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Biomedical subjects

V Bijlani

Publications and source records attributed to V Bijlani.

At least 37 records · Page 2Linked to original sources

Immunohistochemical localization of GABAergic cells in the developing human dorsal lateral geniculate nucleus.

GABAergic neurons were demonstrated in the dorsal lateral geniculate nucleus (dLGN) of human foetuses of 21 weeks gestation using unlabelled antibodies against gamma-aminobutyric acid (GABA). These inhibitory neurons are thus cytochemically identifiable prior to appearance of lamination, at a period when there is reportedly segregation of retinal afferents from both eyes and formation of morphologically defined synapses. Their presence in the prenatal period indicates that the morphological substrate responsible, in part, for the orientation sensitivity of the dLGN neurons exists before birth in man.

Geniculate Bodies↗

DNA loss in the developing cerebellum of nervous mouse: a flow cytometric study.

Flow-cytometry of cerebellar EGL cells of nervous (nr) mouse revealed a reduction in DNA quantity per cell accompanied by an increase in the DNA dispersion during 6-8 days of postnatal life. This loss of DNA is due to a partial degeneration of the cells of EGL during the first week of postnatal life. The surviving cells later on achieve a DNA content equivalent to their bone marrow cells. The flow-cytometric technique also facilitates an early detection of the homozygous nervous mutant, almost 2 weeks before the clinical manifestation of the disease, which to date was not possible.

Animals↗

Contact areas in human elbow joints.

The paper describes the results of in-vitro experiments to determine the contact areas in the elbow joint during different anatomical positions. The casting technique, using wax as a casting material, was used in this study. The shape and size of the contact areas change, in different elbow positions ranging from full extension to full flexion. The joint stability was preserved during the experiments. In full extension the area of contact was observed on the lower-medial aspect of the ulna while in other postures the pressure areas were found as a strip extending from posterolateral to anteromedial. The radio-capitulum joint also revealed contact during flexion under no externally applied loads.

Elbow Joint↗

The intermediolateral gray columns in the spinal cord of Macaca mulatta.

The mean length of spinal segments in Macaca mulatta varied from 0.55 to 1.4 cm. Upper thoracic and lumbar segments were shorter; middle and distal thoracic segments are longer. The intermediolateral gray column extended from the middle of the eighth cervical to the fourth lumbar spinal segments. This column as observed in the serially cut cross-sections varied in shape and in position in different regions of the spinal cord. The mean counts of intermediolateral neurons in the males were significantly higher than females (P less than 0.001) and varied from segment to segment. Their number was slightly higher on the right side and funicular cells were more numerous in male spinal cords than in females. The neurons were of varied shapes from fusiform to multipolar and measured from 7.5 to 25 micrometers in size.

Animals↗

Birth weight and development of cerebellar cortex.

Postnatal development of the cerebellar cortex in the mouse is characterised by proliferation of cells of the external granular cell layer, migration of the granule cells across the molecular layer and simultaneous maturation of the Purkinje cells. At the same time, there is elaboration of the folia and fissures of the cerebellum. These features were studied postnatally in relation to the age and weight of the animal in the inbred strain of C3HeB/FeJ mice fed on standard diet. In every litter there was a difference in body weight of the various pups, and for the present study, the lowest and highest weighing animals from each litter were used. The observations presented here are on animals at the 1st, 7th, 13th and 24th days postnatum. It appears that the size of the cerebellum and the degree of the development of the cerebellar cortex are directly proportional to the weight of the animal for that age period.

Aging↗

"Physiological" and cytotoxic cell death in protein deficiency. A study in developing cerebellum in rats.

Effects of undernutrition on natural ("physiological") and cytotoxic cell death due to X-irradiation was studied in developing cerebellum in rats. Undernutrition was induced right from birth by doubling the litter size. Animals reared in a litter of 8 served as controls. In order to get an idea of the relationship of cell death to phases of the cell cycle, the number of labelled dead cells, in the EGL of the fissure prima, was estimated, at time intervals following administration of 3HTdR in a group of 9-day-old rats. No differences were observed in the quantum of "physiological" cell death as well as in the rate of nuclear autolysis in the two groups. Undernutrition, however, prolonged the G2-M junction in animals X-irradiated with 200 rads. The kinetics of appearance of labelled dead cells suggested that irrespective of the diet the cells die immediately following mitosis, although the "decision to die" was taken at the end of S-phase. It is concluded that the reduction in cell number in the brain in undernutrition is not due to increased cell death.

Animals↗

Undernutrition and the developing cerebellar cortex in the rat.

Undernutrition of the newborn rats, produced during the first 3 weeks by increasing the litter size and restricting the mother's diet, resulted in reduction of the body and brain weights of the experimental animals. One group of undernourished animals showed especially severe reduction of body and cerebellar weights. These animals, on the 10th postnatal day, had an immature cerebellar cortex corresponding to that of the 7th day postnatal control animals. The external granular layer persisted in the cerebellar cortex of the underweight animals until the 23rd day, while it disappeared by 20th day in the control animals. Mitotic activity was evident until the 21st postnatal day in these animals while it stopped in the normal animal by 16th postnatal day. There was no marked difference in the fine structure of the various cell types in the control and undernourished animals. Midsagittal tracings of the cerebellar cortex showed a reduced surface area in the undernourished animals, while the thickness of the external granular layer and molecular layer did not show any significant difference when compared to that of the control animals, thus showing a reduction in total cell number, but not per unit area. The normal morphological appearance of the cerebellar cortex in the underfed animals of higher weight probably indicates that these animals are adequately nourished in spite of the reduction in weight when compared to the control animals, which probably are overfed.

Animals↗

Early development of visual cortex in human fetuses.

Prenatal development of visual cortex (area 17) was studied in human fetuses of 8-9, 13-15 and 16-18 weeks of gestation, with a view to analyse the early critical events. Under light microscope, five zones of development were seen in all the age groups. The total thickness of cortex of area 17 as well as that of its cortical plate was measured with the help of camera lucida. It was observed that the total thickness of the cortex increased with increase in age. Diversity in the shape, size, staining intensity and arrangement of neurons was noted in the different zones. Most of the cells were found to have a thin rim of cytoplasm and a prominent nucleus with multiple nucleoli. The cells in subventricular zone and cortical plate were regularly arranged in vertical rows while in other zones, they were irregularly scattered. Several mitotic figures were seen in the ventricular zone at 8-9 weeks but later they were also noticed in subventricular and intermediate zones. In the later ages the mitotic figures were observed to be fewer in the ventricular zone. No mitosis was seen in cortical plate at any age period.

Cell Division↗