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Biomedical subjects

Y Ishida

Publications and source records attributed to Y Ishida.

At least 397 records · Page 22Linked to original sources
PubMed1993

Isolation of camelliaside C from "tea seed cake" and inhibitory effects of its derivatives on arachidonate 5-lipoxygenase.

A new flavonol glycoside, camelliaside C, was isolated from "tea seed cake" prepared from the defatted seeds of Camellia sinensis O. Kuntze. The structure was determined as kaempferol 3-O-beta-D-galactopyranosyl-(1-->2)-beta-D-glucopyranoside by spectroscopic methods (FAB-MS, UV, IR, 1H- and 13C-NMR) and the enzymatic transformation of camelliaside C to astragalin. Camelliaside C showed an inhibitory effect on the arachidonate 5-lipoxygenase of RBL-1 cells (IC50:1.4 x 10(-4)M) as did camelliaside A and B isolated from the same product.

Animals↗
PubMed1993

Effects of OM-853, a novel indolonaphthyridine derivative, on behavioral responses in the forced swim test in rats.

Effects of OM-853 on behavioral responses in the forced swim test were studied. OM-853 significantly reduced the duration of immobility without any change in the exploratory activity. Imipramine also reduced the duration of immobility, but idebenone did not. On the other hand, vinpocetine enhanced the duration with a suppressive effect on ambulation. The anti-immobility effect of OM-853 was reversed by pretreatment with haloperidol. These results demonstrate that the effect of OM-853 on the swim test is different from that of idebenone and vinpocetine. Furthermore, the present results suggest that OM-853 may exert its anti-immobility activity through facilitated transmission of the dopaminergic and/or adrenergic systems.

Animals↗
PubMed1993

Spondylolysis after posterior decompression of the lumbar spine. 35 patients followed for 3-9 years.

Radiographs were examined in 35 patients who had had posterior decompression without fusion of the lumbar spine. Spondylolysis was found in 10 patients. Segmental range of motion, degree of vertebral slippage and width of decompression were analyzed by radiography. There was greater vertebral slippage after surgery in patients with postoperative spondylolysis than in those without spondylolysis. We conclude that excessive bony decompression may cause postoperative spondylolysis.

Adult↗
PubMed1993

[Effects of recombinant human granulocyte colony-stimulating factor on superoxide production by neutrophil in cancer patients receiving chemotherapy].

The in vivo effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on the number and function of peripheral neutrophils were studied in time sequence in 9 cancer patients receiving anticancer cytotoxic chemotherapy; 6 patients with transitional cell carcinoma of urothelium treated with CAP (the combination of cyclophosphamide, adriamycin and cisplatin) and the other 3 with testicular tumor treated with PEB (the combination of cisplatin, etoposide and bleomycin). The neutrophil function was evaluated by superoxide production, measuring chemiluminescence of the neutrophil suspension by a photometer. In the 1st course, when no rhG-CSF was administered, the neutrophil function declined significantly (p < 0.01) as the peripheral neutrophil count (PNC) decreased, reached the minimum almost at the same day as PNC reached the nadir, and returned to the normal level at the beginning of the next course. In the 2nd course, when rhG-CSF (75 micrograms/body) was administered subcutaneously daily for 14 consecutive days beginning at 72 hours after the chemotherapy, the nadir of neutropenia was elevated (p < 0.01), the period of neutropenia (< 1,000/mm3) was shortened (p < 0.01), the recovery from neutropenia (> 1,500/mm3) was accelerated (p < 0.01) as compared to the 1st course, and an marked increase of PNC (p < 0.01) to the peak on the next day of the last administration of rhG-CSF was observed. In addition, deterioration of neutrophil function was alleviated (p < 0.05) and the neutrophil function was enhanced (p < 0.01-0.05) during rhG-CSF administration, even at the nadir of neutropenia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Biological and biochemical characteristics of murine megakaryoblastic cell line L8057.

Biological and biochemical characteristics of a murine megakaryoblastic cell line (L8057), derived from an irradiated C3H/He mouse, were studied. The L8057 cells grew in liquid cultures with a doubling time of 24 to 27 hours. By light and electron microscopy, the L8057 cells were small and basophilic with a high nuclear/cytoplasmic ratio, but large cells (approximately 25 to 60 microns) were sometimes seen. Western blot analysis of cell extracts demonstrated that murine megakaryocyte and platelet antigens, glycoprotein (GP) IIb/IIIa, fibronectin, and factor VIII:RAg were expressed in L8057 cells. Acetylcholinesterase (AChE)-positive cells were rare (< 2.0%). Flow cytometric analysis demonstrated that 8.7% of the cells were spontaneously polyploid (> 4N DNA levels). In response to phorbol diester (TPA, 50 nm), L8057 cells showed a decrease in proliferation and a marked increase in cell size and amount of cytoplasm. The morphology of the cells became similar to that of megakaryocytes, with larger and lobulated nuclei and expansion of the demarcation membrane system compartment. The proportion of cells with ploidy levels greater than 4N increased to 40.8% (8N, 21.3 +/- 3.2%; 16N, 13.1 +/- 2.6%; > or = 32N, 6.4 +/- 4.9% [n = 4]). More than 90% of the cells became AChE-positive. TPA also increased the expression of GP IIb/IIIa, fibronectin and factor VIII:RAg. Thus, the L8057 cell line provides a potentially superior model with which to study the characteristics of megakaryocytic biology, differentiation and biochemistry.

Acetylcholinesterase↗
PubMed1993

Detection of postural cerebral hypoperfusion with technetium-99m-HMPAO brain SPECT in patients with cerebrovascular disease.

Seventeen of 19 patients (67 +/- 8 yr, 17 males and 2 females) had more than 75% unilateral stenosis or occlusion of the internal carotid or middle cerebral artery and two patients had carotid endarterectomy that previously had 90% stenosis of the internal carotid artery. They were studied during upright 99mTc-HMPAO brain SPECT. HMPA was injected immediately after arising from a supine position. Patients were classified into Group A (n = 10) with occlusion of the internal carotid or the middle cerebral artery or Group B (n = 9) with more than 75% unilateral stenosis of the internal carotid or the middle cerebral artery and with carotid endarterectomy. Additional cerebral blood flow perfusion abnormalities between upright and supine 99mTc-HMPAO brain SPECT were detected in seven patients in Group A and in only one patient in Group B. Semiquantitative analysis showed that the asymmetric ratios between upright and supine positions changed significantly in Group A from 0.82 +/- 0.15 to 0.89 +/- 0.10 (p < 0.01), but not in Group B, from 0.89 +/- 0.11 to 0.92 +/- 0.12 (ns). Additional perfusion abnormalities were relevant to occlusion of the internal carotid or middle cerebral artery indicated postural cerebral hypoperfusion. We conclude that upright 99mTc-HMPAO brain SPECT visualizes postural cerebral hypoperfusion possibly related to silent cerebral ischemia.

Aged↗
PubMed1993

[Relationship between reduced myocardial uptake of beta-methyl-p-(123I)- iodophenyl-pentadecanoic acid (123I-BMIPP) and regional diastolic ventricular dysfunction in patients with hypertrophic cardiomyopathy].

To assess whether regionally depressed myocardial uptake of beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid (123I-BMIPP), is related to regional ventricular diastolic dysfunction in patients (pts) with hypertrophic cardiomyopathy (HCM), we carried out 123I-BMIPP myocardial SPECT and radionuclide ventriculography (RNV) at rest in 9 HCM pts (eight pts with asymmetric septal hypertrophy (ASH), and one patient with apical hypertrophy). The defects of 123I-BMIPP were semiquantitatively estimated by segmental analysis. Regional LV function was determined by sector analysis in RNV: regional peak filling rate (rPFR), regional time to peak filling rate (rTPFR), and early 1/3 filling rate (1/3 fil) were estimated in the LV septal and posterior sectors. Wall thickness was evaluated with M-mode echocardiography. As results, the defects of 123I-BMIPP myocardial SPECT, were found frequently in septal wall, but any defect was not recognized in all septum with significant hypertrophy. Also, the degree of septal hypertrophy was not significantly related to BMIPP defect score. However, the regional diastolic function (rPFR, rTPFR, 1/3 fil) in the septal lesions with 123I-BMIPP defects was decreased more than those without 123I-BMIPP defect in HCM. Furthermore, the relative regional diastolic dysfunction (the differences between rTPFR and 1/3 fil in the septum and in the posterior wall) was significantly related to BMIPP defect score. In conclusion, this results suggest that the decreased uptake of 123I-BMIPP is related to regional diastolic dysfunction more than wall hypertrophy.

Aged↗
PubMed1993

[A case of radiation-induced chronic constrictive pericarditis developing 16 years after irradiation].

We reported a 51-yr-old female with radiation-induced chronic constrictive pericarditis. At age 29, she had received a mastectomy and postoperative irradiation because of left breast cancer. At age 45, she had syncope and was diagnosed with complete atrioventricular block and a pacemaker was implanted. At that time, pericardial thickening with effusion was noted. The following year, tricuspid regurgitation was noted. On catheter study, a dip and plateau pattern of the right ventricular pressure curve appeared. At age 50, tricuspid regurgitation worsened due to the lead wire of the pacemaker compressing the leaflet, and the pacemaker was reimplanted. However, the following year, she complained of general fatigue and dyspnea and was admitted to our hospital. On 67Ga study, diffuse accumulation in the cardiac region appeared. There was no perfusion defect detected in the left myocardium, but right myocardial damage was suspected by thallium study. In 99mTc-HSA RI angiography, right atrium dilatation appeared and a pericardial halo around the ventricles was seen. She underwent pericardectomy, tricuspid replacement and pacemaker reimplanted, but she died. On autopsy, pericardial thickening and adhesion, right myocardial fibrosis, the fibrotic change of the bundle branches were seen. We reported a case of radiation-induced constrictive pericarditis. Radionuclide studies were useful in diagnosing and following the patient.

Breast Neoplasms↗
PubMed1993

[The significance of 201Tl/123I MIBG (metaiodobenzylguanidine) mismatched myocardial regions for predicting ventricular tachycardia in patients with idiopathic dilated cardiomyopathy].

123I-MIBG (MIBG) regional defects in myocardial regions with preserved 201Tl (Tl) uptake have been observed in patients with idiopathic dilated cardiomyopathy (DCM). To evaluate whether the presence of Tl/MIBG mismatched regions is related to the occurrence of ventricular tachycardia (VT), we performed myocardial dual SPECT imaging with Tl (111 MBq) and MIBG (111 MBq) in 17 patients with DCM, 11 (Gp A) with and 6 (Gp B) without VT. Myocardial dual SPECT imaging was performed at 15 minutes after and 4 hours after the tracer injection. The regional tracer uptake was scored visually in 6 segments of the basal, middle, and apical short-axial images and in 2 apical segments of the midventricular vertical long-axial image by a four-point scoring system (0 = normal, 1 = moderate, 2 = severe and 3 = complete defect). Then, the severity of tracer maldistributions was assessed by the difference between total defect scores (TDSs) of Tl and MIBG (delta TDS). TDS was not different between Gps A and B in both Tl and MIBG images. However, delta TDS was larger in Gp A than in Gp B (13.5 +/- 6.5 vs. 5.8 +/- 3.0, p < 0.05). Also, the number of segments with the mismatched tracer uptake was larger in Gp A than in Gp B (12.5 +/- 3.0 vs. 8.3 +/- 1.5, p < 0.01). In the electrophysiologic study, we found that the fractionated area corresponded to the mismatched region in 3 of 5 patients in Gp A. These results suggest that regional sympathetic denervation is a possible factor which provocates VT, and myocardial dual SPECT imaging with Tl and MIBG is a useful method for predicting VT in patients with DCM.

3-Iodobenzylguanidine↗
PubMed1993

[Cystic lymphangioma of the scrotum. Apropos of a case].

The authors present the case of a cystic lymphangioma in the scrotum, a tumor which usually occurs in the neck, but is rarely observed in this region. Patient was a 22 year-old man, admitted for fever and a mass within the scrotum. The tumor was completely resected and no recurrence has been observed after a 6 month follow-up.

Adult↗
PubMed1992

Structure-activity relationships of mu-conotoxin GIIIA: structure determination of active and inactive sodium channel blocker peptides by NMR and simulated annealing calculations.

A synthetic replacement study of the amino acid residues of mu-conotoxin GIIIA, a peptide blocker for muscle sodium channels, has recently shown that the conformation formed by three disulfide bridges and the molecular basicity, especially the one around the Arg13 residue, are important for blocking activity. In the present study, we determined the three-dimensional structure of an inactive analog, [Ala13]mu-conotoxin GIIIA, and refined that of the native toxin by NMR spectroscopy combined with simulated annealing calculations. The atomic root-mean-square difference of the mutant from the native conotoxin was 0.62 A for the backbone atoms (N, C alpha, C') of all residues except for the two terminal residues. The observation that the replacement of Arg13 by Ala13 does not significantly change the molecular conformation suggests that the loss of activity is not due to the conformational change but to the direct interaction of the essential Arg13 residue with the sodium channel molecules. In the determined structure, important residues for the activity, Arg13, Lys16, Hyp(hydroxyproline)17, and Arg19, are clustered on one side of the molecule, an observation which suggests that this face of the molecule associates with the receptor site of sodium channels. The hydroxyl group of Hyp17 is suggested to interact with the channel site with which the essential hydroxyl groups of tetrodotoxin and saxitoxin interact.

Alanine↗
PubMed1992

Involvement of MAP kinase activators in angiotensin II-induced activation of MAP kinases in cultured vascular smooth muscle cells.

In cultured vascular smooth muscle cells (VSMC) angiotensin II (ang II) induces tyrosine and serine/threonine phosphorylation and activation of two mitogen-activated protein (MAP) kinases. When extracts of ang II-stimulated VSMC were fractionated by Mono Q anion-exchange column chromatography, three peaks of the activities which in vitro activate inactive MAP kinases were detected. These MAP kinase activator activities were not detected in extracts of unstimulated VSMC. In vitro activation of MAP kinases by the MAP kinase activators was accompanied by tyrosine and serine/threonine phosphorylation of MAP kinases. These results suggest that the MAP kinase activators are involved in the ang II-induced phosphorylation and activation of MAP kinases in VSMC.

Angiotensin II↗
PubMed1992

T cell receptor-mediated recognition of self-ligand induces signaling in immature thymocytes before negative selection.

Shaping of the T cell repertoire by selection during intrathymic maturation involves T cell receptor (TCR) recognition of major histocompatibility complex/self-antigen complexes. In this communication, we studied the ability of minor lymphocyte stimulating (Mls) determinants to act as self-tolerogens in the selection of the T cell repertoire. We demonstrate that unprimed T cells from normal as well as TCR transgenic mice form Mls-specific conjugates with antigen-presenting cells, and that this TCR-ligand interaction leads to elevation of intercellular Ca2+ ([Ca2+]i). Peripheral T cells from TCR transgenic mice expressing receptors specific for self-Mls antigen show no reactivities to Mlsa. However, a proportion of immature thymocytes from these mice show specific binding and strong [Ca2+]i elevation in response to self-antigen-presenting cells, although these thymocytes do not proliferate. This self-reactivity of thymocytes is inhibited by antibodies specific for TCR, CD4, CD8, class II molecules, lymphocyte function-associated antigen 1, and intercellular adhesion molecule 1. These results demonstrate for the first time that before thymic negative selection, immature T cells can specifically interact with cells bearing self-antigen, and suggest that the resulting TCR-dependent signal transduction events provide a basis for negative selection of self-reactive T cells.

Animals↗
PubMed1992

Expression of high affinity binding sites for erythropoietin on L8057 cells, a mouse megakaryoblastic cell line, associated with cell differentiation.

In this study, specific binding sites were examined for erythropoietin (EPO) on the mouse leukemic cell line, L8057. This cell line is megakaryoblastic in origin as evidenced by an enlargement of cell size, multinuclearity, intense activity of acetylcholinesterase, more expression of glycoprotein IIb and IIIa antigen, and higher ploidy distribution after the treatment with 12-o-tetradecanoylphorbor-13-acetate (TPA). The original undifferentiated cells possessed a single class of low affinity binding sites for recombinant human (rh) EPO with a Kd of 3.5 nM. Following the treatment with TPA, high affinity binding sites (Kd; 440 pM) were expressed in addition to the low affinity sites. EPO stimulated the incorporation of 3H-leucine into TPA-treated L8057 cells, and the maximal effect of EPO was observed at the same order as the Kd value of high affinity sites. The present data demonstrates that the expression of high affinity binding sites for EPO is associated with the differentiation of L8057 cells which have megakaryocytic characteristics. Furthermore, protein synthesis stimulated by EPO may be mediated through the high affinity sites.

Acetylcholinesterase↗
PubMed1992

Induced expression of PD-1, a novel member of the immunoglobulin gene superfamily, upon programmed cell death.

The classical type of programmed cell death is characterized by its dependence on de novo RNA and protein synthesis and morphological features of apoptosis. We confirmed that stimulated 2B4.11 (a murine T-cell hybridoma) and interleukin-3 (IL-3)-deprived LyD9 (a murine haematopoietic progenitor cell line) died by the classical type of programmed cell death. Assuming that common biochemical pathways might be involved in the deaths of 2B4.11 and LyD9, we isolated the PD-1 gene, a novel member of the immunoglobulin gene superfamily, by using subtractive hybridization technique. The predicted PD-1 protein has a variant form of the consensus sequence found in cytoplasmic tails of signal transducing polypeptides associated with immune recognition receptors. The PD-1 gene was activated in both stimulated 2B4.11 and IL-3-deprived LyD9 cells, but not in other death-induced cell lines that did not show the characteristic features of the classical programmed cell death. Expression of the PD-1 mRNA in mouse was restricted to the thymus and increased when thymocyte death was augmented by in vivo injection of anti-CD3 antibody. These results suggest that activation of the PD-1 gene may be involved in the classical type of programmed cell death.

Amino Acid Sequence↗