Usefulness of Obese Animal Models in Antiobesity Drug Development

Obese animal models have played key roles to elucidate the etiology of obesity and develop antiobesity drugs. In the first half of the chapter, we introduce the characteristics of obese animal models. In the second half of the chapter, we show the results of pharmacological studies using obese animal models for new antiobesity drugs

Analysis of haemodynamics and angiogenic response to ischaemia in the obese type 2 diabetic model Spontaneously Diabetic Torii <i>Lepr^fa</i> (SDT fatty) rats

Peripheral artery disease (PAD) is defined as peripheral blood flow impairment, especially in the legs, caused by atherosclerotic stenosis. The disease decreases quality of life because of intermittent claudication or necrosis of the leg. The hindlimb ischaemia model, in which ischaemia is induced by femoral artery ligation, is often utilized as a PAD model. In the hindlimb ischaemia model, nonmetabolic syndrome animals are mainly used. In this study, we investigated the usefulness of Spontaneously Diabetic Torii Leprfa (SDT fatty) rats, a new model for obese type 2 diabetes, as a new PAD animal model. We found that hindlimb blood flow in SDT fatty rats was significantly lower than that in Sprague–Dawley (SD) rats under nonischaemic conditions. Furthermore, SDT fatty rats showed a significantly higher plasma nitrogen oxide level, shorter prothrombin time, and shorter activated partial thromboplastin time than SD rats. In addition, we found that the change in blood flow 7 days after induction of hindlimb ischaemia and the number of Von Willebrand factor‐positive vessels in gastrocnemius muscles were significantly lower in SDT fatty rats than in SD rats. These results suggest that excess production of reactive oxygen species and coagulation activation could be involved in lower blood flow in non‐ischaemic rats and that decreased angiogenesis could be involved in the poor recovery of blood flow in SDT fatty rats with hindlimb ischaemia. Taken together, our results suggest that SDT fatty rats might be useful as a new model for PAD with metabolic syndrome

New Stepwedge for Bootstrap Sensitometry in Medical Radiography

A new stepwedge has been developed for bootstrap sensitometry, which is used for determining the characteristic curve of radiographic screen/film systems. Since each step of the stepwedge is separated by the lead septum, flare generated under one step will not penetrate the region of another step. The metal of the stepwedge can be changed with various materials. Characteristic curves obtained with new stepwedge bootstrap (NSB) and conventional stepwedge bootstrap (CSB) techniques were compared with those obtained for screen/film systems with inverse sqare sensitometry. The inverse square method was used as the reference standard for accuracy. The NSB method provided characteristic curves that agreed well with those obtained using the inverse square method. The slope of the curve in the CSB method was lower than that in the inverse square or NBS method, because of scatter radiation. The shape of the characteristic curve from the NSB method did not vary with the materials of step metals (aluminum and copper). The cumulative error involved when using the bootstrap method is also discussed

Characteristic improvement of a novel current observer based induction motor speed sensorless system

We have proposed a current observer-based induction motor speed sensorless vector control system which is composed in a rotating reference frame. The characteristic improvement of this system is discussed by taking into account iron loss, stator resistance identification, current low-pass filter and speed estimation low-pass filter. The stability of the system has been investigated by the trajectories of poles and zeros. The effectiveness of the proposed system has been investigated by digital simulation and experimentation.2010 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM 2010) : Pisa, Italy, 2010.06.14-2010.06.1

Transcriptional Repression of Cdc25B by IER5 Inhibits the Proliferation of Leukemic Progenitor Cells through NF-YB and p300 in Acute Myeloid Leukemia

The immediately-early response gene 5 (IER5) has been reported to be induced by γ-ray irradiation and to play a role in the induction of cell death caused by radiation. We previously identified IER5 as one of the 2,3,4-tribromo-3-methyl-1-phenylphospholane 1-oxide (TMPP)-induced transcriptional responses in AML cells, using microarrays that encompassed the entire human genome. However, the biochemical pathway and mechanisms of IER5 function in regulation of the cell cycle remain unclear. In this study, we investigated the involvement of IER5 in the cell cycle and in cell proliferation of acute myeloid leukemia (AML) cells. We found that the over-expression of IER5 in AML cell lines and in AML-derived ALDHhi (High Aldehyde Dehydrogenase activity)/CD34+ cells inhibited their proliferation compared to control cells, through induction of G2/M cell cycle arrest and a decrease in Cdc25B expression. Moreover, the over-expression of IER5 reduced colony formation of AML-derived ALDHhi/CD34+ cells due to a decrease in Cdc25B expression. In addition, over-expression of Cdc25B restored TMPP inhibitory effects on colony formation in IER5-suppressed AML-derived ALDHhi/CD34+ cells. Furthermore, the IER5 reduced Cdc25B mRNA expression through direct binding to Cdc25B promoter and mediated its transcriptional attenuation through NF-YB and p300 transcriptinal factors. In summary, we found that transcriptional repression mediated by IER5 regulates Cdc25B expression levels via the release of NF-YB and p300 in AML-derived ALDHhi/CD34+ cells, resulting in inhibition of AML progenitor cell proliferation through modulation of cell cycle. Thus, the induction of IER5 expression represents an attractive target for AML therapy

Analysis of Tempormandibular Joint by Image Processing -Discrimination of Condylar Position-

Tomography is clinically useful in the diagnosis of the temporomandibular joint (TMJ) syndrome. The TMJ is formed by the condyle and the glenoid fossa, and there exists TMJ space between them. Image processing was employed in the present study, and the reference points of the condyle and the glenoid fossa were determined from the tomogram. Subsequently, the TMJ space was measured automatically in the image analysis. The TMJs of 98 patients were examined practically and the characteristics of each result were studied. There is a possibility of discriminating an abnormal condylar position from a normal one by making use of the TMJ space and the distance between two reference points

Dose Distributions at Standard Diagnostic X-Ray Energy

Exposure dose has been indicated by surface dose or transit dose, but they could not indicate dose distributions inside the body. Modulex as the radiation therapy planning system was used for dose distributions at standard diagnostic X-ray energy. X-ray is low energy X-ray at standard diagnostic radiography, so alterations of the energy and the scattering dose distribution by absorbers are quite different from those at high energy X-rays. Mix-DP was put to the homogeneous tissue use, then Bone equivalent phantom or Lung equivalent phanton was put to the inhomogeneous tissue use. Density correction factors for inhomogeneous phantoms were gotten by the calculation of the water equivalent thickness. In Bone the inhomogeneous correction depended strongly on the bone thickness. In Lung it was in need of one density correction factor and the scattering correction method for the decrease of the back scattering. The calculated dose distributions by Modulex agreed with measured data when each correction was carried out, and it was indicated that those data apply to inclinical situations

Total Skin Electron Beam Therapy

The peripherally T-cell lymphoma; Mycosis fungoides etc, has the good radiation sensitivity, and has been adapted for total skin electron beam therapy. In this study the pendular irradiation method was used for the purpose of total skin electron beam therapy in Mycosis fungoides, and physical data on the radiation field and the electron beam energy were useful clinically.皮膚に限局した一連の末梢型T細胞リンパ腫は放射線に対する感受性が高く、電子線治療の適応となる疾患である。こららの疾患は一般的に全身の皮膚に浸潤するため、治療に際してはTarget Volumeの深さに合わせた最小限のエネルギーで全身隈なく照射する必要がある。筆者等は最近臨床で遭遇した菌状息肉症の患者を治療するため、その患者に合った物理的なデータを測定した。照射野の拡大には振子照射法を用い、エネルギー低減方法は装置に装備されている鉛のスキャタラーを低原子番号で、しかも加工のしやすい塩化Vinyl板に交換する方法を工夫した。データとして治療効果、副作用に関係する線量率、エネルギー、及び照射野内平坦度について測定した結果、距離が長くなる関係から線量率が低下する全身照射法の欠点は解消できなかったが、エネルギー及び平坦度については使用可能なデータを得ることができた

Early development and neurogenesis of Temnopleurus reevesii

Sea urchins are model non-chordate deuterostomes, and studying the nervous system of their embryos can aid in the understanding of the universal mechanisms of neurogenesis. However, despite the long history of sea urchin embryology research, the molecular mechanisms of their neurogenesis have not been well investigated, in part because neurons appear relatively late during embryogenesis. In this study, we used the species Temnopleurus reevesii as a new sea urchin model and investigated the detail of its development and neurogenesis during early embryogenesis. We found that the embryos of T. reevesii were tolerant of high temperatures and could be cultured successfully at 15–30°C during early embryogenesis. At 30°C, the embryos developed rapidly enough that the neurons appeared at just after 24 h. This is faster than the development of other model urchins, such as Hemicentrotus pulcherrimus or Strongylocentrotus purpuratus. In addition, the body of the embryo was highly transparent, allowing the details of the neural network to be easily captured by ordinary epifluorescent and confocal microscopy without any additional treatments. Because of its rapid development and high transparency during embryogenesis, T. reevesii may be a suitable sea urchin model for studying neurogenesis. Moreover, the males and females are easily distinguishable, and the style of early cleavages is intriguingly unusual, suggesting that this sea urchin might be a good candidate for addressing not only neurology but also cell and developmental biology

Photon background caused by the reduction of the electron beam energy - Materials of scattering foil -

The total skin electron beam therapy has been one of the clinical treatment for peripherally T-cell lymphoma; Mycosis fungoides, adult T-cell lymphoma, and so on. The crucial points in this treatment are not only having an optimum energy level of electron beam for a target volume (a tissue) but also keeping the photon back ground low. It is not easy to regulate those points by the control panel, however, for the equipment that is conventinally used for electron beam, theoretically, is to exchange lead (Pb), which is ordinarily used, to a low atomic number material as a scattering foil. We examined several different kinds and / or various thickness as a scattering foil material that can make the electron beam lower without an increase of the contaminant as X-ray. We hereby reported the results, and strongly suggested the following two materials in use; acrylic plate, carbon board, and so on, which are easily available and worked, would be practically useful for the total skin electron beam therapy