2,307 research outputs found

    Detection and quantification of poliovirus infection using FTIR spectroscopy and cell culture

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    <p>Abstract</p> <p>Background</p> <p>In a globalized word, prevention of infectious diseases is a major challenge. Rapid detection of viable virus particles in water and other environmental samples is essential to public health risk assessment, homeland security and environmental protection. Current virus detection methods, especially assessing viral infectivity, are complex and time-consuming, making point-of-care detection a challenge. Faster, more sensitive, highly specific methods are needed to quantify potentially hazardous viral pathogens and to determine if suspected materials contain viable viral particles. Fourier transform infrared (FTIR) spectroscopy combined with cellular-based sensing, may offer a precise way to detect specific viruses. This approach utilizes infrared light to monitor changes in molecular components of cells by tracking changes in absorbance patterns produced following virus infection. In this work poliovirus (PV1) was used to evaluate the utility of FTIR spectroscopy with cell culture for rapid detection of infective virus particles.</p> <p>Results</p> <p>Buffalo green monkey kidney (BGMK) cells infected with different virus titers were studied at 1 - 12 hours post-infection (h.p.i.). A partial least squares (PLS) regression method was used to analyze and model cellular responses to different infection titers and times post-infection. The model performs best at 8 h.p.i., resulting in an estimated root mean square error of cross validation (RMSECV) of 17 plaque forming units (PFU)/ml when using low titers of infection of 10 and 100 PFU/ml. Higher titers, from 10<sup>3 </sup>to 10<sup>6 </sup>PFU/ml, could also be reliably detected.</p> <p>Conclusions</p> <p>This approach to poliovirus detection and quantification using FTIR spectroscopy and cell culture could potentially be extended to compare biochemical cell responses to infection with different viruses. This virus detection method could feasibly be adapted to an automated scheme for use in areas such as water safety monitoring and medical diagnostics.</p

    Total Synthesis and Antimalarial Activity of 2-(-Hydroxybenzyl)-Prodigiosins, Isoheptylprodigiosin, and Geometric Isomers of Tambjamine MYP1 Isolated from Marine Bacteria.

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    Highly efficient and straightforward synthetic routes toward the first total synthesis of 2-(-hydroxybenzyl)-prodigiosins (-), isoheptylprodigiosin (), and geometric isomers of tambjamine MYP1 ((/)-) have been developed. The crucial steps involved in these synthetic routes are the construction of methoxy-bipyrrole-carboxaldehydes (MBCs) and a 20-membered macrocyclic core and a regioselective demethylation of MBC analogues. These new synthetic routes enabled us to generate several natural prodiginines - in larger quantity. All of the synthesized natural products exhibited potent asexual blood-stage antiplasmodial activity at low nanomolar concentrations against a panel of parasites, with a great therapeutic index. Notably, prodiginines and - provided curative in vivo efficacy against erythrocytic at 25 mg/kg Ă— 4 days via oral route in a murine model. No overt clinical toxicity or behavioral change was observed in any mice treated with prodiginines and tambjamines

    Inhibition of the mitochondrial pyruvate carrier protects from excitotoxic neuronal death.

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    Glutamate is the dominant excitatory neurotransmitter in the brain, but under conditions of metabolic stress it can accumulate to excitotoxic levels. Although pharmacologic modulation of excitatory amino acid receptors is well studied, minimal consideration has been given to targeting mitochondrial glutamate metabolism to control neurotransmitter levels. Here we demonstrate that chemical inhibition of the mitochondrial pyruvate carrier (MPC) protects primary cortical neurons from excitotoxic death. Reductions in mitochondrial pyruvate uptake do not compromise cellular energy metabolism, suggesting neuronal metabolic flexibility. Rather, MPC inhibition rewires mitochondrial substrate metabolism to preferentially increase reliance on glutamate to fuel energetics and anaplerosis. Mobilizing the neuronal glutamate pool for oxidation decreases the quantity of glutamate released upon depolarization and, in turn, limits the positive-feedback cascade of excitotoxic neuronal injury. The finding links mitochondrial pyruvate metabolism to glutamatergic neurotransmission and establishes the MPC as a therapeutic target to treat neurodegenerative diseases characterized by excitotoxicity

    Random field Ising systems on a general hierarchical lattice: Rigorous inequalities

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    Random Ising systems on a general hierarchical lattice with both, random fields and random bonds, are considered. Rigorous inequalities between eigenvalues of the Jacobian renormalization matrix at the pure fixed point are obtained. These inequalities lead to upper bounds on the crossover exponents {Ď•i}\{\phi_i\}.Comment: LaTeX, 13 pages, figs. 1a,1b,2. To be published in PR

    Voting behavior during FDA Medical Device Advisory Committee panel meetings

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    Objectives During premarket review, the US Food and Drug Administration may ask its Medical Device Advisory Committee (MDAC) Panels to assess the safety and effectiveness of medical devices being considered for approval. The objective of this study is to assess the relationship, if any, between individual votes and Panel recommendations and: (1) the composition of Panels, specifically the expertise and demographic features of individual members; or (2) Panel members’ propensity to speak during Panel deliberations. Methods This was a retrospective cohort study of routinely collected data from voting members of MDAC panels convened between January 2011 to June 2016 to consider premarket approval. Data sources were verbatim transcripts available publicly from the FDA. Number of words spoken, directionality of votes on device approval, profession, and demographics were collected. Results 658,954 words spoken by 536 members during 49 meetings of 11 Panels were analyzed. Based on multivariate analysis, biostatisticians spoke more (+373 words; P = 0.0002), and women (-187 words; P = 0.0184) and other non-physician voting members less (-213 words; P = 0.0306), than physicians. Speaking more was associated with abstaining (P = 0.0179), and with voting against the majority (P = 0.0153). Non-physician, non-biostatistician members (P = 0.0109), and those having attended more meetings as a voting member (P = 0.0249) were more likely to vote against approval. In bivariable analysis, unanimous Panels had a greater proportion of biostatisticians (mean 0.1580; 95% CI 0.1237–0.1923) than non-unanimous Panels (0.1107; 95% CI 0.0912–0.1301; p = 0.0201). Conclusions Panelists likely to vote against the majority include non-physician, non-biostatisticians; experienced Panelists; and more talkative members. The increased presence of biostatisticians on Panels leads to greater voting consensus. Having a diversity of opinions on Panels, including in sufficient numbers those members likely to dissent from majority views, may help ensure that a diversity of opinions are aired before decision-making
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