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1.
Blood Adv ; 6(5): 1525-1535, 2022 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-34507354

RESUMEN

Individual comorbidities have distinct contributions to nonrelapse mortality (NRM) following allogeneic hematopoietic cell transplantation (allo-HCT). We studied the impact of comorbidities individually and in combination in a single-center cohort of 573 adult patients who underwent CD34-selected allo-HCT following myeloablative conditioning. Pulmonary disease, moderate to severe hepatic comorbidity, cardiac disease of any type, and renal dysfunction were associated with increased NRM in multivariable Cox regression models. A Simplified Comorbidity Index (SCI) composed of the 4 comorbidities predictive of NRM, as well as age >60 years, stratified patients into 5 groups with a stepwise increase in NRM. NRM rates ranged from 11.4% to 49.9% by stratum, with adjusted hazard ratios of 1.84, 2.59, 3.57, and 5.38. The SCI was also applicable in an external cohort of 230 patients who underwent allo-HCT with unmanipulated grafts following intermediate-intensity conditioning. The area under the receiver operating characteristic curve (AUC) of the SCI for 1-year NRM was 70.3 and 72.0 over the development and external-validation cohorts, respectively; corresponding AUCs of the Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI) were 61.7 and 65.7. In summary, a small set of comorbidities, aggregated into the SCI, is highly predictive of NRM. The new index stratifies patients into distinct risk groups, was validated in an external cohort, and provides higher discrimination than does the HCT-CI.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Adulto , Comorbilidad , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Humanos , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Acondicionamiento Pretrasplante , Trasplante Homólogo
2.
J Mol Diagn ; 21(3): 390-407, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30862547

RESUMEN

The quantification of changes in gene copy number is critical to our understanding of tumor biology and for the clinical management of cancer patients. DNA fluorescence in situ hybridization is the gold standard method to detect copy number alterations, but it is limited by the number of genes one can quantify simultaneously. To increase the throughput of this informative technique, a fluorescent bar-code system for the unique labeling of dozens of genes and an automated image analysis algorithm that enabled their simultaneous hybridization for the quantification of gene copy numbers were devised. We demonstrate the reliability of this multiplex approach on normal human lymphocytes, metaphase spreads of transformed cell lines, and cultured circulating tumor cells. It also opens the door to the development of gene panels for more comprehensive analysis of copy number changes in tissue, including the study of heterogeneity and of high-throughput clinical assays that could provide rapid quantification of gene copy numbers in samples with limited cellularity, such as circulating tumor cells.


Asunto(s)
Genómica , Hibridación Fluorescente in Situ/métodos , Algoritmos , Línea Celular Tumoral , Cromosomas Artificiales Bacterianos/genética , Color , Hibridación Genómica Comparativa , Colorantes Fluorescentes/química , Humanos , Sondas Moleculares/química , Reproducibilidad de los Resultados
3.
Clin Podiatr Med Surg ; 34(3): 289-300, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28576189

RESUMEN

Foot and ankle surgeons frequently treat digital deformities of the lesser toes surgically. Arthrodesis of the proximal interphalangeal joint is the workhorse procedure for correction of hammer toe contractures. Fusion of the interphalangeal joint can be fixated with a variety of methods, including K-wire fixation, intramedullary implants, absorbable pins, and screws. Each method of fixation has advantages and disadvantages, such as variations in complication rates, cost, and fusion rates. Further research is necessary to determine the best method of fixation for digital interphalangeal joint fusion."


Asunto(s)
Artrodesis , Deformidades del Pie/cirugía , Articulación del Dedo del Pie/cirugía , Deformidades del Pie/diagnóstico por imagen , Humanos
4.
ACS Appl Mater Interfaces ; 9(10): 8783-8795, 2017 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-28229601

RESUMEN

High magnetizations are desirable for spintronic devices that operate by manipulating electronic states using built-in magnetic fields. However, the magnetic moment in promising dilute magnetic oxide nanocomposites is very low, typically corresponding to only fractions of a Bohr magneton for each dopant atom. In this study, we report a large magnetization formed by ion implantation of Co into amorphous TiO2-δ films, producing an inhomogeneous magnetic moment, with certain regions producing over 2.5 µB per Co, depending on the local dopant concentration. Polarized neutron reflectometry was used to depth-profile the magnetization in the Co:TiO2-δ nanocomposites, thus confirming the pivotal role of the cobalt dopant profile inside the titania layer. X-ray photoemission spectra demonstrate the dominant electronic state of the implanted species is Co0, with a minor fraction of Co2+. The detected magnetizations have seldom been reported before and lie near the upper limit set by Hund's rules for Co0, which is unusual because the transition metal's magnetic moment is usually reduced in a symmetric 3D crystal-field environment. Low-energy positron annihilation lifetime spectroscopy indicates that defect structures within the titania layer are strongly modified by the implanted Co. We propose that a clustering motif is promoted by the affinity of the positively charged implanted species to occupy microvoids native to the amorphous host. This provides a seed for subsequent doping and nucleation of nanoclusters within an unusual local environment.

5.
Nat Commun ; 8: 14344, 2017 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-28181495

RESUMEN

Metastasis-competent circulating tumour cells (CTCs) experience oxidative stress in the bloodstream, but their survival mechanisms are not well defined. Here, comparing single-cell RNA-Seq profiles of CTCs from breast, prostate and lung cancers, we observe consistent induction of ß-globin (HBB), but not its partner α-globin (HBA). The tumour-specific origin of HBB is confirmed by sequence polymorphisms within human xenograft-derived CTCs in mouse models. Increased intracellular reactive oxygen species (ROS) in cultured breast CTCs triggers HBB induction, mediated through the transcriptional regulator KLF4. Depletion of HBB in CTC-derived cultures has minimal effects on primary tumour growth, but it greatly increases apoptosis following ROS exposure, and dramatically reduces CTC-derived lung metastases. These effects are reversed by the anti-oxidant N-Acetyl Cysteine. Conversely, overexpression of HBB is sufficient to suppress intracellular ROS within CTCs. Altogether, these observations suggest that ß-globin is selectively deregulated in cancer cells, mediating a cytoprotective effect during blood-borne metastasis.


Asunto(s)
Regulación Neoplásica de la Expresión Génica , Neoplasias/sangre , Neoplasias/genética , Globinas beta/genética , Animales , Antioxidantes/metabolismo , Apoptosis/genética , Línea Celular Tumoral , Supervivencia Celular/genética , Citoprotección/genética , Humanos , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel/metabolismo , Masculino , Ratones , Neoplasias/patología , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patología , Especies Reactivas de Oxígeno/metabolismo , Estrés Fisiológico , Regulación hacia Arriba/genética , Globinas beta/metabolismo
6.
J Clin Invest ; 126(9): 3219-35, 2016 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-27500490

RESUMEN

Increased expression of zinc finger E-box binding homeobox 1 (ZEB1) is associated with tumor grade and metastasis in lung cancer, likely due to its role as a transcription factor in epithelial-to-mesenchymal transition (EMT). Here, we modeled malignant transformation in human bronchial epithelial cells (HBECs) and determined that EMT and ZEB1 expression are early, critical events in lung cancer pathogenesis. Specific oncogenic mutations in TP53 and KRAS were required for HBECs to engage EMT machinery in response to microenvironmental (serum/TGF-ß) or oncogenetic (MYC) factors. Both TGF-ß- and MYC-induced EMT required ZEB1, but engaged distinct TGF-ß-dependent and vitamin D receptor-dependent (VDR-dependent) pathways, respectively. Functionally, we found that ZEB1 causally promotes malignant progression of HBECs and tumorigenicity, invasion, and metastases in non-small cell lung cancer (NSCLC) lines. Mechanistically, ZEB1 expression in HBECs directly repressed epithelial splicing regulatory protein 1 (ESRP1), leading to increased expression of a mesenchymal splice variant of CD44 and a more invasive phenotype. In addition, ZEB1 expression in early stage IB primary NSCLC correlated with tumor-node-metastasis stage. These findings indicate that ZEB1-induced EMT and associated molecular changes in ESRP1 and CD44 contribute to early pathogenesis and metastatic potential in established lung cancer. Moreover, TGF-ß and VDR signaling and CD44 splicing pathways associated with ZEB1 are potential EMT chemoprevention and therapeutic targets in NSCLC.


Asunto(s)
Transición Epitelial-Mesenquimal , Receptores de Hialuranos/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas de Unión al ARN/metabolismo , Homeobox 1 de Unión a la E-Box con Dedos de Zinc/metabolismo , Animales , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Células Pequeñas/genética , Carcinoma de Células Pequeñas/metabolismo , Línea Celular , Transformación Celular Neoplásica , Femenino , Humanos , Neoplasias Pulmonares/genética , Ratones , Ratones Endogámicos NOD , Ratones SCID , Microcirculación , Invasividad Neoplásica , Metástasis de la Neoplasia , Fenotipo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Receptores de Calcitriol/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Homeobox 1 de Unión a la E-Box con Dedos de Zinc/genética
7.
Clin Cancer Res ; 22(5): 1103-10, 2016 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-26446944

RESUMEN

PURPOSE: The T790M gatekeeper mutation in the EGFR is acquired by some EGFR-mutant non-small cell lung cancers (NSCLC) as they become resistant to selective tyrosine kinase inhibitors (TKI). As third-generation EGFR TKIs that overcome T790M-associated resistance become available, noninvasive approaches to T790M detection will become critical to guide management. EXPERIMENTAL DESIGN: As part of a multi-institutional Stand-Up-To-Cancer collaboration, we performed an exploratory analysis of 40 patients with EGFR-mutant tumors progressing on EGFR TKI therapy. We compared the T790M genotype from tumor biopsies with analysis of simultaneously collected circulating tumor cells (CTC) and circulating tumor DNA (ctDNA). RESULTS: T790M genotypes were successfully obtained in 30 (75%) tumor biopsies, 28 (70%) CTC samples, and 32 (80%) ctDNA samples. The resistance-associated mutation was detected in 47% to 50% of patients using each of the genotyping assays, with concordance among them ranging from 57% to 74%. Although CTC- and ctDNA-based genotyping were each unsuccessful in 20% to 30% of cases, the two assays together enabled genotyping in all patients with an available blood sample, and they identified the T790M mutation in 14 (35%) patients in whom the concurrent biopsy was negative or indeterminate. CONCLUSIONS: Discordant genotypes between tumor biopsy and blood-based analyses may result from technological differences, as well as sampling different tumor cell populations. The use of complementary approaches may provide the most complete assessment of each patient's cancer, which should be validated in predicting response to T790M-targeted inhibitors.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/genética , Resistencia a Antineoplásicos/genética , Receptores ErbB/genética , Inhibidores de Proteínas Quinasas/administración & dosificación , Adulto , Afatinib , Anciano , Anciano de 80 o más Años , Biopsia , Carcinoma de Pulmón de Células no Pequeñas/sangre , Carcinoma de Pulmón de Células no Pequeñas/patología , Receptores ErbB/sangre , Clorhidrato de Erlotinib/administración & dosificación , Femenino , Gefitinib , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Mutación , Células Neoplásicas Circulantes/efectos de los fármacos , Quinazolinas/administración & dosificación
8.
Adv Mater ; 27(9): 1593-9, 2015 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-25640006

RESUMEN

A layer-by-layer gelatin nanocoating is presented for use as a tunable, dual response biomaterial for the capture and release of circulating tumor cells (CTCs) from cancer patient blood. The entire nanocoating can be dissolved from the surface of microfluidic devices through biologically compatible temperature shifts. Alternatively, individual CTCs can be released through locally applied mechanical stress.


Asunto(s)
Separación Celular/instrumentación , Técnicas Analíticas Microfluídicas/instrumentación , Nanoestructuras , Células Neoplásicas Circulantes , Materiales Biocompatibles/química , Biopsia con Aguja Fina , Neoplasias de la Mama/sangre , Neoplasias de la Mama/genética , Línea Celular Tumoral , Separación Celular/métodos , Supervivencia Celular , Diseño de Equipo , Gelatina/química , Humanos , Neoplasias Pulmonares/sangre , Neoplasias Pulmonares/genética , Masculino , Ensayo de Materiales , Técnicas Analíticas Microfluídicas/métodos , Modelos Teóricos , Nanoestructuras/química , Células Neoplásicas Circulantes/química , Neoplasias de la Próstata/sangre , Análisis de la Célula Individual/instrumentación , Análisis de la Célula Individual/métodos , Estrés Mecánico , Temperatura
9.
Proc Natl Acad Sci U S A ; 111(41): 14788-93, 2014 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-25267614

RESUMEN

Aggressive neuroendocrine lung cancers, including small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), represent an understudied tumor subset that accounts for approximately 40,000 new lung cancer cases per year in the United States. No targeted therapy exists for these tumors. We determined that achaete-scute homolog 1 (ASCL1), a transcription factor required for proper development of pulmonary neuroendocrine cells, is essential for the survival of a majority of lung cancers (both SCLC and NSCLC) with neuroendocrine features. By combining whole-genome microarray expression analysis performed on lung cancer cell lines with ChIP-Seq data designed to identify conserved transcriptional targets of ASCL1, we discovered an ASCL1 target 72-gene expression signature that (i) identifies neuroendocrine differentiation in NSCLC cell lines, (ii) is predictive of poor prognosis in resected NSCLC specimens from three datasets, and (iii) represents novel "druggable" targets. Among these druggable targets is B-cell CLL/lymphoma 2, which when pharmacologically inhibited stops ASCL1-dependent tumor growth in vitro and in vivo and represents a proof-of-principle ASCL1 downstream target gene. Analysis of downstream targets of ASCL1 represents an important advance in the development of targeted therapy for the neuroendocrine class of lung cancers, providing a significant step forward in the understanding and therapeutic targeting of the molecular vulnerabilities of neuroendocrine lung cancer.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Linaje de la Célula , Tumores Neuroendocrinos/genética , Oncogenes , Carcinoma Pulmonar de Células Pequeñas/genética , Adenocarcinoma/genética , Adenocarcinoma/patología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/genética , Línea Celular Tumoral , Supervivencia Celular , Inmunoprecipitación de Cromatina , Regulación Neoplásica de la Expresión Génica , Humanos , Inmunohistoquímica , Tumores Neuroendocrinos/patología , Pronóstico , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Carcinoma Pulmonar de Células Pequeñas/patología
10.
Cancer Discov ; 4(11): 1299-309, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25139148

RESUMEN

UNLABELLED: Glioblastoma (GBM) is a highly aggressive brain cancer characterized by local invasion and angiogenic recruitment, yet metastatic dissemination is extremely rare. Here, we adapted a microfluidic device to deplete hematopoietic cells from blood specimens of patients with GBM, uncovering evidence of circulating brain tumor cells (CTC). Staining and scoring criteria for GBM CTCs were first established using orthotopic patient-derived xenografts (PDX), and then applied clinically: CTCs were identified in at least one blood specimen from 13 of 33 patients (39%; 26 of 87 samples). Single GBM CTCs isolated from both patients and mouse PDX models demonstrated enrichment for mesenchymal over neural differentiation markers compared with primary GBMs. Within primary GBMs, RNA in situ hybridization identified a subpopulation of highly migratory mesenchymal tumor cells, and in a rare patient with disseminated GBM, systemic lesions were exclusively mesenchymal. Thus, a mesenchymal subset of GBM cells invades the vasculature and may proliferate outside the brain. SIGNIFICANCE: GBMs are locally invasive within the brain but rarely metastasize to distant organs, exemplifying the debate over "seed" versus "soil." We demonstrate that GBMs shed CTCs with invasive mesenchymal characteristics into the circulation. Rare metastatic GBM lesions are primarily mesenchymal and show additional mutations absent in the primary tumor.


Asunto(s)
Neoplasias Encefálicas/patología , Glioblastoma/patología , Células Neoplásicas Circulantes/patología , Animales , Biomarcadores de Tumor/sangre , Neoplasias Encefálicas/sangre , Transición Epitelial-Mesenquimal , Expresión Génica , Glioblastoma/sangre , Humanos , Ratones
11.
Clin Cancer Res ; 20(15): 4154-66, 2014 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-24907115

RESUMEN

PURPOSE: Lung cancer stem cells (CSC) with elevated aldehyde dehydrogenase (ALDH) activity are self-renewing, clonogenic, and tumorigenic. The purpose of our study is to elucidate the mechanisms by which lung CSCs are regulated. EXPERIMENTAL DESIGN: A genome-wide gene expression analysis was performed to identify genes differentially expressed in the ALDH(+) versus ALDH -: cells. RT-PCR, Western blot analysis, and Aldefluor assay were used to validate identified genes. To explore the function in CSCs, we manipulated their expression followed by colony and tumor formation assays. RESULTS: We identified a subset of genes that were differentially expressed in common in ALDH(+) cells, among which ALDH1A3 was the most upregulated gene in ALDH(+) versus ALDH -: cells. shRNA-mediated knockdown of ALDH1A3 in non-small cell lung cancer (NSCLC) resulted in a dramatic reduction in ALDH activity, clonogenicity, and tumorigenicity, indicating that ALDH1A3 is required for tumorigenic properties. In contrast, overexpression of ALDH1A3 by itself it was not sufficient to increase tumorigenicity. The ALDH(+) cells also expressed more activated STAT3 than ALDH -: cells. Inhibition of STAT3 or its activator EZH2 genetically or pharmacologically diminished the level of ALDH(+) cells and clonogenicity. Unexpectedly, ALDH1A3 was highly expressed in female, never smokers, well-differentiated tumors, or adenocarcinoma. ALDH1A3 low expression was associated with poor overall survival. CONCLUSIONS: Our data show that ALDH1A3 is the predominant ALDH isozyme responsible for ALDH activity and tumorigenicity in most NSCLCs, and that inhibiting either ALDH1A3 or the STAT3 pathway are potential therapeutic strategies to eliminate the ALDH(+) subpopulation in NSCLCs.


Asunto(s)
Aldehído Oxidorreductasas/metabolismo , Biomarcadores de Tumor/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/enzimología , Neoplasias Pulmonares/enzimología , Células Madre Neoplásicas/patología , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Aldehído Oxidorreductasas/antagonistas & inhibidores , Aldehído Oxidorreductasas/genética , Animales , Biomarcadores de Tumor/genética , Western Blotting , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Técnicas para Inmunoenzimas , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Ratones , Ratones Endogámicos NOD , Ratones SCID , Células Madre Neoplásicas/enzimología , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , ARN Interferente Pequeño/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción STAT3/genética , Análisis de Matrices Tisulares , Células Tumorales Cultivadas , Ensayo de Tumor de Célula Madre , Ensayos Antitumor por Modelo de Xenoinjerto
12.
Angew Chem Int Ed Engl ; 53(21): 5322-6, 2014 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-24740816

RESUMEN

Aging in super glassy polymers such as poly(trimethylsilylpropyne) (PTMSP), poly(4-methyl-2-pentyne) (PMP), and polymers with intrinsic microporosity (PIM-1) reduces gas permeabilities and limits their application as gas-separation membranes. While super glassy polymers are initially very porous, and ultra-permeable, they quickly pack into a denser phase becoming less porous and permeable. This age-old problem has been solved by adding an ultraporous additive that maintains the low density, porous, initial stage of super glassy polymers through absorbing a portion of the polymer chains within its pores thereby holding the chains in their open position. This result is the first time that aging in super glassy polymers is inhibited whilst maintaining enhanced CO2 permeability for one year and improving CO2/N2 selectivity. This approach could allow super glassy polymers to be revisited for commercial application in gas separations.

13.
J Chem Phys ; 140(4): 044320, 2014 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-25669536

RESUMEN

Utilising a high-resolution, trap-based positron beam, we have measured both elastic and inelastic scattering of positrons from water vapour. The measurements comprise differential elastic, total elastic, and total inelastic (not including positronium formation) absolute cross sections. The energy range investigated is from 1 eV to 60 eV. Comparison with theory is made with both R-Matrix and distorted wave calculations, and with our own application of the Independent Atom Model for positron interactions.

14.
Sci Transl Med ; 5(179): 179ra47, 2013 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-23552373

RESUMEN

Circulating tumor cells (CTCs) are shed into the bloodstream from primary and metastatic tumor deposits. Their isolation and analysis hold great promise for the early detection of invasive cancer and the management of advanced disease, but technological hurdles have limited their broad clinical utility. We describe an inertial focusing-enhanced microfluidic CTC capture platform, termed "CTC-iChip," that is capable of sorting rare CTCs from whole blood at 10(7) cells/s. Most importantly, the iChip is capable of isolating CTCs using strategies that are either dependent or independent of tumor membrane epitopes, and thus applicable to virtually all cancers. We specifically demonstrate the use of the iChip in an expanded set of both epithelial and nonepithelial cancers including lung, prostate, pancreas, breast, and melanoma. The sorting of CTCs as unfixed cells in solution allows for the application of high-quality clinically standardized morphological and immunohistochemical analyses, as well as RNA-based single-cell molecular characterization. The combination of an unbiased, broadly applicable, high-throughput, and automatable rare cell sorting technology with generally accepted molecular assays and cytology standards will enable the integration of CTC-based diagnostics into the clinical management of cancer.


Asunto(s)
Antígenos de Neoplasias/metabolismo , Separación Celular/métodos , Microfluídica/métodos , Células Neoplásicas Circulantes/patología , Línea Celular Tumoral , Forma de la Célula , Tamaño de la Célula , Femenino , Humanos , Fenómenos Magnéticos , Masculino , ARN Neoplásico/metabolismo
15.
J Chem Phys ; 138(7): 074301, 2013 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-23445003

RESUMEN

We present total, elastic, and inelastic cross sections for positron and electron scattering from tetrahydrofuran (THF) in the energy range between 1 and 5000 eV. Total cross sections (TCS), positronium formation cross sections, the summed inelastic integral cross sections (ICS) for electronic excitations and direct ionization, as well as elastic differential cross sections (DCS) at selected incident energies, have been measured for positron collisions with THF. The positron beam used to carry out these experiments had an energy resolution in the range 40-100 meV (full-width at half-maximum). We also present TCS results for positron and electron scattering from THF computed within the independent atom model using the screening corrected additivity rule approach. In addition, we calculated positron-impact elastic DCS and the sum over all inelastic ICS (except rotations and vibrations). While our integral and differential positron cross sections are the first of their kind, we compare our TCS with previous literature values for this species. We also provide a comparison between positron and electron-impact cross sections, in order to uncover any differences or similarities in the scattering dynamics with these two different projectiles.


Asunto(s)
Elasticidad , Electrones , Furanos/química , Modelos Moleculares , Conformación Molecular , Fenómenos Ópticos , Termodinámica
16.
J Chem Phys ; 138(7): 074302, 2013 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-23445004

RESUMEN

Cross section results from a joint experimental and theoretical investigation into positron scattering from 3-hydroxy-tetrahydrofuran (3H-THF) are presented. Total and positronium (Ps) formation cross sections have been measured from 1 to 190 eV using the positron beamline at the Australian National University, which has an energy resolution between 60 and 100 meV. The total cross section (TCS) and the elastic and total inelastic integral cross sections in the energy range between 1 and 1000 eV have been computed within the Independent Atom Model using the Screening Corrected Additivity Rule approach. In addition, we have calculated elastic differential cross sections at selected incident energies. Our computations represent the first theoretical results reported for this target species, while our measured Ps formation cross sections are also novel. Comparison of the present TCS with the previous results from the University of Trento shows a good level of agreement at the lowest energies. We also provide a comparison between the present cross sections for 3H-THF and those from our earlier study on the parent molecule tetrahydrofuran.


Asunto(s)
Electrones , Furanos/química , Modelos Moleculares , Elasticidad , Conformación Molecular , Fenómenos Ópticos , Termodinámica
17.
J Pharmacol Exp Ther ; 343(1): 233-45, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22815533

RESUMEN

Blockade of the histamine H(3) receptor (H(3)R) enhances central neurotransmitter release, making it an attractive target for the treatment of cognitive disorders. Here, we present in vitro and in vivo pharmacological profiles for the H(3)R antagonist 2-[4'-((3aR,6aR)-5-methyl-hexahydro-pyrrolo[3,4-b]pyrrol-1-yl)-biphenyl-4-yl]-2H-pyridazin-3-one (ABT-288). ABT-288 is a competitive antagonist with high affinity and selectivity for human and rat H(3)Rs (K(i) = 1.9 and 8.2 nM, respectively) that enhances the release of acetylcholine and dopamine in rat prefrontal cortex. In rat behavioral tests, ABT-288 improved acquisition of a five-trial inhibitory avoidance test in rat pups (0.001-0.03 mg/kg), social recognition memory in adult rats (0.03-0.1 mg/kg), and spatial learning and reference memory in a rat water maze test (0.1-1.0 mg/kg). ABT-288 attenuated methamphetamine-induced hyperactivity in mice. In vivo rat brain H(3)R occupancy of ABT-288 was assessed in relation to rodent doses and exposure levels in behavioral tests. ABT-288 demonstrated a number of other favorable attributes, including good pharmacokinetics and oral bioavailability of 37 to 66%, with a wide central nervous system and cardiovascular safety margin. Thus, ABT-288 is a selective H(3)R antagonist with broad procognitive efficacy in rodents and excellent drug-like properties that support its advancement to the clinical area.


Asunto(s)
Cognición/efectos de los fármacos , Cognición/fisiología , Antagonistas de los Receptores Histamínicos H3/farmacología , Nootrópicos/farmacología , Piridazinas/farmacología , Pirroles/farmacología , Receptores Histamínicos H3/fisiología , Animales , Reacción de Prevención/efectos de los fármacos , Reacción de Prevención/fisiología , Cobayas , Células HEK293 , Antagonistas de los Receptores Histamínicos H3/química , Humanos , Masculino , Ratones , Nootrópicos/química , Unión Proteica/fisiología , Piridazinas/química , Pirroles/química , Ratas , Ratas Endogámicas SHR , Ratas Long-Evans , Ratas Sprague-Dawley , Reconocimiento en Psicología/efectos de los fármacos , Reconocimiento en Psicología/fisiología
18.
Cancer Res ; 70(23): 9937-48, 2010 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-21118965

RESUMEN

Aldehyde dehydrogenase (ALDH) is a candidate marker for lung cancer cells with stem cell-like properties. Immunohistochemical staining of a large panel of primary non-small cell lung cancer (NSCLC) samples for ALDH1A1, ALDH3A1, and CD133 revealed a significant correlation between ALDH1A1 (but not ALDH3A1 or CD133) expression and poor prognosis in patients including those with stage I and N0 disease. Flow cytometric analysis of a panel of lung cancer cell lines and patient tumors revealed that most NSCLCs contain a subpopulation of cells with elevated ALDH activity, and that this activity is associated with ALDH1A1 expression. Isolated ALDH(+) lung cancer cells were observed to be highly tumorigenic and clonogenic as well as capable of self-renewal compared with their ALDH(-) counterparts. Expression analysis of sorted cells revealed elevated Notch pathway transcript expression in ALDH(+) cells. Suppression of the Notch pathway by treatment with either a γ-secretase inhibitor or stable expression of shRNA against NOTCH3 resulted in a significant decrease in ALDH(+) lung cancer cells, commensurate with a reduction in tumor cell proliferation and clonogenicity. Taken together, these findings indicate that ALDH selects for a subpopulation of self-renewing NSCLC stem-like cells with increased tumorigenic potential, that NSCLCs harboring tumor cells with ALDH1A1 expression have inferior prognosis, and that ALDH1A1 and CD133 identify different tumor subpopulations. Therapeutic targeting of the Notch pathway reduces this ALDH(+) component, implicating Notch signaling in lung cancer stem cell maintenance.


Asunto(s)
Adenocarcinoma/metabolismo , Aldehído Deshidrogenasa/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Neoplasias Pulmonares/metabolismo , Receptores Notch/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/patología , Aldehído Deshidrogenasa/genética , Familia de Aldehído Deshidrogenasa 1 , Animales , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Humanos , Inmunohistoquímica , Estimación de Kaplan-Meier , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Ratones , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Ratones Transgénicos , Neoplasias Experimentales/genética , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Pronóstico , Interferencia de ARN , Receptor Notch3 , Receptores Notch/genética , Retinal-Deshidrogenasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Análisis de Matrices Tisulares , Trasplante Heterólogo
19.
J Neurosci ; 30(31): 10369-79, 2010 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-20685980

RESUMEN

Oligomers of the beta-amyloid (Abeta) peptide have been indicated in early neuropathologic changes in Alzheimer's disease. Here, we present a synthetic Abeta(20-42) oligomer (named globulomer) with a different conformation to monomeric and fibrillar Abeta peptide, enabling the generation of highly Abeta oligomer-specific monoclonal antibodies. The globulomer-derived antibodies specifically detect oligomeric but not monomeric or fibrillar Abeta in various Abeta preparations. The globulomer-specific antibody A-887755 was able to prevent Abeta oligomer binding and dynamin cleavage in primary hippocampal neurons and to reverse globulomer-induced reduced synaptic transmission. In amyloid precursor protein (APP) transgenic mice, vaccination with Abeta globulomer and treatment with A-887755 improved novel object recognition. The cognitive improvement is likely attributable to reversing a deficit in hippocampal synaptic spine density in APP transgenic mice as observed after treatment with A-887755. Our findings demonstrate that selective reduction of Abeta oligomers by immunotherapy is sufficient to normalize cognitive behavior and synaptic deficits in APP transgenic mice.


Asunto(s)
Péptidos beta-Amiloides/inmunología , Precursor de Proteína beta-Amiloide/genética , Anticuerpos Monoclonales/uso terapéutico , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/inmunología , Análisis de Varianza , Animales , Anticuerpos Monoclonales/inmunología , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Hipocampo/citología , Hipocampo/inmunología , Inmunoprecipitación , Masculino , Ratones , Ratones Transgénicos , Neuronas/citología , Neuronas/inmunología , Ratas , Ratas Wistar , Reconocimiento en Psicología
20.
Cell Stem Cell ; 7(1): 2-4, 2010 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-20621039

RESUMEN

In this issue of Cell Stem Cell, Curtis et. al. (2010) reveal that the identities of lung cancer stem cell populations differ depending on the specific tumor oncogenotype in three murine lung adenocarcinoma models. These findings highlight the importance of determining the cancer stem cell oncogenotype for genotypically diverse malignancies.

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