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Biomedical subjects

K Kitano

Publications and source records attributed to K Kitano.

At least 91 records · Page 5Linked to original sources
PubMed1995

Secretion of active human lysozyme by Acremonium chrysogenum using a Fusarium alkaline protease promoter system.

We constructed expression vectors for Acremonium chrysogenum using a Fusarium alkaline protease promoter region and tested their potential as secretion systems for foreign proteins using the human (h)-lysozyme gene as an indicator. The gene encoding h-lysozyme was linked to the coding region of (1) the carboxy terminal of the alkaline protease pre peptide, (2) the carboxy terminal of the prepro peptide, (3) three amino acids of the mature protein preceded by the prepro peptide and (4) the carboxy terminal of chicken lysozyme signal peptide, inserted into the genomic DNAs of A. chrysogenum and expressed under the control of the alkaline protease promoter. The transformants of A. chrysogenum with each of these plasmids secreted enzymatically active h-lysozyme. A maximum yield in excess of 40 mg l-1 was obtained when h-lysozyme was linked to the carboxy terminal of alkaline protease prepro peptide. The majority of the amino terminal sequence of the purified h-lysozyme from the culture supernatant was identical with that of authentic h-lysozyme, but it showed some heterogeneity.

Acremonium↗
PubMed1995

The largest variant of platelet glycoprotein Ib alpha has four tandem repeats of 13 amino acids in the macroglycopeptide region and a genetic linkage with methionine145.

Platelet membrane glycoprotein Ib alpha (GPIb alpha) bears the human platelet alloantigen (HPA)-2 and molecular weight (MW) polymorphisms on sodium dodecyl sulfate-polyacrylamide gels. HPA-2 arises from a threonine/methionine dimorphism at residue 145 of the GPIb alpha sequence, whereas different numbers of tandem repeats of a 39-bp sequence encoding 13-amino acids corresponding to a region between serine399 and threonine411 of the GPIb alpha account for the latter. To identify the genetic basis of the MW polymorphism among Japanese, we counted the tandem repeats in 103 individuals. In addition to the reported three variants with one, two, or three tandem repeats, we identified a new variant with four perfect tandem repeats of the 39-bp sequence that corresponded to the largest phenotype. Phenotypic analysis of the MW polymorphism on 12 individuals including all four phenotypes completely accorded in the genotype. We also determined the genotype of HPA-2 and found that methionine145 was in complete linkage disequilibrium, with the larger variants containing three or four tandem repeats. These results imply a model of evolutionary steps in the gene encoding GPIb alpha.

Alleles↗
PubMed1995

Novel thiazole derivatives as inhibitors of superoxide production by human neutrophils: synthesis and structure-activity relationships.

Neutrophils have an important role in the self-defense systems of organisms through the production of superoxide. On the other hand, it has been proposed that abnormal amounts of superoxide produced by neutrophils are a serious factor in tissue injury. A series of novel thiazole derivatives was prepared and evaluated inhibitory effect on superoxide production by human neutrophils in vitro. Among these compounds, 6-[2-(3,4-diethoxyphenyl)thiazol-4-yl]-pyridine-2-carboxylic acid (OPC-6535) was selected as one of the most promising compounds. The synthesis and structure-activity relationships of these compounds are reported herein.

Adult↗
PubMed1995

Efficient production of anti-(hepatitis B virus) antibodies and their neutralizing activity in chimpanzees.

For industrial production of human monoclonal antibodies (hmAb) against hepatitis B virus surface antigen (HBsAg), we scaled-up a short-term perfusion culture in serum-free medium, which was chosen as the most suitable culture method, to a 50-1 fermentor equipped with a rotating shear filter. Using hydrophobic chromatography as the initial step of hmAb purification, the mAb HBW4, HBW6 and W471 were isolated in good quality from the respective culture broths in yields of approximately 75%. Each of the three purified hmAb alone, and a cocktail of the three, protected chimpanzees against HB virus, when injected intravenously 3 h after viral challenge, as long as the serum antibody levels were significant. A pharmacokinetic study using cynomolgus monkeys demonstrated that the hmAb have a long plasma half-life and bioavailability of approximately 76% upon intramuscular injection in primates. Thus, anti-HBsAg hmAb produced by an industrial process are expected to be successfully used in clinical fields.

Animals↗
PubMed1995

Production and characterization of monoclonal antibodies against human natriuretic peptide receptor-A or -B.

Monoclonal antibodies (mAbs) against human natriuretic peptide receptor-A (NPR-A) or NPR-B were produced using NPR-expressing Chinese hamster ovary (CHO) cells and soluble chimeric NPRs consisting of the extracellular domain of each receptor fused to Fc region of human IgG. Three anti-NPR-A mAbs, designated as A144, A397 and A416, bound to human NPR-A but not to NPR-B, while an anti-NPR-B mAb B136 reacted with human NPR-B but not with NPR-A. Competition analysis with the anti-NPR-A mAbs revealed that two mAbs, A144 and A416, recognize an identical or the adjacent site of the receptor and that A397 is directed against another epitope. No anti-NPR-A mAb affected binding of atrial natriuretic peptide (ANP) to NPR-A, while the anti-NPR-B mAb B136 inhibited binding of C-type natriuretic peptide (CNP) to NPR-B. Inhibition of the ligand-binding by B136 is specific in that the mAb showed no effect on the binding of ANP to NPR-A. B136 also blocked CNP-mediated intracellular cGMP accumulation in NPR-B-expressing cells. These results suggest that the region recognized by B136 may be related to the ligand-binding region of NPR-B. NPR-A- and NPR-B-expressing cells were selectively detected by immunostaining using the mAbs. These findings demonstrate that the mAbs will be useful to elucidate the role of the natriuretic peptides and their receptors in normal and disease states in humans [correction of human].

Animals↗
PubMed1995

The detection of clonal proliferation in granular lymphocyte-proliferative disorders of natural killer cell lineage.

The clonal proliferation of large granular lymphocytes can be detected in patients with T-cell-lineage granular lymphocyte-proliferative disorders (T-GLPD) by Southern blotting T-cell receptor genes. However, this cannot be applied to patients with natural killer-cell-lineage GLPD (NK-GLPD) as it lacks a clonal marker. We therefore investigated the use of two other diagnostic techniques in evaluating clonal proliferation in Japanese patients with NK-GLPD (n = 4) and T-GLPD (n = 3) by chromosomal analysis of peripheral blood mononuclear cells (PBMC) stimulated with either interleukin-2 or phytohaemagglutinin, and Epstein-Barr viral (EBV) genomic DNA analysis. Chromosomal analysis revealed abnormal karyotypes in the PBMC of three of four patients with NK-GLPD, whereas EBV analysis showed a monoclonal terminal configuration in the PBMC in the fourth patient. Southern blots revealed rearrangements of the TCR genes in all three patients with T-GLPD but in none of those with NK-GLPD. It is suggested that these methods may be useful in detecting the abnormal proliferation of large granular lymphocytes in NK-GLPD.

Adult↗
PubMed1995

Sequence analysis of a gene cluster involved in metabolism of 2,4,5-trichlorophenoxyacetic acid by Burkholderia cepacia AC1100.

Burkholderia cepacia AC1100 utilizes 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) as a sole source of carbon and energy. PT88 is a chromosomal deletion mutant of B. cepacia AC1100 and is unable to grow on 2,4,5-T. The nucleotide sequence of a 5.5-kb chromosomal fragment from B. cepacia AC1100 which complemented PT88 for growth on 2,4,5-T was determined. The sequence revealed the presence of six open reading frames, designated ORF1 to ORF6. Five polypeptides were produced when this DNA region was under control of the T7 promoter in Escherichia coli; however, no polypeptide was produced from the fourth open reading frame, ORF4. Homology searches of protein sequence databases were performed to determine if the proteins involved in 2,4,5-T metabolism were similar to other biodegradative enzymes. In addition, complementation studies were used to determine which genes were essential for the metabolism of 2,4,5-T. The first gene of the cluster, ORF1, encoded a 37-kDa polypeptide which was essential for complementation of PT88 and showed significant homology to putative trans-chlorodienelactone isomerases. The next gene, ORF2, was necessary for complementation and encoded a 47-kDa protein which showed homology to glutathione reductases. ORF3 was not essential for complementation; however, both the 23-kDa protein encoded by ORF3 and the predicted amino acid sequence of ORF4 showed homology to glutathione S-transferases. ORF5, which encoded an 11-kDa polypeptide, was essential for growth on 2,4,5-T, but the amino acid sequence did not show homology to those of any known proteins. The last gene of the cluster, ORF6, was necessary for complementation of PT88, and the 32-kDa protein encoded by this gene showed homology to catechol and chlorocatechol-1,2-dioxygenases.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1995

Overexpression of the PRAD1 oncogene in a patient with multiple myeloma and t(11;14)(q13;q32).

The t(11;14)(q13;q32) chromosomal translocation is associated with several B-cell lymphoproliferative disorders and is thought to result in upregulation of expression of PRAD1/cyclin D1 proto-oncogene. A patient with multiple myeloma of IgG kappa-type with t(11;14)(q13;q32) is now shown to overexpress PRAD1. The clinical stage of the disease was advanced (IIIA), with a myeloma cell count of 94.6% in the bone marrow. Chromosomal analysis of bone marrow cells showed t(11;14)(q13;q32) in five of 20 metaphases as well as other karyotypic features. Northern blot analysis of RNA prepared from myeloma cells revealed overexpression of PRAD1. Multiple myeloma with t(11;14)(q13;q32) has been associated with an aggressive clinical course. Although neither myeloma cells in the peripheral blood nor extramedullary lesions were apparent in the present patient, the myeloma was refractory to several chemotherapeutic regimens from the beginning. Detection of PRAD1 expression may offer an easier alternative to cytogenetic analysis in myeloma and is a potentially useful indicator of a poor prognosis.

Blotting, Northern↗
PubMed1995

Decay-accelerating-factor-deficient erythrocytes during the long-term clinical course of patients with paroxysmal nocturnal hemoglobinuria.

We performed long-term follow-up studies of 5 patients with paroxysmal nocturnal hemoglobinuria (PNH). The percentages of decay-accelerating-factor (DAF)-deficient erythrocytes were almost stable or slowly increased during the 2-4 years' observation periods when the effects of treatment with drugs or blood transfusion and pregnancy were excluded. However, a tendency of increase in the percentages of DAF-deficient erythrocytes was observed along with the duration of the disease. Our findings suggest that the growth advantage of PNH clones beyond the normal hematopoiesis may be different from the other clonal stem cell disorders.

Adult↗
PubMed1995

Non-toxic concentrations of cephem antibiotics for intravitreal application--evaluation by in vitro electroretinogram.

Non-toxic concentrations of ceftazidime (CAZ), cefuzonam sodium (CZON) and cefmetazole sodium (CMZ) for intravitreal use were assessed by the electroretinogram in in vitro perfused eyecups of albino rabbits. None of the a-wave, the b-wave and the oscillatory potentials deteriorated with 300 microM CAZ, 300 microM CZON or 500 microM CMZ. The oscillatory potentials were delayed and/or diminished at the concentration which did not change the a- and b-waves (500 microM and 1.0 mM for CAZ and CZON, 1.0 mM for CMZ). Thus, the oscillatory potentials were more vulnerable to these chemicals than the a- and b-waves. Not only the classical a- and b-waves, but also the oscillatory potentials should be examined in retinal toxicology studies by the electroretinogram.

Animals↗
PubMed1995

[Aplastic anemia complicated with secondary hemochromatosis after allogenic bone marrow transplantation].

We report a case of aplastic anemia complicated with secondary hemochromatosis after allogenic bone marrow transplantation (BMT). A 29-year-old man was diagnosed as having aplastic anemia at the age of 8. At the age of 28, BMT was performed from his HLA-identical sister. Total volume of blood transfusion before BMT was about 28,000 ml, and in three months after BMT was 8,000 ml. The transplantation was successful, but one month after BMT, dry eyes, skin pigmentation and hepatomegaly appeared. Serum bile duct enzymes and ferritin also increased remarkably. Moreover after thirteen months, glucose tolerance impaired seriously. Abdominal computed tomography (CT) revealed atrophic pancreas and an increased CT density in the liver and the tail of the pancreas. A large amount of iron deposition were also found in liver and stomach biopsy specimens. We concluded that diabetes mellitus was due to secondary hemochtomatosis in the present case. There is a possibility that tissue damage due to iron deposits may have been accelerated through BMT in this patient with a history of many blood transfusions.

Adult↗
PubMed1994

Erythrocytosis complicated by multiple paraganglioma.

We report the case of a 22-year-old woman with onset of erythrocytosis at the age of 9 years. Endocrinological and radiological examinations revealed an elevated catecholamine level and the presence of multiple abdominal tumors. After the removal of the tumors, the catecholamine level normalized, whereas erythropoietin remained at the same level and erythrocytosis persisted. The tumor lysate contained considerable amounts of catecholamine but not erythropoietin. Moreover, no erythropoietin mRNA was detected in the tumor by in situ hybridization. These data suggest that this paraganglioma did not produce erythropoietin. A review of the literature showed the existence of patients with early-onset erythrocytosis complicated with paraganglioma, whose erythrocytosis was not relieved even after the resection of paraganglioma.

Abdominal Neoplasms↗
PubMed1994

Primary cutaneous plasmacytosis: report of three cases and review of the literature.

BACKGROUND: Cutaneous plasmacytosis is a rare disease characterized by peculiar multiple eruptions and hypergammaglobulinemia. More than 40 cases have been reported, mainly in Japan, although information concerning the disorder was limited to individual case reports. OBJECTIVE AND METHODS: To clarify the clinicopathological and laboratory features, we reviewed 41 cases. RESULTS: All patients were Japanese and the male-to-female ratio was 1:0.6. The onset ages ranged from 20 to 62 years, with a mean and median of 37 and 37 years. A superficial lymphadenopathy was detected in 58% (22/38), and polyclonal hypergammaglobulinemia was found in 93% (38/41). No cases were associated with any apparent underlying diseases. The course was chronic without spontaneous remission. Four patients died, 3 of whom succumbed to leukemia, respiratory failure or renal failure, respectively. CONCLUSION: The results suggest that the condition appears to be a variant of reactive plasmacytic disorders of unknown origin.

Adult↗
PubMed1994

Cloning and nucleotide sequence of the alkaline protease gene from Fusarium sp. S-19-5 and expression in Saccharomyces cerevisiae.

We have cloned a genomic DNA encoding the alkaline protease (Alp) of Fusarium sp. S-19-5 from a genomic DNA library and sequenced the nucleotides. Complementary DNA encoding Alp was also isolated from the cDNA library after amplifying the gene by PCR using partial sequences of the Alp genomic DNA as primers. The Alp gene has an open reading frame of 1137 nucleotides containing three introns. A TATA box (TAAATA) was observed 112 base pairs upstream from the translation initiation codon in the 5'-non coding region. The Alp protein has a pre region consisting of 14 amino acids and a pro region of 85 amino acids preceding the mature region, which consists of 280 amino acids. The amino acid sequence of Fusarium Alp has 52% homology with that of Aspergillus oryzae and 51% homology with that of Acremonium chrysogenum. The entire cDNA encoding Fusarium Alp was introduced into Saccharomyces cerevisiae, which then secreted enzymatically active Alp into the culture medium.

Acremonium↗
PubMed1994

High level expression of Fusarium alkaline protease gene in Acremonium chrysogenum.

We transformed Acremonium chrysogenum with the genomic DNA of the alkaline protease (Alp) from Fusarium sp. S-19-5 including its promoter. Most of the transformants thus obtained produced a large amount of Alp. PCR and Southern hybridization analysis of genomic DNAs from these transformants showed chromosomal integration of the full-length Alp gene. SDS-PAGE analysis of the supernatant from the transformants showed the presence of Fusarium Alp. The amino terminus of the Alp produced in A. chrysogenum was identical to that of native Fusarium Alp. These results indicate that the Alp promoter, signal sequence, and introns functioned correctly in A. chrysogenum. One of the transformants produced more than 4 g of the Alp per liter in a jar fermentor.

Acremonium↗
PubMed1994

Acquired amegakaryocytic thrombocytopenic purpura with humoral inhibitory factor for megakaryocyte colony formation.

A 67-year-old man with thrombocytopenia, and amegakaryocytic but otherwise normal bone marrow, was evaluated. Antibody against thrombocytes was negative and the half-life of thrombocytes was normal. In vitro clonal culture of the patient's bone marrow cells yielded no megakaryocyte colony with normal granulocyte-macrophage and erythroid colony formation. Megakaryocyte colony formation of the control bone marrow cells was significantly suppressed by the addition of the patient's serum to the culture, suggesting the existence of humoral inhibitory factor(s) for megakaryocyte colony formation. Therapeutic trials with plasma exchange, cyclosporine, prednisolone, and cyclosporine plus prednisolone were all unsuccessful, but serious bleeding has been absent.

Aged↗
PubMed1994

[Conservative therapy for retinoblastoma--effect of melphalan on in vitro electroretinogram].

The effect of melphalan (an alkylic anti-cancer drug) on rabbit and human in vitro ERGs was studied to establish the non-toxic concentration of melphalan in chemo-thermotherapy for retinoblastoma. The ERGs were recorded before and 15 min after the perfusate was changed from the control solution to a melphalan-containing solution. Melphalan 10 micrograms/ml and 40 micrograms/ml caused no significant effect on the a-wave, the b-wave, or the oscillatory potential in either the rabbit or the human in vitro ERG. Melphalan 50 micrograms/ml significantly reduced the b-wave, but the change was reversible. Considering the minimum inhibitory concentration of melphalan against retinoblastoma cells on colony assay (4 micrograms/ml), melphalan is one of the most effective drugs for the conservative treatment of retinoblastoma.

Animals↗