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Biomedical subjects

A Abramovici

Publications and source records attributed to A Abramovici.

At least 73 records · Page 4Linked to original sources
PubMed1978

Glycogen metabolism in the placenta of streptozotocin diabetic rats.

Administration of STZ prior to mating, induced significant impairment in glycogen metabolism in term rat placentae. Glycogen retention was observed in the treated placentae, while glycogen synthetase activity was reduced. The glycogenolytic pathway seemed to proceed mainly through amyloglucosidase enzyme whose activity increased threefold. Glucose-6-phosphatase showed a moderate activation, mainly in the labyrinth zone, while phosphorylase was slightly inhibited. These changes were accompanied by a decrease in placental insulin levels. The possible defensive role played by the placenta in cases of maternal hyperglycemia was postulated.

Animals↗
PubMed1978

Incipient histopathological lesions in citral-induced microphthalmos in chick embryos.

Microphthalmos was indeed experimentally in 3-day-old chick embryos by intraamniotic injection of citral. Various degrees of this particular microphthalmic syndrome were observed. Severe cases were always accompanied by destructive changes in the ipsilateral part of the head. The corneal epithelium lost its continuity and the lens showed, even in the early stages, severe degenerative changes with spherophakia. The neural retina seemed to be affected later and showed hyperplasia and fold formation, while the retinal pigment epithelium was only mildly affected. The mesenchyme behaved differently according to its location: the superficial corneal and ciliary mesenchyme underwent hyperplasia, while the deeper choroidal mesoderm showed edematous changes only. This temporal and spatial distribution of pathological changes in the eye structures favors the assumption that citral acts locally. The experimental microphthalmic syndrome is not only due to the direct effect of the exogenous teratogenic factor on the ocular anlagen but is also the result of subsequent adaptive changes of these structures to the new environmental condition.

Acyclic Monoterpenes↗
PubMedDate not supplied

Histochemical and quantitative biochemical changes in mucopolysaccharides of the term placenta of the diabetic rat.

Full-term placentae of rats with streptozotocin-induced diabetes were analysed histochemically and biochemically for changes in mucopolysaccharide content. The experimental diabetes induced severe cystic degeneration in the spongiosa zone of the placenta and this was accompanied by extracellular deposition of hyaluronate and neutral polysaccharides. The labyrinth zone was affected to a lesser extent. Biochemical analysis also revealed quantitative differences in the total contents of mucopolysaccharides (MPS) between the two zones of the placenta in both diabetic and normal placentae. The spongiosa had a higher total mucopolysaccharide content than the labyrinth. Polysaccharides of low molecular weight were always predominant. The amount of hyaluronate exceeded the quantitites of sulphated mucopolysaccharides which were found in relatively small amounts in both placental zones. In diabetic placentae there was a two- to threefold increase, which was more pronounced in the spongiosa. The increase was observed among all types of MPS. A close correlation between the accumulation of MPS in the placenta and the degree of maternal hyperglycaemia was found. The placentae of the three streptozotocin-resistant animals showed neither histological nor biochemical changes. It is suggested that the accumulation of MPS in the diabetic placenta might be a consequence of a shift in carbohydrate metabolism induced by hyperglycaemia or a persistence of the fetal metabolic features as a part of a retarded maturational process of the placenta.

Animals↗
PubMedDate not supplied

Histochemical localization of acidic glycosaminoglycans in normal human placentae.

First-trimester and term placentae were studied histochemically with alcian blue stain before and after specific enzyme treatments. A specific deposition of glycosaminoglycans was detected in the villous stroma, fetal blood vessels and on the surface of the syncytiotrophoblast, the latter being discontinuous and of variable thickness. Treatments of sections with hyaluronidases from Streptomyces and from bovine testes and with chondroitinase ABC indicated the presence of (1) chondroitin sulphates and hyaluronic acid mainly in the stroma; (2) heparan sulphate and dermatan sulphate associated with villous fetal blood vessels and the intervillous surface of the syncytiotrophoblast. It is suggested that the location of individual glycosaminoglycans could be related to their functions with regard to the maintenance of the structural integrity of the placenta by preventing its compression and to their involvement in blood anticoagulation and in lipid metabolism.

Alcian Blue↗
PubMedDate not supplied

Placental ultrasonographic biochemical and histochemical studies in human fetuses affected with Niemann-Pick disease type A.

Placental ultrasonographic, bio- and histochemical studies were performed on four unrelated fetuses affected with Niemann-Pick disease Type A, following prostaglandin-induced abortion at about the 19th week of gestation. An accumulation of sphingomyelin in the placentae of affected fetuses indicates the essential role of the enzyme sphingomyelinase, even during the early stages of gestation. A fair correlation between histochemical localization of sphingomyelin in the placentae and ultrasonographic findings was found, indicating the value of ultrasonic echo wave information in the diagnosis of metabolic disorders.

Abortion, Induced↗