Search results for "Barrier"
showing 10 items of 678 documents
Clients’ Experiences With Internet-Based Psychological Treatments for Mental Disorders: Protocol for a Metasynthesis of Qualitative Studies
2018
Background: Given the rise of internet-based treatments as an effective therapeutic tool for psychological disorders, it is necessary to carry out research that examines clients’ experiences with this type of intervention. The qualitative methodology has been found to be useful for analyzing clients’ perceptions in terms of facilitators and barriers, acceptability, and negative effects of internet-based treatments. However, a lack of integration of these primary studies has prevented their findings from being applied to new research and in clinical practice. Objective: The objective of this paper is to describe the protocol for a metasynthesis of qualitative studies exploring the experience…
Cellular mechanisms of IL-17-induced blood-brain barrier disruption.
2009
Recently T-helper 17 (Th17) cells were demonstrated to disrupt the blood-brain barrier (BBB) by the action of IL-17A. The aim of the present study was to examine the mechanisms that underlie IL-17A-induced BBB breakdown. Barrier integrity was analyzed in the murine brain endothelial cell line bEnd.3 by measuring the electrical resistance values using electrical call impedance sensing technology. Furthermore, in-cell Western blots, fluorescence imaging, and monocyte adhesion and transendothelial migration assays were performed. Experimental autoimmune encephalomyelitis (EAE) was induced in C57BL/6 mice. IL-17A induced NADPH oxidase- or xanthine oxidase-dependent reactive oxygen species (ROS)…
Innovative in vitro method and permeability estimation procedure to predict drug transport across the blood-brain barrier
2014
La Barrera Hematoencefálica (BHE) es una entidad caracterizada por su naturaleza restrictiva al paso de sustancias. Las propiedades de la barrera están determinadas por la confluencia de tres componentes principales: 1) uniones celulares endoteliales con presencia de proteínas especificas intramembrana y citoplasmáticas unidas estrechamente al citoesqueleto. Esta circunstancia restringe la difusión paracelular de compuestos. Adicionalmente a las células endoteliales, la barrera presenta una membrana basal, en la cual se localizan pericitos y astrocitos, que conforman una capa que refuerza las propiedades de la barrera; 2) la presencia de transportadores de absorción y la sobreexpresión de t…
Polyoxypregnanes as safe, potent, and specific ABCB1-inhibitory pro-drugs to overcome multidrug resistance in cancer chemotherapy in vitro and in vivo
2021
Multidrug resistance (MDR) mediated by ATP binding cassette subfamily B member 1 (ABCB1) is significantly hindering effective cancer chemotherapy. However, currently, no ABCB1-inhibitory drugs have been approved to treat MDR cancer clinically, mainly due to the inhibitor specificity, toxicity, and drug interactions. Here, we reported that three polyoxypregnanes (POPs) as the most abundant constituents of Marsdenia tenacissima (M. tenacissima) were novel ABCB1-modulatory pro-drugs, which underwent intestinal microbiota-mediated biotransformation in vivo to generate active metabolites. The metabolites at non-toxic concentrations restored chemosensitivity in ABCB1-overexpressing cancer cells v…
Alkamides from Echinacea angustifolia Interact with P-Glycoprotein of Primary Brain Capillary Endothelial Cells Isolated from Porcine Brain Blood Ves…
2013
The blood-brain barrier prevents the passage of toxic compounds from blood circulation into brain tissue. Unfortunately, drugs for the treatment of neurodegenerative diseases, brain tumors, and other diseases also do not cross the blood-brain barrier. In the present investigation, we used isolated porcine brain capillary endothelial cells and a flow cytometric calcein-AM assay to analyze inhibition of P-glycoprotein, a major constituent of the blood-brain barrier. We tested 8 alkamides isolated from Echinacea angustifolia and found that four of them inhibited P-glycoprotein-mediated calcein transport in porcine brain capillary endothelial cells.
Binding mode analysis of ABCA7 for the prediction of novel Alzheimer's disease therapeutics
2021
Graphical abstract
Characterization of Intertidal Macrofaunal Communities of Two Sandy Beaches under Different Anthropogenic Pressures
2022
The macrofauna in the intertidal zone of sandy beaches provides the trophic connectivity between land and sea, by linking microbiome, meiofauna, and megafauna, representing a food source for several terrestrial animals, including shorebirds and mammals. However, the macrozoobenthos in urbanised beaches is subjected to intense disturbances, such as breakwater barriers and tourism, which limit or impede the energy transfer from the marine to the terrestrial habitats. Because the information about diversity and abundance of the macrozoobenthos of the intertidal zone on the Mediterranean sandy coasts is scant, the main objective of this study is to increase the knowledge on the macrofauna livin…
Skin-PAMPA: a new method for fast prediction of skin penetration.
2011
The goal of this study was to develop a quick, reliable, and cost-effective permeability model for predicting transdermal penetration of compounds. The Parallel Artificial Membrane Permeability Assay (PAMPA) was chosen for this purpose, as it already has been successfully used for estimating passive gastrointestinal absorption and blood-brain barrier permeability. To match the permeability of the rate-limiting barrier in human skin, synthetic certramides, which are analogs of the ceramides present in the stratum corneum, were selected for the skin-PAMPA model. The final skin-PAMPA membrane lipid mixture (certramide, free fatty acid, and cholesterol) was selected and optimized based on data …
Taciturn patients in health counseling at a hospital: passive recipients or active participators?
2001
This study explored patients’ taciturnity as observed on videotape during hospital health counseling situations with a nurse. Health counseling sessions, 38 in number, were videotaped, transcribed verbatim, and analyzed by using an adaptation of conversation analysis. The data analysis included information on 18 selected patients who spoke little and did not introduce new topics, but rather supported the discussion on the theme chosen by the nurse. When we examined nurses’ and patients’ speech word by word, we discovered four participation frames that produced taciturnity: in the hands of professionals, compliant, guilty, and polite. These could fluctuate during interaction. The findings i…
De la encuesta a la base de datos: experiencia de trabajo de campo del estudio «Inmigración, trabajo y salud» (Proyecto ITSAL)
2011
Objective: Despite the need for information in the area of migration and health, the available data are sparse. We describe the field work in a cross-sectional study on the health of immigrant workers in Spain. Method: A convenience sample of workers from Colombia, Ecuador, Morocco and Rumania in four cities was targeted, using a block-walking approach. The outcome rates of the American Association of Public Opinion Research were estimated. Results: Of 6,504 persons approached, 71.4% were eligible contacts. Of these contacts, only 57.8% completed interviews. Response and cooperation rates were above 50%. Conclusions: Block-walking enabled surveyors to access difficult-to-reach groups. The u…