The mechanism of cytochrome P-450 catalyzed steroid hydroxylations in rat liver microsomes has been investigated by employing derivatives of iodosylbenzene as oxygen donors. The model steroid ...substrate androstenedione which was hydroxylated in positions 7 alpha, 6 beta, and 16 alpha was used in reactions supported by NADPH, iodosylbenzene, and iodosylbenzene derivatives. Evidence for cytochrome P-450 involvement in iodosylbenzene-sustained androstenedione hydroxylation included inhibition by substrates and modifiers of cytochrome P-450. The most efficient oxygen donors were (diacetoxyiodo)-2-nitrobenzene greater than (diacetoxyiodo)-2-chlorobenzene greater than 2-nitroiodosylbenzene greater than (dinitratoiodo)-2-nitrobenzene greater than (diacetoxyiodo)benzene greater than (diacetoxyiodo)-2-methoxybenzene greater than 4-(diacetoxyiodo)toluene greater than iodosylbenzene. The capacity of the oxidation agents to serve as oxygen donors in cytochrome P-450 dependent steroid hydroxylation is probably dependent upon several factors such as the tendency of iodosyl compounds to associate, which decreases coordination with the heme iron, the presence of bulky substituents in the 2 position (decreases association), and the presence of electron-withdrawing substituents (tends to decrease coordination with the heme iron). The rates of 7 alpha, 6 beta, and i6 alpha hydroxylation of androstenedione catalyzed by (diacetoxyiodo)-2-nitrobenzene were 108-, 130-, and 167-fold higher, respectively, than the rates of the NADPH-supported reactions. These results strongly suggest that the rate-limiting step in NADPH-sustained cytochrome P-450 catalyzed reactions is the rate of reduction of cytochrome P-450.
A prospective study of women attending a surgical emergency department in an 8-month period showed that 117 (9%) had been battered. Offered in-patient treatment was accepted and completed by 58 women ...(the index group), while 59 declined or did not complete treatment (the drop-out group). Both groups were compared with age-matched controls. In the battered group there were more foreign-born women and more divorces than in the control group. The drop-out group differed from the index group either in being less severely injured and seeking only certification of injury for legal purposes, or in having more previous psychiatric morbidity. The consumption of somatic and psychiatric care during the preceding 10 years was significantly greater in the battered group than in the controls, probably due to the maltreatment and reluctance to report it spontaneously. Breaking of a battering pattern at an early stage requires awareness by surgeons, general practitioners and psychiatrists that recurrent injuries of unclear origin may be due to such violence.
Deselenation and the Mass Spectra of 3,3'-Di-indolyl Selenides
Acta chemica Scandinavica/Acta chemica Scandinavica. B, Organic chemistry and biochemistry/Acta chemica Scandinavica. A, Physical and inorganic chemistry/Acta chemica Scandinavica. Series B. Organic chemistry and biochemistry/Acta chemica Scandinavica. Series A, Physical and inorganic chemistry
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