2,146 research outputs found
Recommended age groups and frequency of mammography screening : a systematic review
Esta revisão teve por objetivo avaliar a
força de evidência do atual indicador de desempenho
português relativo ao rastreio do Câncer da
Mama através da mamografia, de modo a determinar
o grupo etário e a periodicidade recomendadas.
Foram pesquisados artigos nas principais
bases de dados internacionais de literatura médica.
Incluímos artigos publicados entre Janeiro de
2006 e Janeiro de 2012 que correspondiam aos
objetivos da revisão. Foi utilizada a taxonomia
SORT para a classificação dos resultados. Dos 253
artigos encontrados foram selecionados cinco que
cumpriam os critérios de inclusão. Estes incluem
três revisões sistemáticas (RS), uma meta-análise
(MA) e uma norma de orientação clínica (NOC)
baseada numa RS. Os artigos selecionados avaliaram
a redução da mortalidade por câncer da
mama através do rastreio com mamografia. A realização
do rastreio mamográfico entre os 50 e os
69 anos é recomendado em todos os artigos que
avaliam esta faixa etária. A NOC recomenda o
rastreio bienal. Em suma, a mamografia deverá
ser realizada entre os 50 e os 69 anos com uma
periodicidade bienal. Estes resultados vão ao encontro
do atual indicador de desempenho do rastreio
do câncer da mama em Portugal.The scope of this review was to assess the strength of evidence for the current Portuguese performance indicator on breast cancer screening with mammography in order to determine the recommended age group and periodicity for screening. A search for articles was conducted in the main international databases of medical literature. Articles published between January 2006 and January 2012 addressing the objectives of this review were included. The SORT taxonomy was used to classify the results. Of the 253 articles, five articles met the inclusion criteria and were selected for review. These included three systematic reviews, one meta-analysis and one clinical guideline based on a systematic review. A reduction in breast cancer mortality with mamography screening was the outcome in all articles selected. Mammography screening between 50 and 69 years was recommended in all articles that assess this age group. The clinical guidelines recommended screening every two years. In conclusion, the current literature recommends mammography for women every two years between the ages of 50 and 69 years. This is consistent with the current performance indicator for breast cancer screening in Portugal
Lulo cell line derived from Lutzomyia longipalpis (Diptera: Psychodidae) : A novel model to assay Leishmania spp. and vector interaction
Background: Leishmania (Vianna) braziliensis, Leishmania (Leishmania) amazonensis and Leishmania (Leishmania) chagasi are important parasites in the scenario of leishmaniasis in Brazil. During the life cycle of these parasites, the promastigote forms adhere to the midgut epithelial microvillii of phlebotomine insects to avoid being secreted along with digestive products. Lulo cells are a potential model that will help to understand the features of this adhesion phenomenon. Here, we analyze the interaction between Leishmania spp. promastigotes and Lulo cells in vitro, specifically focusing on adhesion events occurring between three Leishmania species and this cell line. Methods. Confluent monolayers of Lulo cells were incubated with promastigotes and adhesion was assessed using both light microscopy and scanning electron microscopy. Findings. The results indicate that species from the subgenera Leishmania and Viannia have great potential to adhere to Lulo cells. The highest adherence rate was observed for L. (L.) chagasi after 24 h of incubation with Lulo cells (27.3 1.8% of cells with adhered promastigotes), followed by L. (L.) amazonensis (16.0 0.7%) and L. (V.) braziliensis (3.0 0.7%), both after 48 h. In the ultrastructural analysis, promastigote adherence was also assessed by scanning electron microscopy, showing that, for parasites from both subgenera, adhesion occurs by both the body and the flagellum. The interaction of Lulo cells with Leishmania (L.) chagasi showed the participation of cytoplasmic projections from the former closely associating the parasites with the cells. Conclusions: We present evidence that Lulo cells can be useful in studies of insect-parasite interactions for Leishmania species. © 2011 Côrtes et al; licensee BioMed Central Ltd
Perspectives on the Trypanosoma cruzi-host cell receptor interaction
Chagas disease is caused by the parasite Trypanosoma cruzi. The critical initial event is the interaction of the trypomastigote form of the parasite with host receptors. This review highlights recent observations concerning these interactions. Some of the key receptors considered are those for thromboxane, bradykinin, and for the nerve growth factor TrKA. Other important receptors such as galectin-3, thrombospondin, and laminin are also discussed. Investigation into the molecular biology and cell biology of host receptors for T. cruzi may provide novel therapeutic targets
Significance of glycolytic metabolism-related protein expression in colorectal cancer, lymph node and hepatic metastasis
Background: Colorectal cancer (CRC) is one of the most common malignancies and a leading cause of cancer death worldwide. Most cancer cells display high rates of glycolysis with production of lactic acid, which is then exported to the microenvironment by monocarboxylate transporters (MCTs). The main aim of this study was to evaluate the significance of MCT expression in a comprehensive series of primary CRC cases, lymph node and hepatic metastasis.
Methods: Expressions of MCT1, MCT4, CD147 and GLUT1 were studied in human samples of CRC, lymph node and hepatic metastasis, by immunohistochemistry.
Results: All proteins were overexpressed in primary CRC, lymph node and hepatic metastasis, when compared with non-neoplastic tissue, with exception of MCT1 in lymph node and hepatic metastasis. MCT1 and MCT4 expressions were associated with CD147 and GLUT1 in primary CRC. These markers were associated with clinical pathological features, reflecting the putative role of these metabolism-related proteins in the CRC setting.
Conclusion: These findings provide additional evidence for the pivotal role of MCTs in CRC maintenance and progression, and support the use of MCTs as biomarkers and potential therapeutic targets in primary and metastatic CRC.This work was supported by the Fundação para a Ciência e a Tecnologia
(FCT) grant ref. PTDC/SAU-FCF/104347/2008, under the scope of ‘Programa
Operacional Temático Factores de Competitividade’ (COMPETE) of ‘Quadro
Comunitário de Apoio III’ and co-financed by the Fundo Europeu De Desenvolvimento
Regional (FEDER). Ricardo Amorim was recipient of the fellowship
SFRH/BD/98002/2013, from Fundação para a Ciência e a Tecnologia (FCT
Portugal).info:eu-repo/semantics/publishedVersio
Numerical modeling of the thermal contact in metal forming processes
Heat flow across the interface of solid bodies in
contact is an important aspect in several engineering applications.
This work presents a finite element model for the
analysis of thermal contact, which takes into account the
effect of contact pressure and gap dimension in the heat
flow across the interface between two bodies. Additionally,
the frictional heat generation is also addressed, which
is dictated by the contact forces predicted by the mechanical
problem. The frictional contact problem and thermal
problem are formulated in the frame of the finite element
method. A new law is proposed to define the interfacial heat
transfer coefficient (IHTC) as a function of the contact pressure
and gap distance, enabling a smooth transition between
two contact status (gap and contact). The staggered scheme
used as coupling strategy to solve the thermomechanical
problem is briefly presented. Four numerical examples are presented to validate the finite element model and highlight
the importance of the proposed law on the predicted
temperature.The authors gratefully acknowledge the financial
support of the Portuguese Foundation for Science and Technology
(FCT) under the project PTDC/EMS-TEC/1805/2012 and by
FEDER funds through the program COMPETE Programa Operacional
Factores de Competitividade, under the project CENTRO-07-0224-
FEDER-002001 (MT4MOBI). The second author is also grateful to the
FCT for the postdoctoral grant SFRH/BPD/101334/2014. The authors
would like to thank Prof. A. Andrade-Campos for helpful contributions
on the development of the finite element code presented in this work.info:eu-repo/semantics/publishedVersio
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