Search results for "Defence mechanism"
showing 10 items of 34 documents
Apoptosis: focus on sea urchin development
2009
It has been proposed that the apoptosis is an essential requirement for the evolution of all animals, in fact the apoptotic program is highly conserved from nematodes to mammals. Throughout development, apoptosis is employed by multicellular organisms to eliminate damaged or unnecessary cells. Here, we will discuss both developmental programmed cell death (PCD) under normal conditions and stress induced apoptosis, in sea urchin embryos. Sea urchin represent an excellent model system for studying embryogenesis and cellular processes involved in metamorphosis. PCD plays an essential role in sculpting and remodelling the embryos and larvae undergoing metamorphosis. Moreover, this marine organi…
Old Weapons for New Wars: Bioactive Molecules From Cnidarian Internal Defense Systems
2016
The renewed interest in the study of genes of immunity in Cnidaria has led to additional information to the scenario of the first stages of immunity evolution revealing the cellular processes involved in symbiosis, in the regulation of homeostasis and in the fight against infections. The recent study with new molecular and functional approach on these organisms have therefore contributed with unexpected information on the knowledge of the stages of capturing activities and defense mechanisms strongly associated with toxin production. Cnidarians are diblastic aquatic animals with radial symmetry; they represent the ancestral state of Metazoa, they are the simplest multicellular organisms tha…
Mars-105 study : Time-courses and relationships between coping, defense mechanisms, emotions and depression
2013
International audience; This study investigated the time-courses and the relationships between coping, defense mechanisms, emotions and depression considered as key factors in adaptation to ICE (Isolated and Confined Extreme) environments. During the space simulation, the Mars-105 experiment, positive emotion decreased significantly and significant positive correlations were found between mature defenses and both positive emotions and Task-Oriented Coping (TOC), as well as between Disengagement-Oriented Coping (DOC) and symptoms of depression. These findings show the impact of space simulation on affective states and the relations of defense to both coping and emotion, which underline the r…
Defensive strategies in a big obese group [MECCANISMI DI DIFESA IN UN GRUPPO DI PERSONE CON OBESITA']
2013
Aim. The aim of this study was to explore thè defense mechanisms of people with moderate and severe obesity. In fact, thè defensive structure is an effective predictor for thè best management of thè disease. Methods. 204 people (164 F-40 M) bave been recruited: 40 with BMI between 30 and 34.9, with moderate obesity, 36 with BMI between 35 and 39.9, with severe obesity, and 128 with BMI>40, with serious obesity, ali of them pertaining to thè clinic for obesity treatment at University Hospital of Palermo. Ali subjects were administered thè Defense Mechanisms Inventory (DMI), a type of reactive that explores defense mechanisms. The psychiatric comorbidity was excluded by thè DSM (SCIDI and II)…
Insect immunity: oral exposure to a bacterial pathogen elicits free radical response and protects from a recurring infection
2014
Background: Previous exposure to a pathogen can help organisms cope with recurring infection. This is widely recognised in vertebrates, but increasing occasions are also being reported in invertebrates where this phenomenon is referred to as immune priming. However, the mechanisms that allow acquired pathogen resistance in insects remain largely unknown. Results: We studied the priming of bacterial resi stance in the larvae of the tiger moth, Parasemia plantaginis using two gram-negative bacteria, a pathogenic Serratia marcescens and a non-pathogenic control, Escherichia coli. Asublethaloraldoseof S. marcescens provided the larvae with effective protection against an otherwise lethal septic…
Age-related changes in antioxidant defence mechanisms and peroxidation in isolated hepatocytes from spontaneously hypertensive and normotensive rats
1994
International audience; The effects of age and hypertension on the antioxidant defence systems and the lipid peroxidation in rat isolated hepatocytes were studied. Four different age groups (1, 3, 6 and 12 months) were considered in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. Age-associated changes were observed on vitamin E status, glutathione (GSH) level, MDA formation and glutathione peroxidase (GSH-Px) activity in both strains. Maximal levels or activities of these parameters were found at 3 and 6 months, except for MDA which was low at 3 months. Then, a fall was observed at 12-month-old compared to 6-month values. In addition, GSH-Px activity was sig…
Relationships between Coping Strategies and Defense Mechanisms in sport performance
2008
In an exploratory study, the relationships between two major concepts in psychological adjustment, coping strategies, and defense mechanisms were investigated. Sport competition is an example of a real-world context in which people's responses to stressful situations can be investigated. The extent to which participants reported different uses of coping strategies and defense mechanisms was assessed in terms of performance. 26 elite kayakers were classified into one of two groups, depending on the discrepancy between their standard performance and their performance in competition. Correlations were found among the coping strategies of seeking social support, positive reappraisal/planful pr…
TLR2: for or against Candida albicans?
2005
In a recent issue of Trends in Microbiology, Netea and coworkers presented their opinion that toll-like receptors (TLRs) are involved in escape from the defense mechanisms of the host [1]. In their article, the authors clearly identified three major TLR-mediated escape mechanisms that are used by microbial pathogens, such as Yersinia, Mycobacterium and Candida. Here, we wish to comment on the roll of TLR2 in Candida albicans infections. Netea's interesting hypothesis, that TLR2 expression might confer to mice an increased susceptibility to C.
MENTAL FUNCTIONING IN A GROUP OF OBESE PATIENTS CANDIDATES FOR BARIATRIC TREATMENT: DEFENCE MECHANISMS AND ALEXITHYMIA
2017
Several studies confirm that obesity with comorbidity psychiatric disorders decreases the long-term success of surgical treatment. The prevalence of psychiatric disorders varies from 30% to 76% between the obese patients candidate for bariatric treatment (Hudson et al., 2007; Striegel-Moore et al., 2009). It goes without saying that it is essential to prearrange a correct assessment in patient with a severe obesity who are candidate for surgical treatment in order to ensure a long term successful treatment. The aim of the study is to outline some psychological factors that could promote and maintain conditions of severe obesity and to identify weak points in widely applied care pathway. Thi…
Host defence mechanisms against bacterial aggression in periodontal disease : basic mechanisms
2009
Periodontal diseases are complex bacteria-induced infections characterised by an inflammatory host response to plaque microbiota and their by-products. Most of these microorganisms have virulence factors capable of causing massive tissue destruction both directly, through tissue invasion and the production of harmful substances, or indirectly, by activation of host defense mechanisms, creating an inflammatory infiltrate of potent catabolic activity that can interfere with normal host defense mechanisms. In response to the aggression, host defense mechanisms activate innate and adaptive immune responses. Our aim is to offer a general overview of the main mechanisms involved in the host respo…