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Biomedical subjects

T Suyama

Publications and source records attributed to T Suyama.

At least 55 records · Page 3Linked to original sources
PubMed1987

Elimination of viruses (human immunodeficiency, hepatitis B, vesicular stomatitis and Sindbis viruses) from an intravenous immunoglobulin preparation.

More than 10(4) plaque-forming units (pfu)/ml of HIV are inactivated during the alcohol fractionation step from plasma to fraction (Fr)-II+III, greater than 10(4) pfu/ml is inactivated from Fr-II+III to Fr-II and greater than 10(4) pfu/ml is inactivated during the polyethylene glycol (PEG) fractionation process from Fr-II+III to intravenous IgG (IVIG). The total inactivation rate from plasma to IVIG via Fr-II+III or Fr-II was calculated to be greater than 10(8) or 10(12), respectively. The PEG fractionation method produces an intact and unmodified IVIG. In addition, the PEG fractionation method at a low ionic strength was found to be effective for the elimination of greater than 10(5) units of other viruses, including hepatitis B, vesicular stomatitis and Sindbis viruses.

Chemical Fractionation↗
PubMed1987

Myelopathy due to diffuse thickening of the cervical dura mater in Maroteaux-Lamy syndrome: report of a case.

A rare case of diffuse thickening of the cervical dura mater leading to cord compression in Maroteaux-Lamy syndrome (mucopolysaccharidosis VI) is reported. Spinal computed tomographic scans after intrathecal metrizamide injection and magnetic resonance images are shown. This condition presents as cervical myelopathy. Early decompression can be beneficial for patients with this infrequent metabolic disorder.

Adult↗
PubMed1986

The activation of pro-urokinase by plasma kallikrein and its inactivation by thrombin.

Plasma kallikrein was found to be a good activator of pro-urokinase, the inactive zymogen form of urokinase. The complete activation of pro-urokinase by plasma kallikrein was obtained in 2 h with an enzyme/substrate weight ratio of 1/30. The rate of activation of pro-urokinase by plasma kallikrein was comparable to that catalyzed by plasmin and trypsin. The rate of activation of pro-urokinase by factor XIIa was approximately one-seventh of that by plasma kallikrein. The activation of the zymogen was due to the cleavage of a single internal peptide bond, resulting in the conversion of a single chain pro-urokinase (Mr = 55,000) into two-chain urokinase (Mr = 33,000 and 22,000), and these two chains were linked by a disulfide bond(s). These results indicate an important role of plasma kallikrein for the activation of pro-urokinase in the factor XII-dependent intrinsic pathway of fibrinolysis. Thrombin also converted pro-urokinase to a two-chain form that was not activatable by plasmin, plasma kallikrein, and factor XIIa. Thrombin specifically cleaved the Arg 156-Phe 157 bond which is located 2 residues prior to the activation site of Lys 158-Ile 159.

Amino Acid Sequence↗
PubMed1986

Establishment of passive hemagglutination assay (PHA) system for anti-HBc in plasma.

A sensitive and specific assay system for anti-HBc, the passive hemagglutination (PHA) method, has been established. The reactivity of PHA cells prepared by conjugating purified recombinant HBcAg-particles with fixed sheep blood cells (SRBC) was highly specific to monoclonal- and polyclonal anti-HBc IgGs. The sensitivity of PHA method was higher than that of radioimmunoassay (RIA). However, uncertainty for the positivity of anti-HBc still remained in plasma with the PHA titers lower than 2(5). A relatively high ratio (19%, 37 of 196) of anti-HBc-positive plasma, which had been confirmed to be HBsAg negative, was demonstrated in blood donors whose bloods have been considered suitable for transfusion. The hazards of anti-HBc-positive bloods and the importance of anti-HBc detection in plasma are discussed in this paper.

Antibodies, Monoclonal↗
PubMed1986

Formation of tubuloreticular inclusions in mitogen-stimulated human lymphocyte cultures by endogenous or exogenous alpha-interferon.

Tubuloreticular inclusions (TRI) were induced in normal blood lymphocytes after incubation with Staphylococcus aureus Cowan 1 (STA), but they were not induced by pokeweed mitogen (PWM), as we reported previously. TRI were also induced in Raji cells when grown in the medium of STA culture. Alpha-interferon (alpha IFN) was detected only in the medium of STA culture and not in PWM culture. The cells of PWM cultures formed TRI when exposed to various concentrations of human leukocyte alpha IFN. The incidences of TRI-positive cells in the presence of 50-500 IU/ml of alpha IFN were 3-5% on day 2 and increased to 10% on day 7. On days 5-7 of the PWM cultures, plasmacytoid cells containing TRI were seen not infrequently. In the presence of a high concentration of alpha IFN (10,000 IU/ml), which was sufficient to inhibit cell growth and differentiation, the growth of the TRI region was not altered and the incidence of TRI-positive cells was 9% on day 2 and increased to 15% on day 7. Our observations suggest that the TRI formation in STA culture is attributable to the alpha IFN produced endogenously by STA-stimulated cells and that some relationship might exist between the incidences of TRI-positive cells in these mitogen-stimulated cultures and the biologic functions of IFN.

Burkitt Lymphoma↗
PubMed1986

[Experimental studies on the ossification of the posterior longitudinal ligament of the cervical spine].

Fluor, which is a natural substance contained in rice, vegetables, marine products and some seasonings, is assimilated into the body through ingestion. Approximately 60% of the total amount of this fluor intake would be based on rice. A histological study of cervical spine, knee ligaments, Achilles tendon and viscera of rabbits (approx. 12-16 weeks old) was made after injection with sodium fluoride in this study. The rabbits were divided into three groups: Group A (administered NaF 86.2 mg/kg, 5.7 mg/ml, 7 rabbits); Group B (administered NaF 31.5 mg/kg, 2.85 mg/ml, 6 rabbits) and a Control Group of 3 rabbits. Five rabbits in Group A (71.4%) and all six rabbits in Group B (100%) developed ossification of the posterior longitudinal ligament. Ossification of the yellow ligament was also found in two rabbits in Group A and one in Group B. No ossification was found in the Control Group. Both enchondral and intramembranous ossification were found in ossification of posterior longitudinal ossification in the rabbits.

Animals↗
PubMed1985

Primary structure of single-chain pro-urokinase.

Single-chain pro-urokinase is an inactive proenzyme form of human urokinase with a single-chain structure and a Mr of 50,000 and converted to the active two-chain form by catalytic amounts of plasmin. It was isolated from culture fluid of human kidney cells and subjected to chemical (CNBr) and proteolytic (lysyl endopeptidase) degradation. The resulting peptides were separated by reverse-phase high performance liquid chromatography and subjected to automated sequence analysis. Amino acid sequence of 85% of the 411 residues recovered in 17 peptides were found to be consistent with those of the A chain (157 amino acids) and B chain (253 amino acids) of human urokinase reported by Günzler and co-workers (Günzler, W. A., Steffens, G.J., Otting, F., Kim, S.-M., A., Frankus, E., and Flohé, L. (1982) Hoppe-Seyler's Z. Physiol. Chem. 363, 133-141; 1155-1165; Steffens, G.J., Günzler, W.A., Otting, F., Frankus, E., and Flohé, L. (1982) Hoppe-Seyler's Z. Physiol. Chem. 363, 1043-1058). It revealed the presence of Lys at position 158 in single-chain pro-urokinase through which the two polypeptide chains of human urokinase are unified into one molecule. In addition, firm evidence was found that upon activation by plasmin single-chain pro-urokinase is cleaved at the Lys-Ile bond between residues 158 and 159, resulting in the formation of a two-chain urokinase molecule held together by one disulfide linkage. These results indicate that the cleavage at the Lys-Ile bond between residues 158 and 159 is responsible for conformational change, appearance of enzyme activity and reduction of its high affinity for fibrin.

Amino Acid Sequence↗
PubMed1985

Proteolytic cleavage of single-chain pro-urokinase induces conformational change which follows activation of the zymogen and reduction of its high affinity for fibrin.

A plasminogen activator secreted from human kidney cells was highly purified by affinity chromatography on an anti-urokinase IgG-Sepharose column. The purified plasminogen activator was inactive and had a single-chain structure and a Mr of 50,000. It not only did not incorporate diisopropyl fluorophosphate, which reacts with active site serine residue in urokinase, but also did not bind to p-aminobenzamidine-immobilized CH-Sepharose, to which urokinase bind via its side-chain binding pocket present in active center. The plasminogen activator was converted to the active two-chain form with the same Mr by catalytic amounts of plasmin. Its potential enzymatic activity was quenched completely by anti-urokinase IgG, but not by anti-tissue plasminogen activator Ig. These results indicate that the plasminogen activator is an inactive proenzyme form of human urokinase. Therefore, the plasminogen activator was termed single-chain pro-urokinase. The cleavage of single-chain pro-urokinase by plasmin induced conformational change which followed the generation of reactive serine residue at active site, the increase enzyme activity and the reduction of its high affinity for fibrin. These findings suggest that conformational change occurs in both regions responsible for enzyme activity and affinity for fibrin upon activation of single-chain pro-urokinase.

Antibodies↗
PubMed1985

Angiographic classification of aneurysms of the horizontal segment of the anterior cerebral artery.

Ten aneurysms of the horizontal portion of the anterior cerebral artery (A1) were analyzed. These 10 aneurysms were classified into three types according to the mode of the origin of the neck of the aneurysm from the A1 segment: (a) an aneurysm originating from the junction of the A1 segment and the lenticulostriate artery, (b) one from the proximal end of the fenestration of the A1, and (c) one from the top of the A1 loop (elongation and kinking of the A1 segment). In these aneurysms, their size, the side of the A1 segment with an aneurysm, the multiplicity of aneurysms, the coexistence of hypertension, the grade of the patients, the laterality of the subarachnoid blood clots (as seen on computed tomography scans) and surgical outcome were analyzed.

Adult↗
PubMed1985

Molecular cloning of cDNA coding for human preprourokinase.

A cDNA library was constructed in pBR322 from 18S to 20S mRNA that was extracted from human kidney cells, fractionated on oligo(dT)-cellulose column and sucrose-density gradient, and confirmed for urokinase production in Xenopus laevis oocytes. The Escherichia coli RR1 transformants were hybridized to synthetic oligonucleotide probe prepared according to the known amino acid sequence, Glu 73 to Glu 77 of human urinary urokinase chain B. The entire cloned cDNA covers a 2250-bp region, wherein the 1293-bp sequence codes for preprourokinase consisting of 431 amino acids, with the first 20 residues being a signal peptide. The 5'-untranslated region is at least 80 bp long and the 3'-untranslated region is longer than 850 bp.

Amino Acid Sequence↗
PubMed1985

Thrombolytic properties of an inactive proenzyme form of human urokinase secreted from human kidney cells.

The relative fibrin-binding, fibrinolytic and fibrinogenolytic properties of single-chain pro-urokinase, an inactive proenzyme form of human urokinase purified from cultured human kidney cells, and urokinase were compared. The affinity of single-chain pro-urokinase for fibrin was much higher than that of urokinase. In Vitro thrombolytic studies showed that single-chain pro-urokinase is approximately three times more potent in fibrinolysis than urokinase and that it does not degrade fibrinogen in the plasma at a concentration, at which complete plasma clot lysis takes place; whereas, urokinase extensively degrades the fibrinogen in the plasma. These specific, potent thrombolytic properties of single-chain pro-urokinase seem to be due to its high affinity for fibrin and to its conversion from the inactive single-chain form to the active two-chain form on the thrombus by the catalytic amount of plasmin generated during coagulation. This single-chain pro-urokinase obtained from human kidney cells by tissue culture should prove advantageous than urokinase in thrombolytic therapy.

Autoradiography↗
PubMed1985

Development of a corticosteroid incorporated in lipid microspheres (liposteroid).

Anti-inflammatory properties of liposteroid, a lipid emulsion containing dexamethasone palmitate in the particles, were investigated in comparison with those of water-soluble dexamethasone phosphate. In the acute inflammatory model of carrageenin oedema in rats, liposteroid was as effective as dexamethasone phosphate, whereas liposteroid was twice as effective on formalin granuloma, 3.3 times on adjuvant arthritis and 5.3 times on carrageenin granuloma in rats. Distribution of dexamethasone to the inflammatory lesion in rats with adjuvant arthritis was markedly higher in the liposteroid group than in the dexamethasone phosphate group: 1.5 times higher in 2-6 hours and approximately twice in 24 h. The uptake rate of steroid by rat peritoneal macrophages was greater with liposteroid than with dexamethasone phosphate. Furthermore, the inhibitory effects of liposteroid on Fc receptor dependent phagocytosis activity, superoxide anion release and chemotaxis of the macrophages were more potent than those of dexamethasone phosphate. Dexamethasone palmitate itself had very weak activity compared with dexamethasone in the blanching phenomena test in volunteers and dexamethasone palmitate in liposteroid was hydrolysed to dexamethasone in human monocytes. This study suggests that corticosteroids incorporated in lipid emulsions are taken up by the macrophages to a much greater extent than free corticosteroids and strongly suppress macrophage functions, resulting in stronger anti-inflammatory activity.

Animals↗
PubMed1984

A perfluorochemical emulsion as an oxygen carrier.

Fluosol-DA 20%, a perfluorochemical emulsion consisting of 7 parts perfluorodecalin (FDC) and 3 parts perfluorotripropylamine (FTPA), has been used as an oxygen carrier in clinical studies. The emulsion, however, must be stored frozen because it is not stable for long in a liquid state. To increase the stability of perfluorochemical emulsions, a series of experiments on stability, elimination, and toxicity were conducted on different perfluorochemicals. F-4-Methyloctahydroquinolidizine (FMOQ) was selected as the best material. The tissue half-life of FMOQ in rats was estimated to be 7 days, which is the same as that of FDC, a perfluorochemical in Fluosol-DA 20%. FMOQ emulsified with a mixture of yolk phospholipid and Pluronic F-68 was stable at 4 degrees C for 6 months. Rats exchange-transfused to a hematocrit of 4% with this emulsion survived for 13 weeks.

Animals↗