ABSTRACT
<p><b>BACKGROUND</b>The properties of subchondral bone influence the integrity of articular cartilage in the pathogenesis of osteoarthritis (OA). However, the characteristics of subchondral bone alterations remain unresolved. The present study aimed to observe the dynamic alterations in the microarchitecture, mineralization, and mechanical properties of subchondral bone during the progression of OA.</p><p><b>METHODS</b>A medial meniscal tear (MMT) operation was performed in 128 adult Sprague Dawley rats to induce OA. At 2, 4, 8, and 12 weeks following the MMT operation, cartilage degeneration was evaluated using toluidine blue O staining, whereas changes in the microarchitecture indices and tissue mineral density (TMD), mineral-to-collagen ratio, and intrinsic mechanical properties of subchondral bone plates (BPs) and trabecular bones (Tbs) were measured using micro-computed tomography scanning, confocal Raman microspectroscopy and nanoindentation testing, respectively.</p><p><b>RESULTS</b>Cartilage degeneration occurred and worsened progressively from 2 to 12 weeks after OA induction. Microarchitecture analysis revealed that the subchondral bone shifted from bone resorption early (reduced trabecular BV/TV, trabecular number, connectivity density and trabecular thickness [Tb.Th], and increased trabecular spacing (Tb.Sp) at 2 and 4 weeks) to bone accretion late (increased BV/TV, Tb.Th and thickness of subchondral bone plate, and reduced Tb.Sp at 8 and 12 weeks). The TMD of both the BP and Tb displayed no significant changes at 2 and 4 weeks but decreased at 8 and 12 weeks. The mineral-to-collagen ratio showed a significant decrease from 4 weeks for the Tb and from 8 weeks for the BP after OA induction. Both the elastic modulus and hardness of the Tb showed a significant decrease from 4 weeks after OA induction. The BP showed a significant decrease in its elastic modulus from 8 weeks and its hardness from 4 weeks.</p><p><b>CONCLUSION</b>The microarchitecture, mineralization and mechanical properties of subchondral bone changed in a time-dependent manner as OA progressed.</p>
Subject(s)
Animals , Male , Rats , Collagen , Metabolism , Osteoarthritis , Diagnostic Imaging , Metabolism , Rats, Sprague-Dawley , X-Ray MicrotomographyABSTRACT
<p><b>OBJECTIVE</b>To study the correlation of insulin resistance (IR) with TCM syndrome type and activity of fibrinolytic system in patients with coronary arterial disease (CAD).</p><p><b>METHODS</b>One hundred and twelve CAD patients were classified according to TCM Syndrome into 4 types, the Xin-blood stasis (XBS) type, the phelgm blocking Xin-channel (PBXC) type, the Qi-insufficiency with blood stasis (QIBS) type and the both Qi-Yin deficiency (QYD) type. Patients' fasting blood glucose (FBG), fasting blood insulin (FIns) were measured, the insulin sensitive index (ISI) calculated. Data were compared between various types, also with those obtained from 30 healthy persons in the control group respectively. Moreover, activity of tissue plasminogen activator (t-PA) and content of plasminogen activator inhibitor-1 (PAI-1) were determined in 90 patients selected from the 112 to conduct linear correlation analysis of IR with t-PA activity and PAI-1 content.</p><p><b>RESULTS</b>FBG and FIns levels in the CAD patients were higher than those in the healthy control significantly (P < 0.01); ISI in the 4 syndrome type of CAD patients were all lower than that in the control (P < 0.01). IR existed in all the 4 types, but the level in the XBS type and the PBXC type was more severe than in the other two types. Correlation analysis showed that IR was correlated with t-PA activity and PAI-1 content (P < 0.01).</p><p><b>CONCLUSION</b>IR often exists in CAD patients, the severity of IR varies in patients of different TCM syndrome types, and IR is correlated with the abnormality of fibrinolytic system activity.</p>