Environmental illness in athletes.

This article examines environmental illness in athletes. Causes, symptoms, and treatment of heat-related illness, cold-related illness, and altitude-related illness are discussed.

Intercellular transfer of P-glycoprotein mediates acquired multidrug resistance in tumor cells.

The overexpression of P-glycoprotein (P-gp) causes resistance to chemotherapy in many tumor types. Here, we report intercellular transfer of functional P-gp from P-gp-positive to P-gp-negative cells in vitro and in vivo. The expression of acquired P-gp is transient in isolated cells but persists in the presence of P-gp-positive cells or under the selective pressure of colchicine.

A protein kinase C inhibitor induces phenotypic reversion of ras-transformed pancreatic cancer cells and cooperatively blocks tumor cell proliferation with an anti- ras peptide.

Purpose: We have previously found that the staurosporine derivative, CGP 41 251, that has a high specificity for inhibiting protein kinase C (PKC), selectively blocks oncogenic ras-p21-induced oocyte maturation and that PKC and jun-N-terminal kinase (JNK), with which oncogenic ras-p21 directly interacts, reciprocally require each other's activation. We sought to determine whether CGP 41 251 blocks proliferation of ras-transformed mammalian cells and whether it synergistically exerts this effect with a ras-p21 peptide (residues 96-110) that interferes with the interaction of ras-p21 with JNK.

Methods: We incubated ras-transformed rat pancreatic cancer TUC-3 cells and their normal counterpart pancreatic acinar BMRPA1 cells with CGP 42 251 alone and in the presence of the ras-p21 96-110 peptide, both in pre- and post-monolayer phases and determined cell counts and morphology and, for TUC-3 cells, their ability to grow on soft agar.