336 research outputs found
Competition controls the rate of transition between the peripheral pools of CD4+CD25− and CD4+CD25+ T cells
Recent reports have hinted that it is possible to regenerate CD4+CD25+ regulatory T cells (Treg) from CD4+CD25− cells, a phenomenon termed conversion. We evaluated the relative contribution of this process to the Treg pool by transferring purified populations of CD4+ T cells into T cell-deficient mice. We report that conversion of CD25− cells into the CD4+CD25+Treg pool is minor if other bona fide CD25+ Tregs are present. Moreover, in the same hosts, the loss of CD25 expression by a population of Tregs also decreases in the presence of co-injected CD4+CD25− cells. Thus, the rate of exchange between CD25− and CD25+ T-cell populations is determined by the presence or absence of T-cell competitors. Our results attest for the role of competition in the contribution of different T-cell subsets for the regeneration of the peripheral CD4+ T-cell pool during lymphopeni
Evaluation of antimicrobial resistance of different phylogroups of Escherichia coli isolates from feces of breeding and laying hens
Animal and food sources are seen as a potential transmission pathway of multi-drug resistance (MDR) micro-organisms to humans. Escherichia. coli is frequently used as an indicator of fecal contamination in the food industry and known as a reservoir of antimicrobial resistance genes (ARGs). Microbial contamination as a major outcome for the poultry and egg industry and is a serious public health problem. In the present study we performed the quantification of β-glucoronidase positive E. coli in 60 fecal samples of breeding and laying hens collected in Portugal in 2019. Phylogenetic and pathotypic characterization, antimicrobial susceptibility, and detection of resistant extended-spectrum β-lactamase (ESBL) genes were assessed. The phylogenetic and pathogenic characterization and detection of ESBL genes were assessed by real-time PCR and antimicrobial susceptibility was evaluated using the disk diffusion method. Overall, E. coli quantification was 6.03 log CFU/g in breeding hens and 6.02 log CFU/g in laying hens. The most frequent phylogroups were B1. None of the isolates was classified as diarrheagenic E. coli (DEC). In total, 57% of the isolates showed MDR and 3.8% were positive for ESBL. Our study highlights that consumers may be exposed to MDR E. coli, presenting a major hazard to food safety and a risk to public health.This research received no external funding.info:eu-repo/semantics/publishedVersio
The Phoenix Deep Survey: Optical and near infrared imaging catalogs
The Phoenix Deep Survey is a multi-wavelength galaxy survey based on deep 1.4
GHz radio imaging (Hopkins et al., 2003). The primary goal of this survey is to
investigate the properties of star formation in galaxies and to trace the
evolution in those properties to a redshift z=1, covering a significant
fraction of the age of the Universe. By compiling a sample of star-forming
galaxies based on selection at radio wavelengths we eliminate possible biases
due to dust obscuration, a significant issue when selecting objects at optical
and ultraviolet wavelengths. In this paper, we present the catalogs and results
of deep optical (UBVRI) and near-infrared (Ks) imaging of the deepest region of
the existing decimetric radio imaging. The observations and data-processing are
summarised and the construction of the optical source catalogs described,
together with the details of the identification of candidate optical
counterparts to the radio catalogs. Based on our UBVRIKs imaging, photometric
redshift estimates for the optical counterparts to the radio detections are
explored.Comment: 56 pages inc. 16 page table; November issue of ApJ
Molecular characterization of short-term primary cultures and comparison with corresponding tumor tissue of Brazilian glioblastoma patients
Background: Glioblastoma, the most frequent and malignant adult brain tumor, has been extensively studied. However, there is no effective treatment, and to overcome this challenging scenario, it is essential to improve preclinical biological models. This study aimed to molecularly characterize short-term glioblastoma primary cultures and to compare them with patient tumor profiles.
Methods: Glioblastoma cell lines were established from Barretos Cancer Hospital patients diagnosed with glioblastoma. The cells were cultured with DMEM (+)10% FBS (+)1% PS and were molecularly characterized using array CGH (aCGH), next-generation and Sanger sequencing.
Results: We established four short-term glioblastoma cultures and we found that the primary cells exhibited a diversity of chromosomal aberrations, with gain of chromosome 7 and loss of chromosomes 10, 13 and 17p being the most frequent alterations. Mutation profiling showed that hotspot TERT promoter mutations were present in 3/4 cases, followed by mutations in TP53 (2/4) and in the RB1, BRAF and PTEN (1/4) genes. A similar chromosomal and mutation pattern was observed in all short-term cultures and matched frozen tumors.
Conclusions: Herein, short-term glioblastoma primary cultures were successfully characterized and had genetic make-ups that were similar to those of patient tumors, suggesting that short-term primary cultures are suitable in vitro models for studies of glioblastoma biology.Universal/CNPq (475358/2011-2-Reis RM), FAPESP (2012/19590-0-Reis RM) and the MCTI/CNPq No. 73/2013 (Reis RM) grants. Bidinotto LT was a recipient of the FAPESP fellowship (2011/08523-7 and 2012/08287-4)info:eu-repo/semantics/publishedVersio
Growth of (Perylene)(2) [PD(MNT)(2)] crystals
The conditions for [pd(mnt)(2)]he growth of [pd(mnt)(2)]Perylene) [pd(mnt)(2)] [Pd(mnt) [pd(mnt)(2)]] crystals either by chemical oxidation and electrochemical routes are [pd(mnt)(2)]escribed. The electrocrystallisation is limited by close [pd(mnt)(2)]roximity of [pd(mnt)(2)]he oxidation [pd(mnt)(2)]otentials of [pd(mnt)(2)]he [pd(mnt)(2)]erylene [pd(mnt)(2)]onor and [Pd(mnt) [pd(mnt)(2)]] - anion, and [pd(mnt)(2)]epending on [pd(mnt)(2)]he experimental conditions [pd(mnt)(2)]ifferent [pd(mnt)(2)]orphologies can be obtained. [pd(mnt)(2)]Per) [pd(mnt)(2)] [Pd(mnt) [pd(mnt)(2)]] crystals obtained by elecrocrystallisation were found [pd(mnt)(2)]o be [pd(mnt)(2)]ainly of [pd(mnt)(2)]he β-polymorph with [pd(mnt)(2)]roperties comparable [pd(mnt)(2)]o [pd(mnt)(2)]he Cu, Ni and Pt analogues [pd(mnt)(2)]reviously [pd(mnt)(2)]escribed at variance with [pd(mnt)(2)]hose obtained by chemical oxidation which are [pd(mnt)(2)]ainly of [pd(mnt)(2)]he α-polymorph
Caracterização e análise financeira do processo de extração de óleo de polpa de pequi no Cerrado brasileiro.
Resumo ? O presente estudo realizou caracterização e análise financeira do processo de extração de óleo de polpa de pequi, uma atividade secular de populações tradicionais do Território da Cidadania Alto Rio Pardo (MG). O estudo considerou os custos de insumos e de trabalho das sete etapas do processo produtivo, além da consideração dos riscos de contaminação de ferro no cozimento e na despolpa, mas desconsiderou a comparação entre o lucro obtido por hora de trabalho e o valor da diária de trabalho local, afinal, as relações capitalistas de produção não estão plenamente inseridas na realidade local. Entre as sete etapas analisadas, três apresentaram variações, sendo elas, a colheita (duas variáveis), cozimento (seis variáveis) e despolpa (quatro variáveis), resultando em 48 cenários hipotéticos de processos de extração. Entre eles, quatro combinações são recomendadas ao contexto de vida das famílias rurais locais (colheita na unidade de produção; cozimento no tacho de cobre ou na panela de alumínio; despolpa no engenho manual ou no engenho a motor) e uma combinação é mais adequada ao contexto dos processos agroindustriais coletivos presentes na região (colheita na unidade de produção; cozimento na panela de inox; despolpa no engenho a motor)
Domain wall brane in squared curvature gravity
We suggest a thick braneworld model in the squared curvature gravity theory.
Despite the appearance of higher order derivatives, the localization of gravity
and various bulk matter fields is shown to be possible. The existence of the
normalizable gravitational zero mode indicates that our four-dimensional
gravity is reproduced. In order to localize the chiral fermions on the brane,
two types of coupling between the fermions and the brane forming scalar is
introduced. The first coupling leads us to a Schr\"odinger equation with a
volcano potential, and the other a P\"oschl-Teller potential. In both cases,
the zero mode exists only for the left-hand fermions. Several massive KK states
of the fermions can be trapped on the brane, either as resonant states or as
bound states.Comment: 18 pages, 5 figures and 1 table, references added, improved version
to be published in JHE
Complete blood count parameters as biomarkers of retinopathy of prematurity: a Portuguese multicenter study
Purpose: To evaluate complete blood count (CBC) parameters in the first week of life as predictive biomarkers for the development of retinopathy of prematurity (ROP).
Methods: Multicenter, prospective, observational study of a cohort of preterm infants born with gestational age (GA) < 32 weeks or birth weight < 1500 g in eight Portuguese neonatal intensive care units. All demographic, clinical, and laboratory data from the first week of life were collected. Univariate logistic regression was used to assess risk factors for ROP and then multivariate regression was performed.
Results: A total of 455 infants were included in the study. The median GA was 29.6 weeks, and the median birth weight was 1295 g. One hundred and seventy-two infants (37.8%) developed ROP. Median values of erythrocytes (p < 0.001), hemoglobin (p < 0.001), hematocrit (p < 0.001), mean corpuscular hemoglobin concentration (p < 0.001), lymphocytes (p = 0.035), and platelets (p = 0.003) of the group of infants diagnosed with ROP any stage were lower than those without ROP. Mean corpuscular volume (MCV) (p = 0.044), red blood cell distribution width (RDW) (p < 0.001), erythroblasts (p < 0.001), neutrophils (p = 0.030), neutrophils-lymphocytes ratio (p = 0.028), and basophils (p = 0.003) were higher in the ROP group. Higher values of MCV, erythroblasts, and basophils remained significantly associated with ROP after multivariate regression.
Conclusion: In our cohort, the increase in erythroblasts, MCV, and basophils in the first week of life was significantly and independently associated with the development of ROP. These CBC parameters may be early predictive biomarkers for ROP.info:eu-repo/semantics/publishedVersio
Predictive and therapeutic implications of a novel PLCγ1/SHP2-driven mechanism of cetuximab resistance in metastatic colorectal cancer
© 2022 The Authors; Published by the American Association for Cancer Research. This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 International (CC BY-NC-ND)Purpose: Cetuximab is an EGFR-targeted therapy approved for the treatment of RAS wild-type (WT) metastatic colorectal cancer (mCRC). However, about 60% of these patients show innate resistance to cetuximab. To increase cetuximab efficacy, it is crucial to successfully identify responder patients, as well as to develop new therapeutic approaches to overcome cetuximab resistance.
Experimental design: We evaluated the value of EGFR effector phospholipase C gamma 1 (PLCγ1) in predicting cetuximab responses, by analyzing progression-free survival (PFS) of a multicentric retrospective cohort of 94 treated patients with mCRC (log-rank test and Cox regression model). Furthermore, we used in vitro and zebrafish xenotransplant models to identify and target the mechanism behind PLCγ1-mediated resistance to cetuximab.
Results: In this study, levels of PLCγ1 were found increased in RAS WT tumors and were able to predict cetuximab responses in clinical samples and in vitro and in vivo models. Mechanistically, PLCγ1 expression was found to bypass cetuximab-dependent EGFR inhibition by activating ERK and AKT pathways. This novel resistance mechanism involves a noncatalytic role of PLCγ1 SH2 tandem domains in the propagation of downstream signaling via SH2-containing protein tyrosine phosphatase 2 (SHP2). Accordingly, SHP2 inhibition sensitizes PLCγ1-resistant cells to cetuximab.
Conclusions: Our discoveries reveal the potential of PLCγ1 as a predictive biomarker for cetuximab responses and suggest an alternative therapeutic approach to circumvent PLCγ1-mediated resistance to cetuximab in patients with RAS WT mCRC. In this way, this work contributes to the development of novel strategies in the medical management and treatment of patients with mCRC.M. Martins' research was supported by Liga Portuguesa Contra o Cancro (LPCC): Terry Fox Fundation; Investigador FCT- Fundação para a Ciência e Technologia (IF/00409/2014) and IMM Bridge grant; RC-D research was supported by Fundação para a Ciência e Technologia (SFRH/BD/139138/2018). A. Fernandes was supported by LPCC-IMM BIOBANK; R. Fior was supported by Champalimaud Foundation and L. Costa was supported by Merck Serono.info:eu-repo/semantics/publishedVersio
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