588 research outputs found
Torsion and Inflammation of Meckel's Diverticulum: Rare Cause of Acute Abdominal Pain
Meckel's diverticulum is a remnant of the embryologic vitelline duct. It was named after its anatomical
and embryological description, in the early 19th century, by Johann Meckel. It is known as a true
diverticulum of the small bowel and is typically estimated to be present in 2% of the general population,
with only a very small percentage being symptomatic. In this report, we present a 14-year-old boy with
complaints of abdominal pain, fever, nausea, vomiting and diarrhea. During physical examination we
observed peritoneal irritation and raised inflammatory markers. Surgical exploration revealed torsion
and inflammation of a large Meckel's diverticulum with a gangrenous area. In order to ensure the
removal of etopic tissue, if present, segmental bowel resection with primary anastomosis was performed.
Histopathological analysis did not find ectopic tissue. The operative and postoperative courses were
uneventful. Meckel's diverticulum is an important differential diagnosis in acute abdominal pain in
children.info:eu-repo/semantics/publishedVersio
Persistence of Left Superior Vena Cava Associated to Esophageal Atresia: Presentation of 5 Cases
Objectivos: A atresia do esófago estå associada a uma variedade de malformaçÔes congénitas de outros órgãos. A
persistĂȘncia da veia cava superior esquerda e uma das malformaçÔes venosas torĂĄcicas mais comuns, ocorrendo em 0,3% da população. O objectivo deste estudo Ă© caracterizar a persistĂȘncia da veia cava superior esquerda nos doentes com atresia do esĂłfago tratados no Hospital Dona EstefĂąnia.
MĂ©todos: Estudo retrospectivo dos doentes admitidos por atresia do esĂłfago desde Janeiro 2002 a Dezembro 2013. As
seguintes variĂĄveis foram estudadas, considerando, idade gestacional, o peso Ă nascença, o sexo, tipo de atresia do esĂłfago, ecocardiograma no prĂ©-operatĂłrio, malformaçÔes associadas, abordagem cirĂșrgica, eventual ecocardiograma no pĂłs-operatĂłrio e angioressonĂąncia.
Resultados: De um total de 107 doentes, em cinco casos foi diagnosticada persistĂȘncia da veia cava superior esquerda. Destes, apenas um tinha diagnostico prĂ©-natal. A restante investigação revelou um doente com atresia duodenal e outro com
malformação do aparelho urinårio, coloboma e malformação bilateral dos pavilhÔes auriculares. Todos os cinco doentes foram
submetidos a toracotomia, esofagoesofagostomia primĂĄria apĂłs laqueação da fĂstula traqueo-esofĂĄgica e angio-ressonĂąncia para caracterizar a malformação vascular. NĂŁo houve registo de complicaçÔes, quer intra-operatĂłrias quer pĂłs-operatĂłrias.
ConclusĂŁo: Apesar do estudo prĂ©-operatĂłrio, apenas se diagnosticou persistĂȘncia da veia cava superior esquerda num dos doentes. O diagnĂłstico Ă© geralmente feito de forma incidental durante a colocação rotineira de catĂ©teres venosos centrais Ă esquerda. Ă importante identificar estes doentes e caracterizar o seu padrĂŁo de retorno venoso cardĂaco, pelo risco de complicaçÔes embĂł1icas paradoxais para o sistema arterial
Perivascular Epithelioid Cell Tumor: A Case Report of a Rare Entity
Perivascular epithelioid cell tumor is a rare mesenchymal tumor with myomelanocytic differentiation. It mainly
occurs in middle-aged females and can be found at any location. The differential diagnosis is broad but
the immunohistochemical biomarkers establish the diagnosis. A 4-year-old girl was referred to a pediatric
gastroenterology clinic due to recurrent umbilical pain and the workup revealed biliary lithiasis. She remained
in follow-up, asymptomatic, no physical findings, and stable ultrasound. Six years later, a supra-umbilical
mass was detected by ultrasound, and the magnetic resonance imaging revealed a highly vascularized intraperitoneal tumor with well-defined limits. Surgical mass resection was performed, and the histology revealed morphological and immunohistochemical aspects of a perivascular epithelioid cell tumor of the abdominal wall. Given the size of the lesion (> 5 cm) and admitting uncertain malignant potential, she was submitted to margin enlargement. Four years later, she remains asymptomatic without clinical or imagiological evidence of relapse.info:eu-repo/semantics/publishedVersio
Interacting mindreaders
Could interacting mindreaders be in a position to know things which they would be unable to know if they were manifestly passive observers? This paper argues that they could. Mindreading is sometimes reciprocal: the mindreader's target reciprocates by taking the mindreader as a target for mindreading. The paper explains how such reciprocity can significantly narrow the range of possible interpretations of behaviour where mindreaders are, or appear to be, in a position to interact. A consequence is that revisions and extensions are needed to standard theories of the evidential basis of mindreading. The view also has consequences for understanding how abilities to interact combined with comparatively simple forms of mindreading may explain the emergence, in evolution or development, of sophisticated forms of social cognition
Cognitive loading affects motor awareness and movement kinematics but not locomotor trajectories during goal-directed walking in a virtual reality environment.
The primary purpose of this study was to investigate the effects of cognitive loading on movement kinematics and trajectory formation during goal-directed walking in a virtual reality (VR) environment. The secondary objective was to measure how participants corrected their trajectories for perturbed feedback and how participants' awareness of such perturbations changed under cognitive loading. We asked 14 healthy young adults to walk towards four different target locations in a VR environment while their movements were tracked and played back in real-time on a large projection screen. In 75% of all trials we introduced angular deviations of ±5° to ±30° between the veridical walking trajectory and the visual feedback. Participants performed a second experimental block under cognitive load (serial-7 subtraction, counter-balanced across participants). We measured walking kinematics (joint-angles, velocity profiles) and motor performance (end-point-compensation, trajectory-deviations). Motor awareness was determined by asking participants to rate the veracity of the feedback after every trial. In-line with previous findings in natural settings, participants displayed stereotypical walking trajectories in a VR environment. Our results extend these findings as they demonstrate that taxing cognitive resources did not affect trajectory formation and deviations although it interfered with the participants' movement kinematics, in particular walking velocity. Additionally, we report that motor awareness was selectively impaired by the secondary task in trials with high perceptual uncertainty. Compared with data on eye and arm movements our findings lend support to the hypothesis that the central nervous system (CNS) uses common mechanisms to govern goal-directed movements, including locomotion. We discuss our results with respect to the use of VR methods in gait control and rehabilitation
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Failure behavior of internally pressurized flawed and unflawed steam generator tubing at high temperatures -- Experiments and comparison with model predictions
This report summarizes experimental work performed at Argonne National Laboratory on the failure of internally pressurized steam generator tubing at high temperatures ({le} 700 C). A model was developed for predicting failure of flawed and unflawed steam generator tubes under internal pressure and temperature histories postulated to occur during severe accidents. The model was validated by failure tests on specimens with part-through-wall axial and circumferential flaws of various lengths and depths, conducted under various constant and ramped internal pressure and temperature conditions. The failure temperatures predicted by the model for two temperature and pressure histories, calculated for severe accidents initiated by a station blackout, agree very well with tests performed on both flawed and unflawed specimens
The role of motor simulation in action perception: a neuropsychological case study
Research on embodied cognition stresses that bodily and motor processes constrain how we perceive others. Regarding action perception the most prominent hypothesis is that observed actions are matched to the observerâs own motor representations. Previous findings demonstrate that the motor laws that constrain oneâs performance also constrain oneâs perception of othersâ actions. The present neuropsychological case study asked whether neurological impairments affect a personâs performance and action perception in the same way. The results showed that patient DS, who suffers from a frontal brain lesion, not only ignored target size when performing movements but also when asked to judge whether others can perform the same movements. In other words DS showed the same violation of Fittsâs law when performing and observing actions. These results further support the assumption of close perception action links and the assumption that these links recruit predictive mechanisms residing in the motor system
Making oneself predictable: reduced temporal variability facilitates joint action coordination
Performing joint actions often requires precise temporal coordination of individual actions. The present study investigated how people coordinate their actions at discrete points in time when continuous or rhythmic information about othersâ actions is not available. In particular, we tested the hypothesis that making oneself predictable is used as a coordination strategy. Pairs of participants were instructed to coordinate key presses in a two-choice reaction time task, either responding in synchrony (Experiments 1 and 2) or in close temporal succession (Experiment 3). Across all experiments, we found that coactors reduced the variability of their actions in the joint context compared with the same task performed individually. Correlation analyses indicated that the less variable the actions were, the better was interpersonal coordination. The relation between reduced variability and improved coordination performance was not observed when pairs of participants performed independent tasks next to each other without intending to coordinate. These findings support the claim that reducing variability is used as a coordination strategy to achieve predictability. Identifying coordination strategies contributes to the understanding of the mechanisms involved in real-time coordination
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