La prolifération des canaux biliaires et la formation de structures tubulaires au cours des affections hépatiques en pathologie humaine et expérimentale

Doctorat en sciences médicalesinfo:eu-repo/semantics/nonPublishe

La prolifération des canaux biliaires et la formation de structures tubulaires au cours des affections hépatiques en pathologie humaine et expérimentale

Doctorat en sciences médicalesinfo:eu-repo/semantics/nonPublishe

La prolifération des canaux biliaires et la formation de structures tubulaires au cours des affections hépatiques en pathologie humaine et expérimentale

Doctorat en sciences médicalesinfo:eu-repo/semantics/nonPublishe

Degree of differentiation and blood vessel proximity in B16 melanoma

Corded structures consisting of rows of viable tumour cells around a central blood vessel are present in a number of transplantable mouse tumours, including transplantable B16 melanomas. These tumours were used to assess, by stereological means at the EM level, the range of differentiation of the melanoma cells, according to their position in relation to the central blood vessel. The mitotic index was also determined for perivascular and peripheral tumour cells separately. Furthermore, the transition of peripherally located cells into necrotic tumour cells is described at the EM level. Results show an important increase in differentiation in peripheral tumour cells, whereas the mitotic index is highest in perivascular cells. Necrotic peripheral cells show features of apoptotic necrosis, together with necrosis of the ischaemic type. Results indicate that both proliferation and differentiation of melanoma cells are related to their position around a central blood vessel, and that peripheral necrosis is not exclusively due to lack of oxygen. © 1982 Springer-Verlag.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Regional variations in proliferation rate and degree of differentiation in B16 melanomas

The relationship between proliferation rate and degree of differentiation has been studied in different regions of transplantable B16 melanomas. The regions studied were peripheral parts of the tumours and the inner (perivascular) and outer (external) zones of so-called corded structures. The highest proliferation rates and the poorest cellular differentiation (estimated by volume densities of premelanosomes and melanosomes) occurred in the perivascular zones of corded structures. Conversely, the lowest proliferation rates and the best cellular differentiation was encountered in the external zones of corded structures. Proliferation rates and cellular differentiation in the peripheral parts of the tumours were intermediate between the values obtained in the perivascular or external regions of corded structures. The results in corded structures indicate an inverse relationship between proliferation rate and degree of differentiation, and a positive correlation between proliferative capacity and blood vessel proximity. The intermediate values in the peripheral parts of tumours may reflect the presence of a mixed population of cells which vary in their proximity to the nearest blood vessel. © 1984 Springer-Verlag.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Comparison of cell growth in different parts of breast cancers

This study was performed to answer the question: which parts of breast cancers are active in terms of proliferation as measured by the Ki‐67 antibody and in terms of cell division as measured by the mitotic index. Forty‐six breast samples were studied, including 34 breast cancers and 12 benign conditions. The intraductal component of infiltrating breast cancers showed a significantly lower proliferation index than the infiltrating component. The cells at the periphery of infiltrating tumour strands showed a higher proliferation activity than the cells in the core. These findings suggest that infiltration advances through preferential active growth of the cells at the invasion front. Copyright © 1990, Wiley Blackwell. All rights reservedSCOPUS: ar.jFLWNAinfo:eu-repo/semantics/publishe

Menkes kinky-hair disease. A report on its pathology

Two cases of Menkes disease belonging to different families are reported in order to illustrate different types of central nervous system involvement. In the first case which documents the sex-linked recessive inheritance, arteriographic studies have shown that the vascularization of the brain was severely impaired. Postmortem examination revealed lesions of the elastic membranes of large and medium calibre arteries, widespread and extremely severe necroses of grey and white matter with relative sparing of the territories irrigated by the vertebro-basilar system. The dendritic tree of the Purkinje cells was atrophied, somal sprouts were not found. Electron microscopy showed the mitochondria to be morphologically normal. In the second case, there was a bilateral demyelination predominating in the temporal lobes' white matter while arterial alterations and anoxic lesions were present but less prominent. The Purkinje cells were normal. Considering the role of copper as a co-factor for different enzymes, it is possible to explain many features of Menkes disease on the basis of a lack of copper (Danks et al. 1972a, b). Multiple elements play a role in the pathogenesis of the C.N.S. lesions: some alterations, such as the parenchymatous necroses, depend from circulatory disturbances related to arterial abnormalities; others, such as the demyelination, the dystrophic features etc. could be linked to various enzymatic deficiencies susceptible to interfere with postnatal myelination and differentiation of cell membranes as illustrated by the study of spontaneous and experimental animal diseases. © 1978 Springer-Verlag.SCOPUS: ar.jinfo:eu-repo/semantics/publishe