Search results for " α"

Preliminary Studies for the Preparation of Casein-loaded Liposomes to Inhibit Aβ1-40 Fibrillogenesis

2018

αs1-Casein is a natural protein which constitutes the most prevalent form of casein in bovine milk. αs1-Casein is amphiphilic, almost unfolded, and consist of two highly hydrophobic zones separated by an hydrophilic region. Previous studies have demonstrated the ability of αs1-Casein to inhibit in vitro the nucleation phase of amyloid β-peptide (Aβ) fibrillogenesis by sequestering Aβ species on its surface. One of the main hallmark for Alzheimer Disease (AD) is the extracellular deposition in brain tissues of proteinaceous plaques, rich of well-ordered Aβ peptide amyloid aggregates. Although such an evidence, oligomeric intermediates in the fibrillogenesis have been discovered to be the mos…

The three α1-adrenoceptor subtypes show different spatio-temporal mechanisms of internalization and ERK1/2 phosphorylation

2013

AbstractWe analyzed the kinetic and spatial patterns characterizing activation of the MAP kinases ERK 1 and 2 (ERK1/2) by the three α1-adrenoceptor (α1-AR) subtypes in HEK293 cells and the contribution of two different pathways to ERK1/2 phosphorylation: protein kinase C (PKC)-dependent ERK1/2 activation and internalization-dependent ERK1/2 activation. The different pathways of phenylephrine induced ERK phosphorylation were determined by western blot, using the PKC inhibitor Ro 31-8425, the receptor internalization inhibitor concanavalin A and the siRNA targeting β-arrestin 2. Receptor internalization properties were studied using CypHer5 technology and VSV-G epitope-tagged receptors. Activ…

A new hyaluronic acid pH sensitive derivative obtained by ATRP for potential oral administration of proteins

2013

Atom transfer radical polymerization (ATRP) has been successfully employed to obtain a new derivative of hyaluronic acid (HA) able to change its solubility as a function of external pH and then to be potentially useful for intestinal release of bioactive molecules, included enzymes and proteins. In particular, a macroinitiator has been prepared by linking 2-bromo-2-methypropionic acid (BMP) to the amino groups of ethylenediamino derivative of tetrabutyl ammonium salt of HA (HA-TBA-EDA). This macroinititor, named HA-TBA-EDA-BMP has been used for the ATRP of sodium methacrylate (MANa) using a complex of Cu(I) and 2,2'-bipyridyl (Byp) as a catalyst. The resulting copolymer, named HA-EDA-BMP-MA…

Vitamin E activates CRABP-II gene expression in cultured human fibroblasts, role of protein kinase C

2004

The treatment of human fibroblasts with different tocopherols in the presence of retinol caused an increase in cytoplasmic retinoic acid binding protein II (CRABP-II) mRNA and protein. The possibility of an involvement of protein kinase C (PKC) in the response to tocopherols was supported by the results obtained with the PKC-specific inhibitors, calphostin C and bisindolylmaleimide I. The effect of alpha-tocopherol was prevented by okadaic acid, suggesting that a protein phosphatase is responsible for PKC dephosphorylation produced by the presence of tocopherols. The results shown support the hypothesis that phosphorylation/dephosphorylation of RXRalpha via PKC may be involved in the regula…

SYNTHESIS, PHYSICO-CHEMICAL AND BIOLOGICAL CHARACTERIZATION OF A PACLITAXEL MACROMOLECULAR PRODRUG

2004

Paclitaxel was attached to poly(hydroxyethylaspartamide) via a succinic spacer arm by a two-step protocol: (1) synthesis of 2'-O-succinyl-paclitaxel; (2) synthesis of PHEA-2'-O-succinyl-paclitaxel. The 2'-O-succinyl-paclitaxel derivative and the macromolecular conjugate were characterized by UV, IR, NMR and mass spectrometry analysis. The reaction yields were over 95% and the purity of products over 98%. Paclitaxel release and degradation from 2'-O-succinyl-paclitaxel occurred at a faster rate at pH 5.5 than 7.4. After 30 h of incubation at pH 5.5 and 7.4 the released free paclitaxel was about 40 and 20%, respectively. In plasma both drug release and degradation were found to occur at a hig…

Neurogranin as a Novel Biomarker in Alzheimer's Disease

2020

Abstract Background In this study, we investigated the possible role of 2 novel biomarkers of synaptic damage, namely, neurogranin and α-synuclein, in Alzheimer disease (AD). Methods The study was performed in a cohort consisting of patients with AD and those without AD, including individuals with other neurological diseases. Cerebrospinal fluid (CSF) neurogranin and α-synuclein levels were measured by sensitive enzyme-linked immunosorbent assays (ELISAs). Results We found significantly increased levels of CSF neurogranin and α-synuclein in patients with AD than those without AD. Neurogranin was correlated with total tau (tTau) and phosphorylated tau (pTau), as well as with cognitive declin…

Regulation of phospholipase D activity in synaptosomes permeabilized with Staphylococcus aureus alpha-toxin.

1998

In order to investigate the regulation of presynaptic phospholipase D (PLD) activity by calcium and G proteins, we established a permeabilization procedure for rat cortical synaptosomes using Staphylococcus aureus alpha-toxin (30-100 microg/ml). In permeabilized synaptosomes, PLD activity was significantly stimulated when the concentration of free calcium was increased from 0.1 microM to 1 microM. This activation was inhibited in the presence of KN-62 (1 microM), an inhibitor of calcium/calmodulin-dependent kinase II (CaMKII), but not by the protein kinase C inhibitor, Ro 31-8220 (1-10 microM). Synaptosomal PLD activity was also stimulated in the presence of 1 microM GTPgammaS. When Rho pro…

A contemporary assessment of nocturia: definition, epidemiology, pathophysiology, and management--a systematic review and meta-analysis

2012

Abstract Context Nocturia is a common urologic symptom that has been covered in a variety of reported studies in the literature but is not specifically covered in current guidelines. Objective To comprehensively review the literature pertaining to the definition, etiologies, and consequences of nocturia and assess the evidence supporting the use of conservative medical and interventional therapy. Evidence acquisition A literature search was conducted using the keyword nocturia , restricted to articles in the English language, after 2000 and before April 2012, in PubMed/Medline, Embase, Scopus, Web of Science, and Cochrane Library databases. Regarding treatment modalities, studies were inclu…

Biocompatible micelles based on squalene portions linked to pegylated polyaspartamide as potential colloidal drug carriers

2011

Total oxidation of VOCs on mesoporous iron oxide catalysts: Soft chemistry route versus hard template method

2016

9 figures, 3 tables.-- Supplemantary information available