[The inhibition of accessory gene regulator C specific binding peptides on biofilm formation of Staphylococcus epidermidis on the surface of polyvinyl chloride in vitro].

Objective: To investigate the effect of accessory gene regulator C (agr C) specific binding peptides (named N1) on the biofilm formation of Staphylococcus epidermidis on the surface of polyvinyl chloride (PVC) materials in vitro. Methods: Firstly, the two strains (ATCC35984, ATCC12228) were cultured with N1 at concentrations of 100, 200, 400, 800, and 1 600 µg/mL, respectively. The control group was cultured with agrC specific binding unrelated peptides (named N0) at the same concentrations and the absorbance ( A) value was measured after 24 hours to determine the optimal bacteriostatic concentration of N1. The two strains were cultured with N1 and N0 of the optimal concentration, respectively. The A values were measured at 6, 12, 18, 24, 30, and 48 hours to observe the effect of N1 on the biofilm formation ability of Staphylococcus epidermidis. On this basis, the surface structure of the biofilm on the surface of PVC material was observed by scanning electron microscopy after 6, 12, 18, 24, and 30 hours of incubation with PVC material sheet. The thickness of the biofilm was observed by laser confocal microscopy after 6, 12, 18, and 24 hours of incubation with ATCC35984 strain. Results: The optimal bacteriostatic concentration of N1 was 800 µg/mL. ATCC 12228 strain did not form obvious biofilm after being cultured with N1 and N0. When ATCC35984 strain was cultured with N1 and N0 for 12 hours, the difference in biofilm formation ability between groups N1 and N0 was statistically significant ( P<0.05), but there was no significant difference at 6, 18, 24, 30, and 48 hours ( P>0.05). Scanning electron microscopy examination showed that mature biofilm structure was observed in ATCC35984 strain and was not observed in ATCC12228 strain. Laser confocal microscopy observation showed that the number of bacteria in the group N1 was significantly lower than that in the group N0 at 12 hours, and the most of bacteria were dead bacteria. There was no significant difference in the number of bacteria at 6, 18, and 24 hours, and the most of them were live bacteria. The biofilm thickness of group N1 was significantly lower than that of group N0 at 12 and 18 hours ( P<0.05). Conclusion: The intensity of N1 inhibiting the formation of Staphylococcus epidermidis biofilm is dose-dependent. During the aggregation period, N1 can inhibit the biofilm formation by hindering the bacterial growth and aggregation. The inhibition effect on mature biofilm is not obvious.

Wide exposure in uniportal video-assisted thoracoscopic surgery for radical resection of lung cancer / 中国胸心血管外科临床杂志

@#Objective To investigate the advantage of the concept of wide exposure in uniportal video-assisted thoracoscopic surgery (uniportal-VATS) for radical resection of lung cancer and assess its safety and feasibility. Methods Clinical data of 255 patients (110 males and 145 females, a mean age of 54.3±7.9 years) with non-small cell lung cancer (NSCLC) who received wide exposure in uniportal-VATS or three portal VATS (3P-VATS) during August 2017 to March 2018 were retrospectively analyzed. There were 153 patients (67 males and 86 females, a mean age of 56.1±8.5 years) in the uniportal-VATS group and 102 patients (43 males and 59 femals, a mean age of 54.4±7.4 years) in the 3P-VATS group. The clinical effects were compared between the two groups. Results There was no statistical difference in the operation time between the uniportal-VATS and 3P-VATS (135.0±45.6 min vs. 142.0±39.5 min, P>0.05). The overall number of dissected stations (6.9±1.0) and LNs (14.5±3.0) in the uniportal-VATS group were similar with those in the 3P-VATS group (7.1±1.0, 15.1±1.7). The dissected stations of N2 LNs (uniportal-VATS: 4.1±1.7, 3P-VATS: 3.9±0.8) and number of dissected N2 LNs (uniportal-VATS: 8.0±0.9, 3P-VATS: 7.8±1.1) were both similar between the two groups. The duration of postoperative tube drainage and postoperative hospital stay of uniportal-VATS group (3.5±1.8 d and 7.2±0.9 d) were much shorter than those of 3P-VATS group (4.0±1.3 d and 8.8±2.0 d). No significant difference was found in incidence of postoperative complication between the two groups except that the incidence of subcutaneous emphysema in the uniportal-VATS group was much lower. There was no perioperative death in the two groups. Conclusion The concept of wide exposure in uniportal-VATS can meet the requirment of radical resection and it is a safe and valid method which can be used for radical resection of lung cancer.