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Biomedical subjects

J Bulux

Publications and source records attributed to J Bulux.

23 records · Page 2Linked to original sources
PubMed1990

Test-retest reproducibility of the relative dose response for vitamin A status in Guatemalan adults: issues of diagnostic sensitivity.

The relative dose response (RDR) test has been used as a functional measure of whole-body stores of vitamin A in humans. We have examined the reproducibility of the RDR procedure in a population of Guatemalan adult subjects who would be expected to show a moderate prevalence of hypovitaminosis A. Fifty-one subjects were administered a standard RDR test, and the plasma samples were analyzed for retinol, tocopherol, retinol binding protein (RBP) and prealbumin (PAL). Thirty-four of the subjects underwent repeat RDR tests 7 d later. Plasma levels in fasted subjects were as follows: retinol, 1.35 +/- 0.30 mumol/L; RBP, 37.8 +/- 7.7 mg/L; PAL, 187.0 +/- 39.0 mg/L; and tocopherol, 16.6 +/- 6.2 mumol/L. RDRs ranged from -35.2% to +63.1%, with a mean of 2.6 +/- 10.4%. Overall, we observed poor within-subject reproducibility of the RDR procedure whether expressed numerically or by diagnostic classification. Moreover, in contrast to previous studies in children, we observed fewer positive RDR tests than would be expected for the population studied. Nevertheless, the mean RDR was inversely proportional to fasting retinol levels, thus confirming the validity of the biological basis of the RDR procedure in humans. Because of high intra-individual variability with this test, investigators should be cautious when using the RDR procedure in serial studies to monitor the efficacy of therapeutic interventions or subject compliance to dietary regimens.

Administration, Oral↗
PubMed1990

Weanling diarrhea: a case report.

This case report describes a 14-month-old Guatemalan boy suffering from diarrhea and malnutrition. He had been healthy and experienced normal growth until weaning, which began at six months of age. Introduction of semisolid foods at this time was accompanied by bouts of diarrhea and a reduced growth rate. After admission to hospital at 14 months of age, he was found to have protein-energy malnutrition of the edematous type (kwashiorkor) and to be infected with Giardia lamblia. Therapy with metronidazole and a high-protein diet resulted in satisfactory weight gain and cessation of the diarrhea.

Animals↗
PubMed1989

Conjunctival impression cytology: feasibility of a field trial to detect subclinical vitamin A deficiency.

Two hundred and thirty-six Guatemalan children aged 2-14 y were examined for subclinical vitamin A deficiency by use of conjunctival impression cytology (CIC). The feasibility of the technique and quality of a modified touch procedure were assessed. Neither lid speculum nor physical restraint in the form of a papoose board was used. The CIC technique was easily performed on children aged greater than 3 y but was more difficult among those less than or equal to 3 y. Laboratory processing of specimens is uncomplicated but interpretation may be problematic and requires clearly defined criteria of normal and abnormal cytology as well as careful standardization of readers.

Adolescent↗
PubMed1989

Conjunctival impression cytology (CIC) to detect subclinical vitamin A deficiency: comparison of CIC with biochemical assessments.

By use of sensitivity and specificity analysis, conjunctival impression cytology (CIC) was compared with fasting serum vitamin A levels and relative dose response (RDR) of Guatemalan children. One impression was taken from the temporal bulbar aspect of each eye, fasting serum vitamin A levels were then drawn, 480 RE of oil-based retinyl palmitate was given, and a 5-h postdosing vitamin A level was drawn (RDR procedure). For a 20% RDR cutoff, the sensitivity of CIC was 23% with a specificity of 80% and a positive predictive value of 9% (n = 213 children). Compared with fasting vitamin A levels alone (with 0.70 mumol/L as abnormal), the sensitivity of CIC was 26%, specificity was 81%, and positive predictive value was 22% (n = 221 children). There was no significant difference in the mean serum retinol level between those with abnormal and normal CIC. In this study population CIC does not identify the same group of children with marginal vitamin A as identified biochemically.

Adolescent↗