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Biomedical subjects

R Johnson

Publications and source records attributed to R Johnson.

At least 775 records · Page 43Linked to original sources
PubMedDate not supplied

Extrahepatic glucuronidation of morphine in the dog.

The pharmacokinetic disposition of morphine was studied in sham-operated dogs, dogs with hepatic devascularization, and dogs with bile duct and ureter ligation after iv administration of 1 mg/kg of morphine. In sham-operated dogs, morphine is rapidly distributed and eliminated, with a terminal half-life of 65 +/- 30 min. Morphine glucuronide appeared in plasma within 5 min and rose rapidly to levels an order of magnitude higher than morphine levels, before both declined in parallel. In hepatic devascularized dogs, there was a marked delay in morphine elimination due to a 47% reduction in clearance. The appearance of morphine glucuronide in plasma was not delayed, but the AUC of morphine glucuronide was reduced by 56% compared to control for the first 180 min. In bile duct- and ureter-ligated dogs, elimination of morphine was increased and morphine glucuronide elimination from plasma was decreased, suggesting that glucuronide normally excreted in bile is hydrolyzed back to the parent compound and reabsorbed in sham-operated control animals. In conclusion, morphine was glucuronidated by both hepatic and extrahepatic glucuronyltransferases to an approximately equal extent in the dog.

Animals↗
PubMedDate not supplied

Reducing the incidence of falls in high risk patients.

The incidence of patient falls in any acute and chronic care facility is a continuing challenge for nursing administrators. A computerized program was designed to identify common characteristics of 180 patients who had experienced a fall during 1986 at a midwest hospital. Based on analysis of the data, an integrated process of assessment, diagnosis, and intervention was developed and implemented. Early indications of success have been identified.

Accident Prevention↗
PubMedDate not supplied

Parental influence on child preference of a dentist.

It is the attitudes of our society that create sexual bias and stereotyping, which develop in the preschool years. One hundred and seventy children, 4-5 years of age, were interviewed and their mothers were given a questionnaire. The child's preference for a dentist was related to his or her own gender, with girls selecting women more often than boys selecting men. Parents did not appear to influence the child's selection.

Attitude↗
PubMedDate not supplied

Evidence for a hepatic-renal antagonism in the production of hepatic erythropoietin.

A tandem perfusion of the liver and kidneys of hepatectomized (hepx) rats was performed to ascertain the precise levels and time of appearance of the previously reported hepatic erythropoietic factor (HEF) and its antagonist, the renal inhibitory factor (RIF). Hepatic erythropoietic factor is produced by the hepx animal and is capable of augmenting the hepatic erythropoietin (Ep) response to hypoxia when administered to normal rats, whereas RIF acts to diminish this Ep response. Renal inhibitory factor does not directly affect Ep but appears to alter its synthesis owing to an inhibition to HEF production and/or action. In the present study, levels of HEF and RIF were determined at different intervals following hepx by in situ perfusion of the livers and kidneys of these animals. Levels of HEF are significantly higher than controls in rats at 24 to 72 hrs post hepx whereas its antagonist, the RIF, is not detectable until between 48 and 72 hrs after hepx. Inhibition of RIF of the hepatic Ep response is nearly total by 96 hrs following surgery. In previous studies, an increase in the hepatic Ep response to hypoxia was noted from 24 to 72 hrs after hepx. Peak hepatic Ep levels occurred at 72 hrs post hepx and declined thereafter, manifesting near normal hepatic Ep levels at 96 hrs after hepx. The present study provides an explanation for these findings by demonstrating that production of Ep by the hepx animal is dependent on the relative levels of a stimulatory (HEF) and an inhibitory (RIF) factor.

Animals↗
PubMedDate not supplied

Subcapital prosthesis fracture in total hip arthroplasty: case report.

There have recently been multiple reports of late complications of femoral stem fractures occurring after total hip replacement arthroplasty of the hip. The case presented is the first case reported in the English literature of a subcapital prosthesis fracture involving a Charnley-Mueller design femoral component. Revision surgery was carried out with satisfactory replacement of the failed component.

Adult↗