Immediate Tooth Autotransplantation with Root Canal Filling and Partially Demineralized Dentin/Cementum Matrix into Congenital Missing Tooth Region

This clinical report describes immediate tooth auto-transplantation with an autograft of partially demineralized dentin/cementum matrix (pDDM), based on an orthodontic treatment plan for a 16-year-old male patient with a congenital missing tooth (#45). First, vital teeth (#14, #24) were extracted, and root canal filling (#14) was immediately performed with the support of a fixation device. Simultaneously, the tooth (#24) was crushed in an electric mill for 1 min, and the crushed granules were partially demineralized in 2% HNO3 solution for 20 min as the graft material. Next, the donor tooth was transplanted into the created socket (#45), and stabilized using an enamel bonding agent. The wet pDDM was loaded into the location of the congenital missing tooth, and the flap was repositioned. The bonding agent for stabilization was removed at 28 days, and also small contact points between the transplanted tooth and the upper premolar (#14) were added using photopolymerizable composite resin. X-ray photos were taken sequentially, and there were no postoperative complications. The radiographic images showed that the periodontal ligament space and alveolar ridge line could be observed at 18 months. The pDDM was harmonized with the mandible, and the remodeled bone-like shadow was observed in the graft region. We concluded that immediate tooth transplantation with root canal fillings and autogenous pDDM may be a valuable alternative to dental implanting or bridge formation for patients with a congenital missing tooth, followed by orthodontic treatment

Association between Casual Serum Triglyceride Levels and Bone Resorption Activity in Japanese Middle-aged and Elderly Women

High serum triglyceride (TG) levels may lower bone fracture risk, but the association between serum TG and bone resorption activity is unclear. The aim of the present study was to analyze this association using casual serum TG levels in patients with and without accelerated bone resorption. A case-control study was performed in 39 patients with accelerated bone resorption and in 69 controls, treated between April 2011 and March 2016 at the Internal Medicine Clinic. Bone resorption activity was assessed by urinary N-telopeptide of type I collagen (uNTx; a marker of bone resorption), which is routinely measured at the Internal Medicine Clinic. Cases were female outpatients aged ≥40 years in whom uNTx levels were ≥54.3nmol bone collagen equivalent (BCE)/mmol creatinine. Subjects with casual serum TG levels ＞150mg/dl were diagnosed with potential hypertriglyceridemia (PHTG). Propensity score-adjusted multinomial logistic regression was performed to estimate the odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for PHTG in cases compared with controls. Correlations between uNTX and casual serum TG levels in all patients were evaluated using multivariate regression. The prevalence of PHTG was significantly lower in cases than in controls (OR 0.20; 95% CI 0.05-0.65; P=0.006). uNTx levels were negatively associated with casual serum TG levels in all patients (r=-0.07, P=0.046). These results suggest that serum TG levels are negatively associated with bone resorption activity. Reduced bone resorption activity may explain, in part, the reduced fracture risk in Japanese middle-aged and elderly female patients with hypertriglyceridemia

Overexpression/enhanced kinase activity of BCR/ABL and altered expression of Notch1 induced acute leukemia in p210BCR/ABL transgenic mice

Chronic myelogenous leukemia (CML) is a hematopoietic disorder, which begins as indolent chronic phase but inevitably progresses to fatal blast crisis. p210BCR/ABL, a constitutively active tyrosine kinase, is responsible for disease initiation but molecular mechanism(s) underlying disease evolution remains largely unknown. To explore this process, we employed retroviral insertional mutagenesis to CML-exhibiting p210BCR/ABL transgenic mice (Tg). Virus infection induced acute lymphoblastic leukemia (ALL) in p210BCR/ABL Tg with a higher frequency and in a shorter latency than wild-type littermates, and inverse PCR detected two retrovirus common integration sites (CISs) in p210BCR/ABL Tg tumors. Interestingly, one CIS was the transgene itself, where retrovirus integrations induced upregulation of p210BCR/ABL and production of truncated BCR/ABL with an enhanced kinase activity. Another CIS was Notch1 gene, where retrovirus integrations resulted in overexpression of Notch1 and generation of Notch1 lacking the C-terminal region (Notch1C) associated with stable expression of its activated product, C-terminus-truncated Notch intracellular domain (NICDC). In addition, generation of Tg for both p210BCR/ABL and Notch1C developed ALL in a shortened period with Stat5 activation, demonstrating the cooperative oncogenicity of Notch1C/NICDC with p210BCR/ABL involving Stat5-mediated pathway. These results demonstrated that overexpression/enhanced kinase activity of BCR/ABL and altered expression of Notch1 induce acute leukemia in a transgenic model for CML

皮下組織および筋間組織におけるBMP‐2促進骨誘導によるヒト酸不溶性象牙質

Dentin matrix is well known as the most insoluble collagen in human body. We already confirmed the osteoinductive property by granules of human demineralized dentin matrix (DDM) histologically. Human DDM granules and human demineralized root-dentin (DRD) mass were prepared from adult vital teeth. The hard tissue induction by DDM alone or DRD alone was estimated at 4 weeks after implantation. The DDM alone induced bone and cartilage independently. In addition, the bioassay by recombinant human BMP-2 (5.0 .MU.g)/DDM or BMP-2 (5.0 .MU.g)/DRD was estimated in mouse subcutaneous or intramuscular tissues, respectively. Histological examination showed that the BMP-2/DDM induced bone and marrow, and the DDM granules were partially absorbed by new bone. The morphometric analysis demonstrated that the BMP-2/DDM showed 36.3% in the volume of bone and marrow, while the DDM alone showed 1.3% at 4 weeks. Moreover, the BMP-2/DRD also induced active bone formation on the root surface and in the pulp cavity. These results indicate that BMP-2 significantly accelerated bone formation in decalcified dentin implants. Human recycled DDM and DRD might be effective materials as osteoinductive collagenous carriers of BMP-2 for bone engineering. (Author abst.)人体において象牙質はほとんど不溶性コラーゲンであると知られている。ヒト脱ミネラル化歯質(DDM)の顆粒による骨誘導性を組織学的に確認した。ヒトDDM顆粒とヒト脱ミネラル化歯根象牙質(DRD)を成人の活歯から作製した。移植して4週間後のDDM単独またはDRD単独で誘導された硬組織を評価した。また,組換ヒトBMP‐2(5.0μg)/DDMまたはBMP‐2(5.0μg)/DRDによるバイオアッセイをそれぞれマウス皮下組織または筋間組織において評価した。組織学的評価の結果,BMP‐2/DDM誘導骨および髄質,およびDDM顆粒は新骨によって部分的に吸収されることが分かった。形態的分析では,4週間後の骨と髄質の体積の36.3%はBMP‐2/DDMであったが,DDM単独では1.3%であった。BMP‐2/DDMは歯根面や歯根管でも活性な骨形成を誘導した。これらの結果から,BMP‐2は脱石灰象牙質移植において骨形成を著しく促進することが示唆された。ヒト再生DDMおよびDRDは骨工学におけるBMP‐2の骨誘導コラーゲン担体として有効な材料である。(翻訳著者抄録