was induced in pregnant rats by administration of streptozotocin and the changes of the feto-placental unit were investigated. Dead fetuses were found in 12% of the untreated diabetic animals. In comparison to the controls, the fetal weights were significantly smaller and placental weights greater in diabetic animals. The changes were clearly characterized by the ratio fetal placental weight. Edema and cystic degeneration were characteristic of insulin treated diabetic placentas while fibrosis and ischemia were observed mainly in untreated animals. Insulin treatment resulted in hemorrhages and necrosis in the placenta of normal pregnant rats; the change is ascribed to hypoglycaemia.

Animals↗
PubMed1974

Comparative cytogenetical and morphological studies in ovarian dysgenesis.

In 14 cases of the Turner syndrome and pure gonadal dysgenesis streak gonads were studied histologically. In cases where the 46,XX line was unimpaired the blood vessels of the gonad showed severe degeneration in at least 30 to 50%. These streak gonads usually contained some of the characteristic ovarian elements as well as the vascular lesions. In gonosomal monosomy, on the other hand, a similar intensive vascular degeneration could not be found and the gonad consisted of indeterminate connective tissue. These observations are strong indications of a close correlation between karyotype and the histology of the streak gonad, which may supply further information on the manner and timing of the development of the streak gonad.

Adolescent↗