Cerebral venous thrombosis: retrospective analysis of 49 cases

Introduction: Cerebral Venous Thrombosis (CVT) is a rare and potentially life-threatening disease, accounting for about 0.5% of stroke cases. However, it is believed to be an underdiagnosed condition. Early diagnosis requires a high degree of suspicion and appropriate use of imaging modalities. Objectives: Imagiological and clinical characterization of CVT cases diagnosed at our hospital from 2004 to 2007. Methods: This study was a retrospective, cross-sectional analysis from 2004 to 2007, using our institution database. We reviewed hospital discharge data to assess the incidence of CVT. The study population consisted of 49 patients. Retrospective review of the clinical data and imaging studies of these patients was then performed. Results: Of the 49 patients with confirmed CVT, 38 were female. Patient age varied between 16 and 75 years, with an average of 42.6 years. Thrombotic risk factors were found in 43 patients; the most frequent was dyslipidemia (n = 22) followed by oral contraceptive use (n = 18). Initial head Computerized Tomography (CT) was normal in six cases. Diagnosis was made by Magnetic Resonance (MR) in 38 cases, Cerebral CT-Venography in 10 cases and Digital Subtraction Angiography in one case. Average time from onset of symptoms to diagnosis was nine days; this was not significantly different when comparing the group diagnosed by MR with the group diagnosed by CT-Venography. Right transverse sinus was the most frequent location of thrombosis (n = 36). Only in four cases thrombosis did not involve the lateral sinuses. Conclusions: Lateral sinus thrombosis is a frequent variety of CVT, accounting for 91.8% of our cases. A negative Head CT scan does not exclude the presence of cerebral venous thrombosis; therefore appropriate imaging study should be performed whenever there's a high degree of clinical suspicion. Cerebral CT-Venography seems to be a good alternative to MR for the diagnosis of CVT

An empirical evaluation of imputation accuracy for association statistics reveals increased type-I error rates in genome-wide associations

<p>Abstract</p> <p>Background</p> <p>Genome wide association studies (GWAS) are becoming the approach of choice to identify genetic determinants of complex phenotypes and common diseases. The astonishing amount of generated data and the use of distinct genotyping platforms with variable genomic coverage are still analytical challenges. Imputation algorithms combine directly genotyped markers information with haplotypic structure for the population of interest for the inference of a badly genotyped or missing marker and are considered a near zero cost approach to allow the comparison and combination of data generated in different studies. Several reports stated that imputed markers have an overall acceptable accuracy but no published report has performed a pair wise comparison of imputed and empiric association statistics of a complete set of GWAS markers.</p> <p>Results</p> <p>In this report we identified a total of 73 imputed markers that yielded a nominally statistically significant association at <it>P </it>< 10 ^-5for type 2 Diabetes Mellitus and compared them with results obtained based on empirical allelic frequencies. Interestingly, despite their overall high correlation, association statistics based on imputed frequencies were discordant in 35 of the 73 (47%) associated markers, considerably inflating the type I error rate of imputed markers. We comprehensively tested several quality thresholds, the haplotypic structure underlying imputed markers and the use of flanking markers as predictors of inaccurate association statistics derived from imputed markers.</p> <p>Conclusions</p> <p>Our results suggest that association statistics from imputed markers showing specific MAF (Minor Allele Frequencies) range, located in weak linkage disequilibrium blocks or strongly deviating from local patterns of association are prone to have inflated false positive association signals. The present study highlights the potential of imputation procedures and proposes simple procedures for selecting the best imputed markers for follow-up genotyping studies.</p

The enigmatic monotypic crab plover Dromas ardeola is closely related to pratincoles and coursers (Aves, Charadriiformes, Glareolidae)

The phylogenetic placement of the monotypic crab plover Dromasardeola (Aves, Charadriiformes) remains controversial. Phylogenetic analysis of anatomical and behavioral traits using phenetic and cladistic methods of tree inference have resulted in conflicting tree topologies, suggesting a close association of Dromas to members of different suborders and lineages within Charadriiformes. Here, we revisited the issue by applying Bayesian and parsimony methods of tree inference to 2,012 anatomical and 5,183 molecular characters to a set of 22 shorebird genera (including Turnix). Our results suggest that Bayesian analysis of anatomical characters does not resolve the phylogenetic relationship of shorebirds with strong statistical support. In contrast, Bayesian and parsimony tree inference from molecular data provided much stronger support for the phylogenetic relationships within shorebirds, and support a sister relationship of Dromas to Glareolidae (pratincoles and coursers), in agreement with previously published DNA-DNA hybridization studies

Information literacy and evidence-based medicine

The academic research and those involving the clinical decisions making are presented on juxtaposed form in health-care providers' practice, demand improvements and specialization of new necessary abilities to the professionals of information. Starting from this premise, we decide to investigate in the literature the publications in the areas that dealt, at the same time, with the thematic ones: Evidence-Based Medicine and Information Literacy. The objective of this work was to concept Evidence-Based Medicine and Information Literacy through literature revision and to designate the confluence of these thematic ones in health care providers' practice. As a result of this analysis, it was verified that the professional of information needs to know the users, how the information is organized and how it presents itself, to get better search results, to reduce uncertainties and at the same time to provide to these researchers a bigger support for decision making. It was concluded that a demand for information needs directly that the professional of information applies the ability to take care appealing it to both qualification and knowledge to get to the suitable information, using the correct tools, answering the demand without leaving trustworthiness doubts. This professional, as a mediator, contributes very much for the practice of the Evidence-Based Medicine and the spreading of services and accesses to it as well as education and promotion.201738

The dynamics of apparent horizons in Robinson-Trautman spacetimes

We present an alternative scheme of finding apparent horizons based on spectral methods applied to Robinson-Trautman spacetimes. We have considered distinct initial data such as representing the spheroids of matter and the head-on collision of two non-rotating black holes. The evolution of the apparent horizon is presented. We have obtained in some cases a mass gap between the final Bondi and apparent horizon masses, whose implications were briefly commented in the light of the thermodynamics of black holes.Comment: 9 pages, 7 figure

Dataset on SARS-CoV-2 non-pharmaceutical interventions in Brazilian municipalities

Brazil has one of the fastest-growing COVID-19 epidemics worldwide. Non-pharmaceutical interventions (NPIs) have been adopted at the municipal level with asynchronous actions taken across 5,568 municipalities and the Federal District. This paper systematises the fragmented information on NPIs reporting on a novel dataset with survey responses from 4,027 mayors, covering 72.3% of all municipalities in the country. This dataset responds to the urgency to track and share findings on fragmented policies during the COVID-19 pandemic. Quantifying NPIs can help to assess the role of interventions in reducing transmission. We offer spatial and temporal details for a range of measures aimed at implementing social distancing and the dates when these measures were relaxed by local governments

Polymyalgia Rheumatica (PMR) Special Interest Group at OMERACT 11: outcomes of importance for patients with PMR

We worked toward developing a core outcome set for clinical research studies in polymyalgia rheumatica (PMR) by conducting (1) patient consultations using modified nominal group technique; (2) a systematic literature review of outcome measures in PMR; (3) a pilot observational study of patients presenting with untreated PMR, and further discussion with patient research partners; and (4) a qualitative focus group study of patients with PMR on the meaning of stiffness, using thematic analysis. (1) Consultations included 104 patients at 4 centers. Symptoms of PMR included pain, stiffness, fatigue, and sleep disturbance. Function, anxiety, and depression were also often mentioned. Participants expressed concerns about diagnostic delay, adverse effects of glucocorticoids, and fear of relapse. (2) In the systematic review, outcome measures previously used for PMR include pain visual analog scores (VAS), morning stiffness, blood markers, function, and quality of life; standardized effect sizes posttreatment were large. (3) Findings from the observational study indicated that asking about symptom severity at 7 AM, or "on waking," appeared more relevant to disease activity than asking about symptom severity "now" (which depended on the time of assessment). (4) Preliminary results were presented from the focus group qualitative study, encompassing broad themes of stiffness, pain, and the effect of PMR on patients' lives. It was concluded that further validation work is required before a core outcome set in PMR can be recommended. Nevertheless, the large standardized effect sizes suggest that pain VAS is likely to be satisfactory as a primary outcome measure for assessing response to initial therapy of PMR. Dissection of between-patient heterogeneity in the subsequent treatment course may require attention to comorbidity as a potential confounding factor

Polymorphism analysis of the CTLA-4 gene in paracoccidioidomycosis patients

The CTLA-4 protein is expressed in activated T cells and plays an essential role in the immune response through its regulatory effect on T cell activation. Polymorphisms of the CTLA-4 gene have been correlated with autoimmune, neoplastic and infectious illnesses. This work aimed to verify possible associations between single nucleotide polymorphisms (SNPs) in CTLA-4, -318C/T in the promoter and +49A/G in exon 1 and paracoccidioidomycosis (PCM) caused by Paracoccidioides brasiliensis. For this purpose, 66 chronic form PCM patients and 76 healthy controls had their allele, genotype and haplotype frequencies determined. The genetic admixture structure of the patients and controls was evaluated to eliminate ancestral bias. The comparison of frequencies indicated no significant differences between patients and controls that could link the SNPs to PCM. Groups were admixture matched with no difference observed in population ancestry inference, indicating that the absence of association between CTLA-4 polymorphisms and PCM could not be attributed to ancestral bias. This study showed that there was no association between the CTLA-4 SNPs -318 and +49 and the resistance or susceptibility to PCM.22022