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Biomedical subjects

H Barriere

Publications and source records attributed to H Barriere.

At least 19 recordsLinked to original sources
PubMed1991

Gap junctional intercellular communication between cultured ependymal cells, revealed by lucifer yellow CH transfer and freeze-fracture.

In order to analyze intercellular communication between ependymal cells in mammalian brain, we have studied gap junctional communication of ependymal and glial cells in long term primary cultures derived from fetal mouse or rat hypothalamus and choroid plexus obtained in serum supplemented media with two complementary methods: 1) dye transfer of Lucifer Yellow CH after intracellular microinjection of the different cellular types, and 2) freeze-fracture of the same cultured ependymal cells. In our culture conditions, we have shown that the GJIC capacity to transfer dye was very different according to cellular types microinjected with Lucifer Yellow CH in the following respects: 1) in ependymal cells, GJIC was always important: ciliated ependymal cells, which are numerous in hypothalamic ependymal cultures (10-120 coupled cells), choroidal ependymocytes in plexus cultures (15-250 coupled cells), and non-choroidal ependymocytes in diencephalic roof cultures (10-30 coupled cells), and 2) in astroglial cells found in these primary cultures, no GJIC was observed in spite of the presence of well-differentiated gap junctions revealed by freeze-fracture replicas. All these results show a strong GJIC in ependymal cells and indicate the very good functional state of these cells in vitro.

Animals↗
PubMed1988

Polarity reversal of inside-out thyroid follicles cultured within collagen gel: structure of the junctions assessed by freeze-fracture and lanthanum permeability.

The organization of tight junctional complexes (TJs) was studied in cultured porcine thyroid cells during the inversion of polarity induced by collagen-embedding of inside-out follicles, using freeze-fracture replicas and lanthanum penetration. During the early steps of polarity reversal, freeze-fractures showed that TJs generally persisted. They increased in width and progressively branched out into the basolateral surfaces, towards the basal pole. Later, the number of TJ strands decreased and gap junctions inserted within TJ networks were found between cells in reversed follicles, in the same manner as in typically polarized follicles, embedded in collagen or in suspension. The de novo formation of TJ complexes was rarely found in the reversing structures. Despite the heterogeneity of TJs assessed by freeze-fracture, impermeability to lanthanum tracer was noted in inside-out structures. During the reversal process, some TJs remained unstained, whereas others displayed permeability to lanthanum. This heterogeneity might be due to the "opening" of a small number of junctions (perhaps only one by aggregate). When the process was achieved after 48 hr in collagen, the tightness of the junctions was complete, confirmed by the absence of lanthanum in luminal cavities of newly formed follicles.

Animals↗
PubMed1986

Monoclonal anti-interleukin 2 (15-2) antibody binding to granular layer keratinocytes of human skin.

Among several monoclonal antibodies (moABs) directed against human interleukin 2 (IL-2), the 15-2 moAB raised in our laboratory against unglycosylated recombinant IL-2 (produced in Escherichia coli) cross-reacted with a human skin epitope. This moAB gave a strong staining on the cell-surface membranes of keratinocytes from the granular layer of the epidermis. In addition, the 15-2 moAB stained 15% of epidermal cell suspensions obtained from suction blisters and reacted with cells from the spinous layer in parakeratosis and psoriasis, as well as with spinous epithelioma cells. Preincubation of the 15-2 moAB with pure human recombinant IL-2 abrogated skin binding, whereas a polyclonal antikeratin antiserum did not block 15-2 skin binding. Two other anti-IL-2 moABs, one directed against unglycosylated recombinant IL-2 (17-2 moAB) and one against glycosylated natural IL-2 (9B11 IE5 moAB), were unreactive on skin. Taken together, the data suggest that the 15-2 moAB binds to an epitope cross-reacting with, but different from, IL-2 which is located in the cell-surface membranes of granular layer cells. This cross-reactive epitope may provide a useful probe for the study of human epidermal cell differentiation.

Animals↗
PubMed1986

Cutaneous immunological studies in diagnosis of acute graft-versus-host disease.

A comparative study of the healthy skin of patients who had undergone bone marrow grafting and not developed graft-versus-host disease (GVHD) and of patients with cutaneous lesions of acute GVHD has been carried out. The aim of this study was to assess the diagnostic value of cutaneous immunopathology in the diagnosis of acute GVHD. A double-labelling immunofluorescence technique was used with a panel of monoclonal antibodies. The results showed a lack of specificity for GVHD in the distribution of Langerhans cells, but confirmed the diagnostic value of HLA-DR staining of epidermal keratinocytes. Cellular polymorphism of the T cell infiltrate in the dermis was observed (T helpers 40% and T suppressors 20%). The expression of the 55-57 Kd keratin polypeptide and of bullous pemphigoid antigen showed modification during acute GVHD while that of pemphigus antigen remained unchanged.

Acute Disease↗
PubMed1986

Polarity reversal of inside-out thyroid follicles cultured within collagen gel: an ultrastructural study.

Inside-out porcine thyroid follicles in culture undergo polarity reversal after being embedded in collagen gel. The newly-formed follicles reexpress some specific thyroid functions lost in inside-out follicles (Chambard et al., 1984. We present here an ultrastructural study of the inversion of polarity in this model system. This process takes place within 24 to 48 hr, without any opening of the original tight junctions, as shown by fixation in the presence of ruthenium red. A general shrinkage of cellular aggregates was noted soon after embedding. At the apical pole, three different modifications were observed: structural changes appeared in the kinocilium, microvilli and underlying cytoskeleton as early as 10 min after embedding, mainly when the apical pole of the cells was in close contact with the collagen fibers; large cytoplasmic lamellipod- or pseudopod-like extensions, covering the adjacent apical domain, protruded from outer apical regions; some other apical areas invaginated and formed channels inside the aggregates. The last two processes prevented close contact between apical cell surfaces and collagen fibers and allowed a persistence of the initial polarity in some of the cells. Newly-formed lumens were closed 24 hr after embedding in gel and the outer surface of the cellular aggregates in close contact with collagen fibers looked like a basal membrane. These mechanisms proceeded at different rates and involved different numbers of cells, but they all appeared to be related to the transformation of inside-out follicles into follicular structures.

Animals↗
PubMed1985

Thermography as a predictive tool for laser treatment of port-wine stains.

The argon laser, which has been proven both useful and safe for port-wine stain therapy, interacts with the hemoglobin of the vessels. In a percentage of cases, this treatment is still inefficient, and there is a lack of correlation between these bad results and clinical or histologic criteria. Thermography, which explores the vascularization of the port-wine stain, leads us to consider port-wine stains from a physical point of view. This very simple test shows no correlation with the clinical parameters of port-wine stain but is closely related to the results obtained with laser therapy. It seems to be a good criterion to estimate the argon laser treatment prognosis.

Adolescent↗
PubMed1983

[The laser in dermatology. Critical study of 63 cases].

With reference to their personal experience in sixty-three patients, the authors try to specify the indications of laser treatment in dermatology: evenly-colored flat angiomas, especially those of the face, which should not be treated before the age of fourteen. Vasoconstriction induced by the application of ice prior to treatment seems helpful. Widespread anal or vaginal venereal warts are another good indication. In common warts laser treatment is indicated only in some specific cases. The authors do not advocate laser treatment in malignant tumors. Results in tattoos are often unsatisfactory.

Hemangioma↗