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PubMed1995

Down-regulation of Langerhans cell protein kinase C-beta isoenzyme expression in inflammatory and hyperplastic dermatoses.

The family of protein kinase C (PKC) isoenzymes plays a fundamental part in signal transduction, and thereby regulates important cellular functions, including growth, differentiation, cytokine production and adhesion molecule expression. In lesional psoriatic skin, Ca(2+)-dependent PKC activity, PKC-beta protein and epidermal Langerhans cell (LC) PKC-beta immunostaining are significantly decreased, indicating activation and subsequent down-regulation of PKC. Whether these changes occur in other inflammatory/hyperplastic dermatoses is, however, unknown. We examined PKC-alpha and PKC-beta expression in normal skin, psoriasis, cutaneous T-cell lymphoma (CTCL), lamellar ichthyosis, non-bullous ichthyosiform erythroderma, atopic dermatitis, urushiol-induced allergic contact dermatitis, and sodium lauryl sulphate (SLS)-induced irritant contact dermatitis. Cryostat sections were stained for PKC-alpha and PKC-beta, and the LC marker CD1a, using an immunoperoxidase technique and specific monoclonal antibodies. Double-labelling studies, in normal skin, revealed co-expression of PKC-beta and CD1a by epidermal LCs. Analysis of the number of PKC-beta+ and CD1a+ epidermal LCs, in diseased compared with normal skin, revealed three categories: (i) in psoriasis and CTCL, the PKC-beta+ epidermal LC number was significantly reduced, whereas the CD1a+ epidermal LC number was unchanged; (ii) in allergic and irritant contact dermatitis, both PKC-beta+ and CD1a+ epidermal LCs were significantly reduced in number; and (iii) in atopic dermatitis, the PKC-beta+ epidermal LC number was normal, and CD1a+ epidermal LCs were significantly increased in number. Moreover, the ratio of epidermal LC PKC+/CD1a+ was reduced in all the dermatoses studied, suggesting activation of PKC-beta, with subsequent down-regulation. Within the dermis, increased PKC-beta staining of infiltrating cells was observed in all the conditions studied except lamellar ichthyosis and non-bullous ichthyosiform erythroderma. These data indicate that: (i) down-regulation of LC PKC-beta occurs in a variety of inflammatory and hyperplastic skin disorders, and is not unique to psoriasis, and (ii) the pattern of epidermal LC PKC-beta and CD1a expression varies among the diseases studied. In mice, PKC activation induces LC migration. Thus, down-regulation of epidermal LC PKC-beta associated with reduced CD1a+ epidermal LCs in allergic and irritant contact dermatitis suggests that PKC-beta may transduce the signal for migration of LCs from human epidermis.

Adult↗

PubMed1995

A new diagnostic classification for hypertension.

Many epidemiologic studies have shown that the risks associated with high blood pressure are considerably greater in those with target-organ damage and other risk factors. Clinical trials also have shown that although lowering blood pressure decreases the incidence of premature cardiovascular diseases, those with target-organ damage and other cardiovascular risk factors benefit considerably more than those with comparable levels of blood pressure who are free of complications or additional risk factors. The classification schemes currently in use for hypertension, which are based only on the level of blood pressure, provide inadequate risk stratification, can be misleading, and may lead to making erroneous therapeutic decisions. We propose a new diagnostic classification for hypertension that combines the level of blood pressure with the presence of other risk factors for premature cardiovascular events and target-organ damage in order to provide a more accurate risk assessment and offer superior guidance for therapeutic decisions. This scheme includes a new category for the elderly with elevated systolic blood pressure, who we now know have excessive morbidity and mortality rates if their diastolic blood pressure is low. Our new classification scheme is simple to use and yet comprehensive, and we feel it provides better risk stratification and is a better guide to therapeutic decision-making than those now in use.

Aged↗

PubMedDate not supplied

Juvenile xanthogranuloma on the palm.

Juvenile xanthogranuloma is a xanthomatous and granulomatous condition that frequently arises before 1 year of age and mainly occurs on the head and trunk. We report a rare solitary juvenile xanthogranuloma on the right palm of a 10-year-old girl, present for one year. This solitary involvement of the palm has been reported only twice before.

Cell Nucleus↗