Correlation between static limb alignment and peak knee adduction angle during gait is affected by subject pain in medial knee osteoarthritis.

BACKGROUND: Although increases in knee adduction moment (KAM) and angle (KAA) during gait are considered key pathologies that produce mechanical overload in the medial compartment of knee osteoarthritis (OA), it is unclear how these pathologies are related to subjective pain. The purpose of this study was to examine how subjective pain is related to such pathologies. METHODS: Gait analysis was performed in 31 participants with medial knee OA. The knees were classified into three groups based on Kellgren-Lawrence (KL) grade: early (0 and 1), moderate (2), and severe (3 and 4). Subjective pain was evaluated by the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index pain score. The knees were classified into low- and high-pain groups based on the pain score. RESULTS: The WOMAC pain score did not correlate with either peak KAM or peak KAA. Although a positive correlation between static limb alignment and peak KAA was observed in the low-pain group, it was not observed in the high-pain group. Knee flexion angle at heel strike correlated negatively with the gap between static femorotibial angle and peak KAA in the high-pain group. CONCLUSIONS: Although a direct correlation between subjective pain and peak KAM or KAA was not observed, our results suggest a compensatory movement in the high-pain group of participants to reduce KAA increases in the early stance phase. Such movements would be one of the reasons why it is difficult to obtain a consistent relationship between subjective pain and load-related parameters.

Purification and enzymatic characterization of secretory glycoside hydrolase family 3 (GH3) aryl ß-glucosidases screened from Aspergillus oryzae genome.

By a global search of the genome database of Aspergillus oryzae, we found 23 genes encoding putative ß-glucosidases, among which 10 genes with a signal peptide belonging to glycoside hydrolase family 3 (GH3) were overexpressed in A. oryzae using the improved glaA gene promoter. Consequently, crude enzyme preparations from three strains, each harboring the genes AO090038000223 (bglA), AO090103000127 (bglF), and AO090003001511 (bglJ), showed a substrate preference toward p-nitrophenyl-ß-d-glucopyranoside (pNPGlc) and thus were purified to homogeneity and enzymatically characterized. All the purified enzymes (BglA, BglF, and BglJ) preferentially hydrolyzed aryl ß-glycosides, including pNPGlc, rather than cellobiose, and these enzymes were proven to be aryl ß-glucosidases. Although the specific activity of BglF toward all the substrates tested was significantly low, BglA and BglJ showed appreciably high activities toward pNPGlc and arbutin. The kinetic parameters of BglA and BglJ for pNPGlc suggested that both the enzymes had relatively higher hydrolytic activity toward pNPGlc among the fungal ß-glucosidases reported. The thermal and pH stabilities of BglA were higher than those of BglJ, and BglA was particularly stable in a wide pH range (pH 4.5-10). In contrast, BglJ was the most heat- and alkaline-labile among the three ß-glucosidases. Furthermore, BglA was more tolerant to ethanol than BglJ; as a result, it showed much higher hydrolytic activity toward isoflavone glycosides in the presence of ethanol than BglJ. This study suggested that the mining of novel ß-glucosidases exhibiting higher activity from microbial genome sequences is of great use for the production of beneficial compounds such as isoflavone aglycones.