Não compactação do Ventrículo Esquerdo. Revisão da Literatura a Propósito de um Caso Clínico

A não compactação isolada do ventrículo esquerdo (NCIVE) constitui uma etiologia rara de miocardiopatia dilatada, caracterizando-se do ponto de vista morfológico por apresentar dilatação do ventrículo esquerdo, com exuberante padrão trabecular. Embora não esteja claramente demonstrado, é geralmente aceite que a NCIVE resulta da paragem do processo de compactação miocárdica durante a embriogénese. Têm sido descritas formas familiares, estando identificadas alterações de genes que codificam proteínas de ligação entre a matriz extra-celular e o citoesqueleto. O quadro clínico é frequentemente dominado por sintomas e manifestações de insuficiência cardíaca, sendo as complicações cardio-embólicas e disrítmicas, causa frequente de morbilidade e mortalidade. O diagnóstico tem por base critérios clínicos e ecocardiográficos, e a estratégia terapêutica assenta nas recomendações estabelecidas para o tratamento da insuficiência cardíaca, destacando-se a importância da hipocoagulação e prevenção de disrtimias malignas. Os autores descrevem o caso clínico de um homem de 29 anos, internado por um quadro de insuficiência cardíaca congestiva em classe IV da NYHA, com dilatação do ventrículo esquerdo, acompanhada de exuberante trabeculação das paredes, disfunção sistólica grave e volumoso trombo apical. A evolução clínica foi favorável após terapêutica farmacológica convencional e perfusão de levosimendan, tendo tido alta melhorado, em classe I-II da NYHA. Cerca de 18 meses após alta hospitalar, faleceu subitamente no domicílio. A propósito do caso, foi feita uma revisão da literatura actual sobre a NCIVE, no que se refere à etiopatogenia, critérios de diagnóstico e orientação terapêutica

Collider Phenomenology with Split-UED

We investigate the collider implications of Split Universal Extra Dimensions. The non-vanishing fermion mass in the bulk, which is consistent with the KK-parity, largely modifies the phenomenology of Minimal Universal Exta Dimensions. We scrutinize the behavior of couplings and study the discovery reach of the Tevatron and the LHC for level-2 Kaluza-Klein modes in the dilepton channel, which would indicates the presence of the extra dimensions. Observation of large event rates for dilepton resonances can result from a nontrivial fermion mass profile along the extra dimensions, which, in turn, may corroborate extra dimensional explanation for the observation of the positron excess in cosmic rays.Comment: 23 pages, 15 figure

Multi-Photon Signals from Composite Models at LHC

We analyze the collider signals of composite scalars that emerge in certain little Higgs models and models of vectorlike confinement. Similar to the decay of the pion into photon pairs, these scalars mainly decay through anomaly-induced interactions into electroweak gauge bosons, leading to a distinct signal with three or more photons in the final state. We study the standard model backgrounds for these signals, and find that the LHC can discover these models over a large range of parameter space with 30 fb$^{-1}$ at 14 TeV. An early discovery at the current 7 TeV run is possible in some regions of parameter space. We also discuss possibilities to measure the spin of the particles in the $\gamma \gamma$ and $Z\gamma$ decay channels.Comment: 18 pages, LaTe

Síndrome coronária aguda de origem paradoxal

We describe a rare case of acute myocardial infarction secondary to paradoxical embolism complicating acute pulmonary embolism. A 44-year-old woman presented to the emergency department with chest pain. The physical examination was unremarkable except for oxygen saturation of 75%, and the electrocardiogram showed ST-segment elevation in the inferior leads. Urgent coronary angiography showed a distal occlusion of the right coronary artery and multiple thrombi were aspirated. Despite relief of chest pain and electrocardiogram normalization, her oxygen saturation remained low (90%) with high-flow oxygen by mask. The transthoracic echocardiogram showed a mass in the left atrium and dilatation of the right chambers, while the transesophageal echocardiogram showed a thrombus attached to the interatrial septum in the region of the foramen ovale. Color flow imaging was consistent with a patent foramen ovale. Thoracic computed tomography angiography documented thrombi in both branches of the pulmonary trunk. After five days on anticoagulation, the patient underwent surgical foramen ovale closure

General analysis of signals with two leptons and missing energy at the Large Hadron Collider

A signal of two leptons and missing energy is challenging to analyze at the Large Hadron Collider (LHC) since it offers only few kinematical handles. This signature generally arises from pair production of heavy charged particles which each decay into a lepton and a weakly interacting stable particle. Here this class of processes is analyzed with minimal model assumptions by considering all possible combinations of spin 0, 1/2 or 1, and of weak iso-singlets, -doublets or -triplets for the new particles. Adding to existing work on mass and spin measurements, two new variables for spin determination and an asymmetry for the determination of the couplings of the new particles are introduced. It is shown that these observables allow one to independently determine the spin and the couplings of the new particles, except for a few cases that turn out to be indistinguishable at the LHC. These findings are corroborated by results of an alternative analysis strategy based on an automated likelihood test.Comment: 18 pages, 3 figures, LaTe

Candida albicans repetitive elements display epigenetic diversity and plasticity

Transcriptionally silent heterochromatin is associated with repetitive DNA. It is poorly understood whether and how heterochromatin differs between different organisms and whether its structure can be remodelled in response to environmental signals. Here, we address this question by analysing the chromatin state associated with DNA repeats in the human fungal pathogen Candida albicans. Our analyses indicate that, contrary to model systems, each type of repetitive element is assembled into a distinct chromatin state. Classical Sir2-dependent hypoacetylated and hypomethylated chromatin is associated with the rDNA locus while telomeric regions are assembled into a weak heterochromatin that is only mildly hypoacetylated and hypomethylated. Major Repeat Sequences, a class of tandem repeats, are assembled into an intermediate chromatin state bearing features of both euchromatin and heterochromatin. Marker gene silencing assays and genome-wide RNA sequencing reveals that C. albicans heterochromatin represses expression of repeat-associated coding and non-coding RNAs. We find that telomeric heterochromatin is dynamic and remodelled upon an environmental change. Weak heterochromatin is associated with telomeres at 30?°C, while robust heterochromatin is assembled over these regions at 39?°C, a temperature mimicking moderate fever in the host. Thus in C. albicans, differential chromatin states controls gene expression and epigenetic plasticity is linked to adaptation