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Hayasaki T, Sakurai M, Hayashi T, Murakami K, Hanawa T. Analysis of pharmacological effect and molecular mechanisms of a traditional herbal medicine by global gene expression analysis: an exploratory study. J Clin Pharm Ther 2007; 32:247-52. [PMID: 17489876 DOI: 10.1111/j.1365-2710.2007.00818.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVES Although traditional herbal medicines have been used for more than 2000 years, there are few studies on their molecular mechanisms of action. We examined the pharmacological effect and mechanism of action of a traditional herbal medicine (Kososan) with global gene expression analysis using a DNA chip. METHODS Fourteen healthy subjects were given the herbal medicine (Kososan) for 2 weeks and interviewed. Peripheral blood was collected before and after 2-week medication. Based on the outcomes of the interview, the subjects were divided into responders and non-responders. We analysed the blood samples from responder and non-responder groups, respectively, using a DNA chip. RESULTS In the Kososan responder group, 70 genes were over-expressed (2-fold or more), and their over-expression was normalized by Kososan (0.5-fold or less), whereas 24 genes were under-expressed (0.5-fold or less), and the under-expression was normalized by Kososan (2-fold or more). CONCLUSION This exploratory study suggests that gene expression profiling is a possible approach for studying the effects of complex herbal remedies. Some of the genes studied seem to have functions related to the pharmacological effects of Kososan, which have been known for a long time.
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Koba T, Hamada K, Sakurai M, Matsumoto K, Hayase H, Imaizumi K, Tsujimoto H, Mitsuzono R. Branched-chain amino acids supplementation attenuates the accumulation of blood lactate dehydrogenase during distance running. J Sports Med Phys Fitness 2007; 47:316-22. [PMID: 17641599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
AIM We investigated the effect of branched-chain amino acids (BCAA) supplementation on tissue damage during distance running. METHODS Eight male distance runners (mean +/- standard deviation; age: 20.4+/-1.2 years, body weight: 58.4+/-4.2 kg) participated in a double blinded cross over designed study conducted during training camp. During each intervention period, the subjects were asked to participate in a 25-km run, and the blood BCAA and lactate dehydrogenase (LDH) level, an index of tissue damage, were measured pre- and post-run. Either a drink containing BCAA (0.4% BCAA in a 4% carbohydrate solution) or an iso-calorie placebo drink was provided to the subjects 5 times during the run without any restriction in the volume. RESULTS The total volume of the drink consumed by the subjects did not differ substantially between the trials: 591+/-188 (2.36 g BCAA) vs 516+/-169 mL in BCAA and placebo trial, respectively. During the run, the blood BCAA concentration was maintained in the BCAA trial. However, the blood BCAA concentration level tended to decrease in the placebo trial (P<0.1). The extent of the blood LDH increase in the BCAA trial was significantly less than that of the placebo trail (48% vs 58%, P<0.05). CONCLUSION Maintaining the blood BCAA level throughout a long distance run contributes to a reduction in the LDH release and, therefore, the effect of BCAA supplementation is suggested to reduce the degree of muscle damage.
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Kobayashi H, Sakurai M, Kobayashi T. Extensor digitorum longus tenosynovitis caused by talar head impingement in an ultramarathon runner: a case report. J Orthop Surg (Hong Kong) 2007; 15:245-7. [PMID: 17709872 DOI: 10.1177/230949900701500226] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Stenosing tenosynovitis of the extensor digitorum longus tendon is an injury related to ultramarathon running. A 32-year-old male ultramarathon runner developed chronic tenosynovitis of the ankle dorsiflexors. He was diagnosed with extensor digitorum longus tenosynovitis caused by talar head impingement associated with exostosis. He failed to respond to non-operative management and decided to undergo tenosynovectomy of the extensor digitorum longus tendon. The pain was relieved without functional disturbance of the foot and ankle, and the patient returned to running 3 weeks postoperatively. At the 2-year follow-up, he was participating fully in ultramarathons.
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Misu H, Takamura T, Matsuzawa N, Shimizu A, Ota T, Sakurai M, Ando H, Arai K, Yamashita T, Honda M, Yamashita T, Kaneko S. Genes involved in oxidative phosphorylation are coordinately upregulated with fasting hyperglycaemia in livers of patients with type 2 diabetes. Diabetologia 2007; 50:268-77. [PMID: 17187250 DOI: 10.1007/s00125-006-0489-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Accepted: 09/19/2006] [Indexed: 01/06/2023]
Abstract
AIMS/HYPOTHESIS Mitochondrial oxidative phosphorylation (OXPHOS) plays an important role in the pathophysiology of type 2 diabetes. Genes involved in OXPHOS have been reported to be down-regulated in skeletal muscle from patients with type 2 diabetes; however, hepatic regulation is unknown. MATERIALS AND METHODS We analysed expression of genes involved in OXPHOS from the livers of 14 patients with type 2 diabetes and 14 subjects with NGT using serial analysis of gene expression (SAGE) and DNA chip analysis. We evaluated the correlation between expression levels of genes involved in OXPHOS and the clinical parameters of individuals with type 2 diabetes and NGT. RESULTS Both gene analyses showed that genes involved in OXPHOS were significantly upregulated in the type 2 diabetic liver. In the SAGE analysis, tag count comparisons of mitochondrial transcripts showed that ribosomal RNAs (rRNA) were 3.5-fold over-expressed, and mRNAs were 1.2-fold over-expressed in the type 2 diabetes library. DNA chip analysis revealed that expression of genes involved in OXPHOS, which correlated with several nuclear factors, including estrogen-related receptor-alpha or peroxisome proliferator-activated receptor-gamma, was a predictor of fasting plasma glucose levels, independently of age, BMI, insulin resistance and fasting insulin levels (p = 0.04). Surprisingly, genes involved in OXPHOS did not correlate with peroxisome proliferator-activated receptor-gamma coactivator-1alpha or nuclear respiratory factor 1. CONCLUSIONS/INTERPRETATION Our results indicate that upregulation of genes involved in OXPHOS in the liver, which are regulated by different mechanisms from genes in the skeletal muscle, is associated with fasting hyperglycaemia in patients with type 2 diabetes.
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Kinohira Y, Akutsu Y, Li HL, Hamazaki Y, Sakurai M, Saiki Y, Kodama Y, Nishimura H, Yamanaka H, Shinozuka A, Gokan T, Katagiri T. Coronary Arterial Plaque Characterized by Multislice Computed Tomography Predicts Complications Following Coronary Intervention. Int Heart J 2007; 48:25-33. [PMID: 17379976 DOI: 10.1536/ihj.48.25] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND A reliable, noninvasive assessment of plaque configuration would constitute an important step forward for predicting complications following percutaneous coronary intervention (PCI). Multislice computed tomography (MSCT) holds promise with respect to allowing for differentiation of coronary lesion configuration. However, it has not yet been clarified whether the characteristics of coronary artery plaque measured by MSCT predict complications after PCI. The aim of this study was to investigate the relationship between plaque configuration and complications after coronary intervention in patients with stable angina pectoris. METHODS MSCT was performed in patients with angina pectoris who were scheduled for PCI prospectively, and 26 patients (70 +/- 11 years, 18 males) with coronary artery plaque in a stenotic coronary artery measured by MSCT were recruited for this study. Thirty-five plaques in the stenotic coronary lesions were divided into 3 groups based on the CT density as soft, intermediate, and hard, and were compared with the complications after PCI. RESULTS The soft plaque group before PCI (n = 11) was significantly associated with the appearance of slow flow (n = 4) or a compromised side branch (n = 1) after PCI, whereas the hard plaque group before PCI (n = 17) was associated with the appearance of dissection (n = 2) or perforation (n = 1) after PCI (P = 0.004). The intermediate plaque group (n = 7) had only one complication, a compromised side branch (n = 1). CONCLUSION Coronary arterial plaque characterized by MSCT can predict intervention-related complication. It may be important for the risk stratification of the patients scheduled to undergo PCI to investigate plaque configuration by MSCT.
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Sakurai M, Watanabe YI, Watanabe K, Ohtsuki T. A protein extension to shorten RNA: elongated elongation factor-Tu recognizes the D-arm of T-armless tRNAs in nematode mitochondria. Biochem J 2006; 399:249-56. [PMID: 16859488 PMCID: PMC1609916 DOI: 10.1042/bj20060781] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Nematode mitochondria possess extremely truncated tRNAs. Of 22 tRNAs, 20 lack the entire T-arm. The T-arm is necessary for the binding of canonical tRNAs and EF (elongation factor)-Tu (thermo-unstable). The nematode mitochondrial translation system employs two different EF-Tu factors named EF-Tu1 and EF-Tu2. Our previous study showed that nematode Caenorhabditis elegans EF-Tu1 binds specifically to T-armless tRNA. C. elegans EF-Tu1 has a 57-amino acid C-terminal extension that is absent from canonical EF-Tu, and the T-arm-binding residues of canonical EF-Tu are not conserved. In this study, the recognition mechanism of T-armless tRNA by EF-Tu1 was investigated. Both modification interference assays and primer extension analysis of cross-linked ternary complexes revealed that EF-Tu1 interacts not only with the tRNA acceptor stem but also with the D-arm. This is the first example of an EF-Tu recognizing the D-arm of a tRNA. The binding activity of EF-Tu1 was impaired by deletion of only 14 residues from the C-terminus, indicating that the C-terminus of EF-Tu1 is required for its binding to T-armless tRNA. These results suggest that C. elegans EF-Tu1 recognizes the D-arm instead of the T-arm by a mechanism involving its C-terminal region. This study sheds light on the co-evolution of RNA and RNA-binding proteins in nematode mitochondria.
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Yokoshiki H, Sasaki K, Shimokawa J, Sakurai M, Tsutsui H. Nonreentrant atrioventricular nodal tachycardia due to triple nodal pathways manifested by radiofrequency ablation at coronary sinus ostium. J Electrocardiol 2006; 39:395-9. [PMID: 16895765 DOI: 10.1016/j.jelectrocard.2005.08.017] [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] [Received: 05/15/2005] [Indexed: 11/28/2022]
Abstract
We report a case of complex supraventricular tachycardia manifested by radiofrequency delivery. Initially, the patient presented with orthodromic atrioventricular reentrant tachycardia via a left-sided accessory pathway that was successfully eliminated. Atrial tachycardia originating from coronary sinus ostium was also induced. Radiofrequency delivery at the coronary sinus ostium induced a narrow QRS tachycardia with irregular R-R intervals. A detailed analysis explained that the tachycardia could be a nonreentrant mechanism due to triple atrioventricular nodal pathways: an atrial excitation evokes double ventricular response due to simultaneous activation of the fast and slow pathways, and the next one activates ventricle through the intermediate pathway.
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Katagiri T, Takei M, Sakurai M, Matsuyama T, Sakai T. [Antiinflammatory action of angiotensin receptor blocker]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 2006; 64 Suppl 5:506-11. [PMID: 16895219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
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109
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Kamiya N, Yasogawa Y, Nishi Y, Takahashi Y, Kondo Y, Hirai T, Sakurai M, Masumizu K, Onosato W, Koyama T. [A case of long-term, high-dose transdermal fentanyl application for lung cancer pain]. Gan To Kagaku Ryoho 2006; 33:377-80. [PMID: 16531723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Transdermal fentanyl patch represents a new administration route for cancer pain relief. We reported here a successful experience with a high-dose of transdermal fentanyl for cancer pain therapy. A 71-year-old woman suffering from metastatic lung cancer to bone had already been treated with radiation at a different hospital. She suffered from severe lumbar pain upon admission to our hospital. During the past 15 months, she has been treated with 30 mg or more of transdermal fentanyl for cancer pain relief. No severe side effects were observed, and she experienced a better quality of life at home using this patch long-term.
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Yamashita T, Ogawa S, Aizawa Y, Atarashi H, Inoue H, Ohe T, Okumura K, Ohtsu H, Kato T, Kamakura S, Kumagai K, Kurachi Y, Kodama I, Koretsune Y, Saikawa T, Sakurai M, Sugi K, Nakaya H, Hirai M, Hirayama A, Fukatani M, Mitamura H, Yamazaki T, Watanabe E. Randomized Study of Angiotensin II Type 1 Receptor Blocker vs Dihydropiridine Calcium Antagonist for the Treatment of Paroxysmal Atrial Fibrillation in Patients With Hypertension The J-RHYTHM II Study Design for the Investigation of Upstream Therapy for Atrial Fibrillation. Circ J 2006; 70:1318-21. [PMID: 16998266 DOI: 10.1253/circj.70.1318] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Mega trials of rhythm vs rate control could not demonstrate the usefulness of available antiarrhythmic drugs, so a more effective and safer therapy for atrial fibrillation (AF) is now required. One candidate is the so-called "upstream therapy", which refers to the blockade of upstream modifying elements (renin - angiotensin system, cathecholamines, oxidative stress etc) that contribute to the arrhythmogenic substrate. METHODS AND RESULTS The Japanese Rhythm Management Trial II for Atrial Fibrillation (J-RHYTHM II study) is a randomized comparative evaluation of an angiotensin II type 1 blocker (candesartan) and a dihydropiridine calcium blocker (amlodipine), both combined with antithrombotic therapy, as an antiarrhythmic therapy for the treatment of paroxysmal AF (PAF) associated with hypertension. To test the usefulness of this therapy, this study will reveal the recurrence rate of asymptomatic as well as symptomatic PAF during 1-year of treatment with candesartan or amlodipine, using daily transtelephonic monitoring. CONCLUSIONS The J-RHYTHM II study will follow 400 patients with PAF and hypertension who were treated at approximately 50 sites throughout Japan, and will provide clinically important information.
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Imaizumi H, Sakurai M, Kashimoto O, Kikawa T, Suzuki O. Comparative study on osteoconductivity by synthetic octacalcium phosphate and sintered hydroxyapatite in rabbit bone marrow. Calcif Tissue Int 2006; 78:45-54. [PMID: 16397737 DOI: 10.1007/s00223-005-0170-0] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Accepted: 09/30/2005] [Indexed: 11/29/2022]
Abstract
Octacalcium phosphate (OCP) is thought to be a precursor of the mineral crystals in biological apatite. Synthetic OCP has been shown to be converted into an apatite structure when implanted in murine calvarial bone, to enhance bone regeneration more than synthetic hydroxyapatite (HA), and to degrade faster than biodegradable beta-tricalcium phosphate. This study was designed to investigate whether OCP implantation enhances the formation and resorption of new bone (remodeling) concomitant with OCP degradation when implanted intramedullary in a rabbit femur for 12 weeks, compared to sintered HA ceramic. Histological and histomorphometric analyses using undecalcified specimens showed that the area of bone apposition was significantly higher on OCP than on HA between 2 and 3 weeks, whereas it subsequently became smaller on OCP than on HA. The area attacked by multinucleated giant cells, including tartrate-resistant acid phosphatase (TRAP)-positive cells, was significantly higher for OCP than for HA at 8 weeks. Radiography revealed resorption of OCP but not of HA. The results disclose some osteoconductive characteristics of synthetic OCP in the bone marrow space: (1) enhancement of bone regeneration at the initial bone apposition stage and (2) stimulation of resorption of the newly formed bone coupled with OCP biodegradation mediated by TRAP-positive osteoclast-like cells. These results suggest that synthetic OCP would be a more useful bone substitute than HA in implant applications where rapid bone formation and concomitant implant resorption are important considerations.
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Nishio K, Sakurai M, Kusuyama T, Shigemitsu M, Fukui T, Kawamura K, Itoh S, Konno N, Katagiri T. A randomized comparison of pioglitazone to inhibit restenosis after coronary stenting in patients with type 2 diabetes. Diabetes Care 2006; 29:101-6. [PMID: 16373904 DOI: 10.2337/diacare.29.01.06.dc05-1170] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Recent studies have demonstrated that the treatment with thiazolidinediones reduces in-stent restenosis. The aim of this study was to elucidate the mechanism of the efficacy of pioglitazone for preventing in-stent restenosis in type 2 diabetic patients. RESEARCH DESIGN AND METHODS We conducted a prospective, randomized trial involving 54 type 2 diabetic patients referred for coronary stenting who were randomly assigned to either the control or the pioglitazone group. Quantitative coronary angiography was performed at study entry and at 6 months follow-up. Endothelial nitric oxide synthase (eNOS), tumor necrosis factor alpha, interleukin-6, leptin, and adiponectin were measured at study entry and at 6 months follow-up. RESULTS A total of 28 patients were randomly assigned to the control group, and 26 patients were assigned to the pioglitazone group. There were no significant differences in glycemic control levels or in lipid levels in the two groups at baseline or at follow-up. Insulin, homeostasis model assessment of insulin resistance, eNOS, and leptin at follow-up were significantly reduced in the pioglitazone group compared with the control group. The late luminal loss and in-stent restenosis were significantly less in the pioglitazone group than in the control group. Leptin independently correlated with late luminal loss at multiple regression analysis. CONCLUSIONS The treatment with pioglitazone in type 2 diabetic patients significantly reduced leptin. This decreased leptin improved insulin resistance and endothelial function with the reduction of insulin. The improved endothelial function affected the reduction of in-stent restenosis.
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Sakurai M, Mullen KT. Peripheral chromatic sensitivity for rectified stimuli in each cone-opponent system. J Vis 2005. [DOI: 10.1167/5.8.1017] [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] Open
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Suematsu T, Sato A, Sakurai M, Watanabe K, Ohtsuki T. A unique tRNA recognition mechanism of Caenorhabditis elegans mitochondrial EF-Tu2. Nucleic Acids Res 2005; 33:4683-91. [PMID: 16113240 PMCID: PMC1188084 DOI: 10.1093/nar/gki784] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2005] [Revised: 08/04/2005] [Accepted: 08/04/2005] [Indexed: 12/03/2022] Open
Abstract
Nematode mitochondria expresses two types of extremely truncated tRNAs that are specifically recognized by two distinct elongation factor Tu (EF-Tu) species named EF-Tu1 and EF-Tu2. This is unlike the canonical EF-Tu molecule that participates in the standard protein biosynthesis systems, which basically recognizes all elongator tRNAs. EF-Tu2 specifically recognizes Ser-tRNA(Ser) that lacks a D arm but has a short T arm. Our previous study led us to speculate the lack of the D arm may be essential for the tRNA recognition of EF-Tu2. However, here, we showed that the EF-Tu2 can bind to D arm-bearing Ser-tRNAs, in which the D-T arm interaction was weakened by the mutations. The ethylnitrosourea-modification interference assay showed that EF-Tu2 is unique, in that it interacts with the phosphate groups on the T stem on the side that is opposite to where canonical EF-Tu binds. The hydrolysis protection assay using several EF-Tu2 mutants then strongly suggests that seven C-terminal amino acid residues of EF-Tu2 are essential for its aminoacyl-tRNA-binding activity. Our results indicate that the formation of the nematode mitochondrial (mt) EF-Tu2/GTP/aminoacyl-tRNA ternary complex is probably supported by a unique interaction between the C-terminal extension of EF-Tu2 and the tRNA.
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Sakurai M, Ohtsuki T, Suzuki T, Watanabe K. Unusual usage of wobble modifications in mitochondrial tRNAs of the nematode Ascaris suum. FEBS Lett 2005; 579:2767-72. [PMID: 15907479 DOI: 10.1016/j.febslet.2005.04.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2005] [Revised: 04/05/2005] [Accepted: 04/07/2005] [Indexed: 10/25/2022]
Abstract
To understand the decoding property of nematode mitochondrial tRNAs with unusual secondary structures, post-transcriptional modifications at wobble positions of Ascaris suum mitochondrial tRNAs corresponding to two-codon families ending with a purine were analyzed. 5-Carboxymethylaminomethyluridine (cmnm(5)U) was identified at the wobble positions of tRNA(Lys), tRNA(Glu) and tRNA(Gln), while 5-carboxymethylaminomethyl-2-thiouridine (cmnm(5)s(2)U) was present in tRNA(UAA)(Leu)andtRNA(Trp). In most bacterial and mitochondrial tRNAs, the 2-thiouridine derivative is present in tRNAs for Lys, Glu and Gln. These is no report that cmnm(5)s(2)U is used in tRNA(UAA)(Leu)andtRNA(Trp). The unusual usage of wobble modifications might assist decoding of nematode mitochondrial mRNAs.
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Sakurai M, Ohtsuki T, Watanabe K. Modification at position 9 with 1-methyladenosine is crucial for structure and function of nematode mitochondrial tRNAs lacking the entire T-arm. Nucleic Acids Res 2005; 33:1653-61. [PMID: 15781491 PMCID: PMC1069008 DOI: 10.1093/nar/gki309] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The mitochondria of the nematode Ascaris suum have tRNAs with unusual secondary structures that lack either the T-arm or D-arm found in most other organisms. Of the twenty-two tRNA species present in the mitochondria of A.suum, twenty lack the entire T-arm and two serine tRNAs lack the D-arm. To understand how such unusual tRNAs work in the nematode mitochondrial translation system, we analyzed post-transcriptional modifications of 11 mitochondrial tRNA species purified from A.suum, 10 of which lacked a T-arm and one of which lacked a D-arm. The most characteristic feature of nematode mitochondrial tRNAs lacking a T-arm was the presence of 1-methyladenosine at position 9 (m1A9). Synthesis of T-armless tRNAs with or without the modified nucleoside showed that T-armless tRNAs without the modification had much lower aminoacylation and EF-Tu-binding activities than native tRNAs. The addition of a single methyl group to A9 of these tRNAs was sufficient to restore nearly native levels of aminoacylation and EF-Tu-binding activity as well as tertiary structure, suggesting that m1A9 is a key residue for the activity of T-armless tRNAs. Thus, m1A9 is indispensable for the structure and function of T-armless tRNAs of nematode mitochondrial origin.
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Sakurai M, Yoshimori A. Bandwidth analysis of solvation dynamics in a simple liquid mixture. J Chem Phys 2005; 122:104509. [PMID: 15836334 DOI: 10.1063/1.1857480] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The time-dependent energy distribution of solvation dynamics is studied by molecular dynamics simulations of a Lennard-Jones mixture. We calculate the response functions of the average and the variance which correspond to the spectral peak shift and bandwidth. Our calculation shows that the variance relaxation is slower than that of the average. The result agrees qualitatively with the experimental results. Dividing the obtained response functions into subcomponents caused by each solvent, we find that the relaxation is dominated by that solvent which strongly interacts with the solute. Extracting the redistribution component from the response functions, we find that it causes the slower relaxation of the response function. Thus, we conclude that the difference of the slower relaxations between the average and variance is caused by the redistribution process.
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Ohno T, Sakurai M. Critical period for activity-dependent elimination of corticospinal synapses in vitro. Neuroscience 2005; 132:917-22. [PMID: 15857697 DOI: 10.1016/j.neuroscience.2005.01.056] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2004] [Revised: 01/04/2005] [Accepted: 01/25/2005] [Indexed: 11/24/2022]
Abstract
There is no in vitro model of the critical periods for developmental plasticity, the time windows of plastic changes during development, which may hinder in-depth mechanistic analysis. We have shown previously that the corticospinal tract with synaptic connections can be reconstructed in in vitro co-cultures using slices of the sensorimotor cortex and spinal cord of the rat. In our in vitro system, corticospinal synapses form widely over spinal gray matter during early development, after which those on the ventral side are eliminated in an activity and N-methyl-D-aspartate (NMDA)-dependent manner. A detailed quantitative analysis of the time course of sensitivity to an NMDA blocker was made with this system. Synapse distribution was evaluated by recording field excitatory post-synaptic potentials evoked by deep cortical layer stimulation. Corticospinal axon terminal distribution was examined by anterograde labeling with biocytin. We showed that the D-2-amino-5-phosphonovaleric acid (APV) effect is irreversible for at least the length of culture. When APV was removed from the medium before 6 days in vitro(DIV) or after 11 DIV, elimination of ventral synapses was not blocked. APV sensitivity showed a clearly defined time window. A 6-11 DIV application was necessary and sufficient for the full, irreversible block of synapse elimination. From 6-11 DIV, APV sensitivity seems to decrease gradually but not linearly. This system provides an in vitro model of critical periods for developmental plasticity of central synapses which up to now has not been available.
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Betsuyaku T, Yonezawa K, Sakurai M, Kitabatake A. Positional Ventricular Tachycardia. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2004; 27:1437-9. [PMID: 15511255 DOI: 10.1111/j.1540-8159.2004.00650.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A 60-year-old man showed nonsustained repetitive monomorphic VT in the left lateral position, but this was terminated by deep inspiration. Echocardiography and MRI demonstrated a false tendon extending from the apex to the basal septum where the VT could have originated. Spontaneous remission occurred during the 16-year follow-up.
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Sakurai M, Thirstrup C, Aono M. Optical selection rules in light emission from the scanning tunneling microscope. PHYSICAL REVIEW LETTERS 2004; 93:046102. [PMID: 15323776 DOI: 10.1103/physrevlett.93.046102] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2004] [Indexed: 05/24/2023]
Abstract
It is reported that optical selection rules still apply in light emission from the scanning tunneling microscope (STM). Linear polarization of isochromat light emitted from the tunneling gap between a STM tip made of tungsten (W) and a silicon (Si) sample with a (001) clean surface strongly depends on the bias voltage between tip and sample. The results show that pi* and sigma* surface states, for example, of the Si(001) sample contribute to emission of p- and s-polarized light, respectively, in accordance with optical selection rules.
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Kaburaki T, Sato S, Kawashima H, Sakurai M, Numaga J, Fujino Y, Araie M. A hypopyon is a sign of post-trabeculectomy endophthalmitis or not? Eye (Lond) 2004; 19:692-3. [PMID: 15184940 DOI: 10.1038/sj.eye.6701556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Takamura T, Sakurai M, Ota T, Ando H, Honda M, Kaneko S. Genes for systemic vascular complications are differentially expressed in the livers of type 2 diabetic patients. Diabetologia 2004; 47:638-47. [PMID: 15298340 DOI: 10.1007/s00125-004-1366-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
AIMS/HYPOTHESIS Type 2 diabetes is characterised by excessive hepatic glucose production and frequently leads to systemic vascular complications. We therefore analysed the relationship between the gene expression profile in the liver and the pathophysiology of Type 2 diabetes. METHODS Liver biopsy samples were obtained from twelve patients with Type 2 diabetes and from nine non-diabetic patients. To assay gene expression globally in the livers of both groups, we made complementary DNA (cDNA) microarrays consisting of 1080 human cDNAs. Relative expression ratios of individual genes were obtained by comparing cyanine 5-labelled cDNA from the patients with cyanine 3-labelled cDNA from reference RNA from the liver of a non-diabetic patient. RESULTS On assessing the similarities of differentially expressed genes, the gene expression profiles of the twelve diabetic patients formed a separate cluster from those of the non-diabetic patients. Of the 1080 genes assayed, 105 (9.7%) were up-regulated and 134 (12%) were down-regulated in the diabetic livers (p<0.005). The genes up-regulated in the diabetic patients included those encoding angiogenic factors such as vascular endothelial growth factor, endothelin and platelet-derived growth factor. They also included TGF superfamily genes such as TGFA and TGFB1 as well as bone morphogenetic proteins. Among the down-regulated genes in the diabetic patients were molecules defending against stress, e.g. flavin-containing monooxygenase and superoxide dismutase. CONCLUSIONS/INTERPRETATION These findings suggest that livers of patients with Type 2 diabetes have gene expression profiles indicative of an increased risk of systemic vascular complications.
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MESH Headings
- Adult
- Aged
- Cytokines/metabolism
- DNA, Complementary/biosynthesis
- DNA, Complementary/genetics
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/pathology
- Diabetes Mellitus, Type 2/physiopathology
- Diabetic Angiopathies/genetics
- Diabetic Angiopathies/pathology
- Diabetic Angiopathies/physiopathology
- Female
- Fluorescent Dyes
- Gene Expression Regulation/physiology
- Humans
- Image Processing, Computer-Assisted
- Liver/metabolism
- Liver/pathology
- Liver Cirrhosis/pathology
- Male
- Middle Aged
- Multigene Family/genetics
- Oligonucleotide Array Sequence Analysis
- RNA, Antisense
- RNA, Messenger/biosynthesis
- RNA, Messenger/isolation & purification
- Reverse Transcriptase Polymerase Chain Reaction
- Risk Assessment
- Signal Transduction/genetics
- Stress, Physiological/physiopathology
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Tabayashi K, Takahashi G, Motoyoshi N, Kokubo H, Sakurai M, Oda K, Saiki Y, Iguchi A. [Spinal cord protection during most or all of descending thoracic or thoracoabdominal aneurysm repair]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 2004; 57:301-6. [PMID: 15071864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
OBJECTIVES The purpose of this study is to evaluate usefulness of perfusion cooling for regional spinal cord hypothermia during most or all of thoracic or thoracoabdominal aneurysm repair. METHODS From 1987 to 2003, 103 patients underwent most or all of thoracic or thoracoabdominal aneurysm repair. Forty-eight patients underwent operation using distal aortic perfusion, mild hypothermia and segment sequential repair (group MH). Fifty-five patients underwent the same operation as group MH except epidural perfusion cooling and drainage of cerebrospinal fluid (CSF) [group EC & CSFD]. The aorta was replaced sequentially in segment and several paris of intercostal and lumbar arteries were reconstructed in 2 groups. RESULTS Cardiopulmonary bypass time of group MH and group EC & CSFD was averaged 235 and 241 minutes, respectively. The lowest CSF temperature in group EC & CSFD was averaged 24.7 degrees C, and the difference between nasopharyngeal and CSF temperature was averaged 6.4 degrees C. The rate of spinal cord injury of group MH and EC & CSFD was 10.4% and 3.6%, respectively. Hospital mortality of group MH and EC & CSFD was 8.3% and 5.5%, respectively. The incidence of spinal cord injury and hospital mortality of group EC & CSFD were decreased compared to them of group MH. CONCLUSION We conclude that the perfusion cooling of epidural space and CSF drainage are effective method in reducing postoperative spinal cord injury.
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Tsuchiyama N, Ando H, Ota T, Sakurai M, Takamura T. Modulating effects of olanzapine on the development of diabetic ketoacidosis. Diabet Med 2004; 21:300-1. [PMID: 15008848 DOI: 10.1111/j.1464-5491.2004.01113.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Motoyoshi N, Takahashi G, Sakurai M, Tabayashi K. Safety and efficacy of epidural cooling for regional spinal cord hypothermia during thoracoabdominal aneurysm repair⋆. Eur J Cardiothorac Surg 2004; 25:139-41. [PMID: 14690749 DOI: 10.1016/s1010-7940(03)00677-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Twenty-four consecutive patients underwent epidural cooling as an adjunct to elective thoracoabdominal aortic repair under moderate systemic hypothermia. One patient suffered from postoperative paraplegia (4%), and another died from subarachnoidal hemorrhage (4%). Details of the technique, the associated care, and the pitfalls will be discussed.
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