Nucleoside reverse transcriptase inhibitors (NRTIs) are widely used as antiviral and anticancer agents, although they require intracellular phosphorylation into their antivirally active form, the triphosphorylated nucleoside analogue metabolites. We report on the synthesis and characterization of a new class of nucleoside triphosphate analogues comprising a C-alkyl-phosphonate moiety replacing the γ-phosphate. These compounds were converted into bioreversibly modified lipophilic prodrugs at the γ-phosphonate by the attachment of an acyloxybenzyl (ester) or an alkoxycarbonyloxybenzyl (carbonate) group.
View Article and Find Full Text PDFThe ongoing Corona Virus Disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has emphasized the urgent need for antiviral therapeutics. The viral RNA-dependent-RNA-polymerase (RdRp) is a promising target with polymerase inhibitors successfully used for the treatment of several viral diseases. We demonstrate here that Favipiravir predominantly exerts an antiviral effect through lethal mutagenesis.
View Article and Find Full Text PDFFollowing the strategy of installing porosity in coordination polymers predefined by linker geometry, we employed the new tetratopic linker molecule 1,1,2,2-tetrakis[4-phosphonophenyl]ethylene (HTPPE) for the synthesis of new porous metal phosphonates. A high-throughput study was carried out using Ni and Co as metal ions, and a very strong influence of the reactor size on the product formation is observed while maintaining the same reaction parameters. Using small autoclaves ( = 250 μL), single crystals of isostructural mononuclear complexes of the composition [Ni(HDPBP)(HO)] () and [Co(HDPBP)(HO)] () are formed.
View Article and Find Full Text PDFAims: To determine whether enzyme-inducing antiseizure drugs (ASDs) affect the risk of developing chronic obstructive pulmonary disease (COPD) or lung cancer in smokers.
Methods: Cases of COPD and lung cancer and matched controls without these conditions were identified from a population of smokers with ≥1 prescription for any type of ASD in the Clinical Practice Research Datalink UK database of patients managed in primary care (1995-2016). A matched case-control study was performed utilising multivariate logistic regression analyses of exposure to enzyme-inducing ASDs compared to non-enzyme-inducing ASDs.
Many patients with pulmonary arterial hypertension do not achieve treatment goals with monotherapy, and therefore combination therapy is becoming the standard of care. The soluble guanylate cyclase stimulator riociguat is licensed for the treatment of pulmonary arterial hypertension; here we present findings from patients who were receiving combined riociguat plus endothelin receptor antagonists or non-intravenous prostanoids in the randomized, placebo-controlled PATENT-1 study and its open-label extension (PATENT-2). Moreover, we include new data from patients receiving early sequential combination therapy (three to six months of endothelin receptor antagonist treatment) or long-term background endothelin receptor antagonist therapy (>6 months).
View Article and Find Full Text PDFNicotinic acid adenine dinucleotide phosphate (NAADP) is a second messenger that evokes calcium release from intracellular organelles by the engagement of calcium release channels, including members of the Transient Receptor Potential (TRP) family, such as TRPML1, the (structurally) related Two Pore Channel type 1 (TPC1) and TPC2 channels as well as Ryanodine Receptors type 1 (RYR1; Guse, 2012). NAADP evokes calcium release from acidic calcium stores of many cell types (Guse, 2012), and NAADP-sensitive Ca stores have been described in hippocampal neurons of the rat (Bak et al., 1999; McGuinness et al.
View Article and Find Full Text PDFInvasive lobular breast carcinoma (ILC) accounts for 10% to 15% of breast cancers diagnosed annually. Evidence suggests that some aspects of endocrine treatment response might differ between invasive ductal carcinoma (IDC) and ILC, and that patients with ILC have worse long-term survival. We analyzed The Cancer Genome Atlas dataset and observed lower levels of ESR1 mRNA (P = 0.
View Article and Find Full Text PDFThe antiviral efficacy of many nucleoside analogues is strongly dependent on their intracellular activation by host cellular kinases to yield ultimately the bioactive nucleoside analogue triphosphates (NTP). The metabolic conversion of nucleoside analogues into their triphosphates often proceeds insufficiently. We developed a nucleoside triphosphate (NTP) delivery system (the Triro approach), in which the γ-phosphate is covalently modified by two different biodegradable masking units, one is the acyloxybenzyl (AB) moiety and the other is the alkoxycarbonyloxybenzyl (ACB) group.
View Article and Find Full Text PDFThe ongoing Corona Virus Disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has emphasized the urgent need for antiviral therapeutics. The viral RNA-dependent-RNA-polymerase (RdRp) is a promising target with polymerase inhibitors successfully used for the treatment of several viral diseases. Here we show that Favipiravir exerts an antiviral effect as a nucleotide analogue through a combination of chain termination, slowed RNA synthesis and lethal mutagenesis.
View Article and Find Full Text PDFTissue-specific occurrence and formation of endogenous sesquiterpene lactones has been assessed and suggests physiological function as antagonists of auxin-induced plant growth in sunflower. Sunflower, Helianthus annuus, accumulate high concentrations of bioactive sesquiterpene lactones (STL) in glandular trichomes, but in addition, structurally different STL occur in only trace amounts in the inner tissues. The spatial and temporal production of these endogenous STL during early phases of plant development is widely unknown and their physiological function as putative natural growth regulators is yet speculative.
View Article and Find Full Text PDFPurpose: Three previous studies reported controversial results regarding selective serotonin reuptake inhibitor (SSRI) exposure and cataract development. We therefore aimed to assess risk of cataract associated with previous exposure to SSRI using data from a large health insurance in Switzerland.
Methods: In a case-control study, we analyzed individuals insured by the Helsana Group, a large Swiss health insurance provider.
Background: RESPITE evaluated patients with pulmonary arterial hypertension and an inadequate response to phosphodiesterase type 5 inhibitors (PDE5i) who switched to riociguat. This post hoc analysis assessed response to this switch in parameters associated with clinical improvement.
Methods: RESPITE was a 24-week, uncontrolled pilot study (n = 61).
The National School Lunch Program provides nutritious and inexpensive lunches, but low participation and food waste are challenges in many schools. Interventions aim to improve participation in the program, but little is known about how students' perceptions affect their participation. This study explored how middle school students in a rural state perceive school food service staff, food served, and lunchroom atmosphere.
View Article and Find Full Text PDFContext: Consensus regarding diagnosis and management of osteoporosis in premenopausal women (PW) is still lacking due to few studies carried out in this population.
Design: The European Calcified Tissue Society and the International Osteoporosis Foundation convened a working group to produce an updated review of literature published after 2017 on this topic.
Results: Fragility fractures in PW are rare and mostly due to secondary osteoporosis (ie, in presence of an underlying disease such as hormonal, inflammatory, or digestive disorders).
Purpose: To evaluate the feasibility and safety of a coaxial dual-wavelength optical coherence tomography (OCT) device (marked as Hydra-OCT).
Methods: Healthy participants without ocular pathology underwent retinal imaging using the Hydra-OCT allowing for simultaneous measurement of retinal scanning of 840 and 1,072 nm wavelength. Before and after measurement, best-corrected visual acuity and patients' comfort were assessed.
We disclose a study on nucleoside triphosphate (NTP) analogues in which the γ-phosphate is covalently modified by two different biodegradable masking units and d4T as nucleoside analogue that enable the delivery of d4TTP with high selectivity in phosphate buffer (pH 7.3) and by enzyme-triggered reactions in human CD4 T-lymphocyte CEM cell extracts. This allows the bypass of all steps normally needed in the intracellular phosphorylation.
View Article and Find Full Text PDFInterventions targeting school meals have been used to combat obesity in rural youth. Parents play a powerful role in childhood nutrition; however, we know little about parents' perceptions of school meal programs. This study aimed to understand parents' perceptions of school meal programs.
View Article and Find Full Text PDFBackground: Cardiovascular magnetic resonance (CMR) studies in patients with implanted cardioverter/defibrillators (ICD) are increasingly required in daily clinical practice. However, the clinical experience regarding the feasibility as well as clinical value of CMR studies in patients with subcutaneous ICD (S-ICD) is still limited. Besides safety issues, image quality and analysis can be impaired primarily due the presence of image artefacts associated with the generator.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
November 2020
Purpose: Rhabdoid tumor of the kidney (RTK) is one of the most aggressive childhood renal tumors. Overall survival ranges from 22% to 47%. The indication for radiation therapy (RT) in usually very young patients is an ongoing discussion.
View Article and Find Full Text PDFWith an estimated number of new cases annually of approximately 1.4 million, leishmaniasis belongs to the most important parasitic diseases in the world. Nevertheless, existing drugs against leishmaniasis in general have several drawbacks that urgently necessitate new drug development.
View Article and Find Full Text PDFMigratory species form an important component of biodiversity; they link ecosystems across the globe, but are increasingly threatened by global environmental change. Understanding and mitigating threats requires knowledge of how demographic processes operate throughout the annual cycle, but this can be difficult to achieve when breeding and non-breeding grounds are widely separated. Our goal is to quantify the importance of variability in survival during the breeding and non-breeding seasons in determining variation in annual survival using a single population and, more broadly, the extent to which annual survival across species reflects variation in probability of surviving the migratory period.
View Article and Find Full Text PDFThe development of nucleoside triphosphate prodrugs is one option to apply nucleoside reverse transcriptase inhibitors. Herein, we report the synthesis and evaluation of d4TTP analogues, in which the γ-phosphate was modified covalently by lipophilic alkyl residues, and acyloxybenzyl prodrugs of these γ-alkyl-modified d4TTPs, with the aim of delivering of γ-alkyl-d4TTP into cells. Selective formation of γ-alkyl-d4TTP was proven with esterase and in CD4 -cell extracts.
View Article and Find Full Text PDFBackground: Coronary microvascular dysfunction (CMD) is present in various non-ischemic cardiomyopathies and in particular in those with left-ventricular hypertrophy. This study evaluated the diagnostic value of the novel cardiovascular magnetic resonance (CMR) parameter "myocardial transit-time" (MyoTT) in distinguishing cardiac amyloidosis from other hypertrophic cardiomyopathies.
Methods: N = 20 patients with biopsy-proven cardiac amyloidosis (CA), N = 20 patients with known hypertrophic cardiomyopathy (HCM), and N = 20 control patients without relevant cardiac disease underwent dedicated CMR studies on a 1.
The reproductive number in Switzerland was between 1.5 and 2 during the first third of March, and has consistently decreased to around 1. After the announcement of the latest strict measure on 20 March 2020, namely that gatherings of more than five people in public spaces are prohibited, the reproductive number dropped significantly below 1; the authors of this study estimate the reproductive number to be between 0.
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