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1.
Nature ; 627(8003): 281-285, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38286342

RESUMEN

Tight relationships exist in the local Universe between the central stellar properties of galaxies and the mass of their supermassive black hole (SMBH)1-3. These suggest that galaxies and black holes co-evolve, with the main regulation mechanism being energetic feedback from accretion onto the black hole during its quasar phase4-6. A crucial question is how the relationship between black holes and galaxies evolves with time; a key epoch to examine this relationship is at the peaks of star formation and black hole growth 8-12 billion years ago (redshifts 1-3)7. Here we report a dynamical measurement of the mass of the black hole in a luminous quasar at a redshift of 2, with a look back in time of 11 billion years, by spatially resolving the broad-line region (BLR). We detect a 40-µas (0.31-pc) spatial offset between the red and blue photocentres of the Hα line that traces the velocity gradient of a rotating BLR. The flux and differential phase spectra are well reproduced by a thick, moderately inclined disk of gas clouds within the sphere of influence of a central black hole with a mass of 3.2 × 108 solar masses. Molecular gas data reveal a dynamical mass for the host galaxy of 6 × 1011 solar masses, which indicates an undermassive black hole accreting at a super-Eddington rate. This suggests a host galaxy that grew faster than the SMBH, indicating a delay between galaxy and black hole formation for some systems.

2.
BMC Prim Care ; 23(1): 309, 2022 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-36460965

RESUMEN

BACKGROUND: The interdisciplinary research training group (POKAL) aims to improve care for patients with depression and multimorbidity in primary care. POKAL includes nine projects within the framework of the Chronic Care Model (CCM). In addition, POKAL will train young (mental) health professionals in research competences within primary care settings. POKAL will address specific challenges in diagnosis (reliability of diagnosis, ignoring suicidal risks), in treatment (insufficient patient involvement, highly fragmented care and inappropriate long-time anti-depressive medication) and in implementation of innovations (insufficient guideline adherence, use of irrelevant patient outcomes, ignoring relevant context factors) in primary depression care. METHODS: In 2021 POKAL started with a first group of 16 trainees in general practice (GPs), pharmacy, psychology, public health, informatics, etc. The program is scheduled for at least 6 years, so a second group of trainees starting in 2024 will also have three years of research-time. Experienced principal investigators (PIs) supervise all trainees in their specific projects. All projects refer to the CCM and focus on the diagnostic, therapeutic, and implementation challenges. RESULTS: The first cohort of the POKAL research training group will develop and test new depression-specific diagnostics (hermeneutical strategies, predicting models, screening for suicidal ideation), treatment (primary-care based psycho-education, modulating factors in depression monitoring, strategies of de-prescribing) and implementation in primary care (guideline implementation, use of patient-assessed data, identification of relevant context factors). Based on those results the second cohort of trainees and their PIs will run two major trials to proof innovations in primary care-based a) diagnostics and b) treatment for depression. CONCLUSION: The research and training programme POKAL aims to provide appropriate approaches for depression diagnosis and treatment in primary care.


Asunto(s)
Enfermedad Crónica , Grupo de Atención al Paciente , Farmacia , Atención Primaria de Salud , Humanos , Depresión/diagnóstico , Reproducibilidad de los Resultados , Conducta Cooperativa , Farmacéuticos , Médicos Generales , Proyectos de Investigación , Enfermedad Crónica/terapia , Multimorbilidad
3.
Appl Radiat Isot ; 122: 116-120, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28130979

RESUMEN

A radiation detection system consisting of two cerium doped lanthanum bromide (LaBr3:Ce) scintillation detectors in a gamma-gamma coincidence configuration has been used to demonstrate the advantages that coincident detection provides relative to a single detector, and the advantages that LaBr3:Ce detectors provide relative to high purity germanium (HPGe) detectors. Signal to noise ratios of select photopeak pairs for these detectors have been compared to high-purity germanium (HPGe) detectors in both single and coincident detector configurations in order to quantify the performance of each detector configuration. The efficiency and energy resolution of LaBr3:Ce detectors have been determined and compared to HPGe detectors. Coincident gamma-ray pairs from the radionuclides 152Eu and 133Ba have been identified in a sample that is dominated by 137Cs. Gamma-gamma coincidence successfully reduced the Compton continuum from the large 137Cs peak, revealed several coincident gamma energies characteristic of these nuclides, and improved the signal-to-noise ratio relative to single detector measurements. LaBr3:Ce detectors performed at count rates multiple times higher than can be achieved with HPGe detectors. The standard background spectrum consisting of peaks associated with transitions within the LaBr3:Ce crystal has also been significantly reduced. It is shown that LaBr3:Ce detectors have the unique capability to perform gamma-gamma coincidence measurements in very high count rate scenarios, which can potentially benefit nuclear safeguards in situ measurements of spent nuclear fuel.

5.
Br J Cancer ; 98(12): 1959-65, 2008 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-18506148

RESUMEN

In this study, we investigated the kinetics of oxaliplatin-DNA adduct formation in white blood cells of cancer patients in relation to efficacy as well as oxaliplatin-associated neurotoxicity. Thirty-seven patients with various solid tumours received 130 mg m(-2) oxaliplatin as a 2-h infusion. Oxaliplatin-DNA adduct levels were measured in the first cycle using adsorptive stripping voltammetry. Platinum concentrations were measured in ultrafiltrate and plasma using a validated flameless atomic absorption spectrometry method. DNA adduct levels showed a characteristic time course, but were not correlated to platinum pharmacokinetics and varied considerably among individuals. In patients showing tumour response, adduct levels after 24 and 48 h were significantly higher than in nonresponders. Oxaliplatin-induced neurotoxicity was more pronounced but was not significantly different in patients with high adduct levels. The potential of oxaliplatin-DNA adduct measurements as pharmacodynamic end point should be further investigated in future trials.


Asunto(s)
Antineoplásicos/sangre , Aductos de ADN/sangre , Leucocitos/metabolismo , Neoplasias/sangre , Compuestos Organoplatinos/sangre , Antineoplásicos/efectos adversos , Antineoplásicos/farmacología , Humanos , Compuestos Organoplatinos/efectos adversos , Compuestos Organoplatinos/farmacología , Oxaliplatino
6.
Allergy ; 63(6): 695-702, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18325077

RESUMEN

BACKGROUND: We have identified a monoclonal anti-human immunoglobulin E (IgE) antibody, which recognizes FcepsilonRI-bound IgE and prevents binding of IgE to FcepsilonRI. In this study, we assessed the binding kinetics and affinity of monoclonal antibody 12 (mAb12) for IgE and investigated whether mAb12 can be used for depletion of IgE and isolation of IgE-bearing cells from peripheral blood. METHODS: Binding kinetics and affinity for IgE were studied using Biacore surface plasmon resonance technique experiments. IgE antibodies were depleted from serum using sepharose-coupled mAb12 and IgE-bearing cells were enriched from heparinized blood samples with mAb12. The extent and biological relevance of IgE depletion were studied by quantitative IgE measurements and basophil histamine release experiments. Specific binding of mAb12 to IgE-bearing cells (basophils, mast cells, IgE-secreting plasma cells) was demonstrated by FACS. RESULTS: Monoclonal antibody 12 shows rapid association (k(a) = 5.46e5/Ms) with IgE, almost no dissociation (k(d) = 8.8e-5/s) and an affinity for IgE (K(D) = 1.61e-10 M), which is as high as that of FcepsilonRI. Immobilized mAb12 could be used to deplete IgE antibodies and isolate IgE-bearing cells from peripheral blood in a single-step procedure. CONCLUSIONS: Monoclonal antibody 12 is a high affinity anti-human IgE antibody, which efficiently removes IgE and IgE-bearing cells from peripheral blood and may thus be used for extracorporeal depletion of IgE and IgE-bearing cells.


Asunto(s)
Anticuerpos Antiidiotipos/inmunología , Anticuerpos Monoclonales/inmunología , Afinidad de Anticuerpos , Inmunoglobulina E/inmunología , Receptores de IgE/inmunología , Rinitis Alérgica Estacional/inmunología , Adulto , Alérgenos/inmunología , Anticuerpos Monoclonales/metabolismo , Basófilos/inmunología , Basófilos/metabolismo , Femenino , Liberación de Histamina , Humanos , Inmunoglobulina E/sangre , Masculino , Mastocitos/inmunología , Mastocitos/metabolismo , Persona de Mediana Edad , Células Plasmáticas/inmunología , Células Plasmáticas/metabolismo , Polen/inmunología , Receptores de IgE/metabolismo
8.
J Surg Res ; 129(1): 46-51, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16085104

RESUMEN

BACKGROUND: A reduction of plasma ascorbic acid concentration in the post-operative period has been well documented and is associated with an increase in post-operative complications. The underlying reason for the decreased concentration of ascorbic acid in the plasma is not clear. However, only an increased post-operative requirement for ascorbic acid would justify a substitution. Therefore, we investigated the pre-operative and post-operative metabolic clearance of ascorbic acid. MATERIALS AND METHODS: We calculated the metabolic clearance subsequent to intravenous bolus injection of 6 mg ascorbic acid/kg body weight in 15 patients before and after they underwent major maxillofacial surgery. Blood samples were taken before and 5, 15, 30, 45, 60, 90, 120, and 240 min after administration of ascorbic acid before and after the operation. Urine was collected. Ascorbic acid in plasma and urine was analyzed using a high performance liquid chromatographic technique. RESULTS: The pre-operative metabolic clearance was 7.6 +/- 2.22 l/h (mean +/- SD), increasing significantly to 12.1 +/- 4.87 l/h on the first post-operative day (P < 0.001). Doses of approximately 1150 mg ascorbic acid would be necessary to compensate for the observed loss and to raise plasma ascorbic acid to high normal values. CONCLUSIONS: There is a significantly increased post-operative metabolic clearance of ascorbic acid that might be considered when framing future dose recommendations in post-operative patients.


Asunto(s)
Antioxidantes/metabolismo , Ácido Ascórbico/sangre , Periodo Posoperatorio , Adulto , Anciano , Ácido Ascórbico/administración & dosificación , Ácido Ascórbico/farmacocinética , Creatinina/orina , Humanos , Tasa de Depuración Metabólica , Persona de Mediana Edad , Cuidados Posoperatorios
9.
Mol Genet Genomics ; 267(2): 262-9, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11976970

RESUMEN

Editing of plastid RNAs proceeds by C-to-U, in hornwort species also by extensive U-to-C, transitions, which predominantly lead to the restoration of codons for structurally and/or functionally important, conserved amino acid residues. So far, only one instance of editing outside coding regions has been reported - in the psbL/ psbF intergenic region of Ginkgo biloba. This site was proposed to have no functional importance. Here we present an evaluation of an editing site in the ndhI/ ndhG intergenic region in a related group of monocot plants. Efficient editing of this site, as well as the phylogenetic conservation of the resulting uridine residue, point at an important role for the sequence restored by editing. Two potential functions can be envisaged. (1) RNA secondary structure predictions suggest that the C-to-U conversion at this site can lead to a modified stem/loop structure of the ndhG 5' UTR, which could influence ndhG expression. (2) Alternatively, editing of the ndhI/ ndhG intergenic region may tag a so far unidentified small (12-codon) ORF, and lead to the restoration of a conserved phenylalanine codon. A screen with specific antibodies elicited against the putative peptide failed to detect such a peptide in chloroplast fractions. However, this failure may be attributable to its low and/or development-specific expression.


Asunto(s)
Magnoliopsida/genética , Magnoliopsida/metabolismo , Edición de ARN , ARN de Planta/genética , ARN de Planta/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , ADN de Plantas/genética , Genes , Genes de Plantas , Datos de Secuencia Molecular , NADH Deshidrogenasa/genética , Conformación de Ácido Nucleico , Plastidios/genética , ARN de Planta/química , Sistemas de Lectura , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico
10.
J Environ Health ; 64(3): 31-5, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11605325

RESUMEN

Using animal infectivity tests, the authors evaluated a water disinfection device, UV Waterworks (UVW), for its ability to inactivate Cryptosporidium parvum oocysts. The UVW employs low-pressure, germicidal ultraviolet (UV) light, delivering a dose of approximately 120 millijoules per square centimeter (mJ/cm2) under ideal water conditions at a flow rate of 4 gallons per minute (gpm). Dechlorinated tap water containing live oocysts was passed through the UVW at 4 gpm. The oocysts were captured on a filter, separated from the filter, and concentrated into inocula--10 microliters (microL) each, containing between 10(3) and 10(7) oocysts--which were administered orally into 60 neonatal mice. After one week, the mice were killed, and sections of their terminal ilea were analyzed microscopically for signs of Cryptosporidium infection. In spite of the high dose of oocysts, none of the mice showed signs of infection. A process control run with the UV lamp off resulted in 95 percent infection at a dose of 10(3) oocysts per inoculum. The calculated reduction in oocyst infectivity from passage through UV Waterworks was at least 5.4 orders of magnitude. The authors conclude that exposure to low-pressure UV at 120 mJ/cm2 effectively disables Cryptosporidium.


Asunto(s)
Cryptosporidium parvum/patogenicidad , Purificación del Agua/métodos , Administración Oral , Animales , Animales Recién Nacidos , Desinfectantes , Ratones , Oocitos , Presión , Pruebas de Toxicidad , Rayos Ultravioleta , Movimientos del Agua , Abastecimiento de Agua
11.
J Pediatr ; 137(3): 361-6, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10969261

RESUMEN

OBJECTIVE: To determine whether consumption of oats is safe in children with newly diagnosed celiac disease who are starting a gluten-free diet. STUDY DESIGN: We conducted a self-controlled, open-label, 6-month trial of a commercial oat breakfast cereal product. Primary outcome variables were small bowel histomorphology and anti-tissue transglutaminase IgA antibody titer. RESULTS: The 10 children who completed the study were 6.8 +/- 4.0 (mean +/- SD) years of age and 5 were male. Over 6.6 +/- 0.7 months, they consumed 24 grams of oat cereal per day, or 1.2 +/- 0.9 g/kg/d. Compared with start of study, at completion there was a significant decrease in biopsy score (P <.01), intra-epithelial lymphocyte count (P <.005), anti-tissue transglutaminase IgA antibody titer (P <.01), and number of symptoms (P <.01). CONCLUSIONS: We conclude that consumption of a commercially available oat cereal product for 6 months is safe for children with celiac disease beginning a gluten-free diet. Studies are needed to determine the long-term safety of including oat cereal in the gluten-free diet.


Asunto(s)
Avena , Enfermedad Celíaca/dietoterapia , Enfermedad Celíaca/diagnóstico , Enfermedad Celíaca/inmunología , Enfermedad Celíaca/patología , Niño , Femenino , Glútenes , Humanos , Inmunoglobulina A/análisis , Intestino Delgado/enzimología , Intestino Delgado/inmunología , Intestino Delgado/patología , Recuento de Linfocitos , Masculino , Radioinmunoensayo , Estadísticas no Paramétricas , Transglutaminasas/inmunología
12.
Plant J ; 22(2): 97-104, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10792825

RESUMEN

The chloroplast genomes of most higher plants contain two giant open reading frames designated ycf1 and ycf2. In tobacco, ycf1 potentially specifies a protein of 1901 amino acids. The putative gene product of the ycf2 reading frame is a protein of 2280 amino acids. In an attempt to determine the functions of ycf1 and ycf2, we have constructed several mutant alleles for targeted disruption and/or deletion of these two reading frames. The mutant alleles were introduced into the tobacco plastid genome by biolistic chloroplast transformation to replace the corresponding wild-type alleles by homologous recombination. Chloroplast transformants were obtained for all constructs and tested for their homoplastomic state. We report here that all transformed lines remained heteroplastomic even after repeated cycles of regeneration under high selective pressure. A balanced selection was observed in the presence of the antibiotic spectinomycin, resulting in maintenance of a fairly constant ratio of wild-type versus transformed genome copies. Upon removal of the antibiotic and therewith release of the selective pressure, sorting out towards the wild-type plastid genome occurred in all transplastomic lines. These findings suggest that ycf1 and ycf2 are functional genes and encode products that are essential for cell survival. The two reading frames are thus the first higher plant chloroplast genes identified as being indispensable.


Asunto(s)
ADN de Cloroplastos/genética , Genes Esenciales , Nicotiana/genética , Sistemas de Lectura Abierta/genética , Proteínas de Plantas/genética , Plantas Tóxicas , Cloroplastos/genética , Mapeo Cromosómico , Mutagénesis Insercional , Plastidios/genética , Polimorfismo de Longitud del Fragmento de Restricción , Eliminación de Secuencia , Nicotiana/citología
13.
Brain Res Mol Brain Res ; 45(2): 325-30, 1997 May.
Artículo en Inglés | MEDLINE | ID: mdl-9149108

RESUMEN

Expression of calcium/calmodulin-activated adenylyl cyclase type I (ACI) mRNA has been determined in the cochlea and in an organ-of-Corti subdissected tissue fraction by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Amplification products of predicted size were obtained from the mouse cochlea and rat organ of Corti with nucleotide sequences corresponding to respective ACI brain transcripts. In addition, ACI template was detected in a rat inner hair cell cDNA library by PCR. Immunoreactivity to ACI has been localized within the organ of Corti to the inner hair cell, with diaminobenzidine staining found in both the cell body and in the stereocilia. Evidence, thus, has been obtained that both ACI transcript and protein are expressed in the inner hair cell, the primary mechanosensory receptor cell of the cochlea. We hypothesize that ACI is activated by calcium influx through a calcium/calmodulin interaction and that this adenytyl cyclase isoform may have a role in modulation of receptoneural afferent transmission and/or mechanosensory transduction in the cochlea.


Asunto(s)
Adenilil Ciclasas/biosíntesis , Células Ciliadas Auditivas Internas/enzimología , Transcripción Genética , Animales , Secuencia de Bases , Cartilla de ADN , ADN Complementario , Biblioteca de Genes , Ratones , Ratones Endogámicos CBA , Datos de Secuencia Molecular , Órgano Espiral/enzimología , Reacción en Cadena de la Polimerasa , ARN Mensajero/biosíntesis , Ratas , Ratas Endogámicas ACI
14.
Am Ind Hyg Assoc J ; 55(5): 395-402, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8209844

RESUMEN

This work demonstrates for the first time the feasibility of computed tomography (CT) reconstructions of pollutant concentrations in a real room setting. A remote sensing Fourier transform infrared spectrometer was mounted on a moving base in a controlled ventilation chamber. A passive tracer was released from a point source into the room under constant ventilation conditions. A series of experiments gathered multiple path-averaged measurements in a two-dimensional plane for CT reconstruction. Simultaneous readings were gathered with a multiple-point sampling array for later comparison to the CT reconstructed concentrations. Good qualitative agreement between the reconstruction and point sample data was obtained. Limitations encountered due to the temporal resolution, size, and geometry of the experimental apparatus are clearly surmountable with better instrumentation.


Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Contaminación del Aire Interior/análisis , Gases/análisis , Tomografía Computarizada por Rayos X , Calibración , Exposición a Riesgos Ambientales , Estudios de Factibilidad , Análisis de Fourier , Procesamiento de Imagen Asistido por Computador , Espectrofotometría Infrarroja
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