Tandem-repeat proteins conformational mechanics are optimized to facilitate functional interactions and complexations.

The architectures of tandem-repeat proteins are distinct from those of globular proteins. Individual modules, each comprising small structural motifs of 20-40 residues, are arrayed in a quasi one-dimensional fashion to form striking, elongated, horseshoe-like, and superhelical architectures, stabilized solely by short-range interaction. The spring-like shapes of repeat arrays point to elastic modes of action, and these proteins function as adapter molecules or 'hubs,' propagating signals within multi-subunit assemblies in diverse biological contexts. This flexibility is apparent in the dramatic variability observed in the structures of tandem-repeat proteins in different complexes. Here, using computational analysis, we demonstrate the striking ability of just one or a few global motions to recapitulate these structures. These findings show how the mechanics of repeat arrays are robustly enabled by their unique architecture. Thus, the repeating architecture has been optimized by evolution to favor functional modes of motions. The global motions enabling functional transitions can be fully visualized at http://bahargroup.org/tr_web.

Assessing the vulnerability of endangered and endemic brooding sea urchin Cassidulus mitis in response to climate change: Impacts on larvae and settlers in the southwestern Atlantic.

Echinoderms play important roles in marine ecosystems and exhibit high sensitivity to environmental changes. The echinoid Cassidulus mitis has been considered an endangered species due to its restricted geographic distribution and unique reproductive behavior, with an epibenthic lecithotrophic larva and offspring brooded among the female spines during initial development until the settler stage. We studied the effects of low salinities (30 and 26) and high temperatures (27 and 31 °C) on the early development of C. mitis in a predicted scenario of global climate change through four parameters: 1. survival and 2. chronology of larval development, and 3. survival and 4. growth of settlers. Both larvae and settlers of C. mitis can survive under these scenarios, probably due to the lecithotrophic and epibenthic larval characteristics and developmental strategies of this species. However, all experimental conditions affected at least one of the initial developmental studied parameters of C. mitis, potentially compromising the species' viability in a scenario of climate change.

Direct Measurement of Nucleoside Ribohydrolase Enzyme Activities in Trichomonas vaginalis Cells Using 19F and 13C-Edited 1H NMR Spectroscopy.

Trichomoniasis is the most common nonviral sexually transmitted infection, affecting an estimated 275 million people worldwide. The causative agent is the parasitic protozoan Trichomonas vaginalis. Although the disease itself is typically mild, individuals with trichomonal infections have a higher susceptibility to more serious conditions. The emergence of parasite strains resistant to current therapies necessitates the need for novel treatment strategies. Since T. vaginalis is an obligate parasite that requires nucleoside salvage pathways, essential nucleoside ribohydrolase enzymes are promising new drug targets. Fragment screening and X-ray crystallography have enabled structure-guided design of inhibitors for two of these enyzmes. Linkage of enzymatic and antiprotozoal activity would be a transformative step toward designing novel, mechanism-based therapeutic agents. While a correlation with inhibition of purified enzyme would be mechanistically suggestive, a correlation with inhibition of in-cell enzyme activity would definitively establish this linkage. To demonstrate this linkage, we have translated our NMR-based activity assays that measure the activity of purified enzymes for use in T. vaginalis cells. The 19F NMR-based activity assay for the pyrimidine-specific enzyme translated directly to in-cell assays. However, the 1H NMR-based activity assay for the purine-specific enzyme required a switch from adenosine to guanosine substrate and the use of 13C-editing to resolve the substrate 1H signals from cell and growth media background signals. The in-cell NMR assays are robust and have been demonstrated to provide inhibition data on test compounds. The results described here represent the first direct measurement of enzyme activity in protozoan parasite cells.

Desarrollo de una Escala de Calidad de la Información transmitida por Medios de Comunicación Electrónicos (ECIME) / Development of a Quality Information Scale broadcasted by Electronic Media (QISEM)

Resumen La producción de la información, en relación con su calidad dentro de la práctica periodística en general, está supeditada a diversos criterios, como la veracidad de la fuente, la acreditación de los autores, la comprensión del texto y la relevancia de la información, entre otros indicadores. El objetivo del presente trabajo fue desarrollar una escala para evaluar la calidad de la información transmitida por medios de comunicación en Internet. Para ello, se realizaron tres etapas generales: la primera estuvo conformada por 13 estudios, donde, después de un análisis de contenido, se extrajeron las dimensiones o aspectos de la calidad de la información más frecuentemente mencionados. Posteriormente, se procedió a la detección de 35 indicadores, clasificados en 5 dimensiones; en la segunda se obtuvieron 65 ítems, a partir de la clasificación de 5 dimensiones y los 35 indicadores; en la tercera se pilotó el instrumento obtenido, el cual adquirió un formato de lista de verificación integrado por 38 ítems, y con el propósito de determinar la validez de discriminación y la confiabilidad de la escala, se aplicó a una muestra no aleatoria de 100 noticias sobre COVID-19, publicadas en sitios de internet durante el 21 de enero de 2020 y el 31 de julio de 2021. La escala desarrollada permitió evaluar la calidad de la información que se transmite por medios de comunicación electrónicos, por lo que puede ser utilizada para mejorar las prácticas de los encargados de construir el contenido informativo y divulgarlo.

Abstract Information production, regarding its quality within journalistic practice in general, is subject to various criteria, such as the veracity of the source, the accreditation of the authors, the understanding of the text, and the relevance of the information, among other indicators. The objective of the present work was to develop a scale to assess the quality of information broadcasted by media on the Internet. To achieve this goal, three general stages were carried out: the first consisted of 13 studies, where, after a content analysis, the most frequently mentioned quality information dimensions were extracted. Subsequently, 35 indicators classified in 5 dimensions were detected. In the second stage, 65 items were obtained from the classification of 5 dimensions and 35 indicators. In the third stage, the obtained instrument was piloted. The instrument acquired a checklist format made up of 38 items. To determine the discrimination validity and the reliability of the scale, it was applied to a non-random sample of 100 COVID-19 news posted on internet sites from January 21st, 2020, to July 31, 2021. The developed scale allowed the evaluation of the quality of information broadcasted by electronic media, it can therefore be used to improve the practices of those in charge of constructing the informative content and disseminating it.

Development of an Innovative Mechatronic Binder Machine.

This paper describes the development of a mechatronic punch and bind office machine. Integrating smart technologies in the existing traditional business machines will ease the evolution of these systems, enabling productivity and efficiency. The development of an experimental platform that enables further advances in servitization is required. To increase the binding rate of the office document, as well as to reduce the likelihood of errors, efforts have been made to develop a measuring system that allows the document to be properly measured and specifies the appropriate binding spine at the same time. As a complement, developments have been conducted in a system that enables the verification of the inserted spine. In addition, a system for automated document binding along with an integrated platform that allows the communication between all systems is presented. In both its hardware design and its underlying sensors, the new system has several advantages, providing significant performance improvements and upgradability over existing systems. This alternative comprises a system that enables a variety of sheets of paper, plastic or other materials to be punched.

Chemical defense in developmental stages and adult of the sea star Echinaster (Othilia) brasiliensis.

To date, evidence regarding the performance of secondary metabolites from larval stages of sea stars as an anti-predation defense relates only to a few species/specimens from a few geographic ranges. Unfortunately, this hinders a comprehensive global understanding of this inter-specific predator-prey interaction. Here, we present laboratory experimental evidence of chemical defense action in the early developmental stages and adults of the sea star Echinaster (Othilia) brasiliensis from Brazil against sympatric and allopatric invertebrate consumers. Blastulae, early and late brachiolarias of E. (O.) brasiliensis were not consumed by the sympatric and allopatric crabs Mithraculus forceps. Blastulae were also avoided by the sympatric and allopatric individuals of the anemone Anemonia sargassensis, but not the larval stages. Extracts from embryos (blastula) and brachiolarias of E. (O.) brasiliensis from one sampled population (João Fernandes beach) significantly inhibited the consumption by sympatric M. forceps, but not by allopatric crabs and A. sargassensi anemone. In this same site, extracts from adults E. (O.) brasiliensis significantly inhibited the consumption by sympatric and allopatric specimens of the crab in a range of concentrations. Whereas equivalent extract concentrations of E. (O.) brasiliensis from other population (Itaipu beach)inhibited the predation by allopatric M. forceps, while sympatric individuals of this crab avoided the only the higher level tested. Then, early stages and adult specimens of E. (O.) brasiliensis can be chemically defended against consumers, but this action is quite variable, depending on the type (anemone or crab) and the origin of the consumer (sympatric or allopatric).

Locomotion and righting behavior of sea stars: a study case on the bat star Asterina stellifera (Asterinidae) / Comportamiento de locomoción y enderezamiento en estrellas de mar: un caso de estudio sobre la estrella Asterina stellifera (Asterinidae)

Introduction: The locomotion behavior of an organism involves the integration of aspects like body symmetry, sensory and locomotor systems. Furthermore, various ecological factors seem to be related to locomotion characteristics, such as foraging strategy, migration trends, response to predators and competitors, and environmental stress. Objective: To analyze locomotion and the influence of body symmetry in the crawling and righting movements of the sea star Asterina stellifera. Methods: We carried out laboratory experiments in aquariums in the presence/absence of water current and on a horizontal and vertical surface. Results: The speed is similar to speed in other species of similar size. Both the speed and linearity of displacement were independent of individual body size. A water current leads to faster crawling and straight paths, but there is no rheotaxis: streams do not affect locomotion. Speed and linearity of displacement were independent of individual body size. The displacement pattern described here may be an adaptation of organisms that present dense populations in communities with high prey abundance, as is the case of A. stellifera. Conclusions: Like other asteroids, this species did not show an Anterior/Posterior plane of symmetry during locomotion, or righting movement: it does not tend to bilaterality.

Introducción: El comportamiento de locomoción de un organismo implica la integración de aspectos como la simetría corporal, los sistemas sensorial y locomotor. Además, varios factores ecológicos parecen estar relacionados con las características de la locomoción, como la estrategia de alimentación, las tendencias migratorias, la respuesta a los depredadores y competidores y el estrés ambiental. Objetivo: Analizar el patrón general de locomoción y la influencia de la simetría corporal en la locomoción y enderezamiento de la estrella de mar Asterina stellifera. Métodos: Realizamos experimentos de laboratorio en acuarios en presencia / ausencia de corriente de agua y en superficie horizontal y vertical. Resultados: La velocidad es similar a la velocidad en otras especies de tamaño similar. Tanto la velocidad como la linealidad del desplazamiento fueron independientes del tamaño corporal individual. Una corriente de agua conduce a una velocidad de desplazamiento mayor y a trayectorias más rectas, pero no hay reotaxis: una corriente de agua no afecta el patrón de locomoción. La velocidad y la linealidad del desplazamiento fueron independientes del tamaño corporal individual. El patrón de desplazamiento aquí descrito puede ser una adaptación de organismos que presentan densas poblaciones en comunidades con alta abundancia de presas, como es el caso de A. stellifera. Conclusiones: Al igual que otros asteroides, esta especie no mostró un plano de simetría Anterior / Posterior durante la locomoción o el movimiento de enderezamiento: no tiende a la bilateralidad.

How can an infaunal brooding echinoid be maintained in the laboratory? A case study with Cassidulus mitis (Echinoidea: Cassiduloida) / ¿Cómo se puede mantener un equinoide infantil en el laboratorio? Un estudio de caso con Cassidulus mitis (Echinoidea: Cassiduloida)

Introduction: Cassiduloids play a prominent role in echinoid evolutionary history because they probably are the ancestral group of clypeasteroids. Some extant species are brooding and rare in the environment. Consequently, there are no studies on their maintenance in the laboratory. Objective: Establish an efficient aquarium system for C. mitis, endemic to Brazil, for ontogenetic studies. Methods: Four aquarium systems were built, with 3 replicates each one: (1) with seawater flow [F]; (2) with seawater flow and air injection into sediment [FA]; (3) without seawater flow but with air injection into the sediment [A]; and (4) without both seawater flow and air injection into the sediment [C]. Each experimental aquarium (three per treatment) had two adults. Each of the two sets of experiments lasted about 60 days. Results: We observed low mortality in the first 30 days in all systems and, after 30 days, it was higher in those with air-pumped into the sediment (system A in the first set of experiments, and system FA in the second one). Conclusions: For experiments lasting 30 days, our four systems are suitable. For longer periods, we recommend aquaria with seawater flow and without air-pumps into the sediment.

Introducción: Los casiduloides desempeñan un papel destacado en la historia evolutiva de los equinoides porque probablemente son el grupo ancestral de clipeasteroides. Algunas especies existentes son inquietantes y raras en el medio ambiente. En consecuencia, no existen estudios sobre su mantenimiento en laboratorio. Objetivo: Establecer un sistema de acuario eficiente para C. mitis, endémica de Brasil, para estudios ontogenéticos. Métodos: Se construyeron cuatro sistemas de acuarios, con 3 réplicas cada uno: (1) con flujo de agua de mar [F]; (2) con flujo de agua de mar e inyección de aire en el sedimento [FA]; (3) sin flujo de agua de mar pero con inyección de aire en el sedimento [A]; y (4) sin flujo de agua de mar ni inyección de aire en el sedimento [C]. Cada acuario experimental (tres por tratamiento) tenía dos adultos. Cada uno de los dos conjuntos de experimentos duró aproximadamente 60 días. Resultados: Observamos una baja mortalidad en los primeros 30 días en todos los sistemas y, después de 30 días, fue mayor en aquellos con aire bombeado al sedimento (sistema A en el primer conjunto de experimentos y sistema FA en el segundo). Conclusiones: Para experimentos de 30 días, nuestros cuatro sistemas son adecuados. Para períodos más largos, recomendamos acuarios con flujo de agua de mar y sin bombas de aire en el sedimento.

Initial experience with Duplex scan combined with contrast-enhanced ultrasound for follow-up of endovascular abdominal aortic aneurysm repair.

Background: Microbubble contrast enhanced ultrasound (CEUS) is an accurate diagnostic method for follow-up after endovascular abdominal aortic aneurysm repair (EVAR) that has been well-established in international studies. However, there are no Brazilian studies that focus on this follow-up method. Objectives: The objective of this study was to report initial experience with CEUS at a tertiary hospital, comparing the findings of CEUS with those of conventional Doppler ultrasound (DUS), with the aim of determining whether addition of contrast to the standard ultrasonographic control protocol resulted in different findings. Methods: From 2015 to 2017, 21 patients in follow-up after EVAR underwent DUS followed by CEUS. The findings of these examinations were analyzed in terms of identification of complications and their capacity to identify the origin of endoleaks. Results: There was evidence of complications in 10 of the 21 cases examined: seven patients exhibited endoleaks (33.3%); two patients exhibited stenosis of a branch of the endograft (9.52%); and one patient exhibited a dissection involving the external iliac artery (4.76%). In the 21 patients assessed, combined use of both methods identified 10 cases of post-EVAR complications. In six of the seven cases of endoleaks (85.71%), use of the methods in combination was capable of identifying the origin of endoleakage. DUS alone failed to identify endoleaks in two cases (28.5%) and identified doubtful findings in another two cases (28.5%), in which diagnostic definition was achieved after employing CEUS. Conclusions: CEUS is a technique that is easy to perform and provides additional support for follow-up of infrarenal EVAR.

Experiência inicial com ultrassom Doppler com contraste por microbolhas em adição ao ultrassom Doppler convencional para seguimento de correção endovascular de aneurisma de aorta abdominal / Initial experience with Duplex scan combined with contrast-enhanced ultrasound for follow-up of endovascular abdominal aortic aneurysm repair

Resumo Contexto O ultrassom contrastado por microbolhas (CMUS) é uma modalidade diagnóstica de acurácia bem demonstrada por estudos internacionais para seguimento de reparo endovascular do aneurisma de aorta abdominal (EVAR). Não existem, no entanto, estudos nacionais focados nesse método de seguimento. Objetivos O objetivo deste estudo foi relatar a experiência inicial com CMUS em um hospital terciário, traçando uma comparação dos achados do CMUS com o ultrassom Doppler convencional (USGD), com o intuito de verificar se a adição de contraste ao protocolo padrão de controle ultrassonográfico incorreu alteração nos achados. Métodos Entre 2015 e 2017, 21 pacientes em seguimento de EVAR foram submetidos ao USGD seguido de CMUS. Foram avaliados os achados de exame referentes à identificação de complicações, bem como à capacidade de identificação da origem da endofuga. Resultados Entre os 21 casos avaliados, 10 complicações foram evidenciadas no total: sete pacientes apresentaram endofuga (33,3%); dois pacientes apresentaram estenose em ramo de endoprótese (9,52%); e um paciente apresentou dissecção em artéria ilíaca externa (4,76%). Em 21 pacientes avaliados, o uso combinado dos métodos identificou 10 casos de complicações pós-EVAR. Em seis dos sete casos de endofugas (85,71%), o uso dos métodos combinados foi capaz de identificar a origem. O USGD isolado falhou na identificação da endofuga em dois casos (28,5%), identificando achados duvidosos em outros dois casos (28,5%), que obtiveram definição diagnóstica após associação do CMUS. Conclusões O CMUS é uma técnica de fácil execução, a qual adiciona subsídios ao seguimento de EVAR infrarrenal.

Abstract Background Microbubble contrast enhanced ultrasound (CEUS) is an accurate diagnostic method for follow-up after endovascular abdominal aortic aneurysm repair (EVAR) that has been well-established in international studies. However, there are no Brazilian studies that focus on this follow-up method. Objectives The objective of this study was to report initial experience with CEUS at a tertiary hospital, comparing the findings of CEUS with those of conventional Doppler ultrasound (DUS), with the aim of determining whether addition of contrast to the standard ultrasonographic control protocol resulted in different findings. Methods From 2015 to 2017, 21 patients in follow-up after EVAR underwent DUS followed by CEUS. The findings of these examinations were analyzed in terms of identification of complications and their capacity to identify the origin of endoleaks. Results There was evidence of complications in 10 of the 21 cases examined: seven patients exhibited endoleaks (33.3%); two patients exhibited stenosis of a branch of the endograft (9.52%); and one patient exhibited a dissection involving the external iliac artery (4.76%). In the 21 patients assessed, combined use of both methods identified 10 cases of post-EVAR complications. In six of the seven cases of endoleaks (85.71%), use of the methods in combination was capable of identifying the origin of endoleakage. DUS alone failed to identify endoleaks in two cases (28.5%) and identified doubtful findings in another two cases (28.5%), in which diagnostic definition was achieved after employing CEUS. Conclusions CEUS is a technique that is easy to perform and provides additional support for follow-up of infrarenal EVAR.

Intraspecific genetic structure, divergence and high rates of clonality in an amphi-Atlantic starfish.

Intraspecific genetic diversity and divergence have a large influence on the adaption and evolutionary potential of species. The widely distributed starfish, Coscinasterias tenuispina, combines sexual reproduction with asexual reproduction via fission. Here we analyse the phylogeography of this starfish to reveal historical and contemporary processes driving its intraspecific genetic divergence. We further consider whether asexual reproduction is the most important method of propagation throughout the distribution range of this species. Our study included 326 individuals from 16 populations, covering most of the species' distribution range. A total of 12 nuclear microsatellite loci and sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene were analysed. COI and microsatellites were clustered in two isolated lineages: one found along the southwestern Atlantic and the other along the northeastern Atlantic and Mediterranean Sea. This suggests the existence of two different evolutionary units. Marine barriers along the European coast would be responsible for population clustering: the Almeria-Oran Front that limits the entrance of migrants from the Atlantic to the Mediterranean, and the Siculo-Tunisian strait that divides the two Mediterranean basins. The presence of identical genotypes was detected in all populations, although two monoclonal populations were found in two sites where annual mean temperatures and minimum values were the lowest. Our results based on microsatellite loci showed that intrapopulation genetic diversity was significantly affected by clonality whereas it had lower effect for the global phylogeography of the species, although still some impact on populations' genetic divergence could be observed between some populations.

Early time course of variation in coelomic fluid ionic concentrations in sea urchins abruptly exposed to hypo- and hyper-osmotic salinity challenges: Role of size and cross-section area of test holes.

Echinoderms are restricted to the marine environment and are osmoconformer invertebrates. However, some species live in unstable environments. Especially those species, and those of larger body size, tend to show variable, albeit transient, ionic gradients between their coelomic fluid and external seawater. In order to further examine how sea urchin size relates to apparent ionic permeability of their body wall/epithelia, specimens of Echinometra lucunter, Lytechinus variegatus, Paracentrotus gaimardi, and Arbacia lixula-A. lixula of two distinct populations, Rio de Janeiro and Santa Catarina-were abruptly transferred from 35 psu to either 25 or 45 psu. Sodium, chloride, magnesium, and potassium concentrations were assayed in their coelomic fluids after 0, 1, 2, and 3 hr of exposure. Relative area of putative permeable (i.e., cross section areas of soft tissues, or test holes) surfaces (PPS) was estimated in empty tests as the sum of the peristomial area (oral hole in the empty test) and the total cross-section area of ambulacral holes, divided by the total volume (TV) of the test. L. variegatus and E. lucunter, the largest species, had PPS/TV values similar to that of the much smaller P. gaimardi. A. lixula was the "most putatively-permeable and conformer" among them all, especially urchins from the Santa Catarina population. Internal ionic levels equilibrated faster with external water in 45 than in 25, and differences among ions were observed. Body size is relevant, among many other factors, to aid conformers such as sea urchins to dwell in intertidal unstable habitats.

Evaluación de los estilos de aprendizaje en estudiantes de medicina / Assessing learning styles in medical students

Los estudiantes se diferencian en sus preferencias de los estilos (modalidades) para aprender. Los estilos de aprendizaje han ganado un lugar de importancia entre los docentes en los diferentes niveles de educación. Conocerlas puede mejorar no sólo el enfoque del estudiante en particular, de la producción de cursos de capacitación, escritura de libros o materiales de enseñanza, sino, también, del ambiente y los procesos educativos. Realizamos este estudio para conocer las preferencias de estilos de aprendizaje de nuestros estudiantes en el Departamento de Salud Colectiva de la Carrera de Medicina de la Universidad Nacional del Comahue. Se realizó un estudio de diseño transversal. Participaron 95 estudiantes de la cátedra de Fisiopatología del año 2014. Fue utilizado el cuestionario VARK. Fueron 69% mujeres y 31% hombres. Cuando se realizó la comparación de las modalidades de acuerdo con el sexo, se observó mayor proporción de hombres con modalidad unimodal (48%) que de mujeres (27%). Del total, el 33.7% presentó un modalidad unimodal; al realizar la agrupación de modalidades, el 40% fue bimodal, el 20% trimodal y el 6.3% cuatrimodal. Del 40% que presentó preferencia bimodal, el 36% fue la combinación de auditivo/lectoescritura, seguido por el 26% que fue auditivo/cinestésico. Los resultados nos muestran que la mayoría de nuestros estudiantes tuvieron un modo multimodal de aprendizaje. Se destacan dos preferencias sensoriales, la auditiva y la cinestésica, seguida por la lectoescritura y, por último, la modalidad visual. No todos aprendemos de la misma manera, esto lo debemos tener en cuenta para diseñar las estrategias de enseñanza a nuestros estudiantes. El conocimiento de las modalidades de aprendizaje en nuestros estudiantes nos muestra que el diseño propuesto de técnicas de enseñanza aprendizaje que estamos utilizando sería adecuado a ellas

Students differ in their preferences for learning styles (modalities). Knowledge about learning styles among students has become a relevant issue for teachers from all educational levels. Therefore, knowing those preferences would allow teachers not only to focus on development of training programs, textbooks and educational materials but also on the teaching-learning process. We conducted this study to determine the preferences of learning styles of our students from the Collective Health Department at the School of Medicine of the Universidad Nacional del Comahue. It was a cross-sectional study involving ninety-five students from the 2014 Pathophysiology course. The VARK questionnaire was used. 69% of students were women and 31% were men. When comparing the styles according to gender a greater proportion of men showed unimodal modality (48%), while 33.7% of students presented a unimodal mode of learning. On the other hand, of those who presented more than one modality of learning, 40% preferred bimodal style, 20% trimodal and 6.3% cuatrimodal. Of the 40% presenting a bimodal modality, 36% were a combination between auditory/reading-writing and 26% were auditory/kinesthetic. The results showed that most of our students used a multimodal form of learning. The most common sensory preferences were auditory and kinesthetic, secondly reading-writing, and lastly the visual mode. We do not all learn in the same way, and this must be borne in mind when designing teaching strategies for our students. Knowledge of their styles of learning shows us that the teaching and learning techniques we are using appear to be adequate

Development of the Sea Star Echinaster (Othilia) brasiliensis, with Inference on the Evolution of Development and Skeletal Plates in Asteroidea.

We describe the development and juvenile morphology of the sea star Echinaster (Othilia) brasiliensis in order to explore evolutionary developmental modes and skeletal homologies. This species produces large, buoyant eggs (0.6 ± 0.03 mm diameter), and has a typical lecithotrophic brachiolaria larva. The planktonic brachiolaria larva is formed 2-4 days after fertilization, when cilia cover the surface. Early juveniles are completely formed by 18 days of age. Initial growth is supported by maternal nutrients while the stomach continues to develop until 60 days after fertilization, when juveniles reach about 0.5 mm of radius length. The madreporite was observed 88 days after fertilization. In the youngest juvenile skeleton of E. (O.) brasiliensis, the madreporite and odontophore are homologous to those of other recent, non-paxillosid asteroids, and follow the Late Madreporic Mode. The emergence of plates related to the ambulacral system follows the Ocular Plate Rule. The development and juvenile skeletal morphology of this species are similar to those of the few other studied species in the genus Echinaster. This study corroborates the notion that the mode of development--including a short-lived lecithotrophic brachiolaria larva--in all Echinaster species shares a similar pattern that may be conserved throughout the evolutionary history of the group.

Volumetry and biomechanical parameters detected by 3D and 2D ultrasound in patients with and without an abdominal aortic aneurysm.

The objective was to demonstrate the ability of ultrasound (US) with 3D properties to evaluate volumetry and biomechanical parameters of the aorta in patients with and without abdominal aortic aneurysm (AAA). Thirty-one patients with normal aortas (group 1), 46 patients with AAA measuring 3.0-5.5 cm (group 2) and 31 patients with AAA ⩾ 5.5 cm (group 3) underwent a 2D/3D-US examination of the infra-renal aorta, and the images were post-processed prior to being analyzed. In the maximum diameter, the global circumferential strain and the global maximum rotation assessed by 2D speckle-tracking algorithms were compared among the three groups. The volumetry data obtained using 3D-US from 40 AAA patients were compared with the volumetry data obtained by a contemporary computed tomography (CT) scan. The median global circumferential strain was 2.0% (interquartile range (IR): 1.0-3.0), 1.0% (IR: 1.0-2.0) and 1.0% (IR: 1.0-1.75) in groups 1, 2 and 3, respectively (p < 0.001). The median global maximum rotation decreased progressively from group 1 to group 3 (1.38º (IR: 0.77-2.13), 0.80º (IR: 0.57-1.0) and 0.50º (IR: 0.31-0.75), p < 0.001). AAA volume estimations by 3D-US correlated well with CT (R(2) = 0.76). In conclusion, US with 3D properties is non-invasive and has the potential to evaluate volumetry and biomechanical characteristics of AAA.

Can contrast-enhanced ultrasound with second-generation contrast agents replace computed tomography angiography for distinguishing between occlusion and pseudo-occlusion of the internal carotid artery?

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of contrast-enhanced ultrasound with a second-generation contrast agent in distinguishing between occlusion and pseudo-occlusion of the cervical internal carotid artery, comparing it with that of conventional Doppler ultrasound and the gold standard, computed tomography angiography. METHOD: Between June 2006 and June 2012, we screened 72 symptomatic vascular surgery outpatients at a public hospital. Among those patients, 78 cervical internal carotid arteries were previously classified as occluded by Doppler ultrasound (without contrast). The patients were examined again with Doppler ultrasound, as well as with contrast-enhanced ultrasound and computed tomography angiography. The diagnosis was based on the presence or absence of flow. RESULTS: Among the 78 cervical internal carotid arteries identified as occluded by Doppler ultrasound, occlusion was confirmed by computed tomography angiography in only 57 (73.1%), compared with 59 (77.5%) for which occlusion was confirmed by contrast-enhanced ultrasound (p>0.5 vs. computed tomography angiography). Comparing contrast-enhanced ultrasound with Doppler ultrasound, we found that the proportion of cervical internal carotid arteries classified as occluded was 24.4% higher when the latter was used (p<0.001). CONCLUSIONS: We conclude that, in making the differential diagnosis between occlusion and pseudo-occlusion of the cervical internal carotid artery, contrast-enhanced ultrasound with a second-generation contrast agent is significantly more effective than conventional Doppler ultrasound and is equally as effective as the gold standard (computed tomography angiography). Our findings suggest that contrast-enhanced ultrasound could replace computed tomography angiography in this regard.

Can contrast-enhanced ultrasound with second-generation contrast agents replace computed tomography angiography for distinguishing between occlusion and pseudo-occlusion of the internal carotid artery?

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of contrast-enhanced ultrasound with a second-generation contrast agent in distinguishing between occlusion and pseudo-occlusion of the cervical internal carotid artery, comparing it with that of conventional Doppler ultrasound and the gold standard, computed tomography angiography. METHOD: Between June 2006 and June 2012, we screened 72 symptomatic vascular surgery outpatients at a public hospital. Among those patients, 78 cervical internal carotid arteries were previously classified as occluded by Doppler ultrasound (without contrast). The patients were examined again with Doppler ultrasound, as well as with contrast-enhanced ultrasound and computed tomography angiography. The diagnosis was based on the presence or absence of flow. RESULTS: Among the 78 cervical internal carotid arteries identified as occluded by Doppler ultrasound, occlusion was confirmed by computed tomography angiography in only 57 (73.1%), compared with 59 (77.5%) for which occlusion was confirmed by contrast-enhanced ultrasound (p>0.5 vs. computed tomography angiography). Comparing contrast-enhanced ultrasound with Doppler ultrasound, we found that the proportion of cervical internal carotid arteries classified as occluded was 24.4% higher when the latter was used (p<0.001). CONCLUSIONS: We conclude that, in making the differential diagnosis between occlusion and pseudo-occlusion of the cervical internal carotid artery, contrast-enhanced ultrasound with a second-generation contrast agent is significantly more effective than conventional Doppler ultrasound and is equally as effective as the gold standard (computed tomography angiography). Our findings suggest that contrast-enhanced ultrasound could replace computed tomography angiography in this regard. .

Plasmocitoma solitario de cráneo / Solitary plasmacytoma of the skull

El plasmocitoma solitario de cráneo (PSC) es raro y han sido publicados pocos casos en la literatura. El PSC puede presentarse dentro de un amplio espectro de cuadros clínicos, que van desde una lesión ósea aislada, de comportamiento benigno, hasta el mieloma múltiple (MM), de comportamiento extremadamente maligno. Por lo tanto, el diagnóstico adecuado del PSC requiere excluir el compromiso sistémico del MM a términos de definir el tratamiento y pronostico correspondientes.