Biomedical subjects

Kiyoshi Ito

Publications and source records attributed to Kiyoshi Ito.

At least 73 records · Page 4Linked to original sources

PubMed2003

Characterization of an alpha-ketoglutarate-resistant sake yeast mutant with high organic acid productivity.

A yeast with high organic acid productivity was isolated from alpha-ketoglutarate-resistant mutants obtained by mutagenizing a sake yeast, Kyokai no. 701 (K-701). The new strain, 20G-R39, produces about twice as much malate and succinate as the parental strain. DNA microarray analyses revealed that the transcriptional levels of genes involved in the TCA cycle, oxidative phosphorylation, and respiration were higher in strain 20G-R39 than in strain K-701. Expression of these genes is regulated by the Hap2/3/4/5p complex, and especially by expression of the HAP4 gene. In a Northern blot analysis, the transcriptional level of the HAP4 gene was higher in strain 20G-R39 than in strain K-701. We constructed a plasmid that expresses the HAP4 gene constitutively and introduced it into strain K-701. The HAP4-overexpression-strain produced more malate and succinate than strain K-701 both in YPD medium and in a sake brewing test. These results indicate that strain 20G-R39 produces more organic acids than strain K-701 because strain 20G-R39 has a higher level of expression of the HAP4 gene than strain K-701.

Journal Article↗

PubMed2003

The correlation between the response to progestogen treatment and the expression of progesterone receptor B and 17beta-hydroxysteroid dehydrogenase type 2 in human endometrial carcinoma.

OBJECTIVE: In situ metabolism and synthesis of oestrogens are considered to play important roles in the pathogenesis and development of human endometrial endometrioid adenocarcinoma. Approximately 3-5% of patients with these neoplasms are under age 40, some of whom have been treated with progestogen alone as a primary therapy for both atypical endometrial hyperplasia and adenocarcinoma in order to preserve their fertility. Medroxyprogesterone acetate (MPA) has been used extensively in the treatment of both breast and endometrial disorders as an endocrine therapy. However, details of the alterations of in situ oestrogen metabolism following progestogen treatment have yet to be fully elucidated. DESIGN, PATIENTS AND MEASUREMENTS: In this study we examined the immunolocalization of 17beta-hydroxysteroid dehydrogenase (17beta-HSD) types 1 and 2, oestrogen receptor (ER), progesterone receptor (PR)A + PRB, PRB, and Ki67 in progestogen-treated endometrial endometrioid adenocarcinoma (16 cases). We compared our findings both prior to and following treatment. These findings were then correlated with the treatment outcome of individual patients in order to elucidate factors associated with the response to treatment. RESULTS: 17beta-HSD type 2 immunoreactivity was detected in 8/16 cases examined, whereas 17beta-HSD type 1 immunoreactivity was undetected in all cases examined. 17beta-HSD type 2 positive immunostaining, PRA + PRB labelling index (LI), and PRB/PRA + PRB ratio were all significantly higher in cases responding to the treatment than in those not responding. There were no significant correlations between responsive and nonresponsive cases for positive 17beta-HSD type 1 immunostaining, Ki67 LI, ER LI and age. There were no significant differences in the positive immunostaining for 17beta-HSD types 1 and 2, Ki67 LI, ER LI, PRA + PRB LI, age and PRB/PRA + PRB ratio between specimens taken prior to and following progestogen treatment. CONCLUSION: These results suggest that in situ abundance of 17beta-HSD type 2 and PR, especially PRB, can predict the possible response of patients with endometrial carcinoma to progestogen treatment.

17-Hydroxysteroid Dehydrogenases↗

PubMed2003

Carboplatin-based chemotherapy in patients with gynecological malignancies on long-term hemodialysis.

We report on three cases of long-term dialysis patients with gynecological malignancies who were successfully treated with chemotherapy. Two epithelial ovarian carcinoma patients were treated with a single agent, carboplatin (100-200 mg/m2). One recurrent endometrial carcinoma patient was treated with carboplatin (200 mg/m2) and paclitaxel (135 mg/m2). Hemodialysis was started 2 h after the carboplatin infusion and lasted 4 h in all three cases. All patients tolerated these therapies without significant myelosuppression or severe side-effects. Our findings suggest these regimens are feasible, and the combination of paclitaxel and carboplatin is effective chemotherapy when administered to long-term hemodialysis patients with recurrent endometrial carcinoma.

Adult↗

PubMed2003

Immunolocalization of nuclear transcription factors, DAX-1 and COUP-TF II, in the normal human ovary: correlation with adrenal 4 binding protein/steroidogenic factor-1 immunolocalization during the menstrual cycle.

Steroid synthesis in the human ovary is regulated by the temporal and spatial expression of enzymes involved in each step of ovarian steroidogenesis. Recent studies have demonstrated that DAX-1 and COUP-TFII negatively regulate adrenal 4 binding protein (Ad4BP)/steroidogenic factor-1 (SF-1)-dependent transcription of steroidogenic enzymes in experimental animals. In this study the expression patterns of these proteins in human normal ovaries were examined using immunohistochemistry and compared with those of steroidogenic enzymes. In the ovarian follicle and corpora lutea, immunoreactive DAX-1 protein was detected predominantly in granulosa cells, whereas COUP-TFII was identified in thecal cells. In granulosa cells, both immunoreactive DAX-1 and Ad4BP/SF-1 protein expression increased after the preantral follicular stage. DAX-1 immunoreactivity was relatively high compared with that of Ad4BP/SF-1 in all follicular stages from premordial to nondominant. The increase in expression of Ad4BP/SF-1 immunoreactivity between follicles in the preantral and dominant stages of follicular development was greater than that in DAX-1 expression. In thecal cells, immunoreactive COUP-TFII was consistently elevated throughout the menstrual cycle, whereas Ad4BP/SF-1 immunoreactivity increased according to the development of the follicle. These results indicated that DAX-1 and COUP-TFII may play a role in the modulation of Ad4BP/SF-1-dependent transcription of steroidogenic enzymes in different cell types and follicular stages in normal cycling human ovaries.

Adult↗

PubMed2003

Cloning and sequence analysis of endoglucanase genes from an industrial fungus, Aspergillus kawachii.

Three endoglucanase genes (cel5A, cel5B, and cel61A) were cloned from an industrial fungus, Aspergillus kawachii. Yeasts transformed with these cDNAs showed endoglucanase activity in medium. Cel5A and Cel61A contained a type 1 cellulose-binding domain (CBD1) at the C-terminus of the enzyme. The putative catalytic regions of Cel5A and Cel5B showed homology with various endoglucanases belonging glycosyl hydrolase family 5 (GH5). Cel5B showed high homology with Cel5A in catalytic region, but it lacked CBD1 and linker. The cel5A contained four introns, whereas cel5B contained five introns. The putative catalytic region of Cel61A showed homology with enzymes belonging to GH61. The cel61A contained no introns.

Amino Acid Sequence↗

PubMed2003

Mode of alpha-amylase production by the shochu koji mold Aspergillus kawachii.

Aspergillus kawachii produces two kinds of alpha-amylase, one is an acid-unstable alpha-amylase and the other is an acid-stable alpha-amylase. Because the quality of the shochu depends strongly on the activities of the alpha-amylases, the culture conditions under which these alpha-amylases are produced were examined. In liquid culture, acid-unstable alpha-amylase was produced abundantly, but, acid-stable alpha-amylase was not produced. The acid-unstable alpha-amylase was produced significantly when glycerol or glucose was used as a carbon source, similarly to the use of inducers such as starch or maltose. In liquid culture, A. kawachii assimilated starch at pH 3.0, but no alpha-amylase activity was recognized in the medium. Instead, the alpha-amylase was found to be trapped in the cell wall. The trapped form was identified as acid-unstable alpha-amylase. Usually, acid-unstable alpha-amylase is unstable at pH 3.0, so its stability appeared to be due to its immobilization in the cell wall. In solid-state culture, both kinds of alpha-amylase were produced. The production of acid-stable alpha-amylase seems to be solid-state culture-specific and was affected by the moisture content in the solid medium.

Aspergillus↗

PubMed2003

Novel aminopeptidase specific for glycine from Actinomucor elegans.

Glycyl aminopeptidase was purified 600-fold from a cell extract of Actinomucor elegans by ammonium sulfate fractionation and sequential chromatography on DEAE-Toyopearl, Toyopearl HW65C, and FPLC-Superdex 200 HR, with recovery of 3.3% of the activity. The enzyme highly specifically hydrolyzed Gly-X (amino acid, peptide, or arylamide) bonds. The enzyme hydrolyzed other amino acid residues but at a rate of less than one fifth that with Gly. The order was Gly >> Ala >> Met > Arg > Ser > Leu. The Km value for glycyl-2-naphthylamide was 0.24 mM. The enzyme was most active at pH 8.0 with glycyl-2-naphthylamide as the substrate and its optimal temperature was 40 degrees C. The enzyme was inhibited by iodoacetic acid, and p-chloromercuribenzoate but not done by diisopropylfluorophosphate, o-phenanthroline, or EDTA. Magnesium and calcium had no effect on enzymic activity, but the activity was suppressed by cadmium, zinc, and copper ions. The molecular mass was estimated to be 320 kDa by gel filtration on FPLC-Superdex 200 HR and 56.5 kDa by SDS-PAGE, so the enzyme probably was a hexamer.

Aminopeptidases↗

PubMed2002

Crystal structure of formaldehyde dehydrogenase from Pseudomonas putida: the structural origin of the tightly bound cofactor in nicotinoprotein dehydrogenases.

Formaldehyde dehydrogenase from Pseudomonas putida (PFDH) is a member of the zinc-containing medium-chain alcohol dehydrogenase family. The pyridine nucleotide NAD(H) in PFDH, which is distinct from the coenzyme (as cosubstrate) in typical alcohol dehydrogenases (ADHs), is tightly but not covalently bound to the protein and acts as a cofactor. PFDH can catalyze aldehyde dismutations without an external addition of NAD(H). The structural basis of the tightly bound cofactor of PFDH is unknown. The crystal structure of PFDH has been solved by the multiwavelength anomalous diffraction method using intrinsic zinc ions and has been refined at a 1.65 A resolution. The 170-kDa homotetrameric PFDH molecule shows 222 point group symmetry. Although the secondary structure arrangement and the binding mode of catalytic and structural zinc ions in PFDH are similar to those of typical ADHs, a number of loop structures that differ between PFDH and ADHs in their lengths and conformations are observed. A comparison of the present structure of PFDH with that of horse liver ADH, a typical example of an ADH, reveals that a long insertion loop of PFDH shields the adenine part of the bound NAD(+) molecule from the solvent, and a tight hydrogen bond network exists between the insertion loop and the adenine part of the cofactor, which is unique to PFDH. This insertion loop is conserved completely among the aldehyde-dismutating formaldehyde dehydrogenases, whereas it is replaced by a short turn among typical ADHs. Thus, the insertion loop specifically found among the aldehyde-dismutating formaldehyde dehydrogenases is responsible for the tight cofactor binding of these enzymes and explains why PFDH can effectively catalyze alternate oxidation and reduction of aldehydes without the release of cofactor molecule from the enzyme.

Alcohol Dehydrogenase↗

PubMed2002

Preliminary crystallographic studies of the creatinine amidohydrolase from Pseudomonas putida.

Creatinine amidohydrolase (creatininase; EC 3.5.2.10) from Pseudomonas putida has been overexpressed in Escherichia coli and crystallized by the hanging-drop method. The crystal belongs to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 102.0, b = 150.7, c = 167.1 A. Native data were collected to 1.8 A resolution by a rotation method at 100 K using an ADSC Quantum 4R CCD detector with synchrotron radiation.

Amidohydrolases↗

PubMed2002

Expression of androgen receptor and 5alpha-reductases in the human normal endometrium and its disorders.

Androgen metabolism and actions are considered to play a very important role in the development and progression of the normal human endometrium and its disorders. Details regarding androgen actions in these tissues, however, have not been well studied. We first immunolocalized the androgen receptor (AR) and 5alpha-reductases, which catalyze the conversion of testosterone to the bioactive and potent androgen, 5alpha-dihydrotestesterone (DHT), in 18 normal cycling human endometria, 27 endometrial hyperplasia and 46 endometrioid endometrial adenocarcinomas. We also examined the mRNA expression of AR and 5alpha-reductases in 7 cases of endometrioid endometrial adenocarcinomas using reverse transcription polymerase chain reaction (RT-PCR). In the normal human endometrium, AR was immunolocalized predominantly in stromal cells of the proliferative phase of the menstrual cycle and in epithelial cells of the secretory phase, whereas 5alpha-reductase types 1 and 2 immunoreactivities were detected in the cytoplasm of epithelial cells but not in stromal cells throughout all phases of the menstrual cycle. In endometrial hyperplasia, the median labeling index (LI) for AR was 48.1%, whereas positive immunostaining for 5alpha-reductase Type 1 and Type 2 was detected in only 1 case. In endometrial carcinoma, AR immunoreactivity was detected in the nuclei of carcinoma cells and the number of positive cases was 39/44 (88.6%). Median LI for AR was 36.1%. Immunoreactivity for 5alpha-reductase Type 1 and Type 2 was detected in the cytoplasm of carcinoma cells and the number of positive cases was 37/44 cases (84.1%) and 34/44 (77.3%) for 5alpha-reductase Types 1 and 2, respectively. A significant positive correlation was detected between 5alpha-reductase Type 1 and Type 2 immunoreactivity (p < 0.001). AR LI was not correlated with the presence or absence of Type 1 and Type 2 5alpha-reductases. Results from our RT-PCR studies were consistent with those of immunohistochemistry. These results suggest that DHT may play more important roles than testosterone in the regulation of androgen action in endometrial cancer and normal human endometrium, especially in the secretory phase, in which both AR and 5alpha-reductase are increased. Androgenic actions may be also regulated predominantly by serum testosterone and not by DHT in endometrial hyperplasia because of the absence of 5alpha-reductases in the site of its actions.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

PubMed2002

Second allogeneic hematopoietic stem cell transplantation for leukemia relapse after first allogeneic transplantation: outcome of 16 patients in a single institution.

Sixteen patients who underwent a second allogeneic hematopoietic stem cell transplantation (HSCT2) for leukemia relapse after the first allogeneic transplantation (HSCT1) were studied. The patients included 7 patients with acute myelogenous leukemia, 8 with acute lymphoblastic leukemia, and 1 with chronic myelogenous leukemia. The median patient age at HSCT2 was 22 years (range, 12 to 44 years). The median interval between HSCT1 and HSCT2 was 19 months (range, 2 to 46 months). At HSCT2, 7 patients were in complete remission (CR), 7 had relapsed, and 2 had bone marrow aplasia. In 14 patients, donors for HSCT2 were the same as those for HSCT1. Two donors were replaced, 1 for another HLA-matched sibling and 1 for an unrelated cord blood donor. Four patients (25%) died within 100 days after HSCT2 from veno-occlusive disease, sepsis, interstitial pneumonitis, or chronic graft-versus-host disease (GVHD), without leukemia relapse. Seven patients (44%) developed leukemia relapse and died between 4 and 20 months after HSCT2. Five patients (31%) survived beyond 4 years. One patient died from chronic GVHD without leukemia relapse 55 months after HSCT2. The 4 other patients were alive between 79 and 134 months after HSCT2 (median follow-up, 106 months). Factors that favorably influenced survival were age younger than 20 years and CR duration after HSCT1 longer than 12 months. HSCT2 is considered to be beneficial for select patients. Preparative regimens, GVHD prophylaxis, and donor choice for HSCT2 need to be studied to obtain a more successful outcome for HSCT2.

Adolescent↗

PubMed2002

No V(H) somatic hypermutation was detected in B-cells of a patient with macroglobulinemia due to splenic marginal zone lymphoma.

B-cell diseases are classified on the basis of the normal differentiation stages. We report here a case of a patient with a long history of leukocytosis, splenomegaly without lymphadenopathy, and hyperviscosity symptoms. Clinically, the patient's diagnosis was leukemic Waldenstrom macroglobulinemia. Chromosomal analysis revealed translocation t(2;7)(p11;q22) along with disease progression. Death occurred from pulmonary infection at 46 months after the initial presentation. At autopsy, malignant lymphocytes were found in the marginal areas of the spleen with spreading to the bone marrow and the liver. The histologic findings were consistent with splenic marginal zone lymphoma. We examined the sequences of the immunoglobulin V(H) gene in cells from the initial peripheral blood and from the spleen at autopsy and found that the sequences were identical and had no somatic hypermutation. Macroglobulinemia can occur in various B-cell disorders, including splenic marginal zone lymphoma, even with the transformation of unmutated B-lymphocytes.

B-Lymphocytes↗

PubMed2002

A clinical comparison of unrelated cord blood transplantation and unrelated bone marrow transplantation for adult patients with acute leukaemia in complete remission.

We performed a clinical comparison of unrelated cord blood transplantation (UCBT) and unrelated bone marrow transplantation in adult acute leukaemia patients in complete remission (CR) who received the same conditioning regimen, graft-versus-host disease (GvHD) prophylaxis and supportive treatment. The incidence of acute GvHD was almost the same between the two groups, but the haematopoietic recovery was delayed and the incidence of chronic GvHD was higher in the UCBT group. The probability of 2 year disease-free survival was similar between the two groups. These results suggest that adult acute leukaemia patients in CR without a suitable donor should be considered as candidates for UCBT.

Adult↗

PubMed2002

Two homologous genes, DCW1 (YKL046c) and DFG5, are essential for cell growth and encode glycosylphosphatidylinositol (GPI)-anchored membrane proteins required for cell wall biogenesis in Saccharomyces cerevisiae.

The cell wall of Saccharomyces cerevisiae consists of glucan, chitin and various kinds of mannoproteins. Major parts of mannoproteins are synthesized as glycosylphosphatidylinositol (GPI)-anchored proteins and are then transferred to cell wall beta-1,6-glucan. A glycosyltransferase has been hypothesized to catalyse this transfer reaction. A database search revealed that the products of YKL046c and DFG5 are homologous to bacterial mannosidase. These genes are homologous to each other and have primary structures characteristic of GPI-anchored proteins. Although single disruptants of ykl046c and dfg5 were viable, ykl046cDelta was hypersensitive to a cell wall-digesting enzyme (zymolyase), suggesting that this gene is involved in cell wall biosynthesis. We therefore designated this gene as DCW1 (defective cell wall). A double disruptant of dcw1 and dfg5 was synthetically lethal, indicating that the functions of these gene products are redundant, and at least one of them is required for cell growth. Cells deficient in both Dcw1p and Dfg5p were round and large, had cell walls that contained an increased amount of chitin and secreted a major cell wall protein, Cwp1p, into the medium. Biochemical analyses showed that epitope-tagged Dcw1p is an N-glycosylated, GPI-anchored membrane protein and is localized in the membrane fraction including the cell surface. These results suggest that both Dcw1p and Dfg5p are GPI-anchored membrane proteins and are required for normal biosynthesis of the cell wall.

Amino Acid Sequence↗

PubMed2002

Malignant astrocytoma of the conus medullaris treated by spinal cordectomy.

We present a case of malignant astrocytoma of the conus medullaris in a 48-year-old man treated by spinal cordectomy. Preoperative examination revealed a tumor at the T12 to L1 level, and intraparenchymal invasion up to T8. The spinal cord was amputated caudally to the root entry zones of the T9 sensory roots. Additional cordectomies were repeated three times because of tumor infiltration at the cut end. At each procedure, the cord was segmentally transected just caudal to the root entry zones of the p reserving-aid sensory roots to minimize the neural deficit. The final transected level was between T3 and T4, and the cut end did not pathologically reveal any tumor invasion. However, the patient died from tumor recurrence and dissemination. Although the attempt to control the tumor by long segment cordectomy was unsuccessful, spinal cordectomy with wide margin may be a possible treatment for patients with malignant astrocytoma of the conus medullaris presenting with complete deficit below the lesion a nd no dissemination, if in an early stage.

Astrocytoma↗

PubMed2002

Cloning and sequencing of the Thermus aquaticus glycerol facilitator gene.

The gene glpK, encoding glycerol kinase of Thermus aquaticus has been identified [Biosci. Biotechnol. Biochem., 62 (1998) 2375-2381]. In the present work, the nucleotide sequence of glpFK operon and the gene glpF encoding glycerol facilitator were determined. T. aquaticus GlpF was predicted to contain 272 amino acids with six putative transmembrane segments and two half-membrane-spanning segments that contained the motif Asn-Pro-Ala, respectively. The amino acid residues involved in the discrimination of glycerol were deduced to be Trp44, Tyr182, and Arg188.

Amino Acid Sequence↗

PubMed2002

Successful unrelated cord blood transplantation for relapse after autologous transplantation in non-Hodgkin's lymphoma.

We report a 34-year-old male with relapsed non-Hodgkin's lymphoma (NHL) after autologous peripheral blood stem cell transplantation successfully treated with unrelated cord blood transplantation (CBT). The conditioning regimen included 12 Gy total body irradiation and cyclophosphamide. After the conditioning, a total of 3.14 x 10(7)/kg cord blood nucleated cells was infused on 14 February 2000. An absolute neutrophil count greater than 5 x 10(8)/l and a self-sustained platelet count greater than 50 x 10(9)/l were achieved on days 21 and 43, respectively. During the follow up period, grade I acute graft-versus-host disease (GVHD) and limited chronic GVHD occurred, but both were successfully treated with a dose modification of cyclosporine. After a follow-up period of 16 months, the patient is alive and free of disease. To our knowledge this is the first report of a successful unrelated CBT for an adult NHL patient who relapsed after autologous transplantation.

Adult↗

PubMed2002

Three-dimensional contrast medium-enhanced computed tomographic cisternography for preoperative evaluation of surgical anatomy of intradural paraclinoid aneurysms of the internal carotid artery: technical note.

OBJECTIVE AND IMPORTANCE: Precise preoperative evaluation is especially important when internal carotid artery aneurysms in the paraclinoid region are clipped, because these vascular structures are located in close proximity to various important structures such as the optic nerve and anterior clinoid process. We report a new method for "simultaneously" describing the interrelationships among the aneurysm, internal carotid artery, optic nerve, and bony structures with three-dimensional contrast medium-enhanced computed tomographic (3-D CMECT) cisternography. METHODS: Informed consent was obtained from the patient. An 8-ml injection of iotrolan (Isovist; Schering, Berlin, Germany) (240 mg I/ml) was administered into the lumbar intrathecal space. A computed tomographic scan of the head was obtained 2 hours later with a multislice Asteion computed tomographic scanner (Toshiba, Inc., Tokyo, Japan). An Alatoview workstation (Silicon Graphics, Mountain View, CA) was used to reconstruct the three-dimensional images. RESULTS: These images, as generated by 3-D CMECT cisternography, were found to accurately demonstrate the interrelationships of the internal carotid artery, aneurysm, and surrounding structures preoperatively. The findings obtained from these images proved to be quite similar to the intraoperative findings. 3-D CMECT cisternography clarified whether the paraclinoid aneurysm was intradural or extradural. CONCLUSION: 3-D CMECT cisternography was found to provide a useful means for preoperative evaluation of lesions in the paraclinoid area.

Aged↗