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Biomedical subjects

D Hanau

Publications and source records attributed to D Hanau.

104 records · Page 6Linked to original sources
PubMed1981

[The infundibular adenoma: a follicular poroma with sebaceous and apocrine differentiation (author's transl)].

Tricholemmal adnexal pilar tumors may be classified according to the tricholemmal zone whose structure they reproduce and according to their degree of maturation or dedifferentiation. The pilar sheath acanthoma (dilated pore of Winer), the tumor of follicular infundibulum and the follicular poroma (inverted follicular keratosis) are related to the infundibulum and keratinize according to the epidermal pattern. The tricholemmal cysts (of simple or proliferating type) and the keratinizing tricholemmoma are related to the upper part of the isthmus of the anagen hair and keratinize according to the specific pattern of the outer root sheath at this isthmic level. The tricholemmoma is related to the lower tricholemma which does not keratinize and the cells of which are glycogen-rich. In this vertical didactic classification, there exist combinations and filiations of the different tumors. In a serial analysis of 68 skin adnexal tumors diagnosed as follicular poromas, we observed 6 cases with sebaceous and apocrine differentiation. For this organoid tumor issued from the infundibular epithelium we propose the term of "infundibular adenoma".

Adenoma↗
PubMed1981

[Pinkus' trichodiscoma (author's transl)].

The trichodiscoma first described by Pinkus (1966) is a small cutaneous tumor of the human retropilar hair disk; these lesions generally multiple and probably more common than previously appreciated occur in adult patients most often associated with perifollicular fibromas and acrochordons. We observed 2 female patients (39 and 47-year-old) with multiple trichodiscomas; a linear group of 7 tumors on the scalp in the first and multiple lesions disseminated on the chest in the second. Histologically and--in one case--electronmicroscopically the most striking features are: the paucity of the Merkel's cells in the overlying basal layer of the epidermis, the hyperplasia of the capillary blood vessels and of their endothelial cells, the presence of thick myelinated nerve fibers in the depth of the lesion but not in the vicinity of the epidermis, the proliferation of a loose dermal connective tissue, the occurrence of sparse hair follicles connected to the trichodiscoma but frequently located on its margin. One can conclude that trichodiscoma mainly consists of a hyperplasia of the dermal components of the hair disk; Merkel's cells though belonging to the normal hair disk are not involved in the histogenesis of the tumour. In his comprehensive paper (1974), Pinkus predicted that the description of the trichodisoma will lead to the identification of patients having only one or a few lesions: our first case may be considered as a circumscribed paucilesional clinical form.

Adult↗
PubMed1980

Contact dermatitis in children.

It is generally admitted that contact dermatitis seldom appears in children. Eighty-seven cases, however, have been diagnosed at the Department of Allergology of the Dermatological Clinic in Strasbourg in the past 10 years (1969-1978). No element of atopic diathesis could be found in any of them. We have reviewed the cases with a positive patch test to try to derive both theoretical and practical conclusions.

Adolescent↗
PubMed1980

Ultrastructure of early pigmentary changes in Dowling-Degos' disease.

Dowling-Degos' anomaly is characterized by a reticular and spotted pigmentation of the skin folds; this pigmentary disturbance, occurring most often in women, is a dominant inherited genodermatosis which worsens progressively and may exhibit in the early phase rapid changes in severity after emotional stress. In a 9-year-old girl, an electonmicroscopic study of pigmented lesions showed a strong melanocytic activity with quantitative increase of the melanosomes; the average size of the melanosomes was not different when compared to normal Caucasoid skin, but in the keratinocytes they were distributed according to a dispersed pattern as in black skin. The pigmentary state of Dowling-Degos' disease is another example of melanocyte-keratinocyte interaction where the epidermal melanin pattern and the size of pigment granules are not in striking correlation. An accelerated rate of melanogenesis and pigmentation may be another factor determining a non-aggregated distribution of the melanosomes within the keratinocytes. The nature of the stimulus of pigmentation in these skin areas which are not sun-exposed is still unclear.

Child↗
PubMed1980

[Rhodamine B: a tracer of follicular keratinization (author's transl)].

The mixture at equal volumes of a 0.1 p. 100 solution of rhodamine B in distilled water and of a 0.25 p. 100 solution of toluidine blue in Walpole's pH 4.4 buffer dyes each pilar sheath differently. At the level of the medulla, the granules fix rhodamine B, so do the cortical cells at the level of the keratogenic zone. Once they are keratinized, however, cortical cells remain colorless. Concerning the cells of the inner root sheath, on the other hand, their trichohyaline granules are dyed by rhodamine B, whereas the keratinized cells turn dark blue under the effect of toluidine blue. The trichilemmal keratin both of the isthmus of the anagen hair and of the follicular sac becomes light red. This technique, which can be easily applied to the trichogram, allows us to identify more or less mature pilar anlages in in adnexal tumors, to differentiate keratinizing cysts and to trace various pathological keratins. Thanks to a chemical study, it was shown that the mixture rhodamine B-toluidine blue is only a mechanical mixture which works through its acide-bases properties.

Basal Cell Carcinoma↗
PubMed1979

Trichilemmal tumor undergoing specific keratinization: "keratinizing trichilemmoma".

Numerous tumors with follicle-like direction of differentiation have been described. At least three of them connected to the overlying epidermis are related to the outer root sheath or trichilemma: the tumor of follicular infundibulum (Mehregan & Butler 1961) and the inverted follicular keratosis (Helwig 1955) or follicular poroma (Duperrat & Mascaro 1963) have been related to the infundibulum, the tricholemmoma (Headington & French 1961) to the lower outer root sheath. On the occasion of a case first diagnosed as proliferating trichilemmal cyst of the scalp, we think we have individualized a tumor exhibiting ability to undergo trichilemmal keratinization. We describe its histogenesis and stress its peculiarties compared with other lesions showing trichilemmal keratinization.

Aged↗
PubMed1979

Lipoid proteinosis (Urbach-Wiethe syndrome).

A Jewish-Iranian family suffered from lipoid proteinosis. The 8 affected siblings were from consanguineous matings and presented a wide range of phenotypic expressions. Minimal manifestations in 2 heterozygote carriers and the possibility of autosomal recessive inheritance are discussed.

Adolescent↗
PubMedDate not supplied

In vitro binding and internalization of HIV envelope glycoproteins by human epidermal Langerhans cells does not require the CD4-gp120-binding site.

Langerhans cells (LC) are epidermal dendritic cells which express several surface antigens, among them the CD4 antigens. Recent data demonstrated that LC constitute target and storage cells for HIV. To better understand the interactions between HIV and LC, we investigated, in the present work, the fate of HIV envelope glycoproteins (gp120 and gp160) incubated with healthy human trypsinized LC in suspensions. After trypsin treatment, only the epitope for OKT4 appeared to be resistant on LC. In the absence of antigenic sites identified by OKT4A, Leu3a or BL4 (epitopes implicated in HIV binding), LC bound and internalized recombinant HIV gp120 or gp160. This finding supports the hypothesis that there exists at the surface of LC a second molecule which may act as an HIV receptor.

Antibodies, Monoclonal↗
PubMedDate not supplied

Trypsin-resistant gp120 receptors are upregulated on short-term cultured human epidermal Langerhans cells.

The CD4 molecule is known to be the preferential receptor for the HIV1 envelope glycoprotein. Epidermal Langerhans cells (LC) are dendritic cells which express several surface antigens, among them the CD4 antigens. LC infection was suggested when these cells were seen to present buddings coincident with membrane thickening of roughly 100 nm in size. These buddings were similar in ultrastructural aspect to HIV buddings on in vitro infected promonocytic cells (U937). To clarify the exact role of CD4 molecules in LC infection induced by HIV1, we investigated the possible involvement of between native and recombinant HIV1 gp120 and the LC surface. We also assessed the expression of CD4 molecules on LC membranes dissociated by means of trypsin from their neighbouring keratinocytes. The cellular phenotype was monitored using flow cytometry. We show that human LC can bind the viral envelope protein and that this binding does not depend on CD4 protein expression. The amount of surface bound gp120 was not consistent with the amount of CD4 antigens present on LC membranes. The gp120-binding sites on LC in suspension appear to be typsin-resistant while the CD4 antigens (at least the epitopes known to bind HIV1) are trypsin-sensitive. A burst of gp120 receptor expression was detected on 1-day cultured LC while the CD4 antigens disappeared. These findings lead to the logical conclusion that the binding of gp120 is due to the presence of a LC surface molecule which is different from CD4 antigens.

Antibodies, Monoclonal↗
PubMedDate not supplied

Comparative study of in vitro CD1a and HLA-class I antigens endocytosis by human thymocytes and Langerhans cells.

Langerhans cells and thymocytes were comparatively studied for their monoclonal antibody-induced endocytic activity. The two cell types were CD1a or Class I-HLA immunolabeled, incubated under similar conditions and the effects induced on membrane mobility were analyzed by a fluorescence method for the thymocytes and at the ultrastructural level for both cell types. We provide evidence that thymocytes are able to cap and internalize by receptor-mediated endocytosis CD1a antigen and Class I-HLA, whereas Langerhans cells present only a process of internalization by receptor-mediated endocytosis for both membrane antigens.

Antigens, CD1↗