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1.
Int Endod J ; 53(9): 1299-1306, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32535964

RESUMEN

AIM: To assess the influence of artefacts generated by metal posts on the detection of simulated internal root resorption (IRR) in adjacent teeth using cone-beam computed tomography (CBCT) and to verify the impact of metal artefact reduction (MAR) on these cases. METHODOLOGY: CBCT images of 14 premolar teeth were acquired before and after IRR simulation using chemical and mechanical procedures, in an OP300 Maxio unit, with and without MAR. Each tooth was placed in the socket of a human mandible and scanned under three different conditions: (i) without adjacent teeth - control group; (ii) distal adjacent tooth restored with metal post; and (iii) with both adjacent teeth restored with metal post. Five oral radiologists scored the IRR detection using a 5-point scale. Diagnostic values were obtained for the tested groups and compared using two-way analysis of variance (α = 0.05). RESULTS: The presence of a single adjacent tooth restored with metal post did not significantly influence the diagnostic values for IRR detection (P > 0.05). The presence of both adjacent teeth with metal posts, without MAR application, was associated with a significantly lower area under the ROC curve (Az) compared to the control (P = 0.0182). In this case, the application of MAR increased Az, leading to nonsignificant differences from the control group and the group with one adjacent restored tooth (P > 0.05). Sensitivity decreased significantly when two adjacent restored teeth were present, regardless of MAR application (P = 0.0379). Specificity was not affected by the conditions tested (P > 0.05). CONCLUSION: CBCT detection of IRR was impaired by artefacts only when both adjacent teeth restored with metal posts were present. In such cases, activation of MAR improved the performance on this diagnostic task.


Asunto(s)
Resorción Radicular , Tomografía Computarizada de Haz Cónico Espiral , Fracturas de los Dientes , Tomografía Computarizada de Haz Cónico , Humanos , Metales , Raíz del Diente
2.
Clim Dyn ; 53(7): 4189-4216, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31929689

RESUMEN

Objective methods for identifying and quantifying atmospheric blocking have been developed over recent decades, primarily targeting North Atlantic blocks. Differences arise from these methods, leading to changes in the resultant blocking climatology. To understand these differences, and better inform future assessments built on quantitative detection of blocks, this paper examines blocking properties produced by three different objective detection algorithms over the global extratropics. Blocking criteria examined include 500 hPa geopotential height anomaly ( Z ∗ ), column-averaged potential vorticity anomaly ( P V ∗ ), and 500 hPa geopotential height gradient (AGP). Results are analyzed for blocking climatologies and for instantaneous blocking patterns, as well as distributions of block size, speed, duration, and distance traveled. The results emphasize physical characteristics of the flow field and the subsequent blocking regions that emerge; overall, P V ∗ and Z ∗ blocked regions often have higher pattern correlation and spatial similarity, though these two methods also display high agreement with AGP in some instances. Z ∗ finds the largest (and greatest number of) blocked regions, while P V ∗ -detected regions are smallest in all instances except Southern Hemisphere winter. In some cases, P V ∗ tracks a nearby jet streak, leading to differences with height-based algorithms. All three algorithms detect some questionable low-latitude blocks that are stationary and persist but do not impair zonal flow, although at different times. Therefore, careful consideration of the algorithm biases is important in future blocking studies. For example, linking extreme weather to detected blocking could vary substantially depending on the algorithm used.

3.
Bull Environ Contam Toxicol ; 89(1): 119-24, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22527003

RESUMEN

Our objective was to evaluate the temporal evolution of mercury exposure in two riverside communities, Barreiras and São Luiz do Tapajós, downstream of gold mining areas in the Tapajós basin, Brazilian Amazon. The quantification of mercury in hair sample was made by atomic absorption spectrophotometry in the period between 1994 and 2010. In São Luiz do Tapajós the mercury exposure varied, in log units, from the peak of 1.21 ± 0.03 µg/g in 1996 to 1.16 ± 0.07 µg/g in 2007. Mercury exposure in Barreiras varied, in log units, from 1.25 ± 0.04 µg/g in 1994 to 1 ± 0.03 µg/g in 2010, peaking in 1995 at 1.25 ± 0.06 µg/g. Total mercury concentration found in both communities had no statistical differences across the years (p > 0.05) and they were higher than non-mercury exposed communities in Brazil and in South America. We concluded that the mercury exposure in the Tapajós basin is more than regulatory levels or higher than the general population.


Asunto(s)
Exposición a Riesgos Ambientales/estadística & datos numéricos , Cabello/metabolismo , Mercurio/metabolismo , Contaminantes Químicos del Agua/metabolismo , Adulto , Brasil , Femenino , Contaminación de Alimentos/estadística & datos numéricos , Cabello/química , Humanos , Masculino , Mercurio/análisis , Persona de Mediana Edad , Minería , Características de la Residencia , Ríos/química , Contaminantes Químicos del Agua/análisis
4.
Bull Environ Contam Toxicol ; 87(4): 377-80, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21874404

RESUMEN

Total mercury concentrations were determined in muscle, liver and kidney of Cichlia ocellaris and Colossoma macropomum sampled at Tapajos and Carnapijo Rivers in Amazon ecosystem during the flood period of 2009. In background area the highest levels of mercury were observed in liver of piscivorous (0.3 ± 0.03 ug/g dry wt) and non piscivorous fish (0.20 ± 0.1 ug/g dry wt), but in contaminated area the highest level of mercury in piscivorous fish was detected in liver (0.45 ± 0.27 ug/g dry wt) and in muscle (0.26 ± 0.05 ug/g dry wt) of non piscivorous fish. These results suggested that the presence of anthropogenic source plays a key role in the pattern of mercury distribution in fish tissues.


Asunto(s)
Characiformes/metabolismo , Cíclidos/metabolismo , Mercurio/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Brasil , Monitoreo del Ambiente , Riñón/metabolismo , Hígado/metabolismo , Músculos/metabolismo , Ríos/química
5.
Cell Biol Int ; 32(8): 913-9, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18499485

RESUMEN

The present work quantifies hyaluronan (HA) during the late pregnancy and post-partum in order to provide a better understanding of the role of HA in the adaptations that occur in the pubic symphysis during this period. HA was quantified in situ (histochemically) and in interpubic tissue extracts by fluorimetric assay. Samples were taken from virgin mice and from pregnant animals at various stages of pregnancy: 12th-18th days into pregnancy, the day of delivery (D19) and the 3rd and 5th day post-partum. The quantitative fluorimetric analysis indicated a gradual increase of HA in the interpubic tissue throughout late pregnancy (2.4-14.6 microg/mg dry weight). This was followed by a decrease beginning on D19 (12.4 microg/mg), reaching close to virgin levels (2.2 microg/mg) on the 5th day post-partum. The same optical density changes could be seen in the HA staining. Furthermore, the histochemical analysis demonstrated the presence of HA both in the extracellular matrix of the tissue and within its cells. Such results indicate that the extracellular presence of HA may contribute to the transformation of the symphysis into a flexible structure. In addition, HA's intracellular presence (until the 18th day of pregnancy) may contribute to cellular proliferation. Finally, during parturition and on the 5th day post-partum, HA may contribute to the maintenance of the myofibroblastic phenotype of ligament cells, aiding the ligament involution after parturition.


Asunto(s)
Matriz Extracelular/metabolismo , Ácido Hialurónico/metabolismo , Periodo Posparto/metabolismo , Preñez/metabolismo , Sínfisis Pubiana/metabolismo , Animales , Femenino , Ratones , Embarazo
6.
Environ Res ; 107(1): 53-9, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-17905226

RESUMEN

Mercury is a hazardous metal that has become an important issue of environmental contamination in Amazon areas. Human intoxication by mercury causes sensory deficits, motor dysfunction, delayed psychomotor development, genotoxicity, and several other health problems. One of the major cellular mechanisms of mercury toxicity is the oxidative stress which may lead to membrane peroxidation and generation of reactive oxygen species. The antioxidant defense, which includes scavenger compounds such as glutathione and antioxidant enzymes such as catalase, might prevent these injuries to occur. Thus, the objective of this work was to evaluate hair mercury levels and the strength of antioxidant defenses, evaluated by glutathione levels and catalase activity in the blood of exposed and non-exposed women living in Amazon populations. For each location, no statistically significant difference (P<0.05) was detected for age versus mercury content. However, women from populations under the influence of gold mining activity exhibit high mercury levels in hair samples, above the tolerance limit accepted by the World Health Organization. In addition, a significant correlation was found between high mercury content, high glutathione level, and lower catalase activity. These data suggest that chronic mercury intoxication may deplete antioxidant enzymatic activity, which can be used as an important peripheral marker. Knowledge originated by this monitoring will better assist the development of preventive strategies and governmental actions against the problem of mercury contamination.


Asunto(s)
Catalasa/sangre , Glutatión/sangre , Cabello/química , Mercurio/análisis , Adolescente , Adulto , Anciano , Brasil , Exposición a Riesgos Ambientales/estadística & datos numéricos , Femenino , Depuradores de Radicales Libres/sangre , Humanos , Persona de Mediana Edad
7.
Oral Dis ; 13(6): 538-43, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17944669

RESUMEN

AIM: To evaluate the clinical effects of laser therapy on the prevention and reduction of oral mucositis in patients who underwent hematopoietic stem cell transplantation (HSCT). PATIENTS AND METHODS: From January 2003 to September 2004, 24 patients received prophylactic laser therapy (L+ group). The applications started from the beginning of the conditioning regimen up to day +2. The oral assessment was performed daily until day +30. This group was compared with historical controls, namely 25 patients, who did not receive laser therapy (L- group). RESULTS: All patients developed some grade of mucositis. However, the L- group presented initial mucositis by 4.36 days, whereas the L+ group presented it in 6.12 days (P = 0.01). The maximum mucositis occurred between day +2 and day +6 with healing by day +25 in the L- group and between day +2 and day +7 with healing by day +14 for the L+ group (P = 0.84). Laser therapy also reduced the time of oral pain from 5.64 to 2.45 days (P = 0.04), and decreased the consumption of morphine (P = 0.07). CONCLUSION: This study suggests that laser therapy can be useful in oral mucositis to HSCT patients and improve the patient's quality of life. However, controlled randomized trials should be performed to confirm the real efficacy of laser therapy.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas/efectos adversos , Láseres de Semiconductores/uso terapéutico , Terapia por Luz de Baja Intensidad/métodos , Estomatitis/radioterapia , Adolescente , Adulto , Métodos Epidemiológicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estomatitis/etiología , Estomatitis/prevención & control , Factores de Tiempo
8.
Cell Tissue Res ; 330(1): 161-7, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17704950

RESUMEN

Marked changes in mice pubic symphysis occur by the end of pregnancy. Tissue remodeling involves a dynamic balance between cell proliferation and programmed cell death as well as changes in the extracellular matrix components. Therefore, it is important to consider both of these cellular behaviors when investigating the mechanism that regulates interpubic tissue remodeling, growth during late pregnancy and partus ensuring involution during the postpartum period. Proliferating and programmed death cells were identified by immunohistochemistry (proliferating cell nuclear antigen and TUNEL detection, respectively) and the rates at which these processes occurred were determined by morphometric analysis. The results demonstrated that cellular proliferation was intense during the period of ligament formation, from D15 to D18, thereafter abruptly declining on D19. From parturition (D19) onwards, an ever-increasing decline in the cellular proliferation levels could be observed. The quantitative analyses of cellular death showed opposite results when compared to cellular proliferation. During early pregnancy the cycle of cellular renovation was clearly proliferative and during late mouse pregnancy the cycle was directed by programmed cellular death. Although the high levels of cellular death during postpartum involution could be shown by the TUNEL-positive cells, we were unable to observed picnotic nucleus at the light microscopy.


Asunto(s)
Muerte Celular/fisiología , División Celular/fisiología , Periodo Posparto/fisiología , Sínfisis Pubiana/citología , Sínfisis Pubiana/fisiología , Animales , Apoptosis/fisiología , Femenino , Etiquetado Corte-Fin in Situ , Ratones , Modelos Animales , Embarazo , Antígeno Nuclear de Célula en Proliferación/análisis
9.
Braz J Med Biol Res ; 40(3): 415-24, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17334540

RESUMEN

We measured visual performance in achromatic and chromatic spatial tasks of mercury-exposed subjects and compared the results with norms obtained from healthy individuals of similar age. Data were obtained for a group of 28 mercury-exposed subjects, comprising 20 Amazonian gold miners, 2 inhabitants of Amazonian riverside communities, and 6 laboratory technicians, who asked for medical care. Statistical norms were generated by testing healthy control subjects divided into three age groups. The performance of a substantial proportion of the mercury-exposed subjects was below the norms in all of these tasks. Eleven of 20 subjects (55%) performed below the norms in the achromatic contrast sensitivity task. The mercury-exposed subjects also had lower red-green contrast sensitivity deficits at all tested spatial frequencies (9/11 subjects; 81%). Three gold miners and 1 riverine (4/19 subjects, 21%) performed worse than normal subjects making more mistakes in the color arrangement test. Five of 10 subjects tested (50%), comprising 2 gold miners, 2 technicians, and 1 riverine, performed worse than normal in the color discrimination test, having areas of one or more MacAdam ellipse larger than normal subjects and high color discrimination thresholds at least in one color locus. These data indicate that psychophysical assessment can be used to quantify the degree of visual impairment of mercury-exposed subjects. They also suggest that some spatial tests such as the measurement of red-green chromatic contrast are sufficiently sensitive to detect visual dysfunction caused by mercury toxicity.


Asunto(s)
Percepción de Color/efectos de los fármacos , Defectos de la Visión Cromática/inducido químicamente , Sensibilidad de Contraste/efectos de los fármacos , Mercurio/toxicidad , Enfermedades Profesionales/inducido químicamente , Exposición Profesional/efectos adversos , Adolescente , Adulto , Anciano , Brasil , Estudios de Casos y Controles , Defectos de la Visión Cromática/diagnóstico , Exposición a Riesgos Ambientales/efectos adversos , Contaminantes Ambientales , Humanos , Masculino , Personal de Laboratorio Clínico , Mercurio/orina , Persona de Mediana Edad , Minería , Enfermedades Profesionales/diagnóstico , Espectrofotometría Atómica , Factores de Tiempo
10.
Braz. j. med. biol. res ; 40(3): 415-424, Mar. 2007. tab
Artículo en Inglés | LILACS | ID: lil-441755

RESUMEN

We measured visual performance in achromatic and chromatic spatial tasks of mercury-exposed subjects and compared the results with norms obtained from healthy individuals of similar age. Data were obtained for a group of 28 mercury-exposed subjects, comprising 20 Amazonian gold miners, 2 inhabitants of Amazonian riverside communities, and 6 laboratory technicians, who asked for medical care. Statistical norms were generated by testing healthy control subjects divided into three age groups. The performance of a substantial proportion of the mercury-exposed subjects was below the norms in all of these tasks. Eleven of 20 subjects (55 percent) performed below the norms in the achromatic contrast sensitivity task. The mercury-exposed subjects also had lower red-green contrast sensitivity deficits at all tested spatial frequencies (9/11 subjects; 81 percent). Three gold miners and 1 riverine (4/19 subjects, 21 percent) performed worse than normal subjects making more mistakes in the color arrangement test. Five of 10 subjects tested (50 percent), comprising 2 gold miners, 2 technicians, and 1 riverine, performed worse than normal in the color discrimination test, having areas of one or more MacAdam ellipse larger than normal subjects and high color discrimination thresholds at least in one color locus. These data indicate that psychophysical assessment can be used to quantify the degree of visual impairment of mercury-exposed subjects. They also suggest that some spatial tests such as the measurement of red-green chromatic contrast are sufficiently sensitive to detect visual dysfunction caused by mercury toxicity.


Asunto(s)
Humanos , Masculino , Adolescente , Adulto , Persona de Mediana Edad , Percepción de Color/efectos de los fármacos , Defectos de la Visión Cromática/inducido químicamente , Sensibilidad de Contraste/efectos de los fármacos , Mercurio/toxicidad , Enfermedades Profesionales/inducido químicamente , Exposición Profesional/efectos adversos , Brasil , Estudios de Casos y Controles , Defectos de la Visión Cromática/diagnóstico , Contaminantes Ambientales , Exposición a Riesgos Ambientales/efectos adversos , Personal de Laboratorio , Minería , Mercurio/orina , Enfermedades Profesionales/diagnóstico , Espectrofotometría Atómica , Factores de Tiempo
11.
Environ Int ; 33(1): 56-61, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16930706

RESUMEN

Mercury is a hazardous metal responsible for environmental contamination and human intoxication. Methylmercury, a very toxic organic compound, bio-accumulates through food chain, and is responsible for chronic mercury exposure of riverside Amazonian communities with a diet rich in fish. Uncertainties about the reference exposure dose that could have damaging consequences for nervous system development makes necessary the biomonitoring of these Amazonian populations, especially children. In this work, a comparative study was performed in exposed and non-exposed children living in the Amazon. A total of 168 children were analyzed to find possible correlations between gender, age, location, and hair mercury content. For each location, no statistically significant differences (P<0.05) were detected for gender and age versus mercury content. However, mean mercury levels in hair samples may indicate a tendency of boys to average higher hair concentrations. Also, in the community with highest levels of mercury, the limit of 10 micro g/g of mercury was surpassed by 65% of 2-6 years and 50% of 7-12 years children but only by 27% of 0-1 year babies, pointing to a lower bioaccumulation and/or the existence of a protection mechanism in babies. Log normal distributions of mercury concentrations for each location showed that children from populations under influence of gold mining activity contain the highest mercury levels in hair samples, though this intoxication may have decreased when compared to previous studies. Knowledge originated by this monitoring will better assist in the development of prevention strategies and government actions targeting the mercury contamination of Amazonian environment.


Asunto(s)
Mercurio/análisis , Ríos , Población Rural , Contaminantes Químicos del Agua/análisis , Brasil , Niño , Preescolar , Exposición a Riesgos Ambientales/análisis , Femenino , Cabello/química , Humanos , Lactante , Recién Nacido , Masculino
12.
Acta Radiol ; 47(10): 1029-35, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17135004

RESUMEN

PURPOSE: To evaluate the role of cardiac sympathetic innervation in patients whose clinical features consisted of chest pain, transient ST-segment elevation, left ventricular apical akinesis, minimal elevation of cardiac enzymes, and onset of symptoms shortly after a severe stress condition. MATERIAL AND METHODS: Five female patients, mean age 67+/-14 years, underwent thoracic 123I-MIBG (planar and SPECT) and 67Ga citrate (planar) scans within 5 days after the onset of symptoms. The 123I-MIBG myocardial washout rate between early (30 min) and delayed (3 hours) planar images was calculated. All patients presented findings consistent with takotsubo-like syndrome. Echocardiograms showed the characteristic wall motion pattern of significant apical dysfunction. Acute-phase coronary angiographies revealed a non-obstructive pattern. A peculiar apical akinesis and basal normokinesis were observed on the ventriculograms. RESULTS: Impairment of cardiac neuronal uptake of 123I-MIBG based on a reduction of the heart-to-mediastinum uptake ratio was observed in all patients, while the washout rate was raised in four patients. All patients presented an apical uptake defect in the 123I-MIBG SPECT and planar images and a normal 67Ga scintigraphy. CONCLUSION: Our data indicate that ampulla cardiomyopathy (AC) is associated with a cardiac sympathetic innervation deficit characterized by a reduced global 123I-MIBG uptake and an apical uptake defect. The lack of 67Ga uptake in the acute phase of this syndrome indicates that AC is probably not associated with an inflammatory process.


Asunto(s)
3-Yodobencilguanidina , Cardiomiopatías/diagnóstico por imagen , Aturdimiento Miocárdico/diagnóstico por imagen , Radiofármacos , Tomografía Computarizada de Emisión de Fotón Único , Disfunción Ventricular Izquierda/diagnóstico por imagen , Anciano , Citratos , Angiografía Coronaria , Ecocardiografía , Femenino , Galio , Humanos , Persona de Mediana Edad , Sensibilidad y Especificidad , Síndrome
13.
Braz. j. med. biol. res ; 39(3): 411-414, Mar. 2006. ilus, graf
Artículo en Inglés | LILACS | ID: lil-421369

RESUMEN

Four populations in the Amazon area were selected for a comparative study of mercury-exposed and non-exposed populations: São Luiz do Tapajós, Barreiras, Panacauera, and Pindobal Grande. The highest mercury levels in human hair samples were found in São Luiz do Tapajós and Barreiras, greatly exceeding the limits established by the World Health Organization. Panacauera showed an intermediate level below 9 µg/g. This was the first comparative and simultaneous evaluation of mercury exposure in the Amazon area. Also, thanks to this type of monitoring, we were able to eliminate the uncertainties about the reference dose. On the basis of these data, we can conclude that the mercury levels detected in exposed populations of the Tapajós River basin may be dangerous not only because they are above the World Health Organization limits, but also because the simultaneous mercury detection in non-exposed populations with similar characteristics provided a valid control and revealed lower mercury levels. Our results support the importance of continuous monitoring in both exposed and non-exposed populations.


Asunto(s)
Adolescente , Adulto , Anciano , Humanos , Persona de Mediana Edad , Exposición a Riesgos Ambientales/análisis , Cabello/química , Mercurio/análisis , Ríos/química , Brasil , Monitoreo del Ambiente/métodos
14.
Braz J Med Biol Res ; 39(3): 411-4, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16501821

RESUMEN

Four populations in the Amazon area were selected for a comparative study of mercury-exposed and non-exposed populations: São Luiz do Tapajós, Barreiras, Panacauera, and Pindobal Grande. The highest mercury levels in human hair samples were found in São Luiz do Tapajós and Barreiras, greatly exceeding the limits established by the World Health Organization. Panacauera showed an intermediate level below 9 microg/g. This was the first comparative and simultaneous evaluation of mercury exposure in the Amazon area. Also, thanks to this type of monitoring, we were able to eliminate the uncertainties about the reference dose. On the basis of these data, we can conclude that the mercury levels detected in exposed populations of the Tapajós River basin may be dangerous not only because they are above the World Health Organization limits, but also because the simultaneous mercury detection in non-exposed populations with similar characteristics provided a valid control and revealed lower mercury levels. Our results support the importance of continuous monitoring in both exposed and non-exposed populations.


Asunto(s)
Exposición a Riesgos Ambientales/análisis , Cabello/química , Mercurio/análisis , Ríos/química , Adolescente , Adulto , Anciano , Brasil , Monitoreo del Ambiente/métodos , Humanos , Persona de Mediana Edad
15.
Sci Total Environ ; 349(1-3): 284-8, 2005 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-16091288

RESUMEN

The aim of the present study was to evaluate mercury and selenium concentrations in hair samples of reproductive age women from riverside communities of the Tapajós River basin. We studied 19 pregnant and 21 non-pregnant women, 13 to 45 years old, living in the region for at least 2 years, and having a diet rich in fish. The analysis of Se and total Hg were performed in the Instituto de Pesquisas Energéticas e Nucleares (IPEN, São Paulo, Brazil) by using a Varian AA220-FS atomic absorption spectrometer with a flow injection system. There were no differences between the two groups - pregnant and non-pregnant -- concerning age (23.80 +/- 6.92 and 26.60 +/- 9.60 years old, respectively) and residential time (20.21 +/- 8.30 and 22.20 +/- 10.90 years, respectively). The geometric means and ranges for total Hg concentration were similar (p > 0.05): 8.25 microg/g (1.51-19.43) in pregnant and 9.39 microg/g (5.25-21.00) in non-pregnant women, respectively. Total Hg concentrations were also similar in different gestational stages. However, there was a significant difference between the two groups (p < 0.05, Student t test) in relation to Se concentration: 0.61 microg/g (0.40-2.33) in pregnant and 2.46 microg/g (0.92-5.74) in non-pregnant women, respectively. We concluded that Hg exposure levels in reproductive age women were only slightly higher than a provisional tolerable weekly intake of MeHg would provide, that Hg concentration in maternal hair samples was independent of gestational age, and that low Se concentration in pregnant women indicates high mineral consumption by fetal organism to satisfy their metabolic requirements raised during pregnancy, including as a protective mechanism for Hg cytotoxic effects.


Asunto(s)
Contaminantes Ambientales/análisis , Contaminación de Alimentos , Cabello/química , Mercurio/análisis , Selenio/análisis , Adolescente , Adulto , Animales , Brasil , Monitoreo del Ambiente , Contaminantes Ambientales/metabolismo , Femenino , Peces , Humanos , Mercurio/metabolismo , Persona de Mediana Edad , Embarazo , Ríos , Selenio/metabolismo
16.
Cell Biol Int ; 29(6): 458-71, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15951206

RESUMEN

During pregnancy, an interpubic ligament is formed in the mouse pubic symphysis. In late stages, this ligament undergoes "relaxation" to allow proper delivery, which is expected on the 19th day. Proteoglycans and hyaluronic acid play an important role in the remodeling of the extracellular matrix in these tissues. Glycosaminoglycans and proteoglycans were studied by electron microscopic, immunohistochemical and biochemical methods in samples of mouse pubic symphysis from the 12th to 18th day of pregnancy. At the ultrastructural level, using cuprolinic blue and enzymatic digestion by chondroitin lyases, two types of proteoglycan filaments were observed in the fibrocartilage on the 12th day, as well as in D 15, D 17 and D 18 pubic ligaments. The only sulfated glycosaminoglycan in these filaments was chondroitin sulfate, as shown by chondroitin lyase treatment. Their electrophoretic mobility, before and after enzymatic degradation, corroborated this inference. The ratio of chondroitin sulfate/dry weight of symphysis showed two phases of increase: between D12 and D 15, and between D 17 and D 18. We suggest that the first corresponds mainly to an increase in decorin when the ligament is formed, and the second to versican, during "relaxation". Versican and hyaluronic acid, working as water holding molecules would be responsible for the hydration of the ligament at the end of pregnancy, allowing an increase in resiliency. The presence of hyaluronic acid was confirmed by labeling with HA-probe in the perichondrium, fibrocartilage and ligament. The role of collagen fibers as physical restrictors of the complete expansion of glycosaminoglycans and hyaluronic acid in tissue is discussed.


Asunto(s)
Glicosaminoglicanos/análisis , Glicosaminoglicanos/ultraestructura , Preñez/fisiología , Proteoglicanos/análisis , Proteoglicanos/ultraestructura , Sínfisis Pubiana/metabolismo , Sínfisis Pubiana/ultraestructura , Animales , Condroitín Liasas/metabolismo , Electroforesis en Gel de Agar , Femenino , Glicosaminoglicanos/química , Ácido Hialurónico/análisis , Inmunohistoquímica , Indoles/farmacología , Ratones , Compuestos Organometálicos/farmacología , Embarazo , Proteoglicanos/química , Azufre/química
17.
Micron ; 35(8): 685-93, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15288647

RESUMEN

Reference is usually made to the parallel orientation towards the main line of exerted tension at the pubic joint in mice, for supporting forces applied to the joint. Despite the wealth of morphological information about the extracellular matrix in this joint, little is known regarding the involvement of the crimp of collagen fibers in the dramatic transformations occurring in this region during the last 3 days of pregnancy. Examination of the collagenous architecture suggests that the biomechanical properties are directly related to fibril diameters, composition of ground substance and changes in the bundle morphology, particularly in the crimp structure. The purpose of this study was to further describe the transformation of the collagen fibers of the pubic symphysis during late mouse pregnancy. We examined the architecture of collagen fibers in the symphysis and pubic ligament through the Picrosirius-polarization method and also through scanning electron microscopy to directly visualize and measure the crimping from pregnant and virgin mice. The crimp angle and the length of five consecutive crimps were measured according to Patterson-Kane et al. [Connect. Tissue Res. 36 (1997) 253]. It could be demonstrated that the angles progressively decreased and the crimp length increased, denoting that the fibers have untwisted during the relaxation process. Our findings suggest that a disruption of the helical arrangement of the collagen containing fibers may contribute to explaining the rapid remodeling that occurs at the end of pregnancy and that is responsible for an increase in pliancy and length of the pubic ligament in mice.


Asunto(s)
Colágeno/ultraestructura , Preñez/metabolismo , Sínfisis Pubiana/ultraestructura , Animales , Colágeno/metabolismo , Femenino , Ratones , Microscopía Electrónica de Rastreo , Embarazo , Sínfisis Pubiana/citología
18.
Environ Int ; 27(4): 285-90, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11686639

RESUMEN

There is increasing concern about the potential neurotoxic effects of exposure to methylmercury for the 6 million people living in the Amazon, even in regions situated far away from the gold mines (garimpos), considered to be the major source of mercury pollution. In November 1998, a spot investigation on mercury contamination was conducted in three fishing villages (Barreiras, Rainha, and Sao Luiz do Tapajos) on the Tapajos River, an effluent of the Amazon, situated several hundred kilometers downstream from the gold-mining areas. A total of 132 fishermen and their families volunteered for the current study. As was anticipated, the total mercury levels in the head hair collected from the fishing villages were relatively high (14.1-20.8 ppm on the average) and the number of subjects with a high total mercury level over 10 ppm (the least upper bound of a normal value) was 103 (78.0%) in total, along with various symptoms, thereby suggesting wide mercury contamination in the Tapajos River basin. Moreover, in view of the absence of other diseases (e.g., alcoholism or malaria), a high intake of fish containing a methylmercury level, and high hair mercury levels in addition to the various symptoms such as sensory disturbance (especially glove-and-stocking type, which is characteristic of Minamata disease), tremor, failure in two-point discrimination, and slight balancing failure, several subjects examined were diagnosed with mild Minamata disease. The findings obtained suggest, thus, that the mercury pollution in the Amazon should be crucially observed for head hair mercury level and health in a much broader region.


Asunto(s)
Contaminación de Alimentos/análisis , Cabello/química , Intoxicación del Sistema Nervioso por Mercurio/etiología , Mercurio/análisis , Mercurio/toxicidad , Contaminación Química del Agua , Adolescente , Adulto , Anciano , Animales , Brasil , Niño , Preescolar , Femenino , Peces , Humanos , Lactante , Masculino , Persona de Mediana Edad , Exposición Profesional
19.
Rev Soc Bras Med Trop ; 33(2): 181-4, 2000.
Artículo en Portugués | MEDLINE | ID: mdl-10881131

RESUMEN

This study evaluates human exposure to methylmercury in fishermen and their families in four villages on the Tapajós river: Rainha, Barreiras, São Luís do Tapajós and Paraná-Mirim. Hair analyses were performed with atomic absorption spectophotometry. Total hair mercury levels varied between 2.9mg/g and 71.5mg/g. Paraná-Mirim showed the lowest level. The highest level was found in São Luís do Tapajós and Barreiras. The hair mercury was six to seven times higher than the established safe limit of 10mg/g. No statistically significant difference was found between the mean level of total mercury taken from the inhabitants living downstream and upstream in Itaituba village (p > 0.05). These results confirm that human exposure to methylmercury is occurring on the Tapajós river and suggest that continued fish ingestion in that region is a potential risk factor for the appearance of symptoms and signs of Minamata disease. An immediate epidemiological survey program is recommended.


Asunto(s)
Cabello/química , Mercurio/análisis , Población Rural , Animales , Brasil , Exposición a Riesgos Ambientales/efectos adversos , Peces , Humanos , Contaminantes Químicos del Agua/análisis
20.
Rev Bras Enferm ; 50(2): 197-214, 1997.
Artículo en Portugués | MEDLINE | ID: mdl-9775933

RESUMEN

The theme of this research refers to children suffering congenital malformation through an analysis of their mothers' reactions in dealing with such a situation. It deals with a descriptive study along the qualitative line through the phenomenological approach. In order to attain that purpose, interviews were made and data collected. The analysis was built under the view of meaning, the orientation of those mothers, i.e. the outlook of the world from their perspective, which was tracked from the meanings (units of meaning) to actual sense based on the philosophical insight of Dr. Martin Heidegger, aiming at characterizing the mother-being in her daily life.


Asunto(s)
Actitud Frente a la Salud , Anomalías Congénitas/psicología , Relaciones Madre-Hijo , Madres/psicología , Niño , Existencialismo , Humanos , Investigación Metodológica en Enfermería , Encuestas y Cuestionarios
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