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R F Morfin

Publications and source records attributed to R F Morfin.

8 recordsLinked to original sources
PubMed1979

Quantitation of zearalenone by gas-liquid chromatography on capillary glass columns.

A procedure is described for the quantitation of zearalenone from corn by gas-liquid chromatography. An internal standard, zearalanone, is first mixed with the finely ground corn, followed by extraction with ethyl acetate, purification by thin-layer chromatography and formation of trimethyl silyl ether (TMS) and methyl oxime (MOX) derivatives. Positive identification of zearalenone is based upon the retention times of the TMS and MOX-TMS derivatives being identical with those of the standards, comparison of chromatograms from both derivatives and characteristic twin peaks of zearalenone MOX-TMS. The detection limit of 100 parts per 10(9) zearalenone in corn could only be improved by modification of the described procedure.

Chromatography, Gas↗
PubMed1977

Analysis of C19O3 steroids by thin-layer and gas-liquid chromatography and mass spectrometry.

The separation of twenty-six saturated and two unsaturated C19O3 steroids has been studied by thin-layer chromatography on silica gel F254, with seven mobile phases, and by gas-liquid chromatography on packed columns with four stationary phases; combination of both techniques permitted separation of all the test compounds. The mass spectra of the steroids were obtained by gas chromatography-mass spectrometry and are presented. Fragmentation processes have been studied, and characteristic ions that may be used for multiple ion detection or lead to identification of biologically produced C19O3 steroids are discussed.

Androstanes↗
PubMed1977

Correlative study of the morphology and C19-steroid metabolism of benign and cancerous human prostatic tissue.

Perineal punch biopsy specimens of human prostate with benign hyperplasia (BPH), well- and poorly-differentiated adenocarcinoma and transitional-cell carcinoma were incubated with testosterone-1,2-3H and 5alpha-dihydrotestosterone-1,2-3H. Incubations were carried out using a single tissue-radiosubstrate ratio and time point. Resulting radiosteroid patterns were related to histologic and ultrastructural features of these tissues. Well differentiated neoplasms had ultrastructural characteristics closely resembling hyperplastic epithelia. Both in BPH and in well differentiated carcinomas the C19-steroids were mainly metabolized by the 17beta-hydroxysteroid pathway. In contrast, cells in poorly-differentiated adenocarcinoma and transitional-cell carcinoma lacked the cytoplasmic organelles responsible for secretion; formation of 5alpha-reduced 17beta-hydroxysteroids was decreased in these carcinomas, while conversion to 17-oxosteroid radiometabolites remained unchanged or was greatly increased. These results indicate that loss of prostatic differentiation is attended by a trend from reductive toward oxidative radiotestosterone metabolism. Even in NAPDH-supplemented preparations of the majority of poorly-differentiated tumors, there was diminished transformation to 5alpha-dihydrotestosterone, the key intracellular hormone in the expression of androgenic activity in the prostate. These findings may explain why poorly-differentiated prostatic neoplasms are frequently unresponsive to anti-androgenic therapy.

Androgens↗