Percutaneous Treatment of Superficial Femoral Artery Stenosis Secondary to Radiation Arteritis.

Radiation arteritis is a rare cause of lower extremity peripheral arterial occlusive disease, and has been traditionally treated with open interventions. There have been only a few reported cases of endovascular interventions for this disease. Previous reports described endovascular treatment in the iliac and common femoral regions, but intervention in the superficial femoral artery have not been described. Described here is a case of acute lower extremity ischemia caused by remote radiation arteritis of the superficial femoral artery, which was successfully treated by percutaneous endovascular technique.

A conserved role for Hox paralog group 4 in regulation of hematopoietic progenitors.

Regulatory circuits that control stem cell fate decisions can be identified and understood by manipulating individual regulatory elements genetically. While impractical in the rare somatic stem cells of primary tissue, this approach is feasible in embryonic stem cells differentiated in vitro into the somatic stem cell type of interest. We present an improved highly efficient targeting system allowing genes to be integrated into a predetermined, doxycycline-inducible locus, and corresponding inducible embryonic stem cell lines to be generated rapidly. We apply this system to evaluate a key hematopoietic progenitor cell regulatory element, HoxB4, and its mammalian paralogs, whose effects have not yet been tested in this context. We show that all Hox paralog group 4 members, A4, B4, C4, and D4, have similar effects on hematopoietic stem and progenitor self-renewal in vitro, and thus classify Hox paralog group 4 as promoting self-renewal. Each paralog group 4 member both promotes proliferation and inhibits differentiation, enabling the exponential expansion of hematopoietic progenitors from the c-kit(+)/CD41(+) cell fraction of day 6 murine embryoid bodies. By evaluating a set of deletion mutants we show that sequences in addition to the homeodomain and hexapeptide motif are required for this activity. These results highlight the utility of this expression system to perform functional and structural analyses of genetic regulators of cell fate decisions.

The amygdala: is it an essential component of the neural network for social cognition?

Observations from human subjects with focal brain lesions and animal subjects with experimental lesions have implicated a variety of brain regions in the mediation of social behavior. Previous studies carried out in the macaque monkey found that lesions of the amygdala not only decrease emotional reactivity but also disrupt normal social interactions. We have re-investigated the relationship between amygdala lesions and social behavior in cohorts of mature and neonatal rhesus monkeys who were prepared with selective and complete bilateral ibotenic acid lesions of the amygdaloid complex. These animals display clear alterations in emotional and social behavior. We interpret these changes as due to a loss of the ability to evaluate environmental stimuli as potential threats. However, adult animals with bilateral lesions of the amygdala demonstrate normal, and even increased, social interactions with conspecifics. Moreover, neonatal animals, prepared with amygdala lesions at 2 weeks of age, also demonstrate species typical social behaviors such as the generation of facial expressions, grooming and play behavior. These results argue against the idea that the amygdala is essential for the interpretation of social communication or for the expression of social behavior. Because it does appear to participate in the evaluation of the "safety" of social interactions, we believe that it does have a role in modulating the amount of social behavior in which an organism will participate. However, our current answer to the question posed in the title of this paper is no!