Lycium barbarum polysaccharide protects against osteonecrosis of femoral head via regulating Runx2 expression.

BACKGROUND: Osteonecrosis of femoral head (ONFH) is a pathological state caused by lack of blood supply in femoral head. This study aimed to explore the function of Lycium barbarum polysaccharide (LBP), an antioxidant agent extracted from L. barbarum, on ONFH. METHODS: Osteonecrosis rat model was generated using lipopolysaccharide (LPS) and methylprednisolone followed by examination of body weight, blood glucose, morphology, and BMSC osteoblast differentiation. The effect and underlying mechanism of LBP on the proliferation, apoptosis, and osteoblast differentiation of BMSC were determined with or without LPS or hypoxia treatment using CCK-8. Alizarin Red S staining, flow cytometry, and western blot, respectively. RESULT: LBP could protect against glucocorticoid-induced ONFH in rats, resulting in improved sparse trabecular bone, empty lacunae and bone cell coagulation. Moreover, LBP promoted the proliferation and osteoblast differentiation of bone mesenchymal-derived stem cells (BMSCs) in a dose-dependent manner. Furthermore, LBP enhanced osteoblast differentiation of BMSCs under hypoxia condition. Mechanistically, we found that LBP treatment enhanced Runx2 and ALP expression in BMSCs. LBP restored the expression of Runx2 and ALP under hypoxia, suggesting that LBP might be involved in regulating Runx2/ALP expression and contributed to osteoblast differentiation. Knockdown of Runx2 significantly inhibited BMSCs proliferation, while LBP treatment did not rescue the osteoblast differentiation ability of BMSCs with Runx2 knockdown. CONCLUSION: Our findings suggested that LBP protects against ONFH via regulating Runx2 expression, which could be utilized to treat patients suffering ONFH.

Clinical application of different operative approach of total knee replacement in knee valgus patients. Retrospective cohort study.

PURPOSE: According to the severity of knee valgus, different operative approaches were applied in total knee replacement. Hence, we assessed the safety and efficacy of different operative approaches in the level IV study. METHODS: From May 2011 to March 2014, a retrospectively analysis was conducted among 31 patients with knee valgus (mild in 10 cases, moderate in 8 cases and severe in 13 cases based on Keblish grade). Medial approach trip knee replacement was performed in mild and moderate patients, which were assigned as medial approach group. Lateral approach was performed in severe patients, which was assigned as lateral approach group. Relevant results were compared between medial approach group and lateral approach group, including valgus corrected angle, postoperative knee joint activity and Kss score. Furthermore, operative time, postoperative blood loss, patellar trajectory and anterior knee pain were also compared between the two groups. RESULTS: All operations were successful without obvious complications. In medial approach group, postoperative knee valgus angle was (7 ±â€¯1)°. Three months after operation, degree of knee joint activity was (85.2 ±â€¯5.2)°, and KSS score of knee joint was (80.1 ±â€¯5.2). Significant differences were detected in these compared with preoperative data (all P < .05). Moreover, similar results were found in lateral approach group with postoperative knee valgus angle as (8.2 ±â€¯2.3)°, degree of knee joint activity three months after operation as (85.2 ±â€¯5.3)°, and KSS score of knee joint as (80.3 ±â€¯3.2). However, no significant differences were found among these three groups in operative time, postoperative blood loss, patellar trajectory or anterior knee pain. CONCLUSIONS: Different operative approaches in total knee replacement according to the severity of knee valgus were proved as effective and safe procedures, which deserved further application.

Detection of anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis patients undergoing total knee arthroplasty.

Rheumatoid arthritis (RA) is the most common chronic inflammatory joint disorder and anti-cyclic citrullinated peptide antibody (anti-CCP Ab) is regarded as a serological marker for diagnosing early and late RA. In the present study, we aimed to determine the levels of anti-CCP Ab in serum, synovial tissue (ST) and synovial fluid (SF) in RA patients undergoing total knee arthroplasty (TKA). 23 patients were included. Rheumatoid factor (RF) and anti-CCP Ab in serum were detected prior to surgery and then at 1, 3, 6 and 12 months after TKA. Synovial samples were obtained by knee arthroscopy and used for anti-CCP detection. One month after TKA, anti-CCP levels were significantly reduced (P < 0.01) in RA patients. However, their levels were not significantly different between pre-surgery and 1 year post-surgery (P > 0.05). Furthermore, anti-CCP levels in ST were much higher than in serum. These findings suggest that RA patients should continue antirheumatic therapy after TKA. ST is the preferred place for the synthesis of anti-CCP Ab.

Elevated chemerin levels in synovial fluid and synovial membrane from patients with knee osteoarthritis.

To test the serum, synovial fluid and synovial membrane levels of the adipokine chemerin in patients with knee osteoarthritis (KOA) and investigate their relationships with the severity of articular cartilage damage and synovitis. According to the American College of Rheumatology criteria for diagnosis of osteoarthritis (OA), 30 cases with OA diagnoses (OA group) were selected from patients who underwent arthroscopic surgery in our hospital from June 2013 to February 2014. Another 30 cases with other knee joint diseases (non-OA group) were included as controls. The synovial fluid and serum levels of chemerin were assayed by ELISA, and the synovial membrane level of chemerin was assayed by the immunohistochemical method. The severity of the knee articular cartilage damage and synovitis-related pathological changes were evaluated by arthroscopy using the Outerbridge and Ayral scores, respectively. The synovial fluid and synovial membrane levels of chemerin in the OA group were higher than those in the non-OA group. Statistically significant differences were found between the two groups in the synovial fluid and synovial membrane levels of chemerin (P < 0.05). The synovial fluid and synovial membrane levels of chemerin were positively correlated with the serum level of high-sensitivity C-reactive protein (HS-CRP), Outerbridge score and Ayral score in the OA group. The synovial fluid and synovial membrane levels of chemerin are increased in KOA patients and are positively correlated with the severity of KOA.

[Development of a quantitative real-time polymerase chain reaction for detecting Bartonella henselae].

OBJECTIVE: To develop a quantitative real-time polymerase chain reaction (PCR) for detecting Bartonella henselae. METHODS: According to the 16S-23S rRNA intervening sequences (IVS) specific for B. henselae, one pair of primers and one TaqMan-MGB probe were designed. A quantitative real-time PCR was developed with the primers, the probe, and the IVS, a standard template, in DNA sequence detection system (ABI 7900HT). RESULTS: The standard curve was established with the standard template and the relationship between the value of threshold cycle (Ct) and the DNA copy number was linear (r = 0.997). The sensitivity of this quantitative real-time PCR was about 1000 times higher than that of a common PCR used to detect homologous DNA. By this quantitative real-time PCR, the DNA sample of B. henselae was positively detected but not from other rickettsial or bacterial DNA samples. The variation coefficients of intra- and inter-assay reproducibility were 0.2%-1.9%. Using the real-time quantitative PCR to detect samples from mice that were experimentally infected with B. henselae, the small amount of B. henselae DNA was detected in blood samples on days 2, 3, and 5 and large amount of B. henselae DNA was detected in spleen samples on days 1 and 2 after infection. CONCLUSION: Results from our study suggested that this quantitative real-time PCR was highly specific, sensitive and with good repeatability for detection of B. henselae. It seemed quite useful for rapid detection of tiny DNA of B. henselae in various samples and laboratory diagnosis of bartonellosis caused by B. henselae.

[Study on the development of a real-time quantitative polymerase chain reaction assay to detect Rickettsia].

OBJECTIVE: To develop a real-time quantitative polymerase chain reaction(PCR) assay for detecting Rickettsia rickettsii. METHODS: The primers and TaqMan-MGB probe were designed according to the ompB gene of R. rickettsii. A DNA fragment of ompB gene amplified from R. rickettsii by PCR was used as a standard template for the development of the method. RESULTS: 5 copies of ompB fragments of R. rickettsii were detected. The genomic DNA of R. rickettsii was detected by the developed quantitative PCR assay. However, the genomic DNA from another rickettsial or bacterial agent was not determined. Through this developed method, the positive results were obtained from the animals and cells, artificially infected with R. rickettsii. CONCLUSION: The real-time quantitative PCR assay seemed to be highly sensitive and specific which might be used to rapidly detect R. rickettsia DNA in various samples and to early diagnose patients infected by R. rickettsii.

[Detection of Rickettsia prowazekii by quantitative real-time PCR].

OBJECTIVE: To develop a quantitative real-time polymerase chain reaction (PCR) for detecting Rickettsia prowazekii. METHODS: Primers and TaqMan-MGB probes designed based on ompB gene of R. prowazekii, were used to develop this method. RESULTS: For the quantitative real-time PCR, the relationship between the values of threshold cycle (Ct) and the DNA copy number was linear (r = 0.999) and the sensitivity was about 100 times higher than that of the nested PCR for detecting the same DNA sample. The results of the genomic DNA samples of other rickettsial and bacterial agents detected by real-time PCR were all negative. DNAs extracted from blood samples of guinea pig infected with R. prowazekii were examined by real-time PCR and the positive results were obtained from some of these samples. However, the results of some samples in nested PCR assay were all negative. CONCLUSION: These results suggested that the real-time PCR was highly specific and sensitive for detection of R. prowazekii that was useful for the detection of tiny DNA of R. prowazekii in blood samples from patients suspected of having epidemic typhus.

Recombinant 56-kilodalton major outer membrane protein antigen of Orientia tsutsugamushi Shanxi and its antigenicity.

The gene encoding the 56-kDa protein of Orientia tsutsugamushi Shanxi was amplified by a nested PCR and cloned into the expression vector pQE30. The 56-kDa protein of O. tsutsugamushi Shanxi (Sxh56) was expressed as a fusion protein with the His(6)-binding protein of Escherichia coli by deleting the signal peptide-encoding sequence from the 5' end of the open reading frame. The recombinant protein formed inclusion bodies when expressed in E. coli M15. The recombinant protein was examined for reactivity with mouse sera against three antigenic prototypes of O. tsutsugamushi by an immunoblot assay. The recombinant Sxh56 reacted only to polyclonal antiserum to O. tsutsugamushi Gilliam in an enzyme-linked immunosorbent assay (ELISA) and in an immunoblot assay. Recombinant Sxh56 was purified by Ni-nitrilotriacetic acid affinity chromatography and injected into mice to evaluate its ability to stimulate immune responses. High levels of immunoglobulin G and T-cell proliferation appeared in mice immunized with the recombinant protein. The recombinant Sxh56 was used in an ELISA to evaluate the ability of the method to detect antibodies to O. tsutsugamushi in human and animal sera. Thirty sera from mice infected with O. tsutsugamushi Gilliam or Shanxi and 55 sera from normal mice were detected in the ELISA with recombinant Sxh56, and the sensitivity and specificity were 96.67 and 100%, respectively. One hundred fifty-one positive sera and 412 negative sera to O. tsutsugamushi Gilliam were detected in an indirect immunofluorescence assay with the recombinant protein, and the sensitivity and specificity were 96.36 and 88.08%, respectively. These results strongly suggest that the recombinant Sxh56 is a suitable type-specific immunodiagnostic antigen and vaccine candidate.