Teste de imunofluorescência indireta para a detecção de anticorpos contra o vírus da encefalite St.Louis

An in house indirect immmunofluorescence assay ( IFA ) in relation to neutralization (NT) reference test, was assessed as a fast and cheap method to carry out serological surveys for St. Louis Encephalitis virus (SLE). Sera obtained from 213 blood donors were analyzed by both tests. The prevalence of seropositivity obtained with IFA was lower than (30.98%) that observed on NT (41.78%). The relative specificity rate of IFA was 96.77% whereas its relative sensitivity rate was 69.66%. Kappa index showed a good correlation between both tests. The results indicate that neutralization assay is still the serological test with the highest sensitivity and specificity relative rates for detecting antibodies against SLE virus. Nevertheless, the IFA could be useful as an alternative test in order to learn the circulation of the Flavivirus genus in a certain area.Com a finalidade de dispor de um método rápido e de baixo custo para realizar estudos séricos dirigidos ao virus da encefalite St.Louis (ESL), avaliamos a técnica de imunofluorescência indireta (IFI) artesanal em relação ao teste referência de neutralização (NT). Examinaram-se 213 soros de doadores de sangue. A prevalência dos anticorpos obtidas na técnica de IFI (30,98%) foi mais baixa do que a pesquisada com NT (41,78%). A taxa de especificidade relativa da IFI foi 96,77%, enquanto sua taxa de sensibilidade relativa foi 69,66%. O índice Kappa demonstrou boa concordância entre os dois testes. Os resultados achados revelam que a NT continua sendo a técnica sorológica de maior taxa de especificidade e sensibilidade relativa para a detecção de anticorpos IgG para o vírus ESL. Contudo, a IFI poderia ser o teste de escolha em estudos da circulação desta arbovirose na população humana

Attempts at memory control induce dysfunctional brain activation profiles in Generalized Anxiety Disorder: An exploratory fMRI study

Suppression of aversive memories through memory control has historically been proposed as a central psychological defense mechanism. Inability to suppress memories is considered a central psychological trait in several psychiatric disorders, including Generalized Anxiety Disorder (GAD). Yet, few studies have attempted the focused identification of dysfunctional brain activation profiles when patients with Generalized Anxiety Disorders attempt memory control. Using a well-characterized behavioral paradigm we studied brain activation profiles in a group of adult GAD patients and well-matched healthy controls (HC). Participants learned word-association pairs before imaging. During fMRI when presented with one word of the pair, they were instructed to either suppress memory of, or retrieve the paired word. Subsequent behavioral testing indicated both GAD and HC were able to engage in the task, but attempts at memory control (suppression or retrieval) during fMRI revealed vastly different activation profiles. GAD were characterized by substantive hypo-activation signatures during both types of memory control, with effects particularly strong during suppression in brain regions including the dorsal anterior cingulate and the ventral prefrontal cortex. Attempts at memory control in GAD fail to engage brain regions to the same extent HC, providing a putative neuronal signature for a well-established psychological characteristic of the illness

Interleukin-13 induces expression and release of interleukin-1 decoy receptor in human polymorphonuclear cells.

The aim of this study was to examine whether interleukin-13 (IL-13), a cytokine with anti-inflammatory activities, affected expression of interleukin-1 (IL-1) receptors (R) in human polymorphonuclear cells (PMN). Treatment with IL-13 augmented both type I and type II (decoy) R transcripts, with the latter being by far the most represented. The transcriptional inhibitor actinomycin D blocked the induction of IL-1 R mRNAs by IL-13. Nuclear run-off experiments demonstrated an augmented transcriptional rate of IL-1 decoy R in IL-13-treated B lymphoblastoid cells. The protein synthesis inhibitor cycloheximide blocked type I R expression but superinduced decoy R expression. IL-13 augmented the binding of radiolabeled IL-1 beta on the PMN surface with an increased number of IL-1 receptors and no change in Kd values. IL-13 induced the surface expression of IL-1 decoy R and the release by PMN of an IL-1-binding protein identified as a soluble version of the IL-1 decoy R. These results show that PMN is an important target for IL-13 and that induction of expression and release of the IL-1 decoy R, in concert with inhibition of cytokine synthesis, may represent an important mechanism by which IL-13 blocks IL-1, a central mediator of inflammatory reactions

An analysis of observed daily maximum wind gusts in the UK

The greatest attention to the UK wind climatology has focused upon mean windspeeds, despite a knowledge of gust speeds being essential to a variety of users. This paper goes some way to redressing this imbalance by analysing observed daily maximum gust speeds from a 43-station network over the period 1980–2005. Complementing these data are dynamically downscaled reanalysis data, generated using the PRECIS Regional Climate Modelling system, for the period 1959–2001. Inter-annual variations in both the observed and downscaled reanalysis gust speeds are presented, with a statistically significant (at the 95% confidence interval) 5% increase across the network in daily maximum gust speeds between 1959 and the early 1990s, followed by an apparent decrease. The benefit of incorporating dynamically downscaled reanalysis data is revealed by the fact that the decrease in gust speeds since 1993 may be placed in the context of a very slight increase displayed over the longer 1959–2001 period. Furthermore, the severity of individual windstorm events is considered, with high profile recent events placed into the context of the long term record. A daily cycle is identified from the station observations in the timing of the daily maximum gust speeds, with an afternoon peak occurring between 12:00–15:00, exhibiting spatial and intra-annual variations

Realisation and characterisation of Cu-based references for neutron imaging calibration purposes and first results

The long-term purpose of this study is to assess the capabilities of the new Neutron Imaging beamline developed at the LENA facility of Pavia (Italy) for the characterisation of bronze artefacts. In this preliminary work, a set of Cu-based reference alloys has been produced and analysed in order to test and calibrate the facility. The first step involved the production of Cu-based alloys with chemical composition and microstructure similar to ancient artefacts. The chemical composition of the reference alloys was analysed by Optical Emission Spectroscopy. Secondly, some samples were artificially patinated with different chemical treatments obtaining an artificial corrosion products layer comparable to natural corrosion. X-Ray Diffraction, Scanning Electron Microscopy and Raman Spectroscopy have been used to characterise the corrosion patina. The main corrosion products on sulphate-induced patina are cuprite and brochantite, whereas atacamite and clinoatacamite were detected on chloride-induced patinas. Finally, preliminary Neutron Imaging measurements were performed on a first set of coated and uncoated specimens in order to try to correlate the neutrons attenuation coefficients with the chemical compositions with promising results

Epidemiología y diversidad genética del virus de la hepatitis C en la región central de Argentina

El virus de la hepatitis C (HCV) es el principal agente causante de hepatitis crónica, en el mundo. Basado en la divergencia de la secuencia de nucleótidos se lo ha clasificado en 6 genotipos y varios subtipos. La distribución de genotipos ha sido asociada a vías específicas de transmisión y a los movimientos poblacionales. Esta diversidad constituye las bases del manejo clínico del paciente y provee la información decisiva para las estrategias terapéuticas. Asimismo, la heterogeneidad genética de HCV continúa siendo el mayor obstáculo para el desarrollo de vacunas y terapias efectivas. Estudios previos realizados en Argentina demuestran que la distribución de genotipos es diferente entre regiones geográficas muy cercanas. En general el genotipo 1 es el más prevalente en la región este de nuestro país y en la región central existe una particular alta prevalencia de genotipo 2 (HCV-2) (>55%), 2c, y HCV-1 en usuarios de drogas endovenosas. A fin de confirmar la existencia de dos eventos de transmisión independientes con claras implicancias clínico terapéuticas, el objetivo de este proyecto es completar y profundizar el estudio del proceso de diversificación de estos genotipos en Córdoba mediante análisis moleculares y bioinformáticos. Así, más muestras y otras regiones genómicas deberían ser analizadas (NS5B/E2) para determinar el origen y caracterizar los patrones de diversificación. En este sentido, un reciente estudio serológico, realizado por personal del ministerio de Salud, que involucró a 3782 individuos habitantes de cuatro áreas geográficas de la provincia de Córdoba reveló una alta prevalencia de HCV (>5%). Dichas muestras son la base del estudio propuesto en este pla

Nutraceuticals and Diet Supplements in Crohn's Disease: A General Overview of the Most Promising Approaches in the Clinic

: Crohn's disease (CD) is a chronic inflammatory gastrointestinal disorder requiring lifelong medications. The currently approved drugs for CD are associated with relevant side effects and several studies suggest an increased use of nutraceuticals among CD patients, seeking for what is perceived as a more "natural" approach in controlling this highly morbid condition. Nutraceuticals are foods or foods' components with beneficial health properties that could aid in CD treatment for their anti-inflammatory, analgesic and immunoregulatory activities that come along with safety, high tolerability, easy availability and affordability. Depending on their biological effect, nutraceuticals' support could be employed in different subsets of CD patients, both those with active disease, as adjunctive immunomodulatory therapies, and/or in quiescent disease to provide symptomatic relief in patients with residual functional symptoms. Despite the increasing interest of the general public, both limited research and lack of education from healthcare professionals regarding their real clinical effectiveness account for the increasing number of patients turning to unconventional sources. Professionals should recognize their widespread use and the evidence base for or against their efficacy to properly counsel IBD patients. Overall, nutraceuticals appear to be safe complements to conventional therapies; nonetheless, little quality evidence supports a positive impact on underlying inflammatory activity