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Biomedical subjects

M G MacDonald

Publications and source records attributed to M G MacDonald.

34 records · Page 2Linked to original sources
PubMed1984

Potentiation of the toxic effects of acetaminophen in mice by concurrent infection with influenza B virus: a possible mechanism for human Reye's syndrome?

Using weanling mice of two different genetic strains we demonstrated a potentiation of the toxic effects of acetaminophen by prior infection with influenza B virus. The C57BL/6N (B6) strain of mice is genetically predisposed to increased toxicity from acetaminophen when the hepatic cytochrome P-450 mixed function oxidase system is preinduced. When B6 animals are pretreated with influenza B virus and an mixed function oxidase system inducing agent before administering acetaminophen, we observed a significant incidence of atypical "fatty" liver pathology on light microscopy similar to the microvesicular steatosis seen in human Reye's syndrome. Electron microscopic changes in the liver of these animals resemble those published to date in human Reye's syndrome.

Acetaminophen↗
PubMed1981

Development of the hepatic mixed-function oxidase system and its metabolism of warfarin in the perinatal rat.

The development of the rat hepatic microsomal mixed-function oxidase system was investigated by analyzing its components in fetal and young pups of postconceptional age 18-54 days. Cytochrome P-450 and cytochrome b5 concentrations and NADPH-cytochrome c reductase and R-warfarin hydroxylase activities were determined as a function of postconceptional age. The cytochromes and reductase were present and increased with age before birth, and major increases were detected in the first 2 days after birth. The cytochrome P-450 concentration increased again markedly at puberty, whereas reductase activity increased before puberty and reached the adult level at puberty. Metabolism of warfarin to specific metabolites indicated that at 37 days postconception the isozyme cytochrome P-450 UT-C began to predominate. Its domination of the hepatic cytochrome P-450 pool increased with age.

Aging↗
PubMed1977

Correlation of cord bilirubin levels with hyperbilirubinaemia in ABO incompatibility.

We studied 91 offspring of ABO incompatible preganacies and 30 controls resulting from O--O pregnancies to test whether cord bilirubin levels could be used to predict the severity of hyperbilirubinaemia in ABO incompatibility. Blood group, direct Coombs's test, and serum bilirubin estimations were carried out on cord blood, and bilirubin estimations at 12, 24, 36, and 48 hours of life.

ABO Blood-Group System↗
PubMedDate not supplied

Airway management in the premature infant.

Out of 262 premature newborn patients admitted with a diagnosis of respiratory distress, it was necessary to treat 70 with a ventilator. Of these 70, 25 eventually underwent tracheostomy. Indications for tracheostomy were that of an infant needing prolonged endotracheal intubation greater than one week. The procedure itself was easily performed and an overall complication rate of 7% was the result. Of the patients who underwent tracheostomy, 8% had significant complications. There was no death attributable to the treatment regime. We feel, therefore, that a combination approach starting with the endotracheal tube and progressing to tracheostomy when necessary, provided the best care for premature infants requiring intensive airway management.

Humans↗
PubMedDate not supplied

The potential toxicity to neonates of multivitamin preparations used in parenteral nutrition.

This study compares two groups of infants weighing less than 1500 g at birth. In the propylene glycol (PG) group, 30 infants received MVI-Concentrate containing 300 mg of PG daily with their intravenous nutrition (ivn), and vitamin E, 50 mg/week by intramuscular injection. In the mannitol group, 30 infants received MVI-Pediatric (containing 245 mg mannitol), 65% of a vial/day. Serum and urine osmolality, serum PG, blood-urea-nitrogen, creatinine, sodium, and glucose were measured on days 0, 2, 5, 12, 19, 26, 33 and 40 of ivn. Weight, urine output, and fluid intake were measured daily. Vitamin E levels were measured on days 5, 26, and 33 of ivn. There were no significant differences between the groups in birth weight, gestational age, sex, age, or weight at start of ivn. Our results indicated that neither MVI-Concentrate nor MVI-Pediatric was associated with a clinically significant diuresis. MVI-Pediatric, 65% of a vial/day, may produce higher than desirable blood levels of vitamin E, and use of drugs containing PG can produce significant blood levels of PG, in very low birth weight infants.

Diuresis↗
PubMedDate not supplied

Defining death.

Explore the source record for details and available documents.

Death↗
PubMedDate not supplied

Intravenous access in newborn infants: impact of extended umbilical venous catheter use on requirement for peripheral venous lines.

Central venous lines are used to care for critically ill neonates in cases of limited peripheral venous access. This prospective, randomized study evaluated the risks and benefits of the use of single- and double-lumen umbilical venous catheters for up to 14 days. Patients were randomized to one of three treatment arms: (1) single-lumen umbilical catheter, (2) double-lumen umbilical catheter, or (3) no umbilical catheter; peripheral intravenous lines only. Infants in the groups treated with an umbilical venous catheter had significantly fewer venipunctures and peripheral intravenous lines placed during their first 2 weeks of life than those in the peripheral line only group. Less time and money were spent obtaining peripheral line placement in the umbilical venous catheter groups. The incidence rates of sepsis and complications were not higher in treated patients than in control patients. The double-lumen catheter further reduced peripheral venipunctures and lines. We conclude that an umbilical venous catheter used during the first 2 weeks of life is a relatively safe, less stressful, cost-effective means of providing intravenous therapy to neonates.

Catheterization, Peripheral↗