Search PubMed⌕ Search

Biomedical subjects

S Shimizu

Publications and source records attributed to S Shimizu.

At least 703 records · Page 39Linked to original sources
PubMed1991

[Phase I clinical study on 99mTc-MIBI].

A phase I clinical study on 99mTc-hexakis 2-methoxy isobutylisonitrile (99mTc-MIBI) was carried out in 6 normal volunteers. There was no significant change in vital signs and laboratory parameters attributing to the reagent other than complaint of slight and transient metallic taste immediately after the injection in 4 volunteers. The highest dosimetry was calculated as 1.1 mGy/37 MBq at lower large intestine, which was within the acceptable range. 99mTc-MIBI was rapidly cleared from the blood and accumulated in the heart immediately after the injection with 1.4% dose and 1.8% dose at 5 min at rest and at stress, respectively. The retention of radioactivity in the heart well continued for at least several hours. The heart-to-lung ratio was over 2.00 at 5 min and heart-to-liver ratio was over 1.00 at 60 min. Myocardial planar and SPECT images were obtained with high quality. In conclusion, 99mTc-MIBI is a useful myocardial perfusion imaging agent.

Adult↗
PubMed1991

Inhibition of cholesterol absorption and synthesis in rats by sesamin.

The effects of sesamin, a lignan from sesame oil, on various aspects of cholesterol metabolism were examined in rats maintained on various dietary regimens. When given at a dietary level of 0.5% for 4 weeks, sesamin reduced the concentration of serum and liver cholesterol significantly irrespective of the presence or absence of cholesterol in the diet, except for one experiment in which the purified diet free of cholesterol was given. On feeding sesamin, there was a decrease in lymphatic absorption of cholesterol accompanying an increase in fecal excretion of neutral, but not acidic, steroids, particularly when the cholesterol-enriched diet was given. Sesamin inhibited micellar solubility of cholesterol, but not bile acids, whereas it neither bound taurocholate nor affected the absorption of fatty acids. Only a marginal proportion (ca. 0.15%) of sesamin administered intragastrically was recovered in the lymph. There was a significant reduction in the activity of liver microsomal 3-hydroxy-3-methylglutaryl coenzyme A reductase after feeding sesamin, although the activity of hepatic cholesterol 7 alpha-hydroxylase, drug metabolizing enzymes, and alcohol dehydrogenase remained uninfluenced. Although the weight and phospholipid concentration of the liver increased unequivocally on feeding sesamin, the histological examination by microscopy showed no abnormality, and the activity of serum GOT and GPT remained unchanged. Since sesamin lowered both serum and liver cholesterol levels by inhibiting absorption and synthesis of cholesterol simultaneously, it deserves further study as a possible hypocholesterolemic agent of natural origin.

Absorption↗
PubMed1991

[No rearrangement of the breakpoint cluster region in two juvenile chronic myeloid leukemia].

We performed cytogenetic studies and breakpoint cluster region (bcr) rearrangement analysis in two cases of juvenile chronic myeloid leukemia (JCML) which is special type of chronic myeloid leukemia (CML). Case 1 (8-month-old male) and case 2 (3-month-old female) showed clinical and hematologic manifestations similar to CML. Each of case 1 and 2 had normal karyotype and no bcr rearrangement. These findings suggest that JCML is a different heterogeneous disorder from that of adult CML.

Female↗
PubMed1991

A case of mixed lineage acute non-lymphocytic leukemia with t(5;12)(p13;p13).

A two-year-old boy had mixed lineage acute non-lymphocytic leukemia (ANLL) with a 46,XY, t(5;12)(p13;p13) karyotype. He was admitted to the hospital with fever and petechiae. Morphological and cytochemical characteristics showed the blasts to meet the standard French-American-British criteria for M1, but surface marker analysis showed the blasts to express both myeloid (CD33: 91.3%) and T-cell (CD2: 82.3%, CD7: 97.9%) antigens. The boy was treated with an ANLL protocol, and successfully brought to a remission which has continued for more than 30 months.

Antigens, Differentiation↗
PubMed1991

[A case of renal oncocytoma with multilocular cyst].

A 63-year-old woman was admitted to our hospital for a left renal tumor with multiple cystic lesions. Computed tomography and renal angiography revealed a hypovascular tumor 9 cm in diameter and multilocular cyst with a thick wall. Renal cell carcinoma and multilocular cystic nephroma were suspected, and left nephrectomy was performed. Histopathological diagnosis of this tumor was renal oncocytoma.

Adenoma↗
PubMed1991

Purification of transferrins and lactoferrin using DEAE affi-gel blue.

1. A simple method for purifying transferrins and lactoferrin is described. 2. The method consists of a preliminary step of dye-ligand chromatography using DEAE Affi-Gel Blue as the gel matrix at pH 7.5. In this chromatographic step, the transferrins and lactoferrin were readily separated from the bulk of the other proteins by start buffer elution. 3. Differences in the chromatographic behaviour of the various serum transferrins (monkey, human, rabbit, pig, chicken and duck) and ovotransferrin upon DEAE Affi-Gel Blue chromatography can be attributed to differences in the anionic charge of the transferrins in 0.02 M potassium phosphate buffer, pH 7.5, thus resulting in the differential retardation of these protein molecules by the gel matrix. 4. The result of DEAE Affi-Gel Blue chromatography of human lactoferrin is different from that for the transferrins. This may possibly reflect the differences in the strength of interaction between lactoferrin and transferrin with this gel matrix.

Amino Acid Sequence↗
PubMed1990

Granulocyte-macrophage colony-stimulating factor enhances macrophage accessory function in con A-stimulated T-cell proliferation.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been reported to augment various macrophage (M phi) functions, including antigen presentation in the antibody-producing response. We investigated the augmentative effect of GM-CSF on M phi A-cell activity in concanavalin A-stimulated T-cell proliferation. Pretreatment with GM-CSF of peritoneal M phi enhanced the T-cell proliferative response. This effect of GM-CSF was dose dependent and GM-CSF supplementation was needed at the beginning of M phi culture. We observed that GM-CSF induced M phi spreading and firm attachment accompanied with enlargement of the cytoplasm, but could not induce de novo expression of Ia antigen. GM-CSF treatment enabled M phi to produce more interleukin (IL)-1 and IL-6 upon stimulation with lipopolysaccharides or polyinosinic-polycytidylic acid, but was unable to stimulate M phi directly. This was confirmed by Northern blot analysis. These results indicate that GM-CSF augments M phi A-cell activity through the enhancement of the capacity of M phi to produce IL-1 and IL-6.

Animals↗
PubMed1990

Isolation and expression of cDNA for different forms of hepatocyte growth factor from human leukocyte.

Human leukocyte cDNA library was screened to isolate cDNA clones coding for hepatocyte growth factor using cDNA from human liver as a probe. Nucleotide and deduced amino acid sequences were analyzed for two of four clones obtained. One of them contained an open reading frame coding for a polypeptide chain of 728 amino acid residues like that of cDNA clone derived from human liver. In another clone a spontaneous deletion of 15 base pairs was found within the coding sequence. When expressed transiently using COS-1 cells both clones produced protein with similar biological activity against rat hepatocyte in vitro.

Amino Acid Sequence↗
PubMed1990

Rearrangements in the human T-cell-receptor alpha-chain locus in patients with adult T-cell leukemia carrying translocations involving chromosome 14q11.

We describe 5 cases of adult T-cell leukemia (ATL) carrying translocations at chromosome 14q11, where the genes for alpha- and delta-chains of the T-cell receptor (TCR alpha/delta) reside (Croce et al., 1985; Isobe et al., 1988). Since the TCR alpha/delta locus is the region where several types of chromosome translocations occur in T-cell tumors, rearrangements of the TCR alpha/delta locus in those ATL cases were studied as a first step to characterize these translocations at the molecular level. For this purpose we have generated an extensive series of probes to define the specificity and the diversity of rearrangement occurring at the widely spanned J alpha-C alpha locus and the complex D delta-J delta-C delta-V delta 2 locus. Using a set of probes, we have found the deletion of the TCR delta locus in all ATL cases, and at least 2 rearrangements in the J delta locus in each case of ATL. It is possible that translocations in the TCR alpha locus may be involved in ATL.

Chromosome Mapping↗
PubMed1990

Effect of morphine on Na+,K(+)-ATPase from homogenate of synaptosomes and of synaptic membrane of rat cerebral cortex.

Effects of morphine on noradrenaline release from rat cerebrocortical synaptosomes and on the Na+,K(+)-ATPase activity in homogenates of synaptosomes and of synaptic membranes were examined. Both morphine (10(-3)-10(-5) M) and methionine-enkephalin (M-Enk; 10(-5) M) inhibited the enhanced [3H]noradrenaline [( 3H]NA) release evoked by high concentrations of K+ from synaptosomes and these inhibitory actions were antagonized by naloxone (10(-4), 10(-5) M). Morphine (10(-3)-10(-5) M) and M-Enk (10(-5) M) stimulated the Na+,K(+)-ATPase activity in homogenates of synaptosomes but not of synaptic membranes in the incubation medium containing 2.2 X 10(-6)-4.7 X 10(-7) M free Ca2+ and these stimulatory effects were antagonized by naloxone. In homogenates of synaptic membranes, the same concentrations of morphine and M-Enk stimulated the Na+,K(+)-ATPase activity suppressed by FeCl2 (5 X 10(-7) M) but not by CuCl2 nor ZnCl2, and these stimulatory effects were antagonized by naloxone. Significant levels of Fe2+ were liberated from synaptosomes during the preparation of synaptic membrane using distilled water. These results suggest that both morphine and M-Enk stimulate the suppressed Na+,K(+)-ATPase activity by interacting with Fe2+ at opioid receptor sites, and they may play a role in the suppression of membrane depolarization and/or the release of NA through their stimulatory action on the Na+,K(+)-ATPase activity probably suppressed by Fe2+ in the rat cerebral cortex.

Animals↗
PubMed1990

DNA autosensitivity in two Japanese sisters.

Two cases of DNA autosensitivity in Japanese sisters are reported. Both patients developed painful ecchymoses and other bleeding disorders. Skin tests with autologous leukocyte lysates and calf thymus DNA produced intermediate-type reactions that were identical to spontaneous skin reactions. Pretreatment of DNA with either DNase or chloroquine sulfate inhibited these reactions. Our studies suggest that anti-DNA antibodies might contribute to the clinical symptoms of this disorder.

Adult↗
PubMed1990

Reovirus type 2-induced diabetes in mice prevented by immunosuppression and thymic hormone.

Reovirus type 2 that had been isolated from a cow with diarrhoea and passaged in bovine kidney cell culture produced a Type 1 (insulin-dependent) diabetes-like syndrome when inoculated into NC mice. The infection resulted in insulitis and destruction of islet cells. Viral antigens were found in islet cells by staining with fluorescein-labelled antibody to reovirus type 2. The destruction of islet cells resulted in abnormalities shown on glucose tolerance testing. Studies on the susceptibility of the host showed that only certain strains of mice had overtly abnormal glucose tolerance tests when infected with reovirus type 2. To assess the immunological role in the pathogenesis of reovirus type 2-induced diabetes, infected mice were subjected to immunosuppressive or thymic hormone treatment. The administration of either anti-thymocyte serum or serum thymic factor reduced or prevented the development of the diabetes-like syndrome, while Arg-Lys-Asp-Val-Try did not show any therapeutic effects.

Animals↗
PubMed1990

Luminol chemiluminescence reaction catalyzed by a microbial peroxidase.

A peroxidase produced by microorganisms belonging to the genera Arthromyces and Coprinus was found to be a potent catalyst for the chemiluminescent oxidation of luminol, the luminescence produced per unit of microbial peroxidase protein being well over 100 times as strong as that produced by horseradish peroxidase. No large difference in Km value for H2O2 in the presence of luminol was found between Arthromyces ramosus peroxidase and horseradish peroxidase (7.0 and 15.5 microM, respectively), but Vmax of the Arthromyces peroxidase was 500 times greater than that of the horseradish peroxidase. It was also found that the Arthromyces peroxidase surpasses, beyond expectation, the horseradish peroxidase in the initial velocity of the chemiluminescence reaction with the stopped-flow method. The Arthromyces peroxidase was used for the glucose and cholesterol assays, which were notably more sensitive than the corresponding assays involving the horseradish peroxidase.

Calibration↗
PubMed1990

Possible existence of an intermediate pool of ubiquinone in rat heart mitochondria.

1. The existence of an intermediate pool of ubiquinone in intact mitochondria of rat heart was investigated. 2. The incorporation of [3H-methyl]S-adenosylmethionine into ubiquinone-9 was not influenced by the co-synthesis of the intermediate, 3-nonaprenyl-4-hydroxybenzoate. 3. In the intermediate-depleted mitochondria, the synthetic rate of the intermediate, 3-nonaprenyl-4-hydroxybenzoate was similar to that of ubiquinone. 4. The possible existence of 3-nonaprenyl-4-hydroxybenzoate as a metabolic pool under physiological condition is discussed.

Animals↗