32 research outputs found

    Cross-inhibition leads to group consensus despite the presence of strongly opinionated minorities and asocial behaviour

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    Strongly opinionated minorities can have a dramatic impact on the opinion dynamics of a large population. Two factions of inflexible minorities, polarised into two competing opinions, could lead the entire population to persistent indecision. Equivalently, populations can remain undecided when individuals sporadically change their opinion based on individual information rather than social information. Our analysis compares the cross-inhibition model with the voter model for decisions between equally good alternatives, and with the weighted voter model for decisions among alternatives characterised by different qualities. Here we show that cross-inhibition, differently from the other two models, is a simple mechanism, ubiquitous in collective biological systems, that allows the population to reach a stable majority for one alternative even in the presence of asocial behaviour. The results predicted by the mean-field models are confirmed by experiments with swarms of 100 locally interacting robots. This work suggests an answer to the longstanding question of why inhibitory signals are widespread in natural systems of collective decision making, and, at the same time, it proposes an efficient mechanism for designing resilient swarms of minimalistic robots

    Genistein improves viability, proliferation and mitochondrial function of cardiomyoblasts cultured in physiologic and peroxidative conditions

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    Phytoestrogens exert protective effects on the cardiovascular system through mechanisms that have yet to be clearly demonstrated. The aim of this study was to evaluate the protective effects exerted by genistein on cardiomyoblasts (H9C2) against oxidative stress, nitric oxide (NO) release, viability, proliferation/migration and mitochondrial function. H9C2 cultured in physiological or peroxidative conditions, were treated with genistein in the absence or presence of estrogen receptors (ERs), G protein\u2011\u200bcoupled\u2011estrogenic\u2011receptors (GPER), Akt, extracellular\u2011\u200bsignal\u2011regulated kinases 1/2 (ERK1/2) and p38 mitogen activated protein kinase (p38MAPK) blockers. Cell viability, proliferation, migration, mitochondrial membrane potential, mitochondrial oxygen consumption and oxidant/antioxidant system, were measured by specific assays. Western blot assay was used for the analysis of NO synthase (NOS) subtypes' and expression and activation of various kinases. In all experiments 17\u3b2\u2011estradiol was used for comparison. The results showed that phytoestrogens and estrogens can increase cell viability, proliferation/migration and improve mitochondrial membrane potential and oxygen consumption of H9C2. Furthermore, NO release was modulated by genistein and 17\u3b2\u2011estradiol. These effects were reduced or abolished by the pre\u2011treatment with ERs, GPER, Akt, ERK1/2 and p38MAPK blockers. Finally, a reduction of reactive oxygen species production and an increase of glutathione content was found in response to the two agents. In H9C2 cultured in physiological conditions, genistein induced endothelial NOS\u2011dependent NO production through the involvement of estrogenic receptors and by the modulation of intracellular signalling related to Akt, ERK1/2, and p38MAPK. Moreover, estrogens and phytoestrogens protected H9C2 against oxidative stress by reducing inducible NOS expression and through the modulation of the antioxidant system and mitochondrial functioning

    Human Chorionic Gonadotropin Protects Vascular Endothelial Cells from Oxidative Stress by Apoptosis Inhibition, Cell Survival Signalling Activation and Mitochondrial Function Protection.

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    Background/Aim: Previous reports have made it hypothetically possible that human chorionic gonadotropin (hCG) could protect against the onset of pregnancy-related pathological conditions by acting as an antioxidant. In the present study we planned to examine the effects of hCG against oxidative stress in human umbilical vein endothelial cells (HUVEC). Methods: HUVEC were subjected to peroxidation by hydrogen peroxide. The modulation of nitric oxide (NO) release by hCG and its effects on cell viability, glutathione (GSH) levels, mitochondrial membrane potential and mitochondrial transition pore opening (MPTP) were examined by specific dyes. Endothelial and inducible NO synthase (eNOS and iNOS), Akt and extracellular -signal-regulated kinases 1/2 (ERK1/2) activation and markers of apoptosis were analyzed by Western Blot. Results: In HUVEC, hCG reduced NO release by modulating eNOS and iNOS. Moreover, hCG protected HUVEC against oxidative stress by preventing GSH reduction and apoptosis, by maintaining Akt and ERK1/2 activation and by keeping mitochondrial function. Conclusion: The present results have for the first time shown protective effects exerted by hCG on vascular endothelial function, which would be achieved by modulation of NO release, antioxidant and antiapoptotic actions and activation of cell survival signalling. These findings could have clinical implications in the management of pregnancy-related disorders

    Preeclampsia and intrauterine growth restriction: role of human umbilical cord mesenchymal stem cells-trophoblast cross-talk

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    Background: Oxidative stress is involved in the pathogenesis and maintenance of pregnancy-related disorders, such as intrauterine growth restriction (IUGR) and preeclampsia (PE). Human umbilical cord mesenchymal stem cells (hUMSCs) have been suggested as a possible therapeutic tool for the treatment of pregnancy-related disorders in view of their paracrine actions on trophoblast cells. Objectives: To quantify the plasma markers of peroxidation in patients affected by PE and IUGR and to examine the role of oxidative stress in the pathophysiology of PE and IUGR in vitro by using hUMSCs from physiological and pathological pregnancies and a trophoblast cell line (HTR-8/SVneo). Study design: In pathological and physiological pregnancies the plasma markers of oxidative stress, arterial blood pressure, serum uric acid, 24h proteinuria, weight gain and body mass index (BMI) were examined. Furthermore, the pulsatility index (PI) of uterine and umbilical arteries, and of fetal middle cerebral artery was measured. In vitro, the different responses of hUMSCs, taken from physiological and pathological pregnancies, and of HTR-8/SVneo to pregnancy-related hormones in terms of viability and nitric oxide (NO) release were investigated. In some experiments, the above measurements were performed on co-cultures between HTR-8/SVneo and hUMSCs. Results: The results obtained have shown that in pathological pregnancies, body mass index, serum acid uric, pulsatility index in uterine and umbilical arteries and markers of oxidative stress were higher than those found in physiological ones. Moreover, in PE and IUGR, a relation was observed between laboratory and clinical findings and the increased levels of oxidative stress. HTR-8/SVneo and hUMSCs showed reduced viability and increased NO production when stressed with H2O2. Finally, HTR-8/SVneo cultured in cross-talk with hUMSCs from pathological pregnancies showed a deterioration of cell viability and NO release when treated with pregnancy-related hormones. Conclusion: Our findings support that hUMSCs taken from patients affected by PE and IUGR have significant features in comparison with those from physiologic pregnancies. Moreover, the cross-talk between hUMSCs and trophoblast cells might be involved in the etiopathology of IUGR and PE secondary to oxidative stress

    Modulation of Oxidative Stress by 17 β-Estradiol and Genistein in Human Hepatic Cell Lines In Vitro

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    BACKGROUND/AIMS: estrogens and phytoestrogens exert hepatoprotection through mechanisms not clearly examined yet. Here, we investigated the protective effects exerted by 17\u3b2-estradiol and genistein against oxidative stress in hepatocytes and hepatic stellate cells (HSCs) and the involvement of specific receptors and the intracellular signalling. METHODS: Huh7.5 and LX-2, alone or in co-culture with Huh7.5, were treated with 17\u3b2-estradiol and genistein alone or in the presence of menadione and of estrogen receptors (ERs) and G protein-coupled-estrogenic-receptors (GPER) blockers. Cell viability, mitochondrial membrane potential and oxidant/antioxidant system were measured by specific kits. Western Blot was used for the analysis of Akt and p38-mitogen-activated-protein kinases (MAPK) activation and \u3b1-smooth-muscle actin expression. RESULTS: In Huh7.5, 17\u3b2-estradiol and genistein prevented the effects of peroxidation by modulating Akt and p38MAPK activation. Similar antioxidant and protective findings were obtained in LX-2 of co-culture experiments, only. ERs and GPER blockers were able to prevent the effects of 17\u3b2-estradiol and genistein. CONCLUSION: In Huh7.5 and LX-2, 17\u3b2-estradiol and genistein counteract the effects of peroxidation through the involvement of ERs and GPER and by an intracellular signalling related to Akt and p38MAPK. As concerning LX-2, paracrine factors released by Huh7.5 play a key role in protection against oxidative stress

    Anti-Vascular Endothelial Growth Factors Protect Retinal Pigment Epithelium Cells Against Oxidation by Modulating Nitric Oxide Release and Autophagy

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    Background/Aims: the anti-vascular endothelial growth factors (VEGF), Aflibercept and Ranibizumab, are used for the treatment of macular degeneration. Here we examined the involvement of nitric oxide (NO), mitochondria function and of apoptosis/autophagy in their antioxidant effects in human retinal pigment epithelium cells (RPE). Methods: RPE were exposed to Ranibizumab/Aflibercept in the absence or presence of NO synthase (NOS) inhibitor and of autophagy activator/blocker, rapamicyn/3-methyladenine. Specific kits were used for cell viability, NO and reactive oxygen species detection and mitochondrial membrane potential measurement, whereas Western Blot was performed for apoptosis/ autophagy markers and other kinases detection. Results: In RPE cultured in physiological conditions, Aflibercept/Ranibizumab increased NO release in a dose and time-dependent way. Opposite results were obtained in RPE pretreated with hydrogen peroxide. Moreover, both the anti-VEGF agents were able to prevent the fall of cell viability and of mitochondrial membrane potential. Those effects were reduced by the NOS inhibitor and 3-methyladenine and were potentiated by rapamycin. Finally, Aflibercept and Ranibizumab counteracted the changes of apoptosis/autophagy markers, NOS, Phosphatidylinositol-3-Kinase/Protein Kinase B and Extracellular signal–regulated kinases 1/2 caused by peroxidation. Conclusion: Aflibercept and Ranibizumab protect RPE against peroxidation through the modulation of NO release, apoptosis and autophagy

    Outcomes of music therapy interventions in cancer patients. A review of the literature

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    Background: Effectiveness of music-based interventions (MI) on cancer patients\u2019 anxiety, depression, pain and quality of life (QoL) is a current research theme. MI are highly variable, making it challenging to compare studies. Objective and methods: To summarize the evidence on MI in cancer patients, 40 studies were reviewed following the PRISMA statement. Studies were included if assessing at least one outcome among anxiety, depression, QoL and pain in patients aged 65 18, with an active oncological/onco-haematological diagnosis, participating to any kind of MT, during/after surgery, chemotherapy or radiotherapy. Results: A positive effect of MI on the outcomes measured was supported. Greater reductions of anxiety and depression were observed in breast cancer patients. MI involving patients admitted to a hospital ward were less effective on QoL. Conclusion: The increasing evidence about MI effectiveness, tolerability, feasibility and appreciation, supports the need of MI implementation in Oncology, Radiotherapy and Surgery wards, and promotion of knowledge among health operators

    Results of a phase 1, randomized, placebocontrolled first-in-human trial of griffithsin formulated in a carrageenan vaginal gel

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    HIV pre-exposure prophylaxis (PrEP) is dominated by clinical therapeutic antiretroviral (ARV) drugs. Griffithsin (GRFT) is a non-ARV lectin with potent anti-HIV activity. GRFT’s preclinical safety, lack of systemic absorption after vaginal administration in animal studies, and lack of cross-resistance with existing ARV drugs prompted its development for topical HIV PrEP. We investigated safety, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of PC-6500 (0.1% GRFT in a carrageenan (CG) gel) in healthy women after vaginal administration. This randomized, placebo-controlled, parallel group, double-blind first-in-human phase 1 study enrolled healthy, HIV-negative, non-pregnant women aged 24–45 years. In the open label period, all participants (n = 7) received single dose of PC- 6500. In the randomized period, participants (n = 13) were instructed to self-administer 14 doses of PC-6500 or its matching CG placebo (PC-535) once daily for 14 days. The primary outcomes were safety and PK after single dose, and then after 14 days of dosing. Exploratory outcomes were GRFT concentrations in cervicovaginal fluids, PD, inflammatory mediators and gene expression in ectocervical biopsies. This trial is registered with ClinicalTrials. gov, number NCT02875119. No significant adverse events were recorded in clinical or laboratory results or histopathological evaluations in cervicovaginal mucosa, and no anti-drug (GRFT) antibodies were detected in serum. No cervicovaginal proinflammatory responses and no changes in the ectocervical transcriptome were evident. Decreased levels of proinflammatory chemokines (CXCL8, CCL5 and CCL20) were observed. GRFT was not detected in plasma. GRFT and GRFT/CG in cervicovaginal lavage samples inhibited HIV and HPV, respectively, in vitro in a dose-dependent fashion. These data suggest GRFT formulated in a CG gel is a safe and promising on-demand multipurpose prevention technology product that warrants further investigation

    The genetic architecture of the human cerebral cortex

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    The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder
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