Seichiro Sagami

ELECTRON MICROSCOPIC STUDY OF THE EFFECT OF VITAMIN A ON THE DIFFERENTIATION OF RECONSTRUCTED EMBRYONIC CHICK SKIN

In reconstructed embryonic chick skin, the mass of epidermal cells was separated from the mesenchymal portion by a continuous basallamina. The findings on the cytoplasmic organelles, e.g. filamentous structures, desmosomes, keratohyalin, and membrane coating granules of the peripheral and central epidermal cells, corresponded to those of the epidermis when the centre of the cell‐mass was presumed to he the surface of the epidermis. The addition of 5 i.u./ml. vitamin A in the culture medium inhibited the process of keratinization. Filamentous structures and desmosomes were sparse even in the centre of the epidermal cell‐mass. There were wide intercellular spaces and the basal lamina was obscure and discontinuous. The endoplasmic reticulum was dilated and the Golgi zones were distinct. Thus the vitamin A‐treated cell resembles the secretory cell and shows less tendency to differentiate towards a keratinocyte. The development of lysosomes in the vitamin A‐treated cells confirmed that vitamin A releases protease.

Therapeutic experience of basal cell epithelioma carried out in accordance with a fresh organization method of Mohs.

64歳, 女性の鼻背部基底細胞上皮腫に対し, Mohsの新鮮組織法 (Mohs micrographicsurgery fresh-tissue technique) に準じた方法で摘出し, 正中前額皮弁により再建した症例を経験した。Mohsの新鮮組織法は, 視診・触診にて, 術前に腫瘍の切除範囲が決定しにくいような基底細胞上皮腫には, 良い適応と思われた。

Antigen presenting cells and T lymphocyte in the induction phase of contact hypersensitivity

When a sensitizing substance that induces contact hypersensitivity, fluorescein isothiocyanate (FITC), was painted on abdominal skin of mice, FITC+ cells appeared in the inguinal lymph node after 24 hours. The FITC+ cell in the lymph node was relatively large in size, and it did not appear to be a T lymphocyte. When FITC was painted on either murine tail skin or skin pre-treated by tape stripping, the number of FITC+ cells in the inguinal lymph node was significantly less than that in the positive control. In the mesenteric lymph nodes, which have a different lymph flow from that of the skin regional lymph node, FITC+ cells did not increase in number, and the few FITC+ cells were not significantly different in number among above-mentioned experimental systems. In the inguinal lymph nodes on the 4th day after painting of picryl chloride (PCl) on the abdominal skin of mice, L3T4+ cells, which expressed an interleukin 2 receptor (IL-2R), increased in number. On the other hand, when PCl was painted on either tail skin or skin treated by tape stripping, L3T4+ IL-2R+ cells did not increase in the skin regional lymph nodes. The number of L3T4+ IL-2R+ cells in the mesenteric lymph nodes did not increase in any of the experimental systems mentioned above. These results suggest some relationship between antigen presenting cells and T lymphocytes, as well as one between the skin and the regional lymph nodes, in an induction phase of sensitization in contact hypersensitivity.