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Biomedical subjects

H Sugiyama

Publications and source records attributed to H Sugiyama.

At least 37 records · Page 2Linked to original sources
PubMed2003

Effects of heat stress and mechanical stretch on protein expression in cultured skeletal muscle cells.

Effects of heat stress, mechanical stretching or a combination of both on the expression of heat shock proteins (HSPs) and total protein level were studied in a culture system. Rat skeletal muscle cells (L6) were cultured on flexible-bottomed culture plates. They were subjected to one of the four following conditions: (1) 97 h incubation at 37 degrees C, (2) 1 h incubation at 41 degrees C followed by 96 h incubation at 37 degrees C, (3) 1 h incubation at 37 degrees C followed by 96 h cyclic stretching (18% of initial length, 2-s stretch and 4-s release) at 37 degrees C or (4) 1 h incubation at 41 degrees C followed by 96 h cyclic stretching at 37 degrees C. The expression of HSP72 and HSP90 and total protein was determined in the crude homogenates, supernatant and pellets. Cellular protein concentrations in the homogenates and pellets were increased by heat stress and/or mechanical stress (stretch). A cumulative effect of the combination of heating and stretch on the protein concentration in the homogenates and in the pellets was noted. The expressions of HSP72 and HSP90 in the pellets were also increased by heat stress and/or stretch. However, HSP90 in the supernatant did not change following heat stress and/or stretch. The regulation of HSP72 and HSP90 expression in skeletal muscle cells may be closely related to total protein, the abundance of which is also stimulated by mechanical and heat stresses. These observations suggest strongly that heating and passive stretch of muscle may be useful as a means of increasing muscle mass, not only in athletes but also in patients during rehabilitation.

Animals↗
PubMed2003

Enhancement of neurogenesis by running wheel exercises is suppressed in mice lacking NMDA receptor epsilon 1 subunit.

Neurogenesis continues throughout adulthood in the dentate gyrus in mice, and is regulated by environmental, endocrine, and pharmacological stimuli. Although running wheel exercises have been reported to enhance neurogenesis, details of molecule mechanisms of the enhancement are not well understood. We report here that the hippocampal neurogenesis is enhanced when wild-type mice are raised in cages with running wheels for 3 weeks, but the wheel exercise does not enhance the neurogenesis in mice lacking the NMDA receptor epsilon1 subunit. Brain-derived neurotrophic factor (BDNF) has been reported to affect neuronal cell proliferation and survival. We examined the BDNF levels in the hippocampi of wild-type and epsilon1 knockout mice, and found that the BDNF level was increased through wheel exercises in the wild-type but not in the knockout mice. The enhancement of neurogenesis by the wheel exercise was also found to be reversible: when the exercise-stimulated wild-type mice were returned to the environment without running wheels for 3 weeks, the neurogenesis was the same as that in the mice which had never experienced the exercise. These results suggest that the wheel exercise may activate NMDA receptors in the hippocampus, which in turn may enhance BDNF production and neurogenesis.

Animals↗
PubMed2003

Successful treatment of refractory T-cell acute lymphoblastic leukemia by unmanipulated stem cell transplantation from an HLA 3-loci mismatched (haploidentical) sibling.

We describe a patient with refractory T-cell acute lymphoblastic leukemia who successfully underwent unmanipulated stem cell transplantation from an HLA 3-loci mismatched (haploidentical) sibling. In order to avoid severe graft-versus-host disease (GVHD), we used intensified GVHD prophylaxis consisting of tacrolimus, a short course of methotrexate, methylprednisolone, and mycophenolate mofetil. Hematopoietic reconstitution was rapid, with neutrophil count >5 x 10(8)/l on day +16, and platelet count >2 x 10(10)/l on day +25. There was no evidence of clinical acute GVHD. Bacterial, fungal, and viral infections were well controlled with antibiotics. The patient is still in complete remission past day +400. We suggest that unmanipulated HLA-mismatched transplantation with intensified GVHD prophylaxis is an alternative option for patients who do not have an HLA-identical donor.

Adult↗
PubMed2003

Successful treatment of bcr/abl-positive acute mixed lineage leukemia by unmanipulated bone marrow transplantation from an HLA-haploidentical (3-antigen-mismatched) cousin.

We describe a patient with bcr/abl-positive acute mixed lineage leukemia who successfully underwent transplantation in primary induction failure, using unmanipulated bone marrow from a human leukocyte antigen (HLA)-haploidentical cousin. The tumor burden was successfully reduced by the administration of imatinib mesylate (STI571) before transplantation. As graft-versus-host disease (GVHD) prophylaxis, a combination of tacrolimus and a short course of methotrexate, methylprednisolone, and mycophenolate mofetil was used. Hematopoietic reconstitution was rapid, and acute GVHD was limited to the skin (grade I). The patient is still in complete remission past day +400. This successful case suggests that HLA-haploidentical transplantation using unmanipulated marrow from a distantly related relative can be considered for patients in urgent situations who do not have HLA-identical donors.

Adult↗
PubMed2003

Ntg1 and Ntg2 proteins as 5-formyluracil-DNA glycosylases/AP lyases in Saccharomyces cerevisiae.

PURPOSE: 5-Formyluracil (5-foU) is a potentially mutagenic lesion of thymine produced in DNA by ionizing radiation and various chemical oxidants. The present authors reported previously that MutM, Nth and Nei in Escherichia coli removed 5-foU from DNA. The present study identified 5-foU DNA glycosylases in Saccharomyces cerevisiae in order to clarify the repair mechanisms of 5-foU in eukaryotic cells. MATERIALS AND METHODS: The borohydride-trapping assay and DNA-nicking assay were carried out to detect and characterize the repair activities for 5-foU in extracts from S. cerevisiae with oligonucleotides containing 5-foU at specific sites. RESULTS: Two proteins in crude extracts from S. cerevisiae formed covalent complexes with oligonucleotides containing site-specific 5-foU in the presence of NaBH4. Extracts from S. cerevisiae strains defective in either the NTG1 or the NTG2 gene lacked either one or the other of these two proteins. Purified Ntg1 and Ntg2 were trapped in such complexes by the 5-foU-containing oligonucleotides in the presence of NaBH4. Furthermore, purified Ntg1 and Ntg2 efficiently cleaved the oligonucleotide at the 5-foU site. CONCLUSIONS: The results indicate that both Ntg1 and Ntg2 are involved in the repair of 5-foU in DNA, and thereby serve to reduce mutations in S. cerevisiae.

Base Sequence↗
PubMed2002

Mid-term outcome after partial left ventriculectomy in pediatric patients.

From May 1998 to April 2000, we performed partial left ventriculectomy (PLV) in 3 pediatric patients with dilated cardiomyopathy (DCM). At the time of the surgery, their age ranged from eight months to three years. The first patient eventually had to receive a heart transplant, but all patients treated with PLV are alive to this day. Patient #1 was diagnosed with DCM at the age of five months, PLV was done on a semi-urgent basis at the age of eight months, when medium dose IV catecholamine therapy and mechanical ventilation were required. Fraction shortening (FS) as shown by echocardiography increased postoperatively from 8% to 15% along with marked clinical improvement. Her heart failure deteriorated three months after the surgery, and received a heart transplant in the United States when she was one year and two months old. Patient #2 developed severe heart failure two months after correction of a ventricular septal defect. Aggressive medical therapy failed to improve his condition, therefore PLV was done on an elective basis at the age of three years and five months. [The patient was initially hospitalized and underwent low dose catecholamine.] Postoperative course was well. The ventriculography one year after surgery showed an improvement of the left ventricular FS from 12% to 27% after PLV. He was still doing well at his most recent check up. Patient #3 was diagnosed with DCM as a neonate. PLV was done on an elective basis at the age of two years and five months. Her postoperative course was generally well. FS on echocardiography increased postoperatively from 10% to 25% along with marked clinical improvement. The timing of performing PLV is the most essential factor for postoperative course in our experiences. We consider that the best timing is when aggressive catecholamine infusion or mechanical ventilation is required. The mid-term outcome of PLV of pediatric patients is considered to be acceptable. We believe that PLV should be considered as a viable option for severe DCM patients.

Cardiac Surgical Procedures↗
PubMed2002

Application of synchrotron X-ray imaging to phase objects in orthopedics.

Novel imaging of the fine structures of the ribs of a pig and a specimen of human osteosarcoma utilizing the spatial coherence of X-rays was successfully performed with an incident X-ray energy of 30 keV at SPring-8, Japan. The image contrast appearing at the periphery of trabecular bone, small calcifications and small fractures is caused by the phase shift of the X-rays at the boundary of these objects that have different X-ray refractive indices. The image is recorded on mammography film without an intensifying screen. Comparison of the image contrast using different sample-to-film distances, Z, such as Z = 5 m and Z approximately 0 m, showed that the former images were always more informative, i.e. better in resolution and/or image contrast when imaging trabecular bone, bone marrow and small fractures in compact bone, and for imaging cartilage. Radiography using synchrotron X-rays for phase objects should be a powerful tool for diagnosis in orthopedics, especially for bone disease.

Animals↗
PubMed2002

Polymerase chain reaction (PCR)-based molecular discrimination between Paragonimus westermani and P. miyazakii at the metacercarial stage.

The metacercariae of the lung flukes, Paragonimus westermani and P. miyazakii, are of known medical importance as the pathogens causing human paragonimiasis. They are both found in the same freshwater crab species in Japan and are morphologically quite similar. The aim of the present study was to establish molecular methods for accurate discrimination between individual metacercariae of the two species. In the first step, we amplified and sequenced the second internal transcribed spacer (ITS2) region of ribosomal DNA. Searches of nucleotide databases revealed that the ITS2 sequences generated from the metacercarial DNA were identical to those previously reported for the adults of the respective species. Utilizing a nucleotide difference between the two species, we have established two PCR-based techniques; PCR-restriction fragment length polymorphism and direct PCR-amplification using species-specific primers. Both techniques showed that the individual metacercariae of the two species could be unequivocally discriminated from one another. The present results suggest that the ITS2 region is useful for species discrimination irrespective of the life cycle stages of the lung flukes. Established techniques can thus be used for epidemiological investigations of the prevalence of human lung fluke metacercariae.

Animals↗
PubMed2002

The role of mast cells in the development of 2, 4, 6-trinitrobenzene sulfonic acid-induced colitis in rats.

BACKGROUND: The role of mast cells in Crohn disease (CD) remains to be established. The aim of this study was to elucidate this in the development of CD-like colitis in rats by the use of mast-cell-deficient Ws/Ws and their control W+/W+ rats. METHODS: CD-like colitis was induced in both groups by an enema of 10 mg of 2,4, 6-trinitrobenzene sulfonic acid (TNBS) in 50% ethanol. Colonic damage, adhesion and colonic weight were measured at 7 and 14 days after the TNBS/ethanol enema. Rat mast cell protease-2 (RMCP-2) in the colonic tissue was also measured at 7 days after the enema. RESULTS: There was no significant difference between W+/W+ and Ws/Ws rats in terms of colonic damage, adhesion or colonic weight. The tissue content of RMCP-2 in Ws/Ws rats treated with either saline or TNBS/ethanol was only maintained at a much lower level than that in W+/W+ rats with the corresponding treatment. CONCLUSIONS: These results demonstrate that mast cells are not essential in the development of 2, 4, 6-trinitrobenzene sulfonic acid-induced colitis in rats.

Animals↗
PubMed2002

Characterization of 2-hydroxyadenine DNA glycosylase activity of Escherichia coli MutY protein.

PURPOSE: 2-Hydroxyadenine (2-ohA) is an oxidation product of adenine generated in DNA by ionizing radiation and various chemical oxidants. 2-ohA has mutational potential comparable to that of 8-oxoguanine in bacteria and mammalian cells. Recent studies have shown that 2-ohA is removed from DNA by a human MutY homolog, MYH protein, in vitro. On the other hand, the repair mechanisms for 2-ohA in Escherichia coli are not yet understood. MATERIALS AND METHODS: Gel shift assays were used to assess the binding activity of E. coli full-length MutY protein and its N-terminal (residues 1-226) domain (M25) to 2-ohA/G-, 2-ohA/A-, 2-ohA/C- and 2-ohA/T-containing 24-mer oligonucleotides. Furthermore, whether these proteins specifically cleave 2-ohA-containing duplex oligonucleotides was examined. RESULTS: The purified MutY and M25 proteins had similar binding affinities to 2-ohA/G-, 2-ohA/A- and 2-ohA/C-containing oligonucleotides. MutY protein removed 2-ohA preferentially from 2-ohA/G mispairs. M25 protein showed the reduced catalytic activity for 2-ohA/G-containing oligonucleotides. CONCLUSIONS: E. coli MutY protein has a DNA glycosylase activity that removes 2-ohA from 2-ohA/G mispairs in DNA. The C-terminal domain is required for the removal of 2-ohA from DNA, but is not crucial for binding to 2-ohA-containing oligonucleotides.

DNA↗
PubMed2002

WT1 as a novel target antigen for cancer immunotherapy.

Wild-type Wilms' tumor gene WT1 is expressed at high levels not only in most of acute myelocytic, acute lymphocytic, and chronic myelocytic leukemia, but also in various types of solid tumors including lung cancer. We tested the ability of the gene product (WT1) to serve as a target antigen for tumor specific immunotherapy both in human in vitro system and mouse in vivo system. In the latter, we can evaluate the efficacy and the side effects of WT1 vaccination in vivo. In the human in vitro system, two WT1 peptides that contain HLA-A2.1 binding anchor motifs were determined to bind to HLA-A2.1 molecules. Peripheral blood mononuclear cells (PBMC) from an HLA-A2.1-psitive donor were repeatedly stimulated in vitro with TAP-deficient T2 cells pulsed with each of these two peptides, and CD8-positive cytotoxic T lymphocytes (CTLs) that specifically lyse WT1-expressing, HLA-A2.1-positive tumor cells were induced. Other groups also have succeeded in generating CTLs which specifically lyse WT1-expressing leukemia cells, and which do not inhibit colony-formation of normal hematopoietic cells that express WT1 at physiological levels. In the mouse in vivo system, immunization of C57BL/6 mice with one WT1 peptide with relatively high binding affinity for H-2D(b) molecules, which contain H-2D(b) binding anchor motifs, induced CTLs, which specifically lysed WT1-expressing tumor cells in an H-2D(b)-restricted manner. Furthermore, mice immunized with the WT1 peptide (peptide vaccination) or WT1 cDNA (DNA vaccination) rejected challenges by WT1-expressing tumor cells and survived with no signs of auto-aggression to WT1-expressing normal organs by the induced CTLs. The WT1 protein has been identified as a novel tumor antigen and recent investigations provide a rationale for developing WT1-based adoptive T cell therapy and vaccination against various kinds of malignant neoplasms.

Animals↗
PubMed2001

Effects of proteasome inhibitors on the synaptic localization of Vesl-1S/Homer-1a proteins.

The Vesl-1S/Homer-1a proteins are upregulated during seizure and long-term potentiation, but are rapidly degraded by ubiquitin-proteasome systems under normal conditions. We examined the distribution of Vesl-1S proteins in cultured hippocampal neurons. Application of proteasome inhibitors caused accumulation of Vesl-1S immunoreactivity in the neurons which showed a punctate distribution in the cortical regions of the cells, and these puncta were found to be juxtaposed with synaptophysin, a presynaptic, synapse-specific protein. These results suggest that Vesl-1S protein is synaptically targeted.

Acetylcysteine↗
PubMed2001

Expression of vesl-1S/homer-1a, a gene associated with long-term potentiation, in the brain of the epileptic EI mouse.

The El mouse is an animal model for hereditary epilepsy. It undergoes a convulsive seizure lasting 10-30 s after vestibular stimulation, such as "tossing-up". To better characterize the effects of seizure activity in the El mouse, we examined the expression profile of vesl-1S/homer-1a mRNA in the brain. It has been shown that this mRNA is expressed after long-term potentiation or seizures induced by electrical or pharmacological stimulations. The basal level of vesl-1S mRNA was very low even in seizure-susceptible El mice. The El mouse hippocampus, but not that of ddY mice, showed a remarkable increase in vesl-1S mRNA expression in the dentate granule cell layer after seizure induced by "tossing-up". The mRNA remained for about 3 h after the seizure and disappeared after 8 h.

Animals↗
PubMed2001

Facile allylic C-H bond activation on the bridging disulfide ligand in the Ru(III) dinuclear complex having a conjugated RuSSRu core.

Treatment of [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)](2)(mu-S(2))](CF(3)SO(3))(4) (1), which is prepared by the reaction of [[RuCl(P(OCH(3))(3))(2)](2)(mu-S(2))(mu-Cl)(2)] (2) with 4 equiv of AgCF(3)SO(3), with terminal alkenes such as 1-pentene, allyl ethyl ether, allyl phenyl ether, 1,4-hexadiene, and 3-methyl-1-butene, resulted in the formation of complexes carrying a C(3)S(2) five-membered ring, [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)](2)[mu-SCH(2)CH(2)CR(1)R(2)S]](CF(3)SO(3))(4) (3, R(1) = CH(2)CH(3), R(2) = H, 40%; 4, R(1) = OCH(2)CH(3), R(2) = H, 60%; 5, R(1) = OC(6)H(5), R(2) = H, 73%; 6, R(1) = CH=CHCH(3), R(2) = H, 48%; 7, R(1) = R(2) = CH(3), 40%). Reaction of 1 with methylenecycloalkanes was found to give several different types of products, depending on the ring size of the substrates. A trace of [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)](2)[mu-SCH(CH(2)CH(2))CH(CH(3))S]](CF(3)SO(3))(4) (9) having a C(2)S(2) four-membered ring to bridge the two Ru atoms was obtained by the reaction of 1 with methylenecyclobutane, whereas the reaction with methylenecyclohexane gave [[Ru(P(OCH(3))(3))(2)(CH(3)CN)(3)](2)[mu-S(CH(2)(C=CHCH(2)CH(2)CH(2)CH(2))S)](CF(3)SO(3))(3) (10) in 69% yield via C-S bond formation and elimination of a proton. Throughout these reactions with alkenes giving a variety of products, the activation of the allylic C-H bond is always the essential and initial key step.

Journal Article↗
PubMed2001

Structural determination of an exocellular mannan from Rhodotorula mucilaginosa YR-2 using ab initio assignment of proton and carbon NMR spectra.

The structure of the title mannan was determined exclusively by NMR. Because of the short relaxation time of the native mannan (100 kDa), a partially hydrolyzed mannan (10 kDa) was used for proton assignments by COSY, to correlate proton and carbon signals by HMQC, and to determine linkage positions between residues by HMBC. A further hydrolyzed mannan (oligomers of approximately 1.5 kDa) was used to determine the anomeric configuration, using Wilker's quasi-3D method [Wilker, W.; Leibfritz, D. Magn. Reson. Chem. 1995, 33, 632-638]. The procedure presented here can be used to determine the structure of any polysaccharide.

Carbon Isotopes↗
PubMed2001

Synthesis of 6-(2-thienyl)purine nucleoside derivatives that form unnatural base pairs with pyridin-2-one nucleosides.

Unnatural bases, 2-amino-6-(2-thienyl)purine and 2-amino-6-(2-furanyl)purine, were newly designed to replace the previously developed purine analogue, 2-amino-6-(N,N-dimethylamino)purine, which specifically pairs with pyridin-2-one. These nucleoside derivatives were synthesized via the 6-substitution of 6-iodopurine nucleosides with tributylstannylthiophene or tributylstannylfuran. As compared with 2-amino-6-(N,N-dimethylamino)purine, 2-amino-6-(2-thienyl)purine reduced the interference in the stacking interactions with the neighboring bases in a DNA duplex and improved the efficiency of the enzymatic incorporation of the nucleoside triphosphate of pyridin-2-one opposite the unnatural base.

Base Pairing↗