Effects of protein kinase C activators on phorbol ester-sensitive and -resistant EL4 thymoma cells.

Phorbol ester-sensitive EL4 murine thymoma cells respond to phorbol 12-myristate 13-acetate with activation of ERK mitogen-activated protein kinases, synthesis of interleukin-2, and death, whereas phorbol ester-resistant variants of this cell line do not exhibit these responses. Additional aspects of the resistant phenotype were examined, using a newly-established resistant cell line. Phorbol ester induced morphological changes, ERK activation, calcium-dependent activation of the c-Jun N-terminal kinase (JNK), interleukin-2 synthesis, and growth inhibition in sensitive but not resistant cells. A series of protein kinase C activators caused membrane translocation of protein kinase C's (PKCs) alpha, eta, and theta in both cell lines. While PKC eta was expressed at higher levels in sensitive than in resistant cells, overexpression of PKC eta did not restore phorbol ester-induced ERK activation to resistant cells. In sensitive cells, PKC activators had similar effects on cell viability and ERK activation, but differed in their abilities to induce JNK activation and interleukin-2 synthesis. PD 098059, an inhibitor of the mitogen activated protein (MAP)/ERK kinase kinase MEK, partially inhibited ERK activation and completely blocked phorbol ester-induced cell death in sensitive cells. Thus MEK and/or ERK activation, but not JNK activation or interleukin-2 synthesis, appears to be required for phorbol ester-induced toxicity. Alterations in phorbol ester response pathways, rather than altered expression of PKC isoforms, appear to confer phorbol ester resistance to EL4 cells.

Gestational diabetes mellitus; resource utilization and costs of diagnosis and treatment.

The recommendation to test every woman for gestational diabetes mellitus (GDM) has a defined cost. The management of women diagnosed with GDM will use additional health resources. This examines the cost and resource utilization of a consecutive group of women diagnosed over a 1-year period. The cost of testing a woman for GDM is around $10.00 with slight variations depending on the testing procedure. The annual cost of testing in NSW would be less than 1 million dollars. Women diagnosed with GDM used the resources of a diabetes education centre for an average of 2.8 hours and attended for 3.4 (2.3) medical visits. Insulin was required by 18.7% of the women for 9.7 (4.7) weeks using 47.7 (21.2) units each day. Testing women for GDM is a low-cost item. Managing a woman diagnosed with GDM may cost several hundred dollars. Cost reductions could be made by reducing the amount of insulin used and by avoiding hospitalization.