Contributos para a elaboração de um manual de procedimentos de compras públicas

A área de compras públicas tem vindo a assumir um papel preponderante na gestão estratégica das instituições públicas. Decorrente da publicação do Código dos Contratos Públicos, e na sequência das sucessivas alterações legislativas, quer nacionais, quer comunitárias, as instituições devem ter um Manual de Procedimentos que compreenda a multiplicidade de aspetos relacionados com a área de compras. O presente projeto tem como objetivo de estudo contribuir para a elaboração de um Manual de Procedimentos na área das Compras Públicas. O objetivo último será, por um lado, permitir ao auditor, no âmbito de uma auditoria à área de compras, formar uma opinião e emitir um parecer sobre a matéria analisada, e por outro lado, contribuir para aperfeiçoar os Sistemas de Controlo Interno dessas Instituições. Pela revisão da literatura, fomos conduzidos a abordar o contexto regulamentar da área de compras em Portugal, a analisar a perspetiva estratégica desta área, passando por uma descrição das diversas fases que compõem o processo de compras públicas, considerando ainda, uma abordagem ao sistema de controlo interno e riscos de negócio. Por fim, foi efetuada uma análise sobre a perspetiva de auditoria, na qual os auditores, quer internos, quer externos, têm um papel fundamental na promoção de melhorias na contratação pública, particularmente na adoção de uma abordagem construtiva e realçando as boas práticas. Decorrente da revisão da literatura, aferimos as perguntas de investigação e aplicamos a metodologia de um estudo de caso único numa instituição de ensino superior, através da elaboração de entrevistas e observação direta e participativa do investigador. As conclusões finais revelaram que o modelo de análise utilizado no nosso estudo tem no universo dos Serviços da Presidência do Instituto Politécnico do Porto uma taxa de confirmação de 59%, realçando-se positivamente o resultado da componente relativa à operacionalização das compras públicas, e destacando-se, de forma menos significativa, a componente relativa à política e gestão estratégica.

Focal Malignant Liver Lesions: Diagnosis by Dynamic Incremental CT, Early Phase

The purpose of our study was to evaluate the accuracy of dynamic incremental bolus-enhanced conventional CT (DICT) with intravenous contrast administration, early phase, in the diagnosis of malignancy of focal liver lesions. A total of 122 lesions were selected in 74 patients considering the following criteria: lesion diameter 10 mm or more, number of lesions less than six per study, except in multiple angiomatosis and the existence of a valid criteria of definitive diagnosis. Lesions were categorized into seven levels of diagnostic confidence of malignancy compared with the definitive diagnosis for acquisition of a receiver-operator-characteristic (ROC) curve analysis and to determine the sensitivity and specificity of the technique. Forty-six and 70 lesions were correctly diagnosed as malignant and benign, respectively; there were 2 false-positive and 4 false-negative diagnoses of malignancy and the sensitivity and specificity obtained were 92 and 97%. The DICT early phase was confirmed as a highly accurate method in the characterization and diagnosis of malignancy of focal liver lesions, requiring an optimal technical performance and judicious analysis of existing semiological data.

Predicting Outcome after Cardiopulmonary Arrest in Therapeutic Hypothermia Patients: Clinical, Electrophysiological and Imaging Prognosticators

INTRODUCTION: Predicting outcome in comatose survivors of cardiac arrest is based on data validated by guidelines that were established before the era of therapeutic hypothermia. We sought to evaluate the predictive value of clinical, electrophysiological and imaging data on patients submitted to therapeutic hypothermia. MATERIALS AND METHODS: A retrospective analysis of consecutive patients receiving therapeutic hypothermia during years 2010 and 2011 was made. Neurological examination, somatosensory evoked potentials, auditory evoked potentials, electroencephalography and brain magnetic resonance imaging were obtained during the first 72 hours. Glasgow Outcome Scale at 6 months, dichotomized into bad outcome (grades 1 and 2) and good outcome (grades 3, 4 and 5), was defined as the primary outcome. RESULTS: A total of 26 patients were studied. Absent pupillary light reflex, absent corneal and oculocephalic reflexes, absent N20 responses on evoked potentials and myoclonic status epilepticus showed no false-positives in predicting bad outcome. A malignant electroencephalographic pattern was also associated with a bad outcome (p = 0.05), with no false-positives. Two patients with a good outcome showed motor responses no better than extension (false-positive rate of 25%, p = 0.008) within 72 hours, both of them requiring prolonged sedation. Imaging findings of brain ischemia did not correlate with outcome. DISCUSSION: Absent pupillary, corneal and oculocephalic reflexes, absent N20 responses and a malignant electroencephalographic pattern all remain accurate predictors of poor outcome in cardiac arrest patients submitted to therapeutic hypothermia. CONCLUSION: Prolonged sedation beyond the hypothermia period may confound prediction strength of motor responses.

USE OF THE POLYMERASE CHAIN REACTION FOR THE DIAGNOSIS OF ASYMPTOMATIC Leishmania INFECTION IN A VISCERAL LEISHMANIASIS-ENDEMIC AREA

The diagnosis of asymptomatic infection with Leishmania (Leishmania) chagasi has become more important over recent years. Expansion of visceral leishmaniasis might be associated with other routes of transmission such as transfusion, congenital or even vector transmission, and subjects with asymptomatic infection are potential reservoirs. Moreover, the identification of infection may contribute to the management of patients with immunosuppressive conditions (HIV, transplants, use of immunomodulators) and to the assessment of the effectiveness of control measures. In this study, 149 subjects living in a visceral leishmaniasis endemic area were evaluated clinically and submitted to genus-specific polymerase chain reaction (PCR), serological testing, and the Montenegro skin test. Forty-nine (32.9%) of the subjects had a positive PCR result and none of them developed the disease within a follow-up period of three years. No association was observed between the results of PCR, serological and skin tests. A positive PCR result in subjects from the endemic area did not indicate a risk of progression to visceral leishmaniasis and was not associated with a positive result in the serological tests.

DETERMINATION OF VIRAL TROPISM BY GENOTYPING AND PHENOTYPING ASSAYS IN BRAZILIAN HIV-1-INFECTED PATIENTS

The clinical application of CCR5 antagonists involves first determining the coreceptor usage by the infecting viral strain. Bioinformatics programs that predict coreceptor usage could provide an alternative method to screen candidates for treatment with CCR5 antagonists, particularly in countries with limited financial resources. Thus, the present study aims to identify the best approach using bioinformatics tools for determining HIV-1 coreceptor usage in clinical practice. Proviral DNA sequences and Trofile results from 99 HIV-1-infected subjects under clinical monitoring were analyzed in this study. Based on the Trofile results, the viral variants present were 81.1% R5, 21.4% R5X4 and 1.8% X4. Determination of tropism using a Geno2pheno[coreceptor] analysis with a false positive rate of 10% gave the most suitable performance in this sampling: the R5 and X4 strains were found at frequencies of 78.5% and 28.4%, respectively, and there was 78.6% concordance between the phenotypic and genotypic results. Further studies are needed to clarify how genetic diversity amongst virus strains affects bioinformatics-driven approaches for determining tropism. Although this strategy could be useful for screening patients in developing countries, some limitations remain that restrict the wider application of coreceptor usage tests in clinical practice.

Caracterização da intervenção da Fisioterapia em indivíduos com dor crónica lombar, e seus resultados a nível da dor e capacidade funcional

RESUMO: Objectivo: Este trabalho teve como objectivo contribuir para o processo de adaptação cultural da Quebec Back Pain Disability Scale (QBPDS), através do estudo da sua Validade de Constructo e Poder de Resposta, e caracterizar a intervenção realizada pela fisioterapia (FT) e os resultados obtidos em utentes com dor crónica lombar (DCL). Introdução: A redução da incapacidade funcional associada à DCL é um dos principais objectivos e resultados da intervenção da FT nestes utentes. Com o intuito de proceder à sua avaliação, pode recorrer-se a um conjunto de diferentes instrumentos de medida, sendo a QBPDS uma das escalas mais utilizadas para medir a incapacidade. Embora esta tenha sido anteriormente adaptada para a população portuguesa, não foram determinadas as suas propriedades psicométricas. Por outro lado, apesar da literatura referir que os serviços de FT são bastante procurados por indivíduos com DCL, em Portugal, a informação existente sobre a prática da FT nesta condição clínica e sobre os resultados obtidos é ainda escassa. Metodologia: Recorreu-se a um estudo de coorte prospectivo com uma amostra de conveniência, constituída por 119 indivíduos com DCL, que iniciaram fisioterapia em 16 centros/ hospitais/ clínicas de Fisioterapia/ utentes no domicílio, e cumpriam os critérios de inclusão e exclusão estabelecidos. Os utentes foram avaliados no momento pré-intervenção e num segundo momento até 6 semanas depois. As propriedades psicométricas da Quebec Back Pain Disability Scale –Versão Portuguesa (QBPDS-VP) avaliadas foram a Validade de Constructo e o Poder de Resposta. Posteriormente procedeu-se à caracterizar a prática da FT quanto às modalidades utilizadas, número de sessões de tratamento e duração do episódio de cuidados. Adicionalmente descreveu-se os resultados obtidos após a intervenção da FT, ao nível da dor e incapacidade. Resultados: Os resultados revelaram um resultado positivo para a Validade de Constructo da QBPDS-VP e um elevado Poder de Resposta (área abaixo da curva ROC = 0,736; IC95%=0,639-0,833). Apresenta ainda uma diferença mínima clinicamente importante (DMCI) de 7 pontos (sensibilidade =72,4% e especificidade = 69,8%). Aquando da intervenção da FT em casos de DCL, existe uma grande diversidade de modalidades realizadas combinadas em diferentes pacotes de intervenção, e verificou-se um número médio de sessões realizadas de 14,22 visitas por utente, numa duração de episódio de cuidados maioritariamente superior a 6 semanas. Os resultados da intervenção revelaram uma redução significativa da incapacidade funcional e da intensidade da dor (z= -7,440 e z=-6,625; respectivamente, p=0,000). Conclusão: Os resultados do presente estudo revelam que a QBPDS-VP possui uma boa Validade de Constructo e Poder de Resposta. Revela ainda que a intervenção da FT em casos de DCL, apesar de apresentar grande diversidade nas modalidades utilizadas por vezes até divergentes das recomendações dadas pelas normas de orientação clínica, e uma duração do episódio de cuidados aparentemente superior aos dados fornecidos pela literatura; proporciona uma redução significativa dos níveis de dor e incapacidade em utentes com DCL.------------ ABSTRACT: Objective: The aim of this study is to contribute to the process of cultural adaptation of the Quebec Back Pain Disability Scale (QBPDS), through the study of its Construct Validity and Responsiveness, and characterize the intervention performed by physical therapy (PT) and the results in patients with chronic low back pain (CLBP). Introduction: The reduction in functional disability associated with CLBP is one of the main purpose and results of physical therapy intervention in these patients. With the intention of evaluating them, the professionals can resort to a set of different measuring instruments, and the QBPDS is one of the most commonly used scales for measuring disability. Although this has been previously adapted for the Portuguese population, it was not determined its psychometric properties. Moreover, despite the literature noted that services for PT are quite sought by individuals with CLBP, in Portugal, the existing information on the practice of PT in this clinical condition and the results obtained are still scarce. Methodology: It was used a prospective cohort study with a convenience sample consisting of 119 individuals with CLBP, who started therapy at 16 centers / hospitals / Physiotherapy clinics / household physiotherapy, and fulfiled the inclusion and exclusion criteria established . The patients were assessed at pre-intervention and a second time after 6 weeks. Psychometric properties of the Quebec Back Pain Disability Scale-Portuguese version (QBPDS-VP) were evaluated to construct validity and responsiveness. Subsequently, it was proceeded to the characterization the practice of FT regarding to the modalities used, the number of treatment sessions and duration of the episode of care. Additionally it was described the results obtained after the intervention of the PT, the level of pain and the disability. Results: The results revealed a positive result for the Construct Validity of the QBPDS- VP and a high responsiveness (area under the ROC curve = 0.736, 95% CI 0.639 to 0.833). Minimal clinically important difference (MCID) also presents a 7-point (sensitivity = 72.4% and specificity = 69.8%). In the PT intervention in cases of CLBP there is a great diversity of procedures performed combined in different packages intervention, and it was found an average number of sessions of 14.22 visits per user, with a duration of the episode of care mostly higher to 6 weeks. The results of the intervention showed a significant reduction of disability and pain intensity (z = -7.440 z = -6.625, respectively, p = 0.000).Conclusion: The results of this study show that QBPDS-VP has a good construct validity and responsiveness. It also reveals that the PT intervention in cases of CLBP, despite showing great diversity in the methods used, that sometimes are also divergent to the recommendations given by clinical guidelines, and with a duration of episode of care apparently superior to data provided by the literature, provides an significant reduction in the levels of pain and disability in patients with DCL.

Predição de Pré-Eclâmpsia no Primeiro Trimestre em Gravidezes de Baixo Risco: Determinação do Cut-Off numa Amostra da População Portuguesa

Objective:We aimed to identify the cut-off for risk of pre-eclampsia (PE) in Portuguese population by applying the first trimester prediction model from Fetal Medicine Foundation (FMF) in a prospective enrolled cohort of low risk pregnant women. Population and methods: A prospective cohort of low risk singleton pregnancies underwent routine first-trimester scree - ning from 2011 through 2013. Maternal characteristics, blood pressure, uterine artery Doppler, levels of pregnancy-associated plasma protein-A (PAPP-A) and free b-human chorionic gonadotropin were evaluated. The prediction of PE in first trimester was calculated through software Astraia, the outcome obtained from medical records and the cutoff value was subse quently calculated. Results:Of the 273 enrolled patients, 7 (2.6%) developed PE. In first trimester women who developed PE presented higher uterine arteries resistance, represented by higher values of lowest and mean uterine pulsatility index, p <0.005. There was no statistical significance among the remaining maternal characteristics, body mass index, blood pressure and PAPP-A. Using the FMF first trimester PE algorithm, an ideal cut-off of 0.045 (1/22) would correctly detect 71% women who developed PE for a 12% false positive rate and a likelihood ratio of 12.98 (area under the curve: 0.69; confidence interval 95%: 0.39-0.99). By applying the reported cutoff to our cohort, we would obtain 71.4% true positives, 88.3% true negatives, 11.4% false positives and 28.6% false negatives. Conclusion: By applying a first trimester PE prediction model to low risk pregnancies derived from a Portuguese population, a significant proportion of patients would have been predicted as high risk. New larger studies are required to confirm the present findings.

Longitudinal study of the indirect immunofluorescence and complement fixation tests for diagnosis of chagas' disease in immunosuppressed patients submitted to renal transplantation

Clinical and serological follow-up of 7 patients submitted to renal transplantation and presenting positive serological reactions to Chagas 'disease before immunossupression did not show significant changes in indirect immunofluorescence and complement fixation titres for Chagas ' disease, or signs and symptoms indicating exacerbation of the disease during follow- up. In addition, 18 of 66 recipients of renal transplants considered to be non-chagasic before immunosuppression showed at least one positive result to the indirect immunofluorescence test for Chagas ' disease during the study period. The results suggest that the immunosuppression State induced in chagasic patients submitted to renal transplant did notpromoted exacerbation of the chronic infection in these patients and not interfere with the serological response of chronic chagasics, thus permitting the use of these serologic reactions for diagnostic purposes in these cases. However, the positive results ofthe indirect immunofluorescence test in non- chagasic patients indicate the needforjudicious interpretation ofthe indirect immunofluorescence test for the diagnosis of Chagas' disease in renal transplanted patients.

Prospective study of strongyloidosis in patients with hematologic malignancies

Immunocompromised individuals infected with Strongyloides stercoralis may develop severe hyperinfection or disseminated disease with high mortality. Patients with hematological malignancies are at risk because of immunodepression produced either by the disease or its treatment. A prospective study was undertaken at the Hospital de Clínicas de Porto Alegre, from July 1994 to July 1995. Seventy-two (HIV negative), had 3 stool samples collected at different days and had not received recent anti-helmintic therapy. Larvae, isolated in a modified Baermann method, were found in 6 patients, with a resultant prevalence of 8.3%. No complicated strongyloidosis was documented. The positive result for S. stercoralis larvae was significantly associated (p < 0.001) with eosinophilia. Knowledge of prevalence figures and incidence of severe disease is important to adequate guidelines for empirical treatment besides the rigorous search for strongyloidosis in patients with hematological malignancies.

Low frequency of side effects following an incidental 25 times concentrated dose of yellow fever vaccine

In August/1999, a group of 14 adults from the staff of a private hospital in Contagem -- Minas Gerais State, Brazil, received unintentionally a 25 times concentrated dose of the 17-DD yellow fever vaccine (Bio-Manguinhos), due to a mistake at the reconstitution step. All patients were clinically and laboratorially evaluated at days 5, 13 and 35 post vaccination. Frequency of side effects and clinical observations of this group of individuals were not different from the observed in recipients immunized with normal doses of the vaccine. At the second and third evaluation none of the subjects reported symptoms. None of the patients presented abnormalities at the physical examination at none of the time points and in all cases the blood examination was normal, except for a reduced number of platelets that was detected in one subject at the first and second evaluation and reverted to normal at third evaluation. At the first evaluation point, 8 subjects were serum negative and 6 serum positive for yellow fever at the plaque reduction neutralization test. In 5 subjects the observed titre was 10 times higher as the baseline of 2.36 Log10 mUI/ml. The samples collected at second and third evaluation (13th and 35th days) demonstrated that all subjects responded to the vaccination with the exception of one that did not present a positive result in any of the samples collected. This evaluation confirms the safety of the 17-DD yellow fever vaccine.

Rastreio combinado do 1º trimestre e doenças autoimunes : Impacto das variaveis pré-analíticas na avaliação do risco

RESUMO: Contexto: As anomalias congénitas, com particular destaque para as neuploidias , afectam aproximadamente 2% dos recém-nascidos, constituindo causas frequentes de morbilidade e mortalidade. Actualmente, a avaliação do grau de risco para as aneuploidias mais prevalentes (T21, T13, T18) é efectuada através do “Rastreio Combinado do 1º Trimestre”, devendo as grávidas com risco acrescido ser sujeitas a exames invasivos (ex.biópsia das vilosidades coriónicas,amniocentese). Quanto mais qualidade existir num rastreio, menos falsos positivos existirão e menor o número de exames diagnósticos invasivos desnecessários. As doenças autoimunes são doenças inflamatórias crónicas em cuja fisiopatologia se encontram distúrbios da imunidade humoral e celular, dependentes de factores genéticos, hormonais,psicológicos e ambientais. Atingem mais o sexo feminino e durante a idade fértil,podendo influenciar o outcome da gravidez e a saúde neonatal causando significativa morbilidade e mortalidade. O lúpus eritematoso sistémico para além de potencialmente afectado pelas alterações imunoendócrinas fisiológicas da gravidez, associa-se frequentemente a problemas de fertilidade. Recentemente, foi sugerido que as anormalidades ocorridas durante a invasão precoce do sinciciotrofoblasto, resultando em deficiente diferenciação, deficiente maturação e diminuição na produção de hCG, poderão ser o mecanismo fisiopatológico primário para as perdas fetais no primeiro trimestre, nos doentes com SLE. A ocorrência de níveis elevados de hCG total e ß-hCG livre no rastreio para despiste de síndrome de Down do segundo e do primeiro trimestre foi assinalada em grávidas portadoras de lúpus, mas a escassez de estudos comprovativos e a pequena dimensão das amostras estudadas constituiu uma limitação significativa na fidedignidade dos resultados obtidos. Objectivos: O estudo teve como objectivos i. estabelecer valores normativos Portugueses e de distribuição para as MoM’s dos parâmetros séricos do primeiro trimestre, por semana de gestação:(PAPP-A e ß-hCG livre), ii. avaliar a influência que as doenças autoimunes têm sobre as MoM’s individuais dos parâmetros bioquímicos PAPP-A e/ou ß-hCG livre, utilizados no rastreio pré-natal combinado do 1º trimestre, e iii. saber se as doenças autoimunes podem condicionar um aumento da taxa de resultados falsos positivos, com consequente aumento do número de amniocenteses. Metodologia: Estudo longitudinal prospectivo, consistindo num rastreio pré-natal combinado de 1º trimestre para pesquisa de aneuploidias, em duas amostras provenientes do Reino Unido (n= 45,854) e de Portugal (n=3122). Foram avaliados parâmetros socio-demográficos, ecográficos, laboratoriais, e calculados os indicadores de desempenho do rastreio combinado. A execução analítica dos testes bioquímicos séricos (PAPP-A e ß-hCG livre) foi realizada no autoanalisador Brahms Kryptor e no autoanalizador 6000 Delfia Xpress. Compararam-se os grupos autoimune e não autoimune das amostras. Resultados: Relativamente às características populacionais, o grupo auto imune tinha valores significativamente superiores nas variáveis idade materna e idade gestacional. Comparando os grupos com e sem doença autoimune, constatou-se a existência de uma elevação das MoM’s da ß-hCG livre nas grávidas com doença autoimune, nomeadamente nos casos de lúpus eritematoso sistémico. Conclusões: os resultado obtidos reforçam a indicação do rastreio combinado do 1º trimestre certificado pela FMF nas grávidas com doenças autoimunes, nomeadamente para as doentes com LES; no entanto, devem ser calculados e introduzidos factores de correcção no algoritmo de risco, de modo a evitar a subida no número de resultados falso-positivos, e consequentemente a sobre- utilização de métodos invasivos.------------ ABSTRACT: Context: Congenital anomalies, with particular reference to aneuploidias, affect approximately 2% of newborns, and are frequent causes of morbidity and mortality. Currently, the risk evaluation for the most prevalent aneuploidias (T21, T13, T18) is carried out through the “combined first trimester screening”, and pregnant women with increased risk are subjected to invasive tests (e.g. villus biopsy done, amniocentesis). The more quality exists in a screening, less false positives exists and fewer unnecessary invasive diagnostic exams. Autoimmune diseases are chronic inflammatory diseases in whose pathophysiology are immune humoral and cellular disorders, dependent on genetic factors, hormonal, psychological and environmental factors. The disease is more prevalent among females, during the child-bearing age, and may influence the outcome of pregnancy and neonatal health causing significant morbidity and mortality. Lupus Erythematosus in addition to potentially affected by immunoendocrine physiological changes of pregnancy, is often associated with fertility problems. Recently, it has been suggested that the abnormalities that occurred during the early invasion of the syncytiotrophoblast, resulting in insufficient differentiation, deficient maturation and decrease in production of hCG may be the primary pathophysiological mechanism for fetal losses in the first quarter, in patients with SLE. The occurrence of elevated levels of total hCG and free ß-hCG in screening for Down’s syndrome of the second and first trimester was reported in pregnant women with lupus, but the paucity of supporting studies and the small size of the samples studied constituted a significant limitation on the trustworthiness of the results obtained. Objectives: this study aims to i. establish normative values for the serum parameters MoM’s (PAPP-A and free β-hCG) and it’s distribution, in the first trimester, by week of pregnancy; ii. assess the influence that the autoimmune diseases have on the MoM’s of individual biochemical PAPP-A and/or β-hCG, used in antenatal screening combined for the first trimester, and iii. whether the autoimmune diseases may make an increased rate of false positives, with consequent increase in the number of amniocenteses.Methodology: Prospective longitudinal study, consisting of a combined first trimester antenatal screening for aneuploidies lookup in two samples from the United Kingdom (n=45.854) and Portugal (n= 3.122). Socio-demographic, echographic and laboratory parameters were evaluated, and combined screening performance indicators were calculated. The analytical run of serum biochemical tests (PAPP-A and ß-hCG) was held at the Brahms Kryptor and in Delfia Xpress 6000. Comparisons between autoimmune group and non-autoimmune group were made. Results: Relating to population characteristics, the autoimmune group had significantly diferente values in the variables maternal age and gestational age. Comparing the groups with and without autoimmune disease, it was noted that there is an elevation of the MoM’s of free ß-hCG levels in pregnant women with autoimmune disease, particularly in cases of systemic lupus erythematosus. Conclusions: The results obtained reinforce the indication of FMF certified combined screening in pregnant women with autoimmune diseases, notably to the patients with SLE; However, correction factors should be calculated and entered in the risk algorithm, in order to avoid the rise in the number of false positive results, and consequently the over-use of invasive methods.

The usefulness of Umelosa hepatitis C vírus qualitative kit as supplemental test for confirmation of hepatitis C virus infection

Forty voluntary blood donors from two different blood banks in Havana, Cuba, who were repeatedly reactive on the routine screening of antibodies to hepatitis C virus, by Umelisa HCV test, were analyzed for the presence of HCV RNA using a nested PCR assay of the HCV 5' untranslated region, Umelosa HCV qualitative. Sera from 45 patients of a specialized gastroenterology consultation, positive to Umelisa HCV, were also assayed with the Umelosa HCV qualitative, to establish their condition related to the presence of HCV RNA previously to the indication of a treatment or after three, six or twelve months of antiviral therapy. Serum HCV-RNA was detected in 21/40 (52.5%) donors who had repeatedly positive ELISA results, confirming the HCV infection for them. In specialized consultation HCV-RNA was detected by PCR analysis in 30/45 (66%) analyzed sera.

Optimization of breast tomosynthesis image reconstruction using parallel computing

Breast cancer is the most common cancer among women, being a major public health problem. Worldwide, X-ray mammography is the current gold-standard for medical imaging of breast cancer. However, it has associated some well-known limitations. The false-negative rates, up to 66% in symptomatic women, and the false-positive rates, up to 60%, are a continued source of concern and debate. These drawbacks prompt the development of other imaging techniques for breast cancer detection, in which Digital Breast Tomosynthesis (DBT) is included. DBT is a 3D radiographic technique that reduces the obscuring effect of tissue overlap and appears to address both issues of false-negative and false-positive rates. The 3D images in DBT are only achieved through image reconstruction methods. These methods play an important role in a clinical setting since there is a need to implement a reconstruction process that is both accurate and fast. This dissertation deals with the optimization of iterative algorithms, with parallel computing through an implementation on Graphics Processing Units (GPUs) to make the 3D reconstruction faster using Compute Unified Device Architecture (CUDA). Iterative algorithms have shown to produce the highest quality DBT images, but since they are computationally intensive, their clinical use is currently rejected. These algorithms have the potential to reduce patient dose in DBT scans. A method of integrating CUDA in Interactive Data Language (IDL) is proposed in order to accelerate the DBT image reconstructions. This method has never been attempted before for DBT. In this work the system matrix calculation, the most computationally expensive part of iterative algorithms, is accelerated. A speedup of 1.6 is achieved proving the fact that GPUs can accelerate the IDL implementation.

Assessment of Notch1 ligands production - key protein targets in breast cancer

Cell-to-cell communication is required for many biological processes in development and adult life. One of the most common systems utilized by a wide range of eukaryotes is the Notch signalling pathway. Four Notch receptors and five ligands have been identified in mammals that interact via their extracellular domains leading to transcription activation. Studies have shown that the Notch ligands expression is undetectable in normal breast tissues, but moderate to high expression has been detected in breast cancer. Thus, any of the Notch1 ligands can be studied as possible therapeutic targets for breast cancer. To study Notch pathway proteins there is the need to obtain stable protein solutions. E. coli is the host of excellence for recombinant proteins for the ease of use, fast growth and high cell densities. However, the expression of mammalian proteins in such systems may overwhelm the bacterial cellular machinery, which does not possess the ability for post-translational modifications, or dedicated compartments for protein synthesis. Mammalian cells are therefore preferred, despite their technical and financial increased demands. We aim to determine the best expression and purification conditions for the different ligand protein constructs, to develop specific function-blocking antibodies using the Phage Display technology. Moreover, we propose to crystallize the Notch1 ligands alone and in complex with the phage display selected antibodies, unveiling molecular details. hJag2DE3 and hDll1DE6 proteins were purified from refolded inclusion bodies or mammalian cell culture supernatants, respectively, and purity was confirmed by SDS-PAGE (>95%). Protein produced in mammalian cells showed to be more stable, apparently with the physiological disulfide pattern, contrary to what was observed in the refolded protein. Several nano-scale crystallization experiments were set up in 96-well plates, but no positive result was obtained. We will continue to pursue for the best expression for the Notch ligand constructs in both expression systems.

Decline in prevalence and asymmetric distribution of human T cell lymphotropic virus 1 and 2 in blood donors, State of Minas Gerais, Brazil, 1993 to 2007

INTRODUCTION: Human T cell lymphotropic virus types 1 and 2 (HTLV-1/2) are endemic in Brazil and are screened for in transfusion services since 1993. This study evaluated the evolution of the prevalence of HTLV-1 and 2 in blood donors of the Hemominas Foundation from 1993 to 2007, and its geographical distribution in State of Minas Gerais, Brazil. METHODS: The Hemominas Foundation is a centralized blood center in Minas Gerais, Brazil. The sources of data were the Hemominas Foundation Technical Bulletin and files from the centralized serological laboratory. Donors were tested in the period using enzyme linked immuno sorbent assays (ELISA), followed by Western blot, when repeatedly reactive. The data were analyzed by EPIINFO 6.2 and TABWIN 3.5 softwares. RESULTS: The average seroprevalence in the period 1993-2007 was 0.1%. A steady decline occurred from 0.4% in 1993 to below 0.1% in 2002 and later, with a transient peak of 0.5% in 1994. HTLV reactivity distribution was asymmetrical in the state, with regions of higher prevalence, interspersed with low prevalence areas. Comparison of positive and negative donors verified that increasing age was proportional to virus positivity. Odds ratio for age ranged from 1.43 (30 to 39 years-old) to 3.09 (50 to 65 years-old). Women had a greater chance of being positive (OR-1.64), as previously described. CONCLUSIONS: Possible explanations for HTLV-1/2 prevalence decline are the exclusion of positive donors from the donor pool, an increase in repeat donors and ELISA test improvement, with reduction in the number of false positive results.