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Canonical Wnt/β-catenin signaling has been implicated in multiple developmental events including the regulation of proliferation, cell fate, and differentiation. In the inner ear, Wnt/β-catenin signaling is required from the earliest stages of otic placode specification through the formation of the mature cochlea. Within the avian inner ear, the basilar papilla (BP), many Wnt pathway components are expressed throughout development. Here, using reporter constructs for Wnt/β-catenin signaling, we show that this pathway is active throughout the BP (E6-E14) in both hair cells (HCs) and supporting cells. To characterize the role of Wnt/β-catenin activity in developing HCs, we performed gain- and loss-of-function experiments in vitro and in vivo in the chick BP and zebrafish lateral line systems, respectively. Pharmacological inhibition of Wnt signaling in the BP and lateral line neuromasts during the periods of proliferation and HC differentiation resulted in reduced proliferation and decreased HC formation. Conversely, pharmacological activation of this pathway significantly increased the number of HCs in the lateral line and BP. Results demonstrated that this increase was the result of up-regulated cell proliferation within the Sox2-positive cells of the prosensory domains. Furthermore, Wnt/β-catenin activation resulted in enhanced HC regeneration in the zebrafish lateral line following aminoglycoside-induced HC loss. Combined, our data suggest that Wnt/β-catenin signaling specifies the number of cells within the prosensory domain and subsequently the number of HCs. This ability to induce proliferation suggests that the modulation of Wnt/β-catenin signaling could play an important role in therapeutic HC regeneration. © 2013 Wiley Periodicals, Inc. Develop Neurobiol 74: 438–456, 2014

Clinical, hemodynamic and angiographic data were analyzed in 66 patients with coronary artery disease and severe generalized left ventricular dysfunction (ischemic cardiomyopathy) in order to determine their prognosis and examine the results of medical and surgical management. Seventy-six percent of patients had angina, 85 percent a history of one or more myocardial infarctions, 73 percent cardiomegaly, 38 percent mitral regurgitation, 98 percent severe stenosis of two or three major coronary arteries, and 100 percent a left ventricular ejection fraction of 25 percent or less. Forty-two patients were managed medically, and 24 surgically with aortocoronary bypass grafts or ventricular plication, or both. The clinical and hemodynamic findings in both groups were nearly identical. In a follow-up period of 12 months, the mortality rate was 31 percent in the medical group and 50 percent in the surgical group, with 83 percent of the surgical deaths occurring within 1 month of operation. There was no significant difference in the functional status of medical and surgical survivors. Regardless of therapy, patients with mitral regurgitation or a left ventricular end-diastolic pressure of 24 mm Hg or greater had a significantly higher mortality rate than patients without these findings. This study indicates that patients with ischemic cardiomyopathy have a poor prognosis, and surgical intervention with current available techniques has a high operative mortality rate without significantly altering the symptoms in the survivors.

PACEMAKERS have been subject to interference from a variety of sources. In the case reported below, pacemaker failure arose from commercial radar. Case Report A 65-year-old man with angina pectoris was hospitalized for syncope. His previously normal electrocardiogram showed complete atrioventricular block, with a rate of 35 per minute. A bipolar electrode catheter was inserted and attached to a demand pacing unit.† He was then evacuated by air to Wilford Hall USAF Medical Center. The blood pressure was 164/74, and the pulse 86, with a regular rate. A transvenous pacing catheter was in place via the right brachial vein. The . . .