Search results for " interaction"
showing 10 items of 5187 documents
Non-covalent interactions of N-phenyl-1,5-dimethyl-1H-imidazole-4-carboxamide 3-oxide derivatives—a case of intramolecular N-oxide hydrogen bonds
2017
The crystal structures of new N-phenyl-1,5-dimethyl-1H-imidazole-4-carboxamide 3-oxide derivatives are reported. The results of X-ray diffraction showed the existence of intramolecular hydrogen bonding between carboxamide nitrogen donors and N-oxide oxygen acceptors. The use of Quantum Theory of Atoms in Molecules allowed its classification as a strong interaction, with energy about 10 kcal/mol, and of intermediate character between closed shell and shared bonds. Comparison of experimental data and quantum theoretical calculations indicated that a substituent attached to the phenyl ring in the para position influences the strength and geometry of the title hydrogen bonding. Stronger π-elect…
Antibodies to cell surface ganglioside GD3 perturb inductive epithelial-mesenchymal interactions
1988
Abstract Most epithelial sheets emerge during embryogenesis by a branching and growth of the epithelium. The surrounding mesenchyme is crucial for this process. We report that branching morphogenesis and the formation of a new epithelium from the mesenchyme in the embryonic kidney can be blocked by a monoclonal antibody reacting with a surface glycolipid, disialoganglioside G D3 . In contrast, a more than 10-fold excess of antibodies to adhesive glycoproteins (N-CAM, L -CAM, fibronectin) fails to inhibit morphogenesis. Although the anti-G D3 antibody affected epithelial development, the disialoganglioside G D3 was expressed not in the epithelium, but in the mesenchyme surrounding the develo…
Potential drug-drug interaction between duloxetine and acenocoumarol in a patient with Alzheimer's disease
2007
Abstract Background : Recent evidence suggests that duloxetine may increase the effect of warfarin, thereby increasing the possibility of bleeding. However, a MEDLINE search for articles published between 1980 and May 2007 (terms: duloxetine , anticoagulants , acenocoumarol , and interaction ; no language restriction) did not yield any reports of an interaction between concomitant use of duloxetine and acenocoumarol. Objective : The aim of this study was to describe a potential drug-drug interaction between duloxetine and acenocoumarol in a patient with Alzheimer's disease. The possible mechanism of this potential interaction is examined. Case summary : This report presents the case of a 63…
Accumulation and Adverse Effects of Metoprolol and Propranolol After Concurrent Administration of Cimetidine
1983
Pharmacokinetics of metoprolol, propranolol and atenolol were investigated in six healthy volunteers following 7 days of oral monotherapy with these drugs and after 7 days concurrent administration of each of these betareceptor antagonists with cimetidine. Application of cimetidine did not lead to any interaction with atenolol, whereas mean peak plasma levels of metoprolol were increased by 70%, and those of propranolol by 95% due to concurrent administration of cimetidine (p < 0.05). The AUC of the two last mentioned beta blockers behaved similarly (p < 0.05). Measurement of exercise-induced tachycardia on the 6th day of administration showed no differences between monotherapy with the bet…
Effectiveness of tDCS at Improving Recognition and Reducing False Memories in Older Adults
2021
Background: False memories tend to increase in healthy and pathological aging, and their reduction could be useful in improving cognitive functioning. The objective of this study was to use an active–placebo method to verify whether the application of transcranial direct current stimulation (tDCS) improved true recognition and reduced false memories in healthy older people. Method: Participants were 29 healthy older adults (65–78 years old) that were assigned to either an active or a placebo group
Estradiol or genistein prevent Alzheimer's disease-associated inflammation correlating with an increase PPAR gamma expression in cultured astrocytes.
2009
Inflammation has been implicated in neurodegenerative disorders such as Alzheimer's disease (AD). The main inflammatory players in AD are the glial cells which initiate the inflammatory response. One of the earliest neuropathological changes in AD is the accumulation of astrocytes at sites of A beta deposition. It is desirable to find methods of tipping the balance towards anti-inflammatory state. Estrogenic compounds have shown anti-inflammatory and also antioxidant activity. Astrocytes were pretreated with 17-beta estradiol or with genistein, and 48 h later treated with 5 microM amyloid beta (A beta) for 24 h. We found that A beta induces inflammatory mediators, such as cyclooxygenase 2 (…
Different mechanism of relaxation induced by aporphine alkaloids in rat uterus.
1993
Abstract We have examined the uterine relaxant action of three aporphine molecules (S-glaucine, S-boldine and R-apomorphine) in two experimental conditions, with and without calcium in the bathing solution, and compared these effects with those obtained with the calcium antagonists verapamil and diltiazem. The present study shows that the alkaloids relax the uterine muscle but with different mechanisms of action. In Ca2+-containing solution all three alkaloids relaxed the uterus previously contracted by KCl or acetylcholine, but in Ca2+-free medium only R-apomorphine was able to relax oxytocin-induced contraction. The calcium antagonists, verapamil and diltiazem, relaxed KCl- or acetylcholi…
Computational fluid dynamics simulation to evaluate aortic coarctation gradient with contrast-enhanced CT
2014
Coarctation of aorta (CoA) is a narrowing of the aorta leading to a pressure gradient (Delta P) across the coarctation, increased afterload and reduced peripheral perfusion pressures. Indication to invasive treatment is based on values of maximal (systolic) trans-coarctation Delta P. A computational fluid dynamic (CFD) approach is herein presented for the non-invasive haemodynamic assessment of Delta P across CoA. Patient-specific CFD simulations were created from contrast-enhanced computed tomography (CT) and appropriate flow boundary conditions. Computed Delta P was validated with invasive intravascular trans-CoA pressure measurements. Haemodynamic indices, including pressure loss coeffic…
Severe Tremor After Cotrimoxazole-Induced Elevation of Venlafaxine Serum Concentrations in a Patient With Major Depressive Disorder
2013
: We describe a female patient who was an extensive metabolizer of cytochrome P450 isoenzyme (CYP) 2D6 and an intermediate metabolizer of CYP2C19 (genotype: CYP2C19 *1/*2). She exhibited high serum concentrations of venlafaxine and O-desmethylvenlafaxine and developed severe tremor after comedication with cotrimoxazole (sulfamethazole/trimethoprim). Venlafaxine is mainly metabolized by O- and N-demethylation. O-demethylation is catalyzed by the highly polymorphic CYP2D6 and N-demethylation by several enzymes, CYP2C19, CYP2C9, and CYP3A4. The observed overall pharmacokinetic effect was most probably the result of decreased N-demethylation of venlafaxine by (1) reduced expression of CYP2C19 d…
Mucosa-dependent muscarinic liberation of prostaglandins from rat isolated trachea.
1995
1. The present study examined whether cholinoceptor stimulation modulates the release of arachidonic acid-derived mediators from rat isolate tracheae. 2. Tracheae were preincubated with [3H]-arachidonic acid and the outflow of 3H-compounds was determined. Acetylcholine and the muscarinic agonist, carbachol but not nicotine, increased the rate of tritium outflow maximally by about 30%. The M3 receptor-preferring antagonist rho-fluoro-hexahydrosiladiphenidol was more effective than pirenzepine and methoctramine in antagonizing the effect of acetylcholine. 3. High performance liquid chromatography analysis (methanol gradient) of the released 3H-compounds showed that one peak, co-eluting with […