Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Más filtros











Intervalo de año de publicación
1.
PeerJ ; 11: e14651, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36650841

RESUMEN

The biogeographic region of Argentinean Puna mainly extends at elevations higher than 3,000 m within the Andean Plateau and hosts diverse ecological communities highly adapted to extreme aridity and low temperatures. Soils of Puna are typically poorly evolved and geomorphology is shaped by drainage networks, resulting in highly vegetated endorheic basins and hypersaline basins known as salar or salt flats. Local communities rely on soil fertility for agricultural practices and on pastures for livestock rearing. From this perspective, investigating the scarcely explored microbiological diversity of these soils as indicators of ecosystems functioning might help to predict the fragility of these harsh environments. In this study we collected soil samples from 28 points, following a nested design within three different macro-habitats, i.e., Puna grassland, hypersaline salar and family-run crop fields. Total fungi and arbuscular mycorrhizal fungi (AMF) occurrence were analyzed using eDNA sequencing. In addition, the significance of soil salinity and organic matter content as significant predictors of AMF occurrence, was assessed through Generalized Linear Mixed Modeling. We also investigated whether intensive grazing by cattle and lama in Puna grasslands may reduce the presence of AMF in these highly disturbed soils, driving or not major ecological changes, but no consistent results were found, suggesting that more specific experiments and further investigations may address the question more specifically. Finally, to predict the suitability for AMF in the different macro-habitats, Species Distribution Modeling (SDM) was performed within an environmental coherent area comprising both the phytogeographic regions of Puna and Altoandino. We modeled AMF distribution with a maximum entropy approach, including bioclimatic and edaphic predictors and obtaining maps of environmental suitability for AMF within the predicted areas. To assess the impact of farming on AMF occurrence, we set a new series of models excluding the cultivated Chaupi Rodeo samples. Overall, SDM predicted a lower suitability for AMF in hypersaline salar areas, while grassland habitats and a wider temperature seasonality range appear to be factors significantly related to AMF enrichment, suggesting a main role of seasonal dynamics in shaping AMF communities. The highest abundance of AMF was observed in Vicia faba crop fields, while potato fields yielded a very low AMF occurrence. The models excluding the cultivated Chaupi Rodeo samples highlighted that if these cultivated areas had theoretically remained unmanaged habitats of Puna and Altoandino, then large-scale soil features and local bioclimatic constraints would likely support a lower suitability for AMF. Using SDM we evidenced the influence of bioclimatic, edaphic and anthropic predictors in shaping AMF occurrence and highlighted the relevance of considering human activities to accurately predict AMF distribution.


Asunto(s)
Micorrizas , Humanos , Animales , Bovinos , Micorrizas/genética , Suelo , Ecosistema , Entropía , Agricultura/métodos
2.
Medicina (B Aires) ; 66(6): 526-32, 2006.
Artículo en Español | MEDLINE | ID: mdl-17240623

RESUMEN

UNLABELLED: The thyroid carcinoma (TC) is not very frequent among all cancers. Its course is slow and is high potentially curable. Our aim was to analyse the characteristics in patients with TC. A retrospective analysis on 171 patients, with an average age of 41.1 (+/- 14.6), who asked for TC to our service between the years 2000-04, was performed. From case histories it was evaluated: anamnesis, diagnostic image, histopathology and evolution. Tumours were grouped for size and TNM (tumour-nodule-metastasis) in stages (S). A stimulated serum thyroglobulin level >2 ng/ml and positive image with 131I or another nuclear marker were considered as positive for residual TC. In the totality of the analyzed patients 88% were female, 62% below 45 years old, and in 77% the thyroid function was normal. The fine needle aspiration (FNA) was diagnostic in 78%. Papillary thyroid carcinoma (PTC) in 96%. The 63% was SI; 14% SII; 19% SIII and 4% SIV. During follow-up, we observed that 90% of patients with Tg between 2 and 10 had evidence of residual TC, and 100% with Tg >10 ng/ml, whereas 18% of those whose stimulated Tg <2 presented positive image. There was not found significative correlation with pathologic antecedents or relevant image signs. IN CONCLUSION: TCP was the most frequent carcinoma in women, in patients younger than 45 years and in those who have euthyroid function. A stimulated serum thyroglobulin level was a good indicator for residual TC, but failed to select those patients who were disease free.


Asunto(s)
Carcinoma Papilar/patología , Neoplasias de la Tiroides/patología , Adulto , Biomarcadores de Tumor/sangre , Carcinoma Papilar/sangre , Femenino , Bocio Nodular/sangre , Bocio Nodular/patología , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasia Residual , Pronóstico , Estudios Retrospectivos , Factores Sexuales , Tiroglobulina/sangre , Neoplasias de la Tiroides/sangre , Nódulo Tiroideo/sangre , Nódulo Tiroideo/patología , Tirotropina/sangre
3.
Medicina (B.Aires) ; Medicina (B.Aires);66(6): 526-532, 2006. tab
Artículo en Español | BINACIS | ID: bin-119055

RESUMEN

Entre todos los tumores, el carcinoma tiroideo (CT) es poco frecuente, se caracteriza por su lenta evolución y elevado porcentaje de curación. Nuestro objetivo es estudiar las características de los pacientes con CT. Analizamos retrospectivamente a 171 pacientes, edad media al diagnóstico 41.1( ± 14.6 años), que consultaron entre los años 2000-04 por CT. Se evaluaron datos de anamnesis, métodos de diagnóstico, anatomía patológica y evolución. Agrupamos a los tumores por el tamaño y según TNM (tumor-adenopatía-metástasis) en estadios (E). La presencia de tiroglobulina estimulada (Tg) > 2 ng/ml e imagen positiva (con 131I u otro radiotrazador) fueron consideradas como positivas para CT residual. De la población total el 88% fue sexo femenino, el 62% menores de 45 años, y el 77.1% tuvo función tiroidea normal. La punción con aguja fina (PAAF) fue diagnóstica en 78%. El 96% fue carcinoma papilar (CTP), 63% presentaban E I; 14% E II; 19% E III y 4% E IV. Se detectó CT residual en el 90% de los pacientes con Tg entre 2 y 10, y en el 100% con Tg > 10 ng/ml, mientras que con Tg < 2 el 18% mostró imagen positiva. No encontramos correlación significativa con antecedentes patológicos ni con ningún signo relevante en imágenes. En conclusión, en nuestra población el CTP fue predominante. Más frecuente en mujeres, en menores de 45 años y en eutiroideos. El nivel de Tg estimulada es un buen indicador de CT residual, pero no es una prueba suficiente para seleccionar pacientes libres de enfermedad (AU)


The thyroid carcinoma (TC) is not very frequent among all cancers. Its course is slow and is high potentially curable. Our aim was to analyse the characteristics in patients with TC. A retrospective analysis on 171 patients, with an average age of 41.1 (±14,6), who asked for TC to our service between the years 2000-04, was performed. From case histories it was evaluated: anamnesis, diagnostic image, histopathology and evolution. Tumours were grouped for size and TNM (tumour-nodule-metastasis) in stages (S). A stimulated serum thyroglobulin level > 2 ng/ml and positive image with 131I or another nuclear marker were considered as positive for residual TC. In the totality of the analyzed patients 88% were female, 62% below 45 years old, and in 77% the thyroid function was normal. The fine needle aspiration (FNA) was diagnostic in 78%. Papillary thyroid carcinoma (PTC) in 96%. The 63% was SI; 14% SII; 19% SIII and 4% SIV. During follow-up, we observed that 90% of patients with Tg between 2 and 10 had evidence of residual TC, and 100% with Tg > 10 ng/ml, whereas 18% of those whose stimulated Tg < 2 presented positive image. There was not found significative correlation with pathologic antecedents or relevant image signs. In conclusion: TCP was the most frequent carcinoma in women, in patients younger than 45 years and in those who have euthyroid function. A stimulated serum thyroglobulin level was a good indicator for residual TC, but failed to select those patients who were disease free (AU)


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Neoplasias de la Tiroides/patología , Carcinoma Papilar/patología , Neoplasias de la Tiroides/sangre , Carcinoma Papilar/sangre , Nódulo Tiroideo/sangre , Nódulo Tiroideo/patología , Bocio Nodular/sangre , Bocio Nodular/patología , Tirotropina/sangre , Tiroglobulina/sangre , Biomarcadores de Tumor/sangre , Neoplasia Residual , Estadificación de Neoplasias , Metástasis de la Neoplasia , Pronóstico , Biopsia con Aguja Fina , Microscopía de Túnel de Rastreo , Estudios Retrospectivos , Factores Sexuales , Tomógrafos Computarizados por Rayos X , Espectroscopía de Resonancia Magnética
4.
Medicina (B.Aires) ; Medicina (B.Aires);66(6): 526-532, 2006. tab
Artículo en Español | BINACIS | ID: bin-123176

RESUMEN

Entre todos los tumores, el carcinoma tiroideo (CT) es poco frecuente, se caracteriza por su lenta evolución y elevado porcentaje de curación. Nuestro objetivo es estudiar las características de los pacientes con CT. Analizamos retrospectivamente a 171 pacientes, edad media al diagnóstico 41.1( ± 14.6 años), que consultaron entre los años 2000-04 por CT. Se evaluaron datos de anamnesis, métodos de diagnóstico, anatomía patológica y evolución. Agrupamos a los tumores por el tamaño y según TNM (tumor-adenopatía-metástasis) en estadios (E). La presencia de tiroglobulina estimulada (Tg) > 2 ng/ml e imagen positiva (con 131I u otro radiotrazador) fueron consideradas como positivas para CT residual. De la población total el 88% fue sexo femenino, el 62% menores de 45 años, y el 77.1% tuvo función tiroidea normal. La punción con aguja fina (PAAF) fue diagnóstica en 78%. El 96% fue carcinoma papilar (CTP), 63% presentaban E I; 14% E II; 19% E III y 4% E IV. Se detectó CT residual en el 90% de los pacientes con Tg entre 2 y 10, y en el 100% con Tg > 10 ng/ml, mientras que con Tg < 2 el 18% mostró imagen positiva. No encontramos correlación significativa con antecedentes patológicos ni con ningún signo relevante en imágenes. En conclusión, en nuestra población el CTP fue predominante. Más frecuente en mujeres, en menores de 45 años y en eutiroideos. El nivel de Tg estimulada es un buen indicador de CT residual, pero no es una prueba suficiente para seleccionar pacientes libres de enfermedad (AU)


The thyroid carcinoma (TC) is not very frequent among all cancers. Its course is slow and is high potentially curable. Our aim was to analyse the characteristics in patients with TC. A retrospective analysis on 171 patients, with an average age of 41.1 (±14,6), who asked for TC to our service between the years 2000-04, was performed. From case histories it was evaluated: anamnesis, diagnostic image, histopathology and evolution. Tumours were grouped for size and TNM (tumour-nodule-metastasis) in stages (S). A stimulated serum thyroglobulin level > 2 ng/ml and positive image with 131I or another nuclear marker were considered as positive for residual TC. In the totality of the analyzed patients 88% were female, 62% below 45 years old, and in 77% the thyroid function was normal. The fine needle aspiration (FNA) was diagnostic in 78%. Papillary thyroid carcinoma (PTC) in 96%. The 63% was SI; 14% SII; 19% SIII and 4% SIV. During follow-up, we observed that 90% of patients with Tg between 2 and 10 had evidence of residual TC, and 100% with Tg > 10 ng/ml, whereas 18% of those whose stimulated Tg < 2 presented positive image. There was not found significative correlation with pathologic antecedents or relevant image signs. In conclusion: TCP was the most frequent carcinoma in women, in patients younger than 45 years and in those who have euthyroid function. A stimulated serum thyroglobulin level was a good indicator for residual TC, but failed to select those patients who were disease free (AU)


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Neoplasias de la Tiroides/patología , Carcinoma Papilar/patología , Neoplasias de la Tiroides/sangre , Carcinoma Papilar/sangre , Nódulo Tiroideo/sangre , Nódulo Tiroideo/patología , Bocio Nodular/sangre , Bocio Nodular/patología , Tirotropina/sangre , Tiroglobulina/sangre , Biomarcadores de Tumor/sangre , Neoplasia Residual , Estadificación de Neoplasias , Metástasis de la Neoplasia , Pronóstico , Biopsia con Aguja Fina , Microscopía de Túnel de Rastreo , Estudios Retrospectivos , Factores Sexuales , Tomógrafos Computarizados por Rayos X , Espectroscopía de Resonancia Magnética
5.
Medicina (B.Aires) ; Medicina (B.Aires);66(6): 526-532, 2006. tab
Artículo en Español | LILACS | ID: lil-453020

RESUMEN

Entre todos los tumores, el carcinoma tiroideo (CT) es poco frecuente, se caracteriza por su lenta evolución y elevado porcentaje de curación. Nuestro objetivo es estudiar las características de los pacientes con CT. Analizamos retrospectivamente a 171 pacientes, edad media al diagnóstico 41.1( ± 14.6 años), que consultaron entre los años 2000-04 por CT. Se evaluaron datos de anamnesis, métodos de diagnóstico, anatomía patológica y evolución. Agrupamos a los tumores por el tamaño y según TNM (tumor-adenopatía-metástasis) en estadios (E). La presencia de tiroglobulina estimulada (Tg) > 2 ng/ml e imagen positiva (con 131I u otro radiotrazador) fueron consideradas como positivas para CT residual. De la población total el 88% fue sexo femenino, el 62% menores de 45 años, y el 77.1% tuvo función tiroidea normal. La punción con aguja fina (PAAF) fue diagnóstica en 78%. El 96% fue carcinoma papilar (CTP), 63% presentaban E I; 14% E II; 19% E III y 4% E IV. Se detectó CT residual en el 90% de los pacientes con Tg entre 2 y 10, y en el 100% con Tg > 10 ng/ml, mientras que con Tg < 2 el 18% mostró imagen positiva. No encontramos correlación significativa con antecedentes patológicos ni con ningún signo relevante en imágenes. En conclusión, en nuestra población el CTP fue predominante. Más frecuente en mujeres, en menores de 45 años y en eutiroideos. El nivel de Tg estimulada es un buen indicador de CT residual, pero no es una prueba suficiente para seleccionar pacientes libres de enfermedad


The thyroid carcinoma (TC) is not very frequent among all cancers. Its course is slow and is high potentially curable. Our aim was to analyse the characteristics in patients with TC. A retrospective analysis on 171 patients, with an average age of 41.1 (±14,6), who asked for TC to our service between the years 2000-04, was performed. From case histories it was evaluated: anamnesis, diagnostic image, histopathology and evolution. Tumours were grouped for size and TNM (tumour-nodule-metastasis) in stages (S). A stimulated serum thyroglobulin level > 2 ng/ml and positive image with 131I or another nuclear marker were considered as positive for residual TC. In the totality of the analyzed patients 88% were female, 62% below 45 years old, and in 77% the thyroid function was normal. The fine needle aspiration (FNA) was diagnostic in 78%. Papillary thyroid carcinoma (PTC) in 96%. The 63% was SI; 14% SII; 19% SIII and 4% SIV. During follow-up, we observed that 90% of patients with Tg between 2 and 10 had evidence of residual TC, and 100% with Tg > 10 ng/ml, whereas 18% of those whose stimulated Tg < 2 presented positive image. There was not found significative correlation with pathologic antecedents or relevant image signs. In conclusion: TCP was the most frequent carcinoma in women, in patients younger than 45 years and in those who have euthyroid function. A stimulated serum thyroglobulin level was a good indicator for residual TC, but failed to select those patients who were disease free


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Carcinoma Papilar/patología , Neoplasias de la Tiroides/patología , Biopsia con Aguja Fina , Carcinoma Papilar/sangre , Bocio Nodular/sangre , Bocio Nodular/patología , Espectroscopía de Resonancia Magnética , Microscopía de Túnel de Rastreo , Metástasis de la Neoplasia , Estadificación de Neoplasias , Neoplasia Residual , Pronóstico , Estudios Retrospectivos , Factores Sexuales , Tomógrafos Computarizados por Rayos X , Tiroglobulina/sangre , Neoplasias de la Tiroides/sangre , Nódulo Tiroideo/sangre , Nódulo Tiroideo/patología , Tirotropina/sangre , Biomarcadores de Tumor/sangre
6.
J Nucl Med ; 43(1): 61-5, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11801704

RESUMEN

UNLABELLED: A dose limit-based criterion was proposed to authorize hospital discharge of thyroid carcinoma patients treated with 131I. Evaluation of accumulated doses to determine the effective half-life, the expected accumulated dose at 1 m, and the hospitalization time was performed to ensure that the dose limit was satisfied for each patient. Situations involving different dose limits and occupancy factors were analyzed. This study dealt only with external exposure; the problem of internal contamination was not considered. METHODS: Fourteen patients treated postoperatively with 131I were studied. The range of activity was 1,110-8,175 MBq. Electronic dosimeters and thermoluminescent dosimeter chips were placed on the left pectoral muscle. Dose was measured for a mean of approximately 2.5 d. The accumulated doses were plotted as a function of time and then fitted using an exponential model to obtain the parameters of total accumulated dose and effective half-life. The doses to the public and relatives at 1 m were calculated with point source approximation and several occupancy factors. RESULTS: The fit function parameters of accumulated doses in the first 36 h predicted the behavior of the total accumulated dose within a 5% error in the parameters. Estimated values of the accumulated dose 1 m from the patient were generally <5 mSv, even for an occupancy factor of 100%. For more restrictive dose constraints, hospitalization times were calculated according to different occupancy factors, as suggested in the European Commission guide. From the fit of the measured data, values of effective half-life for each patient were obtained. CONCLUSION: To apply the dose limit-based criterion, one must calculate the patient-specific parameters, as can be done using the accumulated dose. Knowledge of patient-specific parameters ensures that the patient will not expose any individual to levels greater than the dose limit. The calculated hospitalization times were less than those recommended, especially for countries with more restrictive dose limits. The type of measurements performed in this study reveals more realistic doses for the treatment of thyroid carcinoma with 131I.


Asunto(s)
Radioisótopos de Yodo/uso terapéutico , Protección Radiológica , Neoplasias de la Tiroides/radioterapia , Adolescente , Adulto , Femenino , Semivida , Humanos , Radioisótopos de Yodo/administración & dosificación , Tiempo de Internación , Masculino , Persona de Mediana Edad , Alta del Paciente , Aislamiento de Pacientes , Radiometría , Dosificación Radioterapéutica , Dosimetría Termoluminiscente
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA