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Biomedical subjects

N G Pavlova

Publications and source records attributed to N G Pavlova.

15 recordsLinked to original sources

[Organization and cytochemical features of barrier structures in human placenta].

The aim of the present study was to investigate structural pattern of human placental barrier elements using light and electron microscopy and immunocytochemistry. Some important peculiarities of organization of the placental barrier were detected: difference in structure and amount of collagen IV in the basal lamina of endothelium and trophoblast, occurrence of smooth muscle actin in the capillary wall forming syncytiocapillary membranes. In the intercapillary stroma of terminal villi, both fibroblasts and macrophages but not myofibroblasts were found. Since smooth muscle cells and myofibroblasts are absent, pericytes are most likely cells to contain smooth muscle actin in the area of syncytiocapillary membranes.

Actins↗

Fluorescent microscopic study of epithalon binding in maternal and fetal rabbit tissues in health and under conditions of placental insufficiency.

Epithalon (regulatory tetrapeptide) labeled with dansil (fluorescent stain) easily penetrates into all tissues and organs of pregnant rabbit females and through the placenta into fetal organs. Incorporation of labeled epithalon in placental tissues is more often observed in fetuses developing under conditions of placental insufficiency than in normal fetuses.

Animals↗

[Structural organization of macrophages in forming human placenta].

Placental macrophages (Kashchenko-Hofbauer cells) belong to a special population of tissue macrophages of human fetal provisional organs. The aim of the present study was to investigate the structure of Kashchenko-Hofbauer cells at the stage of placenta formation using the methods of light and electron microscopy and immunocytochemistry. Cytological and cytochemical peculiarities of Kashchenko-Hofbauer cells revealed in this study, leave no doubt that they belong to the tissue macrophages group. Their cytoplasm is strongly reactive with antibodies against CD68 lysosomal antigen suggesting potentially high phagocytic activity of these cells. Weak nuclear labeling with proliferation marker PCNA was found in placental macrophages.

Antigens, CD↗

Glutathione-dependent system of antioxidant defense in the placenta in preterm delivery.

Components of the antioxidant defense system in placental tissues were studied in women with normal pregnancy and full-term delivery and women with spontaneous abortions at 28-36 weeks. In women with spontaneous abortions glutathione peroxidase activity in placental tissues increased and the content of SH compounds decreased, which led to exhaustion of the antioxidant defense system. Glutathione-S-transferase activity also decreased, which attests to impaired detoxifying function of the placenta.

Abortion, Spontaneous↗

[Bcl-2 protein expression in developing human brain].

Using immunocytochemical methods, the expression of bcl-2 antiapoptotic protein was studied in developing brain of human 5-8-week embryos. It was established that during the period studied several zones of bcl-2-positive cell concentration were present. These included the ventricular zone of the brain vesicles wall, cortical plate, medullary nuclei, vascular plexus primordium (in 5-6-week embryos), IV ventricle roof and vascular plexus of rhombencephalon. In the area of forming leptomeninx, bcl-2 protein was demonstrated in the endothelium of blood vessels. The detection of intensified expression of bcl-2 protein in some cellular populations of developing human brain proves their increased stability against apoptosis and indicates their priority significance in the provision of normal neurohistogenesis.

Brain↗

Functional and biochemical criteria for investigation of brain development disorders.

Functional state and creatine kinase (CK) activity in the amniotic fluid and blood of anencephalic fetuses was studied in the second trimester of pregnancy with the following pathomorphological investigation of the state of their CNS to reveal possible markers of development disorders. The extent of neurological disorders in newborn infants was retrospectively compared with data from functional studies of components of a biophysical profile (motor-cardiac reflex, heart rhythm oscillations, respiratory movements) and with CK activity in the amniotic fluid and blood of fetuses with hemolytic disease and fetuses of diabetic mothers and normal mothers in the third trimester of pregnancy. The results revealed informative indices of fetal CNS developmental disorders in the prenatal period that are of importance for predicting a prognosis of the extent of neurological disorders in newborn infants. These results will allow the establishment of criteria for evaluation of fetuses to reveal possible disorders in the formation of the CNS.

Amniocentesis↗

[Morphophysiological analysis of the formation of mechanisms of the activity-rest cycle in human ontogenesis].

The natural behavior of normal and anencephalic fetuses at 20 to 41 weeks of the development was studied by ultrasound monitoring and continuous recording of heart rate (HR) and motor activity (MA), followed by processing and presentation on [symbol: see text]CM computer. The statistical characteristics of HR and MA changes in the anencephalic fetuses were corrected by the degree of CNS deficiency. The comparative study of 20 normal and 34 anencephalic fetuses showed: 1) when the spinal cord was present, stable HR (about 150 bpm) seems to be due to cardiac automatism and sharp decelerations unaccompanied by MA were recorded; 2) in fetuses with the medulla oblongata present showed a decrease in baseline HR up to 140 bpm, repeated pronounced decelerations and spontaneous single motor acts dissociated with the latter; 3) when a rudiment of the midbrain was present, some reductions in the amplitude of decelerations and manifestation of weak accelerations, cluster motor acts, brief episodes of the active state were revealed; 4) the quiet state was observed in fetuses with the cerebral cortex; 5) the rest-activity cycle formed with further differentiation of the cerebral cortex.

Anencephaly↗