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Biomedical subjects

S Hayashi

Publications and source records attributed to S Hayashi.

At least 37 records · Page 2Linked to original sources
PubMed2004

Allogeneic peripheral blood stem cell transplantation from two- or three-loci-mismatched related donors in adult Japanese patients with high-risk hematologic malignancies.

With the increasing frequency of haploidentical transplantation, it is becoming more important to establish the degree of HLA mismatch that can be accepted. We retrospectively analyzed clinical data of 50 adult Japanese patients with high-risk hematologic malignancies who underwent allogeneic peripheral blood stem cell transplantation (PBSCT) from two- or three-loci-mismatched related donors with HLA class I and II gene disparities in the graft-versus-host direction. They were treated at 20 transplant centers between 1996 and 2002. In all, 18 patients received unmanipulated PBSC, while 32 received purified CD34+ blood cells. Conventional (n=31) or reduced-intensity (n=19) conditioning regimens were used. Of the 39 patients (78%) who survived for > or =28 days after transplant, 37 (95%) achieved neutrophil engraftment, while graft failure and rejection occurred in two of 39 (5%) and three of 37 (8%) patients, respectively. Stepwise Cox regression analysis revealed a significantly lower incidence of grades II-IV acute GVHD in patients receiving purified CD34+ cells (hazard ratio 0.32; 95% CI 0.12-0.84; P=0.022). By 1 year post transplant, 28 patients (56%) had died of transplant-related problems, including infectious complications (30%). Although the number of patients is small, our data suggest that transplant-related problems, particularly infectious complications, are major obstacles to the success of this therapy.

Adolescent↗
PubMed2004

Cathepsin D, but not cathepsin E, degrades desmosomes during epidermal desquamation.

BACKGROUND: We previously reported that an ambient aspartic proteinase is crucial to desquamation of the stratum corneum at pH 5. Identification of this aspartic proteinase by using enzyme inhibitors suggested it to be cathepsin D, although we could not exclude cathepsin E. OBJECTIVES: To determine the identity of this aspartic proteinase and its distribution within the stratum corneum. METHODS: We measured enzyme activities of cathepsin D and cathepsin E in the salt and detergent extracts from callus stratum corneum, using a fluorogenic peptide as a substrate and comparing the effect of addition of Ascaris pepsin inhibitor (specific for cathepsin E) with that of pepstatin A (which inhibits both cathepsin D and cathepsin E). Both enzymes were then extracted and purified from plantar stratum corneum samples and identified by Western blotting. Immunofluorescence microscopy was used to investigate the localization of proteinases within human plantar stratum corneum sample sections. RESULTS: We found that 20% of total aspartic proteinase activity could be attributed to cathepsin E, the remainder to cathepsin D. Two subunits of cathepsin D were identified, a mature active form at 33 kDa and an intermediate active form at 48 kDa; cathepsin E was also identified at 48 kDa, although in a stained band 10-fold weaker in the immunoblot. Immunofluorescence microscopy showed the antibody to cathepsin D to be localized in the lipid envelopes of the stratum corneum, whereas that to cathepsin E stained the tissue diffusely. The labelling for cathepsin D was similar to that observed for desmosomes, and immunoelectron microscopy confirmed that cathepsin D was present on desmosomes. On the other hand, cathepsin E occurred intracellularly within the squames. CONCLUSIONS: We conclude that cathepsin D, and not cathepsin E, causes desquamation by degrading desmosomes.

Cathepsin D↗
PubMed2004

Retinoic acid disintegrated desmosomes and hemidesmosomes in stratified oral keratinocytes.

BACKGROUND: Although it is known that retinoic acid (RA) regulates the cellular differentiation of skin keratinocytes, the effects of RA on the anchoring junction have not been clarified. The effects of all-trans RA on cell-cell and cell-matrix connections of gingival epithelial (GE)1 cells in a multilayered culture were investigated. METHODS: Ultrastructures of GE1 cells were observed and immunohistochemistry was used to detect keratin 4, keratin 13, and desmoglein expression. Reverse transcription-polymerase chain reaction was performed to detect expression of desmosome and hemidesmosome-associating adhesion molecules, keratin 13, and keratin14. RESULTS: Retinoic acid caused immunohistochemical diminution of keratin 4, keratin 13, and desmoglein. Ultrastructurally, RA induced drastic loss of typical desmosomes and complete loss of hemidesmosomes. RA significantly decreased the transcript levels of keratin 13, keratin 14, desmoglein 1, and desmocollin 1 in a dose-dependent manner. The 230-kD bullous pemphigoid antigen (BPAG1) gene expression was also reduced by RA, whereas transcript levels of integrin alpha6, integrin beta4, the 180-kD bullous pemphigoid antigen (BPAG2), and laminin 5 were not affected. CONCLUSION: These results indicated that RA disintegrated not only desmosomes by depriving the cells of desmoglein 1, desmocollin 1, keratin 13, and keratin 4, but also hemidesmosomes by reducing the expression of BPAG1 and keratin 14 in basal keratinocytes.

Animals↗
PubMed2004

Using a DNA microarray method to examine gene expression in brain from clozapine-injected mice.

After our 2002 report on the changes of gene expression in the brain from phencyclidine-treated mouse by using DNA microarray (Toyooka et al., Ann. N.Y. Acad. Sci. 965: 10-20), we decided to apply this DNA microarray method for the brain of the mouse treated with other drugs. We are now examining the effects of clozapine on the brain function. Clozapine is an atypical antipsychotic drug. Clozapine has affinity for neurotransmitter receptors, including D4 dopamine, serotonin, histamine, and adrenergic receptors. MacGibbon et al. (Mol. Brain Res. 23: 21-32) reported that clozapine and haloperidol produced a differential pattern of immediate early gene expression in rat caudate-putamen. Kobayashi et al. (Br. J. Pharmacol. 123: 421-426) have observed the effects of clozapine on the opioid receptors and G-protein-activated inwardly rectifying potassium channel of Xenopus oocytes. Thomas et al. (J. Neurochem. 76: 789-796) found that clozapine increases apolipoprotein D expression in the mouse brain. Therefore, we are going to apply this DNA microarray method to examine the effects of clozapine on mouse brain function. After we injected clozapine into mice for 20 days, we decapitated the mice. We then used the DNA microarray method to examine the gene expression of mouse brain. We found some changes in the mouse brain treated with clozapine. For example, the intensity of a potassium channel spot decreased, and that of a serotonin receptor spot increased.

Animals↗
PubMed2004

Absence of mutations in the Wilms' tumor gene wt1 in de novo non-small cell lung cancers.

We recently demonstrated that the WT1 gene was overexpressed in the majority of de novo lung cancers regardless of cancer subtypes. Here, we examined WT1 genomic DNA in 38 cases of de novo non-small cell lung cancers (NSCLC) for mutations using direct sequencing. The sequencing analysis showed no mutations of WT1 genomic DNA in any of 38 de novo non-small cell lung cancers examined. These results indicated that the non-mutated, wild-type WT1 gene played an important role in de novo NSCLC.

Adult↗
PubMed2003

Restenosis of the sigmoid sinus after stenting for treatment of intracranial venous hypertension: case report.

We report what we believe to be the first case of restenosis of the sigmoid sinus after stenting, in a 42-year-old man with an arteriovenous malformation with progressive right hemiparesis secondary to venous hypertension. Angiography revealed severe stenosis of the left sigmoid sinus, which was dilated with a self-expandable stent. Six months after the procedure, however, the sinus was again severely stenosed. Intravascular sonography revealed intimal proliferation in the stented sinus. It was dilated percutaneously, and the venous pressure decreased from 51 to 33 mmHg. On sonography, the intimal tissue decreased in thickness and the diameter of the stent enlarged a little.

Adult↗
PubMed2003

Leptin as an adjunct of insulin therapy in insulin-deficient diabetes.

AIMS/HYPOTHESIS: The purpose of this study was to assess the therapeutic implication of leptin in insulin-deficient diabetes. METHODS: Insulin-deficient diabetes was induced by streptozotocin (STZ) in transgenic skinny mice overexpressing leptin. Plasma concentrations of glucose, insulin, and leptin were measured. The effects on body weight, food intake, and hypothalamic gene expressions were analyzed. After diabetes was induced, graded doses of insulin ranging from 0.4 to 51.2 mU.g(-1).day(-1) were injected. Co-administration of leptin and insulin was also carried out using osmotic pumps. RESULTS: After STZ injection, both transgenic and non-transgenic littermates developed marked hyperglycaemia as a result of severe hypoinsulinaemia [termed diabetic transgenic skinny mice overexpressing leptin (diabetic TGM) and diabetic non-transgenic littermates (diabetic WT) respectively], although diabetic TGM were more sensitive to exogenously administered insulin than diabetic WT. Diabetic WT were hypoleptinaemic and hyperphagic relative to non-diabetic WT, whereas diabetic TGM, which remained hyperleptinaemic, were less hyperphagic than diabetic WT. After STZ injection, hypothalamic expressions of orexigenic and anorexigenic peptide mRNAs were up-regulated and down-regulated, respectively, in diabetic WT, whereas they were unchanged in diabetic TGM. Diabetic TGM became normoglycaemic, when treated with insulin at such doses that did not improve hyperglycaemia in diabetic WT. We found that a sub-threshold dose of insulin that does not affect glucose homeostasis is effective in improving the diabetes in normal mice rendered diabetic by STZ injection, when combined with leptin. CONCLUSIONS/INTERPRETATION: This study suggests that leptin could be used as an adjunct of insulin therapy in insulin-deficient diabetes, thereby providing an insight into the therapeutic implication of leptin as an anti-diabetic agent.

Agouti-Related Protein↗
PubMed2003

Spinal epidural metastasis from pineal germinoma.

A 16-year-old boy first presented with a pineal tumour identified by neuroimaging but without positive serum or cerebrospinal fluid markers. The tumour disappeared after 50 Gy cranial irradiation. One year later he returned with spinal epidural metastasis from the pineal germinoma and required emergency surgery. Intraoperative findings showed that the spinal tumour had originated from cerebrospinal fluid dissemination and had passed through the spinal nerve sleeve. The pathologic diagnosis of the tumour was of a pure germinoma metastasis. An epidural tumour frequently requires emergency diagnosis and treatment. Attention should be paid to the possibility of this rare but serious clinical situation caused by a metastasis from a pineal germinoma.

Adolescent↗
PubMed2003

Influence of transplanted dose of CD56+ cells on development of graft-versus-host disease in patients receiving G-CSF-mobilized peripheral blood progenitor cells from HLA-identical sibling donors.

We investigated effects of variations in the cellular composition of G-CSF-mobilized peripheral blood progenitor cell (G-PBPC) allografts on clinical outcomes of allogeneic PBPC transplantation. We retrospectively analyzed transplanted doses of various immunocompetent cells from 27 HLA-identical sibling donors in relation to engraftment, incidence of graft-versus-host disease (GVHD), and survival. Significant variability was documented in both absolute numbers and relative proportions of CD34+, CD2+, CD3+, CD4(high)+, CD4+25+, CD8(high)+, CD19+, CD56+, and CD56+16+ cells contained in these allografts. Stepwise Cox regression analysis revealed that the CD56+ cell dose was significantly inversely correlated with the incidence of GVHD. Thus, there was a significantly higher incidence of grade II acute GVHD in patients receiving a lower CD56+16+ cell dose (hazard ratio (HR) 0.0090; 95% confidence interval (CI), <0.00001-3.38; P=0.031), a higher incidence of chronic GVHD in those receiving allografts with a lower CD56+16+ to CD34+ ratio (HR <0.00001; 95% CI <0.00001-0.0007; P=0.0035), and a higher incidence of extensive chronic GVHD in those receiving allografts with a lower CD56+ to CD34+ ratio (HR <0.00001; 95% CI <0.00001-0.053; P=0.0083). These results suggest that CD56+ cells in G-PBPC allografts from HLA-identical sibling donors may play an important role in preventing the development of GVHD.

Adult↗
PubMed2003

Role of mitogen-activated protein kinases in influenza virus induction of prostaglandin E2 from arachidonic acid in bronchial epithelial cells.

BACKGROUND: Influenza virus (IV) infection causes airway inflammation; however, it has not been determined whether IV infection could catabolize arachidonic acid cascade in airway epithelial cells. In addition, the responsible intracellular signalling molecules that catabolize arachidonic acid cascade have not been determined. OBJECTIVE: In the present study, to clarify these issues, we examined the cyclooxygenase (COX) expression, cytosolic phospholipase A2 (cPLA2) phosphorylation and prostaglandin E2 (PGE2) release in human bronchial epithelial cells (BEC) upon IV infection, and the role of mitogen-activated protein kinase (MAPK) including extracellular signal-regulated kinase (ERK), p38 MAPK and c-Jun-NH2-terminal kinase (JNK) in catabolizing arachidonic acid cascade in BEC. METHODS: COX-2 expression, phosphorylation of cPLA2 and phosphorylation of ERK, JNK and p38 MAPK were determined by Western blot. The concentrations of PGE2 were determined by ELISA. PD 98059 as a specific inhibitor of MAPK kinase-1 (MEK-1), an up-stream kinase of ERK, SB 203580 as a specific inhibitor of p38 MAPK and CEP-11004 as a specific inhibitor of JNK cascade were used to investigate the role of ERK, p38 MAPK and JNK in catabolizing arachidonic acid cascade in BEC. RESULTS: The results showed that (1) IV infection increases COX-2 expression, cPLA2 phosphorylation and PGE2 release, (2) ERK, p38 MAPK and JNK were phosphorylated, (3) CEP-11004 and PD 98059 predominantly attenuated COX-2 expression and cPLA2 phosphorylation, respectively, (4) SB 203580 did not remarkably affect COX-2 expression and cPLA2 phosphorylation, and (5) each inhibitor dose-dependently attenuated PGE2 release by various extents. CONCLUSION: These results indicate that IV infection activates three distinct MAPKs, ERK, p38 MAPK and JNK, to participate to various extents in the induction of PGE2 synthesis from arachidonic acid in BEC.

Arachidonic Acid↗
PubMed2003

Dipeptidyl peptidase IV on activated T cells as a target molecule for therapy of rheumatoid arthritis.

The extracellular domain of the T cell co-stimulatory molecule CD26 possesses dipeptidyl peptidase IV (DP IV) enzyme activity. Activated T cells are known to increase expression of cell surface DP IV and some specific inhibitors of this enzyme have been reported to suppress T cell function. Previously we have identified a DP IV inhibitor, designated TMC-2, found in culture supernatant of Aspergillus oryzae. Administration of TMC-2 to rats with adjuvant arthritis caused marked suppression of paw swelling. To elucidate the mechanism of TMC-2 antiarthritic activity, we have studied its effects on T cell function. Here we show that TMC-2 inhibited DP IV activity of CD26 immunoprecipitated from T cell lysates, and also inhibited proliferative responses of T cells to specific antigen or anti-CD3 antibody. Suppression of IL-2 production was demonstrated at both the mRNA and protein levels. TMC-2 did not alter the PTPase activity of pure CD45, but when this molecule was co-precipitated from T cell lysates together with associated CD26, its PTPase was virtually completely abolished by TMC-2. These results suggest that modulation of CD45 PTPase activity might be responsible for functional suppression of T cells by TMC-2. Because the effects of TMC-2 on T cells were reversible and it was not toxic at the concentrations used, TMC-2 may be a candidate novel therapeutic agent for rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed2002

Heterogeneity of presenile dementia with bone cysts (Nasu-Hakola disease): three genetic forms.

Nasu-Hakola disease (NHD) is an autosomal recessive disorder characterized by presenile dementia and bone cysts. Finnish patients revealed a large deletion in DAP12 gene encoding a key element for transducing activation signal. The authors examined six Japanese cases for DAP12 alleles. Five of the six had loss-of-function mutation, either a single-base deletion or a novel point mutation. The single patient without mutation normally expressed DAP12 protein. Japanese NHD has at least three genetic forms regarding DAP12.

Adaptor Proteins, Signal Transducing↗
PubMed2002

The acceleration of cosmic-ray protons in the supernova remnant RX J1713.7-3946.

Protons with energies up to approximately 10(15) eV are the main component of cosmic rays, but evidence for the specific locations where they could have been accelerated to these energies has been lacking. Electrons are known to be accelerated to cosmic-ray energies in supernova remnants, and the shock waves associated with such remnants, when they hit the surrounding interstellar medium, could also provide the energy to accelerate protons. The signature of such a process would be the decay of pions (pi(0)), which are generated when the protons collide with atoms and molecules in an interstellar cloud: pion decay results in gamma-rays with a particular spectral-energy distribution. Here we report the observation of cascade showers of optical photons resulting from gamma-rays at energies of approximately 10(12) eV hitting Earth's upper atmosphere, in the direction of the supernova remnant RX J1713.7-3946. The spectrum is a good match to that predicted by pion decay, and cannot be explained by other mechanisms.

Journal Article↗
PubMed2002

Effect of early induction of hypothermia on severe head injury.

Although therapeutic hypothermia for patients with head injury has improved the outcome, the results in the most severe cases (GCS 3-6) have not been satisfactory so far. We induced hypothermia in head injury patients within 3 hours after the trauma, and compared the outcome of the treatment without hypothermia. Fourteen patients with GCS less than 6 were entered into this study (age range 13 to 58, mean 27.0 years). Seven of them were treated by hypothermia and 6 by the conventional method. The patients undergoing hypothermia were cooled to 34 degrees C within 3 hours after injury, kept at 32-34 degrees C for 48 hours, and then rewarmed. The outcome was evaluated at 6 months post-trauma, and the results were compared in the two groups. Therapeutic hypothermia dramatically suppressed brain swelling on CT in 3 of 7 patients. Four patients including these 3 showed a favorable outcome (good or moderate disability) and 3 died in the hypothermia group. In the conventional treatment group, only 1 patient was moderately disabled and 6 exhibited an unfavorable outcome (severely disabled, vegetative, or death). Early induction of hypothermia can improve the outcome in patients with severe head injury by reducing the severe brain swelling.

Craniocerebral Trauma↗
PubMed2002

Inhibitory effects of 14-membered ring macrolide antibiotics on bleomycin-induced acute lung injury.

14-membered ring macrolides have been reported to have anti-inflammatory effects and to decrease neutrophil infiltration into the airways in chronic lower respiratory tract diseases. This study investigated the potential inhibitory effects of macrolide antibiotics on bleomycin-induced acute lung injury. Four drugs were studied: two 14-membered ring macrolides, clarithromycin (CAM) and roxithromycin (RXM); a 15-membered ring macrolide, azithromycin (AZM); and a 16-membered ring macrolide, josamycin (JM). Their effects were compared with macrolide untreated, pretreated, and post-treated groups. An acute lung injury was inhibited by pretreatment with CAM or RXM, which significantly ameliorated the bleomycin-induced increases in the total cell and neutrophil counts in bronchoalveolar lavage (BAL) fluids and the wet lung weight. The pretreatment with CAM or RXM also suppressed inflammatory cell infiltration and interstitial lung edema in the histopathological study. These inhibitory effects were associated with a decreased KC concentration in the BAL fluid and a decreased number of apoptotic cells in the lungs. Posttreatment with CAM or RXM had no marked inhibitory effects. Pretreatment with AZM was much less effective, and JM showed no inhibitory effects. These findings suggest that 14-membered ring macrolides have different effects on inflammatory lung disease than 15- and 16-membered ring macrolides and may be therapeutic agents for acute lung injury and pulmonary fibrosis.

Animals↗
PubMed2002

Antileukinate, a hexapeptide inhibitor of CXC-chemokine receptor, suppresses bleomycin-induced acute lung injury in mice.

A hexapeptide, Ac-RRWWCR-NH(2) (Antileukinate), has been reported to be a potent inhibitor of CXC-chemokine receptor. However, the in vivo anti-inflammatory activity of this agent has not been tested except in a rabbit skin edema model. This study was undertaken to investigate the effect of subcutaneously administered Antileukinate on experimental bleomycin-induced acute lung injury in mice, in which CXC-chemokines have been reported to be involved. Lung injury was assessed on the basis of histopathology, the number of total cells, the percentage of neutrophils, and protein concentration in the bronchoalveolar lavage (BAL) fluid, and the wet lung weight at 7 days after intratracheal instillation of bleomycin. Histopathological studies revealed that treatment with Antileukinate markedly suppressed inflammatory cell infiltration and interstitial lung edema. The neutrophil counts in the BAL fluid were significantly decreased in the Antileukinate-treated group. The suppression of pulmonary edema was further confirmed by the reduction of wet lung weight and total protein concentration in the BAL fluid. These findings suggest that Antileukinate is able to inhibit acute lung injury by suppressing neutrophil mobilization induced by CXC-chemokines.

Animals↗