Coherent beam combining of high power quasi continuous wave tapered amplifiers.

We demonstrate coherent beam combining of four high brightness tapered amplifiers in pulsed, quasi continuous wave (QCW) operation, seeded by a 976 nm laser diode. The maximum power of 22.7 W was achieved with > 64% combining efficiency in a close to diffraction limited beam. We discuss turn-on dynamics of tapered amplifiers operated in pulsed mode in detail.

Tuberculosis in pregnancy:a challenging differential diagnosisfor inflammatory bowel disease.

OBJECTIVE: To describe a case of tuberculosis with intestinal variant in a pregnant woman in the 17th week of pregnancy. DESIGN: Case report. SETTING: Department of Obstetrics, Federal University of São Paulo (UNIFESP), São Paulo-SP, Brazil. CONCLUSION: Tuberculosis is a public health problem that concerns many countries in the world. It was declareda public emergency by the World Health Organization in 2005. Its presence during pregnancy brings maternal risk and fetal impairment if not treated quickly and properly. The intestinal variant is not the most common form of the disease and may be confused with inflammatory bowel diseases, especially Crohns disease. Knowledge of the specific characteristics, combined with a detailed medical history and appropriate diagnostic methods can make all the difference in gestational prognosis. We report the case of a pregnant woman who wrongly underwent treatment for inflammatory bowel disease at another service. After admission to our university hospital, fruitful diagnostic clarification was achieved and the patient was diagnosed and treated for tuberculosis. We describe the details of the investigation and, in particular, review the main characteristics in the literature for differentiating the two diseases.

ATP5H/KCTD2 locus is associated with Alzheimer's disease risk.

To identify loci associated with Alzheimer disease, we conducted a three-stage analysis using existing genome-wide association studies (GWAS) and genotyping in a new sample. In Stage I, all suggestive single-nucleotide polymorphisms (at P<0.001) in a previously reported GWAS of seven independent studies (8082 Alzheimer's disease (AD) cases; 12 040 controls) were selected, and in Stage II these were examined in an in silico analysis within the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium GWAS (1367 cases and 12904 controls). Six novel signals reaching P<5 × 10(-6) were genotyped in an independent Stage III sample (the Fundació ACE data set) of 2200 sporadic AD patients and 2301 controls. We identified a novel association with AD in the adenosine triphosphate (ATP) synthase, H+ transporting, mitochondrial F0 (ATP5H)/Potassium channel tetramerization domain-containing protein 2 (KCTD2) locus, which reached genome-wide significance in the combined discovery and genotyping sample (rs11870474, odds ratio (OR)=1.58, P=2.6 × 10(-7) in discovery and OR=1.43, P=0.004 in Fundació ACE data set; combined OR=1.53, P=4.7 × 10(-9)). This ATP5H/KCTD2 locus has an important function in mitochondrial energy production and neuronal hyperpolarization during cellular stress conditions, such as hypoxia or glucose deprivation.

Meta-analysis of 74,046 individuals identifies 11 new susceptibility loci for Alzheimer's disease.

Eleven susceptibility loci for late-onset Alzheimer's disease (LOAD) were identified by previous studies; however, a large portion of the genetic risk for this disease remains unexplained. We conducted a large, two-stage meta-analysis of genome-wide association studies (GWAS) in individuals of European ancestry. In stage 1, we used genotyped and imputed data (7,055,881 SNPs) to perform meta-analysis on 4 previously published GWAS data sets consisting of 17,008 Alzheimer's disease cases and 37,154 controls. In stage 2, 11,632 SNPs were genotyped and tested for association in an independent set of 8,572 Alzheimer's disease cases and 11,312 controls. In addition to the APOE locus (encoding apolipoprotein E), 19 loci reached genome-wide significance (P < 5 × 10(-8)) in the combined stage 1 and stage 2 analysis, of which 11 are newly associated with Alzheimer's disease.

An oscillator circuit to produce a radio-frequency discharge and application to metastable helium saturated absorption spectroscopy.

We present a rf gas discharge apparatus which provides an atomic frequency reference for laser manipulation of metastable helium. We discuss the biasing and operation of a Colpitts oscillator in which the discharge coil is part of the oscillator circuit. Radiofrequency radiation is reduced by placing the entire oscillator in a metal enclosure.

Detecting inertial effects with airborne matter-wave interferometry.

Inertial sensors relying on atom interferometry offer a breakthrough advance in a variety of applications, such as inertial navigation, gravimetry or ground- and space-based tests of fundamental physics. These instruments require a quiet environment to reach their performance and using them outside the laboratory remains a challenge. Here we report the first operation of an airborne matter-wave accelerometer set up aboard a 0g plane and operating during the standard gravity (1g) and microgravity (0g) phases of the flight. At 1g, the sensor can detect inertial effects more than 300 times weaker than the typical acceleration fluctuations of the aircraft. We describe the improvement of the interferometer sensitivity in 0g, which reaches 2 x 10-4 ms-2 / √Hz with our current setup. We finally discuss the extension of our method to airborne and spaceborne tests of the Universality of free fall with matter waves.

Absence of allelic imbalance involving EMSY, CAPN5, and PAK1 genes in papillary thyroid carcinoma.

Papillary thyroid cancer (PTC) accounts for 80% of all thyroid malignancies, and genetic alterations associated to its etiology remain largely unknown. Chromosomal band 11q13 seems to be one of the most frequently amplified regions in human cancer, providing several candidate genes that need detailed characterization. The aim of our study was to investigate the existence of allelic imbalance at EMSY, CAPN5, and PAK1, as candidate genes within 11q13.5-q14 region using a single nucleotide polymorphism-based analysis. We selected a panel of 9 polymorphisms that were analyzed in 41 thyroid carcinoma samples, their contralateral non-pathological tissue and 178 controls from the general population. We did not detect allelic imbalance at these loci in our series. However, we observed a difference in the EMSY-haplotype distribution among PTC patients when compared to controls (odds ratio=2.00; p=0.02). We conclude that 11q13.5-q14 is not imbalanced in PTC, but there is evidence suggesting that EMSY might be of relevance in PTC etiology.

Genética de la osteoporosis posmenopáusica: Nuevos conocimientos y nuevos conceptos sobre su relación con los polimorfismos genéticos en la ruta estrogénica / The genetics of postmenopausal osteoporosis: New understanding and new concepts of its relationship with genetic polymorphisms

La osteoporosis posmenopáusica es una enfermedad compleja, sujeta a fuertes influencias ambientales pero con una base genética no menos importante, tanto en la manera de adquisición como de pérdida de la masa ósea. El estudio genético nos está permitiendo identificar a pacientes con riesgo de padecer enfermedades comunes como ésta, y en su evolución como herramienta clínica hemos pasado de la búsqueda de genes candidatos al análisis unilocus de sus polimorfismos genéticos y sus relaciones con determinados factores ambientales. El siguiente paso será analizar las posibles interacciones génicas y la relación entre los hallazgos genéticos y la respuesta a los tratamientos más comunes

Postmenopausal osteoporosis is a complex disease, which is subject to strong environmental influences but with a no less important genetic basis, both in the manner of acquisition and loss of bone mass. Genetic studies are enabling us to identify patients at risk of suffering from common diseases like this, and in its evolution as a clinical tool we have advanced from the search for candidate genes to unilocus analysis of their genetic polymorphisms and their relationships with certain environmental factors. The next step will be to analyse possible gene interactions and the relationship between genetic findings and the response to the most common treatments (AU)

Learning the nodal stations in the abdomen.

The normal pathways of lymphatic drainage from the abdominal organs have been well described in the classic anatomy literature. Knowledge of the location and nomenclature of the common nodal stations in the abdomen are essential for complete report of radiological findings. CT is ubiquitous in the evaluation of oncology patients. Utilizing colour-coded CT images of the abdomen we will present the nomenclature and location of the nodal stations for common abdominal neoplasms, including those of the stomach, pancreas, liver, colon and the kidney. Understanding the nomenclature and the usual lymphatic pathways of metastasis will help radiologists detect disease spread from abdominal tumours. The goal of this pictorial review is to present the nodal stations, nomenclature and location of regional lymph nodes for the most common abdominal neoplasms. In addition, the reader can use this document as a handbook to learn and review this information.

Cancer broncogenico: tipo celular y presentacion radiologica: Estudio multicentrico / Bronchogenic cancer: Cellular type and radiographic patterns

Introducción: Los textos y descripciones clásicas señalan patrones diferentes de presentación del cáncer broncogénico según el tipo celular, que han comenzado a ser cuestionados. Objetivo: Identificar los patrones del cáncer broncogénico en la radiografía del tórax de acuerdo con el tipo celular y compararlos con las descripciones usuales. Tipo de Estudio: Serie de casos. Lugar de Estudio: Cuatro hospitales en Bogotá: Hospital Central de la Policía, Instituto Nacional de Cancerología, Hospital Santa Clara, Hospital de la Samaritana. Pacientes y Métodos: En pacientes con diagnóstico histológico de cáncer broncogénico y clasificación precisa del tipo celular se revisaron en forma estándar las principales características radiológicas al momento del diagnóstico y se compararon con las series más conocidas (Clínica Mayo y Marshfield). Resultados: En 236 pacientes (edad promedio 61 años, 39 por ciento mujeres), la mayoría escamocelular (37 por ciento ) o adenocarcinoma (36 por ciento ), la localización de los adenos en general sigue la tendencia reciente (predominio central: 60 por ciento ) al igual que los escamocelulares (72 por ciento ) y las características radiológicas generales son similares entre estos tipos celulares más frecuentes. En etapas tempranas del adeno tiende a localizarse más hacia la periferia y los escamocelulares son tanto centrales como periféricos. En etapas avanzadas todos los tipos celulares predominan en localización central. Conclusión: En esta serie de casos no se encuentra diferencia significativa en la localización entre escamo y adenocarcinoma, siendo estos resultados diferentes a los de las descripciones clásicas. Es probable que la presentación radiológica del tumor esté cambiando y que parte de los hallazgos se expliquen por el estado al momento del diagnóstico

Metilación y expresión del gen FMR1 / Methylation and expression for the FMR1 gene

Objetivo. En este artículo se hace una breve revisión sobre la metilación del ADN, las enzimas y proteínas involucradas en la formación del complejo represor y la importancia de la metilación del gen FMR1 en el síndrome X frágil. Desarrollo. El estado de metilación de regiones de control en el genoma desempeña un papel fundamental en la regulación de la expresión genética. En genes susceptibles, los que contienen una isla CpG en el promotor, la metilación de la citosina favorece un estado represivo de la cromatina que previene la unión de los factores de transcripción. Las enzimas ADN metiltransferasas transfieren un grupo metilo de la S-adenosilmetionina al carbono 5 de la citosina en las secuencias CG. Se ha descrito un grupo de proteínas que reconocen a las citosinas metiladas y reclutan al correpresor y las desacetilasas de las histonas. La pérdida del grupo acetilo de las histonas produce la compactación de la cromatina. El síndrome X frágil se debe, en la mayoría de los casos, a la expansión por encima de un umbral de las repeticiones CGG del primer exón del gen FMR1. Por causas no bien conocidas estas expansiones se acompañan de la metilación del promotor y como consecuencia del silencio del gen. Conclusiones. La metilación del ADN etiqueta a los genes de forma que la misma secuencia de bases puede tener repercusiones fenotípicas diferentes. La metilación aberrante de los genes es causa de diversas patologías como el síndrome X frágil. El conocimiento de los mecanismos de represión de la expresión genética por metilación y el estudio de agentes que haga reversible el proceso son importantes para el tratamiento de dichas enfermedades (AU)

Imagenes de resonancia magnetica con tecnica de difusion en el diagnostico de enfermedad cerebrovascular isquemica, definicion de caracteristicas operativas / Magnetic resonance imaging with diffusion protocols in diagnostic of ischemic stroke

Introducción: Para el diagnóstico temprano de la enfermedad cerebrovascular (ECV) isquémica se han propuesto nuevos métodos de imágenes de resonancia magnética (IRM) funcional, como las técnicas de perfusión y difusión, cuyas características operativas apenas comienzan a ser definidas. Objetivo: Definir características operativas de las IRM funcional de difusión para el diagnóstico de ECV y compararlo con los métodos más frecuentes, usando como estándar de referencia el diagnóstico clínico final al egreso del paciente. Tipo de Estudio: Estudio de corte transversal para determinar y comparar características operativas de métodos diagnósticos. Lugar de Estudio: Servicio de Neuroradiología Clínica del Country, Bogotá. Pacientes y Métodos: Pacientes referidos para estudio por sospecha clínica de ECV con síntomas de menos de 24 horas. Se realizó TAC, IRM convencional e IRM funcional de difusión en un resonador de 1.5 T. Se definió anormalidad en la difusión como aumento en la intensidad de la señal (disminución del coeficiente de difusión aparente) El estándar de oro fue el diagnóstico del clínico al egreso. A partir de estos datos se calcularon las características operativas y se compararon con las de otros métodos de uso corriente en neuroradiología (TAC, I RM convencional). Resultados: Se incluyeron 17 pacientes. En 13 el diagnóstico final fue ECV isquémica, de los cuales las IRM funcional de difusión fueron positivas en todos. La sensibilidad es de 100 por ciento , la especificidad de 100 por ciento , lo mismo que los valores predictivos. Las cifras igualan y superan las de los demás métodos estudiados. Conclusión: El rendimiento diagnóstico de esta nueva técnica para evaluación de la ECV isquémica es apropiado y similar a lo descrito en la literatura. Se justifica considerar su uso en forma más frecuente y ampliar la experiencia con este método

Exactitud diagnostica y confiabilidad de las imagenes de resonancia magnetica de rodilla, comparacion con la artroscopia / Value of MRI of the knee using arthroscopic as gold standar

Introducción Los informes acerca de la precisión diagnóstica de las imágenes de resonancia magnética de rodilla son variables y siguen siendo motivo de discusión. Objetivo Evaluar la precisión diagnóstica de las imágenes por resonancia magnética de la rodilla, usando como estándar de referencia los hallazgos de la artroscopia. Tipo de estudio Estudio de evaluación de una prueba diagnóstica. Pacientes y métodos Casos consecutivos de pacientes remitidos para resonancia magnética de rodilla por diferentes indicaciones. Interpretación de las imágenes por un mismo radiólogo, de acuerdo a criterios preestablecidos. Descripción de los hallazgos de la artroscopia por un solo ortopedista, tras la evaluación estandarizada de la articulación, sin conocer el informe del radiólogo participante en el estudio. Comparación de los hallazgos radiológicos con los de la artroscopia. Cálculo de las características operativas (sensibilidad, especificidad y valores predictivos) de cada signo radiológico. Resultados Se incluyeron 79 pacientes (158 ligamentos y 158 meniscos) durante un período de dos años. La indicación más frecuente para el estudio fue sospecha de lesión de meniscos. La confiabilidad (variabilidad interobservador) de la lectura radiológica fue buena (coeficiente Kappa entre 0.57 y 0.79) y las imágenes diagnósticas tuvieron apropiado rendimiento para la identificación de ruptura** de los ligamentos (Sensibilidad 88 por ciento , Especificidad 94 por ciento ), y desgarro de los meniscos (Sensibilidad 81 por ciento , Especificidad 84 por ciento ). ConclusiónSe definen las características operativas de la resonancia para la identificación de lesiones intraarticulares de la rodilla, que muestran valores superiores a 80 por ciento , similares a los reportados en la literatura, con altos valores predictivos negativos. La probabilidad de encontrar alteración de ligamentos o meniscos ante un informe normal de resonancia es muy baja#R

[Methylation and expression of the FMR1 gene]. / Metilación y expresión del gen FMR1.

OBJECTIVE: In this paper we present a brief review on DNA methylation, the enzymes and proteins involved in the repression complex and the importance of methylation of FMR1 gene in fragile X syndrome. DEVELOPMENT: Methylation status of control region in the genome plays a critical role in the regulation of gene expression. In susceptible genes containing CpG island in the promoter, cytosine methylation favors a repressive chromatin structure that prevents the binding of transcriptional activators to the promoter. The enzyme DNA methyltransferase transfers a methyl group from the S-adenosylmethionine to the 5 carbon of cytosine in the CG sequences. Several proteins have been described that recognize the methyl cytosine and recruit the co-repressor and the histones deacetylases. The lost of the acetyl groups produces the compacting of the chromatin. Fragile X syndrome is due, in the majority of the cases, to the expansion above a threshold of the CGG repeats in the first exon of FMR1 gene. These expansions are concomitant with the methylation of the promoter and the silencing of FMR1. CONCLUSIONS: DNA methylation is a tag that enables different phenotypic expression from an identical nucleotide sequence. Aberrant methylation is the cause of different pathologies including fragile X syndrome. The comprehension of the mechanisms by which methylation induces the silencing of the genes and the study of agents that could revert this process are important for the treatment of these diseases.

Diagnostico por escanografia de la apendicitis aguda de dificil diagnostico clinico / Diagnosis by CT of acute appendicitis in the atypical and difficult clinical situation

Se realizó un estudio prospectivo de concordancia para determinar el desempeño de la escanografía de abdomen en el diagnóstico de apendicitis aguda de cuadro clínico atípico y de difícil diagnóstico. Se compararon las escanografías de alta resolución de 65 pacientes atendidos en el servicio de urgencias del Hospital San Ignacio, con el diagnóstico definitivo de anatomía patológica o el seguimiento clínico del paciente. Se determinó una sensibilidad diagnóstica de 75 por ciento y especificidad de 88 por ciento , con Valor Predictivo Positivo (VPP) 75 por ciento de y Valor Predictivo Negativo (VPN) de 87 por ciento , y coeficiente de concordancia Kappa de 0.63. La razón de probabilidades para un examen positivo es de 4 : 1 y para un examen negativo de 0.17 : 1. Los resultados demuestran un acuerdo sustancial entre el diagnóstico escanográfico y el patrón de oro constituido por el diagnóstico anatomopatológico o la evolución clínica del paciente, indicativo de la importancia y utilidad de la escanografía en pacientes con apendicitis aguda de difícil diagnóstico

Genotoxic activity of mebendazole in Aspergillus nidulans.

Mebendazole is an anthelmintic drug widely used in Cuba and in Mexico. Its interaction with tubulin interferes with the assemblage of the mitotic apparatus in the parasite cells, thus suggesting a possible genotoxic activity leading to chromosomal malsegregation. The heterozygous diploid strain D30 of Aspergillus nidulans was used to establish the ability of mebendazole to induce mitotic recombination and/or chromosomal non-disjunction, and the haploid strain FGSC #219 of A. nidulans was used to study the ability of mebendazole to induce point mutations in the methG suppressor system. Our results show that mebendazole can induce chromosomal non-disjunction but it fails to promote point mutations.

Molecular biochemistry and pharmacology of peptic ulcer treatment. A review.

The membrane-bound ATP-dependent energy systems (ATP-membrane ATPase-ADP and ATP-adenylate cyclase-cAMP) play an essential role in the physiological regulation of the gastrointestinal mucosa and its damage in rat and man. A good, physiologically, hormonally and pharmacologically well controlled and regulated feedback system exists between the two energy systems. The significant increase of ATP transformation into ADP or cAMP represents a causative metabolic background of the development of gastric, duodenal and jejunal ulcer (damage) in man and rat. The ulcer preventive effects of vitamin A, beta-carotene, atropine, cimetidine, prostacyclin I2, and surgical vagotomy were studied in connection with their effects on the membrane-bound ATP-dependent energy systems of the gastric, duodenal and jejunal mucosa in man and rat. Atropine and cimetidine were applied in cytoprotective and antisecretory doses, and the tissue levels of ATP, ADP, AMP, cAMP and lactate were measured. The results indicated that the disturbed equilibrium between the two energy supply systems can be modified (normalized) by drugs and surgical vagotomy; the drug effect depends on the actual biochemism of the gastroduodenal mucosa; the values of affinities (pD2) and intrinsic activities (alpha) of the different drugs differ in relation to membrane-bound ATP-splitting enzymes; the changes in the membrane-bound ATP-dependent energy systems of the damaged rat gastric mucosa, produced by vitamin A and beta-carotene, depend on their cytoprotective doses which are connected with their cytoprotective effects; the biochemical changes induced by drugs (given in cytoprotective and anti-secretory doses) differ only quantitatively but not qualitatively; the drug effects on the membrane-located ATP-splitting enzymes (membrane ATPase and adenylate cyclase) in human gastric, duodenal and jejunal mucosa are similar to those in rats, but their affinities (pD2) and also their intrinsic activities (alpha) differ to the enzyme systems.

Evidence of the gastric cytoprotective effects of vitamin A, atropine and cimetidine on the development of gastric mucosal damage produced by administration of indomethacin in healthy subjects.

Certain compounds such as prostaglandins, atropine, cimetidine and carotenes are able to prevent the development of gastric mucosal damage produced in experimental animals or in man by intragastric administration of necrotizing agents such as indomethacin without significantly inhibiting gastric acid secretion. The clinical background of this gastric cytoprotection and its importance for man is not yet known, although the beneficial effects of these compounds have been demonstrated in human therapy. In the present study, carried out in 66 healthy human subjects, it was found that vitamin A at a dose of 100,000 IU i.m., atropine at 0.125 mg i.m., and cimetidine at 12.5 mg i.m., which doses do not inhibit the gastric basal secretion nor the maximal secretory response to pentagastrin stimulation, each prevented the gastric microbleeding produced by the oral application of indomethacin. It is concluded that this gastric cytoprotection, characteristic of prostaglandins but extending to atropine, cimetidine and vitamin A, holds good in man as well as experimental animals. Thus the potential clinical significance of gastric cytoprotection induced by these compounds may be considerable.