141 research outputs found

    ANALISI DEL DIFFERENZIAMENTO NEURONALE INDOTTO DALL’ACIDO RETINOICO IN CELLULE DI TERATOCARCINOMA EMBRIONALE MURINO.

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    In humans, the loss of sensory hair cells is an irreversible process leading to hearing loss. Regenerative medicine, that is the replacement of degenerating cells with neural stem cells, has been proposed for treatment of inner ear sensorineural damage. The pluripotent mouse P19 embryonal carcinoma (EC) cell line usually grows into an epithelial monolayer and, after aggregation and treatment with retinoic acid (RA), differentiates into neural cells, including neurons and glial cells. Thus, the mouse P19 cells have been extensively used as a model to study molecular mechanisms of neural differentiation in vitro and might represent an useful tool in regenerative medicine. A first aim of the present study was to optimize culture conditions to promote the RA-induced neural differentiation of P19 cells. To this purpose, cell viability, morphology and functional activity after RA treatment have been evaluated. The results indicate that the formation of embryoid bodies from P19 cells is enhanced in presence of neuronal basal medium (NBM). Following a 48h-treatment with RA (10-6M), a massive neuronal differentiation was induced and, three-five days after the treatment, the P19 cells showed a clear expression of the neurofilament proteins NF-68 and NF-160, two markers of terminal neuronal differentiation, detected by immunofluorescence. Furthermore, 10 days after the treatment with RA, the functional activity of differentiated cells has been demonstrated by their ability to uptake [3H]GABA. Once experimental conditions favoring the RA-induced neuronal differentiation have been established, the expression of some proteins, such as protein kinase C 6 (PKCz), protein kinase C a (PKCa), extracellular signalregulated kinases 1/2 (ERK1/2) and caspase-3, at different times after RAtreatment,\ud has been investigated. Western blot and immunocytochemical studies indicate that RA-treatment induced direct or indirect changes of the levels of the proteins under investigation, thus suggesting a possible involvement of these proteins in the signal pathways associated with RA-induced differentiation in P19 cells. Taken together, the present results suggest that the reported culture conditions favor a rapid differentiation of neural stem cells from P19 cells, and contribute to the understanding of the molecular mechanisms possibly involved in RA-induced neuronal differentiation. Thus, this approach could represent a reliable basis for studies of “regenerative therapy” of sensorineural hearing loss

    Psychostimulant effect of the synthetic cannabinoid JWH-018 and AKB48: Behavioral, neurochemical, and dopamine transporter scan imaging studies in mice

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    JWH-018 and AKB48 are two synthetic cannabinoids (SCBs) belonging to different structural classes and illegally marketed as incense, herbal preparations, or chemical supply for theirs psychoactive cannabis-like effects. Clinical reports from emergency room reported psychomotor agitation as one of the most frequent effects in people assuming SCBs. This study aimed to investigate the psychostimulant properties of JWH-018 and AKB48 in male CD-1 mice and to compare their behavioral and biochemical effects with those caused by cocaine and amphetamine. In vivo studies showed that JWH-018 and AKB48, as cocaine and amphetamine, facilitated spontaneous locomotion in mice. These effects were prevented by CB1 receptor blockade and dopamine (DA) D1/5 and D2/3 receptors inhibition. SPECT-CT studies on dopamine transporter (DAT) revealed that, as cocaine and amphetamine, JWH-018 and AKB48 decreased the [123I]-FP-CIT binding in the mouse striatum. Conversely, in vitro competition binding studies revealed that, unlike cocaine and amphetamine, JWH-018 and AKB48 did not bind to mouse or human DAT. Moreover, microdialysis studies showed that the systemic administration of JWH-018, AKB48, cocaine, and amphetamine stimulated DA release in the nucleus accumbens (NAc) shell of freely moving mice. Finally, unlike amphetamine and cocaine, JWH-018 and AKB48 did not induce any changes on spontaneous [3H]-DA efflux from murine striatal synaptosomes. The present results suggest that SCBs facilitate striatal DA release possibly with different mechanisms than cocaine and amphetamine. Furthermore, they demonstrate, for the first time, that JWH-018 and AKB48 induce a psychostimulant effect in mice possibly by increasing NAc DA release. These data, according to clinical reports, outline the potential psychostimulant action of SCBs highlighting their possible danger to human health

    Surgical site infection after caesarean section. Space for post-discharge surveillance improvements and reliable comparisons

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    Surgical site infections (SSI) after caesarean section (CS) represent a substantial health system concern. Surveying SSI has been associated with a reduction in SSI incidence. We report the findings of three (2008, 2011 and 2013) regional active SSI surveillances after CS in community hospital of the Latium region determining the incidence of SSI. Each CS was surveyed for SSI occurrence by trained staff up to 30 post-operative days, and association of SSI with relevant characteristics was assessed using binomial logistic regression. A total of 3,685 CS were included in the study. A complete 30 day post-operation follow-up was achieved in over 94% of procedures. Overall 145 SSI were observed (3.9% cumulative incidence) of which 131 (90.3%) were superficial and 14 (9.7%) complex (deep or organ/space) SSI; overall 129 SSI (of which 89.9% superficial) were diagnosed post-discharge. Only higher NNIS score was significantly associated with SSI occurrence in the regression analysis. Our work provides the first regional data on CS-associated SSI incidence, highlighting the need for a post-discharge surveillance which should assure 30 days post-operation to not miss data on complex SSI, as well as being less labour intensive

    The coming together of allosteric and phosphorylation mechanisms in the molecular integration of A2A heteroreceptor complexes in the dorsal and ventral striatal-pallidal GABA neurons

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    The role of adenosine A2A receptor (A2AR) and striatal-enriched protein tyrosine phosphatase (STEP) interactions in the striatal-pallidal GABA neurons was recently discussed in relation to A2AR overexpression and cocaine-induced increases of brain adenosine levels. As to phosphorylation, combined activation of A2AR and metabotropic glutamate receptor 5 (mGluR5) in the striatal-pallidal GABA neurons appears necessary for phosphorylation of the GluA1 unit of the AMPA receptor to take place. Robert Yasuda (J Neurochem 152: 270–272, 2020) focused on finding a general mechanism by which STEP activation is enhanced by increased A2AR transmission in striatal-pallidal GABA neurons expressing A2AR and dopamine D2 receptor. In his Editorial, he summarized in a clear way the significant effects of A2AR activation on STEP in the dorsal striatal-pallidal GABA neurons which involves a rise of intracellular levels of calcium causing STEP activation through its dephosphorylation. However, the presence of the A2AR in an A2AR-fibroblast growth factor receptor 1 (FGFR1) heteroreceptor complex can be required in the dorsal striatal-pallidal GABA neurons for the STEP activation. Furthermore, Won et al. (Proc Natl Acad Sci USA 116: 8028–8037, 2019) found in mass spectrometry experiments that the STEP splice variant STEP(61) can bind to mGluR5 and inactivate it. In addition, A2AR overexpression can lead to increased formation of A2AR-mGluR5 heterocomplexes in ventral striatal-pallidal GABA neurons. It involves enhanced facilitatory allosteric interactions leading to increased Gq-mediated mGluR5 signaling activating STEP. The involvement of both A2AR and STEP in the actions of cocaine on synaptic downregulation was also demonstrated. The enhancement of mGluR5 protomer activity by the A2AR protomer in A2AR-mGluR5 heterocomplexes in the nucleus accumbens shell appears to have a novel significant role in STEP mechanisms by both enhancing the activation of STEP and being a target for STEP(61)

    Evolutionary history of the little fire ant Wasmannia auropunctata before global invasion: Inferring dispersal patterns, niche requirements and past and present distribution within its native range

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    The evolutionary history of invasive species within their native range may involve key processes that allow them to colonize new habitats. Therefore, phylogeographic studies of invasive species within their native ranges are useful to understand invasion biology in an evolutionary context. Here we integrated classical and Bayesian phylogeographic methods using mitochondrial and nuclear DNA markers with a palaeodistribution modelling approach, to infer the phylogeographic history of the invasive ant Wasmannia auropunctata across its native distribution in South America. We discuss our results in the context of the recent establishment of this mostly tropical species in the Mediterranean region. Our Bayesian phylogeographic analysis suggests that the common ancestor of the two main clades of W. auropunctata occurred in central Brazil during the Pliocene. Clade A would have differentiated northward and clade B southward, followed by a secondary contact beginning about 380 000 years ago in central South America. There were differences in the most suitable habitats among clades when considering three distinct climatic periods, suggesting that genetic differentiation was accompanied by changes in niche requirements, clade A being a tropical lineage and clade B a subtropical and temperate lineage. Only clade B reached more southern latitudes, with a colder climate than that of northern South America. This is concordant with the adaptation of this originally tropical ant species to temperate climates prior to its successful establishment in the Mediterranean region. This study highlights the usefulness of exploring the evolutionary history of invasive species within their native ranges to better understand biological invasions. © 2016 European Society for Evolutionary Biology

    CNTN6 mutations are risk factors for abnormal auditory sensory perception in autism spectrum disorders

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    Contactin genes CNTN5 and CNTN6 code for neuronal cell adhesion molecules that promote neurite outgrowth in sensory-motor neuronal pathways. Mutations of CNTN5 and CNTN6 have previously been reported in individuals with autism spectrum disorders (ASDs), but very little is known on their prevalence and clinical impact. In this study, we identified CNTN5 and CNTN6 deleterious variants in individuals with ASD. Among the carriers, a girl with ASD and attention-deficit/hyperactivity disorder was carrying five copies of CNTN5. For CNTN6, both deletions (6/1534 ASD vs 1/8936 controls; P=0.00006) and private coding sequence variants (18/501 ASD vs 535/33480 controls; P=0.0005) were enriched in individuals with ASD. Among the rare CNTN6 variants, two deletions were transmitted by fathers diagnosed with ASD, one stop mutation CNTN6W923X was transmitted by a mother to her two sons with ASD and one variant CNTN6P770L was found de novo in a boy with ASD. Clinical investigations of the patients carrying CNTN5 or CNTN6 variants showed that they were hypersensitive to sounds (a condition called hyperacusis) and displayed changes in wave latency within the auditory pathway. These results reinforce the hypothesis of abnormal neuronal connectivity in the pathophysiology of ASD and shed new light on the genes that increase risk for abnormal sensory perception in ASD

    Ruxolitinib in cytopenic myelofibrosis: Response, toxicity, drug discontinuation, and outcome

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    BackgroundPatients with cytopenic myelofibrosis (MF) have more limited therapeutic options and poorer prognoses compared with patients with the myeloproliferative phenotype. Aims and MethodsPrognostic correlates of cytopenic phenotype were explored in 886 ruxolitinib-treated patients with primary/secondary MF (PMF/SMF) included in the RUX-MF retrospective study. Cytopenia was defined as: leukocyte count <4 x 10(9)/L and/or hemoglobin <11/<10 g/dL (males/females) and/or platelets Overall, 407 (45.9%) patients had a cytopenic MF, including 249 (52.4%) with PMF. In multivariable analysis, high molecular risk mutations (p = .04), intermediate 2/high Dynamic International Prognostic Score System (p < .001) and intermediate 2/high Myelofibrosis Secondary to Polycythemia Vera and Essential Thrombocythemia Prognostic Model (p < .001) remained associated with cytopenic MF in the overall cohort, PMF, and SMF, respectively. Patients with cytopenia received lower average ruxolitinib at the starting (25.2 mg/day vs. 30.2 mg/day, p < .001) and overall doses (23.6 mg/day vs. 26.8 mg/day, p < .001) and achieved lower rates of spleen (26.5% vs. 34.1%, p = .04) and symptom (59.8% vs. 68.8%, p = .008) responses at 6 months compared with patients with the proliferative phenotype. Patients with cytopenia also had higher rates of thrombocytopenia at 3 months (31.1% vs. 18.8%, p < .001) but lower rates of anemia (65.6% vs. 57.7%, p = .02 at 3 months and 56.6% vs. 23.9% at 6 months, p < .001). After competing risk analysis, the cumulative incidence of ruxolitinib discontinuation at 5 years was 57% and 38% in patients with cytopenia and the proliferative phenotype (p < .001), whereas cumulative incidence of leukemic transformation was similar (p = .06). In Cox regression analysis adjusted for Dynamic International Prognostic Score System score, survival was significantly shorter in patients with cytopenia (p < .001). ConclusionsCytopenic MF has a lower probability of therapeutic success with ruxolitinib as monotherapy and worse outcome. These patients should be considered for alternative therapeutic strategies
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