PubMed Health⌕ Search

Biomedical subjects

M Masuda

Publications and source records attributed to M Masuda.

At least 19 recordsLinked to original sources
PubMed1992

A novel anti-HIV synthetic peptide, T-22 ([Tyr5,12,Lys7]-polyphemusin II).

Tachyplesin and polyphemusin are antimicrobial peptides recently isolated from the hemocytes of horseshoe crabs (Tachypleus tridentatus and Limulus polyphemus). We synthesized them and their analogs and examined their antiviral activity against human immunodeficiency virus (HIV) type 1 in vitro. The infection of human T cells with the virus was markedly inhibited by some of them at low concentrations. In this structure-activity study, we found that [Tyr5,12, Lys7]-polyphemusin II, which was designated as T22, had extremely high anti-HIV activity. Its 50% inhibitory concentration (EC50) was 0.008 micrograms/ml, while its 50% cytotoxic concentration (CC50) was 54 micrograms/ml and these values were comparable to those of AZT. This result indicates that T22 would be a potential candidate for the therapy of HIV infection.

Amino Acid Sequence↗
PubMed1992

Successful pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension associated with anticardiolipin antibodies: report of a case.

Chronic pulmonary thromboembolism with pulmonary hypertension is a rare but most unique syndrome in the broad spectrum of pulmonary embolism. This report describes a successful pulmonary thromboendarterectomy performed for a totally occluded right pulmonary artery on a 43 year old man who presented with positive cardiolipin antibodies. The surgery was performed through a median sternotomy with cardiopulmonary bypass and intermittent periods of deep hypothermic circulatory arrest. We are convinced that this method allows for complete removal of the thrombotic obstruction and should be the procedure of choice for patients with very proximal obstruction of a pulmonary artery.

Adult↗
PubMed1992

Improvement of nitrogen supply for L-threonine production by a recombinant strain of Serratia marcescens.

Serratia marcescens T-2000 was previously reported to be an L-threonine-producing strain that harbors the recombinant plasmid carrying the mutant-type threonine operon. This strain produced 55 g of L-threonine/L of the medium containing urea as a nitrogen source after 72 h of cultivation. In the urea-containing medium, transitory stop of the growth was observed during the early period of cultivation when the entire amount of ammonium ion formed from urea via heat decomposition disappeared in the medium. This indicated that the shortage of ammonium supply in cells might delay both the cell growth and the L-threonine production. The use of ammonia water as a nitrogen source for L-threonine production was therefore studied, because microbial cells generally assimilate this source more readily than urea. When ammonia water was automatically fed to the medium so as to maintain the pH of the medium at around 7, the growth was accelerated, and the L-threonine production reached a maximum of 65 g/L at 48 h. Under these conditions, sucrose, a carbon source, was continuously fed to the medium, resulting in the production of 100 g of L-threonine/L at 96 h. Thus, the L-threonine production of the recombinant L-threonine-producing strain could be increased by devising the method for supply of a nitrogen source.

Ammonia↗
PubMed1992

A case of transfusion-associated graft-versus-host disease not prevented by white cell-reduction filters.

A case of transfusion-associated graft-versus-host disease (TA-GVHD) in a patient with non-Hodgkin's lymphoma is reported. The patient, a 67-year-old woman, was diagnosed as having diffuse, mixed type non-Hodgkin's lymphoma, at clinical stage IIIA. She was treated with combination chemotherapy and received multiple blood transfusions for anemia and thrombocytopenia. Although white cells (WBCs) were reduced in the transfused components by WBC-reduction filters, the patient developed TA-GVHD that was confirmed by skin biopsy. It is suggested that the WBC reduction attained with these filters does not prevent TA-GVHD in immunocompromised patients. It is recommended that all blood components should be irradiated before transfusion to such patients.

Aged↗
PubMed1992

An antigenic structure of the trans-activator protein encoded by human T-cell leukemia virus type-I (HTLV-I), as defined by a panel of monoclonal antibodies.

In order to study an antigenic structure of the trans-activator protein encoded by human T-cell leukemia virus type-I (HTLV-I), tax1 antigen, we generated and characterized a panel of rat anti-tax1 monoclonal antibodies (MAbs) designated WATM-1, WATM-2, WATM-3, and WATM-4. These MAbs were derived from WKA rats immunized with HTLV-I-transformed (HTLV-I+) syngeneic T cells. Immunoblot assays showed that: (1) All the MAbs reacted with the tax1 antigen in HTLV-I+ cell lines and a recombinant tax1 antigen, PX141 (containing entire tax1 polypeptide); (2) WATM-3 and WATM-4, but not WATM-1 or WATM-2, reacted with a truncated tax1 antigen, XD59 (tax1 amino acids 180-338); (3) None of them reacted with another truncated tax1 antigen, XD128 (tax1 amino acids 1-47 and 286-353); and (4) each of the four MAbs had different reactivity with tax1-related antigens in the range 38-41 kDa expressed in simian cell lines infected with various HTLV-I-related simian retroviruses (STLV-I). None of the MAbs reacted with HTLV-II tax antigen. Human sera containing anti-tax1 antibodies interfered specifically with the antigen-specific binding of all the MAbs. These results suggest that the present rat MAbs are directed against various epitopes on the tax1 antigen. An antigenic structure of the tax1 antigen deduced from reactivity of a panel of anti-tax1 MAbs including the present rat MAbs is discussed.

Animals↗
PubMed1992

Bactericidal activities of rat defensins and synthetic rabbit defensins on Staphylococci, Klebsiella pneumoniae (Chedid, 277, and 8N3), Pseudomonas aeruginosa (mucoid and nonmucoid strains), Salmonella typhimurium (Ra, Rc, Rd, and Re of LPS mutants) and Escherichia coli.

Rat defensins were purified and tested for in vitro bactericidal assay against gram-positive and gram-negative bacteria. Staphylococcus aureus (209P, Cowan I, Smith diffuse and Smith compact) were resistant to defensins, whereas Staphylococcus epidermidis, Staphylococcus saprophyticus, Micrococcus lysodeikticus and Bacillus subtilis were less sensitive. Gram-negative bacteria, such as Pseudomonas aeruginosa (mucoid and K) and Klebsiella pneumoniae (Chedid, 277, and 8N3 which were heavily capsulated, moderately capsulated and noncapsulated, respectively) were all very sensitive to defensins and killed within 20 min. Escherichia coli was moderately sensitive and the rough mutants of lipopolysaccharide (LPS) of Salmonella typhimurium LT2, such as Ra, Rc, Rd, and Re were equally sensitive to defensins, being killed within 40 min. Lysozyme did not show any bactericidal activity except against M. lysodeikticus and B. subtilis, whereas it enhanced the bactericidal activity of defensins against P. aeruginosa, E. coli, and K. pneumoniae and suppressed the killing activity of defensins against S. typhimurium and S. aureus. With regard to the three synthetic rabbit defensins, NP1, NP4, and NP5, NP1 showed strong bactericidal activity against K. pneumoniae 277, comparable to that of rat defensins. Neither NP4 nor NP5 showed any bactericidal activity, while NP5 rather enhanced the bactericidal activity of NP1 against K. pneumoniae 277.

Animals↗
PubMed1992

Expression of 85-kDa protein of adriamycin-resistant tumor cells during hematopoietic differentiation of THP-1 and HEL cells.

An 85-kDa protein was identified in adriamycin-resistant tumor cells recognized by monoclonal antibody MRK-20. Recently, the monoclonal antibody MRK-20 was found to be reactive to human peripheral mononuclear cells. In order to investigate the molecular function of the 85-kDa protein, we carried out flow cytometric analysis of the expression of the 85-kDa protein during monocytic differentiation of the hematopoietic cells. Human myelomonocytic leukemia THP-1 cells were induced to differentiate into macrophage-like cells by treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA). A maximum of 55% of the cells expressed the 85-kDa protein along with the CD-14 antigen, which is a surface marker of monocytes and macrophages. The kinetic analysis revealed that the 85-kDa protein appeared prior to the expression of the CD-14 antigen. The 85-kDa protein was also coexpressed with CD-14 in THP-1 cells that were induced to differentiate by recombinant tumor necrosis factor-alpha, which is one of the physiological inducers of monocytic differentiation. In human erythroleukemia, HEL cells, the 85-kDa protein was constitutively coexpressed with CD-14. The expression of both the 85-kDa protein and CD-14 was drastically reduced during the megakaryocytic differentiation of the HEL cells with TPA. These results suggest that the 85-kDa protein could be expressed on monocytic cells as well as CD-14 and that the expression of the 85-kDa protein might be regulated at an earlier stage of monocytic differentiation of hematopoietic cells than the expression of CD-14.

Antigens, CD↗
PubMed1992

Mutations of the p53 tumour suppressor gene in haematologic neoplasms.

Mutations of the p53 tumour suppressor gene have frequently been observed in several types of solid tumours and are believed to be implicated in the development of these tumours. To determine the relevance of p53 mutations in haematologic neoplasms, we performed polymerase chain reaction-single strand conformation polymorphism analysis on the p53 gene in 45 patients with various types of haematologic neoplasms. In exons 5-8 containing highly conserved regions, mobility shifts indicating sequence alterations were detected in four of the 45 patients, and subsequent sequencing was performed. A point mutation resulting in a novel stop codon was detected at codon 213 in one of 23 cases of chronic myelogenous leukaemia (one of five cases of blast crisis). Point mutations causing amino acid substitutions were detected in one of four cases of myelodysplastic syndrome at codon 195, one of three cases of adult T-cell leukaemia at codon 281, and one of eight cases of acute lymphoblastic leukaemia at codon 281, and these missense mutations were accompanied by loss of the wild type allele. Patients harbouring these nonsense and missense mutations were in advanced disease stages. These findings suggest that mutational inactivation of the p53 gene is infrequent but is involved in the tumorigenesis of several types of haematologic neoplasms at least in some cases.

Amino Acid Sequence↗
PubMed1992

Immune responses and serum levels of cytokines in adult T-cell leukemia patients and human T-cell leukemia virus type-I carriers.

To find predictive parameters for development and progression of adult T-cell leukemia (ATL) in human T-cell leukemia virus type-I (HTLV-I) carriers, we investigated cellular immune responses such as mitogenic responses and natural killer activity of the peripheral blood mononuclear cells (PBMC). And serum or plasma levels of cytokines, including tumor-necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and immunosuppressive acidic protein (IAP), were also measured in patients with ATL, healthy HTLV-I carriers and healthy HTLV-I non-carriers as controls. Results are as follows: (1) increased spontaneous proliferation and decreased mitogenic responses of PBMC already existed in HTLV-I carriers; (2) IAP was significantly higher in patients with acute/lymphoma type ATL than in those with chronic/smoldering type, HTLV-I carriers and HTLV-I non-carriers. These results suggest that spontaneous proliferation or mitogenic responses and IAP may be useful parameters for the development and progression of ATL from the carriers. Since HTLV-I carriers already have various grades of immunosuppression, we should seriously try to prevent further HTLV-I transmission.

Carrier State↗
PubMed1992

[Plasma beta-glucan levels in deep fungal infections accompanying hematological diseases and clinical efficacy of miconazole--a multi-institutional study].

Miconazole (400-1200 mg/day) was administered to patients with deep mycosis and suspected deep mycosis, and the efficacy evaluated. beta-Glucan was determined as the early diagnostic parameter of deep mycosis, and the relationships between the clinical efficacy of miconazole and the titers of beta-glucan were also evaluated. Forty-nine cases were evaluated, including 2 cases of deep mycosis and 47 cases of suspected deep mycosis. Most of the patients had hematological malignancies. The rate of efficacy was 100% (2/2) in deep mycosis, 66.0% (31/47) in suspected deep mycosis, and 67.3% (33/49) in total. beta-Glucan was determined in 39 cases before the administration of miconazole. The rate of beta-glucan positivity was 100% (1/1) in deep mycosis and 44.7% (17/38) in suspected deep mycosis. beta-Glucan was also determined before and after the administration of miconazole in 11 cases. The titers of beta-glucan became negative in 6 cases, decreased in 2 cases and increased in 3 cases. Thus, the beta-glucan titers became negative or decreased in 72.7% (8/11) of the cases. Efficacy of miconazole was 83.3% (5/6) in the cases in which beta-glucan became negative, 50.0% (1/2) in the cases in which the titers of beta-glucan decreased, and 33.3% (1/3) in the cases in which the titers of beta-glucan increased. Miconazole was effective in the treatment of deep mycosis, and the titers of beta-glucan correlated well with the clinical efficacy of miconazole. The determination of beta-glucan appears to be useful for the diagnosis of deep mycosis.

Adolescent↗
PubMed1992

[A case of tracho-bronchial aspergillosis complicated with acute myeloblastic leukemia].

A 59-year-old male was admitted to our hospital in Jan. 1991 with complaints of general malaise and palpitation. Laboratory findings on admission showed anemia, thrombocytopenia and leukopenia consisted of 2.0% myeloblasts with Auerbodies. The bone marrow study showed granuloid hyperplasia with 45.5% myeloblasts. The diagnosis of acute myeloblastic leukemia (M1) was made. After BHAC-AMP therapy, he obtained complete remission. However, he complained of fever and cough, and his chest X ray film showed a focal infiltrative shadow in the right upper lung field. Antibiotics for bacteria and fungus were administered and the abnormal shadow improved in a week. However, as he had hemosputum, the bronchoscopic examination was performed, and multiple ulcers covered by yellow-white tissue were revealed on the wall of the trachea and bilateral main bronchi. Biopsy specimens obtained by transbronchial biopsy showed bronchial aspergillosis. Though intravenous infusion and inhalation of amphotericin B were effective for aspergillosis, he had a relapse of the leukemia and died in autumn, 1991.

Aspergillosis↗
PubMed1992

Anti-human immunodeficiency virus activity of a novel synthetic peptide, T22 ([Tyr-5,12, Lys-7]polyphemusin II): a possible inhibitor of virus-cell fusion.

More than 40 peptides associated with tachyplesin and polyphemusin, which are highly abundant in hemocyte debris of the horseshoe crabs Tachypleus tridentatus and Limulus polyphemus, were synthesized. Among these peptides, we found that a novel compound, which was called T22 ([Tyr-5,12, Lys-7]polyphemusin II), strongly inhibited the human immunodeficiency virus type 1 (HIV-1)-induced cytopathic effect and viral antigen expression. Its 50% effective concentration was 0.008 micrograms/ml, while its 50% cytotoxic concentration was 54 micrograms/ml. The anti-HIV activity of T22 was observed with several strains of HIV-1, including zidovudine-resistant strains, and with HIV-2 within the concentration range of 0.006 to 0.071 microgram/ml. T22 efficiently inhibited giant cell formation on the cocultivation of MOLT-4/HIV and MOLT-4 cells but modestly inhibited direct HIV binding. T22 did not inhibit reverse transcriptase activity. A time-of-addition study, which involved monitoring of the appearance of proviral DNA by using the polymerase chain reaction technique, found that T22 exerted its effect on a process, most probably virus-cell fusion or uncoating, immediately after virus adsorption.

Amino Acid Sequence↗
PubMed1992

Molecular characterization of a neuropathogenic and nonerythroleukemogenic variant of Friend murine leukemia virus PVC-211.

PVC-211 murine leukemia virus (MuLV) is a replication-competent, ecotropic type C retrovirus that was isolated after passage of the Friend virus complex through F344 rats. Unlike viruses in the Friend virus complex, it does not cause erythroleukemia but causes a rapidly progressive hind limb paralysis when injected into newborn rats and mice. We have isolated an infectious DNA clone (clone 3d) of this virus which causes neurological disease in animals as efficiently as parental PVC-211 MuLV. The restriction map of clone 3d is very similar to that of the nonneuropathogenic, erythroleukemogenic Friend murine leukemia virus (F-MuLV), suggesting that PVC-211 MuLV is a variant of F-MuLV and that no major structural alteration was involved in its derivation. Studies with chimeric viruses between PVC-211 MuLV clone 3d and wild-type F-MuLV clone 57 indicate that at least one determinant for neuropathogenicity resides in the 2.1-kb XbaI-ClaI fragment containing the gp70 coding region of PVC-211 MuLV. Compared with nonneuropathogenic ecotropic MuLVs, the env gene of PVC-211 MuLV encodes four unique amino acids in the gp70 protein. Nucleotide sequence analysis also revealed a deletion in the U3 region of the long terminal repeat (LTR) of PVC-211 MuLV clone 3d compared with F-MuLV clone 57. In contrast to the env gene of PVC-211 MuLV, particular sequences within the U3 region of the viral LTR do not appear to be required for neuropathogenicity. However, the changes in the LTR of PVC-211 MuLV may be responsible for the failure of this virus to cause erythroleukemia, because chimeric viruses containing the U3 region of F-MuLV clone 57 were erythroleukemogenic whereas those with the U3 of PVC-211 MuLV clone 3d were not.

3T3 Cells↗
PubMed1992

[A case of foreign body granuloma due to aspiration of a twig of Cryptomeria].

A 65-year-old man was admitted to Oita Medical School Hospital with complaints of hemoptysis and left anterior chest pain. Chest X-ray film showed a nodular shadow, about 1 cm in diameter, in the left S8 area. A specimen obtained by transbronchial biopsy showed no malignant findings. However, left lower lobectomy was performed because of the possibility of malignancy. The resected specimen contained a twig of cryptomeria within dark-red lung tissue. Histologically, the foreign body granuloma was surrounding a vegetable fiber. We had no information of an episode of pruning a cryptomeria and aspiration of a twig before the operation. Cryptomeria is an extremely rare bronchopulmonary foreign body, and the present case suggests that bronchopulmonary foreign body granuloma is an important disease in the differential diagnosis of pulmonary nodules.

Aged↗
PubMed1992

[Clinical significance of rheumatoid factor--its complement activating property and isotype].

We investigated the relationship between complement-activating properties of rheumatoid factors (RF) and their isotypes. Active and inactive RA patients without extra-articular symptoms (EAS) and those with EAS were studied. Patients with SLE, liver cirrhosis (LC) and normal volunteers were served as controls. Isotype of RF was measured by ELISA and complement activation (CA) of RF was measured by hemolytic assay. The CA values were significantly higher in RA patients with EAS than those in RA patients without EAS and with other diseases. The IgG and IgM-RF values were significantly higher in active RA without EAS than in inactive RA. Positive correlations between IgM-RF values and CA values were observed in RA with or without EAS, SLE and LC. The Sephadex G-200 gel filtration analysis of sera revealed CA in only 19S IgM fraction. Additionally, we purified 19S IgM-RF from sera of RA, SLE and LC patients by affinity chromatography, and found 19S IgM-RF had CA. These data suggest that serum IgM-RF may play a critical role in the pathogenesis of RA, especially in RA with EAS.

Arthritis, Rheumatoid↗