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T Horiuchi

Publications and source records attributed to T Horiuchi.

At least 235 records · Page 13Linked to original sources
PubMed1996

Sterol 14-demethylase P450 (P45014DM*) is one of the most ancient and conserved P450 species.

To determine the orthology of sterol 14-demethylase (P45014DM), the only known P450 enzyme distributed widely in eukaryotes with a conserved metabolic role, the full-length amino acid sequences of rat and human P45014DMs were determined from the cloned cDNA sequences, and compared with those of the corresponding fungal proteins (CYP51). The amino acid identity value between given pairs of P45014DMs ranged from 93% (human/rat) to 39% (human or rat/Saccharomyces cerevisiae). All the P45014DMs formed a single cluster in a phylogenetic tree constructed from representative P450 protein sequences currently available. The nearest neighbors to the P45014DM cluster in the phylogenetic tree were CYP7 (cholesterol 7 alpha-hydroxylase) and CYP8 (prostacyclin synthase), and the divergence point of fungal and mammalian P45014DMs was clearly more recent than that of P45014DM and CYP7/CYP8. These lines of evidence show that fungal and mammalian P45014DMs are really orthologous. This is the first example of orthologous P450s occurring in distinct kingdoms. P45014DM may be an ancient P450 which arose before the divergence of major eukaryotic branches and has been conserved throughout evolution. The amino acid identity value (93%) between human and rat P45014DMs was comparable to those observed for some housekeeping enzymes. In addition, a processed pseudogene of P45014DM was found in a rat genomic DNA library, suggesting the expression of P45014DM in germ line cells. These facts suggest that P45014DM may be a housekeeping enzyme essential for the viability of mammals.

Amino Acid Sequence↗
PubMed1996

Lanosterol 14-demethylase activity expressed in rat brain microsomes.

The occurrence of sterol 14-demethylase in rat brain microsomes was confirmed. The brain microsomes from adult rats converted lanosterol into its 14-demethylated products, 4,4-dimethylcholesta-8, 24-dienol, and 4,4-dimethylcholesta-8,14,24-trienol, in the presence of NADPH and molecular oxygen. This metabolism of lanosterol was inhibited by carbon monoxide and ketoconazole, a potent inhibitor of sterol 14-demethylase P450 (P45014DM or CYP51). These facts indicated the occurrence of lanosterol 14-demethylation in rat brain microsomes and its dependency on P45014DM. A representative value of the lanosterol demethylase activity of the brain microsomes was 8.4 pmol/min/mg protein or 640 pmol/ min/nmol of total P450. The former was about one-thirteenth of the corresponding value observed with liver microsomes from the same rats, while the latter was 4-times higher than the corresponding value obtained with the liver microsomes. This fact suggested that the ratio of P45014DM to other P450 species was higher in brain than in liver. Lanosterol 14-demethylation is situated at the root of the sterol-biosynthetic branch of the mevalonic acid pathway. Therefore, the present finding enzymologically supports the existence of the sterol biosynthetic pathway in brain.

Animals↗
PubMed1996

p53 antisense oligonucleotide inhibits growth of human colon tumor and normal cell lines.

We examined the relationship between the expression of mutant p53 proteins and tumor cell growth using a p53 antisense oligonucleotide (5'-CCCTGCTCCCCCCTGGCTCC-3'). The oligonucleotide inhibited the growth of three human colon tumor cell lines (DLD-a, SW620 and WiDr), which produce only mutant p53 proteins with different mutation sites. Treatment of DLD-1 cells with the p53 antisense oligonucleotide caused a decrease in the level of p53 mutant protein. Synthesis of DNA in DLD-1 and SW620 cells was inhibited more potently than that of RNA or protein after antisense treatment. Furthermore, these cells were accumulated in the S phase when DNA synthesis was inhibited. Meanwhile, the antisense oligonucleotide also inhibited the growth of three human normal cell lines (WI-38, TIG-1 and Intestine 407). While treatment of WI-38 and TIG-1 cells with the antisense oligonucleotide inhibited synthesis of DNA more potently than that of RNA or protein, these normal cells were accumulated in the G0/G1 phase. These results suggest that p53 proteins, either with or without mutation, play a pivotal role in the growth of tumor and normal cells, but that mutant and wild-type p53 proteins may function differently in cell growth.

Base Sequence↗
PubMed1996

Allergenic epitopes of ovalbumin (OVA) in patients with hen's egg allergy: inhibition of basophil histamine release by haptenic ovalbumin peptide.

We studied allergenic determinants that induce hypersensitivity to OVA, the major allergen in egg allergy, using immunoblot and histamine release assays. Immunoblot analysis demonstrated a part of the OVA epitope was in the C-terminal region comprising residues 347-385 (OVA347-385). Histamine was released from basophils of a patient with egg allergy upon stimulation with the OVA fragment corresponding to OVA347-385. Furthermore, detailed epitope mapping using overlapping peptides (residues 347-366, OVA-A; residues 357-376, OVA-B; and residues 367-385, OVA-C) in the OVA 347-385 region was carried out using the histamine release assay. In order for histamine release from basophils to occur, the allergen must possess two or more allergenic determinants located on the protein molecule at distances that would be equivalent to the distances between IgE molecules on the membrane surface. these results suggest that there are at least two epitopes that bind IgE antibodies on each OVA peptide. In addition, one epitope that binds IgE antibodies in two patients appears to reside in the haptenic peptide OVA357-366 (OVA-B1). The histamine release from basophils stimulated by OVA-B was completely inhibited by OVA-B1 in one of these patients. Similarly, OVA-B1 inhibited the histamine release produced by OVA-A in the other by more than 40%. These results suggest that haptenic synthetic peptides could regulate the allergic reaction in the effector phase if common epitope(s) recognized by IgE antibodies in the patients with egg allergy can be found. These are the first studies that provide an antigen-specific approach to inhibiting histamine release from basophils by a haptenic peptide recognized by IgE antibodies in an allergic disorder.

Allergens↗
PubMed1996

Relationship of interleukin-8 and colony-stimulating factors to neutrophil migration in aseptic meningitis.

Polymorphonuclear neutrophilic leucocyte (PMNL) migration into the subarachnoid space in aseptic meningitis of probable enteroviral aetiology was evaluated in relation to cerebrospinal fluid and serum levels of interleukin-8 (IL-8), macrophage colony-stimulating factor (M-CSF) and granulocyte colony-stimulating factor (G-CSF). IL-8 levels reached a plateau within 12h of onset, while M-CSF and G-CSF levels reached a peak between 12 and 24 h after onset, corresponding to the peak increase in PMNL count. G-CSF levels had the closest correlation with PMNL count. M-CSF levels were weakly correlated with PMNL count. IL-8 levels were not correlated with PMNL count except within 12 h of onset. IL-8 and G-CSF were detected predominantly in cerebrospinal fluid, while the M-CSF levels in the two compartments were not different except between 12 and 24 h after onset. It is considered that IL-8 triggers rapid and transient migration of PMNL, and that G-CSF then promotes gradual and consistent infiltration of PMNL.

Adolescent↗
PubMed1996

T lymphocytes and silica-induced pulmonary inflammation and fibrosis in mice.

BACKGROUND: Silica-induced pulmonary inflammation and fibrosis in animals provides a good model for chronic pulmonary inflammation and fibrosis. Although lymphocytes are implicated in the pathogenesis of pulmonary fibrosis, experimental models using silica-treated athymic nude mice have not been successful in showing the fibrogenic mechanism regulated by T cells. The aim of this study was to re-evaluate the role of T lymphocytes in the development of silicosis by comparing the response to silica administration of nude athymic mutants with that of euthymic animals. METHODS: Suspensions of silica particles were transnasally administered to nude athymic mice (Balb/c nu/nu) as well as to their euthymic littermates (Balb/c nu/+). The degree of pulmonary inflammation and fibrosis was assessed on days 14, 28, and 56 based upon histological observation, analysis of collagen deposition in the lungs, and analysis of the cellular constituent, protein, and phospholipid content in the bronchoalveolar lavage fluid. RESULTS: Histologically, athymic mice developed less severe interstitial pneumonitis than euthymic mice. In euthymic mice the lung hydroxyproline content increased with time after silica administration from 6.48 (0.38) micrograms hydroxyproline/mg dry lung weight on day 0 to 8.87 (0.41) micrograms/mg on day 56. A gradual increase in lung hydroxyproline content was also observed in athymic mice but the increase was significantly smaller than in euthymic mice (6.63 (0.43) micrograms/mg on day 0, 7.90 (0.19) micrograms/mg on day 56). Administration of silica resulted in an increase in the number of macrophages and neutrophils and in the total protein and phospholipid content of the bronchoalveolar lavage (BAL) fluid in both mouse strains. No significant difference was detected between athymic and euthymic mice in the numbers of macrophages, but the increase in neutrophils in the BAL fluid of athymic mice was significantly smaller than in euthymic mice on days 14 and 56. The total protein and phospholipid content of the BAL fluid from athymic mice was lower than that from euthymic mice. CONCLUSIONS: T lymphocytes appear to be involved in the pathogenesis of silica-induced pneumonitis. Since pulmonary fibrosis develops even in nude athymic mice, T cells do not seem to play a primary part in fibrogenic response but they regulate, at least to some extent, the response of inflammatory cells and fibrogenesis of the lung.

Animals↗
PubMed1996

The critical role of intercellular adhesion molecule-1 in Masugi nephritis in rats.

Intercellular adhesion molecule-1 (ICAM-1, CD54), an adhesion molecule of the immunoglobulin superfamily, is an endothelial cell surface ligand for such leukocyte integrins as lymphocyte-function-associated molecule 1 (LFA-1, CD11a/CD18), Mac-1 (CD11b/CD18) and CD43. These molecules mediate adhesive interactions between leukocytes and endothelial cells and are critically involved in infiltration of leukocytes into inflammatory lesions. We examined the expression of ICAM-1 in renal tissues of Masugi nephritis rats and directly examined the role of ICAM-1 by administration of neutralizing monoclonal antibodies (MAbs) to rat ICAM-1, LFA-1 alpha-subunit (LFA-1 alpha), beta-subunit (LFA-1 beta) and Mac-1 alpha-subunit (Mac-1 alpha). Within 3 h after injection of nephrotoxic serum, increased expression of ICAM-1 was detected in the glomeruli by in situ hybridization and an immunofluorescence study. Proteinuria was significantly suppressed by the MAbs against ICAM-1, Mac-1 alpha and LFA-1 beta. Neutrophil infiltration into the glomeruli was significantly prevented by injection of the MAbs against ICAM-1, LFA-1 alpha and LFA-1 beta. These results indicate that both ICAM-1/LFA-1 and ICAM-1/Mac-1 pathways are involved in neutrophil infiltration into the glomeruli. On the other hand, monocytic infiltration was prevented by the MAbs against ICAM-1, LFA-1 alpha and LFA-1 beta but not by anti-Mac-1 alpha MAb. Due to these results, ICAM-1 is considered to be a critical molecule involved in the pathogenesis of the leukocyte infiltration into the glomeruli in the heterologous phase of Masugi nephritis. Anti-ICAM-1 antibody may be beneficial in the treatment of leukocyte-mediated glomerular diseases.

Animals↗
PubMed1996

Biological characterization of gastric surface mucous cell line GSM06 from transgenic mice harboring temperature-sensitive simian virus 40 large T-antigen gene.

We investigated the biological features of gastric surface mucous cell line GSM06, established from transgenic mice harboring the temperature-sensitive simian virus 40 large T-antigen gene. GSM06 cells grew until confluent monolayers were formed at the permissive temperature (33 degrees C), showing that the cessation of cell growth may be due to contact inhibition. Moreover, the cells did not grow in a soft agar gel. However, chromosome numbers of the cells were not normal. When GSM06 cells were cultured in Daigo's T medium supplemented with growth factors and 10% fetal bovine serum at 33 degrees C for 1, 3 or 9 days, the cells gradually grew to confluent monolayers (day 9). Morphological observations revealed that the cells time-dependently formed microvilli-like structures and yielded periodic acid-Schiff-positive glycoproteins on the cell surface with the growth of the structures. When GSM06 cells were cultured on a membrane filter for 1-9 days, elevated transepithelial resistance was noted in a culture period-dependent fashion. On day 9, junctional complexes such as tight junctions and desmosomes were observed between the cells. In addition, prostaglandin E2 production was evoked from the cells from day 1. In order to determine cell viability, GSM06 cells were labeled with the fluorescence dye 2',7'-bis(carboxyethyl)-carboxyfluorescein. Exposure of GSM06 cells to ethanol (7.5-17.5%) elicited cell injuries in a concentration-related manner on day 1, whereas these cytotoxic effects were attenuated on days 3 and 9, suggesting that this protection may be, at least in part, related to the increased glycoproteins and transepithelial resistance. GSM06 cells possessing these unique characteristics should be highly useful as an in vitro model of gastric epithelium.

Animals↗
PubMed1996

Increased surface tension of the lung and surfactant in bleomycin-induced pulmonary fibrosis in rats.

The increased elastic recoil of the lung in bleomycin-induced pulmonary fibrosis in the rat is due in part to increased surface forces. This study was designed to determine the role of surface tension in situ and in vitro 21 d after instillation of bleomycin. Using sequentially measured pressure-volume curves generated with air, saline, air after lavage with Tween 20, and saline, surface tension was significantly higher in bleomycin-treated lungs than in untreated lungs (4.7 +/- 1.1 versus 1.8 +/- 0.2 dyne/cm, p < 0.01). Surface tension was determined in vitro with a Wilhelmy balance using bronchoalveolar lavage fluid, surfactant, and organic solvent lipid extracts of surfactant. Bleomycin treatment resulted in elevated minimal surface tensions: BALF (20.7 +/- 0.6 versus 13.6 +/- 3.8 dyne/cm, p < 0.02), isolated surfactant (12.0 +/- 1.3 versus 3.0 +/- 0.5 dyne/cm, p < 0.02), and the organic solvent lipid extracted surfactant (11.0 versus 3.2 dyne/cm). These results indicate that the physical properties of surfactant in lungs of rats treated with bleomycin are abnormal and contribute to the increased elastic recoil in this model of pulmonary fibrosis.

Animals↗
PubMed1996

Different effects of carboxy-terminal deletion in the adrenodoxin molecule on cytochrome c and acetylated cytochrome c reductions.

In immunoblotting analysis using a rabbit antibody to bovine adrenodoxin, the total proteins of the bovine adrenal cortex gave two bands, suggesting the presence of two forms of adrenodoxin in vivo: full-length and carboxy-terminal deleted adrenodoxins. To examine the effect of the carboxy-terminal deletion of adrenodoxin on its activity, cDNAs for Arg115stop mutant adrenodoxin and for Asp113stop mutant adrenodoxin were constructed. The wild type [Ad(2-128)] and carboxy-terminal deleted [Ad(2-114) and Ad(2-112)] recombinant adrenodoxins expressed in Escherichia coli were purified to give a single band on SDS-PAGE. They showed an A414/A276 value of 0.92. In an NADPH-cytochrome c reduction assay, the Km values for cytochrome c in the reconstituted system with AD(2-128), Ad(2-114) and Ad(2-112) were 39, 235 and 618 mM, respectively. The Vmax values were 638, 700 and 898 mol/min/mol flavin, respectively. In an NADPH-acetylated cytochrome c reduction assay, the maximum activity of Ad(2-128) was obtained at 50 mM NaCl, while the maximum activities of Ad(2-114) and Ad(2-112) were obtained at 100 mM NaCl; the latter values were 4-times higher than that of Ad(2-128). In the presence of 100 mM NaCl, the Km values for acetylated cytochrome c in the system reconstituted with Ad(2-128), Ad(2-114) and Ad(2-112) were 220, 33 and 22 microM, respectively. The Vmax values were 352, 305 and 382 mol/min/mol flavin, respectively. These results indicate that the effects of the carboxy-terminal deletion of adrenodoxin on NADPH-cytochrome c and acetylated cytochrome c reductions are different; the carboxy-terminal region (residues 113-128) of adrenodoxin largely contributes to the binding with cytochrome c but disturbs the binding with acetylated cytochrome c.

Acetylation↗
PubMed1996

Plasminogen activator activity in the bovine oocyte-cumulus complex and early embryo.

In this study fibrinolytic assay systems were used to assess the plasminogen activator (PA) potential and plasmin generating ability of oocyte-cumulus complexes isolated from preovulatory bovine follicles (2-8 mm diameter) and of fertilized oocytes from the day of fertilization up to, and including, the hatched blastocyst stage (day 12). During embryo development, the culture medium was changed every 24 hr and samples examined for PA activity. Irrespective of the stage of maturity, no plasminogen or PA could be detected in unfertilized oocytes from which the cumulus layer had been removed. Both plasminogen and PA were found in the cumulus layer indicating that this, rather than the oocyte, was the source of these proteins in the oocyte-cumulus complex. Following oocyte fertilization, no PA activity was detected in either the developing embryo or in the culture medium before day 7. When the embryos had developed to the expanded blastocyst stage, days 7-8, PA production began with activity being detected in both the embryos and their culture medium. Between days 8 and 12, when embryos had reached the hatched blastocyst stage, the PA activity had increased significantly (p<0.05). Analysis of the culture media confirmed this increase in production of PA activity and, based on zymography, it was estimated that the molecular weight of the PA was 78 k daltons.

Animals↗
PubMed1996

Total capsular calcification in a prolactinoma--case report.

A 42-year-old male presented with a prolactin-producing pituitary adenoma with an atypical radiological appearance. The tumor was incidentally found by magnetic resonance imaging, which demonstrated a cystic tumor in the enlarged and partially empty sella turcica. Computed tomography revealed the tumor was surrounded by calcification with an egg-shell appearance. The serum prolactin level was 37 ng/ml. The operative finding was a calcified shell-containing cystic tumor. Immunohistochemical staining revealed prolactin-positive cells. The combination of the unusual calcification, and enlarged and partially empty sella was considered to be a sequela of spontaneous degeneration of the tumor.

Adult↗
PubMed1996

[A case of abnormal hemoglobin (HbJ Cape Town) with high serum levels of HbAlc].

We describe a case of hemoglobinopathy detected on admission for examination for high blood glucose levels and abnormal liver function. In 1991, it was pointed out that he had postprandial hyperglycemia. In 1994, at age 60, he had lassitude and anorexia. He was admitted to our hospital on the suspicion of diabetes mellitus and liver disease. Glycosylated hemoglobin levels was very high, but the 75 gram oral glucose tolerance test result was within the normal range. After abstinence from alcohol, his glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and gamma glutamyl traspeptidase became normal. Diabetes was excluded and abnormal hemoglobinopathy had been suspected. We analyzed his abnormal hemoglobin. In isoelectro-phoresis a fast moving variant was detected suggesting the presence of abnormal hemoglobin at the cathode. We fractionated hemolytic globin by CM-chromatography and detected an abnormal peak before the alpha chain band. Subsequently, we sequenced isolated abnormal alpha chain and detected the substitution of Ariginine for Glutamamine at position 92 (Hb J Cape Town). So far he has not demonstrated any symptoms or signs of HbJ Cape Town. Hemoglobinopathy is not uncommon in aged people.

Amino Acids↗
PubMed1996

[Self-judgment of personality traits and cognitive dimensions of the self].

When people make a judgment as to whether a trait describes themselves or not, cognitive structure about the self must play an important role. Cognitive dimensions are a characteristic of such cognitive structure. The present study examined whether a self-referent information processing was mediated by cognitive dimensions of the self. For the purpose, Klein, Loftus, and Burton's task facilitation paradigm (1989) was adapted, which consisted of performing in succession two tasks, initial and target, for each trait adjective used. Experiment 1, which examined the evaluative dimension, showed that an evaluative processing in the target task was facilitated when the initial task was self-referent. Experiment 2, which examined six dimensions, showed that processing of the relevant dimension in the target task was facilitated when the initial task was self-referent. These results suggest that a self-referent information processing is mediated by cognitive dimensions of the self.

Adult↗
PubMed1996

[Rigid spine syndrome associated with marked hypoxemia and hypercapnia].

A 48-year-old man was referred to our hospital because of hypoxemia (PaO2 = 43 mmHg), hypercapnia (PaCO2 = 70 mmHg), complete atrio-ventricular block, and heart failure. He also had limitation of spine flexion, scoliosis, deformity of the rib cage, and constriction of the ankle joints, complicated by cor pulmonale. These findings were compatible with rigid spine syndrome. To avoid progressive pulmonary hypertension and hypoxemia, nasal BiPAP and home oxygen therapy (0.5 liters/minute) were begun. Rigid spine syndrome is clinically characterized by limitation of spine flexion, and the limitation of thoracic movement often causes severe constrictive respiratory dysfunction. This syndrome should be considered when evaluating patients who have both thoracic deformity, especially scoliosis, and respiratory failure.

Heart Block↗
PubMed1996

[Two cases of malignant lymphoma with initial symptoms like orbital cellulitis and complicated by hemophagocytosis].

We reported 2 patients with malignant lymphoma complicated by hemophagocytic syndrome. Their clinical signs at onset were those of orbital cellulitis. Lymphoma complicated with hemophagocytosis is called lymphoma-associated hemophagocytosis syndrome (LAHS) and its prognosis is reported to be very poor. So far as we know, this is the first report in the ophthalmological field. In our patients, we suspected that the lesions occurred from the orbit or skin of this area. The first patient was a 22-year-old man and the second patient a 16-year-old girl. The diagnosis was very difficult at the onset of disease. Within 6 months after the first opthalmological examination, both died. When orbital cellulitis is suspected and antibiotic therapy is ineffective, we should suspect hemophagocytic syndrome (HPS) and should examine serum ferritin which is a good markers of HPS. Early biopsy and consultation with a hematologist are very important.

Adolescent↗
PubMed1996

[The role of anti L-asparaginase antibody in childhood acute lymphoblastic leukemia].

The function of IgG antibody with regard to L-asparaginase (L-asp) was investigated in vivo. Blood samples were collected before, during and after IV administration of L-asp (6,000 U/sqm for 10 days) in 18 children with acute lymphoblastic leukemia (ALL) previously treated with L-asp. Using enzyme-linked immunosorbent assay (ELISA), serum levels of L-asp and anti-L-asp IgG antibody were measured simultaneously. In 11 cases, the level of anti-L-asp IgG antibody increased prior to, but decreased to within the normal range after drug administration whereas the level of serum L-asp increased after drug administration. In 5 cases, the level of anti-L-asp IgG antibody increased as the level of serum L-asp decreased after drug administration. In contrast, in the 13 cases with no increase in anti-L-asp IgG antibody during L-asp administration, the serum L-asp level was stable. These data indicate that anti-L-asp IgG antibodies play an important role in the immunoclearance of L-asp. We would like to continue to carefully follow patients showing high titers of anti-L-asp IgG antibody during the administration of L-asp.

Antineoplastic Agents↗