90 research outputs found
Learn from Your Elders: Developmental Biology Lessons to Guide Maturation of Stem Cell-Derived Cardiomyocytes
Feasibility and Safety of Lung Cancer Screening and Prevention Program During the COVID-19 Pandemic
GLP-1 Mediates Regulation of Colonic ACE2 Expression by the Bile Acid Receptor GPBAR1 in Inflammation
Background & Aims: ACE2, a carboxypeptidase that generates Ang-(1-7) from Ang II, is highly expressed in the lung, small intestine and colon. GPBAR1, is a G protein bile acid receptor that promotes the release of the insulinotropic factor glucagon-like peptide (GLP)-1 and attenuates intestinal inflammation. Methods: We investigated the expression of ACE2, GLP-1 and GPBAR1 in two cohorts of Crohn’s disease (CD) patients and three mouse models of colitis and Gpbar1−/− mice. Activation of GPBAR1 in these models and in vitro was achieved by BAR501, a selective GPBAR1 agonist. Results: In IBD patients, ACE2 mRNA expression was regulated in a site-specific manner in response to inflammation. While expression of ileal ACE2 mRNA was reduced, the colon expression was induced. Colon expression of ACE2 mRNA in IBD correlated with expression of TNF-α and GPBAR1. A positive correlation occurred between GCG and GPBAR1 in human samples and animal models of colitis. In these models, ACE2 mRNA expression was further upregulated by GPABR1 agonism and reversed by exendin-3, a GLP-1 receptor antagonist. In in vitro studies, liraglutide, a GLP-1 analogue, increased the expression of ACE2 in colon epithelial cells/macrophages co-cultures. Conclusions: ACE2 mRNA expression in the colon of IBD patients and rodent models of colitis is regulated in a TNF-α-and GLP-1-dependent manner. We have identified a GPBAR1/GLP-1 mechanism as a positive modulator of ACE2
SARS-CoV-2 infects human pluripotent stem cell-derived cardiomyocytes, impairing electrical and mechanical function
BMJ Open
ObjectivesThe raising unit price of cigarette has been shown to be one of the most effective ways of reducing cigarette consumption and increasing rates of successful quitting. However, researchers have shown that price-sensitive smokers have used a variety of strategies to mitigate the effect of the rising price of cigarettes on their smoking habits. In particular, 23\ue2\u20ac\u201c34% of adult smokers in the US use cheaper brands, and 18\ue2\u20ac\u201c55% use coupons or promotions. Little is known about the discount use by type of brands. As such, the main purpose of this analysis is to evaluate the uses and price discount effects of these price-related discounts by manufacturers and major brands.SettingAn analysis based on the cross-sectional 2009\ue2\u20ac\u201c2010 National Adult Tobacco Survey (NATS).Participants11\ue2\u20ac\u2026766 current smokers aged 18 or above in the USA.Primary outcome measuresPrice-related discount was defined as smokers who used coupons, rebates, buy-one-get-one-free, two-for-one or any other special promotions for their last cigarettes purchase.ResultsThe use of price-related discounts and associated price impact vary widely by cigarette manufacturer and brand. Approximately one of three Camel, one of four Marlboro and one of eight Newport smokers used price-related discounts on their latest cigarette purchases. The average price reductions of discounts offered by Philip Morris (PM) or R.J. Reynolds (RJR) were around 29 cents per pack while that of Lorillard (Newport only) was 24 cents per pack. Cigarette brands that provided significant per pack price reductions include: PM Marlboro (28 cents), RJR brand Camel (41 cents), Doral (50 cents), Kool (73 cents) and Salem (80 cents), and Lorillard Newport (24 cents).ConclusionsPolicies that decrease price-minimisation strategies will benefit public health
Unexpected detection of SARS-CoV-2 antibodies in the prepandemic period in Italy
There are no robust data on the real onset of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and spread in the prepandemic period worldwide. We investigated the presence of SARS-CoV-2 receptor-binding domain (RBD)–specific antibodies in blood samples of 959 asymptomatic individuals enrolled in a prospective lung cancer screening trial between September 2019 and March 2020 to track the date of onset, frequency, and temporal and geographic variations across the Italian regions. SARS-CoV-2 RBD-specific antibodies were detected in 111 of 959 (11.6%) individuals, starting from September 2019 (14%), with a cluster of positive cases (>30%) in the second week of February 2020 and the highest number (53.2%) in Lombardy. This study shows an unexpected very early circulation of SARS-CoV-2 among asymptomatic individuals in Italy several months before the first patient was identified, and clarifies the onset and spread of the coronavirus disease 2019 (COVID-19) pandemic. Finding SARS-CoV-2 antibodies in asymptomatic people before the COVID-19 outbreak in Italy may reshape the history of pandemic
The Standard Model in Strong Fields: Electroweak Radiative Corrections for Highly Charged Ions
Electroweak radiative corrections to the matrix elements are calculated for highly charged hydrogenlike ions. These
matrix elements constitute the basis for the description of the most parity
nonconserving (PNC) processes in atomic physics. The operator
represents the parity nonconserving relativistic effective atomic Hamiltonian
at the tree level. The deviation of these calculations from the calculations
valid for the momentum transfer demonstrates the effect of the strong
field, characterized by the momentum transfer ( is the
electron mass). This allows for a test of the Standard Model in the presence of
strong fields in experiments with highly charged ions.Comment: 27 LaTex page
Discovery of a AHR pelargonidin agonist that counter-regulates Ace2 expression and attenuates ACE2-SARS-CoV-2 interaction
The severe acute respiratory syndrome (SARS)-CoV-2 is the pathogenetic agent of Corona Virus Induced Disease (COVID)19. The virus enters the human cells after binding to the angiotensin converting enzyme (ACE)2 receptor in target tissues. ACE2 expression is induced in response to inflammation. The colon expression of ACE2 is upregulated in patients with inflammatory bowel disease (IBD), highlighting a potential risk of intestinal inflammation in promoting viral entry in the human body. Because mechanisms that regulate ACE2 expression in the intestine are poorly understood and there is a need of anti-SARS-CoV-2 therapies, we have settled to investigate whether natural flavonoids might regulate the expression of Ace2 in intestinal models of inflammation. The results of these studies demonstrated that pelargonidin activates the Aryl hydrocarbon Receptor (AHR) in vitro and reverses intestinal inflammation caused by chronic exposure to high fat diet or to the intestinal braking-barrier agent TNBS in a AhR-dependent manner. In these two models, development of colon inflammation associated with upregulation of Ace2 mRNA expression. Colon levels of Ace2 mRNA were directly correlated with Tnf-α mRNA levels. Molecular docking studies suggested that pelargonidin binds a fatty acid binding pocket on the receptor binding domain of SARS-CoV-2 Spike protein. In vitro studies demonstrated that pelargonidin significantly reduces the binding of SARS-CoV-2 Spike protein to ACE2 and reduces the SARS-CoV-2 replication in a concentration-dependent manner. In summary, we have provided evidence that a natural flavonoid might hold potential in reducing intestinal inflammation and ACE2 induction in the inflamed colon in a AhR-dependent manner
Mass-transport-induced kinetic transitions during the electrochemical formation of three-dimensional dendritic silver deposits under ohmic control
The influence of mass transport processes on the growth of three-dimensional dendritic Ag deposits on a Pt quasi-spherical substrate at a relatively large cathodic overpotential has been investigated. After a certain induction time a first stage of dendritic growth of Ag can be observed. The deposit formed at this stage exhibits a fractal surface and non-fractal mass—volume properties. For charge densities greater than a certain critical value, a second stage of growth can be distinguished. At this second stage the contribution of free convection changes the shape of the deposit. The fastest growth of the Ag electrodeposit is determined by the rate of migration of sulphate ions in the electric field. A model accounting for the parametric relationships derived from the experiments is presented.Instituto de Investigaciones FisicoquÃmicas Teóricas y Aplicada
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SARS-CoV-2 Infects Human Pluripotent Stem Cell-Derived Cardiomyocytes, Impairing Electrical and Mechanical Function
COVID-19 patients often develop severe cardiovascular complications, but it remains unclear if these are caused directly by viral infection or are secondary to a systemic response. Here, we examine the cardiac tropism of SARS-CoV-2 in human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) and smooth muscle cells (hPSC-SMCs). We find that that SARS-CoV-2 selectively infects hPSC-CMs through the viral receptor ACE2, whereas in hPSC-SMCs there is minimal viral entry or replication. After entry into cardiomyocytes, SARS-CoV-2 is assembled in lysosome-like vesicles and egresses via bulk exocytosis. The viral transcripts become a large fraction of cellular mRNA while host gene expression shifts from oxidative to glycolytic metabolism and upregulates chromatin modification and RNA splicing pathways. Most importantly, viral infection of hPSC-CMs progressively impairs both their electrophysiological and contractile function, and causes widespread cell death. These data support the hypothesis that COVID-19-related cardiac symptoms can result from a direct cardiotoxic effect of SARS-CoV-2
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