Search results for "pyridines"
showing 10 items of 310 documents
Trans-epithelial transport of the betalain pigments indicaxanthin and betanin across Caco-2 cell monolayers and influence of food matrix.
2012
Purpose: This study investigated the absorption mechanism of the phytochemicals indicaxanthin and betanin and the influence of their food matrix (cactus pear and red beet) on the intestinal transport. Methods: Trans-epithelial transport of dietary-consistent amounts of indicaxanthin and betanin in Caco-2 cell monolayers seeded on TranswellR inserts was measured in apical to basolateral (AP-BL) and basolateral to apical (BL-AP) direction, under an inwardly directed pH gradient (pH 6.0/7.4, AP/BL) mimicking luminal and serosal sides of human intestinal epithelium. The effect of inhibitors of membrane transporters on the absorption was also evaluated. Contribution of the paracellular route was…
Characterization of particle morphology of biochanin A molecularly imprinted polymers and their properties as a potential sorbent for solid-phase ext…
2014
Abstract Molecularly imprinted polymers (MIPs) with biochanin A as a template were obtained using a bulk polymerization with non-covalent imprinting approach. The polymers were prepared in acetonitrile as porogen, using ethylene glycol dimethacrylate (EDMA) as cross-linking agent. The synthesis, with an application of 1′,1′-azobis(cyclohexanecarbonitrile) (ACHN) as an initiator, has been performed thermally. During the synthesis process the effect of different functional monomers such as methacrylic acid (MAA), acrylamide (AA) and 4-vinylpyridine (4-VP) was investigated. The application of nitrogen sorption porosimetry, scanning electron microscopy (SEM), and Fourier transform infrared spec…
Effect of histamine and histamine analogues on human isolated myometrial strips.
1992
1. The effect of histamine and histamine H1- and H2-receptor agonists on isolated myometrium strips of premenopausal women has been examined. The effect of acetylcholine was also determined. 2. Histamine, 2-pyridylethylamine, 4-methylhistamine and acetylcholine, but not dimaprit, produced a concentration-related contractile response in human isolated myometrial strips. Histamine also produced a further contraction in human isolated myometrial strips precontracted with KCl (55 mM). 3. The contractile response to histamine was antagonized by the histamine H1-receptor antagonist, clemizole (0.1 microM) but was potentiated by the histamine H2-receptor antagonist, ranitidine (10 microM). Clemizo…
Distribution of betalain pigments in red blood cells after consumption of cactus pear fruits and increased resistance of the cells to ex vivo induced…
2005
Betalain pigments are bioavailable phytochemicals recently acknowledged as natural radical scavengers. This work, which extends previous research on the postabsorbitive fate of dietary betalains, investigated the distribution of betanin and indicaxanthin in red blood cells (RBCs) isolated from healthy volunteers (n = 8), before and during the 1-8 h interval after a cactus pear fruit meal, and the potential antioxidative activity of the pigments in these cells. A peak concentration of indicaxanthin (1.03 +/- 0.2 microM) was observed in RBCs isolated at 3 h after fruit feeding, whereas the concentration at 5 h was about half, and even smaller amounts were measured at 8 h. Indicaxanthin was no…
Absorption, excretion, and distribution of dietary antioxidant betalains in LDLs: potential health effects of betalains in humans
2004
Background: Betalains were recently identified as natural antioxidants. However, little is known about their bioavailability from dietary sources. Objective: The objective was to evaluate the bioavailability of betalains from dietary sources. Design: The plasma kinetics and urinary excretion of betalains were studied in healthy volunteers (n 8) after a single ingestion of 500 g cactus pear fruit pulp, which provided 28 and 16 mg indicaxanthin and betanin, respectively. The incorporation of betalains in LDL and the resistance of the particles to ex vivo–induced oxidation was also researched. Results: Betanin and indicaxanthin reached their maximum plasma concentrations 3 h after the fruit me…
Leptin and leptin receptor expression in asthma.
2009
Background The adipokine leptin is a potential new mediator for bronchial epithelial homeostasis. Asthma is a chronic inflammatory disease characterized by airway remodeling that might affect disease chronicity and severity. TGF-β is a tissue growth factor the dysregulation of which is associated with airway remodeling. Objective We sought to determine whether a bronchial epithelial dysfunction of the leptin/leptin receptor pathway contributes to asthma pathogenesis and severity. Methods We investigated in vitro the presence of leptin/leptin receptor on human bronchial epithelial cells. Then we studied the effect of TGF-β and fluticasone propionate on leptin receptor expression. Finally, th…
Safety and Efficacy of Sorafenib in Patients With Advanced Hepatocellular Carcinoma in Consideration of Concomitant Stage of Liver Cirrhosis
2009
GOALS AND BACKGROUND: The multikinase inhibitor sorafenib provides survival benefit for patients with advanced hepatocellular carcinoma (HCC) and liver cirrhosis (LCI) Child-Pugh A. We report our experiences with sorafenib in advanced HCC, particularly in patients with LCI Child-Pugh B/C, where only limited data are available in regard to safety and efficacy of sorafenib. METHODS: Thirty-four patients with advanced HCC were treated with sorafenib regardless of liver function and prior anticancer therapy. Adverse events (AEs) were graded using Common Toxicity Criteria version 3.0, tumor response was assessed according to Response Evaluation Criteria in Solid Tumors. RESULTS: Fifteen patients…
A Phase I dose-escalation study of third-line regorafenib with trifluridine/tipiracil in metastatic colorectal cancer
2021
Aim: To determine a recommended Phase II dose of the oral fluoropyrimidine trifluridine/tipiracil (FTD/TPI) combined with the multi-kinase inhibitor regorafenib (REG) in refractory metastatic colorectal cancer patients. Materials & methods: A conventional 3 + 3 dose finding design was used. FTD/TPI was administered on days 1–5 and 8–12 of a 28-day cycle, REG on days 2–22. Two dose levels were used: FTD/TPI 25 mg/m2 b.i.d. + REG 120 mg/d, then escalated to FTD/TPI 35 mg/m2 b.i.d. + REG 120 mg/d. Results: In total, 12 patients were treated at two dose levels. Three dose-limiting toxicities were observed; all were grade 3 hypertension causally attributed to REG. Recommended Phase II dose …
Roxindole, a dopamine autoreceptor agonist, in the treatment of major depression
1993
Roxindole is a potent autoreceptor-“selective” dopamine agonist originally developed for the treatment of schizophrenic syndromes. The drug also inhibits 5-HT uptake and has 5-HT1A agonistic actions. In this open clinical trial 12 in-patients suffering from a major depressive episode (DSM-III-R) were treated with roxindole for 28 days in a fixed dosage of 15 mg per day. A reduction of at least 50% in HAMD-17 total scores was observed in 8 out of 12 patients after 4 weeks (mean HAMD-17 reduction of 56% in all patients), while 4 patients did not respond to roxindole treatment. Half of the patients showed a complete psychopathological remission (HAMD-17 <8). Roxindole's onset of antidepressant…
Phase 1/2 study of cyclin-dependent kinase (CDK)4/6 inhibitor palbociclib (PD-0332991) with bortezomib and dexamethasone in relapsed/refractory multi…
2015
This phase 1/2 study was the first to evaluate the safety and efficacy of the cyclin-dependent kinase (CDK) 4/6-specific inhibitor palbociclib (PD-0332991) in sequential combination with bortezomib and dexamethasone in relapsed/refractory multiple myeloma. The recommended phase 2 dose was palbociclib 100 mg orally once daily on days 1-12 of a 21-day cycle with bortezomib 1.0 mg/m2 (intravenous) and dexamethasone 20 mg (orally 30 min pre-bortezomib dosing) on days 8 and 11 (early G1 arrest) and days 15 and 18 (cell cycle resumed). Dose-limiting toxicities were primarily cytopenias; most other treatment-related adverse events were grade≤3. At a bortezomib dose lower than that in other combina…