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Biomedical subjects

R Irie

Publications and source records attributed to R Irie.

At least 19 recordsLinked to original sources
PubMed2001

Asymmetric epoxidation with a photoactivated [Ru(salen)] complex.

(Nitrosyl)(salen)ruthenium(II) complex 1 was found to serve as an efficient catalyst for the epoxidation of conjugated olefins under photoirradiation, with 2,6-dichloropyridine N-oxide (2) or tetramethylpyrazine N,N'-dioxide as a stoichiometric oxidant. High enantioselectivity was achieved irrespective of the substitution pattern of olefins. The choice of solvent depends on stability of the resulting epoxides: high enantioselectivity is generally observed in the reaction with ethereal solvents, but use of benzene is recommended when the resulting epoxides are acid-sensitive.

Journal Article↗
PubMed2001

RBP1L1, a retinoblastoma-binding protein-related gene encoding an antigenic epitope abundantly expressed in human carcinomas and normal testis.

BACKGROUND: Antibodies isolated from cancer patients have been used to identify genes encoding tumor-associated antigen epitopes relevant to immune responses in cancer patients. In this report, we used an immunoglobulin G (IgG) purified from serum of a patient with breast cancer to identify its corresponding epitope, gene, and protein-retinoblastoma-binding protein-1-like protein-1 (RBP1L1)-and determined whether it is a potential molecular marker for various cancers. METHODS: IgG purified from the serum of a patient with breast cancer was used to screen an MCF-7 breast cancer cell complementary DNA (cDNA) expression library for immunoreactive clones. The cDNAs identified were cloned and sequenced. Immunoreactivity of specific amino acids in the epitope was determined by western blot analysis and enzyme-linked immunosorbent assay. The cellular location of the antigen was determined by immunoperoxidase staining with purified RBP1L1-specific IgG. Gene expression in various human carcinomas and normal tissues was examined by northern blot analysis and the reverse transcription-polymerase chain reaction. RESULTS: Our purified IgG recognized just one epitope on RBP1L1. The complete 5802-base-pair RBP1L1 cDNA encodes a 1226-amino acid protein containing the antigenic epitope IKPSLGSKK. The derived protein sequence of RBP1L1 shares 74% and 37% amino acid identity, respectively, with a partial sequence of the retinoblastoma-binding protein and the complete sequence of retinoblastoma-binding protein-1. The RBP1L1 epitope was localized to the cytoplasm of MCF-7 cells but was not detected in peripheral blood mononuclear cells. High expression of RBP1L1 messenger RNA was found in human breast, lung, colon, pancreatic, and ovarian cancers and in normal testis, but expression was limited in other normal tissues. CONCLUSIONS: RBP1L1 appears to be a molecular marker associated with a broad range of human malignancies.

Biomarkers, Tumor↗
PubMed2001

HUNT: launch of a full-length cDNA database from the Helix Research Institute.

The Helix Research Institute (HRI) in Japan is releasing 4356 HUman Novel Transcripts and related information in the newly established HUNT database. The institute is a joint research project principally funded by the Japanese Ministry of International Trade and Industry, and the clones were sequenced in the governmental New Energy and Industrial Technology Development Organization (NEDO) Human cDNA Sequencing Project. The HUNT database contains an extensive amount of annotation from advanced analysis and represents an essential bioinformatics contribution towards understanding of the gene function. The HRI human cDNA clones were obtained from full-length enriched cDNA libraries constructed with the oligo-capping method and have resulted in novel full-length cDNA sequences. A large fraction has little similarity to any proteins of known function and to obtain clues about possible function we have developed original analysis procedures. Any putative function deduced here can be validated or refuted by complementary analysis results. The user can also extract information from specific categories like PROSITE patterns, PFAM domains, PSORT localization, transmembrane helices and clones with GENIUS structure assignments. The HUNT database can be accessed at http://www.hri.co.jp/HUNT.

Computational Biology↗
PubMed2000

Short step enantioselective synthesis of (-)-swainsonine.

Recent discovery of asymmetric desymmetrization of meso-heterocycles using (R,R)-(salen)manganese complex 2 as a catalyst allowed easy access to optically active 2,3,4-trisubstituted pyrrolidines. Taking advantage of this new reaction, we could achieve the short-step synthesis of (-)-swainsonine 1.

Alkaloids↗
PubMed2000

Maximizing yellow pigment production in fed-batch culture of Monascus sp.

Yellow pigment production in exponential fed-batch cultivation of Monascus sp. was studied. Due to the difficulty of measuring the optical density for accurate determination of the cell concentration, a capacitance probe was employed on-line. The feed rate needed to keep the specific growth rate, mu, constant in fed-batch culture was determined on the basis of the cell concentration measured by the capacitance probe. Control of mu was improved by using updated information on the cell concentration compared with the simple feed-forward determination method using the initial cell concentration only. The highest specific pigment production rate was achieved with a mu of 0.02 h(-1) in the feeding phase. However, among several fermentation examined, the largest pigment production in the final step was obtained at a mu of 0.01 h(-1); in each case the same amount of substrates was used. An investigation of the optimal initial glucose concentration revealed that pigment production was maximum when the initial glucose concentration in the batch mode was 10 g/l and mu was 0.01 h(-1) in the fed-batch mode. It was also found that the pellet weight in the fermentation could be accurately estimated by image analysis. The ratio of the mycelium weight to the total cell weight estimated from information on the total cell weight and the estimated pellet weight was found to be more than 80%. However, no clear quantitative relationship could be discerned between the specific pigment production rate, rho, and the ratio of mycelium in the cell population.

Journal Article↗
PubMed2000

An integrated analysis and database system for full-length cDNA.

Annotation and database system of full-length cDNA sequences was developed. As the components of the system, ORF annotation system, functional annotation system based on database search results, mapping annotation system, and integrated retrieval and display system were developed. In the ORF annotation system integrated analyses using conventional tools are performed and useful retrieval interface using motif list are introduced. In the functional annotation system based on database search results, a new method that characterizes a given unknown cDNA was developed by using a profile of similarity level over words appearing in sequence database entries. In the mapping annotation system, we linked by similarity searches full-length cDNA sequences with database DNA sequences that are already mapped on chromosomes. By using these links, full-length cDNAs can be retrieved by the retrieval condition of physical mapping information. Genetic disease information mapped on the physical mapping site can also be displayed by this system. Furthermore, we constructed an integrated database system for these analyzed data, and thus enabled annotation and selection of full-length cDNAs from points of both gene function and mapping information.

Chromosome Mapping↗
PubMed1999

DNA sequence comparison considering both amino acid and nucleotide insertions/deletions because of evolution and experimental error.

Amino acid similarity often needs to be considered in DNA sequence comparison to elucidate gene functions. We propose a Smith-Waterman-like algorithm which considers amino acid similarity and insertions/deletions in sequences at the DNA level and at the protein level in a hybrid manner. The algorithm is applied to cDNA sequences of Oryza sativa and those of Arabidopsis thaliana. The results are compared with the results of application of NCBI's tblastx program (which compares the sequences in the BLAST manner after translation). It is shown that the present algorithm is very helpful in discovering nucleotide insertions/deletions originating from experimental errors as well as amino acid insertions/deletions due to evolutionary reasons.

Algorithms↗
PubMed1995

Immunohistological reaction mechanism of anti-monosialoganglioside monoclonal antibody, MAb 202, showing predominant cytotoxicity for malignant melanoma.

Mouse monoclonal IgM antibody (MAb 202) can cause melanoma cell necrosis in vivo. We analysed its immune mechanism in three melanoma patients to whom MAb 202 was administered. After the MAb 202 administration, histopathological analysis showed necrosis of melanoma cells expressing only GM3 in two patients. Another patient carrying both GM3 and GD3 showed infiltration of lymphocytes within the tumor nest but no tumor cells or nest necrosis. Immunohistological examination using anti-mouse IgM antibody revealed MAb 202 bound on the surface of melanoma cells in two patients but not in the third (positive for both GM3 and GD3). In vitro, MAb 202 reacted with the melanoma cells of the same two patients, but not with any other tissues of these individuals. We found no reaction of MAb 202 to non-melanoma cells including normal melanocytes and glia cells. Our trials suggest, 1) MAb 202 reacts directly to monosialogangliosides on the melanoma cell surface and then leads to the cytotoxicity reaction, or 2) MAb 202 induces lymphocyte infiltration and possibly then promotes the secretion of some cytokines.

Adult↗
PubMed1993

[Leiomyosarcoma of ileocecal mesentery--a case report].

We report a case of leiomyosarcoma whose origin was near the root of ileocecal mesentery and extended into the retroperitoneum. Preoperative imaging examination, including CT, MRI and angiography clearly displayed its origin and retroperitoneal extension. These results contributed to treatment planning.

Cecum↗
PubMed1992

Chalcone tetramers, lophirachalcone and alatachalcone, from Lophira alata as possible anti-tumor promoters.

Two chalcone tetramers were isolated as inhibitors of Epstein-Barr virus (EBV)-activation induced by a tumor promoter, teleocidin B-4, from a medicinal plant in tropical west Africa, Lophira alata (Ochnaceae). One of them was identified as lophirachalcone. The other, named alatachalcone, was new, and the structure was determined by spectral properties. Both compounds also showed potent inhibitory activities against teleocidin B-4-induced inflammation on mouse ear. In an initiation-promotion experiment on mouse skin, alatachalcone (16 nmol) significantly inhibited tumor promotion caused by 12-O-tetradecanoylphorbol-13-acetate (TPA, 1.6 nmol).

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1991

Inhibitory effects of new types of biflavonoid-related polyphenols; lophirone A and lophiraic acid, on some tumor promoter-induced biological responses in vitro and in vivo.

Lophirone A, isolated as a new type of biflavonoid-related inhibitor of Epstein-Barr virus (EBV) activation, was tested for further inhibitory properties against tumor promotion by short-term system. Lophirone A (200 micrograms) significantly inhibited inflammation of mouse ear (inhibitory effect (IE) = 70%) by 12-O-hexadecanoyl-16-hydroxyphorbol-13-acetate (HHPA, 2 micrograms). It also inhibited both Ca(2+)- and phospholipid-dependent protein kinase C (PKC) activation by 12-O-tetradecanoylphorbol-13-acetate (TPA, IC50 = 50 microM). Application of lophirone A (160 nmol) reduced the number of tumors per mouse (IE = 85%) in an initiation-promotion experiment using dimethylbenz[a]anthracene (DMBA, 0.19 mumol) and TPA (1.6 nmol) on ICR mouse skin. Lophiraic acid, a related polyphenol, was negative in all of the short-term tests. An important chemical factor which may reduce the activities of flavonoid class of inhibitors for tumor promotion was indicated.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1990

Ganglioside composition of human melanoma and response to antitumor treatment.

Ganglioside composition of human melanoma was correlated with sensitivity of melanoma to antitumor treatment with chemotherapeutic agents and radiation. The cytotoxic effect of each treatment was evaluated on 16 melanoma cell lines using the human tumor colony-forming assay. Ganglioside fractions were extracted and purified from each cell line and analyzed for the four major gangliosides in melanoma (GM3, GM2, GD3, and GD2) by thin-layer chromatography (TLC) and TLC scanner. GD2 content positively correlated with sensitivity to radiation (r = 0.753, p less than 0.001) and vincristine (r = 0.779, p less than 0.001). In contrast, GM3 content inversely correlated with sensitivity to radiation (r = -0.658, p less than 0.01) and vincristine (r = -0.692, less than 0.01). The gangliosides GD3 and GM2 were shown to have no significant correlation with any of these treatments.

Antineoplastic Agents↗
PubMed1989

Strong anti-tumor effect of monosialoganglioside specific monoclonal antibody 202: a clinical trial in a cancer patient with melanoma.

Mab 202, a mouse monoclonal IgM antibody which recognizes sialic acid alpha 2----3 galactosyl residue in monosialogangliosides and reacts with human melanoma cells but not with normal cells, was administered to a melanoma patient by either intralesional injection or intravenous infusion. Mab 202 induced regressions of the metastatic tumors without side effects. Histopathologic examination showed remarkable degenerative and necrotic changes in the tumor, around which lymphocytes, eosinophils, plasma cells and macrophages infiltrated. Immunoperoxidase staining revealed Mab 202 binding to melanoma cells. Clinical and pathologic evidence suggested that Mab 202 has cytotoxic effects against melanoma cells. Mab 202 may therefore be useful in the treatment of human malignant melanoma.

Antibodies, Monoclonal↗
PubMed1987

Expression of alien H-2 and non-H-2 antigens on a murine mammary tumor cell line, MM46.

Tumor-associated surface antigens on MM46, a transplantable ascites tumor from a spontaneous mammary carcinoma in a C3H/He mouse, were investigated. A complement-dependent microcytotoxicity test showed the expression of MM antigen, whose specificity appeared to be identical or cross-reactive with that of Ly-6.2 antigen, as reported previously. Moreover, MM46 was also found to express alien H-2 antigenic specificities, H-2.31 and H-2.28. H-2.31 represents the private specificity of the H-2Kd molecule, while H-2.28 represents a public specificity among molecules encoded by H-2K, H-2D, and H-2L loci in the majority of original H-2 haplotypes, including H-2d, but not H-2k, of inbred laboratory mice. The expression of MM antigen was found to be closely associated with the appearance of hypotetraploid tumor cells. These results suggest that alien H-2 and non-H-2 antigens appeared during ascites tumor cell conversion.

Aneuploidy↗
PubMed1983

Impaired glucose tolerance related to changes in the energy metabolism of the remnant liver after major hepatic resection.

In 70% hepatectomized rabbits, the glucose tolerance patterns after an oral glucose load were characterized by a longstanding increase of blood glucose for more than 180 min (a linear pattern) at 24 hr after hepatectomy and by a return toward normal range within 180 min (a parabolic pattern) at 96 hr later. At the linear stage, the concentrations of pyruvate and lactate of the remnant liver increased to 192% and 203%, respectively, of sham-operated controls at 1 hr after an oral glucose load. At 3 hours after glucose load, the concentrations of glucose-6-phosphate, fructose-6-phosphate, pyruvate, and lactate increased to 191%, 192%, 174% and 298%, respectively. By contrast, at the parabolic stage, no significant changes were observed. On the other hand, the energy charge level of the remnant liver decreased to 0.767 at the linear stage and returned to near normal levels at the parabolic stage. The ketone body ratio (acetoacetate/beta-hydroxybutyrate) in the arterial blood decreased to 0.415 at the linear stage, concomitant with the increase in total ketone body and NEFA concentrations, and returned to near normal levels at the parabolic stage. These findings suggest that the reduced mitochondrial redox potential, reflected by the decrease in ketone body ratio, inhibits pyruvate dehydrogenase. This prevents the entrance of pyruvate into the Krebs cycle and results in the inhibition of glucose oxidation, leading to a linear pattern after an oral glucose load.

Animals↗
PubMed1982

Clinical experience of postoperative hepatic failure treatment with pig or baboon liver cross-hemodialysis with an interposed membrane.

The present study emphasizes the principle of using liver support to restore the blood ketone body ratio (acetoacetate/beta-hydroxybutyrate), which reflects the redox potential of liver mitochondria and correlates with hepatic energy charge (ATP + 0.5ADP/ATP + ADP + AMP). Eleven surgical patients with grade IV hepatic coma were treated by an ex vivo pig or baboon liver cross-hemodialysis with an interposed Cuprophan membrane when their blood ketone body ratios had decreased to below 0.4 compared with the normal of above 0.7. Three patients were treated by cross-hemodialysis using a standard Cuprophan membrane dialyzer without increase of blood ketone body ratio and without marked beneficial effect. However, five of eight patients who had blood ketone body ratios of above 0.25 became fully alert after treatment by cross-hemodialysis using the larger pore size and greater surface area Cuprophan membrane, concurrent with a rise in the decreased blood ketone body ratio, and three of them were later discharged. By contrast, in the three patients with blood ketone body ratios below 0.25, there was no restoration of consciousness and no improvement in their blood ketone body ratios by this liver support. It is suggested that, as long as the blood ketone body ratio remained over 0.25, this metabolic liver support is effective in restoring grade IV hepatic coma.

Aged↗