9 resultados para Delayed Diagnosis


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ABSTRACT: Schizophrenia with its disabling features has been placed in the top ten of global burden of disease and is associated with long-term decline in functional ability. General Practitioners not only have an important role in treating patients with an established diagnosis of schizophrenia but they can also contribute significantly by identifying people in early stages of psychosis as they are the first hand medical help available and the duration of untreated psychosis is a good indicator of patient’s prognosis. This cross sectional survey, conducted at the clinics of General Practitioners, was designed to assess the knowledge and practices of general practitioners in Peshawar on diagnosis and treatment of schizophrenia. A semi structured questionnaire was used to assess their knowledge and practices regarding schizophrenia. The Knowledge/Practice was then categorized as good or poor based on their responses to the questions of the administered questionnaire. Overall, the results showed that the knowledge and practices of general practitioners of district Peshawar were poor regarding schizophrenia and may be responsible for delayed diagnosis, inadequate treatment and poor prognosis.

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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Electrotécnica e Computadores

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Thesis for the Master degree in Structural and Functional Biochemistry

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Dissertação para obtenção do Grau de Doutor em Engenharia Electrotécnica e Computadores especialidade: Robótica e Manufactura Integrada

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This dissertation is presented to obtain a Master degree in Structural and Functional Biochemistry

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Resumo: Os resultados das nossas investigações, apresentadas ao longo desta dissertação,contribuíram para a otimização do diagnóstico invasivo e não invasivo da osteodistrofia renal e permitiram evidenciar a relevância, para a expressão clínica e histológica da ODR, de algumas articularidades específicas da população hemodialisada, nomeadamente: a utilização de membranas de hemodiálise mais biocompatíveis e com elevada permeabilidade, o recurso a técnicas de hemodiafiltração com otimização da capacidade convectiva, as limitações dos marcadores bioquímicos de remodelação óssea ou a insuficiência / deficiência em vitamina D nativa (bem como os resultados da suplementação com esta vitamina). Testámos, pela primeira vez em doentes hemodialisados, novos marcadores da formação e reabsorção óssea, que validámos mediante a comparação com os resultados da histomorfometria óssea. No seu conjunto, e de forma integrada, as nossas investigações permitiram-nos: - Evidenciar a diminuição da expressão do recetor da PTH/PTHrP na cartilagem de crescimento, num modelo animal de IRC, o que explica, pelo menos em parte, o atraso de crescimento observado nesta patologia, bem como a diminuição da resposta à ação da PTH; - Demonstrar as vantagens da determinação da isoforma óssea da fosfatase alcalina, em relação à fosfatase alcalina total, no diagnóstico diferencial entre baixa e elevada remodelação óssea; - Utilizar, pela primeira vez em hemodialisados, a piridinolina e a desoxipiridinolina no diagnóstico da reabsorção óssea. Este foi o primeiro marcador sérico específico da atividade osteoclástica, utilizado com sucesso em doentes anúricos em hemodiálise. Evidenciámos uma excelente correlação destes dois marcadores bioquímicos com a superfície osteoclástica e com o número de osteoclastos/mm2;- Demonstrar as acentuadas limitações de outros marcadores da formação e reabsorção óssea (nomeadamente a osteocalcina, o propeptido carboxiterminal do procolagénio tipo I-PICP, e o Telopeptido do colagénio tipo I – ICTP) com base nas correlações entre os doseamentos séricos ou plasmáticos destes marcadores e a biópsia óssea com avaliação histomorfométrica; -Evidenciar as limitações induzidas pela sobrecarga alumínica na interpretação dos níveis séricos dos marcadores não invasivos da remodelação óssea;-Testar a eficácia e segurança da utilização de “microdoses” de desferroxamina na terapêutica da intoxicação alumínica, em doentes com acentuada exposição a este metal;-Demonstrar que os doentes hemodialisados cronicamente com dialisadores de poliacrilonitrilo (membranas de alta permeabilidade),apresentavam menor ativação osteoblástica e osteoclástica, que os doentes dialisados com membranas de cuprofano(baixa permeabilidade), sendo os níveis de iPTH semelhantes em ambos os grupos estudados. Estes resultados apontam para uma menor ativação da remodelação óssea quando se utilizam membranas de hemodiálise mais biocompatíveis e/ou de maior permeabilidade, o que se poderá relacionar com a ultrafiltração de mediadores da ativação celular ou com a menor ativação dos mecanismos estimuladores da remodelação óssea, por parte destas membranas. Entre os mediadores da remodelação óssea que demonstrámos serem relevantes e estarem aumentados no soro de hemodialisados com membranas de baixo fluxo, contam-se a beta-2-microglobulina (2-M) e algumas citoquinas, com ação estimuladora das linhagens celulares envolvidas na remodelação óssea. Demonstrámos igualmente uma correlação positiva dos níveis séricos de 2-M com os níveis séricos da osteocalcina, da isoenzima óssea da fosfatase alcalina (marcadores da formação óssea) e com os níveis séricos da piridinolina (marcador da reabsorção óssea). Os níveis séricos de 2-M correlacionaram-se ainda, de forma negativa, com o volume osteoide (matriz óssea não calcificada). Nestes doentes hemodialisados, demonstrámos a presença de níveis séricos aumentados da interleucina-1, do antagonista do recetor da interleucina-1, da interleucina-6 e do recetor solúvel da interleucina-6. Salientamos as relações inversas que observámos, por um lado entre os níveis de antagonista do recetor da interleucina-1 e a superfície osteoblástica, e por outro lado entre o rácio do recetor da interleucina-6 / interleucina-6 (IL6-r/IL6) e a superfície osteoclástica. De acordo com estes nossos resultados originais, entendemos que a interferência nos níveis circulantes e na ativação local destes mediadores poderá justificar, em grande parte, o aumento da prevalência de doença óssea adinâmica, descrita por nós e por outros grupos. Evidenciámos uma elevadíssima prevalência de doença adinâmica (>50% dos doentes), numa população de hemodialisados sem exposição prévia ao alumínio, tratados de acordo com os K/DOQI “guidelines” e que ao longo de um ano mantiveram níveis séricos de cálcio e de fósforo controlados. Consequentemente, os doentes tratados de forma otimizada apresentaram uma prevalência surpreendentemente elevada de doença adinâmica. Os nossos resultados (classificados com o grau de evidência máxima pelos peritos KDIGO) contribuíram para dar suporte à grande diferença nos guidelines K/DOQI (2003) e KDIGO (2009) no que respeita aos valores alvo da PTH. Estamos conscientes que de que o facto de termos uma percentagem tão elevada de doença óssea adinâmica nas nossas populações de hemodialisados, bem como a demonstração de que alguns doentes com valores de PTH intacta (2ª geração) de cerca de 600 pg/ml tinham doença óssea adinâmica, condicionaram os novos objetivos KDIGO para a PTH. Os nossos resultados suportam, em nossa opinião, a adequação e vantagem da utilização dos critérios da KDIGO em vez dos KDOQI. Tendo em conta que os primeiros definem objetivos para a PTH entre 2 e 9 vezes o limite superior do normal e não se comprometem com valores alvo absolutos e rígidos (definidos previamente nos KDOQI entre 150 e 300 pg/mL), esta nova abordagem parece-nos mais correta.Na nossa investigação clínica, caracterizámos ainda a população hemodialisada portuguesa no que respeita aos níveis séricos de calcidiol, identificando a população com suficiência, insuficiência ou deficiência em vitamina D3. Documentámos uma acentuada prevalência de insuficiência e mesmo de deficiência nesta vitamina, numa vasta população de hemodialisados, a qual, muito provavelmente, reflete de forma fidedigna, o que se pode observar na restante população de doentes portugueses IRC em estádio 5d (em diálise). Descrevemos, pela primeira vez em doentes hemodialisados, uma associação entre deficiência em calcidiol e a presença de fatores de risco cardiovascular (que têm sido identificados nos doentes urémicos). A nossa investigação conduziu-nos a resultados originais, ao identificar os níveis baixos de 25(OH)vitamina D3 como um provável fator de risco cardiovascular em hemodialisados, visto que a deficiência nesta vitamina se associou, de forma muito significativa, ao aumento da prevalência de calcificações vasculares, a inflamação, a pressão de pulso mais elevada, a hipertrofia ventricular esquerda, a insuficiência cardíaca e a níveis séricos aumentados de “BNP-Brain natriuretic peptide”. Finalmente, numa avaliação prospetiva, de intervenção terapêutica, corrigimos a insuficiência ou deficiência em 25(OH)vitamina D3 e demonstrámos que essa correção se associou a uma redução dos fatores de risco cardiovascular. Esta última intervenção foi totalmente inovadora, visto ser a primeira avaliação prospetiva da evolução dos fatores de risco cardiovasculares, em função da suplementação com vitamina D nativa, em doentes hemodialisados. Em resumo, pensamos que os resultados das nossas investigações, acima sumarizadas e apresentadas ao longo dos diversos capítulos desta dissertação,contribuiram para uma nova perspetiva da osteodistrofia renal e para recolocar o foco da atenção dos nefrologistas no tecido ósseo e no eixo paratormona – vitamina D – remodelação óssea. Este eixo surje claramente envolvido em múltiplos processos fisiopatológicos, que suportam a elevada morbilidade e mortalidade (nomeadamente de causa cardiovascular) observada nos doentes urémicos.---------ABSTRACT: The results of our research, presented throughout this thesis, contributed towards the optimisation of the invasive and non-invasive diagnosis of renal osteodystrophy. They have also highlighted the importance, to the clinical and histological expression of the ODR, of some specific characteristics of the haemodialysis population, including: the use of biocompatible high permeability haemodialysis membranes, the use of haemodiafiltration techniques with convection enhancement, as well as the limitations of biochemical markers of bone turnover or native vitamin D insufficiency/deficiency (along with the supplementation results of this vitamin). New bone formation and resorption markers, which were validated by comparison with the results of bone histomorphometry, have been tested for the first time on haemodialysis patients.As a whole, and in an integrated approach, our research enabled us to: - Show the decrease of the PTH/PTHrP receptor expression in cartilage growth, used on an IRC animal model, which explains, to some extent, not only the delayed growth observed in this pathology, but also the slow response to PTH. - Point out the advantages of the determination of bone isoform of alkaline phosphatase, in relation to the total alkaline phosphatase, in the differential diagnosis between low and high-bone turnover.- Use pyridinoline and deoxypyridinoline in the diagnosis of bone resorption for the first time on haemodialysis patients. This was the first specific serum market of the osteoclastic activity, which was successfully used on anuric patients undergoing haemodialysis treatment. We also observed an excellent correlation of these biochemical markers with the osteoclastic surface and the number of osteoclasts/mm2. - Demonstrate the sharp limitations of other markers of bone formation and resorption (namely osteocalcin, carboxyterminal propeptide of type I-PICP procollagen and telopeptide of type I-ICTP collagen) based on correlations between these markers’ serum or plasma assays and bone biopsy with histomorphometric assessment.-Show the limitations induced by aluminium overload in the interpretation of serum levels of bone remodelling non-invasive markers.-Test the efficacy and the safety of the use of deferoxamine “microdoses” for treatment of aluminium overload among patients with high levels of serum aluminium. - Demonstrate that patients with chronic haemodialysis dialysers of polyacrylonitrile (high permeability membranes) show a lower osteoblastic and osteoclastic activation than those undergoing dialysis with cuprofan membranes (low permeability), being the iPTH levels similar in both groups of patients. These findings point towards a lower activation of bone remodelling when using more biocompatible dialysis membranes and/or of higher permeability, which may relate to the ultrafiltration of cell activation mediators or to the lower activation of the stimulating mechanisms of bone remodelling, regarding the membranes. Beta-2-microglobulin (2-M) and some cytokines that play a role/participate in bone remodelling are among the bone remodelling mediators, which we demonstrated to be relevant and to be increased in the serum of haemodialysis with low flow membranes. We also proved that there is a positive correlation of serum 2-M levels not only with serum osteocalcin levels, of the bone isoenzyme of alkaline phosphatase (bone forming markers), but also with levels of serum pyridinoline (bone resorption marker).Serum 2-M levels correlate negatively with the volume of osteoid (uncalcified bone matrix). We also demonstrated the presence of elevated serum levels of interleukin-1,interleukin-1 receptor antagonist, interleukin-6 and soluble interleukin-6 receptor in haemodialysis patients. We stress the inverse relationship which we observed on one hand between the interleukin-1 receptor antagonist levels and the osteoblastic surface and on the other between the ratio of interleukin-6 receptor / interleukin-6 (IL6-r/IL6) and the osteoblastic surface. According to these unique findings, we believe that the interference in the circulating levels and in the local activation of these mediators may partly explain the rising prevalence of adynamic bone disease. A high prevalence of adynamic disease has also been observed in a haemodialysis population (>50% of patients) with no previous exposure to aluminium. The patients were treated according to K/DOQI guidelines and maintained controlled serum calcium and phosphorus levels over one year. As a result, the patients who received optimised treatment showed a surprisingly high prevalence of adynamic disease. Our results, which were ranked with the highest degree of evidence by KDIGO experts, contributed to the great difference regarding the target values of PTH in the K/DOQI (2003) and KDIGO (2009) guidelines. We are aware that the finding of such a high percentage of adynamic bone disease in our haemodialysis population, as well as the evidence that some patients with intact PTH values (2nd generation) of 600 pg/ml suffered from adynamic bone disease, have hindered, the new KDIGO objectives to PTH.In our opinion, our results support the suitability and the advantage of using KDIGO criteria instead of KDOQI. This seems to be the right approach when taking into consideration that KDIGO sets objectives to PTH between 2 and 9 times the normal upper limit and does not compromise with the rigid and absolute target values (between 150 and 300 pg/mL) previously defined by KDOQI. In our clinical research, the Portuguese haemodialysis population was characterised in terms of serum clacidiol levels and identified as having vitamin D3 sufficiency, insufficiency or deficiency. It was also recorded the prevalence of severe vitamin D3 insufficiency and even deficiency in a large haemodialysis population, which most likely provides a reliable picture of the rest of the population in IRC Portuguese patients with 5d stage (undergoing dialysis). We described for the first time in aemosialysis patients an association between calcidiol deficiency and the presence of ardiovascular risk factors, (which have been identified on uraemic patients).Our research led us to unique findings by having identified the low levels of 25(OH) vitamin D3 as a likely cardiovascular risk factor in patients undergoing haemodialysis treatment, given that deficiency in this vitamin has been significantly associated not only with a rise in the prevalence of vascular calcifications, but also inflammation, left ventricular hypertrophy, high pulse pressure and high serum BNPBrain natriuretic peptide levels. Finally, based on a prospective assessment of therapeutic intervention, 25(OH)vitamin D3 insufficiency or deficiency was corrected and we were able to demonstrate that this same correction was associated with a reduction in cardiovascular risk factors. This was a forward-looking intervention regarding the supplementation of native vitamin D in haemodialysis patients, since it was the first prospective assessment of the evolution of cardiovascular risk factors. In short, the results of our research, summarised above and presented throughout the various chapters of this thesis, contributed towards a new perspective of the renal osteodystrophy and also to draw the nephrologists’ attention to the bone tissue and to the axis PTH – vitamin D – bone remodelling. This axis appears clearly involved in multiple physiopathological processes, which support the high morbidity and mortality rate, (particularly of cardiovascular causes), observed in uraemic patients.

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Breast cancer is the most common type of cancer among women all over the world. An important issue that is not commonly addressed in breast cancer imaging literature is the importance of imaging the underarm region—where up to 80% of breast cancer cells can metastasise to. The first axillary lymph nodes to receive drainage from the primary tumour in the breast are called Sentinel Node. If cancer cells are found in the Sentinel Node, there is an increased risk of metastatic breast cancer which makes this evaluation crucial to decide what follow-up exams and therapy to follow. However, non-invasive detection of cancer cells in the lymph nodes is often inconclusive, leading to the surgical removal of too many nodes which causes adverse side-effects for patients. Microwave Imaging is one of the most promising non-invasive imaging modalities for breast cancer early screening and monitoring. This novel study tests the feasibility of imaging the axilla region by means of the simulation of an Ultra-Wideband Microwave Imaging system. Simulations of such system are completed in several 2D underarm models that mimic the axilla. Initial imaging results are obtained by means of processing the simulated backscattered signals by eliminating artefacts caused by the skin and beamforming the processed signals in order to time-align all the signals recorded at each antenna. In this dissertation several image formation algorithms are implemented and compared by visual inspection of the resulting images and through a range of performance metrics, such as Signal-to-Clutter Ratio and FullWidth Half Maximum calculations. The results in this study showed that Microwave Imaging is a promising technique that might allow to identify the presence and location of metastasised cancer cells in axillary lymph nodes, enabling the non-invasive evaluation of breast cancer staging.

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Towards a holistic perspective of CRM, this project aims to diagnose and propose a strategy and market segmentation for Siemens Healthcare. The main underlying principle is to apply a full customer-centric outlook taking own business properties into consideration while preserving Siemens Healthcare’s culture and vision. Mainly focused on market segmentation, this project goes beyond established boundaries by employing an unbiased perspective of CRM while challenging current strategy, goals, processes, tools, initiatives and KPIs. In order to promote a sustainable business excellence strategy, this project aspires to streamline CRM strategic importance and driving the company one step forward.

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Nowadays, many of the manufactory and industrial system has a diagnosis system on top of it, responsible for ensuring the lifetime of the system itself. It achieves this by performing both diagnosis and error recovery procedures in real production time, on each of the individual parts of the system. There are many paradigms currently being used for diagnosis. However, they still fail to answer all the requirements imposed by the enterprises making it necessary for a different approach to take place. This happens mostly on the error recovery paradigms since the great diversity that is nowadays present in the industrial environment makes it highly unlikely for every single error to be fixed under a real time, no production stop, perspective. This work proposes a still relatively unknown paradigm to manufactory. The Artificial Immune Systems (AIS), which relies on bio-inspired algorithms, comes as a valid alternative to the ones currently being used. The proposed work is a multi-agent architecture that establishes the Artificial Immune Systems, based on bio-inspired algorithms. The main goal of this architecture is to solve for a resolution to the error currently detected by the system. The proposed architecture was tested using two different simulation environment, each meant to prove different points of views, using different tests. These tests will determine if, as the research suggests, this paradigm is a promising alternative for the industrial environment. It will also define what should be done to improve the current architecture and if it should be applied in a decentralised system.