Effect of Cu(2+)-ions on semiconductor properties of synthetic DOPA melanin polymer.

The purpose of the present study was to examine semiconductor properties of synthetic DOPA melanin, which are basic for future biological applications. DC conductivity, electron spin resonance (ESR), and atomic absorption spectroscopy (AAS) measurements have been performed to investigate the effect of Cu(2+)-ions on the semiconductor properties of melanin polymer synthesized from DOPA (3,4-dihydroxyphenylalanine). DOPA melanin - Cu2+ complexes examined show the decrease of both thermal activation energy delta Ea and pre-exponential factor sigma o values upon doping.

Electrical conductivity of synthetic DOPA-melanin polymer for different hydration states and temperatures.

The dependence of the d.c. conductivity on the hydration and temperature (293-343 K) for synthetic DOPA-melanin polymer is presented.

Metoclopramide-induced hyperprolactinaemia: effects on corpus luteum function, endometrial steroid receptor concentrations and 17 beta-hydroxysteroid dehydrogenase activity.

Induced hyperprolactinaemia impairs ovarian follicular development, especially during the recruitment period. The consequences of hyperprolactinaemia during the luteal phase alone on corpus luteum function have not been characterized, nor have the actions of excessive circulating PRL on the endometrium. In this study, postovulatory 5-d administration of metoclopramide (MC) increased serum concentrations of PRL and decreased those of pregnenolone and progesterone indicating inhibition of steroidogenesis in the corpus luteum.

Prediction of clinical outcome with estrogen and progestin receptor concentrations and their relationships to clinical and histopathological variables in endometrial cancer.

Concentrations of cytosol estrogen (ERC) and cytosol progestin (PRC) receptors were assayed in malignant tissue specimens of 230 patients with endometrial cancer, and those of nuclear estrogen and nuclear progestin receptors, and 17 beta-hydroxysteroid dehydrogenase activities in about 100 specimens. Endometrial cancer was at an early stage in 205 and advanced in 25 patients. As a supplement to surgical and radiation therapy, all patients received p.