Connexin 43 (Cx43) is expressed in the embryonic heart, cardiac neural crest (CNC) and neural tube, and germline knockout (KO) of Cx43 results in aberrant cardiac outflow tract (OFT) formation and abnormal coronary deployment. Prior studies suggest a vital role for CNC expression of Cx43 in heart development. Surprisingly, we found that conditional knockout (CKO) of Cx43 in the dorsal neural tube and CNC mediated by Wnt1-Cre failed to recapitulate the Cx43-null OFT phenotype, although coronary vasculature was abnormal in this mutant line. A broader CKO mediated by P3pro (Pax3)-Cre, involving both ventral and dorsal aspects of the thoracic neural tube and CNC, resulted in infundibular bulging and coronary anomalies similar to those seen in germline Cx43-null hearts. P3pro-Cre-mediated loss of Cx43 in the neural tube was characterized by a late phase of cellular delamination from the dorsal and lateral neural tube, a markedly increased abundance of neuroepithelium-derived cells outside of the neural tube and an excess of such cells infiltrating the heart and infundibulum. Thus, expression of Cx43 in the CNC is crucial for normal coronary deployment, but Cx43 is not required in the CNC for normal OFT morphogenesis. Rather, this study suggests a novel function for Cx43 in which Cx43 acts through non-crest neuroepithelial cells to suppress cellular delamination from the neural tube and thereby preserve normal OFT development.

Despite agreement among stakeholders that senior centers can promote physical and mental health, research on senior center use in urban populations is limited. Our objective was to describe demographic and health factors associated with senior center use among urban, low-income older adults in order to inform programming and outreach efforts. We used data from a 2009 telephone survey of 1036 adults randomly selected from rosters of New York City public housing residents aged 65 and older. We analyzed senior center use by race/ethnicity, age, gender, health, housing type, and income, and used a forward selection approach to build best-fit models predicting senior center use. Older adults of all ages and of both genders reported substantial use of senior centers, with nearly one third (31.3%) reporting use. Older adults living alone, at risk of depression, or living in specialized senior housing had the greatest use of centers. Senior center use varied by race/ethnicity, and Englishspeaking Hispanics had a higher prevalence of use than Spanish-speaking Hispanics (adjusted prevalence ratio [PR]=1.69, 95% CI: 1.11-2.59). Spanish-speaking communities and older adults living in non-senior congregate housing are appropriate targets for increased senior center outreach efforts.

Unintentional injuries, or accidents, are common among older adults and can lead to long-term disability and even death. However, injuries are preventable and should not be considered a normal part of aging. Recent FallsFalls, the most common cause of injury among older adults nationally and in NYC, result from a complex set of factors including loss of gait and balance, environmental hazards, the use of multiple medications, and vision problems. 1,2 Comparable to national estimates among adults aged 65 and older 3 three in 10 (29%) older NYCHA residents reported a recent fall. Unlike the prevalence of falls in the US, which are more commonly reported among women than men and increase in prevalence with age, the prevalence of recent falls among older NYCHA residents did not vary by gender or age. 3 Black residents reported fewer recent falls than white and Hispanic residents, and older residents living alone were more likely to report a recent fall than those living with others.Falls can be caused by current disability but can also contribute to disabling conditions and poor quality of life. 2,4 Adults who have experienced a fall may also develop a fear of falling that causes them to limit their physical activity and become isolated. This, in turn, decreases physical and mental health and increases risk for future falls. 2,4 Similar to older adults nationally, 2 older NYCHA residents who reported a recent fall were more likely to report being physically inactive than those who did not (39% vs. 27%). Severe vision trouble, a risk factor for falling, 2,4 was also associated with recent falls among older NYCHA residents: those with severe vision trouble were more likely than those without to report a recent fall (36% vs. 26%).Chronic health conditions, whether the condition itself or the side effects of prescribed medication to treat the condition, have been associated with an increased risk of falling. 3 Older residents diagnosed with multiple chronic conditions were more likely to report a recent fall than those with one or no conditions (32% Editor's Note. The following survey is reprinted and adapted for the Care Management Journals format with permission from the New York City Housing Authority. Part 1 appeared in Care Management Journals, 13(3), 2012.

Imaging of the mammalian cardiac right ventricle (RV) is particularly challenging, especially when a two-dimensional method such as conventional histology is used to evaluate the morphology of this asymmetric, crescent-shaped chamber. MRI may improve the characterization of mutants with RV phenotypes by allowing analysis of the samples in any plane and by facilitating three-dimensional image reconstruction. MRI was used to examine the conditional knockout Cx43-PCKO mouse line known to have RV malformations. To help delineate the cardiovascular system and facilitate identification of the right ventricular outflow tract (RVOT), embryonic day (E) 17.5 embryos were perfusion fixed through the umbilical vein followed by a gadolinium-based contrast agent mixed in 7% gelatin. Micro-MRI experiments were performed at 7 T and followed by paraffin embedding of specimens, histological sectioning and hematoxylin and eosin (H&E) staining. Imaging of up to four embryos simultaneously allowed for higher throughput than traditional individual imaging techniques, while intravascular contrast afforded excellent signal-to-noise characteristics. All control embryos (n ¼ 4) and heterozygous Cx43 knockout embryos (n ¼ 4) had normal-appearing right ventricular outflow tract contours by MRI. Obvious abnormalities in the RVOT, including abnormal bulging and infiltration of contrast into the wall of the RV, were seen in three out of four Cx43-PCKO mutants with MRI. Furthermore, three-dimensional reconstruction of MR images with orthogonal projections as well as maximum-intensity projection allowed for visualization of the relationship of infundibular bulging segments to the pulmonary trunk in Cx43-PCKO mutant hearts. The addition of MRI to standard histology in the characterization of RV malformations in mutant mouse embryos aids in the assessment and understanding of morphologic abnormalities. Flexibility in the viewing of MR images, which can be retrospectively sectioned in any desired orientation, is particularly useful in the investigation of the RV, an asymmetric chamber that is difficult to analyze with two-dimensional techniques.

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