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Biomedical subjects

T Urano

Publications and source records attributed to T Urano.

At least 253 records · Page 14Linked to original sources
PubMed1990

Evaluation of live trivalent vaccine of measles AIK-C strain, mumps Hoshino strain and rubella Takahashi strain, by virus-specific interferon-gamma production and antibody response.

A trivalent measles-mumps-rubella live virus vaccine, containing measles AIK-C strain, mumps Hoshino strain, and rubella Takahashi strain, was evaluated in 229 children, aged 1 to 5 years. The vaccine induced a high seroconversion rate: 221 (98.7%) out of 224 subjects initially seronegative for measles virus, 167 (93.3%) out of 179 initially seronegative for mumps virus, and 212 (99.1%) out of 214 initially seronegative for rubella virus. It also induced a sufficient cellular immunity against each of the three viruses in over 90% of the subjects, as judged by virus-specific interferon-gamma (IFN-gamma) production. Virus-specific IFN-gamma production was observed 10 days after vaccination by stimulation with measles virus and rubella virus and 14 days after vaccination by stimulation with mumps virus. Mumps-virus-specific IFN-gamma production was observed in 7 out of 12 recipients without seroconversion for mumps virus. And measles-virus-specific IFN-gamma production was demonstrated in one out of three recipients without seroconversion for measles virus. A significant correlation was observed between the serum antibody and IFN-gamma production six weeks after vaccination for measles virus (r = 0.201, P less than 0.01) and for mumps virus (r = 0.174, P less than 0.05) but not for rubella virus (r = -0.045, P less than 0.05). The incidence of febrile reactions of greater than or equal to 37.5 C was quite low, 14.4%, and that of greater than or equal to 39 C occurred in only 1.3% of the recipients. These results suggested that the trivalent vaccine induced sufficient humoral and cellular immunity and yet resulted in no more untoward reaction than observed from the measles vaccine alone.

Antibodies, Viral↗
PubMed1990

Changes in plasminogen activator inhibitor 1 and tissue-type plasminogen activator during exercise in patients with coronary artery disease.

As depressed fibrinolysis is implicated in the pathogenesis of coronary artery disease, we have studied the activation of fibrinolysis during maximal, symptom-limited exercise in a group of 68 men. After exercise they were divided, according to their coronary angiography and exercise 201Tl emission computed tomography results, into three groups. Group 1: persons with normal exercise 201Tl emission computed tomography results and no underlying diseases who served as controls; group 2: patients with coronary artery disease without exercise-induced myocardial ischemia, and group 3: patients with coronary artery disease with transient, exercise-induced myocardial ischemia. Before and at peak exercise we measured the plasminogen activator activity (PAA) in the euglobulin fraction of plasma by an amidolytic method and the concentrations of tissue plasminogen activator (t-PA), activator-inhibitor complex - plasminogen activator inhibitor 1 (PAI-1) complexed with t-PA - and total PAI-1 by enzyme immunoassay. The concentration of free PAI-1 in plasma was calculated by subtraction of the concentration of activator-inhibitor complex from that of total PAI-1. Under basal conditions, group 3 had significantly higher free and total PAI-1 levels than group 1. There were no statistically significant differences between the three groups in PAA, t-PA, and activator-inhibitor complex levels. At peak exercise, group 1 showed the highest release of t-PA accompanied with highest increases in PAA as well as in activator-inhibitor complex, the proportion of released t-PA antigen not bound to PAI-1 being highest in group 1. Free PAI-1 decreased significantly, but there were no differences between individual groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Heat and ozone resistance of Bacillus spores isolated from laboratory animals].

Heat resistance of free-spores of 78 Bacillus strains isolated from laboratory animals was examined. Spores of 41 out of 78 strains survived for 320 minutes at 70 degrees C, 27 for 160 min, at 100 degrees C, only one for 20 min. at 110 degrees C by autoclaving, and none for 5 min. at 120 degrees C. D-values at 100 degrees C of 9 strains determined were between 5.03 and 30.06 min. Spores of 9 strains from stock cultures were exposed to ozone gas at various conditions. Ozone resistance of spores was closely dependent upon relative humidity. D-values of the spores tested by treatment with 200 ppm ozone at 60% RH were over 200 min., especially over 1,000 min. in 4 strains, indicating that exposure to ozone at a moderate humidity for 6 hours could not sterilize Bacillus spores. At 90% RH, however, treatment with 200 ppm ozone for 6 hr. might be effective for a routine sterilization in laboratory animal facilities.

Animals↗
PubMed1990

Interferon-gamma production closely related to antibody production in lymphocyte cultures stimulated with mumps virus.

Enzyme-linked immunosorbent assay (ELISA) antibody to mumps virus and virus specific interferon (IFN)-gamma production were investigated in lymphocyte cultures stimulated with mumps virus before and after immunization with live mumps vaccine. Synthesis of immunoglobulin (Ig) M but not Ig G was enhanced after vaccination. Spontaneous production of mumps ELISA antibodies in lymphocyte culture increased after vaccination and substantially higher levels of antibodies were produced when lymphocytes were stimulated with mumps virus after vaccination. The production of mumps ELISA antibodies was closely related to IFN-gamma production (r = 0.326, p less than 0.01) but not to IFN-alpha production (r = 0.084, p greater than 0.05).

Antibodies, Viral↗
PubMed1990

[Clinical characteristics of the lung diseases due to Mycobacterium avium and Mycobacterium intracellulare classified by DNA probe test].

Clinical characteristics of the lung diseases due to M. avium and M. intracellulare classified by DNA probe test were investigated. Between M. avium and M. intracellulare, there was no significant differences in the samples' backgrounds and the clinical characteristics except for their prognoses. The prognosis of the lung diseases due to M. intracellulare was better than those due to M. avium, and M. avium was revealed to be highly susceptible to Cyclocerine than M. intracellulare. No remarkable difference was found in the susceptibility to other antituberculous drugs.

DNA Probes↗
PubMed1989

Urinary UK, t-PA and urinary trypsin inhibitor in health and glomerular diseases.

The concentrations of two different plasminogen activators(PAs), urokinase (UK), tissue-type plasminogen activator (t-PA) and urinary trypsin inhibitor (UTI) were determined in the urine and blood from 48 normal subjects and 92 patients with glomerulonephritis using highly sensitive enzyme immunoassay (EIA). The values of UK clearance were approximately 1.5-fold larger than those of creatinine clearance and at least 60.8% of UK was reabsorbed in the renal tubules, which suggest that one of major secretion site of UK is located in the outer region of the glomerular basement membrane (GBM), that is glomerular epithelium. Decreased urinary excretion of UK was observed in the glomerular disease depending on their severity and correlated with the increasing degree of FDP D-dimer excretion. On the other hand, the values of t-PA clearance were quite smaller than those of creatinine clearance, which suggest that urinary t-PA originated from the blood circulation or the inner side of the GBM (possibly glomerular endothelium) and filtrated from the GBM. Like UK, urinary t-PA also decreased in glomerular diseases. UTI which is highly anionic and has a comparable size with albumin was excreted increasingly in glomerulo-nephritis due to loss of the anionic charge barrier of the GBM. No significant correlations were noted between UTI excretion and UK or t-PA excretion.

Adolescent↗
PubMed1989

Influence of various structural domains of fibrinogen and fibrin on the potentiation of plasminogen activation by recombinant tissue plasminogen activator.

Fibrinogen, fibrin, and related fragments have varying stimulatory effects on the initial rate of the activation of human plasminogen ([ Glu1]Pg) by recombinant tissue plasminogen activator (rt-PA). A detailed analysis of this enhancement was undertaken using various purified and complexed forms of the known domains of fibrin(ogen) with a view to gaining additional knowledge regarding the substructures of fibrinogen and fibrin that are important for their stimulatory capacities. Both arvin-mediated fibrin, as well as fibrinogen fragments generated as a result of its cleavage with CNBr, stimulate the activation in a biphasic manner, most likely as a result of changes in the promoter molecule accompanying the denaturation processes that are normally employed to either solubilize or generate these particular promoters. Using purified fibrinogen and fibrin fragments, it was found that fragment E, which binds to [Glu1]Pg, does not enhance the activation reaction, while fragment D1 has a potentiating effect. This suggests that the binding of [Glu1]Pg to fibrin(ogen) alone is not, in itself, sufficient for stimulation of activation to occur, but that the rt-PA-fibrin(ogen) interaction is fundamental to this same process. All purified and mixtures of fragments containing the fragment D domain (e.g., D2E, X-oligomer, fragment X) stimulate the reaction to a greater degree than fibrinogen and fragment D1. It is concluded that the fibrinogen D domain is a sine qua non for the enhancement reaction, while structures containing the E domain had a symbiotic effect on enhancement.

Binding Sites↗
PubMed1989

Stimulation by fibrinogen of the amidolytic activity of single-chain tissue plasminogen activator.

The amidolytic steady-state kinetic properties of a series of recombinant tissue plasminogen activators (rt-PA) have been examined in the presence and absence of the positive effectors fibrinogen (Fg) and native soluble (des-A)-fibrin (sFn). Two-chain (tc) native rt-PA displayed a Km value of 0.50 mM and a kcat value of 13.2 s-1 toward the substrate, H-D-Ile-Pro-Arg-p-nitroanilide (S2288) at 37 degrees. When these same assays were conducted in the presence of Fg or sFn, the Km and kcat values remained essentially the same. On the other hand, the activity of single-chain (sc) rt-PA was significantly increased in the presence of Fg or sFn, by approximately 3.4- to 4-fold, due to alterations in both the Km and kcat of the reaction. Similar results were obtained with rt-PA deletion variants, obtained by site-directed mutagenesis. With rt-PA domain-deletion derivatives, consisting of kringles 1 (K1)-2 (K2)-protease (P), and K2-P, the amidolytic activities of the scrt-PA preparations were significantly stimulated (2.0- to 2.5-fold) by Fg and sFn, a property not shared by the corresponding tcrt-PA. On the other hand, neither the single- nor two-chain derivatives of a deletion mutant containing only the finger (F)-growth factor (E)-P domains displayed stimulation by Fg or sFn, results suggestive of the importance of the K2 region in the observed Fg- and Fn-induced stimulations rt-PA amidolytic activity. With one strategically important derivative, a molecule containing the amino acid replacement, Cys264----Gly [(Cys264----Gly)-rt-PA], a change resulting in the loss of covalent attachment of the heavy and light chains of tcrt-PA, the amidolytic activities of neither the single-chain nor the two-chain form of the molecule were stimulated by the presence of the above two positive effectors. With the single-chain form of this same derivative, the kcat of the reaction was extremely low (1.5 s-1), but increased to approximately 50.5 s-1 for the two-chain form, this latter value being nearly 4-fold higher than that of any of the wild-type recombinant rt-PA preparations examined. This suggests that the latent heavy chain of rt-PA inhibits the amidolytic activity found in the trypsin-like P domain.(ABSTRACT TRUNCATED AT 250 WORDS)

Amides↗
PubMed1989

Isolation and properties of rat plasma lecithin-cholesterol acyltransferase.

Lecithin-cholesterol acyltransferase was purified from rat plasma and the properties of this enzyme during the purification procedures and those of the purified enzyme were investigated in comparison with the human enzyme. The rat enzyme was not adsorbed on hydroxyapatite, which was employed for the purification of the human enzyme. When purified human enzyme was incubated at 37 degrees C in 0.1 mM phosphate buffer (pH 7.4; ionic strength, 0.00025), no alteration of enzyme activity was observed for up to 6 h. In the case of the rat enzyme, however, approximately 40% of the enzyme activity was lost under the same conditions. The human enzyme and rat enzyme were both retained on a Sepharose 4B column to which HDL3 was covalently linked, in 39 mM phosphate buffer, pH 7.4. Although the human enzyme was eluted from the column in 1 mM phosphate buffer, the rat enzyme was dissociated from the column at a lower buffer concentration (0.1 mM phosphate buffer). These findings indicate that the rat enzyme effectively associated with HDL3 in 39 mM phosphate buffer, pH 7.4, but the association was more sensitive to increase of ionic strength compared with that of the human enzyme.

Animals↗
PubMed1989

Outbreak of herpangina associated with Coxsackievirus B3 infection.

An outbreak of acute febrile illness was observed in summer, 1987, in a welfare home in which 31 healthy infants were accommodated. Within a 5-day period 25 infants (81%) acquired a febrile illness. Coxsackievirus B3 was isolated from 16 (64%) of 25 throat swabs. In the patients in whom viral culture was negative or not performed, 6 were serologically identified as having a coxsackievirus B3 infection. Among 22 patients identified as having a coxsackievirus B3 infection 7 had typical herpangina and the others had pharyngitis with or without a few small vesicles. Serum alpha-interferon was detected in all but 2 cases (one with proved infection and another with indefinite infection). Herpangina can be associated with coxsackievirus B3 as well as with the more frequently associated coxsackievirus Group A; this explosive type of outbreak might be transmitted by a small particle aerosol.

Antibodies, Viral↗
PubMed1989

Serum anti-PT and anti-FHA antibody levels, and agglutinin titers after administration of acellular pertussis vaccines.

Simultaneous evaluation of acellular pertussis vaccines from three manufacturers (Takeda, Biken, and Chiba) was performed. After receiving two doses of acellular pertussis vaccine in the form of DPT (diphtheria pertussis tetanus), both infants and children showed high serum anti-PT (pertussis toxin) and anti-FHA (filamentous hemagglutinin) antibody levels. These levels were equivalent to those observed in children in the convalescent stage of natural pertussis infection. Children who received 2 doses of Biken vaccine showed higher anti-PT and anti-FHA antibody levels than those who received Takeda or Chiba vaccine. Elevation of agglutinin titers was observed in children who received either Takeda or Chiba vaccine.

Antibodies, Bacterial↗
PubMed1988

Effectors of the activation of human [Glu1]plasminogen by human tissue plasminogen activator.

The activation of human [Glu1]plasminogen [( Glu1]Pg) by human recombinant (rec) two-chain tissue plasminogen activator (t-PA) is inhibited by Cl-, at physiological concentrations, and stimulated by epsilon-aminocaproic acid (EACA), as well as fibrin(ogen). Chloride functions as a result of its binding to [Glu1]Pg, with a Ki of approximately 9.0 mM, thereby rendering [Glu1]Pg a less effective substrate for two-chain rec-t-PA. EACA stimulates the activation in Cl-(-)containing solutions, with a Ka of approximately 4.0 mM, primarily by reversal of the Cl-(-)inhibitory effect. Fibrinogen appears to exert its stimulatory properties mainly through effects on the enzyme, two-chain rec-t-PA, with a Ka of approximately 3.7 microM in activation systems containing physiological levels of Cl-. Analysis of the results of this paper reveals that normal plasma components, Cl- and fibrinogen, exert major regulatory roles on the ability of [Glu1]Pg to be activated by two-chain rec-t-PA, in in vitro systems. The presence of Cl- inhibits the stimulation of [Glu1]Pg activation that would normally occur in the presence of fibrinogen, a result of possible importance to the observation that some degree of systemic fibrinogenolysis accompanies therapeutic use of tissue plasminogen activator.

Aminocaproic Acid↗
PubMed1988

Reaction of tissue-type plasminogen activator with 4-methylumbelliferyl-p-guanidinobenzoate hydrochloride.

It has recently been reported that the fluorogenic serine proteolytic active site titrant, 4-methyl-umbelliferyl-p-guanidinobenzoate (MUGB), cannot be employed in this capacity for tissue-type plasminogen activator (TPA) [Geiger, M., and Binder, B.R. (1987) Biochim. Biophys. Acta 912, 34-40]. Since this observation has such important ramifications in this area of research, we have studied the reaction of MUGB with recombinant (rec)TPA under a variety of experimental conditions and find that MUGB is indeed an effective titrant of rec-two chain TPA (recTCTPA) at 4 degrees, a condition under which the deacylation rate constant is diminished to the point that acylation can be readily observed. The KS for the interaction of MUGB with recTCTPA is 43 microM-46 microM, the acylation rate constant, k2, is approximately 3.6 min-1-4.2 min-1, and the rate constant for deacylation of p-guanidinobenzoyl-recTCTPA is 0.084 min-1-0.110 min-1. This same recTCTPA, after treatment with diisopropylfluorophosphate, does not react with MUGB. Single-chain TPA (recSCTPA) has been found to acylate more slowly than its two-chain counterpart and to exhibit a higher degree of turnover of the acyl-enzyme with this reagent. These results demonstrate that the active site concentration of TCTPA can be accurately determined by titration with MUGB, a consideration which is essential to the proper kinetic evaluation of this agent and its genetic variants. On the other hand, the presteady state kinetic characteristics for MUGB toward SCTPA are not favorable for its use as a titrant with this form of the enzyme.

Acylation↗
PubMed1988

The activation of human [Glu1]plasminogen by human single-chain urokinase.

The activation of human [Glu1]plasminogen ([Glu1]Pg) by single-chain human urokinase (SCUKase) displays a substantial lag phase at physiological levels of [Glu1]Pg. Employing a monoclonal antibody that exhibits a high level of specificity for SCUKase, as compared to two-chain urokinase (TCUKase), we have demonstrated conclusively that during this lag phase a progressive loss of SCUKase occurs, most likely resulting from its conversion to TCUKase, in a reaction catalyzed by plasmin (HPm). The overall activation of [Glu1]Pg by SCUKase is inhibited by physiological levels of Cl- and stimulated by epsilon-amino caproic acid. Kinetic studies demonstrate that both these effects are based on first, the reaction of [Glu1]Pg with the TCUKase that is formed during the activation, and, second, the concomitant rate at which HPm is provided for the conversion of SCUKase to TCUKase. The results indicate that at physiological levels of [Glu1]Pg, its activation in the presence of SCUKase is regulated in one manner by the rate at which SCUKase is converted to TCUKase, in a process that is strongly influenced by physiological levels of Cl-. Finally, and importantly, we show that SCUKase possesses very little, if any, inherent ability to activate [Glu1]Pg at a rate that influences the kinetics of HPm generation under physiological conditions of [Glu1]Pg and Cl- concentrations.

Aminocaproic Acid↗
PubMed1988

Roles for chloride ion and fibrinogen in the activation of [Glu1]plasminogen in human plasma.

Using two-dimensional immunoelectrophoresis and an antibody to alpha 2-antiplasmin, we assessed the plasmin generated in serum under different conditions as the plasmin-alpha 2-antiplasmin complex. Activation in serum of human [Glu1]plasminogen ([Glu1]Pg) by recombinant tissue plasminogen activator was inhibited by the normal serum levels of Cl- and was enhanced by physiological levels of fibrinogen in the presence or absence of Cl-. These results agree with the recognized ability of Cl- to induce a conformation in [Glu1]Pg less favorable for its activation than the conformation that results without Cl-. The enhancing effect of fibrinogen surpassed the inhibitory effect of Cl- over a wide range of recombinant tissue plasminogen activator concentrations in physiological serum. Lesser inhibition by Cl- was seen in a purified clot-lysis system, suggesting that [Glu1]Pg conformation when attached to soluble fibrin matrix was less affected by the anion. The data regarding the roles of circulating fibrinogen and Cl- in controlling the plasma level of activated [Glu1]Pg have important implications in thrombolytic therapy with recombinant tissue plasminogen activator.

Chlorides↗
PubMed1988

Suppressive effect of macrophages on interferon-gamma production by human peripheral lymphocytes stimulated with Mycoplasma pneumoniae.

Production of interferon (IFN)-gamma was investigated in human peripheral lymphocytes stimulated with Mycoplasma pneumoniae. Lymphocytes obtained from non-immune individuals produced no IFN. IFN-gamma was produced by T cells obtained from immune individuals, and the helper/inducer T cells produced two- to sixfold higher titer of IFN-gamma than the suppressor/cytotoxic T cells. The addition of macrophages in T cell cultures suppressed the production of IFN-gamma; this differs from the previous result wherein the addition of macrophages enhanced the production of IFN-gamma, when stimulated with mumps virus or measles virus.

Adult↗