RESUMEN
Antimicrobial peptides (AMPs) distribute widely in many organisms. As an important part of the nonspecific immune functions of organisms, AMPs can not only protect the body from bacteria, fungi, parasites, viruses, and other pathogens, but also have the functions of mediating catalysis, apoptosis, immune regulatory activity, accelerating wound healing and osteogenetic effects. AMPs have become a research focus for antimicrobial coating on titanium implant surface and have shown a promising prospect. In this paper, we reviewed the antimicrobial mechanism, loading method, and application status of AMPs applied on titanium implant surface.
RESUMEN
Objective To investigate the effect of hypertonic saline on cerebral water content, tumor necrosis factor-α (TNF-α) level and neuronal apoptosis following focal cerebral ischemia-reperfusion (IR) injury in rats and explore the mechanisms involved. Methods Ninety-six rats were randomized equally into 4 groups, namely the shame-operated group, untreated IR injury group, and 4.2% and 7.5% hypertonic saline groups (HS-A and HS-B groups, respectively). In the latter 3 groups, cerebral ischcmia was induced by middle cerebral artery occlusion for 2 h followed by administration of the corresponding treatments. Serum sodium concentration was measured at 5 min before and at 30, 60 and 90 min after the reperfilsion. At 22 h of rcperfusion, the rats were sacrificed after neurological deficit evaluation, and brain edema was assessed by measuring the wet-to-dry weight ratio of the brain tissue. TNF-α expression in the ischemic brain tissue was measured by enzyme-linked immunosorbent assay (ELISA), and the neuronal apoptosis was analyzed using TUNEL assay. Results In the saline-treated rats, serum sodium level increased significantly after saline administration, lasting for 60 min before recovering the normal levels in HS-A group and for over 90 min in HS-B group. Compared with that in the sham-operated group, the brain water content in rats of the IR group increased in both of the hemispheres, but more obviously in the ischemic hemisphere. In the two saline-treated groups, the water content decreased significantly in the bilateral hemispheres, which was especially obvious in the ischemic hemisphere;administration of 7.5% saline resulted in greater water content reduction in the ischemic hemisphere than 4.2% saline. Compared with the IR group, the two saline-treated groups showed significant reduction in TNF-α levels and apoptotic cells in the brain along with decreased neurological deficits. Conclusion Hypertonic saline can ameliorate cerebral focal IR injury by decreasing the cerebral water content, TNF-α level and neuronal apoptosis following the injury.