Biomedical subjects

F Kaneko

Publications and source records attributed to F Kaneko.

130 records · Page 8Linked to original sources

PubMedDate not supplied

Melanocytoma of the foramen magnum.

This report concerns a 66-year-old man with a melanocytoma arising at the foramen magnum. Magnetic resonance imaging disclosed a well-circumscribed tumor extending from the medulla oblongata to C1 with gadolinium enhancement. A heavily pigmented tumor located under the leptomeninges was removed surgically. Although the patient died 8 months later of renal cell carcinoma, no recurrence or metastasis of the melanocytoma was detected by radiographic examination. Microscopically, the resected tumor was composed of polygonal to spindle-shaped cells containing large amounts of melanin. The bland nuclei of the tumor cells were of uniform size. No mitotic figures were seen. The tumor cells were positively immunostained for S-100 protein and by antibody HMB-45. They were not stained using the Ki-67 (MIB-1) antibody, indicating low proliferative activity. The ultrastructural examination revealed numerous mature melanosomes and basal laminae surrounding nests of cells. The tumor was diagnosed as a melanocytoma on the bases of its microscopic features and the lack of Ki-67 immunoreactivity. The ultrastructural and immunohistochemical features of melanocytomas are distinct from those of meningiomas. It is likely that melanocytomas and melanotic schwannomas represent opposite extremes of the continuous spectrum of neuroectodermal tumors derived from the neural crest.

Aged↗

PubMedDate not supplied

Subcorneal pustular dermatosis-type IgA pemphigus induced by thiol drugs.

We report a case of subcorneal pustular dermatosis (SPD)-type IgA pemphigus arising in a 49 year-old woman with rheumatoid arthritis who had been treated with chrysotherapy. Scaly erythemic plaques containing vesicles and pustules occurred on her chest and abdomen during the course of anti-rheumatic treatments using prednisolone at 11 mg/day and thiol compounds (bucillamine and gold sodium thiomalate). Histological investigations revealed subcorneal pustules containing many neutrophils and a few acantholytic cells, and intercellular IgA deposits at the upper epidermis of the eruptions without any other immunoglobulins and complement component C3. Circulating IgA antibodies directed against intercellular spaces of the epidermis were found by prolonged incubation of normal skin specimens in medium containing 20% patient's serum in an explant culture, although standard indirect immunofluorescence for IgA antibodies was negative. The eruptions were treated successfully with prednisolone, 30 mg/day, dapsone, 50 mg/day, and discontinuance of the thiol compound. In addition to the coexistent rheumatoid arthritis, both thiol compounds might have been responsible for the development of the eruptions.

Abdomen↗

PubMedDate not supplied

Recalcitrant trichophytic granuloma associated with NK-cell deficiency in a SLE patient treated with corticosteroid.

Although deep trichophytic infection often occurs in immunocompromised patients, the immune deficiency in such patients has not been clarified. A 28-year-old man who suffered from recalcitrant trichophytic granuloma and tinea universalis during treatment for SLE with corticosteroid is described here to define the immunological abnormalities. In addition to routine immunological tests, we evaluated the patient's innate and specific immune functions to dermatophytes, including T cell, natural killer (NK) cell and neutrophil functions and activation of the complement cascade. We measured the minimum inhibitory concentration (MIC) of itraconazole for the isolated fungus and its concentrations in the patient's serum and pus. Trichophyton (T.) rubrum was constantly isolated from the exudates of the patient's skin lesions, although the concentrations of itraconazole in his serum (198 ng/ml) and lesions (210 ng/ml) were sufficient to inhibit the growth of the isolated fungus in vitro. Specific cell-mediated immune responses, determined by T cell stimulation and IFN-gamma production, were evoked following stimulation with trichophytic antigens. The patient's innate immunity, assessed by activation of the complement cascade and neutrophil-mediated phagocytosis, was not impaired. The number of circulating NK cells was markedly decreased (0.2% of the peripheral blood mononuclear cells), and was associated with low NK cell activity against K-562 cells even though lymphopenia had improved. The deficiency of innate immunity mediated by NK cells might be responsible for a part of the persistence of trichophytic granuloma in our case. Dermatophytes usually affect the horny layer of the skin and do not invade the living layers because the host immune system uses various mechanisms to eliminate the fungi. Both specific T cell-mediated immunity and nonspecific immunological mechanisms provide host defense against fungal infections. An adaptive immune response is usually preceded by innate immune responses mediated by neutrophils, NK cells, and circulating proteins such as complement components and anti-microbial peptides. However, in patients with localized or systemic immunological defects, granulomatous cutaneous infection of dermatophytes mostly caused by trichophytic fungi may occur [1]. Trichophytic granuloma includes Majocchi's granuloma [2] and disseminated trichophytic granuloma [3]. Recently, we experienced a patient with trichophytic granuloma and tinea universalis caused by Trichophyton (T.) rubrum infection during treatment with corticosteroid for systemic lupus erythematosus (SLE). We describe the clinical details of this patient, focusing on his immunological defects which led to the persistence of the fungal infection.

Adult↗

PubMedDate not supplied

Regulatory effects of 1alpha,25-dihydroxyvitamin D3 on inflammatory responses in psoriasis.

Topical application of 1alpha,25-dihydroxyvitamin D3 (VD3) is thought to be beneficial in psoriasis because of its action in regulating keratinocyte proliferation and inflammation mediated by various cytokines. We assessed the effect of VD3 on the production levels of interferon (IFN)-alpha, interleukin (IL)-6, IL-8 and tumor necrosis factor (TNF)-alpha in mitogen-stimulated peripheral blood mononuclear cells (PBMC) of psoriatic patients. The results demonstrated that VD3 significantly inhibited IFN- , IL-6, and IL-8 levels produced by concanavalin A (Con A)-stimulated PBMC of psoriatic patients in a dose-dependent manner, and reduced mRNA expression for IFN- and IL-8. These findings suggest that in addition to the direct anti-proliferation effect on keratinocytes, VD3 may down-regulate the inflammatory cytokine production by infiltrating cells in psoriatic lesions.

Adult↗