Search results for "post"

A clustering package for nucleotide sequences using Laplacian Eigenmaps and Gaussian Mixture Model.

2018

International audience; In this article, a new Python package for nucleotide sequences clustering is proposed. This package, freely available on-line, implements a Laplacian eigenmap embedding and a Gaussian Mixture Model for DNA clustering. It takes nucleotide sequences as input, and produces the optimal number of clusters along with a relevant visualization. Despite the fact that we did not optimise the computational speed, our method still performs reasonably well in practice. Our focus was mainly on data analytics and accuracy and as a result, our approach outperforms the state of the art, even in the case of divergent sequences. Furthermore, an a priori knowledge on the number of clust…

2016

Neuronal activity has been shown to be essential for the proper formation of neuronal circuits, affecting developmental processes like neurogenesis, migration, programmed cell death, cellular differentiation, formation of local and long-range axonal connections, synaptic plasticity or myelination. Accordingly, neocortical areas reveal distinct spontaneous and sensory-driven neuronal activity patterns already at early phases of development. At embryonic stages, when immature neurons start to develop voltage-dependent channels, spontaneous activity is highly synchronized within small neuronal networks and governed by electrical synaptic transmission. Subsequently, spontaneous activity pattern…

Alterations in reelin and reelin receptors in Down syndrome.

2019

Reelin is an extracellular matrix glycoprotein that modulates synaptic function and plasticity, with a crucial role in neuronal migration. Changes in the expression of this protein have been reported in neurodegenerative diseases, such as Alzheimer's disease (AD). This molecule is produced by Cajal-Retzius neurons during development and by inhibitory neurons in the adult nervous system. Individuals with Down syndrome (DS) present an early development of AD; therefore, we analyzed the alterations in this molecule and its receptors in the murine model for DS Ts65Dn as well as in human with DS. We performed immunofluorescence analysis for reelin and its receptors very-low-density lipoprotein r…

Binge-like ethanol treatment in adolescence impairs autophagy and hinders synaptic maturation: Role of TLR4.

2018

Abstract Adolescence is a developmental period of brain maturation in which remodeling and changes in synaptic plasticity and neural connectivity take place in some brain regions. A different mechanism participates in adolescent brain maturation, including autophagy processes that play a role in synaptic development and plasticity. Alcohol is a neurotoxic compound whose abuse in adolescence causes TLR4 response activation by triggering neuroinflammation, neural damage and behavioral alterations. However, the potential participation of autophagy in long-term neurochemical and cognitive dysfunctions induced by binge ethanol drinking in adolescence is uncertain. We therefore evaluated whether …

Auxiliary α2δ1 and α2δ3 Subunits of Calcium Channels Drive Excitatory and Inhibitory Neuronal Network Development

2020

VGCCs are multisubunit complexes that play a crucial role in neuronal signaling. Auxiliary α2δ subunits of VGCCs modulate trafficking and biophysical properties of the pore-forming α1 subunit and trigger excitatory synaptogenesis. Alterations in the expression level of α2δ subunits were implicated in several syndromes and diseases, including chronic neuropathic pain, autism, and epilepsy. However, the contribution of distinct α2δ subunits to excitatory/inhibitory imbalance and aberrant network connectivity characteristic for these pathologic conditions remains unclear. Here, we show that α2δ1 overexpression enhances spontaneous neuronal network activity in developing and mature cultures of …

Asymmetry Between Pre- and Postsynaptic Transient Nanodomains Shapes Neuronal Communication.

2020

Synaptic transmission and plasticity are shaped by the dynamic reorganization of signaling molecules within pre- and postsynaptic compartments. The nanoscale organization of key effector molecules has been revealed by single-particle trajectory (SPT) methods. Interestingly, this nanoscale organization is highly heterogeneous. For example, presynaptic voltage-gated calcium channels (VGCCs) and postsynaptic ligand-gated ion channels such as AMPA receptors (AMPARs) are organized into so-called nanodomains where individual molecules are only transiently trapped. These pre- and postsynaptic nanodomains are characterized by a high density of molecules but differ in their molecular organization an…

Astrocyte sodium signaling and the regulation of neurotransmission.

2015

The transmembrane Na(+) concentration gradient is an important source of energy required not only to enable the generation of action potentials in excitable cells, but also for various transmembrane transporters both in excitable and non-excitable cells, like astrocytes. One of the vital functions of astrocytes in the central nervous system (CNS) is to regulate neurotransmitter concentrations in the extracellular space. Most neurotransmitters in the CNS are removed from the extracellular space by Na(+) -dependent neurotransmitter transporters (NeuTs) expressed both in neurons and astrocytes. Neuronal NeuTs control mainly phasic synaptic transmission, i.e., synaptically induced transient pos…

Postmastectomy Radiation Therapy in Women with T1-T2 Tumors and 1 to 3 Positive Lymph Nodes: Analysis of the Breast International Group 02-98 Trial.

2017

Purpose To analyze the impact of postmastectomy radiation therapy (PMRT) for patients with T1-T2 tumors and 1 to 3 positive lymph nodes enrolled on the Breast International Group (BIG) 02-98 trial. Methods and Materials The BIG 02-98 trial randomized patients to receive adjuvant anthracycline with or without taxane chemotherapy. Delivery of PMRT was nonrandomized and performed according to institutional preferences. The present analysis was performed on participants with T1-T2 breast cancer and 1 to 3 positive lymph nodes who had undergone mastectomy and axillary nodal dissection. The primary objective of the present study was to examine the effect of PMRT on risk of locoregional recurrence…

Targeted next-generation sequencing of circulating-tumor DNA for tracking minimal residual disease in localized colon cancer.

2019

A high percentage of patients diagnosed with localized colon cancer (CC) will relapse after curative treatment. Although pathological staging currently guides our treatment decisions, there are no biomarkers determining minimal residual disease (MRD) and patients are at risk of being undertreated or even overtreated with chemotherapy in this setting. Circulating-tumor DNA (ctDNA) can to be a useful tool to better detect risk of relapse.One hundred and fifty patients diagnosed with localized CC were prospectively enrolled in our study. Tumor tissue from those patients was sequenced by a custom-targeted next-generation sequencing (NGS) panel to characterize somatic mutations. A minimum varian…

BRCA1/2 molecular assay for ovarian cancer patients: A survey through Italian departments of oncology and molecular and genomic diagnostic laboratori…

2019

In Italy, 5200 new ovarian cancers were diagnosed in 2018, highlighting an increasing need to test women for BRCA1/2. The number of labs offering this test is continuously increasing. The aim of this study was to show the results coming from the intersociety survey coordinated by four different Clinical and Laboratory Italian Scientific Societies (AIOM, SIAPEC-IAP, SIBIOC, and SIGU). A multidisciplinary team belonging to the four scientific societies drew up two different questionnaires: One was targeted toward all Italian Departments of Medical Oncology, and the second toward laboratories of clinical molecular biology. This survey was implemented from September 2017 to March 2018. Seventy-…