51
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Hirota N, Kuroda H, Takoi K, Kaneko T, Kaneda H, Yoshida I, Takashio M, Ito K, Takeda K. Brewing Performance of Malted Lipoxygenase-1 Null Barley and Effect on the Flavor Stability of Beer. Cereal Chem 2006. [DOI: 10.1094/cc-83-0250] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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52
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Yoshihara T, Morimoto A, Kuroda H, Imamura T, Ishida H, Tsunamoto K, Naya M, Hibi S, Todo S, Imashuku S. Allogeneic stem cell transplantation in children with acute lymphoblastic leukemia after isolated central nervous system relapse: our experiences and review of the literature. Bone Marrow Transplant 2006; 37:25-31. [PMID: 16247416 DOI: 10.1038/sj.bmt.1705202] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The prognosis of patients with acute lymphoblastic leukemia (ALL) and central nervous system (CNS) relapse has historically been very poor. Although chemo-radiotherapy has improved outcomes, some patients still have a poor prognosis after CNS relapse. Therefore, allogeneic hematopoietic stem cell transplantation (allo-SCT) has recently become an option for treatment of CNS leukemia; however, information, particularly on the long-term outcome of transplant recipients, is limited. We performed allo-SCT in eight pediatric patients with ALL (n=7) or T-cell type non-Hodgkin's lymphoma (n=1), who had isolated CNS relapse. All patients survived for a median of 70.5 (range, 13-153) months after SCT. Sequelae developed late in some patients: mental retardation (IQ=47) in one patient, severe alopecia in two patients, limited chronic graft-versus-host-disease in three patients, and amenorrhea and/or hypothyroidism in three patients. Except for a pre-school child with post transplant CNS relapse, six out of seven patients show normal school/social performance. Our results clearly indicate a high cure rate of isolated CNS relapse by allo-SCT in pediatric lymphoid malignancies; however, there needs to be further studies to determine which are the appropriate candidates for transplantation and what is the best transplant regimen to achieve high cure rate and maintain good quality of life.
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Kawashita Y, Ohtsuru A, Miki F, Kuroda H, Morishita M, Kaneda Y, Hatsushiba K, Kanematsu T, Yamashita S. Eradication of hepatocellular carcinoma xenografts by radiolabelled, lipiodol-inducible gene therapy. Gene Ther 2006; 12:1633-9. [PMID: 16079887 DOI: 10.1038/sj.gt.3302531] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The promoter region of the early-growth response-1(Egr-1) gene has been shown to be activated by external radiation, thus making a selective tumoricidal effect possible. A previous experiment showed that the Egr-1 promoter can be activated by internal radiation using radioisotopes as well as external radiation. Internal radiation using I-131 lipiodol (I-131-Lip) has been established as one of the most useful therapeutic strategies against hepatoma. We herein linked the Egr-1 promoter to the herpes simplex virus-thymidine kinase (HSV-TK) gene, and investigated its efficacy in hepatoma gene therapy in combination with I-131-Lip. A luciferase assay showed the Egr-1-promoter activity to be markedly increased in hepatoma tissue specimens in an I-131-dose-dependent manner, whereas a less than two-fold increase in this activity was observed in other organs. In addition, the radioactivity derived from I-131 was selectively accumulated in the tumor tissue specimens. To examine the efficacy of EgrTK/ganciclovir (GCV) gene therapy in vivo, subcutaneous hepatoma xenografts in nude mice were transfected using a hemagglutinating virus of Japan (HVJ)-liposome vector. Complete tumor regression was observed in all the EgrTK-transfected tumors following combination treatment with I-131-Lip and GCV 42 days after treatment without any side effects (n=8). In contrast, the tumors continued to grow in all control mice (n=10). Furthermore, the serum alpha-fetoprotein levels decreased in the combination therapy group, while they increased in the controls. In conclusion, these data indicate that Egr-1 promoter-based gene therapy combined with internal radiation has a selective effect on hepatoma tumors while also showing an improved in vivo efficacy. This combination therapy might, therefore, be an effective human hepatoma gene therapy, even in advanced multiple cases.
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Kanazawa M, Fujita N, Yamanoue H, Shiiki S, Shimizu T, Tatsukuchi S, Ikeda S, Yoshizato R, Kuroda H, Shigeno Y, Hatae S. P7.06 Efforts toward Information-Sharing and Dissemination of Hospital Infection Control. Continuation of Seminar by Japan Infection Control Hospital Group. J Hosp Infect 2006. [DOI: 10.1016/s0195-6701(06)60135-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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55
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Yamanoue H, Fujita N, Shiiki S, Shimizu T, Kanazawa M, Tatsukuchi S, Ikeda S, Yoshizato R, Kuroda H, Shigeno Y, Hatae S. P7.09 Changing Infection Control in the Course of 10 Years in Japan. J Hosp Infect 2006. [DOI: 10.1016/s0195-6701(06)60138-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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56
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Hirota N, Kaneko T, Kuroda H, Kaneda H, Takashio M, Ito K, Takeda K. Characterization of lipoxygenase-1 null mutants in barley. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2005; 111:1580-4. [PMID: 16228190 DOI: 10.1007/s00122-005-0088-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Accepted: 08/10/2005] [Indexed: 05/04/2023]
Abstract
This study describes the discovery and characterization of lipoxygenase-1 (LOX-1) null mutants in barley. Six lines did not exhibit any significant LOX activity in the silenced seed extract. Immunological analysis showed that these lines lacked the authentic LOX-1 protein. Genetic analysis of the F2 population revealed that this trait was governed by a single recessive gene located at the LoxA locus on chromosome 4H. The six LOX-1 null mutants shared similar features and the same unique polymorphism in a structural gene region, implying that these mutants might be derived from the same ancestral origin.
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Akiyama T, Matsunaga T, Terui T, Miyanishi K, Tanaka I, Sato T, Kuroda H, Takimoto R, Takayama T, Kato J, Yamauchi N, Kogawa K, Sakamaki S, Hirayama Y, Kohda K, Niitsu Y. Involvement of transforming growth factor-β and thrombopoietin in the pathogenesis of myelodysplastic syndrome with myelofibrosis. Leukemia 2005; 19:1558-66. [PMID: 16034467 DOI: 10.1038/sj.leu.2403875] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We investigated the cause of myelofibrosis and proliferation of megakaryocytes in myelodysplastic syndrome with myelofibrosis (MDS-MF (+)). Plasma-transforming growth factor-beta1 (PTGF-beta1) concentrations closely correlated with myelofibrosis grade in MDS-MF (+) and were higher than those in idiopathic myelofibrosis (IMF), essential thrombocythemia (ET), idiopathic thrombocytopenic purpura (ITP), MDS-without MF (MDS-MF (-)) or healthy volunteers (HV). Peripheral blood mononuclear cells from MDS-MF (+) patients expressed more TGF-beta1 mRNA than those from IMF, MDS-MF (-) or HV. When we immunostained bone marrow specimens of MDS-MF (+) for TGF-beta, the intensity of blasts was apparently higher than that of megakaryocytes, while in MDS-MF (-), megakaryocytes were immunostained with a similar intensity as that in MDS-MF (+), but blasts were negative for staining. In IMF, megakaryocytes, monocytes and small mononuclear cells representing CD34+ cells were all similarly stained with a much lower intensity than that of blasts in MDS-MF (+). The number of bone marrow megakaryocytes were increased the most in MDS-MF (+), followed by ET, ITP, MDS-MF (-) and NHL and correlated with plasma thrombopoietin (TPO) levels or with plasma TGF-beta1 levels, respectively, in each disease. Thus, in MDS-MF (+), both myelofibrosis and the increased megakaryocytes were ascribed to overproduction of TGF-beta1 from blasts.
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Yoshihara T, Morimoto A, Inukai T, Kuroda H, Ishida H, Sugita K, Goi K, Imamura T, Todo S, Maruya E, Saji H, Nakazawa S, Imashuku S. Non-T-cell-depleted HLA haploidentical stem cell transplantation based on feto-maternal microchimerism in pediatric patients with advanced malignancies. Bone Marrow Transplant 2005; 34:373-5. [PMID: 15220959 DOI: 10.1038/sj.bmt.1704597] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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59
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Cui JG, Kuroda H, Chandrasekharan NV, Pelaez RP, Simmons DL, Bazan NG, Lukiw WJ. Cyclooxygenase-3 Gene Expression in Alzheimer Hippocampus and in Stressed Human Neural Cells. Neurochem Res 2004; 29:1731-7. [PMID: 15453269 DOI: 10.1023/b:nere.0000035809.70905.8a] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The cyclooxygenase (COX) superfamily of prostaglandin synthase genes encode a constitutively expressed COX-1, an inducible, highly regulated COX-2, and a COX-3 isoform whose RNA is derived through the retention of a highly structured, G + C-rich intron 1 of the COX-1 gene. As generators of oxygen radicals, lipid mediators, and the pharmacological targets of nonsteroidal anti-inflammatory drugs (NSAIDs), COX enzymes potentiate inflammatory neuropathology in Alzheimer's disease (AD) brain. Because COX-2 is elevated in AD and COX-3 is enriched in the mammalian CNS, these studies were undertaken to examine the expression of COX-3 in AD and in [IL-1beta + Abeta42]-triggered human neural (HN) cells in primary culture. The results indicate that while COX-2 remains a major player in propagating inflammmation in AD and in stressed HN cells, COX-3 may play ancillary roles in membrane-based COX signaling or when basal levels of COX-1 or COX-2 expression persist.
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Imashuku S, Teramura T, Konishi K, Kikuchi A, Tamura S, Maeda Y, Kuroda H. Treatment of Epstein-Barr virus-associated peripheral T-cell lymphoma. Br J Dermatol 2004; 150:1038-40. [PMID: 15149529 DOI: 10.1111/j.1365-2133.2004.05945.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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61
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Ganeev RA, Baba M, Morita M, Rau D, Fujii H, Ryasnyansky AI, Ishizawa N, Suzuki M, Kuroda H. Nonlinear optical properties of CdS and ZnS nanoparticles doped into zirconium oxide films. ACTA ACUST UNITED AC 2004. [DOI: 10.1088/1464-4258/6/4/024] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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62
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Ganeev RA, Baba M, Morita M, Ryasnyansky AI, Suzuki M, Turu M, Kuroda H. Fifth-order optical nonlinearity of pseudoisocyanine solution at 529 nm. ACTA ACUST UNITED AC 2004. [DOI: 10.1088/1464-4258/6/2/021] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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63
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Ono K, Kuroda H, Tanabe T. [Double valve replacement for infective endocarditis following osteomyelitis; report of two cases]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 2004; 57:83-5. [PMID: 14733105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Infective endocarditis(IE) is relatively common but it is lethal complication of osteomyelitis. We report the case of 2 patients who had been diagnosed as IE during their conservative therapy of osteomyelitis. Both of the patients had been admitted because of severe back pain. Then IE was revealed from congestive heart failure and/or persistent fever. As several times of echocardiogram showed the progression of valvular lesion despite their antibiotic therapies, they underwent the operation of aortic and mitral valve replacements. On bacteremia-related disease like osteomyelitis, high index of suspicion and early diagnosis of IE are essential to its successful treatment.
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64
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Imashuku S, Teramura T, Morimoto A, Naya M, Kuroda H. Prolonged hypogammaglobulinemia following rituximab treatment for post transplant Epstein–Barr virus-associated lymphoproliferative disease. Bone Marrow Transplant 2003; 33:129-30. [PMID: 14647260 DOI: 10.1038/sj.bmt.1704307] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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65
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Nakasone H, Kuroda H, Kato T, Tabuchi T. Nitrogen removal from water containing high nitrate nitrogen in a paddy field (wetland). WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2003; 48:209-216. [PMID: 15137172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Nowadays, it has become very common to find in Japan that nitrate nitrogen concentrations are very high in spring water and in well water where the land use of a watershed is agricultural. We have often observed around 50 mg/L of nitrate nitrogen in the spring water where we live. Crops produced in those fields are mainly vegetables such as celery, cabbage, lettuce, carrots, and so on. Green tea is also popular in Japan. In order to produce good quality green tea, farmers apply a great amount of nitrogen fertilizer. This amount can reach up to 1,000 kg/ha in some areas, although the average application amounts to 628 kg/ha in Japan. As a result, ground water that is rich in nitrate flows into the river, which results in a high nitrogen concentration in river water and ground water. Further, this causes a low pH in river water in some tributary rivers in Japan, though this kind of case is very rare. We knew from field tests that if water contained a high nitrogen concentration and was introduced into paddy fields, high nitrogen removal would be performed. This paper presents the outline and results of a system on how to remove nitrogen using paddy fields (wetlands). Further, this paper presents the evaluated results of the removal quantity at the watershed level.
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66
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Ozaki T, Ganeev RA, Ishizawa A, Kanai T, Kuroda H. Highly directive 18.9 nm nickel-like molybdenum x-ray laser operating at 150 mJ pump energy. PHYSICAL REVIEW LETTERS 2002; 89:253902. [PMID: 12484886 DOI: 10.1103/physrevlett.89.253902] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2002] [Indexed: 05/24/2023]
Abstract
We experimentally demonstrate that by longitudinally pumping 2 mm long molybdenum preformed plasma with high-intensity 475 fs duration laser pulse, a highly directive soft-x-ray laser at 18.9 nm wavelength is generated. The divergence of the beam is evaluated to be of the submilliradian order, and only requires a pump laser energy of 150 mJ.
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67
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Shinohara M, Kuroda H, Fukaya Y, Sato E, Makino H. Detection of skeletal muscle fatigue using an accelerometer in dynamic cardiomyoplasty. J Artif Organs 2002. [DOI: 10.1007/s100470200050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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68
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Ishizawa A, Ganeev RA, Kanai T, Kuroda H, Ozaki T. Measurements of blue shifts due to collisionless absorption in harmonic generation from subpicosecond laser-produced plasmas. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 66:026414. [PMID: 12241304 DOI: 10.1103/physreve.66.026414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2001] [Revised: 03/25/2002] [Indexed: 05/23/2023]
Abstract
Harmonic generation from solid surface plasmas is studied using a subpicosecond Nd:glass laser system. For a 45 degrees angle of incidence, the speculars up to the fifth harmonics are blue shifted when the laser intensity exceeds 2 x 10(16) W cm(-2). The second harmonic is blueshifted by approximately 16 A, and the fifth harmonic is blue shifted by approximately 51 A for p polarization at the intensity of 1 x 10(17) W cm(-2). We observed the blue shift of the fifth harmonics and found that the magnitude of blue shift is higher compared with that for the second harmonics. The blue shift is interpreted as a collisionless absorption due to the anomalous skin effect. It is also found that the divergence of harmonics preserves a smaller divergence when using a shorter pulse length for the driving laser.
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69
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Kuroda H, Ohtsuru A, Futakuchi M, Kawashita Y, Nagayama Y, Fukuda E, Namba H, Shirai T, Kanematsu T, Yamashita S. Distinctive gene expression of receptor-type tyrosine kinase families during rat hepatocarcinogenesis. Int J Mol Med 2002. [DOI: 10.3892/ijmm.9.5.473] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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70
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Yakushi K, Ida T, Ugawa A, Yamakado H, Ishii H, Kuroda H. Polarized reflectance spectra of single crystals of the phthalocyanine radicals NiPc(AsF6)0.5, H2Pc(AsF6)0.67, and LiPc. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100173a016] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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71
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Petrov AK, Chernyshev AV, Chesnokov EN, Gorelik SR, Kuibida LV, Nomaru K, Kuroda H. Doklady Physical Chemistry 2002; 385:189-191. [DOI: 10.1023/a:1019963106717] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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72
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Igarashi T, Kuroda H, Takahashi S, Asashima M. Cloning and characterization of the Xenopus laevis p8 gene. Dev Growth Differ 2001; 43:693-8. [PMID: 11737149 DOI: 10.1046/j.1440-169x.2001.00613.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The p8 gene encodes a transcription factor with a basic helix-loop-helix motif and has been cloned in rat, mouse and human. It is upregulated in acute pancreatitis. In the present study, the Xenopus laevis homolog of p8 (Xp8) was isolated by PCR. The full-length Xp8 cDNA consists of 677 bp and encodes 82 amino acids. The basic helix-loop-helix region is well conserved between X. laevis and mammals. Overexpression of an Xp8-EGFP fusion protein indicated that Xp8 was localized to nucleus, as in mammals. Analysis by RT-PCR showed that expression of Xp8 was increased after gastrulation and maintained into later developmental stages. Expression was detected in the prospective neural region at the neurula stage by whole-mount in situ hybridization. At the larval stage, Xp8 was expressed in central nervous regions, such as ventrolateral brain, trigeminal nerve, vestibulocochlear nerve and dorsal neural tube. Expression was also detected in the basal cement gland, olfactory placode, ear vesicle, notochord and anus. This specific pattern of expression suggests that Xp8 may play a role in the development of the central nervous system in X. laevis.
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Hasegawa R, Kitahara H, Watanabe K, Kuroda H, Amano J. Mitral stenosis and regurgitation with systemic lupus erythematosus and antiphospholipid antibody syndrome. THE JAPANESE JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY : OFFICIAL PUBLICATION OF THE JAPANESE ASSOCIATION FOR THORACIC SURGERY = NIHON KYOBU GEKA GAKKAI ZASSHI 2001; 49:711-3. [PMID: 11808093 DOI: 10.1007/bf02913510] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Cases of valvular disease accompanied by systemic lupus erythematosus and antiphospholipid antibody syndrome are uncommon. Here, we present a surgical case of mitral stenosis and regurgitation with systemic lupus erythematosus and antiphospholipid antibody syndrome. Mitral valve replacement was performed, and the postoperative course was uneventful. Pathohistological findings of the mitral valve showed degenerative change due to chronic inflammation, proliferative fibrous change and calcification without thrombus formation.
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74
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Kondoh H, Saito N, Matsui F, Yokoyama T, Ohta T, Kuroda H. Structure of Alkanethiolate Monolayers on Cu(100): Self-Assembly on the Four-Fold-Symmetry Surface. J Phys Chem B 2001. [DOI: 10.1021/jp015517r] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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75
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Kuroda R, Kontani K, Kanda Y, Katada T, Nakano T, Satoh Y, Suzuki N, Kuroda H. Increase of cGMP, cADP-ribose and inositol 1,4,5-trisphosphate preceding Ca2+ transients in fertilization of sea urchin eggs. Development 2001; 128:4405-14. [PMID: 11714667 DOI: 10.1242/dev.128.22.4405] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Transient increases, or oscillations, of cytoplasmic free Ca2+ concentration, [Ca2+]i, occur during fertilization of animal egg cells. In sea urchin eggs, the increased Ca2+ is derived from intracellular stores, but the principal signaling and release system involved has not yet been agreed upon. Possible candidates are the inositol 1,4,5-trisphosphate receptor/channel (IP3R) and the ryanodine receptor/channel (RyR) which is activated by cGMP or cyclic ADP-ribose (cADPR). Thus, it seemed that direct measurements of the likely second messenger candidates during sea urchin fertilization would be essential to an understanding of the Ca2+ signaling pathway. We therefore measured the cGMP, cADPR and inositol 1,4,5-trisphosphate (IP3) contents of sea urchin eggs during the early stages of fertilization and compared these with the [Ca2+]i rise in the presence or absence of an inhibitor against soluble guanylate cyclase. We obtained three major experimental results: (1) cytosolic cGMP levels began to rise first, followed by cADPR and IP3 levels, all almost doubling before the explosive increase of [Ca2+]i; (2) most of the rise in IP3 occurred after the Ca2+ peak; IP3 production could also be induced by the artificial elevation of [Ca2+]i, suggesting the large increase in IP3 is a consequence, rather than a cause, of the Ca2+ transient; (3) the measured increase in cGMP was produced by the soluble guanylate cyclase of eggs, and inhibition of soluble guanylate cyclase of eggs diminished the production of both cADPR and IP3 and the [Ca2+]i increase without the delay of Ca2+ transients. Taken together, these results suggest that the RyR pathway involving cGMP and cADPR is not solely responsible for the initiating event, but contributes to the Ca2+ transients by stimulating IP3 production during fertilization of sea urchin eggs.
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