BackgroundPseudomonas aeruginosa is a common pathogen in chronic respiratory tract infections. It typically makes a biofilm, which makes treatment of these infections difficult. In this study, we investigated the inhibitory effects of N-acetylcysteine (NAC) on biofilms produced by P. aeruginosa.ResultsWe found that minimum inhibitory concentrations (MICs) of NAC for most isolates of P. aeruginosa were 10 to 40 mg/ml, the combination of NAC and ciprofloxacin (CIP) demonstrated either synergy (50%) or no interaction (50%) against the P. aeruginosa strains. NAC at 0.5 mg/ml could detach mature P. aeruginosa biofilms. Disruption was proportional to NAC concentrations, and biofilms were completely disrupted at 10 mg/ml NAC. Analysis using COMSTAT software also showed that PAO1 biofilm biomass decreased and its heterogeneity increased as NAC concentration increased. NAC and ciprofloxacin showed significant killing of P. aeruginosa in biofilms at 2.5 mg/ml and > 2 MIC, respectively (p < 0.01). NAC-ciprofloxacin combinations consistently decreased viable biofilm-associated bacteria relative to the control; this combination was synergistic at NAC of 0.5 mg/ml and CIP at 1/2MIC (p < 0.01). Extracellular polysaccharides (EPS) production by P. aeruginosa also decreased by 27.64% and 44.59% at NAC concentrations of 0.5 mg/ml and 1 mg/ml.ConclusionsNAC has anti-bacterial properties against P. aeruginosa and may detach P. aeruginosa biofilms. Use of NAC may be a new strategy for the treatment of biofilm-associated chronic respiratory infections due to P. aeruginosa, although it would be appropriate to conduct clinical studies to confirm this.

Background: In recent years, many clinical studies have confirmed the value of laparoscopy-assisted gastrectomy (LAG) in gastric cancer surgery, especially in early stages. But the safety and oncologic adequacy of laparoscopy-assisted D2 radical gastrectomy for advanced gastric cancer are still in debate. We conducted a prospective randomized trial to compare open versus laparoscopy-assisted D2 radical gastrectomy in advanced gastric cancer. Methods: For this study, 123 patients who had been diagnosed endoscopically with gastric cancer were randomly assigned to either LAG (n = 61) or open gastrectomy (OG) (n = 62) which ran from March 2008 to December 2009. Clinical characteristics, operative findings, postoperative recovery, morbidity, pathological report and survival rate were compared. D2 lymph node dissection was performed in 49 patients in the LAG group and 47 patients in the OG group with advanced gastric cancer. We adopt sub-group analysis in this paper. Results: The clinical characteristics of patients in the LAG and OG groups who were in the advanced stage, included age, sex, BMI and concurrent illness, and their ECOG scores were well matched. Operative findings, postoperative recovery, morbidity, pathological findings including tumor location, depth of invasion, TNM stage, histological grade and surgical extension in the two groups were also similar. Compared to the OG group, the mean operating time was significantly longer for the LAG group (267.88 ± 54.284 min in the LAG group vs. 182.02 ± 41.016 min in the OG group, p = 6.383 × 10^–13); the mean number of days when body temperature exceeded 37°C was significantly shorter in the LAG group (p = 6.34 × 10^–8). There were no postoperative deaths in both the groups. The postoperative morbidity rate was 12.24% in the LAG group and 19.15% in the OG group with no significant difference (p = 0.357). However, pulmonary infection was observed more frequently in the OG group (p = 0.038). After a mean follow-up of 22.1354 months (from 4 to 36 months), 14 and 15 patients died of gastric cancer in the LAG and OG groups, respectively. Two and one patient died of nongastric cancer in the LAG and OG groups, respectively. The overall survival rates were 67.1% and 53.8% in the LAG and OG groups, respectively. The estimated mean survival time was 29.387 months in the LAG group and 28.978 months in the OG group. There was no statistically significant difference in the overall survival rate for patients in both groups – LAG and OG (log-rank test, p = 0.911, Tarone Ware test, p = 0.994, and Breslow test, p = 0. 961). Conclusion: LAG with D2 lymph node dissection is a safe and feasible procedure with adequate lymphadenectomy, good curability and survival rate for the treatment of advanced gastric cancer.

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BackgroundKnowledge of predominant microbial patterns in community-acquired pneumonia (CAP) constitutes the basis for initial decisions about empirical antimicrobial treatment, so a prospective study was performed during 2003–2004 among CAP of adult Chinese urban populations.MethodsQualified patients were enrolled and screened for bacterial, atypical, and viral pathogens by sputum and/or blood culturing, and by antibody seroconversion test. Antibiotic treatment and patient outcome were also assessed.ResultsNon-viral pathogens were found in 324/610 (53.1%) patients among whom M. pneumoniae was the most prevalent (126/610, 20.7%). Atypical pathogens were identified in 62/195 (31.8%) patients carrying bacterial pathogens. Respiratory viruses were identified in 35 (19%) of 184 randomly selected patients with adenovirus being the most common (16/184, 8.7%). The nonsusceptibility of S. pneumoniae to penicillin and azithromycin was 22.2% (Resistance (R): 3.2%, Intermediate (I): 19.0%) and 79.4% (R: 79.4%, I: 0%), respectively. Of patients (312) from whom causative pathogens were identified and antibiotic treatments were recorded, clinical cure rate with β-lactam antibiotics alone and with combination of a β-lactam plus a macrolide or with fluoroquinolones was 63.7% (79/124) and 67%(126/188), respectively. For patients having mixed M. pneumoniae and/or C. pneumoniae infections, a better cure rate was observed with regimens that are active against atypical pathogens (e.g. a β-lactam plus a macrolide, or a fluoroquinolone) than with β-lactam alone (75.8% vs. 42.9%, p = 0.045).ConclusionIn Chinese adult CAP patients, M. pneumoniae was the most prevalent with mixed infections containing atypical pathogens being frequently observed. With S. pneumoniae, the prevalence of macrolide resistance was high and penicillin resistance low compared with data reported in other regions.

The 5-day regimen of levofloxacin 750 mg daily is non-inferior to 7-14-day conventional regimen of 500 mg daily in clinical efficacy for treatment of mild to moderate Chinese CAP population. The short course regimen allows the reduction of antimicrobial drug exposure and is well tolerated.