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Biomedical subjects

S Fukui

Publications and source records attributed to S Fukui.

At least 145 records · Page 8Linked to original sources
PubMed1989

[Anesthetic management of a patient with acromegaly complicated with hyperthyroidism].

A rare anesthetic experience of a 30-year-old woman with acromegaly complicated with Basedow's disease is reported. After the thyroid function was successfully controlled by drug therapy, resection of pituitary adenoma was performed under general anesthesia. Anesthesia was induced and maintained with NLA. No problem was observed during the operation and postoperative period. Careful attention should be paid to the management of circulation, respiration, metabolism and endocrinium through the perioperative period.

Acromegaly↗
PubMed1988

A monoclonal antibody that recognizes a cluster of a disaccharide, NeuAc alpha(2----6)GalNAc, in mucin-type glycoproteins.

The structure of an epitopic carbohydrate recognized by a monoclonal antibody, MLS 102, was determined. A disaccharide, NeuAc alpha (2----6)GalNAc, the major prosthetic group of ovine submaxillary mucin (OSM) and related synthetic glycosides, NeuAc alpha(2----6)GalNAc alpha----Ser, NeuAc alpha(2----6)GalNAc beta----Ser, and NeuAc alpha (2----6)GalNAc beta----propyl, reacted with MLS 102 to similar extents, but the reaction was considerably weaker compared to that of OSM. This difference in reactivity could be ascribed to the occurrence of a cluster of the disaccharide on OSM. Purification of MLS 102-reactive antigens from a Triton X-100 extract of LS 180 cells by means of immunoaffinity chromatography gave mucin fractions (cMLS 102 antigen) with an OSM-like domain. Correlation between the content of the disaccharide, NeuAc alpha(2----6)GalNAc, in mucins and their reactivity with MLS 102 was observed.

Antigen-Antibody Complex↗
PubMed1988

Immunoaffinity isolation of a sialyl-Le(a) oligosaccharide from human milk.

A cancer-associated antigen, sialyl-Le(a) oligosaccharide, was isolated from human milk using a monoclonal antibody recognizing carbohydrate moieties of mucin-type glycoproteins. The structure was identified as: (Formula: see text) based on 500-MHz 1H-NMR spectroscopy. This oligosaccharide comprises 0.07% of sialyloligosaccharides in human milk. The NMR spectra of two fellow oligosaccharides, Le(a) oligosaccharide (or lacto-N-fucopentaose II) and LS-tetrasaccharide a, are also given.

Antibodies, Monoclonal↗
PubMed1988

A monoclonal antibody that recognizes sialyl-Lea oligosaccharide, but is distinct from NS 19-9 as to epitope recognition.

A murine monoclonal antibody, designated as MSW 113, was generated using a human colonic cancer cell line, SW 1116, as the immunogen. MSW 113 was shown to be directed mainly to mucin-type oligosaccharide with sialyl-Lea antigens. The reactivity of MSW 113 to sialyl-Lea was stronger than that of NS 19-9, which is believed to be raised against the same determinant group. MSW 113 binds to sialyl-Lea-ol, LS-tetrasaccharide a, and disialyllacto-N-tetraose with higher affinities, compared to NS 19-9. These two antibodies could clearly be distinguished in that MSW 113 bound to sialic acid but not to fucose, whereas NS 19-9 bound to fucose but not to sialic acid. Thus, MSW 113 is directed more toward sialic acid-containing terminal structures while NS 19-9 is directed toward fucose-containing internal structures. MSW 113 was found to be useful for detecting antigens in the bloodstream of patients, especially those with pancreas cancer. Even NS 19-9 negative patient sera were positive for MSW 113.

Antibodies, Monoclonal↗
PubMed1988

Production of monoclonal antibodies directed against carbohydrate moieties of cell surface glycoproteins.

Through the use of a technique for raising monoclonal antibodies, coupled with a solid-phase radioimmunoassay utilizing immobilized glycopeptides prepared from the surface membranes of the colorectal cancer cells (LS 180) used for the immunization, carbohydrate-directed monoclonal antibodies were obtained. One of the monoclonal antibodies, MLS 102, reacted immunohistochemically intensely with the colorectal cancer cell surface and the mucinous glycoproteins secreted by the cancer cells, but only weakly with normal colon tissue. The antigenic determinant recognized by MLS 102 was the carbohydrate moiety of glycoproteins with terminal sialic acid. The antigens defined by other monoclonal antibodies, MLS 103 and 104, were immunohistochemically detected in both normal colonic epithelial and cancer cells. These antibodies seemed to recognize the carbohydrate moieties of both glycoproteins and glycolipids. The method described in this report can be generally applied to raise cell surface carbohydrate-directed antibodies.

Animals↗
PubMed1988

Nucleotide sequences of Saccharomycopsis fibuligera genes for extracellular beta-glucosidases as expressed in Saccharomyces cerevisiae.

We isolated two genes for extracellular beta-glucosidase, BGL1 and BGL2, from the genomic library of the yeast Saccharomycopsis fibuligera. Gene products (BGLI and BGLII) were purified from the culture fluids of Saccharomyces cerevisiae transformed with BGL1 and BGL2, respectively. Molecular weights of BGLI and BGLII were estimated to be 220,000 and 200,000 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The two beta-glucosidases showed the same enzymatic characteristics, such as thermo-denaturation kinetics and dependencies on pH and temperature, but quite different substrate specificities: BGLI hydrolyzed cellobiose efficiently, but BGLII did not. This result is consistent with the observation that the S. cerevisiae transformant carrying BGL1 fermented cellobiose to ethanol but the transformant carrying BGL2 did not. Southern blot analysis revealed that the two beta-glucosidase genes were derived from Saccharomycopsis fibuligera and that the nucleotide sequences of the two genes are closely related. The complete nucleotide sequences of the two genes were determined. BGL1 and BGL2 encode 876- and 880-amino-acid proteins which were shown to be highly similar to each other. The putative precursors begin with hydrophobic segments that presumably act as signal sequences for secretion. Amino acid analysis of the purified proteins confirmed that BGL1 and BGL2 encode BGLI and BGLII, respectively.

Amino Acid Sequence↗
PubMed1988

Characterization of a DNA uptake reaction through the nuclear membrane of isolated yeast nuclei.

Isolated yeast nuclei were able to incorporate 3H-labeled pJDB219 DNA in vitro in the presence of ATP and Mg2+. The number of plasmid molecules incorporated into each nucleus was calculated to be 60 under the conditions we used. Enzyme-histochemical staining of the incorporated biotinylated pJDB219 with streptavidin-biotinylated-peroxidase complex indicated a uniform distribution of the incorporated plasmids within each nucleus. After intranuclear incorporation, substrate pJDB219 DNAs (open and closed circular forms) were changed to the linear form and were weakly digested over the longer incubation period (over 60 min). Facile release of the once-incorporated plasmid DNA was never observable; discharge of the incorporated [3H]pJDB219 during a 60-min incubation was less than 5%. The addition of adenylyl-imidodiphosphate, N,N'-dicyclohexylcarbodiimide (DCCD), or quercetin inhibited in vitro DNA uptake reaction. DCCD and quercetin inhibited the nuclear ATPase and apparent protein kinase, respectively; hence, the involvement of these enzymes in the nuclear DNA transport system was suggested.

Adenosine Triphosphate↗
PubMed1988

The role of intracoronary thrombus in unstable angina: angiographic assessment and thrombolytic therapy during ongoing anginal attacks.

Intracoronary thrombus is regarded as a potentially important factor in the etiology of unstable angina, but the incidence of intracoronary thrombus in unstable angina has not been clearly defined. To determine the occurrence of intracoronary thrombus during ongoing angina pectoris, coronary angiography was performed during spontaneous ischemic attacks in 37 patients with prolonged rest angina. All patients exhibited significant (greater than 50%) stenoses of at least one major coronary artery. Of the 37 patients, 21 (57%) had intracoronary thrombus in major coronary arteries, whereas 14 (38%) had fixed narrowings without evidence of intracoronary thrombus and two exhibited coronary spasm. ST segment elevation was observed in 16 of 21 patients with thrombus and in all of the patients with coronary spasm, but all the patients with organic stable obstruction showed ST segment depression. Twenty of the 21 patients with thrombus improved after thrombolytic therapy with intracoronary injection of urokinase; obstructed arteries were reopened, or narrowings were attenuated, with relief of ischemic symptoms. In patients with fixed obstructions, the rate-pressure product during active symptoms was significantly higher than during an asymptomatic period, indicating that a transient increase in myocardial oxygen demand may contribute to the ischemic attack in these patients. A high incidence (71%) of recurrent symptoms was observed in patients with intracoronary thrombus even after successful thrombolysis, in contrast to a much lower incidence (36%) in those without intracoronary thrombus. Myocardial infarction within 4 weeks after catheterization was observed more frequently in patients with intracoronary thrombus (24%) than in those without thrombus (7%).(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1987

Interaction with phospholipids of a membrane thiol peptidase that is essential for the signal transduction of mating pheromone in Rhodosporidium toruloides.

Interaction with phospholipids of a membrane thiol peptidase [referred to as trigger peptidase (TPase), T. Miyakawa et al. (1987) J. Bacteriol. 169, 1626-1631] that plays a key role in the signalling of a lipopeptidyl mating pheromone at the cell surface of pheromone-target cell (mating type a) of Rhodosporidium toruloides was studied. The activity of highly purified TPase which requires phospholipids was restored by reconstitution of the enzyme into liposomes prepared with phospholipids extracted from the yeast cell. The presence of Ca2+ was essential for both the reconstitution process and the catalytic reaction of TPase. Triton X-100 mixed micelles containing phospholipids also activated the enzyme. The specificity and stoichiometry of activation by phospholipids was investigated by determination of TPase in the presence of mixed micelles that contained defined classes and numbers of phospholipid molecules in the Triton X-100 micelles. It was demonstrated that TPase is activated by mixed micelles containing 2-6 molecules of phosphatidylserine or phosphatidylethanolamine. Other phospholipids of the membranes of this organism, such as phosphatidylcholine and phosphatidylglycerol, had little effect on activation, indicating that the amino group of the phospholipids may be required for the function of TPase. Direct evidence for the interaction of TPase and Triton X-100/phosphatidylserine mixed micelles was obtained by molecular sieve chromatography on Sephacryl S-200. These data established that a phospholipid bilayer is not a requirement for TPase activation, and that the purified enzyme can be activated by a relatively small number of phospholipid molecules of specific classes.

Calcium↗
PubMed1987

Activation and cleavage of the carbon-cobalt bond of adeninylethylcobalamin by diol dehydrase.

Adeninylethylcobalamin (AdeEtCbl) underwent cleavage of the C-Co bond by interaction with apoprotein of diol dehydrase from Klebsiella pneumoniae ATCC 8724, although this analog was quite inactive as coenzyme. Spectroscopic observation indicates that AdeEtCbl was converted to the enzyme-bound hydroxocobalamin without intermediates. The conversion was stoichiometric (1:1) and obeyed the second-order reaction kinetics (k = 0.027 min-1 microM-1 at 37 degrees C) depending upon concentrations of apoprotein and AdeEtCbl. This suggests that the complex formation is the rate-determining step and that AdeEtCbl undergoes rapid C-Co bond cleavage once it binds to the apoenzyme. Substrates and oxygen did apparently not affect the rate of the C-Co bond cleavage. The experiments using [adenine-U-14C]AdeEtCbl and [1(3)-3H]glycerol demonstrated that 9-ethyladenine was the only product formed from the adeninylethyl group of AdeEtCbl during the conversion and that an additional hydrogen atom in the 9-ethyladenine is not derived from the substrate. 1H NMR measurement of the 9-ethyladenine formed enzymatically from AdeEtCbl and DL-1,2-[1,1,2-2H3]propanediol also led to the same conclusion. All of these results indicate that the C-Co bond of AdeEtCbl is activated by diol dehydrase and undergoes heterolysis forming Co(III) and a carbanion or a carbanion-like species, in clear contrast to the homolysis of the C-Co bond of adenosylcobalamin in the normal catalytic process. 9-Ethyladenine formed remained tightly associated with the enzyme. Longer chain homologs, i.e. adeninylpropylcobalamin, adeninylbutylcobalamin, and adeninylpentylcobalamin did not undergo such cleavage of the C-Co bond by diol dehydrase.

Adenine↗
PubMed1987

Mucin-carbohydrate directed monoclonal antibody.

To raise monoclonal antibodies recognizing cancer-associated alterations of the carbohydrate structure of glycoproteins, Balb/c mice were immunized with human colonic cancer cells (LS 180 from ATCC). One of the generated hybridomas produced a monoclonal antibody that bound to the carbohydrate moiety of mucin-type glycoproteins from LS 180. The antibody did not bind to glycoproteins from another colonic cancer cell line, SW 1116, or to glycolipids from any of the colonic cancer cell lines. The antibody bound to ovine and bovine submaxillary mucins (OSM and BSM). NeuAc alpha 2----6Ga1NAc seemed to be involved in the epitope.

Animals↗
PubMed1987

Inhibition of membrane Ca2+-ATPase in vitro by mating pheromone in Rhodosporidium toruloides, a heterobasidiomycetous yeast.

Direct addition of physiological concentrations of rhodotorucine A, a lipopeptide mating pheromone of Rhodosporidium toruloides, to the particulate fraction of the target cell strongly inhibited Ca2+-ATPase activity. The pheromone effect was mating-type specific. Membrane Ca2+-ATPase solubilized by a nonionic detergent and further purified by calmodulin-affinity chromatography was also inhibited by the pheromone. Rhodotorucine A S-oxide, a biologically inactive analogue, had no effect on Ca2+-ATPase. The results suggested that the inhibition of membrane Ca2+-ATPase is a critical event in the signaling of mating pheromone and the inhibition of membrane Ca2+-pump could be responsible for the pheromone-induced rapid raise of intracellular Ca2+ concentration reported.

Basidiomycota↗