Trajectories of perceived exertion and pain over a 12-week neuromuscular exercise program in patients with knee osteoarthritis.

BACKGROUND: Exercise programs rely on the overload principle, yet patients with knee osteoarthritis (OA) may not adequately progress exercises due to fear of exacerbating symptoms. OBJECTIVE: To describe trajectories for perceived exertion and exercise-induced knee pain during a neuromuscular exercise program for patients with knee OA. DESIGN: Participants with knee OA completed a 12-week neuromuscular exercise program consisting of weekly supervised sessions plus home exercises. During each supervised session, the Borg's rating of perceived exertion (RPE; 6 = no exertion, 20 = maximal exertion) and knee pain (pre, post, max) using Numeric Rating Scales (NRS; 0 = no pain, 10 = worst imaginable pain) were completed. Mean changes in RPE and pain from weeks 1-12 were calculated. Mixed effects regression was used to investigate trajectories over time (weeks) for RPE, and maximum pain (pre-to-max) and pain-change (pre-to-post) during exercise. RESULTS: 56 patients (95%) completed the program. From week 1-12, RPE increased by 2.6 (95%CI, 1.7 to 3.5), from 'somewhat hard' to 'very hard', while max pain decreased by 1.0 NRS (95%CI, 0.5 to 1.3) and pain-change decreased by 0.9 NRS (95%CI, 0.4 to 1.3). Linear mixed effects regression showed a quadratic increase for RPE over time until between weeks 9 and 10, then RPE plateaued. Maximum pain decreased linearly over time. Pain-change showed a quadratic decrease over time until approximately week 9, then pain-change plateaued. CONCLUSIONS: In patients with knee OA participating in a 12-week neuromuscular exercise program, perceived exertion during exercise progressed from 'somewhat hard' to 'very hard' at 9 weeks, while exercise-induced knee pain decreased. Patients were able to work harder while experiencing decreases rather than increases in pain.

Genetic fingerprinting of grape plant (Vitis vinifera) using random amplified polymorphic DNA (RAPD) analysis and dynamic size-sieving capillary electrophoresis.

Dynamic size-sieving capillary electrophoresis with laser-induced fluorescence detection (DSCE-LIF) was combined with random amplified polymorphic DNA (RAPD) analysis to demonstrate the feasibility of the genetic analysis of grape plant varieties and clones within a variety. Parameters of the genomic DNA extraction process, as well as those of the RAPD analysis, were optimized specifically for this application. Polymorphic DNA fragments were generated for four different grape plant varieties including Cabernet Franc, Cabernet Sauvignon, Merlot, and Chardonnay. Relative to slab gel electrophoresis (SGE) with ethidium bromide staining, DSCE-LIF provided superior separation efficiency and detection limits in the analysis of DNA polymorphic bands. Optimal DSCE-LIF analyses were achieved using a 10-fold RAPD sample dilution, hydrodynamic sample injection, and 100 ng/mL of YO-PRO-1 DNA intercalator in the dynamic size-sieving buffer solution. In addition, the reproducibility of both the DSCE-LIF and RAPD analyses were demonstrated.

The use of dynamic size-sieving capillary electrophoresis and mismatch repair enzymes for mutant DNA analysis.

The detection of base pair mismatches in limiting amounts of DNA is important in the early diagnosis of cancer and other genetic diseases. The specific type and exact location of a bp mismatch in certain genes can yield information on the likelihood of a patient developing a genetic disease, as well as the severity of the disease. We demonstrate two methods of specific DNA point mutation detection and identification that involve the integration of mismatch repair cleavage enzyme analyses with dynamic size-sieving capillary electrophoresis. The mismatch repair cleavage enzymes employ the very mechanism that a cell uses in its own mismatch recognition and repair systems. One analysis employs an isothermal signal amplification process, and the other involves polymerase chain reaction (PCR) (Hoffmann-LaRoche, Nutley, NJ, U.S.A.) for amplification of the DNA. Separation of the DNA fragments using dynamic size-sieving CE yields a cleaved fragment, providing definitive evidence of a bp mismatch. The specificity and sensitivity of the assay are facilitated by the detection of fluorescently labeled DNA fragments using laser-induced fluorescence detection; picogram quantities of a target DNA can be analyzed reproducibly.