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Biomedical subjects

E Dupont

Publications and source records attributed to E Dupont.

287 records · Page 16Linked to original sources
PubMedDate not supplied

Individual gap junction plaques contain multiple connexins in arterial endothelium.

Gap-junctional intercellular communication in endothelial cells is implicated in the coordination of growth, migration, and vasomotor responses. Up to 3 connexin types, connexin40 (Cx40), Cx37, and Cx43 may be expressed in vascular endothelium according to vascular site, species, and physiological conditions. To establish how these connexins are organized at the level of the individual endothelial gap junction, we used affinity-purified connexin-specific antibodies raised in 3 different species to permit double and triple immunolabeling in combination with confocal and electron microscopy. Using HeLa cells transfected with Cx37 and Cx40 for characterization, the anti-Cx37 antibody (raised in rabbit) and the anti-Cx40 antibody (raised in guinea pig) were shown to recognize single bands of 37 and 40 kDa, respectively, on Western blots and to give prominent punctate labeling at the cell borders, specifically in the corresponding transfectant. By applying these antibodies together with mouse monoclonal anti-Cx43 for double and triple immunofluorescence labeling at confocal microscopy, rat aortic and pulmonary arterial endothelia were found to express all 3 connexin types, whereas coronary artery endothelium expressed Cx40 and Cx37 but lacked Cx43. High-resolution en face confocal viewing of the aortic endothelium after double labeling demonstrated frequent colocalization of connexins, with distinct variation in the expression pattern within a given cell, where it made contact with different neighbors. Triple immunogold labeling at the electron-microscopic level revealed that aortic endothelial gap junctions commonly contain all 3 connexin types. This represents the first definitive demonstration of any cell type in vivo expressing 3 different connexins organized within the same gap-junctional plaque.

Animals↗
PubMedDate not supplied

[Hippocrates, father of semiology and medical deontology].

Elaborated 24 centuries ago, Hippocrate's and his school's works are considerable. They concern all aspects of medicine, surgery and even obstetrics, tackled by three approaches: clinical observation by constitution for each patient of what can be considered as the ancestor of the current medical file and by use of clinical signs still in application in modern semeiology; the Oath, basis of benevolence ethic, still taken nowadays but in an actualized form by future medical doctors; humoral theory which proposes a physiopathological concept of diseases and deduces a therapeutical approach still in use until the end of 19th century, by lack of sufficient knowledge about organs function and origin of diseases. It consists in an amalgam of archaic concepts, elaborated by presocratic philosophers about matter's structure transposed to body fluids and presented in a pseudocoherent form. Current concepts of diseases, especially role of pathogens render it obsolete.

Diagnosis↗
PubMedDate not supplied

Ontogeny of 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase (3 beta-HSD) in human testis as studied by immunocytochemistry.

The enzyme complex 3 beta-hydroxy-5-ene-steroid dehydrogenase/delta 5-delta 4 isomerase (3 beta-HSD) is involved in the biosynthesis of all classes of active steroids, including androgens. To correlate possible changes in 3 beta-HSD with the well-known variations in testosterone secretion during development, the authors localized this enzyme by immunocytochemistry during fetal and postnatal periods of development in the human testis. In the fetal testis, 3 beta-HSD was detected in Leydig cells during the second and third trimester of gestation. In 8-month-old and 11-year-old boys, however, no immunoreaction could be detected in the testis. In pubertal boys, Leydig cells appeared well developed and immunopositive. Since the fluctuations in 3 beta-HSD immunoreactivity are similar to those already observed for androgen secretion, activation of 3 beta-HSD by trophic hormones may play an important role in androgen production during fetal and postnatal development.

Adolescent↗
PubMedDate not supplied

Familial Crohn's disease in multiple siblings: no linkage to the HLA system.

We report five families with 3 or more children having Crohn's disease. In one family, 6 out of 11 siblings were affected. HLA haplotype study in affected children showed that the probability of random segregation was only 38 percent, making improbable a linkage between the histocompatibility locus and the development of Crohn's disease. However similar clinical patterns in siblings could suggest a genetic factor not linked to the HLA system.

Adolescent↗
PubMedDate not supplied

The active T rosette: an early marker for T-cell activation.

This review summarizes some of the recent observations regarding the active T-rosette assay. This test, performed under suboptimal technical conditions, identifies a subpopulation of T lymphocytes with high-avidity receptors for sheep red blood cells. They are Ia-positive but appear to lack an Fc receptor. They can be either OKT4-positive or OKT8-positive. Isolated active T-rosette populations are capable of recognizing and killing allogeneic cells and they also modulate B-cell immunoglobulin production. They are directly correlated in vivo with specific cutaneous reactivity to an antigen. More interestingly, the percentage of active rosettes specifically increases in vitro after one hour of incubation with soluble or cellular antigens. This test fully correlates with the lymphocyte stimulation test. In the case of human mixed lymphocyte culture, the increase in active T rosettes is due to antigenic differences in the HLA D-DR region. The neoformation of active T rosettes is due to the early release of a rosetting factor. Drugs which are able to modulate T-cell functions, such as thymosin, transfer factor, isoprinosine and NPT-15392, also increase the percentage of active T rosettes. Therefore, the newly formed active T rosettes appear to be an early marker for lymphocyte activation.

Animals↗
PubMedDate not supplied

[Minimal encephalitis in patients with renal transplant. Clinicopathological study and discussion of the role of the cytomegalovirus (author's transl)].

An autopsy was performed in ten patients recipients of renal allograft who died from cytomegalovirus pulmonary infection. In six patients, encephalitis lesions disseminated in the whole brain were observed. These lesions were not symptomatic. The particular features of this entity and its relationships with the type of immunosuppression therapy are discussed.

Brain↗
PubMedDate not supplied

Cytokines in alcoholic liver cirrhosis.

Interest for cytokines involvement in experimental and human liver injury has considerably increased over recent years. The present paper reviews the current knowledge in the field of alcoholic cirrhosis. The role of interleukin-1, tumor necrosis factor, interleukin-6, interleukin-8 and interleukin-10 are discussed together with their possible diagnostic and prognostic significance. Prospects for future investigations such as immunotherapy are underlined.

Bacterial Infections↗
PubMedDate not supplied

The SANGUIS Study in Belgium: an overview of methods and results. Safe and good use of blood in surgery.

SANGUIS was multicentric European study involving more than 7,000 patients in 43 teaching hospitals during a one year period. The goal of the study was to describe current transfusion practice for elective surgery in adult. The present paper summarizes the data collected on the 1,193 patients enrolled in Belgium. It also introduces the final report of the SANGUIS study in Belgium, which will be published as a special issue of the Acta Chirurgica Belgica.

Adult↗
PubMedDate not supplied

Chronic hereditary pancreatitis.

Chronic hereditary pancreatitis is a rare disease accounting for 0.9% of chronic pancreatitis cases. Onset is at an earlier age than chronic alcoholic pancreatitis, often with recurrent painful episodes in childhood. We report the occurrence of hereditary pancreatitis in 3 members of a family over 3 generations.

Adenocarcinoma↗