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Biomedical subjects

B Caballero

Publications and source records attributed to B Caballero.

At least 37 records · Page 2Linked to original sources
PubMed1997

Serum and plasma markers of nutritional status in children infected with the human immunodeficiency virus.

OBJECTIVE: To determine whether reduced serum or plasma protein and micronutrient levels are common in children infected with the human immunodeficiency virus (HIV) and whether these levels are different in children with growth retardation compared to those with normal growth. SUBJECTS: Children were separated into three groups: (a) HIV-infected with growth retardation (HIV + Gr); (b) HIV-infected with normal growth (HIV+); (c) HIV-uninfected with normal growth (HIV-). All children were afebrile and free of acute infection at the time of study. During a 24-hour stay in the Pediatric Clinical Research Unit, blood was drawn for analysis of total protein, albumin, zinc, selenium, and vitamin A levels; growth measurements were obtained; and dietary intake was assessed by 24-hour weighed food intake and 24-hour dietary recall. STATISTICAL ANALYSIS: Mean differences between groups were assessed by analysis of variance, and differences in the frequency of nutrient deficiency were determined by chi 2 analysis. RESULTS: Thirty-eight children between 2 and 11 years of age were studied: 10 HIV + Gr, 18 HIV+, and 10 HIV-. No statistically significantly differences were noted in mean levels of albumin, prealbumin, zinc, and selenium. Mean serum level of vitamin A was significantly higher in the HIV + Gr group than in the other two groups. There were no significant differences between groups in the frequency of deficiency for any nutrient studied. Mean energy and nutrient intake was similar among groups. APPLICATIONS/CONCLUSIONS: Abnormal serum or plasma protein or micronutrient levels were uncommon in this cohort of HIV-infected children, even in children with growth retardation. Routine monitoring of the level of proteins and micronutrients studied is unnecessary in the absence of specific clinical indicators of deficiency.

Biomarkers↗
PubMed1997

High bone mass as a marker for breast cancer risk.

Postmenopausal women in the highest quartile for metacarpal bone mass were found to have an increased risk of developing breast cancer, after adjusting for age and other variables known to influence breast cancer risk. Although the mechanisms responsible for this relationship have not been identified, postmenopausal bone mass may serve as an indicator of cumulative estrogen exposure.

Bone Density↗
PubMed1997

Environmental factors affecting nutritional status in urban areas of developing countries.

The demographic and economic transition that many developing countries are undergoing is producing important changes in diet and lifestyle that greatly impact on disease risks. Among the risk behaviors associated with socioeconomic transition and urbanization are excessive dietary fat intake, sedentary lifestyle, smoking, and environmental contamination. Combined with a reduced infant mortality and increased life expectancy, those risk factors lead to an increasing prevalence of chronic disease like non-insulin dependent diabetes and coronary heart disease. This disease. This disease profile is a relatively new phenomenon in developing countries, where health programs have traditionally focused on "acute" interventions such as immunization or oral rehydration. A new approach will be needed to address chronic diseases, which frequently demand a life-long and technically complex medical management, and may have significant impact on the quality of life and productivity of the population. Efforts to address this situation should focus on a) expanding the information base on diet, nutritional status and lifestyle changes in populations migrating to urban areas; b) developing and evaluating approaches for improving diet quality in urban populations, including fortification and community-based supplementation programs; c) understanding better the social and behavioral determinants of nutritional status in the urban poor; and d) defining the role of the food industry and of agricultural production for improving the quality of the food supply in urban areas.

Asia↗
PubMed1996

Cuban epidemic neuropathy, 1991 to 1994: history repeats itself a century after the "amblyopia of the blockade".

The 1991 to 1994 epidemic of neuropathy in Cuba has been one of the more devastating in recent history, affecting more than 50,000 people throughout the entire country with clinical manifestations of optic and peripheral neuropathy. Although the causes are not entirely clear, it seems that a combination of acute nutritional deficiency and the toxic effects of tobacco and possibly other unidentified toxic substances is involved. The epidemic coincided with the acute worsening of the economic situation on the island following political changes in Eastern European countries and a tightening of the US economic embargo. This paper reviews reports of a strikingly similar epidemic known as the "Amblyopia of the Blockade," which occurred in Cuba almost a century ago when the island was undergoing a US naval blockade during the Cuban-Spanish-American war. It discusses the parallelism with the recent epidemic as well as the implications of this historical evidence to clarify further the ultimate causes of these epidemics.

Amblyopia↗
PubMed1995

Accurate energy compensation for intragastric and oral nutrients in lean males.

Lean healthy males received either parenteral or enteral infusions of pure fat or carbohydrate (2092 kJ), or isotonic saline, to determine their influences on food intake and energy regulation in self-selected lunch and dinner meals. In the first study, six males received intravenous infusions for 3.5 h in the morning, followed by lunch 30 min after the infusion ended and dinner 6 h later. No compensation was seen for energy differences in intravenous infusions. In the second study, six males received intragastric infusions for 15 min or 3.5 h. Rapid intragastric infusions of fat or carbohydrate and slow infusions of fat significantly reduced intake at lunch, whereas slow carbohydrate infusions did not. In both studies, subjects reduced intake at lunch 30 min after 2092-kJ yogurt preloads varying in fat and carbohydrate, demonstrating their ability to respond to orally derived energy. These results support the existence of mechanisms in the gastrointestinal tract for the rapid detection of the energy content of ingested nutrients or foods in lean males.

Adult↗
PubMed1994

Epidemic optic neuropathy in Cuba. Eye findings.

OBJECTIVE: To characterize and establish a clinical definition of the optic neuropathy that appeared in epidemic form in Cuba in 1992 and 1993. METHODS: At the invitation of the Cuban Ministry of Health, Havana, members of ORBIS International and the Pan American Health Organization, assembled teams that traveled to Cuba in May 1993. We were initially briefed by Cuban national experts in the areas of virology, nutrition, toxicology, ophthalmology, neurology, and public health. We then examined 20 patients on our own. Thirteen of these patients underwent a comprehensive neuro-ophthalmologic examination, including neurologic examination, ophthalmologic examination, visual fields, optic nerve function studies, contrast sensitivity studies, and funduscopy. We returned 4 months later to perform an additional 12 comprehensive neuro-ophthalmologic and follow-up examinations. RESULTS: Only seven of the 13 patients who were alleged to have the optic form of the epidemic and who were rigorously and systematically examined on the first visit demonstrated a bilateral optic neuropathy. These seven patients had several features that included decreased visual acuity, poor color vision, central scotomas, decreased contrast sensitivity, saccadic eye movements, and most prominent and distinctive of all, nerve fiber layer wedge defects of the papillomacular bundle. Our clinical definition was then implemented by the Cuban ophthalmologists and epidemiologists. On returning 4 months later, we found that all newly presented patients were correctly diagnosed to have the epidemic disease. With the new case definition and the application of a few simple psychophysical tests, the false-positive rate of diagnosis became much lower. After vitamin therapy, we reexamined the patients seen on our initial visit, and all showed marked improvement. CONCLUSIONS: The Cuban epidemic was characterized by an optic neuropathy with features that were similar to those of tobacco/alcohol amblyopia and Leber's optic atrophy. Recent political, economic, and social changes in Cuba may have contributed to the nutritional and/or toxic compromise of mitochondrial function of an acquired nature, which led to selective retinal ganglion cell damage. We have termed this condition Cuban epidemic optic neuropathy.

Adult↗
PubMed1994

Use of cyclic parenteral nutrition in infants less than 6 months of age.

Cyclic parenteral nutrition is the technique of infusing the intravenous solution in less than 24 hours, during a portion of the day or night, allowing the patient freedom from the intravenous tubing and pump apparatus. In addition, adverse effects of long-term parenteral therapy, such as liver complications, were reported to be decreased with the use of cyclic parenteral nutrition in adult patients. Literature on the method and effects of cycling in young infants is minimal. This report describes cyclic parenteral nutrition use with guidelines for cycling and the potential beneficial metabolic effects in 10 infants less than 6 months of age who required long-term parenteral nutrition support. Diagnosis, gestational age, length of time on parenteral nutrition, macronutrient intake, growth, and biochemical parameters for the patients are presented. Overall, cyclic parenteral nutrition was well tolerated without clinical symptoms of hypoglycemia, elevated capillary blood glucose concentrations, or abnormal urine glucose levels. The direct bilirubin concentrations showed a decrease or stabilization after cycling was initiated in eight of 10 patients.

Age Factors↗
PubMed1993

Vitamin E improves the action of insulin.

Vitamin E supplementation for four months produced a significant improvement in glucose utilization and hepatic response to insulin in normal and diabetic subjects.

Diabetes Mellitus, Type 2↗
PubMed1991

Mineral homeostasis in obesity: effects of euglycemic hyperinsulinemia.

We explored the effects of insulin on mineral homeostasis in five lean and six moderately obese nondiabetic premenopausal women. Serum and urine minerals were measured before and during the steady-state phase of a euglycemic insulin clamp. Each subject participated in two insulin clamp studies on separate days at insulin infusion rates of 10 and 40 mU/m2/min. Euglycemic hyperinsulinemia was associated with (1) a significant increase in urinary calcium excretion when expressed per minute with no change in total serum calcium; (2) a decrease in urine and serum phosphate; (3) a decrease in serum potassium with no change in urine potassium; and (4) no measurable effects on urine or serum sodium. At any given insulin level, the obese individuals excreted significantly more calcium, phosphate, and potassium per minute than lean controls. While insulin administration had no effect on serum parathyroid hormone (PTH) or vitamin D levels, baseline serum 1,25(OH)2D concentration was significantly higher and serum ultrafilterable calcium was significantly lower in obese subjects than in lean controls.

Adult↗
PubMed1991

Differential effects of insulin resistance on leucine and glucose kinetics in obesity.

The effects of insulin resistance on glucose and amino acid metabolism were studied in obese nondiabetic women (body mass index [BMI], (32.8 +/- 2) and in lean controls. Glucose disposal rate, hepatic glucose production, and leucine carbon flux and oxidation were simultaneously measured during the postabsorptive state and during euglycemic hyperinsulinemia, by means of primed, constant infusions of D-[6,6-2H2]glucose and L-[1-13C]leucine. Each subject participated in two insulin clamp studies on separate days, at infusion rates of 10 and 40 mU (m2.min)-1, producing plasma insulin levels of 20 to 25 and 70 to 80 microU/mL, respectively. Fat-free mass (FFM) was calculated from underwater weighing measurements. Insulin-mediated glucose disposal rate was significantly slower in the obese group: 2.05 +/- 0.05 versus 3.84 +/- 0.18 mg (kg.min)-1 in controls during the 10-mU insulin clamp, and 3.80 +/- 0.23 versus 9.16 +/- 0.47 mg (kg.min)-1 during the 40-mU clamp. The insulin-induced decrease in plasma levels of branched chain amino acids was also significantly blunted in the obese group. Baseline leucine flux was similar in lean and obese subjects (78 +/- 3 and 71 +/- 2 mumol (kg.h)-1, respectively), and its decline in response to insulin infusion was also comparable (8% and 10% during the 10-mU/m2 clamp, and of 17% and 18% during the 40-mU/m2 clamp in lean and obese, respectively). Basal leucine carbon oxidation (from [13C]leucine and [13C]alpha ketoisocaproate [alpha-KIC] plasma enrichments) was also similar in lean and obese, and did not change significantly with insulin infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Plasma amino acid concentrations in healthy elderly men and women.

Postabsorptive plasma concentrations of the large neutral amino acids (LNAAs) were measured in 74 elderly (age 71 +/- 8 y) and 138 young (age 26 +/- 5 y) healthy subjects. Plasma concentrations of valine, leucine, and isoleucine were significantly lower in young females than in young males. This gender-related difference was not observed among elderly subjects because aging was associated with a significant rise in plasma LNAAs in females but not in males. Multiple-regression analysis of plasma amino acid concentrations from female subjects revealed a significant and positive effect of age on plasma valine, leucine, isoleucine, phenylalanine, and tyrosine but not on plasma tryptophan or methionine. Tryptophan was the only amino acid to exhibit a significant response to age in males, consisting of a 14% decline in the elderly subjects. Percentile ranges are presented for young and elderly females and males for each of the amino acids.

Adult↗
PubMed1991

A balanced carbohydrate: protein diet in the management of Parkinson's disease.

Although restricting dietary protein is a proposed adjunct to treating Parkinson's disease (PD), the effect of carbohydrate consumption is unknown. We measured plasma levodopa and large neutral amino acid (LNAA) levels in nine PD patients treated with carbidopa/levodopa and different isocaloric meals containing high protein-low carbohydrate, low protein-high carbohydrate, and balanced 5:1 carbohydrate:protein mixtures. We found that levodopa levels increased significantly regardless of the type of diet, but that plasma LNAA levels varied less and motor performance was superior after the balanced diet than after the other two meals. We conclude that PD patients can consume nutritionally adequate meals and still maintain a stable plasma levodopa:LNAA ratio.

Amino Acids↗