SummaryBackgroundCelecoxib has a positive effect on human osteoarthritic cartilage, but the mechanisms remain unclear. The aim of this study was to test whether celecoxib could inhibit the apoptosis of chondrocyte and ameliorate type II collagen synthesis to relieve symptoms of OA (osteoarthritis).Material/Methods130 Wistar rats were randomly divided into 4 groups as celecoxib (CE), ibuprofen (IBP), indomethacin (IN) and normal saline group (NS). The osteoarthritis was induced by the excision of the left Achilles tendon. At the 3th, 6th, 9th month of treatment, the histological structure of articular cartilage was observed using HE staining. Type II collagen was examined using immunohistochemistry. Chondrocyte apoptosis was detected by TUNEL staining, and the change of ultra-microstructure of chondrocyte was examined through a transmission electron microscope.ResultsCE reduced the OA-like histological changes and suppressed chondrocyte apoptosis. However, IN or IBP had deleterious effects on articular cartilage and enhanced the chondrocyte apoptosis. IBP promoted the expression of type II collagen, and IN inhibited its expression, but had no effect in the CE group.ConclusionsCE had favorable action on OA progression, and may be the ideal choice in the treatment of chronic destructive joint disease where anti-inflammatory drugs need to be used for a prolonged period.

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Capsaicin, a pungent molecular compound present in many hot peppers, exerts anticancer activities against various human cancer cell lines by inducing apoptosis. However, the effects of capsaicin on human osteosarcoma (OS) as well as the related mechanisms remain to be fully elucidated. In the present study, the anticancer effects of capsaicin on 3 human OS cell lines (MG63, 143B and HOS) were investigated. Various concentrations of capsaicin (50–300 µM) effectively decreased cell viability in all 3 OS cell lines in a dose-dependent manner. Notably, capsaicin-induced apoptosis was observed when OS cells were treated with relatively high concentrations of capsaicin (starting at 250 µM). In addition, the mitochondrial apoptotic pathway was involved in the capsaicin-induced apoptosis in the OS cells. Meanwhile, our results also indicated that at relatively low concentrations (e.g., 100 µM), capsaicin could inhibit the proliferation, decrease the colony forming ability and induce G0/G1 phase cell cycle arrest of OS cells in a dose-dependent manner. Moreover, our results revealed that the anticancer effects induced by capsaicin on OS cell lines involved multiple MAPK signaling pathways as indicated by inactivation of the ERK1/2 and p38 pathways and activation of the JNK pathway. Furthermore, the results of animal experiments showed that capsaicin inhibited tumor growth in a xenograft model of human OS. In conclusion, these results indicate that capsaicin may exert therapeutic benefits as an adjunct to current cancer therapies but not as an independent anticancer agent.

In a power system, remote measurements are used by a controller to provide damping torque for inter-area oscillations. In this study, the operating conditions that give rise to inter-area oscillations are investigated using Stochastic Subspace Identification (SSI) based modal analysis. In a power system, generators can be grouped based on coherency and the groups can be represented by Virtual Generators (VGs). Damping inter-area oscillations using Virtual Generator based Power System Stabilizer (VG-PSS) that generates a supplementary control signal to the excitation system of one or more synchronous generators is presented. The generator choice for VG-PSS location is determined based on the generator that has maximum controllability on dominant weakly damped inter-area mode(s) in a power system. Modal analysis using SSI and real-time simulation results on the IEEE 68-bus power system are presented to illustrate the effectiveness of VG-PSSs in damping inter-area oscillations. In addition, the effect of time delays encountered as a result of wide area measurements and communications are considered in the studies presented.

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The effects of long-term use of celecoxib, ibuprofen, and indomethacin on types I, II, and III collagen metabolism were evaluated in rat osteoarthritis (OA) model. One hundred and thirty wistar rats were randomly divided into 4 groups: the celecoxib group, the ibuprofen group, the indomethacin group, and the normal saline group. The osteoarthritis was induced by the excision of the left Achilles tendon. In the 3rd, 6th, and 9th month of treatment after surgically induced osteoarthritis, the articular cartilage was observed with microscope using HE staining. The expression of proteoglycans was semiquantified using toluidine blue staining. And, the expressions of types I, II, and III collagen in chondrocytes were examined using immunohistochemistry. The results suggested that celecoxib had no remarkable effects on the expression of types I, II, and III collagen. Ibuprofen upgraded the expression of types I, II, and III collagen and increased the synthesis of collagen. Indomethacin suppressed the expression of type II collagen and enhanced the expression of types I and III collagen. Therefore, during the long-term use of NSAIDs in osteoarthritis, celecoxib may have no remarkable influences on collagen metabolism of the articular cartilage and may be the ideal choice in the treatment of chronic destructive joint disease when anti-inflammatory drugs need to be used for a prolonged period. Ibuprofen may be unfavorable, and indomethacin may be harmful to collagen metabolism in OA treatment.

Background A retrospective study investigated the degeneration trend of uncovertebral joints in a healthy population based on CT assessment. Methods A total of 200 males and 160 females, aged 21–79 years old (50.82 ± 17.06), who underwent CT examination in our hospital from September 2020 to March 2021 were enrolled. Sixty patients were included in each age group. According to the Kellgren and Lawrence classification and CT was used to evaluate the uncovertebral joints degeneration in different groups. Results With the increase of age, the degeneration of each segment was gradually aggravated. The uncovertebral joints started degenerating in the 20 s, and the C5–6 is the most degenerative segment, followed by the C4–5 and C6–7. Significant degeneration occurred in each segment between the 40 s and 60 s and became more severe after the 70 s. Conclusions The modified Kellgren and Lawrence classification based on CT scan could provide a quantitative assessment of uncovertebral joints degeneration in a healthy population and could provide more details for artificial cervical arthroplasty.

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