Alternative splicing induces cytoplasmic localization of RBFOX2 protein in calcific tendinopathy.

BACKGROUND: Calcific tendinopathy (CT) is characterized by deposits of calcium, most commonly found in the shoulder tendons. The exact cause and pathogenesis of CT are not fully understood. This study analyzed the expression pattern of RNA-binding protein fox-1 homolog 2 (RBFOX2), a crucial splicing regulator in tissue differentiation. METHODS: Normal and calcific tendons were compared for RBFOX2 mRNA level using quantitative reverse-transcription polymerase chain reaction. Intracellular localization of RBFOX2 protein was investigated using immunofluorescence microscopy. Normal and calcific tendon cDNAs were used to clone RBFOX2. Sequencing analysis identified coding sequences of the RBFOX2 isoform. RESULTS: The intracellular localization of RBFOX2 protein differed with disease status, with RBFOX2 localized in the cytoplasm in calcific tendons and the nucleus in normal tendons. Analysis of the RBFOX2 protein-coding sequence showed that exon 10, responsible for nuclear localization, was absent in calcific tendons. Splicing of RBFOX2 target genes CHD2 and MBNL1 was significantly affected by cytoplasmic localization of RBFOX2 in calcific tendons. DISCUSSION: Given the function of RBFOX2 as a splicing regulator in the nucleus, cytoplasmic localization of RBFOX2 protein in calcific tendons may have affected overall splicing events and altered gene expression. These results provide insights for comprehension of CT pathogenesis.

Immediate arthroscopy following ORIF for tibial plateau fractures provide early diagnosis and treatment of the combined intra-articular pathologies.

PURPOSE: To evaluate the effectiveness of immediate arthroscopy and clinical outcomes following open reduction and internal fixation (ORIF) of tibial plateau fractures. METHODS: Sixty patients (36 men and 24 women, median age 56 (20-78) years) were divided into Group I (ORIF only: 26 patients, median age 58 (25-78) years) or Group II (ORIF with immediate arthroscopy: 34 patients, median age 55 (20-75) years) in tibial plateau fractures (Schatzker Type II-VI fractures). In the first part of this study, ORIF only was performed without arthroscopic treatment. In the second part, ORIF with immediate arthroscopic examination and treatment was performed. Clinical outcomes, utilizing range of motion (ROM), International Knee Documentation Committee (IKDC) score and hospital for special knee score (HSS) were assessed. RESULTS: At the final follow-up, HSS score was 81 ± 11 points in Group I and 83 ± 9 points in Group II. The IKDC score was 85 ± 8 points in Group I and 86 ± 6 points in Group II. In Group II, concomitant intra-articular lesions in 10 patients (29%) were found and treated simultaneously. However, there were no significant differences in clinical scores or ROM between the two groups. CONCLUSION: Immediate arthroscopy following ORIF for tibial plateau fracture is an effective procedure that provides accurate information for fracture reduction, leading to immediate treatment of concomitant intra-articular lesions without complications. LEVEL OF EVIDENCE: III.

Delayed Lateral Row Anchor Failure in Suture Bridge Rotator Cuff Repair: A Report of 3 Cases.

Compared to single row repair, use of lateral row anchors in suture bridge rotator cuff repair enhances repair strength and increases footprint contact area. If a lateral knotless anchor (push-in design) is inserted into osteoporotic bone, pull-out of the lateral row anchor can developed. However, failures of lateral row anchors have been reported at several months after surgery. In our cases, even though complete cuff healing occurred, delayed pull-out of the lateral row anchor in the suture bridge repair occurred. In comparison to a conventional medial anchor, further biomechanical evaluation of the pull-out force, design, and insertion angle of the lateral anchor is needed in future studies. We report three cases with delayed pull-out of lateral row anchor in suture bridge rotator cuff repair with a literature review.

Culture conditions and medium components for the production of mycelial biomass and exo-polysaccharides with Paecilomyces japonica in liquid culture.

In this study, the liquid culture conditions were optimized for maximal production of mycelial biomass and exo-polysaccharide by Paecilomyces japonica. The effects of medium composition, C/N ratio and physical parameters were investigated. From these experiments, 30 g glucose, 20 g yeast extract, 0.5 g KH2PO4, and 0.1 g CuCl2 2H2O in 1-l distilled water were found to be the most suitable carbon, nitrogen, and mineral sources, respectively. The optimal temperature, initial pH, agitation, and aeration were determined to be 27°C, uncontrolled pH, 400 rpm, and 1.0 vvm, respectively. Under these optimal conditions, the maximum mycelial growth and polysaccharides production were 23.1 g/l and 2.5 g/l, respectively.

Use of scopoletin to inhibit the production of inflammatory cytokines through inhibition of the IkappaB/NF-kappaB signal cascade in the human mast cell line HMC-1.

Scopoletin (6-methoxy-7-hydroxycoumarin) is a coumarin compound and a pharmacologically active agent that has been isolated from several plant species. However, as yet there is no clear explanation of how scopoletin affects the production of inflammatory cytokine. We therefore used cells from the human mast cell line (HMC-1) to investigate this effect. Scopoletin significantly and dose-dependently inhibits the way in which phorbol 12-myristate 13-acetate (PMA) plus A23187 induces the production of inflammatory cytokines such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-8 (P<0.05). The maximal rates at which scopoletin (0.2 mM) inhibited the production of TNF-alpha, IL-6, and IL-8 were 41.6%+/-4.2%, 71.9%+/-2.5%, and 43.0%+/-5.7%, respectively. In activated HMC-1 cells, the expression level of nuclear factor (NF)-kappaB/Rel A protein was increased in the nucleus whereas the level of NF-kappaB/Rel A in nucleus was decreased by treatment with scopoletin. Scopoletin decreased PMA plus A23187-induced luciferase activity. Scopoletin also inhibits IkappaBalpha phosphorylation and degradation in cytoplasm. These results indicate that scopoletin has a potential regulatory effect on inflammatory reactions that are mediated by mast cells.