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Biomedical subjects

M Lafarga

Publications and source records attributed to M Lafarga.

83 records · Page 5Linked to original sources
PubMed1978

In vivo phagocytosis by developing myocardial cells: an ultrastructural study.

Phagocytosis of naturally degenerating cells, by healthy myocardial cells of the bulbus cordis of 5--7-day chick embryos, was studied by electron microscopy. Myocardial cells showed cell processes surrounding dead cell fragments. The cell fragments appeared to be internalized later and digested within phagosomes. Ruthenium red was employed to ascertain whether the cell fragments were in fact internalized or located in pockets of the cell membrane. The results are discussed in the light of present knowledge of phagocytosis.

Animals↗
PubMed1977

Cytological and cytochemical studies of the necrotic area of the bulbus of the chick embryo heart: phagocytosis by developing myocardial cells.

The muscular wall of the bulbus cordis of the chick embryo was studied by electron microscopy during H. H. stages 27--31. Results show that the muscle cells of the bulbus undergo necrosis during these stages. The morphology of dead cells in this area is similar to that described in other embryonic myogenic tissues. Although dead myocytes appear acid-phosphatase-negative, lysosomes may well be involved in this necrotic process as there is a significant number of cells with autolytic lesions among the neighbouring healthy muscle cells. The phagocytosis of the cell detritus resulting from the degenerative process appears to be carried out by neighbouring myocytes and by macrophages. The significance of these results is discussed both from the cytological and from the morphogenetic point of view.

Acid Phosphatase↗
PubMed1976

Coated vesicles in the rat adrenal glomerular zone after a low-sodium diet.

In rats subjected to a low-sodium diet, a great activity was observed of the coated vesicles at Golgi complex and cell surfaces of glomerular adrenal zone. These findings are related to the function of these organoids in the uptake and transport of necessary substances under stimulating conditions of the zone.

Adrenal Glands↗
PubMed1976

Ultrastructural study of binucleation in cells of the rat adrenal glomerular zone after a prolonged low-sodium diet.

Binucleate cells have been found in the glomerular zone of the adrenal cortex in rats subjected to low-sodium diets. By considering the various possibilities for their production, both the findings of nuclei in process of constriction and nuclei identical in form, confronted and smaller in size than those of neighbour cells, are in agreement with an amitotic nuclear division as the possible mechanism for the formation of these cells.

Adrenal Cortex↗
PubMed1975

Chromaffin cells in the glomerular zone of adult rat adrenal cortex.

The occasional presence of islets of chromaffin cells in the glomerular zone of the adrenal cortex of adult rats, is reported in this light and electron microscope study. A possible error in organogenesis of the gland and the possible persistence of some foetal characteristics in these ectopic cells are discussed.

Adrenal Cortex↗
PubMed1975

Ultrastructural study of pericytes in the rat supraoptic nucleus.

Pericytes of the supraoptic nucleus of normal rats have been studied with the electron microscope. These cells are morphologically similar to those of pericytes in other parts of the nervous system. The pericytes and their cytoplasmic processes were surrounded by basal membrane. The nucleus contained large masses of heterochromatin. The cytoplasm, less dense than that of the endothelial cells, contained numerous free ribosomes, cisternae of granular endoplasmic reticulum, various dictyosomes of the Golgi complex, isolated microtubules, a few mitochondria, and, occasionally, a diplosome. The presence of numerous lysosomes in some pericytes suggested that the cells are phagocytic even in normal circumstances.

Animals↗
PubMedDate not supplied

[Osmosensitive neurons in the retrochiasmatic area of the hypothalamus. An ultrastructural study].

An ultrastructural study has been conducted of the response of rat retrochiasmatic area neurons to an intraperitoneal injection of hypertonic sodium chloride. The formation of numerous communications between nuclear envelope and the granular endoplasmic reticulum (GER) is seen as a response of these neurons to the osmotic stimulus. Some of the GER cisterns may establish contact with the neuronal membrane. The quantity of polyribosomal rosettes increases, especially in the nuclear cytoplasmic infoldings. These results are interpreted as a change in the programmed activity of synthesis of these neurons. Previous electrophysiologic studies appear to demonstrate the possibility of these neurons being osmoreceptors. These ultrastructural observations seem to confirm this hypothesis.

Animals↗
PubMedDate not supplied

[Uhl's anomaly associated with atresia of the pulmonary valve].

A case of Uhl's anomaly in a newborn who died in congestive cardiac failure at 18 days of age is described. There was severe cardiomegaly on chest X-ray, right atrial hypertrophy on E.C.G., and a delayed tricuspid valve closure of 0,8 seconds on M-mode echocardiogram. The necropsy study showed a huge right atrial and right ventricular dilatation, a very thin right ventricular wall (1 mm.) with an important reduction in the number of muscular fibers, a pulmonary valve atresia, and a patent ductus arteriosus and foramen ovale. We have only three cases Uhl's anomaly associated with pulmonary atresia, and no one with such an important delay of the tricuspid valve closure on the echocardiogram.

Electrocardiography↗