146 research outputs found
Percutaneous Trans-Thoracic Procedures in Children With Tumors of Thoracic Wall, Mediastinum and Lung. The Experience of a Single Institution
Background
While percutaneous trans-thoracic procedures (PTTP) are commonly performed in adults with
tumors of thoracic wall, mediastinum and lung, the experience is limited in children, in whom
however less invasive methods should be the choice for the diagnosis or the identification of
small pulmonary nodules that need to be removed, sparing lung tissue. The results of the PTTP
performed by the interventional radiologists in our Pediatric Surgery Department are analyzed.
Methods
CT-guided biopsies, utilizing a 64-slice CTscanner, with low-radiation dose, were performed
applying the coaxial technique with 16-18G needles with a single tissue path. For localization
of lung nodules before surgery, two 20G-hook wires were positioned beyond the nodule. CT
images after each manipulation of the needles were obtained. US-guided biopsies were
performed either with or without coaxial technique through a needle bracket. Younger patients
required sedation. All patients underwent a chest radiogram two hours after the procedure and
remained under observation for 24 hours.
Results
From January 2015 to March 2019, 23 procedures were performed in 22 patients (Age:16M-
19Y): 6 patients underwent CT-guided biopsy (4 lung nodules, 2 mediastinal mass); 3
underwent 4 CT-guided hook-wire localization of pulmonary nodules, just before surgery; 13
underwent US-guided biopsy (posterior mediastinum 2; anterior mediastinum 5,
thoracic/intrathoracic mass 5). Adequate core biopsies were obtained in all patients, except
three, who underwent thoracoscopy/thoracotomy. The hook-wires were successfully
positioned in all cases, as confirmed by histology. After the procedure, two patients presented
perilesional hemorrhage and one pneumothorax, but they did not required treatment.
Conclusion
PTTP were successful in most patients, without significant complications. These techniques
should be encouraged to avoid diagnostic aggressive surgical approaches in children with
cancer. For all cases a multidisciplinary team is essential to discuss the indications and planning
the procedures
Chronic Stress Induces Maladaptive Behaviors by Activating Corticotropin-Releasing Hormone Signaling in the Mouse Oval Bed Nucleus of the Stria Terminalis
The bed nucleus of the stria terminalis (BNST) is a forebrain region highly responsive to stress that expresses corticotropin-releasing hormone (CRH) and is implicated in mood disorders, such as anxiety. However, the exact mechanism by which chronic stress induces CRH-mediated dysfunction in BNST and maladaptive behaviors remains unclear. Here, we first confirmed that selective acute optogenetic activation of the oval nucleus BNST (ovBNST) increases maladaptive avoidance behaviors in male mice. Next, we found that a 6 week chronic variable mild stress (CVMS) paradigm resulted in maladaptive behaviors and increased cellular excitability of ovBNST CRH neurons by potentiating mEPSC amplitude, altering the resting membrane potential, and diminishing M-currents (a voltage-gated K+Ā current that stabilizes membrane potential) inĀ ex vivoĀ slices. CVMS also increased c-fos+Ā cells in ovBNST following handling. We next investigated potential molecular mechanism underlying the electrophysiological effects and observed that CVMS increased CRH+Ā and pituitary adenylate cyclase-activating polypeptide+Ā (PACAP; a CRH upstream regulator) cells but decreased striatal-enriched protein tyrosine phosphatase+Ā (a STEP CRH inhibitor) cells in ovBNST. Interestingly, the electrophysiological effects of CVMS were reversed by CRHR1-selective antagonist R121919 application. CVMS also activated protein kinase A (PKA) in BNST, and chronic infusion of the PKA-selective antagonist H89 into ovBNST reversed the effects of CVMS. Coadministration of the PKA agonist forskolin prevented the beneficial effects of R121919. Finally, CVMS induced an increase in surface expression of phosphorylated GluR1 (S845) in BNST. Collectively, these findings highlight a novel and indispensable stress-induced role for PKA-dependent CRHR1 signaling in activating BNST CRH neurons and mediating maladaptive behaviors
Re-evaluating the resource potential of lomas fog oasis environments for Preceramic hunter-gatherers under past ENSO modes on the south coast of Peru
Lomas ā ephemeral seasonal oases sustained by ocean fogs ā were critical to ancient human ecology on the desert Pacific coast of Peru: one of humanityās few independent hearths of agriculture and āpristineā civilisation. The role of climate change since the Late Pleistocene in determining productivity and extent of past lomas ecosystems has been much debated.
Here we reassess the resource potential of the poorly studied lomas of the south coast of Peru during the long Middle Pre-ceramic period (c. 8,000 ā 4,500 BP): a period critical in the transition to agriculture, the onset of modern El NiƱo Southern Oscillation (āENSOā) conditions, and eustatic sea-level rise and stabilisation and beach progradation.
Our method combines vegetation survey and herbarium collection with archaeological survey and excavation to make inferences about both Preceramic hunter-gatherer ecology and the changed palaeoenvironments in which it took place. Our analysis of newly discovered archaeological sites ā and their resource context ā show how lomas formations defined human ecology until the end of the Middle Preceramic Period, thereby corroborating recent reconstructions of ENSO history based on other data.
Together, these suggest that a five millennia period of significantly colder seas on the south coast induced conditions of abundance and seasonal predictability in lomas and maritime ecosystems, that enabled Middle Preceramic hunter-gatherers to reduce mobility by settling in strategic locations at the conļ¬uence of multiple eco-zones at the river estuaries. Here the foundations of agriculture lay in a Broad Spectrum Revolution that unfolded, not through population pressure in deteriorating environments, but rather as an outcome of resource abundance.We thank the Ministerio de Cultural del PerĆŗ for granting permission for archaeological fieldwork (ResoluciĆ³n Directoral NĀŗ 933-2012-DGPC-VMPCIC/MC, 19 December 2012 and NĀŗ 386-2014-DGPA-VMPCIC/MC, 22 August 2014) and the export of samples for dating; Don Alberto Benavides Ganoza and the people of Samaca for facilitating fieldwork; the Leverhulme Trust (grant number RPG-117) and the late Don Alberto Benavides de la Quintana (grant number RG69428) and the McDonald Institute for Archaeological Research for funding Cambridge Universityās One River Archaeological Project, and the NERC Radiocarbon facility (grant number NF/2013/2/2) for funding radiocarbon dating. We also thank the Servicio Nacional Forestal y de Fauna Silvestre (SERFOR) and the Servicio Nacional de Ćreas Naturales Protegidas por el Estado (SERNANP), Peru for permits for the Proyecto Kew PerĆŗ to carry out botanical and ecological survey, and Delsy Trujillo, Eric RamĆrez, Consuelo Borda and other participants of the Proyecto Kew PerĆŗ: ConservaciĆ³n, RestauraciĆ³n de HĆ”bitats y Medios de Vida Ćtiles, Ica, Peru.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.quascirev.2015.10.02
ATP-Dependent Unwinding of U4/U6 snRNAs by the Brr2 Helicase Requires the C Terminus of Prp8
The spliceosome is a highly dynamic machine requiring multiple RNA-dependent ATPases of the DExD/H-box family. A fundamental unanswered question is how their activities are regulated. Brr2 function is necessary for unwinding the U4/U6 duplex, a step essential for catalytic activation of the spliceosome. Here we show that Brr2-dependent dissociation of U4/U6 snRNAs in vitro is activated by a fragment from the C terminus of the U5 snRNP protein Prp8. In contrast to its helicase-stimulating activity, this fragment inhibits Brr2 U4/U6-dependent ATPase activity. Notably, U4/U6 unwinding activity is not stimulated by fragments carrying alleles of prp8 that in humans confers an autosomal dominant form of retinitis pigmentosa. Because Brr2 activity must be restricted to prevent premature catalytic activation, our results have important implications for fidelity maintenance in the spliceosome
Stoichiometry of the degradation of dissolved and particulate biogenic organic matter in the NW Iberian upwelling
The average composition of the dissolved and particulate products of early
degradation of marine phytoplankton has been established for the first time in a coastal
upwelling system using a mixing analysis along isopycnal surfaces combined with a
stoichiometric model. About 17ā18% of the mineralized organic matter is derived
from the decomposition of organic particulates, and 16ā35% is from the dissolved
organic matter. The remaining 50ā70% is derived probably from large fast sinking
particles. On average, the mineralized material on large particles has the closest
composition to the Redfield formula. The ratio of dissolved saccharides to dissolved
organic matter respiration is >40% higher than expected from a material of Redfield
composition. Finally, the ratio of lipid to particulate organic matter respiration is >80%
larger than expected from a material of Redfield composition. Regarding the
decomposition of hard structures, biogenic silica dissolves predominantly in the inner
shelf, where organic carbon oxidation is more intense, and diatom deposition occurs
preferentially
Exploiting protein flexibility to predict the location of allosteric sites
Background: Allostery is one of the most powerful and common ways of regulation of protein activity. However, for most allosteric proteins identified to date the mechanistic details of allosteric modulation are not yet well understood. Uncovering common mechanistic patterns underlying allostery would allow not only a better academic understanding of the phenomena, but it would also streamline the design of novel therapeutic solutions. This relatively unexplored therapeutic potential and the putative advantages of allosteric drugs over classical active-site inhibitors fuel the attention allosteric-drug research is receiving at present. A first step to harness the regulatory potential and versatility of allosteric sites, in the context of drug-discovery and design, would be to detect or predict their presence and location. In this article, we describe a simple computational approach, based on the effect allosteric ligands exert on protein flexibility upon binding, to predict the existence and position of allosteric sites on a given protein structure. Results: By querying the literature and a recently available database of allosteric sites, we gathered 213 allosteric proteins with structural information that we further filtered into a non-redundant set of 91 proteins. We performed normal-mode analysis and observed significant changes in protein flexibility upon allosteric-ligand binding in 70% of the cases. These results agree with the current view that allosteric mechanisms are in many cases governed by changes in protein dynamics caused by ligand binding. Furthermore, we implemented an approach that achieves 65% positive predictive value in identifying allosteric sites within the set of predicted cavities of a protein (stricter parameters set, 0.22 sensitivity), by combining the current analysis on dynamics with previous results on structural conservation of allosteric sites. We also analyzed four biological examples in detail, revealing that this simple coarse-grained methodology is able to capture the effects triggered by allosteric ligands already described in the literature. Conclusions: We introduce a simple computational approach to predict the presence and position of allosteric sites in a protein based on the analysis of changes in protein normal modes upon the binding of a coarse-grained ligand at predicted cavities. Its performance has been demonstrated using a newly curated non-redundant set of 91 proteins with reported allosteric properties. The software developed in this work is available upon request from the authors
Sequential induction of three recombination directionality factors directs assembly of tripartite integrative and conjugative elements
Tripartite integrative and conjugative elements (ICE3) are a novel form of ICE that exist as three separate DNA regions integrated within the genomes of Mesorhizobium spp. Prior to conjugative transfer the three ICE3 regions of M. ciceri WSM1271 ICEMcSym1271 combine and excise to form a single circular element. This assembly requires three coordinated recombination events involving three site-specific recombinases IntS, IntG and IntM. Here, we demonstrate that three excisionasesāor recombination directionality factorsāRdfS, RdfG and RdfM are required for ICE3 excision. Transcriptome sequencing revealed that expression of ICE3 transfer and conjugation genes was induced by quorum sensing. Quorum sensing activated expression of rdfS, and in turn RdfS stimulated transcription of both rdfG and rdfM. Therefore, RdfS acts as a āmaster controllerā of ICE3 assembly and excision. The dependence of all three excisive reactions on RdfS ensures that ICE3 excision occurs via a stepwise sequence of recombination events that avoids splitting the chromosome into a non-viable configuration. These discoveries expose a surprisingly simple control system guiding molecular assembly of these novel and complex mobile genetic elements and highlight the diverse and critical functions of excisionase proteins in control of horizontal gene transfer
Biomarker candidates of neurodegeneration in Parkinsonās disease for the evaluation of disease-modifying therapeutics
Reliable biomarkers that can be used for early diagnosis and tracking disease progression are the cornerstone of the development of disease-modifying treatments for Parkinsonās disease (PD). The German Society of Experimental and Clinical Neurotherapeutics (GESENT) has convened a Working Group to review the current status of proposed biomarkers of neurodegeneration according to the following criteria and to develop a consensus statement on biomarker candidates for evaluation of disease-modifying therapeutics in PD. The criteria proposed are that the biomarker should be linked to fundamental features of PD neuropathology and mechanisms underlying neurodegeneration in PD, should be correlated to disease progression assessed by clinical rating scales, should monitor the actual disease status, should be pre-clinically validated, and confirmed by at least two independent studies conducted by qualified investigators with the results published in peer-reviewed journals. To date, available data have not yet revealed one reliable biomarker to detect early neurodegeneration in PD and to detect and monitor effects of drug candidates on the disease process, but some promising biomarker candidates, such as antibodies against neuromelanin, pathological forms of Ī±-synuclein, DJ-1, and patterns of gene expression, metabolomic and protein profiling exist. Almost all of the biomarker candidates were not investigated in relation to effects of treatment, validated in experimental models of PD and confirmed in independent studies
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