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Biomedical subjects

M Okuda

Publications and source records attributed to M Okuda.

At least 271 records · Page 15Linked to original sources
PubMed1990

Analysis of GFA-protein mRNA expression in developing bovine brain by in situ hybridization and northern blot hybridization.

Using bovine brains of adult and developmental stages, the time and place of the appearance of mRNA for glial fibrillary acidic protein (GFA-protein) were studied by in situ- and Northern blot-hybridization. Double-stranded cDNA labeled with [3H]dCTP or [32P]dCTP was used as the probe for this mRNA. To compare the location of GFA-protein mRNA and GFA-protein itself on serial sections. GFA-protein immunohistochemistry was used. By in situ hybridization with adult bovine brain. GFA-protein mRNA was detected in astroglia, most of which were in the white matter. The distribution of these astroglia by in situ hybridization was consistent with the findings by GFA-protein immunohistochemistry and Northern blot hybridization, indicating that each techniques were specific. Concerning fetal stages, GFA-protein mRNA could be detected in the brain of a fetal calf with a body length of 28 cm by in situ hybridization using the 32P-labeled probe, and the mRNA was localized in the subpial area and the fornix. These results indicated that glial maturation first became recognizable at least in the subpial area and the fornix in the brain of a fetal calf measuring 28 cm. In this fetal brain, GFA-protein mRNA was almost undetectable by Northern blot hybridization. This suggested that in situ hybridization was more sensitive and useful for the analysis of gene expression than Northern blot hybridization, when the target mRNA is present in only a limited area, such as in the brain.

Animals↗
PubMed1990

[Essential thrombocythemia transformed to acute myeloblastic leukemia].

A 48-year-old woman was referred to Tohoku University Hospital in November 1981 because of leukocytosis pointed out in a group examination. At that time white blood cell count was 26.8 x 10(3)/microliters with no blasts, platelet count 268.0 x 10(4)/microliters and hemoglobin 11.4 g/dl. Bone marrow aspirates showed marked increase of megakaryocytes (15,900/microliters). Bone marrow chromosome analysis revealed 46, XX, -18, +mar without Ph1 chromosome, and DNA analysis showed no bcr rearrangement. She was diagnosed as having essential thrombocythemia and was treated with busulfan. On November 1986, she developed remarkable leukocytosis with leukemic blasts. White blood cells reached 153 x 10(3)/microliters with 33% blasts. Her blasts were positive for peroxidase staining, but negative for platelet peroxidase on electron microscopic study and platelet specific glycoproteins. A diagnosis of acute myeloblastic leukemia (M2) was made. The patient received various combination chemotherapy, which was ineffective, and she died due to pneumonia on June, 1989. In Japan, there has been reported only 8 cases of essential thrombocythemia transformed to acute leukemia. The clinical pictures of these 9 cases were discussed.

Cell Transformation, Neoplastic↗
PubMed1989

Effects of various catecholamines on high-energy phosphates of rat liver and brain during hemorrhagic shock measured by 31P-NMR spectroscopy.

The effects of dopamine, epinephrine and norepinephrine on energy metabolism as well as intracellular pH in rat liver and brain during hemorrhagic shock were examined by in vivo 31P-NMR spectroscopy. The hemorrhagic shock was induced by arterial bleeding to a mean arterial pressure (MAP) of 30-40 mmHg. Upon the induction of hemorrhagic shock, there was a dramatic fall in adenosine triphosphate (ATP) and a rise in inorganic phosphate (Pi) in the liver. The intracellular pH indicated severe acidosis. However, no change in these parameters was observed in the brain during hemorrhagic shock. After infusion of the above catechollamines following 10 min of hemorrhagic shock, MAP increased to 90-100% of its control value. Only dopamine improved hepatic energy metabolism, whereas brain energy metabolism was not affected by any of them. This suggests that dopamine protects liver function during hemorrhagic shock without affecting brain energy metabolism.

Journal Article↗
PubMed1989

High-performance liquid chromatography of reducing carbohydrates as strongly ultraviolet-absorbing and electrochemically sensitive 1-phenyl-3-methyl-5-pyrazolone derivatives.

We found that 1-phenyl-3-methyl-5-pyrazolone reacts with reducing carbohydrates almost quantitatively to yield 2:1 compounds having no stereoisomers, which strongly absorb the uv light at 245 nm and are easily oxidizable on a glassy carbon electrode. Reverse-phase partition chromatography on a column of Capcell Pak C18 with uv or electrochemical detection allowed rapid analysis of aldoses and N-acetylhexosamines with the detection limit of 1 pmol or 100 fmol, respectively. This method proved especially useful for analysis of component monosaccharides of glycorproteins. It was also shown to be valid for separation of reducing oligosaccharides; maltodextrins with a degree of polymerization up to 19 were similarly derivatized and separated on this stationary phase.

Animals↗
PubMed1989

Juvenile hormone inhibits ecdysone secretion and responsiveness to prothoracicotropic hormone in prothoracic glands of Bombyx mori.

The role of juvenile hormone (JH) in the regulation of prothoracic gland activity was investigated during the early days of the last (fifth) larval instar of Bombyx mori. Allatectomy on the day of larval ecdysis into the fifth instar or 1 day before ecdysis shortened the time between larval ecdysis and gut purge. Prothoracic glands of the freshly ecdysed fifth instar larvae were inactive and did not respond to the prothoracicotropic hormone (PTTH), whereas those larvae that were allatectomized 1 day before ecdysis exhibited secretory activity in vitro and were capable of responding to PTTH. When corpora allata were removed from freshly ecdysed fifth instar larvae, the prothoracic glands became competent to respond to PTTH in 6 hr and exhibited secretory activity in vitro 9 hr after the allatectomy. Treatment of allatectomized larvae with a JH analog resulted in the recovery of the normal inactive state of the glands. These data suggest that JH acts during the early stages of the instar to suppress both the secretory activity of prothoracic glands and also the acquisition of competence to respond to PTTH.

Animals↗
PubMed1989

Augmentation of the resistance against Escherichia coli by oral administration of a hot water extract of Chlorella vulgaris in rats.

In previous studies, we demonstrated that a hot water extract of Chlorella vulgaris (CVE) augmented the resistance against an intraperitoneal infection with Escherichia coli by its intraperitoneal, intravenous or subcutaneous administration. The augmented resistance appeared to be attributable to the enhanced activity of polymorphonuclear leukocytes (PMN). In this study, the effect of oral administration of CVE against Escherichia coli infection was examined. Male Fisher rats (F344/DuCrj) were administered 1000 mg/kg of CVE orally for 14 days and challenged with 2.7 x 10(8) Escherichia coli intraperitoneally. The numbers of living bacteria in the peritoneal cavity, blood, spleen and liver at 1, 6, and 24 h after the inoculation were counted. The bacterial numbers increased during 1-6 h and reached the peak at 6 h in both control and CVE-administered groups. The bacterial numbers decreased to an undetectable level at 24 h in both groups. In a CVE-administered group, the numbers of viable bacteria in each organ were remarkably lower than those in a control group in all organs so far tested. Whereas, the leukocyte numbers, especially PMN numbers, in the peritoneal cavity and peripheral blood maintained higher levels in the CVE-administered group at 6 h after E. coli inoculation. Chemiluminescent responses of peritoneal exudate cells induced by casein or E. coli were higher in a CVE-administered group. These results form the basis for the judgment that the degree of effectiveness of bacteria clearance from the peritoneal cavity shown by oral CVE administration may be strong enough to warrant developing this material as a new type of biological response modifier.

Administration, Oral↗
PubMed1989

Characterization and deposition of the proteins in the outermost layer of Bacillus megaterium spore.

It was proved that three spore coat proteins of 48, 36, and 22 kDa (P48, P36, and P22) were the components of the outermost layer (OL) of Bacillus megaterium ATCC 12872 spore by analysis of the isolated OL. And it was indicated that these proteins were deposited not by disulfide bond, but by ionic and/or hydrophobic bonds on the spore. Among them, P36 and P22 were expected to be located on the very surface of the spore by immunological analysis. In the OL deficient mutant of B. megaterium ATCC 12872, MAE05, whose spore was lacking in these OL proteins and galactosamine-6-phosphate polymer, both P36 and P22 were present in the mother cell cytoplasm and deposited on the forespores, but they disappeared with the lysis of mother cells. An OL protein-releasing factor having proteolytic activity was detected in the culture supernatant at the late sporulating stage of both the wild-type and the mutant strains. But the factor could not act on the proteins of the mature spores and the forespores at t10 (tn indicates n hr after the end of exponential growth) of the wild-type strain. Moreover, P36 and P22 were found in the spores of a revertant of MAE05 which could form galactosamine-6-phosphate polymer, suggesting that this sugar polymer played the role in protecting the OL proteins against the protease-like substance after the deposition.

Bacillus megaterium↗
PubMed1989

Contribution of external Ca2+ to the modulation by prostaglandin E2 of the release of acetylcholine from the myenteric plexus of guinea pig ileum.

The effects of external concentration of Ca2+ [( Ca2+]o) on the modulation by indomethacin (IND) or prostaglandin E2 (PGE2) of the evoked release of acetylcholine (ACh) were investigated in the myenteric plexus of guinea pig ileum. An increase in the [Ca2+]o from 0.45 to 3.6 mM depressed both the spontaneous and the nicotine-induced release of ACh, while the releases of ACh induced by electrical-field stimulation (EFS) or by high K+ were augmented. IND and PGE2 did not modify the release of ACh induced by EFS and high K+, at any given [Ca2+]o tested. The nicotine-induced release of ACh was significantly inhibited by IND with no relation to [Ca2+]o, and these inhibitory effects of IND were prevented by PGE2. At 0.45 mM [Ca2+]o, the extent of the recovery by PGE2 was less potent than those at other [Ca2+]o. IND inhibited the spontaneous release of ACh at lower [Ca2+]o, and such inhibition was not observed in the presence of PGE2. Thus, the modulatory actions of PGE2 on the spontaneous and the nicotine-induced release of ACh may depend partially on [Ca2+]o.

Acetylcholine↗
PubMed1989

B cell hyperresponsiveness in Sjögren's syndrome.

We examined the production of and responsiveness to B cell growth factor (BCGF) by using proliferation assays in patients with Sjögren's syndrome (SS). We also studied the ability of SS B cells to respond to B cell stimulatory factors (BSF) by measuring the amount of IgG produced in vitro. SS patients showed normal production of and responsiveness to BCGF. They were also demonstrated to show a normal response to Staphylococcus aureus Cowan I (SAC). In addition, cell surface antigens of B cells in the peripheral blood of SS patients were not altered compared with normal controls. However, SS B cells produced a significant amount of IgG in vitro in response to BSF stimulation with or without anti-IgM antibody. Furthermore, there was a positive correlation between the hyperresponsiveness of B cells to BSF in vitro and serum IgG level in SS. We, therefore, suggest that the enhanced response of B cells to BSF might contribute to polyclonal B cell activation in SS.

Adult↗
PubMed1989

[Effects of prostaglandin E1 infusion during cardiopulmonary bypass].

Effects of continuous prostaglandin E1 (PGE1) infusion 0.03 micrograms.kg-1.min-1 on hemodynamics, body temperature and urine output during cardiopulmonary bypass (CPB) were studied. Systemic vascular resistance was kept significantly lower in PGE1 administration group than control group. Differences between core and peripheral temperature decreased faster in the PGE1 administration group than the control group. Mean arterial pressure was stable at 40mmHg during CPB in the PGE1 group and 60mmHg in the control group. However, there were no significant differences in urine output between the PGE1 administration group (10.8ml.kg-1.h-1) and the control group (9.4ml.kg-1.h-1). This study indicates that continuous PGE1 infusion (0.03 micrograms.kg-1.min-1) is a method of choice for vasodilation and improvement of peripheral perfusion during hypothermia of CPB.

Adult↗
PubMed1988

Extensive cerebral infarction due to involvement of both anterior cerebral arteries by Wegener's granulomatosis.

The central nervous system is often affected in Wegener's granulomatosis (WG), but massive cerebral infarction due to occlusion of branches of the anterior cerebral arteries (ACA) by granulomatous lesions or thrombosis, or both, has seldom been reported. A case is reported here of a 67 year old man with WG complicated by generalised necrotising vasculitis in the lung, kidney, and gastrointestinal tract, and cerebral infarction in the territory of both anterior cerebral arteries, probably caused by thrombosis and a contiguous invasion of granulomatous lesion from the nasal cavity.

Aged↗
PubMed1988

Discordant interleukin 2 production in monozygotic twins concordant for systemic lupus erythematosus.

We present data from monozygotic twins concordant for SLE. IL-2 production by peripheral blood mononuclear cells from the patients, when they were discordant for SLE activity, were measured employing cellular mixing experiments. Macrophages from active SLE had a suppressive effect on IL-2 production. Furthermore, SLE T cells appeared to have a defect in IL-2 production irrespective of disease activity. These defects might play an important role in the disordered immunoregulation in SLE.

Adult↗