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L Roncali

Publications and source records attributed to L Roncali.

At least 145 records · Page 8Linked to original sources
PubMed1979

[Correlations between the processes of cell differentiation and development of blood vessels in the (chick embryo) adenohypohhysis].

Utilizing semi-thin and, respectively, thick sections after indian ink injections, we have analyzed morphohistogenesis and vessel development in the adenohypophysis of chick embryos from the 4th to the 19th incubation day. Our preliminary results indicate that a close correlation exists between cellular differentiation and vasculogenesis. Vessels begin to enter the gland only at the 6th day when the first endocellular granules become detectable, and, from the 10th day, they markedly increase in number and size, gradually acquiring a peculiar sinusoidal arrangement around cellular groups, as cell differentiation further progresses.

Animals↗
PubMed1976

Vascular patterns in the chick embryo spinal cord in normal and experimentally modified development.

The development of the vascular patterns of the lumbosacral segments of the chick embryo spinal cord has been analyzed in normal as well as in experimental conditions, after complete removal of the hind limb primordium. The results indicate that in both conditions the development of the vascular network follows the time-space sequence of the cytoarchitectural modifications of the cord, supporting the view that the vascularization does not exert a morphogenetic influence.

Age Factors↗
PubMedDate not supplied

GABA immunoreactivity in the human cerebellar cortex: a light and electron microscopical study.

The distribution of gamma-aminobutyric acid (GABA) in surgical samples of human cerebellar cortex was studied by light and electron microscope immunocytochemistry using a polyclonal antibody generated in rabbit against GABA coupled to bovine serum albumin with glutaraldehyde. Observations by light microscopy revealed immunostained neuronal bodies and processes as well as axon terminals in all layers of the cerebellar cortex. Perikarya of stellate, basket and Golgi neurons showed evident GABA immunoreactivity. In contrast, perikarya of Purkinje neurons appeared to be negative or weakly positive. Immunoreactive tracts of longitudinally- or obliquely-sectioned neuronal processes and punctate elements, corresponding to axon terminals or cross-sectioned neuronal processes, showed a layer-specific pattern of distribution and were seen on the surface of neuronal bodies, in the neuropil and at microvessel walls. Electron microscope observations mainly focussed on the analysis of GABA-labelled axon terminals and of their relationships with neurons and microvessels. GABA-labelled terminals contained gold particles associated with pleomorphic vesicles and mitochondria and established symmetric synapses with neuronal bodies and dendrites in all cortex layers. GABA-labelled terminals associated with capillaries were seen to contact the perivascular glial processes, basal lamina and endothelial cells and to establish synapses with subendothelial unlabelled axons.

Aged↗
PubMedDate not supplied

Angiogenesis spectrum in the stroma of B-cell non-Hodgkin's lymphomas. An immunohistochemical and ultrastructural study.

Samples of lymph nodes from 88 patients with B-cell non-Hodgkin's lymphoma (B-NHL) grouped by the Working Formulation (WF) and from 15 patients with benign lymphadenopathies were investigated immunohistochemically and ultrastructurally for changes in angiogenesis and stromal distribution of two subendothelial basement membrane (BM) components, namely laminin and type IV collagen. The microvessel number was usually low in lymphadenopathies, and increased significantly in low-grade B-NHL. Intermediate-grade tumors displayed a further significant increase that was mainly due to their diffuse subtypes rather than to the follicular subtype. High-grade B-NHL showed the highest counts. By contrast with the lymphadenopathies studied, the stroma of B-NHL reacted intensely with both BM components, whose linear co-expression was significantly associated with low-grade and follicular intermediate-grade B-NHL, while expression of laminin alone in a granular pattern was detected in diffuse intermediate-grade and high-grade tumors. Ultrastructural analysis revealed immature vessels more frequently in diffuse intermediate-grade, and in high-grade B-NHL. These in situ data suggest that angiogenesis occurring in B-NHL increases along their progression path, and emphasize the importance of angiogenesis as an epigenetic phenomenon of B-NHL progression.

Analysis of Variance↗