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Biomedical subjects

I Kudo

Publications and source records attributed to I Kudo.

At least 145 records · Page 8Linked to original sources
PubMed1991

Blue rubber bleb nevus syndrome with disseminated intravascular coagulation and thrombocytopenia: successful treatment with high-dose intravenous gammaglobulin.

A 63-year-old woman was diagnosed as having blue rubber bleb nevus syndrome (BRBNS) with disseminated intravascular coagulation (DIC). Hematological data showed typical DIC: PT 13.2 sec, activated PTT 55.3 sec, fibrinogen 20 mg/100 ml, FDP-E 928 ng/ml, D-dimer 3,477 ng/ml, platelet count 25 x 10(3)/microliters. Although hypofibrinogenemia was successfully controlled by the continuous infusion of heparin, 10,000 units/day, thrombocytopenia has continued. Based on shortened platelet life span, high level of platelet associated IgG, and increased number of megakaryocyte in the bone marrow, the thrombocytopenia was thought to be due to antiplatelet antibody. Her platelet count returned to normal after intravenous infusion of high-dose gamma globulin (IVIg, Sandoz) at the dose of 400 mg/kg for 2-5 days, while corticosteroid, Gabexate mesilate, synthetic thrombin inhibitor MD-805, urinastatin and warfarin had no effect. Thus, DIC or thrombocytopenia may become a serious complication in some patients with BRBNS and IVIg may be useful for correcting thrombocytopenia in the patient.

Disseminated Intravascular Coagulation↗
PubMed1991

[CO diffusing capacity during continuous negative extra-thoracic pressure].

Eight healthy males were studied to compare CO diffusing capacity (DLCO) during spontaneous breathing with that during continuous negative extra-thoracic pressure (CNETP). Mean DLCO was 33.0 +/- 5.1 ml.min-1.mmHg-1 during spontaneous breathing and 33.5 +/- 4.5 ml.min-1.mmHg-1 during CNETP with an end-expiratory negative extra-thoracic pressure (EENETP) of -20 cmH2O, and there was no significant difference between them (P less than 0.05). Pulmonary capillary blood volume, which was measured only in a male, was 76.7 ml during spontaneous breathing and 80.5 ml during CNETP. This change dose not seem to be significant. The results suggest that the effect of pulmonary diffusing capacity changes during EENETP on improvement of oxygenation may not be significant.

Adult↗
PubMed1991

[Orthostatic purpura: report of two cases].

Two patients with orthostatic purpura were reported. Case 1: A 47-year-old man was admitted to our institution because of multiple purpuric eruptions over the legs after the long periods of sitting or standing. Bleeding time was 4.0 min. Platelet aggregation induced by ADP was disaggregated and no aggregation was observed when induced by collagen and epinephrine. He was diagnosed as having release abnormality of the platelets caused by glutathione administered for treatment of liver damage for several years. Purpura, however, appeared even though platelet function became normal after discontinuing glutathione. Purpura proved to be induced by the long periods of sitting or standing. Case 2: A 37-year-old woman was admitted to our hospital because of purpuric eruptions over the legs for three years. Bleeding time was 2.0 min. Platelet aggregation induced by ADP, epinephrine, collagen and ristocetin was normal. Purpura was caused by long periods of standing without movement. Wearing elastic pantyhose showed reduced appearance of the purpura. Biopsy specimens from both patients revealed no abnormal findings. Both patients had no abnormal results in coagulation studies. Purpura seemed to be caused by the increased capillary pressure after the prolonged periods of standing. No case report concerning orthostatic purpura or mechanical purpura has been published.

Adult↗
PubMed1991

Lysophospholipase L1 from Escherichia coli K-12 overproducer.

After screening 900 E. coli strains of the Clarke and Carbon collection for by lysophospholipase L1 activities, we isolated a clone bearing the plasmid pLC6-34, which showed an increased level of lysophospholipase L1 activity. Strains bearing the plasmid pC124, a subclone of pLC6-34 in plasmid vector pUC8, showed approximately 11.4 times higher lysophospholipase L1 activity than that of the parental strain. Starting from those overproducing strains, the lysophospholipase L1 was purified to near homogeneity by sequential use of ammonium sulfate fractionation, Sephacryl S-300, DEAE-cellulose, hydroxyapatite and Sephacryl S-200 column chromatographies. The apparent molecular weight of the purified lysophospholipase L1 was estimated to be 20,500-22,000 both by SDS-polyacrylamide gel electrophoresis and by gel permeation chromatography. The specific activity of the homogeneous lysophospholipase L1 was 10,400 nmol/min/mg protein when 1-acyl-sn-glycero-3-phosphoethanolamine was used as the substrate. The amino acid sequence of the amino-terminal portion of purified lysophospholipase L1 was determined and was different from that of lysophospholipase L2, which had previously been purified from the envelope fraction of E. coli strains bearing its cloned structural gene, pldB [Karasawa, K., Kudo, I., Kobayashi, T., Sa-eki, T., Inoue, K., & Nojima, S. (1985) J. Biochem, 98, 1117-1125]. The gene responsible for overproduction of lysophospholipase L1 activity was designated as pldC (phospholipid degradation C). Its restriction enzyme map was also different from that of cloned pldB. These results further confirmed that, in E. coli, there are two lysophospholipases with distinct characteristics.

Amino Acid Sequence↗
PubMed1990

Exacerbation of rat adjuvant arthritis by intradermal injection of purified mammalian 14-kDa group II phospholipase A2.

Appreciable phospholipase A2 activity was detected in a hind paw homogenate from rats with adjuvant arthritis or carrageenan-induced edema. The activity was neutralized by treatment with antibody raised against rat platelet secretory phospholipase A2, indicating that 14-kDa group II phospholipase A2 was induced in the hind paw during the process of inflammation. Injection of purified rat platelet phospholipase A2 into the hind paw of rats with adjuvant-induced arthritis resulted in exacerbation of edema in a dose-dependent manner, whereas no effect was observed on either normal rats or animals with carrageenan-induced edema under the same experimental conditions. These results suggest the importance of mammalian group II phospholipase A2 in the pathogenesis of some types of inflammation.

Animals↗
PubMed1990

Structure of gene coding for rat group II phospholipase A2.

The gene coding for rat group II phospholipase A2 was isolated from a rat genomic library by using the cDNA for rat platelet phospholipase A2 as a hybridization probe. The rat group II phospholipase A2 gene spanned about 3.5 kilobase pairs and consisted of five exons. Southern blot analysis revealed that a single copy of this gene exists in the rat haploid genome. A TATA-like sequence and two AP-2 binding site-like loci were found upstream from the tentatively identified transcription initiation site.

Amino Acid Sequence↗
PubMed1990

Monoclonal antibodies against human synovial phospholipase A2.

Four monoclonal antibodies (HP-1, HP-2, HP-3 and HP-4) with differing reactivities were raised against human synovial fluid phospholipase A2. None of them bound to exocrine phospholipases A2, such as those from pancreas or snake venom. However, antibodies HP-1 and HP-3 showed cross-reactivity with rabbit and rat platelet secretory phospholipases A2, which share common enzymatic and structural features with the human synovial enzyme. Antibodies HP-1, HP-2 and HP-3 inhibited the activity of human synovial phospholipase A2. The antibodies were used to develop a rapid immunoaffinity column chromatographic procedure for enzyme purification. In some preparations, the recovery of total activity after immunoaffinity column chromatography was more than 100% suggesting the existence of endogenous inhibitory factors of phospholipase A2 in human synovial fluid.

Animals↗
PubMed1990

Immunochemical detection of 'platelet type' phospholipase A2 in the rat.

Polyclonal antibodies were raised against rat platelet phospholipase A2. One of them, designated as R377 was prepared by immunizing a rabbit with the intact enzyme. The other antibody, designated as R385, was prepared by immunizing with the enzyme treated with 2-mercaptoethanol. The antibody R377 bound to rat platelet phospholipase A2 almost exclusively, while the antibody R385 reacted not only with rat platelet phospholipase A2 but with the enzymes obtained from snake venom or mammalian pancreas. The antibody R377 bound to the non-reduced rat platelet phospholipase A2 bearing intact intramolecular disulfide bonds, but not to the reduced enzyme. In contrast, the antibody R385 reacted with both non-reduced and reduced enzymes. R377 may recognize the conformational structure of the enzyme. Both antibodies inhibited the enzyme activity. The antibody R377, but not R385, interfered with the interaction of the enzyme with heparin, which is one of the characteristic properties of rat platelet phospholipase A2. The antibody R377 reacted with phospholipases A2 of bone-marrow cells and of peritoneal exudated cells prepared from caseinate-treated rats, indicating that some myeloid cells other than platelets also contain 'platelet type' phospholipase A2. An immunochemical method for measurement of rat 'platelet type' phospholipase A2 was developed. The sensitivity of this method was 10 ng/ml of phospholipase A2 in the preparation. One of the advantages of the present immunochemical method is that the measurement was not affected by the presence of an endogenous inhibitor(s) of enzymatic activity.

Animals↗
PubMed1990

Proteinaceous inhibitors of phospholipase A2 purified from inflammatory sites in rats.

We have purified two phospholipase A2 inhibitory proteins (37 and 33 kDa) from peritoneal fluid of dexamethasone-treated rats. The extracellular phospholipase A2 found in inflammatory sites differed from the exocrine phospholipase A2 in susceptibility to these endogenous inhibitors; both proteins inhibited the activity of the extracellular phospholipase A2 purified from sites of inflammation but did not affect appreciably the activity of either porcine pancreatic or Naja naja venom phospholipase A2. The amino acid sequence of the NH2-terminal portion of the purified proteins did not resemble that of lipocortins so far reported, but it was almost identical to that of parts of human or mouse complement component C3. These findings may indicate that degraded products of C3 are involved in the regulation of activity of a class of mammalian phospholipase A2.

Amino Acid Sequence↗
PubMed1990

Detection and subcellular localization of rabbit platelet phospholipase A2 which preferentially hydrolyzes an arachidonoyl residue.

Like rat platelets, rabbit platelets contain a secretory 14-kDa group II phospholipase A2 [Mizushima, H., Kudo, I., Horigome, K., Murakami, M., Hayakawa, M., Kim, D.K., Kondo, E., Tomita, M., & Inoue, K. (1989) J. Biochem. 105, 520-525]. The present study was undertaken to determine whether or not, in addition to that of the 14-kDa group II enzyme, rabbit platelets exhibit another phospholipase A2 activity. A rabbit platelet soluble fraction was prepared by sonication and centrifugation. When this soluble fraction was subjected to heparin-Sepharose column chromatography, phospholipase A2 activity was detected in both heparin-binding and heparin-non-binding fractions. The activity detected in the heparin-binding fraction appeared to belong to the secretory 14-kDa phospholipase A2, because it bound to anti-human 14-kDa group II phospholipase A2 monoclonal antibody. The activity found in the heparin-non-binding fraction did not appreciably react with the same antibody. When platelets were gently disrupted by the nitrogen cavitation method, the heparin-non-binding activity was mainly recovered in the platelet cytosolic fraction. The heparin-non-binding phospholipase A2 hydrolyzed a phospholipid bearing an arachidonoyl residue at the sn-2 position more effectively than one with a linoleoyl residue. The biochemical features of the activity observed in the heparin-non-binding fraction generally resembled those of human platelet soluble phospholipase A2 [Kim, D.K., Kudo, I., & Inoue, K. (1988) J. Biochem. 104, 492-494].(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Macrothrombocytopenia with deafness, nephritis, cataract, short small intestine, and double ureter].

A 23 year old female, born in 1957, was diagnosed as having idiopathic thrombocytopenic purpura at the age of 3 and treated with prednisolone during her childhood with no response. On her regular check-up in 1978, facial edema and proteinuria suggested renal disease. The family history was negative for bleeding diathesis or renal disease. Close examination revealed the following: WBC 4,200/microliters without leukocyte inclusions, RBC 3.42 x 10(6)/microliters, Hb 11.7 g/dl. PT 10.6 sec, APTT 28.9 sec. Platelet count 4,500/microliters by HEMATRAK 360, and 40 x 10(3)/microliters measured by microscopic method. Giant platelets were noted on peripheral blood smear with an average diameter of 6.1 microns. Bleeding time (Duke) was 12.0 min. Number of megakaryocytes was increased although platelet production was remarkably decreased. Results of platelet aggregation and retention tests were normal. Platelet life span (T1/2) was 2.3 days. Sensory neural hearing loss, congenital cataract, double ureter and short small intestine were also found. Chromosome analysis showed 46XX. She underwent splenectomy resulting in increase of the platelet count to 226 x 10(3)/microliters. The increased platelet count, however, gradually decreased to the initial count in 2 years although the bleeding tendency was improved. In 1987, renal function deteriorated, causing intractable hypertension. The serum creatinine was 4.8 mg/dl. The following year she developed cerebral bleeding and died 4 days after the episode. The serum creatinine was 8.6 mg/dl.

Adult↗
PubMed1990

[Bleeding time and volume in vitro by THROMBOSTAT].

We tested an in vitro system simulating bleeding time reported by Kratzer et al. Primary hemostasis was studied perfusing an artificial vessel with citrated blood under a constant pressure of 40 mmHg, measuring the blood volume perfused (bleeding volume) and the time until blood flow stopped (bleeding time). The artificial vessel consists of a glass capillary simulating arteriole and a filter covered with collagen type I to provide a surface for the adhesion of platelets. The bleeding volume (mean +/- SD microliters) was 317.7 +/- 93.8 in controls (n = 19), 487.3 +/- 242.1 in idiopathic thrombocytopenic purpura (n = 9), 666.8 +/- 224.1 in aplastic anemia and paroxysmal nocturnal hemoglobinuria (n = 4), greater than 820 in von Willebrand's disease (n = 3), 231.0 +/- 74.5 in hemophilia A (n = 3), 499.0 +/- 269.4 in liver cirrhosis (n = 6), and 457.7 +/- 229.0 in myeloproliferative disorders (n = 11). When citrated blood was applied to this system after incubation with monoclonal antibodies (MoAb) to von Willebrand factor or platelet membrane glycoprotein Ib (GPIb), bleeding volume was significantly increased while no effects were observed after incubation with MoAb to GPIIb/IIIa, factor VIII: CAg and factor XIIIa. These data suggest that in vitro model of primary hemostasis could be used for not only diagnosing bleeding disorders although 'time' is not reliable, but also investigating the mechanisms of hemostasis.

Antibodies, Monoclonal↗
PubMed1989

In vivo release and clearance of rat platelet phospholipase A2.

Intravenous injection of ADP into rats produced a rapid increase of plasma phospholipase A2 activity with a concomitant decrease in platelet count. Phospholipase A2 activity in plasma reached a peak within 1 min and thereafter declined sharply. This phospholipase A2 activity was reactive with a monoclonal antibody specific for rat platelet-derived phospholipase A2. These findings, together with the fact that ADP is a stimulant specific for platelets, suggest that the phospholipase A2 observed may be released into plasma from activated platelets in vivo. When platelet-derived phospholipase A2 was purified, labeled with 125I, and injected intravenously into rats, the radioactivity in the plasma decreased rapidly: the half-life of the enzyme in the blood stream was less than 30 s. Addition of either heparin or anti-phospholipase A2 monoclonal antibody directed against the domain of the enzyme responsible for binding to heparin retarded the clearance of the enzyme, suggesting that phospholipase A2 might be adsorbed onto heparan sulfate proteoglycans on the endothelial cell surface. Examination of the distribution of radioactivity in vivo revealed that most of the enzyme was rapidly taken up by the liver and degraded to acid-soluble materials.

Adenosine Diphosphate↗
PubMed1989

ESR study on synthetic glyceroglycolipid liposomal membranes.

We previously reported that glyceroglycolipid liposomes without cholesterol activated mouse peritoneal macrophages in vivo and in vitro, whereas glyceroglycolipid liposomes containing equimolar cholesterol did not. In order to characterize the properties of the glyceroglycolipid membranes, ESR spectroscopic studies were carried out with an acyl spin-labeled galactosyl ceramide (SL-GC) or a headgroup spin-labeled phospholipid (SL-6-DPPA) in 1,2-dipalmitoyl[beta-cellobiosyl-(1'---3)]glycerol (Cel-DAG) liposomal membranes. The ESR spectrum of the SL-GC in the Cel-DAG liposomes at 37 degrees C was a single broad line, indicating that the SL-GC molecules were excluded almost completely from Cel-DAG domains and formed clusters in the membranes. The spectrum of SL-6-DPPA in the Cel-DAG liposomes at 37 degrees C showed broad resonance lines with the central peak being the highest, while that at 60 degrees gave narrow lines with the low-field peak being the highest. This observation and rotational correlation time analysis showed that the molecular motions of spin-label moiety of the SL-6-DPPA were extremely restricted at 37 degrees C but not above Tc. These results suggest that below Tc the Cel-DAG molecules are packed tightly and restricted in motion in the membrane. Incorporation of cholesterol into the Cel-DAG liposomal membranes gave (1) the spectra of the SL-GC triplet, and (2) the spectra of the SL-6-DPPA narrow resonance with the low-field peak being the highest. These results suggest that cholesterol disturbs the rigid-packed structure of the Cel-DAG membrane and increases the molecular motions of the Cel-DAG. The DSC analysis of Cel-DAG with and without cholesterol agreed well to the results of the ESR technique. Thus we assume that peritoneal macrophages recognize the rigid-packed carbohydrate residues which are restricted in motion on the Cel-DAG membranes.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1989

Purification and characterization of extracellular phospholipase A2 from human synovial fluid in rheumatoid arthritis.

Extracellular phospholipase A2 was purified about 1.7 X 10(5) fold to near homogeneity from human synovial fluid of rheumatoid arthritis by sequential use of column chromatographies on heparin-Sepharose, butyl-Toyopearl, and reversed-phase HPLC. The final preparation showed a single band on SDS-polyacrylamide gel electrophoresis, and its molecular mass was estimated to be approximately 13,700 daltons. The purified enzyme had a pH optimum of 9.0 and required Ca2+ for maximum activity. It hydrolyzed phosphatidyl-ethanolamine more effectively than phosphatidylserine and phosphatidylcholine. These properties were similar to those of an extracellular phospholipase A2 detected in the peritoneal cavity of caseinate-treated rats.

Arthritis, Rheumatoid↗