Lesion detection performance in an anthropomorphic chest phantom: comparative analysis of low-dose CT data on two hybrid imaging systems

Introduction: multimodality environment; requirement for greater understanding of the imaging technologies used, the limitations of these technologies, and how to best interpret the results; dose optimization; introduction of new techniques; current practice and best practice; incidental findings, in low-dose CT images obtained as part of the hybrid imaging process, are an increasing phenomenon with advancing CT technology; resultant ethical and medico-legal dilemmas; understanding limitations of these procedures important when reporting images and recommending follow-up; free-response observer performance study was used to evaluate lesion detection in low-dose CT images obtained during attenuation correction acquisitions for myocardial perfusion imaging, on two hybrid imaging systems.

Visual function assessment in medical imaging research

Background - Medical image perception research relies on visual data to study the diagnostic relationship between observers and medical images. A consistent method to assess visual function for participants in medical imaging research has not been developed and represents a significant gap in existing research. Methods - Three visual assessment factors appropriate to observer studies were identified: visual acuity, contrast sensitivity, and stereopsis. A test was designed for each, and 30 radiography observers (mean age 31.6 years) participated in each test. Results - Mean binocular visual acuity for distance was 20/14 for all observers. The difference between observers who did and did not use corrective lenses was not statistically significant (P = .12). All subjects had a normal value for near visual acuity and stereoacuity. Contrast sensitivity was better than population norms. Conclusion - All observers had normal visual function and could participate in medical imaging visual analysis studies. Protocols of evaluation and populations norms are provided. Further studies are necessary to understand fully the relationship between visual performance on tests and diagnostic accuracy in practice.

Isolation of human fungi from soil and identification of two endemic areas of Cryptococcus neoformans and Coccidioides immitis

The present study was carried out in two different areas of Province of Cordoba, Argentina, where there was a suspicious of endemic mycosis. The previous data were the presence of a clinical case of pulmonary cryptococcosis in one area (Alta Gracia) and the previous findings of a high incidence of coccidioidin and cryptococcin reactors in the population of the second one (Villa Dolores). In both areas soil samples for fungi were studied and Cryptococcus neoformans was found in 2/25 samples from Alta Gracia. In Villa Dolores Coccidioides immitis was isolated in 2/40 samples, and C. neoformans in 1/40 samples. Delayed hypersensitivity test with cryptococcin was determined in the population from Alta Gracia and it was found to be 5.3%. Positive cutaneous tests with coccidioidin (33.8%) and cryptococcin (31.9%) in Villa Dolores were obtained. With these findings two endemic areas of systemic mycoses in Cordoba, Argentina were delimited.

Possibility of in-hospital infection by Cryptococcus neoformans in patients with AIDS

The objective of the present work was to carry out a survey of soil samples taken from different areas of a hospital of infectious disease located in the city of Cordoba, where three AIDS patients were hospitalized during different periods in the same ward. The three of them returned with meningeal cryptococcosis between three or five months after having been discharged. Cryptococcus neoformans was isolated in 8/10 samples collected outside the hospital, near the pigeon house. The samples collected from the AIDS patients ward and its surroundings were negative. These findings suggest that the patients may have been infected by the fungus during their first stay in hospital.

Serological, electrophoretic and biological properties of Fasciola hepatica antigens

Fasciola hepatica somatic antigen, its partially purified fractions and excretion-secretion products were investigated as to serological, electrophoretic and biological properties. In a Sephadex G-100 column (SG-100), Fasciola hepatica total antigen (FhTA) gave 5 fractions, and SDS-PAGE analysis showed they were glycoproteins ranging from 14 to 94 kDa molecular weight (MW). When these fractions were analyzed by enzyme linked immunotransfer blot (EITB) and immunodiffusion in gel (ID) with serum from immunized rats with FhTA, the presence of different antigenic components was revealed. In the SDS-PAGE of excretor-secretor antigen (ESA), it was possible to observe peptides from 12 to 22 kDa, which were also present in FhTA. When the FhTA, its fractions and the ESA were analyzed by EITB with the immune rat serum (IRS), it was observed that only some fractions of the SG-100 shared antigens with the FhTA and ESA. Moreover, DTH and ITH responses were studied in FhTA immunized rats challenged with these different antigen components, revealing that the protein/carbohydrate ratio is important for inducing DTH response. The ESA was the most active component in the DTH and ITH response.

Preliminary report of HIV and Toxoplasma gondii occurrence in pregnant women from Mozambique

Toxoplasmosis, a protozoan disease, causes severe disease in fetuses during pregnancy and deadly encephalitis in HIV patients. There are several studies on its seroprevalence around the world, but studies focusing on African countries are limited in number and mostly anecdotal. We studied two groups of samples from Mozambique by ELISA, using serum samples from 150 pregnant women and six Cerebrospinal fluid (CSF) samples from AIDS patients with encephalitis. HIV status was confirmed, and CD4 blood counts were obtained from HIV-positive pregnant women. IgG seroprevalence of the group as a whole was 18.7% (28/150), with a higher prevalence in HIV-positive individuals compared to those who were HIV-negative (31.3%, [18/58] vs. 10.9%, [10/92]) patients. These data may be biased due to cumulative effects of exposition affecting disease prevalence. If corrected, this data may indicate an interaction of HIV and T. gondii. Prevalence of both diseases increases with age, but this is more clearly seen for toxoplasmosis (p < 0.005) than HIV infection, possibly explained by higher transmission of HIV after childhood. In HIV patients suffering from encephalitis, CSF serology showed that 33% of specific IgG CSF had a high avidity, which was in accordance with the data from the group of pregnant women. Lower prevalence rates of both infections in older groups could be explained by more deaths in the infected groups, resulting in an artificially lower prevalence. Using CD4 counts as a marker of time of HIV infection, and correcting for age, patients with contact with T. gondii had fewer CD4 cells, suggesting prolonged HIV disease or other causes. Toxoplasma IgG prevalence is higher in HIV+ groups, which could be ascribed to HIV- and T. gondii-associated risk factors, such as exposure to higher and more diverse social contacts. The low incidence of Toxoplasma IgG in younger age groups shows that transmission could be related to better access to cyst-containing meat in adulthood, as environmental transmission due to oocysts is usually blamed for higher incidence in children. Taken together, these data support the urgent need of research in toxoplasmosis in Africa, especially in the presence of HIV epidemics.

O hieróglifico : da imagem à escrita

Durante muito tempo interroguei-me por que razão a civilização egípcia era, simultaneamente, tão simples e tão atraente para as crianças. Há anos atrás, quando ouvi Arthur Rubinstein falar de Mozart dizendo que ele era demasiado fácil para as crianças e excessivamente difícil para os adultos, julguei encontar, finalmente, a resposta para a minha questão. Para uma criança, em Mozart, como no Egipto, o apelo é o da simplicida de, da naturalidade, do se ns íve l, da "melodiosa cor". Mas o adulto descobre-lhe s as diferentes camadas de sentido e mergulha numa complexidade que parece desvanecer o encanto original. Que me perdoe Mozart a quem continuadamente chamo para o horizonte egípcio, mas assim como ele "acordou" os homens e os deuses com a sua música, também os hieróglifos, os "pequenos de senhos animados" que tocam as crianças, despertaram o mundo e os homens do Egipto antigo.

Comparação de alguns métodos para o dimensionamento de estacas de brita: aplicação a um caso de estudo

Dissertação para obtenção do Grau de Mestre em Engenharia geológica (Geotecnia)

The Intensive Care Global Study on Severe Acute Respiratory Infection (IC-GLOSSARI): a Multicenter, Multinational, 14-Day Inception Cohort Study

PURPOSE: In this prospective, multicenter, 14-day inception cohort study, we investigated the epidemiology, patterns of infections, and outcome in patients admitted to the intensive care unit (ICU) as a result of severe acute respiratory infections (SARIs). METHODS: All patients admitted to one of 206 participating ICUs during two study weeks, one in November 2013 and the other in January 2014, were screened. SARI was defined as possible, probable, or microbiologically confirmed respiratory tract infection with recent onset dyspnea and/or fever. The primary outcome parameter was in-hospital mortality within 60 days of admission to the ICU. RESULTS: Among the 5550 patients admitted during the study periods, 663 (11.9 %) had SARI. On admission to the ICU, Gram-positive and Gram-negative bacteria were found in 29.6 and 26.2 % of SARI patients but rarely atypical bacteria (1.0 %); viruses were present in 7.7 % of patients. Organ failure occurred in 74.7 % of patients in the ICU, mostly respiratory (53.8 %), cardiovascular (44.5 %), and renal (44.6 %). ICU and in-hospital mortality rates in patients with SARI were 20.2 and 27.2 %, respectively. In multivariable analysis, older age, greater severity scores at ICU admission, and hematologic malignancy or liver disease were independently associated with an increased risk of in-hospital death, whereas influenza vaccination prior to ICU admission and adequate antibiotic administration on ICU admission were associated with a lower risk. CONCLUSIONS: Admission to the ICU for SARI is common and associated with high morbidity and mortality rates. We identified several risk factors for in-hospital death that may be useful for risk stratification in these patients.

Caracterização das expectativas dos pais face à fisioterapia respiratória infantil

A incidência das doenças respiratórias infantis é elevada a nível mundial, sendo a principal causa de mortalidade no mundo. Resultados apresentados no Congresso Nacional de Pediatria, em 2008 revelaram que 83% dos internamentos tinham como diagnóstico bronquiolite. (Gonzaga et al., 2006 e Rodrigues et al., 2008). Estas doenças representam uma carga significativa, não só em termos de custos a nível dos sistemas de saúde, mas também em termos de perda de produtividade por parte dos pais e, alteração da vida familiar. O recurso à fisioterapia respiratória infantil, tem vindo a ser crescente devido à sua reconhecida efectividade. E, ainda que a literatura valorize a expectativa como factor influente nos resultados clínicos da fisioterapia e na satisfação global do utente, não foram encontrados estudos referentes à categorização das expectativas dos pais face à fisioterapia respiratória infantil. Assim, assumiu-se como principal objectivo caracterizar as expectativas dos pais face à fisioterapia respiratória infantil. Como não se encontraram quaisquer estudos nesta área, optou-se por realizar um estudo qualitativo, de carácter descritivo, exploratório e retrospectivo para identificação das expectativas percepcionadas pelos pais antes e após o tratamento de fisioterapia respiratória infantil e, como são construídas. Utilizou-se como referencial teórico modelo de expectativas de Thompson e Sunol (1995) cit. por Bialosky et al., (2010) que classifica as expectativas em 4 categorias: preditivas, idealizadas, normativas e vagas ou sem uma ideia pré-concebida. A técnica principal de recolha de dados foi o grupo focal. Os participantes deste estudo são mãe ou pai (apenas um dos pais) de crianças que tenham tido pelo menos um episódio de patologia respiratória aguda e, que recorreram à fisioterapia, em regime hospitalar (com e sem internamento), ambulatório com e sem acordo com o SNS e domiciliário, num total de 18. Como instrumento de recolha de dados utilizou-se um guião de entrevista. As discussões foram conduzidas, transcritas e analisadas pelo investigador. Os procedimentos para a análise dos dados foram análise comportamental, o sumário etnográfico e a codificação dos dados via análise de conteúdo. De acordo com o modelo, as expectativas iniciais dos pais, cujos filhos nunca tinham feito fisioterapia respiratória são essencialmente categorias do tipo idealista ou do tipo vagas ou sem uma ideia pré-concebida. As idealistas estão relacionadas com o desejo de melhoria do bebé e do retorno às rotinas, ou são baseadas em construções falsas ou exageradas face à técnica aplicada na FRI. As vagas ou sem um ideia pré-concebida foram motivadas por não haver conhecimento ou experiência anterior de FRI. A estruturação mental das crenças e percepções associadas à FRI antes do tratamento é um processo individual e multifactorial. Foram identificados alguns géneros de crença: crenças ligadas à patologia, crenças ligadas à técnica de FRI e a crença que a saúde é controlada por factores externos. Identificou-se ainda uma construção mental definida como a percepção da importância atribuída à (falta de) saúde da criança e há ainda a considerar factores inerentes à criança e aos pais. No final do tratamento as expectativas são sobretudo do tipo preditivo (os pais procuram resultados) e do tipo afectivas ou emocionais. As preditivas estão relacionadas com a percepção dos benefícios e com o conhecimento adquirido no decorrer do contacto com a fisioterapia. A categoria do tipo afectivo ou emocional foi adicionada ao modelo inicial e, está relacionada com as expectativas relativas ao perfil do fisioterapeuta. Foram identificadas várias barreiras, que terão que ser valorizadas à luz do novo contexto sociopolítico tais como políticas de saúde, comparticipações e recursos humanos. O contacto com a FRI permitiu aos pais o conhecimento dos locais, do processo e o ganho de empowerment, que lhes permitirá reduzir a ansiedade e melhorar quer a sua capacidade interventiva no processo quer o desenvolvimento de competências de participação na resolução do problema do seu filho.

Cinética da secagem de clones de café (Coffea canephora Pierre) em terreiro de chão batido

Objetivou-se com o presente trabalho estudar a cinética da secagem de quatro clones de café da espécie Coffea canephora submetidos à secagem em terreiro de chão batido, bem como ajustar diferentes modelos matemáticos aos valores experimentais selecionando aquele que melhor representa o fenômeno em estudo. Foram utilizados frutos de café dos clones: Cpafro 194, Cpafro 193, Cpafro 167 e Cpafro180, colhidos com os teores de água iniciais de 1,20; 1,32; 1,51 e 1,46 (decimal base seca (b.s.)), respectivamente. A secagem prosseguiu em terreiro de chão batido até que o produto atingisse o teor de água de 0,137; 0,133; 0,142 e 0,140 (decimal b.s.) respectivamente para os clones Cpafro 194, Cpafro 193, Cpafro 167 e Cpafro 180. Aos dados experimentais foram ajustados dez modelos matemáticos citados na literatura específica e utilizados para representação do processo de secagem de produtos agrícolas. Baseando-se em parâmetros estatísticos, conclui-se que os modelos Verma, Dois Termos e Aproximação da Difusão foram adequados para representação da secagem dos quatro clones de café analisados, e além destes, para o clone Cpafro 167, os modelos Thompson, Page, Newton, Logarítmico, Henderson e Pabis e Exponencial de Dois Termos também se mostraram satisfatórios na descrição do fenômeno; já o tempo necessário para a secagem em terreiro de chão batido dos clones de café Cpafro 194, Cpafro 193, Cpafro 167 e Cpafro 180 foi de 189,5 h.

MET is required for the recruitment of anti-tumoural neutrophils

Mutations or amplification of the MET proto-oncogene are involved in the pathogenesis of several tumours, which rely on the constitutive engagement of this pathway for their growth and survival. However, MET is expressed not only by cancer cells but also by tumour-associated stromal cells, although its precise role in this compartment is not well characterized. Here we show that MET is required for neutrophil chemoattraction and cytotoxicity in response to its ligand hepatocyte growth factor (HGF). Met deletion in mouse neutrophils enhances tumour growth and metastasis. This phenotype correlates with reduced neutrophil infiltration to both the primary tumour and metastatic sites. Similarly, Met is necessary for neutrophil transudation during colitis, skin rash or peritonitis. Mechanistically, Met is induced by tumour-derived tumour necrosis factor (TNF)-a or other inflammatory stimuli in both mouse and human neutrophils. This induction is instrumental for neutrophil transmigration across an activated endothelium and for inducible nitric oxide synthase production upon HGF stimulation. Consequently, HGF/MET-dependent nitric oxide release by neutrophils promotes cancer cell killing, which abates tumour growth and metastasis. After systemic administration of a MET kinase inhibitor, we prove that the therapeutic benefit of MET targeting in cancer cells is partly countered by the pro-tumoural effect arising from MET blockade in neutrophils. Our work identifies an unprecedented role of MET in neutrophils, suggests a potential 'Achilles' heel' of MET-targeted therapies in cancer, and supports the rationale for evaluating anti-MET drugs in certain inflammatory diseases.

Regulamentação, concentração e instituições bancárias em contexto de crise

Dissertação de mestrado em Economia Monetária, Bancária e Financeira

The family haloplasmataceae

Haloplasmataceae is a family within the order Haloplasmatales, which currently includes one single genus and species: Haloplasma contractile. This family has unusual phenotypic features the most noticeable being a unique morphology and cellular contractility cycle and a distinct phylogenetic position between the Firmicutes and the Tenericutes (Mollicutes). Members of the Haloplasmataceae have been isolated from the upper sediments of a deep-sea anoxic brine in the Red Sea, but cultivation-independent studies have found related sequences in a wide range of biotopes including other extreme environments, contaminated soils and marine sediments, as well as intestinal samples. The isolation and description of new representatives of this family might therefore result in significant changes to the current description.