Stability and effect of ingestion on the levels of folate in plasma

The physiological demand of folates increases during adolescence, pregnancy and lactation due to the rapid growth and anabolic activity during these stages of life. The periconceptional deficiency of folates is a risk for the presence of neural tube defects. We studied the stability of folates concentration in plasma and the effect of ingestion of a breakfast rich in folates on the postprandial levels of this micronutrient, up to two hours after food intake. For the stability assay the samples were stored protected from light at -70 degrees C and analysed at time intervals of 1, 8, 30, 90 and 120 days. The mean folates concentration in plasma was higher in postprandial stage (8.9 ng/dl) that in fasting (7.9 ng/dl), which represents a statistically significant (p < 0.01) increase of 11%. This study confirms that fasting is important in folates determination for diagnosis and research purposes to establish deficiency prevalence of this micronutrient in a population. Concerning the stability of folates concentration, we did not find a significant difference between the several time analysis (p > 0.1); this suggests that folates concentrations in plasma remain stable under the experimental conditions described.     

Concentraciones deficientes de vitamina D en pacientes con obesidad mórbida. Estudio de caso-control

ObjectivesRecent studies show a high prevalence of vitamin D deficiency in the general population, especially in the elderly. There are also studies reporting the same observations in the morbidly obese, although few of these studies have compared morbidly obese individuals with non-obese persons. The objectives of this study were to estimate the prevalence of vitamin D deficiency and secondary hyperparathyroidism in both groups and to assess whether there is a relationship between obesity and vitamin D deficiency.MethodsThis study was carried out in 138 patients in the Guadalajara University Hospital (Spain) between December 2008 and December 2009. Of these, 50.7% were morbidly obese and 49.3% were not obese. Fasting blood samples were taken from both groups for determination of 25-hydroxyvitamin D, intact parathyroid hormone, calcium, albumin and phosphorus, among other biochemical parameters.ResultsThe mean concentration of 25-hydroxyvitamin D was 16.6±8.12 ng/ml in the morbidly obese group and 21.9±7.34 ng/ml in the non-obese group (p<0.0001). The prevalence of vitamin D deficiency was 80% in morbidly obese patients and 41% in non-obese patients (p<0.0001). There were no statistically significant differences in concentrations of parathyroid hormone, calcium or phosphorus between the two groups.ConclusionsA high prevalence of vitamin D deficiency was found in both groups studied, although the concentration of 25-hydroxyvitamin D was significantly lower in the morbidly obese. Morbid obesity is closely linked to vitamin D deficiency. To prevent this deficiency, determination of 25-hydroxyvitamin D should be included in clinical practice guidelines for the treatment of obesity.     

Decalcification by ascorbic acid for immuno- and affinohistochemical techniques on the inner ear

An ascorbic acid decalcifying solution was applied to immuno- and affinohistochemical studies on the inner ear. Rat inner ears fixed in 4% paraformaldehyde in PBS or in 2% acetic acid in ethanol solutions were adequately decalcified in an ascorbic acid solution, at a temperature of 4°C. The decalcifying solution was prepared with 1% ascorbic acid and 0.84% sodium chloride in distilled water (pH 2.5–2.6). The decalcification time was in a direct relationship to the specimen calcification. In this study, two neuroactive substances (γ-aminobutyric acid and calcitonin gene-related peptide), neurofilaments, and the galectine endogenous lectin were successfully detected immunohistochemically. Accepted: 20 May 1999