Concentration of tumor biomarkers using aqueous biphasic systems

According to the World Health Organization, around 8.2 million people die each year with cancer. Most patients do not perform routine diagnoses and the symptoms, in most situations, occur when the patient is already at an advanced stage of the disease, consequently resulting in a high cancer mortality. Currently, prostate cancer is the second leading cause of death among males worldwide. In Portugal, this is the most diagnosed type of cancer and the third that causes more deaths. Taking into account that there is no cure for advanced stages of prostate cancer, the main strategy comprises an early diagnosis to increase the successful rate of the treatment. The prostate specific antigen (PSA) is an important biomarker of prostate cancer that can be detected in biological fluids, including blood, urine and semen. However, the commercial kits available are addressed for blood samples and the commonly used analytical methods for their detection and quantification requires specialized staff, specific equipment and extensive sample processing, resulting in an expensive process. Thus, the aim of this MSc thesis consisted on the development of a simple, efficient and less expensive method for the extraction and concentration of PSA from urine samples using aqueous biphasic systems (ABS) composed of ionic liquids. Initially, the phase diagrams of a set of aqueous biphasic systems composed of an organic salt and ionic liquids were determined. Then, their ability to extract PSA was ascertained. The obtained results reveal that in the tested systems the prostate specific antigen is completely extracted to the ionic-liquid-rich phase in a single step. Subsequently, the applicability of the investigated ABS for the concentration of PSA was addressed, either from aqueous solutions or urine samples. The low concentration of this biomarker in urine (clinically significant below 150 ng/mL) usually hinders its detection by conventional analytical techniques. The obtained results showed that it is possible to extract and concentrate PSA, up to 250 times in a single-step, so that it can be identified and quantified using less expensive techniques.

Concentration of tumor biomarkers using aqueous biphasic systems

According to the World Health Organization, around 8.2 million people die each year with cancer. Most patients do not perform routine diagnoses and the symptoms, in most situations, occur when the patient is already at an advanced stage of the disease, consequently resulting in a high cancer mortality. Currently, prostate cancer is the second leading cause of death among males worldwide. In Portugal, this is the most diagnosed type of cancer and the third that causes more deaths. Taking into account that there is no cure for advanced stages of prostate cancer, the main strategy comprises an early diagnosis to increase the successful rate of the treatment. The prostate specific antigen (PSA) is an important biomarker of prostate cancer that can be detected in biological fluids, including blood, urine and semen. However, the commercial kits available are addressed for blood samples and the commonly used analytical methods for their detection and quantification requires specialized staff, specific equipment and extensive sample processing, resulting in an expensive process. Thus, the aim of this MSc thesis consisted on the development of a simple, efficient and less expensive method for the extraction and concentration of PSA from urine samples using aqueous biphasic systems (ABS) composed of ionic liquids. Initially, the phase diagrams of a set of aqueous biphasic systems composed of an organic salt and ionic liquids were determined. Then, their ability to extract PSA was ascertained. The obtained results reveal that in the tested systems the prostate specific antigen is completely extracted to the ionic-liquid-rich phase in a single step. Subsequently, the applicability of the investigated ABS for the concentration of PSA was addressed, either from aqueous solutions or urine samples. The low concentration of this biomarker in urine (clinically significant below 150 ng/mL) usually hinders its detection by conventional analytical techniques. The obtained results showed that it is possible to extract and concentrate PSA, up to 250 times in a single-step, so that it can be identified and quantified using less expensive techniques.

Ajustamento psicossocial e adesão terapêutica em doentes oncológicos: estudo em doentes com cancro colorectal

O cancro do cólon e reto (CCR) representa uma das neoplasias malignas mais relevantes, não só pela morbilidade mas também pelas altas taxas de mortalidade. Paralelamente, esta neoplasia representa uma elevada sobrecarga psicossocial, para o indivíduo, que se reflete na existência de sintomatologia depressiva e ansiosa e de uma qualidade de vida deficitária e que se estima influenciar o processo de adesão terapêutica. Assim, o presente estudo tem como objetivo estudar a associação das variáveis sóciodemográficas, clínicas e de ajustamento psicossocial, com a adesão terapêutica em doentes com cancro colo-rectal. Trinta e cinco pacientes com cancro colo-rectal, acompanhados na Liga Portuguesa Contra o Cancro, foram selecionados de acordo com o método de amostragem de conveniência. Os instrumentos de avaliação psicossocial utilizados consistiram nos seguintes: questionário de variáveis sociodemográficas e clínicas; na Escala de Ansiedade e Depressão Hospitalar (EADH); no questionário de Qualidade de Vida da Organização Europeia de Investigação e Tratamento de Cancro (QLQC30) e na Escala de Adesão Geral (EAG). Os resultados obtidos revelam a existência de relações significativas entre sintomatologia psicopatológica, qualidade de vida e adesão ao tratamento em pacientes com CCR, mais espeficamente, encontrou-se que: a sintomatologia psicopatológica correlacionou-se negativamente com adesão ao tratamento e com a qualidade de vida, e a adesão ao tratamento associou-se positivamente com a qualidade de vida. Concluimos que o presente estudo contribui com a clarificação do sofrimento psicossocial do paciente com CCR e da interação das variáveis demográficas, clínicas e de ajustamento psicossocial com a adesão terapeutica destes doentes. Implicações clinicas e de investigação são apontadas neste contexto.