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T Nishimura

Publications and source records attributed to T Nishimura.

At least 343 records · Page 19Linked to original sources
PubMed1998

[Evaluation of clinical utility of 99mTc-MIBI scintigraphy in the localization of thyroid, breast and lung/mediastinum tumors--a report of multicenter phase III clinical trials].

Phase III clinical study in 136 patients diagnosed or strongly suspected of thyroid, lung/mediastinum or breast cancer was performed to determine clinical utility of 99mTc-MIBI in the localization of tumors, and the results in 135 were evaluated. Except taste peculiar in 43 patients and nausea in one, no adverse events were reported. Seven abnormal changes in vital signs and 27 in clinical laboratories were noted, which were all judged as having no or unlikely relationship to the agent. Out of 177 malignant lesions, 156 (88%) were detected with 99mTc-MIBI regardless of their histology or location. Of 6 benign tumors, 3 were detected. Fifteen sites of false positive in 11 malignant tumor patients and 5 sites in 6 patients with non-tumor disease were observed. Our study indicates that 99mTc-MIBI is a safe and excellent agent for the localization of tumors. Especially, the fact that 99mTc-MIBI detected remote metastatic lesions with high sensitivity is a great advantage over the other conventional imaging modalities.

Adult↗
PubMed1997

Manipulation of Th1/Th2 balance in vivo by adoptive transfer of antigen-specific Th1 or Th2 cells.

We have investigated the possibility that the Th1/Th2 balance in vivo may be modulated by adoptive transfer of Th1 or Th2 cells induced in vitro. Thl cells were induced from I-Ad-binding OVA323-339-specific T-cell receptor-transgenic (TCR-Tg) mouse spleen cells by culturing with OVA323-339 peptide and antigen presenting cells (APC) in the presence of IL-2, IL-12 and anti-IL-4 mAb. Th2 cells were induced from TCR-Tg mouse spleen cells by culturing with IL-2, IL-4 and anti-IL-12 mAb in addition to OVA323-339 plus APC. Immunomodulating activities of both Th1 and Th2 cells were determined by their effect on delayed type hypersensitivity (DTH) responses or cytokine production. No significant DTH responses (footpad swelling) were observed in untreated BALB/c mice following a single injection of OVA323-339-pulsed syngeneic spleen cells. However, adoptive transfer of Th1 cells into BALB/c mice induced strong dose dependent DTH responses in response to I-Ad-bound OVA323-339 but not unrelated peptide. In contrast, only slight DTH responses were detected in BALB/c mice transferred with Th2 cells. In parallel with the DTH responses, increased levels of serum IFN-gamma were demonstrated in mice adoptively transferred with Th1, while no significant increase was observed in Th2-transferred mice. In vitro analysis also demonstrated that both spleen cells and popliteal lymph node cells prepared from Th1-transferred mice showed Th1-type cytokine production, while cells obtained from Th2-transferred mice revealed Th2-dominant cytokine production. Such immune deviation induced by antigen-specific Th1 cells was demonstrated up to three months after cell transfer. Therefore, it may be possible to manipulate the Th1/Th2 balance in vivo by adoptive transfer of antigen-specific Th1 or Th2 cells.

Adoptive Transfer↗
PubMed1997

Actions of barium on rapidly inactivating potassium current in bullfrog sympathetic neurons.

Whole-cell/voltage-clamp recordings were made from dissociated bullfrog sympathetic neurons to examine the inhibitory actions of barium (0.01-3 mM) on a rapidly inactivating A-type potassium current (IA). The IC50 value was about 0.9 mM. Barium (1 mM) approximately halved the maximum amplitude of IA (approximately 1.7 nA near 0 mV) without significantly affecting a voltage for the 50%-activation (approximately -40 mV) and that for the 50%-inactivation (approximately -90 mV), nor did it affected the time course of IA. The results suggest that the barium block is independent of the kinetics of the A-channels in bullfrog sympathetic neurons.

Animals↗
PubMed1997

Screening of fungal beta-xylanases for production of acidic xylooligosaccharides using in situ reduced 4-O-methylglucuronoxylan as substrate.

Fungal beta xylanases were screened for production of acidic xylooligomers from 4-O-methylglucuronoxylan. In situ reduced hardwood xylan was used as substrate because the products of neutral- and acidic-branched xylooligomers help define substrate specificity of the enzymes. Borohydride reduction in situ transformed 30% of 4-O-methyl-alpha-D-glucopyranosyluronic acid residues into 4-O-methyl-alpha-D-glucopyranosyl residues and reduced C-1 end groups in the xylan backbones. A total of ten beta-xylanase fractions from four fungi were partially purified by chromatography by anion exchange and molecular sieving, and graded qualitatively for enzymatic hydrolysis of the substrate. The yield of acidic xylooligomers was highly affected by whether alpha-glucuronidases were present in the beta-xylanase fractions. Some fractions gave free 4-O-methyl-alpha-D-glucopyranosyluronic acid, but none of the enzyme fractions could release free 4-O-methyl-alpha-D-glucose. Among the beta-xylanase fractions studied, xylanase II of Trichoderma viride was the best producer of aldotetraouronic acid [2-O-(4-O-methyl-alpha-D-glucopyranosyluronic acid)-D-xylotriose]. The results obtained suggested that there was a difference in the steric hindrance of the branch point on fungal beta-xylanases between 4-O-methyl-alpha-D-glucopyranosyl and 4-O-alpha-D-glucopyranosyluronic acid residues.

Basidiomycota↗
PubMed1997

Failure of parturition in mice lacking the prostaglandin F receptor.

Mice lacking the gene encoding the receptor for prostaglandin F2alpha (FP) developed normally but were unable to deliver normal fetuses at term. Although these FP-deficient mice showed no abnormality in the estrous cycle, ovulation, fertilization, or implantation, they did not respond to exogenous oxytocin because of the lack of induction of oxytocin receptor (a proposed triggering event in parturition), and they did not show the normal decline of serum progesterone concentrations that precedes parturition. Ovariectomy at day 19 of pregnancy restored induction of the oxytocin receptor and permitted successful delivery in the FP-deficient mice. These results indicate that parturition is initiated when prostaglandin F2alpha interacts with FP in ovarian luteal cells of the pregnant mice to induce luteolysis.

Animals↗
PubMed1997

Assembly and regulation of the CD40 receptor complex in human B cells.

CD40 is a member of the tumor necrosis factor (TNF) receptor superfamily. Studies with human B cells show that the binding of CD154 (gp39, CD40L) to CD40 recruits TNF receptor- associated factor 2 (TRAF2) and TRAF3 to the receptor complex, induces the downregulation of the nonreceptor-associated TRAFs in the cell and induces an increased expression of Fas on the cell surface. Combined signaling through the interluekin 4 receptor and CD40 induces an increased expression of Fas with a commensurate increase in the level of TRAF2, but not TRAF3, that is recruited to the receptor complex. In contrast, engagement of the membrane immunoglobulin and CD40 limits Fas upregulation and reduces the recruitment of TRAF2, relative to TRAF3, to the CD40 receptor complex. These studies show that the TRAF composition of the CD40 receptor complex can be altered by signals that influence B cell differentiation.

B-Lymphocytes↗
PubMed1997

The role of phorbol ester-sensitive protein kinase C isoforms in lymphokine-activated killer cell-mediated cytotoxicity: dissociation between perforin-dependent and Fas-dependent cytotoxicity.

Treatment of lymphokine-activated killer (LAK) cells with phorbol ester (PMA) caused the downmodulation of LAK activity concomitantly with the inhibition of serine esterase (SE) release, which has been shown as a marker for perforin-dependent cell-mediated cytotoxicity. The reduction of perforin-dependent LAK activity by PMA-treatment appeared to be due to the disappearance of PMA-sensitive protein kinase C (PKC) isoforms such as PKC alpha, gamma, epsilon, theta. In contrast, Fas-mediated LAK activity was refractory against PMA-induced downregulation. Treatment of LAK cells with PMA caused a disappearance of cytotoxicity against Fas L5178Y tumor cells, while cytotoxicity against Fas+ transfectants was not affected by PMA treatment. Moreover, Fas-mediated LAK activity of perforin-knockout mice was not inhibited by PMA treatment. These results clearly demonstrated that Fas-mediated cytotoxicity could be dissociated from perforin-mediated cytotoxicity by their different requirement of PMA-sensitive PKC isoforms.

Animals↗
PubMed1997

Involvement of IL-4-producing Vbeta8.2+ CD4+ CD62L- CD45RB- T cells in non-MHC gene-controlled predisposition toward skewing into T helper type-2 immunity in BALB/c mice.

It was found that freshly isolated BALB/c CD4+ T cells produced high levels of IL-4 and IL-10 in response to immobilized anti-CD3 mAb, while C57BL/6 CD4+ T cells produced low amounts of IL-4 and IL-10. The high IL-4-producing ability of BALB/c mice was demonstrated to be genetically dominant and it was controlled by non-MHC gene (or genes). The cells responsible for IL-4 production in BALB/c mice were defined as TCRVbeta8.2+ CD4+ CD62L- CD45RB- memory-type T cells, which were distinct from NK1.1+ CD4+ NKT cells. Although these memory-type T cells were also detected in C57BL/6 mouse spleen at the same frequency, they showed a functionally different property from BALB/c CD4+ CD62L- CD45RB- T cells in terms of IL-4 production. The fact that germfree BALB/c mouse spleen cells also produced high levels of IL-4 suggested that the IL-4 producer in BALB/c mice might be developed under the influence of unknown factors other than environmental Ags. The CD4+ CD62L- CD45RB- T cells obtained from BALB/c mice accelerated the development of IL-4-producing memory-type CD4+ T cells from CD4+ CD62L+ CD45RB+ naive T cells prepared from OVA-specific TCR-transgenic mice. Therefore, IL-4-producing CD4+ CD62L- CD45RB- T cells might play an important role in the preferential induction of Th2-dominant immunity in BALB/c mouse strain.

Animals↗
PubMed1997

cDNA cloning and expression of chicken aminopeptidase H, possessing endopeptidase as well as aminopeptidase activity.

Chicken aminopeptidase H is a cysteine protease possessing endopeptidase as well as aminopeptidase activity [Rhyu, M. R., Nishimura, T., Kato, Y., Okitani, A. & Kato, H. (1992) Eur. J. Biochem. 208, 53-59]. This enzyme exhibits molecular masses of 400 kDa on gel filtration and 52 kDa on SDS/PAGE, indicating that it consists of eight subunits with the same molecular mass. In the current study, we cloned the cDNA for the catalytic subunit of chicken aminopeptidase H. The open reading frame of the aminopeptidase H gene consists of 1362 base pairs encoding a 52-kDa protein consistent with the molecular mass determined on SDS/PAGE; the deduced amino acid sequence contains all the partial sequences determined for the purified enzyme. The sequence is similar to that of the bleomycin hydrolase of rabbit lung, which has been partially determined. The recombinant 52-kDa protein expressed in COS7 cells exhibited both aminopeptidase and endopeptidase activities, which were inhibited by monoiodoacetic acid. Furthermore, the expression of aminopeptidase H in COS7 cells was also recognized on immunoblotting. This gene is the first one for aminopeptidase H in an animal tissue whose sequence has been completely determined.

Amino Acid Sequence↗
PubMed1997

Identification and characterization of the genes for mitochondrial ribosomal proteins of Saccharomyces cerevisiae.

We have purified 13 large subunit proteins of the mitochondrial ribosome of the yeast Saccharomyces cerevisiae and determined their partial amino acid sequences. To elucidate the structure and function of these proteins, we searched for their genes by comparing our sequence data with those deduced from the genomic nucleotide sequence data of S. cerevisiae and analyzed them. In addition, we searched for the genes encoding proteins whose N-terminal amino acid sequences we have reported previously [Grohmann, L., Graack, H.-R., Kruft, V., Choli, T., Goldschmidt-Reisin, S. & Kitakawa, M. (1991) FEBS Lett. 284, 51-56]. Thus, we were able to identify and characterize 12 new genes for large subunit proteins of the yeast mitochondrial ribosome. Furthermore, we determined the N-terminal amino acid sequences of seven small subunit proteins and subsequently identified the genes for five of them, three of which were found to be new.

Amino Acid Sequence↗
PubMed1997

Reduction of telencephalin immunoreactivity in the brain of patients with Alzheimer's disease.

Telencephalin (TLN) is a cell adhesion molecule expressed in the telencephalon of the mammalian central nervous system. We have investigated immunohistochemically the expression of TLN in human brain tissue from control subjects and patients with Alzheimer's disease (AD). In control brain, neuropil of the gray matter was stained diffusely with the anti-TLN antibody. TLN immunoreactivity was markedly decreased in the brain of AD patients, particularly in the hippocampal formation.

Aged↗
PubMed1997

Glial tau-positive structures lack the sequence encoded by exon 3 of the tau protein gene.

Tau protein comprises six distinct isoforms defined by the presence or absence of sequences encoded by alternatively spliced exon 2, 3 and 10. We have investigated immunohistochemically the expression of exon 3-derived fragment (E-3) of tau protein in brains of patients with Alzheimer's disease (AD) and other neurodegenerative diseases in which the abnormal accumulation of tau protein takes place. In AD, a subset of neurofibrillary tangles, neuropil threads and dystrophic neurites in senile plaques were stained positively with an anti-E-3 antibody. In sharp contrast, glial tau-positive structures, such as astrocytic plaques and oligodendroglial coiled bodies, were negative for E-3 in all cases examined in this study. This is the first report to discriminate tau-positive inclusions in glial cells from those in neurons at the molecular level.

Aged↗
PubMed1997

Therapeutic effect of co-enzyme Q10 on idiopathic dilated cardiomyopathy: assessment by iodine-123 labelled 15-(p-iodophenyl)-3(R,S)-methylpentadecanoic acid myocardial single-photon emission tomography.

It has been reported that myocardial mitochondrial function can be improved by the administration of co-enzyme Q10 (CoQ10). Recently, iodine-123 labelled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) was developed for metabolic imaging using single-photon emission tomography (SPET). This study was conducted to determine whether the therapeutic effects of CoQ10 on idiopathic dilated cardiomyopathy can be evaluated by BMIPP myocardial SPET. Fifteen patients, comprising 14 men and one woman (mean age: 64+/-12 years), were examined. CoQ10 was administered at 30 mg/day for a period of 35.7+/-12.4 days. BMIPP myocardial SPET was carried out before and after CoQ10 treatment. The count ratio of the heart (H) to the upper mediastinum (M) (H/M ratio) was calculated using a region of interest method with anterior planar imaging. Representative short-axis tomograms were divided into 27 segments (three slicesxnine segments). Each segmental score was analysed semiquantitatively using a four-point scoring system (normal=0, mild low uptake=1, severe low uptake=2, defect=3). The H/M ratio showed a significant improvement, from 2.39+/-0.39 to 2.54+/-0.47, after treatment (P<0.05). The BMIPP total defect score after CoQ10 treatment was significantly decreased to 10.1+/-4.3, compared to 13. 9+/-4.5 without CoQ10 treatment (P<0.001). However, the percent fractional shortening measured using echocardiography was not significantly different before and after CoQ treatment (19.2+/-8.1 vs 19.7+/-7.1). BMIPP myocardial SPET was confirmed to be sensitive in evaluating the therapeutic effects of CoQ10 in patients with idiopathic dilated cardiomyopathy. This method is unique, since the therapeutic effects can be estimated from the perspective of metabolic SPET imaging.

Cardiomyopathy, Dilated↗
PubMed1997

Enhancement of [123I]beta-CIT binding in the striatum with clomipramine: is there a serotonin-dopamine interaction?

Many reports support the concept of serotonergic-dopaminergic interaction in the brain. However, at present, there are few methods to study this relationship in vivo. The purpose of this study was to investigate the effect of serotonin (5-HT) uptake inhibitor, clomipramine, on a dopamine (DA) transporter ligand, [123I]beta-CIT (RTI-55), in rat brain. Dose-dependent changes in [123I]beta-CIT specific binding induced by clomipramine were studied in the striatum (rich in DA transporter) and the hypothalamus (rich in 5-HT transporter). The changes in the time-activity curves of [123I]beta-CIT specific binding after clomipramine injection were also examined in these two regions. Using the cerebellum as the reference region, k3 and k4 values with and without clomipramine administration were estimated by a two-compartment kinetic analysis. Clomipramine inhibited [123I]beta-CIT specific binding in the hypothalamus, but enhanced its specific binding in the striatum in a dose-dependent manner. Kinetic analysis showed that k3 in the striatum was increased by 55%. In conclusion, enhancement of [123I]beta-CIT binding in the striatum after clomipramine administration indicated the possibility of 5-HT-DA interaction.

Animals↗
PubMed1997

Hypothermia inhibits the alveolar epithelial injury caused by hyposmotic albumin solution during preservation of the resected human lung.

This study was conducted to determine whether hypothermia inhibited alveolar epithelial injury in the resected human lung during preservation. Hyposmotic albumin solution, 248 mOsm/kg, was instilled into the alveolar spaces of resected human lungs which were inflated with an airway pressure of 7 cmH2O and stored at either 37 degrees C or 8 degrees C for 4 h. Alveolar fluid was aspirated and the influx of lactate dehydrogenase (LDH) and globulin into the alveolar spaces, as markers of alveolar epithelial injury, was measured. Ion transport and fluid clearance across the alveolar epithelium were calculated by the changes in electrolyte and albumin concentrations in the alveolar fluid, respectively. While the LDH levels and globulin concentrations increased significantly in the hyposmotic experiments at 37 degrees C, hypothermia inhibited these increases. Alveolar fluid clearance at 37 degrees C increased to 20% in the hyposmotic experiments compared with 12% in the control isosmotic experiments; however, sodium and chloride transport in the hyposmotic experiments was not significantly different from that in the isosmotic experiments. Thus, we conclude that hypothermia at 8 degrees C inhibits alveolar epithelial injury caused by the hyposmotic solution in resected human lungs. Moreover, alveolar ion and fluid clearance mechanisms were preserved across the injured alveolar epithelial cells.

Epithelium↗
PubMed1997

Evaluation of left ventricular ejection fraction from radial long-axis tomography: a new reconstruction algorithm for ECG-gated technetium-99m sestamibi SPECT.

UNLABELLED: Radial long-axis tomography can provide views similar to contrast left ventriculography (LVG) including the basal and apical areas of the left ventricle, not possible in routine short-axis tomography. We applied this method to ECG-gated Tc-99m Sestamibi (MIBI) myocardial SPECT images to estimate the left ventricular ejection fraction (LVEF). METHODS: ECG-gated Tc-99m MIBI SPECT was performed with a temporal resolution of 10 frames per R-R interval. LVEF was calculated on the basis of left ventricular volume estimates at end diastole (ED) and end systole (ES) with using an ellipsoid body model. To validate this method, LVEF's derived from ECG-gated Tc-99m MIBI SPECT were compared with those from LVG in 11 patients with coronary artery disease. RESULTS: There was a close linear correlation between LVEF values calculated from Tc-99m MIBI SPECT and those from LVG (r = 0.89, p < 0.001), although the gated SPECT underestimated LVEF compared to LVG. The technique showed excellent reproducibility (intra-observer variability, r = 0.96, p < 0.001; inter-observer variability, r = 0.71, p < 0.005). CONCLUSION: The radial long-axis tomography technique gives a good estimate of LVEF, in agreement with estimates based on LVG. ECG-gated Tc-99m MIBI SPECT can, therefore, be applicable to assess myocardial perfusion and ventricular function at the same time.

Adult↗
PubMed1997

Detection of impaired fatty acid metabolism in right ventricular hypertrophy: assessment by I-123 beta-methyl iodophenyl pentadecanoic acid (BMIPP) myocardial single-photon emission computed tomography.

Fatty acid metabolism has been reported to be impaired earlier than myocardial blood flow in left ventricular hypertrophic myocardium, e.g., in hypertrophic cardiomyopathy or hypertensive heart disease. The purpose of this study was to determine whether impaired fatty acid metabolism also occurs in right ventricular (RV) hypertrophy. The subjects consisted of 6 patients with chronic obstructive pulmonary disease, 4 with primary pulmonary hypertension, 2 each with refractory pulmonary tuberculosis, tricuspid insufficiency, pulmonary embolism, 1 each with atrial septal defect, ventricular septal defect (Eisenmenger complex), Ebstein anomaly, and endocardial defect, and 7 healthy controls. SPECT imaging with Tl-201 (Tl) and I-123 beta-methyliodophenyl pentadecanoic acid (BMIPP), and Tc-99m RBC first pass and gated blood pool scintigraphy were performed. Based on Tl planar images, the subjects were classified into 3 groups: 7 patients with no RV visualization (Group A), 11 with moderate RV visualization (Group B) and 9 with marked RV visualization (Group C). As a semi-quantitative evaluation by Tl myocardial SPECT, 3 regions in 3 representative short axial images were divided into 9 segments, each of which was graded from 0 to +3, and their sum was calculated as the RV score. The right ventricular ejection fraction (RVEF) and the left ventricular ejection fraction were obtained by Tc-99m RBC cardiac scintigraphy. The groups with marked visualization of the right ventricle had lower RVEF (p < 0.01), and there was a good correlation between the RVEF and the RV score with both Tl and BMIPP (Tl: r = -0.79, BMIPP: r = -0.70). Although a good correlation was demonstrated between the RV score with Tl and BMIPP in Groups A and B (r = 0.86, p < 0.001), in Group C, in which there was marked RV T1 visualization, the RV score with BMIPP was significantly smaller than with Tl (BMIPP vs. Tl: 11.5 +/- 3.7 vs. 16.4 +/- 3.8, p < 0.01). These findings suggest that impaired fatty acid metabolism may exist in severely hypertrophic right ventricle due to RV overload.

Aged↗