Retinoid signaling by all-trans retinoic acid and all-trans retinoyl-beta-D-glucuronide is attenuated by simultaneous exposure of human keratinocytes to retinol.

Retinol and retinyl esters are converted with time to slowly increasing amounts of all-trans retinoic acid (RA) in cultured human keratinocytes. Exogenous RA has been shown to limit retinol oxidation and to increase retinol esterification. Because significant amounts of retinol are present in biologic systems, we examined whether RA and all-trans-retinoyl-beta-D-glucuronide (RAG) interact with retinol in exhibiting their activities on HaCaT keratinocytes maintained in a retinoid-free culture system.

Hereditary progressive mucinous histiocytosis.

We describe hereditary progressive mucinous histiocytosis, a rare autosomal dominant non-Langerhans cell histiocytosis, in a mother and daughter. Both had similar, progressive eruptions of skin-colored to red-brown papules on the nose, hands, forearms, and thighs. Light microscopy showed small collections of epithelioid histiocytes and telangiectatic vessels in the upper dermis of early lesions.

Cutaneous metastatic angiosarcoma with a lethal outcome, following radiotherapy for a cervical carcinoma.

A cutaneous metastatic angiosarcoma was diagnosed in a 79-year-old woman 19 years after radiotherapy for a carcinoma of the uterine cervix. The diagnosis was confirmed by immunohistochemical staining (factor VIII-related antigen and BMA 120) and electron microscopic examination. Surgical treatment of the large tumour, which was situated in the gluteal region, was not feasible, but electron beam therapy resulted in complete remission.

[Idiopathic clubbing of the fingers. Pathogenetic mechanisms and differential etiologic diagnosis].

We report on a patient with marked clubbing of the fingers and toes with watch-glass deformity of the nails, diagnosed as idiopathic clubbing. New findings on the pathogenesis of clubbing provide evidence for the important role of cytokines, especially platelet-derived growth factor and tumor necrosis factor-alpha. The differential diagnosis includes, besides rare primary forms, clubbing in malignant neoplasias and chronic inflammatory diseases of the heart, the lung, the upper gastrointestinal tract and the liver.

[Bacillary epithelioid angiomatosis in advanced HIV infection].

A patient with advanced HIV infection developed multiple angiomatous papules and nodules on the upper chest within a few days. At first sight the lesions resembled disseminated Kaposi's sarcoma; the differential diagnosis, however, included eruptive haemangiomas and pyogenic granulomas. Such distinct clinical characteristics as the collarette-like desquamation at the borders of the tumours led to the suspicion of bacillary epithelioid angiomatosis in HIV infection, which was then confirmed by histology and ultrastructural demonstration of bacillary colonies within the lesions.

Intrastriatal cerebellar grafts: differentiation of cerebellar anlage and sprouting of Purkinje cell axons.

Pieces of cerebellar primordia were obtained from G16 (day 16 of gestation) rat fetuses and stereotaxically injected into the striatum of adult Wistar rats. The transplants were allowed to integrate with the host brain for 2 h up to 6 months after implantation. Ninety four out of 105 transplants perfectly integrated with the host brain (90%) and established the typical trilaminar histoarchitecture of cerebellar cortex.

Corticosteroids induce proliferation but do not influence TNF- or IL-1 beta-induced ICAM-1 expression of human dermal microvascular endothelial cells in vitro.

The effects of hydrocortisone, dexamethasone, betamethasone 17-valerate and clobetasol propionate at concentrations of 10(-5)-10(-12) M on the proliferation of human dermal microvascular endothelial cells (HDMEC) were studied in vitro. In addition, confluent HDMEC were treated with TNF (1000 U/ml) or IL-1 beta (1000 U/ml) alone or in combination with the corticosteroids (10(-5) M, 10(-6) M) for 24 h, and cytokine-induced expression of intercellular adhesion molecule-1 (ICAM-1) was assessed by immunocytochemistry. Controls were treated either with growth medium or with the corticosteroids alone.

Cytokine-stimulated human dermal microvascular endothelial cells produce interleukin 6--inhibition by hydrocortisone, dexamethasone, and calcitriol.

The effects of lipopolysaccharide (LPS), recombinant human tumor necrosis factor-alpha (TNF), recombinant human interleukin 1-beta (IL-1 beta), and interferon-gamma (IFN-gamma) on IL-6 production were determined by enzyme-linked immunosorbent assay (ELISA) and by Northern blot analysis in cultured human dermal microvascular endothelial cells (HDMEC). Unstimulated HDMEC did not produce significant amounts of IL-6, whereas lipopolysaccharide (LPS), TNF, and IL-1 beta were potent inducers of HDMEC-derived IL-6 production. Treatment with IFN-gamma had no effect.

Central nervous system lesions in von Hippel-Lindau syndrome.

CNS manifestations were studied in 97 gene carriers of von Hippel-Lindau syndrome (HLS). Haemangioblastomas of the CNS were found in 43 patients (44%), 23 females and 20 males. The mean age at diagnosis was 39 years (12-73 years).

Cytokine regulation of proliferation and ICAM-1 expression of human dermal microvascular endothelial cells in vitro.

The effects of recombinant human interleukin 1 alpha (IL-1 alpha), interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6), granulocyte/macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor-alpha (TNF) on the cell proliferation and the expression of intercellular adhesion molecule-1 (ICAM-1) were assessed in cultured human dermal microvascular endothelial cells (HDMEC). IL-1 alpha and IL-1 beta stimulated the proliferation of HDMEC in a dose-dependent manner, whereas in control experiments using human umbilical vein endothelial cells (HUVEC), IL-1 alpha and IL-1 beta did not stimulate HUVEC growth. Also GM-CSF stimulated the proliferation of HDMEC, whereas IL-6 did not affect endothelial cell growth in vitro.

Mapping of phenytoin-inducible cytochrome P450 immunoreactivity in the mouse central nervous system.

The distribution of phenytoin-inducible cytochrome P450 in non-treated mouse brain and spinal cord was analysed immunohistochemically using polyclonal antibodies against phenytoin-induced mouse cerebral microsomal P450. This P450 protein was proved in Ouchterlony [Volk B. et al.