Prevention of Root Caries Using Oxalic Acid.

Certain dentin hypersensitivity treatment materials include oxalic acid to coat dentin surfaces with minerals, while certain organic acids possess a remineralization effect. Herein, an organic acid that inhibits the demineralization and coating of root surfaces was evaluated. Specimens were produced using five non-carious extracted bovines. Four different acids were used: oxalic acid (OA), malonic acid (MA), polyacrylic acid (PA), and succinic acid (SA). Each acid was applied to the root surface and washed using distilled water or a remineralization solution, and the surface was observed using scanning electron microscopy (SEM). All the surfaces of each specimen, barring the polished surface, were covered with wax and immersed in an automatic pH cycling system for two weeks. Dentin demineralization was analyzed using transverse microradiography (TMR) before and after pH cycling. SEM analysis demonstrated that the three acid groups demineralized the dentin surface, whereas the OA group generated crystals covering the dentin surface, even in a distilled water environment. TMR analysis revealed that the OA groups showed significantly lower integrated mineral loss compared with the other groups, even in the distilled water environment. The results suggest that OA generates insoluble calcium oxalate crystals on the dentin and suppresses demineralization even under low saliva conditions.

Size- and Morphology-Controlled Preparation of Surface-Modified Water-Dispersible Fullerene Nanoparticles for Bioapplications.

In this study, we investigated water-dispersible surface modification for size- and shape-controlled fullerene nanoparticles (C60P) based on a condensation reaction with di-amino alkane. This modification provided for water dispersibility of C60P and the capability for secondary modification as well. The resultant C60P particles have several useful physical properties: water-dispersibility for ease of injection; fluorescence for detection and quantification; and a characteristic morphology to assist identification. These properties will widely extend the applications of these particles, especially into the biological fields of bioimaging and drug delivery.

Movement-related cortical magnetic fields associated with self-paced tongue protrusion in humans.

Sophisticated tongue movements are coordinated finely via cortical control. We elucidated the cortical processes associated with voluntary tongue movement. Movement-related cortical fields were investigated during self-paced repetitive tongue protrusion. Surface tongue electromyograms were recorded to determine movement onset. To identify the location of the primary somatosensory cortex (S1), tongue somatosensory evoked fields were measured. The readiness fields (RFs) over both hemispheres began prior to movement onset and culminated in the motor fields (MFs) around movement onset. These signals were followed by transient movement evoked fields (MEFs) after movement onset. The MF and MEF peak latencies and magnitudes were not different between the hemispheres. The MF current sources were located in the precentral gyrus, suggesting they were located in the primary motor cortex (M1); this was contrary to the MEF sources, which were located in S1. We conclude that the RFs and MFs mainly reflect the cortical processes for the preparation and execution of tongue movement in the bilateral M1, without hemispheric dominance. Moreover, the MEFs may represent proprioceptive feedback from the tongue to bilateral S1. Such cortical processing related to the efferent and afferent information may aid in the coordination of sophisticated tongue movements.

Left thoracoabdominal approach for adenocarcinoma of the esophagogastric junction.

BACKGROUND/AIMS: To evaluate usefulness of esophagogastrectomy via left thoracoabdominal (LT) approach for adenocarcinoma of the esophagogastric junction (AEG), the results of surgery stratified by Siewert's classification, were analyzed retrospectively. METHODOLOGY: The tumor diameter, distance of the proximal tumor border from the esophagogastric junction, and length of the esophagus in the resected specimens of consecutive 171 AEG patients were measured. The surgical approach was classified as total esophagectomy (TE), esophagogastrectomy via LT, or transhiatal/abdominal (HA) approach. RESULTS: Sixteen patients underwent TE, 71 had LT, and 84 had HA. Overall survival of the TE and LT groups was significantly lower than that of the HA group. The difference was seen between LT and HA for type II T3 tumors, but the tumor diameter in LT was significantly larger than that in HA. The approach could not be determined by Siewert's classification, but by distance of proximal tumor border from the junction. The tumors with distance over 5cm might be indicated for the TE approach; 5-3cm, the LT; within 3cm, the HA. The percentage of patients in whom the LT approach is indicated might be only 19%. CONCLUSION: Left thoracoabdominal esophagogastrectomy may be valid for some AEG.

Apoptosis inhibitor expressed by macrophages tempers autoimmune colitis and the risk of colitis-based carcinogenesis in TCRalpha-/- mice.

BACKGROUND: Crohn's disease and ulcerative colitis (UC) are the two main entities involved in human inflammatory bowel disease (IBD). However, their precise etiologies remain unclear. To study the development of mucosal inflammation, and chronic inflammation-based dysplasia and carcinoma formation, we examined possible roles of the apoptosis inhibitor expressed by macrophages (AIM) in an experimental IBD model. METHODS: In this study, we used T cell receptor alpha deficient (TCRalpha(-/-)) mice, a known UC-like colitis model. We generated TCRalpha(-/-) x AIM(-/-) double knockout mice by crossbreeding TCRalpha(-/-) with AIM(-/-) mice. At 24 weeks of age, mice were killed to obtain colon tissues for pathological examinations. TCRalpha(-/-) x AIM(+/-) mice, heterozygous littermates of TCRalpha(-/-) x AIM(-/-) mice, were used as controls. RESULTS: Severe colitis was observed in TCRalpha(-/-) x AIM(-/-) mice, when compared with TCRalpha(-/-) x AIM(+/-) mice. Dysplasia was detected in TCRalpha(-/-) x AIM(-/-) mice, but not in TCRalpha(-/-) x AIM(+/-) mice. Adenocarcinoma formation was observed from dysplasia only in TCRalpha(-/-) x AIM(-/-) mice. CONCLUSION: Not only a high incidence of severe colitis but also dysplasia and adenocarcinoma formation were observed in TCRalpha(-/-) x AIM(-/-) mice only. AIM have some regulatory roles in inflammation and progression of dysplasia to carcinoma in TCRalpha(-/-) mice.

Detection of bone marrow micrometastasis in gastric cancer patients by immunomagnetic separation.

BACKGROUND: Micrometastasis to the bone marrow can predict widespread disease and a poor prognosis of cancer patients after surgery. The purpose of this study was to evaluate the clinical significance of detecting micrometastasis in the bone marrow of gastric cancer patients. METHODS: Bone marrow and peripheral blood samples were obtained from 53 gastric cancer patients at the time of surgery. These samples were enriched by immunomagnetic separation and immunostained with an anti-cytokeratin antibody. Expression of vascular endothelial growth factor and erbB-2/HER2 was examined in the primary tumors. RESULTS: Cytokeratin-positive cancer cells were observed in the bone marrow of 16 (30%) of 53 patients. Among them, two patients also had cancer cells in the peripheral blood. The presence of bone marrow micrometastasis was correlated with the depth of invasion and lymph node metastasis but was not associated with peritoneal dissemination. Detection of bone marrow micrometastasis was not correlated with vascular endothelial growth factor or HER2 expression in the primary tumors. Four patients with micrometastasis had recurrence in the liver or lungs, but this did not occur in patients without micrometastasis. CONCLUSIONS: Detection of cancer cells in the bone marrow might be an indicator of postoperative hematogenous metastasis in gastric cancer patients.