Biomedical subjects

M Matsuda

Publications and source records attributed to M Matsuda.

At least 811 records · Page 45Linked to original sources

PubMed1990

Establishment of stable mouse/human-human hybrid cell lines producing large amounts of anti-tetanus human monoclonal antibodies with high neutralizing activity.

To establish stable hybrid cell lines producing human anti-tetanus antibody with high toxin-neutralizing activity, peripheral lymphocytes from humans hyperimmunized with tetanus toxoid were, after in vitro antigen stimulation, fused with a mouse/human heteromyeloma or human lymphoblastoid cell line and cloned. Unlike the IgM secretors (six clones), the IgG secretors we obtained (six clones) produced anti-tetanus human monoclonal antibodies with high neutralizing activity (the highest one, cell line G2, 4.3 IU/100 micrograms IgG). Appropriate combinations of three or four kinds of monoclonal antibodies of the IgG type resulted in markedly increased neutralizing activity comparable with that of anti-tetanus human polyclonal immunoglobulin preparations currently used clinically on the basis of toxin-specific IgG content. Five of these cell lines produced 10-20 micrograms of antibody per ml for more than 3 months. The cell line G2 produced 6 mg of antibody per day in serum-free medium in a 500-ml bioreactor in perfusion culture and 13-104 mg in a nude mouse. These cell lines satisfied, for the first time, the minimal requirements for applying human monoclonal antibodies to clinical use.

Animals↗

PubMed1990

Effect of gabaculine on metabolism and release of gamma-aminobutyric acid in synaptosomes.

Synaptosomes isolated from mouse brain were incubated with [14C]glutamate and [3H]gamma-amino-butyric acid ([3H]GABA), and then [14C]GABA (newly synthesized GABA) and [3H]GABA (newly captured GABA) in the synaptosomes were analysed. (1) the [3H]GABA was rapidly degraded in the synaptosomes, (2) when the synaptosomes were treated with gabaculine (a potent inhibitor of GABA aminotransferase), the degradation of [3H]GABA was strongly inhibited, (3) the gabaculine treatment brought about a significant increase in Ca2(+)-independent release of [3H]GABA with no effect on Ca2(+)-dependent release, (4) no effects of gabaculine on degradation and release of [14C]GABA were observed. The results indicate that there are at least two pools of GABA in synaptosomes and support the possibilities that GABA taken up into a pool which is under the influence of GABA aminotransferase is released Ca2(+)-independently and that GABA synthesized in another pool which is not under the influence of GABA aminotransferase is released Ca2(+)-dependently.

4-Aminobutyrate Transaminase↗

PubMed1990

Sequential changes of cerebral blood flow after aneurysmal subarachnoid haemorrhage.

A total of 226 measurements of cerebral blood flow (CBF) were performed in 96 postoperative patients with aneurysmal subarachnoid haemorrhage (SAH). The global CBF was significantly reduced in the first week after SAH, and the extent of the CBF reduction was less in the patients with good outcome than in those with fair/poor outcome. The good outcome patients showed a progressive increase in CBF in the following 3 weeks. Although the CBF decreased further in the second week in some of those patients, it turned to a steady increase thereafter. On the other hand, in the fair/poor outcome patients CBF remained far below the normal control value for at least 3 months after SAH. When looking into the effect of age on CBF in the patients with good outcome, those in their thirties and forties had a significantly reduced CBF during the first 2 weeks, whereas in those in their fifties and sixties a significant reduction persisted for 3 months to 1 year after SAH. Management of the older patients needs special attention even if they are apparently in good clinical condition, since the CBF threshold to ischaemia is diminished.

Adult↗

PubMed1990

Clinicopathological study of myocardial infarction with normal or nearly normal extracardiac coronary arteries. Quantitative analysis of contraction band necrosis, coagulation necrosis, hemorrhage, and infarct size.

In order to clarify the pathogenesis of acute myocardial infarction (MI) in hearts with normal coronary arteries, infarct size, and the extent of contraction band necrosis (CBN), coagulation necrosis, and hemorrhage were quantitatively examined using an image analyzer in 5 autopsy cases of MI with normal or nearly normal extracardiac coronary arteries. One patient died 40 h after acute MI. A second patient with acute MI due to severe spasm of segment 6, confirmed by cineangiography, died three days later. The third patient had already suffered a subarachnoid hemorrhage, and died 10 h after the onset of acute MI. The fourth patient had aortic stenosis and regurgitation. She developed acute MI due to total occlusion of segment 6, confirmed by cineangiography 4 h after the onset, and died 61 days later. Autopsy revealed old anteroseptal MI with normal coronary arteries and valvular thrombi. The fifth patient had a malignancy, and died one day after the onset of acute MI. Autopsy revealed multiple occlusive thrombi in the small intramural coronary arteries of the left ventricular wall supplied by segment 14, without any stenosis in the feeding vessel. Most infarcts were localized in the territory supplied by 1 or 2 of the 3 epicardial coronary arteries, and coincided with the clinically diagnosed infarct site. The infarct size ranged from 3%-26% of the left ventricular wall, and infarcts were generally localized to the inner third of the wall (67 +/- 20%). Histological examination of the four patients with acute MI revealed diffuse CBN (86 +/- 14% of the infarcted area) and/or hemorrhage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Two cases of Graves' disease with antithyroid hormone antibodies: implication on the role of thyroglobulin as an antigen.

We have experienced two cases of Graves' disease with antithyroid hormone autoantibodies (Case 1: anti-T4; Case 2: anti-T3) who finally underwent subtotal thyroidectomy after antithyroid drug treatment. Using serial sera obtained before and after operation, the correlation between titers of antithyroglobulin (anti-Tg) and anti-T4 or anti-T3 autoantibodies was examined in each case. There was a significant positive correlation between titers of anti-T4 (Case 1, r = 0.90, p less than 0.05), or anti-T3 (Case 2, r = 0.64, p less than 0.01) and anti-Tg antibodies. Using the homogenate of the thyroid tissue, it was found that the sole iodoprotein in the thyroid gland in each patient was 660 KDa Tg. In addition, Tg purified from the thyroid gland from Case 2 showed different immunological activity with normal Tg in two out of four murine monoclonal anti-Tg antibodies tested. On the other hand, Tg from Case 1 had identical immunological activity with normal Tg in every four monoclonal antibodies. These results are consistent with the view that the antigen responsible for the development of antithyroid hormone autoantibodies is Tg, at least in our two cases. The reason for the persistence of anti-T3 autoantibodies in Case 2, despite the subtotal thyroidectomy, could be due to some unidentified structural abnormalities of Tg which was detected only by the monoclonal anti-Tg antibodies.

Adenoma↗

PubMed1990

Fragment A-B of tetanus toxin does not block neuromuscular transmission in the goldfish.

While 4 micrograms of Fragment A-B of tetanus toxin (which lacks the binding site for nervous tissue) causes flaccid paralysis and death in mice, 26 micrograms has no toxic effect in goldfish. Antibodies to either A-B or to fragment C (which contains the binding site) block the paralytic effect of whole toxin in goldfish. It is concluded that binding is necessary for the neuromuscular blocking action of the toxin in goldfish.

Animals↗

PubMed1990

Interface between the meningioma and the brain on magnetic resonance imaging.

Magnetic resonance imaging of 31 meningiomas in 29 patients was retrospectively reviewed and compared with pathologic specimens in 25 tumors to investigate how magnetic resonance imaging could delineate a tumor-brain interface. The thick, collagenous connective tissue, which was seen around four tumors, was shown as a low signal intensity rim on both a T1-weighted image and a T2-weighted image. A rim of low signal intensity on a T1-weighted image and high signal intensity on a T2-weighted image most likely represented cerebrospinal fluid space: this finding was seen around eight tumors. No distinct rim could be identified in five tumors. Of these five, two tumors grew invasively into the brain. Although mixed features predominated in meningiomas, magnetic resonance imaging could well delineate a tumor-brain relationship in most of the cases.

Adult↗

PubMed1990

Magnetic resonance imaging with aneurysmal subarachnoid hemorrhage: comparison with computed tomography scan.

Magnetic resonance studies of 27 consecutive preoperative and 33 postoperative patients with cerebral aneurysm and subarachnoid hemorrhage were reviewed. Magnetic resonance imaging using a 0.5- or 0.22-Tesla unit was at least as accurate as computed tomography scan for detection of acute subarachnoid hemorrhage. Magnetic resonance imaging was superior to computed tomography scan for demonstrating blood in the ventricles or posterior fossa subarachnoid space, transependymal migration of the cerebrospinal fluid, and several kinds of iatrogenic intracranial pathologies in postoperative patients. Ischemic lesions, particularly fresh lesions caused by delayed cerebral vasospasm, were much better shown on magnetic resonance imaging than on computed tomography scan. Nonferromagnetic Sugita clips caused significant artifacts, but the area of artifacts was consistently smaller, and a reasonable evaluation of structures relatively closer to the clip was possible with magnetic resonance imaging rather than computed tomography scan.

Adult↗

PubMed1990

Cerebral hemodynamics in patients with normal pressure hydrocephalus: correlation between cerebral circulation time and dementia.

Regional cerebral blood flow and regional cerebral circulation time were measured in 13 demented patients with chronic hydrocephalus, mostly normal pressure hydrocephalus. The average hemispheric, frontal, and temporal cerebral blood flows were significantly reduced. The average regional cerebral circulation time values were significantly prolonged in the frontal, temporal, and thalamic regions, most markedly in the frontal white matter, where periventricular lucency was observed on computed tomography. Clinical improvement was obtained in all patients after operation. While postoperative regional cerebral blood flow values did not change compared with preoperative ones, postoperative regional cerebral circulation time values were significantly reduced in all the regions measured, and most markedly in the frontal white matter. The present results suggest that microcirculation in the frontal lobe is closely correlated with dementia in association with pressure exerted on the nerve fibers in the frontal white matter in patients with normal pressure hydrocephalus.

Aged↗

PubMed1990

Human immunodeficiency virus vpr gene encodes a virion-associated protein.

The vpr gene of human immunodeficiency virus type 1 (HIV-1) is one of the seven accessory genes that are believed to have roles in the virus replication cycle. We report here the detection of a 13 kD vpr protein in sucrose gradient-purified HIV-1. This protein was not detected in cells infected with a virus having a truncated vpr gene that lacks the potential to encode for 26 C-terminal amino acid residues. These findings raise the possibility that virion-associated vpr proteins may be involved in the early life cycle of HIV-1 replication and suggest that the C-terminal region of the vpr gene is essential for its expression.

Amino Acid Sequence↗

PubMed1990

Characterization of thrombin- and plasmin-resistant mutants of recombinant human single chain urokinase-type plasminogen activator.

Recombinant human single-chain urokinase-type plasminogen activator (suc-PA) (SM0: wild type) and its variants resistant to plasmin and/or thrombin (SM1: Lys135 to Gln; SM3: Phe157 to Asp; and SM4: Lys135 to Gln and Phe157 to Asp) have been constructed by site-directed mutagenesis with the aim of producing more efficient thrombolytic agents [Miyake, T. et al. (1988) J. Biochem. 104, 643-647]. In the present study, we characterized the recombinant variant scu-PAs expressed in Escherichia coli. They appeared to have structural integrity because their heat-stabilities, immunological reactivities, and circular dichroism spectra were essentially identical to those of each other and of native scu-PA (nscu-PA). In the presence of thrombin, SM3 and SM4 showed efficient clot lysis by all of the assays used, compared with SM0, SM1, and nscu-PA. While in the absence of thrombin, when measured by a fibrin plate method in a purified system, SM3 and SM4 had lower specific activities than SM0, SM1, and nscu-PA, because of their catalytic constants for conversion to the two-chain form (tcu-PA) by plasmin are lower. However, SM4 lysed clots as efficiently as SM0 in plasma by retaining the single-chain form, whereas SM0 was partly converted to the two-chain form.

Autoradiography↗

PubMed1990

Chemical modification of gamma-carboxyglutamic acid residues in prothrombin elicits a conformation similar to that of abnormal (des-gamma-carboxy)prothrombin.

Chemical modification of gamma-carboxyglutamic acid (Gla) residues in human prothrombin to gamma-methyleneglutamic acid (gamma-MGlu) residues elicited a conformation similar, if not identical, to that of des-gamma-carboxy prothrombin or PIVKA-II, i.e., prothrombin molecules induced by vitamin K antagonists or vitamin K deficiency states. The reaction seems to proceed sequentially by preferentially modifying a Gla at residue 32 that is located innermost among 10 Gla residues of human prothrombin. The initial modification resulted in nearly 50% losses of barium salt adsorption, the procoagulant activity and thrombin generation by the prothrombinase complex. The subsequent modification of two Gla residues at positions 6 and 16 gave rise to the immunoreactivity to an established monoclonal antibody that specifically recognizes the des-gamma-carboxy prothrombin. Further modification of Gla residues increased the reactivity to the antibody, indicating that the conformation recognized by the antibody was stabilized so as to more readily fit the recognition site of the antibody. The appearance of the immunoreactivity was obviously related to the modification of Gla residues in prothrombin, since all other similarly treated derivatives of prothrombin lacking the Gla-domain failed to react with the antibody. Such chemically modified prothrombins may serve as models for studying abnormal des-gamma-carboxy prothrombin produced in vitamin K deficiency states.

1-Carboxyglutamic Acid↗

PubMed1990

Delayed intermolecular gamma-chain cross-linking by factor XIIIa in fibrinogen Asahi characterized by a gamma-Met-310 to Thr substitution with an N-glycosylated gamma-Asn-308.

In an abnormal fibrinogen with gamma-Met-310 to Thr substitution accompanied by an extra oligosaccharide attached to gamma-Asn-308, factor-XIIIa-mediated intermolecular gamma-dimer formation of fibrin was found to be markedly delayed. The delayed gamma-dimer formation was not due to impaired fibrin polymerization because the fibrinogen gamma-chain also failed to be efficiently cross-linked by factor XIIIa. Since fluorescent amine was normally incorporated into the abnormal gamma-chain by factor XIIIa, we conclude that the abnormal molecules were unable to align their gamma-chains in an anti-parallel fashion because of inaccessibility of the molecules with a profoundly perturbed conformation near the carboxyl terminal region of the gamma-chain included in the D domain.

Fibrinogen↗

PubMed1990

A new method for repairing skin defects of the lower leg under unsatisfactory conditions: utilization of peroneal island flap from the opposite sound leg.

As a new procedure for the repair of tissue defects in the lower leg under unsatisfactory conditions, we have devised a surgical procedure for peroneal island flap transfer from the opposite sound leg. This report presents three patients treated by cross-leg island flaps with reversed blood flow. This procedure can be applied for reconstruction of the leg with severe circulatory disturbance caused by arterial damage due to trauma and arterial disease such as Buerger's disease. Furthermore, joint exercise is possible because the pedicle is long and no rigid immobilization is required.

Humans↗

PubMed1990

Characterization of the erythropoietic progenitor cells (BFU-E) in paroxysmal nocturnal haemoglobinuria (PNH).

In order to investigate erythropoiesis in paroxysmal nocturnal haemoglobinuria (PNH), the relative proportions of complement-mediated lysed erythroblasts in individual bursts of two cases of PNH were analysed by a modified complement lysis sensitivity test using the trypan blue dye exclusion method. All bursts contained both complement-sensitive and complement-insensitive erythroblasts and the ratio between them varied from burst to burst. The means +/- SD of the haemolytic percentages of individual bursts in cases 1 and 2 were 30.9 +/- 10.8% (n = 20, ranging from 13.2% to 52.8%) and 54.8 +/- 16.4% (n = 31, ranging from 26.4% to 82.5%), respectively. In addition, the cumulative frequency distributions of the proportions of complement-mediated lysed erythroblasts in individual bursts approached normal frequency distributions. These results suggest that two red cell populations with different susceptibilities to complement in PNH are derived from a single population of erythropoietic progenitor cells rather than a dual population of normal and PNH erythropoietic progenitor cells.

Bone Marrow↗

PubMed1990

Diagnosis of iliopsoas pyomyositis by ultrasonography and CT.

A patient with iliopsoas muscle pyomyositis was successfully treated with intravenous antibiotics alone. The diagnosis was made by ultrasonography and X-ray computed tomography after five days of spiking fevers. Ultrasonography and X-ray computed tomography revealed swelling of the muscle body but no abscess formation. We emphasize the usefulness of early diagnostic imaging to allow conservative treatment of iliopsoas muscle pyomyositis.

Child↗

PubMed1990

Open reading frame vpr of simian immunodeficiency virus encodes a virion-associated protein.

The genomes of simian immunodeficiency viruses isolated from rhesus macaques (SIVmac) contain an open reading frame (ORF), vpr, which has a coding potential of 97 to 101 amino acid residues. In this study, a vpr ORF-encoded protein of approximately 11 kDa was identified, and anti-vpr antibodies were detected in rhesus macaques infected by SIVmac. These results provide clear evidence that the vpr ORF is a coding gene of SIVmac. The vpr protein, like the vpx protein which is encoded by another accessory gene of SIVmac, was also found to be associated with viral particles. This observation demonstrates that more than one accessory gene product can be present in the virions of this family of retroviruses and raises the possibility that the vpr protein may have a role in early part of the virus life cycle.

Base Sequence↗

PubMed1990

A glycoprotein in the plasma membrane matrix as a major potential substrate of p60v-src.

A potential substrate of p60v-src in Rous sarcoma virus-transformed cells was found to be a 130-kilodalton (kDa) glycoprotein which binds to lectin-Sepharose and can be immunoprecipitated by an anti-phosphotyrosine antibody. This glycoprotein was shown to be distinct from the fibronectin receptor and a cellular protein phosphorylated in p60v-src immune complexes. The protein was a transmembrane protein localized in the plasma membrane and resistant to extraction with Triton X-100. The 130-kDa protein was also highly phosphorylated in cells transformed by Fujinami sarcoma virus or Y73 but not in cells infected with Rous sarcoma virus mutants that encode p60v-src lacking myristoylated N termini. Phosphorylation of this glycoprotein was temperature dependent in cells infected with temperature-sensitive mutants. The good correlation between its phosphorylation and morphological transformation, together with its relative abundance among phosphorylated proteins and its subcellular localization, suggests that phosphorylation of the 130-kDa glycoprotein is one of the primary events important for cell transformation by p60v-src and related oncogene products.

Animals↗