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1.
Polymers (Basel) ; 16(5)2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38475362

RESUMO

The goal of this research was to create an antibacterial biopolymeric coating integrating lytic bacteriophages against Salmonella enterica for use in ripened cheese. Salmonella enterica is the main pathogen that contaminates food products and the food industry. The food sector still uses costly and non-selective decontamination and disease control methods. Therefore, it is necessary to look for novel pathogen biocontrol technologies. Bacteriophage-based biocontrol seems like a viable option in this situation. The results obtained show promise for food applications since the edible packaging developed (EdiPhage) was successful in maintaining lytic phage viability while preventing the contamination of foodstuff with the aforementioned bacterial pathogen.

2.
Med Res Rev ; 44(2): 497-538, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37602483

RESUMO

Rheumatoid arthritis (RA) is a progressive, chronic, autoimmune, inflammatory, and systemic condition that primarily affects the synovial joints and adjacent tissues, including bone, muscle, and tendons. The World Health Organization recognizes RA as one of the most prevalent chronic inflammatory diseases. In the last decade, there was an expansion on the available RA therapeutic options which aimed to improve patient's quality of life. Despite the extensive research and the emergence of new therapeutic approaches and drugs, there are still significant unwanted side effects associated to these drugs and still a vast number of patients that do not respond positively to the existing therapeutic strategies. Over the years, several references to the use of flavonoids in the quest for new treatments for RA have emerged. This review aimed to summarize the existing literature about the flavonoids' effects on the major pathogenic/molecular targets of RA and their potential use as lead compounds for the development of new effective molecules for RA treatment. It is demonstrated that flavonoids can modulate various players in synovial inflammation, regulate immune cell function, decrease synoviocytes proliferation and balance the apoptotic process, decrease angiogenesis, and stop/prevent bone and cartilage degradation, which are all dominant features of RA. Although further investigation is necessary to determine the effectiveness of flavonoids in humans, the available data from in vitro and in vivo models suggest their potential as new disease-modifying anti-rheumatic drugs. This review highlights the use of flavonoids as a promising avenue for future research in the treatment of RA.


Assuntos
Artrite Reumatoide , Flavonoides , Humanos , Flavonoides/farmacologia , Flavonoides/uso terapêutico , Qualidade de Vida , Artrite Reumatoide/tratamento farmacológico , Inflamação
3.
Materials (Basel) ; 16(13)2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37444966

RESUMO

Polyamide 6 (PA6) thermoplastic composites have higher recyclability potential when compared to conventional thermoset composites. A disruptive liquid molding manufacturing technology named Thermoplastic Resin Transfer Molding (T-RTM) can be used for processing composites due to the low viscosity of the monomers and additives. In this process, polymerization, crystallization and shrinkage occur almost at the same time. If these phenomena are not controlled, they can compromise the reproducibility and homogeneity of the parts. This work studied the influence of packing pressure, as a process variable, throughout the filling and polymerization stages. To assess the process reproducibility and parts' homogeneity, physical, thermal and mechanical properties were analyzed in different areas of neat PA6 and composite parts. This study showed that a two-stage packing pressure can be successfully used to increase parts' homogeneity and process reproducibility. The use of 3.5 bar packing pressure during the polymerization stage resulted in mechanical properties with lower standard deviations, indicating a higher degree of homogeneity of the manufactured parts and higher process reproducibility. These results will be used for establishing the actual state of the technology and will be a base for future process optimization.

4.
Antibiotics (Basel) ; 12(6)2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37370307

RESUMO

This research work aimed at developing an edible biopolymeric microcapsular wrapping (EBMW) integrating lytic bacteriophage particles for Salmonella enterica, with potential application in poultry feed for biocontrol of that pathogen. This pathogen is known as one of the main microorganisms responsible for contamination in the food industry and in foodstuff. The current techniques for decontamination and pathogen control in the food industry can be very expensive, not very selective, and even outdated, such as the use of broad-spectrum antibiotics that end up selecting resistant bacteria. Hence, there is a need for new technologies for pathogen biocontrol. In this context, bacteriophage-based biocontrol appears as a potential alternative. As a cocktail, both phages were able to significantly reduce the bacterial load after 12 h of treatment, at either multiplicity of infection (MOI) 1 and 10, by 84.3% and 87.6%, respectively. Entrapment of the phage virions within the EBMW matrix did not exert any deleterious effect upon their lytic activity. The results obtained showed high promise for integration in poultry feed aiming at controlling Salmonella enterica, since the edible biopolymeric microcapsular wrapping integrating lytic bacteriophage particles developed was successful in maintaining lytic phage viability while fully stabilizing the phage particles.

5.
Sci Total Environ ; 871: 162140, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36764529

RESUMO

The circulation of motor vehicles with an exhaust system is one of the leading causes of pollution. Due to the risk factor for human health and contribution to climate change, countries have been growing efforts to achieve a sustainable level of air quality and limit carbon dioxide (CO2) emissions in recent years. Hence, there has been significant interest in developing technological innovations such as alternative fuels and lighter thermoplastic composites for auto applications. Thermoplastic nanocomposites show substantial properties improvements, incorporating much lower nanofiller percentages than fibre-reinforced thermoplastic composites, allowing for a reduction in the weight of automotive parts (AP). For these motivations, this study presents a comparative life cycle assessment (LCA) of poly(propylene) (PP)-based graphene nanoplatelets (GnPs) nanocomposite and PP/glass fibre (GF) composite for automotive applications. The AP selected as the functional unit was the front end part of 1.5 tons weight car. The LCA included preparing raw materials, AP manufacturing, AP use, and AP end-of-life (EoL). Three different EoL scenarios were considered in this analysis. Several midpoint environmental impact indicators were evaluated. Overall, the results suggest that the different EoL scenarios do not affect the global environmental impact of both AP systems. The environmental impacts of the AP depend on the type of material. The AP of the PP-based GnPs nanocomposite exhibited a weight 28 % lower than the AP of the PP/GF composite. This lightweight resulted in energy and emissions savings, especially during the AP use stage, which was the stage with the most significant contribution in most environmental impact categories. Using nanocomposite reduced the AP environmental impact from 17 % to 75 %, depending on the impact category. The study suggested that substituting traditional composite with a new lighter nanocomposite can decrease the global environmental impacts caused by AP.

6.
Toxicol Lett ; 376: 13-19, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36638931

RESUMO

Electronic cigarette usage has significantly expanded among young people and pregnant women in the last decade. Although there are already some data regarding the short- and long-term consequences of e-cigarettes on human health, their effect on embryo and lung development still needs to be fully disclosed. In this sense, this study describes, for the first time, the impact of electronic cigarette aerosol on early lung development. For this purpose, ex vivo chick (Gallus gallus) embryonic lungs were cultured in vitro for 48 h in e-cigarette aerosol exposed-medium or unexposed medium. Chick lung explants were also cultured in a cigarette smoke-exposed medium for comparison purposes. Lung explants were morphologically analyzed to assess the impact on lung growth. Additionally, TNF-α levels were determined in the supernatant as a marker of pro-inflammatory response. The results suggest that electronic cigarette aerosol impairs lung growth and promotes lung inflammation. However, its impact on early lung growth seems less detrimental than conventional cigarette smoke. This work provides significant data regarding the impact of e-cig aerosol, adding to the efforts to fully understand its effect on embryo development. The validation of these effects may eventually lead to new tobacco control recommendations for pregnant women.


Assuntos
Fumar Cigarros , Sistemas Eletrônicos de Liberação de Nicotina , Adolescente , Animais , Feminino , Humanos , Gravidez , Aerossóis , Galinhas , Pulmão , Nicotiana
7.
Int J Biol Macromol ; 229: 849-860, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36572084

RESUMO

The development of suitable bioinks is an important research topic in the field of three-dimensional (3D) bioprinting. Herein, novel hydrogel-based bioinks composed of nanofibrillated cellulose (NFC) and gellan gum (GG) in different NFC/GG mass proportions (90:10, 80:20, 70:30, and 60:40) were developed and characterized. The increase in the content of GG, as well as its combination with NFC, enhanced their rheological properties, increasing both storage (G') and loss (G") moduli and the G' recovery capacity of the hydrogels (from 70.05 ± 3.06 % (90:10) to 82.63 ± 1.21 % (60:40)), as well as their mechanical properties, increasing the compressive stiffness and stress from 114.02 ± 10.93 Pa (90:10) to 337.16 ± 34.03 Pa (60:40) and from 18.27 ± 1.32 kPa (90:10) to 47.17 ± 3.59 kPa (60:40), respectively. The hydrogels were non-cytotoxic against human keratinocyte cells (HaCaT), with cell viabilities above 70 % for up to 72 h. The hydrogel 60:40 was loaded with HaCaT cells (3 × 106 cells mL-1) and bioprinted. The cell viability was maintained elevated until day 7 (90 ± 3 %) after bioprinting. These results highlight that the combination of these two biopolymers was a good strategy for the development of novel hydrogel-based bioinks for extrusion 3D bioprinting applications.


Assuntos
Bioimpressão , Hidrogéis , Humanos , Hidrogéis/farmacologia , Engenharia Tecidual/métodos , Celulose/farmacologia , Bioimpressão/métodos , Impressão Tridimensional , Alicerces Teciduais
8.
Front Psychol ; 13: 817699, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35465505

RESUMO

Proximity and interpersonal contact are prominent components of social connection. Giving affective touch to others is fundamental for human bonding. This brief report presents preliminary results from a pilot study. It explores if exposure to bonding scenes impacts the activity of specific muscles related to physical interaction. Fingers flexion is a very important component when performing most actions of affectionate contact. We explored the visuo-motor affective interplay by priming participants with bonding scenes and assessing the electromyographic activity of the fingers flexor muscle, in the absence of any overt movements. Photographs of dyads in social interaction and of the same dyads not interacting were employed. We examined the effects upon the electromyographical activity: (i) during the passive exposure to pictures, and (ii) during picture offset and when expecting the signal to perform a fingers flexion task. Interacting dyads compared to matched non-interacting dyads increased electromyographic activity of the fingers flexor muscle in both contexts. Specific capture of visual bonding cues at the level of visual cortex had been described in the literature. Here we showed that the neural processing of visual bonding cues reaches the fingers flexor muscle. Besides, previous visualization of bonding cues enhanced background electromyographic activity during motor preparation to perform the fingers flexion task, which might reflect a sustained leakage of central motor activity downstream leading to increase in firing of the respective motor neurons. These data suggest, at the effector level, an implicit visuo-motor connection in which social interaction cues evoke intrinsic dispositions toward affectionate social behavior.

9.
Cureus ; 14(2): e21958, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35282562

RESUMO

Positron emission tomography (PET) tracers (Fluorine-18 Fluorocholine [18F-Fluorocholine] and Carbon-11 Choline [11C-Choline]) have been widely used with promising accuracy in detecting abnormal parathyroids, being crucial for an effective and safe minimally invasive parathyroidectomy. We report a case of a 72-year-old woman with a long-term personal history of osteoporosis and recurrent nephrolithiasis with the need for invasive interventions. Primary hyperparathyroidism was biochemically assumed, although localization of the hyperfunctioning parathyroid had been challenging since cervical ultrasound and technetium-99m sestamibi scintigraphy were negative/equivocal. An 18F-Fluorocholine positron emission tomography/computed tomography (PET/CT) was performed, having identified a small cervical nodule with increased tracer uptake, compatible with a right parathyroid adenoma. After its removal, the patient went into clinical and biochemical remission. 18F-Fluorocholine PET/CT allowed an effective and safe parathyroidectomy as conventional imaging modalities were inaccurate in detecting the abnormal parathyroid, in this patient with serious hyperparathyroidism-related complications.

10.
Neural Plast ; 2021: 6649135, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33688339

RESUMO

Predicting upcoming sensorimotor events means creating forward estimates of the body and the surrounding world. This ability is a fundamental aspect of skilled motor behavior and requires an accurate and constantly updated representation of the body and the environment. To test whether these prediction mechanisms could be affected by a peripheral injury, we employed an action observation and electroencephalogram (EEG) paradigm to assess the occurrence of prediction markers in anticipation of observed sensorimotor events in healthy and brachial plexus injury (BPI) participants. Nine healthy subjects and six BPI patients watched a series of video clips showing an actor's hand and a colored ball in an egocentric perspective. The color of the ball indicated whether the hand would grasp it (hand movement), or the ball would roll toward the hand and touch it (ball movement), or no event would occur (no movement). In healthy participants, we expected to find distinct electroencephalographic activation patterns (EEG signatures) specific to the prediction of the occurrence of each of these situations. Cluster analysis from EEG signals recorded from electrodes placed over the sensorimotor cortex of control participants showed that predicting either an upcoming hand movement or the occurrence of a tactile event yielded specific neural signatures. In BPI participants, the EEG signals from the sensorimotor cortex contralateral to the dominant hand in the hand movement condition were different compared to the other conditions. Furthermore, there were no differences between ball movement and no movement conditions in the sensorimotor cortex contralateral to the dominant hand, suggesting that BPI blurred specifically the ability to predict upcoming tactile events for the dominant hand. These results highlight the role of the sensorimotor cortex in creating estimates of both actions and tactile interactions in the space around the body and suggest plastic effects on prediction coding following peripheral sensorimotor loss.


Assuntos
Mãos/fisiologia , Movimento/fisiologia , Córtex Sensório-Motor/fisiologia , Percepção Espacial/fisiologia , Tato/fisiologia , Adulto , Mapeamento Encefálico/métodos , Eletroencefalografia/métodos , Feminino , Força da Mão/fisiologia , Humanos , Masculino , Percepção do Tato/fisiologia , Adulto Jovem
11.
Neurocase ; 27(2): 169-177, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33779507

RESUMO

The present study aims at the cerebellum's role in prediction mechanisms triggered by action observation. Five cerebellar patients and six age-paired control subjects were asked to estimate the occluded end point position of the shoulder's trajectories in Sit-to-Stand (STS) or Back-to-Sit (BTS) conditions, following or not biological rules. Contrarily to the control group, the prediction accuracy of the end point position in cerebellar patients did not depend on biological rules. Interestingly, both groups presented similar results when estimating the vanishing position of the target. Taken together, these results suggest that cerebellar damage affectsthe capacity of predicting upcoming actions by observation.


Assuntos
Cerebelo , Movimento , Humanos , Movimento (Física)
12.
Future Microbiol ; 15: 881-896, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32716215

RESUMO

Aim: A sodium alginate-based biohydrogel was prepared integrating choline oleate deep euthetic solvent as facilitator of transdermal delivery and a cocktail of lytic bacteriophages for Acinetobacter baumannii, aiming at treating soft-tissue infections by the aforementioned pathogen. Materials & methods: Two bacteriophages were isolated from a hospital sewage and a wastewater treatment plant sewage in Sorocaba (Brazil), and characterized via SDS-PAGE electrophoresis, transmission electron microscope and evaluation of lytic spectra of the bacteriophage cocktail. The biohydrogel was prepared and characterized by DSC, FTIR, XRD, DESEM, XRT and transdermal permeation of the bacteriophage cocktail. Results & conclusion: The physico-chemical characterization of the biohydrogel produce indicated adequate structural characteristics and ability to promote/facilitate transdermal delivery of bacteriophage particles, thus showing potential for biopharmaceutical applications.


Assuntos
Antibacterianos/farmacologia , Bacteriófagos/fisiologia , Colina/farmacologia , Ácido Oleico/farmacologia , Vírion , Acinetobacter baumannii/efeitos dos fármacos , Brasil , Dano ao DNA , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Humanos , Hidrogéis/farmacologia , Terapia por Fagos
13.
Front Pharmacol ; 11: 243, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32390824

RESUMO

In this research project, synthesis and characterization of ionic liquids and their subsequent utilization as facilitators of transdermal delivery of human insulin was pursued. Choline geranate and choline oleate ionic liquids (and their deep eutectic solvents) were produced and characterized by nuclear magnetic resonance (1H NMR), water content, oxidative stability, cytotoxicity and genotoxicity assays, and ability to promote transdermal protein permeation. The results gathered clearly suggest that all ionic liquids were able to promote/facilitate transdermal permeation of insulin, although to various extents. In particular, choline geranate 1:2 combined with its virtually nil cyto- and geno-toxicity was chosen to be incorporated in a biopolymeric formulation making it a suitable facilitator aiming at transdermal delivery of insulin.

14.
Biofabrication ; 12(3): 035017, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32316003

RESUMO

Embedded bio-printing has fostered significant advances toward the fabrication of soft complex tissue-like constructs, by providing a physical support that allows the freeform shape maintenance within the prescribed spatial arrangement, even under gravity force. Current supporting materials still present major drawbacks for up-scaling embedded 3D bio-printing technology towards tissue-like constructs with clinically relevant dimensions. Herein, we report a a cost-effective and widely available supporting material for embedded bio-printing consisting on a continuous pseudo-plastic matrix of xanthan-gum (XG). This natural polisaccharide exhibits peculiar rheological properties that have enabled the rapid generation of complex volumetric 3D constructs with out-of-plane features. The freedom of design within the three orthogonal axes through the independent and controlled bio-printing process opens new opportunities to produce on demand large arbitrary shapes for personalized medicine. Additionally, we have demonstrated the versatile functionality of XG as a photocurable gel reservoir to engineer perfused cell-laden hydrogel constructs, addressing other practical biomedical applications such as in vitro models and organ-on-chip platforms.


Assuntos
Elasticidade , Matriz Extracelular/química , Impressão Tridimensional , Animais , Bioimpressão , Linhagem Celular , Camundongos , Perfusão , Polissacarídeos Bacterianos/química , Reologia , Viscosidade
15.
Food Chem ; 323: 126826, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32335460

RESUMO

During beer ageing, endogenous barrel microbes grow spontaneously and transform wort/beer composition, being Dekkera bruxellensis and Saccharomyces cerevisiae among the main contributors to the chemical and sensory profile of aged beer. This work aims at the application of multi-starter cultures to mimic and accelerate biological modifications occurring during barrel ageing of beer, in controlled fermentation processes. Co-cultures of D.bruxellensis/S.cerevisiae were conducted under conditions commonly found in barrel aged beer production: different pitching rates, high glucose concentration and presence of ethanol and wood extracts. Selective pressures and competition between yeasts influenced microbial growth and metabolite production, namely ethanol, acetic acid and target volatile compounds (esters, alcohols, terpenols, volatile acids and volatile phenols). Metabolic profiles of co-cultures combined traits of both species, and differed from those of pure cultures. Lastly, multi-starters were successfully applied in combination with wood in a controlled and accelerated fermentation process for mimicking barrel ageing transformations.

16.
Molecules ; 25(3)2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32023947

RESUMO

Knowledge of composition of beverages volatile fraction is essential for understanding their sensory attributes. Analysis of volatile compounds predominantly resorts to gas chromatography coupled with mass spectrometry (GC-MS). Often a previous concentration step is required to quantify compounds found at low concentrations. This work presents a liquid-liquid microextraction method combined with GC-MS (LLME/GC-MS) for the analysis of compounds in fermented beverages and spirits. The method was validated for a set of compounds typically found in fermented beverages comprising alcohols, esters, volatile phenols, and monoterpenic alcohols. The key requirements for validity were observed, namely linearity, sensitivity in the studied range, accuracy, and precision within the required parameters. Robustness of the method was also evaluated with satisfactory results. Thus, the proposed LLME/GC-MS method may be a useful tool for the analysis of several fermented beverages, which is easily implementable in a laboratory equipped with a GC-MS.


Assuntos
Alimentos Fermentados/análise , Microextração em Fase Líquida/métodos , Compostos Orgânicos Voláteis/análise , Álcoois/análise , Ésteres/análise , Cromatografia Gasosa-Espectrometria de Massas , Monoterpenos/análise , Fenóis/análise
17.
Microorganisms ; 7(10)2019 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-31569525

RESUMO

Mead is a traditional beverage that results from the alcoholic fermentation of diluted honey performed by yeasts. Although the process of mead production has been optimized in recent years, studies focused on its sensory properties are still scarce. Therefore, the aim of this work was to analyse the sensory attributes of mead produced with free or immobilized cells of the Saccharomyces cerevisiae strains QA23 and ICV D47, and to establish potential correlations with its volatile composition. In the volatile composition of mead, the effect of yeast condition was more important than the strain. In respect to sensory analysis, the most pleasant aroma descriptors were correlated with mead obtained with free yeast cells, independently of the strain. Both sensory analysis and volatile composition indicates that the most pleasant mead was produced by free yeast cells. Although this study has provided a significant contribution, further research on the sensory quality of mead is still needed.

18.
Food Chem ; 295: 156-164, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174744

RESUMO

During ageing, wood adsorbs volatile compounds from beverages. However, chemical interactions involved in sorption still remain unclear, as well as wood capacity to transfer such compounds to subsequent matrices when reused. Therefore, extractions were conducted from used wood manipulating variables such as ethanol concentration, contact temperature and pH, in order to determine their effect in the interaction and consequent recovery of wine volatiles from wood. Mathematical models were outlined, which demonstrated an exclusive effect of ethanol concentration on the extraction of wine volatiles adsorbed in wood, more prominent for compounds of higher hydrophobicity. Thus adsorption of wine volatiles was shown to be based on hydrophobic interactions. Recovery of wood extractives was also modeled, confirming the known positive effect of ethanol and temperature on the overall extraction of characteristic wood compounds. When reused, wood transferred wine compounds to hydroalcoholic matrices, demonstrating its impact and potential as a vector for aroma transference.


Assuntos
Quercus/química , Compostos Orgânicos Voláteis/química , Vinho/análise , Madeira/química , Adsorção , Etanol/química , Concentração de Íons de Hidrogênio , Temperatura , Fatores de Tempo
19.
Food Sci Nutr ; 7(2): 617-627, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30847141

RESUMO

The aim of this study was the production of blueberry wine and the characterization of the volatile compounds of fermented and aging in bottle products. Multivariate data analysis indicated similarity of volatile compounds released when fermentations were conducted at laboratory-scale and midscale, with the exception of one replicate creating a distinctive group characterized by low concentrations of acetaldehyde, methanol, 1-hexanol, and ethyl hexanoate, and the production of polyalcohols such as 2,3-butanediols. This experiment was the only one where no adjustments of YAN were performed. Some of the major volatile compounds (acetaldehyde, ethyl acetate, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-phenylethanol) were found above their perception thresholds. Esters and terpenic compounds were the groups of volatiles expressed the most in blueberry wines, followed by volatile fatty acids, alcohols, and norisoprenoids (3-hydroxy-7,8-dihydro-ß-ionone, 3-oxo-α-ionol, and 3-hydroxy-7,8-dihydro-ß-ionol). The wines that experienced bottle-aging are characterized by high concentrations of ethyl esters, diethyl succinate, ethyl lactate, and diethyl malonate. The results contribute for deeper knowledge of the technological procedure, analytical characteristics, and volatile compounds of blueberry wines, reinforcing the interest in this beverage and opening perspectives for further studies on the production of new blueberry-based products with differential characteristics that value its nutraceutical and functional properties.

20.
Front Psychol ; 10: 191, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30804849

RESUMO

Threatening cues and surrounding contexts trigger specific defensive response patterns. Posturography, a technique for measuring postural strategies, has been used to evaluate motor defensive reactions in humans. When exposed to gun pointed pictures, humans were shown to exhibit an immobility reaction. Short and long-term exposure to violent video games was shown to be a causal risk factor for increased violent and aggressive behavior. Assaultive violence with a gun is a major trigger for motor defensive reactions, and post-traumatic stress disorder (PTSD) is the most characteristic psychiatric sequelae. Recent studies point to links between PTSD symptoms and emotional shortfalls in non-clinical trauma-exposed samples. The present study investigated defensive reactions to gun threat and PTSD symptoms in heavy players of violent video games compared to non-players. Male university students were screened according to use of violent video games and divided in three groups: non-players, moderate players, and heavy players. Stimuli were pictures depicting a man pointing a gun directed at the participant. In matched control pictures, non-lethal objects replaced the gun. Posturography was recorded and PTSD symptoms were assessed. When exposed to the threat pictures, non-players exhibited the expected reduction in amplitude of body sway (immobility), heavy players presented atypical augmented amplitude of body sway, and moderate players showed intermediate reactivity. Heavy players presented a significant distinct reaction compared to non-players. They also scored significantly higher in PTSD symptoms than non-players. Disadvantageous defensive reactions and higher vulnerability to PTSD symptoms, revealed in the present study, add to other shortcomings for heavy players.

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