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Biomedical subjects

Y Ishida

Publications and source records attributed to Y Ishida.

At least 343 records · Page 19Linked to original sources
PubMed1995

[A case of leiomyosarcoma of the diverticulum of urinary bladder].

A 77-year-old man was admitted to our hospital complaining of gross hematuria. Cystoscopy showed an approximately 4-cm non-papillary tumor in and out of the diverticulum of the left posterior wall. Total cystectomy was performed. Histopathological diagnosis was pleomorphic leiomyosarcoma. According to TNM classification of bladder cancer, the stage of this tumor was pT3bpN0M0. The patient had local recurrence two months after the operation, and died a month later. This is the second case of leiomyosarcoma of the diverticulum of urinary bladder reported in Japan.

Aged↗
PubMed1994

IL-2 can support growth of CD8+ T cells but not CD4+ T cells of human IL-2 receptor beta-chain transgenic mice.

We have generated transgenic mice expressing the human (h) IL-2R beta-chain on lymphoid cells under the control of the mouse H-2Kd promoter. Spleen cells and thymocytes of the transgenic mice were cultured in the presence of 5 nM hIL-2. After a 10-day culture, the expanded populations were analyzed by flow cytometry and shown to be composed of CD8+ T cells and gamma delta T cells. Surprisingly, CD4+ T cells of the transgenic mice did not proliferate in response to hIL-2, although the CD4+ T cells expressed the transgenic hIL-2R beta-chain as well as the endogenous gamma-chain on their surface and bound 125I-labeled IL-2. When CD4+ T cells of the transgenic mice were stimulated with anti-CD3 mAb, the CD4+ T cells proliferated in response to hIL-2. These findings suggest that CD4+ T cells may require another triggering signal to respond to IL-2 even when IL-2Rs are expressed. By contrast, CD8+ T cells and gamma delta T cells respond to IL-2 as long as IL-2Rs are expressed.

Animals↗
PubMed1994

Circadian rhythms of adenosine triphosphate contents in the suprachiasmatic nucleus, anterior hypothalamic area and caudate putamen of the rat--negative correlation with electrical activity.

Contents of adenosine triphosphate (ATP) in the suprachiasmatic nucleus (SCN), anterior hypothalamic area (AH) and caudate putamen (CPu) were determined every 4 h in rats kept under constant dark conditions. All tested regions of the brain exhibited circadian rhythms in ATP content. Among these, the amplitude of the rhythm was largest in the SCN. Peaks of the ATP content were observed at circadian time 18 in the SCN, 6 in the AH and 10 in the CPu. In view of the observation that at around these peak times electrical or glucose uptake activity of each brain region was lowest, the present result suggests that ATP content is negatively correlated with electrical or glucose uptake activity.

Adenosine Triphosphate↗
PubMed1994

Purification and properties of bovine liver holocarboxylase synthetase.

Holocarboxylase synthetase was purified 18,000-fold from bovine liver cytosol by a sequence of ammonium sulfate fractionation, alumina C gamma fractionation, DEAE-Sepharose CL-6B, EAH-Sepharose 4B, Sephacryl S-200 HR, Bio-Gel HTP, and Phenyl-Superose HR 5/5 chromatographies. Holocarboxylase synthetase activity was assayed using apopropionyl-CoA carboxylase from a patient with holocarboxylase synthetase deficiency as a substrate. Apopropionyl-CoA carboxylase was easily prepared from cultured lymphoblasts from this patient. Enzyme activity coincided with a 64,000-Da protein band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Additionally, the molecular mass of the native enzyme was estimated to be 60,000 Da by gel filtration on Sephacryl S-200 HR. These results suggest that purified holocarboxylase synthetase from bovine liver cytosol is a monomeric enzyme. Its Km value for biotin was estimated to be 13 nM.

Animals↗
PubMed1994

Isolation and characterization of 21 novel expressed DNA sequences from the distal region of human chromosome 4p.

We have established an approach to the isolation of expressed DNA sequences from a defined region of the human chromosome. The method relies on the direct screening of cDNA libraries using pooled single-copy microclones generated by a laser chromosome micro-dissection in conjunction with a single unique primer polymerase chain reaction (SUP-PCR) procedure. We applied this method to the distal region of human chromosome 4p (4p15-4pter), which contains the Huntington disease (HD) and the Wolf-Hirschhorn syndrome (WHS) loci. Twenty-one nonoverlapping and region-specific cDNA clones encoding novel genes were isolated in this manner. Ten of 21 clones were subregionally assigned to 4p16.1-4pter, and the remainder mapped to the region proximal to 4p16.1. Northern blot and reverse transcription followed by the PCR (RT-PCR) analysis revealed that 16 of these 21 clones detected transcripts in total RNA from human tissues. Our method is applicable to other chromosomal regions and is a powerful approach to the isolation of region-specific cDNA clones.

Base Sequence↗
PubMed1994

Targeted disruption of the CD3 eta locus causes high lethality in mice: modulation of Oct-1 transcription on the opposite strand.

CD3 zeta and eta chains are components of the T cell antigen receptor (TCR) complex and are transcribed from a common gene by alternative splicing. TCR complexes containing the zeta eta dimer have been thought to mediate different functions than complexes containing the zeta 2 dimer. To analyze the role of eta in the development and function of T cells, we generated eta-deficient mice without affecting zeta by gene targeting in embryonic stem cells. Homozygous mutant embryos developed normally. Unexpectedly, however, these mice exhibited high mortality soon after birth for unknown reason(s). Analysis of surviving homozygous animals revealed that the development and function of T cells were normal in the absence of the eta chain. Recently, the zeta/eta locus was reported to encode a transcription factor, Oct-1, on the opposite DNA strand. Our targeting strategy resulted in modulation of Oct-1 transcription--reduction of the authentic Oct-1 mRNA and induction of aberrant transcripts. Although differences in tissue distribution and DNA binding capacity of Oct-1 between wild-type and eta-deficient mice were not evident from in situ hybridization and gel shift analysis, the high mortality in the eta-deficient strain may well be due to the disturbance of Oct-1 transcription by the mutation in the zeta/eta locus. Such possible complexities have to be taken into account in the interpretation of gene targeting experiments.

Animals↗
PubMed1994

Antigen-specific cell conjugate formation and long-lasting calcium responses in recognition of Mls cellular superantigen by cloned murine T lymphocytes.

T lymphocyte recognition of cell-associated minor lymphocyte stimulation (Mls) superantigen was studied by simultaneous flow cytometric measurement of T cell free ionized intracellular calcium ([Ca2+]i) with the fluorescent probe indo-1 and T cell binding to antigen-presenting cells stained with a long-chained, membrane-fixed cyanine dye. Cloned T cell-B lymphocyte antigen-presenting cell conjugate formation and increased T cell [Ca2+]i were antigen specific and tightly linked in four Mls-reactive T cell clones. The T cell-antigen-presenting cell conjugates were extremely stable and, like T cell [Ca2+]i elevation, were maintained for more than 2 hr. Three ligand-receptor pairs, (i) T cell receptor/antigen+class II, (ii) CD4/class II, and (iii) LFA-1/ICAM-1, were obligatory participants in T cell recognition of cell-bound superantigen since monoclonal antibodies to any of them blocked formation of cell conjugates. Despite previous reports, Mls recognition occurred by the conventional T cell recognition pathway with easily detected phosphoinositide hydrolysis. B cell activation greatly enhances their recognition by Mls-specific T cells.

Animals↗
PubMed1994

Structure and chromosomal localization of the human PD-1 gene (PDCD1).

A cDNA encoding mouse PD-1, a member of the immunoglobulin superfamily was previously isolated from apoptosis-induced cells by subtractive hybridization. To determine the structure and chromosomal location of the human PD-1 gene, we screened a human T cell cDNA library by mouse PD-1 probe and isolated a cDNA coding for the human PD-1 protein. The deduced amino acid sequence of human PD-1 was 60% identical to the mouse counterpart, and a putative tyrosine kinase-association motif was well conserved. The human PD-1 gene was mapped to 2q37.3 by chromosomal in situ hybridization.

Amino Acid Sequence↗
PubMed1994

Detection of coronary artery disease by dynamic planar and single photon emission tomographic imaging with technetium-99m teboroxime.

To test the clinical significance of technetium-99m teboroxime regional myocardial clearance in the detection of coronary artery disease, 25 patients underwent dynamic planar or single-photon emission tomographic (SPET) myocardial imaging with 99mTc-teboroxime after exercise and again 2 h later at rest. All patients underwent both thallium-201 exercise and redistribution SPET and coronary arteriography. The early phases of exercise 99mTc-teboroxime myocardial clearance determined by dynamic planar imaging showed a significant difference between normal and post-stenotic myocardial regions (clearance rate constant k: 0.047 +/- 0.005 min-1 versus 0.034 +/- 0.003 min-1, P < 0.001). Reflecting this "differential clearance" between myocardial regions, an early redistribution-like phenomenon was observed in a significant number of myocardial segments by comparing serially acquired post-exercise 99mTc-teboroxime SPET images. These results indicated that the analysis of 99mTc-teboroxime myocardial clearance was of potential use in the detection of coronary artery disease, yielding additional information to that provided by the tracer distribution analysis. Although the early redistribution-like phenomenon of 99mTc-teboroxime could be the source of underestimation of ischaemia if acquisition of the initial post-exercise image were delayed, it could also prove useful in the early differentiation of ischaemia from scar because when the phenomenon was observed in delayed post-exercise images, the rest study could be omitted under some circumstances.

Coronary Angiography↗
PubMed1994

Notes on the acetylcholine-induced relaxation of porcine coronary arteries.

Intact and rubbed coronary arteries responded to acetylcholine (ACh) with contractions in a cumulative dose-dependent manner. The rubbed artery contracted at a lower concentration of ACh (3 x 10(-8) M) than the threshold level of the agonist in the intact artery (10(-7) M). Only in the intact artery was the second cumulative dose-response to ACh (10(-6) M) decreased by 60% (p < 0.05). Pretreatment of the intact artery with methylene blue or NG-monomethyl-L-arginine (L-NMMA) increased the contractile response to ACh. The ACh-induced increase of the cGMP level in the intact artery was eliminated by removal of the endothelial cells and by pretreatment of the artery with either methylene blue or L-NMMA. These findings indicate that the endothelial cells in the coronary artery are responsible for the ACh-induced relaxation, presumably mediated by an endothelium-derived relaxing factor.

Acetylcholine↗
PubMed1994

Multidirectional contraction of human hypertrophied prostate.

1. The purpose of the present investigation is to evaluate muscle contraction in two directions (longitudinal and circumferential to urethra) physiologically and morphologically for alpha-adrenoceptor agonists. 2. Norepinephrine (10(-7)-10(-4) M), phenylephrine (10(-7)-10(-4) M) and clonidine (10(-7)-10(-4) M) induced contractions in a dose-dependent manner on human prostate from patients with benign prostatic hypertrophy (BPH). 3. No significant differences were observed between longitudinal and circumferential directions of human prostate in 50% of the maximal muscle contraction (EC50 values) and the maximal muscle contractions caused by any agents used. 4. Morphometric analysis for muscle in prostates was performed using formalin-fixed, paraffin-embedded sections stained by the Mallory-Azan method. 5. There was no significant difference in the density of the muscle area between longitudinal and circumferential directions of prostatic strips. 6. These results suggest that there are no significant differences in responsiveness of alpha-adrenoceptor agonists and the smooth muscle contents in longitudinal and circumferential directions to urethra, for human hypertrophied prostate.

Adrenergic alpha-Agonists↗
PubMed1994

Effects of L- and D-enantiomers of N omega-nitro-arginine on NMDA-evoked striatal dopamine overflow.

The microdialysis method was utilized to study the effects of N omega-nitro-L-arginine (L-NNA) and N omega-nitro-D-arginine (D-NNA), an inhibitor of nitric oxide (NO) synthesis from L-arginine and its D-enantiomer, on spontaneous and N-methyl-D-aspartate (NMDA)-evoked overflow of striatal extracellular dopamine (DA) in unanesthetized, freely moving rats. Perfusion of 3-10 mM NMDA through the microdialysis probe resulted in a dose-dependent increase in striatal DA overflow. Perfusion of 500 microM L-NNA alone did not change the DA level significantly, but when added to 3 mM NMDA, it substantially suppressed the NMDA-evoked increase of DA. Perfusion of 500 microM D-NNA altered neither the basal nor the NMDA-evoked DA level. Data suggest that the stimulatory effect of NMDA in DA release involves activation of the L-arginine-NO pathway in the striatum.

Animals↗
PubMed1994

Isolation and characterization of mutations in the human holocarboxylase synthetase cDNA.

Holocarboxylase synthetase (HCS) plays an essential role in biotin utilization in eukaryotic cells and its deficiency causes biotin-responsive multiple carboxylase deficiency in humans. We have cloned the human HCS cDNA and show that antiserum against the recombinant protein immunoprecipitates human HCS. A one base deletion resulting in a premature termination and a missense mutation (Leu to Pro) were found in cells from siblings with HCS deficiency. Human HCS shows homology to BirA, which acts as both a biotin-[acetyl-CoA-carboxylase] ligase and a biotin repressor in E. coli, suggesting a functional relationship between the two proteins. The human HCS gene maps to chromosome 21q22.1.

Amino Acid Sequence↗
PubMed1994

Myocardial involvement in patients with sarcoidosis. An analysis of 75 patients.

The authors studied 75 nonselected patients (30 men and 45 women; mean age 48 years) with sarcoidosis retrospectively to assess the applicability of nuclear examinations for detecting myocardial involvement. All patients were studied with Tl-201 myocardial perfusion scan (TMPS), Ga-67 myocardial scan (GMS), and left ventricular ejection fraction (LVEF) using ECG-gated radionuclide ventriculography. The positive GMS group had a significantly higher occurrence of abnormality on TMPS (100%) than the negative GMS group (41%). Patients with TMPS abnormality and positive GMS showed significantly lower LVEF (36.3%) than those of normal perfusion or negative GMS. When LVEF decreased, occurrences of TMPS abnormality and positive GMS increased. The authors demonstrate that in patients with sarcoidosis LVEF was closely related to TMPS and GMS, and LVEF reflected the progression of sarcoid heart disease and can be considered a reliable indicator of cardiac function. Patients with sarcoidosis with TMPS abnormality and positive GMS should be thought to have myocardial sarcoidosis and their cardiac functions can be assessed by ECG-gated radionuclide ventriculography, while the remaining patients should be examined with TMPS and GMS periodically for detection of myocardial involvement.

Adult↗