Hikotaro Yoshida

Immunohistochemical studies in mite antigen-induced patch test sites in atopic dermatitis

The role of mite allergen in atopic dermatitis is still unclear. In this study, we investigated whether an eczematous reaction could be induced by patch testing with dust mite antigen. We succeeded in reproducing an eczematous lesion and the mite RAST-positive AD group showed a positive reaction much more than the RAST-negative group. Many mite antigen-bearing Langerhans cells, also possessing IgE molecules, were found by the use of an immuno-double labelling technique. By using immunoelectron microscopy, it was observed that the mite antigens were trapped by some macrophages, which were apposed to lymphocytes. To investigate the time-course of the reaction, the patch test reactions were read and biopsied after 1 h, 6 h, 24 h and 48 h. An eczematous reaction developed 24 h after patch testing. The mite antigen-bearing Langerhans cells were seen exclusively in the epidermis after 6 h, and mainly in the dermis after 24 h and 48 h. These results suggested that IgE-mediated contact hypersensitivity to mite antigen may develop and play an important role in AD.

House dust mite (HDM) antigen in naturally occurring lesions of atopic dermatitis (AD): The relationship between HDM antigen in the skin and HDM antigen-specific IgE antibody

To elucidate the etiological role of house dust mite (HDM) antigen in the pathogenesis of atopic dermatitis (AD), we conducted immunohistochemical studies on the localization of HDM antigen in naturally occurring lesions of AD. HDM antigens were found in the epidermis and dermis in 19 of 38 cases. All of the 19 patients had HDM antigen-specific IgE antibody, but HDM antigen was not detected in the lesions of patients without HDM antigen-specific IgE or in control skin specimens. Most HDM antigens were located on Langerhans cells (LCs) or near helper T cells. Our findings suggest that HDM antigen is the causative factor in the development of eczematous lesions of AD, and thus we hypothesized that IgE-mediated allergic contact sensitivity to HDM antigen plays an important role in the pathogenesis of AD.

High affinity IgE receptor (FcεRI) expression on eosinophils infiltrating the lesions and mite patch tested sites in atopic dermatitis

Expression of the high affinity IgE receptor (FcεRI) on eosinophils has recently been reported. This led us to evaluate FcεRI expression on eosinophils in atopic dermatitis (AD). Double immunofluorescence stainings with an anti-FcεRI monoclonal antibody (mAb) and a polyclonal antieosinophil cationic protein (ECP) antibody were performed on lesional biopsy specimens from patients with AD and from patients with bullous pemphigoid (BP) as controls. In AD and BP lesions, 77% and 70% of eosinophils expressed FcεRI, respectively. However, the intensity of FcεRI staining in AD was much stronger than in BP, suggesting upregulation of FcεRI expression on eosinophils in AD. In addition, the eosinophils infiltrating AD lesions were stained strongly with anti-CD23 mAb and anti-IgE antibody. At the sites of mite patch testing in AD, FcεRI-, CD23- and IgE-positive eosinophils were observed to the same degree as in the lesions, and a considerable number of mite antigen-bearing eosinophils were detected. FcεRI and CD23 were both upregulated on the skin-infiltrating eosinophils in AD and bound IgE molecules.

Topical Treatment of Resistant Warts with Glutaraldehyde

Therapy with glutaraldehyde (GA) was used to treat twenty‐five patients with selectively resistant warts. The patients were categorized as having one or more of the following conditions: 1) the location of the warts was either periungual, palmar or plantar, 2) the age of the patient was five years or younger, 3) the number of warts was two or more.

The expression of placental-type glutathione S-tranferase (GST-?) in human cutaneous squamous cell carcinoma and normal human skin

The expression of human placental-type glutathione S-transferase (GST-π) was investigated in human cutaneous squamous cell carcinoma (SCC) and normal skin using Northern blot and immunohistochemical analysis. In Northern blot examination, the expression of GST-π transcript was recognized in all instances, and SCC showed a significantly higher expression of GST-π than normal skin. In immunohistochemical examination, GST-π was stained well in the cytoplasm of all cells of the stratum granulosum, many cells of the stratum spinosum and a few cells of the stratum basale in normal skin. Some cells of the stratum spinosum and almost all cells of the stratum basale showed only a weakly positive or almost negative reaction for GST-π. No nuclear staining of GST-π was obvious in normal epidermal cells. In SCC, many cells showed strong positivity for GST-π in the cytoplasm, and some were obviously accompanied by nuclear staining of GST-π. These findings suggest that GST-π exists mainly in many cells in the upper layers of the normal epidermis and that GST-π is involved in the process of carcinogenesis.

Contact sensitivity to unsaponifiable substances in sesame oil

A case of contact sensitivity to the unsaponifiable substances in sesame oil is reported. An Ointment composed of 60% sesame oil was used for the treatment of a burn on the forearm. 10 days later. Contact dermatitis developed. The allergens were shown to be sesamolin and sesamolin, which are unsaponifiable substances in sesame oil.

The relationship between eosinophils, OKT6-positive cells and house dust mite (HDM) antigens in naturally occurring lesions of atopic dermatitis

To determine the role of eosinophils in naturally occurring lesions of atopic dermatitis, we observed the distribution of eosinophil cationic protein (ECP) and the relationship between eosinophils, OKT6-positive cells and house dust mite (HDM) antigens. Some specimens showed many EG2-positive stains, although the accumulation of tissue eosinophils was not prominent. EG2 stains were seen not only in eosinophils but also in extracellular granules. Some macrophage-like cells of the dermis showed EG2 stains in the form of phagocytized eosinophil granules. Some EG2-positive eosinophils were in close contact with OKT6-positive cells in the epidermis and dermis. Furthermore, in three patients sensitive to house dust mite (HDM) antigen, HDM antigens invaded the skin with many EG2-positive stains. These results suggest that eosinophils play an active role in the development of eczematous lesions of atopic dermatitis.

False positive reaction to patch testing with aqueous mercuric chloride in an aluminum Finn Chamber.

76% of the product consists of inert ingredients. Dazomet is a· biocide used to control bacterial and fungal growth in pulp and paper systems. It is also widely used in agriculture, being one of the standard soil disinfectants. It is also marketed under the names Mylone and Fungicide 974 (CragTM). A literature search revealed no cases of sensitization reported since 197 4. An earlier report (I) of dazomet allergic contact dermatitis described its use in dilute solution as an algicide for flushing through pipes. The concentrated solution, prior to dilution, was spilt onto the arms and washed off immediately. 2 to 3 days later, a bullous dermatitis appeared. A patch test to dazomet 0.25% aq. was positive (++). SHORT COMMUNICATIONS

Effects of KC-400 (polychlorinated biphenyls) on porphyrin metabolism--liver and blood porphyrin analyses in rats treated with KC-400.

To investigate the influence of polychlorinated biphenyls (PCB) on porphyrin metabolism, Wistar rats were orally administered KC‐400. The mean value of liver/body weight ratio in normal rats was 3.86%, with a range of 3.44% to 5.22%. Their mean blood protoporphyrin level was 23.3 μg/dl packed cell volume (p.c.v.), with a range of 11.8 to 64.4 μg/dl p.c.v., and their mean liver protoporphyrin level was 0.17 μg/gm wet weight, with a range of 0.03 to 0.40 μg/gm wet weight.

Leucocytoclastic vasculitis associated with mixed cryoglobulinaemia and hepatitis C virus infection

Mixed cryoglobulinaemia is frequently associated with chronic hepatitis. We report a patient with mixed cryoglobulinaemia, hepatitis C virus (HCV) infection and palpable purpura. The skin manifestations were diagnosed as leucocytoclastic vasculitis in view of both the clinical appearance and the histological findings. In this study, we demonstrated the presence of IgG–class anti–HCV–antibody. HCV–RNA and IgA–class rheumatoid factor in the cryoprecipitate. These results suggest that the cryoglobulinaemia in this case was caused by aggregation of an immune complex comprised of HCV and anti–HCV antibody with IgA–type–rheumatoid factor, and that this led to a cutaneous vasculitis.