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K Furihata

Publications and source records attributed to K Furihata.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Clinical evaluation of RT-PCR method for detection of HCV-RNA--with special reference to Amplicor HCV].

Detection of the viral genome in serum is the most reliable way to analyze HCV viremia. In the present study, we evaluated the availability of a new detection kit for HCV-RNA, Amplicor HCV, which is based on the RT-PCR microplate hybridization protocol. The procedure of Amplicor HCV is simple, unlike the conventional RT-nested-PCR method. Although Amplicor HCV assay exhibited the lower sensitivity than the the conventional RT-nested-PCR method (10 x for HCV type 1a, 1b and 2b; 10(3) x for type 2a), Amplicor HCV assay could detect the HCV-RNA in all HCV-RNA positive cases by conventional RT-nested PCR method, except for one case who contained low concentration of HCV-RNA (10 copies/ml). The coincidence rate was 99.2% in 120 clinical samples between two assays. Amplicor HCV assay, moreover, could efficiently evaluate the viremia regardless of anti-HCV-2 antibody titer. This assay was useful for monitoring the effect of interferon therapy during and after administration. These results suggest that Amplicor HCV has an excellent availability for the clinical laboratories.

Hepacivirus↗
PubMed1997

Quantitative analysis of human multidrug resistance 1 (MDR1) gene expression by nonisotopic competitive reverse transcriptase polymerase chain reaction assay.

We have established competitive reverse transcriptase polymerase chain reaction (RT-PCR) assay for the quantification of MDR1 mRNA encoding P-glycoprotein (P-gp) by analyzing leukemia sublines of MOLT-3 with various expression of MDR1. The expression was quantified by simultaneous RT-PCR of cellular RNA with decreasing amounts of heterologous competitor RNA, which shares the MDR1 primer sequences with the cellular MDR1 mRNA, but yields a different-sized PCR product. This allows resolution of the amplified cDNA fragments. The amounts of MDR1 mRNA measured by the assay were accurate and reproducible over wide range, and were determined as 31.6, 100, and 316 amol/microgram total RNA in MOLT-3/TMQ70, MOLT-3/ TMQ800, and MOLT-3/VCR1,000, respectively. The relative ratio of MDR1 mRNA measured by the competitive RT-PCR among three sublines was similar to that of MDR1 transcript determined by Northern analysis (1:4:12) and to that of P-gp measured by flow cytometry (FCM) analysis. In mononuclear cells from patients with leukemia, MDR1 mRNA could be sufficiently quantified by the competitive RT-PCR established, while FCM assay could scarcely detet P-gp. This study demonstrated that the competitive RT-PCR assay using heterologous competitor RNA is a rapid, reliable, and non-radioactive procedure and is acceptable for the evaluation of MDR1 expression in clinical samples.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

[Molecular characterization of platelet-specific alloantigens].

Platelet-specific alloantigens have been implicated in the pathogenesis of immune mediated diseases such as neonatal alloimmune thrombocytopenic purpura, post-transfusion purpura and platelet transfusion refractoriness. Recently, it has been paid attention in terms of an inherited risk factor for coronary thrombosis. Because all the established polymorphisms are located on important receptors for adhesive molecules, including integrins alpha 2 beta 1 and alpha IIb beta 3 and GPIb alpha, effects of these polymorphisms on function of the receptors have been studied. In this review, recent studies on molecular characterization of these polymorphisms will be described.

Antigens, Human Platelet↗
PubMed1997

[Determination of neutrophil function by measuring superoxide production with whole blood flow cytometry].

The function of neutrophil can be evaluated by measuring oxidative metabolism using chemiluminescence, tetrazolium dye reduction or the others. Those results are not always satisfactory which would be caused by subtle difference in each preparation of the reagents and the lack of reproducibility. Recently, flow cytometric procedures for semi-quantitating superoxide production in neutrophils have been developed to evaluate their function. This procedure, which requires only small amount of whole blood, can easily and rapidly yield reproducible and reliable data. In this study, we optimized analytical conditions and then determined reference interval to evaluate neutrophil function of patients with various disorders. Optimal concentrations and incubation times of DCFH-DA and PMA were 5 mumol/l for 15 minutes and 25 micrograms/ml for 20 minutes, respectively. Production of superoxide in neutrophil was represented by relative fluorescence intensity(RFI) with assay coefficient of variance(CV) of 4.0-11.1%. Neutrophils had to be examined within 2 hours after venipuncture to obtain reliable data. Reference interval was determined as 170.4 +/- 58.7(mean +/- SD) RFI. Neutrophil function of patients with neutropenia, paroxysmal nocturnal hemoglobinuria(PNH), renal failure, systemic lupus erythematosus(SLE), myeloperoxidase deficiency, myelodysplastic syndrome(MDS), and diabetes mellitus were within the reference interval as evaluated by this method. Only neutrophils of chronic granulomatous disease, which is known to give clearly low superoxide production, showed actually decreased value. These results indicate that this procedure would be clinically useful for diagnosis of patient with impaired neutrophil function.

Adult↗
PubMed1997

[Differentiation of selected abnormal hemoglobin by PCR-RFLP method].

Abnormal hemoglobin is one of the most frequent genetic disorder, of which about 700 variants have been reported in the world. Some abnormal hemoglobins such as HbS and HbC are endemic among limited human populations. We have found five subjects with abnormal hemoglobin in routine hematology analysis using an automated system Sysmex NE-7000. We isolated genomic DNA from the peripheral blood leukocyte of each subject, and amplified a 558 bp fragment of DNA including the entire exons 1 and 2 as well as intron 1 of the beta-globin gene. The amplified DNA fragments were subjected to direct sequencing by the dideoxy termination method on an automated DNA sequencer. The sequence analysis showed the abnormalities including HbA/C, HbS/C, HbE/E, and HbA/G-Szuhu. In the present study, we report a simple method for the mutual differentiation of these abnormal hemoglobins using restriction fragment length polymorphism (PCR-RFLP) method. Digestion of the amplified fragments described above with a restriction enzyme MnlI gave different RFLP patterns for HbA, HbC or S, HbE, and for HbG-Szuhu. RFLP using another enzyme, DdeI, could distinguish for HbS from HbC.

Hemoglobins, Abnormal↗
PubMed1996

Fibrinogen Matsumoto II: gamma 308 Asn-->Lys (AAT-->AAG) mutation associated with bleeding tendency.

Fibrinogen Matsumoto II is a hereditary dysfibrinogenaemia identified in a woman with Basedow's disease and a bleeding tendency. Coagulation tests of the patient's plasma revealed a prolonged thrombin time and a decreased fibrinogen level determined by functional method. Release of fibrinopeptide A and B was normal, whereas fibrin monomer polymerization was delayed. Fibrinogen gamma-chain gene of the propositus was heterozygous for a missense mutation that resulted in Asn-->Lys substitution at codon 308. Though the same amino acid substitution was also attributed to fibrinogen Kyoto I and Bicetre II, fibrinogen Matsumoto II showed different clinical manifestations from them.

Afibrinogenemia↗
PubMed1996

Inhibitory effect of 220-oxa-1,25-dihydroxyvitamin D3 on the proliferation of pancreatic cancer cell lines.

BACKGROUND & AIMS: Effective chemotherapy for pancreatic cancer is urgently needed. The aim of this study was to compare the anti-proliferative activity of a new vitamin D3 analogue, 22-oxa-1,25-dihydroxyvitamin D3 (22-oxa-calcitriol), on pancreatic cancer cells lines with that of 1,25-dihydroxyvitamin D3 (calcitriol) with analysis of vitamin D receptor status. METHODS: Antiproliferative effects of both agents were compared using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method and by measuring the tumor size of xenograft inoculated into athymic mice. Vitamin D receptor contents by Scatchard analysis and mutational analysis of receptor complementary DNA were performed. RESULTS: In vitro, 22-oxa-calcitriol and calcitriol markedly inhibited the proliferation (3 of 9 cell lines) and caused a G1 phase cell cycle arrest by appearance of numerous domes. In vivo, 22-oxa-calcitriol inhibited the growth of BxPC-3 xenografts more significantly than calcitriol without including hypercalcemia. Hs 766T, showing no response to either agent, had the second highest receptor contents with no abnormalities in its primary structure deduced by receptor complementary DNA. CONCLUSIONS: 22-oxa-calcitriol may provide a more useful tool for the chemotherapy of pancreatic cancer than calcitriol. Also, the susceptibility of the cell lines to both agents is not well determined by evaluating either the contents or the mutation of vitamin D receptor.

Animals↗
PubMed1996

Gs alpha mutation may be uncommon in patients with multiple endocrine neoplasia type 1.

Activating mutations of the Gs alpha gene, termed gsp, have been identified in various endocrine tumors. Recently, a high frequency of gsp mutation in patients with multiple endocrinopathies was reported, and a family with both McCune-Albright syndrome and multiple endocrine neoplasia type 1 was described. Each suggests that the oncogenic mutations of Gs alpha may play an important role in tumorigenesis in patients with multiple neoplastic endocrinopathies, and a search for the gsp mutation in multiple endocrine neoplasia type 1 (MEN1) should be undertaken. We, therefore, reevaluated the frequency of gsp mutations in endocrine tumors of patients with MEN1. Of 18 tumors from 13 patients with MEN1, we found no gsp mutations regardless of heredity. We conclude that the gsp mutation may be uncommon in endocrine tumors of MEN1 patients, and thus, this mutation plays little, if any, role in their tumorigenesis.

Adult↗
PubMed1996

Studies on new antitumor antibiotics, leptofuranins A, B, C and D.I. Taxonomy, fermentation, isolation and biological activities.

The retinoblastoma protein (pRB) is inactivated in a wide variety of human cancers. In the course of our screening for antitumor antibiotics by using pRB-inactivated cells, an actinomycete identified as Streptomyces tanashiensis was found to produce four new active substances, leptofuranins A, B, C and D. The leptofuranins arrested the growth of normal cells and induced apoptotic cell death against tumor cells and cells transformed with the adenovirus E1A gene.

Animals↗