Influence of induced ciprofloxacin resistance on efflux pump activity of Klebsiella pneumoniae

Objective

The efflux pump (EP) is one of the major mechanisms of antibiotic resistance in Klebsiella pneumoniae. However, there are few reports on the effect of the abuse of antibiotic use on the activity of EPs. To determine whether the use of low efficacy antibiotics has any effect on the activity of EPs and induces drug resistance in K. pneumoniae, we investigated the effect of ciprofloxacin on the activity of EPs in K. pneumoniae strains.

Methods

Sixteen susceptible K. pneumoniae strains were isolated from patients and their minimum inhibitory concentrations (MICs) of ciprofloxacin were measured in the absence and presence of the pump inhibitor carbonyl cyanide m-chlorophenyl hydrazone (CCCP). The strains were then induced with a gradient of ciprofloxacin until the MICs of the strains showed no further increase, to obtain induced resistant strains. The EP activities of the strains before and after induction were compared using EP inhibition and ethidium bromide (EtBr) accumulation assays.

Results

The MIC values of the strains were 16–256 times higher after induction than before induction. In the presence of CCCP, the MIC values of 50% of the induced strains were 2–4-fold lower than that in the absence of this inhibitor. The EtBr accumulation assay showed that the fluorescence of EtBr in the induced cells was lower than that in the cells before induction.

Conclusions

EPs are widespread in susceptible and drug-resistant K. pneumoniae strains. Induction with ciprofloxacin may increase the activity of EPs in K. pneumoniae. The EtBr accumulation assay is more sensitive than the EP inhibition assay in evaluating the activity of EPs in K. pneumoniae.     

Negotiating teacher professionalism: governmentality and education reform in Hong Kong

This research investigates how the Hong Kong state controls and disciplines the education sector through the regulation and manipulation of discourses. The authoritative narratives are that some schools are failing the students and parents for not being able to provide quality education, and that these schools are not subject to public scrutiny while spending public money. This article seeks to understand the role of such narratives in neoliberal politics and the marketisation of education which lead to governance in the form of initiatives in school quality assurance mechanism; how different actors (Education Bureau, Professional Teachers' Union and individual teachers) are involved in the process; how they negotiate this governance of education; how such governance transforms the self-perception of teachers as well as the perception of teachers by others; and how teachers interpret, appropriate and resist such discursive power.     

Cheating as subversive and strategic resistance: vocational students’ resistance and conformity towards academic subjects in a Swedish upper secondary school

This article is based on a field study in two boy-dominated classes in a vocational programme in a Swedish upper secondary school. The focus of the article is the boys’ perspective on their cheating activities during lessons and tests within academic subjects. Since the boys often regarded these subjects as boring and useless in relation to their future work as construction workers, their cheating is analysed as a matter of anti-school attitudes and a form of resistance to these subjects. Even if cheating is a violation of school norms, celebrated and seen as amusing by the boys, it was also an acknowledgement of the authority of the school; that is they recognised that the academic subjects could have importance for them in the future. Thus, a ‘good’ grade was assumed to improve their chances of getting a job later.     

Peer Counseling in Colleges and Universities:

Peer counseling owes its beginnings to the paraprofessional movement of the '60s. During the last fifteen years, there has been a growing acceptance of peer counseling, particularly on college campuses. It can be defined as the active use of listening and problem-solving skills together with knowledge about growth and development by students in order to help, advise, and counsel other students. The peer counselor assists other students by clarifying thoughts and feelings, be exploring options, or providing needed information. The use of nonprofessionals in counseling roles has a systematic research history in the literature. Further, there is evidence that preparation for the role and reflection on experience as a peer counselor can be a powerful and enabling factor in individual and group development; through providing service to others, students exercise altruism and learn interdependence in the process of individuation. Recommendations are made for program structure, function, and evaluation; it is suggested that peer counseling programs fit well into a matrix of interventions aimed at assisting student development in a learning environment conductive to growth and developmental needs.     

Politeness theory and refusals of requests: Face threat as a function of expressed obstacles

This investigation seeks to extend Wilson, Aleman, and Leatham's (1998) revision of Brown and Levinson's (1987) politeness theory by focusing on the relationship between face threat and refusals to requests. Results support that (a) when requests are refused, threats to the negative face needs of the requester are more prevalent than threats to the negative face of the refuser and (b) depending on the obstacle underlying the refusal, there are differences in type of threat present to the requester's positive face and the refuser's face needs.     

The power of student resistance in action research: teacher educators respond to classroom challenges

The purpose of this research was to study the design and implementation of a newly developed, two‐semester, action research course in a Master of Arts in Teaching program. Over a four‐year period, we (the instructors) used action research methodologies for analysis and evaluation of the course. Throughout this study, students expressed varying reactions to the process of action research, ranging from enthusiasm and acceptance to continual and persistent reluctance to accept the process as ‘real research’. This resistance is the focus of our study. Four years of reflection on our data points to the following reasons for student resistance: lack of understanding about what action research is and its purpose; a discomfort with the emphasis of process over product and the associated investment of time and ability to multi‐task; and willingness to embrace the transformational process of action research as part of learning to teach.     

School reforms,principal leadership,and teacher resistance: evidence from Korea

Many countries design and implement school change with a focus on the fundamental reconfiguration in the structures of schooling. In this article, we examined the relationship between principal leadership and teacher resistance to school reforms driven by external interveners. For an empirical analysis, we took advantage of extensive data derived from 967 teachers and 32 principals in Korean vocational high schools that are now experiencing school reforms launched by the government. Our results revealed the importance of human aspects of school changes and reforms, in particular, driven by the external intervener. We first showed that a principal's initiative leadership is significantly related to the reduction of teacher resistance to change, in particular on the emotional and behavioural dimensions. Not surprisingly, teachers showed a higher level of resistance when their schools participate in the government-driven reform. Finally, teacher resistance depended upon characteristics of teachers as well as principals. These findings provide some useful policy implications for facilitating successful school reform efforts. Foremost, school reformers are advised to rethink the school change model design in a way of fully capturing human aspects in the reform process.     

印度芥菜BjPCS1基因的表达提高烟草对重金属的抗性

在植物体内植物络合素(PC)可与重金属螯合,并进一步转运至液泡贮存,使细胞质的重金属浓度降低,从而达到解毒效果。PC不是基因的直接翻译产物,而是以谷胱甘肽(GSH) 为底物由植物络合素合酶催化而成。将来源于重金属超富集植物印度芥菜(Brassica juncea)的植物络合素合酶基因BjPCS1转入烟草,PCR和Northern结果表明,该基因已经整合到烟草基因组中,并在转录水平上表达。在3种重金属(200mmol/L CdCl₂、400mmol/L ZnCl₂、200mmo/L NiCl₂)胁迫条件下,转基因烟草植株的脯氨酸含量、可溶性糖含量、丙二醛含量、相对电导率和叶绿素含量等指标均优于未转化的对照植株,表明转化BjPCS1基因提高了烟草对3种重金属的抗性,其中转基因烟草抗Cd能力最强,并且转基因烟草的T1代种子在Cd处理的情况下萌发状况明显优于对照。这些结果说明BjPCS1基因在利用基因工程改良植物抗重金属能力和净化环境污染方面,具有良好的应用前景。     

有氧运动和大豆多肽对高脂饮食大鼠胰岛素抵抗形成和血脂代谢的干预作用

目的 :探讨有氧运动和补充大豆多肽对高脂饮食大鼠胰岛素抵抗形成的干预作用及其机制.方法 :在给SD大鼠喂饲高脂饮食的同时,进行10周的有氧运动锻炼或/和补充大豆多肽,实验结束时测定空腹血糖(FPG)、空腹胰岛素(FINS)、血清甘油三酯(TG)、胆固醇(TC)和游离脂肪酸(FFA)等指标,并计算胰岛素敏感性指数(ISI)、稳态模型-IR指数(HOMA-IR).结果:1)10周的高脂饮食可使大鼠FPG、FINS、HOMA-IR指数显著升高,而ISI指数显著降低;2)在高脂饮食诱导大鼠IR形成的同时,进行10周60 min的有氧运动锻炼或补充SPH,可以显著降低高脂饮食大鼠FPG、FINS、HOMA-IR指数,提高ISI指数;与此同时,运动联合补充SPH可使高脂饮食大鼠FINS、HOMA-IR指数进一步降低,跚进一步升高,但无显著性差异;3)HF组大鼠血清TG、TC和FFA显著高于对照组,运动训练或补充SPH可使高脂饮食大鼠血清TG、TC和FFA含量显著降低,且具有显著的交互作用.结论 :1)10周的高脂饮食可以诱导大鼠IR的形成;2)运动训练或补充SPH可以显著地预防高脂饮食大鼠IR的形成,而且,运动锻炼联合补充SPH在一定程度上对预防高脂饮食大鼠IR的形成具有促进作用.3)高脂饮食诱导大鼠m的形成机制与高脂饮食大鼠血脂代谢紊乱有关;而运动训练或补充SPH可以改善血脂代谢来预防m的形成.     

特殊协作关系上的创新阻碍与外部机会研究——浙江台州缝制设备产业集群创新案例解析/FONT

摘要：文章基于台州缝制设备产业集群的企业间协作创新案例,对拥有特殊协作关系（由拥有"乡缘"或"亲缘"关系的企业所组成的特殊生产协作体系）的企业之间创新阻碍机制进行了深入的理论分析和探讨。研究结果表明：特殊协作关系同外部机会是对立的。特殊协作关系往往导致企业创新激励不足（或过小努力）,而创新激励不足又导致企业间协作产品过早出现老化现象,这种现象通过生产协作链的传递作用而牵连至其它相关企业,最终引发整个缝纫机产业集群的技术退化。