140 research outputs found

    Molecular and serological techniques for the diagnosis of culture negative infective endocarditis in Alexandria Main University Hospital

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    AbstractBackground and aimCulture-negative infective endocarditis (CNIE) is a diagnostic dilemma. The study was carried out to estimate the prevalence of CNIE among definite IE cases, to describe the epidemiologic and clinical characteristics of CNIE patients and to diagnose the microbial etiology of CNIE using molecular and serological techniques.Subjects and methodsSixty-five definite IE cases were enrolled in a prospective observational study between January and December 2010. CNIE cases were tested by 16SrRNA and seminested PCR for 35 blood samples, serological tests and the study of ten valve tissue specimens.ResultsCNIE constituted 39 (60%) cases. The mean age of CNIE patients was 31years. Male to female ratio was 2.9:1. Healthcare associated IE accounted for 15.4%, native valve IE for 66.7% and intravenous drug abuse for 20.5% of cases. The mitral valve was the most frequently involved (56.4%). Out of 39 CNIE cases, seminested blood PCR detected 12 cases (ten Staphylococci, two Streptococci). Five cases were reactive by serology (three Bartonella, one Coxiella, and one Brucella). Six cases were positive by analysis of valve tissue (three Staphylococci, three Streptococci). The combined results of all diagnostic tools decreased the percentage of non-identified causes of CNIE from 60% to 24.6%.ConclusionsOur data underlined the role of collecting blood culture before starting antibiotics and the role of seminested PCR in the diagnosis of conventional causes of CNIE. The importance of serology to identify non conventional causes was also highlighted

    Estimation of the number of synapses in the hippocampus and brain-wide by volume electron microscopy and genetic labeling

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    Determining the number of synapses that are present in different brain regions is crucial to understand brain connectivity as a whole. Membrane-associated guanylate kinases (MAGUKs) are a family of scaffolding proteins that are expressed in excitatory glutamatergic synapses. We used genetic labeling of two of these proteins (PSD95 and SAP102), and Spinning Disc confocal Microscopy (SDM), to estimate the number of fluorescent puncta in the CA1 area of the hippocampus. We also used FIB-SEM, a three-dimensional electron microscopy technique, to calculate the actual numbers of synapses in the same area. We then estimated the ratio between the three-dimensional densities obtained with FIB-SEM (synapses/µm) and the bi-dimensional densities obtained with SDM (puncta/100 µm). Given that it is impractical to use FIB-SEM brain-wide, we used previously available SDM data from other brain regions and we applied this ratio as a conversion factor to estimate the minimum density of synapses in those regions. We found the highest densities of synapses in the isocortex, olfactory areas, hippocampal formation and cortical subplate. Low densities were found in the pallidum, hypothalamus, brainstem and cerebellum. Finally, the striatum and thalamus showed a wide range of synapse densities.This work was supported by grants from the following entities: the Spanish “Ministerio de Ciencia, Innovación y Universidades” (Grant PGC2018-094307-B-I00 and the Cajal Blue Brain Project [C080020-09; the Spanish partner of the Blue Brain Project initiative from EPFL, Switzerland]; the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No. 785907 (Human Brain Project, SGA2); the Wellcome Trust (Technology Development Grant 202932); and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (695568 SYNNOVATE). L.T.-R. is a recipient of grants from the EMBO Long-term fellowship 2016–2018 and the IBRO-PERC InEurope grants programme

    Blechnum Orientale Linn - a fern with potential as antioxidant, anticancer and antibacterial agent

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    <p>Abstract</p> <p>Background</p> <p><it>Blechnum orientale </it>Linn. (<it>Blechnaceae</it>) is used ethnomedicinally for the treatment of various skin diseases, stomach pain, urinary bladder complaints and sterilization of women. The aim of the study was to evaluate antioxidant, anticancer and antibacterial activity of five solvent fractions obtained from the methanol extract of the leaves of <it>Blechnum orientale </it>Linn.</p> <p>Methods</p> <p>Five solvent fractions were obtained from the methanol extract of <it>B. orientale</it> through successive partitioning with petroleum ether, chloroform, ethyl acetate, butanol and water. Total phenolic content was assessed using Folin-Ciocalteu's method. The antioxidant activity was determined by measuring the scavenging activity of DPPH radicals. Cytotoxic activity was tested against four cancer cell lines and a non-malignant cell using MTT assay. Antibacterial activity was assessed using the disc diffusion and broth microdilution assays. Standard phytochemical screening tests for saponins, tannins, terpenoids, flavonoids and alkaloids were also conducted.</p> <p>Results</p> <p>The ethyl acetate, butanol and water fractions possessed strong radical scavenging activity (IC<sub>50 </sub>8.6-13.0 μg/ml) and cytotoxic activity towards human colon cancer cell HT-29 (IC<sub>50 </sub>27.5-42.8 μg/ml). The three extracts were also effective against all Gram-positive bacteria tested: <it>Bacillus cereus, Micrococcus luteus</it>, methicillin-susceptible <it>Staphylococcus aureus </it>(MSSA), methicillin-resistant <it>Staphylococcus aureus </it>(MRSA) and <it>Stapylococcus epidermidis</it>(minimum inhibitory concentration MIC 15.6-250 μg/ml; minimum bactericidal concentration MBC 15.6-250 μg/ml). Phytochemical analysis revealed the presence of flavonoids, terpenoids and tannins. Ethyl acetate and butanol fractions showed highest total phenolic content (675-804 mg gallic acid equivalent/g).</p> <p>Conclusions</p> <p>The results indicate that this fern is a potential candidate to be used as an antioxidant agent, for colon cancer therapy and for treatment of MRSA infections and other MSSA/Gram-positive bacterial infectious diseases.</p

    HIV Delays IFN-α Production from Human Plasmacytoid Dendritic Cells and Is Associated with SYK Phosphorylation

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    Plasmacytoid dendritic cells (pDC) are the major producers of type I interferons (IFNs) in humans and rapidly produce IFN-α in response to virus exposure. Although HIV infection is associated with pDC activation, it is unclear why the innate immune response is unable to effectively control viral replication. We systematically compared the effect of HIV, Influenza, Sendai, and HSV-2 at similar target cell multiplicity of infection (M.O.I.) on human pDC function. We found that Influenza, Sendai, HSV-2 and imiquimod are able to rapidly induce IFN-α production within 4 hours to maximal levels, whereas HIV had a delayed induction that was maximal only after 24 hours. In addition, maximal IFN-α induction by HIV was at least 10 fold less than that of the other viruses in the panel. HIV also induced less TNF-α and MIP-1β but similar levels of IP-10 compared to other viruses, which was also mirrored by delayed upregulation of pDC activation markers CD83 and CD86. BDCA-2 has been identified as an inhibitory receptor on pDC, signaling through a pathway that involves SYK phosphorylation. We find that compared to Influenza, HIV induces the activation of the SYK pathway. Thus, HIV delays pDC IFN-α production and pDC activation via SYK phosphorylation, allowing establishment of viral populations

    Pediatric multiple sclerosis: update on diagnostic criteria, imaging, histopathology and treatment choices

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    Pediatric multiple sclerosis (MS) represents less than 5% of the MS population, but patients with pediatric-onset disease reach permanent disability at a younger age than adult onset patients. Accurate diagnosis at presentation and optimal long-term treatment is vital to mitigate ongoing neuroinflammation and irreversible neurodegeneration. However, it may be difficult to early differentiate pediatric MS from acute disseminated encephalomyelitis (ADEM) and neuromyelitis optica spectrum disorders (NMOSD) as they often have atypical presentation that differs from that of adult-onset MS. The purpose of this review is to summarize the updated views on diagnostic criteria, imaging, histopathology and treatment choices
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