Measurement of positron lifetime to probe the mixed molecular states of liquid water

Positron lifetime spectra were measured in liquid water at temperatures between 0c and 50c. The long lifetime of ortho-positronium atoms (o-Ps) determined by electron pick-off in molecular substances decreases smoothly by 10% as the temperature is raised. This lifetime temperature dependence can be explained by combining the Ps-bubble model and the mixture state model of liquid water.Comment: 11 pages, 6 page

Functional Imaging of Hepatic Masses Using Computed Tomography

In order to assess the usefulness of CT functional images, twenty one cases with liver masses were studied. We tried to minimize the motion artifacts by immobilizing the patients with a girdle in performing dynamic CT scans, and by discarding some of the segmented images with serious artifacts before constructing functional images. The qualities of images obtained were considered satisfactory. Of the several transit parameters obtained from the dynamic CT scans, we found the first moment (Ml) to be most useful and the effectiveness of Ml-functional images were studied. In all cases with hepatocellular carcinomas (12 cases) and intrahepatic cholangiocarcinomas (2 cases), the Ml-functional images showed the viable portions of tumors as accumulations of dark pixels reflecting rapid transit times due to arterial blood supply. In three cases with hepatic cavernous hemangiomas, the lesions were represented as bright areas with a well-defined border. In two cases with hepatic abscesses, the Ml-functional images suggested the presence of hyperemia in the surrounding tissue as demonstrated by bright pixels around the lesions. CT functional imaging was proved to be useful for evaluating the circulatory dynamics of contrast material and the differential diagnosis of liver tumors when conventional or dynamic CT studies failed to provide enough information. This technique enabled overall analysis of time-density curves for the entire plane of an image semiautomatically and without the subjective maneuver of setting ROI's (regions of interest)

Dynamin 2 Cooperates with Amphiphysin 1 in Phagocytosis in Sertoli Cells

Testicular Sertoli cells highly express dynamin 2 and amphiphysin 1. Here we demonstrate that dynamin 2 is implicated in phosphatidylserine (PS)-dependent phagocytosis in Sertoli cells. Immunofluorescence and dual-live imaging revealed that dynamin 2 and amphiphysin 1 accumulate simultaneously at ruffles. These proteins are specifically bound in vitro. Over-expression of dominant negative dynamin 2 (K44A) inhibits liposome-uptake and leads to the mis-localization of amphiphysin 1. Thus, the cooperative function of dynamin 2 and amphiphysin 1 in PS-dependent phagocytosis is strongly suggested.</p

Caffeic Acid Phenethyl Ester Induces Vascular Endothelial Growth Factor Production and Inhibits CXCL10 Production in Human Dental Pulp Cells

The survival rate of root non-vital teeth is lower than that of vital teeth. Therefore, to preserve the dental pulp is very important. The vascular endothelial growth factor (VEGF) is the most potent angiogenic factor involved in the vitality of dental pulp including reparative dentin formation. Caffeic acid phenethyl ester (CAPE) is a physiologically active substance of propolis and has some bioactivities such as anti-inflammatory effects. However, there are no reports on the effects of CAPE on dental pulp inflammation. In this study, we investigated the effects of CAPE on VEGF and inflammatory cytokine production in human dental pulp cells (HDPCs) to apply CAPE to an ideal dental pulp protective agent. We found that CAPE induced VEGF production from HDPCs. Moreover, CAPE induced the phosphorylation of p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases (ERK), and stress-activated protein kinase/c-Jun N-terminal kinase (SAP/JNK) in HDPCs. Furthermore, CAPE inhibited C-X-C motif chemokine ligand 10 (CXCL10) production in Pam3CSK4- and tumor necrosis factor-alpha (TNF-α)-stimulated HDPCs. In conclusion, these results suggest that CAPE might be useful as a novel biological material for vital pulp therapy by exerting the effects of VEGF production and anti-inflammatory activities

Trial of Brain Redox Imaging and Estimation of Radiation-Induced Redox Change in Mouse Brain

The in vivo T1-weighted contrasting abilities and signal decay behaviors of several nitroxyl contrast agents, which have been used as redox responsive contrast agents in several magnetic resonance-based imaging modalities, in mouse brain were compared. In addition, daily variations of redox behavior in mouse brain after irradiation of X-ray or carbon-ion beams (C-beam) were tried to estimate based on the in vivo reduction rate of amphiphilic nitroxyl contrast agents.Injection solutions of five types of five-membered-ring nitroxyl contrast agents, i.e. 3-carboxy-2,2,5,5-tetramethylpyrrolidine-N-oxyl (CxP), 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl (CmP), 3-methoxy-carbonyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl (MCP), acetoxymethyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl-3-carboxylate (CxP-AM), and 4-(N-methylpiperidine)-2,2,5,5-tetramethylpyrroline-N-oxyl (23c), and a six-membered-ring nitroxyl contrast agent, i.e. 4-hydroxyl-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPOL), were prepared. The nitroxyl contrast agent was i.v. injected to a mouse through tail vein. Then, the distributions and pharmacokinetics of nitroxyl contrast agents were compared based on the time course of T1-weighted MRI. The MRI experiments using CMP or TEMPOL were repeated for mice irradiated by X-ray or C-beam to their head on several deferent timings, i.e. 1, 2, 4, 8 day(s) after irradiation. C-beam was irradiated at Heavy-Ion Medical Accelerator in Chiba (HIMAC, National Institute of Radiological Sciences/ National Institutes for Quantum and Radiological Science and Technology).The blood-brain-barrier (BBB)-impermeable CxP could not be distributed in the brain. The slightly lipophilic CmP showed slight distribution only in the ventricle, but not in the medulla and cortex. The amphiphilic MCP and TEMPOL had good initial uniform distribution in the brain and showed typical 2-phase signal decay profiles. A brain-seeking nitroxyl probe, CxP-AM, showed an accumulating phase, and then its accumulation was maintained in the medulla and ventricle regions, but not in the cortex. The lipophilic 23c was well distributed in the cortex and medulla, but slightly in the ventricle, and showed relatively rapid linear signal decay.Decay rates of MCP in mouse brain after irradiation of 8 Gy X-ray, 8 Gy C-beam or 16 Gy C-beams did not show marked clear changes, however relatively little decreasing were observed at day 1 and day 2 after irradiation. Decay rates of TEMPOL was increased 1 after irradiation then gradually recovered to the control level. MCP and TEMPOL showed opposite responses but the timing of redox change may be 1 or 2 days after irradiation.Nitroxyl contrast agents equipped with a suitable lipophilic substitution group could be BBB-permeable functional contrast agents. MR redox imaging, which can estimate not only the redox characteristics but also the detailed distribution of the contrast agents, is a good candidate for a theranostic tool. Irradiation of ionized radiation to head could cause alternation of redox status in the brain. Detail of redox mechanisms were still in progress.第7回国際放射線神経生物学会大

カフェイン酸フェネチルエステル（CAPE）がラット象牙芽細胞様細胞のVEGF発現と産生に与える影響

Caffeic acid phenethyl ester (CAPE), the main component of propolis, has various biological activities including anti-inflammatory effect and wound healing promotion. Odontoblasts located in the outermost layer of dental pulp play crucial roles such as production of growth factors and formation of hard tissue termed reparative dentin in host defense against dental caries. In this study, we investigated the effects of CAPE on the upregulation of vascular endothelial growth factor (VEGF) and calcification activities of odontoblasts, leading to development of novel therapy for dental pulp inflammation caused by dental caries. CAPE significantly induced mRNA expression and production of VEGF in rat clonal odontoblast-like KN-3 cells cultured in normal medium or osteogenic induction medium. CAPE treatment enhanced nuclear factor-kappa B (NF-κB) transcription factor activation, and furthermore, the specific inhibitor of NF-κB significantly reduced VEGF production. The expression of VEGF receptor- (VEGFR-) 2, not VEGFR-1, was up regulated in KN-3 cells treated with CAPE. In addition, VEGF significantly increased mineralization activity in KN-3 cells. These findings suggest that CAPE might be useful as a novel biological material for the dental pulp conservative therapy

Formation of meso, N-diphenylprotoporphyrin IX by an aerobic reaction of phenylhydrazine with oxyhemoglobins.

Administration of phenylhydrazine to rabbits resulted in the denaturation of hemoglobins in erythrocytes, causing the formation of intracellular precipitates known as Heinz bodies, severe hemolytic anemia, and reticulocytosis. To elucidate the molecular mechanism of the destabilization, we allowed human oxyhemoglobins to react aerobically with phenylhydrazine. After treatment with acetic acid/HCl and H2SO4/methanol, the chloroform extract contained blue-green pigments of major products accompanied by different minor products. Each product was isolated by column chromatography. By fast-atom-bombardment mass spectrometry (FAB-MS) and proton nuclear magnetic resonance (1H-NMR) spectrometry, dimethyl esters of N-phenylprotoporphyrin IX and meso, N-diphenylprotoporphyrin IX were determined. Other major products also were determined to be dimethyl esters of triphenyl-and tetraphenyl-substituted protoporphyrins by FAB-MS. The formation of meso, N-diphenylprotoporphyrin indicated that the addition of a phenyl radical to the meso-carbon atom of the protoporphyrin ring occurred. Triphenyl and tetraphenyl adducts also indicated the formation of phenyl radicals in the aerobic reaction of phenylhydrazine with oxyhemoglobins. From these results, we suggest that the formation of phenyl radicals and the replacement of heme with phenyl-substituted protoporphyrins cause the destabilization of hemoglobins to induce Heinz bodies and hemolytic anemia with phenylhydrazine.</p

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