Search results for "pyridines"
showing 10 items of 310 documents
Neuroprotective effect of flupirtine in prion disease
2003
Apoptotic neuronal cell death is a hallmark of prion diseases. The apoptotic process in neuronal cells is thought to be caused by the scrapie prion protein, PrPSc, and can be experimentally induced by its peptide fragment, PrP106-126. This process is a target for potential drugs to combat prion disease or to ameliorate its symptoms. Flupirtine (Katadolon), a pyridine derivative that is in clinical use as a nonopioid analgesic, has a potent cytoprotective effect, at concentrations above 1 microg/mL, on neuronal cells treated with PrP(Sc) or PrP106-126. This drug acts as an N-methyl-D-aspartate (NMDA) antagonist, but does not bind to NMDA receptors. Flupirtine normalizes the level of intracel…
Reactive neurogenesis during regeneration of the lesioned medial cerebral cortex of lizards
1995
Abstract This study reports that lesion of the adult lizard medial cortex (lizard hipocampal fascia dentata) induces a short period of intensive neurogenesis which we have termed reactive neurogenesis; a cell proliferation event that occurs in the subjacent ependyma. Specific lesion of the medial cortex was achieved by intraperitoneal injection of the neurotoxin 3-acetylpyridine and proliferating cells were detected using tritiated thymidine or 5-bromodeoxiuridine pulse labelling. After lesion, granule neurons in the lizard medial cortex cell layer appeared pyknotic and died; they were then removed and progressively replaced by a set of new neurons. These neurons were mostly generated from …
Transitory disappearance of microglia during the regeneration of the lizard medial cortex
1994
In normal lizards, microglial cells populate the medial cortex (a zone homologous to the hippocampal fascia dentata), with a preferential distribution along the border between the granular cell layer and the plexiform layers. Intraperitoneal injection of the neurotoxin 3-acetylpyridine (3AP) induces a selective lesion in the medial cortex with a rapid degeneration of the granular layer and its zinc-enriched axonal projection. Within 6-8 weeks, the granular layer is, however, re- populated by a new set of neurons generated in the subjacent ependyma and the cell debris is removed. The aim of this study was to determine to what extent microglia were involved in the scavenging processes during …
Nitroblue-tetrazolium test for the functional evaluation of phagocytic cells: a critical analysis of the methodology.
1981
The reduction of NBT to formazan has been suggested as an indicator of the reduction potential of biological systems. An increase in the amount of reduced formazan reflects the activation of the hexose monophosphate shunt of phagocytes cultivated in vitro, as a result of cellular stimulation by chemical or biological factors, or during phagocytosis. This phenomenon has been widely used for the determination of activated phagocytes by different methods. However, the technical limitations of these methods have not been evaluated carefully. In the investigations presented here three solvents for formazan, pyridine, dioxane and dimethyl-formamide, have been tested for their suitability as extra…
The Chemistry of [1,2,3]Triazolo[1,5- a] pyridines
2003
The reactivity of [1,2,3]triazolo[1,5-a]pyridines 1 is described. Triazolopyridines react with electrophiles in two contrasting ways, giving 3-substituted triazolopyridines 2, or products 3, resulting from triazolo ring opening with loss of molecular nitrogen. The triazolopyridines can be lithiated at -40 degrees C by lithium diisopropylamide in ether giving regiospecifically the 7-lithio derivative. Bromotriazolopyridines have activation towards nucleophilic substitution at position 5 and 7, and benzenoid inertness at position 6. The parent compound 1a is easily hydrogenated giving tetrahydrotriazolopyridine 11a in high yield; when the triazolopyridines have substituents, the hydrogenation…
Enantioselective copper-aminopyridine-catalyzed aza-Henry reaction with chelating N-(2-pyridyl)sulfonyl imines
2012
This article describes a copper-catalyzed aza-Henry reaction. Copper complexes of camphor-derived aminopyridines catalyze the addition of nitromethane to N-(2-pyridyl)sulfonyl aldimines to give the corresponding β-nitrosulfonamides with good yields and variable enantiomeric excesses (up to 83%). An example of transformation of these compounds into N-(2-pyridyl)sulfonyl-α-amino acids and deprotection of the sulfonamide with Mg–MeOH is provided. Chirality 24:441–450, 2012. © 2012 Wiley Periodicals, Inc.
Standard versus personalized schedule of regorafenib in metastatic gastrointestinal stromal tumors: a retrospective, multicenter, real-world study
2021
Background Despite its proven activity as third-line treatment in gastrointestinal stromal tumors (GIST), regorafenib can present a poor tolerability profile which often leads to treatment modifications and transient or permanent discontinuation; thus, in clinical practice physicians usually adopt various dosing and interval schedules to counteract regorafenib-related adverse events and avoid treatment interruption. The aim of this real-world study was to investigate the efficacy and safety of personalized schedules of regorafenib in patients with metastatic GIST, in comparison with the standard schedule (160 mg daily, 3-weeks-on, 1-week-off). Patients and methods Institutional registries a…
Metallo-Polymer Chain Extension Controls the Morphology and Release Kinetics of Microparticles Composed of Terpyridine-Capped Polylactides and their …
2016
Control over morphology and porosity of supramolecular complexed polylactide (PLA) microparticles can be achieved by manipulation of the supramolecular interactions between their constituent polymeric building blocks. It is expected that such modular systems are ideal candidates to serve as degradable delivery carriers. In view of this goal, this study reports about a modular fabrication of biodegradable microparticles from terpyridine (TPy) and bisterpyridine (bisTPy) end-functionalized PLAs that can be transiently extended by chain association through differently strong complexation to three metal cations: Ni2+ , Co2+ , or Fe2+ . Further influence on the morphology of the particles can be…
ZnII and CuII-Based Coordination Polymers and Metal Organic Frameworks by the of Use of 2-Pyridyl Oximes and 1,3,5-Benzenetricarboxylic Acid
2021
The simultaneous use of 2-pyridyl oximes (pyridine-2 amidoxime, H2pyaox
Effect of flupirtine on Bcl-2 and glutathione level in neuronal cells treated in vitro with the prion protein fragment (PrP106-126).
1997
Flupirtine, trade name Katadolon, is a centrally acting nonopioid analgesic that has recently been found to display cytoprotective activity in vitro and in vivo on neurons induced to undergo apoptosis. This report shows that the PrP106-126 fragment of the prion protein, which is the likely etiological agent for a series of encephalopathies, is toxic to cortical neurons in vitro. Simultaneously, PrP106-126 influences the molecular GSH content and the bcl-2 expression in neurons. Significant toxicity (32% reduction in cell viability) was observed at a concentration of 50 microM of the peptide after 9 days of incubation, while at higher concentrations toxicity increased to 70%. Neurotoxicity w…