Search results for " Action"
showing 10 items of 3633 documents
Italian Community Psychology in the COVID-19 Pandemic: Shared Feelings and Thoughts in the Storytelling of University Students
2021
This study investigated how young Italian people experienced the period of peak spread of COVID-19 in their country by probing their emotions, thoughts, events, and actions related to interpersonal and community bonds. This approach to the pandemic will highlight social dimensions that characterized contextual interactions from the specific perspective of Community Psychology. The aim was to investigate young people's experiences because they are the most fragile group due to their difficulty staying home and apart from their peers and because they are, at the same time, the most potentially dangerous people due to their urge to gather in groups. The research involved 568 university student…
Functional Morphology of Human Arteries During Fetal and Postnatal Development
1980
The equilibrium between the distending force of the blood pressure and the arterial wall is determined essentially by a simple law of mechanics, the law of Laplace. According to this law, the total force or tension (T) in the vessel’s wall represents the product of the radius of the vessel (r) and the blood pressure (p), T = r.p. The law of Laplace may be used to estimate and compare the tension produced by blood pressure in vessels of different size and thereby determine the increase in functional load on arteries. Since tension increases not only with blood pressure but also with the radius of the vessel, the highest tension is presumably produced in the wall of the ascending aorta where …
Optical Studies of the Capillary Refill Kinetics in Fingertips
2009
A new methodology for temporal analysis of the capillary refill processes by means of photoplethysmography (PPG) contact probe operating in the blue region of spectrum has been developed. A corresponding prototype device for finger measurements has been created and clinically tested. Results demonstrated that both AC and DC components of the blue PPG bio-signals are sensitive to the capillary occlusion and refill. Real-time measurements of the skin capillary refill kinetics by this technology can be used for noninvasive diagnostics of the peripheral perfusion disorders.
Paracentrin 1, a synthetic antimicrobial peptide from the sea-urchin Paracentrotus lividus, interferes with staphylococcal and Pseudomonas aeruginosa…
2014
The rise of antibiotic-resistance as well as the reduction of investments by pharmaceutical companies in the development of new antibiotics have stimulated the investigation for alternative strategies to conventional antibiotics. Many antimicrobial peptides show a high specificity for prokaryotes and a low toxicity for eukaryotic cells and, due to their mode of action the development of resistance is considered unlikely. We recently characterized an antimicrobial peptide that was called Paracentrin 1 from the 5-kDa peptide fraction from the coelomocyte cytosol of the Paracentrotus lividus. In this study, the chemically synthesized Paracentrin 1, was tested for its antimicrobial and antibiof…
Investigations on the Steroidal Anti-Inflammatory Activity of Triterpenoids fromDiospyros leucomelas*
1995
Three triterpenes were isolated from Diospyros leucomelas and identified as betulin, betulinic acid, and ursolic acid. They showed anti-inflammatory activity in the carrageenan and serotonin paw edema tests and TPA and EPP ear edema tests. The blockade of their effects by progesterone, actinomycin D, and cycloheximide has served to determine the mechanism of action in relationship with that of glucocorticoids. Betulinic acid was the most affected and therefore a mode of action similar to these drugs may be postulated for it.
Differential Effects of Antibiotic Therapy on the Structure and Function of Human Gut Microbiota
2013
The human intestinal microbiota performs many essential functions for the host. Antimicrobial agents, such as antibiotics (AB), are also known to disturb microbial community equilibrium, thereby having an impact on human physiology. While an increasing number of studies investigate the effects of AB usage on changes in human gut microbiota biodiversity, its functional effects are still poorly understood. We performed a follow-up study to explore the effect of ABs with different modes of action on human gut microbiota composition and function. Four individuals were treated with different antibiotics and samples were taken before, during and after the AB course for all of them. Changes in the…
A Mechanistic Approach to theIn VivoAnti-Inflammatory Activity of Sesquiterpenoid Compounds Isolated fromInula viscosa
2001
The present study was designed to examine the anti-inflammatory activity of the sesquiterpenoids ilicic acid and inuviscolide, isolated from Inula viscosa, on cell degranulation, leukotriene biosynthesis, neurogenic drive and glucocorticoid-like interactions. Swiss female mice were used to measure the ear oedema induced by phorbol esters or ethyl phenylpropiolate (EPP), and the paw oedema induced by phospholipase A(2) (PLA(2)) or serotonin. Drug treatment consisted of one topically-applied dose in the ear models and a subcutaneous or intraperitoneal injection in the paw models. Quantitative analysis of leukotriene B(4) (LTB(4)) formation was performed on rat peritoneal neutrophils by high p…
In Vivo Studies on the Anti-Inflammatory Activity of Pachymic and Dehydrotumulosic Acids
2000
Pachymic and dehydrotumulosic acids were studied in different models of acute and chronic inflammation. They proved to be active in most of the methods applied. None of them were active against arachidonic acid-induced ear edema. Dehydrotumulosic acid significantly diminished the mouse ear edema induced by ethyl phenylpropiolate, while pachymic acid was ineffective. When the putative corticoid-like mechanism of both compounds was explored, pachymic acid activity was partially abolished by the glucocorticoid receptor antagonist progesterone, but dehydrotumulosic acid activity was not affected. In vivo experiments demonstrated the inhibition by both principles of the phospholipase A2 (PLA2)-i…
Design, synthesis, DNA-binding and cytotoxicity evaluation of new potential combilexines
2002
Combilexines, compounds in which a DNA intercalator is linked to a minor groove binding component, interact with the DNA in a sequence specific manner to yield in most cases compounds with anticancer activity. A series of new compounds closely related to netropsin in which the two components were linked by an amide group was synthesised as potential combilexines. As some of these compounds showed cytotoxic activity in vitro, an attempt was made to rationalise their mechanism of action. The DNA binding characteristics of the carboxamides were evaluated by thermal denaturation experiments and by ethidium bromide displacement assay. Their ability to inhibit the topoisomerase I was also determi…
Prediction of quinolone activity against Mycobacterium avium by molecular topology and virtual computational screening.
2000
ABSTRACT We conducted a quantitative structure-activity relationship study using a database of 158 quinolones previously tested against Mycobacterium avium-M. intracellulare complex in order to develop a model capable of predicting the activity of new quinolones against the M. avium-M. intracellulare complex in vitro. Topological indices were used as structural descriptors and were related to anti- M. avium-M. intracellulare complex activity by using the linear discriminant analysis (LDA) statistical technique. The discriminant equation thus obtained correctly classified 137 of the 158 quinolones, including 37 of a test group of 44 randomly chosen compounds. This model was then applied to 2…