Concentración de fluoruro en agua subterránea y su relación con los niveles de calcio sérico en niños residentes en el distrito de Loreto, Concepción, Paraguay / Fluoride concentration in groundwater and its relationship with serum calcium levels in children living in Loreto, Concepción, Paraguay

Como parte del ciclo biogeoquímico, el fluoruro del suelo puede disolverse e ingresar al agua. La Organización Mundial de la Salud y la Norma Paraguaya NP 24 001 80 establecen una concentración máxima de 1,5 mg.L-1 de fluoruro en agua de consumo, pudiendo producir fluorosis cuando es elevada, tal como se encontró en niños residentes de Loreto. Estudios indican que la exposición al fluoruro concomitante al déficit de calcio puede agravar la pérdida de masa ósea, causando fragilidad y fluorosis esquelética. Además, se demostró mediante bioensayos en ratones que el exceso de fluoruro reduce la concentración de calcio sérico, por lo que el objetivo del estudio descriptivo con componente analítico fue elaborar un mapa de distribución espacial de fluoruro del agua subterránea de Loreto y relacionar con la calcemia en niños. Se determinó la concentración de fluoruro en muestras de veintitrés pozos de agua subterránea y el calcio sérico de dieciocho niños en edad escolar, ambos por método normalizado. Se identificaron dos pozos con concentraciones superiores al máximo permitido y en 61% de los niños el calcio sérico fue inferior al valor de referencia. Se encontró una correlación débil entre las variables (r = 0,212). El estudio proporciona información relevante sobre sitios con elevadas concentraciones de fluoruro lo que representa un riesgo para la salud pues aun con ingesta adecuada de calcio, los niños presentaron hipocalcemia. Sería importante incluir en estudios posteriores factores no abordados en esta investigación para una evaluación más completa del riesgo de la población expuesta(AU)

As part of the biogeochemical cycle, soil fluoride can dissolve and accumulate in groundwater. World Health Organization and the Paraguayan Standard NP 24 001 80 establishes of 1.5 mg.L-1 of fluoride in drinking water, which can produce fluorosis when it is higher, as it has been found in children of Loreto. Studies indicate that exposure to fluoride concomitant with calcium deficit may aggravate bone loss, causing frailty and skeletal fluorosis. In addition, it was demonstrated through bioassays in mice that excess fluoride reduces serum calcium concentration, the objective of the descriptive study with the analytical component has become a spatial distribution map of Loreto groundwater and related to calcemia in children. The fluoride concentration was determined in samples from twenty-three groundwater wells and serum calcium from eighteen school-age children, both by standard method. Two points were identified with levels above the maximum allowed and in 61% of the children the serum calcium was lower than the reference value. We found a weak correlation between the variables (r = 0.212). It would be important to include in later studies factors not addressed in this research for a more complete risk assessment of the exposed population(AU)

Morpho-toxicology of chlorpyrifos to prolactin cells of a freshwater catfish, Heteropneustes fossilis / Morfotoxicologia de clorpirifos para as células de prolactina de bagre de água doce Heteropneustes fossilis

In the present study, an organophosphorus compound Coroban (active ingredient chlorpyrifos ­ E.C. 20%) was used. In short-term exposure the fish were subjected to 0.8 of 96h LC50 value of chlorpyrifos (1.76 mg L-1) for 96h. In long-term exposure the experiment was performed for 28 days by using 0.2 of 96h LC50 value of chlorpyrifos (0.44 mg L-1). Fish were killed on each time intervals from control and experimental (chlorpyrifos) groups after 24, 48, 72, and 96h in short-term exposure and after 7, 14, 21, and 28 days in long-term experiment. Blood samples were collected and sera were analyzed for calcium. Pituitary glands were fixed for histological studies and stained with Herlant tetrachrome and Heidenhain's azan techniques. Short-term exposure of chlorpyrifos caused decrease in the serum calcium levels. No change was noticed in the prolactin cells of chlorpyrifos treated fish. Long-term treatment with chlorpyrifos provoked hypocalcemia. The prolactin cells of treated fish exhibited slight degranulation after 21 days whereas the nuclear volume remained unchanged. After 28 days, the prolactin cells exhibited further degranulation and the nuclear volume recorded an increase. Cytolysis and vacuolization were also visible.

No estudo presente, o composto organofosforo Coroban (ingrediente ativo clorpirifo ­ E.C. 20%) foi usado. Na exposição a curto prazo os peixes foram submetido a 0,8 de valor LC50 de 96h de clorpirifo (1,76 mg L-1) durante 96h. Na exposição a longo prazo o experimento foi executado durante 28 dias usando 0,2 de valor LC50 de 96h de clorpirifos (0,44 mg L-1). Os peixes foram mortos a cada intervalo dos grupos controle e experimental (clorpirifos) após 24, 48, 72, e 96h em exposição a curto prazo e após 7, 14, 21, e 28 dias no experimento a longo prazo. As amostras de sangue foram colhidas e o soro foi analisado para cálcio. As glândulas pituitárias foram fixadas para estudos histológicos e colorido por tetracromo de Herlant e por técnicas de azan do Heidenhain. A exposição a curto prazo do clorpirifo diminuiu os níveis de cálcio no soro. Nenhuma mudança foi observada nas células de prolactina nos peixes tratados com clorpirifo. O tratamento a longo prazo com clorpirifo causou hipocalcemia. As células de prolactina dos peixes tratados mostraram uma leve degranulação após 21 dias ao passo que o volume nuclear permaneceu inalterado. Depois de 28 dias, as células de prolactina mostraram mais degranulação e o volume nuclear registrou um aumento. Citólise e vacuolização também eram visíveis.

Prevalencia de polimorfismos del receptor de vitamina D en pacientes pediátricos mexicanos con enfermedad renal crónica / Prevalence of vitamin D receptor gene polymorphisms in Mexican children with chronic kidney disease

Introducción. La posible influencia de los diferentes polimorfismos del receptor de vitamina D sobre la regulación del eje calcio-hormona paratiroidea -vitamina D es particularmente importante en pacientes con enfermedad renal crónica, ya que cursan con trastornos en el metabolismo mineral óseo. El objetivo del trabajo fue describir la frecuencia de los polimorfismos rs7975232 (ApaI), rs731236 (TaqI) y rs1544410 (BsmI) en el receptor de vitamina D y su relación con el calcio, el fósforo, la fosfatasa alcalina y la hormona paratiroidea en pacientes pediátricos con enfermedad renal crónica. Métodos. Se incluyeron 31 pacientes con enfermedad renal crónica. Se tomaron muestras de sangre a cada uno para la determinación de marcadores bioquímicos y muestras de ADN para la genotipificación del gen del receptor a vitamina D utilizando el método de la reacción en cadena de la polimerasa y restricción enzimática. Resultados. La edad promedio de los pacientes fue de 15.6 ± 3.6 años. Para ApaI, fueron homocigotos AA siete pacientes (22.58%); Aa, 18 pacientes (58.06%) y AA, seis pacientes (19.35%). Para BsmI, 14 pacientes fueron BB (45.16%) y 17 pacientes fueron Bb (54.83%). Los pacientes BB tuvieron calcio sérico mayor que los Bb (p = 0.04). Para TaqI, fueron TT 19 pacientes (61.3%); Tt, once pacientes (35.48%) y uno, tt (3.22%). Aquellos con alelo t (Tt o tt) presentaron concentraciones de calcio sérico significativamente más bajas que el homocigoto TT. Conclusiones. Se reportaron las frecuencias de genotipos y alelos del receptor de vitamina D en niños mexicanos. Se obtuvieron valores de calcio sérico más elevados en aquellos con alelo BB o TT.

Background. The possible influence of vitamin D receptor (VDR) gene polymorphisms on the regulation of the calcium-parathyroid hormone-vitamin D axis is particularly important in end-stage renal disease (ESRD) patients due to alterations in bone mineral metabolism. The aim of the study was to describe the frequency of VDR gene polymorphisms rs7975232 (ApaI), rs731236 (TaqI), rs1544410 (BsmI) and their relationship with serum calcium, phosphate, alkaline phosphatase and parathyroid hormone in children with ESRD. Methods. Thirty one patients were included in the study. Blood samples were drawn for biochemical determinations and DNA extraction. VDR genotypes were analyzed as restriction fragment length polymorphisms using ApaI, BsmI and TaqI. Results. Mean age of the patients was 15.6 ± 3.6 years. For ApaI, seven patients were AA (22.58%), 18 patients were Aa (58.06%) and six patients were aa (19.35%). For BsmI, 14 patients were BB (45.16%) and 17 were Bb (54.83%). Patients who were homozygous for BB had higher serum calcium concentrations than Bb patients (p = 0.04). For TaqI, 19 patients were TT (61.3%), 11 were Tt (35.48%) and one was tt (3.22%). Those with t allele (Tt or tt) had serum calcium concentrations significantly lower than TT patients. Conclusions. Genotype and allele frequency of the VDR gene is reported in Mexican patients with ESRD. Those with BB or TT genotype had higher serum calcium concentrations.

Efecto de la administración de sales de calcio y precursores de glucosa sobre calcio sérico y cuerpos cetónicos en vacas lecheras posparto / Effect of postpartum administration of calcium salts and glucose precursors on serum calcium and ketone bodies in dairy cows

Subclinical hypocalcemia and ketosis are common diseases in mostly dairy cows in the first days postpartum, increasing the risk for other diseases and decreasing milk production. The objective of this study was to evaluate the effect of postpartum administration of calcium salts and glucose precursors on the concentration of serum calcium and ketone bodies in milk of multiparous dairy cows. Sixteen Holstein cows with two to four calvings and body condition from 3.25 to 3.75 points were utilized and randomized into three groups. Cows of the Group 1 (n = 5) received 700 g of calcium propionate diluted in 10 L of water by a esophageal pump system between 1 and 2 h after calving. Cows of the Group 2 (n = 6) were treated intravenously with 500 mL of calcium borogluconate solution (23%) and 500 mL of propylene glycol as an oral drench. The control Group (n = 5) did not receive any treatment. Blood samples were collected 1 to 2 h after calving (before treatment) and two more samples 12 and 24 h after calving for determination of calcium in serum. Levels of p-hydroxybutyrate were assessed in milk at days 3, 7 and 10 postpartum. The results were analyzed using the multivariate analysis of variance for repeated measures. There were no significant differences in serum concentration of calcium between treatments (F2,13 = 1.0488, P = 0.3782). A significant difference in milk production was found among treatments (F2,13 = 4.1338, P = 0.0408) at days 10 and 60 postpartum. The significant difference in the proportion of cases of subclinical ketosis was registered between groups 1 and 2 (chi square = 5.238; P = 0.0455). Oral administration of 700 g of calcium propionate 1 to 2 h postpartum, does not increase serum calcium concentration, reduces frequency of subclinical ketosis and can increase milk production.

La hipocalcemia subclínica y la cetosis subclínica se presentan en la mayoría de las vacas lecheras en los primeros días posparto, esto último aumenta el riesgo de otras enfermedades y disminuye la producción láctea. El objetivo de este trabajo fue evaluar el efecto de la administración de sales de calcio y precursores de glucosa sobre la concentración sérica de calcio y de cuerpos cetónicos en leche de vacas lecheras multíparas posparto. Se utilizaron 16 vacas de la raza Holstein de dos a cuatro partos, con condición corporal entre 3.25 a 3.75 puntos, las cuales se distribuyeron aleatoriamente en tres grupos. De 1 a 2 h después del parto, las vacas del Grupo 1 (n = 5) recibieron 700 g de propionato de calcio disuelto en 10 L de agua mediante una sonda esofágica y una bomba manual. A las vacas del Grupo 2 (n = 6) se les administró, vía intravenosa, 500 mL de una solución de borogluconato de calcio a 23% y 500 mL de propilenglicol vía oral. Las vacas del Grupo 3 (testigo n = 5) no recibieron tratamiento. Se obtuvieron muestras de sangre de 1 a 2 h después del parto (antes del tratamiento) y luego se tomaron otras dos muestras a las 12 y 24 h, en las que se determinó la concentración sérica de calcio. A los tres, siete y 10 días posparto se determinó la concentración de P-hidroxibutirato en leche. Los resultados fueron analizados por medio de análisis de varianza multivariado para un diseño de mediciones repetidas. No se encontraron diferencias significativas en la concentración sérica de calcio entre los tratamientos (F2,13 = 1.0488, P = 0.3782). En la producción de leche, a los 10 y 60 días posparto, se encontró diferencia significativa entre los tratamientos (F2,1 3 = 4.1338, P = 0.0408). Se encontró diferencia significativa entre la proporción de casos de cetosis entre los grupos 1 y 2 (Ji cuadrada = 5.238; P = 0.0455). La administración oral de 700 g de propionato de calcio 1 a 2 h posparto no aumenta la concentración sérica de calcio, reduce la frecuencia de cetosis subclínica y puede aumentar la producción de leche.

Avaliação da hipercalcemia assintomática em pacientes ambulatoriais / Assessment of asymptomatic hypercalcemia in outpatients

Introdução: Dosagens indiscriminadas de cálcio sérico podem levar à detecção de pacientes assintomáticos, com hipercalcemia, em que o hiperparatireoidismo primário é a causa mais comum. Objetivo: Discutir aforma de avaliação da hipercalcemia detectada em população atendida em regime ambulatorial, avaliando a sua freqüência, com ênfase na pesquisa de hiperparatireoidismo primário. Material e métodos: Foi realizado estudo prospectivo envolvendo 1.049 indivíduos, de 40 a 60 anos, com dosagens séricas de cálcio e albumina, e calculado o valor de cálcio corrigido. Na presença de elevação do cálcio corrigido,foram dosados cálcio iônico, fósforo, paratormônio (PTH) e calciúria. Resultados: A idade foi 49,7 ± 13,7anos e 188 (17,9%) indivíduos apresentaram valores elevados de cálcio corrigido. Desses, 90 pacientescompareceram à segunda avaliação e 19 (2%) mantiveram quadro de hipercalcemia. Os níveis de cálcio iônico (média: 1,2 ± 0,01 mmol/l) foram normais em todos os indivíduos. A calciúria foi 185,8 ± 111,8 mg/24 horas. Os níveis de PTH (média: 46 ± 11,8 pg/ml) foram elevados em três casos, com cintilografia de paratireóides normal. Discussão: A queda na freqüência de hipercalcemia com base novalor do cálcio corrigido e, sobretudo, após dosagem de cálcio ionizável sugere que a dosagem de cálcio livre seja preferida como triagem. Na população estudada não foi diagnosticado hiperparatireoidismo, sugerindo distribuição variável da doença em diferentes populações. Conclusão: Deve ser questionada a dosagem rotineira de cálcio sérico em indivíduos sem quadro clínico que indique a necessidade darealização desse exame. Quando realizada, a dosagem de cálcio iônico deverá ser preferida.

Introduction: Indiscriminate serum calcium measurement may lead to the identification of asymptomatic patientswith hypercalcaemia, which is caused mostly by primary hyperparathyroidism. Objective: To discuss the frequencyof hypercalcaemia and the type of assessment of this condition in an outpatient population, with emphasis on the investigation of primary hyperparathyroidism. Material and methods: In a prospective study 1,049 subjects (age range: 40 to 60 years old) underwent serum calcium and albumin determination and the corrected calcium values were calculated. When there was a rise in the corrected calcium level, ionized calcium, phosphate, parathyroid hormone (PTH) and urinary calcium were measured. Results: The average age was 49.7 ± 13.7 years old, and 188 subjects (17.9%) had elevated corrected calcium levels. Among these, 90 patients underwent the second investigation and 19 (2%) remained hypercalcemic. Ionized calcium levels (average: 1.2 ± 0.01 mmol/L) werenormal in all subjects. Urinary calcium was 185.8 ± 111.8 mg/24 hours. PTH levels (average: 46 ± 11.8 pg/mL)were elevated in three subjects whose parathyroid scintigraphies were normal. Discussion: The fall in the frequencyof hypercalcaemia based on corrected serum calcium levels and mostly after determination of serum ionized calciumsuggests that determinations of serum free calcium are a better screening test. No subject was diagnosed with hyperparathyroidism, what suggests an uneven distribution of the disease in different populations. Conclusion:Routine serum calcium determinations in asymptomatic patients must be questioned. When serum calcium determination is thought necessary, ionized calcium levels should be favored.