45 results on '"Iguchi D"'
Search Results
2. Characteristics of Self-scanning Addressable VCSEL array for Time of Flight
- Author
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Kondo, T., primary, Hayakawa, J., additional, Murata, M., additional, Iguchi, D., additional, Sakita, T., additional, Higuchi, T., additional, Takeyama, K., additional, Ohno, S., additional, and Usami, H., additional
- Published
- 2022
- Full Text
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3. Low-temperature specific heat of the [formula omitted] oxide superconductors under high pressure
- Author
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Isono, T., Iguchi, D., Machida, Y., Izawa, K., Salce, B., Flouquet, J., Ogusu, H., Yamaura, J., and Hiroi, Z.
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- 2011
- Full Text
- View/download PDF
4. Swirling Jet Mixing of a Bath Covered With a Top Slag Layer
- Author
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Iguchi, M., Sasaki, Y., Iguchi, D., Ohmi, T., and Gdoutos, E. E., editor
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- 2007
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5. Management of Two Brazilian Cases of Gorham-Stout Disease.
- Author
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Iguchi, D, primary, Aranha, DVS, additional, Martin, RM, additional, and Correa, PHS, additional
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- 2010
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6. Type B Insulin Resistance Syndrome: Hyperglycemia Switching to Hypoglycemia – Case Report.
- Author
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Melo, PM, primary, Iguchi, D, additional, and Pereira, MAA, additional
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- 2010
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7. Severe Osteomalacia Induced by Biliopancreatic Diversion.
- Author
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Perez, RV, primary, Iguchi, D, additional, Jorgetti, V, additional, Martin, RM, additional, Correa, PHS, additional, Cercato, C, additional, Mancini, MC, additional, and Halpern, A, additional
- Published
- 2010
- Full Text
- View/download PDF
8. Low temperature specific heat of the β-pyrochlore superconductors under high pressure
- Author
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Isono, T., Iguchi, D., Machida, Y., Izawa, K., Salce, B., Flouquet, J., Ogusu, H., Yamaura, J., and Hiroi, Z.
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- 2010
- Full Text
- View/download PDF
9. Pressure Dependence of Upper Critical Field in β-Pyrochlore Oxides
- Author
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Iguchi, D., primary, Isono, T., additional, Machida, Y., additional, Izawa, K., additional, Salce, B., additional, Flouquet, J., additional, Ogusu, H., additional, Yamaura, J., additional, and Hiroi, Z., additional
- Published
- 2011
- Full Text
- View/download PDF
10. Pressure effect on the superconductivity ofβ-pyrochlore oxides
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Isono, T, primary, Iguchi, D, additional, Machida, Y, additional, Izawa, K, additional, Salce, B, additional, Flouquet, J, additional, Ogusu, H, additional, Yamaura, J, additional, and Hiroi, Z, additional
- Published
- 2011
- Full Text
- View/download PDF
11. Low-temperature specific heat of the β-pyrochlore oxide superconductors under high pressure
- Author
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Isono, T., primary, Iguchi, D., additional, Machida, Y., additional, Izawa, K., additional, Salce, B., additional, Flouquet, J., additional, Ogusu, H., additional, Yamaura, J., additional, and Hiroi, Z., additional
- Published
- 2011
- Full Text
- View/download PDF
12. A feasibility study of proximity interconnect technology utilizing transmission line coupling.
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Iguchi, D., Akiyama, Y., Fujii, F., and Otsuka, K.
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- 2010
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13. Proximity interconnect technology utilizing transmission line coupling for Stacked VLSI chips.
- Author
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Iguchi, D., Akiyama, Y., Ito, T., and Otsuka, K.
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- 2008
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14. A chip stacking technology utilizing transmission line coupling.
- Author
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Iguchi, D., Akiyama, Y., Ito, T., and Otsuka, K.
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- 2008
- Full Text
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15. Simulation for reduction effect on electromagnetic noise radiation using board-edge capacitors.
- Author
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Arakaki, H., Iguchi, D., and Ueno, O.
- Published
- 1999
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16. Reduction of electromagnetic radiation from power and ground layers using capacitors.
- Author
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Iguchi, D., Arakaki, H., and Ueno, O.
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- 1999
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17. 10ms direct seeking of 90mm magneto-optical disk with flying optical head
- Author
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Yasukawa, K., primary, Iguchi, D., additional, Yamaguchi, S., additional, Murakami, A., additional, Nomiyama, T., additional, Takahashi, K., additional, and Ueyanagi, K., additional
- Published
- 1991
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18. Mucosal regeneration of gastric ulcer confirmed by electronic endoscopy.
- Author
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Hoshihara, Y, Hashimoto, M, Yamamoto, T, Tanaka, T, Iguchi, D, Kimura, T, Sugawara, K, Fukuchi, S, and Takemoto, T
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- 1995
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19. Effects of lansoprazole on mucosal regeneration in patients with gastric ulcers: evaluation using an electronic endoscope with a magnifying function.
- Author
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Hashimoto, M, Hoshihara, Y, Yamamoto, T, Tanaka, T, Kimura, T, Iguchi, D, Sugawara, K, Fukuchi, S, and Takemoto, T
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- 1995
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20. Three-dimensional noise current distribution on power and ground planes in printed circuit boards
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Ueno, O., primary, Iguchi, D., additional, Arakaki, H., additional, Ito, H., additional, and Ozawa, T., additional
- Full Text
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21. Swirling Jet Mixing of a Bath Covered With a Top Slag Layer.
- Author
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Gdoutos, E. E., Iguchi, M., Sasaki, Y., Iguchi, D., and Ohmi, T.
- Abstract
Mixing of a bath by gas injection is widely used in many engineering fields. In particular, molten iron and steel baths are commonly agitated by Ar gas injection for homogenizing temperature and components and for removing non-metallic inclusions and impurities from molten steel1). In recent years it also finds its applications to parlor wastewater and sludge treatments2). [ABSTRACT FROM AUTHOR]
- Published
- 2007
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22. Pressure effect on the superconductivity of β-pyrochlore oxides.
- Author
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Isono, T., Iguchi, D., Machida, Y., Izawa, K., Salce, B., Flouquet, J., Ogusu, H., Yamaura, J., and Hiroi, Z.
- Published
- 2011
- Full Text
- View/download PDF
23. Three-dimensional noise current distribution on power and ground planes in printed circuit boards.
- Author
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Ueno, O., Iguchi, D., Arakaki, H., Ito, H., and Ozawa, T.
- Published
- 1998
- Full Text
- View/download PDF
24. Infective Endocarditis With Origin in Orbital Vascular Malformation and Maxillary Sinusitis: A Case Report and Review of Four Patients in the Literature.
- Author
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Matsuo T, Iwamoto Y, Okamoto H, and Iguchi D
- Abstract
Infective endocarditis is a life-threatening disease and the early diagnosis is crucial for a better outcome. We report an old adult who developed infective endocarditis in association with new-onset maxillary sinusitis as well as proptosis, which was caused by an orbital mass lesion in the background of pre-existing orbital vascular malformation. A 74-year-old woman was found incidentally to have right orbital vascular (venous) malformation by head magnetic resonance imaging when she was hospitalized for left dorsal pontine infarction. No paranasal sinusitis was noted at that time. She was well until half a year later when she developed fatigue and appetite loss for two days. At the same time, she had proptosis on the right side but did not have a fever. Blood examinations showed leukocytosis and a marked increase of C-reactive protein to 22 mg/dL as well as a moderate increase of bilirubin and liver enzymes. Emergency computed tomography scans from the head to abdomen showed nothing to be noted except for maxillary sinusitis and a retrobulbar orbital mass on the right side, which was in the same location as pre-existing vascular malformation. She began to have empirical antibiotics suspected of infective endocarditis. Head magnetic resonance imaging showed ischemic lesions in the right parietal lobe. Transthoracic and transesophageal echocardiography showed mitral valve regurgitation but no apparent vegetation. Streptococcus anginosus was detected by blood culture and the antibiotics were switched to intravenous penicillin G for 32 days. She was discharged in healthy condition with no proptosis. The orbital vascular malformation might serve as a route for infective endocarditis with the infectious origin in maxillary sinusitis. Maxillary sinusitis would be a predisposing factor for the development of infective endocarditis, and proptosis caused by an infectious focus of abnormal vascular channels in the orbit would lead to the early diagnosis of infective endocarditis. The present patient is unique in showing infective endocarditis in association with orbital vascular malformation., Competing Interests: Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Matsuo et al.)
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- 2024
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25. Bottom-up butterfly model with thorax-pitch control and wing-pitch flexibility.
- Author
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Suzuki K, Iguchi D, Ishizaki K, and Yoshino M
- Subjects
- Animals, Biomechanical Phenomena, Wings, Animal physiology, Wings, Animal anatomy & histology, Butterflies physiology, Butterflies anatomy & histology, Flight, Animal physiology, Models, Biological, Thorax physiology, Computer Simulation
- Abstract
The diversity in butterfly morphology has attracted many people around the world since ancient times. Despite morphological diversity, the wing and body kinematics of butterflies have several common features. In the present study, we constructed a bottom-up butterfly model, whose morphology and kinematics are simplified while preserving the important features of butterflies. The present bottom-up butterfly model is composed of two trapezoidal wings and a rod-shaped body with a thorax and abdomen. Its wings are flapped downward in the downstroke and backward in the upstroke by changing the geometric angle of attack (AOA). The geometric AOA is determined by the thorax-pitch and wing-pitch angles. The thorax-pitch angle is actively controlled by abdominal undulation, and the wing-pitch angle is passively determined because of a rotary spring representing the basalar and subalar muscles connecting the wings and thorax. We investigated the effectiveness of abdominal undulation for thorax-pitch control and how wing-pitch flexibility affects aerodynamic-force generation and thorax-pitch control, through numerical simulations using the immersed boundary-lattice Boltzmann method. As a result, the thorax-pitch angle perfectly follows the desired angle through abdominal undulation. In addition, there is an optimal wing-pitch flexibility that maximizes the flying speed in both the forward and upward directions, but the effect of wing-pitch flexibility on thorax-pitch control is not significant. Finally, we compared the flight behavior of the present bottom-up butterfly model with that of an actual butterfly. It was found that the present model does not reproduce reasonable body kinematics but can provide reasonable aerodynamics in butterfly flights., (© 2024 IOP Publishing Ltd.)
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- 2024
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26. Rare Combination of Abducens Nerve Palsy and Optic Neuritis on the Same Side: Case Report and Review of 8 Patients in Literature.
- Author
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Matsuo T and Iguchi D
- Subjects
- Aged, 80 and over, Humans, Male, COVID-19 Vaccines, Herpesvirus 3, Human, Abducens Nerve Diseases etiology, Abducens Nerve Diseases diagnosis, Herpes Zoster complications, Optic Neuritis etiology
- Abstract
The concurrent development of abducens nerve palsy and optic neuritis on the same side is rare. Here we presented an 82-year-old man who developed the combination of abducens nerve palsy and optic neuritis on the left side 2 months after the sixth inoculation of COVID-19 mRNA vaccine. In past history at 45 years old, he experienced subarachnoid hemorrhage and underwent surgery for the clipping of intracranial aneurysm. The patient had no systemic symptoms, such as general fatigue, fever, arthralgia, and skin rashes. Physical and neurological examinations were also unremarkable. Since the aneurysmal metal clip used at that time was not compatible with magnetic resonance imaging, he underwent computed tomographic (CT) scan of the head and showed no space-occupying lesion in the orbit, paranasal sinuses, and brain. As an old lesion, the anterior temporal lobe on the left side had low-density area with metallic artifact on the left side of the skull base, indicative of metal clipping. In 4 weeks of observation from the initial visit, he showed complete recovery of visual acuity and became capable of abducting the left eye in full degrees. We also reviewed 8 patients with the combination of abducens nerve palsy and optic neuritis in the literature to reveal that the combination of signs did occur in mild meningitis with rare infectious diseases and in association with preceding herpes zoster in the first branch of the trigeminal nerve. The course of the present patient suggested that the combination of signs might be vaccine-associated., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
- Published
- 2024
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27. Light Chain Deposition Disease Recurrence in Renal Allograft after Long-Term Remission.
- Author
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Kobayashi A, Takeda A, Shinjo H, Iguchi D, Ito C, Okada E, Goto N, Futamura K, Okada M, Hiramitsu T, Narumi S, and Watarai Y
- Subjects
- Female, Humans, Middle Aged, Kidney physiology, Kidney pathology, Immunoglobulin Light Chains, Allografts pathology, Kidney Transplantation, Multiple Myeloma pathology, Multiple Myeloma therapy, Paraproteinemias pathology
- Abstract
Light chain deposition disease (LCDD) is a rare manifestation of monoclonal gammopathy, which can lead to renal failure. We previously reported a detailed recurrence process in a case of LCDD after renal transplantation. To the best of our knowledge, no report has described the long-term clinical course and renal pathology findings of recurrent LCDD in patients after renal transplantation. In this case report, we describe the long-term clinical presentation and changes in renal pathology of the same patient after early LCDD relapse in a renal allograft. A 54-year-old woman with recurrent immunoglobulin A λ-type LCDD in an allograft was admitted 1 year post-transplant for bortezomib and dexamethasone therapy. At 2 years post-transplantation, a graft biopsy performed after complete remission was achieved, showing some glomeruli with residual nodular lesions similar to the pre-treatment renal biopsy findings. However, the enlarged subendothelial space disappeared. She remained in complete remission serologically for 6 years. Subsequently, the ratio of serum κ/λ-free light chains decreased gradually. She underwent a transplant biopsy approximately 12 years after renal transplantation due to increased proteinuria and decreased renal function. Compared with the previous graft biopsy, almost all glomeruli showed advanced nodule formation and subendothelial expansion. Because the LCDD case relapsed after long-term remission following renal transplantation, protocol biopsy monitoring might be necessary., (© 2023 S. Karger AG, Basel.)
- Published
- 2023
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28. Long-term peritoneal dialysate exposure modulates expression of membrane complement regulators in human peritoneal mesothelial cells.
- Author
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Kobayashi K, Ozeki T, Kim H, Imai M, Kojima H, Iguchi D, Fukui S, Suzuki M, Suzuki Y, Maruyama S, Ito Y, and Mizuno M
- Abstract
The membrane complement regulators (CRegs) CD46, CD55, and CD59 are highly expressed on human peritoneal mesothelial cells. However, how mesothelial CRegs change according to the peritoneal dialysis (PD) history of patients has remained unclear. We therefore examined longitudinal changes in CRegs in primary cultured mesothelial cells from PD patients (human peritoneal mesothelial cells; HPMCs) and examined which components of PD fluid (PDF) affect CRegs in vitro . We measured levels of soluble C5b-9 in overnight-dwelling PDF in PD patients and also evaluated changes in CRegs expression on HPMCs collected from PDF using flow cytometry and polymerase chain reaction at a 1-year interval of PD therapy. We also evaluated changes in CReg expressions with stimulation by each component of PDF (glucose, lactic acid and pH) using the Met5A human mesothelial cell line. Levels of sC5b-9 in PDF decreased significantly during 1 year, while expressions of CD46 and CD59 proteins and mRNAs increased significantly in HPMCs during 1 year. Analyzing Met-5A cells, we observed that expressions of the three CRegs were increased by glucose and lactic acid in a concentration-dependent manner, but conversely that expressions of CRegs were decreased by lower pH stimulation. History of PD might influence expression of CRegs by HPMCs through properties of PDF such as glucose, lactic acid, and pH. These results suggest that mesothelial cells may alter expression of CRegs for the purpose of protecting the peritoneum and the presence of PDF might affect peritoneal homeostasis associated with the complement system., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Kobayashi, Ozeki, Kim, Imai, Kojima, Iguchi, Fukui, Suzuki, Suzuki, Maruyama, Ito and Mizuno.)
- Published
- 2022
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29. Two-year outcomes of tirabrutinib monotherapy in Waldenström's macroglobulinemia.
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Sekiguchi N, Rai S, Munakata W, Suzuki K, Handa H, Shibayama H, Endo T, Terui Y, Iwaki N, Fukuhara N, Tatetsu H, Iida S, Ishikawa T, Iguchi D, and Izutsu K
- Subjects
- Humans, Imidazoles therapeutic use, Pyrimidines, Quality of Life, Waldenstrom Macroglobulinemia drug therapy
- Abstract
The phase II study of tirabrutinib monotherapy at a daily dose of 480 mg under fasting conditions for treatment-naïve and relapsed/refractory Waldenström's macroglobulinemia (ONO-4059-05 study) demonstrated a promising efficacy and tolerable safety profile. We conducted an unplanned analysis with a median follow-up of 24.8 months to update the efficacy and safety results and to report patient-reported quality of life. Of 27 enrolled patients, 22 patients continued receiving the study drug. The major response assessed by an independent review committee was observed in 25 patients (93%), including one and five patients who newly achieved complete response and very good partial response, respectively, after the primary analysis. The progression-free and overall survival rates at 24 months were 92.6% and 100%, respectively. Serum IgM levels in all patients except one declined and were maintained at low levels, although transient increases occurred after temporal interruption of the study drug. The disease-related symptoms including recurrent fever and hyperviscosity mostly disappeared. Health-related quality of life, assessed by cancer-specific questionnaires, was mostly maintained. Grade 3-4 neutropenia, lymphopenia, and leukopenia were newly recognized in three, two, and one patient, respectively. Grade 3 treatment-related hypertriglyceridemia was also recognized. Nine patients experienced grade 1-2 bleeding events (33%), one patient experienced grade 2 treatment-related atrial fibrillation, and one patient experienced grade 1 treatment-related hypertension. Treatment-related skin adverse events were observed in 14 patients (52%). Taken together, tirabrutinib has durable efficacy with an acceptable safety profile for treatment-naïve and refractory/relapsed Waldenström's macroglobulinemia., (© 2022 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)
- Published
- 2022
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30. C1 inhibitor mitigates peritoneal injury in zymosan-induced peritonitis.
- Author
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Ozeki T, Mizuno M, Iguchi D, Kojima H, Kim H, Suzuki Y, Kinashi H, Ishimoto T, Maruyama S, and Ito Y
- Subjects
- Animals, Epithelial Cells, Epithelium, Fibrin metabolism, Fibrinogen metabolism, Male, Peritoneum cytology, Peritoneum pathology, Rats, Rats, Sprague-Dawley, Complement C1 Inhibitor Protein therapeutic use, Peritoneum drug effects, Peritonitis chemically induced, Zymosan toxicity
- Abstract
Peritonitis, due to a fungal or bacterial infection, leads to injury of the peritoneal lining and thereby forms a hazard for the long-term success of peritoneal dialysis (PD) and remains a lethal complication in patients with PD. This study investigated whether C1 inhibitor (C1-INH) could protect against the progression of peritoneal injuries with five daily administrations of zymosan after mechanical scraping of the rat peritoneum to mimic fungal peritonitis. Severe peritoneal injuries were seen in this model, accompanied by fibrinogen/fibrin exudation and peritoneal deposition of complement activation products such as activated C3 and C5b-9. However, intraperitoneal injection of C1-INH decreased peritoneal depositions of activated C3 and C5b-9, ameliorated peritoneal thickening, reduced the influx of inflammatory cells, and prevented the production of peritoneal fibrous layers with both one and two doses of C1-INH each day. Our results suggest that C1-INH might be useful to protect against peritoneal injuries after causes of peritonitis such as fungal infection. This clinically available agent may thus help extend the duration of PD. NEW & NOTEWORTHY Peritoneal injuries associated with peritonitis comprise an important issue to prevent long-term peritoneal dialysis (PD) therapy. Here, we showed that C1 inhibitor (C1-INH), as an anticomplement agent, protected against peritoneal injuries in a peritonitis animal model related to fungal infection. Therefore, C1-INH might be useful to protect against peritoneal injuries after peritonitis due to fungal infection. This clinically available agent may thus help extend the duration of PD.
- Published
- 2021
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31. Impact of glucagon like peptide-1 receptor agonist and sodium glucose cotransporter 2 inhibitors on type 2 diabetes patients with renal impairment.
- Author
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Hiramatsu T, Ito H, Okumura S, Asano Y, Iguchi D, and Furuta S
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- Aged, Albuminuria diagnosis, Albuminuria etiology, Albuminuria physiopathology, Benzhydryl Compounds adverse effects, Blood Glucose drug effects, Blood Glucose metabolism, Blood Pressure drug effects, Diabetes Mellitus, Type 2 complications, Diabetes Mellitus, Type 2 diagnosis, Diabetes Mellitus, Type 2 physiopathology, Diabetic Nephropathies diagnosis, Diabetic Nephropathies etiology, Diabetic Nephropathies physiopathology, Female, Glomerular Filtration Rate drug effects, Glucosides adverse effects, Humans, Incretins adverse effects, Kidney physiopathology, Liraglutide adverse effects, Male, Middle Aged, Prospective Studies, Sodium-Glucose Transporter 2 Inhibitors adverse effects, Time Factors, Treatment Outcome, Vascular Stiffness drug effects, Ventricular Function, Left drug effects, Albuminuria drug therapy, Benzhydryl Compounds therapeutic use, Diabetes Mellitus, Type 2 drug therapy, Diabetic Nephropathies drug therapy, Glucosides therapeutic use, Incretins therapeutic use, Kidney drug effects, Liraglutide therapeutic use, Sodium-Glucose Transporter 2 Inhibitors therapeutic use, Glucagon-Like Peptide-1 Receptor Agonists
- Abstract
Introduction: Diabetes mellitus is a progressive disease with cardiovascular complications. We evaluated the impact of a glucagon like peptide-1 (GLP-1) receptor agonist and sodium glucose cotransporter 2 (SGLT-2) inhibitors dapagliflozin and empagliflozin on renal and cardiac function in type 2 diabetes patients with renal impairment., Materials and Methods: A total of 156 patients referred with suboptimal glycemic control were assigned to Group G (GLP-1): n = 72 or Group S (SGLT-2 inhibitor)-dapagliflozin ( n = 52) or empagliflozin ( n = 32). Renal function was assessed every 3 months for 36 months. Cardiovascular parameters were evaluated every 12 months for 36 months., Results: Compared with baseline, HbA1c and systolic blood pressure significantly decreased in both groups ( p < 0.05). The estimated glomerular filtration rate decreased, but without significance. Albuminuria decreased significantly in both groups and then subsequently increased after 30 months in Group S. Diastolic cardiac function, assessed by E/e' or left atrial volume index, decreased only in Group G at 36 months., Conclusions: The GLP-1 receptor agonist and SGLT-2 inhibitors were effective for glycemic and blood pressure control and for maintaining renal function. The GLP-1 receptor agonist improved diastolic function at 36 months.
- Published
- 2020
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32. Quality of Life and Emotional Distress in Peritoneal Dialysis and Hemodialysis Patients.
- Author
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Hiramatsu T, Okumura S, Asano Y, Mabuchi M, Iguchi D, and Furuta S
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- Aged, Aged, 80 and over, Cognitive Dysfunction epidemiology, Comorbidity, Depressive Disorder epidemiology, Female, Humans, Japan epidemiology, Male, Middle Aged, Peritoneal Dialysis psychology, Prospective Studies, Kidney Failure, Chronic psychology, Kidney Failure, Chronic therapy, Psychological Distress, Quality of Life psychology, Renal Dialysis methods, Renal Dialysis psychology
- Abstract
Cardiovascular disease-associated morbidity and mortality are reportedly higher in hemodialysis (HD) patients compared with peritoneal dialysis (PD) patients. However, few studies have estimated changes in state of depression and cognitive impairment in patients undergoing HD and PD. The present study evaluated the impact of HD or PD on patients' quality of life (QoL), cognitive impairment, and depression status over 2 years. This 24-month observational, prospective study included 45 HD and 30 PD patients. Patients were assessed before and every 12 months after starting dialysis for 24 months. Measurements included QoL (36-Item Short-Form Health Survey [SF-36]), cognitive impairment (Mini-Mental State Examination [MMSE]), depressive state (Center for Epidemiologic Studies Depression Scale [CES-D]), grip strength, and 24-h urine volume (UV). Physical and social component scores of the SF-36 significantly improved in PD patients at 24 months compared with those observed at baseline (42.8 vs. 39.4; P < 0.05 and 46.4 vs. 37.3; P < 0.05, respectively); however, scores remained unchanged in HD patients. MMSE scores were significantly decreased at 12 and 24 months in HD patients (29.0 vs. 26.0, 25.0; P < 0.05), but remained unchanged in PD patients. Moreover, CES-D scores significantly worsened at 24 months in HD patients (12.8 vs. 16.5), but remained unchanged in PD. Preservation of UV and grip strength was associated with SF-36, CES-D, and MMSE scores. Our findings indicate that PD is associated with higher QoL and recovery from cognitive failure compared with HD., (© 2019 International Society for Apheresis, Japanese Society for Apheresis, and Japanese Society for Dialysis Therapy.)
- Published
- 2020
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33. Design and Effects of the Cinnamic Acids Chemical Structures as Organocatalyst on the Polymerization of Benzoxazines.
- Author
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Rodríguez RB, Iguchi D, Erra-Balsells R, Salum ML, and Froimowicz P
- Abstract
This study focuses on the catalytic effect of the two geometric isomers of a cinnamic acid derivative, E and Z -forms of 3-methoxycinnamic acid (3OMeCA), analyzing the influence of their chemical structures. E and Z -3OMeCA isomers show very good catalytic effect in the polymerization of benzoxazines, decreasing by 40 and 55 °C, respectively, the polymerization temperatures, for catalyst contents of up to 10% w/w. Isothermal polymerizations show that polymerizations are easily realized and analyzed at temperatures as low as 130 °C and at much shorter times using Z -3OMeCA instead of E -3OMeCA. Thus, both cinnamic acids are good catalysts, with Z -3OMeCA being better. The molecular reasons for this difference and mechanistic implications in benzoxazine polymerizations are also presented.
- Published
- 2020
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34. Substituent Effects on NMR Spectroscopy of 2,2-Dimethylchroman-4-one Derivatives: Experimental and Theoretical Studies.
- Author
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Iguchi D, Ravelli D, Erra-Balsells R, and Bonesi SM
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- Algorithms, Carbon chemistry, Chromones analysis, Electrons, Hydrogen, Linear Models, Normal Distribution, Software, Spectrophotometry, Carbon Isotopes analysis, Chemistry methods, Chromones chemical synthesis, Magnetic Resonance Spectroscopy methods
- Abstract
The attribution of
1 H and13 C NMR signals of a library of 5-, 6- and 7-substituted 2,2-dimethylchroman-4-one derivatives is reported. Substituent effects were interpreted in terms of the Hammett equation, showing a good correlation for carbons para - to the substituent group, not for the meta - ones. Similarly, the Lynch correlation shows the additivity of the substituent chemical shifts in the case of both H and C nuclei, again with the exception of the carbons in the meta - position. Density Functional Theory (DFT)-predicted1 H and13 C chemical shifts correspond closely with experimentally observed values, with some exceptions for C NMR data; however, the correlation is valid only for the aromatic moiety and cannot be extended to the heterocyclic ring of the chroman-4-one scaffold.- Published
- 2020
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35. Anti-C5a complementary peptide mitigates zymosan-induced severe peritonitis with fibrotic encapsulation in rats pretreated with methylglyoxal.
- Author
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Iguchi D, Mizuno M, Suzuki Y, Sakata F, Maruyama S, Okada A, Okada H, and Ito Y
- Subjects
- Animals, Complement C5a immunology, Disease Models, Animal, Disease Progression, Male, Peritoneal Fibrosis chemically induced, Peritoneal Fibrosis immunology, Peritoneal Fibrosis pathology, Peritoneum immunology, Peritoneum pathology, Peritonitis chemically induced, Peritonitis immunology, Peritonitis metabolism, Peritonitis pathology, Rats, Sprague-Dawley, Severity of Illness Index, Signal Transduction drug effects, Time Factors, Complement Activation drug effects, Complement C5a antagonists & inhibitors, Complement Inactivating Agents pharmacology, Peritoneal Fibrosis prevention & control, Peritoneum drug effects, Pyruvaldehyde, Zymosan
- Abstract
In a previous study of fungal peritoneal injury in peritoneal dialysis patients, complement (C)-dependent pathological changes were developed in zymosan (Zy)-induced peritonitis by peritoneal scraping. However, the injuries were limited to the parietal peritoneum and did not show any fibrous encapsulation of the visceral peritoneum, which differs from human encapsular peritoneal sclerosis (EPS). We investigated peritoneal injury in a rat model of Zy-induced peritonitis pretreated with methylglyoxal (MGO) instead of scraping (Zy/MGO peritonitis) to clarify the role of C in the process of fibrous encapsulation of the visceral peritoneum. Therapeutic effects of an anti-C5a complementary peptide, AcPepA, on peritonitis were also studied. In Zy/MGO peritonitis, peritoneal thickness, fibrin exudation, accumulation of inflammatory cells, and deposition of C3b and C5b-9 with loss of membrane C regulators were increased along the peritoneum until day 5. On day 14, fibrous encapsulation of the visceral peritoneum was observed, resembling human EPS. Peritoneal injuries and fibrous changes were significantly improved with AcPepA treatment, even when AcPepA was administered following injection of Zy in Zy/MGO peritonitis. The data show that C5a might play a role in the development of encapsulation-like changes in the visceral peritoneum in Zy/MGO peritonitis. AcPepA might have therapeutic effects in fungal infection-induced peritoneal injury by preventing subsequent development of peritoneal encapsulation.
- Published
- 2018
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36. Liraglutide relieves cardiac dilated function than DPP-4 inhibitors.
- Author
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Hiramatsu T, Asano Y, Mabuchi M, Imai K, Iguchi D, and Furuta S
- Subjects
- Aged, Aged, 80 and over, Biomarkers metabolism, Blood Glucose metabolism, C-Reactive Protein metabolism, Cardiomyopathy, Dilated blood, Cardiomyopathy, Dilated physiopathology, Diabetes Mellitus, Type 2 blood, Diabetes Mellitus, Type 2 physiopathology, Diabetic Cardiomyopathies blood, Diabetic Cardiomyopathies physiopathology, Female, Glomerular Filtration Rate physiology, Glycated Hemoglobin metabolism, Humans, Male, Middle Aged, Prospective Studies, Treatment Outcome, Ventricular Dysfunction, Left blood, Ventricular Dysfunction, Left physiopathology, Cardiomyopathy, Dilated drug therapy, Diabetes Mellitus, Type 2 drug therapy, Diabetic Cardiomyopathies drug therapy, Dipeptidyl-Peptidase IV Inhibitors therapeutic use, Hypoglycemic Agents therapeutic use, Liraglutide therapeutic use
- Abstract
Introduction: Diabetes mellitus is a progressive disease with cardiovascular complications. This study evaluated the effects of liraglutide, a glucagon-like peptide-1 analogue and the dipeptidyl peptidase 4 inhibitors sitagliptin and linagliptin on cardiac function in type 2 diabetes patients with renal impairment., Materials and Methods: A total of 139 patients who were referred because of suboptimal glycaemic control were randomly assigned to liraglutide 0.9 mg/d (n = 45), sitagliptin 50 mg/d, (n = 49) or linagliptin 5 mg/d (n = 45) at enrolment and were evaluated. Blood glucose, glycosylated haemoglobin and serum creatinine were assayed every 3 months for 48 months. Echocardiography was performed every 12 months for 48 months., Results: Compared with baseline, fasting glucose, postprandial glucose, and systolic and diastolic pressure, but not estimated glomerular filtration rate, significantly decreased in all three groups. Albuminuria decreased from 24 to 48 months with liraglutide, but only from 24 to 30 months with sitagliptin and linagliptin. Diastolic function, assessed by E/e' or left atrial dimension improved only with liraglutide., Conclusions: Liraglutide was effective for glucose and blood pressure control, reduced albuminuria and improved diastolic function. Diastolic function was not improved by sitagliptin and linagliptin., (© 2018 The Authors. European Journal of Clinical Investigation published by John Wiley & Sons Ltd on behalf of Stichting European Society for Clinical Investigation Journal Foundation.)
- Published
- 2018
- Full Text
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37. Development of Hydrogen-Rich Benzoxazine Resins with Low Polymerization Temperature for Space Radiation Shielding.
- Author
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Iguchi D, Ohashi S, Abarro GJE, Yin X, Winroth S, Scott C, Gleydura M, Jin L, Kanagasegar N, Lo C, Arza CR, Froimowicz P, and Ishida H
- Abstract
A systematic study has been carried out to develop a material with significant protection properties from galactic cosmic radiation and solar energetic particles. The research focused on the development of hydrogen-rich benzoxazines, which are particularly effective for shielding against such radiation. Newly developed benzoxazine resin can be polymerized at 120 °C, which meets the low-temperature processing requirements for use with ultrahigh molecular weight polyethylene (UHMWPE) fiber, a hydrogen-rich composite reinforcement. This highly reactive benzoxazine resin also exhibits low viscosity and good shelf-life. The structure of the benzoxazine monomer is confirmed by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. Polymerization behavior and thermal properties are evaluated by differential scanning calorimetry and thermogravimetric analysis. Dynamic mechanical analysis is used to study chemorheological properties of the benzoxazine monomer, rheological properties of the cross-linked polybenzoxazine, and rheological properties of UHMWPE-reinforced polybenzoxazine composites. The theoretical radiation shielding capability of the composite is also evaluated using computer-based simulations., Competing Interests: The authors declare no competing financial interest.
- Published
- 2018
- Full Text
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38. Angubindin-1, a novel paracellular absorption enhancer acting at the tricellular tight junction.
- Author
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Krug SM, Hayaishi T, Iguchi D, Watari A, Takahashi A, Fromm M, Nagahama M, Takeda H, Okada Y, Sawasaki T, Doi T, Yagi K, and Kondoh M
- Subjects
- Animals, Cell Line, Humans, Male, Mice, Rats, Wistar, Tight Junctions metabolism, ADP Ribose Transferases chemistry, Bacterial Toxins chemistry, Intestinal Absorption, MARVEL Domain Containing 2 Protein metabolism, Peptide Fragments pharmacology, Receptors, Cell Surface metabolism
- Abstract
A limiting barrier for mucosal absorption of drugs is the tight junction (TJ). TJs exist between two adjacent cells (bicellular TJ, bTJ) and at the sites where three cells meet (tricellular TJ, tTJ). We present a novel approach which employs a physiologically regulated pathway for the passage of large molecules through the tTJ. Main barrier-relevant tTJ proteins are tricellulin and angulin-1 to -3. We developed an angulin binder from Clostridium perfringens iota-toxin (Ib) whose receptor is angulin-1. An Ib fragment corresponding to amino acids 421-664 (Ib421-664) of iota-toxin proved to bind in cells expressing angulin-1 and -3, but not angulin-2. This binding led to removal of angulin-1 and tricellulin from the tTJ which enhanced the permeation of macromolecular solutes. Ib421-664 enhanced intestinal absorption in rats and mice. Our findings indicate that Ib421-664, which we designate angubindin-1, is a modulator of the tTJ barrier and that modulation of that barrier qualifies for a new strategy of developing a mucosal absorption enhancer., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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39. Oxazine Ring-Related Vibrational Modes of Benzoxazine Monomers Using Fully Aromatically Substituted, Deuterated, 15 N Isotope Exchanged, and Oxazine-Ring-Substituted Compounds and Theoretical Calculations.
- Author
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Han L, Iguchi D, Gil P, Heyl TR, Sedwick VM, Arza CR, Ohashi S, Lacks DJ, and Ishida H
- Abstract
Polymerization of benzoxazine resins is indicated by the disappearance of a 960-900 cm
-1 band in infrared spectroscopy (IR). Historically, this band was assigned to the C-H out-of-plane bending of the benzene to which the oxazine ring is attached. This study shows that this band is a mixture of the O-C2 stretching of the oxazine ring and the phenolic ring vibrational modes. Vibrational frequencies of 3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazine (PH-a) and 3-(tert-butyl)-3,4-dihydro-2H-benzo[e][1,3]oxazine (PH-t) are compared with isotope-exchanged and all-substituted compounds. Deuterated benzoxazine monomers,15 N-isotope exchanged benzoxazine monomers, and all-substituted benzoxazine monomers without aromatic C-H groups are synthesized and studied meticulously. The various isotopic-exchanges involved deuteration around the benzene ring of phenol, selective deuteration of each CH2 in the O-CH2 -N (2) and N-CH2 -Ar (4) positions on the oxazine ring, or simultaneous deuteration of both positions. The chemical structures were confirmed by1 H nuclear magnetic resonance spectroscopy (1 H NMR). The IR and Raman spectra of each compound are compared. Further analysis of15 N isotope-exchanged PH-a indicates the influence of the nitrogen isotope on the band position, both experimentally and theoretically. This finding is important for polymerization studies of benzoxazines that utilize vibrational spectroscopy.- Published
- 2017
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40. High Levels of Soluble C5b-9 Complex in Dialysis Fluid May Predict Poor Prognosis in Peritonitis in Peritoneal Dialysis Patients.
- Author
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Mizuno M, Suzuki Y, Higashide K, Sei Y, Iguchi D, Sakata F, Horie M, Maruyama S, Matsuo S, Morgan BP, and Ito Y
- Subjects
- Aged, Biomarkers metabolism, Complement C3 metabolism, Complement C4 metabolism, Dialysis Solutions, Female, Humans, Male, Middle Aged, Peritonitis metabolism, Prognosis, Retrospective Studies, Treatment Outcome, Complement Membrane Attack Complex metabolism, Kidney Failure, Chronic complications, Kidney Failure, Chronic therapy, Peritoneal Dialysis adverse effects, Peritonitis diagnosis
- Abstract
Background: We searched for indicators to predict the prognosis of infectious peritonitis by measuring levels of complement proteins and activation products in peritoneal dialysis (PD) fluid (PDF) of patients at early stages of peritonitis. We retrospectively analyzed the relationship between the levels of sC5b-9, C3 and C4 in PDF and the subsequent clinical prognosis., Methods: We measured levels of sC5b-9, C3 and C4 in PDF on days 1, 2 and 5 post-onset of peritonitis in 104 episodes of infectious peritonitis in PD patients from 2008 and retrospectively compared levels with clinical outcomes. Further analysis for the presence of causative microorganisms or to demonstrate bacterial culture negative peritonitis was performed and correlated with change of levels of sC5b-9 in PDF., Results: When PD patients with peritonitis were divided into groups that either failed to recover from peritonitis and were finally withdrawn from PD (group 1; n = 25) or recovered (group 2; n = 79), levels of sC5b-9, C3 and C4 in PDF were significantly higher in group 1 patients compared to those in group 2 on day5. Analysis of microorganisms showed significantly higher sC5b-9 levels in PDF of peritonitis cases caused by culture negative peritonitis in group 1 compared with group 2 when we analyzed for individual microorganisms. Of note, on day5, the sC5b-9 levels in PDF were similarly high in peritonitis caused by fungi or other organisms., Conclusion: Our results suggested that levels of complement markers in PDF, especially sC5b-9, have potential as surrogate markers to predict prognosis of PD-related peritonitis., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2017
- Full Text
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41. Photo-Fries rearrangement of aryl acetamides: regioselectivity induced by the aqueous micellar green environment.
- Author
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Iguchi D, Erra-Balsells R, and Bonesi SM
- Abstract
Photochemical reactions tend to give more than one photoproduct. However, such a reaction can be a powerful synthetic tool when it is possible to conduct it in regioselective conditions yielding a single photoproduct. Water-surfactant solutions as reaction media can be considered as an approach in this context because they show products with different features than those from isotropic solutions. Here we describe results obtained from studying the effect on the prototypical photoreaction, known as the photo-Fries reaction of several substituted acetanilides and α-naphthyl acetamide within surfactant micelles (ionic and non-ionic micelles). This reaction involves homolytic cleavage of a C-N bond to yield a singlet radical pair. The surfactant micelles control the rotational and translational mobility of the radical pair, resulting in noticeable photoproduct selectivity.
- Published
- 2016
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42. Vascular endothelial growth factor receptor-3 is a novel target to improve net ultrafiltration in methylglyoxal-induced peritoneal injury.
- Author
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Terabayashi T, Ito Y, Mizuno M, Suzuki Y, Kinashi H, Sakata F, Tomita T, Iguchi D, Tawada M, Nishio R, Maruyama S, Imai E, Matsuo S, and Takei Y
- Subjects
- Animals, Creatinine analysis, Creatinine blood, Dialysis Solutions chemistry, Enzyme-Linked Immunosorbent Assay, Glucans, Glucose, Humans, Icodextrin, Immunohistochemistry, Mice, Mice, Inbred C57BL, Peritoneal Dialysis methods, Peritoneum injuries, Statistics, Nonparametric, Vascular Endothelial Growth Factor D analysis, Vascular Endothelial Growth Factor D blood, Vascular Endothelial Growth Factor Receptor-3 metabolism, Lymphangiogenesis drug effects, Peritoneal Dialysis adverse effects, Peritoneum drug effects, Pyruvaldehyde adverse effects, Ultrafiltration methods, Vascular Endothelial Growth Factor Receptor-3 pharmacology
- Abstract
Appropriate fluid balance is important for good clinical outcomes and survival in patients on peritoneal dialysis. We recently reported that lymphangiogenesis associated with fibrosis developed in the peritoneal cavity via the transforming growth factor-β1-vascular endothelial growth factor-C (VEGF-C) pathway. We investigated whether VEGF receptor-3 (VEGFR-3), the receptor for VEGF-C and -D, might be a new target to improve net ultrafiltration by using adenovirus-expressing soluble VEGFR-3 (Adeno-sVEGFR-3) in rodent models of peritoneal injury induced by methylglyoxal (MGO). We demonstrated that lymphangiogenesis developed in these MGO models, especially in the diaphragm, indicating that lymphangiogenesis is a common feature in the peritoneal cavity with inflammation and fibrosis. In MGO models, VEGF-D was significantly increased in the diaphragm; however, VEGF-C was not significantly upregulated. Adeno-sVEGFR-3, which was detected on day 50 after administration via tail vein injections, successfully suppressed lymphangiogenesis in the diaphragm and parietal peritoneum in mouse MGO models without significant effects on fibrosis, inflammation, or neoangiogenesis. Drained volume in the peritoneal equilibration test using a 7.5% icodextrin peritoneal dialysis solution (the 7.5% icodextrin peritoneal equilibration test) was improved by Adeno-sVEGFR-3 on day 22 (P<0.05) and day 50 after reduction of inflammation (P<0.01), indicating that the 7.5% icodextrin peritoneal equilibration test identifies changes in lymphangiogenesis. The solute transport rate was not affected by suppression of lymphangiogenesis. In human peritoneal dialysis patients, the dialysate to plasma ratio of creatinine positively correlated with the dialysate VEGF-D concentration (P<0.001). VEGF-D mRNA was significantly higher in the peritoneal membranes of patients with ultrafiltration failure, indicating that VEGF-D is involved in the development of lymphangiogenesis in peritoneal dialysis patients. These results indicate that VEGFR-3 is a new target to improve net ultrafiltration by suppressing lymphatic absorption and that the 7.5% icodextrin peritoneal equilibration test is useful for estimation of lymphatic absorption.
- Published
- 2015
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43. Expression of membrane complement regulators, CD46, CD55 and CD59, in mesothelial cells of patients on peritoneal dialysis therapy.
- Author
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Sei Y, Mizuno M, Suzuki Y, Imai M, Higashide K, Harris CL, Sakata F, Iguchi D, Fujiwara M, Kodera Y, Maruyama S, Matsuo S, and Ito Y
- Subjects
- CA-125 Antigen immunology, Complement Activation, Complement System Proteins immunology, Epithelial Cells pathology, Epithelium immunology, Epithelium pathology, Female, Humans, Interleukin-6 immunology, Male, Membrane Proteins immunology, CD56 Antigen immunology, CD59 Antigens immunology, Epithelial Cells immunology, Gene Expression Regulation immunology, Membrane Cofactor Protein immunology, Peritoneal Dialysis
- Abstract
We investigated the expression of membrane complement regulators (CRegs), CD46, CD55 and CD59 in human mesothelial cells, and correlated with clinical background and level of complement (C) activation products in peritoneal dialysis (PD) fluids (PDF) to clarify influence of the C activation system in PD patients. Expression of CRegs was assessed on primary cultures of mesothelial cells (HPMC) harvested from PD fluid of 31 PD patients. Because expression of CD55 but not CD46 and CD59 in mesothelial cells was significantly correlated to value of dialysate-to-plasma creatinine concentration ratio (D/P Cre) (p<0.005) as an indicator of peritoneal function, we focused on analysis of CD55 expression of HPMCs in comparison with levels of C activation products in the PDF of the PD patients, and their background factors. When comparing expression of the CRegs between systemic neutrophils and HPMC, no correlation was observed, supporting that change of CRegs' expression in HPMC was independently occurring in the peritoneum. Expression of CD55 protein in HPMC was closely correlated with expression at the mRNA level (p<0.0001) and was inversely correlated with levels of sC5b-9 (p<0.05), but not C3, C4, IL6 and CA125 in the PDF. Complications of diabetes, usage of icodextrin and residual renal function were not correlated with change of CD55 expression in HPMCs. Our data show that the process of PD therapy modifies expression of CD55 on peritoneal mesothelium and triggers local C activation. These findings support efforts to modify PD therapy to limit effects on activation and regulation of the C system., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
44. Replacement of domain b of human protein disulfide isomerase-related protein with domain b' of human protein disulfide isomerase dramatically increases its chaperone activity.
- Author
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Horibe T, Iguchi D, Masuoka T, Gomi M, Kimura T, and Kikuchi M
- Subjects
- Amino Acid Motifs, Amino Acid Sequence, Escherichia coli genetics, Escherichia coli metabolism, Humans, Molecular Chaperones genetics, Molecular Sequence Data, Mutation, Oxidation-Reduction, Protein Disulfide-Isomerases genetics, Protein Folding, Protein Structure, Secondary, Protein Structure, Tertiary, Proteins genetics, Recombinant Proteins chemistry, Recombinant Proteins genetics, Recombinant Proteins metabolism, Spectrometry, Fluorescence, Molecular Chaperones chemistry, Molecular Chaperones metabolism, Protein Disulfide-Isomerases chemistry, Protein Disulfide-Isomerases metabolism, Proteins chemistry, Proteins metabolism
- Abstract
We have reported that human protein disulfide isomerase-related protein (hPDIR) has isomerase and chaperone activities that are lower than those of the human protein disulfide isomerase (hPDI), and that the b domain of hPDIR is critical for its chaperone activity [J. Biol. Chem. 279 (2004) 4604]. To investigate the basis of the differences between hPDI and hPDIR, and to determine the functions of each hPDIR domain in detail, we constructed several hPDIR domain mutants. Interestingly, when the b domain of hPDIR was replaced with the b' domain of hPDI, a dramatic increase in chaperone activity that was close to that of hPDI itself was observed. However, this mutant showed decreased oxidative refolding of alpha1-antitrypsin. The replacement of the b domain of hPDIR with the c domain of hPDI also increased its chaperone activity. These observations suggest that putative peptide-binding sites of hPDI determine both its chaperone activity and its substrate specificity.
- Published
- 2004
- Full Text
- View/download PDF
45. Different contributions of the three CXXC motifs of human protein-disulfide isomerase-related protein to isomerase activity and oxidative refolding.
- Author
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Horibe T, Gomi M, Iguchi D, Ito H, Kitamura Y, Masuoka T, Tsujimoto I, Kimura T, and Kikuchi M
- Subjects
- Amino Acid Motifs, Amino Acid Sequence, Base Sequence, DNA, Complementary genetics, Humans, In Vitro Techniques, Molecular Chaperones chemistry, Molecular Chaperones genetics, Molecular Chaperones metabolism, Mutagenesis, Site-Directed, Oxidation-Reduction, Protein Binding, Protein Disulfide-Isomerases metabolism, Protein Folding, Proteins genetics, Recombinant Proteins chemistry, Recombinant Proteins genetics, Recombinant Proteins metabolism, alpha 1-Antitrypsin metabolism, Proteins chemistry, Proteins metabolism
- Abstract
Human protein-disulfide isomerase (hPDI)-related protein (hPDIR), which we previously cloned from a human placental cDNA library (Hayano, T., and Kikuchi, M. (1995) FEBS Lett. 372, 210-214), and its mutants were expressed in the Escherichia coli pET system and purified by sequential nickel affinity resin chromatography. Three thioredoxin motifs (CXXC) of purified hPDIR were found to contribute to its isomerase activity with a rank order of CGHC > CPHC > CSMC, although both the isomerase and chaperone activities of this protein were lower than those of hPDI. Screening for hPDIR-binding proteins using a T7 phage display system revealed that alpha1-antitrypsin binds to hPDIR. Surface plasmon resonance experiments demonstrated that alpha1-antitrypsin interacts with hPDIR, but not with hPDI or human P5 (hP5). Interestingly, the rate of oxidative refolding of alpha1-antitrypsin with hPDIR was much higher than with hPDI or hP5. Thus, the substrate specificity of hPDIR differed from that associated with isomerase activity, and the contribution of the CSMC motif to the oxidative refolding of alpha1-antitrypsin was the most definite of the three (CSMC, CGHC, CPHC). Substitution of SM and PH in the CXXC motifs with GH increased isomerase activity and decreased oxidative refolding. In contrast, substitution of GH and PH with SM decreased isomerase activity and increased oxidative refolding. Because CXXC motif mutants lacking isomerase activity retain chaperone activity for the substrate rhodanese, it is clear that, similar to PDI and hP5, the isomerase and chaperone activities of hPDIR are independent. These results suggest that the central dipeptide of the CXXC motif is critical for both redox activity and substrate specificity.
- Published
- 2004
- Full Text
- View/download PDF
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