292 research outputs found

    Judging the impact of leadership-development activities on school practice

    Get PDF
    The nature and effectiveness of professional-development activities should be judged in a way that takes account of both the achievement of intended outcomes and the unintended consequences that may result. Our research project set out to create a robust approach that school staff members could use to assess the impact of professional-development programs on leadership and management practice without being constrained in this judgment by the stated aims of the program. In the process, we identified a number of factors and requirements relevant to a wider audience than that concerned with the development of leadership and management in England. Such an assessment has to rest upon a clear understanding of educational leadership,a clearly articulated model of practice, and a clear model of potential forms of impact. Such foundations, suitably adapted to the subject being addressed, are appropriate for assessing all teacher professional development

    Hookworm infection, anaemia and genetic variability of the New Zealand sea lion

    Get PDF
    Hookworms are intestinal blood-feeding nematodes that parasitize and cause high levels of mortality in a wide range of mammals, including otariid pinnipeds. Recently, an empirical study showed that inbreeding (assessed by individual measures of multi-locus heterozygosity) is associated with hookworm-related mortality of California sea lions. If inbreeding increases susceptibility to hookworms, effects would expectedly be stronger in small, fragmented populations. We tested this assumption in the New Zealand sea lion, a threatened otariid that has low levels of genetic variability and high hookworm infection rates. Using a panel of 22 microsatellites, we found that average allelic diversity (5.9) and mean heterozygosity (0.72) were higher than expected for a small population with restricted breeding, and we found no evidence of an association between genetic variability and hookworm resistance. However, similar to what was observed for the California sea lion, homozygosity at a single locus explained the occurrence of anaemia and thrombocytopenia in hookworm-infected pups (generalized linear model, F = 11.81, p < 0.001) and the effect was apparently driven by a particular allele (odds ratio = 34.95%; CI: 7.12–162.41; p < 0.00001). Our study offers further evidence that these haematophagus parasites exert selective pressure on otariid blood-clotting processes

    Low-Dose Nitric Oxide as Targeted Anti-biofilm Adjunctive Therapy to Treat Chronic Pseudomonas aeruginosa Infection in Cystic Fibrosis

    Get PDF
    Despite aggressive antibiotic therapy, bronchopulmonary colonization by Pseudomonas aeruginosa causes persistent morbidity and mortality in cystic fibrosis (CF). Chronic P. aeruginosa infection in the CF lung is associated with structured, antibiotic-tolerant bacterial aggregates known as biofilms. We have demonstrated the effects of non-bactericidal, low-dose nitric oxide (NO), a signaling molecule that induces biofilm dispersal, as a novel adjunctive therapy for P. aeruginosa biofilm infection in CF in an ex vivo model and a proof-of-concept double-blind clinical trial. Submicromolar NO concentrations alone caused disruption of biofilms within ex vivo CF sputum and a statistically significant decrease in ex vivo biofilm tolerance to tobramycin and tobramycin combined with ceftazidime. In the 12-patient randomized clinical trial, 10 ppm NO inhalation caused significant reduction in P. aeruginosa biofilm aggregates compared with placebo across 7 days of treatment. Our results suggest a benefit of using low-dose NO as adjunctive therapy to enhance the efficacy of antibiotics used to treat acute P. aeruginosa exacerbations in CF. Strategies to induce the disruption of biofilms have the potential to overcome biofilm-associated antibiotic tolerance in CF and other biofilm-related diseases

    Low-Dose Nitric Oxide as Targeted Anti-biofilm Adjunctive Therapy to Treat Chronic Pseudomonas aeruginosa Infection in Cystic Fibrosis

    Get PDF
    Š 2017 The Authors Despite aggressive antibiotic therapy, bronchopulmonary colonization by Pseudomonas aeruginosa causes persistent morbidity and mortality in cystic fibrosis (CF). Chronic P. aeruginosa infection in the CF lung is associated with structured, antibiotic-tolerant bacterial aggregates known as biofilms. We have demonstrated the effects of non-bactericidal, low-dose nitric oxide (NO), a signaling molecule that induces biofilm dispersal, as a novel adjunctive therapy for P. aeruginosa biofilm infection in CF in an ex vivo model and a proof-of-concept double-blind clinical trial. Submicromolar NO concentrations alone caused disruption of biofilms within ex vivo CF sputum and a statistically significant decrease in ex vivo biofilm tolerance to tobramycin and tobramycin combined with ceftazidime. In the 12-patient randomized clinical trial, 10 ppm NO inhalation caused significant reduction in P. aeruginosa biofilm aggregates compared with placebo across 7 days of treatment. Our results suggest a benefit of using low-dose NO as adjunctive therapy to enhance the efficacy of antibiotics used to treat acute P. aeruginosa exacerbations in CF. Strategies to induce the disruption of biofilms have the potential to overcome biofilm-associated antibiotic tolerance in CF and other biofilm-related diseases

    Sudden cardiac death in childhood RASopathy-associated hypertrophic cardiomyopathy: Validation of the HCM risk-kids model and predictors of events

    Get PDF
    Background: RASopathies account for nearly 20% of cases of childhood hypertrophic cardiomyopathy (HCM). Sudden cardiac death (SCD) occurs in patients with RASopathy-associated HCM, but the risk factors for SCD have not been systematically evaluated. Aim: To validate the HCM Risk-Kids SCD risk prediction model in children with RASopathy-associated HCM and investigate potential specific SCD predictors in this population. Methods: Validation of HCM Risk-Kids was performed in a retrospective cohort of 169 patients with a RASopathy-associated HCM from 15 international paediatric cardiology centres. Multiple imputation by chained equations was used for missing values related to the HCM Risk-Kids parameters. Results: Eleven patients (6.5%) experienced a SCD or equivalent event at a median age of 12.5 months (IQR 7.7–28.64). The calculated SCD/equivalent event incidence was 0.78 (95% CI 0.43–1.41) per 100 patient years. Six patients (54.54%) with an event were in the low-risk category according to the HCM Risk-Kids model. Harrell's C index was 0.60, with a sensitivity of 9.09%, specificity of 63.92%, positive predictive value of 1.72%, and negative predictive value of 91%; with a poor distinction between the different risk groups. Unexplained syncope (HR 42.17, 95% CI 10.49–169.56, p < 0.001) and non-sustained ventricular tachycardia (HR 5.48, 95% CI 1.58–19.03, p < 0.007) were predictors of SCD on univariate analysis. Conclusion: Unexplained syncope and the presence of NSVT emerge as predictors for SCD in children with RASopathy-associated HCM. The HCM Risk-Kids model may not be appropriate to use in this population, but larger multicentre collaborative studies are required to investigate this further

    Phocine distemper Virus: Current knowledge and future directions

    Get PDF
    Phocine distemper virus (PDV) was first recognized in 1988 following a massive epidemic in harbor and grey seals in north-western Europe. Since then, the epidemiology of infection in North Atlantic and Arctic pinnipeds has been investigated. In the western North Atlantic endemic infection in harp and grey seals predates the European epidemic, with relatively small, localized mortality events occurring primarily in harbor seals. By contrast, PDV seems not to have become established in European harbor seals following the 1988 epidemic and a second event of similar magnitude and extent occurred in 2002. PDV is a distinct species within the Morbillivirus genus with minor sequence variation between outbreaks over time. There is now mounting evidence of PDV-like viruses in the North Pacific/Western Arctic with serological and molecular evidence of infection in pinnipeds and sea otters. However, despite the absence of associated mortality in the region, there is concern that the virus may infect the large Pacific harbor seal and northern elephant seal populations or the endangered Hawaiian monk seals. Here, we review the current state of knowledge on PDV with particular focus on developments in diagnostics, pathogenesis, immune response, vaccine development, phylogenetics and modeling over the past 20 years

    Effekte von Morphin, Fentanyl und Ketamin auf leukozytäre Funktion, Transkriptionsfaktoren und Interleukin-8-Synthese

    Get PDF
    In der hier vorliegenden Arbeit wird der Einfluß der in der Anästhesie gebräuchlichen Analgetika Morphin, Fentanyl und Ketamin auf die Funktion neutrophiler Granulozyten dargelegt. Dazu wurden immunologische, durchflußzytometrische und molekularbiologische Untersuchungsverfahren eingesetzt. Die untersuchten Substanzen modulieren die Funktion, transkriptionelle Regulation und Proteinexpression von Granulozyten in unterschiedlicher Weise. Morphin hemmt die Funktion neutrophiler Granulozyten konzentrations- und zeitabhängig. Erstmals wird dargestellt, daß der inhibitorische Effekt von Morphin auf die Phagozytose und den Oxidativen Burst durch die Freisetzung von NO als second messenger hervorgerufen wird. Die verminderte Expression von Komplement-, Fcg- und CD14-Rezeptoren korreliert mit diesen Funktionseinschränkungen. Zudem reguliert Morphin die intrazelluläre Signaltransduktion und führt dadurch zu einer Minderung der LPS-induzierten DNA-Bindungsaktivität der Transkriptionsfaktoren NF-kB und AP-1. Die hemmende Wirkung von Morphin auf transkriptionsregulierende Proteine wird in dieser Arbeit erstmals an humanen Leukozyten nachgewiesen. Dabei stellt die Morphin-abhängige Freisetzung von NO das Schlüsselereignis für die hemmenden Effekte von Morphin dar: Durch NOS-Antagonisten kann die Morphin-induzierte Hemmung von Rezeptorenexpression, Granulozytenfunktion und Transkriptionsfaktoren verhindert werden, während NO-Donoren die Morphin-Wirkung imitieren. Die Blockade von Opiatrezeptoren mit Naloxon hebt die inhibierende Wirkung von Morphin ebenfalls auf, so daß eine Bindung an NO-freisetzende µ-Rezeptoren auf Granulozyten als kausaler Mechanismus angesehen werden kann. Die Inhibierung der Transkriptionsfaktoren NF-kB und AP-1 korreliert im Vollblut nicht mit einer verminderten Produktion von IL-8 als NF-kB- bzw. AP-1-abhängigem Mediator. Die exakten intrazellulären Mechanismen und die funktionelle Bedeutung dieser Granulozyten-inhibierenden Effekte von Morphin auf das Entzündungsgeschehen müssen in zukünftigen Untersuchungen geklärt werden. Fentanyl zeigt weder aktivierende noch inhibierende Wirkungen auf Granulozytenfunktion und Expression von Oberflächenrezeptoren. Grundlage hierfür kann die mangelnde Affinität von Fentanyl für die auf Leukozyten exprimierten Opiatrezeptoren sein. Basierend auf der Annahme, daß diese Substanz immunologisch inert ist, wurden Effekte auf transkriptionelle Regulation und Proteinsynthese nicht untersucht. Ketamin hemmt die Granulozytenfunktion und die Expression von Komplement-, Fcg- und CD14-Rezeptoren konzentrationsabhängig, wobei die Dauer der Ketamin-Inkubation nicht von Bedeutung ist. Erstmals wird in dieser Arbeit ein inhibitorischer Effekt von Ketamin auf die LPS-induzierte DNA-Bindungsaktivität der Transkriptionsfaktoren NF-kB und AP-1 beschrieben, wobei konsekutiv die leukozytäre Produktion von IL-8 auf transkriptioneller Ebene gehemmt wird. Das Ausmaß der Hemmung durch Ketamin hängt dabei von der zur Stimulation eingesetzten LPS-Dosierung ab. Im Gegensatz zu Morphin-induzierten Veränderungen sind diese Effekte unabhängig von NO als second messenger und werden nicht durch Opiat- oder NMDA-Rezeptoren vermittelt. Damit unterscheiden sich die Signaltransduktionswege Ketamin-vermittelter Effekte auf Immunzellen grundlegend von denjenigen, die für die anästhetische und psychomimetische Wirkung dieser Substanz im ZNS verantwortlich sind. Enantiomer-spezifische Effekte spielen für die immunsupprimierende Wirkung von Ketamin nur eine untergeordnete Rolle. Folgestudien sind erforderlich, um die an der Ketamin-abhängigen Inhibierung beteiligten intrazellulären Mediatoren und Stoffwechselwege in Leukozyten zu definieren. Der in dieser Studie erstmals zur Untersuchung von Analgetika-induzierten Veränderungen von Transkriptionsfaktoren angewandte durchflußzytometrische Vollblut-Assay weist eine hohe Reproduzierbarkeit auf, ermöglicht eine verläßliche und schnelle Quantifizierung des nukleären NF-kB- bzw. AP-1-Gehalts und liefert mit klassischen Verfahren vergleichbare Ergebnisse. Bei dieser Technik kann auf eine Zellseparation verzichtet werden, so daß die physiologischen Zustände im Vollblut berücksichtigt werden. Eine eventuelle Anwendung dieses Verfahrens zum Screening von Risikopatienten in Anästhesie und Intensivmedizin sollte in zukünftigen Untersuchungen evaluiert werden. Der differente Einfluß dieser Analgetika auf das Immunsystem sollte bei den verschiedenen Indikationen in Anästhesie, Intensivmedizin und Schmerztherapie Beachtung finden und in klinischen Studien weiter abgeklärt werden, um nicht nur eine effiziente Analgesie zu erzielen, sondern auch um etwaige Vor- bzw. Nachteile einer Immunmodulation durch diese Substanzen berücksichtigen zu können

    Diseases and Causes of Death in European Bats: Dynamics in Disease Susceptibility and Infection Rates

    Get PDF
    Bats receive increasing attention in infectious disease studies, because of their well recognized status as reservoir species for various infectious agents. This is even more important, as bats with their capability of long distance dispersal and complex social structures are unique in the way microbes could be spread by these mammalian species. Nevertheless, infection studies in bats are predominantly limited to the identification of specific pathogens presenting a potential health threat to humans. But the impact of infectious agents on the individual host and their importance on bat mortality is largely unknown and has been neglected in most studies published to date.) were collected in different geographic regions in Germany. Most animals represented individual cases that have been incidentally found close to roosting sites or near human habitation in urban and urban-like environments. The bat carcasses were subjected to a post-mortem examination and investigated histo-pathologically, bacteriologically and virologically. Trauma and disease represented the most important causes of death in these bats. Comparative analysis of pathological findings and microbiological results show that microbial agents indeed have an impact on bats succumbing to infectious diseases, with fatal bacterial, viral and parasitic infections found in at least 12% of the bats investigated.Our data demonstrate the importance of diseases and infectious agents as cause of death in European bat species. The clear seasonal and individual variations in disease prevalence and infection rates indicate that maternity colonies are more susceptible to infectious agents, underlining the possible important role of host physiology, immunity and roosting behavior as risk factors for infection of bats

    The role of the electrocardiographic phenotype in risk stratification for sudden cardiac death in childhood hypertrophic cardiomyopathy.

    Get PDF
    AIMS: The 12-lead electrocardiogram (ECG) is routinely performed in children with hypertrophic cardiomyopathy (HCM). An ECG risk score has been suggested as a useful tool for risk stratification, but this has not been independently validated. This aim of this study was to describe the ECG phenotype of childhood HCM in a large, international, multi-centre cohort and investigate its role in risk prediction for arrhythmic events. METHODS AND RESULTS: Data from 356 childhood HCM patients with a mean age of 10.1 years (Âą4.5) were collected from a retrospective, multi-centre international cohort. Three hundred and forty-seven (97.5%) patients had ECG abnormalities at baseline, most commonly repolarization abnormalities (n = 277, 77.8%); left ventricular hypertrophy (n = 240, 67.7%); abnormal QRS axis (n = 126, 35.4%); or QT prolongation (n = 131, 36.8%). Over a median follow-up of 3.9 years (interquartile range 2.0-7.7), 25 (7%) had an arrhythmic event, with an overall annual event rate of 1.38 (95% CI 0.93-2.04). No ECG variables were associated with 5-year arrhythmic event on univariable or multivariable analysis. The ECG risk score threshold of >5 had modest discriminatory ability [C-index 0.60 (95% CI 0.484-0.715)], with corresponding negative and positive predictive values of 96.7% and 6.7. CONCLUSION: In a large, international, multi-centre cohort of childhood HCM, ECG abnormalities were common and varied. No ECG characteristic, either in isolation or combined in the previously described ECG risk score, was associated with 5-year sudden cardiac death risk. This suggests that the role of baseline ECG phenotype in improving risk stratification in childhood HCM is limited
    • …
    corecore