Defining Fluid Restriction in the Management of Infants Following Cardiac Surgery and Understanding the Subsequent Impact on Nutrient Delivery and Growth Outcomes

Adequacy of nutritional intake during the postoperative period, as measured by a change in weight-for-age z-scores from surgery to the time of discharge, was evaluated in infants (n = 58) diagnosed with a congenital heart defect and admitted for surgical intervention at Miami Children’s Hospital using a prospective observational study design. Parental consent was obtained for all infants who participated in the study. Forty patients had a weight available at hospital discharge. The mean preoperative weight-for-age z-score was -1.3 ±1.43 and the mean weight-for-age z-score at hospital discharge was -1.89 ±1.35 with a mean difference of 0.58 ±0.5 (P Nutritional intake during the postoperative period was inadequate based on a decrease in weight-for-age z-scores from the time of surgery until discharged home. Our findings suggested that limited fluid volume for nutrition likely contributes to suboptimal nutritional delivery during the postoperative period; however, inadequate nutrition prescription may also be an important contributing factor. Development of a nutrition protocol for initiation and advancement of nutrition support may reduce the delay in achieving patient’s nutritional goals and may attenuate the observed decrease in z-scores during the postoperative period.

Iraqi Birth Defects and the WHO Report

Since the U.S.-led invasion of Iraq in 2003, epidemics of birth defects and cancers are rising in many Iraqi cities. In 2012, the World Health Organization (WHO) and the Iraqi Ministry of Health (MoH) undertook a large-scale epidemiological study to determine the prevalence of birth defects in the Iraqi population. A report which appeared on the WHO website in September 2013, claims that "The rates for spontaneous abortion, stillbirths and congenital birth defects found in the [Iraq] study are consistent with or even lower than international estimates." This article discusses the severe shortcomings of this report and questions its reliability .

Regulation of Bone Marrow Stem Cells through Oscillatory Shear Stresses - A Heart Valve Tissue Engineering Perspective

Heart valve disease occurs in adults as well as in pediatric population due to age-related changes, rheumatic fever, infection or congenital condition. Current treatment options are limited to mechanical heart valve (MHV) or bio-prosthetic heart valve (BHV) replacements. Lifelong anti-coagulant medication in case of MHV and calcification, durability in case of BHV are major setbacks for both treatments. Lack of somatic growth of these implants require multiple surgical interventions in case of pediatric patients. Advent of stem cell research and regenerative therapy propose an alternative and potential tissue engineered heart valves (TEHV) treatment approach to treat this life threatening condition. TEHV has the potential to promote tissue growth by replacing and regenerating a functional native valve. Hemodynamics play a crucial role in heart valve tissue formation and sustained performance. The focus of this study was to understand the role of physiological shear stress and flexure effects on de novo HV tissue formation as well as resulting gene and protein expression. A bioreactor system was used to generate physiological shear stress and cyclic flexure. Human bone marrow mesenchymal stem cell derived tissue constructs were exposed to native valve-like physiological condition. Responses of these tissue constructs to the valve-relevant stress states along with gene and protein expression were investigated after 22 days of tissue culture. We conclude that the combination of steady flow and cyclic flexure helps support engineered tissue formation by the co-existence of both OSS and appreciable shear stress magnitudes, and potentially augment valvular gene and protein expression when both parameters are in the physiological range.

Regulation of bone marrow stem cells through oscillatory shear stresses - A heart valve tissue engineering perspective

Heart valve disease occurs in adults as well as in pediatric population due to age-related changes, rheumatic fever, infection or congenital condition. Current treatment options are limited to mechanical heart valve (MHV) or bio-prosthetic heart valve (BHV) replacements. Lifelong anti-coagulant medication in case of MHV and calcification, durability in case of BHV are major setbacks for both treatments. Lack of somatic growth of these implants require multiple surgical interventions in case of pediatric patients. Advent of stem cell research and regenerative therapy propose an alternative and potential tissue engineered heart valves (TEHV) treatment approach to treat this life threatening condition. TEHV has the potential to promote tissue growth by replacing and regenerating a functional native valve. Hemodynamics play a crucial role in heart valve tissue formation and sustained performance. The focus of this study was to understand the role of physiological shear stress and flexure effects on de novo HV tissue formation as well as resulting gene and protein expression. A bioreactor system was used to generate physiological shear stress and cyclic flexure. Human bone marrow mesenchymal stem cell derived tissue constructs were exposed to native valve-like physiological condition. Responses of these tissue constructs to the valve-relevant stress states along with gene and protein expression were investigated after 22 days of tissue culture. We conclude that the combination of steady flow and cyclic flexure helps support engineered tissue formation by the co-existence of both OSS and appreciable shear stress magnitudes, and potentially augment valvular gene and protein expression when both parameters are in the physiological range. ^