Spontaneous axillary artery aneurysm: a case report and review of the literature.

Degenerative arterial aneurysms can occur in any vascular territory. However, they are exceedingly rare in the axillary artery. Complications of axillary artery aneurysms may result in acute vascular insufficiency and neurological deficits. Prompt treatment should be employed in the management of this condition. We report a case of an atraumatic degenerative axillary artery aneurysm that was treated with transaxillary open surgical bypass.

Distribution of constitutively expressed MEF-2A in adult rat and human nervous systems.

Myocyte enhancer factor 2A (MEF-2A) is a calcium-regulated transcription factor that promotes cell survival during nervous system development. To define and further characterize the distribution pattern of MEF-2A in the adult mammalian brain, we used a specific polyclonal antiserum against human MEF-2A to identify nuclear-localized MEF-2A protein in hippocampal and frontal cortical regions. Western blot and immunocytochemical analyses showed that MEF-2A was expressed not only in laminar structures but also in blood vessels of rat and human brains. MEF-2A was colocalized with doublecortin (DCX), a microtubule-associated protein expressed by migrating neuroblasts, in CA1 and CA2 boundaries of the hippocampus. MEF-2A was expressed heterogeneously in additional structures of the rat brain, including the striatum, thalamus, and cerebellum. Furthermore, we found a strong nuclear and diffuse MEF-2A labeling pattern in spinal cord cells of rat and human material. Finally, the neurovasculature of adult rats and humans not only showed a strong expression of MEF-2A but also labeled positive for hyperpolarization-activated, cyclic nucleotide-regulated (HCN) channels. This study further characterizes the distribution pattern of MEF-2A in the mammalian nervous system, demonstrates that MEF-2A colocalizes with DCX in selected neurons, and finds MEF-2A and HCN1 proteins in the neurovasculature network.