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Biomedical subjects

I Yasuda

Publications and source records attributed to I Yasuda.

At least 73 records · Page 4Linked to original sources
PubMed1989

Generation of monoclonal anti-dermatan sulphate antibodies cross-reacting to calf thymus DNA.

Monoclonal anti-dermatan sulphate antibodies were produced with hybridization after immunizing BALB/c mice with dermatan sulphate (DS). These antibodies were tested for cross-reactivity to double-stranded DNA (dsDNA) and heat-denatured DNA (ssDNA). Five clones had binding activity to DS, dsDNA and ssDNA in enzyme-linked immunosorbent assay, but no clones binding to DS alone were produced. Two (2H8 and 3C4) of the five clones were selected for analysis. Their binding activity to DS, ssDNA and dsDNA were inhibited by DS, dsDNA and ssDNA. DNase I treatment abolished the binding activity to dsDNA and ssDNA, completely, but had no effect on the binding activity to DS. On the other hand, chondroitinase ABC treatment of the solid-phased DS augmented the binding to DS. The inhibition assay using digested fractions suggested that the epitope recognized by 2H8 and 3C4 clones could not be in delta Di-4S or delta Di-diSB but in the linkage regions of DS.

Animals↗
PubMed1988

Tracheal dilatation by halothane and enflurane in man.

The effect of halothane and enflurane on tracheal tone were studied in 21 patients during the induction of anesthesia. Endotracheal tube cuff pressure was used to measure tracheal tone. Anesthesia, maintained by nitrous oxide 70% in oxygen, was supplimented with succinylcholine drip infusion to immobilize the patient. Ventilation was controlled by a Volume-preset ventilator. In the halothane group, the initial cuff pressure was 14.8 +/- 1.3 (mean +/- SE) cmH(2)O but 10 min after 0.15 mg/kg of pancuronium injection, it increased to 21.7 +/- 2.3 cmH(2)O (control). Ten min after inhalation of 0.75% of halothane, cuff pressure decreased to 14.7 +/- 2.3 cmH(2)O (34 +/- 11% decrease from the control value). In the enflurane group, the initial cuff pressure was 17.6 +/- 1.8 cmH(2)O and it increased to 21.0 +/- 1.7 cmH(2)O (control) 10 min after pancuronium injection. Ten min after 1.7% of enflurane inhalation, cuff pressure decreased to 17.1 +/- 2.3 cmH(2)O (23.9 +/- 6% decrease from the control value). Halothane and enflurane produced similar tracheal dilatation in healthy individuals.

Journal Article↗
PubMed1988

Prevention by gamma interferon of fatal infection with Listeria monocytogenes in mice treated with cyclosporin A.

The significance of interferons (IFNs) induced by Listeria monocytogenes in the antilisterial defense mechanism was studied in mice. Cyclosporin A (CsA) had no effect on IFN-alpha production that was induced in the bloodstream after intravenous infection of mice with L. monocytogenes, whereas IFN-gamma that was induced in the bloodstreams of control mice 6 h after stimulation with specific antigen in the late phase of infection was suppressed in CsA-treated mice, depending on the dose of the drug injected. The decrease in IFN-gamma production caused an increase in bacterial growth in the spleens and livers of CsA-treated mice. Furthermore, administration of a daily dose of CsA at 80 or 100 mg/kg of body weight resulted in fatal listeriosis, even though the dose was nonlethal for normal mice. The administration of recombinant murine IFN-gamma on day 0 of L. monocytogenes infection prevented CsA-treated mice from developing fatal listeriosis and restored their ability to produce IFN-gamma in the bloodstream, in response to specific antigen in the late phase of infection.

Animals↗
PubMed1988

[Newly designed approach to an aneurysm eroding the sternum and protruding over the sternum].

A 54-year old man was admitted with a complaint of a pulsating tumor (7 x 6 x 2 cm) above the sternum accompanied by dysphagia. DSA showed the pulsating tumor was an aneurysm arising from the ascending aorta. CT gram of the sternum showed that the sternum was destroyed partially at the level of the 1st rib. We did the Y shaped skin incision. The clavicles, 1st and 2nd ribs were dissected out periosteally and perichondrially. We cut the clavicles and ribs, and dissected the mediastinum median to the internal mammary artery. Under the perfusion, F-F bypass and brain perfusion, the upper half of the sternum was dissected safely from the aneurysm. The aneurysm was false aneurysm and the perforating ostium was 3.5 cm in diameter. The margin of the perforating ostium had a deposit of calcium. Using an occlusion balloon catheter from the ostium, patch closure was done. The postoperative course was uneventful. We believe that this new approach is preferable to the severe erosion of the sternum by the aneurysm.

Aortic Aneurysm↗
PubMed1985

Induction of alpha/beta interferon and gamma interferon in mice infected with Listeria monocytogenes during pregnancy.

Alpha/beta interferon (IFN-alpha/beta) was induced in the bloodstream of mice 48 h after intravenous infection with Listeria monocytogenes, whereas IFN-gamma was induced in the bloodstream 6 h after stimulation with specific antigen on day 5 of infection in virgin mice. In contrast, no IFN-alpha/beta or IFN-gamma was produced in the bloodstream of pregnant mice after L. monocytogenes infection. However, unusual acid-labile IFN-alpha/beta instead of IFN-gamma was produced in some of the pregnant mice in response to specific antigen. The bacterial growth in the organs of pregnant mice in the early stage of infection was normal, but resulted in the delay of T-cell-dependent elimination of bacteria from the organs of pregnant animals in the late stage, and numerous bacteria were detected in both the placenta and the fetus. The significance of the IFN system induced by L. monocytogenes infection in pregnant mice is discussed.

Animals↗
PubMed1984

Oligo-2',5'-adenylate synthetase activity in peripheral blood mononuclear leukocytes in various diseases.

Interferon induces oligo-2',5'-adenylate synthetase in cells. In various diseases, interferon was detectable in the circulation or was produced spontaneously from peripheral blood mononuclear leukocytes. The oligo-2',5'-adenylate synthetase activity in peripheral blood mononuclear leukocytes was examined in various diseases, including systemic lupus erythematosus, sarcoidosis, Vogt-Koyanagi-Harada disease, and Behcet's disease. The activity of this enzyme was significantly increased in systemic lupus erythematosus (P less than 0.01), sarcoidosis (P less than 0.01), and Vogt-Koyanagi-Harada disease (P less than 0.01) compared with that in controls, but the increase of activity was not significant in Behcet's disease (P greater than 0.05).

2',5'-Oligoadenylate Synthetase↗
PubMed1984

Coronary thrombolysis with recombinant human tissue-type plasminogen activator: a prospective, randomized, placebo-controlled trial.

Forty-five patients with acute transmural myocardial infarction and angiographically confirmed complete coronary occlusion were prospectively randomized, two for one, to treatment of acute coronary thrombosis with intravenous recombinant human tissue-type plasminogen activator (rt-PA) or placebo. Each of five additional consecutive patients was treated with a high dose of rt-PA for 2 hr. Twenty-five of 33 patients (75%) receiving 0.5 to 0.75 mg/kg of rt-PA over 30 to 120 min had angiographically proven recanalization within 90 min of initiation of therapy. Only one of 14 patients given placebo had spontaneous recanalization within 45 min (p less than .001). Thirteen placebo-treated patients were crossed over to the intracoronary rt-PA group. Nine (69%) exhibited subsequent recanalization within 45 min. Levels of circulating fibrinogen decreased after treatment with rt-PA by an average of only 8% of baseline values. None of the patients manifested a depletion of fibrinogen level to below 100 mg/dl. Six patients who were completely unresponsive to rt-PA were subsequently treated with intracoronary streptokinase and none responded. Thus, either intravenous or intracoronary rt-PA induced coronary thrombolysis without eliciting clinically significant fibrinogenolysis in patients with evolving myocardial infarction due to thrombotic coronary occlusion.

Arteriosclerosis↗
PubMed1982

Chronotropic effects of succinylcholine and succinylmonocholine on the sinoatrial node.

The mechanism of bradycardia caused by the administration of succinylcholine has not been fully elucidated. Accordingly, the effects of succinylcholine and succinylmonocholine on the sinoatrial node were studied in 35 mongrel dogs. The sinus node artery was selectively perfused with autologous blood from a femoral artery at a constant pressure of 100 mmHg, and 30 to 1,000 micrograms of succinylcholine or succinylmonocholine was administered directly into the artery. Succinylcholine caused a transient (63-600 s) dose-related positive chronotropic effect. The heart rate was increased to 14.4 +/- 2.1% (mean +/- SE) above the control value after the administration of 1,000 micrograms of succinylcholine. This positive chronotropic effect was inhibited by pretreatment with pindolol or reserpine. By contrast, succinylmonocholine produced a transient (30-248 s) dose-related negative chronotropic effect. The heart rate was decreased to 17.5 +/- 1.4% below the control value after administration of 1,000 micrograms of succinylmonocholine. The negative chronotropic effect was blocked partially by atropine. It was concluded that the positive chronotropic effect of succinylcholine may be mediated through beta-adrenergic receptor stimulation by catecholamine released from the adrenergic nerve endings in the sinoatrial node, and that the negative chronotropic effect of succinylmonocholine may be the result of excitation of cholinergic receptors in the sinus node. However, a direct effect of succinylmonocholine on the sinus node could not be ruled out.

Animals↗
PubMed1980

Supraclavicular brachial plexus block using a nerve stimulator and an insulated needle.

A technique employing a nerve stimulator and an insulated needle was used for supraclavicular brachial plexus block in 71 patients using 0.5% plain bupivacaine 15-20 ml. The mean minimal stimulating current to produce paraesthesia was 0.09 mA. The plexus was identified at a mean depth of 27 mm below the skin. The block was successful in 98% of patients when the stimulation was felt in the index, middle or ring finger, but was often incomplete when felt in the thumb or little finger.

Brachial Plexus↗
PubMed1978

Cardiac performance during prolonged halothane anaesthesia in the cat. Isolated heart muscle study.

The contractile response of papillary muscles, isolated from normal cats, to prolonged administration of halothane at minimum alveolar anaesthetic concentration (MAC) was studied. Average values of maximal velocity of shortening (Vmax) and maximal developed force (Fm) obtained in 12 muscles during the 1st, 2nd and 3rd hour of exposure to halothane anaesthesia were significantly less than those obtained during the control period and after recovery from halothane. There were no significant differences in values over a 3-h period. When post-extra-systolic potentiation was induced by paired electric stimulation, average values of Vmax and Fm increased significantly. We conclude that prolonged administration of halothane at a constant concentration resulted in a sustained depression of myocardial contractility without tissue tolerance. The myocardium depressed by halothane, however, still retains the ability to respond to additional inotropic stimulation.

Anesthesia, General↗
PubMed1978

Effect of thiamylal on the sensitivity of glycerinated cardiac fibres to calcium.

Clarification of the mechanisms of the myocardial depression produced by thiamylal was sought by studying the effect of thiamylal upon the sensitivity of contractile proteins to calcium (Ca2+), by using glycerinated muscle fibres from the canine right ventricle. The dose--response relationship between the concentration of Ca2+ and the force of contraction of the glycerinated cardiac muscle fibres was not shifted from the control curve by the administration of thiamylal 67 microgram ml-1. This result suggests that the changes in the sensitivity of contractile proteins to Ca2+ are not responsible for the depression of myocardial performance produced by thiamylal.

Animals↗
PubMed1978

Tracheal constriction by morphine and by fentanyl in man.

The effects of morphine and fentanyl on tracheal smooth muscle tone were studied in 38 patients during induction of anesthesia. Endotracheal tube cuff pressure was used to measure tracheal tone. Anesthesia was maintained with nitrous oxide, 70 per cent in oxygen, and pancuronium and ventilation was controlled with a respirator. Morphine, 0.5 mg/kg, produced a biphasic response, initially causing tracheal dilatation and then tracheal constriction. Ten minutes after morphine injection, cuff pressure increased to significantly (21 +/- 8 per cent) above control. Morphine-induced tracheal constriction could be completely blocked by the prior administration of atropine, 0.5 mg. Fentanyl, 0.006 mg/kg, also produced significant tracheal constriction, cuff pressures increasing to 44 +/- 11 per cent above control at 10 min. Fentanyl-induced tracheal constriction could be blocked by pretreatment with droperidol, 0.25 mg/kg. At equianalgesic doses, morphine and fentanyl produced similar tracheal constriction.

Adult↗