Experimental investigation of size broadening of a Kα x-ray source produced by high intensity laser pulses.

The size of a hard Kα x-ray source ([Formula: see text] = 17.48 keV) produced by a high intensity femtosecond laser interacting with a solid molybdenum target is experimentally investigated for a wide range of laser intensity (I ~ 1017-2.8 × 1019 W/cm2) and for four values of the temporal contrast ratio (6.7 × 107 < CR < 3.3 × 1010). Results point out the size enlargement of the x-ray source with the increase of laser intensity and with the deterioration of temporal contrast. It amounts up to sixteen times the laser spot size at the highest laser intensity and for the lowest temporal contrast ratio. Using hydrodynamic simulations, we evaluate the density scale length of the pre-plasma L/λ just before the main pulse peak. This allows us to show that a direct correlation with the laser absorption mechanisms is not relevant to explain the large size broadening. By varying the thickness of the molybdenum target down to 4 µm, the impact of hot electron scattering inside the solid is also proved irrelevant to explain the evolution of both the x-ray source size and the Kα photon number. We deduce that the most probable mechanism yielding to the broadening of the source size is linked to the creation of surface electromagnetic fields which confine the hot electrons at the solid surface. This assumption is supported by dedicated experiments where the evolution of the size enlargement of the x-ray source is carefully studied as a function of the laser focal spot size for the highest contrast ratio.

Exploring phase contrast imaging with a laser-based Kα x-ray source up to relativistic laser intensity.

This study explores the ability of a hard Kα x-ray source (17.48 keV) produced by a 10 TW class laser system operated at high temporal contrast ratio and high repetition rate for phase contrast imaging. For demonstration, a parametric study based on a known object (PET films) shows clear evidence of feasibility of phase contrast imaging over a large range of laser intensity on target (from ~1017 W/cm2 to 7.0 × 1018 W/cm2). To highlight this result, a comparison of raw phase contrast and retrieved phase images of a biological object (a wasp) is done at different laser intensities below the relativistic intensity regime and up to 1.3 × 1019 W/cm2. This brings out attractive imaging strategies by selecting suitable laser intensity for optimizing either high spatial resolution and high quality of image or short acquisition time.

Truncated Gaussian-Bessel beams for short-pulse processing of small-aspect-ratio micro-channels in dielectrics.

In order to control the length of micro-channels ablated at the surface of dielectrics, we use annular filtering apertures for tailoring the depth of focus of micrometric Gaussian-Bessel beams. We identify experimentally and numerically the appropriate beam truncation that promotes a smooth axial distribution of intensity with a small elongation, suitable for processing micro-channels of small aspect ratio. Single-shot channel fabrication is demonstrated on the front surface of a fused silica sample, with sub-micron diameter, high-quality opening, and depth of few micrometers, using 1 ps low-energy (< 0.45 µJ) pulse. Finally, we realize 10 × 10 matrices of densely packed channels with aspect ratio ~5 and a spatial period down to 1.5 µm, as a prospective demonstration of direct laser fabrication of 2D photonic-crystal structures.

High photon flux Kα Mo x-ray source driven by a multi-terawatt femtosecond laser at 100 Hz.

We develop a pulsed hard x-ray Kα source at 17.4 keV produced by the interaction of a multi-terawatt peak power infrared femtosecond laser pulse with a thick molybdenum (Mo) target at a 100 Hz repetition rate. We measure the highest Mo Kα photon production reported to date corresponding to a Kα photon flux of 1×1011 ph/(sr·s) and an estimated peak brightness of ∼2.5×1017 ph/(s·mm2·mrad2(0.1% bandwidth)) at ∼5×1018 W/cm2 driving laser intensity.

Impact of the pulse contrast ratio on molybdenum Kα generation by ultrahigh intensity femtosecond laser solid interaction.

We present an extended experimental study of the absolute yield of Kα x-ray source (17.48 keV) produced by interaction of an ultrahigh intensity femtosecond laser with solid Mo target for temporal contrast ratios in the range of 1.7 × 107-3.3 × 109 and on three decades of intensity 1016-1019 W/cm². We demonstrate that for intensity I ≥ 2 × 1018 W/cm² Kα x-ray emission is independent of the value of contrast ratio. In addition, no saturation of the Kα photon number is measured and a value of ~2 × 1010 photons/sr/s is obtained at 10 Hz and I ~1019 W/cm². Furthermore, Kα energy conversion efficiency reaches the same high plateau equal to ~2 × 10-4 at I = 1019 W/cm² for all the studied contrast ratios. This original result suggests that relativistic J × B heating becomes dominant in these operating conditions which is supposed to be insensitive to the electron density gradient scale length L/λ. Finally, an additional experimental study performed by changing the angle of incidence of the laser beam onto the solid target highlights a clear signature of the interplay between collisionless absorption mechanisms depending on the contrast ratio and intensity.

Resonancia magnética dinámica de mama: estudio comparativo de gadobutrol y Gd-DTPA / Dynamic magnetic resonance imaging of the breast: comparison of gadobutrol vs. Gd-DTPA

Objetivo. Evaluar el perfil farmacocinético del gadobutrol en comparación con el Gd-DTPA, en resonancia magnética de mama con contraste (RM-DC). El objetivo secundario es valorar la eficacia diagnóstica en la detección de lesiones adicionales tumorales en RM-DC, y el perfil de seguridad de ambos contrastes. Material y métodos. Estudio retrospectivo y observacional que incluyó 400 pacientes con diagnóstico histológico de cáncer mamario. A 200 pacientes se les realizó RM-DC con contraste Gd-DTPA (Magnevist®) y a las otras 200 con gadobutrol (Gadovist®). Se analizaron los parámetros farmacocinéticos y la intensidad de señal mediante una ROI (region of interest) en el área intralesional con mayor intensidad de señal en las secuencias poscontraste. Se compararon las variables farmacocinéticas (Ktrans, Kep y Ve) y las curvas de intensidad de señal-tiempo de ambos grupos, así como el número de lesiones adicionales tumorales detectadas con ambos contrastes. Resultados. El realce relativo de intensidad de señal es más alto con gadobutrol que con Gd-DTPA. El gadobutrol muestra significativamente menos lavado (46%) que el Gd-DTPA (58,29%) (p=0,0323). Se observan valores más altos de Ktrans, Kep y Ve para el gadobutrol, siendo la diferencia estadísticamente significativa para los dos primeros parámetros (p=0,001). No se encuentran diferencias en el número de lesiones adicionales malignas confirmadas histológicamente (p=0,387). Conclusiones. El gadobutrol tiene valores más altos de realce, mientras que el Gd-DTPA muestra un lavado más marcado. El gadobutrol no es inferior en cuanto a número de lesiones adicionales malignas detectadas. Ambos contrastes son seguros (AU)

Objective. To compare the pharmacokinetic profile of gadobutrol versus Gd-DTPA in dynamic contrast-enhanced MRI (DCE-MRI) in patients with breast cancer. Secondary objectives included comparing the safety profiles and diagnostic efficacy of the two contrast agents for detecting additional malignant lesions. Material and methods. This retrospective observational study included 400 patients with histologically confirmed breast cancer; 200 underwent DCE-MRI with Gd-DTPA (Magnevist®) and 200 underwent DCE-MRI with gadobutrol (Gadovist®). Pharmacokinetic parameters and signal intensity were analyzed in a region of interest placed in the area within the lesion that had greatest signal intensity in postcontrast sequences. We compared the two groups on pharmacokinetic variables (Ktrans, Kep, and Ve), time-signal intensity curves, and the number of additional malignant lesions detected. Results. The relative signal intensity (enhancement) was higher with gadobutrol than with Gd-DTPA. Washout was lower with gadobutrol than with Gd-DTPA (46% vs. 58,29%, respectively; p=0,0323). Values for Ktrans and Kep were higher for gadobutrol (p=0,001). There were no differences in the number of histologically confirmed additional malignant lesions detected (p=0,387). Conclusions. Relative enhancement is greater with gadobutrol, but washout is more pronounced with Gd-DTPA. The number of additional malignant lesions detected did not differ between the two contrast agents. Both contrasts are safe (AU)

Dynamic magnetic resonance imaging of the breast: Comparison of gadobutrol vs. Gd-DTPA. / Resonancia magnética dinámica de mama: estudio comparativo de gadobutrol y Gd-DTPA.

OBJECTIVE: To compare the pharmacokinetic profile of gadobutrol versus Gd-DTPA in dynamic contrast-enhanced MRI (DCE-MRI) in patients with breast cancer. Secondary objectives included comparing the safety profiles and diagnostic efficacy of the two contrast agents for detecting additional malignant lesions. MATERIAL AND METHODS: This retrospective observational study included 400 patients with histologically confirmed breast cancer; 200 underwent DCE-MRI with Gd-DTPA (Magnevist®) and 200 underwent DCE-MRI with gadobutrol (Gadovist®). Pharmacokinetic parameters and signal intensity were analyzed in a region of interest placed in the area within the lesion that had greatest signal intensity in postcontrast sequences. We compared the two groups on pharmacokinetic variables (Ktrans, Kep, and Ve), time-signal intensity curves, and the number of additional malignant lesions detected. RESULTS: The relative signal intensity (enhancement) was higher with gadobutrol than with Gd-DTPA. Washout was lower with gadobutrol than with Gd-DTPA (46% vs. 58,29%, respectively; p=0,0323). Values for Ktrans and Kep were higher for gadobutrol (p=0,001). There were no differences in the number of histologically confirmed additional malignant lesions detected (p=0,387). CONCLUSIONS: Relative enhancement is greater with gadobutrol, but washout is more pronounced with Gd-DTPA. The number of additional malignant lesions detected did not differ between the two contrast agents. Both contrasts are safe.

Laser-synthesized oxide-passivated bright Si quantum dots for bioimaging.

Crystalline silicon (Si) nanoparticles present an extremely promising object for bioimaging based on photoluminescence (PL) in the visible and near-infrared spectral regions, but their efficient PL emission in aqueous suspension is typically observed after wet chemistry procedures leading to residual toxicity issues. Here, we introduce ultrapure laser-synthesized Si-based quantum dots (QDs), which are water-dispersible and exhibit bright exciton PL in the window of relative tissue transparency near 800 nm. Based on the laser ablation of crystalline Si targets in gaseous helium, followed by ultrasound-assisted dispersion of the deposited films in physiological saline, the proposed method avoids any toxic by-products during the synthesis. We demonstrate efficient contrast of the Si QDs in living cells by following the exciton PL. We also show that the prepared QDs do not provoke any cytoxicity effects while penetrating into the cells and efficiently accumulating near the cell membrane and in the cytoplasm. Combined with the possibility of enabling parallel therapeutic channels, ultrapure laser-synthesized Si nanostructures present unique object for cancer theranostic applications.

Bulk laser-induced damage threshold of titanium-doped sapphire crystals.

The bulk laser-induced damage threshold (LIDT) fluence of Ti:sapphire is determined under single-pulse irradiation from the femtosecond to nanosecond temporal regimes in the visible and near-infrared spectral domains. In the range of explored laser conditions, the LIDT fluence increases with both pulse duration and wavelength. The results are also compared to laser interaction with sapphire samples and show an increased resistance to laser damage when the material is doped with Ti(3+) ions. These conclusions are of interest for robust operation of high-peak-power femtosecond Ti:sapphire laser chains.

Surface ablation of corneal stroma with few-cycle laser pulses at 800 nm.

We report measurements of crater diameter and surface ablation threshold as a function of laser fluence in porcine corneal stroma and fused silica with pulse durations of 7 fs (2.7 optical cycles), 30 fs and 100 fs at 800 nm. For laser pulses with Gaussian radial intensity profile, we show experimentally that the square of the crater diameter is a linear function of the logarithm of the fluence in fused silica, while it is closer to a linear function of the fluence in corneal stroma. Extrapolating these relations to zero diameter indicates that for both media the minimum fluence required for surface ablation is reduced with shorter pulse duration. A simple theoretical model suggests that this effect is due to a more significant contribution of photoionization as the laser pulse duration shortens.

Monitoring photonic nanojets from microsphere arrays by femtosecond laser ablation of thin films.

By comparing finite-difference time-domain near field simulations and femtosecond laser ablation of thin films, we characterize in three dimensional-space photonic nanojets from microsphere arrays. We demonstrate periodic drilling of transparent films with thickness up to 100 nm (onto absorbing substrates) is feasible with 1-microm diameter silica spheres. Working with larger polystyrene spheres, the apparent increase of the propagation length of the photonic nanojets makes possible to drill films as thick as 500 nm. Interestingly, the lateral width of the produced craters can be maintained below 400 nm evidencing the low divergence of the nanojets. For backside illumination of the arrays, the ablation features are located at the top of the microspheres. We reveal field enhancements in and out the spheres as well as laser energy confinement at the particle substrate interface. The wide variety of features observed in the experiments open routes to fabricating nanomaterials.

Esteatocistoma múltiple: relación clínico-radiológica / No disponible

El esteatocistoma múltiple es un raro trastorno cutáneo caracterizado por múltiples pequeños nódulos quísticos hamartomatosos compuestos por los diferentes tejidos de los conductos pilosebáceos situados en tórax, axilas y miembros superiores. En algunas ocasiones esta entidad pasa desapercibida observándose sólo los hallazgos en los estudios de imagen, entre los cuales se encuentra la mamografía. En la mamografía se observan múltiples nódulos hipodensos intradérmicos, bien delimitados, de paredes finas no calcificadas, bilaterales y de distribución periférica. Ecográficamente estos nódulos son hipoecoicos, bien delimitados y con refuerzo posterior. Es por esta razón que el radiólogo debe conocer esta entidad y tenerla presente para llegar al diagnóstico correcto. Presentamos un caso clínico donde la mamografía y la ecografía mostraron lesiones típicas de esta patología y posteriormente la exploración física dio el diagnóstico definitivo(AU)

Steatocystoma multiplex is a rare cutaneous syndrome characterized by multiple small intradermal yellowish nodules located in the thorax, axillae, and upper limbs. Sometimes, this entity goes unnoticed and is shown in imaging studies like mammography. The mammogram shows multiple bilateral hypodense intradermal nodules with well-defined margins and thin, non-calcified walls in the periphery of the breast. At ultrasonography, these nodules are hypoechoic with well-defined margins and posterior echogenicity. Thus, it is important for radiologists to be familiar with steatocystoma multiplex to reach the correct diagnosis. We present a case in which mammography and sonography showed typical lesions of steatocystoma multiplex and later physical examination provided the diagnosis(AU)

[New approach for determining the damage level of biological tissues using femtosecond laser: advantages and application to corneal surgery]. / Nouvelle approche de détermination du seuil d'endommagement de tissus biologiques par laser femtoseconde: intérêt et application à la chirurgie de la cornée.

INTRODUCTION: Optimization of femtosecond laser characteristics in corneal surgery is still needed to improve clinical results. In this study, we describe an original characterization technique able to measure laser damage of corneal tissues precisely and to provide complementary physical results on the laser-matter interaction. METHOD: A femtosecond laser was used to damage corneas not suitable for graft. The epithelium and the Bowman layer are exposed to a set of different single-shot fixed laser fluences. Optical microscopy can determine the probability of laser damage on the corneal surface. The high damage threshold (minimum fluence systematically damaging the cornea) roughly fixes the operating laser fluence conditions, while the low damage threshold sets the maximum laser fluence level preserving tissue integrity (safety level). RESULTS: We precisely evaluate the damage fluence threshold of a tissue, using a statistical approach coupled with optical microscopy analysis. This technique gives essential information on laser-tissue interaction with a high rate of confidence. For corneal epithelium and the Bowman layer, we determine the maximum laser fluence level preserving tissue integrity (safety level) and the minimum fluence level systematically damaging the tissue. High and low threshold fluences of epithelium and the Bowman layers are (5.6 ± 0.4 J/cm(2); 2.7 ± 0.1 J/cm(2)), and (7.1 ± 1.1 J/cm(2); 3.4 ± 0.1 J/cm(2)), respectively. CONCLUSION: These data constitute determinant parameters for clinical applications, since they determine a working window providing the minimal effective irradiation dose that is mandatory for the development of high-quality laser-cutting surgery processes with minimized side effects.

Nanofabrication with pulsed lasers.

An overview of pulsed laser-assisted methods for nanofabrication, which are currently developed in our Institute (LP3), is presented. The methods compass a variety of possibilities for material nanostructuring offered by laser-matter interactions and imply either the nanostructuring of the laser-illuminated surface itself, as in cases of direct laser ablation or laser plasma-assisted treatment of semiconductors to form light-absorbing and light-emitting nano-architectures, as well as periodic nanoarrays, or laser-assisted production of nanoclusters and their controlled growth in gaseous or liquid medium to form nanostructured films or colloidal nanoparticles. Nanomaterials synthesized by laser-assisted methods have a variety of unique properties, not reproducible by any other route, and are of importance for photovoltaics, optoelectronics, biological sensing, imaging and therapeutics.

Neumomediastino espontáneo tras accidente de motocicleta. Caso clínico y revisión de la literatura / Spontaneous pneumomediastinum following a motorcycle accident. Report on a case and review of the literature

Introducción: el neumomediastino espontáneo es una entidad muy rara. Presentamos un caso de esta enfermedad. Caso clínico: varón de 17 años de edad que, tras sufrir un accidente de motocicleta de baja energía, acudió a urgencias por cefalea relacionada con dolor en el cuello. En la exploración física se apreciaba ecolalia, así como amnesia retrógrada del episodio. Destacaba una crepitación a la palpación en la región anterior y lateral derecha del cuello. El resto de la exploración física por aparatos fue normal. Las pruebas de imagen realizadas mostraron aire en el trayecto de la vena yugular derecha. Con el diagnóstico de neumomediastino espontáneo, el paciente quedó ingresado en observación. Con el reposo y la medicación analgésica mejoró en las horas siguientes y se pudo darle el alta sin incidencias. Se presenta el caso y se hace una revisión de la literatura. Conclusiones: el neumomediastino espontáneo normalmente es una enfermedad benigna que suele resolverse favorablemente sin tratamiento(AU)

Introduction: The spontaneous pneumomediastinum is an extremely rare condition. We hereby present a case of this pathology.Clinical case17 year-old man who suffered a low-energy motorcycle accident and came into the emergency department complaining of headache and neck pain. Physical examination showed echolalia and retrograde amnesia and crepitation on the anterior and right lateral part of the neck. No other physical signs were found. Plain radiographs and a CT-scan showed air in the right jugular vein. With the diagnosis of spontaneous pneumomediastinum, the patient remained under observation. With rest and analgesia the patient improved within the next hours and was discharged without any complication. The case is presented and the literature is reviewed.ConclusionsSpontaneous pneumomediastinum is a normally benign pathology that tends to resolve favourably without any treatment (AU)

Aplicaciones clínicas de la resonancia magnética en el cáncer de mama. Parte I / No disponible

La RM de mama es una modalidad de imagen que se ha incorporadoen los últimos años al diagnóstico de la patologíamamaria. La RM dinámica con contraste es la técnica auxiliarde imagen de mayor sensibilidad para el cáncer, aunque sus limitacionesen la especificidad obligan a emplearla para indicacionesrestringidas y siempre asociada a las demás modalidadesde imagen.Actualmente nos encontramos con una técnica sólida queya ha superado su fase de evaluación preclínica y se encuentraplenamente incorporada al proceso asistencial en los centrosque tienen disponibilidad y acceso a la misma.La alta capacidad de la RM con contraste para detectar unalesión nos va a permitir evaluar la extensión; la capacidad,aunque limitada, de tipificación puede permitirnos una buenaaproximación diagnóstica a una segunda lesión detectada demodo incidental, que se caracterizará correlacionándola conotras modalidades y, finalmente, mediante biopsia guiada porRM(AU)

Breast MRI is an imaging modality that has been incorporatedinto the diagnostic algorithm for breast lesions in recentyears. Dynamic contrast-enhanced MRI is an adjuvant techniquewith greater sensitivity for cancer than other conventionaltechniques. However, its low specificity limits its indicationsand means that it must always be used together withother imaging modalities.Breast MRI is currently a well-established technique that hasmoved beyond the preclinical evaluation stage and has beencompletely incorporated into the process of care in centreswhere it is available. Contrast-enhanced MRI's high capacityfor detecting lesions enables us to evaluate the extension ofthe lesion; its capacity for characterizing lesions, although limited,enables a good diagnostic approach to a second lesiondetected incidentally, which can be characterized by correlatingthe findings with other modalities and with the histologicalfindings after MRI-guided biopsy(AU)

Aplicaciones clínicas de la resonancia magnética en el cáncer de mama. Parte II / No disponible

La RM de mama es una modalidad de imagen que se ha incorporadoen los últimos años al diagnóstico de la patologíamamaria. La RM dinámica con contraste es la técnica auxiliarde imagen de mayor sensibilidad para el cáncer, aunque sus limitacionesen la especificidad obligan a emplearla para indicacionesrestringidas y siempre asociada a las demás modalidadesde imagen.Actualmente nos encontramos con una técnica sólida queya ha superado su fase de evaluación preclínica y se encuentraplenamente incorporada al proceso asistencial en los centrosque tienen disponibilidad y acceso a la misma.La alta capacidad de la RM con contraste para detectar unalesión nos va a permitir evaluar la extensión; la capacidad,aunque limitada, de tipificación puede permitirnos una buenaaproximación diagnóstica a una segunda lesión detectada demodo incidental, que se caracterizará correlacionándola conotras modalidades y finalmente mediante biopsia guiada porRM(AU)

Breast MRI is an imaging modality that has been incorporated into the diagnostic algorithm for breast lesions in recent years. Dynamic contrast-enhanced MRI is an adjuvant technique with greater sensitivity for cancer than other, conventional techniques. However, its low specificity limits its indications and means that it must always be used together with other imaging modalities. Breast MRI is currently a well-established technique that has moved beyond the preclinical evaluation stage and has been completely incorporated into the process of care in centers where it is available. Contrast-enhanced MRI's high capacity for detecting lesions enables us to evaluate the extension of the lesion; its capacity for characterizing lesions, although limited, enables a good diagnostic approach to a second lesion detected incidentally, which can be characterized by correlating the findings with those of other modalities and with the histological findings after MRI-guided biopsy(AU)

Análisis de desequilibrios cromosómicos en cáncer de mama ERBB2+, mediante hibridación genómica comparada (CGH) y correlación con hibridación in situ cromogénica (CISH) para los genes ERBB2, C-MYC, TOP2A y CCND1 / No disponible

Introducción: La hibridación genómica comparada (CGH)permite examinar desequilibrios cromosómicos en todo el genomatumoral, detectando ganancias y pérdidas en el materialgenético.Objetivos: Dirigimos el estudio de CGH a determinar losdesequilibrios cromosómicos en un grupo de cánceres demama ERBB2+ y a analizar la correlación entre los resultadosobtenidos mediante CGH e hibridación cromogénica in situ(CISH) en el estudio de los genes ERBB2, C-MYC, TOP2A yCCND1.Material y métodos: Se realizó la CGH en material congeladoa partir de 10 casos de cáncer de mama con sobreexpresiónde ERBB2+, de acuerdo con el protocolo previamente establecido.La técnica de CISH fue realizada en cortes de 2-3 μm a partirde muestras tumorales fijadas en formol e incluidas en parafina,utilizando las sondas ERBB2, C-MYC, TOP2A y CCND1.Resultados: La CGH detectó ganancias en 17q (90%), 8q(80%), 1q (80%), 16p (60%) y 20q (60%) y pérdidas en 3p(50%), 5q (50%), 11q (50%), 14q (50%) y 13q (40%), con unamedia de 20 alteraciones por caso. Se detectaron amplificacionesde alto nivel en 9 regiones cromosómicas diferentes,todas ellas descritas previamente. Los perfiles de gananciasobtenidas con CGH en 17q eran variables: picos de gananciaen 17q12-21.1, picos de ganancias tanto en 17q11.2-q21como en otra región distal/terminal, o ganancias de todo elbrazo 17q. La concordancia entre los resultados de CGH (gananciasen 17q12-qter) y resultados de CISH (> 6 señales/núcleo)para ERBB2 fue del 90% (9/10 casos). Para el resto degenes estudiados, la correlación entre los resultados de CISH yCGH fueron: TOP2A (17q21.2) 70%, C-MYC (8q24) 88%, yCCND1 (11q13) 80%.Conclusiones: El grupo de cánceres ERBB2+ mostró unalto número de alteraciones cromosómicas mediante CGH quees característico de tumores altamente agresivos, algunas deellas relacionadas con peor pronóstico...(AU)

Introduction: Comparative genomic hybridization (CGH)enables chromosomal imbalances in the entire tumor genometo be examined, detecting gains and losses in genetic material.Objectives: We aimed to use CGH to determine chromosomalimbalances in a group of ERBB2+ breast cancers and toanalyze the concordance between the results obtained byCGH and chromogenic in situ hybridization (CISH) in thestudy of the genes ERBB2, C-MYC, TOP2A and CCND1.Material and methods: CGH performed on frozen materialfrom 10 cases of breast cancer with ERBB2 overexpression, accordingto the protocol previously reported. CISH was performedon 2-3μm-thick archived formalin-fixed paraffin-embedded tumorsamples, using the probes ERBB2, C-MYC, TOP2A, CCND1.Results: CGH found gains in 17q (90%), 8q (80%), 1q(80%), 16p (60%) and 20q (60%) and losses in 3p (50%), 5q(50%), 11q (50%), 14q (50%) and 13q (40%), with a mean of20 alterations per case. High level amplifications were detectedin 9 different chromosome regions, all previously reported. Theprofiles of gains obtained by CGH at 17q were variable: peaksof gain in 17q12-21.1, peaks of gain in both 17q11.2-q21 andanother distal/terminal region, or gain in the entire 17q arm.The concordance between CGH results (gains in 17q12-qter)and CISH results (> 6 signals/nucleus) for ERBB2 was 90%(9/10 cases). For the other genes, the correlation between theCISH and CGH results was: TOP2A (17q21.2) 70%, C-MYC(8q24) 88%, and CCND1 (11q13) 80%.Conclusions: The group of ERBB2+ breast cancers had ahigh number of CGH-detected chromosomal alterations, characteristicof highly aggressive tumors and some related with aworse prognosis. CGH determinations of the profile of chromosomalalterations show high concordance with the CISHresults for the specific genes studied(AU)

Dynamic photolytical actinometry of the vacuum-ultraviolet radiation produced by multichannel surface discharges of submicrosecond duration.

Absolute measurements of the vacuum-ultraviolet (VUV) radiation power produced by a planar broadband optical source of submicrosecond light pulse duration are carried out in the transient regime of formation of a photodissociation (bleaching) wave in a photodecomposing absorptive medium. The source is based on a multichannel surface discharge initiated in ArN(2) gas mixtures on the area of approximately 0.1 m(2). The energetic characteristics of the produced VUV radiation are determined on the basis of spatially and temporally resolved observations of the pulsed photolysis of XeF(2) vapors. It is shown that the photon flux intensity produced by the source within the spectral range of 120-200 nm reaches 1.1 x 10(23) photonscm(2) s corresponding to the effective brightness temperature of discharge plasma of 20 kK and to the intrinsic efficiency of the discharge VUV emission of 3.2%. Numerical simulations of the photolysis process show a rather weak sensitivity of the results to the fraction of discharge radiation emitted into the line spectrum, as well as to the angular distribution of emitted radiation. The spectral band of measurements can be selected according to the choice of parent photodecomposing particles.

Utilidad de la resonancia magnética en la evaluación local del cáncer de mama: impacto en el cambio de actitud terapéutica en una serie prospectiva de 338 pacientes / No disponible

Introducción: la estadificación del cáncer de mama implicareunir información no sólo sobre el tamaño del tumor principal,sino también sobre la presencia de multifocalidad, multicentricidad,bilateralidad, componente intraductal extenso oextensión al complejo areola-pezón. El objetivo de nuestro estudioes validar la técnica en nuestro entorno asistencial y evaluarel impacto que la RM de mama con contraste ha tenido sobre338 pacientes consecutivas con diagnóstico de cáncer demama en el proceso de la toma de decisión del modelo de tratamiento.Como objetivo secundario se plantea la correlaciónde los hallazgos de la RM con los hallazgos histopatológicos.Material y métodos: estudiamos con RM a 338 pacientesconsecutivas con diagnóstico de cáncer de mama antes de decidircuál era el abordaje terapéutico más adecuado. La intenciónterapéutica se registró antes y después de cada estudio deRM. Se calculó la sensibilidad, la especificidad, el valor predictivopositivo y el valor predictivo negativo de la RM para lesionesadicionales, así como el coeficiente de correlación linealde Pearson para el diámetro del tumor índice o principal.Resultados: en 145 pacientes (42%) se identificaron 164lesiones adicionales, de las cuales 87 (53%) fueron malignas,28 (17%) fueron benignas, 35 (21,3%) se catalogaron comoprobablemente benignas, en 6 (3,6%) no se alcanzó un diagnósticofinal y 8 (4,9%) no quedaron incluidas en la pieza quirúrgicao bien desaparecieron tras la quimioterapia neoadyuvante.Estos hallazgos implicaron un cambio en la actitudterapéutica en 82 pacientes (24,2%). Este cambio se confirmócon los resultados de la anatomía patológica como correcto en69 paciente (20,4%) y como incorrecto o innecesario en 13pacientes (3,8%). El coeficiente de correlación de Pearson resultóser fuertemente positivo (r = 0,784) cuando se compararonlos resultados de la RM y la anatomía patológica...(AU)

Background: breast cancer staging implies gathering informationnot only on the size of the main tumour, but also onmultifocality, multicentricity, bilaterality, presence of an extensiveintraductal component and extension to the nipple-areolarcomplex. The objective of our study is to demonstrate thatbreast magnetic resonance (MR) is the modality of choice inthe staging of breast cancer patients due to the fact that it addsinformation capable of modifying the therapeutic approach inthese patients. A secondary objective is to validate our resultsin our clinical environment.Material and methods: 338 consecutive patients with abreast cancer diagnosis were studied with breast MR beforedeciding the most appropiate therapeutic approach. Therapeuticintention was registered before and after each MRstudy. Sensibility, specificity, postive predictive value (PPV)and negative predictive value (NPV) of MR for additional lesionswas calculated and Pearson's linear correlation coefficientwas calculated for the index lesion diameter.Results: 164 additional lesions were found in 145 patients(42%) of which 87 (53%) were malignant, 28 (17%) were benign,35 (21,3%) were probable benign, 6 (3,6%) had no diagnosisand 8 (4,9%) were not included in the surgical specimenor else dissappeared after neoadjuvant chemotherapy. Thesefindings implied change in therapeutic approach in 82 patients(24,2%). These change was pathologically validated ascorrect in 69 patients (20,4%) and as unnecessary or incorrectin 13 patients (3,8%). Pearson's linear correlation coefficientwas strongly positive (r = 0,784) when MR and pathology resultswere compared. Sensibility, specificity, PPV and NPV ofMR for additional lesions was 90,6, 55,2, 75,7 and 79,5%respectively...(AU)