Spatial data analysis by epidermal Langerhans cells reveals an elegant system.

Langerhans cells are dendritic cells situated in the mammalian epidermis. In human epidermis, the concentration is between 460 and 1000 mm(-2). Langerhans cells fulfill an essential role in skin immune responses. Numerous scientific reports on Langerhans cells have appeared, but with no systematic research on the pattern of the spatial distributions. On the contrary, in certain fields, a spatial distribution is an important theme, and spatial data analysis has a long history. We hypothesized that epidermal Langerhans cells were set in the best formation for their immuno-surveillance by a sophisticated mechanism. To prove this hypothesis, we have imported spatial data analysis into the study of epidermal Langerhans cells. Here, we show that the distribution is completely regular; the pattern of Voronoi divisions fits the territories; the random packing model simulates their bone marrow derivation; a repulsive interaction is demonstrated and a repulsive potential function is estimated. Spatial data analysis-based computer simulation will be a new method of Langerhans cell study. In addition, this procedure shows promise for future distribution research of certain cells.

Trichosporon cutaneum (Trichosporon asahii) infection mimicking hand eczema in a patient with leukemia.

Trichosporon Cutaneum is a yeast-like fungus that causes white piedra and onychomycosis. Recently, it has also been recognized as an opportunistic pathogen in immunocompromised hosts. We describe a 64-year-old woman who developed a superficial Trichosporon infection mimicking hand eczema during chemotherapy for her chronic myelocytic leukemia. To our knowledge, no cases of superficial infection like this one have previously been reported. This case suggests that careful examination is required in diagnosing Trichosporon infection in immunocompromised hosts, because the infection can be invasive or unusual in appearance.

Actinic keratoses arising only on sun-exposed vitiligo skin.

A 71-year-old woman with vitiligo developed multiple actinic keratoses only on the vitiligo skin of sun-exposed areas. She had worked outdoors as a farmer for a long period. Although actinic skin cancers arising on vitiligo skin have rarely been reported, the present case demonstrates that vitiligo skin is more susceptible to actinic damage than normal skin. Patients with vitiligo should be well informed about the importance of sun protection.

Draining lymph node cells of contact-sensitized mice induce suppression of contact sensitivity.

The application of hapten to the skin of mice can induce contact sensitivity (CS). It has also been well established that draining lymph node (DLN) cells can induce CS to the hapten used for skin painting when injected into naive mice. This is true for DLN cells recovered about 24 h after skin painting with hapten. It is unclear, however, whether DLN cells recovered shortly after hapten application have the same ability. By using an adoptive transfer assay system, we examined the ability of DLN cells recovered from mice at various times after skin painting with hapten to induce CS. DLN cells harvested 18-24 h after the application of fluorescein isothiocyanate (FITC) or 2,4-dinitrofluorobenzene (DNFB) induced strong CS when injected into naive mice. DLN cells harvested 3-6 h after the application of FITC or DNFB induced either only weak or no CS but induced suppression of the subsequent immunization to the two haptens. The suppression was hapten-specific, MHC restricted, and associated with the appearance of splenic suppressor T lymphocytes. Analyses with antibodies and ultraviolet (UV) B radiation demonstrated that suppression-inducing cells in DLNs were Ia+, Thy-1(-), and functionally UV-sensitive. These data suggest that epicutaneous sensitization with hapten first induces immunologically specific suppressor activity in the draining lymph nodes, whereas immunogenic activity becomes predominant later.

Demodex folliculitis on the trunk of a patient with mycosis fungoides.

A 43-year-old man with tumour stage mycosis fungoides developed multiple follicular pustules on the trunk during total-skin electron beam therapy. A potassium hydroxide preparation of the contents of the pustules revealed the presence of Demodex mites. The patient was treated with 6% sulphur lotion with rapid improvement of the cutaneous lesions. We believe that this case represents a pustular folliculitis caused by Demodex mites. Immunosuppression associated with mycosis fungoides and its treatment may have resulted in the proliferation of this obligate parasite of the pilosebaceous follicle, and the development of the folliculitis.

Heterogeneous chemotactic response of eosinophils from patients with atopic dermatitis to eosinophil chemotactic factors.

The chemotactic response of eosinophils from 16 patients with atopic dermatitis (AD) to 5 eosinophil chemotactic factors (ECFs) were examined to clarify whether the response is associated with the clinical severity of AD. The factors included ECF-P15, -P16, -P17, -P18 and -P19 and were derived from a T cell line, STO-2. The patients were divided into 2 groups according to the percentage migration of eosinophils produced by the ECFs: a high-responding group (migration > 40%), and a low-responding group (migration < 30%). In a statistical analysis, eosinophils from patients with AD and atopic respiratory diseases (ARD) were found to be high-responding and those from patients with AD alone low-responding (p < 0.01). In a comparison of the chemotactic response of eosinophils from patients with AD alone at remission and at exacerbation, the percentage migrations in response to ECF-P15 and ECF-P16 at exacerbation were significantly higher than that at remission (p < 0.05). It is thus suggested that this type of heterogeneous response of eosinophils to STO-2-derived ECFs could provide a useful tool for evaluation of disease severity in patients with AD.

Calcinosis cutis in juvenile dermatomyositis responsive to aluminum hydroxide treatment.

Calcinosis cutis is a frequent complication of juvenile dermatomyositis; however, its treatment remains unsatisfactory. We report a case of calcinosis cutis in juvenile dermatomyositis which was successfully treated with oral aluminum hydroxide. Almost complete clearing of calcinosis was observed after 8 months of therapy. There were no adverse effects from therapy. Aluminum hydroxide is worth trying in treating calcinosis cutis.

Mathematical assessment of the spatial distribution of Langerhans cells in guinea pig epidermis.

Two mathematical indexes, Hopkins-Skellam index (HSI) and Morisita index (MI), were applied to assess the distribution of ATPase-stained epidermal Langerhans cells (ELC) in the guinea pig skin. To our knowledge, this is the first report in which the degree of regularity has been expressed numerically by computation based on theoretical equations. The regularity of ELC in the normal skin was confirmed by the value of HSI (P < 0.0001). In the topical steroid applied skin, the number of ELC decreased significantly but the value of HSI was similar to that of the normal skin; while in the ultraviolet B (UVB) exposed skin, both number of ELC and regularity of ELC distribution decreased significantly. The graph of MI for the UVB exposed skin clearly showed that the distribution of ELC had local clumps. The two indexes, HSI and MI have been quite useful for determining the regularity of ELC. These indexes may have a wide application to other cells.

Cutaneous mucinosis associated with SLE--a case provoked by PUVA.

A patient with SLE which was complicated by a characteristic cutaneous mucinosis is reported. The skin lesions were composed of intradermal soft nodules, purple-red plaques, and alopecia of the scalp. Acid mucopolysaccharides accumulated in each lesion. PUVA provoked an infiltrated skin lesion in which acid mucopolysaccharides were deposited in the dermis. Deposition of immunoglobulins and complements were also observed at the dermo-epidermal junction and on the vascular walls. Some immunological processes which may stimulate the synthesis of acid mucopolysaccharides in the dermis were suggested.

Hidroacanthoma simplex showing variation in the appearance of tumor cells in different nests.

We report a case of hidroacanthoma simplex on the inframammary area of an 86-year-old woman. The tumor cells showed considerable variation in appearance in different nests from the same lesion. By light and electron microscopy 5 types of tumor cells were identified. This tumor was thought to originate from the outer cells of the intraepidermal eccrine duct.

Disseminated epidermolytic acanthoma revealed by PUVA.

Disseminated epidermolytic acanthoma was observed during PUVA therapy in a patient with Sézary syndrome. The majority of the lesions resolved within 5 months after the cessation of therapy. This circumstantial evidence together with our knowledge of the effects of PUVA suggest that the skin lesions were revealed by topical photochemotherapy.

Demonstration of dnp groups on the draining lymph node cells of guinea pigs following skin painting with DNCB by peroxidase labelled antibody method.

The distribution of 2,4-dinitrophenyl (DNP) groups in the draining lymph nodes of guinea pigs 12 h after painting the skin with 2,4-dinitrochlorobenzene (DNCB) was examined by a peroxidase labelled antibody method using antibody against DNP groups. DNP groups were detected on cells that were found mainly in the subcapsular sinus of the lymph nodes. Electron microscopic examination showed DNP groups distributed on the surface of lymphocytes. The significance of these findings is discussed.