Differences in prevalence of self-reported oral hypofunction between older adult patients with rheumatoid arthritis and the general older population: A cross-sectional study using propensity score matching.

OBJECTIVE: To examine the association between rheumatoid arthritis (RA) and oral hypofunction (OHF) using propensity score matching (PSM) to adjust for differences between older adults with RA and the general older adult population. METHODS: We conducted a cross-sectional survey among 189 older adults with RA in 2019 (mean age, 71.9 ± 3.6) and 47 178 independent older adult residents in 2016 (mean age, 71.6 ± 4.0), respectively. The questionnaire covered information on socio-demographic characteristics and OHF for both groups. Age, sex, educational level and smoking history were used to determine PSM. Prevalence ratios (PRs) and 95% confidence intervals (CIs) of self-reported OHF (fewer remaining teeth, decreased masticatory function, deterioration of swallowing function and oral dryness) were estimated using Poisson regressions. RESULT: OHF was observed in 44.4% of patients with RA and 27.5% of residents. Before PSM, the prevalence of OHF among patients with RA was higher than that of residents (PR, 1.75; 95% CI, 1.50-2.05). After PSM, there were 189 patients with RA and residents, and the prevalence of OHF among patients with RA was still higher (PR, 1.61; 95% CI, 1.22-2.13). Poisson regression showed that the prevalence of 19 or fewer teeth (PR, 1.06; 95% CI, 0.82-1.36), difficulties eating tough foods (PR, 1.18; 95% CI, 0.90-1.55), difficulties swallowing tea or soup (PR, 1.77; 95% CI, 1.19-2.63), and dry mouth (PR, 2.79; 95% CI, 1.90-4.07) was higher among patients with RA than residents. CONCLUSION: Compared with the general older adult population, patients with RA have a higher prevalence of self-reported OHF.

Reverse Posterior Interosseous Artery Flap for Human Bite Injury to the Hand.

Bite injuries frequently occur on human hands. Human bite injuries to the hand may lead to an infection because of limited soft tissue protection and wound contamination. However, no studies have reported severe bite injuries on hands treated by flaps. We report a case of an 80-year-old woman diagnosed with a major neurocognitive disorder. The patient accidentally had a self-bite injury accompanied with an open metacarpal fracture. Debridement and fixation of the first metacarpal fracture were performed. Afterward, skin necrosis occurred gradually on the dorsum of the hand. Therefore, a reverse posterior interosseous artery (PIA) flap was used, and the postoperative course was uneventful. Given the high risk of infection, human bite injuries, particularly hand bites, should be treated immediately. Delayed treatment for such injuries may lead to extensive soft tissue defects requiring reconstruction with flaps.

Transforming Growth Factor-ß Induces Interleukin-6 Secretion from Human Ligamentum Flavum-Derived Cells through Partial Activation of p38 and p44/42 Mitogen-Activated Protein Kinases.

STUDY DESIGN: This experimental study was performed using human ligamentum flavum-derived cells (HFCs). PURPOSE: To investigate the intracellular signaling mechanism of interleukin-6 (IL-6) secretion in transforming growth factor-ß (TGF- ß)-stimulated HFCs. OVERVIEW OF LITERATURE: Lumbar spinal stenosis (LSS) is a prevalent disease among the elderly, characterized by debilitating pain in the lower extremities. Although the number of patients with LSS has increased in recent years, the underlying pathomechanism remains unclear. Clinical examinations typically rely on magnetic resonance imaging to diagnose patients, revealing ligamentum flavum hypertrophy. Some studies have suggested an association between ligamentum flavum hypertrophy and inflammation/fibrosis, and expression of TGF-ß and IL-6 has been observed in surgically obtained ligamentum flavum samples. However, direct evidence linking TGF-ß and IL-6 expression in HFCs is lacking. METHODS: HFCs were obtained from patients with LSS who had undergone decompression surgery. The cells were stimulated with TGF-ß and pretreated with either the p38 mitogen-activated protein (MAP) kinase inhibitor SB203580 or the p44/42 MAP kinase inhibitor FR180204. IL-6 secretion in the cell culture medium and IL-6 messenger RNA (mRNA) expression levels were analyzed using an enzyme-linked immunoassay and real-time polymerase chain reaction, respectively. RESULTS: TGF-ß administration resulted in a dose- and time-dependent stimulation of IL-6 release. Treatment with SB203580 and FR180204 markedly suppressed TGF-ß-induced IL-6 secretion from HFCs. Moreover, these inhibitors suppressed IL-6 mRNA expression in response to TGF-ß stimulation. CONCLUSIONS: Our findings indicate that TGF-ß induces IL-6 protein secretion and gene expression in HFCs through the activation of p38 or p44/42 MAP kinases. These results suggest a potential association between IL-6-mediated inflammatory response and tissue hypertrophy in LSS, and we provide insights into molecular targets for therapeutic interventions targeting LSS-related inflammation through our analysis of the MAP kinase pathway using HFCs.

Nontuberculous mycobacteriosis oligoarthritis of the right hand misdiagnosed as rheumatoid arthritis: A case report.

Infection with Mycobacterium marinum has several different clinical presentations. Most commonly, it appears as a solitary papulonodular lesion on an extremity. A rare presentation of osteoarticular M. marinum involving multiple small joints and tenosynovitis of the hand, which was misdiagnosed as rheumatoid arthritis, is reported. The patient was initially treated for seronegative rheumatoid arthritis but failed to respond to methotrexate. Magnetic resonance imaging showed arthritis and tenosynovitis. Subsequently, synovial biopsy led to histological and microbiological diagnosis. Antimycobacterial treatment should be started promptly in such cases. The combined use of rifampicin, ethambutol, and clarithromycin appears to be effective, and debridement is indicated in patients with deep-seated infections.

Median Nerve Recovery and Morphological Change on MRI at 24 Months after Open Carpal Tunnel Release.

Background: This study aimed to investigate the relationship between postoperative clinical results and long-term morphological changes in patients with carpal tunnel syndrome (CTS) as observed on magnetic resonance imaging (MRI) before and after open carpal tunnel release (OCTR). Methods: We retrospectively analysed data for 28 hands that had undergone OCTR with at least 24 months of follow-up data. Two-point discrimination (2PD) test results were examined for the first three fingers, as were the distal motor latency (DML) and sensory conduction velocity (SCV) of the median nerve. We also calculated the cross-sectional area (CSA) of the carpal tunnel and the distance from the median nerve to the volar carpal bone at the hamate and the pisiform levels using MRI images. Variables were compared before and 24 months after OCTR. Results: Significant improvements in all variables were observed, including average 2PD scores (Finger I: 13.1 ± 6.2 vs. 7.7 ± 4.3, p < 0.01, Finger II: 11.9 ± 6.6 vs. 7.0 ± 3.5, p < 0.01, Finger III: 13.6 ± 6.1 vs. 7.8 ± 4.5, p < 0.01), average DML (8.3 ± 3.3 vs. 4.3 ± 0.6 m/s, p < 0.01), average SCV (30.8 ± 11.0 vs. 41.3 ± 5.3 m/s, p < 0.01), CSA of the carpal tunnel (hamate level: 194.9 ± 30.6 vs. 254.2 ± 47.6 mm2, p < 0.01, pisiform level: 244.2 ± 46.5 vs. 274.7 ± 75.1 mm2, p = 0.01) and the distance between the median nerve and volar carpal bone (hamate level: 8.7 ± 1.4 vs. 11.2 ± 1.6 mm, p < 0.01, pisiform level: 11.8 ± 1.7 vs. 13.8 ± 2.5 mm, p < 0.01). Conclusions: Our results demonstrate that OCTR is successful in achieving long-term decompression and recovery of the median nerve in patients with CTS. Level of Evidence: Level III (Therapeutic).

IL-1ß promotes osteoclastogenesis by increasing the expression of IGF2 and chemokines in non-osteoclastic cells.

Bone remodeling mediated by bone-forming osteoblasts (OBs) and bone-resorbing osteoclasts (OCs) maintains bone structure and function. Excessive OC activation leads to bone-destroying diseases such as osteoporosis and bone erosion of rheumatoid arthritis (RA). Differentiation of OCs from bone marrow cells (BMCs) is regulated by the bone microenvironment. The proinflammatory cytokine interleukin (IL)-1ß reportedly enhances osteoclastogenesis and plays important roles in RA-associated bone loss. The present study investigated the effect of IL-1ß on OC formation via microenvironmental cells. Treating mouse BMCs with IL-1ß in the presence of receptor activator of NF-κB ligand and macrophage colony-stimulating factor increased the number of OCs. Real-time RT-PCR revealed increased expression of the IL-1ß, IL-1RI, and IL-1RII genes in non-OCs compared with OCs. Removing CD45- cells which cannot differentiate into OCs, from mouse BMCs reduced the IL-1ß-mediated enhancement of osteoclastogenesis. IL-1ß treatment upregulated the expression of inducible nitric oxide synthase, insulin-like growth factor 2 (IGF2), and the chemokines stromal cell derived factor 1, C-X3-C motif ligand 1 (CX3CL1), and CXCL7 in non-OCs. Neutralizing antibodies against these chemokines and IGF2 suppressed osteoclastogenesis in the presence of IL-1ß. These results suggest that IL-1ß enhances osteoclastogenesis by upregulating IGF2 and chemokine expression in non-OCs.

Insulin-like growth factor 2 promotes osteoclastogenesis increasing inflammatory cytokine levels under hypoxia.

Osteoporosis is caused by an imbalance in bone remodeling due to abnormal osteoclast (OC) formation and activation. Hypoxia at the site of inflammation promotes OC formation and activation in various species, including humans. We previously reported that insulin-like growth factor 2 (IGF2) plays an important role in osteoclastogenesis under hypoxia. In our present study, we focused on the mechanism of osteoclastogenesis in regard to IGF2 signaling under hypoxia. We confirmed that the addition of IGF2 promoted osteoclastogenesis under normoxic conditions. Conversely, IGF2-neutralizing antibodies inhibited osteoclastogenesis under both normoxic and hypoxic conditions. IGF2 addition increased levels of phosphorylated Akt (Thr308 and Ser473) and NF-κB (Ser536), indicating activation of the Akt-NF-κB pathway. IGF2 also increased the expression of inducible nitric oxide synthase, which promotes osteoclastogenesis via nitric oxide production. Expression levels of genes encoding inflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-1ß, and IL-6, were upregulated, indicating that IGF2 promotes osteoclastogenesis by increasing the expression of inflammatory cytokines via activation of the Akt-NF-κB pathway. These results suggest that IGF2 is a promising therapeutic target for osteoporosis and rheumatoid arthritis.

The Janus kinase inhibitor (baricitinib) suppresses the rheumatoid arthritis active marker gliostatin/thymidine phosphorylase in human fibroblast-like synoviocytes.

Gliostatin/thymidine phosphorylase (GLS/TP) is known to have angiogenic and arthritogenic activities in the pathogenesis of rheumatoid arthritis (RA). The novel oral Janus kinase (JAK) inhibitor baricitinib has demonstrated high efficacy in RA. However, the effect of baricitinib on fibroblast-like synoviocytes (FLSs), a key component of invasive synovitis, has not been still elucidated. This study investigated whether GLS/TP production could be regulated by JAK/signal transducers and activators of transcription (STAT) signaling in FLSs derived from patients with RA. FLSs were cultured and stimulated by interferon (IFN)γ in the presence of baricitinib. Expression levels of GLS/TP were determined using reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and immunocytochemistry. Phosphorylation of STAT proteins was investigated by Western blot. In cultured FLSs, GLS/TP mRNA and protein levels were significantly induced by treatment with IFNγ and these inductions were suppressed by baricitinib treatment. Baricitinib inhibited IFNγ-induced STAT1 phosphorylation, while JAK/STAT activation played a pivotal role in IFNγ-mediated GLS/TP upregulation in RA. These results suggested that baricitinib suppressed IFNγ-induced GLS/TP expression by inhibiting JAK/STAT signaling, resulting in the attenuation of neovascularization, synovial inflammation, and cartilage destruction.

Impact of social support on severity of depressive symptoms by remission status in patients with rheumatoid arthritis.

OBJECTIVES: We aimed to examine the psychosocial characteristics of patients with rheumatoid arthritis (RA) by remission status and determine the impacts of social support on severity of depressive symptoms. METHODS: We enrolled RA patients aged 40-79 years who visited university hospitals' outpatient clinics. Severity of depressive symptoms (Beck Depression Inventory-II), physical disability (Health Assessment Questionnaire), and support were evaluated. Furthermore, RA disease activity was evaluated by 28-point Disease Activity Score (DAS28) calculation. The independent impacts of instrumental and emotional social support on depressive symptoms by remission status defined as DAS28 score < 2.6 were estimated by multivariable regression analysis. RESULTS: This study included 360 RA patients. In the remission group, emotional support showed a statistically significant negative impact on depressive symptoms, whereas instrumental support had an extremely limited contribution to severity of depressive symptoms. In the non-remission group, instrumental support showed a negative tendency of impact on severity of depressive symptoms, whereas emotional support had a wide range of influence. CONCLUSIONS: Favourable association between emotional support and depressive symptoms is confirmed only among RA patients in remission status. The influence of emotional support in non-remission patients and that of instrumental support regardless of remission status are inconclusive.

The Inducible Nitric Oxide Synthase Pathway Promotes Osteoclastogenesis under Hypoxic Culture Conditions.

Bone homeostasis depends on the balance between bone resorption by osteoclasts (OCs) and bone formation by osteoblasts. Bone resorption can become excessive under various pathologic conditions, including rheumatoid arthritis. Previous studies have shown that OC formation is promoted under hypoxia. However, the precise mechanisms behind OC formation under hypoxia have not been elucidated. The present study investigated the role of inducible nitric oxide synthase (iNOS) in OC differentiation under hypoxia. Primary bone marrow cells obtained from mice were stimulated with receptor activator of NF-κB ligand and macrophage colony-stimulating factor to induce OC differentiation. The number of OCs increased in culture under hypoxia (oxygen concentration, 5%) compared with that under normoxia (oxygen concentration, 20%). iNOS gene and protein expression increased in culture under hypoxia. Addition of an iNOS inhibitor under hypoxic conditions suppressed osteoclastogenesis. Addition of a nitric oxide donor to the normoxic culture promoted osteoclastogenesis. Furthermore, insulin-like growth factor 2 expression was significantly altered in both iNOS inhibition experiments and nitric oxide donor experiments. These data might provide clues to therapies for excessive osteoclastogenesis under several hypoxic pathologic conditions, including rheumatoid arthritis.

Comparison of frailty associated factors between older adult patients with rheumatoid arthritis and community dwellers.

PURPOSE: To determine whether frailty associated factors differ between community dwellers and older adult patients with rheumatoid arthritis (RA). METHODS: We used the cross-sectional data for patients with RA from the RA epidemiological quality-of-life study (n = 210, mean age 71.8 ± 3.7 years) and community dwellers from the Japan Gerontological Evaluation Study (n = 53,255, mean age 71.7 ± 4.0 years). Frailty status was assessed using the Kihon Checklist (KCL), and the primary outcome was frailty (KCL score ≥8 points). Information on predictor variables, including age, sex, marital status, educational level, body mass index (BMI), drinking and smoking status and social participation were obtained from a standardized questionnaire. We employed Poisson regression to calculate the prevalence ratio (PR) of frailty according to its predictors. RESULTS: We found frailty in 37.6% of the patients with RA and 15.7% of the community dwellers. In the multivariate models, BMI and social participation were independently associated with frailty in patients with RA (BMI <18.5: PR, 1.62; 95% confidence interval [CI] 1.09-2.41. BMI ≥25.0: PR, 1.81; 95% CI 1.20-2.71. Active social participation: PR, 0.61; 95% CI 0.42-0.87) and community dwellers (BMI <18.5: PR, 1.77; 95% CI 1.67-1.88. BMI ≥25.0: PR, 1.27; 95% CI 1.22-1.33. Active social participation: PR, 0.46; 95% CI 0.44-0.48). All other predictors were significantly associated with frailty in the community dwellers. CONCLUSION: Maintaining appropriate body weight and participating in social activities are important for preventing frailty in patients with RA as well as community dwellers.

Three-dimensional spheroid culture induces apical-basal polarity and the original characteristics of immortalized human renal proximal tubule epithelial cells.

The proximal tubules, which are part of the kidney, maintain blood homeostasis by absorbing amino acids, glucose, water, and ions such as sodium (Na), potassium, and bicarbonate. Proximal tubule dysfunction is associated with the pathogenesis of many kidney diseases. Renal proximal tubular epithelial cells (RPTECs) are responsible for the main functions of the proximal tubules. Therefore, in vitro experiments using RPTECs would greatly enhance our understanding of nephron physiology and pathobiology. It is preferable to use immortalized cell lines, such as human kidney-2 (HK-2) cells, because they are derived from humans and maintain growth indefinitely. However, tissue-specific RPTEC phenotypes, including apical-basal polarization, are frequently lost in conventional two-dimensional culture methods in part due to microenvironmental deficiencies. To overcome this limitation, we developed a three-dimensional (3D) spheroid culture method for HK-2 cells using an extracellular matrix. HK-2 spheroids in 3D culture formed a tubule-like architecture with cellular polarity and showed markedly restored Na transport function. 3D culture of HK-2 cells also increased expression of kidney development-related genes, including WNT9B. Models of human renal tubules using HK-2 spheroids will greatly improve our understanding of the physiology and pathobiology of the kidney.

p38 Mitogen-Activated Protein Kinase Is Involved in Interleukin-6 Secretion from Human Ligamentum Flavum-Derived Cells Stimulated by Tumor Necrosis Factor-α.

STUDY DESIGN: Human ligamentum flavum-derived cells (HFCs) were obtained from surgical samples for a basic experimental study. PURPOSE: We sought to evaluate the inflammatory response of human ligamentum flavum cells to investigate hypertrophic changes occurring in the ligamentum flavum. OVERVIEW OF LITERATURE: Lumbar spinal stenosis (LSS) is a disease commonly observed in the elderly. The number of patients with LSS has increased over time, yet the pathomechanisms of LSS still have not been fully elucidated. One of the clinical features of LSS is hypertrophy of the ligamentum flavum, which results in narrowing of the lumbar spinal canal. Some reports have suggested that ligamentum flavum hypertrophy is associated with inflammation and fibrosis; meanwhile, the p38 mitogen-activated protein (MAP) kinase is involved in the hypertrophy of human ligamentum flavum cells. METHODS: HFCs were obtained from patients with LSS who underwent surgery. HFCs were stimulated by tumor necrosis factor-α (TNF-α) and a p38 MAP kinase inhibitor, SB203580. Phosphorylation of the p38 MAP kinase was analyzed by western blotting. The concentration of interleukin-6 (IL-6) in the conditioned medium was measured by enzyme-linked immunoassay and IL-6 messenger RNA expression levels were determined by real-time polymerase chain reaction. RESULTS: TNF-α induced the phosphorylation of p38 MAP kinase in a time-dependent manner, which was suppressed by the p38 MAP kinase inhibitor, SB203580. TNF-α also stimulated IL-6 release in both a time- and dose-dependent manner. On its own, SB203580 did not stimulate IL-6 secretion from HFCs; however, it dramatically suppressed the degree of IL-6 release stimulated by TNF-α from HFCs. CONCLUSIONS: This is the first report suggesting that TNF-α stimulates the gene expression and protein secretion of IL-6 via p38 MAP kinase in HFCs. A noted association between tissue hypertrophy and inflammation suggests that the p38 MAP kinase inflammatory pathway may be a therapeutic molecular target for LSS.

Depression, physical function, and disease activity associated with frailty in patients with rheumatoid arthritis.

OBJECTIVES: To investigate the clinical and psychosocial backgrounds of frailty in rheumatoid arthritis (RA) patients. METHODS: Patients with RA between 40 and 79 years of age who visited university hospitals in an urban area were recruited. Well-validated self-reported questionnaires were used to evaluate patient physical function (Health Assessment Questionnaire, HAQ), depressive symptoms (Beck Depression Inventory-II, BDI-II), and frailty (Kihon Checklist). A 28-point Disease Activity Score (DAS-28) was calculated to evaluate RA disease activity. RESULTS: A total of 375 RA patients, 323 of whom were women, were enrolled (average age: 65.2 ± 9.7 years; average disease duration: 16.6 ± 11.9 years). The prevalence rates of frailty, working-age (40-64 years), young-old (65-74 years), and old-old (≥75 years) patients were 18.5, 28.8, and 36.6%, respectively. Higher age and longer disease duration were associated with frailty. Multivariable logistic regression analysis revealed that HAQ, DAS-28, and BDI-II scores were independently associated with frailty in RA patients. CONCLUSION: Frailty is common, even among working-age RA patients. Physical function, disease activity, and depressive symptoms were independently associated with frailty. A multidisciplinary intervention approach, along with adequate pharmacological therapy, may promote successful aging in patients with RA.

Pyogenic tenosynovitis of the wrist due to Corynebacterium striatum in a patient with dermatomyositis: A case report.

INTRODUCTION: Corynebacterium striatum is common contaminant in clinical specimens. Here, we report a rare case of pyogenic tenosynovitis of the wrist caused by C striatum in a dermatomyositis patient taking oral immunosuppressants. PATIENT CONCERNS: A 67-year-old Japanese woman with dermatomyositis had a history of multiple intraarticular injections of corticosteroids to the right wrist joint for the treatment of osteoarthritis. She was admitted to our hospital with a painful lump on the right dorsal wrist lasting for three months. MRI revealed cellulitis of the dorsum of the right wrist and hand and fluid collection in the extensor tendon sheath. C striatum was detected in the cultures of three samples of synovial fluid taken from the dorsal hand. DIAGNOSIS: Pyogenic tenosynovitis of the wrist due to C striatum. INTERVENTIONS: The infection was successfully controlled with synovectomy and adjuvant antibiotic therapy. OUTCOMES: There has been no sign of recurrence for 12-months after the surgical treatment. LESSONS: This is the first reported case of pyogenic tenosynovitis due to C striatum in a patient with dermatomyositis. Clinicians should be aware that patients undergoing immunosuppressive therapy have a risk of C striatum infection.

Treatment of aneurysmal bone cysts using endoscopic curettage.

BACKGROUND: Although aneurysmal bone cysts (ABCs) are benign tumours, they have the potential to be locally aggressive. Various treatment approaches, such as en bloc resection, open curettage, radiotherapy, sclerotherapy, and embolization have been proposed, but the most appropriate treatment should be selected after considering the risk of tumour recurrence and treatment complications. Endoscopic curettage (ESC) may be a less invasive alternative to open curettage for ABC treatment. We aimed to describe the use of ESC for the treatment of ABCs and to report our clinical outcomes, including the incidence rate of recurrence, radiological appearance at final follow-up, time to solid union, complications, and postoperative function. METHODS: Between 1998 and 2015, 30 patients (18 men and 12 women; mean age, 17.4 years) underwent ESC for the treatment of primary ABCs at our hospital (mean postoperative follow-up, 55 months). ESC was performed under arthroscopic guidance for direct visualization, and curettage extended until normal bone was observed in the medullary cavity. To investigate bone healing after ESC, we evaluated the consolidation of cysts at the final evaluation (based on the modified Neer classification) and time to solid union after surgery, which was defined as sufficient cortical bone thickness to prevent fracture and allow physical activities. RESULTS: Recurrence was identified in 3 cases (10%). Curative outcomes were obtained after repeated ESC or open curettage. A log-rank analysis indicated that age < 10 years (p = 0.004) and contact of the tumour with the physis (p = 0.01) increased the risk of tumour recurrence. Residual tumours were identified in 9 cases (30%); these lesions remained inactive over the extended follow-up period. The average time to solid union after endoscopic curettage was 3.2 months. Transient radial nerve palsy was identified in 1 case. Good postoperative functional recovery occurred in all cases. CONCLUSIONS: ESC is a minimally invasive technique for the treatment of ABCs, and the tumour recurrence rate is comparable to that of other standard procedures. However, the application of this method should be carefully considered, especially for patients < 10 years and when the tumour comes in contact with the physis.

Treatment of simple bone cysts using endoscopic curettage: a case series analysis.

BACKGROUND: Endoscopic curettage is considered applicable for the treatment of simple bone cysts with the expectation that it might be less invasive than open curettage. In this study, we investigated the efficacy of endoscopic curettage for the treatment of simple bone cysts. The goal was to investigate the incidence of cyst recurrence and bone healing after endoscopic curettage. Moreover, complications and functionality at the final follow-up were evaluated. METHODS: From 2003 to 2014, 37 patients with simple bone cysts underwent endoscopic curettage. Twenty-four were male and 13 were female, with a mean age of 14.7 years. Endoscopic curettage was performed with the support of an arthroscope via 7-8 mm holes penetrated by cannulated drills with a small incision. The cysts underwent curettage using angled curettes, rongeurs, and an electrical shaver until the normal bone was observed in the medullary cavity. To investigate the bone healing after endoscopic curettage, we evaluated the consolidation of the cyst at the final evaluation (Modified Neer Classification) and the time to solid union after operation, which was defined as the sufficient thickness of the cortical bone to prevent fracture and allow physical activities. RESULTS: Recurrence occurred in seven patients (18.9%). A log-rank analysis revealed that contact with the physis was associated with recurrence (p = 0.006). Among 31 patients (83.7%), the consolidation of cyst was considered healed at the final X-ray follow-up period, and in these patients, the mean time taken for solid union of cortical bone thinning was 4.0 months (standard deviation, 2.4). With regard to major complications of endoscopic curettage, a transient radial nerve palsy and two postoperative fractures occurred. The former problem was managed conservatively and the latter problems by transient internal fixation; these problems were managed without any further complications. All patients had a good postoperative function. CONCLUSIONS: Endoscopic curettage might be a useful alternative as it is a minimally invasive procedure for the treatment of simple bone cysts. Considering the relatively smaller size of this study, further investigation should be necessary for deducing the reliable conclusion.

The Janus kinase inhibitor tofacitinib inhibits TNF-α-induced gliostatin expression in rheumatoid fibroblast-like synoviocytes.

OBJECTIVES: Gliostatin (GLS) is known to have angiogenic and arthritogenic activity, and GLS expression levels in serum from patients with rheumatoid arthritis (RA) are significantly correlated with the disease activity. Tofacitinib is a novel oral Janus kinase (JAK) inhibitor and is effective in treating RA. However, the mechanism of action of tofacitinib in fibroblast-like synoviocytes (FLSs) has not been elucidated. The purpose of this study was to investigate the modulatory effects of tofacitinib on serum GLS levels in patients with RA and GLS production in FLSs derived from patients with RA. METHODS: Six patients with RA who had failed therapy with at least one TNF inhibitor and were receiving tofacitinib therapy were included in the study. Serum samples were collected to measure CRP, MMP-3 and GLS expression. FLSs derived from patients with RA were cultured and stimulated by TNFα with or without tofacitinib. GLS expression levels were determined using reverse transcription-polymerase chain reaction (RT-PCR), EIA and immunocytochemistry, and signal transducer and activator of transcription (STAT) protein phosphorylation levels were determined by western blotting. RESULTS: Treatment with tofacitinib decreased serum GLS levels in all patients. GLS mRNA and protein expression levels were significantly increased by treatment with TNF-α alone, and these increases were suppressed by treatment with tofacitinib, which also inhibited TNF-α-induced STAT1 phosphorylation. CONCLUSIONS: JAK/STAT activation plays a pivotal role in TNF-α-mediated GLS up-regulation in RA. Suppression of GLS expression in FLSs has been suggested to be one of the mechanisms through which tofacitinib exerts its anti-inflammatory effects.

Mithramycin has inhibitory effects on gliostatin and matrix metalloproteinase expression induced by gliostatin in rheumatoid fibroblast-like synoviocytes.

OBJECTIVES: Gliostatin (GLS) has angiogenic and arthritogenic activities and enzymatic activity as thymidine phosphorylase. Aberrant GLS production has been observed in the synovial membranes of patients with rheumatoid arthritis (RA). Matrix metalloproteinases (MMPs) are involved in joint destruction. Promoters of GLS and some MMP genes contain Sp1 binding sites. We examined the inhibitory effect of the Sp1 inhibitor mithramycin on GLS-induced GLS and MMP expression in cultured fibroblast-like synoviocytes (FLSs). METHODS: Synovial tissue samples were obtained from patients with RA. FLSs pretreated with mithramycin were cultured with GLS. The mRNA expression levels of GLS and MMP-1, MMP-2, MMP-3, MMP-9, and MMP-13 were determined using reverse transcription polymerase chain reactions. Protein levels were measured using enzyme immunoassay and gelatin zymography. RESULTS: GLS upregulated the expression of GLS itself and of MMP-1, MMP-3, MMP-9, and MMP-13, an effect significantly reduced by treatment with mithramycin. GLS and mithramycin had no effect on MMP-2 expression. CONCLUSIONS: Mithramycin downregulated the increased expression of GLS and MMP-1, MMP-3, MMP-9, and MMP-13 in FLSs treated with GLS. Because GLS plays a pathological role in RA, blocking GLS stimulation using an agent such as mithramycin may be a novel approach to antirheumatic therapy.

CXCR4+ CD45- Cells are Niche Forming for Osteoclastogenesis via the SDF-1, CXCL7, and CX3CL1 Signaling Pathways in Bone Marrow.

Bone homeostasis comprises the balance between bone-forming osteoblasts and bone-resorbing osteoclasts (OCs), with an acceleration of osteoclastic bone resorption leading to osteoporosis. OCs can be generated from bone marrow cells (BMCs) under the tightly regulated local bone environment. However, it remained difficult to identify the critical cells responsible for providing an osteoclastogenesis niche. In this study, we used a fluorescence-activated cell sorting technique to determine the cell populations important for forming an appropriate microenvironment for osteoclastogenesis and to verify the associated interactions between osteoclast precursor cells and non-OCs. We isolated and removed a small cell population specific for osteoclastogenesis (CXCR4+ CD45- ) from mouse BMCs and cultured the remaining cells with receptor activator of nuclear factor-kappa B ligand (RANKL) and macrophage-colony stimulating factor. The resulting cultures showed significantly less large osteoclast formation. Quantitative RT-PCR analysis revealed that these CXCR4+ CD45- cells expressed low levels of RANK and RANKL, but high levels of critical chemokines including stromal cell derived factor 1 (SDF-1), chemokine (C-X-C motif) ligand 7 (CXCL7), and chemokine (C-X3-C motif) ligand 1 (CX3CL1). Furthermore, an SDF-1-specific antibody strongly suppressed OC formation in RAW264.7 cells and antibodies against SDF-1, CXCL7, and CX3CL1 suppressed OC formation in BMCs. These results suggest that isolated CXCR4+ CD45- cells support an appropriate microenvironment for osteoclastogenesis with a direct effect on the cells expressing SDF-1, CXCL7, and CX3CL1 receptors. The regulation of CXCR4+ CD45- cell function might therefore inform therapeutic strategies for diseases involving loss of bone homeostasis. Stem Cells 2016;34:2733-2743.