Determining the presence of chemicals with suspected endocrine activity in drinking water from the Madrid region (Spain) and assessment of their estrogenic, androgenic and thyroidal activities.

Endocrine disruptors (EDs) are natural or man-made chemicals that can affect the health of organisms by interfering with their normal hormonal functions. Many of these substances can cause their effects at very low doses and, considering the key role played by the endocrine system on development, organisms in early phases of growth (foetal, childhood, puberty) are especially sensitive to the action of EDs. In addition, when combined, they can show additive, antagonistic and synergistic activities. Taking all this into account it is essential to determine the presence of this kind of compounds in drinking water. Thus the main aim of the present study was to monitor the presence of substances with suspected or known endocrine activity in drinking water of the Madrid Region (MR) (Central Spain) and determine possible estrogenic, androgenic, or thyroidal activities. Water samples were collected at different times from a number of supply points that received water from reservoirs or rivers. The sampling point with the highest concentration of the analysed substances (up to 30 compounds) was DW1 (1203 ng L-1). This sampling point receives water from a drinking water treatment plant (DWTP) that serves the population from the south of the MR with treated water from the Tajuña River. DW2 was the second point with the highest concentration of the analysed substances (1021 ng L-1). DW2 receives water from one of the reservoirs in the north of the MR. The highest daily concentrations detected corresponded to the flame retardant Tris (2-chloroethyl)phosphate (TCEP) (266.55 ng L-1) and to the nonylphenol diethoxylate (188.57 ng L-1) at points DW1 and DW4, respectively, both of which are supplied with treated river water. None of the water samples exhibited androgenic, oestrogenic, or thyroidal activities in in vitro assays based on cells stably transfected with the receptors of interest and luciferase as reporter gene. These results demonstrate that water quality in the MR is high and does not present a health risk for the population, although the concentrations of some substances justify the need for local authorities to continually monitor the presence of these contaminants in order to implement any corrective measures if necessary.

Nutritional assessment of patients with secondary hyperparathyroidism / Avaliação nutricional de pacientes com hiperparatireoidismo secundário / Evaluación nutricional de pacientes con hiperparatiroidismo secundario

Secondary hyperparathyroidism (SHPT) is a common complication in patients undergoing hemodialysis. Nutritional counseling is an integral part of treatment, with potential positive impact on retention of calcium and phosphorus. The aim of this study was to monitor the nutritional status during a year of nutritional intervention. Forty-one hemodialysis patients, in the Outpatient Renal Osteodystrophy, Hospital das Clinicas in São Paulo, with a mean age of 43.4 (15.7) years were evaluated. During the evaluation period, some patients underwent parathyroidectomy (PTX) and surgical or chemical analysis was based on three groups according to treatment: diet group (n = 21), PTX chemical group (n = 9) and PTX surgical group (n = 11). Could be evaluated intakes of energy, protein, calcium and phosphorus in the nutrition survey in three days. Weight, height, BMI and% body fat were measured, and biochemical markers of bone metabolism. Dietary measures, and anthropometric and biochemical changes were implemented in early clinical intervention and after one year. There were no significant changes in intakes of energy, protein and calcium during the study, even after nutritional counseling. The dietary phosphorus remained within the recommendations. There were no changes in anthropometric parameters. There was a significant decrease in total serum calcium, ionized calcium, phosphorus, CaxP product and iPTH levels in patients undergoing surgical PTX. Although this practice has shown significant improvement in biochemical parameters of SHPT, dietary control can be effective for non-aggravation of the nutritional status of the parameters of SHPT with low cost.

O hiperparatiroidismo secundário (HPTS) é uma complicação comum em pacientes que realizam hemodiálise. A orientação nutricional é parte integrante do tratamento, com potencial impacto favorável na retenção de cálcio e fósforo. O objetivo deste estudo foi monitorar o estado nutricional durante um ano de intervenção nutricional. Quarenta e um pacientes hemodializados, atendidos no Ambulatório de Osteodistrofia Renal do Hospital das Clínicas, em São Paulo, com média de idade de 43,4 (15,7) anos foram avaliados. Durante o período de avaliação, alguns pacientes foram submetidos à paratiroidectomia (PTX) química ou cirúrgica e a análise foi feita baseada em três grupos, de acordo com o tratamento: grupo dieta (n=21), grupo PTX química (n=9) e grupo PTX cirúrgica (n=11). Puderam ser avaliadas as ingestões de energia, proteína, cálcio e fósforo por inquérito alimentar de três dias. Peso, altura, IMC e % gordura corporal foram mensurados, bem como marcadores bioquímicos do metabolismo ósseo. As medidas dietéticas, antropométricas e bioquímicas foram executadas no início da intervenção clínica e após um ano. Não houve alterações significativas nas ingestões de energia, proteína e cálcio durante o estudo, mesmo após a orientação nutricional. O fósforo dietético permaneceu dentro das recomendações. Não foram observadas alterações nos parâmetros antropométricos. Houve diminuição significativa no cálcio sérico total, cálcio iônico, fósforo, produto CaxP e níveis de PTHi nos pacientes submetidos à PTX cirúrgica. Embora esta prática tenha apresentado significante melhora nos parâmetros bioquímicos do HPTS, o controle dietético pode ser efetivo para o não-agravo do estado nutricional dos parâmetros do HPTS com baixo custo.

El hiperparatiroidismo secundario (HPTS) es una complicación frecuente en pacientes sometidos a hemodiálisis. consejería nutricional es una parte integral del tratamiento, con un impacto potencial positivo en la retención de calcio y fósforo. El objetivo de este estudio fue monitorear el estado nutricional durante un año de la intervención nutricional. Cuarenta y un pacientes en hemodiálisis, en la osteodistrofia renal para pacientes ambulatorios del Hospital das Clínicas de São Paulo, con una edad media de 43,4 (15,7) años fueron evaluados. Durante el período de evaluación, algunos pacientes fueron sometidos a paratiroidectomía (PTX) y el análisis quirúrgica o química se basa en tres grupos según el tratamiento: grupo de la dieta (n = 21), grupo PTX químicos (n = 9) y PTX quirúrgica grupo (n = 11). ¿Podría ser evaluado la ingesta de energía, proteínas, calcio y fósforo en la encuesta de nutrición en tres días. Peso, talla, índice de masa corporal y el% de grasa corporal fueron medidos, y los marcadores bioquímicos del metabolismo óseo. Medidas dietéticas y cambios antropométricos y bioquímicos se llevaron a cabo en la intervención clínica temprana y después de un año. No hubo cambios significativos en la ingesta de energía, proteínas y calcio durante el estudio, incluso después del asesoramiento nutricional. El fósforo en la dieta se mantuvo dentro de las recomendaciones. No hubo cambios en los parámetros antropométricos. Hubo una disminución significativa en el calcio sérico total, calcio iónico, fósforo, producto CaxP y los niveles de PTH en pacientes sometidos a cirugía PTX. Aunque esta práctica ha demostrado una mejora significativa en los parámetros bioquímicos de SHPT, control de la dieta puede ser eficaz para que no se agrave la situación nutricional de los parámetros de SHPT con bajo costo.

Comparability of method results and performance in a national external quality assessment scheme between 1993 and 2003 using thyroid associated analytes as examples.

Six thyroid analytes (free and total triiodothyronine and thyroxine, thyrotropin and thyroglobulin) have been followed up over a 10 year period in a national external quality assessment scheme (EQAS) organised by the Institute for Standardisation and Documentation in the Medical Laboratory (INSTAND). I. The following points were observed: II. The introduction of samples with properties similar to patient serum (filtered, recalcified defibrinated plasma without stripping) improved performance and inter-method comparability for the free thyroid hormones. III. In general, the performance in EQAS has improved over the past decade, an exception being thyroglobulin, where precision has improved at the expense of inter-method comparability. IV. Regular statistical analysis of EQAS data allows adjustment of target ranges to be made when necessary. V. Analytes which are not dependent on binding proteins--thyrotropin and the total thyroid hormones--give rise to similar performance when stripped and spiked plasma or recalcified non-stripped and spiked plasma is used as sample. VI. Whereas certain analytes have had a relatively constant number of participants over the past decade (total thyroid hormones), others have shown a drastic increase (free thyroxine from 67 to 620; thyrotropin from 295 to 724) reflecting the medical demand for the analytes.

Thyrotoxicosis: clinical and laboratory assessment.

Thyroid hormones are triiodothyronine (T3) and thyroxine (T4). The hypophysial thyrotropic hormone, thyroid stimulating hormone (TSH) is their physiologic regulator. Thyrotoxicosis is characterized by clinical symptoms caused by high thyroid hormone concentrations. The commonest forms are: 1) toxic diffuse goiter (Basedow-Flajani-Graves disease), 2) toxic multinodular goiter, 3) toxic adenoma. Other less frequent forms are the iodide-induced, that during Hashimoto thyroiditis, that from inappropriate TSH secretion. The diagnosis is predominantly clinical and confirmed by hormone level determination associated in some cases to functional and morphofunctional tests (TRH test, scintigraphy, thyroid I uptake) and antithyroid antibody assay.

Clinical and laboratory assessment of subclinical thyroid disease.

The availability of highly sensitive in vitro tests for the determination of the free fractions of thyroid hormones (FT3 and FT4) and TSH have allowed the identification of latent thyroid disorders (subclinical hyper- and hypothyroidism) where the clinical signs are minor or absent. The TSH determination is the most sensitive in vitro test to define the thyroid function. FT3 is the most suitable for the correct diagnosis of subclinical hyperthyroidism, while FT4 is diagnostic for subclinical hypothyroidism. In patients with acute or chronic non thyroid disease or in case of assumption of drugs which interfere with in vitro diagnostic tests, the interpretation may be difficult.

Superiority of the use of a pre-incubated complex of primary and second antibody in the radioimmunoassay of thyroid hormones.

We report on the superiority of a radioimmunoassay (RIA) system wherein the second antibody (Ab2) is incorporated as a pre-incubated complex with the primary antibody (Ab1) for the assay of haptens like triiodothyronine (T3) and thyroxine (T4). Separation of the antibody bound and free antigen (Ag) was accomplished by 8% polyethylene glycol (PEG) (final concentration) following a single incubation of less than 1 h. The other advantages of this system are a 15-fold reduction in the quantity of Ab2 (without any need for increasing the concentration of PEG) and the consequent savings in cost.

UK external quality assessment scheme for immunoassays in endocrinology.

UK EQAS provide the UK with a comprehensive system for EQA in endocrinology, as well as in other aspects of clinical chemistry and laboratory medicine. UK EQAS in endocrinology are scientifically designed to yield an objective assessment of participants' performance and stimulate improvements in between-laboratory agreement. The design uses appropriate specimens, based on liquid human serum and prepared with minimal processing and additives in the organising centres to enable detailed study of recovery and other important factors. Target values are validated by reproducibility on repeated distribution and by recovery and parallelism studies. Reports are presented informatively, and emphasise the cumulative scoring system (bias and variance) for performance assessment. Computerised data processing and data presentation form an integral part of these schemes, and a common core computing system is in use throughout these UK EQAS. Participants receive advice and assistance in the interpretation of performance data and, when appropriate, in the resolution of problems.