The synthetic peptide SVVYGLR promotes myogenic cell motility via the TGFß1/Smad signaling pathway and facilitates skeletal myogenic differentiation in vitro.

In the present study, we investigated the possible involvement of the TGF-ß/Smad signaling pathway in the osteopontin-derived SVVYGLR (SV) peptide-mediated migratory activities of myogenic cells and evaluated the facilitative effects of the SV peptide on the differentiation of myogenic cells in vitro. The SV peptide-induced migration in both human-derived satellite cells and myoblasts was substantially suppressed by the TGF-ß1 receptor inhibitor SB431542 or SB505124. Besides, the expression level of the Smad3 phosphorylation was further enhanced by the addition of the SV peptide in comparison with control groups. Furthermore, an increase in the expression of myogenin-positive nuclei and a higher number of nascent myotubes with myosin heavy chain expression was confirmed in cultured myoblasts supplemented with the SV peptide. These results suggest that the involvement of the TGF-ß/Smad signaling pathway in the SV peptide-mediated migration and the facilitative effect of the SV peptide on the differentiation of myogenic cells into myotubes.

Patent ductus arteriosus closure in prematurities weighing less than 1 kg by subaxillary mini-thoracotomy.

The surgical closure of patent ductus arteriosus (PDA) is provided more frequently in extremely low birth weight babies who are usually deemed unsuitable for pharmacological closure. We have adopted subaxillary mini-thoracotomy in order to lessen surgical trauma in these babies; and its clinical results were analyzed. From April 2004 to August 2008, out of 50 babies at the neonatal intensive care unit who underwent the surgical closure of PDA, 22 premature babies weighing less than 1 kg at operation were included in the study. Eleven babies were males and mean gestational age was 27 weeks ranging from 23(+3) to 30(+2) weeks. Mean body weight at operation was 816 g ranging from 490 to 989 g and average age at operation was 17.9+/-11.9 days. Of them, 17 babies (72%) were ventilator dependent preoperatively, as compared with 13 out of 28 (46%) babies that weighed more than 1 kg (P<0.05). Four babies did not survive to discharge. Among 28 babies who were heavier than 1 kg, there were only one death. However, the mortality difference was not statistically significant (P=0.11). All mortalities were caused by inherent problems of prematurity and co-morbidities. Out of 17 babies who had been ventilator dependent preoperatively, 13 weaned off successfully at 17.0+/-23.9 days after the operation. The baby patients heavier than 1 kg weaned at 6.0+/-5.3 days (P=0.27). Surgical outcome of simple and less invasive subaxillary mini-thoracotomy was satisfactory; the surgery is highly recommended for ductal closure in extremely low weight premature babies.