Aortic valve conduit implantation in the descending thoracic aorta in a sheep model: The outcomes of pre-seeded scaffold.

BACKGROUND: We evaluated the outcomes of implanting pre-seeded decellularized aortic valve conduit (AVC) with bone marrow-derived mesenchymal stem cells (MSCs) in a sheep model. METHODS: Eight sheep AVCs were obtained under sterile conditions and decellularized by using detergent-based methods. Decellularized AVCs were seeded with autologous bone marrow-derived MSCs in a dynamic bioreactor system. Pre-seeded AVCs were implanted in the descending thoracic aorta in a sheep model. In all sheep, a decellularized pericardial patch was also anastomosed to the proximal part in order to reduce the incidence of rupture. Pathological evaluations, echocardiography, multislice computed tomography (CT), and CT angiography were performed for the evaluation of implanted AVCs. RESULTS: The longest survival period was 19 months in pre-seeded animals with complete recellularization at the long-term follow-up. Immunohistochemical staining for desmin, smooth muscle actin, and cytokeratin was significantly positive in the pre-seeded samples and reached near normal ranges. CT angiography revealed no intimal tearing after 18 months of follow-up. CONCLUSION: Pre-seeded AVCs with bone marrow-derived MSCs may have satisfactory results in postoperative cell seeding capabilities with promising functional potentiality. This modality may be beneficial and may provide a new era of biological grafts in cardiovascular surgery.

Effect of parenteral administration of ivermectin and erythromycin on abomasal emptying rate in suckling calves.

OBJECTIVE-To evaluate the effect of parenteral administration of ivermectin and erythromycin on abomasal emptying rate in suckling calves. ANIMALS-6 male Holstein-Friesian calves < 15 days old. PROCEDURES-In a crossover study, calves were administered each of 3 treatments (control treatment, 2 mL of saline [0.9% NaCl] solution, IM; erythromycin, 8.8 mg/kg, IM; and ivermectin, 200 microg/kg, IV). Thirty minutes later, calves were bottle-fed 2 L of fresh cow's milk containing acetaminophen (50 mg/kg). Blood samples were collected from a jugular vein at various periods after suckling of milk. Abomasal emptying rate was assessed by use of the time to pharmacokinetically determined maximal plasma acetaminophen concentration. RESULTS-Administration of erythromycin and ivermectin caused a significant increase in abomasal emptying rate, compared with results for the control treatment, as determined on the basis of time to maximal plasma acetaminophen concentration. CONCLUSIONS AND CLINICAL RELEVANCE-Parenteral administration of erythromycin and ivermectin increased the abomasal emptying rate. The macrolide erythromycin can be an effective prokinetic agent in calves and other animals. Ivermectin is classified as a macrolide but has a number of structural differences from erythromycin. The clinical importance of a slight increase in abomasal emptying rate after IV administration of ivermectin remains to be determined because ivermectin is only labeled for SC, oral, and topical administration.