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The aim of this study was to study interactions between stromal bone marrow microenvironment and leukemic cells. We tested the hypothesis that stromal cells prevent apoptosis of AML cells by up-regulating anti-apoptotic proteins in leukemic blasts. In HL-60 and NB-4 cells, serum deprivation-and ara-Cinduced apoptosis was diminished when cells were cocultured with murine MS-5 stromal cells (P Ͻ 0.02). This effect was reproduced with conditioned medium from MS-5 cells. Cocultivation with stromal cells induced Bcl-2 expression levels, both by PCR analysis and flow cytometry. In primary AML (n = 14), ara-C-induced apoptosis was significantly lower in cells cocultured with MS-5 cells than in controls (P Ͻ 0.001). This effect was partially preserved when leukemic cells were separated from stromal cells by a microporous insert (in 5/9 samples, P = 0.04). In addition, Bcl-2 levels were significantly higher in stroma-supported than in control CD34+ AML cells (P Ͻ 0.01). Bcl-X L levels were higher in 5/7 samples grown on stromal layers. Of note, in AML patients resistant to induction chemotherapy (n = 6), Bcl-2 increased significantly after cultivation with stromal cells, but no such increase was noted in cells from chemotherapy-sensitive patients. In conclusion, MS-5 stromal cells prevented apoptosis in HL-60 cells and in primary AML blasts via modulation of Bcl-2 family proteins. The observed association of high Bcl-2 expression in stroma-supported AML blasts in vitro with resistance to chemotherapy in vivo suggests that the same mechanisms may be operational in vivo.

ObjectiveTo investigate the relationship between job satisfaction, work stress, work–family conflict and turnover intention, and explore factors associated with turnover intention, among physicians in Guangdong Province, China.MethodsFrom August to October 2013, physicians completed questionnaires and scales with regard to their job satisfaction, work stress, work–family conflict, and turnover intention. Binary logistic regression and structural equation modelling (SEM) were used in data analysis.ResultsA total of 3963 physicians were approached, with 3563 completing the questionnaire. The mean score of the overall perception of turnover intention of physicians who worked in Guangdong was 2.71 on a scale ranging from 1 to 6. Hours worked per week, working in an urban/rural area, type of institution, and age significantly impacted on turnover intention. Turnover intention was directly and negatively related to job satisfaction, and it was directly, indirectly and positively related to work stress and work–family conflict.ConclusionJob satisfaction, work stress, work–family conflict, hours worked per week, working in an urban/rural area, types of institution and age are influencing factors of turnover intention. Reducing working hours, raising salary, providing more opportunities for career development and training, supporting and encouraging physicians by senior managers could potentially contribute to the reduction in turnover intention.

ObjectivesThis cross-sectional study aimed to explore job satisfaction among healthcare staff in Guangdong following the health system reforms in 2009, and to investigate the association between job satisfaction and work stress, work–family conflict and doctor–patient relationship.DesignCross-sectional survey.SettingThe Fifth National Health Service Survey was carried out in Guangdong, China.ParticipantsAll participants in this study were healthcare staff including physicians, nurses and public health staff from hospitals, health service centres and health clinics. A total of 6583 questionnaires were distributed and collected. After excluding the incomplete questionnaires, 5845 questionnaires were included for the analysis.Outcome measuresSociodemographic information and scores for evaluating job satisfaction, work stress, work–family conflict and doctor–patient relationship were obtained using the questionnaire developed by the National Health and Family Planning Commission of the People's Republic of China. To assess the significantly associated factors on job satisfaction of the healthcare staff in Guangdong, a binary logistic regression model was used.ResultsBased on the 5845 valid responses of the healthcare staff who worked in Guangdong, the mean score of overall perception of job satisfaction was 3.99 on a scale of 1–6. Among the sociodemographic variables, occupation, educational background, professional status, years of service, annual income and night shift frequency significantly influenced the level of job satisfaction. Work stress, work–family conflict and doctor–patient relationship also had significant effect on job satisfaction.ConclusionsThe overall job satisfaction exceeded slightly dissatisfied (score 3) and approached slightly satisfied (score 4). Measures to enhance job satisfaction include the reduction of workload, increase of welfare, maintaining moderate stress and balancing work–family conflict. Moreover, relevant laws should be issued to protect the healthcare staff from violent acts.

Biofilm is a natural form of bacterial growth ubiquitously in environmental niches. The biofilm formation results in increased resistance to negative environmental influences including resistance to antibiotics and antimicrobial agents. Quorum sensing (QS) is cell-to-cell communication mechanism, which plays an important role in biofilm development and balances the environment when the bacteria density becomes high. Due to the prominent points of biofilms implicated in infectious disease and the spread of multi-drug resistance, it is urgent to discover new antibacterial agents that can regulate biofilm formation and development. Accumulated evidences demonstrated that natural products from plants had antimicrobial and chemo-preventive properties in modulation of biofilm formation in the last two decades. This review will summarize recent studies on the discovery of natural anti-biofilm agents from plants with clear-cut mechanisms or identified molecular addresses, as well as some herbs with unknown mechanisms or unidentified bioactive ingredients. We also focus on the progression of techniques on the extraction and identification of natural anti-biofilm substances. Besides, anti-biofilm therapeutics undergoing clinical trials are discussed. These newly discovered natural anti-biofilm agents are promising candidates which could provide novel strategies for biofilm-associated infections.