Search results for "pyridines"
showing 10 items of 310 documents
Activation of angiotensin II type 1 receptors and contractile activity in human sigmoid colon in vitro.
2015
We propose and validate a non-invasive method that enables accurate detection of the discharge times of a relatively large number of motor units during excitatory and inhibitory reflex stimulations. HDsEMG and intramuscular EMG (iEMG) were recorded from the tibialis anterior muscle during ankle dorsiflexions performed at 5%, 10%, and 20% of the maximum voluntary contraction (MVC) force, in 9 healthy subjects. The tibial nerve (inhibitory reflex) and the peroneal nerve (excitatory reflex) were stimulated with constant current stimuli. In total, 416 motor units were identified from the automatic decomposition of the HDsEMG. The iEMG was decomposed using a state-of-the-art decomposition tool a…
Efficacy of delayed thromboprophylaxis with dabigatran: Pooled analysis
2012
Abstract Introduction Oral thromboprophylaxis with dabigatran etexilate should be initiated as a half dose 1 to 4 h after major orthopaedic surgery. However, a delay in dosing could occur for clinical or logistical reasons. A post hoc analysis was carried out to determine if patients with delayed dosing received adequate anticoagulation. Patients and methods The RE-MODEL™ and RE-NOVATE® trials compared 220 mg and 150 mg dabigatran etexilate with 40 mg enoxaparin. Pooled data for major venous thromboembolism (VTE) and VTE-related mortality (efficacy outcome) and major bleeding events (MBE), MBE/clinically relevant bleeding events, and all bleeding events (safety outcomes) were analysed. Resu…
Comparative study of taurine and tauropyrone: GABA receptor binding, mitochondrial processes and behaviour.
2011
Abstract Objectives Taurine, a sulfur-containing amino acid, has high hydrophilicity and is poorly absorbed. Tauropyrone, a taurine-containing 1,4-dihydropyridine derivative, is suggested to have greater activity than taurine owing to improved physicochemical properties that facilitate delivery of the compound to target cells. The aim of this study was to determine whether the 1,4-dihydropyridine moiety in tauropyrone improves the pharmacological efficacy of taurine in vitro and in vivo. Methods The effects of taurine and tauropyrone, as well as of the 1,4-dihydropyridine moiety were compared in in-vitro experiments to determine the binding to GABA receptors and influence on mitochondrial p…
Combination of open field and elevated plus-maze: a suitable test battery to assess strain as well as treatment differences in rat behavior.
1998
Abstract 1. 1. A test battery consisting of a standard open field, an enriched open field and an elevated plus maze was used to study behavior in rats. 2. 2. Male rats of the strains PVG/OlaHsd (PVG) and Sprague-Dawely-Hsd (SPRD) (150–200g body wt) were used to assess interstrain differences as well as handling effects. In a subsequent experiment an other set of male PVG rats (150–200g body wt) treated either with diazepam or zolpidem was used to evaluate the test battery for pharmacological purposes. 3. 3. SPRD rats displayed higher motor activity levels and also higher levels of exploratory behavior than the PVG rats. In contrast plus-maze activity indicated more anxiety of SPRD than PVG …
EFFECTS OF 4-AMINOPYRIDINE ON ACETYLCHOLINE OUTPUT FROM THE CEREBRAL CORTEX OF THE RAT in vivo
1982
Abstract 1 The effects of 4-aminopyridine (4AP) on the output of acetylcholine (ACh) from the cerebral cortex were investigated in unanaesthetized freely moving rats and in anaesthetized rats by means of the `cup technique'. ACh was determined by bioassay on the dorsal muscle of the leech. 2 In unanaesthetized rats intraperitoneal injection of 4AP (3 mg/kg) had no effect on the cortical output of ACh. 3 After injection of morphine (10 mg/kg s.c.), which depressed the spontaneous output of ACh, 4AP increased the cortical output to a level significantly higher than that determined before morphine injection. 4 In rats anaesthetized with either urethane or pentobarbitone, drugs known to decreas…
Attempted synthesis of spongidines by a radical cascade terminating onto a pyridine ring.
2007
Mn(III)-based oxidative free-radical cyclization of an unsaturated beta-keto ester containing a pyridine ring as radical trap has been studied. This intramolecular reaction of nucleophilic carbon-centered radicals with the pyridine ring leads to the stereospecific construction of a tetracyclic compound in which five chiral centers are created in one pot. This synthetic approach represents the first attempt to prepare the anti-inflammatory pyridinium alkaloids spongidine A, B, and D.
Distinct effects of atypical 1,4-dihydropyridines on 1-methyl-4-phenylpyridinium-induced toxicity.
2006
Our previous data obtained from in vivo experiments demonstrated high neuroprotective effects of three novel atypical neuronal non-calcium antagonistic 1,4-dihydropyridine (DHP) derivatives cerebrocrast, glutapyrone and tauropyrone. The present studies were carried out in vitro to clarify, at least in part, their mechanism of action in primary culture of cerebellar granule cells by use of 1-methyl-4-phenylpyridinium (MPP+) as a neurotoxic agent which causes dramatic oxidative stress. Cerebrocrast (highly lipophilic, with a classical two-ring structure) dose-dependently (0.01-10.0 microM, EC50 = 13 nM) reduced MPP+-induced cell death. At the same time, the calcium antagonist nimodipine (refe…
Novel 1H-pyrrolo[2,3-b]pyridine derivative nortopsentin analogues: synthesis and antitumor activity in peritoneal mesothelioma experimental models.
2013
In this study, we describe the synthesis of new nortopsentin analogues, 1H-pyrrolo[2,3-b]pyridine derivatives and their biological effects in experimental models of diffuse malignant peritoneal mesothelioma (DMPM), a rare and rapidly fatal disease, poorly responsive to conventional therapies. The three most active compounds, 1f (3-[2-(5-fluoro-1-methyl-1H-indol-3-yl)-1,3-thiazol-4-yl]-1H-pyrrolo[2,3-b]pyridine), 3f (3-[2-(1H-indol-3-yl)-1,3-thiazol-4-yl]-1-methyl-1H-pyrrolo[2,3-b]pyridine), and 1l (3-[2-(5-fluoro-1-methyl-1H-indol-3-yl)-1,3-thiazol-4-yl]-1-methyl-1H-pyrrolo[2,3-b] pyridine), which were shown to act as cyclin-dependent kinase 1 inhibitors, consistently reduced DMPM cell prol…
Heterocyclic and Phenyl Double-Bond-Locked Combretastatin Analogues Possessing Potent Apoptosis-inducing activity in HL60 and in MDR Cell lines
2005
Two new series of combretastatin (CA-4) analogues have been prepared. The alkenyl motif of CA-4 was replaced either by a five-membered heterocyclic (isoxazoline or isoxazole) or by a six-membered ring (pyridine or benzene). The new compounds have been evaluated for their effects on tubulin assembly and for cytotoxic and apoptotic activities. Five compounds (18b, 20a, 21a, 34b, and 35b) demonstrated an attractive profile of cytotoxicity (IC501 microM) and apoptosis-inducing activity but poor antitubulin activity. The isoxazoline derivatives 18b, 20a, and 21a, demonstrated potent apoptotic activity different from that of natural CA-4. Their ability to block most cells in the G2 phase suggests…
Coordination Polymers Containing Manganese(II)-Azido Layers Connected by Dipyridyl-tetrazine and 4,4′-Azobis(pyridine) Linkers
2013
Two new polynuclear manganese(II) complexes [Mn(dptz)(N(3))(2)](n) (1) and [Mn(azpy)(N(3))(2)](n) (2) (where dptz = dipyridyl-tetrazine and azpy = 4,4'-azobis(pyridine)) have been synthesized by self-assembly of the ligand azide, together with dptz and azpy as secondary spacers. The compounds are characterized by single-crystal X-ray diffraction analyses and variable-temperature magnetic measurements. The structural analyses reveal that in complex 1, which is the first reported Mn(II) complex with the ligand dptz, two μ(1,3) bridging azides connect neighboring manganese ions in a zigzag manner to generate a neutral two-dimensional (2D) sheet which is further connected by the dptz ligands to…