Expression of osteopontin at sites of bone erosion in a murine experimental arthritis model of collagen-induced arthritis: possible involvement of osteopontin in bone destruction in arthritis

OBJECTIVE: To investigate the involvement of osteopontin (OPN) in bone destruction in a murine experimental arthritis model of collagen-induced arthritis (CIA). METHODS: The expression of OPN was examined at both the messenger RNA (mRNA) and protein levels in various arthritic lesions in mice with CIA by in situ hybridization and immunohistochemistry, respectively. In addition, the expression of alpha(v)beta3 integrin, a receptor for OPN, the ligation of which is thought to be essential for bone resorption by osteoclasts, was examined by immunohistochemistry. Plasma concentrations of OPN were measured at different time points in the course of CIA by enzyme-linked immunosorbent assay. RESULTS: OPN mRNA was detected mainly at sites of bone erosion in arthritic lesions, where activated osteoclasts were present; OPN protein was also detected at sites of bone erosion. In the arthritic synovium, OPN was predominantly expressed in the synovial lining layer, but not in lymphoid aggregates. In addition, alpha(v)beta3 integrin was detected coincident with OPN at sites of bone erosion (bone-pannus junction). Plasma OPN levels were markedly elevated at the time points that corresponded to arthritis flares, and higher levels were maintained during the progression of arthritis. CONCLUSION: OPN may mediate bone resorption by osteoclasts in arthritis through ligation with its receptor, alpha(v)beta3 integrin. OPN may be a useful therapeutic target molecule in the prevention of bone destruction in arthritis.     

Pulmonary surfactant transport in alveolar type II cells

Abstract:   Pulmonary surfactant (PS) is a mixture of several lipids (mainly phosphatidylcholine; PC) and four apoproteins (A, B, C and D). The classical hypothesis of PS transport suggests that PS is synthesized in the endoplasmic reticulum and transported to the lamellar body (LB) via the Golgi apparatus. However, recent studies have raised questions regarding this single route. This study examined, independently, the intracellular trafficking route of three different components of PS, that is, PC, SP-A and SP-B. Alveolar type II cells were isolated from Sprague–Dawley rats or Japanese white rabbits. The cells were cultured with either [³H]choline or [³⁵S]methionine/cysteine with or without brefeldin A, which disassembles the Golgi apparatus. LB was purified from disintegrated cells with sucrose density gradient centrifugation. [³H]PC was extracted from radiolabeled media, cells, and the LB fraction with Bligh–Dyer's method. [³⁵S]SP-A or [³⁵S]SP-B was immunoprecipitated from each sample with a specific antibody. [³H]PC was transported and stored to the LB via a Golgi-independent pathway. [³⁵S]SP-A was transported to the Golgi apparatus, underwent glycosylation, and was then constitutively secreted. The secreted [³⁵S]SP-A was re-uptaken into the LB. [³⁵S]SP-B was transported and stored to the LB via the Golgi-dependent pathway. These results indicate that, rather than a single route, surfactant components take different pathways to reside in the LB. These different pathways may reflect the different nature and role of each surfactant component such as surface tension-lowering activity and innate host defense.     

Secondary pouchitis in a post-operative patient with ulcerative colitis, successfully treated by salvage surgery

We report a case of secondary pouchitis, defined as a mucosal inflammatory lesion in the ileal reservoir provoked by pouch-related complication following total colectomy and pouch anal anastomosis, which was successfully treated by salvage surgery- A 20-year-old woman with ulcerative colitis developed acute severe bloody diarrhea following proctocolectomy, ileal pouch-anal anastomosis and diverting ileostomy. She was diagnosed as having a secondary pouchitis mainly caused by a peripouch abscess and partly concerned with the abnormal pouch formation. The remnant rectum and ileal pouch were excised and ileal pouch-anal anastomosis and diverting ileostomy were constructed. The postoperative course was uneventful with no sign of pouchitis. Salvage surgery may be indicated to treat secondary pouchitis when caused by surgery-related complications.     

An imported case of falciparum malaria successfully treated with Artemether-Lumefantrine in Japan

Spread of multi-drug resistant malaria in the endemic areas has made malaria control more difficult. Thus, WHO recommends combination therapy for the treatment of malaria. The aim of combination therapy is to improve efficacy and to reduce the incidence of resistance development to the each component of the combination. Particularly, the combination with artemisinin derivatives shows good outcome in Thailand where high resistance for mefloquine has already been found. We report the first case of falciparum malaria, successfully treated with Artemether-Lumefantrine in Japan. Artemether-Lumefantrine is a newly developed artemisinin-based combination agent for the treatment of uncomplicated multi-drug resistant malaria. This drug has proved highly effective and well tolerated by some clinical trials abroad. This Japanese female case showed a good clinical course without any side effect.     

Successful treatment with low-dose etoposide for hemophagocytic syndrome following reduced-intensity conditioning for cord blood transplantation in a patient with acute myelgenous leukemia

A 56-year-old man was diagnosed with acute myeloid leukemia with myelodysplasia-related changes. Chromosomal analysis showed a complex karyotype. Complete remission could not be achieved even after several induction chemotherapy regimens, and the patient suffered from invasive pulmonary aspergillosis. He was transferred to our hospital and underwent reduced-intensity conditioning cord blood transplantation (RIC-CBT) in a non-remission state. The conditioning regimen involved fludarabine 125 mg/m2 combined with melphalan 140 mg/m2 and total body irradiation (4 Gy). GVHD prophylaxis was tacrolimus alone at relatively low concentrations (app. 5 ng/ml). On days 6 and 9 after CBT, he experienced a pre-engraftment immune reaction and hemophagocytic syndrome (HPS). We started steroid pulse therapy, but this failed to resolve the symptoms. We then administered low-dose etoposide (50 mg/m2). The symptoms gradually resolved after three administrations of etoposide and engraftment was achieved on day 35. Satisfactory hematological recovery was noted on day 300 after CBT and the patient has maintained complete remission to date. HPS is one of the most serious complications following CBT and often results in engraftment failure. This case suggests that repeated administration of etoposide may safely and effectively overcome this serious complication in some cases.