Biomedical subjects

R Ogawa

Publications and source records attributed to R Ogawa.

At least 19 recordsLinked to original sources

PubMed1992

Interactions between recombinant human erythropoietin and serum factor(s) on murine megakaryocyte colony formation.

We investigated the interactions between human erythropoietin (hEpo) and serum factor(s) on murine megakaryocyte (MK) colony formation. Serum-free cultures supported the growth of a large number of murine MK colonies in the presence of murine interleukin-3 (mIL-3). The addition of fetal calf serum (FCS) to mIL-3-containing cultures resulted in only a minimal increase in the number of murine MK colonies. In contrast, hEpo alone had no murine MK colony-stimulating activities in serum-free cultures. hEpo required the presence of FCS, murine serum, or human serum in cultures to promote murine MK colony growth and synergized with these sera to stimulate murine MK colony formation. Furthermore, sera from patients with aplastic anemia showed higher synergistic activities with hEpo than sera from hematologically normal persons (normal human serum). When normal human serum was fractionated by gel-filtration chromatography, two peaks with the synergistic activity were observed in the eluent. However, serum did not show any synergistic effects with hEpo on the growth of murine GM colonies or murine colony-forming unit-erythroid-derived colonies. Although human serum synergized with hEpo to stimulate murine MK colony formation, human cytokines such as IL-3, IL-4, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte-CSF (G-CSF) failed to induce murine MK colony formation in Epo-containing cultures. In cultures containing human IL-1 alpha + human IL-6 + hEpo as well as in cultures containing hEpo, human IL-3 and human GM-CSF failed to show stimulatory effects on murine MK colony formation. Moreover, the synergistic activity of human serum with hEpo could not be neutralized by antibodies such as antihuman IL-1 alpha, antihuman IL-3, antihuman IL-4, antihuman IL-6, antihuman G-CSF, and antihuman GM-CSF. Our data show that serum contains a growth factor(s) that synergizes with Epo to stimulate the proliferation and differentiation of MK precursors, and strongly suggest that this factor(s) is an unique growth factor(s) that is distinct from IL-1 alpha, IL-3, IL-4, IL-6, G-CSF, and GM-CSF.

Anemia, Aplastic↗

PubMed1992

Identification and functional analysis of the fowlpox virus homolog of the vaccinia virus p37K major envelope antigen gene.

A fowlpox virus (FPV) gene with homology to the vaccinia virus p37K major envelope antigen gene was identified and sequenced. The predicted product has a molecular weight of 43,018 Da (p43K). The FPV p43K gene has 37.5% identity with its vaccinia counterpart and higher homology with a molluscum contagiosum virus gene (42.6% identity). Based on upstream sequences, p43K appears to be regulated as a late gene. Recombinant FPV were generated in which a large portion of p43K was replaced by the Escherichia coli lacZ gene. These recombinants failed to produce visible plaques under standard conditions. After prolonged incubation the microplaques developed into small macroscopic plaques. Plaques were purified on the basis of lacZ expression. Single-cycle growth curves comparing the p43K-deleted recombinant (designated fJd43Z) with parental FPV showed that the two viruses produce identical amounts of intracellular virions, but that fJd43Z released 20-fold fewer infectious particles into the medium. CsCl gradient centrifugation of [3H]thymidine-labeled virus was employed to examine differences in the production of physical particles. The two viruses produced equivalent levels of intracellular virions, but fJd43Z failed to produce detectable levels of released particles. FPV p43K is therefore involved in the release of virions from infected cells.

Amino Acid Sequence↗

PubMed1992

Inhibition of lipid peroxidation by prostaglandin oligomeric derivatives.

The inhibition of lipid peroxidation by oligomeric derivatives synthesized from prostaglandin E1 (PGE1) and PGB2 was studied using two rat models. In an in vitro model, the brain was exposed to decapitation-ischemia, the cortex was removed and homogenized, and the formation of thiobarbituric acid reactive substances (TBAR) was measured after exposing the homogenate to in vitro reoxygenation either in the presence or absence of oligomers. It was found that these oligomers could inhibit lipid peroxidation, and that their activities were higher than that of superoxide dismutase (SOD). In an in vivo administration model, either the oligomer or the vehicle was injected i.p. 30 min before decapitation. The brain was exposed to decapitation-ischemia, the cortex was homogenized and exposed to 'in vitro' reoxygenation, after which TBAR value was determined. Ester-type compounds had a greater activity than free-acid type compounds in inhibiting lipid peroxidation. A possible mechanism of the protective effect of these oligomers in ischemia/reperfusion injury may be to scavenge oxygen free radicals.

Alprostadil↗

PubMed1992

Susceptibilities of bacterial cellulose containing N-acetylglucosamine residues for cellulolytic and chitinolytic enzymes.

Detailed characterization of enzyme susceptibility of bacterial cellulose containing N-acetylglucosamine (GlcNAc) residues (N-AcGBC) which possess high susceptibility for cellulase and lysozyme and slight susceptibility for chitinase was studied. Turbidimetric lysozyme assay of N-AcGBC showed that (i) the susceptibilities of various N-AcGBCs for lysozyme were proportional to GlcNAc content, and (ii) N-AcGBC homogenates were divided into two groups based on the rate of turbidity reduction (not dependent on GlcNAc content). High reactivity of N-AcGBC for lysozyme would arise from fine microfibrils characteristic of bacterial cellulose (BC) and random distribution of GlcNAc residues in N-AcGBC because water soluble oligomers of N-AcGBC produced by lysozymic hydrolysis did not inhibit lysozyme activity; however, the random distribution of GlcNAc seemed to result in the slight susceptibility of N-AcGBC for chitinase. The rate of cellulolytic turbidity reduction of N-AcGBC was slower than that of BC, which arose from the inhibition for binding of cellulase by GlcNAc residues.

Acetobacter↗

PubMed1992

Recombinant fowlpox viruses expressing the glycoprotein B homolog and the pp38 gene of Marek's disease virus.

Two Marek's disease virus (MDV) genes, one homologous to the glycoprotein B gene of herpes simplex virus and encoding the B antigen complex and the other encoding a 38-kDa phosphorylated protein (pp38), were inserted into the fowlpox virus (FPV) genome under the control of poxvirus promoters. Randomly selected nonessential regions of FPV were used for insertion, and the vaccinia virus 7.5 kDa polypeptide gene promoter or a poxvirus synthetic promoter was used for expression of MDV genes. Gene expression in cells infected with these recombinants was highly influenced by the promoter (the synthetic promoter being more effective) but was only slightly influenced by the insertion site and by the transcription direction of the insert relative to the direction of the flanking FPV sequences. Cells infected with an FPV recombinant expressing the MDV gB gene reacted positively with a monoclonal antibody specific to this glycoprotein in an immunofluorescence assay. Immunoprecipitation of infected cell lysates showed three glycoproteins identical to those associated with the B antigen complex of MDV (100, 60, and 49 kDa). Cells infected with a recombinant expressing the pp38 gene reacted positively with an anti-pp38 monoclonal antibody in an immunofluorescence assay. The generated protein was phosphorylated and had a molecular weight similar to that of the native pp38 protein. Sera from chickens immunized with an FPV recombinant expressing the MDV glycoprotein B gene reacted with MDV-infected cells.

Animals↗

PubMed1992

Protection against Marek's disease by a fowlpox virus recombinant expressing the glycoprotein B of Marek's disease virus.

Fowlpox virus (FPV) recombinants expressing the glycoprotein B and the phosphorylated protein (pp38) of the GA strain of Marek's disease virus (MDV) were assayed for their ability to protect chickens against challenge with virulent MDV. The recombinant FPV expressing the glycoprotein B gene elicited neutralizing antibodies against MDV, significantly reduced the level of cell-associated viremia, and, similar to the conventional herpesvirus of turkeys, protected chickens against challenge with the GA strain and the highly virulent RB1B and Md5 strains of MDV. The recombinant FPV expressing the pp38 gene failed to either elicit neutralizing antibodies against MDV or protect the vaccinated chickens against challenge with MDV.

Animals↗

PubMed1992

Multiple point mutation of N-ras and K-ras oncogenes in myelodysplastic syndrome and acute myelogenous leukemia.

We analyzed activating mutations of N-ras and K-ras by the polymerase chain reaction and oligonucleotide hybridization in hematological disorders. Activating mutations of these codons were detected in 4 of 20 cases of myelodysplastic syndrome (MDS) and 15 of 77 cases of acute myelogenous leukemia (AML). Our of 19 cases of MDS and AML who carried active mutations, 7 cases were found to have two or more distinct mutations in activating codons of N-ras and K-ras. Ras mutation was found preferentially in progressive disease such as refractory anemia with excess of blasts (RAEB) of RAEB in transformation (RAEB-t). A relatively high incidence of ras mutation was found in M5 AML (40%). No ras mutations were found in other hematological disorders, such as acute lymphoblastic leukemia and chronic myelogenous-leukemia. The most frequent amino acid substitution was that of an aspartate for glycine at codon 12 of N-ras resulting from G to A mutation (11/35). The survival of AML patients who carried ras mutations showed no significant differences from those without ras mutations calculated by Kaplan-Meier. Seven cases of MDS and 7 cases of AML patients could be investigated at various points during their clinical course. Among these 14 cases, we found 2 interesting cases of MDS. The first case lost multiple clones carrying ras mutations during disease progression, the second case acquired mutation of the ras gene during disease progression. These results suggested that multiple point mutations of ras genes may not be initiating events but may contribute to a clonal evolution of MDS and AML.

Adult↗

PubMed1992

Quantitative analysis of rough endoplasmic reticulum in chondrocytes of articular and tracheal cartilage of rabbits following the systemic administration of hydrocortisone.

The rough endoplasmic reticulum (RER) in chondrocytes was analysed stereologically in articular cartilage of knee joints and in tracheal cartilage of rabbits injected intramuscularly with 5 mg/kg hydrocortisone daily for 4 wk. In articular cartilage, RER area per unit cytoplasmic volume decreased in chondrocytes in all (superficial, middle and deep) zones, although the volume of glycogen deposits per unit cytoplasmic volume increased in the middle and deep zones. RER area per chondrocyte also decreased in the 3 zones without changes in average chondrocyte volume in the superficial and deep zones. Furthermore, the volume of glycogen deposits per chondrocyte did not alter in the 3 zones. These indicate a reduction of RER area in articular chondrocytes after hydrocortisone administration and suggest a decrease in the protein-synthesising capacity of these cells. In tracheal cartilage in which 2 zones were identifiable, RER area per unit cytoplasmic volume decreased in chondrocytes in both the superficial and main zones without changes in the volume of glycogen deposits per unit cytoplasmic volume. In addition, RER area per chondrocyte decreased in the main zone. The results suggest that the decrease in RER area in chondrocytes after corticosteroid administration is not specific to articular cartilage but is common to cartilage in various organs.

Animals↗

PubMed1992

[ESR study of free radical formation during ischemia-reperfusion injury in the rat brain and the protective effect of a new antioxidant].

By using the spin-trapping technique and electron spin resonance spectroscopy (ESR), we detected directly oxygen-derived free radicals in the brain exposed to ischemia and reperfusion. Forebrain ischemia was produced in the rat by bilateral occlusion of the common carotid arteries combined with hemorrhagic hypotension. The whole cerebral cortex was homogenized in the presence of the spin trap agent, N-tert-butyl-alpha-phenylnitrone, followed by a Folch extract. Spin-adducts were detected using ESR. As the index of tissue injury, the lipid peroxidation was estimated from both the amount of thiobarbituric acid reactive substance and the formation of conjugated diene. After 10 or 20 min of ischemia, reperfusion induced a burst of spin adduct formation which peaked at 5 min reperfusion time. The peak value increased with the ischemia time. The degree of lipid peroxidation, which was measured after 20 min of reperfusion, also increased with the ischemia time. When the oligomeric derivative was administered (9 mg . kg-1, i.p.) 30 min before ischemic insult, both spin adduct formation and lipid peroxidation were reduced. The results support the current view that free radicals produced upon reperfusion may be the direct cause of the subsequent lipid peroxidation.

Animals↗

PubMed1992

[Adult T cell leukemia with cytomegalovirus retinitis].

A 49-year old female in the course of chemotherapy for adult T-cell leukemia (ATL) noticed blurred vision and visual field defect in her right eye on February 26, 1991. Ophthalmoscopic findings showed exudative necrotizing retinitis with white exudative patches and scattered retinal hemorrhages in both eyes. CMV was isolated from the urine by the shell vial cell culture assay. Anti-viral therapy was commenced using ganciclovir and gamma-globulin, which are rich in anti-CMV antibodies. The exudative lesions were absorbed gradually. The ocular signs and symptoms agreed with the patient's systemic immunosuppressed T cell function state. CMV retinitis should be considered in the differential diagnosis of retinitis in immunocompromised patients. CMV retinitis will certainly be found more frequently in accordance with the increasing number of immunocompromised hosts who have received immunosuppressive therapy or transplantation.

Cytomegalovirus↗

PubMed1992

[Chronic fatigue syndrome--cases in the Kanebo Memorial Hospital].

In our hospital, 134 patients (28 male, 106 female, 10-82 years of age) were diagnosed as having chronic fatigue syndrome (CFS). Some patients had mild elevation of antibodies against Epstein-Barr Virus and immunologic abnormalities (natural killer cell dysfunction and high rates of skin reactivity to house dust, pollen, drugs and common food). In the patients with immunologic abnormalities, we found decreases in serum concentrations of arachidonic acid and dihomogamma-linolenic acid. A Kampo medicine, Ren-Shen-Yang-Rong-Tang was used in the management of 134 patients and 98 patients returned to work or school.

Adolescent↗

PubMed1992

[Effective continuous hemofiltration and plasma exchange for the treatment of subacute type fulminant hepatic failure].

By combination of continuous hemofiltration (CHF) with plasma exchange therapy we successfully treated a patient with subacute type fulminant hepatitis to keep her consciousness alert. The patient was a 55-year-old woman who admitted because of severe jaundice. On the 51st day after the onset she had consciousness disturbance and was transferred to our hospital. We started the therapy of CHF and plasma exchange at the patient's hepatic coma grade 4. On the 5th day her consciousness level recovered to grade 2 and we could keep the level for almost 2 weeks. This combination therapy seemed good not only for the improvement of consciousness of patients in hepatic coma but also to support the hepatic function of almost ahepatic patients.

Female↗

PubMed1992

[The epidemiology and clinical features of anaphylactic and anaphylactoid reactions in the perioperative period in Japan: a survey with a questionnaire of 529 hospitals approved by Japan Society of Anesthesiology].

In an attempt to review the Japanese epidemiology of the anaphylactic and/or anaphylactoid reactions in the perioperative period, we surveyed 529 hospitals approved by Japan Society of Anesthesiology with a questionnaire about drug-induced immediate adverse reactions. Recovery rate of questionnaires was 15% (80 hospitals in 529 hospitals), and 28 cases of anaphylaxis or anaphylactoid reaction were reported. Most patients were in their teens and twenties. Male were 10, and female were 12 (unknown gender; 6). Reaction occurred during the induction of anesthesia in 28.6% of the patients, and during the maintenance of anesthesia in 67.9%. Seventy-five percent of the patients had no past history of drug-induced allergy nor tendencies of atopy. Most frequent clinical signs were cardiovascular (85.7%) and cutaneous (100%) manifestations. Respiratory signs appeared in 42.9% of the patients. Patients were frequently unconscious and covered with drapes, and there is a potentially danger of masking early signs and symptoms of anaphylaxis. In most of the patients, cardiovascular collapse appeared as the first noticeable sign. Causative drugs were confirmed only immunologically in one patient. In other cases causative drugs were presumed based on clinical courses. Anaphylaxis and anaphylactoid reaction are important causes of morbidity and mortality. The incidence in Japan was 0.01% (1:10,000) and the mortality was 4.76%.

Adolescent↗

PubMed1992

[Adult T-cell leukemia with cervical bone tumor showing immunophenotypic change].

A 60-year-old man born in Miyazaki prefecture was admitted to our hospital complaining of skin rash in December 1989. On hematological examinations, leukocyte count was 14,200/microliters with 49% of abnormal lymphocytes showing lobulated nuclei. The surface marker study revealed their phenotype as CD4+8-. Anti human T cell leukemia virus type I (HTLV-I) antibody and monoclonal integration of proviral DNA were positive. From the above results, he was diagnosed as adult T-cell leukemia (ATL). Abnormal lymphocytes gradually decreased without treatment after the first admission. In January, 1990, he began to complain of neck pain. Two months later he was readmitted because of paresis of extremities and disturbance of urination. Vertebral bone mass and a compressed spinal cord in the 4th cervic level were confirmed by MR imaging. He received a resection of tumor and an anterior fusion of vertebrae. The bone tumor was histologically diagnosed as malignant lymphoma, diffuse medium-size cell type and the infiltrating cells had their phenotype as CD4+8+. He was postoperatively treated with combination chemotherapies, but neurological abnormalities did not improve. He died of pneumonia on 35 days after the operation. A postmortem examination revealed extradural tumor formation with ATL cells. This case is considered to be rare in respect of both the disappearance of most peripheral abnormal lymphocytes without any treatments and the cervical bone tumor showing immunophenotypic change.

CD4 Antigens↗

PubMed1992

[Effects of ulinastatin on endotoxin shock in dogs].

The therapeutic effect of ulinastatin, an inhibitor of the protease activity, on endotoxin shock was evaluated using 17 Beagle dogs. Single intravenous injection of ulinastatin at a dose of 5,000 or 25,000 U.kg-1 failed to suppress the endotoxin-induced circulatory disturbance but significantly inhibited increases in pulmonary arterial pressure and pulmonary vascular resistance that occur early following administration of endotoxin. Elevation of PGI2, TXA2 and LTB4 by endotoxin shock was significantly inhibited by administration of 25,000 U.kg-1 of ulinastatin. Elevation of the granulocytic elastase activity was inhibited dose-dependently by administration of ulinastatin. The above results indicate that ulinastatin may be a promising drug for the treatment of endotoxin shock.

Animals↗

PubMed1992

[Methylprednisolone attenuates desensitization to catecholamine after its long-term infusion].

Methylprednisolone (MP), a prototype of glucocorticoids, was administered to patients with shock, low output syndrome and cardiac failure who had required long-term infusion of dopamine (DOA) and/or dobutamine (DOB), when they showed signs of desensitization to catecholamines (CA). Subjects were 141 patients selected from 37 hospitals. The mean infusion periods were 7.0 days with DOA and 7.5 days with DOB. MP elevated systolic and diastolic blood pressure significantly for 1 to 6 hours, concomitantly with increased urinary output. The results suggest that MP could attenuate down regulation of adrenoreceptors induced by long-term CA infusion.

Adolescent↗

PubMed1992

[Lymphokine-activated killer (LAK) cells and interleukin-2 (IL-2) therapy that improved lymphadenopathy in a patient with B cell non-Hodgkin's lymphoma].

A 70-year-old man was admitted to our hospital on March 9, 1989 because of fever, superficial generalized lymphadenopathy, upper abdominal mass and right pleural effusion. The diagnosis of non-Hodgkin's lymphoma (follicular medium sized cell type, B cell) was made by a biopsy of the neck lymph node. Peripheral blood mononuclear cells were obtained from the patient by cytopheresis. The cells were cultured for 8 days with interleukin-2 (IL-2) to generate Lymphokine-activated killer (LAK) cells. The patient received a total of 7.7 x 10(9) LAK cells intravenously over a period of 3 weeks. He also received continuous intravenous infusion of IL-2 for 17 days, starting 2 days before the first infusion of LAK cells. After this therapy, although his superficial generalized lymphadenopathy disappeared or decreased in size, the size of the upper abdominal mass did not decrease. Therefore, it is suggested that adoptive immunotherapy is a beneficial treatments for B cell lymphoma. However, LAK cells should be generated in much larger quantities for a more successful therapeutic result.

Aged↗

PubMed1991

[MR-angiography of veins in the lower extremities].

Phase contrast MR-angiography (MRA) of veins in the lower extremities was performed in 10 healthy volunteers and 2 patients with deep vein thrombosis of the lower extremities. In all volunteers, MRA demonstrated bilateral large saphenous veins, femoral veins and popliteal veins. Deep veins in the leg were visualized in only 3 out of 20 legs examined, but with compression of the thigh they were visualized in 4 out of 7 legs subjected to compression. In patients with deep vein thrombosis, obstruction of the femoral veins and development of the collateral veins were clearly visualized. It is concluded that MRA may be a valuable technic for the evaluation of the veins patency in the lower extremities.

Humans↗