Puerarin protects against Staphylococcus aureus-induced injury of human alveolar epithelial A549 cells via downregulating alpha-hemolysin secretion.

Alpha-hemolysin, a secreted pore-forming toxin, plays an indispensable role in the pathogenicity of Staphylococcus aureus. In this study, the antimicrobial activity of puerarin against S. aureus was investigated; as a result, puerarin showed no influence on the growth of this organism. However, hemolysis and western blotting assays showed that puerarin concentration dependently inhibited the secretion of alpha-hemolysin at low concentrations. Real-time RT-PCR assay was further employed to evaluate the transcriptional level of hla, the gene encoding alpha-hemolysin, and RNAIII, an effector molecule of the agr system. The results indicated that the RNAIII expression and subsequent hla transcription were also inhibited by puerarin in a dose-dependent manner. Furthermore, puerarin significantly prevented human alveolar epithelial A549 cells from S. aureus-induced injury. Thereby, puerarin may be considered as a potential candidate for the development of antivirulence drugs in the treatment of S. aureus-mediated infections.

[Application of portable esophageal dilator in treatment of esophageal stenosis at home].

OBJECTIVE: To explore an economical protocol for esophageal stenosis treatment at home and evaluate the effects of portable esophageal dilator. METHOD: Sixty-seven patients with esophageal stenosis were treated at home by themselves with portable esophageal dilator, which was designed by Prof Wang HT, one of the authors. Twenty-nine cases of esophageal stenosis were caused by chemical damage, 23 cases by esophageal tumor, 13 postoperation cases with hypopharyngeal and upper esophageal tumor and two cases by laryngeal thyroid gland recurrent tumor. Stricture happened at esophageal entrance and upper segment in 15 cases, at middle in 32 cases, both at middle and upper in 17 cases and at whole length of esophagus in three cases. Stricture was not complete atresia and dilators could insert into esophagus in all patients. RESULT: Significant effects were found in 43 patients and good effects in 24 patients. Seven deaths were caused by remote metastasis of recurrent cancer resulting in multiple organ failure or large blood vessels bleeding resulting of tumor erosion. Follow-up visit ranged from the shortest period of four months to the longest period of five years and 1 month, 9.8 months on average. CONCLUSION: Family portable dilator and self-catering dilation is an effective and safe method for treating esophageal stenosis. It is so simple, convenient, painless with low expense that it is especially useful in countryside hospitals and undeveloped rural areas.