Galactomannan detection and diagnosis of invasive aspergillosis.

Contains fulltext : 88569.pdf (publisher's version ) (Open Access

Applying Grading of Recommendations Assessment, Development and Evaluation (GRADE) to diagnostic tests was challenging but doable

AbstractObjectivesThe Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group developed an approach to assess the quality of evidence of diagnostic tests. Its use in Cochrane diagnostic test accuracy reviews is new. We applied this approach to three Cochrane reviews with the aim of better understanding the application of the GRADE criteria to such reviews.Study Design and SettingWe selected reviews to achieve clinical and methodological diversities. At least three assessors independently assessed each review according to the GRADE criteria of risk of bias, indirectness, imprecision, inconsistency, and publication bias. Two teleconferences were held to share experiences.ResultsFor the interpretation of the GRADE criteria, it made a difference whether assessors looked at the evidence from a patient-important outcome perspective or from a test accuracy standpoint. GRADE criteria such as inconsistency, imprecision, and publication bias were challenging to apply as was the assessment of comparative test accuracy reviews.ConclusionThe perspective from which evidence is graded can influence judgments about quality. Guidance on application of GRADE to comparative test reviews and on the GRADE criteria of inconsistency, imprecision, and publication bias will facilitate the operationalization of GRADE for diagnostics

The diagnostic accuracy of serological tests for Lyme borreliosis in Europe: a systematic review and meta-analysis.

Interpretation of serological assays in Lyme borreliosis requires an understanding of the clinical indications and the limitations of the currently available tests. We therefore systematically reviewed the accuracy of serological tests for the diagnosis of Lyme borreliosis in Europe. We searched EMBASE en MEDLINE and contacted experts. Studies evaluating the diagnostic accuracy of serological assays for Lyme borreliosis in Europe were eligible. Study selection and data-extraction were done by two authors independently. We assessed study quality using the QUADAS-2 checklist. We used a hierarchical summary ROC meta-regression method for the meta-analyses. Potential sources of heterogeneity were test-type, commercial or in-house, Ig-type, antigen type and study quality. These were added as covariates to the model, to assess their effect on test accuracy. Seventy-eight studies evaluating an Enzyme-Linked ImmunoSorbent assay (ELISA) or an immunoblot assay against a reference standard of clinical criteria were included. None of the studies had low risk of bias for all QUADAS-2 domains. Sensitivity was highly heterogeneous, with summary estimates: erythema migrans 50% (95% CI 40% to 61%); neuroborreliosis 77% (95% CI 67% to 85%); acrodermatitis chronica atrophicans 97% (95% CI 94% to 99%); unspecified Lyme borreliosis 73% (95% CI 53% to 87%). Specificity was around 95% in studies with healthy controls, but around 80% in cross-sectional studies. Two-tiered algorithms or antibody indices did not outperform single test approaches. The observed heterogeneity and risk of bias complicate the extrapolation of our results to clinical practice. The usefulness of the serological tests for Lyme disease depends on the pre-test probability and subsequent predictive values in the setting where the tests are being used. Future diagnostic accuracy studies should be prospectively planned cross-sectional studies, done in settings where the test will be used in practic

Biomechanical characteristics of rib fracture fixation systems

Background: The primary aim of this study was to determine and compare the biomechanical properties of a fractured or intact rib after implant fixation on an embalmed thorax. Methods: Five systems were fixated on the bilateral fractured or intact (randomly allocated) 6th to 10th rib of five post-mortem embalmed human specimens. Each rib underwent a four-point bending test to determine the bending structural stiffness (Newton per m2), load to failure (Newton), failure mode, and the relative difference in bending structural stiffness and load to failure as compared to a non-fixated intact rib. Findings: As compared to a non-fixated intact rib, the relative difference in stiffness of a fixated intact rib ranged from −0.14 (standard deviation [SD], 0.10) to 0.53 (SD 0.35) and for a fixated fractured rib from −0.88 (SD 0.08) to 0.17 (SD 0.50). The most common failure mode was a new fracture at the most anterior drill hole for the plate and screw systems and a new fracture within the anterior portion of the implant for the clamping systems. Interpretation: The current fixation systems differ in their design, mode of action, and biomechanical properties. Differences in biomechanical properties such as stiffness and load to failure especially apply to fractured ribs. Insight in the differences between the systems might guide more specific implant selection and increase the surgeon's awareness for localizing hardware complaints or failure.Biomaterials & Tissue Biomechanic

Directional growth of a clonal bromeliad species in response to spatial habitat heterogeneity

Item does not contain fulltextHabitat selection by directional growth of plants has previously been investigated but field evidence for this phenomenon is extremely scarce. In this study we demonstrate directional clonal growth in Aechmea nudicaulis, a monocarpic, perennial bromeliad native to spatially heterogeneous sandy coastal plains (restinga) in Brazil. This habitat is characterized by a matrix of bare sand with interspersed vegetation islands. Due to very high soil surface temperatures and other stress factors such as drought, A. nudicauliscan only germinate inside vegetation islands. Nevertheless, this species is very common on bare sand. In this study we tested the hypothesis that clonal fragments occurring at the border and inside vegetation islands show habitat selection by growing preferentially towards the bare sand habitat (i.e. away from the center of vegetation islands). We randomly chose 116 clonal fragments in two distinct micro-environments (inside vegetation islands, and in the border area between bare sand and vegetation islands) in the natural habitat of A.nudicaulisand measured their growth direction in relation to the island center. We measured the growth directions of entire clonal fragments (defined as the line that connects the oldest and the youngest ramets of a clonal fragment) as well as the growth direction of the youngest internode on each fragment (the growth direction of the youngest ramet in relation to its parent ramet). We used Monte Carlo simulations to test for deviations from randomness in the growth direction of clonal fragments and individual internodes. The clonal fragments of A.nudicaulis showed a significant tendency to grow away from the center of vegetation islands. In other words, the main growth direction of clonal fragments growing inside vegetation islands or at the border between bare sand and vegetation islands was preferentially directed towards bare sand environments. Individual internodes at the border of vegetation islands also exhibited this tendency to grow towards the outside of vegetation islands, but internodes growing inside vegetation islands did not show directional growth. These results provide the first field evidence for habitat selection through directional growth of a clonal plant species

Diagnosis of aspergillosis: Role of proteomics

The expansion of the antifungal armamentarium and the implementation of imaging techniques and new nonculture-based fungal diagnostics (NCBFDs) have improved the survival of patients with invasive aspergillosis (IA). However, mortality rates still remain high, possibly influenced by several pitfalls, affecting NCBFDs and reducing the window of opportunity for earlier treatment. A large body of in vitro and in vivo studies has demonstrated that several fungal proteic components are strongly immunogenic, and both the adaptive immunity and the innate branch are heavily involved in the recognition and clearance of fungal pathogens, resulting, on occasion, in a useful tool for the treatment of IA. By evaluating these studies, this review considers the possibility of exploiting either components of the innate or adaptive immunity to support the rapid and early diagnosis of IA. Copyright © 2009 by Current Medicine Group LLC