Ezana M. Azene

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Hyperpolarization-activated cyclic-nucleotide-gated (HCN) channels modulate the firing rates of neuronal and cardiac pacemaker cells. HCN channels resemble voltage-gated K+ channels structurally, but much less is known about their structure-function correlation. Although modulation of K+ channel gating by external K+ is a well-known phenomenon, such a link(More)
OBJECTIVE I(f), encoded by the hyperpolarization-activated, cyclic nucleotide-modulated (HCN) channel gene family, modulates cardiac pacing. During cardiac pacing, changes in membrane potential are rapid, preventing the very slow HCN channels from reaching equilibrium. Here, we examined the properties of HCN channels under non-equilibrium conditions to shed(More)
Although ample evidence suggests the presence of an intracellular activation gate in HCN (pacemaker) channels, mutations in the outer pore can alter gating properties. Here we investigated the role of the outer pore residue A354 in HCN1 gating by systematically converting it to the equivalent residues (T, Y, and F) found in K(+)-channels. A354T negatively(More)
The 2010 RAD-AID Conference on International Radiology for Developing Countries was a multidisciplinary meeting to discuss data, experiences, and models pertaining to radiology in the developing world, where widespread shortages of imaging services reduce health care quality. The theme of this year's conference was sustainability, with a focus on(More)
The RAD-AID Conference on International Radiology for Developing Countries was an assembly of individuals and organizations interested in improving access to medical imaging services in developing countries where the availability of radiology has been inadequate for both patient care and public health programs. The purpose of the meeting was to discuss(More)
An understanding of wave front–obstacle interactions will greatly enhance our knowledge of the mechanisms involved in cardiac arrhythmias and their therapy. The goal of this computational study is to examine the interactions between wave fronts and various obstacles in a two-dimensional sheet of myocardium. The myocardium is modeled as an isotropic sheet(More)
The study was designed to determine the distance between the visible “ice-ball” and the lethal temperature isotherm for normal renal tissue during cryoablation. The Animal Care Committee approved the study. Nine adult swine were used: three to determine the optimum tissue stain and six to test the hypotheses. They were anesthetized and the left renal artery(More)
PMGCT stroma and vessels within the yolk sac tumor component of these tumors. It can be further speculated that expression of hematopoietic growth and differentiation factors in some PMGCT could drive the differentiation of primordial germ cells into hematopoietic progeny. The differentiation factors involved may be responsible for the preferred commitment(More)
BACKGROUND One key element of natural pacemakers is the pacemaker current encoded by the hyperpolarization-activated nucleotide-gated channel (HCN) gene family. Although HCN gene transfer has been used to engineer biological pacemakers, this strategy may be confounded by unpredictable consequences of heteromultimerization with endogenous HCN family members(More)
RATIONALE AND OBJECTIVES To measure perceptions of radiology residents regarding the imaging needs of the developing world and the potential role of an organized global health imaging curriculum during residency training. MATERIALS AND METHODS An electronic survey was created and then distributed to residents in accredited US radiology residency. (More)