Today, many people prefer the simplicity of eating at fast-food restaurants. The prevalence of overweight and obesity thus seems likely to continue to rise in coming decades, and recent evidence has demonstrated that obesity is associated with cancer, infectious diseases, and metabolic syndrome. We hypothesized that obesity induces mechanical changes in the digestive and circulatory organs, which may in turn disrupt homeostasis. This study investigated systemic and local impacts of diet-induced obesity on the immune system, including the mucosal tissues. Mice were administered a high-fat diet (HFD) or normal diet (ND) for 3 weeks, after which plasma and fecal extracts were collected at 6-h intervals. A significant reduction in plasma immunoglobulin (Ig) G and increase in fecal secretory (S-) S-IgA concentrations were observed in HFD-fed mice. In addition, corticosterone levels were significantly higher in the plasma of mice fed HFD when compared with those fed ND, indicating that daily intake of high-fat foods causes physiological stress. Taken together, these results suggest that regular consumption of high-fat foods may negatively impact both systemic and mucosal immune responses.

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　Parametric radiation-based X-ray (PXR), one of the pioneering modalities using an accelerator, is being studied as a new kind of X-ray source in the Laboratory for Electron Beam Research and Application Institute of Quantum Science (LEBRA). The purpose of this study was to evaluate the potential of LEBRA-PXR as a new X-ray source for diagnostic imaging.
　Dog mandibular tissue with malignant melanoma was examined. Simple X-ray images were taken with LEBRA-PXR at several wavelengths(12 keV, 15 keV, 18 keV, 21 keV, 24 keV, 27 keV, 30 keV). An energy subtracted image was generated with the image with the longest wavelength PXR and the image with the shortest wavelength PXR. As a control, an image was taken with conventional X-ray(40 kV, 125 mA, 40 msec; effective energy 21 keV). Simple X-ray images were taken with LEBRA-PXR, and the energy subtracted and conventional X-ray images were compared with the histopathological stained images.
　Compared to conventional X-ray images, LEBRA-PXR images showed contrast related to different wavelengths, reflecting histological differences between tissues. Compared with the histological findings, malignant tumor images with LEBRA-PXR were clearer than conventional X-ray images.
　Using LEBRA-PXR, a type of nearly perfectly monochromatic X-ray source imaging, the images of the malignant tumor displayed different contrasts from conventional X-ray images. LEBRA-PXR is a useful diagnostic imaging tool using a new X-ray source.

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　Orthodontic root resorption (ORR) is an unavoidable pathological consequence of orthodontic tooth movement. It is thought that swinging of the root due to the reciprocating movement of the tooth(jiggling)mayexacerbate ORR. However, little is known about the relationship between ORR and jiggling. We herein investigated the tartrate-resistant acid phosphatase(TRAP)expression in odontoclasts in resorbed roots during experimental tooth movement(jiggling)in vivo.
　Twenty-four eight-week-old male Wistar rats were divided into four groups; a heavy force group(50 g), an optimal force group(10 g), a jiggling force group(compression and tension, repetition; 10 g)and a control group. The expression levels of TRAP protein in odontoclasts in the dental root were determined by immunohistochemical analysis.
　Immunoreactivity for TRAP in resorbed roots exposed to the jiggling force was stronger than that in the other groups on day 21. The number of TRAP-positive odontoclasts wassignificantly elevated in the JF group on day 21 when compared with the other groups.
　These results suggest that “jiggling force” may induce ORR during orthodontic tooth movement, and may be a risk factor for ORR.

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Objective: The purpose of this study was to explore magnetic resonance imaging (MRI) findings of bilateral temporomandibular joints with no signs or symptoms of temporomandibular dysfunction to ascertain how disk displacement develops in both joints.
Study design: Subjects comprised 54 asymptomatic volunteers (38 males, 16 females; average age 21.2±2.8 years). All 108 temporomandibular joints were analyzed by MRI. Results: Unilateral or bilateral disk displacement was present in 37% of subjects; 25 of 108 joints were classified as partial disk displacement (PDD) and 5 of 108 joints were classified as complete disk displacement (CDD). The numbers of subjects with unilateral and bilateral disk displacement were the same. In cases of bilateral disk displacement, the condition of displacement was likely to match on both sides.
Conclusions: CDD may occur without temporomandibular dysfunction, and when disk displacement is bilateral, the condition of both disk displacements is often comparable.

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Osteosarcoma is a malignancy of mesenchymal cells, which have the ability to produce osteoid or immature bone. Osteosarcoma is the most common malignancy originating within bone, but occurs very infrequently in the jaws, comprising only 4% of the number of osteosarcomas of the long bones. Maxillary osteosarcoma presents with common clinical features of pain and swelling. Here we present a rare case of maxillary osteosarcoma in a 12-year-old girl. Diagnosis and preoperative assessment were performed using a combination of conventional radiography and advanced imaging. The aim of this case report is to draw attention to the possibility of diagnosing this tumor based on clinical and radiographic characteristics.

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