The term autoimmune thyroiditis encompasses a group of high prevalence thyroid disorders, which h... more The term autoimmune thyroiditis encompasses a group of high prevalence thyroid disorders, which have been classified in different ways throughout the years. In this article some aspects related to its classification, epidemiology, susceptibility factors, pathogenesis, histology, diagnosis and treatment are reviewed. Some comments on the similar pathogenesis of Graves' disease are also made.
Introduction: Thyroid carcinoma is rare in children and young adults. Most of management guidelin... more Introduction: Thyroid carcinoma is rare in children and young adults. Most of management guidelines are based in data from adult population. Several controversies remain regarding the aggressiveness of clinical presentation and therapeutic approach.Objective: To evaluate all differentiated thyroid carcinoma patients with less than 20 years-old at presentation reflecting the experience of our unit in relation to diagnosis, treatment and follow-up of this clinical entity.Material and Methods: This is a retrospective review of clinical records of all children and young adults followed at Oncology Consultation of Department of Endocrinology of Centro Hospitalar e Universitário de Coimbra between 1996 and 2012.Results: Nineteen patients with mean age of 16 years old were followed, 13 girls and 6 boys. None of the patients had previous neck irradiation. A palpable cervical mass was the presenting complaint in 84.6%. FNA was performed in 15 patients and was diagnostic or suspicious of mali...
Selenium is an essential trace element embedded in several proteins. Most of the known selenoprot... more Selenium is an essential trace element embedded in several proteins. Most of the known selenoproteins are found in the thyroid gland and this is the organ with the highest amount of selenium per gram of tissue. Selenium levels in the body depend on the characteristics of the population and its diet, geographic area, and soil composition. In the thyroid, selenium is required for protection from oxidative damage and for the metabolism of thyroid hormones. The literature suggests that selenium intake is associated with autoimmune thyroid disorders and selenium supplementation in those patients is associated with a reduction in antithyroid antibody levels, improved thyroid ultrasound features, and improved quality of life. Selenium supplementation in Graves' ophthalmopathy is associated with an improved quality of life, less eye involvement, and delayed orbitopathy progression. Supplementation with the organic form is more effective, and benefits in immunological mechanisms have been observed in patients with autoimmune thyroiditis.
Tecnologia de Realidad Virtual (RV) ha evolucionado a un ritmo muy rapido y asi su asequibilidad.... more Tecnologia de Realidad Virtual (RV) ha evolucionado a un ritmo muy rapido y asi su asequibilidad. El equipamiento como los head-mounted displays estan disponibles para el consumidor medio a precios razonables y esto ha potenciado el uso de contenidos como video de 360 de una manera mas natural. La finalidad de este estudio fue evaluar la sensacion de la presencia y cybersickness comparando sujetos segun su genero mientras experimentaban con una aplicacion de realidad virtual compuesta por tipo un tipo video (360 grados y de 3D) utilizando un head-mounted display. Una version portuguesa del Igroup Presence Questionnaire (IPQ) fue utilizada junto con el Simulator Sickness Questionnaire (SSQ). Los resultados han revelado que no hay diferencias significativas entre videos de 2D y 3D videos en la sensacion de la presencia o cybersickness.
Friedreich's ataxia (FA) is one of the genetic syndromes sometimes associated with diabetes a... more Friedreich's ataxia (FA) is one of the genetic syndromes sometimes associated with diabetes and the most common hereditary ataxia. It is a autosomal recessive neurodegenerative disease, caused by a mutation in the FRDA gene, which originates decreased expression of frataxin, a mitochondrial protein involved in iron metabolism. The disorder is usually manifest in childhood and is characterised by ataxia, dysarthria, scoliosis and feet deformity. About two thirds of patients have hypertrophic cardiomyopathy, 10% have diabetes and 20% have another glucose homeostasis disorder. Both insulin resistance and beta-cell dysfunction are implicated in this patients' diabetes pathophysiology. The mean half-life is 35 years. Cause of death is usually related to cardiomyopathy or diabetes' complications. We report the case study of two twin sisters with 28 years old, in whom FA was diagnosed in the first decade, both of them with diabetes since their early twenties. A third sister wit...
Advances in Intelligent Systems and Computing, 2019
Among the wide application areas that Virtual Reality (VR) can have a major impact, one is Educat... more Among the wide application areas that Virtual Reality (VR) can have a major impact, one is Education. However, this potential is still unexplored, and one of these gaps has to do with language learning. Listening activities, which are often only supported by audio, are thought of to be demanding area when it comes to learning a second or foreign language and so therefore an interesting area for VR to take place. This pilot study therefore presents the perceptions of foreign language teachers regarding a novel medium for delivering listening activities to their students: Virtual Reality technology. The results show that foreign language teachers are of the opinion that this technology can help motivate students and potentiate the student's learning curve regarding the listening of a foreign or second language.
The goal for a virtual reality (VR) training system is to enable trainees to acquire all the know... more The goal for a virtual reality (VR) training system is to enable trainees to acquire all the knowledge they need to perform effectively in a real environment. Such a system should provide an experience so authentic that no further real-world training is necessary, meaning that it is sufficient to train in VR. We evaluate the impact of a haptic thermal stimulus, which is of paramount importance to decision making, on trainees performance and knowledge acquisition. A thermal device was created to deliver the stimulus. As a proof of concept, a procedure from firefighter training is selected, in which sensing the temperature of a door with one's hand is essential. The sample consisted of 48 subjects divided among three experimental scenarios: one in which a virtual thermometer is used (visual stimulus), another in which the temperature is felt with the hand (thermal stimulus) and a third in which both methods are used (visual + thermal stimuli). For the performance evaluation, we measured the total time taken, the numbers of correctly executed procedures and identified neutral planes, the deviation from the target height, and the responses to a knowledge transfer questionnaire. Presence, cybersickness, and usability are measured to evaluate the impact of the haptic thermal stimulus. Considering the thermal stimulus condition as the baseline, we conclude that the significantly different results in the performance among the conditions indicate that the better performance in the visual-only condition is not representative of the real-life performance. Consequently, VR training applications need to deliver the correct stimuli for decision making.
Papillary thyroid cancer (PTC) has an indolent nature and usually excellent prognosis. Some PTC c... more Papillary thyroid cancer (PTC) has an indolent nature and usually excellent prognosis. Some PTC clinicopathological features may contribute to the development of aggressive metastatic disease. In this work, we want to evaluate PTC clinicopathological features that are presurgical prognostic predictors of patients’ outcomes and find which indicators are more adequate for tailoring surgical procedures and follow-up. We studied a series of 241 PTC patients submitted to surgery. All patients’ files and histological tumor samples were reviewed. The 8th edition AJCC/UICC (American Joint Committee on Cancer/Union for International Cancer) Controlstaging system and the 2015 American Thyroid Association risk stratification system were used. Total thyroidectomy was performed in 228 patients, lymphadenectomy in 28 patients. Gross extrathyroidal extension (ETE) was present in 10 patients and 31 tumor resection margins were incomplete. Cervical lymph node metastases (LNMs) were present in 34 pat...
Consuming 360 audiovisual content using a Head-Mounted Display (HMD) has become a standard featur... more Consuming 360 audiovisual content using a Head-Mounted Display (HMD) has become a standard feature for Immersive Virtual Reality (IVR). However, most applications rely only on visual and auditory feedback whereas other senses are often disregarded. The main goal of this work was to study the effect of tactile and olfactory stimuli on participants’ sense of presence and cybersickness while watching a 360 video using an HMD-based IVR setup. An experiment with 48 participants and three experimental conditions (360 video, 360 video with olfactory stimulus, and 360 video with tactile stimulus) was performed. Presence and cybersickness were reported via post-test questionnaires. Statistical analysis showed a significant difference in presence between the control and the olfactory conditions. From the control to the tactile condition, mean values were higher but failed to show statistical significance. Thus, results suggest that adding an olfactory stimulus increases presence significantly...
Evaluate the impact of TERTp mutation on the outcomes after initial treatment of 45 patients with... more Evaluate the impact of TERTp mutation on the outcomes after initial treatment of 45 patients with thyroid carcinomas derived from follicular cells (TCDFC) with aggressive histology, in which the role of this mutation is not yet well defined. Analysis of the presence of TERTp (-124C > T and -146C > T), BRAF (V600E), and NRAS (Q 61R) mutations by Sanger sequencing and analysis of their correlation with the patient's outcomes. Forty-five patients with aggressive histopathologic variants were included in the study. Of these, 68.9% had aggressive variants of papillary thyroid cancer (PTC), 22.2% had poorly differentiated thyroid carcinoma (PDTC)/insular carcinoma, and 8.9% had invasive follicular thyroid cancer (FTC) with Hurthle cell features (Hurthle cell carcinoma). Lymph node metastases were present in 46.7% and distant metastases in 54.6%. The response to the initial therapy was excellent in 45.5% and structurally incomplete in 50%. During the follow-up period (median of 5...
Mitochondrial dynamics are known to have an important role in so-called age-related diseases, inc... more Mitochondrial dynamics are known to have an important role in so-called age-related diseases, including cancer. Mitochondria is an organelle involved in many key cellular functions and responds to physiologic or stress stimuli by adapting its structure and function. Perhaps the most important structural changes involve mitochondrial dynamics (fission and fusion), which occur in normal cells as well as in cells under dysregulation, such as cancer cells. Dynamin-related protein 1 (DRP1), a member of the dynamin family of guanosine triphosphatases (GTPases), is the key component of mitochondrial fission machinery. Dynamin-related protein 1 is associated with different cell processes such as apoptosis, mitochondrial biogenesis, mitophagy, metabolism, and cell proliferation, differentiation, and transformation. The role of DRP1 in tumorigenesis may seem to be paradoxical, since mitochondrial fission is a key mediator of two very different processes, cellular apoptosis and cell mitosis. D...
The Journal of clinical endocrinology and metabolism, Jun 6, 2017
Little is known about the frequency of key mutations in thyroid cancer metastases and its relatio... more Little is known about the frequency of key mutations in thyroid cancer metastases and its relationship with the primary tumor genotype. To evaluate the frequency of TERT promoter (TERTp), BRAF and NRAS mutations in metastatic thyroid carcinomas, analyzing primary thyroid tumors, lymph node metastases (LNM) and distant metastases. Mutation analysis was performed in 437 tissue samples from 204 patients, mainly with papillary thyroid carcinomas (PTC) (n=180), including 196 LNM and 56 distant metastases. All the distant metastases included corresponded to radioiodine-refractory metastatic tissue. We found the following mutation frequency in primary PTC, LNM and distant metastases, respectively: TERTp- 12.9%, 10.5%, and 52.4%; BRAF- 44.6%, 41.7%, and 23.8%; NRAS- 1.2%, 1.3%, and 14.3%. There was a significant concordance between the primary tumor genotype and the corresponding LNM for all the genes, in particular BRAF-mutated PTC. The overall concordance between primary tumors and respec...
ABSTRACT Virtual Environments (VE) systems may provide a new way to deliver information and servi... more ABSTRACT Virtual Environments (VE) systems may provide a new way to deliver information and services in many areas, for example in tourism, urban planning and education. In urban VE there is a close link between the virtual environment and the urban environment that are intended to represent. These VE can be an intuitive way to access a set of services with a direct association to the real object or entity to which they are related. In this article, we describe a case study that aimed at exploring the possibility of using new interfaces to exploit and use services in urban VE with a greater sense of immersiveness. The results indicate that the VE interfaces are a natural and intuitive access to digital services. While users have felt a greater difficulty in performing some of the tasks in immersive scenario, the majority considered that this scenario provided a greater sense of immersion and realism.
4th Conference of Enterprise Information Systems - Aligning Technology, Organizations and People (Centeris 2012), 2012
In some business areas there is the need to use representations of places or buildings in order t... more In some business areas there is the need to use representations of places or buildings in order to provide visual informations. These representations are, mainly, reconstructions of scaled real models or virtual representations produced in a Computer-Aided Design (CAD) tool. Recently, procedural modeling has been applied to generate buildings and cities in a short time and with a minimum user intervention. This methodology reveals to be a promising solution for a costeffective alternative in models construction. One of the areas that can benefit from this kind of approach is archeology, for example to test archeological hypothesis. However, the existing solutions are not flexible enough to provide high detailed models containing building interiors and exteriors. This paper aims to present the global architecture and specification of an information system that supports the procedural modeling process, producing enhanced virtual representations of ancient places, including building facades and interiors, using the information available.
Thyroid carcinomas represent a challenging problem from the prognostic standpoint. Despite an ove... more Thyroid carcinomas represent a challenging problem from the prognostic standpoint. Despite an overall good prognosis of the most frequent endocrine malignancy, 10-15 % of papillary thyroid carcinomas (PTCs) turn refractory to radioactive iodine therapy. The increased incidence of thyroid cancer has led to the search for solid prognostic biomarkers that predict the behaviour of these tumours. Clinical and histopathological prognostic factors remain the only safe elements to be used for diagnosis and prognosis of patients with thyroid tumours. Despite the huge amount of genetic information of thyroid tumours, very few new markers revealed diagnostic or prognostic value per se. BRAF mutation can have some value if associated to other clinico-pathological parameters, or in the particular setting of iodine refractory tumours. Others can prove interesting in the future as predictive biomarkers of therapeutic response, but more studies are needed to confirm these potential biomarkers.
Reactivation of telomerase has been implicated in human tumorigenesis, but the underlying mechani... more Reactivation of telomerase has been implicated in human tumorigenesis, but the underlying mechanisms remain poorly understood. Here we report the presence of recurrent somatic mutations in the TERT promoter in cancers of the central nervous system (43%), bladder (59%), thyroid (follicular cell-derived, 10%) and skin (melanoma, 29%). In thyroid cancers, the presence of TERT promoter mutations (when occurring together with BRAF mutations) is significantly associated with higher TERT mRNA expression, and in glioblastoma we find a trend for increased telomerase expression in cases harbouring TERT promoter mutations. Both in thyroid cancers and glioblastoma, TERT promoter mutations are significantly associated with older age of the patients. Our results show that TERT promoter mutations are relatively frequent in specific types of human cancers, where they lead to enhanced expression of telomerase.
The version presented here may differ from the published version or, version of record, if you wi... more The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP URL' above for details on accessing the published version and note that access may require a subscription.
The Journal of Clinical Endocrinology & Metabolism, 2013
Context:Thyroglobulin (Tg) levels measured at the time of remnant ablation after thyroid hormone ... more Context:Thyroglobulin (Tg) levels measured at the time of remnant ablation after thyroid hormone withdrawal (THW) were shown to have prognostic value in predicting disease-free status.Objectives:Our objectives were to determine whether stimulated Tg levels, measured at the time of remnant ablation performed under recombinant human TSH (rhTSH) stimulation, has value in predicting absence of detectable disease 1 year after radioiodine therapy and to compare the results obtained with this approach with a cohort of patients submitted to ablation after THW.Design:This was a prospective observational study.Setting and Patients:The study included 293 consecutive patients treated for a differentiated thyroid carcinoma with no initial evidence of distant metastasis. All patients were submitted to a total or near-total thyroidectomy, followed by ablation either under rhTSH (n = 151) or endogenous TSH stimulation (n = 142). Patients with positive Tg antibodies were excluded.Main Outcome Measur...
The term autoimmune thyroiditis encompasses a group of high prevalence thyroid disorders, which h... more The term autoimmune thyroiditis encompasses a group of high prevalence thyroid disorders, which have been classified in different ways throughout the years. In this article some aspects related to its classification, epidemiology, susceptibility factors, pathogenesis, histology, diagnosis and treatment are reviewed. Some comments on the similar pathogenesis of Graves' disease are also made.
Introduction: Thyroid carcinoma is rare in children and young adults. Most of management guidelin... more Introduction: Thyroid carcinoma is rare in children and young adults. Most of management guidelines are based in data from adult population. Several controversies remain regarding the aggressiveness of clinical presentation and therapeutic approach.Objective: To evaluate all differentiated thyroid carcinoma patients with less than 20 years-old at presentation reflecting the experience of our unit in relation to diagnosis, treatment and follow-up of this clinical entity.Material and Methods: This is a retrospective review of clinical records of all children and young adults followed at Oncology Consultation of Department of Endocrinology of Centro Hospitalar e Universitário de Coimbra between 1996 and 2012.Results: Nineteen patients with mean age of 16 years old were followed, 13 girls and 6 boys. None of the patients had previous neck irradiation. A palpable cervical mass was the presenting complaint in 84.6%. FNA was performed in 15 patients and was diagnostic or suspicious of mali...
Selenium is an essential trace element embedded in several proteins. Most of the known selenoprot... more Selenium is an essential trace element embedded in several proteins. Most of the known selenoproteins are found in the thyroid gland and this is the organ with the highest amount of selenium per gram of tissue. Selenium levels in the body depend on the characteristics of the population and its diet, geographic area, and soil composition. In the thyroid, selenium is required for protection from oxidative damage and for the metabolism of thyroid hormones. The literature suggests that selenium intake is associated with autoimmune thyroid disorders and selenium supplementation in those patients is associated with a reduction in antithyroid antibody levels, improved thyroid ultrasound features, and improved quality of life. Selenium supplementation in Graves' ophthalmopathy is associated with an improved quality of life, less eye involvement, and delayed orbitopathy progression. Supplementation with the organic form is more effective, and benefits in immunological mechanisms have been observed in patients with autoimmune thyroiditis.
Tecnologia de Realidad Virtual (RV) ha evolucionado a un ritmo muy rapido y asi su asequibilidad.... more Tecnologia de Realidad Virtual (RV) ha evolucionado a un ritmo muy rapido y asi su asequibilidad. El equipamiento como los head-mounted displays estan disponibles para el consumidor medio a precios razonables y esto ha potenciado el uso de contenidos como video de 360 de una manera mas natural. La finalidad de este estudio fue evaluar la sensacion de la presencia y cybersickness comparando sujetos segun su genero mientras experimentaban con una aplicacion de realidad virtual compuesta por tipo un tipo video (360 grados y de 3D) utilizando un head-mounted display. Una version portuguesa del Igroup Presence Questionnaire (IPQ) fue utilizada junto con el Simulator Sickness Questionnaire (SSQ). Los resultados han revelado que no hay diferencias significativas entre videos de 2D y 3D videos en la sensacion de la presencia o cybersickness.
Friedreich's ataxia (FA) is one of the genetic syndromes sometimes associated with diabetes a... more Friedreich's ataxia (FA) is one of the genetic syndromes sometimes associated with diabetes and the most common hereditary ataxia. It is a autosomal recessive neurodegenerative disease, caused by a mutation in the FRDA gene, which originates decreased expression of frataxin, a mitochondrial protein involved in iron metabolism. The disorder is usually manifest in childhood and is characterised by ataxia, dysarthria, scoliosis and feet deformity. About two thirds of patients have hypertrophic cardiomyopathy, 10% have diabetes and 20% have another glucose homeostasis disorder. Both insulin resistance and beta-cell dysfunction are implicated in this patients' diabetes pathophysiology. The mean half-life is 35 years. Cause of death is usually related to cardiomyopathy or diabetes' complications. We report the case study of two twin sisters with 28 years old, in whom FA was diagnosed in the first decade, both of them with diabetes since their early twenties. A third sister wit...
Advances in Intelligent Systems and Computing, 2019
Among the wide application areas that Virtual Reality (VR) can have a major impact, one is Educat... more Among the wide application areas that Virtual Reality (VR) can have a major impact, one is Education. However, this potential is still unexplored, and one of these gaps has to do with language learning. Listening activities, which are often only supported by audio, are thought of to be demanding area when it comes to learning a second or foreign language and so therefore an interesting area for VR to take place. This pilot study therefore presents the perceptions of foreign language teachers regarding a novel medium for delivering listening activities to their students: Virtual Reality technology. The results show that foreign language teachers are of the opinion that this technology can help motivate students and potentiate the student's learning curve regarding the listening of a foreign or second language.
The goal for a virtual reality (VR) training system is to enable trainees to acquire all the know... more The goal for a virtual reality (VR) training system is to enable trainees to acquire all the knowledge they need to perform effectively in a real environment. Such a system should provide an experience so authentic that no further real-world training is necessary, meaning that it is sufficient to train in VR. We evaluate the impact of a haptic thermal stimulus, which is of paramount importance to decision making, on trainees performance and knowledge acquisition. A thermal device was created to deliver the stimulus. As a proof of concept, a procedure from firefighter training is selected, in which sensing the temperature of a door with one's hand is essential. The sample consisted of 48 subjects divided among three experimental scenarios: one in which a virtual thermometer is used (visual stimulus), another in which the temperature is felt with the hand (thermal stimulus) and a third in which both methods are used (visual + thermal stimuli). For the performance evaluation, we measured the total time taken, the numbers of correctly executed procedures and identified neutral planes, the deviation from the target height, and the responses to a knowledge transfer questionnaire. Presence, cybersickness, and usability are measured to evaluate the impact of the haptic thermal stimulus. Considering the thermal stimulus condition as the baseline, we conclude that the significantly different results in the performance among the conditions indicate that the better performance in the visual-only condition is not representative of the real-life performance. Consequently, VR training applications need to deliver the correct stimuli for decision making.
Papillary thyroid cancer (PTC) has an indolent nature and usually excellent prognosis. Some PTC c... more Papillary thyroid cancer (PTC) has an indolent nature and usually excellent prognosis. Some PTC clinicopathological features may contribute to the development of aggressive metastatic disease. In this work, we want to evaluate PTC clinicopathological features that are presurgical prognostic predictors of patients’ outcomes and find which indicators are more adequate for tailoring surgical procedures and follow-up. We studied a series of 241 PTC patients submitted to surgery. All patients’ files and histological tumor samples were reviewed. The 8th edition AJCC/UICC (American Joint Committee on Cancer/Union for International Cancer) Controlstaging system and the 2015 American Thyroid Association risk stratification system were used. Total thyroidectomy was performed in 228 patients, lymphadenectomy in 28 patients. Gross extrathyroidal extension (ETE) was present in 10 patients and 31 tumor resection margins were incomplete. Cervical lymph node metastases (LNMs) were present in 34 pat...
Consuming 360 audiovisual content using a Head-Mounted Display (HMD) has become a standard featur... more Consuming 360 audiovisual content using a Head-Mounted Display (HMD) has become a standard feature for Immersive Virtual Reality (IVR). However, most applications rely only on visual and auditory feedback whereas other senses are often disregarded. The main goal of this work was to study the effect of tactile and olfactory stimuli on participants’ sense of presence and cybersickness while watching a 360 video using an HMD-based IVR setup. An experiment with 48 participants and three experimental conditions (360 video, 360 video with olfactory stimulus, and 360 video with tactile stimulus) was performed. Presence and cybersickness were reported via post-test questionnaires. Statistical analysis showed a significant difference in presence between the control and the olfactory conditions. From the control to the tactile condition, mean values were higher but failed to show statistical significance. Thus, results suggest that adding an olfactory stimulus increases presence significantly...
Evaluate the impact of TERTp mutation on the outcomes after initial treatment of 45 patients with... more Evaluate the impact of TERTp mutation on the outcomes after initial treatment of 45 patients with thyroid carcinomas derived from follicular cells (TCDFC) with aggressive histology, in which the role of this mutation is not yet well defined. Analysis of the presence of TERTp (-124C > T and -146C > T), BRAF (V600E), and NRAS (Q 61R) mutations by Sanger sequencing and analysis of their correlation with the patient's outcomes. Forty-five patients with aggressive histopathologic variants were included in the study. Of these, 68.9% had aggressive variants of papillary thyroid cancer (PTC), 22.2% had poorly differentiated thyroid carcinoma (PDTC)/insular carcinoma, and 8.9% had invasive follicular thyroid cancer (FTC) with Hurthle cell features (Hurthle cell carcinoma). Lymph node metastases were present in 46.7% and distant metastases in 54.6%. The response to the initial therapy was excellent in 45.5% and structurally incomplete in 50%. During the follow-up period (median of 5...
Mitochondrial dynamics are known to have an important role in so-called age-related diseases, inc... more Mitochondrial dynamics are known to have an important role in so-called age-related diseases, including cancer. Mitochondria is an organelle involved in many key cellular functions and responds to physiologic or stress stimuli by adapting its structure and function. Perhaps the most important structural changes involve mitochondrial dynamics (fission and fusion), which occur in normal cells as well as in cells under dysregulation, such as cancer cells. Dynamin-related protein 1 (DRP1), a member of the dynamin family of guanosine triphosphatases (GTPases), is the key component of mitochondrial fission machinery. Dynamin-related protein 1 is associated with different cell processes such as apoptosis, mitochondrial biogenesis, mitophagy, metabolism, and cell proliferation, differentiation, and transformation. The role of DRP1 in tumorigenesis may seem to be paradoxical, since mitochondrial fission is a key mediator of two very different processes, cellular apoptosis and cell mitosis. D...
The Journal of clinical endocrinology and metabolism, Jun 6, 2017
Little is known about the frequency of key mutations in thyroid cancer metastases and its relatio... more Little is known about the frequency of key mutations in thyroid cancer metastases and its relationship with the primary tumor genotype. To evaluate the frequency of TERT promoter (TERTp), BRAF and NRAS mutations in metastatic thyroid carcinomas, analyzing primary thyroid tumors, lymph node metastases (LNM) and distant metastases. Mutation analysis was performed in 437 tissue samples from 204 patients, mainly with papillary thyroid carcinomas (PTC) (n=180), including 196 LNM and 56 distant metastases. All the distant metastases included corresponded to radioiodine-refractory metastatic tissue. We found the following mutation frequency in primary PTC, LNM and distant metastases, respectively: TERTp- 12.9%, 10.5%, and 52.4%; BRAF- 44.6%, 41.7%, and 23.8%; NRAS- 1.2%, 1.3%, and 14.3%. There was a significant concordance between the primary tumor genotype and the corresponding LNM for all the genes, in particular BRAF-mutated PTC. The overall concordance between primary tumors and respec...
ABSTRACT Virtual Environments (VE) systems may provide a new way to deliver information and servi... more ABSTRACT Virtual Environments (VE) systems may provide a new way to deliver information and services in many areas, for example in tourism, urban planning and education. In urban VE there is a close link between the virtual environment and the urban environment that are intended to represent. These VE can be an intuitive way to access a set of services with a direct association to the real object or entity to which they are related. In this article, we describe a case study that aimed at exploring the possibility of using new interfaces to exploit and use services in urban VE with a greater sense of immersiveness. The results indicate that the VE interfaces are a natural and intuitive access to digital services. While users have felt a greater difficulty in performing some of the tasks in immersive scenario, the majority considered that this scenario provided a greater sense of immersion and realism.
4th Conference of Enterprise Information Systems - Aligning Technology, Organizations and People (Centeris 2012), 2012
In some business areas there is the need to use representations of places or buildings in order t... more In some business areas there is the need to use representations of places or buildings in order to provide visual informations. These representations are, mainly, reconstructions of scaled real models or virtual representations produced in a Computer-Aided Design (CAD) tool. Recently, procedural modeling has been applied to generate buildings and cities in a short time and with a minimum user intervention. This methodology reveals to be a promising solution for a costeffective alternative in models construction. One of the areas that can benefit from this kind of approach is archeology, for example to test archeological hypothesis. However, the existing solutions are not flexible enough to provide high detailed models containing building interiors and exteriors. This paper aims to present the global architecture and specification of an information system that supports the procedural modeling process, producing enhanced virtual representations of ancient places, including building facades and interiors, using the information available.
Thyroid carcinomas represent a challenging problem from the prognostic standpoint. Despite an ove... more Thyroid carcinomas represent a challenging problem from the prognostic standpoint. Despite an overall good prognosis of the most frequent endocrine malignancy, 10-15 % of papillary thyroid carcinomas (PTCs) turn refractory to radioactive iodine therapy. The increased incidence of thyroid cancer has led to the search for solid prognostic biomarkers that predict the behaviour of these tumours. Clinical and histopathological prognostic factors remain the only safe elements to be used for diagnosis and prognosis of patients with thyroid tumours. Despite the huge amount of genetic information of thyroid tumours, very few new markers revealed diagnostic or prognostic value per se. BRAF mutation can have some value if associated to other clinico-pathological parameters, or in the particular setting of iodine refractory tumours. Others can prove interesting in the future as predictive biomarkers of therapeutic response, but more studies are needed to confirm these potential biomarkers.
Reactivation of telomerase has been implicated in human tumorigenesis, but the underlying mechani... more Reactivation of telomerase has been implicated in human tumorigenesis, but the underlying mechanisms remain poorly understood. Here we report the presence of recurrent somatic mutations in the TERT promoter in cancers of the central nervous system (43%), bladder (59%), thyroid (follicular cell-derived, 10%) and skin (melanoma, 29%). In thyroid cancers, the presence of TERT promoter mutations (when occurring together with BRAF mutations) is significantly associated with higher TERT mRNA expression, and in glioblastoma we find a trend for increased telomerase expression in cases harbouring TERT promoter mutations. Both in thyroid cancers and glioblastoma, TERT promoter mutations are significantly associated with older age of the patients. Our results show that TERT promoter mutations are relatively frequent in specific types of human cancers, where they lead to enhanced expression of telomerase.
The version presented here may differ from the published version or, version of record, if you wi... more The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP URL' above for details on accessing the published version and note that access may require a subscription.
The Journal of Clinical Endocrinology & Metabolism, 2013
Context:Thyroglobulin (Tg) levels measured at the time of remnant ablation after thyroid hormone ... more Context:Thyroglobulin (Tg) levels measured at the time of remnant ablation after thyroid hormone withdrawal (THW) were shown to have prognostic value in predicting disease-free status.Objectives:Our objectives were to determine whether stimulated Tg levels, measured at the time of remnant ablation performed under recombinant human TSH (rhTSH) stimulation, has value in predicting absence of detectable disease 1 year after radioiodine therapy and to compare the results obtained with this approach with a cohort of patients submitted to ablation after THW.Design:This was a prospective observational study.Setting and Patients:The study included 293 consecutive patients treated for a differentiated thyroid carcinoma with no initial evidence of distant metastasis. All patients were submitted to a total or near-total thyroidectomy, followed by ablation either under rhTSH (n = 151) or endogenous TSH stimulation (n = 142). Patients with positive Tg antibodies were excluded.Main Outcome Measur...
Uploads
Papers by miguel melo