Search results for "C3"
showing 10 items of 1295 documents
Demonstration of High-Affinity Binding Sites for C3a Anaphylatoxin on Guinea-Pig Platelets
1978
3H-serotonin release from guinea-pig platelets was demonstrated to be the consequence of C3a binding to these cells. A Scatchard analysis of dose-response data of the 125I-C3a binding pattern to guinea-pig platelets pointed to the existence of binding sites with high and low affinity for the C3a molecule (HA and LA receptors). HA receptors are specific for C3a with intact C-terminal arginine. whereas C3adesarg only interacts with LA receptors. The release of serotonin may be induced by a combined reaction of C3a with HA receptors and LA receptors on the platelet membrane.
Comparative study on biological activities of various anaphylatoxins (C4a, C3a, C5a)
1981
Several anaphylatoxic substances (human C3a, guinea pig C3a, human C4a, guinea pig C5a, and a synthetic C3a-related hexapeptide) were compared with regard to their ability to induce secretion of [3H] serotonin from guinea pig platelets. Functional identity of the C3a preparations, C4a, and the hexapeptide was demonstrated by the phenomenon of crossed desensitization. Whereas C3a of human and guinea pig origin proved to be qualitatively and quantitatively identical, C4a expressed only 3% of the activity of the C3 fragments on a molar basis. Investigations with goat anti-guinea pig C3a demonstrate that human and guinea pig C3a possess one antigenic determinant in common; however, this determi…
Platelet Activation: a New Biological Activity of Guinea-pig C3a Anaphylatoxin
1978
3H-serotonin-release from labelled gp-platelets is established as a sensitive method for testing a new biological activity of gp-C3a anaphylatoxin in an autologous situation. Time-, dose- and temperature-dependent release reactions as well as specific inhibition by carboxypeptidase B and anti-C3a antibodies show that C3a is a potent and specific inducer of platelet activation. Inactive C3a does not induce 3H-serotonin-release but specifically inhibits the action of C3a on platelets.
Comparative study on biological effects of the guinea pig complement-peptide C3a and C3a-related synthetic oligopeptides
1980
Dose-response experiments with guinea pig C3a and a synthetic hexapeptide (amino acid residues 72–77), representing the COOH-terminal sequence of human C3a, were performed in two recently described bioassay systems for C3a, i.e. cytotoxicity against tumor cells measured as LDH and 51Cr-release and non cytolytic serotonin release from guinea pig platelets. Compared to the classical anaphylatoxic assay (guinea pig ileum contraction), nearly identical reactivities were observed in all three test systems with C3a and, although quantitatively different, with hexapeptide.
Circulating immune complexes and platelet thromboxane synthesis in patients with insulin-dependent (type I) diabetes mellitus
1984
Platelets from diabetic subjects with circulating immune complexes (CIC) synthesized greater amounts of thromboxane than did platelets from CIC-negative patients or controls. In view of the known action of CIC on platelet function, a relationship between these two factors may be suggested in the initiation and progression of microangiopathy in diabetes.
The relationship between alexithymia, shame, trauma, and body image disorders: investigation over a large clinical sample.
2013
Emilio Franzoni,1 Stefano Gualandi,1 Vincenzo Caretti,2 Adriano Schimmenti,3 Elena Di Pietro,1 Gaetano Pellegrini,1 Giuseppe Craparo,3 Arianna Franchi,1 Alberto Verrotti,4 Alessandro Pellicciari11Child Neuropsychiatry Unit, University of Bologna, Italy; 2Department of Psychology, University of Palermo, Italy; 3Faculty of Human and Social Sciences, Kore University of Enna, Enna, Italy; 4Department of Pediatrics, University of Chieti, ItalyBackground: The connections between eating disorders (EDs) and alexithymia have not been fully clarified. This study aims to define alexithymia's connections with shame, trauma, dissociation, and body image disorders.Methods: We administered the Dis…
Post-task Effects on EEG Brain Activity Differ for Various Differential Learning and Contextual Interference Protocols
2017
A large body of research has shown superior learning rates in variable practice compared to repetitive practice. More specifically, this has been demonstrated in the contextual interference (CI) and in the differential learning (DL) approach that are both representatives of variable practice. Behavioral studies have indicate different learning processes in CI and DL. Aim of the present study was to examine immediate post-task effects on electroencephalographic (EEG) brain activation patterns after CI and DL protocols that reveal underlying neural processes at the early stage of motor consolidation. Additionally, we tested two DL protocols (gradual DL, chaotic DL) to examine the effect of di…
Neuroergonomic Assessment of Hot Beverage Preparation and Consumption: An EEG and EDA Study.
2020
Neuroergonomics is an emerging field that investigates the human brain in relation to behavioral performance in natural environments and everyday settings. This study investigated the body and brain activity correlates of a typical daily activity, hot beverage preparation, and consumption in a realistic office environment where participants performed natural daily tasks. Using wearable, battery operated and wireless Electroencephalogram (EEG) and Electrodermal activity (EDA) sensors, neural and physiological responses were measured in untethered, freely moving participants who prepared hot beverages using two different machines (a market leader and follower as determined by annual US sales)…
The Approach Behavior to Angry Words in Athletes—A Pilot Study
2019
An increasing number of studies have found that athletes have a higher level of aggression than non-athletes. Anger is an important factor in the generation of aggressive behavior, and anger has been found to relate to both approach behavior and avoidance behavior. The present pilot study compared the aggression level of athletes and non-athletes using the Buss-Perry Aggression Questionnaire, and examined the responses of participants to anger-related stimuli using the manikin task, a paradigm that measures approach-avoidance behavior. In total, 15 athletes and 15 non-athletes finished the questionnaire and the manikin task, which included two conditions. In the anger approach condition, pa…
Adaptive Function and Brain Evolution
2012
Comparing brains is not a mere intellectual exercise but also helps to understand how the brain enables adaptive behavioral strategies to cope with an ever-changing world and how this complex organ has evolved during the phylogeny. For instance, comparative neurobiology helps understanding the specific features of our species, an issue that attracted scientists since the time of Santiago Ramon y Cajal. Following this tradition, 20 years ago Hans ten Donkelaar and Gerhard Roth started the European Conferences on Comparative Neurobiology (ECCN). This e-book includes some of the contributions to the last meeting, the sixth ECCN (Valencia, Spain; April 22-24 2010), plus selected works by severa…