Comparing the Osteogenic Potential and Bone Regeneration Capacities of Dedifferentiated Fat Cells and Adipose-Derived Stem Cells In Vitro and In Vivo: Application of DFAT Cells Isolated by a Mesh Method

Background: We investigated and compared the osteogenic potential and bone regeneration capacities of dedifferentiated fat cells (DFAT cells) and adipose-derived stem cells (ASCs). Method: We isolated DFAT cells and ASCs from GFP mice. DFAT cells were established by a new culture method using a mesh culture instead of a ceiling culture. The isolated DFAT cells and ASCs were incubated in osteogenic medium, then alizarin red staining, alkaline phosphatase (ALP) assays, and RT-PCR (for RUNX2, osteopontin, DLX5, osterix, and osteocalcin) were performed to evaluate the osteoblastic differentiation ability of both cell types in vitro. In vivo, the DFAT cells and ASCs were incubated in osteogenic medium for four weeks and seeded on collagen composite scaffolds, then implanted subcutaneously into the backs of mice. We then performed hematoxylin and eosin staining and immunostaining for GFP and osteocalcin. Results: The alizarin red-stained areas in DFAT cells showed weak calcification ability at two weeks, but high calcification ability at three weeks, similar to ASCs. The ALP levels of ASCs increased earlier than in DFAT cells and showed a significant difference (p Conclusion: DFAT cells are easily isolated from a small amount of adipose tissue and are readily expanded with high purity; thus, DFAT cells are applicable to many tissue-engineering strategies and cell-based therapies

Intermittent parathyroid hormone 1-34 induces oxidation and deterioration of mineral and collagen quality in newly formed mandibular bone

Intermittent parathyroid hormone (PTH) administration is known to promote bone healing after surgical procedures. However, the mechanism and influence of PTH on the mineral and collagen quality of the jaw are not well understood. Most studies have focused on analyzing the bone density and microstructure of the mandible, and have insufficiently investigated its mineral and collagen quality. Oxidative stress activates osteoclasts, produces advanced glycation end products, and worsens mineral and collagen quality. We hypothesized that PTH induces oxidation and affects the mineral and collagen quality of newly formed mandibular bone. To test this, we examined the mineral and collagen quality of newly formed mandibular bone in rats administered PTH, and analyzed serum after intermittent PTH administration to examine the degree of oxidation. PTH administration reduced mineralization and worsened mineral and collagen quality in newly formed bone. In addition, total anti-oxidant capacity in serum was significantly decreased and the oxidative-INDEX was increased among PTH-treated compared to vehicle-treated rats, indicating serum oxidation. In conclusion, intermittent administration of PTH reduced mineral and collagen quality in newly formed mandibular bone. This effect may have been induced by oxidation

A collaborative approach to head and neck carcinoma for oral surgeons, head and neck surgeons, and plastic surgeons: The role of oral surgeons in two cases

There is a medical team approach used in many hospitals for oral cancer patients. The members are head & neck surgeons and plastic surgeons, or oral surgeons and plastic surgeons. However, in Japan, it is very difficult for oral surgeons to cooperate with head & neck surgeons, except in the case of extractions and oral health care, because both surgeons treat oral carcinomas and there is therefore a conflict in their scope of practice. We believe it desirable for head & neck surgeons to treat oral cancer patients with tumors extending to other regions, and oral surgeons should be in charge of occlusion in head and neck carcinomas. We treated two patients with oral carcinomas in collaboration with head and neck surgeons and plastic surgeons, with head & neck surgeons resecting the tumors, plastic surgeons reconstructing, and oral surgeons (dentists) taking charge of the occlusion for patients in the operating room. This collaboration resulted in patients having good position of the temporomandibular joint and occlusions after the operation. We therefore conclude that this collaborative team approach may be of benefit to the patients

The collaborative role of oral surgery with plastic as well as head & neck surgery in head and neck cancers : Preoperative plate-bending method in cases with mandibular reconstruction using plaster 3D models

The collaboration of various medical teams is crucial for the appropriate treatment of cancer patients. However, in Japan, it is very difficult for oral surgeons to cooperate with head and neck surgeons due to conflicts in the treatment of those patients. There have been few studies on this subject. In the current work, we report on the collaboration of head and neck surgeons, plastic surgeons and oral surgeons in operations on two patients with gingival carcinomas in the mandible. We first prepared plaster 3D models of the patients'mouths by means of ink-jet from CT data. We pre-bent the reconstruction plates using the preoperative 3D models. Therefore, we could save the time required to bend the plate. Plaster models are cheaper than resin models. It is also easy to model the surgery using the plate. During the operation, head and neck surgeons resected the tumors, plastic surgeons performed reconstruction with vascularized bone or skin graft, and oral surgeons (dentists) did plate fixation and took charge of the patients'occlusion. This method resulted in patients having good occlusion after the operation

The influence of zoledronate and teriparatide on gamma delta T cells in mice

Background/purpose: Few studies have investigated the possibility that bisphosphonate-related osteonecrosis of the jaw (BRONJ) might reflect an immune response; however, gamma delta T cells have been shown to significantly decline in the blood of BRONJ patients. Additionally, there have been some reports of teriparatide usage for the treatment of BRONJ. In this study, we compared the effects of zoledronate and teriparatide on lymphocyte populations and inflammatory cytokine production in mice. Materials and methods: Thirty female ICR mice were divided into three groups (n = 10 each): a vehicle, a zoledronate, and a teriparatide group. Drugs were administered for 8 weeks in each group. Lymphocytes in the blood and thymus were analyzed and femurs were used for histological observation and lymphocytes analysis of bone marrow. Cytokines were measured in separated serum using Milliplex® multiplex immunoassay analysis. Results: Zoledronate decreased the T cell number in the bone marrow. Additionally, serum levels of interleukin (IL)-2, IL-7, IL-12, IL-15 and RANTES, which are cytokines that affect T cell activation, differentiation and/or proliferation, were significantly lower in zoledronate treated mice. Conversely, teriparatide treatment induced an increase in gamma delta T cells in peripheral blood. Conclusion: Gamma delta T cells in the bone marrow are expected to decrease with zoledronate treatment and increase with teriparatide treatment. If BRONJ involves a loss of gamma delta T cells in the circulation or bone marrow, then the increase in gamma delta T cells that is induced by teriparatide may account for its ability to resolve BRONJ. Keywords: bisphosphonate, BRONJ, zoledronate, teriparatide, gamma delta T cel