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Biomedical subjects

E Carrascal

Publications and source records attributed to E Carrascal.

12 recordsLinked to original sources
PubMed1992

Modifications of "A cells" in the development of experimentally induced pancreatic ductal adenocarcinoma: an ultrastructural and immunohistochemical study.

In the hamster-BOP model, modifications occur in the endocrine portion of the pancreas during the induction of well-differentiated ductal carcinomas. In the present work, using immunohistochemical techniques it was possible to observe that the A cells in preserved islets and in the initial phase of the carcinogenic process were localized in the peripheral part of the islets. In animals with tumours, A cells were found to form part of the tumour glands and/or the tumoral stroma; this localization was seen to depend on the developmental phase of the tumour. A focal dispersion of A cells was observed in the animals with ductal carcinoma.

Adenocarcinoma↗
PubMed1991

Ultrastructural study of the initial phases of pancreatic carcinoma induced by BOP in the Syrian golden hamster.

A serial study was carried out on the lesions induced by N-nitroso-bis(2-oxopropyl)amine (BOP) in the Syrian golden hamster until the appearance of pancreatic ductal carcinomas. During the initial phase, first findings were cytolysis of acinar cells close to blood vessels and other cells, together with a loss of zymogen granules from the cytoplasm, and an increase in the diameters of the acinar lumens. After week 11 a proliferation of ductule-like cells was observed. We consider that a minimum proliferation of cells at the acinus-ductule junction would give rise to pseudoductules composed of remains of acinar cells together with ductule-like cells.

Animals↗
PubMed1988

Leukoderma punctata.

Thirteen patients with vitiligo (1 segmental, 4 focal, 8 generalized) aged 7 to 38, most of them female children, developed numerous punctate hypopigmented and achromic spots. The spots measured 0.5 to 1.5 mm and were located primarily on the sun-exposed areas of the extremities; they appeared following treatment with PUVASOL. Two of these patients experienced a reduction of this leukodermic defect, whereas the remaining patients showed a stable clinical course. Dopa and Fontana stains disclosed, in most cases, decreased but not absent functional melanocytes and a marked reduction of melanin. Ultrastructural studies demonstrated slight to severe damage of keratinocytes and melanocytes similar to that previously reported in vitiligo patients. The phototoxic effect of PUVASOL therapy is suggested as a possible etiologic factor in these patients. A probable relationship among idiopathic guttate hypomelanosis, leukoderma punctata, and vitiligo is discussed.

Adolescent↗
PubMed1986

Morphology of the primary posterior plexus of the rat cochlear nucleus.

Golgi impregnation results confirm the existence of a plexus (previously described with horseradish peroxidase tracing techniques) located in the posteroventral cochlear nucleus. The bulk of axons involved in this plexus could be traced to their origin in the root, and were not related to the V-bifurcating fibres, though some of the posterior branches of the latter contributed to the plexus. The internal structure of the plexus, and the different types of endings are described. These findings are discussed in relation to previous Golgi studies, especially those referring to the neuron and axon population of this area.

Afferent Pathways↗
PubMed1978

Leiomyomatosis peritonealis disseminata. An ultrastructural study.

Electron microscopic features of the eighth documented case of leiomyomatosis peritonealis disseminata identify the main proliferative cell type as a mature leiomyocyte with all its associated ultrastructural features. The histogenesis of this neoplasm is considered to be a multicentric metaplastic change determined by an abnormal tissue response to the elevated hormonal levels occurring in pregnancy or ovarian functioning tumors. It is suggested that the cell of origin is the multipotent subcelomic mesenchymal cell, which retains the capacity to differentiate into several tissues, among them smooth muscle. To illustrate this possibility, myofibroblasts, cells with hybrid characters of fibroblasts and leiomyocytes, were observed; these may represent a transitional stage between the mesenchymal cell and the smooth muscle proliferating cell.

Female↗