Search results for "VITRO"
showing 10 items of 2786 documents
Hepatic metabolism of diclofenac: role of human CYP in the minor oxidative pathways.
1999
The aim of this study was to re-examine the human hepatic metabolism of diclofenac, with special focus on the generation of minor hydroxylated metabolites implicated in the idiosyncratic hepatotoxicity of the drug. Different experimental approaches were used: human hepatocytes, human microsomes, and engineered cells expressing single human CYP (cytochromes P450). Human hepatocytes formed 3'-hydroxy-, 4'-hydroxy-, 5-hydroxy- 4',5-dihydroxy-, and N,5-dihydroxydiclofenac, as well as several lactams. Formation of 4'- and 5-hydroxydiclofenac by human liver microsomes followed a Michaelis-Menten kinetics (Km 9 +/- 1 microM; Vmax 432 +/- 15 pmol/min/mg and Km 43 +/- 5 microM; and Vmax 15.4 +/- 0.6…
Inhibition of skin inflammation in mice by diclofenac in vesicular carriers: Liposomes, ethosomes and PEVs
2013
Diclofenac-loaded phospholipid vesicles, namely conventional liposomes, ethosomes and PEVs (penetration enhancer-containing vesicles) were developed and their efficacy in TPA (phorbol ester) induced skin inflammation was examined. Vesicles were made from a cheap and unpurified mixture of phospholipids and diclofenac sodium; Transcutol P and propylene glycol were added to obtain PEVs, and ethanol to produce ethosomes. The structure and lamellar organization of the vesicle bilayer were investigated by transmission electron microscopy and small and wide angle X-ray scattering, as well as the main physico-chemical features. The formulations, along with a diclofenac solution and commercial Volta…
Mid-region parathyroid hormone-related protein (PTHrP) and gene expression of MDA-MB231 breast cancer cells.
2007
Abstract We have previously shown that PTHrP(38–94) amide restrains growth and invasion in vitro, causes striking toxicity and accelerates death of some breast cancer cell lines, the most responsive being MDA-MB231, for which tumorigenesis was also attenuated in vivo. We have also demonstrated that mid-region PTHrP gains access to the nuclear compartment of these cells and displays DNA-binding properties in vitro by recognizing targets in both cellular chromatin and isolated oligonucleotides. Here, we examined whether PTHrP(38–94) amide was able to modulate gene expression of MDA-MB231 cells, employing a combination of conventional, differential display and semi-quantitative multiplex PCR t…
Fractal-structured multifocal intraocular lens
2017
[EN] In this work, we present a new concept of IOL design inspired by the demonstrated properties of reduced chromatic aberration and extended depth of focus of Fractal zone plates. A detailed description of a proof of concept IOL is provided. The result was numerically characterized, and fabricated by lathe turning. The prototype was tested in vitro using dedicated optical system and software. The theoretical Point Spread Function along the optical axis, computed for several wavelengths, showed that for each wavelength, the IOL produces two main foci surrounded by numerous secondary foci that partially overlap each other for different wavelengths. The result is that both, the near focus an…
Extending in vitro digestion models to specific human populations: Perspectives, practical tools and bio-relevant information
2017
29th International Conference of the European-Federation-of-Food-Science-and-Technology (EFFoST) -- NOV 10-12, 2015 -- Athens, GREECE
Induction of Human P-Glycoprotein in Caco-2 cells: Development of a Highly Sensitive Assay System for P-Glycoprotein-Mediated Drug Transport
2006
The aim of this work is to develop a highly sensitive assay system for P-gp-mediated transport by using two methods, induction of P-gp and short-term culture of Caco-2 cells. To induce P-gp in Caco-2 cells, cells were cultured in vinblastine-containing medium. The mRNA level of P-gp was approximately 7-fold higher in Caco-2 cells cultured with vinblastine (P-gp-induced Caco-2 cells) than in control cells. Western blot analysis showed a significant increase in P-gp expression. After cell differentiation, the mRNA level of P-gp was downregulated, however, P-gp-induced Caco-2 cells still possessed a 5.6-fold higher mRNA level of P-gp compared to control cells. Polarized transport of substrate …
Synthesis of N-acyl Derivatives of Aminocombretastatin A-4 and Study of their Interaction with Tubulin and Downregulation of c-Myc.
2021
11 p.-9 fig.-4 tab.
Determination of hydrodynamic drag forces and drag coefficients on human leg/foot model during knee exercise.
2000
Objective. The purpose of this laboratory experiment was to measure hydrodynamic drag forces in barefoot/hydro-boot conditions and accordingly, to determine the coefficients of drag on human leg/foot model during simulated knee extension–flexion exercise. Design. The prosthesis of the human lower leg was set in a water tank and connected into an isokinetic force dynamometer to measure resistive forces during knee motion. Background. Quantifying resistance for aquatic exercises has been a challenge in hydrotherapy. The use of models of foot/leg provides a practical method to calculate coefficients of drag and to estimate resistance for rehabilitation purposes in musculoskeletal and amputee p…
Recombinant cDNA encapsulation in small liposomes with hepatocyte access ability.
1993
Liposomal encapsulation efficiency of a recombinant cDNA was studied by several procedures. We observed that supernatant fraction of ultracentrifuged liposomes prepared by extrusion through polycarbonate filters of 400 nm pore size yielded a very homogeneous suspension of small (50 nm diameter) unilamellar liposomes with highest DNA/lipid ratio and great ability to access to hepatocytes.
Biopartitioning micellar chromatography: an in vitro technique for predicting human drug absorption.
2001
The main oral drug absorption barriers are fluid cell membranes and generally drugs are absorbed by a passive diffusion mechanism. Biopartitioning micellar chromatography (BMC) is a mode of micellar liquid chromatography that uses micellar mobile phases of Brij35 under adequate experimental conditions and can be useful to mimic the drug partitioning process in biological systems. In this paper the usefulness of BMC for predicting oral drug absorption in humans is demonstrated. A hyperbolic model has been obtained using the retention data of a heterogeneous set of 74 compounds, which shows predictive ability for drugs absorbed by passive diffusion. The model obtained in BMC is compared with …