BackgroundGait analysis has been used for decades to quantify knee function in patients with knee osteoarthritis; however, it is unknown whether and to what extent inter-laboratory differences affect the comparison of gait data between studies. Therefore, the aim of this study was to perform an inter-laboratory comparison of knee biomechanics and muscle activation patterns during gait of patients with knee osteoarthritis.MethodsKnee biomechanics and muscle activation patterns from patients with knee osteoarthritis were analyzed, previously collected at Dalhousie University (DAL: n = 55) and Amsterdam UMC, VU medical center (VUmc: n = 39), using their in-house protocols. Additionally, one healthy male was measured at both locations. Both direct comparisons and after harmonization of components of the protocols were made. Inter-laboratory comparisons were quantified using statistical parametric mapping analysis and discrete gait parameters.ResultsThe inter-laboratory comparison showed offsets in the sagittal plane angles, moments and frontal plane angles, and phase shifts in the muscle activation patterns. Filter characteristics, initial contact identification and thigh anatomical frame definitions were harmonized between the laboratories. After this first step in protocol harmonization, the offsets in knee angles and sagittal plane moments remained, but the inter-laboratory comparison of the muscle activation patterns improved.ConclusionsInter-laboratory differences obstruct valid comparisons of gait datasets from patients with knee osteoarthritis between gait laboratories. A first step in harmonization of gait analysis protocols improved the inter-laboratory comparison. Further protocol harmonization is recommended to enable valid comparisons between labs, data-sharing and multicenter trials to investigate knee function in patients with knee osteoarthritis.
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from the article: "Cow's milk-derived whey hydrolysates are milk substitutes for cow's milk allergic infants. Safety assessment of these hydrolysates is crucial. Currently, huFcεRIα-RBL-2H3 cells, sensitized with serum IgE from cow's milk allergic patients, are used to assess in vitro residual allergenicity. However, limited availability and high inter-lot variation of sera impede the standardization of safety testing. Recently, we generated an oligoclonal pool of chimeric human (chu)IgE antibodies against bovine β-lactoglobulin (BLG) as an alternative for human serum. These antibodies demonstrated increased sensitivity, specificity and reproducibility. An inter-laboratory ring trial using our new degranulation assay with different whey-based hydrolysates was performed at four independent laboratories to investigate the robustness and reproducibility. RBL-2H3 cells expressing huFcεRIα were sensitized with our oligoclonal pool of anti-BLG chuIgE antibodies. The cells were subsequently incubated with an amino-acid based formula (AAF), two extensively hydrolyzed formulas (eHF) and three partially hydrolyzed formulas (pHF) to assess the degranulation upon challenge. Results demonstrated a very strong inter-laboratory correlation and the intra- and inter-laboratory variations were acceptable. The AAF and both eHFs showed no degranulation, whereas all pHFs demonstrated degranulation. The study showed that this degranulation assay is robust and reproducible within and between laboratories. This new in vitro degranulation assay seems predictive for allergenicity outcome and might therefore be considered as a relevant substitute for animal models."
Sustainable urban drainage systems (SuDS) such as swales are designed to collect, store and infiltrate a large amount of surface runoff water during heavy rainfall. Stormwater is known to transport pollutants, such as particle-bound heavy metals, which are known to often accumulate in the topsoil. In this study, a portable XRF instrument is used to provide in situ spatial characterization of soil pollutants. The method uses portable XRF measurements of heavy metals along profiles with set intervals (1 meter) to cover the swale with cross-sections, across the inlet, the deepest point and the outlet. Soil samples are collected, and the In-Situ measurements are verified by the results from laboratory analyses. Stormwater is here shown to be the transporting media for the pollutants, so it is of importance to investigate areas most prone to flooding and infiltration. This quick scan method is time and cost-efficient, easy to execute and the results are comparable to any known (inter)national threshold criteria for polluted soils. The results are of great importance for all stakeholders in cities that are involved in climate adaptation and implementing green infrastructure in urban areas. However, too little is still known about the long-term functioning of the soil-based SuDS facilities.
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