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Biomedical subjects

Y Torii

Publications and source records attributed to Y Torii.

At least 37 records · Page 2Linked to original sources
PubMed2001

Osteonecrosis of the femoral head after allogeneic bone marrow transplantation.

A comparative retrospective analysis of 100 consecutive patients after bone marrow transplantation was performed with magnetic resonance imaging in addition to plain radiography for the development of osteonecrosis of the femoral head. The incidence and risk factors for osteonecrosis of the femoral head were identified, comparing various parameters concerning bone marrow transplantation between the groups with and without evidence of osteonecrosis. Nineteen (19%) of 100 patients had osteonecrosis of the femoral head develop. Four factors were found to be statistically significantly different between patients who had osteonecrosis develop and those who did not: younger age at the time of bone marrow transplantation, chronic graft-versus-host disease, cumulative dose of steroid, and intravenous pulse therapy with methylprednisolone. It was concluded that a low rate of complications and low dose steroid administration would reduce the incidence of osteonecrosis after bone marrow transplantation.

Adolescent↗
PubMed2001

Effects of polysiloxane coating of NaF on the release profile of fluoride ion from Bis-GMA/TEGDMA resin containing NaF.

The aim of this study was to regulate fluoride release from restorative resin containing NaF using N-(beta-aminoethyl)-gamma-aminopropylmethyldimethoxysilane (AMMS) and evaluate factors that regulate fluoride release from the resin. ESCA analysis, FT-IR measurements along with SEM observations demonstrated that a polysiloxane layer was formed on the surface of NaF treated with AMMS. Bis-GMA/TEGDMA resin containing NaF powder treated with AMMS released lower concentrations of fluoride for longer periods when compared with that containing untreated NaF. However, AMMS treatment of NaF was less effective for the regulation of fluoride released from the resin than gamma-methacryloxypropyltrimethoxysilane (gamma-MPTS) treatment, despite its higher hydrophobic polysiloxane layer formation. These findings may have been caused by the higher density of polysiloxane prepared with gamma-MPTS than that prepared with AMMS. The present findings suggested, therefore, that alkoxysilane should be chosen based not only on hydrophobicity but also the density of polysiloxane to effectively regulate fluoride release from the restorative resin containing NaF.

Bisphenol A-Glycidyl Methacrylate↗
PubMed2001

Platelets exposed to elevated levels of endogenous thrombopoietin in vivo have a reduced response to megakaryocyte growth and development factor in vitro.

Thrombopoietin (TPO), or megakaryocyte growth and development factor (MGDF), has been shown to potentiate the sensitivity of normal human platelets to various agonists in vitro. The present study investigated the functional and biochemical properties of platelets from mice rendered thrombocytopenic by sublethal irradiation with regard to the reactivity to recombinant murine MGDF (rmMGDF) in vitro. During the course of reversible thrombocytopenia following irradiation, platelets from irradiated mice which had lower platelet counts and reciprocally higher plasma TPO levels showed lower reactivity to rmMGDF in agonist-induced platelet aggregation. Intravenous injections of recombinant soluble murine c-Mpl (sMpl), which has the ability to capture TPO, after irradiation restored the reactivity of platelets at the platelet nadir to rmMGDF. On the other hand, platelets prepared from normal mice 3 h after a single intravenous injection of pegylated rmMGDF did not respond to rmMGDF. There was a marked decrease in c-Mpl and Janus kinase 2 (JAK2) in platelets from irradiated mice at the platelet nadir. Similar results were observed with platelets from mice administered pegylated rmMGDF. JAK2 was only moderately decreased, however, in platelets from mice given sMpl after irradiation. These results indicate that exposure of platelets to increased endogenous TPO levels in vivo in thrombocytopenic mice leads to a reduction in the platelet reactivity to rmMGDF in vitro. Further, these results suggest that the c-Mpl-mediated signaling pathway, which is essential for the priming effect of rmMGDF, is defective in thrombocytopenic murine platelets.

Animals↗
PubMed2001

[Evaluation of efficacy of ramosetron orally disintegrating tablets and patient preference as to the dosage form in gynecological cancer chemotherapy].

The efficacy of an oral 5-HT3 antagonist, ramosetron orally disintegrating tablet (ODT), in the treatment of chemotherapy-induced emesis was investigated in 21 female patients with cancer. Patient preference for the dosage form was also investigated. Eighteen (85.7%) of 21 patients answered that ODT is easy to take. Eleven (68.8%) of 16 patients who had previously taken granisetron tablets preferred ramosetron ODT to conventional tablets. The complete suppression rate of nausea or vomiting was more than 90% for 6 days. No adverse drug reactions associated with ramosetron were observed. As ambulatory or home chemotherapy becomes frequent, the use of oral 5-HT3 antagonists rather than intravenous agents will be increased. Chemotherapy for elderly cancer patients is becoming frequently used. Considering these circumstances, it is suggested that ramosetron ODT is a palatable and useful treatment of chemotherapy-induced emesis.

Administration, Oral↗
PubMed2000

Ion heating and high-energy-particle production by ion-cyclotron heating in the large helical device

Ion-cyclotron heating was applied to the Large Helical Device. When the proton-cyclotron resonance was near the saddle point of the magnetic field-strength plane, strong ion-cyclotron damping occurred. Under these conditions efficient plasma heating was achieved for more than one minute. A high-energy ion tail was observed, and the effective tail temperature was determined by a balance between the wave acceleration and the electron-drag relaxation. There was no apparent sign of particle orbit loss effect in the investigated density range of 0.8-1.3x10(19) m(-3).

Journal Article↗
PubMed2000

Effect of self-etching primers containing N-acryloyl aspartic acid on dentin adhesion.

The purpose of this study was to evaluate the feasibility of aspartic acid derivative, N-acryloyl aspartic acid (N-AAsp) when used as a self-etching primer prior to the application of a commercial bonding agent containing 10-methacryloxydecyl dihydrogen phosphate. N-AAsp was synthesized by the reaction of DL-aspartic acid and acryloyl chloride. N-AAsp can be dissolved in water up to 25 wt % and can adequately remove the smear layer. When 20 wt % N-AAsp was applied as a self-etching primer, the tensile bonding strength of resin composite to dentin doubled to 16.0 MPa compared with that of the nonetching group or the 40 wt % H(3)PO(4) etching/water rinse group. Scanning electron microscopic observations revealed that the formation of the hybrid layer at the interface between the resin composite and dentin and the thickness of the hybrid layer increased with N-AAsp concentration. The hybrid layer in the specimens treated with 20 wt % N-AAsp aqueous solution presented a uniform structure, whereas those treated with 5 wt % N-AAsp solution showed a porous structure. We conclude that 20 wt % N-AAsp aqueous solution has good potential value as a self-etching primer.

Acid Etching, Dental↗
PubMed2000

Osteopontin-immunoreactive primary sensory neurons in the rat spinal and trigeminal nervous systems.

1200 micrometer(2) and 9% of those in the range 600-1200 micrometer(2) showed the immunoreactivity (ir). DRG neurons <600 micrometer(2)800 micrometer(2) showed the ir and 21% of those in the range 400-800 micrometer(2) were immunoreactive for this protein. TG neurons <400 micrometer(2) were mostly devoid of OPN-ir (2%). Virtually all (99%) Mes5 primary sensory neurons exhibited the ir. Muscle spindles in the soleus and masseter muscles contained OPN-ir spiral axon terminals. In the hard palate and incisor periodontal ligament, unencapsulated corpuscular endings exhibited the ir. The co-expression of OPN with parvalbumin and calcitonin gene-related peptide (CGRP) was also examined in the DRG and TG. In the DRG, virtually all (97%) OPN-ir neurons exhibited parvalbumin-ir. Conversely, 66% of parvalbumin-ir DRG neurons co-expressed OPN-ir. In the TG, 81% of OPN-ir neurons exhibited parvalbumin-ir and 69% of parvalbumin-ir ones showed OPN-ir. Virtually all OPN-ir DRG and TG neurons were devoid of CGRP-ir. The present study indicates that OPN-ir primary sensory neurons in the DRG and Mes5 are spinal and trigeminal proprioceptors. OPN-ir TG neurons appear to include low-threshold mechanoreceptors.

Animals↗
PubMed2000

Cyclopentenone prostaglandins as potential inducers of phase II detoxification enzymes. 15-deoxy-delta(12,14)-prostaglandin j2-induced expression of glutathione S-transferases.

Exposure of cells to a wide variety of chemoprotective compounds confers resistance to a broad set of carcinogens. For a subset of the chemoprotective compounds, protection is generated by an increase in the abundance of protective enzymes, such as glutathione S-transferases (GSTs). In the present study, we developed a cell culture system that potently responds to phenolic antioxidants and found that antitumor prostaglandins (PGs) are potential inducers of GSTs. We screened primary hepatocytes and multiple cell lines for inducing GST activity upon incubation with the phenolic antioxidant (tert-butylhydroquinone) and found that rat liver epithelial RL34 cells most potently responded. Based on an extensive screening of diverse chemical agents on the induction of GST activity in RL34 cells, the J2 series of PGs, 15-deoxy-Delta(12,14)-prostaglandin J2 (15-deoxy-Delta(12,14)-PGJ2) in particular, were found to be potential inducers of GST. Enhanced gene expression of Class pi GST isozyme (GSTP1) by 15-deoxy-Delta(12,14)-PGJ2 was evident as a drastic elevation of the mRNA level. Hence, we examined the molecular mechanism underlying the 15-deoxy-Delta(12, 14)-PGJ2-induced GSTP1 gene expression. From functional analysis of various deletion mutant genes, we found that the 15-deoxy-Delta(12, 14)-PGJ2 reponse element was localized in a region containing a GSTP1 enhancer I (GPEI) that consists of two imperfect phorbol 12-O-tetradecanoylphorbol-13-acetate response elements. When the GPEI was combined with the minimum GSTP1 promoter, the element indeed showed an enhancer activity in response to 15-deoxy-Delta(12, 14)-PGJ2. Point mutations of either of the two imperfect 12-O-tetradecanoylphorbol-13-acetate response elements in GPEI completely abolished the enhancer activity. Gel mobility shift assays demonstrated that 15-deoxy-Delta(12,14)-PGJ2 specifically stimulated the binding of nuclear proteins including the transcription factor c-Jun, but not Nrf2, to GPEI. These results suggest that 15-deoxy-Delta(12,14)-PGJ2 induces the expression of the rat GSTP1 gene through binding of proteins, including c-Jun, to a specific GPEI.

Animals↗
PubMed2000

Differences in survival based on the type of follow-up for the detection of hepatocellular carcinoma: an analysis of 547 patients.

The aim of this study was to identify any significant variables in the prognosis of 547 cases with hepatocellular carcinoma (HCC), and simultaneously confirm the survival among the different surveillance modalities for the initial detection of HCC in a closely followed-up group (regular periodic follow-up with monthly alpha-fetoprotein (AFP) and ultrasonography at least every 4 months), a not closely followed-up group (neither performed with AFP nor ultrasonography regularly) and an incidental group (incidentally discovered due to related symptoms). Five hundred and forty-seven consecutive patients with HCC diagnosed at the Internal Medicine Department of Saga Prefectural Hospital Koseikan from January 1989 to December 1998 were retrospectively analyzed. The 1-, 3- and 5-year survivals in all 547 cases were 69.7, 42.4 and 26.9%, respectively. The 1-, 3- and 5-year survivals in the cases found to have solitary HCC measuring 2 cm or less in diameter at the time of diagnosis were 97.3, 76.2 and 52.3%, respectively. Forty-seven point one percent of the closely followed-up group, which was the high-risk group were found to have solitary HCC measuring 2 cm or less in diameter (48 out of the 102 followed-up cases), while only 18.5 and 11.8% were found in the not closely followed-up group (46 out of 248 cases) and the incidental group (22 out of 186 cases), respectively. The 5-year survival in the closely followed-up, the not closely followed-up and the incidental groups were 42.9, 26.1 and 15.3%, respectively. The significant factors obtained in the closely followed-up group compared to those from the not closely followed-up group included AFP, tumor size, tumor number and portal thrombosis. These findings indicate the importance of a close follow-up for high-risk groups in order to identify HCC at an early stage, and thereby have a positive influence on survival.

Journal Article↗
PubMed2000

Screening of BRCA1 mutation using immunohistochemical staining with C-terminal and N-terminal antibodies in familial ovarian cancers.

We examined the subcellular localization of BRCA1 proteins using immunohistochemical staining with C-terminal (GLK-2 antibody) and N-terminal (Ab-2 antibody) monoclonal antibodies in 44 familial ovarian cancers. Among these, 24 cases were associated with 13 independent germ-line mutations of BRCA1, and loss of heterozygosity (LOH) at one or more BRCA1 microsatellite markers was found in all 21 informative tumors tested. With GLK-2 antibody, cytoplasmic staining was observed in 15 of 16 tumors (93.8%) with mutation in exon 11, and BRCA1 staining was absent in 8 of 8 tumors (100%) with mutation in exons other than exon 11. When immunohistochemical staining was performed with Ab-2 antibody, both nuclear and cytoplasmic staining were observed in 14 of 16 tumors (87.5%) with mutation in exon 11. Interestingly, nuclear staining was observed in 3 of 3 tumors (100%) with mutation downstream of exon 11, even though no staining was detected in 5 of 5 tumors (100%) with mutation upstream of exon 11. On the other hand, in familial ovarian cancers without BRCA1 mutations, nuclear staining or both nuclear and cytoplasmic staining was observed in 18 of 20 specimens (90%) and 20 of 20 specimens (100%) with GLK-2 antibody and with Ab-2 antibody, respectively. These results suggest that an immunohistochemical assay in combination with employing the C-terminal and the N-terminal antibodies appears to have potential as a reliable and useful technique for the screening of BRCA1 mutations, at least to predict the status of mutation, upstream or downstream of exon 11.

BRCA1 Protein↗
PubMed2000

Adhesion in vitro of oral streptococci to porcelain, composite resin cement and human enamel.

We investigated the initial adhesion in vitro of oral streptococci to porcelain inlays. Four strains of streptococci, Streptococcus mitis NCTC12261, Streptococcus oralis ATCC9811, Streptococcus sanguis ATCC10556 and Streptococcus sobrinus OMZ176, were used in this study. The disc specimens were made of porcelain, composite resin cement and human enamel. These specimens, with or without a saliva-coat, were immersed in a suspension of each streptococci strain at 37 degrees C for 1 hr, and the numbers of cells adhering to specimens were counted after staining. The saliva-coat significantly decreased the numbers of adhering cells in all strains tested (t-test, p < 0.05). The adhesion to the porcelain and resin cements could be explained by a thermodynamic approach, although the adhesion to enamel could not be explained. These results indicated the possibility that the mechanism is different in initial adhered strains of streptococci between enamel and dental restorative materials.

Bacterial Adhesion↗
PubMed2000

A case of multiple myeloma which developed into multiple extramedullary involvement in the terminal stage.

A 69-year-old man with a diagnosis of multiple IgG class myeloma received combination chemotherapy. He achieved a partial response with an undetected M spike. However, he demonstrated new lytic bone lesions and multiple extramedullary involvement 10 months after the initial presentation. Polymerase chain reaction (PCR) analysis using a framework 3 (Fr3) V-region primer clarified a discrete band in the extramedullary tumor, while it yielded 4 bands including the same size as the extramedullary tumor produced in the bone marrow sample obtained before the chemotherapy. These findings suggest that a resistant and non-secretory clone was selected by the combination chemotherapy.

Aged↗
PubMed2000

Pulmonary stenosis in recipient twins in twin-to-twin transfusion syndrome: report on 3 cases and review of literature.

This report describes 3 cases of pulmonary stenosis in the recipient twin in twin-twin transfusion syndrome. Fetal echocardiography showed cardiomegaly, tricuspid valve regurgitation, and increased reverse flow in the inferior vena cava, as signs of congestive heart failure in all 3 cases. We diagnosed 2 cases of pulmonary stenosis by fetal echocardiography prenatally and confirmed our findings in all 3 cases postnatally. Two cases underwent postnatal balloon valvuloplasty to release the pulmonary valvular stenosis in neonatal period. The third one died soon after delivery and autopsy showed a slightly thickened pulmonary valve. One of the cases was diagnosed in the early second trimester (20 weeks of pregnancy), the earliest detection of fetal pulmonary stenosis reported in literature. The presence of high peak velocity of the pulmonary artery at 20 weeks of pregnancy preceded the development of pulmonary stenosis in this case. This supports the hypothesis that alterations in fetal hemodynamics may result in structural cardiac abnormality.

Adult↗
PubMed1999

Phase-coherent amplification of matter waves

Phase-coherent matter-wave amplification was demonstrated using Bose- Einstein-condensed rubidium-87 atoms. A small seed matter wave was created with coherent optical Bragg diffraction. Amplification of this seed matter wave was achieved by using the initial condensate as a gain medium through the superradiance effect. The coherence properties of the amplified matter wave, studied with a matter-wave interferometer, were shown to be locked to those of the initial seed wave. The active matter-wave device demonstrated here has great potential in the fields of atom optics, atom lithography, and precision measurements.

Journal Article↗
PubMed1999

Removal of Aromatic Hydrocarbon Compounds by Hydroxypropyl-cyclodextrin.

Activated carbon has been used for the recovery and removal of benzene, toluene, and xylenes in air and water for a long time. However, removal of benzene, toluene, and xylenes from soil is very difficult. They can be removed by an increase in the apparent solubility of organic compounds in soil. The apparent solubilities of benzene, toluene, and xylene were investigated to estimate their inclusion behavior into natural cyclodextrins (CDs) and hydroxypropyl-cyclodextrins (HP-CDs) in the liquid phase. The apparent solubilities of benzene, toluene, and xylenes did not increase by adding natural CDs but did increase when HP-CDs were added. Benzene, toluene, and xylenes in a HP-CD solution depended on the relationship between the molecular diameter of benzene, toluene, and xylenes, the CD cavity size, and the 1-octanol-water partition coefficient. That of p-xylene was larger than that of o-xylene and m-xylene because of the smallest steric hindrance of p-xylene. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Osteocalcin-immunoreactive primary sensory neurons in the rat spinal and trigeminal nervous systems.

Osteocalcin-immunoreactivity (OC-ir) was examined in spinal and trigeminal primary sensory neurons of the adult rat. Sixteen percent of dorsal root ganglion (DRG) neurons were immunoreactive (ir) for this protein. These neurons were mostly large and measured 594-4583 microm(2) (mean+/-S.D.=2243+/-748 microm(2)). Thirty-four percent of DRG neurons >1200 microm(2) and 4% of those in the range 600-1200 microm(2) showed the ir. Virtually all DRG neurons <600 microm(2) were devoid of OC-ir. In the trigeminal ganglion (TG), 25% of neurons exhibited the ir. Such neurons were of various sizes (range=156-2825 microm(2), mean+/-S.D.=1234+/-543 microm(2)). Forty-five percent of TG neurons >800 microm(2) and 6% of those <400 microm(2) were immunoreactive for this protein. Twelve percent of TG neurons in the range 400-800 microm(2) showed the ir. In the mesencephalic trigeminal tract nucleus (Mes5), 63% of primary sensory neurons contained OC-ir. Virtually all OC-ir DRG and Mes5 neurons co-expressed parvalbumin-ir but not CGRP-ir. On the other hand, only 31% of OC-ir neurons co-expressed parvalbumin-ir and 10% co-expressed CGRP-ir in the TG. The present study indicates that DRG and Mes5 primary sensory neurons co-expressing OC- and parvalbumin-irs are spinal and trigeminal proprioceptors. OC-ir TG neurons which co-express parvalbumin- and CGRP-irs appear to include low-threshold mechanoreceptors and nociceptors, respectively.

Animals↗
PubMed1999

Activation of stress signaling pathways by the end product of lipid peroxidation. 4-hydroxy-2-nonenal is a potential inducer of intracellular peroxide production.

In the present study, we studied the signal transduction mechanism that is involved in the expression of c-Jun protein evident after exposure of rat liver epithelial RL34 cells to the major end product of oxidized fatty acid metabolism, 4-hydroxy-2-nonenal (HNE). HNE treatment of the cells resulted in depletion of intracellular glutathione (GSH) and in the formation of protein-bound HNE in plasma membrane. In addition, HNE strongly induced intracellular peroxide production, suggesting that HNE exerted oxidative stress on the cells. Potent expression of c-Jun occurred within 30 min of HNE treatment, which was accompanied by a time-dependent increase in activator protein-1 (AP-1) DNA binding activity. We found that HNE caused an immediate increase in tyrosine phosphorylation in RL34 cells. In addition, HNE strongly induced phosphorylation of c-Jun N-terminal kinases (JNK) and p38 mitogen-activated protein kinases and also moderately induced phosphorylation of extracellular signal-regulated kinases. The phosphorylation of JNK was accompanied by a rapid and transient increase in JNK and p38 activities, whereas changes in the activity of extracellular signal-regulated kinase were scarcely observed. GSH depletion by L-buthionine-S, R-sulfoximine, a specific inhibitor of GSH biosynthesis, only slightly enhanced peroxide production and JNK activation, suggesting that HNE exerted these effects independent of GSH depletion. This and the findings that (i) HNE strongly induced intracellular peroxide production, (ii) HNE-induced JNK activation was inhibited by pretreatment of the cells with a thiol antioxidant, N-acetylcysteine, and (iii) H2O2 significantly activated JNK support the hypothesis that pro-oxidants play a crucial role in the HNE-induced activation of stress signaling pathways. In addition, we found that, among the inhibitors of tyrosine kinases, cyclooxygenase, and Ca2+ influx, only quercetin exerted a significant inhibitory effect on HNE-induced JNK activation. In light of the JNK-dependent induction of c-jun transcription and the AP-1-induced transcription of xenobiotic-metabolizing enzymes, these data may show a potential critical role for JNK in the induction of a cellular defense program against toxic products generated from lipid peroxidation.

Aldehydes↗