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Biomedical subjects

W C MacLean

Publications and source records attributed to W C MacLean.

At least 19 recordsLinked to original sources
PubMed1991

Dietary management of malnourished children with a new enteral feeding.

Balance (nitrogen, fat, carbohydrate) and growth studies were carried out in nine children (6 to 26 months old) recovering from protein-energy malnutrition (PEM) using a concentrated (1 kcal/mL) formula designed specifically for 1- to 6-year-olds. The formula provided 12% of energy as protein (18% whey, 82% casein), 44% of energy as carbohydrate (69% corn syrup solids, 31% sucrose), and 44% of energy as fat (50% high-oleic safflower oil, 30% soy oil, 20% medium-chain triglycerides). Means +/- standard deviations of apparent nitrogen retention and absorption were 90 +/- 3% and 39 +/- 13%, respectively. Mean fecal fat excretion was 1.3 +/- 1.0 g/day. Length-age increased 3.0 +/- 0.8 months and weight-age increased 8.3 +/- 3.8 months during the 2.4 +/- 0.3 months of the study. (Length-age and weight-age were defined as the age (in months) to which the child's length or weight corresponded at the 50th percentile of the National Center for Health Statistics reference data). Thirteen additional 40- to 30-month-old children with kwashiorkor were fed the formula for 8 to 35 days as part of the initial management of PEM. The result was prompt weight gain and increases in serum proteins. Its formulation and the findings of our study indicate that this new formula offers a notable advantage over products designed for infants or adults in the enteral alimentation of young children.

Body Height↗
PubMed1990

Comparative absorption of [13C]glucose and [13C]lactose by premature infants.

Oxidation of orally administered [13C]glucose and [13C]lactose and fecal recovery of malabsorbed substrates were determined in two groups of premature infants. Eighteen studies were performed with six infants at Johns Hopkins Hospital (JHH); 24 studies were performed with nine infants at Columbus Children's Hospital (CCH). The two groups differed in that JHH infants had shorter gestations but were older when studied. Fecal 13C loss after [13C]glucose administration did not differ between the two groups. Compared with glucose, the metabolism of lactose appeared to involve more malabsorption and colonic fermentation in JHH infants than in CCH infants and resulted in higher fecal losses of substrate carbon. Maturation appeared to involve increased proximal intestinal absorption and greater retention of absorbed carbohydrate. Simultaneous absorption of substrate from the small and large intestine may limit the usefulness of breath tests for 13C in the premature infant.

Breath Tests↗
PubMed1990

The nutritional value of oat flour for very young children.

Whole groat flour was consumed by nine infants and young children as 22.5, 45, or 67% of total diet energy (one half of 6.4%, all of 6.4%, or all of 9.6% protein energy). Isonitrogenous and isoenergetic casein control diets were given. Apparent absorption of oat nitrogen (N) was consistently around 75% of intake (casein, 87%), but absorptions of oat energy, carbohydrate, and fat, as percentages of intake, decreased disproportionately as oat flour intake was doubled and then tripled. Apparent retentions were 39 +/- 5% of mixed oat-casein protein intake in the 22.5% diet, the preceding and following casein controls being 38 +/- 8% (NS) and 44.4% (p less than 0.05) of the intakes; 32 +/- 6% from oats in the 45% diet, controls 38 +/- 5 and 46 +/- 5% (both p less than 0.05), and 33 +/- 11% from oats in the 67% diet, controls, 36 +/- 9% (NS). Fasting plasma free total essential amino acid (TEAA) levels of children consuming 45% oats were low (562 +/- 119 mumol of TEAA/L) and did not change significantly after meals. Fasting molar proportions of individual essentials (millimoles of EAA per mole of TEAA) were similar to those from milk protein diets and did not vary significantly 3 and 4 h after feeding, suggesting that no individual amino acid, but rather protein digestibility, was first limiting to N retention. Oats are a satisfactory source of energy, protein, and fat for very young children and many infants.

Amino Acids, Essential↗
PubMed1986

Digestibility and utilization of protein and energy from Nasha, a traditional Sudanese fermented sorghum weaning food.

Whole grain sorghum flour was fermented into Nasha, a traditional Sudanese food, and freeze-dried or drum-dried. It was cooked and fed to convalescent malnourished infants and small children as 61% of total diet calories and all of 6.4% protein calories, with (Lys+) and without lysine supplementation to 3% of protein. Apparent absorptions of nitrogen were 73 +/- 5 and 74 +/- 6% of intake, significantly (P less than 0.01) less than those from preceding (Cas-1, 86 +/- 3%) and following (Cas-2, 85 +/- 3%) isonitrogenous casein diets. Apparent retentions of nitrogen from Nasha (26 +/- 10%) were significantly lower than those from Lys + (34 +/- 9%, P less than 0.05), Cas-1 (35 +/- 11%, P less than 0.01) or Cas-2 (49 +/- 9%, P less than 0.01). Retentions from Cas-2 were higher than those from Cas-1 or Lys + (P less than 0.01). Fecal wet and dry weights were higher (P less than 0.02) during both Nasha diets and Cas-2 than during Cas-1. Fecal energy and carbohydrate were significantly (P less than 0.01) higher from either Nasha diet than from either casein diet; fecal fat was not different. Two children received drum-dried Nasha without further cooking; digestibilities were not different from those of the cooked product but biological value was much lower. When properly cooked and consumed along with small amounts of a good source of lysine, Nasha is a satisfactory weaning food.

Absorption↗
PubMed1986

Rehydration.

Explore the source record for details and available documents.

Child↗
PubMed1985

Efficient storage system for breath hydrogen.

Recommended materials for breath hydrogen collection (plastic syringes with twist lock closure) are only adequate for relatively brief periods because of gradual hydrogen loss and considerable variability between duplicate samples. To document the most favorable storage conditions for breath hydrogen, we compared hydrogen retention in plastic syringes using a conventional twist-in-lock closure versus a simple, inexpensive syringe closure, a Critocap. Hydrogen retention was studied at 25, 5, and -20 degrees C in two different syringe brands over 72 h of storage. An analysis of variance confirms the superiority of Critocaps over twist-in-lock closures (p less than 0.001). Reliability was maximal when samples were placed in environments less than 5 degrees C. When storage time was extended to 7 days, mean hydrogen retention was 86 +/- 6% (means +/- SD).

Breath Tests↗
PubMed1985

Survey: methods of feeding low-birth-weight infants.

The directors of 269 neonatal intensive care units were surveyed to determine how low-birth-weight infants are being fed. Feeding practices were based on birth weight, with the smallest infants receiving parenteral nutrition for the longest time after birth. First enteral feedings usually were given by the nasogastric route in infants with birth weight of 1,500 g or less, but transpyloric feedings were used in 15% of neonatal intensive care units for infants with birth weight less than 1,000 g. The initial enteral feeding was sterile water in 56% to 58% of the neonatal intensive care units, but was glucose water or milk in the others. Once enteral feeding was established, both human milk from the infant's own mother and commercial formula were used. Whether human milk was mixed or alternated with infant formula, or whether some infants in the nursery were fed human milk while others were fed formula, was not determined. The type of infant formula fed to low-birth-weight infants depended on the infant's birth weight and clinical status. Both human milk and formula were supplemented with energy (fat or carbohydrates) and vitamins, but not with calcium and phosphorus, in most neonatal intensive care units. Some vitamins, such as vitamins A and D, may be oversupplemented, while others, such as folic acid, may be undersupplemented.

Birth Weight↗
PubMed1979

Nutritive value of brown and black beans for infants and small children.

A precooked, instantized mixture of brown and black beans, with and without 0.3% DL-methione added, served as the only source of protein in the diets of 10 recovered malnourished infants and children 10 to 42 months of age. At 6.4 to 5.7% dietary protein calories stool wet weights were twice as high, apparent N absorption significantly lower (65.6 +/- 5.9 versus 87.5 +/- 2.3% of intake), and apparent N retention much lower (9.8 +/- 6.1 versus 34.5 +/- 10.2% of intake) than during preceding and following isocaloric and isonitrogenous casein-based diets. The addition of methionine resulted in minimal improvement in N retention and a highly suggestive increase in fasting plasma free methionine. Prolonged feeding of the methionine-enriched beans at 8.0 to 10.9% protein calories supported satisfactory growth and serum albumin levels in two of three children, not so in the smallest one, in whom repeated balance studies demonstrated no decrease over time in stool wet weight and on marginal improvement in N absorption and retention. The poor digestibility of the protein in these beans is the first-limiting factor in its utilization by infants and small children.

Caseins↗
PubMed1979

Growth standards for poor urban children in nutrition studies.

In order to estimate the importance of a variety of environmental and dietary factors as determinants of growth in a group of 123 poor Peruvian urban children between 2 and 19 years old, we found it necessary to express anthropometric measurements in units that were not age- or sex-dependent. Height quotient and weight quotient for each child were calculated from height and weight ages derived from the 50th percentile of the Boston reference data for the appropriate sex. Only 5% of the children had heights above the Boston 50th percentile (height quotient greater than 100) and 18% had weights above the 50th percentile (weight quotient greater than 100), but 88% had weights that were appropriate or excessive for height (weight/height quotient greater than or equal to 1.00). Some CATch-up" gains in relative height and weight were apparent in preschool children but more impressive gains in both linear and ponderal growth, relative to the Boston data, were evident between 8 and 13.5 years in girls and 10 and 17 years in boys. When the same quotients were calculated for a much larger sample from the same socioceonomic level it seemed likely that this last peak was due to earlier puberty and sexual maturation, and that quotients derived from the Boston data would have different meanings at different ages, making them inappropriate for further statistical analysis. New quotients for the study population, derived from the larger Peruvian group, did not have sex- or age-dependent trends. Racial and regional differences in patterns of growth must be taken into account in the interpretation of anthropometric and nutritional data.

Adolescent↗
PubMed1979

Effect of an episode of severe malnutrition and age on lactose absorption by recovered infants and children.

The degree of which the ability to absorb lactose can be regained after recovery from an acute episode of severe malnutrition is in doubt. Lactase activity was indirectly assessed by means of a standard lactose tolerance test (2 g lactose per kilogram of body weight) in 71 Peruvian Mestizo infants and children (age 5 to 55 months) who had suffered such an episode. All were studied just before discharge after several months of hospital rehabilitation, during which linear growth and weight gain had accelerated and signs of significant malabsorption of other nutrients had disappeared. Only 39% of the total group had a positive test (delta blood glucose greater than 25 mg/dl); there was a decreasing proportion of positive responders with increasing age. No difference in response attributable to type or severity of malnutrition was found. Comparison of the present data with previous data from children in the same community who had never been acutely malnourished suggests that acute malnutrition may hasten the permanent decline of lactase activity normally expected later in life.

Acute Disease↗