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1.
Opt Express ; 26(18): 22687-22697, 2018 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-30184925

RESUMEN

Large scale laser interferometric gravitational wave detectors (GWDs), such as GEO 600 require high quality optics to reach their design sensitivity. The inevitable surface imperfections, inhomogeneities, and light-absorption induced thermal lensing in the optics, can convert laser light from the fundamental mode to unwanted higher order modes, and pose challenges to the operation and sensitivity of the GWDs. Here we demonstrate the practical implementation of a thermal projection system which reduces those unwanted effects via targeted spatial heating of the optics. The thermal projector consists of 108 individually addressable heating elements which are imaged onto the beam splitter of GEO 600. We describe the optimization of the spatial heating profile and present the obtained results.

2.
Opt Express ; 24(1): 146-52, 2016 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-26832246

RESUMEN

Beam alignment is an important practical aspect of the application of squeezed states of light. Misalignments in the detection of squeezed light result in a reduction of the observable squeezing level. In the case of squeezed vacuum fields that contain only very few photons, special measures must be taken in order to sense and control the alignment of the essentially dark beam. The GEO 600 gravitational wave detector employs a squeezed vacuum source to improve its detection sensitivity beyond the limits set by classical quantum shot noise. Here, we present our design and implementation of an alignment sensing and control scheme that ensures continuous optimal alignment of the squeezed vacuum field at GEO 600 on long time scales in the presence of free-swinging optics. This first demonstration of a squeezed light automatic alignment system will be of particular interest for future long-term applications of squeezed vacuum states of light.

3.
Opt Express ; 23(7): 8235-45, 2015 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-25968662

RESUMEN

Quantum noise will be the dominant noise source for the advanced laser interferometric gravitational wave detectors currently under construction. Squeezing-enhanced laser interferometers have been recently demonstrated as a viable technique to reduce quantum noise. We propose two new methods of generating an error signal for matching the longitudinal phase of squeezed vacuum states of light to the phase of the laser interferometer output field. Both provide a superior signal to the one used in previous demonstrations of squeezing applied to a gravitational-wave detector. We demonstrate that the new signals are less sensitive to misalignments and higher order modes, and result in an improved stability of the squeezing level. The new signals also offer the potential of reducing the overall rms phase noise and optical losses, each of which would contribute to achieving a higher level of squeezing. The new error signals are a pivotal development towards realizing the goal of 6 dB and more of squeezing in advanced detectors and beyond.

4.
Proc Biol Sci ; 278(1707): 817-25, 2011 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-20861041

RESUMEN

The Galapagos Islands are renowned for their high degree of endemism. Marine taxa inhabiting the archipelago might be expected to be an exception, because of their utilization of pelagic habitats-the dispersal barrier for terrestrial taxa-as foraging grounds. Magnificent frigatebirds (Fregata magnificens) have a highly vagile lifestyle and wide geographical distribution around the South and Central American coasts. Given the potentially high levels of gene flow among populations, the species provides a good test of the effectiveness of the Galapagos ecosystem in isolating populations of highly dispersive marine species. We studied patterns of genetic (mitochondrial DNA, microsatellites and nuclear introns) and morphological variation across the distribution of magnificent frigatebirds. Concordant with predictions from life-history traits, we found signatures of extensive gene flow over most of the range, even across the Isthmus of Panama, which is a major barrier to gene flow in other tropical seabirds. In contrast, individuals from the Galapagos were strongly differentiated from all conspecifics, and have probably been isolated for several hundred thousand years. Our finding is a powerful testimony to the evolutionary uniqueness of the taxa inhabiting the Galapagos archipelago and its associated marine ecosystems.


Asunto(s)
Aves/genética , Ambiente , Aislamiento Social , Migración Animal , Animales , Aves/anatomía & histología , ADN Mitocondrial/química , Ecuador , Flujo Génico , Genotipo , Intrones , Repeticiones de Microsatélite , Datos de Secuencia Molecular , Dinámica Poblacional , Análisis de Secuencia de ADN
5.
Biol Lett ; 7(2): 303-6, 2011 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-20943677

RESUMEN

Intermittent breeding is an important life-history strategy that has rarely been quantified in the wild and for which drivers remain unclear. It may be the result of a trade-off between survival and reproduction, with individuals skipping breeding when breeding conditions are below a certain threshold. Heterogeneity in individual quality can also lead to heterogeneity in intermittent breeding. We modelled survival, recruitment and breeding probability of the red-footed booby (Sula sula), using a 19 year mark-recapture dataset involving more than 11,000 birds. We showed that skipping breeding was more likely in El-Niño years, correlated with an increase in the local sea surface temperature, supporting the hypothesis that it may be partly an adaptive strategy of birds to face the trade-off between survival and reproduction owing to environmental constraints. We also showed that the age-specific probability of first breeding attempt was synchronized among different age-classes and higher in El-Niño years. This result suggested that pre-breeders may benefit from lowered competition with experienced breeders in years of high skipping probabilities.


Asunto(s)
Aves/fisiología , Cruzamiento , El Niño Oscilación del Sur , Conducta Sexual Animal , Adaptación Fisiológica , Animales , Modelos Biológicos , Estaciones del Año , Agua de Mar/química , Temperatura
6.
Artículo en Alemán | MEDLINE | ID: mdl-20700784

RESUMEN

The application of nanotechnology for the treatment, diagnosis, and monitoring of illnesses is summarized under the term nanomedicine. A particularly promising application is attributed to nanoparticular drug delivery systems. The goal of these new carrier systems is the selective enrichment of active substances in diseased tissue structures, an increase in bioavailability, the decrease of the active substance degradation and, above all, the reduction and/or avoidance of unwanted side effects. Apart from numerous nanosystems acting as carriers, the use of iron oxide nanoparticles has to be particularly emphasized. On the one hand, those particles are the carriers of the active substance and, on the other hand, can also be visualized with conventional imaging techniques (x-ray tomography, magnetic resonance imaging), called theranostic. In addition, they can be used for hyperthermia, another important supporting pillar of nanomedicine. Both procedures should lead to a personalized and goal-oriented therapy, which is of special medical and socioeconomic importance in view of the increasing number of cancer patients worldwide.


Asunto(s)
Antineoplásicos/administración & dosificación , Hipertermia Inducida/métodos , Nanomedicina/métodos , Neoplasias/tratamiento farmacológico , Sistemas de Liberación de Medicamentos , Compuestos Férricos , Humanos , Imagen por Resonancia Magnética , Nanopartículas , Medicina de Precisión , Tomografía Computarizada por Rayos X
7.
Radiat Res ; 171(3): 332-41, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19267560

RESUMEN

Monte Carlo simulations are used in the development of a nanotechnology-based multi-pixel beam array small animal microirradiation system. The microirradiation system uses carbon nanotube field emission technology to generate arrays of individually controllable X-ray pixel beams that electronically form irregular irradiation fields having intensity and temporal modulation without any mechanical motion. The microirradiation system, once developed, will be incorporated with the micro-CT system already developed that is based on the same nanotechnology to form an integrated image-guided and intensity-modulated microirradiation system for high-temporal-resolution small animal research. Prospective microirradiation designs were evaluated based on dosimetry calculated using EGSnrc-based Monte Carlo simulations. Design aspects studied included X-ray anode design, collimator design, and dosimetric considerations such as beam energy, dose rate, inhomogeneity correction, and the microirradiation treatment planning strategies. The dosimetric properties of beam energies between 80-400 kVp with varying filtration were studied, producing a pixel beam dose rate per current of 0.35-13 Gy per min per mA at the microirradiation isocenter. Using opposing multi-pixel-beam array pairs reduces the dose inhomogeneity between adjacent pixel beams to negligible levels near the isocenter and 20% near the mouse surface.


Asunto(s)
Método de Montecarlo , Terapia por Rayos X/métodos , Animales , Electrodos , Estudios de Factibilidad , Humanos , Ratones , Nanotubos de Carbono , Neoplasias/patología , Neoplasias/radioterapia , Fantasmas de Imagen , Radiometría , Dosificación Radioterapéutica , Terapia por Rayos X/instrumentación
8.
Science ; 168(3939): 1579-80, 1970 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-17759341

RESUMEN

The sound velocity data for the lunar rocks were compared to numerous terrestrial rock types and were found to deviate widely from them. A group of terrestrial materials were found which have velocities comparable to those of the lunar rocks, but they do obey velocity-density relations proposed for earth rocks.

9.
Science ; 225(4663): 713-6, 1984 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-17810291

RESUMEN

The breeding chronology and reproductive attempts of the seabird community on Christmas Island in the central Pacific Ocean (2 degrees N, 157 degrees W) were interrupted by the 1982-1983 El Niño Southern Oscillation. The resultant reproductive failure and disappearance of the entire seabird community of this equatorial atoll represents the most dramatic interruption on record of a seabird community located distant from coastal upwelling. Our data indicate the effect that the abiotic and biotic aspects of a global atmospheric-oceanic anomaly have on marine birds. The 1982-1983 El Niño Southern Oscillation provides an example of selective pressures and a natural experiment in the study of vertebrate population dynamics.

10.
Science ; 167(3918): 732-4, 1970 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-17781568

RESUMEN

Four experiments on lunar materials are reported: (i) resonance on glass spheres from the soil; (ii) compressibility of rock 10017; (iii) sound velocities of rocks 10046 and 10017; (iv) sound velocity of the lunar fines. The data overlap and are mutually consistent. The glass beads and rock 10017 have mechanical properties which correspond to terrestrial materials. Results of (iv) are consistent with low seismic travel times in the lunar maria. Results of analysis of the microbreccia (10046) agreed with the soil during the first pressure cycle, but after overpressure the rock changed, and it then resembled rock 10017. Three models of the lunar surface were constructed giving density and velocity profiles.

11.
Science ; 216(4543): 249-56, 1982 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-17832725

RESUMEN

The latest Mesozoic and earliest Tertiary sediments at Deep Sea Drilling Project site 524 provide an amplified record of environmental and biostratographic changes at the end of Cretaceous. Closely spaced samples, representing time intervals as short as 10(2) or 10(3) years, were analyzed for their bulk carbonate and trace-metal compositions, and for oxygen and carbon isotopic compositions. The data indicate that at the end of Cretaceous, when a high proportion of the ocean's planktic organisms were eliminated, an associated reduction in productivity led to a partial transfer of dissolved carbon dioxide from the oceans to the atmosphere. This resulted in a large increase of the atmospheric carbon dioxide during the next 50,000 years, which is believed to have caused a temperature rise revealed by the oxygen-isotope data. The lowermost Tertiary sediments at site 524 include fossils with Cretaceous affinities, which may include both reworked individuals and some forms that survived for a while after the catastrophe. Our data indicate that many of the Cretaceous pelagic organisms became extinct over a period of a few tens of thousands of years, and do not contradict the scenario of cometary impact as a cause of mass mortality in the oceans, as suggested by an iridium anomaly at the Cretaceous-Tertiary boundary.

12.
Lancet Psychiatry ; 11(3): 171, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38280385
13.
J Gynecol Obstet Hum Reprod ; 46(7): 601-608, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28698073

RESUMEN

OBJECTIVES: To evaluate, in a French multicenter cohort, the risk of C-section based on a high pre-pregnancy body mass index (BMI). Secondary objectives were to assess the risk of elective C-section, severe post-partum hemorrhage (>1L), severe perineal tears (3rd and 4th degree) and neonatal complications according to pre-pregnancy BMI. STUDY DESIGN: This historical cohort study analyzed records from the French AUDIPOG perinatal database. Inclusion criteria were deliveries≥22 weeks (or with a birth weight≥500g). Women with BMI<18.5kg/m2 (n=31,766) were excluded. After these exclusions, the study sample included 314,851 women between 1999 and 2009. Patients were classified among four BMI subgroups (normal: 18.5-24.9kg/m2, overweight: 25-29.9kg/m2, class I and II obesity: 30-39.9kg/m2 and class III obesity:≥40kg/m2). BMI was calculated using pre-pregnancy self-reported weight. Results were expressed as crude and adjusted relative risks (aRR). RESULTS: A C-section occurred in 16.4%, 22.7%, 28.8% and 39.4% of normal BMI, overweight, obese and class III obese women, respectively (P<10-4). aRR of C-section increased with BMI: 1.26 [95%CI: 1.22-1.30] for BMI between 25-29.9kg/m2; 1.39 [95%CI: 1.34-1.45] for BMI between 30-39.9kg/m2 and 1.72 [95%CI: 1.57-1.90] for BMI≥40kg/m2; but not the elective C-section. Neonatal complications were more frequent with increasing maternal BMI (BMI 25-29.9: aRR=1.09 [95%CI: 1.06-1.12]; BMI 30-39.9: aRR=1.20 [95%CI: 1.16-1.25]; BMI≥40: aRR=1.33 [95%CI: 1.21-1.45]). CONCLUSION: Our study confirmed that pre-pregnancy BMI is an important factor to consider because its elevation is associated with adverse obstetrical outcomes, especially cesarean delivery and neonatal complications.


Asunto(s)
Índice de Masa Corporal , Enfermedades del Recién Nacido/epidemiología , Complicaciones del Trabajo de Parto/epidemiología , Sobrepeso/epidemiología , Complicaciones del Embarazo/epidemiología , Resultado del Embarazo/epidemiología , Trastornos Puerperales/epidemiología , Adulto , Estudios de Cohortes , Femenino , Francia/epidemiología , Humanos , Recién Nacido , Enfermedades del Recién Nacido/etiología , Morbilidad , Obesidad/complicaciones , Obesidad/epidemiología , Complicaciones del Trabajo de Parto/etiología , Sobrepeso/complicaciones , Embarazo , Trastornos Puerperales/etiología , Factores de Riesgo , Adulto Joven
14.
J Gynecol Obstet Hum Reprod ; 46(2): 131-135, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28403968

RESUMEN

OBJECTIVE: Different classification of fetal heart rate (FHR) pattern have been proposed: FHR classified as either "reassuring" or "non-reassuring", the National Institute of Child Health and Human Development (NICHD) published in 2008 a 3-tier system, the French College of Gynecology and Obstetrics (CNGOF) recommended in 2013 a 5-tier system and recently in 2015, the Federation International of Gynecology and Obstetrics (FIGO) proposed a new classification based on a 3-tier system. Our objective was to assess the inter-observer reliability of these 4 existing classifications. STUDY DESIGN: Four observers reviewed 100 FHR without clinical information. FHR were obtained from term singleton pregnancies. Fetal heart rate patterns were classified by one 2-tier ("reassuring vs. non-reassuring"), two 3-tier (NICHD 2008 and FIGO 2015), and one 5-tier (CNGOF 2013) fetal heart classifications. RESULTS: The global agreement between observers was moderate for each classification: 0.58 (0.40-0.74) for the 2-tier, 0.48 (0.37-0.58) for the NICHD 2008, 0.58 (0.53-0.63) for the CNGOF 2013 and 0.59 (0.49-0.67) for the FIGO 2015 classification. When FHR was classified as reassuring, it was classified as normal in 85.5% for the NICHD 2008 and in 94.5% for the FIGO 2015. For the CNGOF 2013, 65.0% were classified as normal and 32.5% as quasi normal. There was strong concordance between FIGO category I and "reassuring" FHR (kappa=0.95). CONCLUSION: Inter-observer agreement of FHR interpretation is moderate whatever the classification used. To evaluate the superior interest of one classification, it will be interesting to compare their impact on need of second line techniques and on neonatal outcome.


Asunto(s)
Cardiotocografía , Sufrimiento Fetal/clasificación , Sufrimiento Fetal/diagnóstico , Monitoreo Fetal , Frecuencia Cardíaca Fetal/fisiología , Cardiotocografía/clasificación , Cardiotocografía/normas , Cardiotocografía/estadística & datos numéricos , Femenino , Monitoreo Fetal/clasificación , Monitoreo Fetal/normas , Monitoreo Fetal/estadística & datos numéricos , Edad Gestacional , Humanos , Variaciones Dependientes del Observador , Embarazo , Reproducibilidad de los Resultados , Terminología como Asunto
15.
PLoS One ; 12(7): e0180653, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28700617

RESUMEN

Analysis of heart rate variability (HRV) is a recognized tool in the assessment of autonomic nervous system (ANS) activity. Indeed, both time and spectral analysis techniques enable us to obtain indexes that are related to the way the ANS regulates the heart rate. However, these techniques are limited in terms of the lack of thresholds of the numerical indexes, which is primarily due to high inter-subject variability. We proposed a new fetal HRV analysis method related to the parasympathetic activity of the ANS. The aim of this study was to evaluate the performance of our method compared to commonly used HRV analysis, with regard to i) the ability to detect changes in ANS activity and ii) inter-subject variability. This study was performed in seven sheep fetuses. In order to evaluate the sensitivity and specificity of our index in evaluating parasympathetic activity, we directly administered 2.5 mg intravenous atropine, to inhibit parasympathetic tone, and 5 mg propranolol to block sympathetic activity. Our index, as well as time analysis (root mean square of the successive differences; RMSSD) and spectral analysis (high frequency (HF) and low frequency (LF) spectral components obtained via fast Fourier transform), were measured before and after injection. Inter-subject variability was estimated by the coefficient of variance (%CV). In order to evaluate the ability of HRV parameters to detect fetal parasympathetic decrease, we also estimated the effect size for each HRV parameter before and after injections. As expected, our index, the HF spectral component, and the RMSSD were reduced after the atropine injection. Moreover, our index presented a higher effect size. The %CV was far lower for our index than for RMSSD, HF, and LF. Although LF decreased after propranolol administration, fetal stress index, RMSSD, and HF were not significantly different, confirming the fact that those indexes are specific to the parasympathetic nervous system. In conclusion, our method appeared to be effective in detecting parasympathetic inhibition. Moreover, inter-subject variability was much lower, and effect size higher, with our method compared to other HRV analysis methods.


Asunto(s)
Feto/fisiología , Frecuencia Cardíaca/fisiología , Sistema Nervioso Parasimpático/fisiología , Administración Intravenosa , Animales , Atropina/administración & dosificación , Atropina/farmacología , Análisis de los Gases de la Sangre , Femenino , Feto/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Modelos Animales , Sistema Nervioso Parasimpático/efectos de los fármacos , Propranolol/administración & dosificación , Propranolol/farmacología , Ovinos , Estrés Fisiológico/efectos de los fármacos
16.
Annu Int Conf IEEE Eng Med Biol Soc ; 2017: 2027-2030, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29060294

RESUMEN

Fetal hypoxia results in a fetal blood acidosis (pH<;7.10). In such a situation, the fetus develops several adaptation mechanisms regulated by the autonomic nervous system. Many studies demonstrated significant changes in heart rate variability in hypoxic fetuses. So, fetal heart rate variability analysis could be of precious help for fetal hypoxia prediction. Commonly used fetal heart rate variability analysis methods have been shown to be sensitive to the ECG signal sampling rate. Indeed, a low sampling rate could induce variability in the heart beat detection which will alter the heart rate variability estimation. In this paper, we introduce an original fetal heart rate variability analysis method. We hypothesize that this method will be less sensitive to ECG sampling frequency changes than common heart rate variability analysis methods. We then compared the results of this new heart rate variability analysis method with two different sampling frequencies (250-1000 Hz).


Asunto(s)
Frecuencia Cardíaca Fetal , Acidosis , Sistema Nervioso Autónomo , Electrocardiografía , Femenino , Corazón Fetal , Hipoxia Fetal , Humanos , Embarazo
17.
Radiat Prot Dosimetry ; 122(1-4): 323-6, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17327240

RESUMEN

A novel single cell irradiation system using carbon nanotube (CNT) based field emission technology is proposed. The system can produce electron microbeam at a large range of pulsation frequencies and dose rates with energy between 20 and 60 keV. Different from any existing single beam microbeam device, the CNT-based system can have 10,000 microbeam pixels, each is approximately 10 microm in size and individually controlled. Microscope imaging will be used for targeting cell(s) and the coordinate(s) identification. A single cell or large number of individually selected cells can be simultaneously irradiated under real time microscope observation. This poster reports our preliminary results in the initial stage of the CNT multipixel microbeam array development-prototype single pixel CNT microbeam device development.


Asunto(s)
Técnicas de Cultivo de Célula/instrumentación , Fenómenos Fisiológicos Celulares/efectos de la radiación , Separación Celular/instrumentación , Nanotecnología/instrumentación , Aceleradores de Partículas/instrumentación , Radiometría/instrumentación , Técnicas de Cultivo de Célula/métodos , Separación Celular/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Transferencia Lineal de Energía , Miniaturización , Nanotecnología/métodos , Sistemas en Línea , Dosis de Radiación , Radiometría/métodos , Sensibilidad y Especificidad , Evaluación de la Tecnología Biomédica
18.
Cancer Res ; 52(21): 6121-4, 1992 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-1327524

RESUMEN

Small cell lung cancer (SCLC) cells express several characteristics of neuronal cells, including synthesis of neuropeptides and expression of the respective receptors. Establishment and maintenance of the neuronal phenotype of SCLC may depend on expression of gene transcription factors inherent to the central nervous system. The present study shows the nervous system-specific transcription factor N-Oct 3 (brain-2) to be expressed in all 13 SCLC cell lines investigated. Furthermore, N-Oct 3 (brain-2) was also found in SCLC-derived skin metastasis. In contrast, in extracts and RNA of non-SCLC cell lines and non-SCLC tumor tissues, such as lung squamous, large cell, and adenocarcinoma, expression of N-Oct 3 (brain-2) was not detectable. These data support the concept that SCLC cells derive from the neuroectodermal cell lineage since expression of N-Oct 3 (brain-2) protein is highly abundant at the neural tube stage and in the adult restricted to the neuroectodermal cell lineage.


Asunto(s)
Carcinoma de Células Pequeñas/química , Neoplasias Pulmonares/química , Factores de Transcripción/análisis , Regulación hacia Abajo , Proteínas de Homeodominio , Humanos , Factores del Dominio POU
19.
J Gynecol Obstet Biol Reprod (Paris) ; 45(4): 353-9, 2016 Apr.
Artículo en Francés | MEDLINE | ID: mdl-26139035

RESUMEN

OBJECTIVE: The primary objective was to describe the evolution of the prevalence of maternal obesity in France. The secondary objectives were to assess changes in the French regions and the place of birth according to type (public/private) and level of care. MATERIAL AND METHODS: Study based population of all births between 1999 and 2009 included in the AUDIPOG database. Our judgment criterion was the body mass index (BMI) divided into classes. RESULTS: Seventy-four thousand and forty-six pregnancies were included. The mean BMI was 22.9±4.5kg/m(2) with an increase between 1999-2001 and 2008-2009 (22.6±4.3kg/m(2) versus 23.1±4.7kg/m(2), P<10(-4)). North was the first region in terms of overweight patients (18%) and obese (10.2%). There was an increase of the birth rate in public maternity, and level II and III regardless of BMI class. Only the class of patients with a BMI ≥40kg/m(2) delivered more frequently in level III with an increase between the first and the last period of the study (20.8% versus 36.8%, P=0.02). CONCLUSION: The BMI is still increasing with more and more patients with a BMI ≥40kg/m(2) referred to level III. This raises the question of the organization of care and follow-up of these patients.


Asunto(s)
Sobrepeso/epidemiología , Complicaciones del Embarazo/epidemiología , Adulto , Índice de Masa Corporal , Femenino , Francia/epidemiología , Humanos , Obesidad/epidemiología , Embarazo , Prevalencia , Adulto Joven
20.
Oncogene ; 14(11): 1287-94, 1997 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-9178889

RESUMEN

The neural POU-domain proteins N-Oct 3 and N-Oct 5 were first identified in electrophoretic mobility retardation assays through their ability to bind to the octamer sequence ATGCAAAT. These two N-Oct factors are detected in extracts from tumor-derived and normal neural cells. They are present differentially, however, in extracts from melanocytes and melanoma cells: N-Oct 3 is present in extracts from both melanocytes and melanoma cells, whereas N-Oct 5 is more evident in extracts from metastatic melanoma cells. We show here that a cDNA encoding N-Oct 3 directs synthesis of both the N-Oct 3 and N-Oct 5 proteins and that the N-Oct 5 protein in neural and melanoma-cell extracts is also related to N-Oct 3. N-Oct 5, however, is apparently not expressed in vivo: It is not detected if cells are rapidly lysed in SDS or if extracts are prepared with a cocktail of protease inhibitors that includes the serine-protease inhibitor 4-(2-Aminoethyl)benzenesulfonyl fluoride hydrochloride (AEBSF). These data suggest that N-Oct 5 is a specific in vitro proteolytic cleavage product of N-Oct 3 and is not directly related to melanocyte malignancy.


Asunto(s)
Factores de Transcripción/metabolismo , Animales , Astrocitos/metabolismo , Células COS , Transformación Celular Neoplásica/genética , ADN Complementario , Proteínas de Homeodominio , Humanos , Hidrólisis , Melanoma/genética , Melanoma/patología , Factores del Dominio POU , Factores de Transcripción/genética , Células Tumorales Cultivadas
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