[Revision rate of periprosthetic joint infection post total hip or knee arthroplasty of 34 hospitals in China between 2015 and 2017: a multi-center survey].

Objective: To investigate the rate of periprosthetic joint infection (PJI) revision surgeries and clinical information of hip-/knee- PJI cases nationwide from 2015 to 2017 in China. Methods: An epidemiological investigation. A self-designed questionnaire and convenience sampling were used to survey 41 regional joint replacement centers nationwide from November 2018 to December 2019 in China. The PJI was diagnosed according to the Musculoskeletal Infection Association criteria. Data of PJI patients were obtained by searching the inpatient database of each hospital. Questionnaire entries were extracted from the clinical records by specialist. Then the differences in rate of PJI revision surgery between hip- and knee- PJI revision cases were calculated and compared. Results: Total of 36 hospitals (87.8%) nationwide reported data on 99 791 hip and knee arthroplasties performed from 2015 to 2017, with 946 revisions due to PJI (0.96%). The overall hip-PJI revision rate was 0.99% (481/48 574), and it was 0.97% (135/13 963), 0.97% (153/15 730) and 1.07% (193/17 881) in of 2015, 2016, 2017, respectively. The overall knee-PJI revision rate was 0.91% (465/51 271), and it was 0.90% (131/14 650), 0.88% (155/17 693) and 0.94% (179/18 982) in 2015, 2016, 2017, respectively. Heilongjiang (2.2%, 40/1 805), Fujian (2.2%, 45/2 017), Jiangsu (2.1%, 85/3 899), Gansu (2.1%, 29/1 377), Chongqing (1.8%, 64/3 523) reported relatively high revision rates. Conclusions: The overall PJI revision rate in 34 hospitals nationwide from 2015 to 2017 is 0.96%. The hip-PJI revision rate is slightly higher than that in the knee-PJI. There are differences in revision rates among hospitals in different regions.

Chondrogenesis of mesenchymal stem cells in a novel hyaluronate-collagen-tricalcium phosphate scaffolds for knee repair.

Scaffolds are expected to play a key role in the induction of chondrogenesis of mesenchymal stem cells (MSCs) for cartilage tissue regeneration. Here, we report the development of a novel tricalcium phosphate-collagen-hyaluronate (TCP-COL-HA) scaffold that can function as a stem cell carrier to induce chondrogenesis and promote cartilage repair, and the investigation of chondroinductive properties of scaffolds containing varying amounts of TCP, COL and HA. TCP-COL-HA scaffolds, as well as TCP-COL scaffolds at two different TCP/COL ratios (50:50 and 25:75), were evaluated for their ability to induce cartilage regeneration from rabbit mesenchymal stem cells (rMSCs) in vitro and in vivo. Chondrogenic differentiation was evaluated by sulphated glycosaminoglycan quantification, collagen type II immunohistochemistry, and qRT-PCR. Mechanical strength was evaluated by the compression test. The results showed that the TCP-COL-HA scaffolds enhanced rMSC chondrogenesis to a greater degree than did the TCP-COL scaffolds; for the latter, the scaffold with the lower TCP/COL ratio (25:75) was superior in terms of promoting rMSC chondrogenesis. Similar results were obtained in an ectopic implantation model in nude mice. In a critical-size rabbit osteochondral defect-repair model, rMSCs seeded on TCP-COL-HA scaffolds showed greater cartilage regeneration and integration into surrounding tissue than the TCP-COL groups, in which cartilage repair was more efficient at the 25:75 than at the 50:50 ratio. These results indicate that the addition of HA and different TCP/COL ratios can affect the chondroinductive capacity of scaffolds, and suggest that the TCP-COL-HA scaffold can serve as an effective cell carrier for cartilage regeneration.

[Interferon α sensitizes human osteosarcoma cells to doxorubicin-induced apoptosis through p53-dependent pathway].

Objective: To investigate the effect of IFNα on doxorubicin-induced apoptosis in human osteosarcoma cells with its molecular mechanisms to provide evidences for improving the treatment of osteosarcoma. Methods: Osteosacoma U2OS and MG63 cells were treated with IFNα and Doxorubicin, alone or in combination, for 72 h . Cytotoxicity was determined with MTT. Apoptosis was evaluated through fluorescence-activated cell sorting, Hoechst33258 staining and DNA ladder assay. The expression of p53, Bax, Bcl-2, Mdm2, p21, caspase-3 and PARP was determined with Western blot. siRNA interference was used to silence p53. Results: IFNα treatment for 72 h did not induce cytotoxicity but greatly enhanced doxorubicin-induced cytotoxicity and apoptosis in p53-wild U2OS cells but not p53-mutant MG63 cells. Compared with other groups, the combination of IFNα and doxorubicin induced more obvious apoptotic morphological changes and DNA ladder. IFNα did not alter the expression of the indicate genes. The expression of p53, Bax, Mdm2 and p21 was up-regulated by doxorubicin and further increased in response to combination. The expression of Bcl-2 was down-regulated by doxorubicin and further decreased in response to combination.There were no differences among groups in MG63 cells. The expression of p53 was effectively blocked by p53-siRNA in U2OS cells. The p53 silencing greatly reduced the cytotoxicity mediated by combination for 72 h, compared with non- and control-siRNA groups. The activation of caspase-3 and PARP mediated by combination was largely suppressed by p53 silence. Conclusion: IFNα sensitizes human osteosarcoma cells to doxorubicin-induced apoptosis through p53-dependent pathway. The combination of IFNα and traditional chemotherapy can be used in osteosarcoma treatment.

CCL3 serves as a potential plasma biomarker in knee degeneration (osteoarthritis).

OBJECTIVE: To explore the ability of chemokines in plasma to detect the presence of pre-X-rays defined knee degeneration and the extent (burden). METHODS: A total of 181 subjects (75 control subjects, 47 pre-X-KD patients and 50 X-KOA patients) were included and subdivided into three subgroups. Articular cartilage loss in pre-X-KD patients were scored on the basis of the ICRS classification during the arthroscopy or documented on MRI with chondral WORMS. The severity of X-KOA was graded using the Kellgren-Lawrence classification through the posterior-anterior knee X-rays. The concentrations of the inflammatory cytokines and chemokines in plasma were quantified using Luminex microbead-based suspension array (SA) and were cross-validated by enzyme-linked immunosorbent assay (ELISA). RESULTS: CCL3 in plasma showed the highest ability to discriminate pre-X-KD patients from the controls with an AUC of 0.799. At a cutoff value of 0.168 pg/ml, the sensitivity was 70.21%, the specificity was 96.00%, the positive predictive value was 91.67% and the negative predictive value was 83.72%. As to define disease burden, the plasma levels of resistin, IL6, IL8, CCL3 and CCL4 showed significant association with the severity of X-rays defined knee OA, with regard to the KL classification. Moreover, significant elevation of IL6, IL8, CCL3 and CCL4 levels in plasma were observed in severe knee OA patients (KL grade IV) compared with those with pre-X-KD (KL grade 0-I). CONCLUSION: We firstly showed that the plasma CCL3 could be potential serum biomarker for knee OA with the capacity to detect pre-X-rays defined changes and stage the severity of damage in knee.

Comparison of the effects of alendronate sodium and calcitonin on bone-prosthesis osseointegration in osteoporotic rats.

UNLABELLED: Alendronate (ALO) and calcitonin (CT), as commonly used antiosteoporosis drugs in current clinical practice, have been experimentally confirmed to produce the effectiveness of promoting osseointegration at the interface between prosthesis and host bone and enhancing the long-term stability of the prosthesis. Our current study compared these two drugs' effects on the osseointegration of prosthesis and found that both of them could promote bone attachment between prosthesis and host bone; moreover, ALO produced more pronounced effectiveness. INTRODUCTION: A series of findings confirmed that ALO and CT improved bone attachment of implant in animals. However, which one shows stronger effectiveness has not yet been reported by previous researches. Our study compared the effects of the two commonly used antiosteoporosis drugs on the bone-prosthesis osseointegration so as to provide valuable reference for current clinical options of medication. METHODS: Forty female SD rats aged 5 months were randomly set into A, B, C, and D groups. Except for group A, the others were ovariectomized to establish osteoporosis model (lumbar bone mineral density (BMD) decreased by 20% 4 weeks after ovariectomy). All the rats received prosthesis implantation at their tibial plateau. Then, the rats in groups C and D were given ALO (7 mg/kg/w) orally and CT (5 IU/kg/day) subcutaneously for 12 weeks, respectively. Prior to the execution, application of tetracycline hydrochloride for staining in vivo was done. After harvesting and embedding, the tibia with implants were cut into thin slides, then the bone histomorphometry was measured to observe the new bone around prosthesis and to calculate the osseointegration rate of the implants. By comparison, the effect of the two drugs on osseointegration was evaluated. RESULTS: (1) Both ALO and CT can effectively enhance the volume of bone mass surrounding the hydroxyapatite (HA) prosthesis and also significantly lever up osseointegration rate to 63.7% and 45.7%, respectively (p < 0.05). However, ALO produced more periprosthesis osseointegration rate than CT, with difference of 18% (p < 0.05). (2) The rats' lumber BMD increased in both ALO and CT groups, from 0.081 ± 0.009 and 0.078 ± 0.009 to 0.116 ± 0.008 and 0.109 ± 0.010 g/cm(2), respectively. Moreover, the effect of ALO was observed more pronounced than that of CT. CONCLUSIONS: In osteoporotic conditions, both administration of ALO orally and CT subcutaneously can enhance periprosthesis bone mass and the effects on osseointegration between host bone and prosthesis. Compared with CT, the effect of ALO is more pronounced.

Expression of nm23 protein in human osteosarcoma in relationship with early metastasis.

Nm23 protein expression was analyzed by immunohistochemical staining using formalin-fixed, paraffin-embedded sections from 39 cases with osteosarcomas and compared with the histologic findings and early metastasis for the purpose of detecting nm23 expression in osteosarcoma and elucidating the clinical significance of its expression. Immunoreactivity of nm23 protein was detected in 48.7% of the total cases. There was no statistical difference between nm23 expression and early metastasis, but there was a trend for cases with nm23 expression to progress to early metastasis within 1 year after operation. The role of nm23 as a tumor metastasis suppressor in osteosarcomas appeared less prominent.

Studies on dental high-speed cutting.

The primary author, an experienced dentist, cut bovine enamel and dentine horizontally and vertically with diamond points driven by an air-turbine, while the rotational cutting speeds and applied loads were simultaneously monitored. Three cutting techniques employed here were successive cutting with moderate force (S-m); intermittent cutting with moderate force (I-m); and intermittent cutting with a smaller force (I-s). It was found that the cut contact time of S-m, I-m and I-s cuts were about 10s, 0.4s and 0.25 s, respectively. The maximum applied load during cutting varied, depending upon the cutting direction and the cutting technique. Vertical S-m cut of enamel resulted in the largest applied load of around 105 g, while horizontal I-s cut of dentine brought about the minimum (approximately 35 g). Cutting volumes of dentine tended to exceed those of enamel. It was confirmed that the I-m cut produced larger cutting effectiveness of diamond points on both enamel and dentine compared with the S-m cut.

[Amplification, rearrangement and over-expression of c-fos gene in human primary brain tumors].

The c-fos gene was used as a probe to detect the Bam HI-digested brain DNA and total RNA isolated from 2 cases of normal human brain and 11 cases of human brain tumor by Southern blot analysis and RNA dot hybridization technique. The result showed an amplification and over-expression of c-fos gene in one case of glioblastoma multiforme. These data suggest that the c-fos gene may take an important role in the carcinogenesis of human primary brain tumor, and the level of c-fos expression may be correlated with the degree of differentiation of brain tumor cells. We also found that there was a rearrangement of c-fos gene in one case of ependymoma. This suggests that, in ependymoma, the c-fos gene may be activated in a way different from that in the brain tumors of astroglia origin.