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Y Yoshida

Publications and source records attributed to Y Yoshida.

At least 739 records · Page 41Linked to original sources
PubMed1994

Beneficial effects of cyclosporine on reoxygenation injury in hypoxic rat liver.

The effect of CsA on hypoxia-reoxygenation injury was studied in perfused rat livers. CsA did not attenuate hypoxic injury, as assessed by the release of lactate dehydrogenase and mitochondrial aspartate aminotransferase. During reoxygenation, the release of lactate dehydrogenase was also not affected by CsA. However, the release of mitochondrial aspartate aminotransferase into the cytosol, which indicates mitochondrial injury, was significantly reduced by CsA. The effect of CsA on mitochondrial function during hypoxia-reoxygenation was also investigated. CsA administration increased both the respiratory control ratio and the adenine nucleotide content after reoxygenation in both isolated mitochondria and perfused livers. In addition, glucose production by perfused livers after reoxygenation was increased by CsA. We conclude that the beneficial effect of CsA on hypoxia-reoxygenation injury may be partly due to protection of the mitochondria against reoxygenation injury.

Animals↗
PubMed1994

A monoclonal antibody against oxidized lipoprotein recognizes foam cells in atherosclerotic lesions. Complex formation of oxidized phosphatidylcholines and polypeptides.

In this study we have used homogenates of human atheromatous plaque as immunogen to establish a murine monoclonal antibody which recognizes oxidized low density lipoprotein (LDL). This monoclonal antibody, FOH1a/DLH3, reacted with oxidized LDL, but enzyme-linked immunosorbent assay showed that it had no reaction with native, acetylated, or malonaldehyde-treated LDL. The antibody cross-reacted with oxidized high density lipoprotein, suggesting that specific sequences of the apolipoprotein B are not essential for antigen recognition by the antibody. Immunohistochemical analysis of thin paraffin sections from human coronary arteries showed that foam cells derived from macrophages in atherosclerotic lesions were heavily stained by this antibody. Several other structures in the lesions, including swollen collagen fibers, cellular debris in necrotic cores, and endothelial cells, were moderately stained. The epitope of this antibody was characterized by a model antigen-generating system using ferrous ion-induced peroxidation of lipids. When the total lipid fraction extracted from LDL was treated with the ferrous ion-induced peroxidation system, the reaction mixture was recognized by the antibody. Antigenic product(s) was produced only when phosphatidylcholine (PC) was treated with the ferrous ion-induced peroxidation, other lipids failed to react to the antibody. To investigate the possible formation of a complex of antigenic product with a polypeptide, a synthetic peptide and a rabbit antiserum against the peptide were used. Reaction mixture of ferrous ion-induced peroxidation of PC in the presence of the peptide was added to a microtiter well precoated with the monoclonal antibody FOH1a/DLH3. After washing, the peptide remaining in the well was detected with rabbit antiserum against the peptide, whereas no reactivity was observed when peptide alone was added to the well. Binding of the antigenic complex to the precoated monoclonal antibody was competed by oxidized PC produced in the absence of any polypeptide. We conclude that oxidized phospholipid product(s) is the epitope of the monoclonal antibody and that the oxidized phospholipid forms complexes with polypeptides. The antigenic materials are detected in foam cells in atherosclerotic lesions.

Amino Acid Sequence↗
PubMed1994

Molecular cloning and biological activity of a novel developmentally regulated gene encoding a protein with beta-transducin-like structure.

In the developing mammalian central nervous system, neural precursor cells show a tightly regulated inverse relationship between cell proliferation and differentiation. The molecular mechanisms which control the inter-relationship between these two events are poorly understood. To approach this problem, we previously identified several novel genes which are most prominently expressed in the early embryonic brain. Further cloning and sequencing of one such gene, Nedd1, revealed that it can encode a protein with a M(r) of 71,000, the amino-terminal half of which shares significant structural similarity with the beta-subunit of heterotrimeric GTP-binding proteins. Nedd1 mRNA is strongly expressed in early embryonic brain, but it can be detected at low levels in a number of adult tissues as well as cell lines and is up-regulated in an embryonal carcinoma cell line upon retinoic acid-induced differentiation. Ectopic expression of Nedd1 gene by means of eukaryotic vectors in various cell lines resulted in varying degrees of growth suppression. The strongest effects were evident in differentiation-competent neuroblastoma-derived cell lines. Our results suggest that the Nedd1 gene may play a role in the differentiation-coupled growth arrest in neuronal cells.

Amino Acid Sequence↗
PubMed1994

Purification and characterization of 240-kDa cGMP-dependent protein kinase substrate of vascular smooth muscle. Close resemblance to inositol 1,4,5-trisphosphate receptor.

The 240-kDa, cGMP-dependent protein kinase substrate protein obtained from porcine aortic smooth muscle, whose phosphorylation was closely associated with stimulation of plasma membrane Ca(2+)-pump ATPase (Yoshida, Y., Sun, H.-T., Cai, J.-Q., and Imai, S. (1991) J. Biol. Chem. 266, 19819-19825), was purified to near homogeneity by three successive chromatographic runs with calmodulin-, concanavalin A-, and heparin-Sepharose columns from microsomes solubilized with Triton X-100. The purified protein was found to bind inositol 1,4,5-trisphosphate (InsP3) in a specific, heparin-inhibitable manner with a Kd of 2.0 nM and Bmax of 450 pmol/mg protein (the binding of inositol 1,3,4,5-tetrakisphosphate was much weaker). In sedimentation experiments on a linear sucrose density gradient the InsP3 binding activity was always with the 240-kDa protein. Protein kinase G phosphorylated the InsP3 receptor purified from the rat cerebellum as well as the 240-kDa protein. Sialic acid content of the protein measured with Limulus polyphemus agglutinin was not significantly different from that of the cerebellar InsP3 receptor. Thus, 240-kDa protein closely resembles InsP3 receptor and may be a type of InsP3 receptor. The only difference was the behavior on SDS-polyacrylamide gel electrophoresis. The 240-kDa protein presented itself as two polypeptides with similar but slightly differing M(r) values, both of which were phosphorylated by protein kinase G.

Amino Acid Sequence↗
PubMed1994

Distinct sites of dopaminergic and glutamatergic regulation of haloperidol-induced catalepsy within the rat caudate-putamen.

Previous studies have indicated that corticostriatal glutamatergic pathways are implicated in the regulation of neuroleptic catalepsy. To obtain a better understanding of the way in which dopamine (DA) and glutamate interact within the caudate-putamen (CP) in the development of catalepsy, we investigated the regional distribution within the rat CP of the cataleptogenic effect of haloperidol and its antagonism by D(-)-2-amino-5-phosphonopentanoic acid (D(-)AP5), a selective antagonist of the N-methyl-D-aspartate (NMDA) glutamate receptor subtype. Bilateral injections of haloperidol (3 micrograms/side) into the rostral ventromedial (VM) CP induced potent catalepsy with a short latency after the injection. In contrast, only a weak cataleptic response, of slower onset, was observed after haloperidol injections into the rostral ventrolateral (VL), rostral dorsomedial (DM), or rostral dorsolateral (DL) CP, or into the nucleus accumbens. D(-)AP5 (5 micrograms/side) injected bilaterally into the dorsorostral CP (DM and DL) strongly inhibited the catalepsy induced by systemic haloperidol (1 mg/kg, i.p.), and this effect lasted longer when the drug was injected into the DM than when it was injected into the DL. D(-)AP5 did not affect haloperidol-induced catalepsy when injected into the ventrorostral (VM and VL) or intermediate dorsal CP. D(-)AP5 injected into the DM, the region most sensitive to the anticataleptic effect of the drug, had no effect on basal levels of DA and its metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid, or on the modification of these levels by haloperidol in either the DM or VM. These findings suggest that, while the catalepsy resulting from DA receptor blockade by haloperidol originates mainly from the VM, the expression of this phenomenon depends on an intact glutamatergic transmission within the dorsorostral CP. In the development of neuroleptic catalepsy, the mesencephalostriatal DAergic and corticostriatal glutamatergic pathways seem to be functionally linked through an indirect, rather than a direct, interaction.

2-Amino-5-phosphonovalerate↗
PubMed1994

Induction and promotion of forestomach tumors by sodium nitrite in combination with ascorbic acid or sodium ascorbate in rats with or without N-methyl-N'-nitro-N-nitrosoguanidine pre-treatment.

In experiment I, short-term effects of combined treatment with anti-oxidants, sodium ascorbate (NaAsA) and sodium nitrite (NaNO2) on forestomach cell proliferation were examined in F344 male rats. Groups of 5 animals aged 6 weeks were treated for 4 weeks with 0.8% catechol, 0.8% hydroquinone, 1% tert-butyl-hydroquinone (TBHQ), 2% gallic acid or 2% pyrogallor alone or in combination with 0.3% NaNO2 in the drinking water and/or 1% NaAsA in the diet. The thicknesses of forestomach mucosa in rats treated with anti-oxidants and NaNO2 in combination were greater than those with antioxidant alone and additional NaAsA treatment further enhanced the thickening of mucosa. It was noteworthy that values for mucosae of animals treated with NaNO2 and NaAsA without anti-oxidant were similar to those for anti-oxidants. In experiment 2, effects of combined treatment with NaAsA or ascorbic acid (AsA) and NaNO2 on carcinogenesis were examined in F344 male rats with or without N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) pre-treatment. Groups of 20 or 15 rats, respectively, aged 6 weeks, were given a single intra-gastric administration of 150 mg/kg body weight of MNNG in DMSO:water = 1:1 or the vehicle alone by stomach tube. Starting 1 week later, they received supplements of 1% NaAsA or 1% AsA in the diet and 0.3% NaNO2 in drinking water in combination, each of the individual chemicals alone, or basal diet until the end of week 52. In MNNG-treated animals, incidences of forestomach papillomas and carcinomas were significantly enhanced in the NaNO2 alone group (84 and 47%, respectively) as compared with the basal diet group (30 and 10%), with further significant increase in carcinomas occurring with additional NaAsA (79%, p < 0.05) or AsA (85%, p < 0.05) treatment. In animals without MNNG, all animals in the NaNO2 group demonstrated mild hyperplasia, additional administration of NaAsA or AsA remarkably enhancing the grade of hyperplasia, and resulting in 53% and 20% incidences, respectively, of papillomas. Thus NaNO2 was demonstrated to exert promoter action for forestomach carcinogenesis, with NaAsA and AsA acting as co-promoters. The results strongly indicate that combined treatment with NaAsA or AsA and NaNO2 may induce forestomach carcinomas in the long term.

Animals↗
PubMed1994

Percutaneous transluminal coronary angioplasty of the left internal thoracic artery graft: a case report in a child.

A 9-year-old girl who had undergone previous coronary artery bypass surgery at the age of 3.5 years for stenoses of the left anterior descending and right coronary arteries resulting from Kawasaki disease presented with recurrent exertional angina. Stenosis was found at the anastomosis of the left internal thoracic artery to the left anterior descending artery. Percutaneous transluminal coronary angioplasty was successfully performed. This is the first reported case of percutaneous transluminal coronary angioplasty of an internal thoracic artery graft in a child.

Angioplasty, Balloon, Coronary↗
PubMed1994

Silver stained nucleolar organizer region proteins and Helix pomatia agglutinin immunostaining in esophageal carcinoma: correlated prognostic factors.

The number of nucleolar organizer region proteins identified by silver staining (AgNORs) and alterations in cell surface glycoproteins identified by Helix pomatia agglutinin (HPA) immunostaining were studied in 96 primary esophageal carcinomas. The number of AgNORs increased with increasing depth of cancer invasion, venous involvement, lymphatic invasion, and tumor stage. Positivity of HPA staining correlated significantly with increasing depth of cancer invasion, venous invasion, and tumor stage. Forty of 42 HPA negative cases had low AgNORs numbers (< 4), while 39 of 54 HPA positive cases had high AgNORs numbers (> or = 4) (P = 0.0001). The survival rate of patients with stage III and IV disease was significantly poorer for those with a high AgNORs score and HPA positivity than in those with a low AgNORs score and HPA negativity. The present study indicates that the AgNORs score is positively correlated with positive HPA staining and that tumors having both factors represent a subgroup of esophageal carcinomas with poor prognosis.

Adult↗
PubMed1994

Simple and sensitive quantitation method for mevalonic acid in plasma using gas chromatography/mass spectrometry.

The combination of gas chromatography and mass spectrometry using a polar capillary column and isobutane chemical ionization made it possible to determine mevalonic acid (MVA) as the lactone at subnanogram levels using 1 mL of plasma. The pretreatment procedure consisted of only three steps, namely lactonization, washing with chloroform and liquid/liquid extraction. This simple, rapid and sensitive method, having good precision and accuracy, is useful for evaluating the change of plasma MVA, which is well correlated with whole-body cholesterol biosynthesis.

Adult↗
PubMed1994

Changes in biliary glutathione level during ischemia-reperfusion of rat liver.

Changes in hepatic and biliary glutathione levels were studied in rat liver treated with tert-butyl hydroperoxide (t-BuOOH) and subjected to ischemia-reperfusion. Immediately after t-BuOOH administration, the oxidized glutathione (GSSG) values and reduced glutathione (GSSG/GSH) ratio in the bile increased dose-dependently and then returned to control level within 10 min, whereas the hepatic ATP level and bile flow rate were not affected by t-BuOOH at doses of up to 1.0 mmol/kg. These data suggested that the liver remains viable on treatment with up to 1.0 mmole/kg t-BuOOH, and that hepatocytes can rapidly dismute t-BuOOH at up to this dose. The hepatic GSH and GSSG levels did not vary appreciably during ischemia for 10 or 30 min or during subsequent reperfusion, but the GSSG/GSH ratio increased after ischemia for 30 min. The rate of bile flow and the biliary level of GSH decreased after ischemia for 30 min in proportion to the decrease in the hepatic ATP level. However, the biliary GSSG concentration did not vary on reperfusion, although GSSG secretion into the bile is also related to the hepatic ATP level. As a result, the GSSG/GSH ratio in the bile increased during reperfusion after ischemia for 30 min. This increased ratio is thought to reflect oxidation of hepatic GSH by hydroperoxide produced during reperfusion. The GSSG/GSH ratio in the bile after 30 min ischemia corresponded to that observed after a small dose (0.07 mmole/kg body wt) of t-BuOOH, which hepatocytes could dismute rapidly without loss of their viability.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1994

Clinical study of biological response modifiers as maintenance therapy for hepatocellular carcinoma.

We conducted a randomized, controlled trial comparing 5-fluorouracil (5-FU) with or without biological response modifiers (BRMs) as a maintenance therapy for hepatocellular carcinoma (HCC) after treatment with percutaneous ethanol injection (PEI), transcatheter arterial embolization (TAE) or arterial infusion of antitumor agents (AI). A total of 58 cases of HCC were classified into 4 groups as follows: group I, PSK with 5-FU (n = 15); group II, lentinan with 5-FU (n = 15); group III, OK-432 with 5-FU (n = 12); and group IV, 5-FU alone as the control (n = 16). The mean survival time, mortality rate, time to progression, and T4/T8 ratio of lymphocytes in the peripheral blood were compared among the four groups. There was no significant difference in the background factors among the groups. In group I, the T4/T8 ratio of lymphocytes was reduced after the therapy. No significant difference was found among the groups in terms of the mean survival time, mortality rate, or time to progression. PEI for initial therapy was superior to the other therapies in terms of the mean survival time and mortality rate. These results suggest that the addition of BRM to maintenance therapy with 5-FU exerts no prognostic benefit on HCC patients treated with PEI, TAE, or AI.

Aged↗
PubMed1994

Acute leucoencephalopathy during cyclosporin A therapy in a patient with nephrotic syndrome.

A 13-year-old girl with nephrotic syndrome (NS) developed acute leucoencephalopathy during combination therapy with cyclosporin A (CyA) and prednisolone (PSL). The patient had a generalized motor seizure followed by coma at 19 days after CyA administration. Magnetic resonance scanning performed on the 1st hospital day revealed white matter lesions in the subcortices of the parietal and occipital lobes, brain stem and cerebellum. These lesions had completely resolved on the 10th hospital day. This episode might be caused by CyA because the clinical course and laboratory data revealed neither inflammation nor other causative factors. To our knowledge, this is the first report of acute leucoencephalopathy during combination therapy with CyA and PSL in a patient with NS.

Acute Disease↗
PubMed1994

Clinical significance of serum iron and ferritin in patients with colorectal cancer.

To clarify the significance of serum iron and ferritin as indicators of iron loss caused by continuous bleeding, and, thus, to determine their value as markers of colorectal cancer, values for the two were compared in male patients with early and advanced colorectal cancer and age-matched male controls. The mean value of serum iron levels in patients with advanced colorectal cancer was significantly decreased compared with values in patients with early colorectal cancer and controls, 50.5 +/- 38.6 micrograms/dl vs 93.0 +/- 32.1 micrograms/dl and 107.1 +/- 32.9 micrograms/dl, respectively (p < 0.001). The mean value of serum ferritin levels in patients with early and advanced colorectal cancer was also significantly decreased compared with controls, 80.5 +/- 35.0 ng/ml (p < 0.01) and 48.8 +/- 72.8 ng/ml (p < 0.001), respectively, vs 117.1 +/- 46.8 ng/ml. However, there was no significant difference between mean serum iron levels in patients with early colorectal cancer and controls. Eighteen (78.3%) of the 23 patients with advanced colorectal cancer and 3 (16.7%) of the 18 patients with early colorectal cancer had serum iron levels below 85 micrograms/dl and serum ferritin levels below 60 ng/ml. Levels of both serum iron and ferritin, without clinically evident anemia, are useful indicators of advanced colorectal cancer.

Aged↗
PubMed1994

Foreign-body granuloma mimicking an extrahepatically growing liver tumor: report of a case.

We herein describe a 74-year-old woman with a foreign-body granuloma mimicking a liver tumor. Imaging studies revealed a pedunculated left lobe mass in the setting of chronic liver disease. She had a past history of a cholecystectomy as well as a previous gynecological operation. A left lateral segmentectomy was performed because of the possibility of a rupture. The dissected specimen showed a foreign-body granuloma caused by gauze. We believe this case to be a very unique granuloma, which should be kept in mind whenever making a diagnosis of a liver tumor particularly in a patient with chronic liver disease, who has a past history of abdominal surgery.

Aged↗
PubMed1994

A case of protein-losing enteropathy in idiopathic thrombocytopenic purpura with decreased IgA.

A young woman presented with high fever and edema in January, 1984, and was diagnosed as having systemic lupus erythematosus. Prednisolone administration failed to improve her symptoms. In May she was admitted to hospital because of elevated erythrocyte sedimentation rate (ESR), hypoproteinemia, hypogammaglobulinemia, hypocomplementemia, positive antinuclear antibody, elevated immune complex level, and diarrhea. Edema disappeared following administration of diuretics and albumin, although the pathogenesis was still undetermined. In September, she was referred to our institution because of severe watery diarrhea and hypoproteinemia. Endoscopic examination showed a diffuse inflammatory lesion in the duodenum and the colon. Radioisotopic 51Cr-albumin study results were compatible with protein-losing enteropathy. Hypoproteinemia and inflammatory changes of the intestine were improved by antibiotics, suggesting that the inflammatory lesion was caused by bacterial infection. Despite the improvements in clinical symptoms and laboratory findings, the serum IgA level was still low and the thrombocytopenia remained. The morphological characteristics of the megakaryocytes were consistent with idiopathic thrombocytopenic purpura. In May, 1986, the thrombocytopenia deteriorated, causing purpura. Prednisolone was administered again, and this resulted in normalization of the platelet count, although the IgA level remained low. Finally the prednisolone was stopped, and the IgA level gradually recovered, with the improvement of the enterocolitis. The exact pathogenesis of the whole picture in this case is unclear, but an 8-year-long clinical course suggests that the protein-losing was caused by an infectious enterocolitis superimposed on IgA deficiency.

Adult↗