Hepatic microsomal alcohol-oxidizing system. Affinity for methanol, ethanol, propanol, and butanol.

Oxidation of methanol, ethanol, propanol, and butanol by the microsomal fraction of rat liver homogenate is described. This microsomal alcohol-oxidizing system is dependent on NADPH and molecular oxygen and is partially inhibited by CO, features which are common for microsomal drug-metabolizing enzymes. The activity of the microsomal alcohol-oxidizing system could be dissociated from the alcohol peroxidation via catalase-H2O2 by differences in substrate specificity, since higher aliphatic alcohols react only with the microsomal system, but not with catalase-H2O2. Following solubilization of microsomes by ultrasonication and treatment with deoxycholate, the activity of the microsomal alcohol-oxidizing system was separated from contaminating catalase by DEAE-cellulose column chromatography, ruling out an obligatory involvement of catalase-H2O2 in the activity of the NADPH-dependent microsomal alcohol-oxidizing system. In intact hepatic microsomes, the catalase inhibitor sodium azide slightly decreased the oxidation of methanol and ethanol, but not that of propanol and butanol, indicating a facultative role of contaminating catalase in the microsomal oxidation of lower aliphatic alcohols only. It is suggested that the microsomal alcohol-oxidizing system accounts, at least in part, for that fraction of hepatic alcohol metabolism which is independent of the pathway involving alcohol dehydrogenase activity.     

Minimally invasive surgery. Implications for hospitals,health workers,and patients.

Minimally invasive surgery is one of the great innovations of health care in the 20th century. It promises to revolutionise surgery by allowing many more operations to be performed with minimal hospitalisation. Pressure from patients has caused many techniques to spread rapidly before they have been adequately assessed. This must be resisted, and policy makers must pay more attention to minimally invasive surgery to ensure that good assessments are made. The widespread use of minimally invasive techniques has important implications for hospitals and health workers. As more patients are treated on an outpatient basis, fewer hospital beds will be needed, and traditional operating rooms will have to adapt to a greater turnover of patients. Surgeons will have to acquire new operating skills, possibly requiring formal training and accreditation, and, as different specialties fight for control of new technologies, surgery may eventually be merged with internal medicine so that specialists will deal with organ systems. Postoperative care will have to be carried out in the community rather than in hospitals, and policy makers will need to reorganise their health systems to cope with these developments.     

Screening for ovarian,prostatic, and testicular cancers.

Screening for cancer should not be offered routinely to a symptomatic people on a population basis unless it has been shown to be effective in reducing mortality in randomised controlled trials. A suitable screening test should have high sensitivity and specificity and a high positive predictive value. There is an ethical imperative to ensure that the benefit to each person from screening is likely to outweight the possible harm. Preliminary studies have identified suitable screening tests for ovarian cancer, and a randomised controlled trail is about to start. There is considerable controversy about whether to screen for prostatic cancer. Likewise, there is uncertainty about the best means of treating localised prostatic cancer. Screening for prostatic cancer raises important ethical considerations which should not be ignored. Testicular self examination is of unproved benefit. Although there is a need for education about the early signs and symptoms of testicular cancer to reduce delay at presentation, a case cannot be made for screening.     

Dexclamol, a candidate for neuroleptanalgesia.

Dexclamol, a potent neuroleptic, was found to potentiate the anesthetic actions of halothane when given at relatively small dose to albino rats. This effect was further enhanced by the addition of phenoperidine, a potent analgesic, at doses that per se did not influence the effects of halothane. Droperidol was used as a standard. In potentiating the effects of halothane, dexclamol behaved both qualitatively and quantitatively in a manner similar to droperidol. Dexclamol, however, was approximately 37 times less potent than droperidol in antagonizing the vasopressor effects of epinephrine.