Eczéma séborrhéique et psoriasis chez le nourrisson: étude comparative morphologique et cinétique

Seborrhoeic dermatitis, psoriasis and atopic dermatitis in infants were studied morphologically and autoradiographically on skin biopsies. A similar picture with an increased germinative cell population and accelerated cell turnover has been found in psoriasis and seborrhoeic dermatitis. These features may suggest a relationship between both diseases.

Biochemical and immunological differences between hydrophobic and hydrophilic strains of Streptococcus mutans

Hydrophobic strains of Streptococcus mutans were compared with paired variants showing reduced hydrophobicity. Extracts of hydrophobic cells contained a number of high-molecular-weight proteins which were not present on cells with decreased hydrophobicity. The proteins were found in purified cell walls, suggesting that they are located on the bacterial surface. Trypsin treatment of whole cells destroyed the proteins and reduced the hydrophobicity. Chemical analysis did not reveal any marked differences in the proportion of cell wall constituents. The amino acid compositions and lipoteichoic acid contents of hydrophobic and hydrophilic cell walls were similar. Culture supernatants from the hydrophilic variants contained high-molecular-weight proteins similar to those extracted from the cell walls of the hydrophobic parent strains, indicating that the variants were impaired in their ability to incorporate the hydrophobicity-associated proteins into the cell wall. The dominant protein had a molecular weight of 190,000, similar to that of antigen I/II (B) of S. mutans.

[Atopy and dermatophyte infection in children]

The atopic chronic dermatophytosis syndrome is uncommon in children. Clinical and immunological characteristics are reviewed. The infecting fungus is Trichophyton rubrum, occasionally Trichophyton interdigitale.

Characterization of cellular infiltrates in skin lesions of atopic eczema by means of monoclonal antibodies

Frozen skin biopsies from 3 acute and 3 chronic lesions of atopic dermatitis were examined by means of various ortho-monoclonal antibodies (OKT3, 4] not equal to----4, OKT6, OKT8; OKIa and OKM1) in an indirect immunofluorescence technique. The results show that both T helper (T4) and T suppressor cytotoxic (T8) lymphocytes are present in the inflammatory infiltration which predominantly contained Ia mononuclear cells. Despite the absence of double staining procedure, the observations suggest that T4 cells predominate over T8 cells in the acute lesions whereas the reverse tendency is noted in the chronic lesions. T8 cells are found mainly in the superficial dermis or even in the epidermis; by contrast, T4 cells tend to be more deeply located in the dermis. The lesions are characterized by a dramatic increase in the number of Langerhans cells (OKT6, OKIa+) that are found not only in the epidermis but also in the dermis.

Contact sensitivity to rubber additives in Belgium

The frequency of positive patch tests to rubber additives in Belgium is recorded. Allergy due to rubber protective gloves represents 41% of the overall sensitivity to rubber.