Development of genotoxicity assay systems that use aquatic organisms.

Our aim is to develop and evaluate monitoring systems that use aquatic organisms to assess the genotoxicity of water in the field and in the laboratory. In a field study, we have shown that the micronucleus assay is applicable to freshwater and marine fishes and that gill cells are more sensitive than hematopoietic cells to micronucleus-inducing agents. Gill cells from Carassius sp. (Funa) and Zacco platypus (Oikawa) collected upstream on the Tomio River (Nara, Japan), tended to have lower micronucleus frequencies than gill cells from fish collected at the midstream of the river. Leiognathus nuchalis (Hiiragi) and Ditrema temmincki (Umitanago), small marine fishes collected periodically at Mochimune Harbor (Shizuoka, Japan), showed seasonal differences in the frequencies of micronucleated gill cells and erythrocytes; they were highest in summer. For laboratory studies, we developed a method for analyzing chromosomal aberrations and micronuclei using Rhodeus ocellatus ocellatus (rose bitterling) embryos. One day after artificial insemination (gastrula stage), we observed structural chromosomal aberrations and micronuclei in the cells of embryos grown in water containing trichloroethylene. Although more work is needed to fully assess their sensitivity, these assays show promise as a means of detecting environmental genotoxins.

Proton radiotherapy for malignant melanoma of the skin.

BACKGROUND: Malignant melanoma, a tumor with reduced radiosensitivity, has been suggested to be overcome by a high-dose fractionation radiotherapy. The proton beam presents physical characteristics that enable such high-dose irradiation. OBJECTIVE: Our aim is to answer whether or not the proton beam can provide useful treatment for cutaneous melanoma. METHODS: Five primary melanomas (4 acral lentiginous and 1 superficial spreading type) and 3 metastatic lymph nodes of 3 different patients were irradiated using the proton beam with a total dose of around 100 Gy fractionated into single doses of approximately 10 Gy. RESULTS: All the macular lesions and a tumor lesion of primary melanoma disappeared completely, and other tumor lesions regressed by 80-90%. The 3 metastatic lymph nodes also regressed by 50-90%. No severe radiation-related complication occurred. CONCLUSION: Proton radiotherapy may prove to be a useful therapeutic modality for the management of cutaneous malignant melanoma.

Proton radiotherapy of skin carcinomas.

At the Proton Medical Research Center, University of Tsukuba, we performed a pilot study of proton-beam radiotherapy in 12 patients with the following types of carcinoma: Bowen's disease (4), oral verrucous carcinoma (5), and squamous cell carcinoma (3). They received total doses of 51-99.2 Gy in fractions of 2-12.5 Gy. All of the tumours responded well to the treatment. All four lesions of Bowen's disease, three of the five oral verrucous carcinomas, and the three squamous cell carcinomas completely regressed following irradiation. Two squamous cell carcinomas recurred during the follow-up period. One recurrent squamous cell carcinoma was successfully treated by a salvage surgical operation, and in the other case the patient refused further therapy. In two verrucous carcinomas there was 90% regression of tumour volume. No severe radiation-related complication occurred. As proton radiotherapy produces good local tumour control without significant morbidity to the surrounding normal tissues, it may prove to be a useful therapeutic modality for the treatment of skin carcinomas.

The existence and distribution of melanocytes in the periodontal ligament of the mongrel dog.

The existence and distribution of melanocytes in the periodontal ligament of the mongrel dog were investigated. Melanocytes were found in the periodontal ligament of the maxillary incisor and premolar segments. Melanocytes in the periodontal ligament varied in number, and generally appeared as dendritic or elongated cells with several, long cytoplasmic processes. These melanocytes were always distributed closer to the tooth root side of the periodontal ligament than the alveolar bone side, but did not contact the cementum. Melanocytes were longitudinally distributed in the apical half of the periodontal ligament. There were no findings suggestive of a relationship between melanocytes and epithelial rests of Malassez or other cellular elements of the periodontal ligament. Although some parts of the gingival mucosa of all dogs in this study showed pigmentation, no relationship was seen between melanocytes in the periodontal ligament and those in the gingival mucosa. This is the first report of melanocytes in the periodontal ligament under normal conditions.

The antagonistic effect of interferon-beta on the interferon-gamma-induced expression of HLA-DR antigen in a squamous cell carcinoma line.

We examined the effect of type I interferon (IFN) on IFN-gamma-induced HLA-DR antigen expression in A431 cells, a human squamous cell carcinoma line. A431 cells expressed HLA-DR antigen when stimulated with IFN-gamma, but not with IFN-beta. Simultaneous addition of IFN-gamma and IFN-beta to A431 cells resulted in significantly decreased HLA-DR antigen expression when compared to treatment with IFN-gamma alone. Kinetic studies revealed that IFN-beta was required concomitantly or prior to stimulation with IFN-gamma in order to down-regulate expression of HLA-DR antigens. IFN-alpha also inhibited IFN-gamma-induced HLA-DR antigen expression in A431 cells. Analysis of cytoplasmic mRNA showed that simultaneous treatment of A431 cells with IFN-gamma and IFN-beta resulted in a marked decrease of the level of DR alpha specific mRNA when compared to a level reached after treatment with IFN-gamma alone. These results suggest that type I IFN antagonize the IFN-gamma-induced HLA-DR antigen expression in human keratinocyte system, and that this antagonistic effect of type I IFN is confirmed as evidenced by a change in HLA-DR mRNA levels.

Xeroderma pigmentosum patients belonging to complementation group F and efficient liquid-holding recovery of ultraviolet damage.

A 73-year-old woman with xeroderma pigmentosum (XP), XP107TO, was assigned to complementation group F. The fibroblast of this patient showed a reduced level (19%) of unscheduled DNA synthesis (UDS) compared with normal cells. XP107TO cells were 2.3 times more hypersensitive to ultraviolet C (UVC) than normal cells and in the same range of other XPF cells. A clinical case report of 2 patients belonging to XP group F is also described; together with these clinical findings, the characteristics of XP group F are discussed. These patients manifested mild clinical symptoms, developing skin cancer in later age, although acute sun sensitivity was observed in early age (usually a few months after birth). Fibroblasts derived from these patients showed a substantially reduced level of UDS, considering its mild clinical features. To analyze the discrepancy of low UDS level and late onset of skin cancer in XPF cells, we examined the UV sensitivity under density-inhibited condition using XPF cells. XP cells belonging to complementation group F showed marked enhancement of UV survival when they were held in a density-inhibited condition for 1-4 d after UV irradiation. The enhancement was also observed in normal and XP group A cells, but the recovery in these cell lines was less than that in XP group F cells. XP group F cells have been shown to possess slow and long-lasting excision repair capacity and this type of repair might be stimulated by holding through time of the repair process within one cell cycle.

Differentiation of the basal cell epithelioma-like changes overlying dermatofibroma.

Epidermis overlying dermatofibroma rarely displays basal cell epithelioma-like changes (BCE-like changes). Based on the histopathological findings, whether BCE-like changes are induced by dermal lesion or adnexal regression secondary to the solid fibrotic growth remains to be explored. From the standpoint of differentiation, we examined the BCE-like changes overlying dermatofibroma, normal epidermis, and hair follicles. PNA and two kinds of anti-keratin monoclonal antibodies were used to detect markers for epidermal differentiation. When PNA and anti-keratin monoclonal antibody (34betaB4) were used, no difference was observed in the staining patterns among BCE-like changes, hair follicles or normal basal cells. With the other anti-keratin antibody (34betaE12), BCE-like changes and normal basal cells were recognized, though the hair matrix was not. Thus the results obtained indicate that normal basal cells show the most similar differentiation to BCE-like changes.

[Long-term follow-up of pyoderma gangrenosum (PG) associated with aortitis syndrome (AOS)].

It is known that PG is often associated with AOS. However, there have been no reports on long term follow-up of PG associated with AOS. We experienced a case of a 16 year old female who suffered from PG and AOS. The onset of both diseases occurred at the same time. On admission, many pustules and ulcers were found on the extremities. There was no finding of vasculitis in histopathological examinations. Development of skin lesions of PG coincided with the progress of AOS. But, AOS was progressive even when the patient was free of skin eruptions. It was concluded that the activity of PG was not always parallel to that of AOS.

Sporotrichosis with bilateral lesions. A case report.

We report on a case of sporotrichosis in which lesions occurred bilaterally on upper limbs at different periods. The patient was an 84-year-old farmer living in Tsukuba City, Japan. The first lesion appeared on the left upper arm and remained untreated. The second lesion appeared on the back of the right hand 5 years later. Findings suggesting internal metastasis could not be confirmed in various examinations. We judged that the lesion of the left upper arm was primary and the lesion at the back of the right hand was caused by autoinoculation.

A monocyte-activation inhibitory factor produced by fibroblasts.

Culture media from human fibroblasts pretreated with culture media from activated normal human monocytes partially inhibited the activation of monocytes. Molecular weight of the major inhibitory factor in these culture media was very close to that of human fibroblast interferon. However, an immunoadsorption experiment using monoclonal antibody to human fibroblast interferon failed to adsorb this inhibitory factor.

[A case of hereditary angioneurotic edema associated with systemic lupus erythematosus].

A 33-year-old woman noticed recurrent and sudden attacks of subcutaneous swelling of the extremities and face since the age of 4 years. Sometimes the attacks involved colicky abdominal pain. Her mother and younger sister had episodes of recurrent swelling of the extremities as well. Complement studies revealed low CH50, C1q, C4, and C1 inhibitor levels, with normal C3 and C5 levels. Similar reductions of CH50 C4 and C1 inhibitor levels were observed in her mother, older, and younger sisters. Therefore, she was diagnosed as hereditary angioneurotic edema. In addition, she was diagnosed as having a butterfly rash at the age of 20 years and had a history of solar sensitivity. Histologically the facial lesion showed liquefaction degeneration of the basal cell layer. Direct immunofluorescent staining of the affected skin lesion showed basement membrane-zone staining of IgG and IgM. Laboratory studies revealed lymphopenia and positive ANF. On the basis of the above findings, hereditary angioneurotic edema associated with systemic lupus erythematosus was diagnosed.

The murine (C3H/He) epidermal Ia+ dendritic cells (Ia+DECs) and Thy-1+ dendritic cells (Thy-1+DECs) in contact hypersensitivity and aging.

The contact sensitivity evaluated by the ear swelling test and the dynamic changes of epidermal Ia+ dendritic cells (Ia+DECs) and Thy-1+ dendritic cells (Thy-1+DECs) were studied in trinitrochlorobenzene (TNCB) sensitized different age group C3H/He mice after challenge. A significant increase of ear swelling was observed between 6 h and 10 days of both 8-10 week (wk) and 40-48 wk groups; the ear swelling indices of 8-10 wk group were significantly higher than those of 40-48 wk group from 18 h to 5 days. A significant decrease of the densities of Ia+DECs from 18 h to 48 h, followed by a gradual increase reaching significant increase of the densities of Ia+DECs from 5 days to 21 days in both 8-10 wk and 40-48 wk groups, was observed; the densities of Thy-1+DECs significantly decreased from 18-48 h, followed by a gradual increase reaching a significant increase from 5 days to 21 days in both 8-10 wk and 40-48 wk groups. In the normal control groups, a significant decline of both Ia+DECs and Thy-1+DECs in the 40-48 wk group was observed. Results suggest that contact allergy may be diminished in aged mice. On the other hand, like Ia+DECs, Thy-1+DECs seem to be involved in the process of contact allergy.

Reticulate hyperpigmentation distributed in a zosteriform fashion: a new clinical type of hyperpigmentation.

We have recently seen two cases of hyperpigmentation in children, which was reticulate and distributed in a zosteriform fashion. As another two cases of hyperpigmentation of this kind in children have been reported previously, described as reticulate hyperpigmentation distributed in a zosteriform fashion, this gives a total of four cases of hyperpigmentation of this kind reported recently from Japan. These four cases differed from progressive cribriform and zosteriform hyperpigmentation, the condition which these cases resembled most closely, with respect to the age of onset of the hyperpigmentation, which in the four Japanese cases was not confined to a dermatome. Like a variant of incontinentia pigmenti (IP), all four cases showed eosinophilia. But they differed from IP in that there was no inflammatory stage, no pigmentary incontinence detectable on histology, and no evidence that the condition was hereditary. These four cases do not conform completely to any described entities and we suggest that they represent a new clinical entity.