114 research outputs found

    The violent youth of bright and massive cluster galaxies and their maturation over 7 billion years

    Get PDF
    In this study, we investigate the formation and evolution mechanisms of the brightest cluster galaxies (BCGs) over cosmic time. At high redshift (z ∼ 0.9), we selected BCGs and most massive cluster galaxies (MMCGs) from the Cl1604 supercluster and compared them to low-redshift (z ∼ 0.1) counterparts drawn from the MCXC meta-catalogue, supplemented by Sloan Digital Sky Survey imaging and spectroscopy. We observed striking differences in the morphological, colour, spectral, and stellar mass properties of the BCGs/MMCGs in the two samples. High-redshift BCGs/MMCGs were, in many cases, star-forming, late-type galaxies, with blue broad-band colours, properties largely absent amongst the low-redshift BCGs/MMCGs. The stellar mass of BCGs was found to increase by an average factor of 2.51 ± 0.71 from z ∼ 0.9 to z ∼ 0.1. Through this and other comparisons, we conclude that a combination of major merging (mainly wet or mixed) and in situ star formation are the main mechanisms which build stellar mass in BCGs/MMCGs. The stellar mass growth of the BCGs/MMCGs also appears to grow in lockstep with both the stellar baryonic and total mass of the cluster. Additionally, BCGs/MMCGs were found to grow in size, on average, a factor of ∼3, while their average Sérsic index increased by ∼0.45 from z ∼ 0.9 to z ∼ 0.1, also supporting a scenario involving major merging, though some adiabatic expansion is required. These observational results are compared to both models and simulations to further explore the implications on processes which shape and evolve BCGs/MMCGs over the past ∼7 Gyr

    Peripheral T-lymphocytes express WNT7A and its restoration in leukemia-derived lymphoblasts inhibits cell proliferation

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>WNT7a, a member of the Wnt ligand family implicated in several developmental processes, has also been reported to be dysregulated in some types of tumors; however, its function and implication in oncogenesis is poorly understood. Moreover, the expression of this gene and the role that it plays in the biology of blood cells remains unclear. In addition to determining the expression of the <it>WNT7A </it>gene in blood cells, in leukemia-derived cell lines, and in samples of patients with leukemia, the aim of this study was to seek the effect of this gene in proliferation.</p> <p>Methods</p> <p>We analyzed peripheral blood mononuclear cells, sorted CD3 and CD19 cells, four leukemia-derived cell lines, and blood samples from 14 patients with Acute lymphoblastic leukemia (ALL), and 19 clinically healthy subjects. Reverse transcription followed by quantitative Real-time Polymerase chain reaction (qRT-PCR) analysis were performed to determine relative <it>WNT7A </it>expression. Restoration of WNT7a was done employing a lentiviral system and by using a recombinant human protein. Cell proliferation was measured by addition of WST-1 to cell cultures.</p> <p>Results</p> <p>WNT7a is mainly produced by CD3 T-lymphocytes, its expression decreases upon activation, and it is severely reduced in leukemia-derived cell lines, as well as in the blood samples of patients with ALL when compared with healthy controls (<it>p </it>≤0.001). By restoring <it>WNT7A </it>expression in leukemia-derived cells, we were able to demonstrate that WNT7a inhibits cell growth. A similar effect was observed when a recombinant human WNT7a protein was used. Interestingly, restoration of <it>WNT7A </it>expression in Jurkat cells did not activate the canonical Wnt/β-catenin pathway.</p> <p>Conclusions</p> <p>To our knowledge, this is the first report evidencing quantitatively decreased <it>WNT7A </it>levels in leukemia-derived cells and that <it>WNT7A </it>restoration in T-lymphocytes inhibits cell proliferation. In addition, our results also support the possible function of <it>WNT7A </it>as a tumor suppressor gene as well as a therapeutic tool.</p

    Global Transcriptome and Deletome Profiles of Yeast Exposed to Transition Metals

    Get PDF
    A variety of pathologies are associated with exposure to supraphysiological concentrations of essential metals and to non-essential metals and metalloids. The molecular mechanisms linking metal exposure to human pathologies have not been clearly defined. To address these gaps in our understanding of the molecular biology of transition metals, the genomic effects of exposure to Group IB (copper, silver), IIB (zinc, cadmium, mercury), VIA (chromium), and VB (arsenic) elements on the yeast Saccharomyces cerevisiae were examined. Two comprehensive sets of metal-responsive genomic profiles were generated following exposure to equi-toxic concentrations of metal: one that provides information on the transcriptional changes associated with metal exposure (transcriptome), and a second that provides information on the relationship between the expression of ∼4,700 non-essential genes and sensitivity to metal exposure (deletome). Approximately 22% of the genome was affected by exposure to at least one metal. Principal component and cluster analyses suggest that the chemical properties of the metal are major determinants in defining the expression profile. Furthermore, cells may have developed common or convergent regulatory mechanisms to accommodate metal exposure. The transcriptome and deletome had 22 genes in common, however, comparison between Gene Ontology biological processes for the two gene sets revealed that metal stress adaptation and detoxification categories were commonly enriched. Analysis of the transcriptome and deletome identified several evolutionarily conserved, signal transduction pathways that may be involved in regulating the responses to metal exposure. In this study, we identified genes and cognate signaling pathways that respond to exposure to essential and non-essential metals. In addition, genes that are essential for survival in the presence of these metals were identified. This information will contribute to our understanding of the molecular mechanism by which organisms respond to metal stress, and could lead to an understanding of the connection between environmental stress and signal transduction pathways

    Safety and efficacy of Favipiravir in moderate to severe SARS-CoV-2 pneumonia

    Get PDF
    Background: We examined the safety and efficacy of a treatment protocol containing Favipiravir for the treatment of SARS-CoV-2. Methods: We did a multicenter randomized open-labeled clinical trial on moderate to severe cases infections of SARS-CoV-2. Patients with typical ground glass appearance on chest computerized tomography scan (CT scan) and oxygen saturation (SpO2) of less than 93 were enrolled. They were randomly allocated into Favipiravir (1.6 gr loading, 1.8 gr daily) and Lopinavir/Ritonavir (800/200 mg daily) treatment regimens in addition to standard care. In-hospital mortality, ICU admission, intubation, time to clinical recovery, changes in daily SpO2 after 5 min discontinuation of supplemental oxygen, and length of hospital stay were quantified and compared in the two groups. Results: 380 patients were randomly allocated into Favipiravir (1 9 3) and Lopinavir/Ritonavir (1 8 7) groups in 13 centers. The number of deaths, intubations, and ICU admissions were not significantly different (26, 27, 31 and 21, 17, 25 respectively). Mean hospital stay was also not different (7.9 days SD = 6 in the Favipiravir and 8.1 SD = 6.5 days in Lopinavir/Ritonavir groups) (p = 0.61). Time to clinical recovery in the Favipiravir group was similar to Lopinavir/Ritonavir group (HR = 0.94, 95% CI 0.75 � 1.17) and likewise the changes in the daily SpO2 after discontinuation of supplemental oxygen (p = 0.46) Conclusion: Adding Favipiravir to the treatment protocol did not reduce the number of ICU admissions or intubations or In-hospital mortality compared to Lopinavir/Ritonavir regimen. It also did not shorten time to clinical recovery and length of hospital stay. © 2021 Elsevier B.V

    Nano structure black cobalt coating for solar absorber

    No full text
    Abstract: Black cobalt thin films on bright nickel plated on brass and copper substrates were prepared by the electrodeposition method. The Influence of substrate metal and heat treatment process on the surface morphology and absorptance of samples was investigated. Surface morphology and spectral reflectance of films were measured by scanning electron microscopy and spectrophotometer in the visible and near-IR region of spectrum respectively. Scanning electron microscopy images showed that the black cobalt films have porous structure. The absorptance of prepared films is over than 90%, which makes them suitable for using as solar absorbers

    PD-1 Expression on CD8+CD28- T cells within inflammatory synovium is associated with Relapse: A cohort of Rheumatoid Arthritis

    No full text
    Defect in T lymphocyte homeostasis could implicate initiation and development of rheumatoid arthritis (RA). Since PD-1 plays a key role in the regulation of T lymphocytes, its expression pattern in various CD8+ T cell subsets could be so effective in RA pathogenesis. Here, we investigated the expression of PD-1 and CXCR3 on CD8+CD28- T cells in association with the IFN-γ levels in patients with RA. A total of 42 RA patients, including 10 newly-diagnosed (ND) and 32 relapsed (RL) cases and also 20 healthy donors were enrolled. Phenotypic characterization of CD8+ T cells derived from peripheral blood (PB) and synovial fluid (SF) was performed by flow cytometry. The plasma and SF IFN-γ levels were also assessed by ELISA. The frequency of CD8+CD28- T cells showed no significant differences between patients and controls while its higher levels were observed in PB, versus SF of RL patients. Relapsed patients also showed higher CXCR3 and especially PD-1 expression on their CD8+CD28- T cells. The IFN-γ concentration was elevated in SF of ND patients while its plasma level was significantly lower in RL subgroup than controls. Although PD-1 could induce immune suppression in effector T cells, it is upregulated during inflammation and its overexpression on CD8+CD28- T cells within inflammatory synovium is associated with severity of disease in our cohort of RA patients. © 2020 European Federation of Immunological Societie

    Simultaneous disruption of circulating miR-21 and cytotoxic T lymphocytes (CTLs): Prospective diagnostic and prognostic markers for esophageal squamous cell carcinoma (ESCC)

    No full text
    Background: Esophageal squamous cell carcinoma (ESCC) as the most prominent type of esophageal cancer (EC) in developing countries encompasses a substantial contribution of cancer-related mortalities and morbidities. Cytotoxic T lymphocytes (CTLs) are the major subset of effector T cells against cancer. However, the microRNAs involved in the development and regulation of CTLs could be disrupted in cancers such as EC. Methods: Here, we evaluated the population of IL-10, TGF-β, IFN-γ, and IL-17a-producing CD3+CD8+ T cells, their association with the circulating levels of miR-21 and miR-29b, and their diagnostic and/or prognostic (after 160 weeks of follow-up) utilities in 34 ESCC patients (12 newly diagnosed: ND, 24 under-treatment: UT) and 34 matched healthy donors. Results: The population of IL-10 and TGF-β-producing CTLs (CD8+ Tregs) were considerably expanded, in addition to the overexpression of miR-21 in both groups (ND and UT) of ESCC patients, while the frequency of Tc17 and CD8+ Treg cells increased only in UT patients. The expression means of TGF-β and IL-10 in CTLs were considered to be excellent biomarkers (1 � area under the curve: AUC �0.9) in distinguishing ESCC patients and associated subgroups from healthy subjects. Moreover, the lower expressions of TGF-β, IL-17a, IL-10, and IFN-γ in CTLs were associated with ESCC better prognosis. Conclusions: The association between the impaired function of CD3+ CD8+ T cell subsets and miR-21 expression could be introduced as novel therapeutic targets and powerful diagnostic and prognostic markers for ESCC. © 2021 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC

    Potassium peroxodisulfate: A convenient oxidizing agent for aromatization of 1,4-dihydropyridines

    No full text
    727-728A series of 13 different 4-substituted 2,6-dimethyl-3,5-diethoxycarbonyl)- 1,4-dihydropyridines have been oxidized to pyridine derivatives by potassium peroxodisulfate in dry and wet acetonitrile solution at reflux condition. Formation of two kinds of products has been observed depending on the type of 4-substituent. Addition of water affects only the rate of oxidation

    Evaluation of specificity and sensitivity of gastric aspirate shake test to predict surfactant deficiency in Iranian premature infants

    No full text
    Introduction Respiratory failure secondary to pulmonary surfactant deficiency is an important cause of severe respiratory distress in term and preterm infants. The aim of this study was to evaluate the specificity and sensitivity of gastric aspirate shake test (GAST) to predict surfactant deficiency in newly born premature infants in Arash Hospital (Iran) during 2012-13. Methods In this case-control study, the case group comprised 69 premature infants (gestational age < 37 weeks) who were admitted to the neonatal intensive care unit due to respiratory distress. The control group included 50 healthy infants.GAST test was done. The subjects were finally categorized as healthy or surfactant-deficient based on clinical and radiological assessments. Results Using statistical methods the sensitivity, specificity, and positive and negative predictive values of GAST were 60, 75, 15, and 52, respectively. There was a significant difference between respiratory distress syndrome (RDS) scores and receiving surfactant in neonates with gestational age below 34 weeks. Moreover, there were significant differences between GAST results and both radiological findings of RDS and receiving oxygen in premature infants (gestational age < 34 weeks). Negative GAST results were more prevalent in neonates who were born to mothers with hypothyroidism, preeclampsia, diabetes mellitus, and premature rupture of membranes. However, this difference was not significant. Conclusion According to our findings, the application of GAST on gastric aspirate secretions is not a useful method to predict surfactant deficiency. Therefore, decisions for RDS management must be made based on clinical and radiological findings. © 2015 International Society for the Study of Hypertension in Pregnancy Published by Elsevier B.V. All rights reserved
    corecore