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Biomedical subjects

N W Solomons

Publications and source records attributed to N W Solomons.

At least 163 records · Page 9Linked to original sources
PubMed1979

Studies on the bioavailability of zinc in man. III. Effects of ascorbic acid on zinc absorption.

As ascorbic acid is known to enhance the absorption of dietary iron and to inhibit the absorption of dietary copper, studies were undertaken to examine the effect of ascorbic acid on the bioavailability of zinc in human subjects. The index of absorption was the change in plasma zinc concentration after a 110-mg aqueous dose of ZnSO4.7H2O (containing 25 mg of elemental zinc). Doses of 0.5, 1.0, and 2.0 g of ascorbic acid, representing a spectrum of Zn:ascorbic acid molar ratios from the dietary to the pharmacological range, failed to produce any significant change in the pattern of zinc absorption. Moreover, 2.0 g of ascorbic acid, equivalent to a Zn:ascorbic acid ratio of 0.145 failed to improve the absorption of 108 mg of elemental zinc incorporated into 120 g of black bean gruel. Ascorbic acid over a range of dosages commonly consumed by man had no demonstrable effect on the absorption of inorganic zinc.

Absorption↗
PubMed1979

Reduced rate of breath hydrogen excretion with lactose tolerance tests in young children using whole milk.

On 14 occasions, 1.75 g/kg of body weight of lactose was given in whole milk to preschool children who had significant malabsorption with aqueous lactose solution. The volume of hydrogen excreted in the breath was less after the milk meal. Moreover, the hydrogen response to the nonabsorbable disaccharide, lactulose, was greater with aqueous, solution than with a liquid meal but their difference disappeared when metoclopramide was given with the lactulose: meal. The slower hydrogen production is attributed to slower intestinal delivery of lactose in meals; this phenomenon may account for clinical lactose tolerance often seen in children with demonstrated lactose malabsorption.

Animals↗
PubMed1979

H2 breath tests during diarrhea.

The peak rise in breath hydrogen and the volume of excess pulmonary excretion of hydrogen in response to a 10 g dose of the non-abosorbable disaccharide, lactulose, was significantly lower in children with active gastroenteritis and diarrhea than in nondiarrheal controls. Thus, despite the fact that the H2 breath test is a convenient, noninvasive technology for use in children, it cannot be recommended for measuring carbohydrate malabsorption in individuals with active, on-going episodes of diarrhea.

Breath Tests↗
PubMed1979

Lactose malabsorption and lactose intolerance: implications for general milk consumption.

A total of 194 publications related to lactose malabsorption or intolerance were reviewed. The poor correlation between lactose malabsorption and intolerance to the amounts of milk ordinarily ingested in a meal, indicates that the assumption of milk tolerance by many populations is exaggerated. The methods for the diagnosis of these conditions were critically evaluated and it is suggested that, a) "physiological" doses of lactose be used; b) milk is the vehicle of choice; c) tests of intolerance be double-blind, and d) analysis of breath hydrogen be used for malabsorption. Most of the evidence indicates that milk consumption allows adequate growth of children, even when they are malnourished and have diarrhea. Nevertheless, it is recommended to substitute temporarily non-human milk by other good sources of dietary protein and energy during episodes of severe diarrhea, and to reintroduce milk to the diet gradually during convalescence. Breast feeding, however, should not be interrupted. These is not enough scientific nor epidemiological support to justify discouraging the use of milk in food supplementation programs, but several aspects that must be considered in such programs are outlined.

Adolescent↗
PubMed1978

Zinc status and vitamin A transport in cystic fibrosis.

Zinc status and the retinol transport system were examined in 18 retinol supplemented cystic fibrosis (CF) patients and 40 age-matched controls. Plasma vitamin A was significantly lower in the CF group as compared to the controls and correlated positively with plasma retinol-binding protein (RBP) in both the CF and control groups. Plasma zinc of the CF group was not significantly lower than controls whereas hair zinc was. Plasma zinc was positively correlated with plasma RBP, vitamin A, and albumin in the CF group but not in the controls. Plasma concentrations of vitamin A, RBP, albumin, and zinc decreased with age in the CF group but not in the controls. The data support previous suggestions that low plasma vitamin A levels in CF are due to defects in the retinol transport system. The zinc status of the CF groups as a whole was judged to be low-normal however a subgroup of CF patients were in the marginal to deficient category. This subgroup also had lower levels of plasma vitamin A and RBP. The data suggest that zinc may be a contributing factor in the low plasma vitamin A/RBP levels of CF patients with marginal or deficient zinc status.

Adolescent↗
PubMed1978

Leukocytic endogenous mediator in Crohn's disease.

Reduced concentrations of plasma zinc associated with elevated levels of serum leukocytic endogenous mediator activity were found in 17 patients hospitalized with acute exacerbation of Crohn's disease. Neither the decrease in plasma zinc nor the increase in leukocytic endogenous activator activity in nine outpatients with quiescent disease was significant. Leukocytic endogenous mediator activity may be increased in inflammatory conditions as well as in microbial infections. Although zinc deficiency may be common in patients with Crohn's disease, exclusive reliance on circulating zinc levels to assess zinc nutriture in active Crohn's disease may be misleading.

Adolescent↗
PubMed1978

[Use of tests based on the analysis of expired air in nutritional studies].

Tests based on the analysis of the gaseous components of expired air have been developed to study intestinal absorption and intermediary metabolism of various nutrients. This paper reviews the breath-analysis tests based on the measurement of CH4, H2, and isotopically-labelled CO2 for studying the intestinal absorption of carbohydrates, fats, and bile salts, and intrahepatic metabolism. New technology employing mass spectrometry allows the use of the stable isotope, carbon-13, instead of the radioactive isotope, carbon-14, for CO2 breath tests. The nutritional application of the breath-analysis tests is discussed, and the advantages of the non-radioactive, non-invasive procedures, especially for use in children and pregnant women in whom standard investigational methods represent a discomfort or a radioactive hazard, are emphasized.

Bile Acids and Salts↗
PubMed1977

Malabsorption associated with diarrhea and intestinal infections.

An episode of diarrhea causes weight loss and a temporary cessation of growth in infants and children. Diarrhea is accompained by malabsorption of sugars, nitrogen, fats, and micronutrients. The mechanisms by which acute diarrheal disease produce malabsorption have not been studied carefully. The nutritional costs of malabsorption may pose a major threat if diarrhea becomes chronic or recurrent. The hydrogen breath test for carbohydrate malabsorption does not require intubation or blood drawing and can be used in children to help clarify the importance of carbohydrate intolerance in the duration and perpetuation of acute diarrhea and intestinal bacterial overgrowth.

Bacterial Infections↗
PubMed1977

Granulocyte function in patients with chronic renal failure: surface adherence, phagocytosis, and bactericidal activity in vitro.

The defects in host defense mechanisms that explain the enhanced susceptibility to infection of patients with chronic renal failure are not understood, and previous studies concerning function of polymorphonuclear leukocytes (PMNL), the major antibacterial defense, conflict. Therefore, the antimicrobial functions of PMNL obtained from chronically uremic patients and serum factors essential for PMNL activity were evaluated. The potential modifying effect of high concentrations of serum from uremic patients on PMNL of uremic patients was determined, and granulocyte adherence, an activity related to recruitment of cells to inflammatory sites, was measured. Phagocytosis of 14C-labeled Staphylococcus aureus and bactericidal activity were normal and unaffected by high concentrations of uremic serum. Serum from uremic patients opsonized staphylococci and yeast normally. Oxidative metabolism of PMNL [14C-1]glucose oxidation, O2 consumption, and quantitative protein iodination) was normal, as was PMNL adherence. If the uremic patient has an increased risk of infection, this risk cannot be ascribed to defects of PMNL responses that have been studied in these patients.

Adult↗
PubMed1977

Zinc deficiency in Crohn's disease.

Zinc nutriture has been studies in 30 patients with Crohn's disease using plasma zinc, hair zinc, and taste acuity as indices. Significant reductions in plasma zinc concentrations and taste acuity were seen in the patient groups as compared with normal controls. Hair zinc content was also generally low with several deficient values encountered among the Crohn's patients. A highly significant correlation between plasma zinc and albumin suggests a possible role of plasma-binding alterations in the depressed plasma zinc levels of patients with Crohn's disease patients and a potential influence on growth and healing in this disease must be considered.

Adult↗