| 1. |
- Capodanno, Davide, et al.
(author)
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Defining Strategies of Modulation of Antiplatelet Therapy in Patients With Coronary Artery Disease : A Consensus Document from the Academic Research Consortium
- 2023
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In: Circulation. - : Ovid Technologies (Wolters Kluwer Health). - 0009-7322 .- 1524-4539. ; 147:25, s. 1933-1944
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Journal article (peer-reviewed)abstract
- Antiplatelet therapy is the mainstay of pharmacologic treatment to prevent thrombotic or ischemic events in patients with coronary artery disease treated with percutaneous coronary intervention and those treated medically for an acute coronary syndrome. The use of antiplatelet therapy comes at the expense of an increased risk of bleeding complications. Defining the optimal intensity of platelet inhibition according to the clinical presentation of atherosclerotic cardiovascular disease and individual patient factors is a clinical challenge. Modulation of antiplatelet therapy is a medical action that is frequently performed to balance the risk of thrombotic or ischemic events and the risk of bleeding. This aim may be achieved by reducing (ie, de-escalation) or increasing (ie, escalation) the intensity of platelet inhibition by changing the type, dose, or number of antiplatelet drugs. Because de-escalation or escalation can be achieved in different ways, with a number of emerging approaches, confusion arises with terminologies that are often used interchangeably. To address this issue, this Academic Research Consortium collaboration provides an overview and definitions of different strategies of antiplatelet therapy modulation for patients with coronary artery disease, including but not limited to those undergoing percutaneous coronary intervention, and consensus statements on standardized definitions.
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| 2. |
- Amorati, Riccardo, et al.
(author)
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Multi-faceted reactivity of alkyltellurophenols towards peroxyl radicals : Catalytic antioxidant versus thiol-depletion effect
- 2013
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In: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 19:23, s. 7510-7522
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Journal article (peer-reviewed)abstract
- Hydroxyaryl alkyl tellurides are effective antioxidants both in organic solution and aqueous biphasic systems. They react by an unconventional mechanism with ROO. radicals with rate constants as high as 107M1s1 at 303K, outperforming common phenols. The reactions proceed by oxygen atom transfer to tellurium followed by hydrogen atom transfer to the resulting RO. radical from the phenolic OH. The reaction rates do not reflect the electronic properties of the ring substituents and, because the reactions occur in a solvent cage, quenching is more efficient when the OH and TeR groups have an ortho arrangement. In the presence of thiols, hydroxyaryl alkyl tellurides act as catalytic antioxidants towards both hydroperoxides (mimicking the glutathione peroxidases) and peroxyl radicals. The high efficiency of the quenching of the peroxyl radicals and hydroperoxides could be advantageous under normal cellular conditions, but pro-oxidative (thiol depletion) when thiol concentrations are low.
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| 3. |
- Amorati, Riccardo, et al.
(author)
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Organochalcogen Substituents in Phenolic Antioxidants
- 2010
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In: Organic Letters. - : American Chemical Society (ACS). - 1523-7060 .- 1523-7052. ; 12:10, s. 2326-2329
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Journal article (peer-reviewed)abstract
- Little is known about the ED/EW character of organochalcogen substituents and their contribution to the O-H bond dissociation enthalpy (BDE) in phenolic compounds. A series of ortho- and para-(S,Se,Te)R-substituted phenols were prepared and investigated by EPR, IR, and computational methods. Substituents lowered the O-H BDE by >3 kcal/mol in the para position, while the ortho-effect was modest due to hydrogen bonding ( approximately 3 kcal/mol) to the O-H group.
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| 4. |
- Angiolillo, Dominick J., et al.
(author)
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International Expert Consensus on Switching Platelet P2Y(12) Receptor-Inhibiting Therapies
- 2017
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In: Circulation. - : LIPPINCOTT WILLIAMS & WILKINS. - 0009-7322 .- 1524-4539. ; 136:20, s. 1955-
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Journal article (peer-reviewed)abstract
- Dual antiplatelet therapy with aspirin and a P2Y(12) inhibitor is the treatment of choice for the prevention of atherothrombotic events in patients with acute coronary syndromes and for those undergoing percutaneous coronary interventions. The availability of different oral P2Y(12) inhibitors (clopidogrel, prasugrel, ticagrelor) has enabled physicians to contemplate switching among therapies because of specific clinical scenarios. The recent introduction of an intravenous P2Y(12) inhibitor (cangrelor) further adds to the multitude of modalities and settings in which switching therapies may occur. In clinical practice, it is not uncommon to switch P2Y(12) inhibitor, and switching may be attributed to a variety of factors. However, concerns about the safety of switching between these agents have emerged. Practice guidelines have not fully elaborated on how to switch therapies, leaving clinicians with limited guidance on when and how to switch therapies when needed. This prompted the development of this expert consensus document by key leaders from North America and Europe with expertise in basic, translational, and clinical sciences in the field of antiplatelet therapy. This expert consensus provides an overview of the pharmacology of P2Y(12) inhibitors, different modalities and definitions of switching, and available literature and recommendations for switching between P2Y(12) inhibitors.
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| 5. |
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| 6. |
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| 7. |
- Johansson, Henrik, et al.
(author)
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Long-lasting Antioxidant Protection : A Regenerable BHA-Analogue
- 2010
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In: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 75:22, s. 7535-7541
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Journal article (peer-reviewed)abstract
- Introduction of an octyltelluro group ortho to the phenolic moiety in 3-tert-butyl-4-hydroxyanisole (BHA) was found to significantly improve the antioxidant characteristics of the material. In contrast to BHA and the corresponding ortho-substituted octylthio- (9c) and octylseleno (9b) derivatives, the organotellurium 9a was regenerable when assayed for its capacity to inhibit azo-initiated peroxidation of linoleic acid in a chlorobenzene/water two-phase system containing N-acetylcysteine as a stoichiometric reducing agent, and peroxyl radicals were quenched more efficiently than with α-tocopherol. In the homogeneous phase, inhibition of styrene autoxidation occurred with a rate constant kinh as large as 1 × 107 M-1 s-1 but with a low (n = 0.4) stoichiometric factor. Evans-Polanij plots of log (kinh) versus BDE(O-H), which are usually linear for phenols with similar steric crowding reacting by H-atom transfer, revealed that compound 9a was more than 2 orders of magnitude more reactive than expected. Although further mechanistic investigations are needed, it seems that the ortho-arrangement of an alkyltelluro group and hydroxyl should be considered a privileged structure for phenolic antioxidants.
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| 8. |
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| 9. |
- Kumar, Sangit, et al.
(author)
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Antioxidant Profile of Ethoxyquin and Some of Its S, Se, and Te Analogues
- 2007
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In: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 72:16, s. 6046-6055
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Journal article (peer-reviewed)abstract
- (Chemical Equation Presented) 6-(Ethylthio)-, 6-(ethylseleno)-, and 6-(ethyltelluro)-2,2,4-trimethyl-1,2-dihydroquinoline-three heavier chalcogen analogues of ethoxyquin-were prepared by dilithiation of the corresponding 6-bromodihydroquinoline followed either by treatment with the corresponding diethyl dichalcogenide (sulfur derivative) or by insertion of selenium/tellurium into the carbon-lithium bond, oxidation to a diaryl dichalcogenide, borohydride reduction, and finally alkylation of the resulting areneselenolate/ arenetellurolate. Ethoxyquin, its heavier chalcogen analogues, and the corresponding 6-PhS, 6-PhSe, and 6-PhTe derivatives were assayed for both their chain-breaking antioxidant capacity and their ability to catalyze reduction of hydrogen peroxide in the presence of a stoichiometric amount of a thiol reducing agent (thiol peroxidase activity). Ethoxyquin itself turned out to be the best inhibitor of azo-initiated peroxidation of linoleic acid in a water/chlorobenzene two-phase system. In the absence of N-acetylcysteine as a coantioxidant in the aqueous phase, it inhibited peroxidation as efficiently as α-tocopherol but with a more than 2-fold longer inhibition time. In the presence of 0.25 mM coantioxidant in the aqueous phase, the inhibition time was further increased by almost a factor of 2. This is probably due to thiol-mediated regeneration of the active antioxidant across the lipid-aqueous interphase. The ethyltelluro analogue 1d of ethoxyquin was a similarly efficient quencher of peroxyl radicals compared to the parent in the two-phase system, but less regenerable. Ethoxyquin was found to inhibit azo-initiated oxidation of styrene in the homogenous phase (chlorobenzene) almost as efficiently (k inh = (2.0 ± 0.2) × 106 M-1 s -1) as α-tocopherol with a stoichiometric factor n = 2.2 ± 0.1. At the end of the inhibition period, autoxidation was additionally retarded, probably by ethoxyquin nitroxide formed during the course of peroxidation. The N-H bond dissociation enthalpy of ethoxyquin (81.3 ± 0.3 kcal/mol) was determined by a radical equilibration method using 2,6-dimethoxyphenol and 2,6-di-tert-butyl-4-methylphenol as equilibration partners. Among the investigated compounds, only the tellurium analogues 1d and, less efficiently, 1g had a capacity to catalyze reduction of hydrogen peroxide in the presence of thiophenol. Therefore, analogue 1d is the only antioxidant which is multifunctional (chain-breaking and preventive) in character and which can act in a truly catalytic fashion to decompose both peroxyl radicals and organic hydroperoxides in the presence of suitable thiol reducing agents.
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| 10. |
- Kumar, Sangit, et al.
(author)
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Catalytic Chain-Breaking Pyridinol Antioxidants
- 2008
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In: Organic Letters. - : American Chemical Society (ACS). - 1523-7060 .- 1523-7052. ; 10:21, s. 4895-4898
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Journal article (peer-reviewed)abstract
- When assayed for their capacity to inhibit azo-initiated peroxidation of linoleic acid in a water/chlorobenzene two-phase system, tellurium-containing 3-pyridinols were readily regenerable by N-acetylcysteine contained in the aqueous phase. The best inhibitors quenched peroxyl radicals more efficiently than alpha-tocopherol, and the duration of inhibition was limited only by the availability of the thiol reducing agent. The compounds were also found to catalyze reduction of hydrogen peroxide in the presence of thiol reducing agent.
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