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Biomedical subjects

K Endo

Publications and source records attributed to K Endo.

At least 505 records · Page 28Linked to original sources
PubMed1993

A novel form of cytochrome P-450 family 4 in human polymorphonuclear leukocytes. cDNA cloning and expression of leukotriene B4 omega-hydroxylase.

Isolation of cDNA clones for human leukotriene B4 (LTB4) omega-hydroxylase clearly demonstrates that the hydroxylase is a member of the cytochrome P-450 (CYP) superfamily. cDNA clones isolated from a human leukocyte cDNA library with CYP4A4 cDNA as a probe encode a protein of 520 amino acids with a molecular weight of 59,805. The deduced amino acid sequence contains an invariant cysteine in the conserved heme-binding domain near the C terminus, characteristic of the P-450 superfamily. The microsomes from yeast cells transfected with an expression vector pAAH5 carrying isolated cDNA catalyzed the omega-hydroxylation of LTB4 with a Km value of 0.71 microM, and its activity was significantly inhibited by carbon monoxide and by antisera against CYP4A4, consistent with the properties previously reported with LTB4 omega-hydroxylase in human polymorphonuclear leukocytes. The amino acid sequence of LTB4 omega-hydroxylase (P-450LTB omega) shows 31-44% similarity to those of CYP4A, CYP4B, and CYP4C, whereas less than 25% similarity was observed with any of the other P-450 families. According to the systematic classification of the P-450 superfamily, P-450LTB omega is classified into the CYP4 family but does not belong to any of the known CYP4 subfamilies. This P-450 composes a new subfamily of CYP4. RNA blot analysis indicated that mRNA hybridized to the cDNA was expressed in the polymorphonuclear leukocytes as well as leukocytes from four individuals. Isolation of the cDNA opens the way to investigate the physiological role and to regulation of the omega-hydroxylase in the inflammation process.

Amino Acid Sequence↗
PubMed1993

Mechanism of inhibition of IgE-dependent histamine release from rat mast cells by xestobergsterol A from the Okinawan marine sponge Xestospongia bergquistia.

Histamine release from rat peritoneal mast cells induced by anti-IgE was essentially complete within 4-5 min. Xestobergsterol A and B, which are constituents of the Okinawan marine sponge Xestospongia bergquistia Fromont, dose-dependently inhibited anti-IgE-induced histamine release from rat mast cells. The IC50 values of xestobergsterol A and B for histamine release in mast cells activated by anti-IgE were 0.07 and 0.11 microM, respectively. Anti-IgE stimulated PI-PLC activity in a mast cell membrane preparation. Xestobergsterol A dose-dependently inhibited the generation of IP3 and membrane-bound PI-PLC activity. Moreover, xestobergsterol A inhibited Ca(2+)-mobilization from intracellular Ca(2+)-stores as well as histamine release in mast cells activated by anti-IgE. On the other hand, xestobergsterol B did not inhibit the membrane-bound and cytosolic PI-PLC activity, IP3 generation or the initial rise in [Ca2+]i in mast cells activated by anti-IgE. These results suggest that the mechanism of inhibition by xestobergsterol A of the initial rise in [Ca2+]i, of the generation of IP3, and of histamine release induced by anti-IgE, was through the inhibition of PI-PLC activity.

Animals↗
PubMed1993

Histamine release from rat mast cells induced by the inhibition of adenosinetriphosphatase for Na and K channels.

6-Tridecylresorcylic acid (TRA) caused histamine release from rat peritoneal mast cells in a dose-dependent manner. The release of histamine by TRA was also time dependent. On the other hand, high K+ (150 mM) strongly inhibited TRA-induced histamine release from rat mast cells. These results suggest that histamine release from mast cells might be associated with K+ channel activity.

Actomyosin↗
PubMed1993

Effect of a potent selective protein kinase C inhibitor on histamine release from rat mast cells.

3,10-Dihydroxy-10-[(dimethylamino)methyl]-2,3,9,10,11,12-hexahydro-9- methyl-9,12-epoxy-1H-diindolo[1,2,3-fg-3',2',1'-k1]pyrrolo[3,4- l][1,6]benzodiazocin-1-one (UCN-01) strongly and dose-dependently inhibited histamine release from rat peritoneal mast cells that was induced by anti-immunoglobulin E (anti-IgE), calcimycin (A 23187), and 1,2-o-tetradecanoyl-13-acetate (TPA). The concentrations of UCN-01 required for 50% inhibition of histamine release induced by anti-IgE, A23187, and TPA were 1.5, 2.7, and 1.4 nM, respectively; these values are similar to those for 50% inhibition of protein kinase C. These results suggest possible participation cells induced by various secretagogues.

Alkaloids↗
PubMed1993

Cryoprotective effect of egg yolk in cryopreservation of porcine embryos.

The objective of the present study was to assess the effect of egg yolk supplementation in solutions for either cooling or freezing of porcine embryos. In Experiment 1, porcine embryos collected on Day 3 to 7 (Day 0 = onset of estrus) were allocated to 12 experimental groups according to their developmental stages (four-cell to compact morula, early blastocyst to blastocyst, expanded blastocyst, and hatched blastocyst) and the concentrations of egg yolk (0, 5, and 10% (v/v)) for cooling to 0 degrees C. Whereas no embryos ranging from four-cell to blastocyst survived, the 10-min exposure to 0 degrees C despite egg yolk supplementation, expanded blastocysts and hatched blastocysts allocated to egg yolk-supplemented groups survived cooling to 0 degrees C. In Experiment 2, porcine expanded and hatched blastocysts collected on Day 6 or 7 were assigned to six experimental groups according to their developmental stages and the type of cryoprotectant used (10% glycerol, 11% Me2SO, and 10% propylene glycol) for freezing at -196 degrees C. All freezing solutions contained either 5 or 10% egg yolk. The embryos were equilibrated with one of the freezing solutions, cooled from 25 to -7 degrees C at 1 degree C/min, seeded at that temperature, then cooled to -36 degrees C at 0.3 degree C/min, and finally plunged into liquid nitrogen for storage. The frozen embryos were thawed by immersion in 37 degrees C water. After the cryoprotectants were removed by dilution, the embryos were cultured for 48 h to evaluate their viability.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Scintigraphic detection of xenografted tumors producing human basic fibroblast growth factor.

A murine monoclonal antibody 3H3 recognizes the basic fibroblast growth factor (FGF) and inhibits the growth of human glioblastoma cells both in vitro and in vivo. We studied the potential of a scintigraphic technique using the 3H3 antibody to detect tumors that produce basic FGF. 125I- and 111In-labeled 3H3 bound to U87MG human glioblastoma cells in vitro. U87MG cells were inoculated subcutaneously into nude mice. After development of the tumor, radiolabeled 3H3 was injected into the subcutaneous space surrounding the tumor. A high level of radioactivity from 3H3 was retained at the tumor, whereas an irrelevant antibody cleared rapidly from the injected site. Radiolabeled 3H3 was not retained in tumors that did not produce basic FGF. Scintigraphic detection of tumors expressing basic FGF would be valuable for the therapeutic application of the antibody.

Animals↗
PubMed1993

A human/mouse chimeric monoclonal antibody against CA125 for radioimmunoimaging of ovarian cancer.

Murine monoclonal antibody 196-14 recognizes the ovarian-cancer-associated antigen CA125, but the epitope it recognizes is different from that of monoclonal antibody OC125. We developed a human/mouse chimeric 196-14 using the variable regions of the murine 196-14 and human heavy-chain (gamma 1) and light-chain (kappa) constant regions. Cell binding and competitive inhibition assays using chimeric 196-14 labeled with 125I, 111In or 99mTc demonstrated that the in vitro immunoreactivity of the chimeric antibody was identical to that of the parental murine monoclonal antibody. However, in mice bearing human ovarian cancer xenografts, the clearance from blood was faster and absolute levels of accumulation in the tumor were lower for the 125I-labeled or 99mTc-labeled chimeric antibody than for the murine antibody labeled with the corresponding radionuclides. The tumor-to-blood radioactivity ratio was not significantly different between the chimeric antibody and the murine antibody, regardless of the radionuclide used for labeling. Chimeric antibody 196-14 labeled with 131I, 111In or 99mTc is promising for the radioimmunoimaging of ovarian cancer.

Adenocarcinoma↗
PubMed1993

Changes in CA125 release and surface expression caused by drugs in uterine cervix adenocarcinoma cells.

The effect of drugs on the release of CA125 antigen and the binding of anti-CA125 monoclonal antibody (MoAb) to malignant cells was evaluated in vitro. TMCC-1, uterine cervical adenocarcinoma cells, were exposed to dexamethasone (DEX), sodium n-butyrate (NaB), dibutyryl cyclic AMP (dbcAMP), retinoic acid (RA), calcitriol (VD3), and interferon-gamma (IFN-gamma). NaB, RA and VD3 increased CA125 release per cell and 125I-labeled anti-CA125 MoAb binding to the cells. DEX also increased the 125I-labeled anti-CA125 MoAb binding to the cells, and CA125 antigen release per cell was also slightly increased. IFN-gamma suppressed both CA125 release and 125I-labeled MoAb binding. A combination of DEX, VD3 and RA and increased the binding of MoAb to TMCC-1 cells, but the amount of bound MoAb was not significantly different from that obtained by single drug treatment. DbcAMP had no significant effect on enhancing MoAb binding. Drugs can increase the binding of anti-CA125 MoAb to malignant cells and they may be applied to increase the tumor uptake of radiolabeled MoAbs in vivo.

Adenocarcinoma↗
PubMed1993

In vivo instability of reduction-mediated 99mTc-labeled monoclonal antibody.

A murine monoclonal antibody that reacts with human osteogenic sarcoma (OST7) was reduced and directly labeled with 99mTc without any loss of immunoreactivity. No fragmentation of the antibody was detected by high performance liquid chromatography after the labeling. However, SDS-PAGE analysis of the labeled antibody demonstrated the presence of low molecular weight species. Although more than 95% of the radioactivity remained bound at the antibody after incubation with human serum for 24 h, 99mTc-labeled OST7 was cleared faster from the circulation than 125I-labeled OST7 or 111In-labeled OST7 in mice. Urinary and fecal excretion of 99mTc were higher than those of 125I. When the 125I-labeled antibody was dual-labeled with 99mTc, the blood clearance of 99mTc was faster than that of 125I, suggesting release of 99mTc from the antibody in vivo. 99mTc-labeled OST7, however, gave a higher tumor-to-blood ratio than 125I- or 111In-labeled OST7 in mice bearing human osteogenic sarcoma. The 99mTc-labeled antibody prepared by the direct method was unstable in vivo, but retained a good tumor targeting ability.

Animals↗
PubMed1993

Similarity and co-expression of tumour-associated antigens recognised by different monoclonal antibodies.

The concentration of carcinoembryonic antigen (CEA), CA130, CA125, SLX, CA19-9, SPan1, and tumour-associated glycoprotein 72 (TAG-72) in the culture supernatant of 15 cancer cell lines and in the sera of 58 cancer patients was measured, and the co-expression of these antigens was examined by double determinant immunoradiometric assays. The high correlation coefficient of the concentrations and significant binding in the double determinant assays indicated a close relationship between CA125 and CA130 and between CA19-9 and SPan1. There was variable binding of the 125I-labelled anti-SLX, anti-CA19-9, and anti-SPan1 antibodies to anti-CA130 beads that had been pre-incubated with the culture supernatants, suggesting the presence of the epitopes of SLX, CA19-9, and SPan1 on the molecule expressing CA130. Similarly, the epitopes of SLX, CA19-9, and SPan1 could be present on the molecule expressing CEA. 125I-labelled anti-CA19-9, anti-SLX, and anti-TAG-72 antibodies were bound in variable proportions to anti-CA130 beads or to anti-CEA beads that had been pre-incubated with patients' sera. However, CEA and CA130 were not expressed on the same molecule, either in the culture supernatant, or in patients' sera. In conclusion, the carbohydrate epitopes of CA19-9, SPan1, SLX, and TAG-72 could be present on the molecule recognised by the anti-CA130 or anti-CEA antibody; however, the epitopes of CA130 and CEA did not co-exist on the same molecule.

Antibodies, Monoclonal↗
PubMed1993

The gene for Machado-Joseph disease maps to human chromosome 14q.

Machado-Joseph disease (MJD) is an autosomal dominant, multisystem neurodegenerative disorder involving predominantly cerebellar, pyramidal, extrapyramidal, motor neuron and oculomotor systems. Although it was first reported in families of Portuguese-Azorean descent, MJD has also been described in non-Azorean families from various countries, being one of the most common hereditary spinocerebellar degenerations. With the use of highly polymorphic microsatellite DNA polymorphisms, we have assigned the gene for MJD to the long arm of chromosome 14 (14q24.3-q32) by genetic linkage to microsatellite loci D14S55 and D14S48 (multipoint lod score Zmax = 9.719).

Chromosome Mapping↗
PubMed1993

Fluctuating thyroid function depending on the balance between stimulating and blocking types of TSH receptor antibodies: a case report.

A 41-year-old hyperthyroid woman visited the hospital in April 1989. She spontaneously developed hypothyroidism in August 1989 and recurrent hyperthyroidism in November 1991. TSH binding inhibitor immunoglobulins (TBII) and thyroid-stimulating antibodies (TSAb) activities were 34.7% (normal range, < 11.0%) and 295.0% (normal range, < 145.0%), respectively, at her first visit. When she was hypothyroid, TBII were 85.9-90.0%, TSAb were 75-190%, and thyroid stimulation-blocking antibodies (TSBAb) activities were 80.0-96.6% (normal range, < 32.2%). When she became hyperthyroid again, TSAb activities were markedly increased to 1108% with TBII and TSBAb activities being 82.2 and 62.8%, respectively. The results indicate that both stimulating and blocking types of TSH receptor antibodies were present in her serum and that her fluctuating thyroid function could be explained by alterations in the balance between the activities of these two types of antibodies.

Adult↗
PubMed1993

Functional analysis of cDNAs for two types of human heme oxygenase and evidence for their separate regulation.

We cloned a cDNA coding for a putative human heme oxygenase isozyme, designated type 2 (HO-2), and analyzed its function by transient expression assays. HeLa cells transfected with either HO-2 cDNAs or a cDNA coding for authentic heme oxygenase (HO-1) expressed the activity of heme oxygenase, although no activity was detected in the mock transfected cells. Using specific anti-HO-1 antibody, we showed that expression of a HO-1 cDNA resulted in the increase in its protein levels, but HO-1 protein was not detectable in the cells expressing HO-2 cDNAs. We thus confirmed the functional identity of HO-1 and HO-2. Then, we analyzed their expression in an erythroid cell line, YN-1-0-A. Treatment with hemin or by heat shock (42 degrees C) led to a remarkable increase in the HO-1 mRNA levels, while HO-2 mRNA expression was not induced at all, suggesting that they are under separate regulation.

Cell Line↗