Search results for "Branes"

Effects of Glutathione on Red Blood Cell Intracellular Magnesium

1999

Abstract —Recent evidence suggests that the endogenous antioxidant glutathione may play a protective role in cardiovascular disease. To directly investigate the role of glutathione in the regulation of glucose metabolism in hypertension, we studied the acute effects of in vivo infusions of this antioxidant (alone or in combination with insulin) on whole body glucose disposal (WBGD) using euglycemic glucose clamp and the effects on total red blood cell intracellular magnesium (RBC-Mg) in hypertensive (n=20) and normotensive (n=30) subjects. The relationships among WBGD, circulating reduced/oxidized glutathione (GSH/GSSG) levels, and RBC-Mg in both groups were evaluated. The in vitro effects…

Alveolar bone preservation in extraction sockets using non-resorbable dPTFE membranes: a retrospective non-randomized study.

2008

Background: The aim of this study was to investigate the clinical regeneration of extraction sockets using high-density polytetrafluoroethylene (dPTFE) membranes without the use of a graft material. Methods: A total of 276 extraction sockets were evaluated in 276 subjects (151 males and 125 females; mean age, 50.2 years; age range: 24 to 73 years). After extraction, flaps were elevated and a dPTFE membrane was placed over the extraction site. The flaps were repositioned and sutured into place. Primary closure was not obtained over the membranes. The cemento-enamel junctions of the adjacent teeth were used as reference points. Measurements were taken postextraction and 12 months after surger…

Changes in Maternal Blood Inflammatory Markers As a Predictor Of Chorioamnionitis: A Prospective Multicenter Study

2014

Problem To evaluate the inflammatory pattern in maternal circulation from women with preterm premature rupture of membranes (PPROM) considering the occurrence of histologically confirmed chorioamnionitis (HCA). Method of study A prospective study was conducted in 121 women with PPROM between 24 and 34 + 0 weeks of gestation. Association between white blood cells (WBC) count, plasma CRP, IL-6, MCP-1 and IP-10 levels, and HCA was assessed. Results The rate of HCA was 44.7% (54/121). During the 5 days preceding delivery, median CRP, WBC, and IL-6 levels were significantly higher in the HCA than in no-HCA group (P < 0.001). Variations in IL-6, IP-10 levels, during the 24–72 hr before delivery, …

The negative predictive value of cervical interleukin-6 for the risk assessment of preterm birth.

2013

To determine the potential clinical use of cervical interleukin-6 (IL-6) as a negative predictor of preterm birth in symptomatic women.Observational prospective study carried out in a tertiary hospital.We studied 100 singleton pregnant women with threatened preterm delivery and intact membranes, between 24 and 34 weeks, recruited during the period 2006-2008. A cervical swab for IL-6 detection was taken and a transvaginal ultrasound scan was performed for measuring the cervical length.Five women delivered within 2 d and six women within 7 d. A high cervical IL-6 concentration was found in these women. The area under the ROC curve for cervical IL-6 was 0.97 for deliveries within 2 d after the…

Effect of TiO2 and Al2O3 Addition on the Performance of Chitosan/Phosphotungstic Composite Membranes for Direct Methanol Fuel Cells

2023

Composite chitosan/phosphotungstic acid (CS/PTA) with the addition of TiO2 and Al2O3 particles were synthesized to be used as proton exchange membranes in direct methanol fuel cells (DMFCs). The influence of fillers was assessed through X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, liquid uptake, ion exchange capacity and methanol permeability measurements. The addition of TiO2 particles into proton exchange membranes led to an increase in crystallinity and a decrease in liquid uptake and methanol permeability with respect to pristine CS/PTA membranes, whilst the effect of the introduction of Al2O3 particles on the characteristics of membranes is almost the op…

Flow cytometric analysis of concanavalin A binding to isolated Golgi fractions from rat liver.

1993

Flow cytometry (FCM) has been used repeatedly to study lectin binding to whole cells. However, there are very few attempts to analyze glycoconjugates in isolated subcellular organelles. We have applied FCM to quantitate the specific binding of fluorescein-conjugated concanavalin A (FITC-Con A) to isolated cis and trans fractions of rat liver Golgi complex, the cell compartment involved in glycoprotein maturation and sorting. Our results show similar intensities of Con A-specific binding in the two fractions. Using this method we show a decreased FITC-Con A binding to both Golgi fractions in ethanol-treated rats, which is consistent to previous work on alcoholic effects on galactosyltransfer…

Electrochemical cell for the preparation of large area Anodic Alumina Membranes

2009

Cholesterol facilitates interactions between α‐synuclein oligomers and charge‐neutral membranes

2015

AbstractOligomeric species formed during α-synuclein fibrillation are suggested to be membrane-disrupting agents, and have been associated with cytotoxicity in Parkinson’s disease. The majority of studies, however, have revealed that the effect of α-synuclein oligomers is only noticeable on systems composed of anionic lipids, while the more physiologically relevant zwitterionic lipids remain intact. We present experimental evidence for significant morphological changes in zwitterionic membranes containing cholesterol, induced by α-synuclein oligomers. Depending on the lipid composition, model membranes are either unperturbed, disrupt, or undergo dramatic morphological changes and segregate …

Real-time polarimetric biosensing using macroporous alumina membranes

2013

We report the first demonstration of real-time biosensing in free standing macroporous alumina membranes. The membranes with their 200 nm diameter pores are ideal candidates for biosensing applications where fast response times for small sample volumes are needed as they allow analytes to flow through the pores close to the bioreceptors immobilized on the pores walls. A bulk refractive index sensitivity of 5.2x10 -6 refractive index units was obtained from signal responses to different concentrations of NaCl solutions flowing through the pores. Finally, after functionalizing the alumina pore surfaces with an epoxysilane and then spotting it with β-Lactoglobulin protein, the interactions bet…

Immuno-SLM—a combined sample handling and analytical technique

2004

Immuno-supported liquid membrane (immuno-SLM) extraction is a new technique that makes use of antibody (Ab)-antigen interactions as the "extraction force" to drive the mass transfer in a selective way. In immuno-SLM, anti-analyte (Ag) Abs are introduced into the acceptor phase of the SLM unit to trap the Ag that passes from the flowing donor through the SLM into the stagnant acceptor. The amount of immuno-extracted analyte (AbAg) is quantified by connecting the immuno-SLM unit on-line with a non-competitive heterogeneous fluorescence flow immunoassay (FFIA) that makes use of a fluorescein-labeled analyte tracer that titrates the residual excess of Ab present in the acceptor. A restricted ac…