Nutritional needs during the first year of life. Some concepts and perspectives

This article reviews some of the recent changes in thinking that are reflected in two reports (Recommended Nutrient Intakes for Canadians and the FAO/WHO/UNU Report on Energy and Protein Requirements) concerning nutrient requirements for infants below one year of age. The author illustrates the concepts underlying the published requirement estimates and hence some of the principles that should underlie the interpretation and application of the estimates.     

The international collaborative study of maternal phenylketonuria: status report 1994

Neonatal screening for phenylketonuria (PKU) has created a problem as females with PKU are reaching child-bearing age. Surveys have revealed that maternal phenylalanine blood concentrations greater than 1200 μmol/l are associated with fetal microcephaly, congenital heart defects and intrauterine growth retardation. It is estimated that as many as 3000 hyperphenylalaninemic females may be at risk of producing these fetal abnormalities. To examine this problem, the international maternal PKU collaborative study was developed to evaluate the efficacy of a phenylalanine-restricted diet in reducing fetal morbidity. Preliminary findings have indicated that phenylalanine restriction should begin before conception for females with PKU planning a pregnancy. Dietary control should maintain maternal blood phenylalanine levels between 120 and 360 μmol/l and should provide adequate energy, protein, vitamin and mineral intake. Pregnant hyperphenylalaninemic females who achieved metabolic control after conception or by the 10th week of pregnancy had a better offspring outcome than anticipated. The results of 402 pregnancies are reviewed.     

Controversies in transfusion medicine. Perioperative hemodilution: pro

Hemodilution can obviate the need for allogeneic transfusion in some patients. However, it is only one component of a comprehensive blood conservation program and should be combined with other techniques whenever possible. While most often employed in teenagers and healthy young adults, ANH has been used in small children, the elderly, and patients of all ages who are undergoing cardiac surgery. Extreme caution should be exercised if ANH is used in patients with coronary artery disease or aortic stenosis who are undergoing noncardiac surgery, because their normal compensatory mechanisms are impaired. What usually is a safe and relatively simple procedure can become a disaster if employed in inappropriately selected patients. Careful hemodynamic monitoring and maintenance of normovolemia are critical.     

Insulin Infusion Normalizes Cardiovascular Responses and Plasma Noradrenaline after Oral Glucose in Type 1 (Insulin-dependent) Diabetes

ABSTRACT. We examined whether the abnormal regulation of the cardiovascular system and plasma noradrenaline observed after oral glucose in insulin-dependent diabetic patients could be normalized by intravenous infusion of insulin. Eight patients with type 1 (insulin-dependent) diabetes were examined after an oral glucose load with and without simultaneous infusion of insulin. Insulin infusion increased plasma insulin from 0.07 to 0.31 nmol/1. In the control experiment (glucose only), mean heart rate and mean arterial systolic blood pressure remained unchanged and plasma noradrenaline (NA) decreased (p < 0.05). After oral glucose plus intravenous insulin, mean heart rate increased by 11 % and mean systolic blood pressure by 5 % (p < 0.05, p < 0.01), whereas plasma NA did not change significantly. The present study indicates that physiologic increments in plasma insulin concentration are of importance in the regulation of the cardiovascular system and plasma NA following an oral glucose load.     

A comparison of the behavioral effects of proteo- and deutero-N,N-dimethyltryptamine

The behavioral effects of N,N-dimethyltryptamine (DMT) and α, α, β, β-tetradeutero-N,N-dimethyltryptamine (D₄DMT) at dose levels of 2.5 and 5.0 mg/kg were examined in rats on a food reinforced schedule. The D₄DMT was observed to produce a significantly greater disruption of behavior, have a longer duration of action and a shorter time to onset than DMT. This potentiation, apparently due to the kinetic isotope effect, suggests that DMT is significantly metabolized and deactivated by deamination at the α-position.