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Biomedical subjects

N W Solomons

Publications and source records attributed to N W Solomons.

At least 19 recordsLinked to original sources
PubMed2005

Monitoring of hematological, inflammatory and oxidative reactions to acute oral iron exposure in human volunteers: preliminary screening for selection of potentially-responsive biomarkers.

BACKGROUND: Iron is an essential micronutrient but also a major catalyst of oxidative and inflammatory reactions. OBJECTIVE: To evaluate the potential utility of selected biomarkers in blood or urine to indicate in vivo oxidative or inflammatory response to oral iron intake at pharmacological doses. METHODS: Three healthy volunteers provided morning, fasting samples of blood and urine on up to 13 study days--3 before, 7 during and 3 following a 7-consecutive-day period of receiving 120 mg of iron per day as ferrous sulfate in commercially available syrup. A series of 23 biomarkers were measured on each collection of biological fluids to monitor iron-responsive changes in biomarkers related to hematological or iron status, inflammation and in vivo oxidation. RESULTS: Among the inflammatory biomarkers measured, white blood cells, serum CRP and urinary neopterin showed no response to iron dosing. Only circulating interleukin-4 (IL-4) and TNF-alpha had abnormal responses with a time association to the oral iron intake. Among the oxidative biomarkers, expression of blood superoxide dismutase (SOD), hemoxygenase-1, catalase as well as circulating thiobarbituric acid reactive substances (TBARS), total oxidative capacity and carbonyl proteins were stable in response to iron exposure. Only urinary TBARS, 8-hydroxy-2-desoxyguanosine and isoprostanes evidenced consistent or suggestive responses to ingestion of the iron challenge. Serum hepcidin concentration increased dramatically in all three subjects after only the first 120 mg dose of iron, and remained elevated even 9 days after cessation of the iron intervention. CONCLUSIONS: Most of the candidate biomarkers show very limited promise as response-indicators to oral iron dosing at the 120 mg dosages or lower, but circulating IL-4, TNF-alpha as well as urinary TBARS, 8-hydroxy-2-desoxyguanosine and isoprostanes showed potential utility as reliable indicators of oxidative and inflammatory response to oral ferrous sulfate.

Administration, Oral↗
PubMed2005

Haematological response to haem iron or ferrous sulphate mixed with refried black beans in moderately anaemic Guatemalan pre-school children.

OBJECTIVE: Combating iron deficiency in toddlers with iron-fortified food has proved difficult in countries with phytate-rich diets. For this purpose, a new haem iron preparation was developed. The study compared changes in iron status after administration of refried beans with beans fortified with a haem iron preparation or ferrous sulphate (FeSO4). DESIGN: In a masked, stratified-randomised intervention trial, children received five 156-g cans of refried black beans per week for 10 consecutive weeks. The beans-only (control), FeSO4 and haem iron groups were offered a cumulative dose of 155 mg, 1625 mg and 1700 mg of iron from the bean intervention, respectively. Haemoglobin (Hb) and ferritin concentrations were determined at baseline and after 5 and 10 weeks. Compliance was examined weekly. SETTING: A low-income community in Guatemala City. SUBJECTS: One hundred and ten children aged 12-36 months with initial Hb values between 100 and 115 g l(-1). RESULTS: The cumulative intake of beans was approximately 80% of that offered, signifying an additional approximately 1300 mg of either haem or inorganic iron in the corresponding treatment groups over 10 weeks. Hb concentrations increased by the order of 7.3-11.4 g l(-1) during the intervention, but without significant differences across treatments. Average ferritin concentrations were unaffected by treatment assignment. However, post hoc analysis by subgroups of initial high ferritin and initial low ferritin found the Hb increments after 10 weeks in the haem iron group (13.1+/-7.7 g l(-1)) to be significantly greater than the respective increases (6.8+/-11.2 and 6.4+/-8.5 g l(-1)) in the inorganic iron and beans-only groups. CONCLUSIONS: Canned refried beans are a candidate vehicle for fortificant iron. Given the improved colour and organoleptic properties imparted by haem iron added to refried beans, its additional potential for benefiting the iron status of consumers with iron deficiency may recommend it over FeSO4.

Anemia, Iron-Deficiency↗
PubMed2002

Modulation of the immune system and the response against pathogens with bovine colostrum concentrates.

The growth, development and health conditions for children living under deprived conditions in developing countries are so adverse that immediate public health measures to reduce morbidity and improve nutrition are urgently needed. Preventing and shortening the course of diarrhoeal episodes, eliminating protozoal colonization, and balancing intestinal microflora would all contribute to these goals. The consumption by humans of part of the colostrum produced when a dairy animal gives birth is an established tradition in many traditional societies. Recent advances in food technology in industrial dairying allow for continuous availability of stabilized bovine colostrum concentrate, both natural and hyperimmunized against specific human pathogens. This is safe for the calves of the producers themselves, for laboratory animals, and generally for humans, with the caveat of the milk-allergic. Moreover, substantial amounts of orally ingested bovine colostrum concentrate survive their passage through the stomach to remain intact and active in the lower reaches of the bowel. Studies in animals, human volunteers and naturally infected humans have demonstrated a therapeutic efficacy of oral bovine colostrum with certain infections. Similarly, attempts to prevent gastrointestinal infections in animals, exposed volunteers and at-risk populations have met with limited success with specific pathogens. It is time to begin to assess the feasibility and potential effectiveness and efficiency of employing seasonal or chronic bovine colostrum feeding in populations of deprived infantile populations to reduce the rates of recurrent gastroenteritis and decrease immunostimulation to improve vitality and nutritional status in early life.

Animals↗
PubMed2002

Fermentation, fermented foods and lactose intolerance.

Lactose (milk sugar) is a fermentable substrate. It can be fermented outside of the body to produce cheeses, yoghurts and acidified milks. It can be fermented within the large intestine in those people who have insufficient expression of lactase enzyme on the intestinal mucosa to ferment this disaccharide to its absorbable, simple hexose sugars: glucose and galactose. In this way, the issues of lactose intolerance and of fermented foods are joined. It is only at the extremes of life, in infancy and old age, in which severe and life-threatening consequences from lactose maldigestion may occur. Fermentation as part of food processing can be used for preservation, for liberation of pre-digested nutrients, or to create ethanolic beverages. Almost all cultures and ethnic groups have developed some typical forms of fermented foods. Lessons from fermentation of non-dairy items may be applicable to fermentation of milk, and vice versa.

Dairy Products↗
PubMed2001

Self-rated health and its relationship to functional status and well-being in a group of elderly Guatemalan subjects.

This study examined the association of self-rated health with physical function and emotional well-being, while controlling for differences in sex, age and anthropometry. Subjects were participants in a multicentre study originated by the International Union of Nutritional Sciences (IUNS). A total of 151 elderly Guatemalan subjects were examined using a questionnaire which included information on self-rated health, activities of daily living, well-being, and a common battery of anthropometric variables. Adjusted odds ratios (OR) obtained with polytomous logistic regression showed that subjects with the highest score on the well-being index compared with those with the lowest were 1.67 times more likely (P-value <0.001, confidence interval (C.I.) = 1.31-2.14) to rate themselves in 'good' health versus 'fair' and 'poor' health. Subjects with the highest score versus those with the lowest on the mobility index were 1.15 times more likely (P-value <0.05, (C.I.) = 1.00-1.32) to rate themselves in 'good' health versus the other health ratings. These are the first results to examine the relationship of self-rated health to physical function and emotional well-being of elderly, free-living Guatemalans.

Activities of Daily Living↗
PubMed2001

Plasma free amino acid concentrations in healthy Guatemalan adults and in patients with classic dengue.

BACKGROUND: Plasma free amino acid patterns in health and disease have been reported. However, amino acid concentrations in adult populations in developing countries and in patients with dengue, as a model for an acute infectious viral disease endemic to the tropics, have not been reported. OBJECTIVE: The purpose of this study was to determine the amino acid profile in both healthy Guatemalan adults from different socioeconomic backgrounds and at 3 time points during the course of classic dengue. DESIGN: The study was carried out in Guatemala and included measurement of plasma free amino acids in 22 healthy control subjects (14 low income, 8 middle class) and 17 febrile patients. Measurements of amino acids were repeated within a 48-h interval in 20 of the healthy Guatemalans. In 9 patients with dengue, amino acids were assayed 3 times: on admission to a local hospital in the coastal plain of Guatemala, on hospital discharge, and 7 d after hospital discharge. RESULTS: Branched-chain amino acid concentrations in healthy adults and dengue patients in Guatemala were lower than normal values reported in the literature for healthy Swedish adults. With the exception of increased phenylalanine concentrations and an increased ratio of phenylalanine to tyrosine, all amino acids as well as the Fischer molar ratio were decreased in the acute phase of dengue. CONCLUSIONS: Healthy Guatemalans have different amino acid patterns than do Swedish subjects independent of socioeconomic status. The systemic viral disease dengue is associated with changes in the plasma free amino acid pattern, reflecting infection-related alterations in amino acid metabolism.

Adult↗
PubMed2001

Can the degree of concordance with recommendations for a cancer prevention diet and lifestyle be assessed from existing survey information data?

BACKGROUND: The World Cancer Research Fund convened an expert committee who analyzed the literature related to the causation of human cancers. Recommendations for preventing cancer through behavioral practices were formatted into a 14-point guideline. OBJECTIVE: We parsed the cancer prevention guidelines to determine to what extent relevant information on individual behavior could be assessed from conventional food-frequency questionnaires, which are being used in surveys conducted in developing countries. DESIGN: We examined a convenience sample of archival forms completed during 2 independent studies (a case-control and a field study) that used an adapted Willett food-frequency questionnaire that was translated into Spanish for use in Guatemala. RESULTS: All dietary related guidelines, except for salt, were evaluated by both questionnaires. Physical activity, food handling, and food preparation were not addressed by either of the questionnaires, although body mass index and dietary supplements were addressed in the case-control study and field-study questionnaires, respectively. CONCLUSIONS: Although concordance with some of the cancer prevention goals and guidelines can be evaluated from the existing questionnaires, adjustments and additions must be made with respect to salt and supplement use, physical activity, and food handling. Actual weight and height measurements are also needed, particularly in low-income populations.

Adult↗
PubMed2000

Demographic and nutritional trends among the elderly in developed and developing regions.

Aging for an individual and aging for a population are related but not the same. For an individual, aging first involves survival to more advanced years, which will inevitably be accompanied by progressive changes in the structure and function of somatic tissues due to a programmed failure of the organism maximally to invest in their maintenance. For a population, aging means an increase in the median age, a dual function of longer survival of individuals and a decrease in fertility. In the wilds of nature, and for all but the recent decades for the human species, survival beyond the peak reproductive years is rare. The hostility of natural selection has its greatest impact on the young and the old. Only captive fowl and beasts, domesticated animal species and Homo sapiens achieve long survival. For humans, life expectancy from birth and from any age thereafter is increasing; median ages of populations and the percentage of persons over 60 y are rising. The affluent developed countries led the way, but developing countries are closing the gap. As of about 1966, a majority of the world's elderly live in developing societies. The rarity of growing old left a dearth of knowledge in the domain of gerontological nutrition, both for lack of motivation to learn and lack of individuals and populations to study. The convening of this workshop signifies that the polarity of interest has shifted 180 degrees. Social, economic, physiological and psychological changes with aging and growing older can both be influenced by diet and influence eating patterns and nutritional status. Many assumptions have been made about these changes, but only recently, with concerted metabolic studies of nutrient requirements in healthy elderly and carefully designed multi-center surveys of the health and nutrition of older segments of populations can a true portrait of the issues be delineated.

Aged↗
PubMed2000

Retinol concentrations in capillary dried blood spots from healthy volunteers: method validation.

BACKGROUND: Vitamin A deficiency (VAD) is a major public health problem in the developing world, leading to >3 million eye-related problems in preschool children. Nearly 250 million children have subclinical VAD, resulting in a 23% increase in childhood mortality. Difficulties in obtaining samples to assess VAD have hampered the detection, intervention, and surveillance of VAD. The use of dried blood spots (DBS) could ameliorate many problems of vitamin A assessment. OBJECTIVE: The objective of this study was to validate the use of retinol in DBS for vitamin A assessment by comparing it with venous and capillary serum retinol. DESIGN: Venous and capillary blood specimens were obtained simultaneously from 20 healthy adult volunteers. From each blood specimen, both DBS and liquid serum were prepared (a total of 80 samples). All specimens were maintained at -70 degrees C until HPLC analysis. RESULTS: The mean retinol concentrations in the 4 sample types were as follows: venous serum (2.02 +/- 0.42 micromol/L, or 58 +/- 12 microg/dL), capillary serum (2.06 +/- 0.42 micromol/L, or 59 +/- 12 microg/dL), venous DBS (2.06 +/- 0.49 micromol/L, or 59 +/- 14 microg/dL), and capillary DBS (2.09 +/- 0.45 micromol/L, or 60 +/- 13 microg/dL). Of the 6 possible 2-way combinations, the R(2) values ranged from 0.77 for capillary DBS versus venous DBS to 0.95 for venous serum versus capillary serum. CONCLUSIONS: DBS retinol measured by HPLC is comparable with serum retinol. Thus, it is possible to compare and combine blood retinol concentration data obtained from DBS with current and historic measurements in serum.

Adolescent↗
PubMed2000

The pharmacokinetic responses of humans to 20 g of alanyl-glutamine dipeptide differ with the dosing protocol but not with gastric acidity or in patients with acute Dengue fever.

Pharmacokinetic responses to oral doses of the dipeptide, L-alanyl-glutamine (Ala-Gln), were evaluated after a single, bolus load or an intermittent dosing in normal healthy subjects (n = 8) to find the optimal mode of oral administration. In a subgroup (n = 4) of the healthy subjects, the influence of a gastric acid suppressor (Omeprazole) was investigated. The influence of an acute episode of classic Dengue fever was examined in eight patients. All modes of administration to healthy subjects significantly increased free plasma Gln and alanine concentrations. Peak increments of plasma Gln concentration were 794+/-107 micromol/L (mean +/- SEM) after bolus intake of 20 g of Ala-Gln and 398+/-61 micromol/L after intermittent intake of the same cumulative dosage of the dipeptide (P<0.01). After intermittent dosing, the maximum peak increase appeared significantly later (P<0.01). Areas under the curve (AUC), expressing the integrated responses over time of plasma free Gln and alanine concentrations, did not differ after bolus and intermittent loads of Ala-Gln. Pretreatment with the acid suppressor, Omeprazole, did not influence Gln (P = 0.79) or alanine (P = 0.90) plasma increment. Dengue patients manifested the same pharmacokinetic responses to a 20 g Ala-Gln bolus as healthy controls. In general, on a micromolar concentration basis, Gln and alanine followed parallel tracks in terms of plasma appearance, clearance and elimination after the oral administration of 20 g of the Ala-Gln dipeptide through the range of conditions and dosing protocols explored here.

Administration, Oral↗
PubMed2000

Hydrational status assessed by bioelectrical impedance spectroscopy and dilution methods in patients with classical dengue fever.

The effects of an episode of acute classical dengue fever on extracellular water (ECW), intracellular water (ICW), and total body water (TBW) were measured in nine patients using conventional dilution techniques; and the findings were compared with the outcome variables from whole body impedance spectroscopy (BIS), extracellular fluid resistance (Recf), and intracellular fluid resistance (Ricf). The patients were assessed on admission with febrile presentation (DI), at discharge after the defervescence of the fever cycle at about five days postadmission (DII), and seven days thereafter (DIII). As a reference group, 15 persons without acute or chronic illness were enrolled. Total body water was unaltered during the course of disease and was not different from that in normal healthy subjects. However, body water shifted from the intracellular to the extracellular compartment in patients from the acute phase to convalescence, as reflected in the ratios of ECW/TBW and ECW/ICW. These ratios were significantly higher in convalescent dengue patients (DIII) than in the reference group (p < 0.05). Increasing ECW, from the acute phase of the disease to convalescence, was associated with a significant decrease in Recf (719 +/- 95, 693 +/- 89, 643 +/- 81 omega; p < 0.0001) and in Recf/Ricf (p < 0.01). Recf and Recf/Ricf were higher in the acute phase (DI) of dengue fever compared to controls (p < 0.05). We conclude that dengue fever is characterized by a relative expansion of ECW during the course of disease and convalescence. BIS was sensitive in determining the hydrational profile in dengue fever patients.

Acute Disease↗
PubMed2000

Bioelectrical impedance spectroscopy in health and disease. Correspondence between whole body and segmental bioelectrical impedance spectroscopy indices in patients with classical dengue fever.

Bioelectrical impedance spectroscopy (BIS) can provide estimates of body composition for both whole body (WB) and body segments (BS). In normal, healthy subjects, BS measurements may be expected to serve as surrogates for WB indices; however, very little is known about this correspondence in people suffering from acute illnesses. The aim of this study was to evaluate the degree of this correspondence in patients with an acute, systemic illness, such as classical dengue fever. Ten adult patients were examined upon admission to the community hospital on the Pacific Coast of Guatemala and after clinical recovery about two weeks later, and compared with a group of healthy subjects living in the same region. BIS was measured with a Xitron 4000B analyzer (Xitron Technologies Inc., San Diego, CA, USA). BS measurements were carried out using Organ et al.'s approach. The BIS data were modeled with the manufacturer's software: extra- (Recf) and intracellular- (Ricf) resistances, and the Recf/Ricf ratio. BIS BS measurements correlate closely with WB in both the acute and the recovery stages of dengue fever, with the leg showing the highest degree of correspondence and the trunk the lowest. Recf indices, per se, generally showed higher correspondence than Ricf or the Recf/Ricf ratio.

Adult↗