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Biomedical subjects

A Satoh

Publications and source records attributed to A Satoh.

At least 163 records · Page 9Linked to original sources
PubMed1990

A novel neutral polysaccharide having activity on the reticuloendothelial system from the root of Glycyrrhiza uralensis.

A neutral polysaccharide, named glycyrrhizan UC, was isolated from the root of Glycyrrhiza uralensis Fischer. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 69,000. Glycyrrhizan UC is composed of L-arabinose:D-galactose:D-glucose:L-rhamnose in the molar ratio of 10:30 27:1. Methylation analysis, carbon-13 nuclear magnetic resonance and periodate oxidation studies indicated its structural feature as an arabino-3,6-galacto-glucan type polysaccharide.

Animals↗
PubMed1990

[An experience of anesthesia in a case of WPW syndrome].

WPW (Wolff-Parkinson-White) syndrome is a rare disease characterized by electro-cardiographic anomalies associated with a history of recurrent supraventricular tachycardia. ECG abnormalities consist of a short PR interval and a broad QSR complex with a slurred upstroke. We experienced general anesthesia in a 29-year-old male with this syndrome for operation of maxillary cyst. Physical laboratory examinations of this patient revealed his conditions of within normal limits with the exception of ECG findings. After premedication with atropine, hydroxyzine and pethilorfan intramuscularly one hour prior to anesthesia, anesthesia was induced with intravenous thiopental 325 mg and the trachea was intubated with intravenous succinylcholine 40 mg. Thereafter anesthesia was maintained with 2.0% enflurane and 67% nitroxide in oxygen under controlled ventilation. During 1 hour operation, vital signs remained stable and paroxysmal tachycardia was not recognized on the ECG. The postoperative course was uneventful.

Adult↗
PubMed1990

Immunoscintigraphy of human tumors transplanted in nude mice with radiolabeled anti-ras p21 monoclonal antibodies.

Anti-ras p21 monoclonal antibody (RASK-3) was used for immunoscintigraphy of human cancer cell lines in nude mice. Iodine-125-labeled RASK-3 was injected into nude mice with either human colon cancers (FCC-1 or BM-314) or lung cancer (KNS-62). Clear images were obtained in all three cancers 7 days after the injection of antibody. No localization of 125I-labeled control monoclonal antibody was observed. The ratio of tissue/blood radioactivity and % ID/g in the tumor were significantly higher than other organs by Day 8. The specific localization index examined by 131I-RASK-3 and 125I-control monoclonal antibody was also higher in the tumor than in other tissues. In the in vitro study, binding of RASK-3 to tumor cells increased significantly by treatment of cells with either lysolecithin or periodate-lysine-paraformaldehyde, which confirmed the intracellular localization of ras p21. The mechanism by which anti-ras p21 antibodies accumulate in tumor sites could be the necrotic changes in tumor cells or changes in membrane permeability of non-necrotic cells. These results provide a strong rationale for the utilization of ras p21 as a target antigen in the imaging of a variety of human cancers.

Animals↗
PubMed1990

[A case of pseudoinfarct of the liver (Zahn's infarct)].

We reported a case of pseudoinfarct (Zahn's infarct) of the liver caused by the inflammatory pseudotumor. A dense segmental staining in the area of Zahn's infarct, which was thought to be characteristic finding, was found on the hepatic angiography. This finding was supposed to be consistent with sinusoidal hyperemia according to the pathological finding.

Adult↗
PubMed1990

[A case of hypothyroidism associated with hypokalemic periodic paralysis].

A case of hypothyroidism associated with hypokalemic periodic paralysis was reported. The patient, a 50 year-old female was admitted because of recurrent paralytic attacks. She had not presented any symptoms of hypothyroidism. Physical examination on admission revealed muscle weakness of limbs, but not enlargement of thyroid glands. Paralytic attack was induced by oral intake of 100 g of glucose, and during attacks, serum K levels ranged from 3.4 to 3.0 mEq/l. She was diagnosed chronic thyroiditis by the high level of TSH and thyroid related anti-antibodies in the serum. Muscle biopsy showed type II atrophy. After the improvement of thyroid function, her paralytic attack disappeared. Present study suggested that hypothyroidism could be a cause of hypokalemic periodic paralysis. This case was very rare and seemed important in etiology of periodic paralysis.

Chronic Disease↗
PubMed1989

Direct evidence for local generation and release of angiotensin II in human vascular tissue.

A direct measurement of both angiotensins I and II immunoreactive substances was made in the perfusate from isolated human umbilical vein perfused with Krebs-Ringer solution which was free of any component of the renin-angiotensin system. The identity of the immunoreactive peptides was confirmed as angiotensin I and angiotensin II by high-performance liquid chromatography in reference to standard compounds. The rate of release of angiotensins was 41.9 +/- 7.4 and 63.4 +/- 12.0 pg for angiotensins I and II, respectively, during the first perfusion period of 30 min, and it remained stable at least for 3 hours. Angiotensin-converting enzyme inhibitor captopril, added to the perfusion medium (10(-9) to 5 x 10(-6) M), suppressed immunoreactive angiotensin II release in a dose-dependent fashion; the maximal percent inhibition of angiotensin II release evoked by captopril (5 x 10(-6) M) was approximately 56%. These results taken together with the previous observations of presence of essential components of the renin-angiotensin system in vascular tissue provide direct evidence for local generation and subsequent release of angiotensin II in vascular beds of human beings.

Angiotensin I↗
PubMed1989

Diagnostic significance of IgG, C3, and C9 at the limb muscle motor end-plate in minimal myasthenia gravis.

We detected deposits of IgG, C3, and C9 (immune complexes) at the limb muscle motor end-plates (biceps brachii muscle) in 16 of 19 patients who exhibited only ocular signs and symptoms of myasthenia gravis that were improved by intravenous injections of edrophonium chloride. Circulating anti-acetylcholine receptor (anti-AChR) antibodies were negative in 6 of the 16 patients, but the motor end-plate fine structure in the postsynaptic regions was abnormal in all 16. Single-fiber EMG revealed no abnormalities in 8 of 13 patients studied. Our results indicate that the detection of immune complexes at the limb muscle end-plate provides a highly sensitive and confirmative method for diagnosing patients with minimal or atypical myasthenia gravis who have no detectable anti-AChR antibodies in their serum.

Adolescent↗
PubMed1988

Plasmapheresis in treatment of human T-lymphotropic virus type-I associated myelopathy.

In 11 of 18 patients with human T-lymphotropic virus type-I (HTLV-I) associated myelopathy (HAM) gait, sensory, and/or sphincter disturbance improved with plasmapheresis (4 to 6 sessions in 2 weeks), and the effects were maintained for 2 to 4 weeks. Plasmapheresis lowered the titre of HTLV-I antibody in serum but not in cerebrospinal fluid, and change of HTLV-I antibody titres did not correlate with the effects of plasmapheresis. These results suggest that plasmapheresis is useful treatment, at least in producing a temporary improvement, in patients with HAM, and that some humoral factor(s), but not HTLV-I antibody, may be important in the pathogenesis of HAM.

Adult↗
PubMed1988

Prognostic implications of cardiac scintigraphic parameters obtained in the early phase of acute myocardial infarction.

A cohort of 76 patients with acute myocardial infarction was studied with infarct-avid scan, radionuclide ventriculography, and thallium-201 myocardial perfusion scintigraphy. Infarct area, left ventricular ejection fraction, and defect score were calculated as radionuclide indices of the extent of myocardial infarction. The correlation was studied between these indices and cardiac events (death, congestive heart failure, postinfarction angina, and recurrence of myocardial infarction) in the first postinfarction year. High-risk patients (nonsurvivors and patients who developed heart failure) had a larger infarct area, a lower left ventricular ejection fraction, and a larger defect score than the others. Univariate linear discriminant analysis was done to determine the optimal threshold of these parameters for distinguishing high-risk patients from others. Radionuclide parameters obtained in the early phase of acute myocardial infarction were useful for detecting both patients with grave complications and those with poor late prognosis during a mean follow-up period of 2.6 years.

Adult↗
PubMed1988

Role of the macrophage in the pathogenesis of experimental autoimmune myasthenia gravis.

To clarify the role of Ia antigen positive macrophages which invade motor end-plates in the induction of the chronic phase, experimental autoimmune myasthenia gravis (EAMG) rats were injected intraperitoneally with silica dust on day 6 after immunization. Silica injection partially inhibited the invasion of motor end-plates with macrophages as compared with a saline injection. The titer of antibodies to the Narke acetylcholine receptor (AChR) in the chronic phase did not differ in either the saline or the silica groups, while the titer of antibodies to rat-AChR (non-crossreactive antibodies) was lower in the silica group than in the saline group. The silica group survived longer than the saline group. These results suggest that Ia antigen positive macrophages in the acute phase act as antigen-presenting cells and play an important role in the production of antibodies to self-AChR in the chronic phase.

Animals↗
PubMed1988

The bialaphos resistance gene (bar) plays a role in both self-defense and bialaphos biosynthesis in Streptomyces hygroscopicus.

We inactivated the bialaphos (BA) resistance gene (bar) of a BA producer, Streptomyces hygroscopicus, by the gene replacement technique. The resulting BA-sensitive mutant (Bar-) was able to produce little BA but considerable amount of an intermediate demethylphosphinothricin (DMPT). The Bar- mutant was still able to convert the N-acetyl derivative (AcDMPT) of DMPT to BA. Introduction of normal bar containing plasmid restored both BA resistance and BA biosynthesis to levels as high as the parental BA producer. By contrast, introducing a multi copy glutamine synthetase gene (glnA) into the Bar- mutant restored BA resistance but not BA production. Thus, the bar gene plays a crucial role in both self-defense and a step of BA biosynthesis in the BA-producing S. hygroscopicus.

Anti-Bacterial Agents↗
PubMed1988

Replacement of Streptomyces hygroscopicus genomic segments with in vitro altered DNA sequences.

We have developed a method for gene replacement in Streptomyces hygroscopicus which permits introduction of an in vitro derived mutation carried on a plasmid into the chromosome. We constructed the plasmid pMSB212 which can replicate in S. hygroscopicus and contains the step5 gene of the bialaphos biosynthetic pathway which was inactivated by a frame-shift mutation caused by filling in the cohesive ends of the EcoR I site in the structural gene. pMSB212 was introduced into a bialaphos producer strain and by protoplast regeneration of the primary thiostrepton-resistant transformants, non-producing mutants, were obtained. Biochemical and genetical analyses indicated that these mutants were specifically blocked by introduction of the frame-shift mutation in the step5 gene on the chromosome. This method will enable us to obtain isogenic mutants of known genes and to identify new genes encoded on a cloned fragment.

Chromosomes, Bacterial↗
PubMed1988

The bialaphos biosynthetic genes of Streptomyces hygroscopicus: cloning and analysis of the genes involved in the alanylation step.

We have isolated and studied the genes involved in the alanylation step in the biosynthesis of a herbicide, bialaphos which is produced by Streptomyces hygroscopicus. Three bialaphos-nonproducing mutants, NP60, NP61 and NP62, isolated from S. hygroscopicus by treatment with N-methyl-N'-nitro-N-nitrosoguanidine were defective for the alanylation step and were not restored to productivity by any locus of the gene cluster previously cloned. Three plasmids were isolated using NP60, NP61 and NP62 as recipients. The genes which restored productivity to NP61 and NP62 hybridized to the contiguous region of the bialaphos biosynthetic gene cluster. The gene cluster involved in the bialaphos production was about 35 kb long. The gene which restored productivity to NP60 did not hybridize to the bialaphos biosynthetic gene cluster. VM3 and VM4, putative alanylation blocked mutants, were derived from a bialaphos producer by gene replacement of an unidentified region of the biosynthetic gene cluster with an in vitro altered DNA sequence. The genes which restored productivity to VM3 and VM4 were located between the genes which code for phosphinomethylmalic acid synthase and demethylphosphinothricin acetyltransferase in the cluster. These results suggest that multiple genes are involved in the alanylation step.

Alanine↗