Hair follicle nevus with hyperplasia of smooth and striated muscle.

We report a peculiar nevus which occurred on the left side of the chin of an 18-year-old male. It had been present for four years and had grown rapidly during the last year. Histologically, many hair follicles, smooth muscles, and striated muscles were found within the reticular dermis. The hair follicles were accompanied by mature sebaceous glands; numerous eccrine glands were seen in the middle and deep dermis. Immunohistochemical stain and phosphotungstic acid hematoxylin stain supported the fact that the muscles seen between the follicles were both smooth and striated. This nevus was considered to be a hair follicle nevus accompanied by hyperplasia of smooth muscles and striated muscles.

[Semi-malignant pitch-acanthoma on the hand of a coke oven worker].

We experienced a case of pitch-acanthoma which had developed on the hand of a coke worker after 15 years from his retirement. The patient was a 75-year-old male, who had worked mainly as a coke-oven worker for 24 years. In the spring of 1988, after 15 years from his retirement, he noticed a small nodule on the dorsal aspect of his right hand. He visited our clinic on June 1988 because the nodule was rapidly growing larger. The diagnosis of pitch-acanthoma was obvious from his occupational history and the characteristic poikilodermatous outlook of his skin. The tumor was removed surgically. Histological examination showed hyperkeratosis and acanthosis with horn-pearl formation. Moreover, a pack of atypical cells was observed within the lesion, suggesting an early malignant change. The patient was heavily exposed to a tar-gas-containing atmosphere in his workplace for quite a long period. As tar or pitch remains within the skin in spite of careful cleansing, workers in this atmosphere have a relatively high risk of developing skin cancer. Our present case shows that such malignant change can occur after long years and we would emphasize the necessity of a long term follow-up, perhaps throughout the lifetime of these workers.

Studies on delayed hypersensitivity to protein antigen. Induction of delayed hypersensitivity by chemically modified antigen.

it was shown in our previous paper that mice primed with chemically modified bacterial alpha-amylase (BaA), which was neither cross-reactive with anti-BaA antibody nor able to induce a humoral anti-BaA response, developed enhanced responses to a subsequent challenge with native BaA and that the magnitude of the immunological memory was closely related to the priming dose of modified BaA. This paper describes the experimental conditions for induction of delayed hypersensitivity (DH) by modified BaA in relation to the development of immunological memory for antibody response to native BaA. Mice primed with either an intraperitoneal (i.p.) or subcutaneous (s.c.) injection of modified BaA in complete Freunds adjuvant (CFA) developed enhanced anti-BaA as the immunogen and modified BaA as the eliciting antigen, the relationship of anti-BaA responses to a subsequent challenge with BaA. In contrast, when mice were immunized with an s.c. injection of the modified BaA only, a significant level of DH to native BaA could be induced, as measured by the footpad reaction (FPR). The highest degree of DH was observed in mice given 50 micrograms of modified BaA. DH was detectable within 5 days and persisted for 25 days after immunization. In the reciprocal combination of native BaA as the immunogen and modified BaA as the eliciting antigen, the relationship of anti-BaA responses to DH was examined. The primary anti-BaA responses induced by an i.p. injection of large doses of BaA was markedly higher than those induced by an s.c. injection, while DH was exhibited only in mice given s.c. injection of BaA in CFA. With respect to DH to native BaA induced by the modified BaA, it was shown that C3H/He mice were high and C57BL/6 mice were low responders.

Effect of priming doses of chemically modified antigen on helper activity.

Mice primed with chemically modified bacterial alpha-amylase (BalphaA) [EC 3.2.1.1 alpha-amylase, B. subtilis], which was neither cross-reactive with anti-BalphaA antibody nor able to induce a humoral anti-BalphaA antibody response, developed enhanced responses to a subsequent challenge with native BalphaA (Nakashima et al. (1974) J. Biochem. 76, 349-357). The present studies were designed to examine the relationship of priming doses of BalphaA derivatives to the level of enhancement of the helper activity. Increasing the priming dose of modified antigens resulted in a greater degree of helper cell response until the maximal level of enhancement was reached. When injections for priming and challenge were given intraperitoneally, priming doses of D-BalphaA, M-BalphaA, and RM-BalphaA required for the maximal enhancement of helper activity were about 15, 50, and 15 mug, respectively. Further increase in the priming dose, conversely, resulted in suppressin of the enhanced helper activity, irrespective of whether the time interval between priming and challenge was 10 or 28 days. Suppression of the enhanced helper activity upon excessive dose priming with modified BalphaA derivatives was not specific for the anti-BalphaA antibody response. On the basis of these results it is suggested that this phenomenon of suppression might be partly accounted for by the regulatory mechanism functioning in antigenic competition.