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Biomedical subjects

S Ogata

Publications and source records attributed to S Ogata.

At least 163 records · Page 9Linked to original sources
PubMed1991

Molecular cloning and characterization of rat contrapsin-like protease inhibitor and related proteins.

A glycoprotein with Mr 63,000 purified from rat serum was found to inhibit trypsin activity but not chymotrypsin or elastase activity, resembling contrapsin purified from mouse serum. To obtain further information on the molecular structure, a cDNA clone (lambda CPi-21) for this contrapsin-like protease inhibitor was isolated from a rat liver cDNA library. The 1.6-kb cDNA insert contained an open reading frame that encodes a 416-residue polypeptide (CPi-21), in which the first 29 residues were suggested to comprise a signal peptide by comparison with the NH2-terminal sequence of the purified protein. The predicted structure also contained other peptide sequences determined by Edman degradation. Four potential N-linked glycosylation sites were found in the molecule, presumably accounting for the larger molecular mass of the mature form. Further screening of the cDNA library with a Pst-XbaI fragment (302 bp) of lambda CPi-21 as a probe yielded two other cDNA clones (lambda CPi-23 and lambda CPi-26), which encode 413-residue and 418-residue polypeptides, respectively. A comparison of their amino acid sequences revealed that CPi-21 has 89 and 71% homology with CPi-23 and CPi-26, respectively. The primary structure of each of the three proteins has about 70% homology with that of mouse contrapsin, in contrast to 43-46% homology with that of rat alpha 1-protease inhibitor. These results indicate that all the CPi proteins presented here belong to a subfamily of "serpins" of which mouse contrapsin was the first member to be identified.

Acute Disease↗
PubMed1991

[A case of acute myocardial infarction due to coronary spasm].

The patient was a 47 year-old man, who has been known to have effort angina since September 1989. His exercise stress ECG has revealed ST elevation in V2-V4 with maximum exercise. He experienced severe chest pain lasting for an hour on the way to his office in the early morning on November 16, 1989, and was admitted to our hospital. His ECG and laboratory findings indicated typical acute anteroseptal myocardial infarction, but the coronary arteriography (CAG) which was performed 7 hours after the onset showed no significant stenotic lesion. After administrating nitrate and calcium antagonist, he has had no attack of angina pectoris and his exercise stress test has revealed no ST-T changes on his ECG. 1 month later, while antianginal drugs were discontinued in order to perform an ergonovine stress test, the patient frequently complained of left anterior chest pain with remarkable ST elevation in precordial leads on his ECG. The CAG at chronic stage revealed that there was a 99% stenosis at Segment 6 of the left anterior descending artery (LAD) which was supplied with good collateral flow from the right coronary artery. The LAD was completely occluded at Segment 6 after intracoronary administration of ergonovine maleate 0.005 mg to the left coronary artery. After the intracoronary infusion of isosorbide dinitrate, there was no significant stenosis seen in the LAD except the minimum wall irregularity at Segment 6. These findings suggested that coronary spasm might play a major role of the occurrence of acute myocardial infarction in this case.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium Channel Blockers↗
PubMed1990

Membrane-anchoring domain of rat liver 5'-nucleotidase: identification of the COOH-terminal serine-523 covalently attached with a glycolipid.

The involvement of glycosylphosphatidylinositol (GPI) in membrane anchoring of 5'-nucleotidase was investigated by chemical analyses. 5'-Nucleotidase purified from rat liver microsomes was subjected to BrCN cleavage, hexane extraction, and high-performance liquid chromatography, resulting in the purification of a single fragment with Mr 2300. Chemical analyses revealed that the purified fragment contains the tetradecapeptide Lys-Val-Ile-Tyr-Pro-Ala-Val-Glu-Gly-Arg-Ile-Lys-Phe-Ser and characteristic components of GPI including ethanolamine, glucosamine, mannose, inositol, palmitic acid, and stearic acid. In addition, it was confirmed that digestion of 5'-nucleotidase with lysyl endopeptidase yielded a fragment containing the dipeptide Phe-Ser and the same GPI components as above. The sequences of the tetradeca- and dipeptides thus determined are identified at positions 510-523 and 522-523, respectively, in the primary structure deduced from the cDNA sequence, which predicts a further extension to position 548, containing a hydrophobic amino acid sequence [Misumi, Y., Ogata, S., Hirose, S., & Ikehara, Y. (1990) J. Biol. Chem. 265, 2178-2183]. Taken together, these results indicate that the mature 5'-nucleotidase molecule lacks the predicted COOH-terminal peptide extension and is attached at serine-523 with GPI, which functions as the membrane anchor of 5'-nucleotidase.

5'-Nucleotidase↗
PubMed1990

Primary structure of human placental 5'-nucleotidase and identification of the glycolipid anchor in the mature form.

A cDNA was cloned coding for human placental 5'-nucleotidase. The 3547-bp cDNA contains an open reading frame that encodes a 574-residue polypeptide with calculated size of 63 375 Da. The NH2-terminal 26 residues comprise a signal peptide, which is followed by the NH2-terminal sequence of the purified protein. four potential N-linked glycosylation sites are found in the molecule, accounting for a larger mass of the mature form (71 kDa). The predicted structure contains a hydrophobic amino acid sequence at the COOH terminus, a possible signal for the post-translational modification by glycophospholipid. To confirm this possibility, we tried to isolate and characterize the membrane-anchoring domain of 5'-nucleotidase. BrCN-cleaved fragments of the protein were extracted with hexane and subjected to HPLC, resulting in purification of a single component of 2.3 kDa. Chemical analyses revealed that the purified fragment contains the tetradecapeptide Lys-Val-Ile-Tyr-Pro-Ala-Val-Glu-Gly-Arg-Ile-Lys-Phe-Ser, ethanolamine, glucosamine, mannose, inositol, palmitic acid, and stearic acid. The peptide sequence determined is identified at positions 510-523 in the primary structure deduced from the cDNA sequence, which predicts a further extension to position 548, containing the hydrophobic amino acid sequence. Thus, it is concluded that the mature 5'-nucleotidase lacks the predicted COOH-terminal peptide extension (524-548), which has been replaced by the glycophospholipid functioning as the membrane anchor of 5'-nucleotidase.

5'-Nucleotidase↗
PubMed1990

Isolation and characterization of human apolipoprotein A-I Fukuoka (110 Glu----Lys). A novel apolipoprotein variant.

A novel genetic variant of apolipoprotein(apo) A-I Fukuoka, has been identified in a Japanese family. This variant has a relative charge of +2 compared to normal apolipoprotein A-I (A-I4), on the isoelectric focusing gels and the same molecular mass and immunologic characteristics as normal apolipoprotein A-I. This variant, transmitted as an autosomal co-dominant inheritance was purified by preparative Immobiline isoelectric focusing. Sequence analysis after cleavage with lysyl endopeptidase and CNBr, followed by high-performance liquid chromatography revealed a single substitution of lysine at position 110, instead of the usual glutamic acid. This mutant apolipoprotein A-I has much the same potential as to activate lecithin-cholesterol acyltransferase.

Amino Acid Sequence↗
PubMed1990

Primary structure of rat liver 5'-nucleotidase deduced from the cDNA. Presence of the COOH-terminal hydrophobic domain for possible post-translational modification by glycophospholipid.

Rat liver 5'-nucleotidase was purified from a crude microsomal fraction, and its molecular mass was estimated to be 73 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified protein was subjected to cleavage with CNBr or lysyl endopeptidase, and the resulting 21 peptides as well as the NH2 terminus of the native protein were sequenced by Edman degradation. For further information on the molecular structure, we constructed a lambda gt11 liver cDNA library and isolated two cDNA clones for 5'-nucleotidase, lambda cNTP6 and lambda cNT34. The 3.2-kilobase cDNA insert of lambda cNTP6 contains an open reading frame that encodes a 576-residue polypeptide with a calculated size of 63,965 Da, which is in reasonable agreement with that of 5'-nucleotidase (62 kDa) immunoprecipitated from cell-free translation products. The NH2-terminal 28 residues comprise a signal peptide, which is followed by the NH2-terminal sequence of the purified protein. The predicted structure contains all the other peptide sequences determined by Edman degradation. Five potential N-linked glycosylation sites are found in the molecule, accounting for the difference in mass between the precursor and mature forms. Another characteristic feature is that the primary structure contains a highly hydrophobic amino acid sequence at the COOH terminus, a possible signal for the post-translational modification by glycophospholipid. In fact, labeling experiments of rat hepatocytes demonstrated that 3H-labeled compounds such as ethanolamine, myo-inositol, and palmitic acid, components of the glycolipid anchor, were incorporated into 5'-nucleotidase. Phosphatidylinositol-specific phospholipase C released 5'-nucleotidase from the cell surface, and the released protein no longer contained the radioactivity of [3H]palmitic acid incorporated.

5'-Nucleotidase↗
PubMed1990

Experimental study of lumbar facet degeneration in monkeys.

Experiments were carried out in young adult monkeys to determine the influence of mechanical stress on degeneration of the lumbar facet joints. Eleven monkeys were used and divided into four groups, the control, upper lumbar laminectomy, discectomy and discectomy + rotation. The monkeys were given fluorochrome agents once a week. After sacrifice, undemineralised sections were studied under fluorescence microscopy. Contact microradiographs were also made. After laminectomy, subperiosteal bony proliferation was seen on the external surface of the superior and inferior articular processes. After discectomy there was localised bony proliferation on the anterior aspect of the superior articular processes. In the group with discectomy + rotation there was evidence of additional proliferation of the calcified cartilage zone at the insertion of the ligamentum flavum which had remodelled to bony tissue. We conclude that rotational stresses are mostly responsible for the development of spinal stenosis.

Animals↗
PubMed1990

The development of synovial plicae in human knee joints: an embryologic study.

An embryologic study about the development of the human knee joint cavity was carried out with special attention to the formation of synovial plicae, using a total of 116 knees of embryos and fetuses. The incidence of synovial plicae in the fetal stage was also investigated. Formation of joint space starts at the middle of the interzone at around 8 weeks of gestation. Multiple small cavitations around the femoral condyle and patella coalesce to form larger cavitations. At around 10 1/2 weeks, the knee joint consists of a single cavity with synovial lining. At certain sites, such as at the medial part of patello-femoral and the infrapatellar regions, mesenchymal tissue strands remain. They may become plica. In the fetal stage from 11 to 20 weeks, an infrapatellar plica was found in 50% of specimens, a suprapatellar plica in 33%, and a mediopatellar plica in 37%. Only the infrapatellar plica showed a decrease in incidence.

Embryonic and Fetal Development↗
PubMed1990

Production of propeptide-directed antibody: its application to the purification of proalbumin and analysis of proalbumin processing.

Antibodies which specifically recognize rat proalbumin, but not mature serum-albumin, were raised. Propeptide (NH2-Arg-Gly-Val-Phe-Arg-Arg) with an additional cysteine residue at the carboxyl terminus was conjugated to ovalbumin through either sulfide or amino group and the conjugates were injected into rabbits. Monospecific antibodies were purified on a propeptide-coupled affinity column and further immobilized as an affinity support, allowing us to purify proalbumin in a single step from rat liver microsomes. The antibodies were also used to analyze the proteolytic processing of proalbumin in primary cultured rat hepatocytes.

Amino Acid Sequence↗
PubMed1990

Increased activity on radiocolloid scintigraphy in splenic hamartoma.

A higher uptake of radiocolloid in a splenic tumor than in the rest of the spleen was observed in a 17-year-old boy. The pathologic diagnosis of the surgically resected tumor was hamartoma composed of anomalous mixtures of splenic elements, and radiocolloid was considered to be distributed to reticuloendothelial cells in the tumor. Radiocolloid scintigraphy, which can demonstrate the function of the reticuloendothelial system, is helpful in the diagnosis of splenic hamartoma.

Adolescent↗
PubMed1990

Yersinia enterocolitica immunodominant 60 kDa antigen, common to a broad range of bacteria, is a heat-shock protein.

Monoclonal antibodies (mAbs) against the Yersinia enterocolitica immunodominant 60 kDa antigen, termed cross-reacting protein antigen (CRPA), were obtained by fusion of spleen cells from mice immunized with CRPA with murine myeloma cells. The reactivities of the mAbs were examined by Western blotting against extracts of Y. enterocolitica and 23 other species of Gram-positive and Gram-negative bacteria. Cross-reactions were recognized with a wide range of bacteria, but not with Gram-positive cocci. The reactivities were different for each mAb, suggesting that both species-specific and multiple cross-reactive epitopes were present on the CRPA molecule. CRPA was produced under heat-shock conditions in Y. enterocolitica and was shown to correspond immunologically to the GroEL protein in Escherichia coli, a protein involved in the morphogenesis of coliphage. In addition to CRPA, at least nine other major heat-shock proteins were detected by two-dimensional gel electrophoresis of extracts of heat-shocked Y. enterocolitica.

Antigens, Bacterial↗
PubMed1990

[Detection of cross-reacting protein antigen from urinary tract pathogens by using reversed passive gelatin agglutination test].

The basic studies on detection and titration of the 60-kDa cross-reacting protein antigen (CRPA), which is common to gram-negative rods, by reversed passive gelatin agglutination test with monoclonal and polyclonal antibodies were performed. The gelatin particles sensitized with 500 micrograms/ml of the monoclonal antibody had an ability to react with 200 ng/ml of the purified CRPA for 1.5 h. In contrast, the particles sensitized with 200 micrograms/ml of the polyclonal antibody had an ability to react with 25 ng/ml of the purified CRPA for 1.5 h. In addition, the detection of the 60-kDa CRPA in urinary tract pathogens, which consisted of 60 bacterial strains representing 14 species, was carried out by using the gelatin particles sensitized with 200 micrograms/ml of the polyclonal antibody. The CRPA was detected in all gram-negative rods of urinary tract pathogens, but not in gram-positive cocci. These results suggested that the detection of the 60-kDa CRPA by reversed passive gelatin agglutination test was a rapid and simple method for screening gram-negative bacteriuria.

Agglutination Tests↗
PubMed1990

Purine Auxotrophic Mutants with Altered Spore Color in Streptomyces azureus. ATCC 14921.

A purine auxotroph with pale purple spores and a derivative with yellowish orange spores were obtained from the wild-type strain of Streptomyces azureus ATCC 14921, which has bluish green spores. The changed color or pigmentation in the mutants was limited to the spores. They accumulated AIR (5'-phosphoribosyl-5-aminoimidazole) due to the lack of AIR carboxylase activity.

Journal Article↗
PubMed1990

Acetabular cover in congenital dislocation of the hip.

The exact measurement of femoral head cover is essential for an assessment of reduction of congenital dislocation of the hip. We have compared standard anteroposterior radiographs with computerised tomograms and thereby classified the shape of the acetabular roof into four types. We found that the CE angle of Wiberg is a more reliable measure of head cover when the lateral point of bony condensation of the roof is chosen as the reference point rather than the edge of the bone, where these two points do not overlap. We conclude that head cover can be more accurately determined in younger children with dysplastic hips by our 'refined' CE angle, than by the original method of Wiberg.

Acetabulum↗
PubMed1990

The early development and ossification of the human clavicle--an embryologic study.

Morphologic studies of the early development of the clavicle were carried out in 46 human embryos and fetuses ranging in age from 6 to 12 weeks. We confirmed that the clavicle is formed by two membranous primary ossification centers appearing by 6 weeks and fusing approximately 1 week later. Cartilage at both ends of the clavicle then develops. In time, the medial cartilaginous mass contributes more to the growth in length of the clavicle than the lateral cartilaginous mass. The spatial orientation of both ossification centers and the development of enchondral bone formation at the ends of the clavicle lead to its characteristic shape. Interestingly, the primary ossification centers contribute little to the growth in length. The junction of the two centers of ossification is situated between the lateral and middle third of the clavicle and, consequently, does not correspond to the site of congenital pseudarthrosis, which is located in the middle part of the clavicle.

Clavicle↗