Search results for "ALANINE"
showing 10 items of 499 documents
Monte Carlo simulation of the response of ESR dosimeters added with gadolinium exposed to thermal, epithermal and fast neutrons
2009
Abstract Monte Carlo numerical calculations of the response of alanine and ammonium tartrate ESR (electron spin resonance) dosimeters exposed to neutron fields with different energy spectra are reported. Results have been obtained for various gadolinium concentrations inside the dosimeters. Furthermore, in order to simulate the in-phantom response we have carried out calculations by varying the depth of the dosimeter. We have found that a large enhancement is obtained for thermal neutrons, because of the very high capture cross section of gadolinium to thermal neutrons. A good enhancement was obtained for epithermal neutrons, whereas the sensitivity improvement in the case of fast neutron i…
On the opioid receptor subtype inhibiting the evoked release of 3H-noradrenaline from guinea-pig atria in vitro
1986
1. Guinea-pig isolated atria were incubated and loaded with 3H-(−)-noradrenaline. The intrinsic nerves were stimulated with trains of 5 or 35 field pulses (4 Hz), and the evoked efflux of 3H-noradrenaline and of total tritium was determined in the presence of atropine, corticosterone, desipramine, and phentolamine by liquid scintillation spectrometry. 2. Ethylketocyclazocine (1.4 nmol/l, IC50), MR 2033 (9.1 nmol/l), dynorphin A (1–13) (25 nmol/l, peptidase inhibitors present), etorphine (71 nmol/l), and [d-Ala2, d-Leu5]-enkephalin (>10 μmol/l, peptidase inhibitors present) inhibited the stimulation-evoked efflux of 3H-noradrenaline in a concentration-dependent manner, but not morphine up to…
Caratterizzazione dosimetrica della facility a neutroni termici del reattore TRIGA di Pavia: studio della dose da fotoni mediante rivelatori ESR di a…
2014
The optimization of the procedures of Neutron Capture Therapy (NCT) for cancer treatments involves research for beam characterization. One major issue for this therapy is the reliable dosimetric determination of the various (neutronic and photonic) components of the employed beam. In particular, the precise and accurate measurements of the gamma photon component is fundamental for evaluating the risks to healthy tissues hit by the mixed field. Among solid state dosimeters the alanine detectors read by Electron Paramagnetic Resonance (EPR) technique present several advantages such as: tissue equivalence for photon and electron beams, linearity of its dose-response over a wide range, high sta…
Cloning and characterization of the phenylalanyl-tRNA synthetase β subunit gene fromCandida albicans
1998
A Candida albicans expression library was constructed from RNA isolated from regenerating protoplasts. A 1.4-kb cDNA clone was used to isolate a genomic fragment. Sequence analysis revealed an open reading frame of 593 amino acids with an overall identity of 63.6% with the phenylalanyl-tRNA synthetase beta subunit (FRS1) of Saccharomyces cerevisiae. We named it CaFRS1. It is located in a single copy in chromosome R, SfiI fragment M. Its expression showed a decrease during the cell wall regeneration process in protoplasts of both yeast and mycelial cells of C. albicans, suggesting its requirement thereof in initial steps of the cell wall synthesis.
Zinc Binding Sites Conserved in Short Neuropeptides Containing a Diphenylalanine Motif
2019
A diphenylalanine motif in peptides plays a crucial role in supramolecular systems. The current work represents a novel strategy in which a diphenylalanine motif in the central domain of neuropeptides conserves the specific Zn2+ binding site and prevents "hopping" of the Zn2+ ion between alternative metal binding sites. Alternative metal binding sites may also include carboxylic atoms in the terminal domains of a peptide. Therefore, one needs to design a peptide in which the metal will not bind the carboxylic groups in the terminal domains. Herein, we propose that engineering and designing peptides with a diphenylalanine motif in the central domain may yield excellent metal chelators.
The effects of alpha-cypermethrin exposure on biochemical and redox parameters in pregnant rats and their newborns
2016
IF 2.388; International audience; Pyrethroid insecticides are extensively used in agriculture and in household activities. During pregnancy, they might affect maternal metabolic status and there after fetal development. In this work, we studied metabolic and redox effects of low dose alpha-cypermethrin exposure in pregnant rats and their offspring. The diet containing alpha cypermethrin at 0.02 mg/kg/day was consumed during the entire gestation. Plasma biochemical parameters as well as liver lipid and oxidative stress markers were determined. Our results showed that alpha-cypermethrin induced an increase in body weight and in plasma glucose and lipid levels, as well as in plasma aspartate a…
Hepatic steatosis and insulin resistance are associated with severe fibrosis in patients with chronic hepatitis caused by HBV or HCV infection.
2011
BACKGROUND AND AIMS: Steatosis and insulin resistance (IR) are the major disease modifying in patients with chronic hepatitis C (CHC). Only few studies evaluated these features in patients with chronic hepatitis B (CHB). We aimed to assess the prevalence and the factors related to steatosis and IR in CHB patients, compared with CHC subjects, and to evaluate the potential association between these features and fibrosis severity. MATERIAL AND METHODS: One hundred and seventy consecutive patients with CHB (28 HBeAg positive, 142 HBeAg negative), were evaluated using liver biopsy and metabolic measurements and matched for sex, age and body mass index with 170 genotype 1 CHC patients. IR was def…
The Impact of Amino Acids on Postprandial Glucose and Insulin Kinetics in Humans
2020
Different amino acids (AAs) may exert distinct effects on postprandial glucose and insulin concentrations. A quantitative comparison of the effects of AAs on glucose and insulin kinetics in humans is currently lacking. PubMed was queried to identify intervention studies reporting glucose and insulin concentrations after acute ingestion and/or intravenous infusion of AAs in healthy adults and those living with obesity and/or type 2 diabetes (T2DM). The systematic literature search identified 55 studies that examined the effects of l-leucine, l-isoleucine, l-alanine, l-glutamine, l-arginine, l-lysine, glycine, l-proline, l-phenylalanine, l-glutamate, branched-chain AAs (i.e., l-leucine, l-iso…
Phosphorylation of CalDAG-GEFI by protein kinase A prevents Rap1b activation.
2013
Summary Background Signaling via protein kinase A (PKA) and protein kinase G (PKG) is critical for maintaining platelets in the resting state. Both kinases down-regulate the activity of the small GTPase Rap1b, a critical signaling switch for integrin activation and platelet aggregation. However, the mechanism of Rap1b regulation by PKA and PKG is largely unknown. Objective To identify the PKA phosphorylation sites in calcium and diacylglycerol-regulated guanine nucleotide exchange factor I (CalDAG-GEFI), the main GEF for Rap1b in platelets, and the effect of CalDAG-GEFI phosphorylation in Rap1b activation. Methods The phosphorylation sites in CalDAG-GEFI were identified by radio-active phos…
Routine HCV PCR screening of blood donations to identify early HCV infection in blood donors lacking antibodies to HCV
2001
BACKGROUND: Detection of early hepatitis C infection of blood donors is still a major problem for blood transfusion. Common anti-HCV screening assays show differences in sensitivity and specificity. The often mild symptoms of acute hepatitis C also cause difficulties in the identification of early HCV infection. The feasibility and efficacy of routine screening of blood donations for HCV RNA were investigated. STUDY DESIGN AND METHODS: Blood donations (n = 251,737) were screened for HCV RNA over 4 years. RNA extraction, amplification, and detection were done by two commercial HCV PCR kits (HCV Cobas Amplicor and HCV Cobas Amplicor 2.0, Roche Diagnostics). Screening was done by pool testing …