302 research outputs found

    Intratumoral patterns of clonal evolution in gliomas

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    Few studies have explored the patterns of clonal evolution in gliomas. Here, we investigate the cytogenetic patterns of intratumoral clonal evolution of gliomas and their impact on tumor histopathology and patient survival. Cytogenetic analysis of 90 gliomas was performed in individual tumor cells (>200 cells/tumor) using multicolor (N = 16 probes) interphase-FISH. Overall, chromosome gains were more frequent than chromosome losses. Gains of chromosome 7 and/or EGFR amplification were detected in 91% of the cases, whereas del(9p21) (77%) and del(10q23) (78%) were the most frequent chromosome losses. Virtually, all cases (99%) showed >/=2 tumor cell clones, with higher numbers among high- versus low-grade gliomas (p = 0.001). Nine different cytogenetic patterns were found in the ancestral tumor clones. In most gliomas, ancestral clones showed abnormalities of chromosome 7, 9p, and/or 10q and cytogenetic evolution consisted of acquisition of additional abnormalities followed by tetraploidization. Conversely, early tetraploidization was associated with low-grade astrocytomas-2/3 pilocytic and 3/6 grade II diffuse astrocytomas-and combined loss of 1p36/19q13 with oligodendrogliomas, respectively; both aberrations were associated with a better patient outcome (p = 0.03). Overall, our results support the existence of different pathways of intratumoral evolution in gliomas

    Amplified and Homozygously Deleted Genes in Glioblastoma: Impact on Gene Expression Levels

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    BACKGROUND: Glioblastoma multiforme (GBM) displays multiple amplicons and homozygous deletions that involve relevant pathogenic genes and other genes whose role remains unknown. METHODOLOGY: Single-nucleotide polymorphism (SNP)-arrays were used to determine the frequency of recurrent amplicons and homozygous deletions in GBM (n = 46), and to evaluate the impact of copy number alterations (CNA) on mRNA levels of the genes involved. PRINCIPAL FINDINGS: Recurrent amplicons were detected for chromosomes 7 (50%), 12 (22%), 1 (11%), 4 (9%), 11 (4%), and 17 (4%), whereas homozygous deletions involved chromosomes 9p21 (52%) and 10q (22%). Most genes that displayed a high correlation between DNA CNA and mRNA levels were coded in the amplified chromosomes. For some amplicons the impact of DNA CNA on mRNA expression was restricted to a single gene (e.g., EGFR at 7p11.2), while for others it involved multiple genes (e.g., 11 and 5 genes at 12q14.1-q15 and 4q12, respectively). Despite homozygous del(9p21) and del(10q23.31) included multiple genes, association between these DNA CNA and RNA expression was restricted to the MTAP gene. CONCLUSIONS: Overall, our results showed a high frequency of amplicons and homozygous deletions in GBM with variable impact on the expression of the genes involved, and they contributed to the identification of other potentially relevant genes

    Reusable photocatalytic optical fibers for underground, deep-sea, and turbid water remediation

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    An approach for underground, deep, and turbid water remediation is presented based on optical fibers with a photocatalytic coating. Thus, photocatalytic TiO2 P25 nanoparticles immobilized in a poly(vinylidene difluoride) (PVDF) matrix are coated on polymeric optical fibers (POFs) and the photocatalytic performance of the system is assessed under artificial sunlight. To the best of our knowledge, poly(methyl methacrylate)-POF coated with TiO2/PVDF and the reusability of any type of POF for photocatalytic applications are not previously reported. The photocatalytic efficiency of the hybrid material in the degradation of ciprofloxacin (CIP) and its reusability are evaluated here. It is shown that 50 w/w% of TiO2 P25 achieves a degradation of 95% after 72 h under artificial sunlight and a reusability of three times leads to a loss of activity inferior to 11%. The efficient removal of ciprofloxacin and the stability of the POF coated with TiO2 P25 successfully demonstrate its suitability in the degradation of pollutants with potential application in regions with low light illumination, as in underground and deep water.Peer ReviewedPostprint (published version

    Novel Role for the AnxA1-Fpr2/ALX Signaling Axis as a Key Regulator of Platelet Function to Promote Resolution of Inflammation

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    Background: Ischemia reperfusion injury (I/RI) is a common complication of cardiovascular diseases. Resolution of detrimental I/RI-generated prothrombotic and proinflammatory responses is essential to restore homeostasis. Platelets play a crucial part in the integration of thrombosis and inflammation. Their role as participants in the resolution of thromboinflammation is underappreciated; therefore we used pharmacological and genetic approaches, coupled with murine and clinical samples, to uncover key concepts underlying this role. Methods: Middle cerebral artery occlusion with reperfusion was performed in wild-type or annexin A1 (AnxA1) knockout (AnxA1-/-) mice. Fluorescence intravital microscopy was used to visualize cellular trafficking and to monitor light/dye-induced thrombosis. The mice were treated with vehicle, AnxA1 (3.3 mg/kg), WRW4 (1.8 mg/kg), or all 3, and the effect of AnxA1 was determined in vivo and in vitro. Results: Intravital microscopy revealed heightened platelet adherence and aggregate formation post I/RI, which were further exacerbated in AnxA1-/- mice. AnxA1 administration regulated platelet function directly (eg, via reducing thromboxane B2 and modulating phosphatidylserine expression) to promote cerebral protection post-I/RI and act as an effective preventative strategy for stroke by reducing platelet activation, aggregate formation, and cerebral thrombosis, a prerequisite for ischemic stroke. To translate these findings into a clinical setting, we show that AnxA1 plasma levels are reduced in human and murine stroke and that AnxA1 is able to act on human platelets, suppressing classic thrombin-induced inside-out signaling events (eg, Akt activation, intracellular calcium release, and Ras-associated protein 1 [Rap1] expression) to decrease IIbβ3 activation without altering its surface expression. AnxA1 also selectively modifies cell surface determinants (eg, phosphatidylserine) to promote platelet phagocytosis by neutrophils, thereby driving active resolution. (n=5-13 mice/group or 7-10 humans/group.) Conclusions: AnxA1 affords protection by altering the platelet phenotype in cerebral I/RI from propathogenic to regulatory and reducing the propensity for platelets to aggregate and cause thrombosis by affecting integrin (IIbβ3) activation, a previously unknown phenomenon. Thus, our data reveal a novel multifaceted role for AnxA1 to act both as a therapeutic and a prophylactic drug via its ability to promote endogenous proresolving, antithromboinflammatory circuits in cerebral I/RI. Collectively, these results further advance our knowledge and understanding in the field of platelet and resolution biology.Fil: Senchenkova, Elena Y.. State University of Louisiana; Estados UnidosFil: Ansari, Junaid. State University of Louisiana; Estados UnidosFil: Becker, Felix. University Hospital Muenster; AlemaniaFil: Vital, Shantel A.. State University of Louisiana; Estados UnidosFil: Al-Yafeai, Zaki. State University of Louisiana; Estados UnidosFil: Sparkenbaugh, Erica M.. University North Carolina Chapel Hill; Estados UnidosFil: Pawlinski, Rafal. University North Carolina Chapel Hill; Estados UnidosFil: Stokes, Karen Y.. State University of Louisiana; Estados UnidosFil: Carroll, Jennifer L.. State University of Louisiana; Estados UnidosFil: Dragoi, Ana-Maria. State University of Louisiana; Estados UnidosFil: Qin, Cheng Xue. Baker Heart And Diabetes Institute; AustraliaFil: Ritchie, Rebecca H.. Baker Heart And Diabetes Institute; AustraliaFil: Sun, Hai. University Hospital Muenster; AlemaniaFil: Cuellar-Saenz, Hugo H.. State University of Louisiana; Estados UnidosFil: Rubinstein Guichon, Mara Roxana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentina. Columbia University; Estados UnidosFil: Han, Yiping W.. Columbia University; Estados UnidosFil: Orr, A. Wayne. University Hospital Muenster; AlemaniaFil: Perretti, Mauro. Queen Mary University Of London; Reino UnidoFil: Granger, D. Neil. State University of Louisiana; Estados UnidosFil: Gavins, Felicity N.E.. State University of Louisiana; Estados Unido

    Envenomation by Micrurus coral snakes in the Brazilian Amazon region: report of two cases

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    Two cases of proven coral snake bites were reported in Belém, Pará State, Brazil. The first case was a severe one caused by Micrurus surinamensis. The patient required mechanical ventilation due to acute respiratory failure. The second case showed just mild signs of envenomation caused by Micrurus filiformis. Both patients received specific Micrurus antivenom and were discharged without further complications. Coral snake bites are scarcely reported in the Amazon region and there is a broad spectrum of clinical manifestations, varying from extremely mild to those which may rapidly lead to death if the patient is not treated as soon as possible
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