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https://www.readbyqxmd.com/read/28646655/syntheses-toxicities-and-anti-inflammation-of-h2s-donors-based-on-non-steroidal-anti-inflammatory-drugs
#1
Meng Li, Jili Li, Taofeng Zhang, Quanyi Zhao, Jie Cheng, Bin Liu, Zhen Wang, Libo Zhao, Chenwei Wang
Three series of H2S donors based on NSAIDs were synthesized and characterized by (1)H-NMR, IR and ESI-HRMS. The H2S-release abilities of all compounds were evaluated in the presence of TECP or cysteine. The results show all compounds were fast H2S-releasers, and their half-lives were in range of 0-20 min. Under the same condition, H2S released from compound 9 was more than any other compounds. In cytotoxicity aspect, all compounds but 1 and 2 displayed much lower toxicities to both LO2 and HepG2 cell lines, and the IC50 values of most compounds were over 800 μM...
June 7, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28646408/a-mechanism-based-pk-pd-model-for-hematological-toxicities-induced-by-antibody-drug-conjugates
#2
Sihem Ait-Oudhia, Weiyan Zhang, Donald E Mager
Antibody-drug conjugates (ADCs) are complex drug platforms composed of monoclonal antibodies (mAbs) conjugated to potent cytotoxic drugs (payloads) via chemical linkers, enabling selective payload delivery to neoplastic cells, resulting in improved efficacy and reduced toxicity. Brentuximab vedotin (Adcetris®, SGN-35) and adotrastuzumab emtansine (Kadcyla®, T-DM1) are the two FDA-approved and commercially available ADCs, and both drugs exhibit ADC-related thrombocytopenia and neutropenia. A pharmacokinetic/pharmacodynamic (PK/PD) model for ADCs was developed to identify the analyte from each ADC that is most associated with the observed hematopoietic toxicities and to determine the role of the apparent in vivo payload release rate on the severity of thrombocytopenia and neutropenia...
June 23, 2017: AAPS Journal
https://www.readbyqxmd.com/read/28645762/calculating-in-situ-degradation-rates-of-hydrocarbon-compounds-in-deep-waters-of-the-gulf-of-mexico
#3
Anne E Thessen, Elizabeth W North
Biodegradation is an important process for hydrocarbon weathering that influences its fate and transport, yet little is known about in situ biodegradation rates of specific hydrocarbon compounds in the deep ocean. Using data collected in the Gulf of Mexico below 700m during and after the Deepwater Horizon oil spill, we calculated first-order degradation rate constants for 49 hydrocarbons and inferred degradation rate constants for an additional 5 data-deficient hydrocarbons. Resulting calculated (not inferred) half-lives of the hydrocarbons ranged from 0...
June 20, 2017: Marine Pollution Bulletin
https://www.readbyqxmd.com/read/28645013/per-and-polyfluoroalkyl-substances-in-human-serum-and-urine-samples-from-a-residentially-exposed-community
#4
Rachel Rogers Worley, Susan McAfee Moore, Bruce C Tierney, Xiaoyun Ye, Antonia M Calafat, Sean Campbell, Million B Woudneh, Jeffrey Fisher
BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) are considered chemicals of emerging concern, in part due to their environmental and biological persistence and the potential for widespread human exposure. In 2007, a PFAS manufacturer near Decatur, Alabama notified the United States Environmental Protection Agency (EPA) it had discharged PFAS into a wastewater treatment plant, resulting in environmental contamination and potential exposures to the local community. OBJECTIVES: To characterize PFAS exposure over time, the Agency for Toxic Substances and Disease Registry (ATSDR) collected blood and urine samples from local residents...
June 20, 2017: Environment International
https://www.readbyqxmd.com/read/28644913/supplement-2-for-the-2004-update-of-the-aapm-task-group-no-43-report-joint-recommendations-by-the-aapm-and-gec-estro
#5
Mark J Rivard, Facundo Ballester, Wayne M Butler, Larry A DeWerd, Geoffrey S Ibbott, Ali S Meigooni, Christopher S Melhus, Michael G Mitch, Ravinder Nath, Panagiotis Papagiannis
Since publication of the 2004 update to the American Association of Physicists in Medicine (AAPM) Task Group No. 43 Report (TG-43U1) and its 2007 supplement (TG-43U1S1), several new low-energy photon-emitting brachytherapy sources have become available. Many of these sources have satisfied the AAPM prerequisites for routine clinical purposes and are posted on the Brachytherapy Seed Registry managed jointly by the AAPM and the Imaging and Radiation Oncology Core Houston Quality Assurance Center (IROC Houston)...
June 23, 2017: Medical Physics
https://www.readbyqxmd.com/read/28644015/photochromic-hydrazone-switches-with-extremely-long-thermal-half-lives
#6
Hai Qian, Susnata Pramanik, Ivan Aprahamian
A family of easily accessible light-activated hydrazone switches has been developed having thermal half-lives of up to 2700 years! Structure-property analysis shows that replacing the rotor pyridyl group of our typical hydrazone switch with a phenyl one leads to the long-live negative photochromic compounds. The switching properties of the hydrazones in both toluene and DMSO were assessed offering insights into the kinetics and thermodynamics of the switching process.
June 23, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28637692/m-6-a-mrna-modifications-are-deposited-in-nascent-pre-mrna-and-are-not-required-for-splicing-but-do-specify-cytoplasmic-turnover
#7
Shengdong Ke, Amy Pandya-Jones, Yuhki Saito, John J Fak, Cathrine Broberg Vågbø, Shay Geula, Jacob H Hanna, Douglas L Black, James E Darnell, Robert B Darnell
Understanding the biologic role of N(6)-methyladenosine (m(6)A) RNA modifications in mRNA requires an understanding of when and where in the life of a pre-mRNA transcript the modifications are made. We found that HeLa cell chromatin-associated nascent pre-mRNA (CA-RNA) contains many unspliced introns and m(6)A in exons but very rarely in introns. The m(6)A methylation is essentially completed upon the release of mRNA into the nucleoplasm. Furthermore, the content and location of each m(6)A modification in steady-state cytoplasmic mRNA are largely indistinguishable from those in the newly synthesized CA-RNA or nucleoplasmic mRNA...
May 15, 2017: Genes & Development
https://www.readbyqxmd.com/read/28634030/effects-of-membrane-curvature-and-ph-on-proton-pumping-activity-of-single-cytochrome-bo3-enzymes
#8
Mengqiu Li, Sanobar Khan, Honglin Rong, Roman Tuma, Nikos S Hatzakis, Lars J C Jeuken
The molecular mechanism of proton pumping by heme-copper oxidases (HCO) has intrigued the scientific community since it was first proposed. We have recently reported a novel technology that enables the continuous characterisation of proton transport activity of a HCO and ubiquinol oxidase from Escherichia coli, cytochrome bo3, for hundreds of seconds on the single enzyme level (Li et al. J Am Chem Soc 137 (2015) 16055-16063). Here, we have extended these studies by additional experiments and analyses of the proton transfer rate as a function of proteoliposome size and pH at the N- and P-side of single HCOs...
June 17, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28632502/targeting-activated-protein-c-to-treat-hemophilia
#9
Stéphanie G I Polderdijk, Trevor P Baglin, James A Huntington
PURPOSE OF REVIEW: Hemophilia is a debilitating disease, marked by frequent, painful bleeding events, joint deterioration and early death. All current treatments consist of i.v. infusions of replacement factor or other procoagulant factors, and are incompletely effective, due in part to the short half-lives of the proteins. An alternative approach is to rebalance hemostasis by inhibiting natural anticoagulant mechanisms. In this article, we explain why activated protein C (APC) is an appropriate and safe target for the treatment of hemophilia...
June 16, 2017: Current Opinion in Hematology
https://www.readbyqxmd.com/read/28628888/an-algorithm-for-filtering-detector-instabilities-in-search-of-novel-non-exponential-decay-and-in-conventional-half-life-determinations
#10
G W Hitt, B Goddard, A A Solodov, D Bridi, A F Isakovic, R El-Khazali
Recent reports of Solar modulation of beta-decay have reignited interest in whether or not radioactive half-lives are constants. A numerical approach for filtering instrumental effects on residuals is developed, using correlations with atmospheric conditions recorded while counting (204)Tl emissions with a Geiger-Müller counter. Half-life oscillations and detection efficiency oscillations can be separated provided their periods are substantially different. A partial uncertainty budget for the (204)Tl half-life shows significant decreases to medium-frequency instabilities correlated with pressure and temperature, which suggests that further development may aid general improvements in half-life determinations...
June 9, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28627805/predicting-the-enzymatic-hydrolysis-half-lives-of-new-chemicals-using-support-vector-regression-models-based-on-stepwise-feature-elimination
#11
Wanxiang Shen, Tao Xiao, Shangying Chen, Feng Liu, Yu Zong Chen, Yuyang Jiang
The enzymatic hydrolysis of chemicals, which is important for in vitro drug metabolism assays, is an important indicator of drug stability profiles during drug discovery and development. Herein, we employed a stepwise feature elimination (SFE) method with nonlinear support vector machine regression (SVR) models to predict the in vitro half-lives in human plasma/blood of various esters. The SVR model was developed using public databases and literature-reported data on the half-lives of esters in human plasma/blood...
June 19, 2017: Molecular Informatics
https://www.readbyqxmd.com/read/28627123/pharmacokinetics-and-relative-bioavailability-of-orally-administered-innovator-formulated-itraconazole-capsules-and-solution-in-healthy-dogs
#12
A E Hasbach, D K Langlois, E J Rosser, M G Papich
BACKGROUND: Itraconazole is commonly used for treatment of systemic and cutaneous mycoses in veterinary medicine. Two formulations, capsule and solution, are used interchangeably in dogs. However, marked differences in bioavailability have been reported in other species. Similar investigations have not been performed in dogs. OBJECTIVE: To determine and compare pharmacokinetics of itraconazole in dogs after oral administration of commercially available capsule and solution formulations intended for use in humans...
June 19, 2017: Journal of Veterinary Internal Medicine
https://www.readbyqxmd.com/read/28616130/quantitative-investigation-of-human-cell-surface-n-glycoprotein-dynamics
#13
Haopeng Xiao, Ronghu Wu
Surface glycoproteins regulate nearly every extracellular event and they are dynamic for cells to adapt to the ever-changing extracellular environment. These glycoproteins contain a wealth of information on cellular development and disease states, and have significant biomedical implications. Systematic investigation of surface glycoproteins will result in a better understanding of surface protein functions, cellular activities and the molecular mechanisms of disease. However, it is extraordinarily challenging to specifically and globally analyze surface glycoproteins...
January 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/28615636/autotransporter-domain-dependent-enzymatic-analysis-of-a-novel-extremely-thermostable-carboxylesterase-with-high-biodegradability-towards-pyrethroid-pesticides
#14
Xianghai Cai, Wei Wang, Lin Lin, Dannong He, Gang Huang, Yaling Shen, Wei Wei, Dongzhi Wei
The EstPS1 gene, which encodes a novel carboxylesterase of Pseudomonas synxantha PS1 isolated from oil well-produced water, was cloned and sequenced. EstPS1 has an open reading frame of 1923 bp and encodes the 640-amino acid carboxylesterase (EstPS1), which contains an autotransporter (AT) domain (357-640 amino acids). Homology analysis revealed that EstPS1 shared the highest identity (88%) with EstA from Pseudomonas fluorescens A506 (NCBI database) and belonged to the carboxylesterase family (EC 3.1.1.1). The optimum pH and temperature of recombinant EstPS1 were found to be 8...
June 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28608440/formation-of-a-tunneling-product-in-the-photo-rearrangement-of-o-nitrobenzaldehyde
#15
Dennis Gerbig, Peter Richard Schreiner
The photochemical rearrangement of o-nitrobenzaldehyde to o-nitrosobenzoic acid, first reported in 1901, has been shown to proceed via a distinct ketene intermediate. In the course of matrix isolation experiments in various host materials at temperatures as low as 3 K, we re-investigated the ketene in its electronic and vibrational ground states and show here that hitherto unreported H-tunneling dominates its reactivity, with half-lives t1/2 of a few minutes. Unexpectedly, the tunneling product is different from o-nitrosobenzoic acid formed in the photoprocess: Once prepared by irradiation, the ketene spontaneously rearranges to an isoxazolone via an intriguing mechanism initiated by H-tunneling...
June 13, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28605646/imidacloprid-application-changes-microbial-dynamics-and-enzymes-in-rice-soil
#16
Bibhab Mahapatra, Totan Adak, Naveen K B Patil, Guru P Pandi G, G Basana Gowda, N N Jambhulkar, Manoj Kumar Yadav, P Panneerselvam, Upendra Kumar, Sushmita Munda, Mayabini Jena
Extensive use of imidacloprid in rice ecosystem may alter dynamics of microorganisms and can change soil biochemical properties. The objective of this study was to assess the effect of imidacloprid on growth and activities of microbes in tropical rice soil ecosystem. Four treatments, namely, recommended dose (at 25g a.i. ha(-1), RD), double the recommended dose (at 50g a.i. ha(-1), 2RD), five times the recommended dose (at 125g a.i. ha(-1), 5RD) & ten times the recommended dose (at 250g a.i. ha(-1), 10RD) along with control were imposed under controlled condition...
June 9, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28605180/a-hydrogel-microsphere-drug-delivery-system-that-supports-once-monthly-administration-of-a-glp-1-receptor-agonist
#17
Eric L Schneider, Brian R Hearn, Samuel J Pfaff, Ralph Reid, David G Parkes, Niels Vrang, Gary W Ashley, Daniel V Santi
We have developed a chemically-controlled very long-acting delivery system to support once-monthly administration of a peptidic GLP-1R agonist. Initially, the prototypical GLP-1R agonist exenatide was covalently attached to hydrogel microspheres by a self-cleaving β-eliminative linker; after subcutaneous injection in rats the peptide was slowly released into the systemic circulation. However, the short serum exenatide half-life suggested its degradation in the subcutaneous depot. We found that exenatide undergoes deamidation at Asn(28)with an in vitro and in vivo half-life of approximately two weeks...
June 12, 2017: ACS Chemical Biology
https://www.readbyqxmd.com/read/28598790/croi-2017-advances-in-antiretroviral-therapy
#18
Joyce Jones, Barbara S Taylor, Hong-Van Tieu, Timothy J Wilkin
The 2017 Conference on Retroviruses and Opportunistic Infections (CROI) featured exciting preclinical data on investigational antiretroviral agents with good in vitro efficacy and long half-lives. Investigational medications, including bictegravir, demonstrated excellent efficacy and tolerability, as did dual-agent therapy with dolutegravir paired with rilpivirine or with lamivudine. Dolutegravir monotherapy proved inadvisable due to virologic failure and resistance. The gap between high- and low-income settings along the HIV care continuum is narrowing, with Zimbabwe, Malawi, and Zambia approaching the 90-90-90 targets established by the joint United Nations Programme on HIV/AIDS (UNAIDS), whereas communities in the Southern United States are falling behind...
May 2017: Topics in Antiviral Medicine
https://www.readbyqxmd.com/read/28598442/distinct-homotypic-b-cell-receptor-interactions-shape-the-outcome-of-chronic-lymphocytic-leukaemia
#19
Claudia Minici, Maria Gounari, Rudolf Übelhart, Lydia Scarfò, Marcus Dühren-von Minden, Dunja Schneider, Alpaslan Tasdogan, Alabbas Alkhatib, Andreas Agathangelidis, Stavroula Ntoufa, Nicholas Chiorazzi, Hassan Jumaa, Kostas Stamatopoulos, Paolo Ghia, Massimo Degano
Cell-autonomous B-cell receptor (BcR)-mediated signalling is a hallmark feature of the neoplastic B lymphocytes in chronic lymphocytic leukaemia (CLL). Here we elucidate the structural basis of autonomous activation of CLL B cells, showing that BcR immunoglobulins initiate intracellular signalling through homotypic interactions between epitopes that are specific for each subgroup of patients with homogeneous clinicobiological profiles. The molecular details of the BcR-BcR interactions apparently dictate the clinical course of disease, with stronger affinities and longer half-lives in indolent cases, and weaker, short-lived contacts mediating the aggressive ones...
June 9, 2017: Nature Communications
https://www.readbyqxmd.com/read/28595133/nonclinical-pharmacokinetic-and-pharmacodynamic-characterisation-of-somapacitan-a-reversible-non-covalent-albumin-binding-growth-hormone
#20
Peter Thygesen, Henrik Sune Andersen, Carsten Behrens, Johannes Josef Fels, Leif Nørskov-Lauritsen, Christian Rischel, Nils Langeland Johansen
OBJECTIVE: Somapacitan is an albumin-binding growth hormone derivative intended for once weekly administration, currently in clinical development for treatment of adult as well as juvenile GH deficiency. Nonclinical in vivo pharmacological characterisation of somapacitan was performed to support the clinical trials. Here we present the pharmacokinetic and pharmacodynamic effects of somapacitan in rats, minipigs, and cynomolgus monkeys. METHODS: Pharmacokinetic studies investigating exposure, absorption, clearance, and bioavailability after single intravenous (i...
May 24, 2017: Growth Hormone & IGF Research
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