Biomedical subjects

R R Isseroff

Publications and source records attributed to R R Isseroff.

40 records · Page 3Linked to original sources

PubMed1984

Phospholipid metabolism in calcium-regulated differentiation in cultured murine keratinocytes.

The present findings associate phospholipid alteration, particularly the turnover of phosphatidylinositol, in Ca2+ induced differentiation of keratinocytes. These conclusions are based on the hydrolysis of 14C-AA from prelabeled PI and the accumulation 14C-DG and 14C-PA after cells are switched from low to normal concentrations of extracellular Ca2+. This novel finding implies that the biological changes which accompany keratinocyte differentiation after switch from low to normal extracellular medium may be due at least in part to increased accumulation of PA and DG which are major deacylation and reacylation products of phosphatidylinositol. A second interesting finding in these studies is the marked transformation of 14C-AA into lipoxygenase products by proliferating keratinocytes cultured in low Ca2+ medium when compared to differentiating cells cultured in normal Ca2+. The significance of decreased generation of lipoxygenase products in epidermal differentiation deserve further exploration.

Animals↗

PubMed1984

Generalized staphylococcal scalded skin syndrome in an anephric boy undergoing hemodialysis.

Generalized staphylococcal scalded skin syndrome (SSSS) is a toxin-related epidermolytic disease that predominantly affects previously healthy infants and children younger than 5 years. In contrast, the majority of the reported adult cases have been associated with underlying diseases, suggesting that immunosuppression and renal insufficiency are important predisposing conditions for this age group. We report herein a case of adult-type SSSS in an anephric 10-year-old boy. Patients undergoing hemodialysis who have chronic renal failure may be uniquely predisposed to the SSSS by virtue of their decreased glomerular filtration rate, associated uremic immunodeficiency, and a high incidence of Staphylococcus aureus bacteremia.

Animals↗

PubMed1983

Plasminogen activator in differentiating mouse keratinocytes.

The activity of the serine protease plasminogen activator (PA) was measured in cell lysates from primary mouse keratinocyte cultures as well as from a number of established mouse keratinocyte lines. Enzyme activity was generally higher in the transformed lines than in the primary cultures; however, among the lines tested, those that expressed the highest degree of morphologic differentiation had the highest levels of cell-associated PA. In both the normal (primary) and transformed (established) keratinocyte cultures, PA activity increased when cultures reached confluence and morphologic evidence of differentiation was noted. The highest specific activity of the enzyme was found in cells shed from differentiating cultures, which consisted predominantly of detergent-resistant cornified envelopes. As the cultures differentiated and these cells were shed from the culture surface, the total cell-associated PA activity of the culture decreased accordingly. In both the normal and transformed keratinocyte cultures, peak PA activity occurred at a time when DNA synthesis was declining. These findings indicate that as keratinocytes differentiate, their intracellular levels of PA increase. The modulation of this endogenous keratinocyte enzyme may play an important, although as yet undefined, role in the normal maturation and terminal differentiation of these cells.

Animals↗

PubMed1983

Plasminogen is present in the basal layer of the epidermis.

This study was undertaken to determine whether plasminogen was present within the epidermis. Cryostat sections of normal human skin were incubated with either whole rabbit antihuman plasminogen serum, the IgG fraction thereof, or the immune-specific IgG fraction thereof, purified by affinity chromatography on plasminogen-Sepharose. Standard indirect immunofluorescent techniques using rhodamine-conjugated goat antirabbit IgG were subsequently employed. Fluorescence was localized to the basal layer of the epidermis. Nonimmune serum and immune serum depleted of its specific anti-plasminogen IgG by prior affinity chromatography yielded negative results, demonstrating the specificity of staining for plasminogen. Our findings indicate that plasminogen is present within the epidermis, localized to the peripheral intracytoplasmic area of basal keratinocytes. This finding supports the hypothesis that a proteolytic event mediated by plasminogen activator with the subsequent generation of plasmin may be involved in normal keratinocyte physiology.

Cell Differentiation↗