Structure and function of a vimentin-associated matrix adhesion in endothelial cells

The alpha4 laminin subunit is a component of endothelial cell basement membranes. An antibody (2A3) against the alpha4 laminin G domain stains focal contact-like structures in transformed and primary microvascular endothelial cells (TrHBMECs and HMVECs, respectively), provided the latter cells are activated with growth factors. The 2A3 antibody staining colocalizes with that generated by alphav and beta3 integrin antibodies and, consistent with this localization, TrHBMECs and HMVECs adhere to the alpha4 laminin subunit G domain in an alphavbeta3-integrin-dependent manner. The alphavbeta3 integrin/2A3 antibody positively stained focal contacts are recognized by vinculin antibodies as well as by antibodies against plectin. Unusually, vimentin intermediate filaments, in addition to microfilament bundles, interact with many of the alphavbeta3 integrin-positive focal contacts. We have investigated the function of alpha4-laminin and alphavbeta3-integrin, which are at the core of these focal contacts, in cultured endothelial cells. Antibodies against these proteins inhibit branching morphogenesis of TrHBMECs and HMVECs in vitro, as well as their ability to repopulate in vitro wounds. Thus, we have characterized an endothelial cell matrix adhesion, which shows complex cytoskeletal interactions and whose assembly is regulated by growth factors. Our data indicate that this adhesion structure may play a role in angiogenesis.

Granulomatous slack skin: an ultrastructural study

BACKGROUND

Granulomatous slack skin is a rare lymphoproliferative disorder characterized clinically by gradual development of pendulous folds of lax erythematous skin in flexural areas, and histologically by non-necrotizing granuloma, with numerous multinucleated giant cells, mononuclear histiocytes, and atypical lymphocytes associated with loss of elastic fibers. Although there are many reports describing the histological and immunophenotypic features of this disease, only a few have described the ultrastructural features.

METHODS

Here we report a case of granulomatous slack skin and describe the ultrastructural findings.

RESULTS AND CONCLUSION

We could detect some previously not noted abnormal findings in multinucleated giant cells, histiocytes, and atypical lymphocytes.

Inflammatory vitiligo in Vogt-Koyanagi-Harada disease

Vogt-Koyanagi-Harada disease is a rare disease characterized by uveitis, meningitis, dysacusis, alopecia, poliosis, and vitiligo. We describe a 48-year-old patient with Vogt-Koyanagi-Harada disease associated with thin inflammatory raised erythema and plaque-type inflammatory erythema superimposed on vitiligo. Interestingly, inflammatory raised erythema was separated from the perfect vitiligo, and the incomplete vitiligo lay between them initially. Thereafter, incomplete vitiligo became completely depigmented with diminution of inflammatory raised erythema. This is the second case of vitiligo with inflammatory raised borders associated with Vogt-Koyanagi-Harada disease. Our results of immunohistochemical and electron microscopic studies suggested the involvement of T-cell-mediated cytotoxicity and apoptosis in the development of skin lesions.

Chemotherapy-induced acral erythema: report of a case and immunohistochemical findings

Chemotherapy-induced acral erythema (CAE) is an uncommon and distinct reaction seen in patients receiving high-dose chemotherapy. The exact pathogenic mechanisms of this disorder are still unknown. We report a 27-year-old woman who presented with red, swollen and painful macules on both palms, clinically consistent with this disease. Histological examination demonstrated vacuolar degeneration of the basal cell layer and spongiotic blisters in the epidermis, especially in the atrophied eccrine ducts and papillary oedema with mild perivascular infiltration of mononuclear and hypersegmented neutrophils. Immunohistochemistry showed that the infiltrating mononuclear cells were CD3-CD16+CD56+ leucocyte function antigen-1+, possibly natural killer cells. The eccrine ducts expressed HLA-DR and intracellular adhesion molecule-1 (ICAM-1). Our findings suggest that cell-to-cell interaction between NK cells and keratinocytes in the eccrine apparatus may induce CAE and may be involved in the pathogenesis of the skin reaction in our patient and possibly in this disease.

Granulomatous slack skin: successful treatment with recombinant interferon-gamma

Granulomatous slack skin is a rare variant of indolent cutaneous lymphoma, characterized by a cutis laxa-like clinical appearance and widespread granulomatous infiltration. A 25-year-old man had suffered from slowly progressive infiltrative, scaly and atrophic plaques and flaccid nodules with deep induration in the axillae, trunk and thighs. Histopathologically, dense lymphoid cell infiltration with numerous multinucleated giant cells (MGC) throughout the dermis to the subcutaneous tissue was observed. T-cell receptor gene rearrangement was detected in the skin lesions. Granulomatous infiltration with MGC was found in enlarged lymph nodes and the liver. Acute exacerbation was successfully treated with systemic recombinant interferon-gamma.

Combined cutaneous hamartoma encompassing benign melanocytic naevus, vellus hair cyst and epidermoid cyst

We describe a combined cutaneous hamartoma in a 57-year-old man, which comprised a vellus hair cyst, an epidermoid cyst and an intradermal melanocytic naevus in a single facial tumour. The vellus hair cyst was filled with keratinous material with unusual slit-like lacunae. While numerous cases of epidermoid cyst have been reported in association with an intradermal melanocytic naevus, our case is a rare example of a lesion combining several hamartomatous elements.

Induction of apoptosis in placentas of pregnant mice exposed to lipopolysaccharides: possible involvement of Fas/Fas ligand system

To explore the pathogenesis in placental dysfunction and abruptio placentae, we analyzed the occurrence of placental cell apoptosis and the role of Fas and Fas ligand (L) in that process in an inflammatory placental dysfunction model of pregnant mice, using lipopolysaccharides (LPS). In the present study, Day 13 pregnant mice were injected i.p. with LPS (50 microg/kg) or saline as a control, and the placentas were isolated at various time points after the injection. Analysis of the isolated DNA in agarose-gel electrophoresis revealed a typical ladder pattern of bands consisting of 180-200 base pairs (bp), which is regarded as a hallmark of apoptosis. The intensity of the bands increased time-dependently, reaching a maximum level at 12 h after LPS injection. In accord with the biochemical data, histochemical analysis using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) revealed that nuclei positive for double-stranded DNA breaks were found in decidua, diploid trophoblasts in the basal zone, and spongiotrophoblasts. The number of positive nuclei was maximized at 12 h after LPS injection. As a next step, we investigated the possible involvement of Fas and Fas L in the induction of apoptosis of the placental cells after LPS injection. Western blot analysis indicated that LPS increased the expression of Fas and Fas L in the placenta by about 4-fold at 12 h and 18 h, respectively, after injection. The cells expressing Fas and Fas L were identified, using immunohistochemistry and nonradioactive in situ hybridization, as decidua, diploid trophoblasts in the basal zone, and spongiotrophoblasts. Furthermore, when the expression of 4-hydroxy-2-nonenal (HNE)-modified proteins was assessed to evaluate the relation of oxidative stress elicited by LPS to the induction of apoptosis, once again decidua, diploid trophoblasts in the basal zone, and spongiotrophoblasts were positive. Therefore, the placental dysfunction by LPS may be brought about by the Fas-mediated apoptosis of various placental cells in a paracrine/autocrine fashion, possibly under the influence of oxidative stress.

In vivo activation of langerhans cells and dendritic epidermal T cells in the elicitation phase of murine contact hypersensitivity

Langerhans cells (LCs) and dendritic epidermal T cells (DETCs) constitute the skin immune system. To demonstrate the kinetics of in vivo activation of murine LCs and DETCs in the elicitation phase of contact hypersensitivity, we measured the cell area positively stained for I-A and gammadeltaT-cell receptor (or Thy-1.2), respectively, under a fluorescence microscope at various time intervals after topical application of dinitrofluorobenzene. The fluorescence-positive area of LCs increased in parallel with that of DETCs at 1 h and 24 h, indicating the biphasic activation of LCs and DETCs. Early activation was hapten-specific and often exhibited close LC-to-DETC apposition. Experiments with in vivo administration of neutralizing anticytokine antibodies revealed that none of interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha and interleukin (IL)-1beta were involved in the induction of early activation of LCs and DETCs, while TNF-alpha and IL-1beta mediated late activation of LCs, and IFN-gamma and IL-1beta mediated that of DETCs. Our results indicate that LCs and DETCs are synchronously and biphasically activated in the epidermis during the elicitation phase of contact hypersensitivity and suggest that different mechanisms may control early and late activation.

Phakomatosis pigmentovascularis type IIIb associated with moyamoya disease

We diagnosed phakomatosis pigmentovascularis type IIIb in an 11-month-old baby who had a giant nevus spilus, a nevus flammeus, and moyamoya disease. Development of the patient was normal until 6 months of age when he developed a sudden onset of focal seizures and left hemiparesis. This patient represents the sixth case of phakomatosis pigmentovascularis type IIIb, including three cases in the Japanese literature, reported thus far. However, to our knowledge, this is the first case with an association to moyamoya disease.

Morphometric and ultrastructural analyses of in vivo-activated murine Langerhans cells induced by administration of a streptococcal preparation (OK-432)

Langerhans cells (LCs) are activated in the epidermis by external and internal stimuli, such as antigens and cytokines, respectively. To reveal the morphologic and functional properties of in vivo-activated LCs during inflammation, we injected the streptococcal preparation OK-432 intradermally into the earskin of mice and performed time-course analyses by immunofluorescence and electron microscopy. Cellular infiltrate appeared in the dermis at 6 h after OK-432 injection and had progressively extended to the dermoepidermal junction at 12 and 24 h. Immunostaining for class II antigen revealed that LCs were enlarged and extended long dendrites during inflammation. Acidic compartments such as lysosomes and multivesicular bodies also increased in number and Golgi apparatuses developed as demonstrated by electron microscopy and morphometric analysis. Birbeck granules, although not showing numerical changes, were translocated from the Golgi area to the subplasmalemmal area. After epicutaneous application of cationic ferritin, LCs often contained endosomes as the result of engulfment by the cytoplasmic projections. The present results indicate that nonspecifically induced dermal inflammation is capable of inducing activation of LCs in vivo, and that in vivo-activated LCs have the capacity for active endocytosis and intracellular digestion or processing.

Merkel cell carcinoma, Bowen's disease and chronic occupational arsenic poisoning

We diagnosed a unique case of Merkel cell carcinoma (MCC) coexisting with Bowen's disease on the sole of the foot of a 72-year-old man who had worked for about 4 years in a factory handling inorganic arsenic. He had a past history of arsenical keratosis and multiple Bowen's disease. The tumour first appeared as a reddish macule and then showed marked growth over the next month. The tumour was excised and the specimen was examined histopathologically. The tumour consisted of two components: a group of atypical cells representing Bowen's disease in the epidermis and another group of atypical cells with a trabecular pattern characteristic of MCC in the dermis. Neither group of cells showed transitional findings, and the tumour elements were divided by a clear basement membrane. The tumour cells in the dermis were positive for neurone-specific enolase, and on electron microscopy had dense core granules in the cytoplasm. Inorganic arsenic can cause various cutaneous neoplasms, but to our knowledge, this is the first report of a case of MCC associated with Bowen's disease.

Subcorneal pustular dermatosis in a patient with hyperthyroidism

A case of subcorneal pustular dermatosis (SPD) is reported in a 48-year-old man with a 2-year history of hyperthyroidism (Graves' disease). SPD has been reported in association with IgA monoclonal gammopathy, but to our knowledge it has not been associated with hyperthyroidism. The coexistence of hyperthyroidism and SPD suggests that immunologic factors may play a role in the pathogenesis of SPD.

Control by treatment with lithium chloride of ornithine decarboxylase in Ehrlich ascites tumor cells

The activity of ornithine decarboxylase (ODC) was increased in Ehrlich ascites tumor cells by a change of the medium. This increase in the activity was inhibited by the addition of LiCl to the medium. Na+ and Mg2+ did not affect the enzyme activity. The inhibition of the enzyme activity with LiCl was not reversed by the addition of inositol or dibutyryl cyclic AMP. Total RNA was isolated from cells treated with LiCl and the relative abundance of the ODC mRNA was measured by Northern blot analysis. These levels in cells treated with LiCl were comparable to those in control cells. In the treated cells, the biological half-life of ODC was 14 min, which was the same as for the control cells. The inhibition by LiCl of ODC activity was not due to the nonspecific toxicity of LiCl. These results suggest that treatment of Ehrlich ascites tumor cells with LiCl suppressed ODC induction during translation, not during transcription or after translation.