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1.
Chemosphere ; 242: 125169, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31675576

RESUMO

A systematic study on desorption of uranium in a natural soil has been carried out to reduce the level of uncertainty associated with the method employed to determine the values of the distribution coefficient (Kd). Generally, the operating method used to extract and analyze the soil solution determines the Kd values. Here, the centrifugation method has been used to obtain soil solution extracts. Several procedural parameters have been considered such as incubation time, the level of soil moisture relative to saturation (saturation degree) and centrifugation speed (equivalent to effective suction). In order to analyze the influence of soil structural characteristics, this study considers three grain-size fractions of soil: loamy coarse sand, loamy fine sand, and loam, all of which are obtained from a natural soil collected in a uranium mineralized area. Our results indicate that neither incubation time nor centrifugation speed influence the determination of Kd for uranium. The results also indicate that the level of soil moisture is the most important factor for determining 238U-Kd. It has been shown that the influence of moisture on Kd also depends on the structural characteristic of the soil. For the loamy coarse sand subsample, the moisture level during the incubation period showed a significant influence on the Kd. In addition, through the use of regression analysis, the pH was identified as the cofactor with the greatest influence on Kd of uranium.


Assuntos
Monitoramento Ambiental/métodos , Poluentes Radioativos do Solo/análise , Solo/química , Urânio/análise , Concentração de Íons de Hidrogênio , Radioquímica , Água/análise
2.
Br J Nutr ; 123(6): 642-651, 2020 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-31831096

RESUMO

Modern lifestyle increases the prevalence of obesity and its co-morbidities in the young population. High-salt (HS) diets are associated with hypertension and cardiac remodelling. The present study evaluated the potential effects of cardiometabolic programming induced by HS intake during puberty in lean and obese rats. Additionally, we investigated whether HS could exacerbate the impairment of cardiovascular parameters in adult life due to postnatal early overnutrition (PO). At postnatal day 3 (PN3), twenty-four litters of Wistar rats were divided into two groups: normal litter (NL, nine pups/dam) and small litter (SL, three pups/dam) throughout the lactation period; weaning was at PN21. At PN30, the pups were subdivided into two more groups: NL plus HS (NLHS) and SL plus HS (SLHS). HS intake was from PN30 until PN60. Cardiovascular parameters were evaluated at PN120. SL rats became overweight at adulthood due to persistent hyperphagia; however, HS exposure during puberty reduced the weight gain and food intake of NLHS and SLHS. Both HS and obesity raised the blood pressure, impaired baro- and chemoreflex sensitivity and induced cardiac remodelling but no worsening was observed in the association of these factors, except a little reduction in the angiotensin type-2 receptor in the hearts from SLHS animals. Our results suggest that the response of newborn offspring to PO and juveniles to a HS diet leads to significant changes in cardiovascular parameters in adult rats. This damage may be accompanied by impairment of both angiotensin signalling and antioxidant defence in the heart.


Assuntos
Barorreflexo/efeitos dos fármacos , Composição Corporal/efeitos dos fármacos , Serviços de Dietética , Obesidade , Cloreto de Sódio na Dieta/administração & dosagem , Remodelação Ventricular/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Ingestão de Líquidos/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Feminino , Masculino , Ratos , Ratos Wistar , Maturidade Sexual
3.
Rev. osteoporos. metab. miner. (Internet) ; 11(4): 92-97, nov.-dic. 2019. graf, tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-187300

RESUMO

OBJETIVO: Actualmente, existen pocos datos sobre la influencia a largo plazo del polimetilmetacrilato (PMMA) en la integridad de los cuerpos vertebrales tras la vertebroplastia percutánea (VP). Resulta de interés investigar la posible relación entre esta técnica y la aparición con el tiempo de fenómenos de osteólisis o la fragmentación del cemento en las vértebras intervenidas. El objetivo de este trabajo fue investigar si, a largo plazo, existe una pérdida de efectividad y/o seguridad de la VP con PMMA. MATERIAL Y MÉTODOS: Se analizaron radiografías de pacientes intervenidos correspondientes al post-operatorio inmediato y al estudio radiológico más reciente (VP hace más de 15 años). Con ambos estudios radiológicos, describimos: la altura del cuerpo vertebral, la angulación de platillos y la presencia de osteólisis alrededor del cemento en el tiempo. RESULTADOS: Un total de 7 pacientes intervenidos mediante VP con PMMA hace 15 o más años accedieron a realizarse una nueva radiografía en nuestro Centro. Tras el análisis de sus imágenes post-operatorias (inmediatas y a 15 ó más años de la cirugía), no se observó en ninguna de las vértebras intervenidas pérdida de altura del cuerpo vertebral cementado, diferencias de angulación en los platillos, presencia de osteólisis alrededor del cemento o fragmentación del PMMA inyectado. CONCLUSIÓN: El PMMA inyectado en el cuerpo vertebral mantiene una situación estable en el tiempo (más de 15 años). No se observan cambios en la interfaz hueso-PMMA, osteólisis y/o cambios en la altura de los cuerpos vertebrales en los casos analizados


OBJETIVE: Currently, there are limited data on the long-term influence of polymethylmethacrylate (PMMA) on the integrity of vertebral bodies after percutaneous vertebroplasty (PVP). Interesting investigation is being carried out into the possible relationship between this technique and the appearance over time of osteolytic phenomena or cement fragmentation in the intervened vertebrae. The objective of our study was to investigate whether there is a loss of effectiveness and/or safety of PVP with PMMA in the long term. MATERIAL AND METHOD: X-rays were analyzed of intervened patients corresponding to the immediate post-operative and the most recent radiological study (PVP more than 15 years previous). With both radiological studies, we describe: the height of the vertebral body, the angulation of lamellar plates and osteolytic presence around the cement over time. RESULTS: A total of 7 patients operated by PVP with PMMA 15 or more years earlier agreed to have a new radiograph in our center. After the analysis of their post-operative images (immediate and 15 or more years after surgery), no loss of height of the cemented vertebral body, differences in angulation in the lamellar plates, presence of osteolysis around the vertebrae was observed in any of the involved vertebrae cement or fragmentation of the injected PMMA. CONCLUSIONS: PMMA injected into the vertebral body remains stable over time (more than 15 years). There are no changes in the bone-PMMA interface, osteolysis and/or changes in the height of the vertebral bodies in the cases analyzed


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Polimetil Metacrilato/administração & dosagem , Vertebroplastia/métodos , Osteólise , Fraturas por Osteoporose/cirurgia , Fatores de Tempo , Resultado do Tratamento , Seguimentos , Índice de Massa Corporal
4.
Chemosphere ; 205: 188-193, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29698829

RESUMO

In order to clarify some of the assumptions and approximations about the use of the distribution coefficient Kd for 226Ra in soils, a systematic study has been performed using centrifugation to extract the soil solution. The separated fractions of the soil solution have different kinetics with respect to the sorption process in the soil, which may in turn condition the final chemical composition and even the speciation of the radionuclides in solution. In the experimental design of this study three factors were considered: the moisture level in the incubation process, incubation time and the speed of centrifugation. Also, three levels were chosen for each factor. In order to analyze the influence of the structural characteristics of the soil, this study was performed with three textural fractions: coarse sand, fine sand, and silt and clay, obtained from an only soil. Also, the soil was naturally enriched with radionuclides of the 238U series. An analysis of variance (ANOVA) was performed in order to assess the influence of the factors studied on the distribution coefficient of 226Ra. The results indicate that different behaviors can be observed depending on the structural characteristic of the soil. In the case of particle size, the soil with the largest grain size showed that the incubation process parameters influence the equilibrium level achieved, while in the case of the smallest edaphic particles, radium is not homogeneously distributed in the soil solution and the Kd value is dependent on the speed of centrifugation.


Assuntos
Rádio (Elemento)/análise , Dióxido de Silício/química , Poluentes Radioativos do Solo/análise , Solo/química , Tamanho da Partícula
5.
Chemosphere ; 168: 832-838, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27825713

RESUMO

The soil-to-plant transfer factors were determined in a granitic area for the two long-lived uranium series radionuclides 238U and 226Ra. With the aim to identify a physical fraction of soil whose concentration correlates linearly with the plant concentration, the soil compartment was analyzed in various stages. An initial study identified the soil compartments as being either bulk soil or its labile fraction. The bulk soil was subsequently divided into three granulometric fractions consisting of: coarse sand, fine sand, and silt and clay. The soil-to-plant transfer of radionuclides for each of these three texture fractions was analyzed. Lastly, the labile fraction was extracted from each textural part, and the activity concentration of the radionuclides 238U and 226Ra was measured. In order to assess the influence of soil texture on the soil-to-plant transfer process, we sought to identify possible correlations between the activity concentration in the plant compartment and those found in the different fractions within each soil compartment. The results showed that the soil-to-plant transfer process for uranium and radium depends on soil grain size, where the results for uranium showed a linear relationship between the activity concentration of uranium in the plant and the fine soil fraction. In contrast, a linear relation between the activity concentration of radium in the plant and the soil coarse-sand fraction was observed. Additionally, the presence of phosphate and calcium in the soil of all of the compartments studied affected the soil-to-plant transfer of uranium and radium, respectively.


Assuntos
Plantas/metabolismo , Rádio (Elemento)/análise , Dióxido de Silício/química , Poluentes Radioativos do Solo/análise , Solo/química , Urânio/análise , Asteraceae/metabolismo , Fabaceae/metabolismo , Plantas/efeitos da radiação , Poaceae/metabolismo , Rádio (Elemento)/metabolismo , Poluentes Radioativos do Solo/efeitos adversos , Poluentes Radioativos do Solo/metabolismo , Urânio/metabolismo
6.
Chemosphere ; 95: 527-34, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24182407

RESUMO

Low-level alpha spectrometry techniques using semiconductor detectors (PIPS) and liquid scintillation (LKB Quantulus 1220™) were used to determine the activity concentration of (238)U, (234)U, (230)Th, (226)Ra, (232)Th, and (210)Pb in soil samples. The soils were collected from an old disused uranium mine located in southwest Spain. The soils were sampled from areas with different levels of influence from the installation and hence had different levels of contamination. The vertical profiles of the soils (down to 40 cm depth) were studied in order to evaluate the vertical distribution of the natural radionuclides. To determine the origin of these natural radionuclides the Enrichment Factor was used. Also, study of the activity ratios between radionuclides belonging to the same radioactive series allowed us to assess the different types of behaviors of the radionuclides involved. The vertical profiles for the radionuclide members of the (238)U series were different at each sampling point, depending on the level of influence of the installation. However, the profiles of each point were similar for the long-lived radionuclides of the (238)U series ((238)U, (234)U, (230)Th, and (226)Ra). Moreover, a major imbalance was observed between (210)Pb and (226)Ra in the surface layer, due to (222)Rn exhalation and the subsequent surface deposition of (210)Pb.


Assuntos
Monitoramento de Radiação , Radioisótopos/análise , Poluentes Radioativos do Solo/análise , Urânio/análise , Radioisótopos de Chumbo/análise , Rádio (Elemento)/análise , Solo/química , Espanha , Tório/análise
7.
J Hazard Mater ; 250-251: 439-46, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23500424

RESUMO

The effect of three chelating agents (citrate, EDTA, and EDDS) on the solubilization of radium from a granitic soil was studied systematically, considering different soil pH values, chelating agent concentrations, and leaching times. For all the chelating agents tested, the amount of radium leached proved to be strongly dependent on the pH of the substrate: only for acidic conditions did the amount of radium released increase significantly relative to the controls. Under the best conditions, the radium released from the amended soil was greater by factors of 20 in the case of citrate, 18 for EDTA, and 14 for EDDS. The greatest improvement in the release of radium was obtained for the citrate amendment at the highest concentration tested (50 mmol kg(-1)). A slightly lower amount of radium was leached with EDTA at 5 mmol kg(-1) soil, but the solubilization over time was very different from that observed with citrate or EDDS. With EDTA, a maximum in radium leaching was reached on the first day after amendment, while with citrate, the maximum was attained on the fourth day. With EDDS, radium leaching increased slightly but steadily with time (until the sixth day), but the net effect for the period tested was the lowest of the three reagents.


Assuntos
Quelantes/química , Ácido Edético/química , Etilenodiaminas/química , Succinatos/química , Ácido Cítrico/química , Concentração de Íons de Hidrogênio , Chumbo/análise , Rádio (Elemento)/análise , Solo/análise , Poluentes Radioativos do Solo/análise , Urânio/análise
8.
Appl Radiat Isot ; 70(4): 609-11, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22221465

RESUMO

In a previous paper the authors proposed a sequential method for the determination of isotopes of uranium, thorium, radium, and lead from environmental samples using alpha-particle spectrometry and LSC techniques. Although the radiochemical yields were suitable when the assays were performed on synthetic samples, application to real environmental samples caused a major decrease in the radiochemical yield, especially for uranium in inorganic samples (soils). A modification of the procedure is described that overcomes this drawback.


Assuntos
Partículas alfa , Poluentes Ambientais/análise , Radioisótopos/análise , Análise Espectral/métodos , Radioisótopos de Chumbo , Poluentes Radioativos/análise , Rádio (Elemento)/análise , Poluentes Radioativos do Solo , Urânio/análise
9.
J Hazard Mater ; 198: 224-31, 2011 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-22047721

RESUMO

A systematic study was made of the effects of three soil amendments on the solubilization of uranium from a granitic soil. The aim was to optimize solubilization so as to enhance bioavailability for the purposes of remediation. The three amendments tested were with citrate, EDTA, and EDDS as chelating agents. The effects of pH, chelator concentration, and leaching time were studied. The most important factor in uranium solubilization was found to be the pH. In the absence of chelating agents, the greatest solubilization was obtained for alkaline conditions, with values representing about 15% of the total uranium activity in the bulk soil. There were major differences in uranium solubilization between the different amendments. The citrate treatment was the most efficient at acidic pH, particularly with the greatest concentration of citrate tested (50 mmol kg(-1)) after 6 days of treatment. Under these conditions, the uranium concentration in solution was greater by a factor of 356 than in the control suspension, and represented some 63% of the uranium concentration in the bulk soil. Under alkaline conditions, the EDTA and EDDS treatments gave the greatest uranium activity concentrations in solution, but these concentrations were much lower than those with the citrate amendment, and were not very different from the control results. The uranium extraction yield with EDDS amendment was greater than with EDTA.


Assuntos
Quelantes/química , Ácido Cítrico/química , Ácido Edético/química , Etilenodiaminas/química , Poluentes do Solo/química , Succinatos/química , Urânio/química , Concentração de Íons de Hidrogênio , Solubilidade
10.
Appl Radiat Isot ; 68(6): 1154-9, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20153657

RESUMO

The soil-to-plant transfer factors of natural uranium isotopes ((238)U and (234)U), (230)Th, (226)Ra, and (210)Pb were studied in a disused uranium mine located in the Extremadura region in the south-west of Spain. The plant samples included trees (Quercus ilex, Quercus suber, and Eucalyptus cameldulensis) and one shrub (Cytisus multiflorus). All of them are characteristic of Mediterranean environments. The activity concentrations in leaves and fruit were determined for the tree species at different stages of growth. For the shrub, the total above-ground fraction was considered in three seasons. For old leaves and fruit, the highest activity concentrations were found in Eucalyptus cameldulensis for all the radionuclides studied, except in the case of (230)Th that presented similar activity concentrations in all of the tree species studied. In every case, the transfer to fruit was less than the transfer to leaves. In the shrub, the results depended on the season of sampling, with the highest value obtained in spring and the lowest in autumn. Important correlations were obtained for (238)U and (226)Ra between the activity ratio in soils with that in leaves or fruit.


Assuntos
Rádio (Elemento)/metabolismo , Poluentes Radioativos do Solo/metabolismo , Tório/metabolismo , Árvores/metabolismo , Urânio/metabolismo , Eucalyptus/metabolismo , Fabaceae/metabolismo , Frutas/metabolismo , Radioisótopos de Chumbo/metabolismo , Folhas de Planta/metabolismo , Quercus/metabolismo , Solo , Espanha
11.
Appl Radiat Isot ; 68(4-5): 828-31, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19833528

RESUMO

A procedure for the determination of (210)Pb, and alpha-emitting radioisotopes of uranium, thorium, and radium from the same aliquot of a sample has been proposed. The key step consisted in the recovery of Pb(II) and Ra by precipitation of insoluble Pb(NO(3))(2), the uranium and thorium radioisotopes remaining in solution. Afterwards, the fractions were handled by specific, well consolidated procedures. Lead-210 was determined by the LSC technique while the uranium, thorium, and radium radioisotopes were measured with silicon alpha-spectrometers. The procedure was applied to a reference sample and several environmental samples obtaining satisfactory results.


Assuntos
Algoritmos , Misturas Complexas/análise , Radioisótopos/análise , Radiometria/métodos , Análise Espectral/métodos , Partículas alfa , Doses de Radiação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
Chemosphere ; 74(2): 293-300, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18848715

RESUMO

Seedlings of Helianthus annuus L. (HA) and Brassica juncea (BJ) were used to test the effect of the pH, the presence of phosphates, and the addition of ethylene-diamine-tetraacetic acid (EDTA) or citrate on the uptake and the translocation of uranium isotopes ((238)U, (235)U, and (234)U) and (226)Ra. The results indicated that the presence of phosphates generally reduces the uptake and transfer of uranium from the roots to the shoots of HA. In the case of BJ, while phosphate enhanced the retention of uranium by roots, the translocation was poorer. Likewise, for (226)Ra, the best translocation was in the absence of phosphates for both species. The addition of citrate increased the translocation of uranium for both species, but had no clear effect on the transfer of (226)Ra. The effect of EDTA was much more moderate both for uranium and for (226)Ra, and for both plant species. Only noticeable was a slightly better uptake of (226)Ra by BJ at neutral pH, although the translocation was lower.


Assuntos
Helianthus/metabolismo , Mostardeira/metabolismo , Rádio (Elemento)/metabolismo , Urânio/metabolismo , Biodegradação Ambiental/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Fosfatos/química , Fosfatos/farmacologia , Raízes de Plantas/metabolismo , Poluentes Radioativos/metabolismo
13.
J Environ Radioact ; 99(8): 1247-54, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18433950

RESUMO

The influence of soil texture on the distribution and availability of (238)U, (230)Th, and (226)Ra in soils was studied in soil samples collected at a rehabilitated uranium mine located in the Extremadura region in south-west Spain. The activity concentration (Bqkg(-1)) in the soils ranged from 60 to 750 for (238)U, from 60 to 260 for (230)Th, and from 70 to 330 for (226)Ra. The radionuclide distribution was determined in three soil fractions: coarse sand (0.5-2mm), medium-fine sand (0.067-0.5mm), and silt and clay (<0.067 mm). The relative mobility of the natural radionuclides in the different fractions was studied by comparison of the activity ratios between radionuclides belonging to the same radioactive series. The lability of these radionuclides in each fraction was also studied through selective extraction from the soils using a one-step sequential extraction scheme. Significant correlations were found for (238)U, (230)Th, and (226)Ra between the activity concentration per fraction and the total activity concentration in the bulk soil. Thus, from the determination of the activity concentration in the bulk soil, one could estimate the activity concentration in each fraction. Correlations were also found for (238)U and (226)Ra between the labile activity concentration in each fraction and the total activity concentration in bulk soil. Assuming that there is some particle-size fraction that predominates in the process of soil-to-plant transfer, the parameters obtained in this study should be used as correction factors for the transfer factors determined from the bulk soil in previous studies.


Assuntos
Rádio (Elemento)/análise , Poluentes Radioativos do Solo/análise , Solo , Tório/análise , Urânio/análise
14.
Sci Total Environ ; 393(2-3): 351-7, 2008 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-18272206

RESUMO

The elimination of natural uranium and (226)Ra from contaminated waters by rhizofiltration was tested using Helianthus annuus L. (sunflower) seedlings growing in a hydroponic medium. Different experiments were designed to determine the optimum age of the seedlings for the remediation process, and also to study the principal way in which the radionuclides are removed from the solution by the sunflower roots. In every trial a precipitate appeared which contained a major fraction of the natural uranium and (226)Ra. The results indicated that the seedlings themselves induced the formation of this precipitate. When four-week-old seedlings were exposed to contaminated water, a period of only 2 days was sufficient to remove the natural uranium and (226)Ra from the solution: about 50% of the natural uranium and 70% of the (226)Ra were fixed in the roots, and essentially the rest was found in the precipitate, with only very small percentages fixed in the shoots and left in solution.


Assuntos
Helianthus/metabolismo , Rádio (Elemento)/metabolismo , Urânio/metabolismo , Poluentes Radioativos da Água/metabolismo , Precipitação Química , Filtração , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Rádio (Elemento)/química , Plântula/metabolismo , Urânio/química , Poluentes Radioativos da Água/química , Purificação da Água/métodos
15.
Rev. ortop. traumatol. (Madr., Ed. impr.) ; 51(6): 314-318, nov.-dic. 2007. ilus, tab
Artigo em Es | IBECS | ID: ibc-65575

RESUMO

Objetivos. Valorar nuestros resultados radiológicos y funcionales tras la estabilización de fracturas periprotésicas de rodilla en fémur distal mediante clavo intramedular acerrojado retrógrado. Material y método. Estudio retrospectivo de 12 pacientes afectados de fractura supracondílea periprotésica de fémur distal. El seguimiento medio fue de 14 meses (6-24 meses). Resultados. Entre las posibles causas de la fractura periprotésica encontramos la existencia de una osteotomía femoral anterior excesiva en cinco de los doce pacientes de nuestro estudio. Se consiguió la consolidación clínica y radiológica en todos los pacientes, tras un período medio de 15 semanas. Como complicaciones cabe señalar la consolidación en mala posición en 3 de los 12 pacientes por falta de reducción durante la cirugía; ninguna precisó tratamiento secundario. Conclusiones. La existencia de una osteotomía anterior excesiva que debilita la cortical femoral podría ser una de las causas de fractura periprotésica, por lo que debe ser evitada. El enclavado intramedular retrógrado para el tratamiento de fracturas periprotésicas de fémur distal es una técnica que proporciona buenos resultados con un índice bajo de complicaciones


Purpose. To assess the radiological and functional results obtained after stabilization of periprosthetic knee fractures in the distal femur by means of a retrograde locked intramedullary nail. Materials and methods. Retrospective study of 12 patients that sustained a periprosthetic supracondylar distal femoral fracture. Mean follow-up was 14 months (range: 6-24 months). Results. Clinical and radiological healing was achieved in all patients over a mean period of 15 weeks. As regards complications, the presence of a malunion in 3 out of the 12 patients was probable related the fact that the fracture was not reduced intraoperatively; however, these did not require secondary treatment. Among the possible causes for the periprosthetic fracture, we could mention the existence of an excessive previous femoral osteotomy in five of the 12 patients in our study. Conclusions. Retrograde intramedullary nailing for the treatment of periprosthetic distal femoral fractures is a technique that has afforded us good results with a low complications rate. The presence of an overly aggressive previous osteotomy that weakened the femoral cortex could be construed to be a likely cause for the periprosthetic fracture; therefore these should be avoided (AU)


Assuntos
Humanos , Fraturas do Fêmur/cirurgia , Prótese do Joelho , Fixação de Fratura/métodos , Pinos Ortopédicos , Osteotomia/efeitos adversos , Artroplastia
16.
Braz. j. med. biol. res ; 40(9): 1221-1230, Sept. 2007. tab
Artigo em Inglês | LILACS | ID: lil-460904

RESUMO

In the late 1980's child malnutrition was still prevalent in Brazil, and child obesity was beginning to rise in the richest regions of the country. To assess the extent of the nutritional transition during the period and the influence of birth weight and maternal smoking on the nutritional condition of schoolchildren, we estimated the prevalence of excess weight and malnutrition in a cohort of Brazilian schoolchildren from 1987 to 1989. We calculated the body mass index (BMI) of 8- to 10-year-old schoolchildren born in Ribeirão Preto in 1978/79. We considered children with a BMI <5th percentile (P5) to be malnourished, children with P5³BMI

Assuntos
Criança , Feminino , Humanos , Recém-Nascido , Masculino , Gravidez , Peso ao Nascer , Transtornos da Nutrição Infantil/epidemiologia , Sobrepeso/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Fumar , Índice de Massa Corporal , Brasil/epidemiologia , Estudos de Coortes , Transtornos da Nutrição Infantil/etiologia , Recém-Nascido de Baixo Peso , Sobrepeso/etiologia , Prevalência , Fatores de Risco , Fatores Socioeconômicos , População Urbana
17.
Braz J Med Biol Res ; 40(9): 1221-30, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17713645

RESUMO

In the late 1980's child malnutrition was still prevalent in Brazil, and child obesity was beginning to rise in the richest regions of the country. To assess the extent of the nutritional transition during the period and the influence of birth weight and maternal smoking on the nutritional condition of schoolchildren, we estimated the prevalence of excess weight and malnutrition in a cohort of Brazilian schoolchildren from 1987 to 1989. We calculated the body mass index (BMI) of 8- to 10-year-old schoolchildren born in Ribeirão Preto in 1978/79. We considered children with a BMI <5th percentile (P5) to be malnourished, children with P5 > or = BMI or = P85 to be overweight. We evaluated the association of these nutritional disorders with birth factors (infant weight, sex, preterm delivery, number of pregnancies, maternal smoking during pregnancy, marital status, and schooling) and type of school using nominal logistic regression. A total of 2797 schoolchildren were evaluated. There was a significant prevalence of malnutrition (9.5%) and excess weight already tended to increase (15.7%), while 6.4% of the children were obese. Excess weight was more prevalent among children attending private schools (odds ratio, OR = 2.27) and firstborn children (OR = 1.69). Maternal smoking during pregnancy protected against malnutrition (OR = 0.56), while children with lower birth weight were at higher risk for malnutrition (OR = 4.23). We conclude that a nutritional transition was under way while malnutrition was still present, but excess weight and related factors were already emerging.


Assuntos
Peso ao Nascer , Transtornos da Nutrição Infantil/epidemiologia , Sobrepeso/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Fumar , Índice de Massa Corporal , Brasil/epidemiologia , Criança , Transtornos da Nutrição Infantil/etiologia , Estudos de Coortes , Feminino , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Masculino , Sobrepeso/etiologia , Gravidez , Prevalência , Fatores de Risco , Fatores Socioeconômicos , População Urbana
18.
Phytomedicine ; 14(2-3): 147-52, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16860978

RESUMO

Isolation and biological characterization of pure compounds was used to identify and characterize estrogenic activity and estrogen receptors (ER) preference in chemical components of Achillea millefolium. This medicinal plant is used in folk medicine as an emmenagogue. In vitro assay, based on recombinant MCF-7 cells, showed estrogenic activity in a crude extract of the aerial parts of A. millefolium. After fractionation of the crude extract with increasing polar solvents, estrogenic activity was found in the methanol/water fraction. Nine compounds were isolated and characterized by HR-MS spectra and 1D- and 2D-NMR techniques. In particular, dihydrodehydrodiconiferyl alcohol 9-O-beta-D-glucopyranoside - a glycosyl-neolignan - was isolated for the first time from the genus Achillea in addition to six flavone derivatives, apigenin, apigenin-7-O-beta-D-glucopyranoside, luteolin, luteolin-7-O-beta-D-glucopyranoside, luteolin-4'-O-beta-D-glucopyranoside, rutin, and two caffeic acid derivatives, 3,5-dicaffeoylquinic acid and chlorogenic acid. Apigenin and luteolin, the most important estrogenic compounds among those tested, were studied for their ability to activate alpha or beta estrogen receptors (ERalpha, ERbeta) using transiently transfected cells. Our results suggest that isolation and biological characterization of estrogenic compounds in traditionally used medicinal plants could be a first step in better assessing further (e.g. in vivo) tests of nutraceutical and pharmacological strategies based on phytoestrogens.


Assuntos
Achillea , Receptor alfa de Estrogênio/efeitos dos fármacos , Receptor beta de Estrogênio/efeitos dos fármacos , Fitoestrógenos/farmacologia , Fitoterapia , Extratos Vegetais/farmacologia , Células Cultivadas/efeitos dos fármacos , Feminino , Humanos , Técnicas In Vitro , Fitoestrógenos/administração & dosagem , Fitoestrógenos/química , Fitoestrógenos/uso terapêutico , Componentes Aéreos da Planta , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico
19.
Proc Natl Acad Sci U S A ; 103(49): 18603-8, 2006 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-17132737

RESUMO

Craniosynostosis, the fusion of one or more of the sutures of the skull vault before the brain completes its growth, is a common (1 in 2,500 births) craniofacial abnormality, approximately 20% of which occurrences are caused by gain-of-function mutations in FGF receptors (FGFRs). We describe a genetic and pharmacological approach for the treatment of a murine model system of Crouzon-like craniosynostosis induced by a dominant mutation in Fgfr2c. Using genetically modified mice, we demonstrate that premature fusion of sutures mediated by Crouzon-like activated Fgfr2c mutant is prevented by attenuation of signaling pathways by selective uncoupling between the docking protein Frs2alpha and activated Fgfr2c, resulting in normal skull development. We also demonstrate that attenuation of Fgfr signaling in a calvaria organ culture with an Fgfr inhibitor prevents premature fusion of sutures without adversely affecting calvaria development. These experiments show that attenuation of FGFR signaling by pharmacological intervention could be applied for the treatment of craniosynostosis or other severe bone disorders caused by mutations in FGFRs that currently have no treatment.


Assuntos
Craniossinostoses/genética , Craniossinostoses/prevenção & controle , Mutagênese Sítio-Dirigida , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais/genética , Animais , Disostose Craniofacial/genética , Disostose Craniofacial/patologia , Disostose Craniofacial/prevenção & controle , Craniossinostoses/patologia , Regulação da Expressão Gênica , Camundongos , Células NIH 3T3 , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/fisiologia
20.
Phytother Res ; 20(7): 576-80, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16619333

RESUMO

A selection of wild plants collected in Valsesia (Northwest Italy) was screened for their in vitro antioxidant activity. Aerial parts of selected plants were dried at room temperature and powdered. Then, four sequential extractions were performed with increasing polarity solvents, i.e. n-hexane, chloroform, chloroform-methanol (9:1, v/v) and methanol. By employing different assays, it was shown that all the methanol extracts of the samples collected were endowed with antioxidant activity, though, as expected, their potency varied according to the different tests. In particular, plants of the Thymus and Achillea genus displayed the highest activity. Given that a diet rich in wild plants is associated with a reduced incidence of degenerative diseases, such as atherosclerosis and cancer, this study suggests that some Valsesia plants could be pharmaceutically exploited.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Plantas/química , Achillea/química , Artemisia/química , Cardamine/química , Gentiana/química , Itália , Extratos Vegetais/química , Timo/química , Valeriana/química
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