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Biomedical subjects

H Meffert

Publications and source records attributed to H Meffert.

At least 73 records · Page 4Linked to original sources

Prolongation of the survival of skin grafts in mice by PUVA treatment.

The combined application of psoralen and UVA radiation to skin grafts induced a prolongation of the survival time of the grafts in mice. This was observed using the H-Y barrier, an allogeneic barrier without H-2 disparities, and a strong H-2 incompatible barrier. The effect is probably due to a reduction of antigen-presenting cells, or to other, unknown mechanisms.

Animals

Prolongation of skin graft survival in mice by in vitro PUVA treatment and failure of induction of specific immunological memory by PUVA-treated grafts.

Treatment of murine skin grafts in vitro with 8-methoxypsoralen and longwave ultraviolet radiation prolonged their subsequent survival on allogeneic recipients, but not in cases where the recipients had been presensitized by a former skin graft of the same donor strain. In contrast to normal skin, grafts pretreated with 8-methoxypsoralen and longwave ultraviolet radiation were not able to induce an immunological memory as revealed by a second transplantation of normal skin. The results show that primary and secondary skin graft rejection can be affected by the combined action of psoralen and ultraviolet radiation.

Animals

Phototoxicity and antipsoriatic effect of a topical methoxypsoralen solution in relation to the application time.

The phototoxicity and antipsoriatic activity of a topically applied 0.075% methoxypsoralen alcohol-glycerol solution was investigated in relation to the interval between drug application and irradiation. On healthy skin, maximum UVA sensitivity for erythema development appeared 40 to 60 min after the application of the methoxypsoralen solution, but in psoriatic plaques the antipsoriatic UVA sensitization reached its maximum after 10 to 20 min. This difference between induction of antipsoriatic effect and erythema sensitivity may be explained by rapid penetration of methoxypsoralen in psoriatic lesions or by different targets at the cellular level for the erythema-producing effect and the antipsoriatic effect.

Administration, Topical