Long-term active antimicrobial coatings for surgical sutures based on silver nanoparticles and hyperbranched polylysine

The goal of this study was to develop a long-term active antimicrobial coating for surgical sutures. To this end, two water-insoluble polymeric nanocontainers based on hyperbranched polylysine (HPL), hydrophobically modified by either using glycidyl hexadecyl ether, or a mixture of stearoyl/palmitoyl chloride, were synthesized. Highly stabilized silver nanoparticles (AgNPs, 2–5?nm in size) were generated by dissolving silver nitrate in the modified HPL solutions in toluene followed by reduction with L-ascorbic acid. Poly(glycolic acid)-based surgical sutures were dip-coated with the two different polymeric silver nanocomposites. The coated sutures showed high efficacies of more than 99.5% reduction of adhesion of living Staphylococcus aureus cells onto the surface compared to the uncoated specimen. Silver release experiments were performed on the HPL-AgNP modified sutures by washing them in phosphate buffered saline for a period of 30?days. These coatings showed a constant release of silver ions over more than 30?days. After this period of washing, the sutures retained their high efficacies against bacterial adhesion. Cytotoxicity tests using L929 mouse fibroblast cells showed that the materials are basically non-cytotoxic.     

Dose-dependent attenuation of intravenous nalbuphine on epidural morphine-induced pruritus and analgesia after cesarean delivery

Epidural morphine in patient-controlled analgesia regimens controls postoperative pain well but easily induces pruritus and other epidural morphine-related side effects. With 90 pregnant American Society of Anesthesiologists physical status II females scheduled for elective cesarean delivery, the present study was designed to evaluate the efficacy and safety profile of patient-controlled antipruritus (PCP) use of intravenous nalbuphine-based regimens for attenuation of postoperative pruritus and related side effects in combination with epidural morphine patient-controlled analgesia with regard to the quality of postoperative pain management. Patients were randomly assigned to two nalbuphine groups (5 μg/kg/hour, Group N5 or 10 μg/kg/hour, Group N10) and bolus dose of 1.6 μg/kg for PCP or the control (normal saline) group. Comparable visual analog scale scores for rest pain at each measured time interval among the three groups demonstrated that adequate pain relief was offered; however, the cumulative dose of nalbuphine administered to the patients in Group N10 attenuated the analgesic effect of epidural morphine in moving pain at POh24 only. Fewer episodes and milder severity of pruritus were observed in patients in Groups N5 and N10 at all postoperative time intervals. Epidural morphine provided good postoperative pain relief but with incommodious side effects. In addition, intravenous nalbuphine not only attenuated the incidence of pruritus but also decreased total morphine consumption. In conclusion, intravenous administration of low-dose nalbuphine (5 μg/kg/hour) for PCP maintained analgesia produced by epidural morphine and offered low pruritus incidence.     

Ascending Thoracic Aortic Aneurysms Protect Against Myocardial Infarctions

There has been increasing evidence that ascending thoracic aortic aneurysms (TAAs) protect against atherosclerosis. However, there have been no studies examining the relationship between ascending TAAs and clinical endpoints of atherosclerosis, such as stroke or peripheral arterial disease. In this study, we aim to characterize the relationship between TAAs and a specific clinical endpoint of atherosclerosis, myocardial infarction (MI). We compared prevalence of coronary artery disease (CAD) and MIs in 487 patients who underwent surgical repair for ascending TAAs to 500 control patients who did not have an ascending TAA. Multivariate binary logistic regression was used to calculate the odds of having MI if a patient had an ascending TAA versus any of several MI risk factors. There was a significantly lower prevalence of CAD and MI in the ascending TAA group than in the control TAA group. The odds of having a MI if a patient had a MI risk factor were all > 1 (more likely to have a MI), with the lowest statistically significant odds ratio being 1.54 (age; p = 0.001) and the highest being 14.9 (family history of MI; p < 0.001). The odds ratio of having a MI if a patient had an ascending TAA, however, was near 0 at 0.05 (p < 0.001). This study provides evidence that ascending TAAs protect against MIs, adding further support to the hypothesis that ascending TAAs protect against atherosclerotic disease.