6,964 research outputs found

    3D bioprinted human cortical neural constructs derived from induced pluripotent stem cells

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    Bioprinting techniques use bioinks made of biocompatible non-living materials and cells to build 3D constructs in a controlled manner and with micrometric resolution. 3D bioprinted structures representative of several human tissues have been recently produced using cells derived by differentiation of induced pluripotent stem cells (iPSCs). Human iPSCs can be differentiated in a wide range of neurons and glia, providing an ideal tool for modeling the human nervous system. Here we report a neural construct generated by 3D bioprinting of cortical neurons and glial precursors derived from human iPSCs. We show that the extrusion-based printing process does not impair cell viability in the short and long term. Bioprinted cells can be further differentiated within the construct and properly express neuronal and astrocytic markers. Functional analysis of 3D bioprinted cells highlights an early stage of maturation and the establishment of early network activity behaviors. This work lays the basis for generating more complex and faithful 3D models of the human nervous systems by bioprinting neural cells derived from iPSCs

    Reactive Arthritis: From Clinical Features to Pathogenesis

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    Reactive arthritis (ReA) is a sterile synovitis which occurs after a gastrointestinal or urogenital infection. ReA belongs to pondyloarthritis (SpA), a group of diseases that share several clinical and radiological features including familiar clustering, absence of rheumatoid factor and association with HLA-B27. Clinically, ReA is characterized by an asymmetric arthritis predominantly affecting the lower limbs, often associated with urethritis, conjunctivitis and other extraarticular symptoms. The ReA prevalence depends on the incidence of causative pathogens. The ReA diagnosis is based on clinical features and serological tests to evidence previous infection. Different treatment including antibiotics, disease modifying antirheumatic drugs (DMARs) and biologic agents has been recommended. Even though knowing that infections trigger the joint inflammation, the ReA pathogenesis remains to be poorly understood. Several animal models and in vitro studies have been used to elucidate the mechanisms involved in ReA development. In this sense, HLA-B27 transgenic rat or mice have been used to explain the role of this molecule in SpA aetiopathogenesis. Moreover, the infectious model of Yersinia-induced ReA in rodents has shed some lights on the relationship between host genetic susceptibility to infection and abnormal immune response in ReA development. Understanding the immune mediators triggering ReA will contribute to find a specific treatment for this arthritis. In this review, we focus on clinical features, epidemiology, treatment, and the different attempts to understand the pathogenesis of ReA.Fil: Di Genaro, Maria Silvia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico San Luis. Instituto Multidisciplinario de InvestigaciĂłn BiolĂłgica de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de QuĂ­mica, BioquĂ­mica y Farmacia; ArgentinaFil: Cargnelutti, Ethelina. Universidad Nacional de San Luis. Facultad de QuĂ­mica, BioquĂ­mica y Farmacia; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico San Luis. Instituto Multidisciplinario de Investigaciones BiolĂłgicas de San Luis; Argentin

    Immunopathogenesis of reactive arthritis: role of the cytokines

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    Reactive arthritis (ReA), also known as postinfectious arthritis, belongs to the group of related arthropathies known as spondyloarthritis (SpA). ReA can arise 1-4 weeks after a gastrointestinal or genitourinary infection, but once arthritis develops the microorganism is not found in the joint. The classical microbes associated with ReA development include Gram-negative aerobic or microaerophilic bacteria containing LPS in their outer membrane. The immunopathogenic mechanisms involved in ReA development are still unknown. A hypothesis suggested that the bacteria probably persist outside the joint, at sites such as gut mucosa or lymph nodes and bacterial antigens might then be transported to the joints. On the other hand, an altered immune response and the unbalanced production of cytokines have been reported in subjects with ReA. Currently, there is increased evidence to suggest that both mechanisms would operate in the immunopathogenesis of ReA. In this review we highlight recent advances on the role of cytokines in the ReA. Particularly, we discuss the roles of some pro- and anti-inflammatory cytokines involved in the immunopathogenesis of ReA.Fil: Eliçabe, Ricardo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Di Genaro, Maria Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentin

    Ovarian function during hormonal contraception assessed by endocrine and sonographic markers: a systematic review

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    This systematic review focuses on the literature evidence for residual ovarian function during treatment with hormonal contraceptives. We reviewed all papers which assessed residual ovarian activity during hormonal contraceptive use, using endocrine markers such as serum anti-MĂĽllerian hormone (AMH) concentrations, FSH, LH, oestradiol, progesterone and sonographic markers such as antral follicle count (AFC), ovarian volume and vascular indices. We considered every type (oestroprogestin or only progestin) and dosage of hormonal contraceptive and every mode of administration (oral, vaginal ring, implant, transdermal patch). We performed an electronic database search for papers published from 1 January 1990 until 30 November 2015 using PubMed and MEDLINE. We pre-selected 113 studies and judged 48 studies suitable for the review. Most studies showed that follicular development continues during treatment with hormonal contraceptives, and that during treatment there is a reduction in serum concentrations of FSH, LH and oestradiol, and also a reduction in endometrial thickness, ovarian volume and the number and size of antral follicles. The ovarian reserve parameters, namely AFC and ovarian volume, are lower among users than among non-users of hormonal contraception; regarding the effect of hormonal contraception on AMH, there are still controversies in the literature

    Going Beyond Test Scores: The Gender Gap in Italian Children's Mathematical Capability

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    This paper investigates the relationship between gender, attitudes, and test scores in mathematics. The study argues that measures of children’s capability in mathematics must include some indicators of attitudes toward the subject. These are particularly important when analyzing gender gaps because attitudes toward mathematics differ by gender. To this end, the study first analyzes the gender gap in attitudes and test scores separately using school fixed effects models. Second, it estimates a structural equation model, which takes into account that mathematical capability is a latent construct for which some indicators (test scores and attitudes) are observed. Using data from the Italian National Institute for the Evaluation of Education Systems (INVALSI) for school years 5 and 10 in 2014 and 2015, results confirm that when mathematics capability, including both attitudes and test scores, is measured, the gap between boys and girls changes, and it is therefore relevant to consider both concepts

    Direct conversion of human pluripotent stem cells into cranial motor neurons using a piggyBac vector

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    Human pluripotent stem cells (PSCs) are widely used for in vitro disease modeling. One of the challenges in the field is represented by the ability of converting human PSCs into specific disease-relevant cell types. The nervous system is composed of a wide variety of neuronal types with selective vulnerability in neurodegenerative diseases. This is particularly relevant for motor neuron diseases, in which different motor neurons populations show a different susceptibility to degeneration. Here we developed a fast and efficient method to convert human induced Pluripotent Stem Cells into cranial motor neurons of the branchiomotor and visceral motor subtype. These populations represent the motor neuron subgroup that is primarily affected by a severe form of amyotrophic lateral sclerosis with bulbar onset and worst prognosis. This goal was achieved by stable integration of an inducible vector, based on the piggyBac transposon, allowing controlled activation of Ngn2, Isl1 and Phox2a (NIP). The NIP module effectively produced electrophysiologically active cranial motor neurons. Our method can be easily extended to PSCs carrying disease-associated mutations, thus providing a useful tool to shed light on the cellular and molecular bases of selective motor neuron vulnerability in pathological conditions

    Basal adenosine modulates the functional properties of AMPA receptors in mouse hippocampal neurons through the activation of A1R A2AR and A3R

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    Adenosine is a widespread neuromodulator within the CNS and its extracellular level is increased during hypoxia or intense synaptic activity, modulating pre- and postsynaptic sites. We studied the neuromodulatory action of adenosine on glutamatergic currents in the hippocampus, showing that activation of multiple adenosine receptors (ARs) by basal adenosine impacts postsynaptic site. Specifically, the stimulation of both A1R and A3R reduces AMPA currents, while A2AR has an opposite potentiating effect. The effect of ARs stimulation on glutamatergic currents in hippocampal cultures was investigated using pharmacological and genetic approaches. A3R inhibition by MRS1523 increased GluR1-Ser845 phosphorylation and potentiated AMPA current amplitude, increasing the apparent affinity for the agonist. A similar effect was observed blocking A1R with DPCPX or by genetic deletion of either A3R or A1R. Conversely, impairment of A2AR reduced AMPA currents, and decreased agonist sensitivity. Consistently, in hippocampal slices, ARs activation by AR agonist NECA modulated glutamatergic current amplitude evoked by AMPA application or afferent fiber stimulation. Opposite effects of AR subtypes stimulation are likely associated to changes in GluR1 phosphorylation and represent a novel mechanism of physiological modulation of glutamatergic transmission by adenosine, likely acting in normal conditions in the brain, depending on the level of extracellular adenosine and the distribution of AR subtypes

    Identification of the zinc finger 216 (ZNF216) in human carcinoma cells. A potential regulator of EGFR activity

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    Epidermal Growth Factor Receptor (EGFR), a member of the ErbB family of receptor tyrosine kinase (RTK) proteins, is aberrantly expressed or deregulated in tumors and plays pivotal roles in cancer onset and metastatic progression. ZNF216 gene has been identified as one of Immediate Early Genes (IEGs) induced by RTKs. Overexpression of ZNF216 protein sensitizes 293 cell line to TNF-α induced apoptosis. However, ZNF216 overexpression has been reported in medulloblastomas and metastatic nasopharyngeal carcinomas. Thus, the role of this protein is still not clearly understood. In this study, the inverse correlation between EGFR and ZNF216 expression was confirmed in various human cancer cell lines differently expressing EGFR. EGF treatment of NIH3T3 cells overexpressing both EGFR and ZNF216 (NIH3T3-EGFR/ZNF216), induced a long lasting activation of EGFR in the cytosolic fraction and an accumulation of phosphorylated EGFR (pEGFR) more in the nuclear than in the cytosolic fraction compared to NIH3T3-EGFR cells. Moreover, EGF was able to stimulate an increased expression of ZNF216 in the cytosolic compartment and its nuclear translocation in a time-dependent manner in NIH3T3-EGFR/ZNF216. A similar trend was observed in A431 cells endogenously expressing the EGFR and transfected with Znf216. The increased levels of pEGFR and ZNF216 in the nuclear fraction of NIH3T3-EGFR/ZNF216 cells were paralleled by increased levels of phospho-MAPK and phospho-Akt. Surprisingly, EGF treatment of NIH3T3-EGFR/ZNF216 cells induced a significant increase of apoptosis thus indicating that ZNF216 could sensitize cells to EGF-induced apoptosis and suggesting that it may be involved in the regulation and effects of EGFR signaling

    Stifle anatomic, tomographic and biomechanical features of growing dogs affected by quadriceps contracture.

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    Quadriceps contracture is a debilitating and uncommon condition, mostly affecting young dogs. Itcan be congenital or acquired ) and is reported to induce muscular hypotrophy/fibrosis, progressive degenerative joint disease, bone hypoplasia and limb hyperextension. The aim of this study was to elucidate anatomic, tomographic and biomechanical features of stifles affected by quadriceps contracture.Seven 2-month-old dead Dobermann Pinschers with unilateral quadriceps contracture were included. Before gross anatomic evaluation, all stifles underwent Computed Tomography before and after intra-articular administration of iodinated contrast medium. Images were acquired in double positioning (stifle extension and flexion) to identify articular cartilage, Ossification Centres’ (OCs) and menisci abnormalities, which were compared between affected and unaffected limbs. In all affected limbs the stifle was back-turned, the distal femur was extra-rotated and the patella was luxated proximo-medially. Severe lack of physiological stifle movements (rolling, gliding, spinning) was observed, so that affected joints could not be flexed. The articular cartilage of the femur was flattened and irregular in thickness, the femoral trochlea was hypoplasic and sloping, the menisci were misshaped. The OC of the distal femur and proximal tibia were misshaped; the tibial plateau was oriented caudodorsally-cranioventrally and significantly smaller (P<0,05). Quadriceps contracture influenced stifle development. The action of quadriceps insertion on the tibia prevented normal development of the plateau, causing wedging and abnormal orientation. Constant compression also induced external rotation of the distal femur (unable to develop distally) and patellar luxation, ending up in genu recurvatum. Static compression was likely responsible for femoral trochlea hypoplasia, articular cartilage and meniscal deformation, due to the lack of physiological stifle movements.Quadriceps contracture induces severe alterations of stifle development in affected puppies. Histology, histochemistry and immunohistochemistry may better define the nature of such bone, cartilage and meniscal alterations
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