Toward allogenizing a xenograft: Xenogeneic cardiac scaffolds recellularized with human-induced pluripotent stem cells do not activate human naïve neutrophils.

The limited availability of human donor organs suitable for transplantation has resulted in ever-increasing patient waiting lists globally. Xenotransplantation is considered a potential option, but is yet to reach clinical practice. Although remarkable progress has been made in overcoming immunological rejection, issues with functionality are still to be resolved. Bioengineering approaches have been used to create cardiac tissues with optimized functions. The use of decellularized xenogeneic cardiac tissues seeded with donor-derived cardiac cells may prove to be a viable strategy as supporting structures of the native tissue such as vasculature can be utilized. Here we used sequential perfusion to decellularize adult rat hearts. The acellular scaffolds were reseeded with human endothelial cells, human fibroblasts, human mesenchymal stem cells, and cardiac cells derived from human-induced pluripotent stem cells. The ability of the resultant recellularized rat scaffolds to activate human naïve neutrophils in vitro was investigated to measure xenogeneic recognition. Our results demonstrate that in contrast to cadaveric xenogeneic hearts, acellular and recellularized xenogeneic scaffolds did not activate human naïve neutrophils and suggest that decellularization removes the xenogeneic antigens that lead to human naïve neutrophil activation thus allowing human cells to populate the now "allogenized" xenogeneic scaffolds.

Data on hypoxia-induced VEGF, leptin and NF-kB p65 expression.

The data set presented here is associated with the article "Intracellular calcium and NF-kB regulate hypoxia-induced leptin, VEGF, IL-6 and adiponectin secretion in human adipocytes" (Al-Anazi et al., 2018). Data illustrate hypoxia-induced VEGF and leptin expression in human adipocytes treated with the calcium chelator BAPTA-AM (1 µM). It also shows NF-κB p65 induced expression by hypoxia. Preadipocytes were differentiated for 14 days and then subjected to 0.5-1.5% oxygen in the presence and absence of BAPTA-AM or the NF-κB inhibitor SN50 for 48 h prior to RNA isolation and PCR analysis.

Intracellular calcium and NF-kB regulate hypoxia-induced leptin, VEGF, IL-6 and adiponectin secretion in human adipocytes.

AIMS: Hypoxia-induced adipokine release has been attributed mainly to HIF-1α. Here we investigate the role of intracellular calcium and NF-kB in the hypoxia-dependent release of leptin, VEGF, IL-6 and the hypoxia-induced inhibition of adiponectin release in human adipocytes. MAIN METHODS: We used intracellular calcium imaging to compare calcium status in preadipocytes and in adipocytes. We subjected both cell types to hypoxic conditions and measured the release of adipokines induced by hypoxia in the presence and absence of HIF-1α inhibitor YC-1, NF-κB inhibitor SN50 and intracellular calcium chelator BAPTA-AM. KEY FINDINGS: We demonstrate reduced intracellular calcium oscillations and increased oxidative stress as the cells transitioned from preadipocytes to adipocytes. We show that differentiation of preadipocytes to adipocytes is associated with distinct morphological changes in the mitochondria. We also show that hypoxia-induced secretion of leptin, VEGF, IL-6 and hypoxia-induced inhibition of adiponectin secretion are independent of HIF-1α expression. The hypoxia-induced leptin, VEGF and IL-6 release are [Ca++]i dependent whereas adiponectin is NF-kB dependent. SIGNIFICANCE: Our work suggests a major role for [Ca++]i in preadipocyte differentiation to adipocytes and that changes in mitochondrial morphology in the adipocytes might underlie the reduced calcium oscillations observed in the adipocytes. It also demonstrates that multiple signaling pathways are associated with the hypoxia-induced adipokine secretion.

Guidelines for the secondary prevention of rheumatic heart disease: Endorsed by Saudi Pediatric Infectious Diseases Society (SPIDS).

Rheumatic fever is a rare yet serious condition develop as a consequence of throat infection caused by Streptococcus pyogenes. It is the leading cause for rheumatic heart disease. Rheumatic heart disease is a worldwide public health concern. It is a chronic condition that results in carditis, irreversible valve damage and heart failure in children and young adults living in low-income countries. The age of onset peaks between 5 and 15 years. Approximately, 3% of patients with untreated acute streptococcal sore throats develop rheumatic fever. Rheumatic fever and rheumatic heart disease can be prevented with appropriate antibiotics administration to prevent the progression of valve damage. The current use of primary and secondary prevention antibiotics in Saudi Arabia is not known. Therefore, this clinical practice guideline is developed, based on the best available evidence, to promote appropriate antibiotics secondary prophylaxis use for prevention of rheumatic heart disease.

Safety of transcatheter patent ductus arteriosus closure in small weight infants.

BACKGROUND: Patent ductus arteriosus (PDA) is a frequent congenital heart disease. Its transcatheter closure has become the treatment of choice in children and adults. However, the device closure of PDA in children with low weight is still challenging with high rate of complications. The aim of this study was to report further experience with trancatheter closure of PDA using the Amplatzer Duct Occluder(ADO) for children weighing less or equal to 8 kg. METHODS: Twenty-two patients (5 male, 17 female) underwent transcatheter closure of a PDA using ADO at a median age of 10 months (range 4 to 26) and a median weight of 7 kg (range 4.3 to 8). Follow-up evaluations were performed with Doppler echocardiography at 24h, and at 6 and 12 months. RESULTS: The device was implanted successfully in all patients. The median fluoroscopy time was 17.25 min (range 10 to 29). Within 24h, color Doppler revealed complete closure in 15 patients (68%), the other patients had a small residual shunt. No deaths were associated with the procedure. Two patients had a slight aortic protrusion of the device without coarctation and in one patient the device encroached partially on the left pulmonary artery without significant acceleration on Doppler echocardiography. All patients were discharged home the next day. All patients completed the 6-month follow-up with complete closure in 18 patients (81%). At the last evaluation in all patients at any time, there has been documentation of complete PDA closure in 20 (91%) of 22 patients. CONCLUSION: In patients weighing less or equal to 8 kg, percutaneous closure of PDA using an ADO is a safe and effective procedure.