LabVIEW-based control and acquisition system for the dosimetric characterization of a silicon strip detector

Theaimofthisworkistopresentanewdataacquisition,control,andanalysissoftwaresystemwrittenin LabVIEW.Thissystemhasbeendesignedtoobtainthedosimetryofasiliconstripdetectorinpolyethylene. It allows the full automation of the experiments and data analysis required for the dosimetric characterization of silicon detectors. It becomes a useful tool that can be applied in the daily routine check of a beam accelerator.MINECO ICTI2013-2016/FPA2013-47327-C2-1-RMINECO ICTI2013-2016/FPA2014-53290-C2-2- PJunta de Andalucía P12-FQM-160

Neuronal and astrocytic tetraploidy is increased in drug-resistant epilepsy

Aims: Epilepsy is one of the most prevalent neurological diseases. A third of patients with epilepsy remain drug-resistant. The exact aetiology of drug-resistant epilepsy (DRE) is still unknown. Neuronal tetraploidy has been associated with neuropathology. The aim of this study was to assess the presence of tetraploid neurons and astrocytes in DRE. Methods. For that purpose, cortex, hippocampus and amygdala samples were obtained from patients subjected to surgical resection of the epileptogenic zone. Post-mortem brain tissue of subjects without previous records of neurological, neurodegenerative or psychiatric diseases was used as control. Results: The percentage of tetraploid cells was measured by immunostaining of neurons (NeuN) or astrocytes (S100β) followed by flow cytometry analysis. The results were confirmed by image cytometry (ImageStream X Amnis System Cytometer) and with an alternative astrocyte biomarker (NDRG2). Statistical comparison was performed using univariate tests. A total of 22 patients and 10 controls were included. Tetraploid neurons and astrocytes were found both in healthy individuals and DRE patients in the three brain areas analysed: cortex, hippocampus and amygdala. DRE patients presented a higher number of tetraploid neurons (p = 0.020) and astrocytes (p = 0.002) in the hippocampus than controls. These results were validated by image cytometry. Conclusions: We demonstrated the presence of both tetraploid neurons and astrocytes in healthy subjects as well as increased levels of both cell populations in DRE patients. Herein, we describe for the first time the presence of tetraploid astrocytes in healthy subjects. Furthermore, these results provide new insights into epilepsy, opening new avenues for future treatment

Polymorphisms associated with adalimumab and infliximab response in moderate-to-severe plaque psoriasis

Aims. This study evaluated the influence of pharmacogenetics in psoriatic patients treated with adalimumab and/or infliximab. Materials & methods: Prospective observational study evaluating the association of 124 polymorphisms with the response to adalimumab or infliximab (PASI75) in patients with moderate-to-severe plaque psoriasis at 3 months (n = 95) and 6 months of treatment (n = 90). Significant SNPs for univariate analysis were subjected to multivariate analysis. Results: Five SNPs were associated with PASI75 at 3 months: rs6661932 (IVL), rs2546890 (IL-12B), rs2145623 (NFKBIA), rs9304742 (ZNF816A) and rs645544 (SLC9A8). Furthermore, rs1061624 (TNFR1B) was associated with PASI75 at 6 months. Conclusion: Nevertheless, these biomarkers should be validated in large-scale studies before implementation in clinical practice

DNA copy number variation associated with anti-tumour necrosis factor drug response and paradoxical psoriasiform reactions in patients with moderate-to-severe psoriasis

Biological drugs targeting tumour necrosis factor are effective for psoriasis. However, 30–50% of patients do not respond to these drugs and may even develop paradoxical psoriasiform reactions. This study search-ed for DNA copy number variations that could predict anti-tumour necrotic factor drug response or the ap-pearance of anti-tumour necrotic factor induced pso-riasiform reactions. Peripheral blood samples were collected from 70 patients with anti-tumour necrotic factor drug-treated moderate-to-severe plaque pso-riasis. Samples were analysed with an Illumina 450K methylation microarray. Copy number variations were obtained from raw methylation data using conumee and Chip Analysis Methylation Pipeline (ChAMP) R packa-ges. One copy number variation was found, harbouring one gene (CPM) that was significantly associated with adalimumab response (Bonferroni-adjusted p-value < 0.05). Moreover, one copy number variation was identified harbouring 3 genes (ARNT2, LOC101929586 and MIR5572) related to the development of paradoxical psoriasiform reactions. In conclusion, this study has identified DNA copy number variations that could be good candidate markers to predict response to ada-limumab and the development of anti-tumour necrotic factor paradoxical psoriasiform reactions.This study was supported by Instituto de Salud Carlos III PI 13/01598 and the Ministry of Science and Innovation and the European Regional Development’s funds (FEDER). Conflicts of interest. FA-S has been a consultant or investigator in clinical trials sponsored by the following pharmaceutical companies: Abbott, Alter, Chemo, Farmalíder, Ferrer, GlaxoSmithKline, Gilead, Janssen-Cilag, Kern, Normon, Novartis, Servier, Teva, and Zambon. ED has potential conflicts of interest (advisory board member, consultant, grants, research support, participation in clinical trials, honoraria for speaking, and research support) with the following pharmaceutical companies: AbbVie (Abbott), Amgen, Janssen-Cilag, Leo Pharma, Novartis, Pfizer, MSD, Lilly and Celgene. ML-V has potential conflicts of interest as she has participated in clinical trials or as consultant with Abbvie (Abbott), Galderma, Janssen-Cilag, Leo Pharma, Pfizer, Novarties, Lilly, Almirall and Celgene. MCO-B has potential conflicts of interest (honoraria for speaking and research support) with Janssen-Cilag and Leo Pharma. The other authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. AS-T has served as a consultant and/or paid speaker for and/or participated in clinical trials sponsored by companies that manufacture drugs used for the treatment of psoriasis, including AbbVie, Celgene, Janssen-Cilag, LEO Pharma, Lilly, Novartis and Pfizer. RB-E has served as a consultant and/or paid speaker for and/or participated in clinical trials sponsored by companies that manufacture drugs used for the treatment of psoriasis, including AbbVie, Celgene, Janssen-Cilag, LEO Pharma, Lilly, Novartis and Pfizer

Neuronal cell cycle: the neuron itself and its circumstances

Neurons are usually regarded as postmitotic cells that undergo apoptosis in response to cell cycle reactivation. Nevertheless, recent evidence indicates the existence of a defined developmental program that induces DNA replication in specific populations of neurons, which remain in a tetraploid state for the rest of their adult life. Similarly, de novo neuronal tetraploidization has also been described in the adult brain as an early hallmark of neurodegeneration. The aim of this review is to integrate these recent developments in the context of cell cycle regulation and apoptotic cell death in neurons. We conclude that a variety of mechanisms exists in neuronal cells for G1/S and G2/M checkpoint regulation. These mechanisms, which are connected with the apoptotic machinery, can be modulated by environmental signals and the neuronal phenotype itself, thus resulting in a variety of outcomes ranging from cell death at the G1/S checkpoint to full proliferation of differentiated neurons.This work was supported by grants from “Ministerio de Economía y Competitividad” (SAF2012–38316) and “Fundación Ramón Areces.”Peer reviewe

Brain-derived neurotrophic factor-dependent cdk1 inhibition prevents G2/M progression in differentiating tetraploid neurons.

Neurodegeneration is often associated with DNA synthesis in neurons, the latter usually remaining for a long time as tetraploid cells before dying by apoptosis. The molecular mechanism preventing G2/M transition in these neurons remains unknown, but it may be reminiscent of the mechanism that maintains tetraploid retinal ganglion cells (RGCs) in a G2-like state during normal development, thus preventing their death. Here we show that this latter process, known to depend on brain-derived neurotrophic factor (BDNF), requires the inhibition of cdk1 by TrkB. We demonstrate that a subpopulation of chick RGCs previously shown to become tetraploid co-expresses TrkB and cdk1 in vivo. By using an in vitro system that recapitulates differentiation and cell cycle re-entry of chick retinal neurons we show that BDNF, employed at concentrations specific for the TrkB receptor, reduces the expression of cdk1 in TrkB-positive, differentiating neurons. In this system, BDNF also inhibits the activity of both endogenous cdk1 and exogenously-expressed cdk1/cyclin B1 complex. This inhibition correlates with the phosphorylation of cdk1 at Tyr15, an effect that can be prevented with K252a, a tyrosine kinase inhibitor commonly used to prevent the activity of neurotrophins through their Trk receptors. The effect of BDNF on cdk1 activity is Tyr15-specific since BDNF cannot prevent the activity of a constitutively active form of cdk1 (Tyr15Phe) when expressed in differentiating retinal neurons. We also show that BDNF-dependent phosphorylation of cdk1 at Tyr15 could not be blocked with MK-1775, a Wee1-selective inhibitor, indicating that Tyr15 phosphorylation in cdk1 does not seem to occur through the canonical mechanism observed in proliferating cells. We conclude that the inhibition of both expression and activity of cdk1 through a BDNF-dependent mechanism contributes to the maintenance of tetraploid RGCs in a G2-like state

Brain-Derived Neurotrophic Factor-Dependent cdk1 Inhibition Prevents G2/M Progression in Differentiating Tetraploid Neurons

Neurodegeneration is often associated with DNA synthesis in neurons, the latter usually remaining for a long time as tetraploid cells before dying by apoptosis. The molecular mechanism preventing G2/M transition in these neurons remains unknown, but it may be reminiscent of the mechanism that maintains tetraploid retinal ganglion cells (RGCs) in a G2-like state during normal development, thus preventing their death. Here we show that this latter process, known to depend on brain-derived neurotrophic factor (BDNF), requires the inhibition of cdk1 by TrkB. We demonstrate that a subpopulation of chick RGCs previously shown to become tetraploid co-expresses TrkB and cdk1 in vivo. By using an in vitro system that recapitulates differentiation and cell cycle re-entry of chick retinal neurons we show that BDNF, employed at concentrations specific for the TrkB receptor, reduces the expression of cdk1 in TrkB-positive, differentiating neurons. In this system, BDNF also inhibits the activity of both endogenous cdk1 and exogenously-expressed cdk1/cyclin B1 complex. This inhibition correlates with the phosphorylation of cdk1 at Tyr15, an effect that can be prevented with K252a, a tyrosine kinase inhibitor commonly used to prevent the activity of neurotrophins through their Trk receptors. The effect of BDNF on cdk1 activity is Tyr15-specific since BDNF cannot prevent the activity of a constitutively active form of cdk1 (Tyr15Phe) when expressed in differentiating retinal neurons. We also show that BDNF-dependent phosphorylation of cdk1 at Tyr15 could not be blocked with MK-1775, a Wee1-selective inhibitor, indicating that Tyr15 phosphorylation in cdk1 does not seem to occur through the canonical mechanism observed in proliferating cells. We conclude that the inhibition of both expression and activity of cdk1 through a BDNF-dependent mechanism contributes to the maintenance of tetraploid RGCs in a G2-like state.Peer Reviewe

Cdk1 is expressed by p75^NTR- and TrkB-positive DCRNs and colocalizes with basally-located mitosis.

<p>Confocal sections from retinas of E6 chick embryos were double labeled with the anti-cdk1 specific mAbs (red) (B-6) (<b>A</b>), [A17] (<b>B</b>), and (17) (<b>C</b>-<b>E</b>), as well as with anti-p75^NTR (p75) (<b>C</b>), anti-phosphoHistone H3 (pH3) (<b>D</b>), or anti-TrkB (<b>E</b>) antibodies (green). Nuclear staining with bisbenzimide is shown in blue (Bisb.). (<b>A</b>,<b>B</b>) Cdk1 immunostaining is observed in the cytoplasm of a subpopulation of retinal cells and often in nuclei located apically (arrows). (<b>C</b>) A subset of cdk1-positive cells co-localize with p75^NTR (arrowhead), whereas many other p75^NTR-positive cells lack cdk1 immunolabeling (arrow). (<b>D</b>) Cdk1-positive cells co-localize with phosphoHistone H3 in the basal retina, close to the presumptive GCL (arrow). Arrowhead: apically located nucleus with cdk1-specific immunoreactivity. (<b>E</b>) TrkB-positive cells co-localize with cdk1 (arrow). Boxes: high magnification of the dashed areas. GCL: ganglion cell layer; PE: pigment epithelium; v: vitreous body. Bar: 20 µm (<b>A</b>-<b>D</b>), 40 µm (<b>E</b>).</p

A model for the regulation of cdk1 by BDNF in DCRNs.

<p>TrkB activation by BDNF prevents the increase cyclin B and cdk1 protein expression (dashed line) and induces phosphorylation of cdk1 at Tyr15 (thick black arrow), thus inhibiting cdk1 kinase activity. This effect participates in the G2/M arrest (grey line) observed in tetraploid RGCs.</p

Generalized expression of TrkB in DCRNs.

<p>After 20 h in vitro, DCRNs were immunolabeled with anti-TrkB antibody (green) and counterstained with bisbenzimide (Bisb.). Bar: 10 µm.</p