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Biomedical subjects

B L Nichols

Publications and source records attributed to B L Nichols.

At least 73 records · Page 4Linked to original sources
PubMed1983

Changes in the nutrient composition of human milk during gradual weaning.

Six lactating women were recruited at 5 to 7 months postpartum for a study of milk composition during gradual weaning. At recruitment all subjects were exclusively breast-feeding their infants. The subjects were asked to reduce the frequency or duration of breast-feeding episodes by approximately one-third each month for a period of 3 months. Milk was collected before weaning began and at 2-wk intervals for 12 wk. The concentrations of protein and Na were 142 and 220% of base-line values, respectively, at the end of this period. Changes in fat composition were difficult to interpret. A linear trend was observed through wk 10, but values for wk 12 were similar to those obtained before weaning was initiated. The concentration of Fe at wk 12 was 172% of the base-line value. The concentration of Ca did not change and that of Zn fell to 58% of the base-line value at wk 12. The significance of the changes in nutrient concentrations, their relationship to the involution of the mammary gland, and the suitability of milk from this stage of lactation for milk banking are evaluated.

Adult↗
PubMed1983

A comparison of dietary methods in nutritional studies.

Dietary intakes of 40 lactating women were measured by a 7-day record (7DR) and compared with results using a 1-day record (1DR), 3-day record (3DR), and a newly developed food frequency form. The estimated intakes of energy, protein, calcium, phosphorus, and iron were used in the comparison. The subjects ranged from 3 wk to 6 months postpartum and all were totally breast-feeding their infants at the time of the study. The 7DR was recorded by the subjects and random days were chosen to provide 1DR and 3DR. The food frequency form is a method developed to estimate nutrient intakes based on the consumption of 105 food items. Intraclass correlation coefficients used to compare methods indicated good, moderate, and poor agreement for 3DR/7DR, 1DR/7DR, and food frequency form/7DR comparisons, respectively. Regression analysis was used to assess further the agreement between 3DR and 7DR. This analysis indicated that the 3DR cannot provide good individual estimates of nutrient intakes, but can provide a reasonable estimate of the general quality of the diet. Intakes also were classified as high (greater than 1 1/3 Recommended Daily Allowance), medium (2/3 to 1 1/3 Recommended Daily Allowance), or low (less than 2/3 Recommended Daily Allowance), and Cohen's kappa was used to measure agreement between methods. None of the intakes was found to agree with the 7DR classification. Intraindividual variation was found to be greater than interindividual variation.

Diet Surveys↗
PubMed1983

Evaluation of the deuterium dilution technique against the test-weighing procedure for the determination of breast milk intake.

A noninvasive isotopic method for the determination of milk intake in breast-fed infants was evaluated against the conventional method of test-weighing. In experiment 1, 48-h breast milk intake was estimated concurrently by the test-weighing procedure and by the deuterium dilution technique. In experiment 2, the isotopic method, modified to minimize fluctuations in water flux, was evaluated against a 24-h test-weighing. In experiment 1, the mean 48-h milk intake estimated by the isotopic method (1616 +/- 353 ml) was significantly higher than that measured by the test-weighing procedure (1449 +/- 234 ml) (p less than 0.01). In experiment 2, 24-h milk intake as determined by test-weighing and deuterium dilution averaged 878.0 +/- 188.1 and 690.7 +/- 141.4 ml/day, respectively, and differed significantly (p less than 0.001). The ability of the deuterium dilution method to predict values obtained by the test-weighing procedure was unsatisfactory for individual estimations. These experiments indicate that the deuterium dilution technique is unacceptable for the determination of breast-milk intake in individuals, but may be satisfactory for a population estimation.

Body Water↗
PubMed1983

Muscle electrolytes in malnutrition syndromes of children.

Muscle electrolyte composition has been studied in 10 infants with marasmus and eight children with kwashiorkor. The presence of altered muscle salt and water concentrations was confined in the latter nutritional syndrome. The marasmic infant, with equivalent or more severe nutritional wasting than the child with kwashiorkor, maintained a more normal muscle electrolyte concentration as indicated by a number of criteria. The pathophysiology of the altered muscle composition in kwashiorkor remains unclear; however, it appears to be more specific than due just to a depletion of available fat and muscle stores. Although possible endocrine mechanisms can be postulated to explain the change in muscle chemistry, the existing evidence is inadequate. Clearly, continuing research is warranted.

Adenosine Triphosphate↗
PubMed1983

Modeling the growth pattern of premature infants.

A model for the accretion of weight of premature infants from birth to hospital discharge has been studied for goodness of fit and other qualities. The model has been fitted to data for weight of 22 infants with typical growth patterns and to a full range of standard premature growth curves. It was found that the model fitted well to the data suggesting its value as an analytic tool in studies of premature growth.

Growth↗
PubMed1983

Impaired polymorphonuclear leukocyte motility in malnourished infants: relationship to functional abnormalities of cell adherence.

The humoral and cellular contributions to PMN motility in vitro were studied in 37 malnourished (PCM) pediatric patients. Early-phase directed migration to BCF and to ZANS was diminished significantly (p less than 0.001) in severe PCM patients as compared to healthy adult or age-matched controls or respective nutritionally restored patients. Abnormalities were reversible after nutritional restoration and unrelated to occurrence of clinical infection. To determine the pathogenic mechanism of impaired PMN mobility in PCM, studies of cell morphology and adhesive function were performed. Abnormalities observed in severe PCM suspensions included significantly (p less than 0.001) increased baseline (unstimulated) adherence values and impaired CF modulation of adhesive function. Diminished enhancement of PMN adherence or decreased (relative to baseline) adherence values were observed in response to BCF (mean % delta = +5) or f-Met-Leu-Phe (mean % delta = -6) as compared to adult PMN values of +28% delta and +31% delta, respectively. That these abnormalities may result from in vivo CF prestimulation was suggested by findings of "activated" PMN morphology in suspensions prior to in vitro stimulation, and abnormalities of the distribution of PMN surface adhesion sites under conditions of chemotactic stimulation. Further investigations will be required to determine the underlying pathogenic mechanism(s) accounting for our observations.

Cell Adhesion↗
PubMed1982

Fecal steroids in diarrhea: IV. Cholera.

Fecal bile acid and neutral sterol patterns were studied in eight healthy adult volunteers who were challenged with Vibrio cholerae classical Ogawa 395 strain in the course of vaccine development studies. Bacterial 7 alpha-dehydroxylation of cholic and chenodeoxycholic acids was not altered during experimentally induced cholera diarrhea, despite the fact that fecal weight in g/day (wet wt) was increased greatly during diarrhea (1913 +/- 390 vs 161 +/- 11 in controls, p less than 0.005). Consistent with the findings on bile acids, no significant changes in the production of coprostanol, epicoprostanol, or coprostanone were observed although the percentage of unmodified cholesterol was increased during the diarrheal episode (20.7 +/- 3.3% vs 11.9 +/- 2.3, p less than 0.02). Total concentrations of both bile acids and cholesterol in mg/g of feces (wet wt) were decreased considerably as a result of diarrhea). However, total bile acid and neutral steroid excretions in mg/kg/day in subjects with and without diarrhea do not appear to be different. Intestinal transit times, measured in eight subjects by the use of carmine red dye, were found to be shortened in diarrhea (5.8 +/- 1.1 hr vs 23.4 +/- 4.1 hr in controls, p less than 0.001). The results from this study are similar to those observed in experimentally induced travellers' diarrhea associated with toxigenic Escherichia coli, but they are in striking contrast to the changes in gastrointestinal steroid metabolism observed in acute shigellosis, an invasive intestinal infection.

Adult↗
PubMed1982

Effects of methods of collection and storage on nutrients in human milk.

The effects of collection technique, storage container, and the duration and temperature of storage on selected nutrient concentrations in mature human milk were evaluated. Milk samples were collected during the fourth week of lactation from women 20-35 years of age by hand expression or suction. Greater volumes and fat concentrations were observed in milks collected by suction. Vitamin A, zinc, iron, copper, sodium, and protein nitrogen concentrations were not affected by storage of milk in either pyrex or polypropylene containers for up to 24 h. The storage temperature had a significant effect on protein nitrogen and ascorbic acid concentrations. These findings indicate that collection methods and storage procedures used for comparatively brief periods will affect the concentrations of selected nutrients of mature human milk. Specific recommendations are made for the collection and storage of milk.

Adult↗
PubMed1982

Immunologic factors in human milk during the first year of lactation.

The effects of the duration of lactation upon lactoferrin, lysozyme, total IgA, SIgA, SIgA antibodies to Escherichia coli somatic antigens and leukocytes in human milk were investigated. Longitudinal and cross-sectional studies were performed with milk collected from women 20 to 35 years of age during te first year of lactation. Collection and storage conditions and immunologic analyses were controlled to minimize confounding variables. The concentrations of lactoferrin, total IgA, and leukocytes and the uptake of 3H-thymidine by phytohemagglutinin-stimulated lymphocytes fell during the first several weeks of lactation; afterward, the levels of lactoferrin and IgA stabilized. Approximately 90% of total IgA in human milk during the year was SIgA. Secretory IgA antibody titers to E. coli increased in some individuals studied longitudinally suggesting that the enteromammary gland pathway of SIgA antibody production was active after several weeks of lactation. Moreover, the concentrations of lysozyme, after falling to a nadir of 20 to 30 micrograms/ml at 2 to 4 weeks, rose to 200 to 300 micrograms/ml by six months and remained elevated. The immunologic system in human milk undergoes remarkable changes which may represent adaptations for the recipient infant.

Adult↗
PubMed1982

Diurnal and longitudinal variations in human milk sodium and potassium: implication for nutrition and physiology.

Human milk sodium ([Nal]) and potassium ([K)] concentrations were measured every 4 h for 24 h in 28 subjects 3.5 to 32 wk postpartum. A diurnal variation in milk Na was seen, which was reciprocal to K. Significant negative correlations between Na and K were seen in these periods: 3.5 to 6; 8 to 18, 20 to 32 wk postpartum (p less than 0.01 for each). The mean 24 h milk sodium concentrations (x(Na)) decreased between 3.5 and 18 wk postpartum (p less than 0.005 by paired t test). Changes in mean potassium (-XK) were not statistically significant. Diet apparently does not affect milk Na. Administration of a low Na diet: 10.8 +/- .9 (SD) mEq Na/day and 60 to 100 mEq K/day for 2 days did not change x(Na). But urinary Na decreased 7-fold as aldosterone increased 5-fold. No significant correlation was seen between 24 h Na excretion in urine and x(Na) in milk (n = 51). A significant positive correlation was seen between urinary K and -XK in milk (r = 0.36), p less than 0.001).

Adolescent↗
PubMed1982

Comparison of acquired monosaccharide intolerance and acute diarrheal syndrome.

In a retrospective study, 9% of the admissions to Ben Taub General Hospital for diarrhea were found to have acquired monosaccharide intolerance (AMI). The course of AMI was compared with that of acute diarrheal syndrome (ADS). The patients with AMI were younger at the time of admission, and, although the mean birthweight and percent of prematurity were approximately the same in the two groups, the AMI patients were found to be malnourished (p less than 0.02). Data suggest that the nutritional insult had occurred between birth and admission, and that malnutrition was a contributing factor in the development of AMI.

Age Factors↗
PubMed1982

Malnutrition in infants with acute diarrheal syndrome.

The data from the charts of 109 infants who were younger than 9 months of age and who had been hospitalized with acute diarrheal syndrome in 1978 were compared with data from the charts of 108 healthy infants of the same age range with the same sex and ethnic distributions who were attending well-child clinics serving the same geographic area during the same year. In a comparison of weight percentiles, 45.3% of the acute diarrheal syndrome patients and 11.3% of the well children were below the 10th percentile. When height percentiles were compared, 41.8% of the acute diarrheal syndrome patients and 15.3% of the well children were below the 10th percentile. The data indicate that malnutrition was a characteristic of infants with acute diarrheal syndrome who required hospitalization.

Acute Disease↗