Difference in Response to a Motor Imagery Task: A Comparison between Individuals with and without Painful Temporomandibular Disorders.

The aim of the study was to investigate the difference in response to a motor imagery task between individuals with and without painful temporomandibular disorders (TMDs). The participants were 24 adults with and without TMD (TMD and control group, resp.). A set of photographic images of the profile view of a person's head and neck and a hand and a foot were presented in a random order. The set consisted of six different orientations with rotations of each image at 0, 60, 120, 180, 240, and 300 degrees and included left and right representations. The participants were required to view the image and make a decision as to whether it was a left or a right side presented, that is, mental rotation (MR) task. Data were collected on 48 tasks (including left and right) at each orientation for each body part. Reaction times (RTs) for correct answers and accuracy in making the left or right judgements were recorded. The RT was slower in the TMD group than in the control group. The RT for the profile image was slower than those for the hand and foot images. For images that were 180 degrees, the RT was slower and the accuracy was lower than those for five of the other image orientations. The judgements made about the 180-degree rotated image were more inaccurate compared to images of all other orientations among all types of stimuli.

BRCA2 protects mammalian cells from heat shock.

PURPOSE: Heat shock induces DNA double-strand breaks (DSBs) in mammalian cells. Mammalian cells are capable of repairing DSBs by utilising the homologous recombination (HR) pathway. Breast cancer susceptibility gene 2 (BRCA2) is known to regulate the HR pathway. Here, we investigate the role of BRCA2 in repairing DNA damage induced by heat shock. MATERIALS AND METHODS: Chinese hamster lung fibroblast cell lines and human tongue squamous cell carcinoma SAS cells were used. RAD51 foci formation assay was used as an HR indicator. Heat sensitivity was analysed with colony forming assays. Phosphorylated histone H2AX (γH2AX) intensity, which correlates with the number of DSBs, was analysed with flow cytometry. RESULTS: RAD51 foci appeared with heat shock, and the number of cells with RAD51 foci was maximal at about 4 h after heat shock. Heat-induced RAD51 foci co-localised with γH2AX foci. BRCA2-deficient cells were sensitive to heat when compared to their parental wild-type cells. Heat-induced γH2AX was higher in BRCA2-deficient cells compared to parental cells. In SAS cells, cells transfected with BRCA2-siRNA were more sensitive to heat than cells transfected with negative control siRNA. Apoptotic bodies increased in number more rapidly in BRCA2-siRNA transfected cells than in cells transfected with negative control siRNA when cells were observed at 48 h after a heat treatment. In addition, cells deficient in BRCA2 were incapable of activating heat-induced G2/M arrest. CONCLUSION: BRCA2 has a protecting role against heat-induced cell death. BRCA2 might be a potential molecular target for hyperthermic cancer therapy.

Unique and reliable rat model for the assessment of cell therapy: bone union in the rat mandibular symphysis using bone marrow stromal cells.

Many kinds of bone graft materials have been developed and reported to repair various bone defects. The defects are usually created by surgical resection of pre-existing bone tissue. However, spontaneous healing of bone defects without implantation of materials could be seen, because bone tissue possesses inherent repairing property. The central portion of the lower jaw bone in many animals consists of fibrous tissue and is called the mandibular symphysis. It persists even in old animals and thus can be interpreted as a physiological bone gap or a non-healing bone defect. We implanted calcium phosphate porous ceramics alone or composites of the ceramics and bone marrow stromal cells (BMSCs) into the bone defect (mandibular symphysis) to examine whether it could be filled with new bone tissue, resulting in bone union. Eight weeks after implantation, micro-computed tomography (micro-CT) and histological and biomechanical analyses demonstrated that bone union of the mandibles occurred in all rats with composites but in none of those with ceramics alone. These results showed that the rat mandibular symphysis is a unique bone defect site for the evaluation of bone graft materials. These analyses demonstrated that ceramics alone could not contribute to bone healing in the defect; however, supplementation with BMSCs drastically changed the properties of the ceramics (turning them into osteogenic ceramics), which completely healed the defect. As BMSCs can be culture-expanded using small amounts of bone marrow, the use of the composites might have clinical significance for the reconstruction of various bone tissues, including facial bone.

[18F]fluoro-2-deoxyglucose-positron emission tomography for the assessment of histopathological response after preoperative chemoradiotherapy in advanced oral squamous cell carcinoma.

BACKGROUND: [(18)F]fluoro-2-deoxyglucose-positron emission tomography (FDG-PET) is widely used to evaluate tumor metabolic activity. The aim of this study was to evaluate the usefulness of FDG-PET in assessing the histopathological response to preoperative concurrent chemoradiotherapy (CRT) in patients with oral squamous cell carcinoma (OSCC). METHODS: Forty-five patients with resectable advanced OSCC who had received preoperative CRT followed by tumor ablative surgery between January 2004 and December 2011 were included in the study. All patients underwent FDG-PET before and after preoperative CRT. The maximum standardized uptake value (SUVmax) before (pre-SUV) and after preoperative CRT (post-SUV) and the SUVmax reduction rate (ΔSUV %) were used to evaluate the response to preoperative CRT. Correlations among SUVmax, histopathological response, and expression of cancer antigen Ki-67 and hypoxia-inducible factor-1α (HIF-1α) were analyzed. RESULTS: Preoperative CRT significantly reduced intratumoral FDG uptake (P < 0.001). The pre-SUV and post-SUV were significantly lower in patients with a pathological complete response (pCR) than in those with a non-pCR (pre-SUV P = 0.037; post-SUV P = 0.001). ΔSUV % was higher in patients with pCR than in those with non-pCR (P = 0.029). The pre-SUV was significantly correlated with Ki-67 and HIF-1α expression in pretreatment biopsy specimens (Ki-67 P = 0.046, R = 0.292; HIF-1α P = 0.007, R = 0.385). The expression of both Ki-67 and HIF-1α was significantly lower in patients with pCR than in those with non-pCR (Ki-67 P < 0.001; HIF-1α P < 0.001). CONCLUSIONS: Low pre-SUV and post-SUV and high ΔSUV % may predict a good histopathological response to preoperative CRT. Ki-67 and HIF-1α expression in pretreatment biopsy specimens were predictors of histopathological response to preoperative CRT.

High LET radiation enhances apoptosis in mutated p53 cancer cells through Caspase-9 activation.

Although mutations in the p53 gene can lead to resistance to radiotherapy, chemotherapy and thermotherapy, high linear energy transfer (LET) radiation induces apoptosis regardless of p53 gene status in cancer cells. The aim of this study was to clarify the mechanisms involved in high LET radiation-induced apoptosis. Human gingival cancer cells (Ca9-22 cells) containing a mutated p53 (mp53) gene were irradiated with X-rays, C-ion (13-100 KeV/microm), or Fe-ion beams (200 KeV/microm). Cellular sensitivities were determined using colony forming assays. Apoptosis was detected and quantified with Hoechst 33342 staining. The activity of Caspase-3 was analyzed with Western blotting and flow cytometry. Cells irradiated with high LET radiation showed a high sensitivity with a high frequency of apoptosis induction. The relative biological effectiveness (RBE) values for the surviving fraction and apoptosis induction increased in a LET-dependent manner. Both RBE curves reached a peak at 100 KeV/microm, and then decreased at values over 100 KeV/microm. When cells were irradiated with high LET radiation, Caspase-3 was cleaved and activated, leading to poly (ADP-ribose) polymerase (PARP) cleavage. In addition, Caspase-9 inhibitor suppressed Caspase-3 activation and apoptosis induction resulting from high LET radiation to a greater extent than Caspase-8 inhibitor. These results suggest that high LET radiation enhances apoptosis by activation of Caspase-3 through Caspase-9, even in the presence of mp53.

Apoptosis-related gene expression after hyperthermia in human tongue squamous cell carcinoma cells harboring wild-type or mutated-type p53.

Hyperthermia is useful for the treatment of human head and neck cancer, as it is relatively easy to perform thermoregulation when compared with deep organs. In this study, we focused attention on the p53 as a predictive indicator of hyperthermic cancer therapy. We used two kinds of cell lines of a human squamous cell carcinoma (SAS) with identical backgrounds of function except for the p53 protein. We assayed the heat sensitivity, frequency of apoptosis, and apoptosis-related gene expression after heat treatment using DNA array. The SAS/neo (wild-type p53; wtp53) cells were sensitive to heat, and the induction of Caspase-3 activation and apoptosis in the wtp53 cells was clearly high compared with the SAS/mp53 (mutated p53; mp53) cells. The gene expression of apoptosis suppressive-genes such as IL-12 p35 decreased in the wtp53 cells, and IL-12 R beta1 increased in the mp53 cells, though apoptosis-promotive genes of Caspase-9, CD30 and CD40 were induced p53-independently by hyperthermia. It is suggested that heat-induced apoptosis was suppressed by IL-12-related genes in the mp53 cells. These findings strongly imply that p53 status is a useful candidate for a predictive indicator of the effectiveness in hyperthermic therapy.

Recombinant growth/differentiation factor-5 (GDF-5) stimulates osteogenic differentiation of marrow mesenchymal stem cells in porous hydroxyapatite ceramic.

To evaluate the growth/differentiation factor-5 (GDF-5) in the in vivo osteogenic potential of bone marrow mesenchymal stem cells (MSCs), we subcutaneously implanted five different kinds of hydroxyapatite (HA) ceramic implants: HA alone, GDF-5/HA composites (GDF/HA), MSCs/HA composites, the MSCs/HA composites supplemented with GDF-5 (GDF/MSCs/HA), and recombinant bone morphogenetic protein-2 (BMP/MSCs/HA). Neither the HA alone nor the GDF/HA composites exhibited any bone formation at any time after implantation. At 4 weeks, the MSCs/HA composites exhibited a certain amount of bone formation in some pore areas. In contrast, at 2 weeks, the GDF/MSCs/HA composites exhibited histologically obvious de novo bone formation together with active osteoblasts in many pore areas and additional bone formation at 4 weeks. In the de novo formed bone, neither chondrocytes nor endochondral bone was detected. The GDF/MSCs/HA composites also showed high alkaline phosphatase (ALP) and osteocalcin expression determined at both the protein and gene levels and the high level of expression was well maintained even at 4 weeks. Compared with GDF/MSCs/HA, the BMP/MSCs/HA composites exhibited excellent osteogenesis with relatively early osteoblastic phenotype expression. The results indicate that GDF-5 synergistically enhances de novo bone formation capability of MSCs/HA composite and suggest that tissue-engineered GDF/MSCs/HA composites could be used as bone graft substitutes.