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Ginsenoside Rg3, a ginsenoside isolated from Panax ginseng, can regulate autophagy via AMP‐activated protein kinase/mammalian target of rapamycin (AMPK/mTOR) signaling pathway. AMPK/mTOR signaling and autophagy have been reported to be involved in osteogenesis. Here, the effect of Rg3 on ovariectomy (OVX)‐induced osteoporosis is explored. In vivo, rats were treated with 20 mg/kg Rg3 after OVX and the body weight (BW) was monitored. Bone mineral density (BMD), hematoxylin–eosin staining of femur tissues, osteogenesis, autophagy, and AMPK/mTOR signaling were analyzed. In vitro, MC3T3‐E1 cells were treated with 0, 1, 5, 10, 20, and 100 μmol/L Rg3. 10 and 20 μmol/L Rg3, which had no significant effect on cell viability and significantly affected AMPK/mTOR signaling, were chosen for further analysis. Then osteogenic differentiation was induced with Rg3 or/and AMPK inhibitor (Compound C). AMPK/mTOR signaling, autophagy, osteogenic differentiation, and mineralization by Alizarin Red staining were analyzed. The expression or activity of AMPK/mTOR signaling‐related proteins, autophagy markers, and osteogenesis markers was measured by western blotting or commercial kits, and cell viability by cell counting kit‐8 assay kits. Rg3 significantly alleviated OVX‐induced BW increases, BMD declines and histological changes of femur tissues, promoted osteogenesis, autophagy, and AMPK signaling, but inhibited mTOR signaling in vivo. Moreover, Rg3 significantly enhanced AMPK signaling, autophagy, osteogenic differentiation, and mineralization, but suppressed mTOR signaling in vitro. However, Compound C significantly reversed Rg3‐induced alterations in vitro, indicating that Rg3 regulated autophagy, osteogenic differentiation, and mineralization via AMPK/mTOR signaling. Hence, it was speculated that Rg3 might attenuate OVX‐induced osteoporosis via AMPK/mTOR signaling pathway.

Macrophage surface antigen‐1 (Mac‐1, CD11b/CD18) has been implicated in the regulation of osteoclastogenesis. In the synovial tissues of patients with aseptic loosening after total hip replacement, CD11b was up‐regulated, which indicated that CD11b is closely involved in osteolysis around the prosthesis. We found that CD11b, but not CD18, promoted osteoclast (OC) maturation. Here, we show CD11b up‐regulated the levels of spleen tyrosine kinase (Syk), c‐Fos and nuclear factor of activated T cells, cytoplasmic‐1 (NFATc1), as well as the activity of extracellular‐regulated kinase (Erk), and as a result, osteoclast precursors (OCPs) differentiated and became tartrate‐resistant acid phosphatase (TRAP)‐positive. In addition, increased tumour necrosis factor‐α (TNF‐α) induced by ultra‐high molecular weight polyethylene (UHMWPE) particles up‐regulated the level of CD11b. Taken together, these findings suggest that CD11b is a positive regulator of osteoclastogenesis and that it functions by activating the Syk signalling pathway, while CD18 does not have the same effect.

BackgroundThe purpose of our study was to determine whether postoperative sagittal component alignments of primary total knee arthroplasty (TKA) using the conventional and navigated technique differed significantly. Additionally, we determined whether the use of navigation systems resulted in hyperextension of the femoral components in Chinese patients.MethodsThis retrospective study reviewed 36 consecutive patients (72 knees) who underwent simultaneous bilateral primary TKAs at our hospital from February 2011 to March 2012. One knee was replaced using a computer-assisted navigation system, and the contralateral knee was replaced with the conventional technique. The radiographic and clinical results of both groups were compared. The relationship between preoperative anatomic angles and component alignments in conventional TKA and navigated TKA was examined.ResultsThe radiographic results showed statistically significant differences only between the navigated and conventional groups for individual femoral coronal and sagittal component alignment. Femoral sagittal component alignment showed less deviation and tended to have hyperextension using the navigated technique (−0.35°) compared with the conventional technique (2.77°). There was no significant difference observed for the Knee Society Score (KSS) between the two groups at 2 years postoperatively.ConclusionsThe sagittal component alignment of primary TKA obtained using the conventional and navigated techniques differed significantly. Navigated TKAs resulted in a higher risk of hyperextension of the femoral components in Chinese patients.

Induction of estrus is an effective management tool for increasing the pregnancy rate in ewes, and there is a long estrus interval after lambing in spring in Small-tail Han ewe. In this study, norgestrel releasing intra-vaginal devices (PRID) and PRID + pregnant mare serum gonadotrophin (PMSG) were used for estrus induction in Small-tail Han ewe, and expression of follicle-stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), estrogen receptor (ER) and progesterone receptor (PGR) mRNA in the ovarial stroma, oviduct ampulla and endometrium was analyzed by quantitative real-time PCR. The results showed that the estrus-induction with PRID and PRID + PMSG almost had the same effects on increasing the percentage of animals in estrus and conception rate of the ewes, and the estrus-induction had no significant effect on the expression of LHR, ER and PGR mRNA in the oviduct ampulla, ovarial stroma and endometrium, and FSHR in the ovarial stroma and endometrium. Furthermore, the estrus-induction could significantly decrease the expression of FSHR mRNA in the ovine oviduct ampulla (P<0.05). Therefore, it was suggested that down-regulation of FSHR in the oviduct ampulla after estrus induction may be helpful for fertilization and early embryo development.

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