1,720,988 research outputs found
Indole derivatives useful for treating resistance to antitumor agents
No full textThe use of a group of indole compounds of formula (I) is described for treating tumours which have developed resistance to antitumour drugs. The compounds of formula (I) can be used in monotherapy, to treat tumours affected by drug resistance, or in co-therapy, as synergistic enhancers of the action of the aforesaid antitumour drugs. In addition, pharmaceutical compositions are described which comprise the indole derivatives of formula (I) in association with antitumour drugs the activity of which is to be enhance
PTH2 receptor-mediated inhibitory effect of parathyroid hormone and TIP39 on cell proliferation
No full textThe parathyroid hormone (PTH) has dual mitogenic and inhibitory effects on cell proliferation, depending on the cell type and experimental conditions. PTH can signal via two different receptors, both positively coupled to the adenylyl cyclase/cyclic AMP pathway which can mimic some of the proliferative effects of PTH. We evaluated the role of the type-2 PTH (PTH2) receptor on cell proliferation in clonal human embryonic kidney HEK293 cells stably expressing the human PTH2 receptor. Using a cyclic AMP-responsive gene-reporter, we confirmed that the tuberoinfundibular peptide (TIP39) and various human (h) PTH fragments including hPTH-(1-34) were potent agonists (EC(50) in the range of 0.01-0.3 nM) whereas the bovine (b) PTH peptides b(Tyr(34))PTH-(7-34) and its tryptophan derivative b[D-Trp(12),Tyr(34)]PTH-(7-34) behaved as antagonists (IC(50)=117 and 249 nM, respectively). hPTH-(1-34) produced a dose-dependent inhibition of cell proliferation (EC(50)=8.5+/-0.4 nM) after 3 days and this effect was fully reversed by the tryptophan derivative antagonist. The same effect was observed with TIP39 which caused a 30% maximal inhibition. These findings reveal that PTH2 receptor activation can inhibit cell proliferation and might explain the dual functionality of PTH on cell proliferation
Antagonism between the anti-inflammatory activity of the cannabinoid WIN 55212-2 and SR 141716A
No full textThe CB1/CB2 receptor agonist WIN 55212-2 (0.75 mg/kg, i.v.) caused a significant reduction in neurogenic plasma extravasation induced by electrical stimulation of the saphenous nerve in anesthetized rats; WIN 55212-2 at 2.5-10 mg/kg, s.c., also produced a significant reduction in the carrageenan-induced paw edema in conscious rats. The selective CB1 antagonist SR 141716A (0.075-0.75 mg/kg i.v.) antagonized the WIN 55212-2 effects in the plasma extravasation model and antagonized the WIN 55212-2 (2.5 mg/kg, s.c.)-induced decreases in rectal temperature and increases in tail-flick latencies. However, SR 141716A (10 mg/kg, p.o.) failed to antagonize the effects of Win 55212-2 (2.5 mg/kg, s.c.) in the carrageenan model, suggesting that cannabinoid receptors found in the periphery may be able to modulate inflammatory processes in rats
Evaluation of in vitro brain penetration: Optimized PAMPA and MDCKII-MDR1 assay comparison
No full textParallel artificial membrane permeability assay (PAMPA) is arising in ADMET screening as a powerful tool to determine the passive permeability of new potential chemical entities. In an attempt to set up a sensitive high throughput method to assess passive blood-brain barrier (BBB) penetration we focused our attention on the effect of solvent and the influence of phospholipids on the permeability in PAMPA. Moreover, the high throughput nature of the assay was maximized by decreasing the incubation time and performing the assay in a cassette mode. UPLC system coupled with a mass spectrometer enormously reduces the analytical time, contemporaneously increasing the sensitivity of the method. Papp values obtained from PAMPA were compared to permeability values from MDCKII-MDR1 assay. Evaluation of the two in vitro models with in vivo data was performed to test the predicting capacity of the two methods. Their contemporary assessment was shown to be an helpful tool in understanding the prevalent mechanism of penetration through the BBB. © 2007 Elsevier B.V. All rights reserved
Indole and Azaindole Derivatives For the Treatment of Inflammatory and Autoimmune Diseases
No full textThe use is described of compounds of formula (I) wherein A is chosen from a phenyl or a heterocyclic ring with 5 or 6 members containing up to two heteroatoms chosen from nitrogen, oxygen and sulfur, X and Y represent carbon or nitrogen, and R1-R6 are as described in the specification, in the prevention and/or treatment of inflammatory and autoimmune diseases
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
New perspectives in bio-analytical techniques for preclinical characterization of a drug candidate : UPLC-MS/MS in in vitro metabolism and pharmacokinetic studies
No full textLead optimization requires rapid bio-analytical turnover for the generation of early absorption, distribution, metabolism, excretion (ADME) and pharmacokinetics (PK) data maintaining a high quality level. Therefore, one of the major challenges in the bio-analytical field is to achieve faster and more sensitive quantification protocols. In the present communication, a comparison between HPLC and ultra performance liquid chromatography (UPLC) performances in terms of sensitivity and resolution is shown using a pharmakokinetic study and a metabolism study as models. The studies highlight the features of the new technology and the resulting impact in the PK throughput and in the characterization of isomeric metabolites using UPLC/MS/MS technique
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