12 results on '"Ohtsu Y"'
Search Results
2. Surgical Repair of Cervical Aortic Arch With Brain Circulation Anomaly Through Clamshell Incision.
- Author
-
Gomibuchi T, Seto T, Yamamoto T, Nakahara K, Ohashi N, Ohtsu Y, Wada Y, Fukui D, and Okada K
- Subjects
- Aged, Aortic Aneurysm, Thoracic diagnosis, Aortic Arch Syndromes diagnosis, Humans, Male, Aortic Aneurysm, Thoracic complications, Aortic Aneurysm, Thoracic surgery, Aortic Arch Syndromes etiology, Aortic Arch Syndromes surgery
- Abstract
We report the successful surgical repair of a cervical aortic arch and diverticulum with a brain circulation anomaly through a clamshell incision. Because of the reliability of selective antegrade cerebral perfusion and superior exposure, we chose an approach through a clamshell incision. We describe the utility of this approach for treating a cervical aortic arch with a diverticulum., (Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
3. Regulated bioanalysis of conformers - A case study with ASP2151 in dog plasma and urine.
- Author
-
Ohtsu Y, Otsuka S, Nakamura T, and Noguchi K
- Subjects
- Animals, Dogs, Linear Models, Reproducibility of Results, Sensitivity and Specificity, Chromatography, High Pressure Liquid methods, Oxadiazoles blood, Oxadiazoles chemistry, Oxadiazoles pharmacokinetics, Oxadiazoles urine, Tandem Mass Spectrometry methods
- Abstract
We developed and validated bioanalytical methods for a potent helicase-primase inhibitor ASP2151 that has two conformers. These conformers elute as unseparated broad peaks under ordinary high-performance liquid chromatographic conditions, indicating discernable differences in hydrophobicity. We observed that column temperature and mobile phase pH have no effect on these peaks and that conformers form a single symmetrical peak when tetrahydrofuran is added to the mobile phase. In addition, we needed to develop semi-automated methods where inter-conversion of the conformers is unlikely to cause sample-to-sample extraction variability. Briefly, following the addition of deuterium-labeled ASP2151 as an internal standard (IS), dog plasma samples or acetonitrile-added urine samples were filtrated. The filtrates were then injected into a column-switching liquid chromatography-tandem mass spectrometry (LC-MS/MS) system and trapped onto an extraction column. Extracts were back-flushed onto an analytical C18 column (4.6×50mm, 3μm) with a mobile phase consisting of methanol, tetrahydrofuran, and 20mmol/L ammonium acetate (45:5:50, v/v/v). The eluent was monitored in the negative atmospheric pressure chemical ionization mode. The calibration curve was linear over a range of 5-1000ng/mL for plasma and 0.5-100μg/mL for urine. Validation data met the acceptance criteria in accordance with regulatory guidance and demonstrated that these methods were selective, accurate, and reproducible. In addition, the present methods were successfully applied to a pharmacokinetic study in dogs., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
4. Selective ligand purification using high-performance affinity beads.
- Author
-
Ohtsu Y, Ohba R, Imamura Y, Kobayashi M, Hatori H, Zenkoh T, Hatakeyama M, Manabe T, Hino M, Yamaguchi Y, Kataoka K, Kawaguchi H, Watanabe H, and Handa H
- Subjects
- Animals, Ligands, Microspheres, Rats, Tacrolimus chemistry, Chromatography, Affinity methods, Tacrolimus isolation & purification, Tacrolimus Binding Protein 1A chemistry
- Abstract
Since the development of affinity chromatography, affinity purification technology has been applied to many aspects of biological research, becoming an indispensable tool. Efficient strategies for the identification of biologically active compounds based on biochemical specificity have not yet been established, despite widespread interest in identifying chemicals that directly alter biomolecular functions. Here, we report a novel method for purifying chemicals that specifically interact with a target biomolecule using reverse affinity beads, a receptor-immobilized high-performance solid-phase matrix. When FK506-binding protein 12 (FKBP12) immobilized beads were used in this process, FK506 was efficiently purified in one step either from a mixture of chemical compounds or from fermented broth extract. The reverse affinity beads facilitated identification of drug/receptor complex binding proteins by reconstitution of immobilized ligand/receptor complexes on the beads. When FKBP12/FK506 and FKBP12/rapamycin complexes were immobilized, calcineurin and FKBP/rapamycin-associated protein were purified from a crude cell extract, respectively. These data indicate that reverse affinity beads are powerful tools for identification of both specific ligands and proteins that interact with receptor/ligand complexes.
- Published
- 2005
- Full Text
- View/download PDF
5. Acute effects of direct cell implantation into the heart: a pressure-volume study to analyze cardiac function.
- Author
-
Ishida M, Tomita S, Nakatani T, Kagawa K, Yamaguchi T, Suga M, Ohtsu Y, Yazawa H, Yagihara T, and Kitamura S
- Subjects
- Animals, Hemodynamics, Injections, Models, Animal, Models, Cardiovascular, Swine, Swine, Miniature, Bone Marrow Transplantation, Cardiac Volume, Cardiomyopathy, Dilated physiopathology, Heart physiology, Ventricular Function, Left, Ventricular Pressure
- Abstract
Background: To safely implant cells into the myocardium, we must establish a volume that prevents compromising cardiac performance. We studied pressure-volume (PV) to investigate the adverse effects of direct cell implantation in the acute phase., Methods: We used 21 minipigs. In the normal heart model, we studied PV by measuring various parameters (including end-systolic pressure, end-systolic elastance, dp/dtmax, end-diastolic volume, and time constant of isovolumetric left ventricular pressure fall [Tau]). We injected solutions into the left ventricular free wall (15 cm(2)). Sampling points were at baseline and after injection of saline (Group I, n = 4) or of blood (Group II, n = 4) at volumes of 1 ml and 10 ml up to 30 minutes after injection. In Group II, we injected additional blood (10 ml) 4 times. In the ischemic heart model, 1 month after ligating the left anterior descending artery, we injected 1 ml saline (Group III, n = 4), bone marrow mononuclear cells (10(8) cells/1 ml; Group IV, n = 4), or bone marrow stromal cells (10(8) cells/1 ml; Group V, n = 3). We studied PV before and after injection., Results: In Group I, we found no significant changes in parameters. In Group II, end-diastolic volume after 10-ml injection (24.4 +/- 3.6 ml) was smaller than end-diastolic volume at baseline (29.5 +/- 5.8 ml, p < 0.01). Tau after 10-ml injection (39.4 +/- 5.3 msec) was greater than at baseline (35.6 +/- 4.0 msec, p < 0.01). One pig died of ventricular fibrillation after a 20-ml injection of blood. We observed no detrimental effects in Groups III, IV, and V., Conclusions: More than 10 ml cell suspension compromised diastolic function. We safely performed direct injection of bone marrow cells (1 x 10(8)/1 ml).
- Published
- 2004
- Full Text
- View/download PDF
6. Bone marrow is a source of regenerated cardiomyocytes in doxorubicin-induced cardiomyopathy and granulocyte colony-stimulating factor enhances migration of bone marrow cells and attenuates cardiotoxicity of doxorubicin under electron microscopy.
- Author
-
Tomita S, Ishida M, Nakatani T, Fukuhara S, Hisashi Y, Ohtsu Y, Suga M, Yutani C, Yagihara T, Yamada K, and Kitamura S
- Subjects
- Animals, Atrial Natriuretic Factor analysis, Bone Marrow Transplantation, Cardiomyopathies, Mice, Mice, Inbred C57BL, Mitochondria ultrastructure, Myofibrils ultrastructure, Myosin Heavy Chains analysis, Regeneration drug effects, Troponin I analysis, Bone Marrow Cells cytology, Bone Marrow Cells physiology, Cell Movement drug effects, Doxorubicin pharmacology, Granulocyte Colony-Stimulating Factor pharmacology, Regeneration physiology
- Abstract
Background: It has been reported previously that granulocyte colony-stimulating factor (GCSF) injection improves infarcted heart function, but the mechanism remains unclear. In this study we sought to determine whether GCSF-mobilized bone marrow cells could regenerate neo-myocardium and repair doxorubicin-induced cardiomyopathy., Methods: C57BL/6 mice were irradiated and bone marrow cells (BMC; 1 x 10(6)) from green fluorescent protein (GFP) mice (GFP-BMC) were transplanted intravenously, followed by splenectomy. Doxorubicin (2.5 mg/kg, 6 times for 2 weeks) was administered intraperitoneally 2 weeks later. GCSF (50 microg/kg/day for 8 days) was administered sub-cutaneously after doxorubicin injection (Group I, n = 11) and 3 weeks later (Group II, n = 8), and saline was injected in Group III animals (n = 8). Eight weeks after doxorubicin injection, the excised hearts were studied immunologically and electron microscopically., Results: Survival rates were 81.8% in Group I, 50.0% in Group II and 62.5% in Group III. The number of GFP-BMC in Group I (15.4 +/- 7.4 per high-power field) was highest (p < 0.05). In all groups, cardiac troponin I-positive cells derived from GFP-BMC were observed in the hearts. GFP-BMC in hearts stained positively against cardiac troponin I (4.3 +/- 2.5%), myosin heavy chain (5.0 +/- 4.3%), atrial natriuretic peptide (ANP; 3.9 +/- 2.4%) and connexin 43 (11.9 +/- 7.3%) in Group I. Myofibrils, mitochondria and fundamental architecture were almost all preserved in Group I, whereas hearts were severely damaged in Groups II and III., Conclusions: Bone marrow was shown to be one of the sources of regenerated cardiomyocytes in the doxorubicin-induced cardiomyopathic heart. Early administration of GCSF enhanced the migration of bone marrow cells into the heart, and attenuated the cardiotoxicity of doxorubicin.
- Published
- 2004
- Full Text
- View/download PDF
7. Bone marrow mononuclear cell transplantation had beneficial effects on doxorubicin-induced cardiomyopathy.
- Author
-
Ishida M, Tomita S, Nakatani T, Fukuhara S, Hamamoto M, Nagaya N, Ohtsu Y, Suga M, Yutani C, Yagihara T, Yamada K, and Kitamura S
- Subjects
- Animals, Atrial Natriuretic Factor blood, Cardiomyopathy, Dilated chemically induced, Cardiomyopathy, Dilated pathology, Cardiomyopathy, Dilated physiopathology, Coronary Circulation, Disease Models, Animal, Doxorubicin, Heart Function Tests, Heart Rate, Male, Myocardium pathology, Myocardium ultrastructure, Neovascularization, Physiologic, Rats, Rats, Inbred Lew, Ventricular Pressure, Bone Marrow Transplantation, Cardiomyopathy, Dilated surgery
- Abstract
Background: Cell transplantation is a promising therapy for treating end-stage heart failure. Bone marrow mononuclear cells (BMMNC) have been used to enhance angiogenesis in ischemic heart disease. However, the effect of BMMNC transplantation in non-ischemic dilated cardiomyopathy is unknown. In this study, we evaluated the efficacy of BMMNC transplantation in doxorubicin-induced cardiomyopathy in a rat model., Methods: Doxorubicin (15 mg/kg, IP) was introduced into 52 Lewis rats. They were divided into 3 groups at 4 weeks after injection: transplant group (TX, BMMNC [1 x 10(6)] implantation, n = 18), control group (CN, saline injection, n = 18), and sham group (SH, thoracotomy, n = 16). At 4 weeks after surgery, we used echocardiography to measure systolic left ventricular diameter (LVDs), diastolic left ventricular diameter (LVDd), fractional shortening (FS), and left ventricular wall thickness/LVDs. We used a Langendorff apparatus to measure systolic, diastolic, and developed pressures. We used radioimmunoassay to measure circulating atrial natriuretic peptide concentration, and we performed histologic study, including electron-microscopic study., Results: Left ventricular wall thickness/LVDs in the TX group was the largest of all groups (p < 0.05). Systolic and developed pressures in the TX group were the greatest (p < 0.005). Systolic left ventricular diameter, FS, and end-diastolic pressure in the TX group were smaller than in the SH group (p < 0.05). These cardiac parameters did not differ significantly between TX and CN groups, but secondary changes (decreased heart weight, developed ascites, and increased atrial natriuretic peptide concentration) caused by doxorubicin-induced heart failure were most attenuated in the TX group. In the TX group, vascular density was greatest (p < 0.05) in the left ventricular free wall and in the septum. In addition, electron microscopy showed that myocardium in the TX group was most maintained., Conclusion: Bone marrow mononuclear cell transplantation had beneficial effects in doxorubicin-induced cardiomyopathy.
- Published
- 2004
- Full Text
- View/download PDF
8. Interrupted aortic arch with ventricular septal defect: an unsuspected fatal congenital anomaly in forensic pathology.
- Author
-
Ng'walali PM, Ohtsu Y, and Tsunenari S
- Abstract
Interrupted aortic arch (IAA) is a relatively rare cardiovascular anomaly worldwide and is very rarely encountered in forensic pathology. A case of clinically unsuspected fatal IAA in a 5-day old neonate is described. A full term female baby was declared dead on arrival at an emergency hospital few hours after having been discharged from a maternity hospital following delivery. There were no noticeable signs and symptoms reported during the short postnatal period. Antenatal medical history was unremarkable and there were no abnormalities noticed at birth. Autopsy revealed an unsuspected IAA arch with ventricular septal defect (VSD) as cause of sudden unexpected death. Although amenable to surgical intervention, IAA may not produce obvious clinical symptoms as was the case for this baby. Such sudden unexpected deaths raise medico-legal questions as to the manner and the precise cause of death. The importance of a full forensic autopsy to clarify such a sudden death was re-emphasized.
- Published
- 2002
- Full Text
- View/download PDF
9. Death as a result of heat stroke in a vehicle: an adult case in winter confirmed with reconstruction and animal experiments.
- Author
-
Ng'walali PM, Kibayashi K, Yonemitsu K, Ohtsu Y, and Tsunenari S
- Abstract
A 54-year-old man was found dead in the driver's seat of his vehicle on a winter's day. Investigations of the vehicle revealed that the engine was running, and the car heater was left on with the maximum temperature and velocity. The body was found excessively sweating. Rectal temperature of the body was 43 degrees C at 10 h post mortem. In autopsy, several superficial skin burns were observed on the face, the shoulders and the legs. The lungs were heavily congested and hemorrhagic. The liver showed typical alcohol-induced micronodular cirrhosis. The alcohol concentrations were 0.17% in the blood of both the left and the right heart, 0.17% in the femoral-vein blood, 0.21% in the bladder urine and 0.34% in the gastric contents. A reconstruction experiment demonstrated that the temperature inside the vehicle rose rapidly and reached 50-58 degrees C in 3 h. Animal experiments showed that the temperature threshold for rats to succumb to heat was between 40 and 45 degrees C. This case shows that heat stroke in a vehicle can occur in adults with chronic diseases or alcoholism, such as in this particular case, even in the winter.
- Published
- 1998
- Full Text
- View/download PDF
10. Synthesis and characterization of polymer-coated mixed-functional stationary phases with several different hydrophobic groups for direct analysis of biological samples by liquid chromatography.
- Author
-
Kanda T, Shirota O, Ohtsu Y, and Yamaguchi M
- Subjects
- Anti-Bacterial Agents blood, Anticonvulsants blood, Blood Proteins isolation & purification, Humans, Indicators and Reagents, Polyethylene Glycols, Spectrophotometry, Ultraviolet, Xanthines blood, Chromatography, High Pressure Liquid instrumentation, Polymers chemistry, Silicon Dioxide chemistry
- Abstract
Three types of polymer-coated mixed-functional (PCMF) silica column-packing materials for the direct analysis of biological liquids have been synthesized. These packing materials all have polyoxyethylene groups as their hydrophilic part but differ in their hydrophobic part (methyl groups for Me-POE, phenyl groups for Ph-POE, and octyl groups for Oc-POE). Retention characteristics with respect to several drug molecules, and protein recovery, were studied for each of the three types with different amounts of hydrophobic groups attached. Of the PCMFs prepared, Oc-POE showed the greatest overall retention, and Me-POE displayed the greatest protein recovery.
- Published
- 1996
- Full Text
- View/download PDF
11. Synthesis of polymer-coated mixed-functional packing materials for direct analysis of drug-containing serum and plasma by high-performance liquid chromatography.
- Author
-
Kanda T, Kutsuna H, Ohtsu Y, and Yamaguchi M
- Subjects
- Humans, Carbamazepine blood, Chromatography, High Pressure Liquid instrumentation, Chromatography, High Pressure Liquid methods, Phenobarbital blood, Phenytoin blood, Polymers, Silicon Dioxide
- Abstract
Silicone polymer-coated mixed-functional (PCMF) silica packing materials were developed for the direct determination of drugs contained in serum or plasma. The new stationary phases were prepared by the following three-step procedure: (1) coating porous silica with a silicone polymer; (2) partial introduction of hydrophobic groups; and (3) introduction of hydrophilic groups. Two PCMFs were synthesized, one having polyoxyethylene groups as hydrophilic groups (PCMF-POE) and the other having oligoglyceryl groups (PCMF-OG). PCMF-POE showed higher recoveries for injected proteins and a greater overall retention for drug molecules than PCMF-OG. PCMF-POE did not show any column deterioration in 500 serum sample injections (10 ml in total).
- Published
- 1994
- Full Text
- View/download PDF
12. Performance of wide-pore silica- and polymer-based packing materials in polypeptide separation: effect of pore size and alkyl chain length.
- Author
-
Tanaka N, Kimata K, Mikawa Y, Hosoya K, Araki T, Ohtsu Y, Shiojima Y, Tsuboi R, and Tsuchiya H
- Subjects
- Acetonitriles, Alkylation, Gels, Molecular Weight, Porosity, Chromatography, Liquid methods, Peptides analysis, Polymers, Silicon Dioxide
- Abstract
The effects of pore size and alkyl chain length of silica- and polymer-based packing materials in the elution of polypeptides with an acetonitrile gradient in the presence of trifluoroacetic acid were studied. Considerable differences were found in the performance of alkylsilylated phases prepared from various wide-pore silica particles assumed to have 30-50-nm pores. The pore size of such silica gels was found to be the critical factor in determining the efficiency for high-molecular-weight polypeptides. Silica C18 phases having small pore volumes below 20 nm pore diameter showed comparable performances to C4 and C8 phases for polypeptides with molecular weights of up to 80,000, and were more stable. Polymer-based packing materials with adequate pore size provided excellent column efficiencies and recoveries for polypeptides with higher chemical stabilities than silica-based materials.
- Published
- 1990
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.