Biomedical subjects

Rie Amano

Publications and source records attributed to Rie Amano.

5 recordsLinked to original sources

PubMed2006

Synthetic nucleosides and nucleotides. 43. Inhibition of vertebrate telomerases by carbocyclic oxetanocin g (C.OXT-G) triphosphate analogues and influence of C.OXT-G treatment on telomere length in human HL60 cells.

Telomerase, responsible for telomere synthesis, is expressed in approximately 90% of human tumor cells but seldom in normal somatic cells. In this study, inhibition by carbocyclic oxetanocin G triphosphate (C. OXT-GTP) and its analogues was investigated in order to clarify the susceptibility of telomerase to various nucleotide analogues. C. OXT-GTP competitively inhibited telomerase activity with respect to dGTP However, C. OXT-GTP had a potent inhibitory effect on DNA polymerase alpha. It was examined whether the nucleoside (C. OXT-G) was able to alter telomere length in cultured human HL60 cells. Contrary to expectation, long-term treatment with 10 microM C. OXT-G was found to cause telomere lengthening.

Animals↗

PubMed2003

Inhibition of vertebrate telomerases by the triphosphate derivatives of carbocyclic oxetanocin analogs.

Telomerase is a cellular endogenous reverse transcriptase that uses its internal RNA as a template for extension of the telomere repeat, thus maintaining telomere length. In order to clarify the susceptibility of telomerase to triphosphate derivatives of carbocyclic oxetanocins, inhibition by 9-[trans-trans-2,3-bis(hydroxymethyl)cyclobutyl]guanine triphosphate (C.OXT-GTP) and its methylene analog, 9-(cis-3-hydroxymethyl-2-methylenecyclobutyl)guanine triphosphate (m-C.OXT-GTP) was investigated. Both compounds showed potent inhibitory activity. Lineweaver-Burk plot analyses showed that the inhibition mode of these compounds was competitive with dGTP, the Ki values for C.OXT-GTP and m-C.OXT-GTP being 2.0 microM and 4.9 microM, respectively, and thus smaller than the Km of dGTP (11 microM).

Adenine↗

PubMed2003

[Late onset diffuse lamellar keratitis].

BACKGROUND: Diffuse lamellar keratitis (DLK) is marked by the presence of diffuse or multifocal infiltrates confined to the laser in situ keratomileusis(LASIK) interface. These infiltrates are culture-negative, and the etiology is thought to be noninfectious. Most cases of DLK occur within the first week or two following surgery. CASE: We describe two cases of diffuse lamellar keratitis that occurred 3 months after LASIK. These patients were treated with intensive topical corticosteroids. RESULTS: We treated the patients with topical corticosteroids, with rapid improvement in patient symptoms, visual acuity, and slit-lamp biomicroscopy. CONCLUSION: DLK may occur three months after LASIK.

Female↗

PubMed2002

Telomerase-inhibitory effects of sugar-modified nucleotide analogs.

Telomerase is an endogenous reverse transcriptase that uses its internal RNA moiety as a template for the synthesis of telomere repeats, thus maintaining telomere length. To study the susceptibility of telomerase to sugar-modified nucleotide analogs, inhibition by arabinofuranosylguanine 5'-triphosphate (araGTP), 3'-azido-2',3'-dideoxyguanosine 5'-triphosphate (AZdGTP), 2',3'-dideoxy-2'-fluoroarabino-furanosylguanine 5'-triphosphate (FaraGTP), and their thymine counterparts was investigated. Among these compounds, all dGTP analogs showed potent inhibitory activity against human telomerase. Conversely, dTTP analogs showed moderate or weak inhibition. Partially purified telomerase from cherry salmon testis utilized ddGTP and AZdGTP as substrates into the 3'-terminus of DNA.

Animals↗

PubMedDate not supplied

Late-onset diffuse lamellar keratitis.

BACKGROUND: Diffuse lamellar keratitis (DLK) is marked by the presence of diffuse or multifocal infiltrates confined to the laser in situ keratomileusis (LASIK) interface. These infiltrates are culture-negative, and the etiology is thought to be noninfectious. Most cases of DLK occur within the first week or 2 following surgery. CASES: We described 2 cases of DLK that occurred 3 months after LASIK. These patients were treated with intensive topical corticosteroids. RESULTS: Treatment with topical corticosteroid was instituted, with rapid improvement in patient symptoms, visual acuity, and slit-lamp biomicroscopic findings. CONCLUSION: DLK may occur as late as 3 months after LASIK.

Administration, Topical↗