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Biomedical subjects

G G Graham

Publications and source records attributed to G G Graham.

At least 109 records · Page 6Linked to original sources

Fasting and postprandial plasma free amino acids of infants and children consuming exclusively potato protein.

Fasting and postprandial plasma free amino acids were studied in nine children on the 9th day of consumption of a diet in which potato protein provided all nitrogen at a marginal level of protein intake (5.03-5.10% protein-calories). The analysis of the potato utilized indicated that 49% of total amino acids (TAA) were free amino acids (AA) and 40% essential amino acids (EAA). Fasting values of TAA and total essential amino acids (TEAA) and the ratios of EAA/TEAA were similar to those obtained previously with milk or casein diets. The low percentage of protein-calories in the diet and relatively poor nitrogen absorption of the potato were reflected in a low (0.236) fasting TEAA/TAA ratio. Met/TEAA and Trp/TEAA ratios were significantly (P less than 0.05) but not markedly lower 3 hours postprandially compared to fasting values, returning to the initial levels 4 hours postprandially. Thr/TEAA ratio was significantly higher (p less than 0.05) at 3 hours but not so at 4 hours. The results suggest that potato protein has an adequate ratio of TEAA/TAA and the balance among individual EAA concentrations should be able to meet the EAA requirements of growing infants and small children if fed and absorbed in sufficient amounts to meet total nitrogen needs.

Amino Acids↗

Prolonged consumption by infants of wheat-based diets with and without casein or lysine supplementation.

Infants consumed 75% of calories as 82% extraction wheat flour with satisfactory short-term protein and energy digestion. Protein needs, represented by N retentions from casein, probably were not satisfied. Long-term (3+ months) studies in four infants showed that 50% calories and 80% protein from wheat (casein added to 8% protein calories) supported weight gain and linear growth more than expected. Prolonged feeding of 75% calories and 100% protein from wheat attempted in three infants. In the oldest (15.5 months), digestibility and growth was satisfactory; in one, despite good digestion, weight gain and growth was inadequate and serum albumin fell until 0.2% lysine was added; and in another, weight gain was satisfactory but albumin fell to 3.25 g/dl and growth was inadequate. In six other infants, lysine addition during the 2nd of 3 months was associated with significant increase in N retention and weight gain and stabilization of albumin; lysine withdrawal resulted in significant decrease in weight gain with no effect on N retention or albumin; growth was barely adequate during 3-month study. Serum cholesterol fell only when dietary protein was inadequate. It is practically impossible for unsupplemented wheat to satisfy protein needs of infants and most small children.

Body Weight↗

Protein quality and digestibility of sorghum in preschool children: balance studies and plasma free amino acids.

The protein quality and digestibility of two high lysine (2.9-3.0 g/100 g protein) and tow conventional varieties (lysine content 2.1-2.2 g/100 g protein) of whole grain sorghum milled as flour were assessed through balance studies in 13 children 6-30 months of age. Sorghum protein provided 6.4 or 8.0% of dietary energy. Control diets contained 64% kcal protein as casein. Children consumed 100-150 kcal/kg body weight/day. Sorghum consumption was associated with weight loss or poor weight gain. We found no difference by variety in apparent nitrogen absorption or retention. Mean absorption and retention of nitrogen (+/- SD) from 26 six-day sorghum dietary periods were 46 +/- 17% and 14 +/- 10% of intake, respectively (corresponding preceding casein control values: 81 +/- 5% and 38 +/- 3%). Stool weight and energy losses during sorghum periods averaged 2.5 to 3 times control values. Plasma amino acids were determined in eleven children after 16 days of sorghum consumption. Fasting concentration of total amino acids (TAA) was similar to values previously obtained with wheat protein at similar levels of intake. Total concentration of essential amino acids (TEAA) was low as were concentrations of lysine (Lys) and threonine (Thr). Analysis of postprandial changes of the Lys/TEAA and Thr/TEAA molar ratios confirmed that Lys was the first limiting amino acid.

Absorption↗

Identification of new urinary metabolites in man of quinine using methane chemical ionization gas chromatography-mass spectrometry.

1. Six new metabolites of quinine have been identified in urine of man by methane chemical ionization g.l.c.--mass spectrometry. 2. Metabolites identified were: unchanged quinine and dihydroquinine, 3-hydroxyquinine, 3-hydroxydihydroquinine, 6'-hydroxycinchonidine, 6'-hydroxydihydrocinchonidine, quinine-10,11-epoxide and quinine-10,11-dihydrodiol. 3. 10-Chloro-11-hydroxydihydroquinine was identified as an artifact of the isolation procedure. 4. Chloroquine and desethylchloroquine (artifacts) were identified in the urine, 17 days after completion of a 48 h treatment with chloroquine.

Gas Chromatography-Mass Spectrometry↗

[Digestibility and protein quality of quinua: comparative study of quinua (Chenopodium Quinoa) seed and flour in children].

Based on the hypothesis that the digestibility of quinua seed is the limiting factor in the utilization of nutrients from this staple, two quinua-based diets were prepared using quinua seeds and quinua flour. Theses diets were offered to children recovering from malnutrition. The digestibility and protein quality of the quinua diets were compared to those of a casein control diet by analyzing the children's metabolic balance. Results showed that digestibility of the quinua diets were compared to those of a casein control diet by analyzing the children's metabolic balance. Results showed that digestibility of the quinua seed is the limiting factor in the protein and energy utilization, and that milling improves significantly the digestibility of fat and carbohydrates. Findings also confirmed that the protein quality of quinua seeds is adequate for human consumption.

Body Weight↗

Urban-rural differences in the growth of Peruvian children.

The growth characteristics of children from four villages in northern Peru were compared with those of poor urban children in the capital city, in whom short stature but generally satisfactory weight for height relationships after infancy had been demonstrated. Height for age and weight for age fell more rapidly during infancy in the rural than in the urban children of both sexes. Rural girls caught up with the urban girls in height during childhood but did not match them in weight until late adolescence. Their weight to height ratios were consistently lower after 1 year of age, most strikingly between 2 and 5 years of age, and did not approach or match those of the urban girls until adolescence. Rural boys did not catch up with the urban boys in height or weight (differences in height were not statistically significant between 6 and 10 years, however) and their ratios remained consistently lower until late adolescence, most strikingly in early childhood and during puberty. Such urban-rural and sex differences, if typical and current, might well call for very different remedial measures at different ages in each of the populations.

Adolescent↗

Determinants of growth among poor children. I. Food and nutrient intakes.

One hundred sixty-seven poor families living in Lima had yearly anthropometric and socioeconomic evaluations for up to 16 years. In 26 of these a 7-day individually-weighed food survey was carried out in 1972 to 1974, immediately following a national food consumption survey. Adult males were markedly under-represented in the survey and probably to a lesser degree in the national one. Mean daily intakes of energy (1975 +/- 498 kcal), total protein (41.1 +/- 12.1 g), and animal protein (14.4 +/- 8.1 g) fell between those of the first and second economic deciles of the city in the national survey, which is where mean incomes were estimated to be. Intakes of the few adult males were approximately 50% higher than the family means, those of adult females approximately 12% lower. Nutrient intakes of the few infants in the survey were markedly different from those of the 2- to 19-year-old children, being heavily dependent on cow milk. There were no significant differences in intake between boys and girls. Children over 2 years of age derived almost 50% of energy and protein from cereals (notably wheat and rice), 11.2% of energy from sugar, 4.3% of energy and 11% of protein for legumes, 4.4% of energy and 14.7% of protein from meat, and 13% of energy from separated fats. Total fat represented 21.8% of energy in their diet. These sources of energy and protein were very similar to those found in the lowest two deciles of the national survey from Lima.

Adolescent↗

Nutritional value of normal, opaque-2 and sugary-2 opaque-2 maize hybrids for infants and children. 1. Digestibility and utilization.

The opaque-2 (o2) gene increases the lysine and tryptophan contents of maize and its protein quality; the sugary-2 (su2) gene improves vitreousness and density but decreases lysine; the double-mutant surgery-2 opaque-2 (su2o2) has the improved kernel characteristics and an even higher protein quality than opaque-2. Digestibility of energy and protein, and protein quality of normal, o2 and su2o2, both as endosperm (E) and whole kernel (WK) meals, were studied in eight convalescent malnourished children, 10--25 months of age. Diets provided 100--125 kcal/kg/day, 10% fat, with all of 6.4% protein calories from one of six maize meals or casein. Endosperm meals provided 83.2, 91.2 and 82.1% of energy, WK meals 73.2, 68.6 and 67.2% of energy in respective diets. Apparent N retention from E meals was lower than from WK meals, both lower than from casein. For each type of meal (E and WK) there was strong correlation between lysine "absorbed" and N retention, but this was higher from WK at equal lysine intakes. For 50% of children to match N retention from casein, presumably equal to requirement, they would have to consume 203.9, 148 or 122.5% of energy requirement as normal, o2 or su2o2 E meals, obviously impossible. For WK meals, they would have to consume 108.2, 90.3 or 84.2% of energy as normal, o2 or su2o2.

Child, Preschool↗

Utilization of the protein and energy of the white potato by human infants.

The digestibility and protein quality of the white potato were studied in 11 infants, ages 8-35 months, recovering from malnutrition. Seven 9-day dietary periods comprised the study. Digestibility was assessed by metabolic balance during the last 6 days of dietary periods in which potato provided 25%, 50% or 75% of dietary energy. Casein-based control dietary periods preceded and/or followed each potato dietary period. Fecal wet and dry weights, fecal energy, computed fecal carbohydrate and fecal fat during consumption of the 25% potato diet did not differ from control. Analysis of variance showed that consumption of increasing amounts of potatoes produced a significant linear increase in all parameters of digestibility except fecal fat. Fecal wet weight and energy content during the 75% potato period were more than double control values. Regression analysis of data from potato dietary periods showed fecal wet weight to be an excellent predictor of fecal dry weight (r = 0.904), energy content (r = 0.785) and computed fecal carbohydrate (r = 0.770). Protein quality of potato was assessed with N balance studies during the dietary periods in which potato provided all dietary protein (approximately 5% protein kcal). Apparent N retention was 78% of that from an isonitrogenous casein control diet. Decreased apparent N absorption was primarily responsible for the difference; the "biologic value" (percent of absorbed N that was retained) was similar for both diets.

Caseins↗