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Biomedical subjects

A Moriyama

Publications and source records attributed to A Moriyama.

At least 19 recordsLinked to original sources

Diminished beta-adrenoceptor-mediated relaxation of femoral arteries from young spontaneously hypertensive rats.

A beta-adrenoceptor agonist, norepinephrine (NE)-induced relaxation in the presence of an alpha-adrenoceptor antagonist and indomethacin was investigated in isolated femoral arteries from 5-week-old Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). NE elicited endothelium-dependent and -independent relaxation in WKY. In endothelium-intact WKY artery, the NE-induced relaxation was reduced by nitro L-arginine (L-NA) and methylene blue. The residual response to NE in the presence of L-NA was further reduced by tetraethylammonium (TEA). Glibenclamide attenuated the NE-induced, endothelium-independent relaxation in WKY. In SHR, on the other hand, the relaxation to NE was solely endothelium-independent, unaffected by a combination of L-NA and TEA and inhibited by glibenclamide. The relaxation in response to NE in SHR was less than that in WKY, regardless of the presence and absence of endothelial cells. When WKY and SHR were treated for 10 days with captopril, the response to NE was increased not only in WKY but also in SHR. The relaxation in captopril-treated SHR consisted of endothelium-dependent and -independent components. The former was attenuated by L-NA and to a greater extent by TEA with L-NA. Sodium nitroprusside- and forskolin-induced, endothelium-independent relaxations in SHR were not significantly different from those in WKY. Captopril did not affect the response to these drugs. The present results indicate that the relaxation to NE is in part mediated by NO and a vasorelaxing factor distinct from NO in WKY but not in SHR. It is suggested that NE-induced, endothelium-independent relaxation in both groups is in part mediated by ATP-sensitive K+ channels. It is also suggested that in SHR, captopril increases the response to NE through increases in endothelial production of NO and the non-NO vasorelaxing factor.

Acetylcholine↗

Production of secretory leukocyte protease inhibitor by human amniotic membranes and regulation of its concentration in amniotic fluid.

Secretory leukocyte protease inhibitor (SLPI) is a potent inhibitor of human leukocyte elastase. SLPI is a protein found in various human fluids, including parotid secretions, cervical mucus, seminal plasma and ascites. Western blot analysis revealed that SLPI protein is detected as a 12 kDa band in both the amniotic fluid and the amniotic membrane. The amniotic fluid concentrations of SLPI were assayed by enzyme-linked immunosorbent assay. SLPI concentrations in the amniotic fluid of women in the third trimester were higher than those in the second trimester. Immunohistochemistry using an anti-SLPI polyclonal antibody revealed positive staining in epithelial cells in amniotic membranes. Reverse transcription-polymerase chain reaction demonstrated that SLPI transcripts could be detected in the amniotic membranes. To determine the mechanism of SLPI production by amniotic cells, purified amniotic cells were stimulated with various cytokines. Amniotic cells produced SLPI in a dose-dependent manner when stimulated with interleukin (IL)-1alpha, IL-1beta, and tumour necrosis factor-alpha. The present findings show that SLPI is produced by the amniotic membranes in response to cytokine concentrations. The SLPI in the amniotic fluid may contribute to immunodefence mechanisms during pregnancy.

Amniotic Fluid↗

Mouse myosin X: molecular architecture and tissue expression as revealed by northern blot and in situ hybridization analyses.

The structure of the coding region of mouse myosin X cDNA was determined. The predicted protein sequence indicated an approximately 240 kDa molecular mass with 2062 amino acids. When aligned with the structure predicted for calf myosin X (GenBank Accession No. U55042), extremely highly conserved pleckstrin homology domains and a myosin tail homology 4 domain were apparent in the tail region, suggesting their importance for myosin X's function. Northern blot analysis revealed the existence of a myosin X mRNA, 8.7 kb in size, in various mouse tissues, while a similar size of human type myosin X mRNA was recognized mainly in the testis. In addition to the adult-type transcripts in mice, a smaller embryo-specific mRNA, 4.8 kb in size, was identified in early to late embryonic stages, suggesting the presence of a shorter myosin X isoform in mouse embryos. In situ hybridization experiments with mouse testis revealed that myosin X mRNA was restricted to Sertoli cells at stages VIII-X of the spermatogenesis cycle, suggesting that myosin X is implicated in the supporting cells during the spermatid morphogenesis.

Amino Acid Sequence↗

Molecular and biochemical characterization of a serine proteinase predominantly expressed in the medulla oblongata and cerebellar white matter of mouse brain.

A full-length cDNA clone of a serine proteinase, mouse brain serine proteinase (mBSP), was isolated from a mouse brain cDNA library. mBSP, which has been recently reported to be expressed in the hair follicles of nude mice, is most similar (88% identical) in sequence to rat myelencephalon-specific protease. The mBSP mRNA was steadily expressed in the brain of adult mice with a transient expression in the early fetal stage during development. The genomic structure of the mouse gene for mBSP was determined. The gene, which is mapped to chromosome 7B4-B5, is about 7.4 kilobases in size and contains 7 exons. Interestingly, the 5'-untranslated region of the mBSP gene was interrupted by two introns. In situ hybridization analyses revealed that mBSP is expressed in the white matter of the cerebellum, medulla oblongata, and capsula interna and capsula interna pars retrolenticularis of mouse brain. Further, mBSP was immunolocalized to the neuroglial cells in the white matter of the cerebellum. Recombinant mBSP was produced in the bacterial expression system and activated by lysyl endopeptidase digestion, and the activated enzyme was purified for characterization. The enzyme showed amidolytic activities preferentially cleaving Arg-X bonds when 4-methylcoumaryl-7-amide-containing peptide substrates were used. Typical serine proteinase inhibitors, such as diisopropyl fluorophosphates, phenylmethanesulfonyl fluoride, soybean trypsin inhibitor, aprotinin, leupeptin, antipain, and benzamidine, strongly inhibited the enzyme activity. The recombinant mBSP effectively hydrolyzed fibronectin and gelatin, but not laminin, collagens I and IV, or elastin. These results suggest that mBSP plays an important role in association with the function of the adult mouse brain.

Animals↗

Efficient extracellular production of recombinant Escherichia coli heat-labile enterotoxin B subunit by using the expression/secretion system of Bacillus brevis and its mucosal immunoadjuvanticity.

A gene encoding the mature Escherichia coli heat-labile enterotoxin B subunit (LTB) was introduced in a vector pNU212 and expressed at high levels in Bacillus brevis HPD31. The maximum amount of recombinant LTB (rLTB) secreted into the modified 5PY medium containing erythromycin was about 350 mg l(-1) when cultivated at 30 degrees C for 8 days. The rLTB purified directly from the culture supernatant by using D-galactose immobilized agarose was identical to the native LTB with respect to the molecular weight determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the amino terminal amino acid sequence. Western blot analysis with antiserum to cholera toxin B subunit (CTB) indicated that rLTB had cross-reactivity to native CTB and its GM1 binding ability was almost the same as that of the CTB. The rLTB predominantly showed the pentameric form when non-boiled samples were applied to SDS-PAGE. When rLTB was administered intranasally to mice with diphtheria toxoid (D(T)), it resulted in the substantial stimulation of D(T)-specific serum IgG antibody, and in the induction of moderate levels of D(T)-specific mucosal IgA antibody responses in the nasal cavities and in the lung, suggesting that purified rLTB acts as a promising immunoadjuvant on mucosal immunizations.

Administration, Intranasal↗

Molecular cloning of neonate/infant-specific pepsinogens from rat stomach mucosa and their expressional change during development.

To clarify the nature of rat neonate/infant-specific pepsinogens, we carried out their purification and molecular cloning. Prochymosin was found to be the major neonatal pepsinogen. The general proteolytic activity of its active form, chymosin, was, however, lower than those of pepsins A and C which are predominant in adult animals. Molecular cloning of rat prochymosin cDNA was achieved along with cDNA for another neonate-specific pepsinogen, pepsinogen F, although determination of pepsinogen F in neonatal gastric mucosa was unsuccessful, presumably due to its lack of proteolytic activity or different proteolytic specificity. Northern blot analysis confirmed that genes for prochymosin and pepsinogen F are expressed only at neonatal/infant stages and the switching of gene expression to that of pepsinogen C occurred at late infant stages. A phylogenetic tree based on nucleotide sequences showed clearly that pepsinogens fall into four major groups, namely prochymosin and pepsinogen F of the neonate/infant and pepsinogens A and C of adult animals. Although, to date, prochymosin and pepsinogen F were believed to be expressed in only a limited number of mammals, the present results suggest that they might be expressed at the neonatal/infant stage in a variety of mammals.

Aging↗

Identification of porcine follipsin as plasma kallikrein, and its possible involvement in the production of bradykinin within the follicles of porcine ovaries.

To determine the identity of porcine follipsin, a plasma kallikrein cDNA clone was isolated from a porcine liver cDNA library. The clone encoded a protein of 643 amino acids, exhibiting identities 79.7, 72. 9, and 74.4% homologous to human, rat, and mouse plasma prekallikrein, respectively. The amino acid sequences of four internal peptides isolated from the tryptic digest of follipsin were all found in the deduced sequence. Authentic plasma kallikrein was purified from porcine plasma and compared directly with follipsin. Actions on synthetic substrates and behaviors with proteinase inhibitors were indistinguishable between these two enzymes. The cDNA was expressed in COS-7 cells and the recombinant protein was prepared from the culture medium of these cells. No active enzyme could be obtained, but the expressed protein was reacted with anti-porcine plasma kallikrein antibody. The mRNA was detected only in the liver in northern blot analysis. RT-PCR analysis of RNAs revealed that porcine testis, in addition to the liver, expressed the corresponding mRNA. In the ovary, plasma kallikrein was detected as a main band of the active form (Mr = 85,000) and the band of the minor inactive precursor form (Mr = 80,000), respectively. In contrast, the liver extract contained only the precursor form. Incubation of high molecular weight kininogen with follicular fluid plasma kallikrein resulted in an increased production of bradykinin. Further, the fresh fluid of large-sized follicles of porcine ovaries was found to contain this peptide hormone at a detectable level. These results indicate that porcine follipsin is plasma kallikrein, and that the enzyme may be involved in the production of bradykinin within ovarian follicles.

Amino Acid Sequence↗

Plasma nitrite/nitrate concentrations as a tumor marker for hepatocellular carcinoma.

Since plasma concentrations of nitrite/nitrate, the stable end-products of nitric oxide, increase in patients with hepatocellular carcinoma (HCC) correlatively to tumor volume, we examined the ability of plasma nitrite/nitrate to discriminate between those patients with HCC and those without and compared the diagnostic performance of the parameter with that of serum alpha-fetoprotein (AFP) concentrations. Plasma nitrite/nitrate and serum AFP concentrations were measured using a Griess reaction and a solid phase enzyme immunoassay, respectively. Eighty-nine patients with chronic liver diseases (CLD) with (n=39) or without HCC (n=50) and 50 healthy control subjects participated in the study. A receiver operating characteristic (ROC) curve was used to determine the optimal cut-off value and accuracy. The areas under ROC curves for nitrite/nitrate and AFP were calculated to be 0.758 and 0.812, respectively, which were not significantly different. There was no correlation between the concentrations of plasma nitrite/nitrate and serum AFP. The sensitivity, the specificity, and diagnostic efficiency were 79.5, 72.0, and 75.3%, respectively, for nitrite/nitrate, and 74.4, 76.0, and 75.3%, respectively, for AFP. Based on a partial ROC curve, the clinical utility of plasma nitrite/nitrate as a tumor marker approximated that of serum AFP, but exceeded in AFP-negative patients. Indeed, nitrite/nitrate was positive in 70% of AFP-negative HCC patients. The simultaneous determinations of serum AFP and plasma nitrite/nitrate concentrations gave significant improvement in detection of HCC in CLD patients compared with that of serum AFP alone.

Adult↗

Dynamic changes in microtubule organization during division of the primitive dinoflagellate Oxyrrhis marina.

The marine dinoflagellate Oxyrrhis marina has three major microtubular systems: the flagellar apparatus made of one transverse and one longitudinal flagella and their appendages, cortical microtubules, and intranuclear microtubules. We investigated the dynamic changes of these microtubular systems during cell division by transmission and scanning electron microscopy, and confocal fluorescent laser microscopy. During prophase, basal bodies, both flagella and their appendages were duplicated. In the round nucleus situated in the cell centre, intranuclear microtubules appeared radiating toward the centre of the nucleus from densities located in some nuclear pores. During metaphase, both daughter flagellar apparatus separated and moved apart along the main cell axis. Microtubules of ventral cortex were also duplicated and moved with the flagellar apparatus. The nucleus flattened in the longitudinal direction and became discoid-shaped close to the equatorial plane. Many bundles of microtubules ran parallel to the short axis of the nucleus (cell long axis), between which chromosomes were arranged in the same direction. During ana-telophase, the nucleus elongated along the longitudinal axis and took a dumbbell shape. At this stage a contractile ring containing actin was clearly observed in the equatorial cortex. The cortical microtubule network seemed to be cut into two halves at the position of the actin bundle. Shortly after, the nucleus divided into two nuclei, then the cell body was constricted at its equator and divided into one anterior and one posterior halves which were soon rebuilt to produce two cells with two full sets of cortical microtubules. From our observations, several mechanisms for the duplication of the microtubule networks during mitosis in O. marina are discussed.

Actins↗

Cloning and characterization of mouse klk27, a novel tissue kallikrein expressed in testicular Leydig cells and exhibiting chymotrypsin-like specificity.

A cDNA clone of a new mouse tissue kallikrein, designated mKlk27, was isolated from an adult mouse testis cDNA library. mKlk27 was expressed in the submaxillary glands and testis of the mouse. In testis, mKlk27 gene was expressed exclusively in the Leydig cells of the adult mouse. Active recombinant mKlk27 exhibited chymotrypsin-like cleavage specificity. A single amino-acid substitution of Gly for Asp at position 209 in mKlk27 resulted in complete loss of its chymotryptic activity but acquisition of tryptic activity. mKlk27 effectively hydrolyzed casein, gelatin and fibronectin. Insulin-like growth factor binding protein-3 was also hydrolyzed by recombinant mKlk27. These results suggest that mKlk27 plays an important role in association with the function of the adult mouse testis.

Amino Acid Sequence↗

Chorioamnionitis decreased incidence of respiratory distress syndrome by elevating fetal interleukin-6 serum concentration.

Respiratory distress syndrome (RDS) of newborns is one of the most important factors determining neonatal morbidity and mortality. The interleukin-6 (IL-6) titre in cord sera of RDS-free neonates born to mothers with histological chorioamnionitis was significantly higher than that in RDS-complicated neonates without chorioamnionitis. Maternal administration of glucocorticoid suppressed the IL-6 concentrations in the cord sera of fetuses with chorioamnionitis. The fetuses without chorioamnionitis who suffered from RDS even after maternal glucocorticoid administration showed a similar IL-6 titre to that of RDS-affected neonates without chorioamnionitis. Examination of the mechanism by which IL-6 decreased the incidence of fetal RDS revealed that H441-4, a human pulmonary adenocarcinoma cell line, stimulated with recombinant (r)-IL-6 started the synthesis of mRNA and protein of pulmonary surfactant protein (SP)-A. The present study shows that IL-6 elevation in fetuses with chorioamnionitis promotes fetal lung maturation by inducing SP-A synthesis, thereby decreasing the incidence of RDS in the preterm neonates.

Cell Line↗

Oncostatin M is produced during pregnancy by decidual cells and stimulates the release of HCG.

Oncostatin M (OSM) is a member of the interleukin-6 superfamily and a multifunctional cytokine that effects the growth and differentiation of many different cell types. OSM concentrations in the sera of pregnant women were found to be significantly higher than those of non-pregnant women. Western blot analysis revealed that the OSM protein was present in the decidua and chorionic tissue in each trimester. Throughout pregnancy, the amount of the OSM protein in the decidua was larger than that in the chorionic tissue. Immunohistochemistry using an anti-OSM monoclonal antibody demonstrated that OSM was mainly localized in the decidual glands and stroma. OSM transcripts in the decidua and the chorionic tissue were detected during each trimester by reverse transcription-polymerase chain reaction (RT-PCR). The regulation of human chorionic gonadotrophin (HCG) release by the placenta in first trimester stimulated with recombinant OSM was also investigated. Stimulation of the placenta by OSM augmented HCG release in a time- and dose-dependent manner. HCG release induced by recombinant human OSM was completely blocked by antibodies against OSM and the signal transducer, gp130, but only partially inhibited by antibodies against the leukaemia inhibiting factor (LIF) receptor. These results suggest that OSM molecules produced by decidual glands and stromal cells during pregnancy have an important role in placental endocrine function.

Antibodies, Monoclonal↗

Increased concentrations of secretory leukocyte protease inhibitor in peritoneal fluid of women with endometriosis.

Secretory leukocyte protease inhibitor (SLPI) is a potent inhibitor of human leukocyte elastase. We investigated whether SLPI was present in the peritoneal fluid of women with endometriosis and to clarify the role of SLPI in the pathogenesis of endometriosis. Western blot analyses revealed that SLPI protein was detected as a 12 kDa band in peritoneal fluid. The peritoneal fluid concentrations of SLPI, elastase and interleukin-6 were assayed by enzyme-linked immunosorbent assays (ELISA). SLPI concentrations and the SLPI/elastase ratio in the peritoneal fluid of women with endometriosis were higher than in samples from women without endometriosis. There was no significant correlation between concentrations of SLPI and interleukin-6 in the peritoneal fluid. Immunohistochemistry using an anti-SLPI polyclonal antibody revealed positive staining in peritoneal macrophages, but not lymphocytes. The present findings suggest that SLPI found in the peritoneal fluid of patients with endometriosis may contribute to the pathogenesis of endometriosis.

Adult↗

Cloning of a rat glia maturation factor-gamma (rGMFG) cDNA and expression of its mRNA and protein in rat organs.

We isolated a rat glia maturation factor-gamma(rGMFG) cDNA and examined the tissue distribution of GMFG in rat by Northern and Western blot analyses. Sequence analysis of the entire cDNA revealed an open reading frame of 426 nucleotides with a deduced protein of 142 amino acid residues. The deduced amino acid sequence of the putative product is highly homologous (78.9%) to rat glia maturation factor-beta (rGMFB). Northern blot analysis indicated that a 0.9-kb mRNA is predominantly expressed in rat thymus, testis, and spleen. GMFG showed a different tissue distribution from GMFB, being present predominantly in proliferative and differentiative organs.

Amino Acid Sequence↗

Identification of components of the intrafollicular bradykinin-producing system in the porcine ovary.

As a step in elucidating the biological role of plasma kallikrein (PK) present in the follicular fluid of mammalian ovaries, we examined pig ovary fluid to determine its constituent activators and substrates. Using the inactive precursor form of plasma kallikrein (prePK) as a substrate, we purified an enzyme capable of activating this protein. The prePK-activating enzyme was shown to be the active enzyme blood coagulation factor XIIa. We also isolated high molecular weight kininogen (HMW-K) from the same fluid. Incubation of HMW-K with the ovarian follicular fluid PK resulted in the production of the nanopeptide bradykinin (BK). Expression of prePK, blood coagulation factor XII, and HMW-K was examined by Northern blot analysis using ovary and liver poly(A)(+) RNA. All these transcripts were found in the liver, but none were found in the ovary. In addition, it was found that BK levels in the fluid derived from the small follicles were approximately 6 times higher than those from medium and large follicles. These results demonstrate the presence of a BK-producing system in the ovarian follicles and suggest the physiological importance of this peptide hormone in the early stages of follicular development and at ovulation.

Amino Acid Sequence↗

Suicide gene therapy for human uterine adenocarcinoma cells using herpes simplex virus thymidine kinase.

In gene therapy, the herpes simplex virus thymidine kinase (HSV-tk) gene is widely used as a suicide agent. Tumor cells expressing HSV-tk are sensitive to nucleoside analogs such as ganciclovir (GCV). An advantage of this system is the bystander killing effect whereby HSV-tk-positive cells exposed to GCV are lethal to surrounding HSV-tk-negative cells. We transfected the HSV-tk gene into a human cervical adenocarcinoma cell line, BU25TK-, and a human endometrial adenocarcinoma cell line, HHUA, by the Lipofectine method. The sensitivity of HSV-tk-positive cells to GCV and bystander killing effect on HSV-tk-negative cells were examined in vitro. HSV-tk-positive cells were sensitive to GCV at concentrations of 1 to 100 microg/ml in a dose- and time-dependent manner. The growth of HSV-tk-negative cells was inhibited when the population of cultured cells contained more than about 3% HSV-tk-positive cells. Moreover, for BU25TK- cells, HSV-tk-positive cells were injected into SCID mice subcutaneously and the effects of GCV therapy and bystander killing at a daily concentration of 25 mg/kg for 14 days were examined. HSV-tk-positive tumors transduced into SCID mice almost disappeared upon GCV treatment. Furthermore, tumor reduction was observed when mixtures of HSV-tk-negative cells containing more than 20% HSV-tk-positive cells were injected into SCID mice. In conclusion, the HSV-tk/GCV system might be applied to both cervical and endometrial adenocarcinoma.

Adenocarcinoma↗