403 research outputs found
The Role of the Aceullular Pertussis Vaccine and the Comeback of 'Pertussis Pete'?
Pertussis or whooping cough is an acute infectious disease of the respiratory tract caused principally by Bordetella pertussis and less commonly by Bordetella parapertussis (1). Until two decades ago, pertussis in adults was a medical curiosity (2-4), but with the purification of specific Bordetella species antigens, the development of reliable enzyme immunoassays allowing accurate serological diagnosis and better understanding of the duration of immunity from vaccination, it has been clearly demonstrated that B pertussis is a common cause of prolonged cough in adults. Indeed, its incidence has been increasing gradually over the past decade in both adults and adolescents. Given the recognition of the importance of pertussis as a cause of prolonged cough in adults and the advent of the new acellular pertussis vaccines, it is timely to review current concepts of the pathogenesis of pertussis, its epidemiology in adults and the utility of the anticipated impact of the acellular vaccine
Consistent model of magnetism in ferropnictides
The discovery of superconductivity in LaFeAsO introduced the ferropnictides
as a major new class of superconducting compounds with critical temperatures
second only to cuprates. The presence of magnetic iron makes ferropnictides
radically different from cuprates. Antiferromagnetism of the parent compounds
strongly suggests that superconductivity and magnetism are closely related.
However, the character of magnetic interactions and spin fluctuations in
ferropnictides, in spite of vigorous efforts, has until now resisted
understanding within any conventional model of magnetism. Here we show that the
most puzzling features can be naturally reconciled within a rather simple
effective spin model with biquadratic interactions, which is consistent with
electronic structure calculations. By going beyond the Heisenberg model, this
description explains numerous experimentally observed properties, including the
peculiarities of the spin wave spectrum, thin domain walls, crossover from
first to second order phase transition under doping in some compounds, and
offers new insight in the occurrence of the nematic phase above the
antiferromagnetic phase transition.Comment: 5 pages, 3 figures, revtex
Approaches to ascertaining comorbidity information: validation of routine hospital episode data with clinician-based case note review
Background
In clinical practice, research, and increasingly health surveillance, planning and costing, there is a need for high quality information to determine comorbidity information about patients. Electronic, routinely collected healthcare data is capturing increasing amounts of clinical information as part of routine care. The aim of this study was to assess the validity of routine hospital administrative data to determine comorbidity, as compared with clinician-based case note review, in a large cohort of patients with chronic kidney disease.
Methods
A validation study using record linkage. Routine hospital administrative data were compared with clinician-based case note review comorbidity data in a cohort of 3219 patients with chronic kidney disease. To assess agreement, we calculated prevalence, kappa statistic, sensitivity, specificity, positive predictive value and negative predictive value. Subgroup analyses were also performed.
Results
Median age at index date was 76.3 years, 44% were male, 67% had stage 3 chronic kidney disease and 31% had at least three comorbidities. For most comorbidities, we found a higher prevalence recorded from case notes compared with administrative data. The best agreement was found for cerebrovascular disease (κ = 0.80) ischaemic heart disease (κ = 0.63) and diabetes (κ = 0.65). Hypertension, peripheral vascular disease and dementia showed only fair agreement (κ = 0.28, 0.39, 0.38 respectively) and smoking status was found to be poorly recorded in administrative data. The patterns of prevalence across subgroups were as expected and for most comorbidities, agreement between case note and administrative data was similar. Agreement was less, however, in older ages and for those with three or more comorbidities for some conditions.
Conclusions
This study demonstrates that hospital administrative comorbidity data compared moderately well with case note review data for cerebrovascular disease, ischaemic heart disease and diabetes, however there was significant under-recording of some other comorbid conditions, and particularly common risk factors
The skin is a significant but overlooked anatomical reservoir for vector-borne African trypanosomes
The role of mammalian skin in harbouring and transmitting arthropod-borne protozoan parasites has been overlooked for decades as these pathogens have been regarded primarily as blood-dwelling organisms. Intriguingly, infections with low or undetected blood parasites are common, particularly in the case of Human African Trypanosomiasis caused by Trypanosoma brucei gambiense. We hypothesise, therefore, the skin represents an anatomic reservoir of infection. Here we definitively show that substantial quantities of trypanosomes exist within the skin following experimental infection, which can be transmitted to the tsetse vector, even in the absence of detectable parasitaemia. Importantly, we demonstrate the presence of extravascular parasites in human skin biopsies from undiagnosed individuals. The identification of this novel reservoir requires a re-evaluation of current diagnostic methods and control policies. More broadly, our results indicate that transmission is a key evolutionary force driving parasite extravasation that could further result in tissue invasion-dependent pathology
The Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH) can measure the impairment, activity limitations and participation restriction constructs from the International Classification of Functioning, Disability and Health (ICF)
Background The International Classification of Functioning, Disability and Health (ICF) model of the consequences of disease identifies three health outcomes, impairment, activity limitations and participation restrictions. However, few orthopaedic health outcome measures were developed with reference to the ICF. This study examined the ability of a valid and frequently used measure of upper limb function, namely the Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH), to operationalise the ICF. Methods Twenty-four judges used the method of Discriminant Content Validation to allocate the 38 items of the DASH to the theoretical definition of one or more ICF outcome. One-sample t-tests classified each item as measuring, impairment, activity limitations, participation restrictions, or a combination thereof. Results The DASH contains items able to measure each of the three ICF outcomes with discriminant validity. The DASH contains five pure impairment items, 19 pure activity limitations items and three participation restriction items. In addition, seven items measured both activity limitations and participation restrictions. Conclusions The DASH can measure the three health outcomes identified by the ICF. Consequently the DASH could be used to examine the impact of trauma and subsequent interventions on each health outcome in the absence of measurement confound
Performance feedback: An exploratory study to examine the acceptability and impact for interdisciplinary primary care teams
Background - This mixed methods study was designed to explore the acceptability and impact of feedback of team performance data to primary care interdisciplinary teams. // Methods - Seven interdisciplinary teams were offered a one-hour, facilitated performance feedback session presenting data from a comprehensive, previously-conducted evaluation, selecting highlights such as performance on chronic disease management, access, patient satisfaction and team function. // Results - Several recurrent themes emerged from participants' surveys and two rounds of interviews within three months of the feedback session. Team performance measurement and feedback was welcomed across teams and disciplines. This feedback could build the team, the culture, and the capacity for quality improvement. However, existing performance indicators do not equally reflect the role of different disciplines within an interdisciplinary team. Finally, the effect of team performance feedback on intentions to improve performance was hindered by a poor understanding of how the team could use the data. // Conclusions - The findings further our understanding of how performance feedback may engage interdisciplinary team members in improving the quality of primary care and the unique challenges specific to these settings. There is a need to develop a shared sense of responsibility and agenda for quality improvement. Therefore, more efforts to develop flexible and interactive performance-reporting structures (that better reflect contributions from all team members) in which teams could specify the information and audience may assist in promoting quality improvement
Different paths to the modern state in Europe: the interaction between domestic political economy and interstate competition
Theoretical work on state formation and capacity has focused mostly on early modern Europe and on the experience of western European states during this period. While a number of European states monopolized domestic tax collection and achieved gains in state capacity during the early modern era, for others revenues stagnated or even declined, and these variations motivated alternative hypotheses for determinants of fiscal and state capacity. In this study we test the basic hypotheses in the existing literature making use of the large date set we have compiled for all of the leading states across the continent. We find strong empirical support for two prevailing threads in the literature, arguing respectively that interstate wars and changes in economic structure towards an urbanized economy had positive fiscal impact. Regarding the main point of contention in the theoretical literature, whether it was representative or authoritarian political regimes that facilitated the gains in fiscal capacity, we do not find conclusive evidence that one performed better than the other. Instead, the empirical evidence we have gathered lends supports to the hypothesis that when under pressure of war, the fiscal performance of representative regimes was better in the more urbanized-commercial economies and the fiscal performance of authoritarian regimes was better in rural-agrarian economie
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