The Oxford Knee Score: Compared performance before and after knee replacement

SummaryBackgroundSelf-administered quality-of-life questionnaires are now crucial to the evaluation of orthopaedic surgical patient-reported outcomes, as they reflect patient satisfaction. The Oxford Knee Score (OKS) is a validated instrument that is widely used to assess outcomes of knee osteoarthritis surgery.HypothesisThe relevance of the OKS (comprehension and relevance of the items and responses, and internal and external validity) and its discriminating performance measured based on the ceiling and floor threshold effects are better before than after knee replacement surgery.Materials and methodsWe included 200 patients (100 scheduled for knee replacement and 100 having had knee replacement more than 1 year earlier). The OKS questionnaire was handed to each patient during the first surgeon visit or during a follow-up visit. The American Knee Society (AKS) score was determined simultaneously.ResultsThe mean OKS was 43.7 (range, 21–56; SD, 6.9) before surgery and 20.5 (range, 12–45; SD, 5.6) after surgery. The floor effect was absent (0%) before surgery and substantial (33%) after surgery; a weak ceiling effect (7%) was noted before surgery and no ceiling effect after surgery. Internal consistency of the OKS was excellent. The OKS correlated negatively with the AKS knee and functional scores, both before and after surgery.DiscussionThe OKS is well-suited to the evaluation of knee function both before and after knee replacement surgery. Before surgery, the absence of substantial floor and ceiling effects lead to excellent discrimination. After surgery, the substantial floor effect limits the ability to discriminate among the best results. Efforts should be made to develop more demanding scoring systems.Level of evidenceLevel 2. Exploratory cohort study with universally applied reference standards

Monte Carlo Simulations indicate that Chromati: Nanostructure is accessible by Light Microscopy

A long controversy exists about the structure of chromatin. Theoretically, this structure could be resolved by scattering experiments if one determines the scattering function - or equivalently the pair distribution function - of the nucleosomes. Unfortunately, scattering experiments with live cells are very difficult and limited to only a couple of nucleosomes

Identification of an autoantibody panel to separate lung cancer from smokers and nonsmokers

<p>Abstract</p> <p>Background</p> <p>Sera from lung cancer patients contain autoantibodies that react with tumor associated antigens (TAAs) that reflect genetic over-expression, mutation, or other anomalies of cell cycle, growth, signaling, and metabolism pathways.</p> <p>Methods</p> <p>We performed immunoassays to detect autoantibodies to ten tumor associated antigens (TAAs) selected on the basis of previous studies showing that they had preferential specificity for certain cancers. Sera examined were from lung cancer patients (22); smokers with ground-glass opacities (GGOs) (46), benign solid nodules (55), or normal CTs (35); and normal non-smokers (36). Logistic regression models based on the antibody biomarker levels among the high risk and lung cancer groups were developed to identify the combinations of biomarkers that predict lung cancer in these cohorts.</p> <p>Results</p> <p>Statistically significant differences in the distributions of each of the biomarkers were identified among all five groups. Using Receiver Operating Characteristic (ROC) curves based on age, c-myc, Cyclin A, Cyclin B1, Cyclin D1, CDK2, and survivin, we obtained a sensitivity = 81% and specificity = 97% for the classification of cancer vs smokers(no nodules, solid nodules, or GGO) and correctly predicted 31/36 healthy controls as noncancer.</p> <p>Conclusion</p> <p>A pattern of autoantibody reactivity to TAAs may distinguish patients with lung cancer versus smokers with normal CTs, stable solid nodules, ground glass opacities, or normal healthy never smokers.</p