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Biomedical subjects

A Porte

Publications and source records attributed to A Porte.

At least 55 records · Page 3Linked to original sources

[Familial cardiomyopathy: a study of two families with myocardial and skeletal muscle biopsies].

Cardiomyopathy was diagnosed in several members of two families. This familial cardiomyopathy showed symmetrical or asymmetrical hypertrophy of the ventricular walls with or without obstruction to the left ventricular outflow tract. Certain forms were asymptomatic and were revealed by the family history and echocardiography. Myocardial and intercostal muscle biopsy was performed for a biochemical and ultrastructural analysis. Different myocardial features were observed in the two families: a large increase in the glycogen deposits in the one, without clinical signs of a glycogen storage disease, and intracellular deposits of a filamentous protein substance in the other.

Cardiomyopathies↗

Accidental acute mercury vapor poisoning.

Accidental acute mercury vapor poisoning in three persons is reported. Three hours after exposure, symptomatology began by chills, vomiting, diarrhea and chest pain. Two patients, respectively 67 and 77 year old, presented severe pulmonary edema, then neurological symptoms with tremor and coma. This toxic pulmonary edema, which entailed artificial ventilation, was followed in both cases by an acute interstitial pulmonary fibrosis which led to death respectively after six and sixteen days. In the third case (a thirty eight year old patient) a skin rash, erythematous and pustuliform was observed. Analysis for total mercury by flameless atomic absorption showed very high mercury levels in blood and urine of the three patients. The effect of treatment by Dimercaptopropanol on renal excretion of mercury was studied. Optic and electron microscopy of the lung of the two patients who died showed the pulmonary changes of acute interstitial fibrosis.

Adult↗

[Origin and formation of different types of vacuoles induced by the multiplication of the alphavirus Sindbis virus in various cell systems].

Spherule-containing vacuoles and nucleocapsid-bearing vacuoles (cytopathic vacuoles types 1 and 2 respectively of Grimley et al. 1968) induced by Alphavirus Sindbis were studied in brains from newborn mice, chicken embryo fibroblasts, and two lines of tumoral glial cells from muridae. Endoplasmic reticulum (ER) elements and finely granular electron-dense material also seen in contact with nucleocapsids seemed to be involved in the formation of the classical single-membrane spherule-containing vacuoles. A second type of spherule-containing vacuoles were characterized by their double membrane and an amorphous electron-dense content and were probably derived from mitochondria. Nucleocapsid-bearing vacuoles were formed from modified ER elements and seemed to be linked to excessive synthesis of viral material. Such ER alterations were not observed in RG6 cells. In these cells, there were only spherule-containing vacuoles, while nucleocapsids were seen associated with the cytoplasmic membrane only.

Animals↗

B-cells of the synovial membrane. II. Differentiation during development of the synovial cavity in the mouse.

Study of pre- and postnatal development of the metatarsophalangeal joint of the mouse shows that the synovial cavity (SC) forms before any differentiation of the synovial mesenchyme. The primitive cleft results from degradation of a thin vascular mesenchymal layer in direct contact with the chondrogenic layers. Differentiation of the synovial membrane coincides with clarification of the SC (3rd to 6th day of postnatal life). When dilatation of the SC occurs (6th to 8th day), the two intimal cells types (A- and B-cells) are well identified. The B-cells already show typical features at day 6; their content of typical dense secretory vesicles is comparable to that of the adult B-cells at day 13. The specific secretory function of B-cells could be correlated with the particular structure of the intimal interstitial tissue and could account for the origin of some protein(s) of the synovial fluid.

Animals↗

B-cells of the synovial membrane. I. A comparative ultrastructural study in some mammals.

Comparative ultrastructural study of the B-cells in the intimal layer of the synovial membrane in mouse, rat, rabbit, guinea-pig and man clearly distinguishes these cells from both the histiocytic A-cells (macrophage-like cells) and the fibroblasts. In addition to the marked development of the rough endoplasmic reticulum and Golgi apparatus, typical dense secretory vesicles apparently of Golgi origin are always found in mouse B-cells and frequently in those of the rat. These secretory characteristics clearly relate these cells to glandular cells engaged in polypeptidic secretion. The variations in the other species studied concern only the figuration of secretory material. Thus, the B-cells appear to constitute a category of secretory cells specific to the synovial membrane, but the function of which has yet to be determined.

Animals↗

Acute interstitial pulmonary fibrosis. Comparative light and electron microscopic study of 19 cases. Pathogenic and therapeutic implications.

Comparative light and electron microscopic studies of the lung were performed in 19 cases of diffuse acute interstitial fibrosis with various etiologies. Our observations emphasize the relation between hyaline membranes (HM) and the evolution of fibrosis. HM formation is due to fibrinous exudates and epithelial necrosis. This phenomenon recurs during the evolution of the disease and appears to be responsible for new waves of fibrosis. Its pathogenesis (humoral or neurovascular ...) remains hypothetical. Modifications of the alveolar epithelium consecutive to septal fibrosis can be clearly distinguished from "fibrinoid necrosis" -type lesions, which results in HM. The formation of HM is accompanied by fibroblastic stimulation which proceeds in spite of epithelial regeneration. The exact stimulus for the proliferation and collagen hypersecretion of fibroblasts remains to be determined. The use, in association with corticosteroid treatment, of a structural analogue of L lysine, acexamic acid, to impede collagenesis reveals encouraging perspectives for improved therapy.

Acute Disease↗

[Secretory aspects and differentiation of B cells of the synovial membrane in mice].

The intimal layer of the synovial membrane (SM) includes essentially 2 cell types: A-cells with macrophagic functions and B-cells generally assimilated to fibroblasts. A comparative study of the B-cells in some mammals revealed that these cells possess specific polypeptidergic secretory features which are particularly clear in the mouse. The B-cells, which are more numerous than A-cells and often entirely line the synovial cavity, probably play an essential role in the metabolism of the SM. A study of the development of the SM in the mouse shows that the primitive cleft is formed before any differenciation of the synovial mesenchyme through degradation of the fine mesenchymal layer in direct contact with the chondrogenic layers. The differenciation of the SM coincides with the clarification and dilatation of the synovial cavity. As soon as the SM organizes into intimal and sub-intimal layers (6 days of life), the 2 intimal cell types can be identified by their macrophagic (A-cells) and secretory (B-cells) features. The B-cells, however, only show an appreciable content of typical secretory vesciles at 13 days. Our ultrastructural observations suggest that the B-cells are the source of some specific proteins of the synovial fluid and that they participate in the maintenance of the peculiar structure of the intimal interstitial tissue.

Age Factors↗

Storage of proteins in the rough endoplasmic reticulum of human hepatocytes in a patient with normal blood proteins, on oral contraceptives.

Aspects of protein storage in the rough endoplasmic reticulum of hepatocytes, comparable with those reported in alpha1-antitrypsine (AAT) deficiency, have been observed in the course of jaundice in a woman presenting no evident abnormality in AAT or other blood proteins. In light microscopy, most hepatocytes contained characteristic globular inclusions but they were PAS negative and did not react with anti-AAT antibodies. This storage of protein ceased at the time the jaundice disappeared. Prolonged treatment with high doses of contraceptive steroids may have been involved in this peculiar reaction of the hepatocytes.

Adult↗

Concentration of dopaminergic fibres in the marginal zone of the bird retina.

Nerve fibres containing dense core vesicles of 100-160 nm diameter are concentrated in a narrow zone (near the ora serrata) of the marginal retina in the pigeon and the chicken. Synaptic junctions exist between terminals containing dense core vesicles and the most marginal ganglion cells; however, numerous fibres seem to end freely near the vitreous body or even penetrate the pars plana of the ciliary body. Histofluorescence demonstrates the aminergic nature of these fibres. Determination of catecholamines with the dansylation technique reveals six times more dopamine in the marginal than in the central retina, whereas the noradrenalin level is unchanged. The dopaminergic fibres originate in neurons of the innermost zone of the inner nuclear layer. The marginal localisation of these fibres apparently excluding any visual function seems rather to indicate a possible photoreceptor system involved in neuro-endocrine regulation.

Adrenergic Fibers↗

Colchicine effects on neurosecretory neurons and other hypothalamic and hypophysial cells, with special reference to changes in the cytoplasmic membranes.

The morphological effects of colchicine on the entire neurosecretory (NS) tract and on various hypothalamic nuclei have been studied. The perturbations in axonal flow, indicated by the accumulation of NS material, coincide with fragmentation of the cytoplasmic membranes, i.e. the Golgi apparatus and the endoplasmic reticulum, whereas the neurotubules remain relatively well preserved. Autophagic destruction of NS material is observed along the entire length of the NS fibres. The rapid and systematic changes in the axoplasmic reticulum, known to store calcium, lead us to envisage a role for this system-similar to that of the sarcoplasmic reticulum-in controlling the transport of NS vesicles. The junctional zone between the stalk and the neural lobe seems to play a particular role in the transport of NS material to the posthypophysial terminals of the NS axons. Colchicine provokes an increase in dense-cored vesicles in most of the neurons of the other hypothalamic nuclei studied: arcuate, suprachiasmatic, periventricular and ventromedial. Membranous alterations are also observed in these sites. Colchicine administered to animals which were hypothyroid, castrated or adrenalectomized, reveals stimulated neurons, identified by their excessive content of dense-cored vesicles. These neurons display no specific localization, for they occur in all hypothalamic nuclei, irrespective of the stimulation. The frequency of stimulation of neurons of the periventricular nucleus is striking.

Animals↗

[Fine structure of the public symphysis in the mouse].

Classical histological descriptions of the modifications of the mouse pubic symphysis (PS) during pregnancy did not take sufficient account of its structural heterogeneity. Precise morphological study of the PS, in adult male and virgin female mice, was carried out under light and electronic microscopy. Our observations on pregnant females are still imcomplete. Two regions of the PS should be distinguished according to their structure and evolution during pregnancy. The cranial region shows diarthrodial articular characteristics. This region disappears in the female during the first pregnancy and is not reconstituted after parturition. The caudal region comprises two types of cells in the female : typical chondrocytes and a peculiar cell-type whose function has yet to be defined. The latter seems to be responsible for the loose structure of the symphyseal cartilage and to contribute to the development of pseudocavities in the ligament in the final days of pregnancy. It is possible that such cells may be stimulated by relaxin and may secrete a hydrophilic factor such as hyaluronic acid.

Animals↗

Encapsulation of implanted foreign bodies by hemocytes in Locusta migratoria and Melolontha melolontha.

Sterile fragments of cellophane, cat-gut, cotton, or beef muscle implanted into the body cavity of Locusta migratoria and Melolontha melolontha are immediately surrounded by granular hemocytes which form a multi-layered capsule around each foreign body. The cytoplasm of the granular hemocytes of the outer zone of the capsule in both species shows an accumulation of fibrous material (microtubules and microfilaments). None of the implanted material appeared to be degraded.

Animals↗