290 research outputs found
Multiple Polyposis of the Gallbladder. Diagnostic Difficulties About One Case
Descreve-se um caso de uma doente de 52 anos de idade, submetida a colecistectomia com o diagnóstico de litiase biliar, baseado na colecistografia oral. No decurso do acto cirúrgico, em que não se palparam cálculos, o diagnóstico inicial foi posto em dúvida. A identificação da polipose múltipla só foi possível após colecistectomia. Com base na experiência colhida neste caso, faz-se uma revisão dos critérios diagnósticos e fundamenta-se a orientação terapêutica, dado o potencial de malignidade destas lesões
que apoio ao diagnóstico de Borreliose de Lyme?
No diagnóstico de borreliose de Lyme, infecção sub-diagnosticada em Portugal, o apoio laboratorial é crucial para o tratamento atempado dos doentes, sob risco destes evoluírem para fases crónicas, resistentes à terapêutica. A difícil confirmação do agente etiológico através da cultura, aliada ao conhecimento actual sobre as elevadas taxas de falsos negativos nos testes serológicos de rastreio, bem como de casos seronegativos de doença, torna da maior importância a implementação da nova tecnologia de amplificação (PCR) de DNA borreliano no diagnóstico de rotina desta patologia. Tratando-se de uma técnica mais rápida e sensível tem-se revelado de maior sucesso do que a cultura. O presente trabalho compara a sensibilidade destas duas técnicas de detecção directa dos agentes do complexo Borrelia burgdorferi sensu lato, em 96 doentes com suspeita clínica desta afecção e em 569 vectores (ixodídeos) capturados em território nacional. Obteve-se o isolamento de borrélias em 1,3% das biópsias cutâneas e em 1,2% dos ixodídeos (carraças) não se tendo registado isolados noutros materiais biológicos humanos. A aplicação da técnica de nested PCR confirmou a presença de DNA de B. burgdorferi sensu lato em 24,8% das amostras analisadas. A identificação dos agentes patogénicos, por técnicas de hibridação (Reverse Line Blot), sequenciação e/ou RFLP, revelou a presença de quatro espécies genómicas: B. garinii, B. lusitaniae, B. valaisiana e B. afzelii. Em conclusão, a amplificação de DNA borreliano permite uma resposta mais rápida e sensível do que a cultura, contribuindo para um diagnóstico laboratorial mais eficaz da borreliose de Lyme humana. Lyme borreliosis (LB) is an under-diagnosed zoonosis in Portugal, specially due to the absence of specific clinical signs. The role of the laboratory diagnosis, together with an epidemiological information, is extremely important for the correct treatment of patients with this pathology. The sensitivity of two laboratory techniques (culture and DNA amplification by nested PCR) for direct detection of Borrelia burgdorferi sensu lato complex agents was evaluated in samples from 96 clinically suspected patients, as also in 569 vector ticks collected throughout Portugal. Borrelia genospecies were identified in 1.3% of the skin biopsies and in 1.2% of the vectors, after growth in selective culture medium (BSK). No growth was obtained from other type of samples. B.burgdorferi sensu lato DNA was present in 24.8% of analyzed samples, as per intergenic rRNA 5S-23S (rrf–rrl) spacer amplification by nested PCR. Four genomic species (B.garinii, B.lusitaniae, B.valaisiana and B.afzelii) were identified by DNA hybridization (Reverse-Line-Blot), sequencing and/or RFLP. In conclusion and taking into account the results found in this study, it seems that Borrelia DNA amplification technique is quicker and present higher sensitivity than culture, providing a more effective laboratory diagnosis of LB in human populations and in vectors.publishe
Lusophone community in the digital age: the ambiguous place of scepticism and performance
(Excerto) "This article addresses the setting up of the political Community of the Portuguese Language Countries (Comunidade dos Países de Língua Portuguesa (CPLP)) and its present-day social and cultural dynamics. As the other articles in this Special Section from Martins, Salgado and Santos also demonstrate, media and communication systems are playing a role in the development of this loose aggregation and in the internal dynamics of the Portuguese language countries."(undefined)info:eu-repo/semantics/publishedVersio
The role of chronic muscle (in)activity on carnosine homeostasis: a study with spinal-cord injured athletes
To examine the role of chronic (in)activity on muscle carnosine (MCarn) and how chronic (in)activity affects MCarn responses to β-alanine supplementation in spinal-cord injured athletes, sixteen male athletes with paraplegia were randomized (2:1 ratio) to receive β-alanine (n=11) or placebo (PL, n=5). They consumed 6.4 g‧d-1 of β-alanine or PL for 28 days. Muscle biopsies of the active deltoid and the inactive vastus lateralis (VL) were taken before and after supplementation. MCarn in the VL was also compared with the VL of a group of individuals without paraplegia (n=15). MCarn was quantified in whole muscle and in pools of individual fibers by High-performance Liquid Chromatography. MCarn was higher in chronically inactive VL vs. well-trained deltoid (32.0±12.0 vs. 20.5±6.1 mmol‧kg-1 DM; p=0.018). MCarn was higher in inactive vs. active VL (32.0±12.0 vs. 21.2±7.5 mmol‧kg-1 DM; p=0.011). In type-I fibers, MCarn was significantly higher in the inactive VL than in the active deltoid (38.3±4.7 vs. 27.3±11.8 mmol‧kg-1 DM, p=0.014). MCarn increased similarly between inactive VL and active deltoid in the β-alanine group (VL: 68.9±55.1%, p=0.0002; deltoid: 90.5±51.4%, p<0.0001), with no changes in the PL group. MCarn content was higher in the inactive VL than in the active deltoid and the active VL, but this is probably a consequence of fiber type shift (type I to type II) that occurs with chronic inactivity. Chronically inactive muscle showed an increase in MCarn after BA supplementation equally to the active muscle, suggesting that carnosine accretion following β-alanine supplementation is not influenced by muscle inactivity
Inter-domain Communication Mechanisms in an ABC Importer: A Molecular Dynamics Study of the MalFGK2E Complex
ATP-Binding Cassette transporters are ubiquitous membrane proteins that convert the energy from ATP-binding and hydrolysis into conformational changes of the transmembrane region to allow the translocation of substrates against their concentration gradient. Despite the large amount of structural and biochemical data available for this family, it is still not clear how the energy obtained from ATP hydrolysis in the ATPase domains is “transmitted” to the transmembrane domains. In this work, we focus our attention on the consequences of hydrolysis and inorganic phosphate exit in the maltose uptake system (MalFGK2E) from Escherichia coli. The prime goal is to identify and map the structural changes occurring during an ATP-hydrolytic cycle. For that, we use extensive molecular dynamics simulations to study three potential intermediate states (with 10 replicates each): an ATP-bound, an ADP plus inorganic phosphate-bound and an ADP-bound state. Our results show that the residues presenting major rearrangements are located in the A-loop, in the helical sub-domain, and in the “EAA motif” (especially in the “coupling helices” region). Additionally, in one of the simulations with ADP we were able to observe the opening of the NBD dimer accompanied by the dissociation of ADP from the ABC signature motif, but not from its corresponding P-loop motif. This work, together with several other MD studies, suggests a common communication mechanism both for importers and exporters, in which ATP-hydrolysis induces conformational changes in the helical sub-domain region, in turn transferred to the transmembrane domains via the “coupling helices”
The type VII secretion system of <i>Staphylococcus aureus</i> secretes a nuclease toxin that targets competitor bacteria
The type VII protein secretion system (T7SS) plays a critical role in the virulence of human pathogens including Mycobacterium tuberculosis and Staphylococcus aureus. Here we report that the S. aureus T7SS secretes a large nuclease toxin, EsaD. The toxic activity of EsaD is neutralised during its biosynthesis through complex formation with an antitoxin, EsaG, which binds to its C-terminal nuclease domain. The secretion of EsaD is dependent upon a further accessory protein, EsaE, that does not interact with the nuclease domain, but instead binds to the EsaD N-terminal region. EsaE has a dual cytoplasmic/membrane localization and membrane-bound EsaE interacts with the T7SS secretion ATPase, EssC, implicating EsaE in targeting the EsaDG complex to the secretion apparatus. EsaD and EsaE are co-secreted whereas EsaG is found only in the cytoplasm and may be stripped off during the secretion process. Strain variants of S. aureus that lack esaD encode at least two copies of EsaG-like proteins most likely to protect themselves from the toxic activity of EsaD secreted by esaD(+) strains. In support of this, a strain overproducing EsaD elicits significant growth inhibition against a sensitive strain. We conclude that T7SSs may play unexpected and key roles in bacterial competitiveness
The Effectiveness of Pharmacological and Non-Pharmacological Interventions for Improving Glycaemic Control in Adults with Severe Mental Illness: A Systematic Review and Meta-Analysis
People with severe mental illness (SMI) have reduced life expectancy compared with the general population, which can be explained partly by their increased risk of diabetes. We conducted a meta-analysis to determine the clinical effectiveness of pharmacological and non-pharmacological interventions for improving glycaemic control in people with SMI (PROSPERO registration: CRD42015015558). A systematic literature search was performed on 30/10/2015 to identify randomised controlled trials (RCTs) in adults with SMI, with or without a diagnosis of diabetes that measured fasting blood glucose or glycated haemoglobin (HbA1c). Screening and data extraction were carried out independently by two reviewers. We used random effects meta-analysis to estimate effectiveness, and subgroup analysis and univariate meta-regression to explore heterogeneity. The Cochrane Collaboration’s tool was used to assess risk of bias. We found 54 eligible RCTs in 4,392 adults (40 pharmacological, 13 behavioural, one mixed intervention). Data for meta-analysis were available from 48 RCTs (n = 4052). Both pharmacological (mean difference (MD), -0.11mmol/L; 95% confidence interval (CI), [-0.19, -0.02], p = 0.02, n = 2536) and behavioural interventions (MD, -0.28mmol//L; 95% CI, [-0.43, -0.12], p<0.001, n = 956) were effective in lowering fasting glucose, but not HbA1c (pharmacological MD, -0.03%; 95% CI, [-0.12, 0.06], p = 0.52, n = 1515; behavioural MD, 0.18%; 95% CI, [-0.07, 0.42], p = 0.16, n = 140) compared with usual care or placebo. In subgroup analysis of pharmacological interventions, metformin and antipsychotic switching strategies improved HbA1c. Behavioural interventions of longer duration and those including repeated physical activity had greater effects on fasting glucose than those without these characteristics. Baseline levels of fasting glucose explained some of the heterogeneity in behavioural interventions but not in pharmacological interventions. Although the strength of the evidence is limited by inadequate trial design and reporting and significant heterogeneity, there is some evidence that behavioural interventions, antipsychotic switching, and metformin can lead to clinically important improvements in glycaemic measurements in adults with SMI
Human oral isolate Lactobacillus fermentum AGR1487 induces a proinflammatory response in germ-free rat colons
Lactobacilli are thought to be beneficial for human health, with lactobacilli-associated infections being confined to immune-compromised individuals. However, Lactobacillus fermentum AGR1487 negatively affects barrier integrity in vitro so we hypothesized that it caused a pro-inflammatory response in the host. We compared germ-free rats inoculated with AGR1487 to those inoculated with another L. fermentum strain, AGR1485, which does not affect in vitro barrier integrity. We showed that rats inoculated with AGR1487 had more inflammatory cells in their colon, higher levels of inflammatory biomarkers, and increased colonic gene expression of pro-inflammatory pathways. In addition, our in vitro studies showed that AGR1487 had a greater capacity to activate TLR signaling and induce pro-inflammatory cytokines in immune cells. This study indicates the potential of strains of the same species to differentially elicit inflammatory responses in the host and highlights the importance of strain characterization in probiotic approaches to treat inflammatory disorders
Are the distributions of variations of circle of Willis different in different populations? – Results of an anatomical study and review of literature
BACKGROUND: Previous studies have proposed correlation between variants of the cerebral arterial circle (also known as circle of Willis) and some cerebrovascular diseases. Differences in the incidence of these diseases in different populations have also been investigated. The study of variations in the anatomy of the cerebral arterial circle may partially explain differences in the incidence of some of the cerebrovascular diseases in different ethnic or racial groups. While many studies have investigated the variations in the anatomy of each segment of the cerebral arterial circle, few have addressed the variants of the cerebral arterial circle as a whole. Similarly, the frequency of occurrence of such variants in different ethnic or racial groups has not been compared. METHODS: 102 brains of recently deceased Iranian males were dissected, in order to observe variations in the anatomy of the cerebral arterial circle. The dissection process was recorded on film and digitized. One resized picture from each dissection, showing complete circle has been made available online. The variations of the circle as whole and segmental variations were compared with previous studies. RESULTS: On the whole, the frequencies of the different variants of the entire cerebral arterial circle and segmental variations were comparable with previous studies. More specifically variants with uni- and bilateral hypoplasia of posterior communicating arteries were the most common in our study, similar to the previous works. No hypoplasia of the precommunicating part of the left anterior cerebral artery (A1), aplasia of A1 or the precommunicating part of the posterior cerebral artery (P1) was seen. In 3% both right and left posterior communcating arteries were absent. CONCLUSION: The anatomical variations found in the cerebral arterial circle of the Iranian males in the current study were not significantly different to those of more diverse populations reported in the literature. While taking into account potential confounding factors, the authors conclude that based on available studies, there is no evidence suggesting that the distributions of the variations of cerebral arterial circle differ in different populations
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