2,870 research outputs found

    Information in a network of neuronal cells: Effect of cell density and short-term depression

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    Neurons are specialized, electrically excitable cells which use electrical to chemical signals to transmit and elaborate information. Understanding how the cooperation of a great many of neurons in a grid may modify and perhaps improve the information quality, in contrast to few neurons in isolation, is critical for the rational design of cell-materials interfaces for applications in regenerative medicine, tissue engineering, and personalized lab-on-a-chips. In the present paper, we couple an integrate-and-fire model with information theory variables to analyse the extent of information in a network of nerve cells. We provide an estimate of the information in the network in bits as a function of cell density and short-term depression time. In the model, neurons are connected through a Delaunay triangulation of not-intersecting edges; in doing so, the number of connecting synapses per neuron is approximately constant to reproduce the early time of network development in planar neural cell cultures. In simulations where the number of nodes is varied, we observe an optimal value of cell density for which information in the grid is maximized. In simulations in which the posttransmission latency time is varied, we observe that information increases as the latency time decreases and, for specific configurations of the grid, it is largely enhanced in a resonance effect

    Resting state functional thalamic connectivity abnormalities in patients with post-stroke sleep apnoea: a pilot case-control study

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    OBJECTIVE: Sleep apnoea is common after stroke, and has adverse effects on the clinical outcome of affected cases. Its pathophysiological mechanisms are only partially known. Increases in brain connectivity after stroke might influence networks involved in arousal modulation and breathing control. The aim of this study was to investigate the resting state functional MRI thalamic hyper connectivity of stroke patients affected by sleep apnoea (SA) with respect to cases not affected, and to healthy controls (HC). PATIENTS AND METHODS: A series of stabilized strokes were submitted to 3T resting state functional MRI imaging and full polysomnography. The ventral-posterior-lateral thalamic nucleus was used as seed. RESULTS: At the between groups comparison analysis, in SA cases versus HC, the regions significantly hyper-connected with the seed were those encoding noxious threats (frontal eye field, somatosensory association, secondary visual cortices). Comparisons between SA cases versus those without SA, revealed in the former group significantly increased connectivity with regions modulating the response to stimuli independently to their potentiality of threat (prefrontal, primary and somatosensory association, superolateral and medial-inferior temporal, associative and secondary occipital ones). Further significantly functionally hyper connections were documented with regions involved also in the modulation of breathing during sleep (pons, midbrain, cerebellum, posterior cingulate cortices), and in the modulation of breathing response to chemical variations (anterior, posterior and para-hippocampal cingulate cortices). CONCLUSIONS: Our preliminary data support the presence of functional hyper connectivity in thalamic circuits modulating sensorial stimuli, in patients with post-stroke sleep apnoea, possibly influencing both their arousal ability and breathing modulation during sleep

    Social closeness,salivary hormones and physical exercise

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    Introduction: Saliva collection and analysis is quickly becoming a useful and non-invasive tool for the evaluation of sport biomarkers. The aim of this study is to create a multidisciplinary assessment model, which can help to provide psychological and physiological responses, related to sport performances, social closeness and performance anxiety management in team sports. Materials and methods: We enrolled in our research 26 female volleyball players aged 13 ± 1 years old of three different teams (T1: 12 players; T2: 9 players; T3: 5 players). Saliva collection was carried out before and after the match for every team. Then we analyzed cortisol and progesterone concentrations through Elisa standard kits. Results: The results of the T-test performed on the total results showed a statistically significant relationship (p < 0.05) in cortisol levels pre and post match: in fact, it has been shown a statistical significant decrease (p < 0.001). The analysis performed using just samples post match shows a negative correlation between social closeness, cortisol and progesterone levels, with p < 0.010 for progesterone vs social closeness and p < 0.012 for cortisol vs social closeness, which indicates that increasing of one of the two hormones reduces relationship. About the winner teams and the looser teams, there is a negative correlation between pre match cortisol levels and performance anxiety (p < 0.042)

    Heat Sensing Receptor TRPV1 Is a Mediator of Thermotaxis in Human Spermatozoa

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    The molecular bases of sperm thermotaxis, the temperature-oriented cell motility, are currently under investigation. Thermal perception relies on a subclass of the transient receptor potential [TRP] channels, whose member TRPV1 is acknowledged as the heat sensing receptor. Here we investigated the involvement of TRPV1 in human sperm thermotaxis. We obtained semen samples from 16 normozoospermic subjects attending an infertility survey programme, testis biopsies from 6 patients with testicular germ cell cancer and testis fine needle aspirates from 6 patients with obstructive azoospermia undergoing assisted reproductive technologies. Expression of TRPV1 mRNA was assessed by RT-PCR. Protein expression of TRPV1 was determined by western blot, flow cytometry and immunofluorescence. Sperm motility was assessed by Sperm Class Analyser. Acrosome reaction, apoptosis and intracellular-Ca2+ content were assessed by flow cytometry. We found that TRPV1 mRNA and protein were highly expressed in the testis, in both Sertoli cells and germ-line cells. Moreover, compared to no-gradient controls at 31°C or 37°C (Ctrl 31°C and Ctrl 37°C respectively), sperm migration towards a temperature gradient of 31-37°C (T gradient) in non-capacitated conditions selected a higher number of cells (14,9 ± 4,2×106 cells T gradient vs 5,1± 0,3×106 cells Ctrl 31°C and 5,71±0,74×106 cells Ctrl 37°C; P = 0,039). Capacitation amplified the migrating capability towards the T gradient. Sperms migrated towards the T gradient showed enriched levels of both TRPV1 protein and mRNA. In addition, sperm cells were able to migrate toward a gradient of capsaicin, a specific agonist of TRPV1, whilst capsazepine, a specific agonist of TRPV1, blocked this effect. Finally, capsazepine severely blunted migration towards T gradient without abolishing. These results suggest that TRPV1 may represent a facilitating mediator of sperm thermotaxis

    Evaluation of the application of italian national guidelines for prevention and management of dental injuries in developmental age

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    Background: The objective of this study is to evaluate the application of National guidelines for prevention and clinical management of traumatic dental injuries (NGPCMTDI) in developmental age published by the Italian Ministry of Health. Methods: In the present retrospective and multicenter study, 246 patients who underwent dental injury were selected to assess the management of the traumatic event compiled with the protocol provided by the National guidelines. Each health worker involved completed a form related to the dental injury in order to standardize the collected data. Two reference centers have been identified for data collection. Analyses for comparisons between groups were performed using the X2 test for categorical variables or by Fisher exact test as appropriate. Statistical significance was assumed at p &lt; 0.05. Results: Evaluating the distribution by age we concluded that: 27.24% of the enrolled patients were aged 1-5 years, 51.63% 6-10 years, and 19.92% 11-17 years. The dental injuries occurred in 10.16% of the situations at home, 50.81% at school, 28.86% during recreation, and 9.35% at the gym. The deciduous dentition is involved in 34.96% of the traumas while the permanent dentition is involved in 69.51%. Conclusion: From the present study it emerged that the National guidelines are not uniformly applied

    A rare case of vulvar superficial myofibroblastoma associated with ambigous and unusual differential diagnosis

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    •Superficial myofibroblastoma of the Labia Majora.•Differential diagnosis between vulvar superficial myofibroblastoma and cyst/hydrocele of Nuck duct.•Differential diagnosis between vulvar superficial myofibroblastoma and inguinal/crural hernia

    Climate Change and Childhood Respiratory Health: A Call to Action for Paediatricians

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    Climate change (CC) is one of the main contributors to health emergencies worldwide. CC appears to be closely interrelated with air pollution, as some pollutants like carbon dioxide (CO2), nitrogen oxides (NOx) and black carbon are naturally occurring greenhouse gases. Air pollution may enhance the allergenicity of some plants and, also, has an adverse effect on respiratory health. Children are a uniquely vulnerable group that suffers disproportionately from CC burden. The increasing global warming related to CC has a big impact on plants' lifecycles, with earlier and longer pollen seasons, as well as higher pollen production, putting children affected by asthma and allergic rhinitis at risk for exacerbations. Extreme weather events may play a role too, not only in the exacerbations of allergic respiratory diseases but, also, in favouring respiratory infections. Even though paediatricians are already seeing the impacts of CC on their patients, their knowledge about CC-related health outcomes with specific regards to children's respiratory health is incomplete. This advocates for paediatricians' increased awareness and a better understanding of the CC impact on children's respiratory health. Having a special responsibility for children, paediatricians should actively be involved in policies aimed to protect the next generation from CC-related adverse health effects. Hence, there is an urgent need for them to take action and successfully educate families about CC issues. This paper aims at reviewing the evidence of CC-related environmental factors such as temperature, humidity, rainfall and extreme events on respiratory allergic diseases and respiratory infections in children and proposing specific actionable items for paediatricians to deal with CC-related health issues in their clinical practice
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