475 research outputs found

    New objects in old structures: The Iron Age hoard of the Palacio III megalithic funerary complex (Almadén de la Plata, Seville, Spain)

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    Cultural contact, exchange and interaction feature high in the list of challenging topics of current research on European Prehistory. Not far off is the issue of the changing role of monuments in the making and maintaining of key cultural devices such as memory and identity. Addressing both these highly-debated issues from a science-based perspective, in this paper we look at an unusual case study set in southern Iberia and illustrate how these archaeological questions can benefit from robust materials-science approaches.We present the contextual, morphological and analytical study of an exceptional Early Iron Age hoard composed of a number of different (and mostly exotic) materials such as amber, quartz, silver and ceramic. This hoard, found under the fallen orthostat of a megalithic structure built at least 2000 years earlier, throws new light on long-distance exchange networks and the effect they could have had on the cultural identities and social relations of local Iberian Early Iron Age communities. Moreover, the archaeometric study reveals how diverse and distant the sources of these item are (Northern Europe to Eastern and Western Mediterranean raw materials, as well as local and eastern technologies), therefore raising questions concerning the social mechanisms used to establish change and resistance in contexts of colonial encounter

    Mesotelioma Maligno Primário do Peritoneu Associado a Carcinoma de Células Renais. Revisão Concisa

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    O Mesotelioma peritoneal maligno é um tumor maligno relacionado frequentemente com exposição prolongada a fibras de amianto, de mau prognóstico, de diagnóstico geralmente tardio, face à pouca expressão clínica na fase inicial da doença. Como o mesotelioma evolui geralmente só na cavidade peritoneal, doentes seleccionados poderão ter maior sobrevivência se for possível a peritonectomia extensa e quimioterapia hipertérmica intraperitoneal intraoperatória. Os autores referem a sincronicidade ainda não descrita, de mesotelioma peritoneal maligno primário e carcinoma de Grawitz. São revistos concisamente: a clínica destes tumores, síndromes paraneoplásicos (disfunção bioquímica hepática, emagrecimento extremo); etiopatogenia da acção cancerígena das fibras de amianto; mecanismos de disseminação intraperitoneal; avaliação tomodensitométrica; importância da imunohistoquímica no diagnóstico histopatológico; estadiamento; importância do tratamento multidisciplinar destes tumores

    New missense variants in RELT causing hypomineralised amelogenesis imperfecta

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    Amelogenesis imperfecta (AI) is a heterogeneous group of genetic diseases characterised by dental enamel malformation. Pathogenic variants in at least 33 genes cause syndromic or non‐syndromic AI. Recently variants in RELT, encoding an orphan receptor in the tumour necrosis factor (TNF) superfamily, were found to cause recessive AI, as part of a syndrome encompassing small stature and severe childhood infections. Here we describe four additional families with autosomal recessive hypomineralised AI due to previously unreported homozygous mutations in RELT. Three families carried a homozygous missense variant in the fourth exon (c.164C > T, p.[T55I]) and a fourth family carried a homozygous missense variant in the 11th exon (c.1264C > T, p.[R422W]). We found no evidence of additional syndromic symptoms in affected individuals. Analyses of tooth microstructure with computerized tomography and scanning electron microscopy suggest a role for RELT in ameloblasts' coordination and interaction with the enamel matrix. Microsatellite genotyping in families segregating the T55I variant reveals a shared founder haplotype. These findings extend the RELT pathogenic variant spectrum, reveal a founder mutation in the UK Pakistani population and provide detailed analysis of human teeth affected by this hypomineralised phenotype, but do not support a possible syndromic presentation in all those with RELT‐variant associated AI

    Protective role of vitamin B6 (PLP) against DNA damage in Drosophila models of type 2 diabetes

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    Growing evidence shows that improper intake of vitamin B6 increases cancer risk and several studies indicate that diabetic patients have a higher risk of developing tumors. We previously demonstrated that in Drosophila the deficiency of Pyridoxal 5' phosphate (PLP), the active form of vitamin B6, causes chromosome aberrations (CABs), one of cancer prerequisites, and increases hemolymph glucose content. Starting from these data we asked if it was possible to provide a link between the aforementioned studies. Thus, we tested the effect of low PLP levels on DNA integrity in diabetic cells. To this aim we generated two Drosophila models of type 2 diabetes, the first by impairing insulin signaling and the second by rearing flies in high sugar diet. We showed that glucose treatment induced CABs in diabetic individuals but not in controls. More interestingly, PLP deficiency caused high frequencies of CABs in both diabetic models demonstrating that hyperglycemia, combined to reduced PLP level, impairs DNA integrity. PLP-depleted diabetic cells accumulated Advanced Glycation End products (AGEs) that largely contribute to CABs as α-lipoic acid, an AGE inhibitor, rescued not only AGEs but also CABs. These data, extrapolated to humans, indicate that low PLP levels, impacting on DNA integrity, may be considered one of the possible links between diabetes and cancer

    Sleep-wake sensitive mechanisms of adenosine release in the basal forebrain of rodents : an in vitro study

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    Adenosine acting in the basal forebrain is a key mediator of sleep homeostasis. Extracellular adenosine concentrations increase during wakefulness, especially during prolonged wakefulness and lead to increased sleep pressure and subsequent rebound sleep. The release of endogenous adenosine during the sleep-wake cycle has mainly been studied in vivo with microdialysis techniques. The biochemical changes that accompany sleep-wake status may be preserved in vitro. We have therefore used adenosine-sensitive biosensors in slices of the basal forebrain (BFB) to study both depolarization-evoked adenosine release and the steady state adenosine tone in rats, mice and hamsters. Adenosine release was evoked by high K+, AMPA, NMDA and mGlu receptor agonists, but not by other transmitters associated with wakefulness such as orexin, histamine or neurotensin. Evoked and basal adenosine release in the BFB in vitro exhibited three key features: the magnitude of each varied systematically with the diurnal time at which the animal was sacrificed; sleep deprivation prior to sacrifice greatly increased both evoked adenosine release and the basal tone; and the enhancement of evoked adenosine release and basal tone resulting from sleep deprivation was reversed by the inducible nitric oxide synthase (iNOS) inhibitor, 1400 W. These data indicate that characteristics of adenosine release recorded in the BFB in vitro reflect those that have been linked in vivo to the homeostatic control of sleep. Our results provide methodologically independent support for a key role for induction of iNOS as a trigger for enhanced adenosine release following sleep deprivation and suggest that this induction may constitute a biochemical memory of this state

    Osteoporosis-related life habits and knowledge about osteoporosis among women in El Salvador: A cross-sectional study

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    BACKGROUND: Osteoporosis is a systemic skeletal disorder, characterized by reduced bone mass, deterioration of bone structure, increased bone fragility, and increased fracture risk. It is more frequent to find among women than men at a 4:1 ratio. Evidence suggests that to adopt changes on some life habits can prevent or delay development of osteoporosis. Several osteoporosis-risk factors have been confirmed in the US and western Europe, but in El Salvador there are neither reliable epidemiological statistics about this skeletal disorder nor studies addressing osteoporosis-risk factors in women. The aim of this study was to determinate the extent of osteoporosis knowledge, the levels of both daily calcium intake and weight-bearing physical activity, and the influence of several osteoporosis-risk factors on these variables in three age groups of Salvadorean women. METHODS: In this exploratory cross-sectional study, an osteoporosis knowledge assessment questionnaire incluiding a food frequency and a physical activity record section were used to collect data and it was delivered through a face-to-face interview. A convenience sample (n = 197) comprised of three groups of women aged 25–35 years, 36–49 years, and over 49 years was taken. Among-group comparisons of means were analyzed by two-way ANOVA. To determinate the overall influence of osteoporosis-risk factors, the multivariate analysis was used. RESULTS: Study results indicated that better educated women had more knowledge about osteoporosis than women with a low education level, regardless of age, even though this knowledge was rather fair. Older women got more weight-bearing physical activity at home and less at place of employment than reported by the younger women; however, neither group performed sufficient high-intensity WBPA to improve bone mass. Regardless of age, the most women consumed 60% or less than the Dietary Reference Intake of calcium and depend on household income, lactose intolerance and coffee rather than milk consumption. CONCLUSION: In summary, the majority of women in this study have modest knowledge on osteoporosis. The knowledge base is not linked to preventive health habits, including sufficient calcium intake and performance of weight-bearing physical activities. They are thus at increased risk for low bone mass

    Eficácia do exercício físico na fadiga dos pacientes com câncer durante o tratamento ativo: revisão sistemática e meta-análise

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    El objetivo del estudio fue determinar la efectividad del ejercicio físico en la fatiga de pacientes con cáncer durante el tratamiento activo. Las bases de datos de PubMed Central, EMBASE y OVID fueron consultadas hasta abril de 2014 para identificar ensayos clínicos aleatorizados, que evaluaran el efecto del ejercicio en la fatiga de pacientes con cáncer sometidos a tratamiento activo. Once estudios (n = 1.407) fueron incluidos. La quimioterapia fue el tratamiento más común (n = 1.028). Los estudios tuvieron bajo riesgo de sesgo y alta calidad metodológica. Las estimaciones de efecto mostraron que el ejercicio físico mejoró significativamente la fatiga (SMD = -3,0; IC95%: -5,21; -0,80), p < 0,0001. Se encontraron efectos similares para el entrenamiento de resistencia (SMD = -4,5; IC95%: -7,24; -1,82), p = 0,001. Se encontraron mejoras significativas en pacientes con cáncer de mama y de próstata (p < 0,05). El ejercicio es una intervención segura y eficaz en el control de la fatiga en pacientes sometidos a tratamiento activoThis study aimed to determine the effectiveness of physical exercise in decreasing fatigue in cancer patients during active treatment. The PubMed Central, EMBASE, and OVID databases were consulted up to April 2014 to identify randomized clinical trials that evaluated the effect of exercise on fatigue in cancer patients undergoing active treatment. Eleven studies (n = 1,407) were included. Chemotherapy was the most common form of treatment (n = 1,028). The studies showed a low risk of bias and high methodological quality. Effect estimates showed that physical exercise significantly improved fatigue (SMD = -3.0; 95%CI: -5.21; -0.80), p < 0.0001. Similar effects were found for resistance training (SMD = -4.5; 95%CI: -7.24; -1.82), p = 0.001. Significant improvements were found in breast and prostate cancer patients (p < 0.05). Exercise is a safe and effective intervention in the management fatigue in cancer patients undergoing active treatmentO objetivo foi determinar a efetividade do exercício físico sobre a fadiga em pacientes com câncer durante o tratamento ativo. As bases de dados PubMed Central, EMBASE e OVID foram consultadas até abril de 2014 para identificar ensaios clínicos randomizados que avaliaram o efeito do exercício sobre a fadiga em pacientes com câncer em tratamento ativo. Onze estudos (n = 1.407) foram incluídos. A quimioterapia foi o tratamento mais comum (n = 1.028). Os estudos tiveram baixo risco de viés e alta qualidade metodológica. As estimativas de efeito mostraram que o exercício melhorou significativamente a fadiga (DMP = -3,0; IC95%: -5,21; -0,80), p < 0,0001. Efeitos semelhantes sobre o treinamento de resistência (DMP = -4,5; IC95%: -7,24; -1,82), p = 0,001 foram encontrados. O exercício físico é uma intervenção segura e eficaz contra a fadiga em pacientes submetidos ao tratamento ativoEl presente trabajo forma parte del Proyecto Práctica del autoexamen de seno y los conocimientos, factores de riesgo y estilos de vida relacionados con el cáncer de mama en mujeres jóvenes de la Universidad Santo Tomás de Bogotá: un análisis transversal (9ª Convocatoria FODEIN- Código del proyecto 4110060001 - 008)

    How protective is cervical cancer screening against cervical cancer mortality in developing countries? The Colombian case

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    <p>Abstract</p> <p>Background</p> <p>Cervical cancer is one of the top causes of cancer morbidity and mortality in Colombia despite the existence of a national preventive program. Screening coverage with cervical cytology does not explain the lack of success of the program in reducing incidence and mortality rates by cervical cancer. To address this problem an ecological analysis, at department level, was carried out in Colombia to assess the relationship between cervical screening characteristics and cervical cancer mortality rates.</p> <p>Methods</p> <p>Mortality rates by cervical cancer were estimated at the department level for the period 2000-2005. Levels of mortality rates were compared to cervical screening coverage and other characteristics of the program. A Poisson regression was used to estimate the effect of different dimensions of program performance on mortality by cervical cancer.</p> <p>Results</p> <p>Screening coverage ranged from 28.7% to 65.6% by department but increases on this variable were not related to decreases in mortality rates. A significant reduction in mortality was found in departments where a higher proportion of women looked for medical advice when abnormal findings were reported in Pap smears. Geographic areas where a higher proportion of women lack health insurance had higher rates of mortality by cervical cancer.</p> <p>Conclusions</p> <p>These results suggest that coverage is not adequate to prevent mortality due to cervical cancer if women with abnormal results are not provided with adequate follow up and treatment. The role of different dimensions of health care such as insurance coverage, quality of care, and barriers for accessing health care needs to be evaluated and addressed in future studies.</p

    In vitro activity of daptomycin, linezolid and rifampicin on Staphylococcus epidermidis biofilms

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    Owing to their massive use, Staphylococcus epidermidis has recently developed significant resistance to several antibiotics, and became one of the leading causes of hospital-acquired infections. Current antibiotics are typically ineffective in the eradication of bacteria in biofilmassociated persistent infections. Accordingly, the paucity of effective treatment against cells in this mode of growth is a key factor that potentiates the need for new agents active in the prevention or eradication of biofilms. Daptomycin and linezolid belong to the novel antibiotic therapies that are active against gram-positive cocci. On the other hand, rifampicin has been shown to be one of the most potent, prevalent antibiotics against S. epidermidis biofilms. Therefore, the main aim of this study was to study the susceptibility of S. epidermidis biofilm cells to the two newer antimicrobial agents previously mentioned, and compare the results obtained with the antimicrobial effect of rifampicin, widely used in the prevention/treatment of indwelling medical device infections. To this end the in vitro activities of daptomycin, linezolid, and rifampicin on S. epidermidis biofilms were accessed, using these antibiotics at MIC and peak serum concentrations. The results demonstrated that at MIC concentration, rifampicin was the most effective antibiotic tested. At peak serum concentration, both strains demonstrated similar susceptibility to rifampicin and daptomycin, with colony-forming units (CFUs) reductions of approximately 3–4 log10, with a slightly lower response to linezolid, which was also more strain dependent. However, considering all the parameters studied, daptomycin was considered the most effective antibiotic tested, demonstrating an excellent in vitro activity against S. epidermidis biofilm cells. In conclusion, this antibiotic can be strongly considered as an acceptable therapeutic option for S. epidermidis biofilm-associated infections and can represent a potential alternative to rifampicin in serious infections where rifampicin resistance becomes prevalent.Bruna Leite acknowledges the financial support from ISAC/Program Erasmus Munds External Cooperation and the IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus of Gualtar. Fernanda Gomes and Pilar Teixeira fully acknowledge the financial support from Fundacao para a Ciencia e Tecnologia (FCT) through the grants SFRH/BD/32126/2006 and SFRH/BPD/26803/2006, respectively

    In vitro and in vivo activities of linezolid alone and combined with vancomycin and imipenem against Staphylococcus aureus with reduced susceptibility to glycopeptides

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    The objective of this study was to evaluate the in vitro and in vivo efficacies of linezolid (35 mg/kg/5 h), vancomycin (60 mg/kg/5 h), imipenem (30 mg/kg/5 h), linezolid+imipenem, linezolid+vancomycin and vancomycin+imipenem against two clinical Staphylococcus aureus isolates with reduced susceptibility to glycopeptides using time–kill curves and the murine peritonitis model. Time–kill curves were performed over 24 h. For the murine peritonitis model, peritonitis was induced by the intraperitoneal inoculation of 108 CFU/ml of each bacterial strain. Four hours later (0 h), the mice were randomly assigned to a control group or to therapeutic groups receiving subcutaneous treatment for 25 h. Bacterial counts in peritoneal fluid, bacteraemia and mortality rates were determined. The time–kill curves showed that the addition of linezolid to imipenem yielded synergistic results after 24 h. The addition of linezolid decreased vancomycin activity. In the animal model, vancomycin and linezolid monotherapies produced comparable bacterial decreases in mice infected with each strain but linezolid achieved higher rates of blood sterilisation. Linezolid tested either in monotherapy or in combination showed similar efficacy against both strains in terms of bacterial killing, number of negative blood cultures and survival. Linezolid and vancomycin were moderately bactericidal and similar in efficacy against glycopeptide-intermediate or -resistant S. aureus. Linezolid combinations, as effective as linezolid tested alone, could be considered as alternative options for the treatment of glycopeptide-intermediate S. aureus (GISA) infections
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