The Role of Polar Pili in the Adherence of Pseudomonas Aeruginosa to Injured Canine Tracheal Cells: A Semiquantitative Morphologic Study

Pseudomonas aeruginosa adheres to respiratory epithelial cells in a highly specific fashion. In order to study the role of P. aeruginosa polar pili in the adherence process we conducted a quantitative morphological electron microscopic examination of P. aeruginosa adherence to SO2 injured canine tracheal cells in vitro. A pilin lacking background strain of P. aeruginosa PAK (BLP2) was constructed using a gene replacement and it in turn was engineered to express either the pilin gene of P. aeruginosa PAO, PAK , or no pilin gene . After 30 minutes incubation of these bacterial strains with injured canine tracheal rings the P. aeruginosa strains expressing pili adhered quantitatively more to the injured tracheal cells than did the pili lacking strains. PAO bearing strains adhered in greater numbers than PAK bearing strains. Healthy tracheal cells did not have any bacteria bound to their surfaces. The bacteria bound to the cilia and lateral edge of the exfoliating tracheal cells. Invasion of tracheal cells by piliated P. aeruginosa bacteria and penetration into the submucosa was also demonstrated. These data confirm the role of pili as important adhesins to injured tracheal cells. The difference in the adherence characteristics of pilin types PAK versus PAO may relate to the differences in the primary structure of these two pilin molecules

Alternatives to project-specific consent for access to personal information for health research: Insights from a public dialogue

<p>Abstract</p> <p>Background</p> <p>The role of consent for research use of health information is contentious. Most discussion has focused on when project-specific consent may be waived but, recently, a broader range of consent options has been entertained, including broad opt-in for multiple studies with restrictions and notification with opt-out. We sought to elicit public values in this matter and to work toward an agreement about a common approach to consent for use of personal information for health research through deliberative public dialogues.</p> <p>Methods</p> <p>We conducted seven day-long public dialogues, involving 98 participants across Canada. Immediately before and after each dialogue, participants completed a fixed-response questionnaire rating individuals' support for 3 approaches to consent in the abstract and their consent choices for 5 health research scenarios using personal information. They also rated how confident different safeguards made them feel that their information was being used responsibly.</p> <p>Results</p> <p>Broad opt-in consent for use of personal information garnered the greatest support in the abstract. When presented with specific research scenarios, no one approach to consent predominated. When profit was introduced into the scenarios, consent choices shifted toward greater control over use. Despite lively and constructive dialogues, and considerable shifting in opinion at the individual level, at the end of the day, there was no substantive aggregate movement in opinion. Personal controls were among the most commonly cited approaches to improving people's confidence in the responsible use of their information for research.</p> <p>Conclusion</p> <p>Because no one approach to consent satisfied even a simple majority of dialogue participants and the importance placed on personal controls, a mechanism should be developed for documenting consent choice for different types of research, including ways for individuals to check who has accessed their medical record for purposes other than clinical care. This could be done, for example, through a web-based patient portal to their electronic health record. Researchers and policy makers should continue to engage the public to promote greater public understanding of the research process and to look for feasible alternatives to existing approaches to project-specific consent for observational research.</p

Optimal taxation under different concepts of justness

A common assumption in the optimal taxation literature is that the social planner maximizes a welfarist social welfare function with weights decreasing with income. However, high transfer withdrawal rates in many countries imply very low weights for the working poor in practice. We reconcile this puzzle by generalizing the optimal taxation framework by Saez (2002) to allow for alternatives to welfarism. We calculate weights of a social planners function as implied by the German tax and transfer system based on the concepts of welfarism, minimum absolute and relative sacrifice, as well as subjective justness. For the latter we use a novel question from the German Socio-Economic Panel. We find that the minimum absolute sacrifice principle is in line with social weights that decline with net income. Absolute subjective justness is roughly in line with decreasing social weights, which is reflected by preferences of men, West Germans, and supporters of the grand coalition parties

Comparison of Viral Isolation and Multiplex Real-Time Reverse Transcription-PCR for Confirmation of Respiratory Syncytial Virus and Influenza Virus Detection by Antigen Immunoassays▿

We evaluated the Prodesse ProFlu-1 real-time reverse transcription-PCR multiplex assay with the SmartCycler instrument for the detection of human respiratory syncytial virus (RSV) and influenza A and B viruses in comparison to conventional cell culture and antigen immunoassays with the BD Directigen A+B and Binax NOW RSV assays over two successive respiratory virus seasons. Ninety-two percent of the 361 specimens tested were nasopharyngeal aspirates obtained from individual patients, of which 119 were positive for RSV and 59 were positive for influenza virus. The median age of the patients whose specimens were positive for RSV and influenza virus were 6.3 months and 42.4 years, respectively. The specificity of all of the methods tested was ≥99%, and the individual sensitivities of NOW RSV, RSV culture, Directigen A+B, influenza virus culture, and the Proflu-1 PCR for influenza/RSV were 82% (95% confidence interval [CI], 73 to 88), 57% (95% CI, 44 to 69), 59% (95% CI, 44 to 72), 54% (95% CI, 38 to 69), and 98% (95% CI, 93 to 100)/95% (95% CI, 85 to 99), respectively. In a clinical setting where viral isolation is performed to confirm rapid antigen immunoassay results for these common respiratory viruses, one-step real-time reverse transcriptase PCR testing can be a more sensitive and timely confirmatory method