10 research outputs found
Radioactive Iodine Administration Is Associated with Persistent Related Symptoms in Patients with Differentiated Thyroid Cancer
Context. Radioiodine (RAI) administration has adverse effects in patients treated for thyroid cancer (DTC), but there is scarce information regarding their intensity and duration. Objective. To evaluate frequency and intensity of early and late RAI-related symptoms in patients with DTC. Design. Observational prospective study. Patients. DTC patients who underwent thyroidectomy, with or without RAI. Measurements. Patients answered 2 surveys: (1) from 0 to 6 months and (2) between 6 and 18 months after initial treatment. Results. 110 patients answered the first survey and 61 both. Nearly 80 percent received RAI. Among early symptoms, periorbital edema, excessive tearing, salivary gland disturbances, dry mouth, taste disorders, and nausea were more frequent and intense among RAI patients. Regarding late symptoms, periorbital edema, salivary gland pain and swelling, and dry mouth were more frequent and intense in RAI patients. Frequency and intensity of adverse effects were not different between low and high RAI doses (50 versus ≥100 mCi). Conclusion. RAI-related symptoms are frequent and usually persist after 6 months of administration, even when low doses are given. This finding must be considered when deciding RAI administration, especially in low risk patients, among whom RAI benefit is controversial
Estimación de parámetros modales variables en el tiempo empleando técnicas Bayesianas y de Newton-Raphson a partir de registros sísmicos
Memoria para optar al título de Ingeniero CivilUsualmente, la modelación de la respuesta sísmica de estructuras es realizada considerando un modelo lineal-elástico en donde se supone que las propiedades dinámicas (frecuencias naturales, formas modales y tasas de amortiguamiento) son invariables en el tiempo. Sin embargo, se ha comprobado que los parámetros modales en estructuras instrumentadas y sujetas a cargas sísmicas pueden variar significativamente durante el tiempo debido a efectos no-lineales que pueden ser atribuidos ya sea a daño de la estructura y/o a otros factores de difícil modelación como son la variación de sus tasas de amortiguamiento debido a la interacción no-lineal con el aire, el suelo y/o con otros elementos no-estructurales. Esto no significa necesariamente una degradación estructural propiamente tal, sino que corresponde a un comportamiento normal que la estructura experimenta durante eventos sísmicos.
El edificio BNCS de san Diego fue densamente instrumentado y ensayado en mesa vibradora justamente con el propósito de estudiar el comportamiento durante eventos sísmicos y cuenta con registros de varios eventos de mediana a alta intensidad. Como resultado, se espera generar una rutina en el programa MATLAB que permita estimar como cambian los parámetros dinámicos (frecuencias, razones de amortiguamiento y formas modales) en el tiempo a través del ajuste de un modelo modal no-lineal con la respuesta medida, cuando el edificio se ve sujeto a movimientos sísmicos. En este contexto, el ajuste de los parámetros dinámicos se realizará con técnicas Bayesianas, las cuales son metodologías que han sido introducidas en el tópico de identificación estructural hace corto tiempo mostrando resultados alentadores. A diferencia de lo realizado en el estado del arte, no se busca calibrar parámetros de modelos de elementos finitos (como se realiza con métodos Bayesianos) sino que se estimará directamente las propiedades dinámicas de la estructura. Para identificar la variación temporal de las propiedades dinámicas se utilizarán métodos Bayesianos que ajusten los parámetros modales por pequeñas y/o medianas ventanas de tiempo.
Complementariamente el ajuste de las propiedades modales se realizará a través de métodos de optimización con Newton-Raphson de forma complementaria a la estimación Bayesiana con el fin de obtener parámetros lo más cercanos a la realidad. En este contexto se observará que la optimización de N-R presenta resultados más alentadores
Actualización en el uso de la biopsia de piel por punch
ResumenLa biopsia punch es una herramienta diagnóstica útil en el estudio de las enfermedades cutáneas, particularmente en dermatología. En los últimos años se han desarrollado nuevas técnicas con usos que van más allá del diagnóstico y se incluyen en el campo de la terapéutica médica, dermatológica y cirugía general. El objetivo de la presente revisión es servir de actualización en biopsia punch, también llamada en sacabocados, tanto para médicos especialistas como no especialistas.AbstractPunch biopsy was considered a sole diagnostic method for years. In the former years, new techniques have been developed. New uses now consider punch biopsy an essential part of the therapeutic arsenal in both dermatology and general surgery. The objective of this review is to serve as an update in punch biopsy
In properly selected patients with differentiated thyroid cancer, antithyroglobulin antibodies decline after thyroidectomy and their sole presence should not be an indication for radioiodine ablation
ABSTRACT Objective Our objective was to evaluate the trend of antithyroglobulin antibodies (TgAb) during follow-up of patients with differentiated thyroid cancer (DTC) treated without RAI, as well as their role in the risk of recurrence. Subjects and methods This was a prospective, descriptive study. A total of 152 consecutive patients with DTC treated in a single institution undergoing total thyroidectomy without RAI and followed for a median of 2.3 years (0.5-10.3) were divided in two groups: TgAb(-) (n = 111) and TgAb(+) (n = 41). Patients were classified according to AJCC 7th and 8th editions, as well as to their risk of recurrence and response to treatment categories. Results Both groups, TgAb(-) and TgAb(+), were similar regarding patient and tumor characteristics. At the end of follow-up, 90 (59.2%), 57 (37.5%), 3 (2%) and 2 (1.3%) patients achieved excellent, indeterminate, biochemically incomplete and structurally incomplete response, respectively. The risk of structural recurrence was similar in both groups (TgAb[-] 0.9% vs. TgAb[+] 2.4%, p = 0.46). In the TgAb(+) group, TgAb became negative in 10 (24.4%), decreased ≥ 50% without negativization in 25 (60.9%), decreased < 50% in 4 (9.8%) and remained stable or increased in 2 (4.9%) cases. The only incomplete structural response had increasing TgAb during follow-up. Conclusions In properly selected patients with DTC, TgAb concentration immediately after total thyroidectomy should not mandate RAI ablation, and their trend during follow-up may impact the risk of recurrence
Papillary thyroid microcarcinoma: characteristics at presentation, and evaluation of clinical and histological features associated with a worse prognosis in a Latin American cohort
ABSTRACT Objective We aimed to describe the presentation of papillary microcarcinoma (PTMC) and identify the clinical and histological features associated with persistence/recurrence in a Latin American cohort. Subjects and methods Retrospective study of PTMC patients who underwent total thyroidectomy, with or without radioactive iodine (RAI), and who were followed for at least 2 years. Risk of recurrence was estimated with ATA 2009 and 2015 classifications, and risk of mortality with 7th and 8th AJCC/TNM systems. Clinical data obtained during follow-up were used to detect structural and biochemical persistence/recurrence. Results We included 209 patients, predominantly female (90%), 44.5 ± 12.6 years old, 183 (88%) received RAI (90.4 ± 44.2 mCi), followed-up for a median of 4.4 years (range 2.0–7.8). The 7th and 8th AJCC/TNM system classified 89% and 95.2% of the patients as stage I, respectively. ATA 2009 and ATA 2015 classified 70.8% and 78.5% of the patients as low risk, respectively. Fifteen (7%) patients had persistence/recurrence during follow-up. In multivariate analysis, only lymph node metastasis was associated with persistence/recurrence (coefficient beta 4.0, p = 0.016; 95% CI 1.3-12.9). There were no PTMC related deaths. Conclusions Our series found no mortality and low rate of persistence/recurrence associated with PTMC. Lymph node metastasis was the only feature associated with recurrence in multivariate analysis. The updated ATA 2015 and 8th AJCC/TNM systems classified more PTMCs than previous classifications as low risk of recurrence and mortality, respectively
Papillary thyroid microcarcinoma: characteristics at presentation, and evaluation of clinical and histological features associated with a worse prognosis in a Latin American cohort
<div><p>ABSTRACT Objective We aimed to describe the presentation of papillary microcarcinoma (PTMC) and identify the clinical and histological features associated with persistence/recurrence in a Latin American cohort. Subjects and methods Retrospective study of PTMC patients who underwent total thyroidectomy, with or without radioactive iodine (RAI), and who were followed for at least 2 years. Risk of recurrence was estimated with ATA 2009 and 2015 classifications, and risk of mortality with 7th and 8th AJCC/TNM systems. Clinical data obtained during follow-up were used to detect structural and biochemical persistence/recurrence. Results We included 209 patients, predominantly female (90%), 44.5 ± 12.6 years old, 183 (88%) received RAI (90.4 ± 44.2 mCi), followed-up for a median of 4.4 years (range 2.0–7.8). The 7th and 8th AJCC/TNM system classified 89% and 95.2% of the patients as stage I, respectively. ATA 2009 and ATA 2015 classified 70.8% and 78.5% of the patients as low risk, respectively. Fifteen (7%) patients had persistence/recurrence during follow-up. In multivariate analysis, only lymph node metastasis was associated with persistence/recurrence (coefficient beta 4.0, p = 0.016; 95% CI 1.3-12.9). There were no PTMC related deaths. Conclusions Our series found no mortality and low rate of persistence/recurrence associated with PTMC. Lymph node metastasis was the only feature associated with recurrence in multivariate analysis. The updated ATA 2015 and 8th AJCC/TNM systems classified more PTMCs than previous classifications as low risk of recurrence and mortality, respectively.</p></div
Carbon allocation in fruit trees: from theory to modelling
International audienceCarbon allocation within a plant depends on complex rules linking source organs (mainly shoots) and sink organs (mainly roots and fruits). The complexity of these rules comes from both regulations and interactions between various plant processes involving carbon. This paper presents these regulations and interactions, and analyses how agricultural management can influence them. Ecophysiological models of carbon production and allocation are good tools for such analyses. The fundamental bases of these models are first presented, focusing on their underlying processes and concepts. Different approaches are used for modelling carbon economy. They are classified as empirical, teleonomic, driven by source–sink relationships, or based on transport and chemical/biochemical conversion concepts. These four approaches are presented with a particular emphasis on the regulations and interactions between organs and between processes. The role of plant architecture in carbon partitioning is also discussed and the interest of coupling plant architecture models with carbon allocatio