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Biomedical subjects

N Ohta

Publications and source records attributed to N Ohta.

At least 91 records · Page 5Linked to original sources
PubMed1998

A highly polymorphic CA repeat marker at the human tumor necrosis factor alpha (TNFA alpha) locus.

Tumor necrosis factor alpha (TNF alpha) in activated monocytes exerts cytotoxic activity and has a variety of other biological effects. We isolated a polymorphic dinucleotide (CA) repeat sequence from a genomic clone containing the gene located at 6p21.3. High heterozygosity (0.80) makes this polymorphism a useful marker in the genetic study of disorders affecting immunological response and cell differentiation.

Alleles↗
PubMed1998

Ovarian fecundity in patients with endometriosis can be estimated by the incidence of apoptotic bodies.

OBJECTIVE: To investigate the incidence of apoptotic bodies in membrana granulosa in patients with endometriosis. DESIGN: Retrospective analysis. SETTING: Yamagata University Hospital. PATIENT(S): Fifty-eight normoovulatory women with endometriosis and 45 patients with male factor infertility underwent ovulation induction for IVF-ET with GnRH analogues and gonadotropins. INTERVENTION(S): Patients underwent follicle aspiration after the administration of hCG. MAIN OUTCOME MEASURE(S): Recovered granulosa cells (GCs) were examined by fluorescence microscopy, and the incidence of apoptotic bodies was tabulated. These data and the other parameters associated with IVF results were analyzed on the basis of both the revised American Fertility Society (AFS) classification of endometriosis and the existence of chocolate cysts. RESULT(S): The incidence of apoptotic bodies in membrana granulosa of patients with endometriosis was significantly higher than that of the control (male factor infertility) group and increased as the stage of the revised AFS classification advanced. The incidence of apoptotic bodies in membrana granulosa was significantly higher in patients with chocolate cysts than in those without chocolate cysts. The patients with endometriosis had smaller numbers of developed follicles (> or = 15 mm), harvested oocytes, and mature oocytes than the male factor infertility patients. The existence of chocolate cysts corresponded with a reduced number of both harvested oocytes and mature oocytes. CONCLUSION(S): Through the apoptosis of GCs, the existence of endometriosis may have negatively affected the follicle development and oocyte quality.

Adult↗
PubMed1998

Characterization of rbcL group IA introns from two colonial volvocalean species (Chlorophyceae).

Group I introns were reported for the first time in the large subunit of Rubisco (rbcL) genes, using two colonial green algae, Pleodorina californica and Gonium multicoccum (Volvocales). The rbcL gene of P. californica contained an intron (PIC intron) of 1320 bp harboring an open reading frame (ORF). The G. multicoccum rbcL gene had two ORF-lacking introns of 549 (GM1 intron) and 295 (GM2 intron) base pairs. Based on the conserved nucleotide sequences of the secondary structure, the PIC and GM1 introns were assigned to group IA2 whereas the GM2 intron belonged to group IA1. Southern hybridization analyses of nuclear and chloroplast DNAs indicated that such intron-containing rbcL genes are located in the chloroplast genome. Sequencing RNAs from the two algae revealed that these introns are spliced out during mRNA maturation. In addition, the PIC and GM1 introns were inserted in the same position of the rbcL exons, and phylogenetic analysis of group IA introns indicated a close phylogenetic relationship between the PIC and GM1 introns within the lineage of bacteriophage group IA2 introns. However, P. californica and G. multicoccum occupy distinct clades in the phylogenetic trees of the colonial Volvocales, and the majority of other colonial volvocalean species do not have such introns in the rbcL genes. Therefore, these introns might have been recently inserted in the rbcL genes independently by horizontal transmission by viruses or bacteriophage.

Amino Acid Sequence↗
PubMed1998

Trypanocidal effects of gallic acid and related compounds.

Gallic acid (3,4,5-trihydroxybenzoic acid) is a naturally abundant plant phenolic compound and it is well known as a component of hydrolyzable tannins. We report here that gallic acid and related compounds have trypanocidal activity against Trypanosoma brucei brucei (GUTat 3.1) in both the long slender bloodstream forms and the procyclic forms, in vitro. LD50 values of gallic acid are 46.96 +/- 1.28 microM for bloodstream forms and 30.02 +/- 3.49 for procyclic forms, respectively. A study of structurally related compounds suggested that the pyrogallol moiety could be responsible for this activity.

Animals↗
PubMed1998

Molecular characterization of the PEND protein, a novel bZIP protein present in the envelope membrane that is the site of nucleoid replication in developing plastids.

Plastid nucleoids are known to bind to the envelope membrane in developing chloroplasts. Here, plastid DNA is extensively replicated. We previously detected a DNA binding protein in the inner envelope membranes of developing plastids in pea and named it PEND (for plastid envelope DNA binding) protein. In this study, we report on the structure and molecular characterization of a cDNA for the PEND protein. As a result of screening cDNA libraries in lambdagt11 with one of the target sequences of the PEND protein as a probe, we obtained a clone (PD2) for a novel DNA binding protein consisting of 633 amino acid residues. Analysis of the N-terminal sequence of the purified PEND protein indicated that the transit peptide is just 16 residues long. The PEND protein was detected specifically in the plastid envelope membrane of young unopened leaf buds by immunoblot analysis. The PEND protein consists of a basic region plus zipper region, an unprecedented sextuple repeat region, and a putative membrane-spanning region. The basic region with a zipper region seems to have diverged from that of other plant transcription factors. In addition, the PEND protein could be a distant homolog of the trans-Golgi network integral membrane proteins. The PEND protein is therefore a novel type of DNA binding protein that binds to the membrane as an intrinsic membrane protein.

Amino Acid Sequence↗
PubMed1998

CD86 (B7-2) antigen on B cells from atopic patients shows selective, antigen-specific upregulation.

To determine whether B7 signals are associated with atopic responses in man, we assayed CD80 and CD86 expression on B cells and monocytes from atopic patients and controls. Peripheral blood mononuclear cells from 10 patients with perennial allergic rhinitis and from 10 normal subjects were cultured in the presence or absence of house-dust-mite antigen, and B cells and monocytes were assayed for expression of CD80 and CD86 by flow cytometry. CD86 on B cells was significantly and selectively upregulated in all atopic subjects, but not in normal subjects, whereas CD80 expression was not altered in B cells from the atopic subjects or controls. In contrast, both CD80 and CD86 were upregulated in monocytes from the atopic subjects as well as the controls. However, CD86 upregulation was significantly higher in the atopic subjects than in controls. Our results seem to suggest that selective upregulation of CD86 on B cells by a challenging antigen may play a critical role in the development of Th2 cells in patients with atopic disease.

Adolescent↗
PubMed1998

A human myeloid cell line producing stem cell growth factor, KPB-M15, secretes another growth factor active on murine hematopoietic progenitor cells.

Human stem cell growth factor (SCGF) produced by a myeloid cell line, KPB-M15, exhibits species-specific hematopoietic activities. However, KPB-M15-conditioned medium induced colony formation of mouse bone marrow cells. KPB-M15-derived colony-stimulating activity (CSA) was purified through Butyl-Toyopearl 650c and Cu2+ chelating-Sepharose 6B chromatography. TSK-G3000SW gel filtration of the purified preparation presented 3 distinct peaks around Vo, 150 kD and 85 kD. Gel fractions extracted from SDS-PAGE had macrophage colony-stimulating factor (M-CSF)-specific amino acid sequences. PCR, Northern hybridization and ELISA demonstrated that KPB-M15 cells secreted a significant amount of M-CSF and IL-6. Anti-M-CSF but not anti-IL-6 antibody abrogated CSA in KPB-M15-CM. IL-6 hardly synergized with M-CSF to enhance colony formation. Collectively, M-CSF is a sole CSA for murine hematopoietic progenitor cells in KPB-M15-CM. This is the first report of a human myeloid cell line, KPB-M15, constitutively producing M-CSF in addition to SCGF and IL-6. It can be useful in investigating the mechanism of production of M-CSF.

Animals↗
PubMed1998

Formation of reactive oxygen intermediates might be involved in the trypanocidal activity of gallic acid.

We investigated the mechanism of the trypanocidal activity of gallic acid (GA). GA-induced trypanocidal activity was significantly reduced by pretreatment with superoxide dismutase (SOD) and/or catalase. The ESR technique with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trapping agent revealed that a DMPO-OH adduct was detected in culture medium containing GA. The intensity of ESR signals of the DMPO-OH adduct was increased in a time dependent manner. SOD also inhibited the formation of GA-induced DMPO-OH adducts. Furthermore, GA enhanced DNA single-strand breaks induced by Fenton reagent. These results suggest the possibility that GA acts as pro-oxidant for trypanocidal activity.

Animals↗
PubMed1998

Trypanocidal effects of curcumin in vitro.

During the course of study searching for the antiparasitic agents from natural compounds, we found that curcumin showed cytotoxicity against African trypanosomes in vitro. The LD50 values of curcumin were 4.77 +/- 0.91 microM for bloodstream forms and 46.52 +/- 4.94 microM for procyclic forms of Trypanosoma brucei brucei (GUTat 3.1 clone).

Animals↗
PubMed1998

Continuous growth of bloodstream forms of Trypanosoma brucei brucei in an axenic culture system containing a low concentration of serum.

An effective axenic culture system for bloodstream forms of Trypanosoma brucei brucei GUT at 3.1 containing a low concentration of serum is described. Bloodstream forms routinely maintained in Iscove's modification of Dulbecco's medium supplemented with 100 microM hypoxanthine, 30 microM thymidine, 40 microM adenosine, 1 mM sodium pyruvate, 50 microM L-glutamine, 100 microM 2-mercaptoethanol and 20% FBS for more than one year were grown in the same medium supplemented with 5% FBS without reducing their growth rate. Then culture adapted trypanosomes in the culture medium containing 5% FBS were transferred into the modified medium supplemented with 0.5% FBS. For the constant growth of bloodstream forms in the medium containing 0.5% FBS, the culture medium was further supplemented with 200 microM L-alanine, 100 microM glycine, 10 microM L-oruithine hydrochloride and 10 microM L-citrullin. The trypanosomes propagated in this culture system for one year retained their infectivity for mice. This culture system was also shown to be useful for cloning of T.b. brucei GUT at 3.1 which is important for separation of mutants.

Animals↗
PubMed1998

Antitrypanosomal effects of traditional Chinese herbal medicines on bloodstream forms of Trypanosoma brucei rhodesiense in vitro.

The antitrypanosomal activity of traditional Chinese herbal medicines and these crude drug ingredients were determined using axenic cultured bloodstream forms of Trypanosoma b. rhodesiense which is one of the two causative agents of African sleeping sickness in man. The drugs tested were 8 traditional Chinese herbal medicines and these 14 crude drug ingredients. Of these traditional Chinese medicines examined, san'o-shasin-to and oren-gedoku-to showed most potent antitrypanosomal effect. The minimal effective concentration (MEC) which killed all bloodstream form populations within 24 hours of both drug exposure was 125 microg/ml. The 50% effective concentration (EC50) of san'o-shashin-to and oren-gedoku-to was 63 and 74 microg/ml, respectively. In the crude drug ingredients tested, Scutellaria baicalensis G. and Coptis japonica M. which are the main components of san'o-shasin-to and oren-gedoku-to, showed the most powerful antitrypanosomal activity. The MEC and EC50 value of these crude drug ingredients were 30 and 60 microg/ml, and 20 and 36 microg/ml.

Animals↗
PubMed1998

[A case of solitary retroperitoneal neurofibroma].

A 70-year-old woman was admitted to our hospital complaining of epigastralgia. Computed tomography, ultrasonography and magnetic resonance imaging revealed a round tumor measuring 6 cm in diameter, which was located in the medial side of the right kidney. It was successfully removed without injury to the surrounding large vessels and organs. Histological diagnosis was benign neurofibroma. This is the 27th case of solitary retroperitoneal neurofibroma reported in Japan.

Aged↗
PubMed1998

[Relationship between apoptosis-related markers and cardiomyopathy].

Increasing interest has been focused on the role of apoptosis in pathogenesis of idiopathic cardiomyopathy. Interactions between soluble Fas, tumor necrosis factor-alpha (TNF-alpha) and Fas ligand have been reported to play a pivotal part in signal transduction of apoptosis. Thus, we measured serum levels of apoptosis-related markers, namely sFas, TNF-alpha and two types of its receptor TNF-RI and TNF-RII in the patients with idiopathic cardiomyopathy. Serum level of TNF-alpha was higher in dilated cardiomyopathy (DCM) group as well as in hypertrophic cardiomyopathy (HCM) group than in the control group. There were significant correlation among TNF-alpha, TNF-RI and TNF-RII in DCM group. However, only slight tendencies among these parameters in HCM group, indicating different pathogenesis from DCM. No transcardiac production of TNF-alpha, TNF-RI and TNF-RII was found in cardiomyopathies in the present study. These data suggested that apoptosis-related markers could be used for the detailed classification of cardiomyopathy. Furthermore, the simultaneous measurement of receptors and their ligands of apoptosis-related markers might underscore clinical implications.

Apoptosis↗
PubMed1997

Purification, characterization, and reconstitution of DNA-dependent RNA polymerases from Caulobacter crescentus.

Cell differentiation in the Caulobacter crescentus cell cycle requires differential gene expression that is regulated primarily at the transcriptional level. Until now, however, a defined in vitro transcription system for the biochemical study of developmentally regulated transcription factors had not been available in this bacterium. We report here the purification of C. crescentus RNA polymerase holoenzymes and resolution of the core RNA polymerase from holoenzymes by chromatography on single-stranded DNA cellulose. The three RNA polymerase holoenzymes Esigma54, Esigma32, and Esigma73 were reconstituted exclusively from purified C. crescentus core and sigma factors. Reconstituted Esigma54 initiated transcription from the sigma54-dependent fljK promoter of C. crescentus in the presence of the transcription activator FlbD, and active Esigma32 specifically initiated transcription from the sigma32-dependent promoter of the C. crescentus heat-shock gene dnaK. For reconstitution of the Esigma73 holoenzyme, we overexpressed the C. crescentus rpoD gene in Escherichia coli and purified the full-length sigma73 protein. The reconstituted Esigma73 recognized the sigma70-dependent promoters of the E. coli lacUV5 and neo genes, as well as the sigma73-dependent housekeeping promoters of the C. crescentus pleC and rsaA genes. The ability of the C. crescentus Esigma73 RNA polymerase to recognize E. coli sigma70-dependent promoters is consistent with relaxed promoter specificity of this holoenzyme previously observed in vivo.

Bacterial Proteins↗
PubMed1997

Peptides derived from a wild-type murine proto-oncogene c-erbB-2/HER2/neu can induce CTL and tumor suppression in syngeneic hosts.

In this analysis, we examined whether peptides derived from a wild-type murine proto-oncogene, c-erbB-2, function as tumor rejection Ags. Expression of murine c-erbB-2 examined by means of reverse transcription-PCR was observed in several normal adult tissues, such as intestine, kidney, and testis. We then transduced human and murine c-erbB-2 cDNA into two mutually noncross-reactive fibrosarcoma lines of BALB/c origin, CMS7 and CMS17. In BALB/c mice immunized with CMS17HE (CMS17 transduced with human c-erbB-2 cDNA), the growth of subsequently challenged CMS7HE (CMS7 transduced with human c-erbB-2 cDNA) was significantly suppressed. CTL against human c-erbB-2-expressing cells were generated from BALB/c spleen cells in vivo and in vitro sensitized by CMS17HE. The CTL activity was also directed against murine c-erbB-2-expressing cells, CMS7ME and CMS17ME, and was blocked by anti-CD8 or anti-Kd mAbs. A series of peptides of human or murine c-erbB-2 compatible with the Kd binding motif was synthesized. The CTL were reactive with P1.HTR (H-2d) pulsed with three of these peptides, p63-71 (human c-erbB-2 derived), p63-71(A) (murine c-erbB-2 derived), and p780-788 (common for human and murine c-erbB-2). Spleen cells immunized in vivo and in vitro with syngeneic spleen cells pulsed with these peptides became cytotoxic for CMS17HE and/or CMS17ME, but not CMS17neo (CMS17 transduced with control vector). The growth of CMS7ME was suppressed in mice immunized with the murine c-erbB-2-derived peptide, p63-71(A) or p780-788. There was no apparent pathologic change in mice that rejected CMS7ME after vaccination with these peptides.

3T3 Cells↗
PubMed1997

Cloning, expression, and characterization of a cDNA encoding a novel human growth factor for primitive hematopoietic progenitor cells.

Multiple growth factors synergistically stimulate proliferation of primitive hematopoietic progenitor cells. A human myeloid cell line, KPB-M15, constitutively produces a novel hematopoietic cytokine, termed stem cell growth factor (SCGF), possessing species-specific proliferative activities. Here we report the molecular cloning, expression, and characterization of a cDNA encoding human SCGF using a newly developed lambdaSHDM vector that is more efficient for differential and expression cloning. cDNA for SCGF encodes a 29-kDa polypeptide without N-linked glycosylation. SCGF transiently produced by COS-1 cells supports growth of hematopoietic progenitor cells through a short-term liquid culture of bone marrow cells and exhibits promoting activities on erythroid and granulocyte/macrophage progenitor cells in primary semisolid culture with erythropoietin and granulocyte/macrophage colony-stimulating factor, respectively. Expression of SCGF mRNA is restricted to myeloid cells and fibroblasts, suggesting that SCGF is a growth factor functioning within the hematopoietic microenvironment. SCGF could disclose some human-specific mechanisms as yet unidentified from studies on the murine hematopoietic system.

Amino Acid Sequence↗