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Biomedical subjects

T Funato

Publications and source records attributed to T Funato.

At least 19 recordsLinked to original sources

Detection of monoclonal proteins by capillary electrophoresis using a zwitterion in the running buffer.

Some cases have been reported in which a small monoclonal protein (M-protein) cannot be detected by conventional cellulose acetate membrane electrophoresis (CAE) or capillary zone electrophoresis (CZE) using a short fused-silica capillary. This is probably because these methods do not have the necessary sensitivity or resolution. To overcome this problem, we improved the CZE system by using a longer capillary and adding a zwitterion to the running buffer (pH 10.0). A comparison of CZE and CAE demonstrated that with the exception of alpha(1)- and alpha(2)-globulin, the correlation was satisfactory in serum samples from 34 patients with M-proteins which had been detected by immunoelectrophoresis. In addition, a comparison of CZE electropherograms with those from CAE showed that small M-proteins that went undetected by CAE could be detected by CZE in four patients whose diseases included epipharyngeal carcinoma, solitary plasmacytoma, Crow-Fukase syndrome and macroglobulinemia. The improved resolution produced by a longer capillary may be effective for the detection of small M-proteins.

Antibodies, Monoclonal↗

In vitro leukemia cell models of Ara-C resistance.

Cells of the human leukemia line K562 were continuously exposed to cytosine arabinoside (Ara-C) at increasing concentrations for 3 months. The resulting cell line, termed K562/AC, showed 48-fold resistance to Ara-C, compared with the parental K562 cells. The sensitivities of K562/AC to adriamycin (ADR), vincristine (VCR) and etoposide (VP16) were similar to those of parental K562. Gene analysis revealed that this cell line lacked expression of the deoxycytidine kinase (dCK) gene, which was evident in Ara-C-sensitive cells. As in K562 cells, multidrug resistance (MDR-1) and multidrug resistance protein (MRP) genes were not expressed in K562/AC. We also established an in vitro model of Ara-C resistance using phosphorothioate antisense oligonucleotides to dCK (dCK-AS). Treatment of K562 with dCK-AS caused decreased dCK expression and 6- to 10-fold increases in resistance to Ara-C, compared with that in cells treated with sense oligonucleotides to dCK (dCK-S) or in non-transfected cells. The cells described here may contribute to the study of a novel mechanism associated with Ara-C resistance, in which reduced dCK activity may play an important role.

Antimetabolites, Antineoplastic↗

A quantitative reverse transcriptase polymerase chain reaction method for the detection of leukaemic cells with t(8;21) in peripheral blood.

We evaluated the usefulness of a recently developed real-time reverse transcriptase polymerase chain reaction (RT-PCR) system to detect minimal residual diseases (MRD) in patients with acute myelogenous leukaemia (AML) with chromosomal translocation t(8:21). The method was simple, rapid and reproducible for the quantity of chimeric AML1-ETO (MTG8) transcripts. The ratio of the absolute copy number of a target gene (AML1-ETO) to a control gene (glyceraldehyde-3-phosphate dehydrogenase, GAPDH) was calculated by using a fluorescence curve prepared from amplicons of serially diluted standard RNA. The relative points of MRD in bone marrow (BM) of 8 patients in the acute phase of the disease was from 0.85 to 3.0, whereas those of MRD in complete remission (CR) decreased to below 6.4 x 10(-3). This method was also applied to evaluate chimeric transcripts in peripheral blood (PB) samples. The values in patients with t(8;21) AML were from 0.97 to 2.0 in the acute phase, whereas those in CR showed less than 2.2 x 10(-4). There was 10(-5)-fold difference in AML1-ETO mRNA expression between PB samples in the acute phase and those in CR. The results suggest that we may easily monitor MRD in patients with t(8;21) AML through quantitative analysis of AML1-ETO transcripts in blood samples.

Chromosomes, Human, Pair 21↗

Anti-K-ras ribozyme induces growth inhibition and increased chemosensitivity in human colon cancer cells.

Colon cancer is one of the carcinomas that is resistant to a variety of therapies. To develop a new therapy by regulating the activated K-ras gene in colon cancers, we prepared synthetic DNA encoding the ribozyme (catalytic RNA), and inserted it into an expression vector (LNCX) originated from a retrovirus. Transfection of the vector into SW620 human colon cancer cells brought about significant suppression of K-ras mRNA synthesis and inhibition of the cell growth. Studies in athymic mice, in which K-ras ribozyme-introduced SW620 cells were transplanted, also revealed a marked reduction of tumor growth in vivo. Furthermore, the ribozyme-introduced tumors became more sensitive to treatment with anti-cancer drugs such as cisplatin, adriamycin, 5-fluorouracil, vincristine, and etoposide. These data suggest that the possible efficacy of anti-K-ras ribozyme increases the chemosensitivity of human colon cancers as well as the inhibitory effect on the growth of human colon cancers.

Antineoplastic Agents↗

Compound heterozygous mutations (PHE53/54DEL and HIS373LEU) of the P450c17 gene result in a 17alpha-hydroxylase/17,20-lyase deficient male pseudohermaphrodite with unambiguous external genitalia.

The autosomal recessive disease 17alpha-hydroxylase/17,20-lyase deficiency is characterized by mutation of the P450c17 enzyme, which catalyzes 17alpha-hydroxylation and 17,20-lysis in the steroidogenic pathways. Although 17 mutations of this enzyme have been reported, only a few of them resulted in a completely unambiguous phenotype of female external genitalia in 46, XY individuals. We report here a Japanese patient with a 46,XY karyotype, who showed such a unambiguous female external genitalia. Nucleotide sequencing of the P450c17 gene revealed the patient to be a compound heterozygote carrying two different mutations (PHE53/54DEL in exon 1 and HIS373LEU in exon 6). As these mutations have been previously detected in unrelated Japanese patients, it is confirmed that these mutations accumulate regionally. Since these mutations could be screened by a multiple genotyping method, the method is applicable when 17alpha-hydroxylase/17, 20-lyase deficiency is suspected in Japanese patients.

Adrenal Hyperplasia, Congenital↗

[The construction of a standard RNA synthesized for quantitative RT-PCR system].

We constructed the standard RNA synthesized for the chimeric AML1-MTG8 transcripts and the house-keeping gene, glyceraldehyde-3-phosphate dehydrogenase(GAPDH) transcripts in real-time quantitative RT-PCR system. AML-MTG8 transcripts was detectable in 10 fg of synthetic RNA(3.5 x 10(3) copies). Linearity was from 3.5 x 10(3) to 3.5 x 10(9) copies. Threshold cycle(CT) is defined as the fractional cycle number at which the reporter fluorescence generated by cleavage of the probe passes a fixed threshold above baseline. The standard curve, where the known amounts of RNAs were used, showed a good correlation between the copies of AML1-MTG8 RNA and CT(r = -0.995). The within-run and day-to-day coefficients of variation(CV) in AML1-MTG8 RNA by this system were 9.5-24.7%(n = 10) and 21.7-42.2% (n = 8), respectively. GAPDH transcripts was detectable in 10 fg of synthetic RNA(6.1 x 10(4) copies). Linearity was from 6.1 x 10(4) to 6.1 x 10(8) copies. The standard curve, where the known amounts of RNAs were used, showed a good correlation between the copies of GAPDH RNA and CT(r = -0.993). The within-run and day-to-day CV in GAPDH RNA by this system were 9.3-14.6%(n = 10) and 14.7-15.8% (n = 10), respectively. Thus, we suggested that synthesized RNA as a standard RNA may be useful in quantitative RT-PCR for clinical application.

Core Binding Factor Alpha 2 Subunit↗

[Genetic diagnosis for drug resistance in cancers].

The failure of chemotherapy to eradicate tumor cells is often due to the development of drug resistance. MDR(multidrug resistance) whose one form of resistance results from a decreased intracellular accumulation of the drugs, most often mediated by the overexpression of P-glycoprotein. MRP also related to pump function of cell membrane in acute leukemia. We have developed the new quantitative assay based on real-time PCR to measure expression of drug-resistance related genes such as MDR-1 and MRP in clinical samples. These results indicates that real-time PCR system is a reliable method to quantitatively determine drug resistant genes expression, it may be to predict responsiveness to chemotherapy by using this technique.

Drug Resistance, Multiple↗

[Activities of antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. Levofloxacin--Surveillance Group].

The surveillance study was conducted to determine the antimicrobial activity of fluoroquinolones (ofloxacin, levofloxacin, ciprofloxacin, tosufloxacin) and other 20 antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. The resistance to fluoroquinolones was remarkable in Enterococci, methicillin-resistant staphylococci and Pseudomonas aeruginosa from UTI. However, many of the common pathogens such as Streptococcus pneumoniae including penicillin-resistant isolates, methicillin-susceptible Stahylococcus aureus, Moraxella catarrhalis, the family of Enterobacteriaceae, Haemophilus influenzae including ampicillin-resistant isolates have been kept to be susceptible to fluoroquinolones. About 90% of P. aeruginosa isolates from RTI were susceptible to fluoroquinolones. In conclusion, the results from this surveillance study suggest that fluoroquinolones are useful in the treatment of various bacterial infections including respiratory infections.

Anti-Infective Agents↗

Complete androgen insensitivity in a 47,XXY patient with uniparental disomy for the X chromosome.

We describe a unique patient with complete androgen insensitivity syndrome and a 47,XXY karyotype. Androgen receptor assay using cultured pubic skin fibroblasts showed no androgen-binding capacity. Sequence analysis of the androgen receptor gene demonstrated two nonsense mutations, one in exon D and one in exon E. Microsatellite marker analysis showed that the patient is homozygous for all five Xq loci examined. The results suggest that the long-arms of the two X chromosomes are identical, i.e., uniparental isodisomy at least for Xq, and carry the same mutations in the androgen receptor gene. This explains how complete androgen insensitivity syndrome occurred in this 47,XXY individual.

Adult↗

SRY mutation and tumor formation on the gonads of XP pure gonadal dysgenesis patients.

We report three patients with XY pure gonadal dysgenesis. Two of these patients developed gonadoblastoma and associated dysgerminoma. Molecular analyses were undertaken to investigate the relationship between the formation of these tumors and Y chromosome aberrations. Deletion analyses were performed by polymerase chain reaction (PCR) amplification of Y chromosome-specific DNA sequences (PABY, SRY, DYS250, DYS254, and DYZ1). A cryptic deletion of the short arm of the Y chromosome that included the PABY, SRY, DYS250, and DYS254 loci was observed in one of the patients (22-years-old) with an associated tumor. In the other two patients who did not demonstrate such a deletion, the sequence of the SRY open reading frame was determined by the dideoxynucleotide method. Two nucleotide substitutions followed by a seven nucleotide deletion were observed in the 3' end of HMG (high mobility group)-box in the other patient (15-years-old) with an associated tumor. The patient (22-years-old) without an associated tumor did not have the cryptic deletion or mutation of SRY. A Y chromosome specific sequence (DYZ1) was demonstrated by PCR amplification of microdissected tumor tissues from these two patients. These results suggest that SRY may play a role in the formation of gonadal tumors, especially dysgerminoma.

Adolescent↗

Point mutations in the steroid-binding domain of the androgen receptor gene of five Japanese patients with androgen insensitivity syndrome.

We analyzed the androgen receptor (AR) gene in five Japanese patients diagnosed with androgen insensitivity syndrome (AIS). All AR genes from the five patients had single-nucleotide substitutions, which introduced a premature termination codon in three patients (Gln640, Arg752, and Gln640 and Trp751), and a single amino acid substitution in two patients (Arg831 to Gln, and Leu812 to Phe). All the mutations occurred in the steroid-binding domain, comprising exons D through G. The three patients with the premature termination codon(s) and the one patient with Arg831Gln were clinically diagnosed as having complete AIS, while the patient with Leu812Phe had a partial form of AIS. Pubic skin fibroblasts from four of the five patients did not show detectable androgen binding. These data on mutations that have not been reported previously, provide valuable information for the further characterization of structural and functional relationships in the steroid-binding domain of the AR protein.

Adult↗

G-CSF induces apoptosis of a human acute promyelocytic leukemia cell line, UF-1: possible involvement of Stat3 activation and altered Bax expression.

Granulocyte colony-stimulating factor (G-CSF) is a cytokine that regulates the proliferation, differentiation and survival of cells in the granulocytic lineage. In this study, however, we found that G-CSF or interleukin-6 (IL-6) induced UF-1, a human acute promyelocytic leukemia cell line, into apoptosis that was confirmed by morphological features and DNA fragmentation. This rare response is demonstrated for the first time with human acute promyelocytic leukemia cell line. The apoptosis induced by G-CSF or IL-6 was not preceded by terminal differentiation characterized by morphological maturation, capability to reduce nitroblue tetrazolium, or surface CD11b expression. Interestingly, Western blot analysis revealed that the stimulation of UF-1 with either G-CSF or IL-6 resulted in excessive activation of both signal transducer and activator of transcription 3alpha (Stat3alpha) and Stat3beta. Furthermore, an additional 18 kDa Bax-related protein was expressed by the stimulation of G-CSF or IL-6, while Bcl-2 and Bcl-X proteins remained unchanged. These findings suggest that UF-1 may be a valuable tool in investigating the aberrant regulation of apoptosis, especially the Stat3 involvement in the mechanism of apoptosis induction.

Apoptosis↗

[In vitro activities of 23 antimicrobial agents against 4,993 gram-positive and gram-negative bacterial strains isolated from multicenter of Japan during 1994--in vitro susceptibility surveillance.Levofloxacin-Surveillance Group].

In a surveillance study conducted during 1994 at 24 medical institutes from different geographical areas of Japan, the susceptibility of clinical isolates to twenty three comparative agents, such as ofloxacin, levofloxacin, ciprofloxacin, tosufloxacin, ampicillin, clavulanic acid/amoxicillin, oxacillin, piperacillin, cefaclor, cefotiam, cefdinir, cefclidin, ceftazidime, cefpirome, imipenem, aztreonam, vancomycin, minocycline, chloramphenicol, clarithromycin, sulfamethoxazole/trimethoprim, amikacin, and gentamicin, were tested by the standard broth micro-dilution method. A total of 4,993 isolates tested in this study included Streptococcus pneumoniae, methicillin susceptible Staphylococcus aureus (MSSA), methicillin resistant Staphylococcus aureus (MRSA), coagllase negative streptococci (CNS), Enterococcus faecalis, Enterococcus faecium, Enterobactericeae, Pseudomonas aeruginosa from patients with urinary tract infections or respiratory tract infections, and Haemophilus influenzae. For MSSA, S. pneumoniae, Enterobacteriaceae, and H. influenzae, more than 70% of the isolates was susceptible to fluoloquinolones. However, resistance occurred in more than 50% of MRSA and P. aeruginosa isolated from UTI. Fluoroquinolones were found to be effective against high level penicillin-resistant S. pneumoniae, the third generation cephem-resistant Enterobacteriaceae and ampicillin-resistant H. influenzae.

Anti-Bacterial Agents↗

[Oncogenes and tumor suppressor genes as a tool for clinical diagnosis of solid tumors].

Over the past few years, numerous clinical studies have examined genetic technology to detect physical alterations of genes, such as mutations, translocations and amplification of oncogenes, deletion of tumor suppressor genes, the presence of oncogenic viruses, and the expression of genes specific to cancer tissues. The ability to identify individuals at high risk for cancer holds the promise of improved prevention and early diagnosis of cancers. The goal of genetic diagnosis in cancer is to provide information on abnormal oncogenes and tumor suppressor genes using recent molecular biology techniques. We introduced a highly sensitive method of detecting micrometastasis using PCR in prostate cancer, and strategies for guidelines in clinical diagnosis.

Genes, Suppressor↗

[Detection of K-ras mutations in colon cancer by PHA-PHFA (preferential homoduplex formation assay)].

The mutations of K-ras gene have been demonstrated at frequencies of about 40% in human colorectal cancer. We applied a developed PCR-preferential homoduplex formation assay (PCR-PHFA) to detect a point mutation of K-ras gene in the surgical specimens from thirty patients with colorectal cancer. This method is based on the strand competition during hybridization between a double labeled amplicon, prepared from biotin and DNP labeled primers, and an unlabeled amplicon. The procedure of this method is simple and speedy, and suitable to detect mutations in a small number of samples. By using this method, the mutations were found in 37% (11/30) and confirmed by sequencing analysis. The results suggest that the PCR-PHFA system may be useful for detecting low frequent mutation of K-ras gene even in the case of an early cancer.

Colorectal Neoplasms↗