No abstract

No abstract

Genetic testing is routinely performed on infants with critical congenital heart disease (CHD). This project reviewed the effect of implementing a genetic testing protocol in this population. Charts of infants with critical CHD were reviewed for genetic testing and results across two time periods: the time before implementation of a genetic testing protocol (pre-protocol) and the time after implementation (post-protocol). The use of karyotype, 22q11.2 Deletion testing, and chromosomal microarray were compared across these two time periods. Records of 891 infants were reviewed. 562 (63%) had at least one of the target genetic tests completed. During the pre-protocol time period, 66% of patients who had genetic testing underwent multiple tests versus 24% during the post-protocol time period (p < 0.01). The rate of patients who underwent genetic testing increased from 60% in the pre-protocol time period to 77% in the post-protocol time period (p < 0.01). The rate of diagnosis of genetic conditions during the pre-protocol period was 26% versus 36% during the post-protocol period (p = 0.01). There was a reduction in cost to patients by $5105.59 per diagnosis during the post-protocol period. Patients with critical CHD in the post-protocol period were less likely to undergo multiple genetic tests and more likely to have a diagnosis of genetic disease. In addition there was a significant reduction in cost per diagnosis during the post-protocol time period. Genetic testing protocols for infants with critical CHD promoted more efficient use of genetic testing and increased the rate of diagnosis of genetic conditions in this population.

Studies of mitochondrial redox signaling predict that the colonial hydroids Eirene viridula and Podocoryna carnea should respond to manipulations of reactive oxygen species (ROS). Both species encrust surfaces with feeding polyps connected by networks of stolons; P. carnea is more 'sheet-like' with closely spaced polyps and short stolons, while E. viridula is more 'runner-like' with widely spaced polyps and long stolons. Treatment with the chemical antioxidant vitamin C diminishes ROS in mitochondrion-rich epitheliomuscular cells (EMCs) and produces phenotypic effects (sheet-like growth) similar to uncouplers of oxidative phosphorylation. In peripheral stolon tips, treatment with vitamin C triggers a dramatic increase of ROS that is followed by tissue death and stolon regression. The enzymatic anti-oxidant catalase is probably not taken up by the colony but, rather, converts hydrogen peroxide in the medium to water and oxygen. Exogenous catalase does not affect ROS in mitochondrion-rich EMCs, but does increase the amounts of ROS emitted from peripheral stolons, resulting in rapid, runner-like growth. Treatment with exogenous hydrogen peroxide increases ROS levels in stolon tips and results in somewhat faster colony growth. Finally, untreated colonies of E. viridula exhibit higher levels of ROS in stolon tips than untreated colonies of P. carnea. ROS may participate in a number of putative signaling pathways: (1) high levels of ROS may trigger cell and tissue death in peripheral stolon tips; (2) more moderate levels of ROS in stolon tips may trigger outward growth, inhibit branching and, possibly, mediate the redox signaling of mitochondrion-rich EMCs; and (3) ROS may have an extra-colony function, perhaps in suppressing the growth of bacteria.