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Biomedical subjects

R Yepez

Publications and source records attributed to R Yepez.

9 recordsLinked to original sources
PubMed1990

A quantitative approach to measuring the social effects of epilepsy.

This paper describes the construction of a postal questionnaire which has been used to investigate the social affects of epilepsy on a wide range of patients. The social profile was designed following extensive patient interviews at the National Hospital for Nervous Diseases and the Chalfont Centre for Epilepsy. The initial research revealed 21 areas of concern for the individual with epilepsy, which are described. Reliability was assessed on a test/retest procedure. Validity was tested via a criterion-related study based on the behaviour of the subject. Following reliability and validity studies 14 areas were eventually selected for the final questionnaire. Instruments have been adapted for both children and adults.

Attitude to Health↗
PubMed1987

Evaluation of iron-deficiency anemia by an iron supplementation trial in children living at a 2,800-m altitude.

Hemoglobin, hematocrit, serum iron and total iron-binding capacity were measured in 38 apparently healthy children living in Quito (2:800 meters in altitude). One child was considered anemic according to the WHO reference adjusted to altitude (hemoglobin less than 12.3 g/dl) and 10 had transferrin saturation of less than 15%. Thirty children received orally 2 mg/kg per day of elemental iron for 3 mth. A significant increase in hemoglobin level, serum iron-concentration, and transferrin saturation, and a significant decrease in total iron-binding capacity were observed. Nine children increased their hemoglobin concentration by greater than 1 g/100 ml and could be considered as true anemics. At the end of the supplementation, only one child had a transferrin saturation coefficient of less than 15%. WHO references for hemoglobin adjusted to altitude seem to underestimate the prevalence of anemia for populations living at high altitudes.

Altitude↗
PubMed1987

Iron status in Ecuadorian pregnant women living at 2,800 m altitude: relationship with infant iron status.

An evaluation of iron status was performed in 84 pregnant women at delivery (and in cord blood from their newborn) and in a control group of 32 menstruating women living in Quito (2800 m altitude). Anemia as defined according to the WHO references adjusted to altitude was observed in 46% of pregnant women. Iron deficiency was defined as the combination of a low serum ferritin level (12 micrograms/l or less) and a low transferrin saturation percentage (less than 16%). A moderate elevation in the serum ferritin concentration (between 13 and 50 micrograms/l) associated with low transferrin saturation indicated iron deficiency in an inflammatory context. Iron deficiency was present in 46% of pregnant women. Anemia was associated with iron deficiency in 59% of cases. A correlation between maternal and cord blood hemoglobin was found and some iron parameters in cord blood were related to maternal iron status, and especially to maternal iron stores assessed by serum ferritin concentration.

Altitude↗
PubMed1979

Interrelation of the pituitary-thyroid system at birth in man.

Samples of cord blood derived from 105 normal babies after uncomplicated deliveries were assayed for thyroxine (T4), tri-iodothyronine (T3), reverse tri-iodothyronine (rT3), thyroxine-binding globulin (TBG) and thyrotrophin (TSH). The values for T3, rT3 and TSH were log-normally distributed (geometric means 0.62 nmol/l, 3.28 nmol/l and 10.9 mu./l respectively) and those for T4 and TBG were normally distributed (means 126 nmol/l and 13.7 mg/l), The data were systematically analysed and no evidence was obtained to suggest that the concentration of TSH, which varied widely, was regulated by any of the thyroid hormones alone or in combination. There was a direct relation between the concentrations of T4 and T3 in the cord blood at birth but not between either of these and rT3. There is thus no evidence of a functional interdependence of the hypothalamic-pituitary-thyroid system in man at birth.

Fetal Blood↗
PubMed1978

Reverse triiodothyronine, thyroid hormone, and thyrotrophin concentrations in placental cord blood.

Reverse triiodothyronine (rT3), triiodothyronine (T3), thyroxine (T4), thyroxine binding globulin (TBG), and thyrotrophin (TSH) were measured in sera from placental cord blood in an unselected series of 272 deliveries. In this series the concentrations of rT3 (mean 3.33 nmol/l, 95% confidence limits 1.6--7.0 nmol/l), were log normally distributed and did not overlap the adult normal range (0.11--0.44 nmol/l). There were no correlations between the cord blood concentrations of rT3, T3, T4, and TSH. The cord serum rT3 concentration was not influenced by maturity, birth-weight, or neonatal risk factors, whereas these factors did affect the concentrations of T3, T4, AND TBG. There is no arteriovenous rT3 concentration difference across the placenta, therefore the cord rT3 reflects the systemic rT3 concentration in the baby at birth. As rT3 in the neonate largely, if not entirely, derives from thyroxine from the fetal thyroid, measurement of the cord rT3 concentration may be a good immediate screening test for neonatal hypothyroidism.

Fetal Blood↗
PubMed1977

The abstract and the concrete, the disciplinary and the interdisciplinary approach in the teaching of physiological sciences.

It is the author's thesis that the knowledge imparted in universities is being increasingly fragmented into a multitude of disciplines, which results in graduates who are trained to perform very limited functions and hence are impeded from developing their full potential. He refers to the position of the physiological sciences in the medical school curriculum and emphasizes the importance of moving from the concrete to the abstract and then back to the concrete in the study of these sciences. He discusses the need to change the institutional structure of the university in order to move away from this "disciplinary" approach to the imparting of knowledge. He feels that a change of this kind should be based on analysis, from a historical and interdisciplinary standpoint, of the concrete problems that arise in every part of society.

Ecuador↗
PubMedDate not supplied

[High altitude anemia: validity of definition criteria].

The effect of iron and folate supplementation on the hemoglobin response and iron status was studied in male and female equatorian medical students: 66 in Quito (2,800 m altitude) and 40 in Guayaquil (sea level). At the end of the supplementation, there was a nearly complete disappearance of biochemical evidence of iron deficiency in the two groups of students. In Quito, 30% of the men and 26% of the women increased their hemoglobin concentration by more than 1 g/dl after one month of supplementation and could be considered as true anemics, compared to 31% of the men and 29% of the women in Guayaquil. This study shows that at sea level, cut-off points defined by WHO for hemoglobin, taking as reference the impact of a supplementation trial, have a specificity of 100% but poor sensitivity (58%). For people living at high altitudes, cut-off limits adjusted for altitude seem unsuitable: the specificity is 98% but the sensitivity is 0%. Studies taking into account all the factors impacting on the hemoglobin level could be useful for defining cut-off points for high-altitude anemia better than those currently recommended.

Adult↗