Osteoblasts induce Ca2+ oscillation-independent NFATc1 activation during osteoclastogenesis

Intercellular cross-talk between osteoblasts and osteoclasts is important for controlling bone remolding and maintenance. However, the precise molecular mechanism by which osteoblasts regulate osteoclastogenesis is still largely unknown. Here, we show that osteoblasts can induce Ca(2+) oscillation-independent osteoclastogenesis. We found that bone marrow-derived monocyte/macrophage precursor cells (BMMs) lacking inositol 1,4,5-trisphosphate receptor type2 (IP(3)R2) did not exhibit Ca(2+) oscillation or differentiation into multinuclear osteoclasts in response to recombinant receptor activator of NF-kappaB ligand/macrophage colony-stimulating factor stimulation. IP(3)R2 knockout BMMs, however, underwent osteoclastogenesis when they were cocultured with osteoblasts or in vivo in the absence of Ca(2+) oscillation. Furthermore, we found that Ca(2+) oscillation-independent osteoclastogenesis was insensitive to FK506, a calcineurin inhibitor. Taken together, we conclude that both Ca(2+) oscillation/calcineurin-dependent and -independent signaling pathways contribute to NFATc1 activation, leading to efficient osteoclastogenesis in vivo.     

Two cases of pulmonary infection by Mycobacterium abscessus in which drug susceptibility testing results conflicted with clinical courses]

We encountered two cases of pulmonary infection by Mycobacterium abscessus (M. abscessus). [Case 1] A 66-year-old man who had been treated for non-tuberculous mycobacterium in the past was admitted because of productive cough. His chest X-ray film showed cavitation and direct microscopy of sputum revealed positive acid-fast bacilli (AFB). He was given rifampicin (RFP), ethambutol (EB), and clarythromycin (CAM), and then his symptoms and radiographic findings improved. [Case 2] A 74-year-old man with multiple myeloma as an underlying disease was admitted because of a cavitation found on chest radiography and a positive result for AFB in his sputum. Standard antituberculous drug therapy with isoniazid (INH), RFP, EB, and pyradinamide (PZA) was initiated and then the chest radiographic findings improved. As M. abscessus was isolated two weeks after the induction of therapy, the therapeutic regimen was changed to another combination therapy consisting of EB, clarithromycin (CAM) and ciprofloxacin (CPFX), and then his symptoms and radiographic findings were further improved. In both cases, the bacilli found in their sputum were identified as M. abscessus by DNA hybridization. They were completely resistant to all anti-tuberculosis agents and many antibiotics with a high value of MIC. However, their symptoms, radiographic abnormalities and the results of sputum examination improved following chemotherapy. The results obtained by MIC measurement were inconsistent with the clinical outcomes. The measurement of the MIC value of antibiotics do not necessarily predict its therapeutic effect.     

Ulcerative colitis followed by the development of Behçet's disease

A 34-year-old man who had a history of ulcerative colitis (UC) was admitted to our hospital with complaints of arthralgia, erythema nodosum, recurrent oral aphthous ulcers and bloody stools. A colonoscopy revealed multiple aphthous ulcers on his cecum and colon and also revealed a transmural ulcer on his rectum consistent with a diagnosis of UC. The patient was HLA-B51 positive. Based on clinical evidence [recurrent oral ulcers, skin lesions (erythema nodosum), positivity for pathergy test] this patient was diagnosed as having Beh?et's disease with gastrointestinal involvement. We describe this rare case of Beh?et's disease with colitis and discuss the difficulties in making a differential diagnosis between Beh?et's disease and the inflammatory bowel diseases.     

Helicobacter pylori infection is positively associated with gallstones: a large-scale cross-sectional study in Japan

Background

Our aim is to elucidate causative factors for gallstones, especially focusing on Helicobacter pylori (HP) infection.

Methods

We analyzed 15,551 Japanese adults who had no history of gastrectomy, cholecystectomy, HP eradication, and didn’t use proton pump inhibitors, anti-diabetic drugs, or anti-cholesterol drugs. 1,057 subjects who previously had HP eradication were analyzed separately.

Results

Gallstones were detected in 409 of 8,625 men (4.74 %) and 285 of 6,926 women (4.11 %) by ultrasonography. Among the 25 factors univariately analyzed, age, HP infection, alcohol intake, weight, body mass index (BMI), and 14 blood test values (AST, ALT, ALP, γ-GTP, T-Chol, HDL-Chol, LDL-Chol, TG, TP, Hb, HbA1c, pepsinogen I, pepsinogen II, and pepsinogen I/II ratio) displayed significant association with gallstones (p < 0.05), whereas gender, smoking, height, and three blood test values (Alb, T-Bil, MCV) did not. Multivariate analysis showed that age, gender, alcohol intake, BMI, γ-GTP, LDL-Chol, TP, and HP infection had significant association (p < 0.05). Successive multiple logistic regression analysis calculating odds ratio (OR) and standardized coefficients (β) showed that age (OR/β = 1.57/0.450), BMI (OR/β = 1.30/0.264), HP infection (OR/β = 1.51/0.206), lower alcohol intake (OR/β = 1.33/0.144), γ-GTP (OR/β = 1.15/0.139), and pepsinogen I/II ratio (OR/β = 1.08/0.038) have significant positive association with gallstones, whereas gender does not. The gallstone prevalence among HP-negative, HP-eradicated, and HP-positive subjects was 3.81, 4.73 and 6.08 %, respectively. The matched analysis controlling age, BMI, γ-GTP, alcohol intake, pepsinogen I/II ratio and gender also demonstrated that gallstone prevalence among HP-eradicated subjects was significantly lower compared with HP-positive subjects (p < 0.05).

Conclusions

HP infection is positively associated with gallstones. HP eradication may lead to prevention of gallstones.     

Clinical characteristics and prognostic implications of NPM1 mutations in acute myeloid leukemia

Recently, somatic mutations of the nucleophosmin gene (NPM1), which alter the subcellular localization of the product, have been reported in acute myeloid leukemia (AML). We analyzed the clinical significance of NPM1 mutations in comparison with cytogenetics, FLT3, NRAS, and TP53 mutations, and a partial tandem duplication of the MLL gene (MLL-TD) in 257 patients with AML. We found NPM1 mutations, including 4 novel sequence variants, in 64 of 257 (24.9%) patients. NPM1 mutations were associated with normal karyotype and with internal tandem duplication (ITD) and D835 mutations in FLT3, but not with other mutations. In 190 patients without the M3 French-American-British (FAB) subtype who were treated with the protocol of the Japan Adult Leukemia Study Group, multivariate analyses showed that the NPM1 mutation was a favorable factor for achieving complete remission but was associated with a high relapse rate. Sequential analysis using 39 paired samples obtained at diagnosis and relapse showed that NPM1 mutations were lost at relapse in 2 of the 17 patients who had NPM1 mutations at diagnosis. These results suggest that the NPM1 mutation is not necessarily an early event during leukemogenesis or that leukemia clones with NPM1 mutations are sensitive to chemotherapy.