Survival of a sars-cov-2 surrogate on flow-pack polyethylene and polystyrene food trays at refrigeration and room temperature conditions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of the current pandemic referred to as coronavirus disease 2019, is spread by direct and indirect transmission between humans, including contact with contaminated surfaces, frozen food, packaging materials, and storage environments. Food contamination may occur in the “farm-to-table” lifecycle through contact with food handlers and environments. In the present study, the survival of a SARS-CoV-2 surrogate (feline coronavirus (FCoV)) at room temperature and refrigeration conditions for different time intervals on two types packaging widely used packaging, namely flow-pack polyethylene and polystyrene food trays, was investigated. FCoV was stable on the flow-pack polyethylene for 48 h and 120 h at room temperature and 4◦C, respectively, while it persisted on polystyrene food trays for 36 h at room temperature and for 120 h at +4◦C. The results of our study highlight the possible implications of food packaging in the spread of SARS-CoV-2 during the current pandemic

Mitochondrial enzyme GLUD2 plays a critical role in glioblastoma progression

Background: Glioblastoma (GBM) is the most frequent and malignant primary brain tumor in adults and despite the progress in surgical procedures and therapy options, the overall survival remains very poor. Glutamate and α-KG are fundamental elements necessary to support the growth and proliferation of GBM cells. Glutamate oxidative deamination, catalyzed by GLUD2, is the predominant pathway for the production of α-KG. Methods: GLUD2 emerged from the RNA-seq analysis of 13 GBM patients, performed in our laboratory and a microarray analysis of 77 high-grade gliomas available on the Geo database. Thereafter, we investigated GLUD2 relevance in cancer cell behavior by GLUD2 overexpression and silencing in two different human GBM cell lines. Finally, we overexpressed GLUD2 in-vivo by using zebrafish embryos and monitored the developing central nervous system. Findings: GLUD2 expression was found associated to the histopathological classification, prognosis and survival of GBM patients. Moreover, through in-vitro functional studies, we showed that differences in GLUD2 expression level affected cell proliferation, migration, invasion, colony formation abilities, cell cycle phases, mitochondrial function and ROS production. In support of these findings, we also demonstrated, with in-vivo studies, that GLUD2 overexpression affects glial cell proliferation without affecting neuronal development in zebrafish embryos. Interpretation: We concluded that GLUD2 overexpression inhibited GBM cell growth suggesting a novel potential drug target for control of GBM progression. The possibility to enhance GLUD2 activity in GBM could result in a blocked/reduced proliferation of GBM cells without affecting the survival of the surrounding neurons

Aqueous reactions of organic triplet excited states with atmospheric alkenes

Triplet excited states of organic matter are formed when colored organic matter (i.e., brown carbon) absorbs light. While these “triplets” can be important photooxidants in atmospheric drops and particles (e.g., they rapidly oxidize phenols), very little is known about their reactivity toward many classes of organic compounds in the atmosphere. Here we measure the bimolecular rate constants of the triplet excited state of benzophenone (3BP∗), a model species, with 17 water-soluble C3–C6 alkenes that have either been found in the atmosphere or are reasonable surrogates for identified species. Measured rate constants (kALK+3BP∗) vary by a factor of 30 and are in the range of (0.24–7.5)&thinsp;×109&thinsp;M−1&thinsp;s−1. Biogenic alkenes found in the atmosphere – e.g., cis-3-hexen-1-ol, cis-3-hexenyl acetate, and methyl jasmonate – react rapidly, with rate constants above 1×109&thinsp;M−1&thinsp;s−1. Rate constants depend on alkene characteristics such as the location of the double bond, stereochemistry, and alkyl substitution on the double bond. There is a reasonable correlation between kALK+3BP∗ and the calculated one-electron oxidation potential (OP) of the alkenes (R2=0.58); in contrast, rate constants are not correlated with bond dissociation enthalpies, bond dissociation free energies, or computed energy barriers for hydrogen abstraction. Using the OP relationship, we estimate aqueous rate constants for a number of unsaturated isoprene and limonene oxidation products with 3BP∗: values are in the range of (0.080–1.7)&thinsp;×109&thinsp;M−1&thinsp;s−1, with generally faster values for limonene products. Rate constants with less reactive triplets, which are probably more environmentally relevant, are likely roughly 25 times slower. Using our predicted rate constants, along with values for other reactions from the literature, we conclude that triplets are probably minor oxidants for isoprene- and limonene-related compounds in cloudy or foggy atmospheres, except in cases in which the triplets are very reactive.</p

ANKRd44 gene silencing: A putative role in trastuzumab resistance in HER2-like breast cancer

Trastuzumab is an effective therapeutic treatment for Her2-like breast cancer; despite this most of these tumors develop resistance to therapy due to specific gene mutations or alterations in gene expression. Understanding the mechanisms of resistance to Trastuzumab could be a useful tool in order to identify combinations of drugs that elude resistance and allow a better response for the treated patients. Twelve primary biopsies of Her2+/hormone receptor negative (ER-/PgR-) breast cancer patients were selected based on the specific response to neoadjuvant therapy with Trastuzumab and their whole exome was sequenced leading to the identification of 18 informative gene mutations that discriminate patients selectively based on response to treatment. Among these genes, we focused on the study of the ANKRD44 gene to understand its role in the mechanism of resistance to Trastuzumab. The ANKRD44 gene was silenced in Her2-like breast cancer cell line (BT474), obtaining a partially Trastuzumab-resistant breast cancer cell line that constitutively activates the NF-kb protein via the TAK1/AKT pathway. Following this activation an increase in the level of glycolysis in resistant cells is promoted, also confirmed by the up-regulation of the LDHB protein and by an increased TROP2 protein expression, found generally associated with aggressive tumors. These results allow us to consider the ANKRD44 gene as a potential gene involved in Trastuzumab resistance

Loss of BMP signaling through BMPR1A in osteoblasts leads to greater collagen cross-link maturation and material-level mechanical properties in mouse femoral trabecular compartments

Bone morphogenetic protein (BMP) signaling pathways play critical roles in skeletal development and new bone formation. Our previous study, however, showed a negative impact of BMP signaling on bone mass because of the osteoblast-specific loss of a BMP receptor (i.e. BMPR1A) showing increased trabecular bone volume and mineral density in mice. Here, we investigated the bone quality and biomechanical properties of the higher bone mass associated with BMPR1A deficiency using the osteoblast-specific Bmpr1a conditional knockout (cKO) mouse model. Collagen biochemical analysis revealed greater levels of the mature cross-link pyridinoline in the cKO bones, in parallel with upregulation of collagen modifying enzymes. Raman spectroscopy distinguished increases in the mature to immature cross-link ratio and mineral to matrix ratio in the trabecular compartments of cKO femora, but not in the cortical compartments. The mineral crystallinity was unchanged in the cKO in either the trabecular or cortical compartments. Further, we tested the intrinsic material properties by nanoindentation and found significantly higher hardness and elastic modulus in the cKO trabecular compartments, but not in the cortical compartments. Four point bending tests of cortical compartments showed lower structural biomechanical properties (i.e. strength and stiffness) in the cKO bones due to the smaller cortical areas. However, there were no significant differences in biomechanical performance at the material level, which was consistent with the nanoindentation test results on the cortical compartment. These studies emphasize the pivotal role of BMPR1A in the determination of bone quality and mechanical integrity under physiological conditions, with different impact on femoral cortical and trabecular compartments

Cation-controlled enantioselective and diastereoselective synthesis of indolines : an autoinductive phase-transfer initiated 5-endo-trig process

The European Research Council has provided financial support under the European Community’s Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no. 259056. We are grateful to EPSRC and Pfizer for an award (to CPJ, EP/G041628/1), and the Tata foundation for a scholarship (to K.S.). We also acknowledge computational support from the NSF’s XSEDE program.A catalytic enantioselective approach to the synthesis of indolines bearing two asymmetric centers, one of which is all-carbon and quaternary, is described. This reaction proceeds with high levels of diastereoselectivity (>20:1) and high levels of enantioselectivity (up to 99.5:0.5 er) in the presence of CsOH·H2O and a quinine-derived ammonium salt. The reaction most likely proceeds via a delocalized 2-aza-pentadienyl anion that cyclizes either by a suprafacial electrocyclic mechanism, or through a kinetically controlled 5-endo-trig Mannich process. Density functional theory calculations are used to probe these two mechanistic pathways and lead to the conclusion that a nonpericyclic mechanism is most probable. The base-catalyzed interconversion of diastereoisomeric indolines in the presence of certain quaternary ammonium catalysts is observed; this may be rationalized as a cycloreversion–cyclization process. Mechanistic investigations have demonstrated that the reaction is initiated via a Mąkosza-like interfacial process, and kinetic analysis has shown that the reaction possesses a significant induction period consistent with autoinduction. A zwitterionic quinine-derived entity generated by deprotonation of an ammonium salt with the anionic reaction product is identified as a key catalytic species and the role that protonation plays in the enantioselective process outlined. We also propose that the reaction subsequently occurs entirely within the organic phase. Consequently, the reaction may be better described as a phase-transfer-initiated rather than a phase-transfer-catalyzed process; this observation may have implications for mechanistic pathways followed by other phase-transfer-mediated reactions.Publisher PDFPeer reviewe

VX Hydrolysis by Human Serum Paraoxonase 1: A Comparison of Experimental and Computational Results

Human Serum paraoxonase 1 (HuPON1) is an enzyme that has been shown to hydrolyze a variety of chemicals including the nerve agent VX. While wildtype HuPON1 does not exhibit sufficient activity against VX to be used as an in vivo countermeasure, it has been suggested that increasing HuPON1's organophosphorous hydrolase activity by one or two orders of magnitude would make the enzyme suitable for this purpose. The binding interaction between HuPON1 and VX has recently been modeled, but the mechanism for VX hydrolysis is still unknown. In this study, we created a transition state model for VX hydrolysis (VXts) in water using quantum mechanical/molecular mechanical simulations, and docked the transition state model to 22 experimentally characterized HuPON1 variants using AutoDock Vina. The HuPON1-VXts complexes were grouped by reaction mechanism using a novel clustering procedure. The average Vina interaction energies for different clusters were compared to the experimentally determined activities of HuPON1 variants to determine which computational procedures best predict how well HuPON1 variants will hydrolyze VX. The analysis showed that only conformations which have the attacking hydroxyl group of VXts coordinated by the sidechain oxygen of D269 have a significant correlation with experimental results. The results from this study can be used for further characterization of how HuPON1 hydrolyzes VX and design of HuPON1 variants with increased activity against VX.United States. Defense Threat Reduction Agenc

Aptamers that recognize drug-resistant HIV-1 reverse transcriptase

Drug-resistant variants of HIV-1 reverse transcriptase (RT) are also known to be resistant to anti-RT RNA aptamers. In order to be able to develop diagnostics and therapies that can focus on otherwise drug-resistant viruses, we have isolated two aptamers against a well-known, drug-resistant HIV-1 RT, Mutant 3 (M3) from the multidrug-resistant HIV-1 RT panel. One aptamer, M302, bound M3 but showed no significant affinity for wild-type (WT) HIV-1 RT, while another aptamer, 12.01, bound to both M3 and WT HIV-1 RTs. In contrast to all previously selected anti-RT aptamers, neither of these aptamers showed observable inhibition of either polymerase or RNase H activities. Aptamers M302 and 12.01 competed with one another for binding to M3, but they did not compete with a pseudoknot aptamer for binding to the template/primer cleft of WT HIV-1 RT. These results represent the surprising identification of an additional RNA-binding epitope on the surface of HIV-1 RT. M3 and WT HIV-1 RTs could be distinguished using an aptamer-based microarray. By probing protein conformation as a correlate to drug resistance we introduce an additional and useful measure for determining HIV-1 drug resistance

The size of juxtaluminal hypoechoic area in ultrasound images of asymptomatic carotid plaques predicts the occurrence of stroke

Objective: To test the hypothesis that the size of a juxtaluminal black (hypoechoic) area (JBA) in ultrasound images of asymptomatic carotid artery plaques predicts future ipsilateral ischemic stroke. Methods: A JBA was defined as an area of pixels with a grayscale value &lt;25 adjacent to the lumen without a visible echogenic cap after image normalization. The size of a JBA was measured in the carotid plaque images of 1121 patients with asymptomatic carotid stenosis 50% to 99% in relation to the bulb (Asymptomatic Carotid Stenosis and Risk of Stroke study); the patients were followed for up to 8 years. Results: The JBA had a linear association with future stroke rate. The area under the receiver-operating characteristic curve was 0.816. Using Kaplan-Meier curves, the mean annual stroke rate was 0.4% in 706 patients with a JBA &lt;4 mm 2, 1.4% in 171 patients with a JBA 4 to 8 mm2, 3.2% in 46 patients with a JBA 8 to 10 mm2, and 5% in 198 patients with a JBA &gt;10 mm2 (P &lt;.001). In a Cox model with ipsilateral ischemic events (amaurosis fugax, transient ischemic attack [TIA], or stroke) as the dependent variable, the JBA (&lt;4 mm2, 4-8 mm2, &gt;8 mm2) was still significant after adjusting for other plaque features known to be associated with increased risk, including stenosis, grayscale median, presence of discrete white areas without acoustic shadowing indicating neovascularization, plaque area, and history of contralateral TIA or stroke. Plaque area and grayscale median were not significant. Using the significant variables (stenosis, discrete white areas without acoustic shadowing, JBA, and history of contralateral TIA or stroke), this model predicted the annual risk of stroke for each patient (range, 0.1%-10.0%). The average annual stroke risk was &lt;1% in 734 patients, 1% to 1.9% in 94 patients, 2% to 3.9% in 134 patients, 4% to 5.9% in 125 patients, and 6% to 10% in 34 patients. Conclusions: The size of a JBA is linearly related to the risk of stroke and can be used in risk stratification models. These findings need to be confirmed in future prospective studies or in the medical arm of randomized controlled studies in the presence of optimal medical therapy. In the meantime, the JBA may be used to select asymptomatic patients at high stroke risk for carotid endarterectomy and spare patients at low risk from an unnecessary operation

Asymptomatic internal carotid artery stenosis and cerebrovascular risk stratification

Background The purpose of this study was to determine the cerebrovascular risk stratification potential of baseline degree of stenosis, clinical features, and ultrasonic plaque characteristics in patients with asymptomatic internal carotid artery (ICA) stenosis. Methods This was a prospective, multicenter, cohort study of patients undergoing medical intervention for vascular disease. Hazard ratios for ICA stenosis, clinical features, and plaque texture features associated with ipsilateral cerebrovascular or retinal ischemic (CORI) events were calculated using proportional hazards models. Results A total of 1121 patients with 50% to 99% asymptomatic ICA stenosis in relation to the bulb (European Carotid Surgery Trial [ECST] method) were followed-up for 6 to 96 months (mean, 48). A total of 130 ipsilateral CORI events occurred. Severity of stenosis, age, systolic blood pressure, increased serum creatinine, smoking history of more than 10 pack-years, history of contralateral transient ischemic attacks (TIAs) or stroke, low grayscale median (GSM), increased plaque area, plaque types 1, 2, and 3, and the presence of discrete white areas (DWAs) without acoustic shadowing were associated with increased risk. Receiver operating characteristic (ROC) curves were constructed for predicted risk versus observed CORI events as a measure of model validity. The areas under the ROC curves for a model of stenosis alone, a model of stenosis combined with clinical features and a model of stenosis combined with clinical, and plaque features were 0.59 (95% confidence interval [CI] 0.54-0.64), 0.66 (0.62-0.72), and 0.82 (0.78-0.86), respectively. In the last model, stenosis, history of contralateral TIAs or stroke, GSM, plaque area, and DWAs were independent predictors of ipsilateral CORI events. Combinations of these could stratify patients into different levels of risk for ipsilateral CORI and stroke, with predicted risk close to observed risk. Of the 923 patients with <70% stenosis, the predicted cumulative 5-year stroke rate was <5% in 495, 5% to 9.9% in 202, 10% to 19.9% in 142, and <20% in 84 patients. Conclusion Cerebrovascular risk stratification is possible using a combination of clinical and ultrasonic plaque features. These findings need to be validated in additional prospective studies of patients receiving optimal medical intervention alone. Copyright © 2010 by the Society for Vascular Surgery