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Biomedical subjects

Y Sakagishi

Publications and source records attributed to Y Sakagishi.

At least 19 recordsLinked to original sources

Characterization of a specific monoclonal antibody 9F5-3a and the development of assay system for oxidized HDL.

We obtained a monoclonal antibody 9F5-3a against oxidative low-density lipoprotein (LDL) modified with CuSO4 and established a sandwich ELISA for detection of oxidized high-density lipoprotein (oxHDL). The 9F5-3a was reacted strongly with oxHDL and to a lesser degree with oxLDL and LDL. In contrast, little or no reactivity was found with HDL. When the generation of oxHDL was limited by the addition of alpha-tocopherol and catalase, reactivity to 9F5-3a was reduced. Incubation of oxHDL with excess lyso-phosphatidylcholine (lyso-PC) also reduced immunoreactivity, but not by only lyso-PC. These results suggested that the epitope is possibly associated with oxHDL-linked lyso-PC induced mainly by the hydroxyl radical.

Animals↗

Comparative biochemical study of coated vesicles purified from cock brains.

Cock brain coated vesicles (CBCVs) were purified and compared with porcine brain coated vesicles (PBCVs) from several biochemical aspects. Clathrin heavy and light chains of CBCVs were immunologically similar to those of PBCVs. Coat proteins (CPs) of CBCVs behaved in almost the same manner as those of PBCVs for limited proteolysis. Dissociation of CPs from CBCVs by treatment with 10 mM Tris-Cl, pH 8.5, or 2M urea resembled that of CPs from PBCVs. pH dependency of dissociation of CPs from CBCVs was slightly different from those of PBCVs.

Animals↗

A variant alkaline phosphatase found in a case of gastric carcinoma with super bone scan.

A rare case of gastric carcinoma associated with increased serum variant alkaline phosphatase activities is presented. A 54 year old man had extremely high serum alkaline phosphatase activity (18,607 U/l) with normal calcium and phosphate concentrations. His bone scintigram showed abnormal findings, 'super bone scan'. He was diagnosed as having Borrmann type 4 gastric carcinoma with diffuse bone metastases by examinations of the upper gastrointestinal tract and iliac bone biopsy. The alkaline phosphatase isozyme of this patient was of the bone type as measured by cellulose acetate membrane electrophoresis and the placenta/bone type by agarose gel electrophoresis, respectively. Immunoelectrophoresis and the immunoprecipitation method using monoclonal antibodies against various alkaline phosphatase isozymes, however, showed that his serum alkaline phosphatase had the liver type antigenicity. Furthermore, it had a larger molecular size and different sugar chains compared with the common liver type alkaline phosphatase. These findings suggest that a unique variant alkaline phosphatase was produced by gastric cancer cells, which is possibly an explanation for the high serum alkaline phosphatase activities in this patient.

Alkaline Phosphatase↗

[Alanine aminotransferase (ALT)].

Alanine aminotransferase (Alt, L-alanine:2-oxoglutalate aminotransferase) is a pyridoxal enzyme which catalyses the reversible interconversion of L-alanine and 2-oxoglutalate to pyruvate and L-glutamate. The enzyme is widely distributed in various tissues from animals and even in some kind of plants. Isoenzymes of human ALT localize in the cytosol (c-ALT) and mitochondria (m-ALT) of tissues such as liver, kidney, skeletal and cardiac muscles. Amino acid sequence of c-ALT from rat and human liver has been wholly determined by Ishiguro et al. It is suggested that c-ALT is associated to the utilization of pyruvate in glycolysis and m-ALT is involved in the conversion of alanine to pyruvate for gluconeogenesis.

Alanine↗

Expression of deoxyuridine triphosphatase during liver regeneration in rat.

Deoxyuridine triphosphatase (dUTPase) activity increases concomitantly with DNA replication in the course of liver regeneration in rat. We confirmed in this report using Western blot analysis and Northern blot hybridization that the increase of dUTPase activity was derived from expression of the gene. The content of dUTPase protein quantitatively coincided with the activity, they reached to the maximum at about 24 h after partial hepatectomy. We also detected a transcript (1.0 kb) presumed to be a rat spleen dUTPase mRNA by the human dUTPase cDNA probe. This transcript appeared in the liver after a lag of about 16 h, reached to the maximum at 24 h, and could be detected until 48 h after partial hepatectomy. The increase of this transcript nearly coincided with the changes of dUTPase activity and the quantity of enzyme protein. These results indicated that the expression of dUTPase gene is related to the DNA replication.

Animals↗

Carbohydrate-mediated recognition of a circulating placental alkaline phosphatase-immunoglobulin M complex.

We detected an abnormal alkaline phosphatase (AP) electrophoretically in the serum of a patient with rheumatoid arthritis, who had a macromolecular AP linked with immunoglobulin M (IgM) bearing a kappa light chain. The IgM isolated from the AP-IgM complex in the patient's serum reacted apparently with all of the AP isozymes tested, i.e. those originating in the liver, bone, intestine and placenta, but the alpha-mannosidase-treated IgM from the patient's serum bound to placental AP (PAP) alone. This suggests that untreated IgM recognizes multivalent epitopes of the AP and that the complex of AP with alpha-mannosidase-treated IgM is a specific antibody-antigen complex. In order to investigate further the multivalent binding capacity for the PAP-untreated IgM complex, we prepared a monoclonal antibody (MoAb) against PAP and identified it as an IgM with a kappa light chain. The binding affinities and their circulating half-lives of the synthetic complexes of PAP and respective MoAbs were examined with and without treatment with several glycosidases. The untreated MoAb bearing IgM had binding affinity for all of the AP isozymes tested, while alpha-mannosidase-treated IgM attached only to PAP, the same as the IgM isolated from the PAP-IgM complex in the patient's serum. The circulating clearance of the PAP-IgM complex in rabbits was faster than either component alone. In addition, the PAP-IgM complex treated with alpha-mannosidase was found to have the shortest half-life of all the complexes of PAP and Igs treated with the several glycosidases tested. These results suggest that the formation of the PAP-IgM complex as an enzyme-linked antibody and the clearance of the complex in vivo are dependent on the sugar moieties of the Igs.

Adult↗

Deoxyuridine triphosphatase in human hepatoma.

1. Deoxyuridine triphosphatase (dUTPase) in human hepatoma was investigated. The apparent activity in a gram weight tissue was about 6 times that of the activity in rat livers after partial hepatectomy. 2. Most catalytic properties of the hepatoma dUTPase were similar to the enzymes from other sources. 3. The hepatoma dUTPase reacted with the antibodies against the rat spleen dUTPase, although the molecular size of the enzyme (46-48 kDa) was different to the rat enzyme. 4. The immunochemical studies indicated that the enzyme was composed of two identical subunits, whose molecular mass was about 22 kDa.

Animals↗

Phosphorylcholine as a unique substrate for human intestinal alkaline phosphatase.

1. The enzymatic nature of human liver, bone, placental and intestinal alkaline phosphatases (ALPs) were investigated with phosphorylcholine (PC), phosphorylethanolamine, pyridoxal-5'-phosphate and p-nitrophenylphosphate at a weakly alkaline pH. 2. The apparent Km value of the intestinal ALP with PC was the highest of all ALPs tested. Intestinal ALP hydrolyzes PC the most and has higher affinity for choline as a transphosphorylating acceptor than the other ALPs. In addition, the intestinal ALP activity with PC was most susceptible to Na2HPO4, in the tested ALPs. 3. The present results suggest that PC is a unique substrate for human intestinal ALP, which may be related to the metabolism of PC or choline as part of phosphatidylcholine.

Alkaline Phosphatase↗

Diazotization reaction of nitric oxide trapped by hemoglobin.

The present study addresses to determine whether hemoglobin within red blood cells can be utilized as a spin-trap agent for nitric oxide. We demonstrate the diazotization method coupled with a gel filtration chromatography, which is simply due to the separation of nitrosylhemoglobin from nitrite, nitrate or other low molecular nitroso-compounds in biological systems and to the liberation of nitric oxide from nitrosyl heme-complexes in the acidic condition. The amount of nitric oxide can be estimated by the difference of absorbances at 542 nm between diazo-compounds formed by Griess reagent and hemichrome by phosphoric acid. Our results indicate that hemoglobin in red cells as a spin-trap agent would be useful for monitoring nitric oxide in the circulation under the several disease states.

Chromatography, Gel↗

Sugar chain heterogeneity of human urinary chorionic gonadotropin determined by serial lectin affinity chromatography: difference between benign and malignant disease.

Human chorionic gonadotropin (hCG) is a glycoprotein of which sugar chains are considered to show structural changes with malignancy. To study the sugar chain heterogeneity of urinary hCG in patients with gynecological disease, we employed serial lectin affinity chromatography (LAC) using concanavalin A (Con A) and phytohemagglutinin-E (PHA-E) which can separate N-glycoside-linked sugar chains, and Jacalin lectin which is specific for O-glycoside-linked sugar chains. The proportion of hCG which did not bind to Con A was clearly higher in patients with cervical cancer than in healthy pregnant women. The complex-type sugar chains bearing bisecting (beta 1-4) N-acetylglucosamine which bound to PHA-E increased in the early stage of cervical cancer, and tri- and tetra-antennary complex type sugar chains also increased in the advanced stages. In addition, the Jacalin-bound hCG increased significantly along with the stage of the cancer, especially in advanced cervical cancer with distant metastases. Taken together, these results show that alteration in sugar chain structures of hCG reflect the advanced stage of cervical cancer.

Carbohydrates↗

Differences between the sugar moieties of liver- and bone-type alkaline phosphatases: a re-evaluation.

We re-evaluated the differences between the sugar moieties of liver and bone alkaline phosphatases (ALPs). Sialic acid was added to ALP sugar moieties by alpha 2,3- or 2,6-sialyltransferase treatment of the asialo-form ALP (neuraminidase-treated ALP). Asialo-bone ALP was converted to a liver-like ALP by the 2,6-sialyltransferase treatment. The resulting liver-like ALP was less susceptible to neuraminidase than non-treated bone ALP, but was still labile to heat exposure at 56 degrees C like non-treated bone ALP. However, after the O-linked sugar moiety had been released by additional treatment with O-glycanase the liver-like ALP became more heat stable at 56 degrees C, like non-treated liver ALP. Non-treated liver ALP reacted specifically with anti-liver ALP monoclonal antibody, and non-treated bone ALP reacted with both anti-liver and anti-bone ALP antibodies. The asialo-bone ALP still reacted with anti-bone ALP antibody, whereas the asialo-form liver ALP showed little, if any, reaction with anti-liver and anti-bone ALP antibodies. Neuraminidase and O-glycanase-treated bone ALP reacted less with anti-bone ALP antibody. After O-glycanase treatment, bone ALP molecules deprived of an O-linked sugar moiety had a molecular size and heat stability similar to liver ALP. The difference between liver and bone ALP molecules may be due not only to their manner of sialic acid linkage but also to the attachment of the O-linked sugar moiety.

Alkaline Phosphatase↗

Computational studies on the decarboxylation of 2-(1-carboxy-1-hydroxyethyl)-3,4-dimethylthiazolium dipolar ion, an analog of the complex of pyruvic acid and coenzyme of the pyruvate decarboxylase.

We have obtained the optimized geometrical structure of 2-(1-carboxy-1-hydroxyethyl)-3,4-dimethylthiazolium dipolar ion and investigated its geometric and electric changes during decarboxylation process by the MNDO-PM3 method, a molecular orbital method. The salient features of the optimized structure are that the dihedral angle of C4-C1-C2-S3 is 5.4 degrees and the distance between thiazolium S3 and carboxyl O6 is about 1.8 A (the bond order between S3 and O6 is about 0.4). The lowest energy decarboxylation profile is the following process. First the dihedral angle of C4-C1-C2-S3 becomes about 90 degrees, then the distance between C1-C2 increases while the dihedral angle holds about 90 degrees, and finally the C1-C2 bond disappears. The most remarkable change caused by the 90 degrees rotation is the disappearance of the S3-O6 bond, and this disappearance causes electric changes that prompt the decarboxylation.

Mathematics↗

Determination of proteins by a reverse biuret method combined with the copper-bathocuproine chelate reaction.

A method of protein determination has been developed which combines the biuret reaction and the copper(I)-bathocuproine chelate reaction. Protein in the specimen forms a Cu(2+)-protein chelate complex (biuret reaction) during the first step. Excess Cu2+ is reduced to Cu+ by ascrobic acid, allowing the Cu+ to form a Cu(+)-bathocuproine chelate complex during the second step. The amount of Cu(+)-bathocuproine chelate complex formed is inversely proportional to the protein concentration. The sensitivity (epsilon = 1.4 x 10(6) 1.mol-1.cm-1 against human albumin) of this method was higher than that of the original Lowry (9.8 x 10(5)), pyrogallol red (1.0 x 10(6)) and commercially available Coomassie Brilliant Blue G.250 methods (6.7 x 10(5)). The color intensities of human gamma-globulin, human globulin (fractions IV-1 and IV-4), bovine albumin, egg albumin and horse gamma-globulin against human albumin (100%) ranged from 92 to 101%. The results obtained with the present method (y) correlated well with those determined by the biuret method (r = 0.998, y = 0.98 chi - 0.002, x = 1.31, y = 1.29 g/l) in 30 diluted sera. These results confirm that this assay is similar in sensitivity to the original Lowry method, is rapid and has similar reactivity to each of the various proteins in biological fluids.

Ascorbic Acid↗

Abnormal alkaline phosphatase of hepatic type in cerebrospinal fluid of a patient with intracranial metastasis from lung cancer.

High alkaline phosphatase (ALP) activity was found in the cerebrospinal fluid of a patient with intracranial metastases from adenocarcinoma of the lung. On agarose gel electrophoresis of the major ALP isoenzyme found in the cerebrospinal fluid, its mobility was different from those of the usual serum ALP isoenzymes. This abnormal mobility might be due to the linked glycan phosphatidylinositol anchor in the ALP molecule, as the mobility became the same as that of the common liver type ALP after treatment with phosphatidylinositol specific phospholipase. The immunochemical antigenicity of the cerebrospinal fluid ALP was identical with that of the common serum liver type ALP, but its sugar moiety was similar to the membranous liver-type ALP rather than the serum liver type ALP. The molecular size of the cerebrospinal fluid ALP was 140 kilodaltons, 12 less than the common serum liver type ALP, suggesting that the ALP in the patient's cerebrospinal fluid was derived from the intracranial metastatic carcinoma.

Alkaline Phosphatase↗

Radical trapping by PBN during reperfusion in rabbit gastric mucosa.

Oxygen free radicals have been considered as a cause of ischemia-reperfusion injury in several organs, but this injury in a stomach, containing acid, may progress to severe damage. Thus, we examined the effect of ischemia-reperfusion and milk-intake on rabbit gastric mucosa. The gastric mucosal blood flow was increased after milk-intake, and gastric rupture was detected. Superoxide dismutase activity measured by an improved nitroblue tetrazolium reduction method and thiobarbituric acid reactive substances in serum is increased during ischemia-reperfusion and milk-intake. By using alpha-phenyl N-tert-butyl nitrone (PBN) as a spin trap and electron paramagnetic resonance (EPR), we detected lipidic radicals from tissue samples in chloroform-methanol solvent only during reperfusion and milk-intake period; no signal was detected before. The EPR signal of spin adducts obtained in the sample after ischemia-reperfusion and milk-intake would be a mixture of peroxyl and alkoxyl radicals from the analysis of coupling constants.

Animals↗

Differences in the enzymatic nature and the sugar-chain structure of gamma-glutamyl transferase between normal and carcinomatous human kidney and prostate.

The enzymatic and immunological nature, and the sugar chain structure, of gamma-glutamyl transferase (GGT) purified from tissues of benign prostatic hypertrophy (BPH), prostatic carcinoma (PCa) and renal cell carcinoma (RCa), were compared with those of the normal prostate (NP) and kidney (NK). The specific activities of GGTs in NP, NK, BPH, PCa and RCa were 78.9, 22.5, 105, 92.5 and 52.5 mU/mg protein, respectively. The molecular masses of GGTs from BPH, PCa and RCa were 72 kDa, 78 and 108 kDa, and 79 and 105 kDa, respectively. The Michaelis constants (Km), optimum pHs and the inhibition of GGT activities by several chemical compounds, revealed that the GGT from BPH, PCa and RCa was similar to that of normal GGT. Immunologically, the IgG fraction against anti-human seminal plasma GGT fused to the all of the GGTs tested. The sugar chain heterogeneities of the various GGTs, detected by the serial-lectin affinity technique, differed from one another. The sugar chain of GGT from BPH resembled the sugar chain from NP. On the contrary, the sugar chains of GGTs from PCa and RCa were markedly different from those from normal tissues. In the GGT from PCa, multi-antennary complex type sugar chains were more increased than the enzyme of NP. In general, as previously reported, the sugar chains of GGTs from carcinomatous tissues of prostate and kidney had an increased content of bisecting GlcNAc (beta 1-->4) containing complex type sugar chains. Moreover, the reductions of the biantennary complex type sugar chain with fucose linkage and the hybrid type sugar chain were obvious in the GGT from carcinomatous tissues of the prostate and kidney.

Adult↗

Intestinal type alkaline phosphatase hyperphosphatasemia associated with liver cirrhosis.

Hyperphosphatasemia due to increased intestinal type serum alkaline phosphatase was noted in a 48-year-old male who had asymptomatic liver cirrhosis. The alkaline phosphatase activity in the serum was 828 U/l (our reference range in adults: 57-194 U/l), 94% of which was of the intestinal type as measured by an immunoprecipitation method. The intestinal component of alkaline phosphatase was separated into two major and some minor components using electrophoresis and isoelectrofocusing. One of the major components had similar mobility to that of a standard intestinal enzyme purified from adult intestine. The components were heat-labile and neuraminidase-resistant. Serial lectin affinity chromatography, however, indicated that sugar chain compositions of the alkaline phosphatase were different from those of the standard tissue intestinal enzyme. These results and further enzymological studies suggest that the patient's serum alkaline phosphatase basically consisted of several intestine-like isoforms.

Alkaline Phosphatase↗