Search results for "O-2"
showing 10 items of 854 documents
The effect of chitosan on the bioaccessibility and intestinal permeability of acyclovir
2019
Chitosan is object of pharmaceutical research as a candidate permeability enhancer. However, chitosan was recently shown to reduce the oral bioavailability of acyclovir in humans. The effect of chitosan on two processes determining the oral bioavailability of acyclovir, bioaccessibility and intestinal absorption, was now investigated. Acyclovir's bioaccessibility was studied using the dynamic TNO gastro-Intestinal Model (TIM-1). Four epithelial models were used for permeability experiments: a Caco-2 cell model in absence and presence of mucus and both rat and porcine excised intestinal segments. Study concentrations of acyclovir (0.8 g/l) and chitosan (1.6 g/l and 4 g/l) were in line with t…
How Does the Benzamide Antipsychotic Amisulpride get into the Brain?—An In Vitro Approach Comparing Amisulpride with Clozapine
2003
This study evaluated the disposition of the two atypical antipsychotics, amisulpride (AMS) and clozapine (CLZ), and its main metabolite N-desmethylclozapine (DCLZ), to their target structures in the central nervous system by applying an in vitro blood-brain barrier and blood-cerebrospinal fluid (CSF) barrier based on monolayers of porcine brain microvessel endothelial cells (PMEC) or porcine choroid plexus epithelial cells (PCEC). Permeation studies through PMEC- and PCEC-monolayers were conducted for 60 min at drug concentrations of 1, 5, 10, and 30 muM applied to the donor compartment. PMEC were almost impermeable for AMS (permeation coefficient, P1 x 10(-7) cm/s) in the resorptive direct…
5-Metiltio-2,6-diazabiciklo[2.2.2]oktān-5-ēn-3-ona un 3,5-bismetiltio-2,6-diazabiciklo[2.2.2]oktēn-3,5-diēna atvasinājumu sintēze
2021
5-metiltio-2,6-diazabiciklo[2.2.2]oktān-5-ēn-3-onu un 3,5-(bismetiltio)-2,6-diazabiciklo[2.2.2]oktān-3,5-diēnu sintēze. Freimanis T., zinātniskais vadītājs Dr. Chem., vadošais pētnieks Žalubovskis R.. Bakalaura darbs. 41 lappuse, 4 attēli, 15 tabulas, 14 literatūras avoti. Latviešu valodā Darbā ir veikta 5-metiltio-2,6-diazabiciklo[2.2.2]oktān-5-ēn-3-onu un 3,5-(bismetiltio)-2,6-diazabiciklo[2.2.2]oktān-3,5-diēnu sintēze trīs stadijās. Pirmajā stadijā tiek sintezēta virkne 1-alkil-8-aril-2,6-diazabiciklooktān-3,5-dionu atvasinājumu ar dažādiem alkil un arilaizvietotājiem pie bicikla C-1 un C-8 atomiem respektīvi. 2.stadijā tiek apskatīta sulfurilēšanas iespējas un 3.stadijā tiek veidoti S-m…
Oxidative DNA damage and disturbance of antioxidant capacity by alternariol in Caco-2 cells
2015
Oxidative stress occurs as a consequence of an imbalance between the prooxidant/antioxidant systems, causing an increase of intracellular generation of reactive oxygen species. Alternariol (AOH), a mycotoxin produced by Alternaria sp. can alter the action of glutathione (GSH) and the enzymes involved in the redox system, causing damage to cellular macromolecules such as DNA. The aims of this work were to determine the induction of oxidative stress by the antioxidant defenses imbalance in relation to glutathione (GSH), glutathione reductase (GR), glutathione transferase (GST), glutathione peroxidase (GPx) levels and DNA damage in Caco-2 cells derived from adenocarcinoma human colon. Oxidativ…
PHEA-graft-polybutylmethacrylate copolymer microparticles for delivery of hydrophobic drugs.
2012
Abstract Polymeric microparticles encapsulating two model hydrophobic drugs, beclomethasone dipropionate (BDP) and flutamide (FLU) were prepared by using the high pressure homogenization-solvent evaporation method starting from a oil-in-water emulsion. For the preparation of polymeric microparticles a α,β-poly(N-2-hydroxyethyl)- d , l -aspartamide (PHEA) graft copolymer with comb like structure was properly synthesized via grafting from atom transfer radical polymerization (ATRP) technique, by using two subsequent synthetic steps. In the first step a polymeric multifunctional macroinitiator was obtained by the conjugation of a proper number of 2-bromoisobutyryl bromide (BIB) residues to the…
New Biodegradable Hydrogels Based on Inulin and α,β-Polyaspartylhydrazide Designed for Colonic Drug Delivery: In Vitro Release of Glutathione and Oxy…
2010
Succinic derivatives of inulin (INU-SA) with two different degrees of derivatization (20% and 30%, mol/mol) were cross-linked with α,β-polyaspartylhydrazide (PAHy) to obtain INUPAHy hydrogels. Cross-linking was performed using N-ethyl-N-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC) and N-hydroxysulfosuccinimide (NHSS) as coupling agents and by varying the reaction time (4 h, 8 h and 24 h). All samples prepared were characterized by FT-IR analysis and swelling measurements in different media. In vitro assays, performed in the presence of inulinase, demonstrated the degradability of the prepared hydrogels. Cell compatibility was evaluated using Caco-2 cells through both direct and …
From attachment to damage: defined genes of Candida albicans mediate adhesion, invasion and damage during interaction with oral epithelial cells.
2010
Candida albicans frequently causes superficial infections by invading and damaging epithelial cells, but may also cause systemic infections by penetrating through epithelial barriers. C. albicans is an unusual pathogen because it can invade epithelial cells via two distinct mechanisms: induced endocytosis, analogous to facultative intracellular enteropathogenic bacteria, and active penetration, similar to plant pathogenic fungi. Here we investigated the molecular basis of C. albicans epithelial interactions. By systematically assessing the contributions of defined fungal pathways and factors to different stages of epithelial interactions, we provide an expansive portrait of the processes an…
CCDC 919328: Experimental Crystal Structure Determination
2013
Related Article: Kamran T. Mahmudov, Maximilian N. Kopylovich, Matti Haukka, Gunay S. Mahmudova, Espandi F. Esmaeila, Famil M. Chyragov, Armando J.L. Pombeiro|2013|J.Mol.Struct.|1048|108|doi:10.1016/j.molstruc.2013.05.041
Synthesis of 5H-pyrido[3,2-b]pyrrolizin-5-one tripentone analogs with antitumor activity
2018
Abstract Pyrrolizinones represent an interesting class of compounds with varied degrees of structural complexity and pharmacological activity. Among these, 9H-pyrido[2,3-b]pyrrolizin-9-one, tripentone analogs, recently reported by us, showed significant antiproliferative activity against human tumor cell lines, inducing apoptosis and not affecting viability of Caco-2 differentiated in normal intestinal-like cells. Considering their interesting biological activity, their 5H-pyrido[3,2-b]pyrrolizin-5-one analogs were efficiently synthesized in good to excellent yields (61–91%). All tripentone derivatives were tested to assess their cytotoxicity against two human tumor cell lines, HCT-116 (hum…
Efecto del arsénico inorgánico presente en los alimentos sobre el epitelio intestinal
2018
El arsénico es un metaloide tóxico ampliamente distribuido en el medioambiente. Su forma inorgánica [As(III) y As(V)] es la más tóxica encontrada en agua y alimentos. La exposición a arsénico inorgánico, descrita en numerosas zonas del planeta y que en la actualidad se estima que afecta a 200 millones de personas, aumenta la incidencia de determinados tipos de cáncer y otras patologías no cancerígenas. Teniendo en cuenta que la principal vía de exposición es la oral, el tracto gastrointestinal se considera la puerta de entrada de este tóxico al organismo; sin embargo, los estudios para determinar los efectos tóxicos del arsénico inorgánico a nivel intestinal son escasos. Esta tesis doctoral…