Serum Cartilage Oligomeric Matrix Protein Concentration Increases More After Running Than Swimming for Older People.

BACKGROUND: Knee osteoarthritis is common in older people. Serum cartilage oligomeric matrix protein (sCOMP) is a biomarker of knee articular cartilage metabolism. The purpose of this study was 2-fold: to (1) determine acute effects of running and swimming on sCOMP concentration in older people; and (2) investigate relationships between sCOMP concentration change due to running and swimming and measures of knee health in older people. HYPOTHESES: Running would result in greater increase in sCOMP concentration than swimming, and increase in sCOMP concentration due to running and swimming would associate positively with measures of poor knee health. STUDY DESIGN: Cross-sectional. LEVEL OF EVIDENCE: Level 3. METHODS: A total of 20 participants ran 5 km and 19 participants swam 1500 m. sCOMP concentration was measured immediately before, immediately after, and 15, 30, and 60 minutes after running or swimming. sCOMP concentration change due to running and swimming was compared. Correlations between sCOMP concentration change due to running and swimming, and other measures of knee health were evaluated, including the Tegner Activity Scale and Knee injury and Osteoarthritis Outcome Score. RESULTS: sCOMP concentration increased 29% immediately after running, relative to baseline, but only 6% immediately after swimming (P < 0.01). No significant relationship was observed between acute sCOMP change due to running and swimming, and observed measures of knee health (P > 0.05). Participants with clinically relevant knee symptoms exhibited greater sCOMP concentration before and after running and swimming (P = 0.03) and had greater body mass (P = 0.04). CONCLUSION: Running results in greater acute articular cartilage metabolism than swimming; however, the chronic effects of this are unclear. Older people with clinically relevant knee symptoms possess greater sCOMP concentration and are heavier, independent of exercise mode and physical activity level. CLINICAL RELEVANCE: These results describe the effects of exercise (running and swimming) for older physically active persons, with and without knee pain.

Development and validation of an HPLC-MS-MS method for quantitating bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (Tinuvin 770) and a related substance in aqueous extracts of plastic materials.

Tinuvin 770 is a light stabilizer present in numerous polymers utilized in medical or pharmaceutical applications (e.g., manufacturing, packaging, delivery systems and devices). Under conditions of use, Tinuvin 770 and its related substances may leach from the polymers and accumulate in pharmaceutical products that are administered to subjects to produce a therapeutic benefit. In order to establish the amounts of Tinuvin 770 that may be extracted from such systems and devices, sensitive and selective analytical methodologies are required. A liquid chromatographic method with tandem mass spectrometric detection (LC-MS-MS; API-ES, positive ion mode) has been developed for the purpose of quantitating Tinuvin 770 and a related substance at low concentrations [200 ng/mL (ppb) or less] in aqueous extracting media. Issues related to injection-to-injection carryover and sample matrix effects were mitigated by the addition of potassium chloride to the test samples, where the potassium ion increases Tinuvin solubility via a "salting in" effect. The developed method was validated for this application by assessing performance characteristics including accuracy, response linearity, precision, specificity, and solution stability. The validated method is suitable for the quantitation of these analytes in the concentration range of 1-200 ng/mL.

Generation of the Extractables Profile for an Elastomeric Material and Investigation of the Accumulation Behavior of Targeted Leachables Including Bis(2,2,6,6-tetramethyl-4-piperidyl) Sebacate (Tinuvin 770) and a Related Substance.

The organic extractables profile of a synthetic polyisoprene material being considered for use as a closure on a bag-type packaging system has been delineated. The predominant organic extractables associated with the test material were bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (Tinuvin 770), several Tinuvin-related substances, fatty acids, and antioxidant-related compounds. Based on their potential product safety impact, Tinuvin and one of its related substances were chosen as target leachables. In order to establish the accumulation behavior of these target leachables under conditions that simulate the desired application, monobags (100-mL fill volume) and multichambered bags (1000-mL fill volume) were constructed with injection sites made from the test material, filled with water, and subjected to accelerated aging including multiple sterilization cycles and long-term storage at 40 °C. Even under the worse-case contact conditions, the accumulation levels of the target leachables were much less than their total available pool in the injection sites.