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Biomedical subjects

L Orcel

Publications and source records attributed to L Orcel.

At least 37 records · Page 2Linked to original sources
PubMed1985

[Structure and function of the fetal umbilical vessels].

A morphological study carried out using electron microscopy has shown that there is an endothelium in the umbilical blood vessels consisting of intercellular spaces which interdigitate with one another and that are not specialization in junction complex. The endothelial cells are rich in their typical organ structure and have pinocytotic vesicles. There media contains a muscular coat which is thicker in the artery than in the veins. The smooth muscle cells also show pinocytotic vesicles. This morphological state leads the authors to two groups of thought: There is active diffusion by a process of "plasma perfusion" from the lumen of the vessels through the vascular wall which forms a physiological system for taking up fluids which in turn is capable of providing for the energy and plastic requirements of the umbilical vessels: The umbilical arteries, because of their thick muscular tunic and because of the ability of the lumen to dilate as there is an absence of an internal elastic membrane, can function not only as tubes for conducting blood but also as organs that regulate the blood flow. On the other hand the umbilical vein, which cannot stretch and cannot retract because its wall is so thin, behaves as an organ to return the blood flow, particularly because it does have an inner limiting layer preventing over-stretching.

Diffusion↗
PubMed1984

Morphological study of the chorio-allantoic fetal membranes.

Morphological study of the chorio-allantoic fetal membranes has demonstrated the existence of foot processes extending from the main body of amniotic cells and containing microfibrils arranged in dense bundles as described in podocytes of renal glomerulae; on the surface fronds and between their bases many small pits and caveolae are seen; in the cytoplasm of amniotic cells large vacuoles are present; they frequently distort the nuclei into crescentic shapes. In the chorion underlying the amnios, fibroblasts and Hofbauer cells are found; their surface often has overlapping filopidal projections. The syncytium bounding the intervillous space shows a marked resemblance to that of the villi. These morphological features seem to indicate that chorio-allantoic fetal membranes might be an important route for the transporting of fluid from the maternal blood in the intervillous space into the amniotic compartment.

Allantois↗
PubMed1984

[New data on the morphology of the allanto-chorion fetal membranes].

The authors have carried out an electron microscopic study on the morphology of the allanto-chorial membranes of late pregnancy. The demonstration of these amniotic cells with their long pedicles which resemble those of renal podocytes, together with the presence of intercellular canals lined by long villi which themselves cross over with one another to make a grid, and the existence of intracellular canals that make transcytoplasmic tunnels, permit the authors to suggest that they are dealing with a morphological illustration of ultrafiltration processes. The authors suggest that the forces that bring about plasma filtration from the intervillous chamber towards the amniotic compartment crossing the allanto-chorial membranes are the same as those that cause glomerular filtration. These are hydrostatic pressure in the intervillous chamber and the oncotic pressure within the amniotic compartment.

Allantois↗
PubMed1984

[Pathologic anatomy of villous tumors].

After defining a number of essential terms and recalling the great many synonyms used in the literature, the authors discuss the macroscopic and histological appearance of villous tumours. They emphasize the importance of a good methodology, the limitations of biopsies and the fact that the prognosis of a lesion can only be established after examination of all of the specimen.

Adenocarcinoma↗
PubMed1983

Ocular findings following intravitreal silicone injection.

In three cases of intraocular silicone oil injection in which the histologic picture is observed at different time intervals, emphasis is given to the fact that fibrous tissue formation around silicone vesicles is a rather constant complication and of early occurrence. Thus, we believe that the removal of liquid silicone from the eye should not take place later than two or three months after the injection. In our first reported case, there was an association of silicone oil injection and vitrectomy with retinal detachment procedures and sympathetic ophthalmia. In the absence of evident histologic or clinical proof, we do not consider silicone oil injection itself as having induced the mechanisms of sympathetic ophthalmia.

Adolescent↗
PubMed1983

[Reabsorption of amniotic fluid through parietal fetal membranes. A hypothesis based on an ultrastructure study].

Recent investigations have shown that the link between water transport and solute transport in epithelia is made possible by subcellular structure build on a striking geometrical plan, namely, long and narrow dead end channels. The most striking feature of our electron microscopic study of the amnion as well as the chorionic cytotrophoblast, was the demonstration of the existence of intercellular channels running between the lateral sides of the cells with typical junctional complexes sealing their proximal ends; thus they constitute long and narrow dead-end channels. In the amnion, these channels open through the basal lamina into the connective tissue, and in the chorionic cytotrophoblast they open in the direction of the decidua. This situation seems to indicate that fluid emerges from the open mouth of the amniotic intercellular channels and then continues to flow into the channels of the cytotrophoblast, across its podocytic processes, to be dumped into the decidua, and finally drained by maternal decidual vessels. This morphological study suggests that parietal fetal membranes might be an important route for transport of solute and fluid from the liquor amnii into the maternal circulation.

Absorption↗
PubMed1982

The evolution of experimental endarteritis in the rabbit abdominal aorta. Light and transmission electron microscopy.

Experimental aortic intimal thickening has been induced in rabbits by sheathing the vessel with a polyethylene cuff. The alterations have been examined by light and transmission electron microscopy, during 12 months. An irregular intimal thickening develops as soon as the 15th day and includes numerous myofibroblasts with some other cells of monocytic or endothelial type. Microfibrils, elastic aggregates and collagen fibers are found in the intercellular space. Simultaneously, the media undergoes a fragmentation of the elastic laminae and the adventitia shows a capillary angiectasis and a granuloma. After 3 months there is, between the intimal smooth muscle cells, a progressive increase of elastic and collagenous material. In the media, elastic break up becomes more frequent after the 4th month and myocytes appear increasingly atrophic, which facilitates the extension of fibrosis. This is accompanied at times by a thinning of the arterial wall with or without localized disappearance of the media. All these modifications are discussed and compared to what we had previously found in the femoral artery [12].

Aging↗
PubMed1982

["Vestigial cells" of the transitional area of the uterine-cervix. Comparative morphological study with the subcylindrical-reserve-cells (author's transl)].

The squamo-cylindrical junction represents a transitional area of unstable epithelium. It consists of slightly differentiated cells which disclosed resemblance in morphological pattern with germinal cells of the basal layer in the exocervical squamous epithelium. These unstable cells, according to the authors, may be derived from the cranial, most cephalic extend of the sinusal vaginal plate which had formed the epithelium of the entire vagina and the vaginal portion of the cervix up to the squamo-columnar junction. Ultrastructural analysis disclosed no similarities between cells of the squamo-columnar junction and subcylindrical reserve cells which exhibited sometimes resemblance to the "mesenchymal cells" found within the surrounding stroma.

Cervix Uteri↗