Biomedical subjects

T Otsuki

Publications and source records attributed to T Otsuki.

At least 73 records · Page 4Linked to original sources

PubMed1999

Expression of fibroblast growth factor and FGF-receptor family genes in human myeloma cells, including lines possessing t(4;14)(q16.3;q32. 3) and FGFR3 translocation.

Recently several chromosomal translocations involved in myeloma cases and myeloma cell lines; i.e., t(11;14)(q13;q32), t('8;14)(q24;q32), t(4;14)(q16.3;q32.3), t(6;14)(p25;q32), and t(14;16)(q32.3;q23), have been identified. These translocations are considered to dysregulate genes which may be concerned with myelomagenesis; i.e., PRAD1/cyclin D1, the c-myc oncogene, FGFR3 (fibroblast growth factor receptor 3), MMSET (multiple myeloma SET domain), MUM1 (multiple myeloma oncogene 1)/IRF4 (interferon regulatory factor 4), and the c-maf oncogene, respectively. However, the cellular biological roles of these genes have not yet been elucidated in myeloma cells. Because two of the seven human myeloma cell lines which were established at Kawasaki Medical School, Okayama, Japan, KMS-11 and KMS-18, have been proven to possess t(4;14)(q16.3;q32.3), we studied the expression levels of the FGFR3 gene in these seven cell lines and 13 primary myeloma specimens. The expression levels of 12 known FGF family genes (FGF-1 to 12) and 4 FGFR genes (FGFR1 to 4) were also examined in seven cell lines. In addition, the growth status of the KMS-11 and KMS-18 lines with FGF-1 or anti-FGF-4 neutralizing monoclonal antibody (MoAb) supplementation was investigated because FGF-1 and 4 are known as the principal ligands for FGFR3. FGFR3 overexpression was observed in both of the cell lines possessing t(4;14)(q16.3;q32.3) and in 3 of 13 case specimens. Anti-FGF-4 neutralizing MoAb caused significant growth inhibition in these two cell lines possessing t(4;14)(q16.3;q32.3). These findings indicate that t(4;14) (q16. 3;q32.3) may provide myeloma cells with a growth advantage via an autocrine mechanism between FGFR3 and FGF-4.

Aged↗

PubMed1999

[Pathological features of dysembryoplastic neuroepithelial tumor (DNT): study of five surgical cases with intractable epilepsies].

The dysembryoplastic neuroepithelial tumor (DNT), characterized by its favorable prognosis, must be precisely differentiated from other gliomas to prevent overtreatment by radio/chemotherapy. We studied, here, pathological features of five surgical cases of DNT with intractable epilepsies. There were two males and three females with a median age of 20.4 years (range 12-41). We evaluated lesional topography, gross appearances and microscopic findings including immunohistochemical data. One tumor was located in the temporal lobe, another two in the parietal lobe, another in the occipital lobe, and the other one in the occipito-parietal junction. The lesions were predominantly intracortical in all cases. Macroscopically, two tumors were grayish-soft, another two were yellowish-elastic, and the other one was resected as soft-mucinous fragments. Microscopically, the main glial components were oligodendrocyte-like cells (OLCs) in all cases, except for one case in which atypical glial cells were also prominent. Histopathological characteristics of the DNTs included the specific glioneuronal elements (the mixture of OLCs and neurons) in four cases, alveolar pattern (all cases), microcystic degeneration (all cases), multinodular architecture (four cases), and adjacent cortical dysplasia (all cases). Immunohistochemically, Ki-67 labelling indices ranged from 0 to 0.8%. OLCs were positive for glial fibrillary acidic protein in two cases, for S-100 protein in all cases, for synaptophysin in two cases, and for class III beta tubulin in all cases. Pathological features of our cases were characterized by its heterogeneous histological appearances and divergent cellular differentiation.

Adolescent↗

PubMed1999

[Primary splenic lymphoma with t(3;14)(q27;q32) chromosomal abnormality and rearrangement of BCL-6 gene].

Primary splenic lymphoma (PSL) is extremely rare, accounting for less than 1% of all reported cases of extranodal lymphoma. A 62-year-old woman was referred to our hospital because of general fatigue. A heterogenous mass with irregular margins was detected in the spleen by abdominal computed tomographic scan, and Gallium scintigraphy demonstrated abnormal accumulation only in the spleen. Malignant lymphoma was strongly suspected on the basis of histologic findings from an ultrasonically guided needle biopsy. The final diagnosis was established by splenectomy as PSL of diffuse large B-cell type. After 6 courses of CHOP chemotherapy, the patient recovered and has been disease-free more than a year. Chromosomal analysis of her tumor cells detected t(3;14)(q27;q32), an abnormality not reported in cases of PSL to date. The rearrangement of BCL-6 was also observed. We discuss the possibility of BCL-6 involvement in Japanese cases of PSL, with reference to case reports dating back over the past decade.

Chromosomes, Human, Pair 14↗

PubMed1999

[B cell acute lymphocytic leukemia with marked leukocytosis and t(3;15)(q27;q2?2)].

We report on a 16-year-old boy with B cell acute lymphocytic leukemia presenting marked leukocytosis (388,000/microliter) and resistance to multidrug chemotherapy. Karyotypical analysis revealed a novel t(3;15)(q27;q2?2) chromosomal abnormality. Because 3q27 is known to be a locus of the bcl-6 gene, which is frequently involved in B cell malignancies, molecular biological analyses were performed. Although no rearrangement was detected in 5 genes including bcl-6 on 3q27 and 2 genes on 15q2, reverse transcriptase-polymerase chain reaction procedures detected relatively strong mRNA expression of the bcl-6, smrp, dvl3, and tpml genes. These results indicate that immature leukemic cells with CD10 and CD34 positivity and rearrangement of the T cell receptor beta gene may coexist with relatively mature subpopulations that are positive for CD19 and CD20 surface markers, bcl-6 expression, and rearrangement of the gene for immunoglobulin kappa.

Adolescent↗

PubMed1998

c-Src and phosphatidylinositol 3-kinase are involved in NGF-dependent tyrosine phosphorylation of Shc in PC12 cells.

The adaptor protein Shc exists in three isoforms; p46, p52, and p66, and is a key regulator of a variety of biological processes. Our previous studies have shown that the tyrosine kinase c-Src phosphorylates Shc in a phosphatidylinositol (PtdIns) 4,5-bisphosphate-dependent manner. Here we demonstrate that PtdIns 3,4,5-trisphosphate stimulates phosphorylation of Shc by c-Src. The phosphorylation is blocked by a glutathione S-transferase fusion protein containing Shc phosphotyrosine binding (PTB) domain or a phosphotyrosine-containing Shc PTB domain-binding peptide. In rat pheochromocytoma cell line PC12, nerve growth factor (NGF) stimulates tyrosine phosphorylation of both Triton-soluble and -insoluble Shc which was maximal at 2-5 min after NGF treatment. We find that pretreatment of PC12 cells with the PtdIns 3-kinase inhibitor wortmannin or LY294002 results in almost half inhibition of the NGF-dependent tyrosine phosphorylation of only Triton-insoluble Shc. Similar inhibitory effect is observed with tyrosine kinase inhibitors genistein and PP1. Upon NGF stimulation, c-Src also becomes tyrosine-phosphorylated and accumulates in the Triton-insoluble fraction. The c-Src events are insensitive to wortmannin but sensitive to genistein. These results suggest that coordinate action of PtdIns 3-kinase and/or PtdIns 3,4,5-trisphosphate and c-Src can function as positive regulator in tyrosine phosphorylation of Shc in vitro and in vivo.

Adaptor Proteins, Signal Transducing↗

PubMed1998

Overexpression of the fanconi anemia group C gene (FAC) protects hematopoietic progenitors from death induced by Fas-mediated apoptosis.

Fanconi anemia is a rare, inherited disorder characterized by bone marrow failure, congenital malformations, and cancer susceptibility. The group C Fanconi anemia gene, FAC, identified by expression cloning methods, encodes a protein of unknown function that may be involved in the response to apoptotic stimuli. Hematopoietic progenitor cells from Fac knock-out mice are hypersensitive to IFN-gamma, a molecule that can induce apoptosis through up-regulation of the Fas death receptor. In this study, we used FAC-overexpressing transgenic mice to examine the relationship between FAC and Fas-triggered cell death. Hematopoietic progenitors from FAC-transgenic mice were up to 10-fold less sensitive to the cytolytic effect of Fas-ligation. Our experiments implicate FAC in the regulation of apoptosis mediated by the Fas death receptor.

Animals↗

PubMed1998

Negative cooperativity in the steady-state kinetics of sugar oxidation by soluble quinoprotein glucose dehydrogenase from Acinetobacter calcoaceticus.

Steady-state-kinetics investigations were carried out for the oxidation of aldose sugars by soluble quinoprotein glucose dehydrogenase (GDH) from Acinetobacter calcoaceticus using N-methylphenazonium methyl sulfate (PMS) as artificial electron acceptor. As is not uncommon for a dye-linked dehydrogenase, the enzyme showed ping-pong behaviour and double-substrate inhibition. However, under conditions that avoided its masking by sugar-substrate inhibition as much as possible, negative kinetic cooperativity with respect to sugar substrate oxidation by this enzyme was demonstrated. Arguments are presented that exclude trivial factors as a cause for the phenomenon observed. Experimental data could be fitted with an equation accounting for biphasic cooperativity containing two sets of apparent kinetic parameters, V1 and K1, and V1 and K2, representing the enzyme's Michaelis-Menten behaviour at low and high substrate concentrations, respectively. Assuming that subunit interaction causes the cooperativity effect, the sets express the performance of soluble GDH's two subunits in two states of mutual interaction. From fitting the experimental data for several sugars with this equation, it appeared that their V1 values were similar, although their K1 values varied considerably. This showed that the cooperativity effect dramatically changes the performance of soluble GDH, as reflected by the V2 and K2 values for glucose (in phosphate buffer) being about 10-fold and 100-fold higher than the V1 and K1 values, respectively. Substituting the Ca2+ involved in activation of pyrroloquinoline quinone (PQQ) in soluble GDH by Sr2+ affected the cooperativity effect (an increase of the K1 value) but not the two turnover rates of the hybrid enzyme for glucose. The data suggest that the two catalytic cycles of soluble GDH have different rate-limiting steps compared with that of PQQ-containing methanol dehydrogenase.

Acinetobacter calcoaceticus↗

PubMed1998

Assessment of mitomycin C sensitivity in Fanconi anemia complementation group C gene (Fac) knock-out mouse cells.

Fanconi anemia (FA) is a genetic disorder defined by cellular hypersensitivity to DNA cross-linking agents, such as mitomycin C (MMC). MMC causes increased FA cell death, chromosome breakage, and accumulation in the G2 phase of the cell cycle. Recently, Fanconi anemia complementation group C (fac) gene knock-out mice have been developed, and SV40-transformed fibroblasts were established from fac homozygous knock-out (-/-), heterozygous (+/-), and wild-type mice (+/+). MMC sensitivity of these cell lines was assessed by three methods: colony-formation assay in the presence of MMC, chromosome breakage, and cell cycle analysis to detect G2 phase arrest. The fac knock-out fibroblasts (-/-) showed a significantly higher sensitivity to MMC than did fibroblasts from wild-type (+/+) or heterozygous (+/-) mice (three experiments). In addition, we analyzed hematopoietic progenitor colony assays of bone marrow cells from fac knock-out (-/-) and heterozygous (+/-) mice. CFU-E, BFU-E, and CFU-GM colony formation from fac nullizygous mouse progenitors was markedly diminished by MMC when compared to growth of progenitors from heterozygous mice. These results show that fac knock-out mouse cells mimic the behavior of human FA-C patient cells in terms of MMC hypersensitivity. The fac knock-out mouse may be used to model some aspects of human FA and should be useful for understanding the function of the FAC protein.

Animals↗

PubMed1998

In vitro excess ammonia production in human myeloma cell lines.

It is well known that cases with multiple myeloma reveal various clinical manifestations such as pancytopenia, hyperproteinemia, renal dysfunction, bone lesions, hypercalcemia and immunodeficiency. Recently, a few more clinical features associated with myeloma, such as salivary type hyperamylasemia and elevated serum C-reactive protein (CRP) concentration, have been reported. The elevation of CRP is thought to be related to interleukin-6 (IL-6) production by myeloma cells, because of identification of IL-6 as an autocrine and/or paracrine growth factor for myeloma cells. More recently, there have been several reports of cases with myeloma associated with hyperammonemia. This hyperammonemia is not considered to be due to liver dysfunction, because in most of these cases tests revealed normal hepatic function, and some cases showed different patterns of serum amino acid distribution than that associated with hepatic failure. However, there have been no apparent observations of ammonia production by myeloma cells. In this study, we used six human myeloma cell lines including KMS-18, which was recently established from a myeloma case associated with hyperammonemia. These lines were treated with MRA (mycoplasma removal agent) to observe ammonia production in vitro. They produced and released significantly higher levels of ammonia into culture medium than non-myeloma hematological cell lines or the HepG2 human hepatic carcinoma cell line. Although attempts to analyze the relative expression levels of the enzymes related to ammonia biosynthesis using the reverse transcriptase-polymerase chain reaction assay failed to detect any differences between these myeloma lines and other cell lines, in vitro excess ammonia production by the myeloma cells was confirmed and the relevance to clinical manifestations is discussed.

Ammonia↗

PubMed1998

Human myeloma cell apoptosis induced by interferon-alpha.

Although there have been reports regarding the clinical effectiveness of IFN alpha in the treatment of myeloma patients during this decade, its biological effects on human myeloma cells have still not been clarified. Recently, apoptosis has been considered as one of the most important mechanisms in the programmed cell death of malignant tumour cells induced by chemotherapeutic agents or cytotoxic immunological defence in malignancy-carrying hosts. Among the several pathways which function to induce apoptosis, Fas and the Fas ligand system have been thought to play an important role in inducing tumour-cell apoptosis, particularly in immunological prevention. In this study we investigated myeloma cell apoptosis induced by IFN alpha using five human myeloma cell lines which were established without any additional supplementation of IL-6. In addition, the mRNA expression levels of apoptosis-related genes employing the reverse transcriptase-polymerase chain reaction (RT-PCR) were also analysed with the KMS-12-PE cell line, which was the most sensitive of the five cell lines in terms of apoptosis induced by IFN alpha. Based on the results, it was determined that IFN alpha induced myeloma cell apoptosis in a dose-dependent manner, but the sensitivity to IFN alpha in the cell lines examined varied and one cell line revealed growth stimulation by IFN alpha. In addition, the apoptosis induced by IFN alpha did not seem to be mediated by the Fas/Fas ligand pathway. Finally, the IL-6, IL-6R, IRF1 and IRF2 genes were up-regulated in KMS-12-PE cells cultured with IFN alpha. Therefore these genes may play an important role during apoptosis induced by IFN alpha.

Antineoplastic Agents↗

PubMed1998

Soluble Fas mRNA is dominantly expressed in cases with silicosis.

Although it is well known that cases with silicosis exhibit various immunological abnormalities, the mechanisms involved in the occurrence of immuno-dysfunction or dysregulation induced by silica compounds have not yet been determined. Fas is a well-known cell surface molecule that is involved in the apoptosis pathway that belongs to the tumour necrosis factor-receptor family. Soluble Fas (sFas) is produced as an alternatively spliced product of the Fas gene and protects cells from apoptosis due to antagonization of the binding between membrane form of the Fas gene (mFas) and the Fas ligand. To determine the role of the Fas/Fas ligand system in silica-induced immunological abnormalities, we investigated Fas and Fas-ligand message expression levels using the multiplex reverse transcription-polymerase chain reaction (RT-PCR) method with peripheral blood mononuclear cells from silicosis cases with no clinical symptoms of autoimmune diseases. Although the relative expression levels of the Fas or Fas-ligand genes were not remarkably altered in these cases, we observed the sFas message was dominantly expressed compared with mFas expression. These results suggest that self-recognizing clones in cases with silicosis survive for decades, escaping the exclusion mechanisms induced by apoptosis. Then they cause the appearance of autoantibodies and the acquisition of autoimmune diseases sequentially.

Adult↗

PubMed1998

Primary and secondary control over age-related changes in physical appearance.

Beliefs about appearance-related changes due to aging were used to test the effects of perceived control and secondary control (acceptance) in a sample of 412 young, early-middle-age, and late-middle-age college-educated adults. Mean difference in aging-related appearance control and hypotheses regarding the adaptiveness of primary and secondary control were examined. Primary control over aging-related appearance was lower in older adults and secondary control was higher. In addition, the results indicated support for the Primacy/Back-Up Model that primary perceived control is important at all levels of actual control. Those with stronger beliefs in their primary control were less distressed. Secondary control served a back-up function in that it was related to less distress only for those who had medium or lower beliefs in primary control. The implications of these findings, that primary control may be advantageous even in low-control circumstances, are discussed.

Adult↗

PubMed1998

A pure antiestrogen, ICI 182,780, stimulates the growth of tamoxifen-resistant KPL-1 human breast cancer cells in vivo but not in vitro.

The critical mechanisms responsible for antiestrogen resistance have not yet been elucidated. We previously established a breast cancer cell line, KPL-1, derived from a patient with recurrent disease which appeared under tamoxifenadministration. In a previous study, we suggested that this cell line is estrogen receptor (ER)-positive but tamoxifen-resistant. In the present study, the effects of a pure antiestrogen, ICI 182,780, on this cell line were investigated. Although tamoxifen inhibited neither cell growth nor estradiol-stimulated transcriptional activity in vitro, ICI 182,780, significantly inhibited both of them. Tamoxifen and ICI 182,780 were then administered to female nude mice bearing KPL-1 tumors. Tamoxifen had no effect on tumor growth, but ICI 182,780 unexpectedly stimulated it (p = 0.022). Estradiol tended to inhibit tumor growth (p = 0.198). Immunohistochemical analysis revealed that ICI 182,780 significantly increased the Ki6-labeling index (p<0.001) but estradiol decreased it (p = 0.035). To explore the possible mechanisms of these phenotypes, the mRNA levels of ER-alpha,ER-beta, transforming growth factor-beta1, fibroblast growth factor (FGF)-1 and FGF-4 in KPL-1 cells were compared with those in other ER-positive human breast cancer cell lines by reverse-transcription polymerase chain reaction. FGF-1 was overexpressed only in KPL-1 cells. This cell line is the first breast cancer cell line to be growth-stimulated by ICI 182,780 in vivo. Paracrine interaction between tumor cells and stromal cells mediated by growth factors, such as FGF-1, might be a key factor to explain the unique hormone responsiveness of KPL-1 cells.

Animals↗

PubMed1998

Molecular approaches to the treatment of Fanconi anemia: recent advances.

Fanconi anemia (FA) is an autosomal recessive disorder that leads to aplastic anemia. Cells from FA patients are abnormally sensitive to DNA cross-linking agents such as mitomycin C. FA consists of at least five subgroups (FA-A through-E). The genes defective in the FA-C and FA-A groups have recently been cloned. Transfection of the normal FA gene into mutant cells corrects the hypersensitivity to DNA cross-linking agents and improves cell viability in vitro. The function of the FA gene products is still unclear, however. For patients lacking a compatible bone marrow transplantation donor, an experimental trial of gene therapy for group C FA is ongoing at the National Institutes of Health.

Clinical Trials as Topic↗

PubMed1998

Establishment of a new human myeloma cell line, KMS-18, having t(4;14)(p16.3;q32.3) derived from a case phenotypically transformed from Ig A-lambda to BJP-lambda, and associated with hyperammonemia.

A new human myeloma cell line, KMS-18, was established from a 58-year-old male with multiple myeloma associated with hyperammonemia. The original leukemic cells and established KMS-18 cells possessed several of the same chromosomal abnormalities, including add(1)(q32), add(10) (q24) and add(17)(p11). In addition, the KMS-18 cells showed novel t(4;14)(p16.3;q32.3) masked translocation which was determined by the FISH method. Moreover, we compared the ammonia production in culture medium of the KMS-18 cell line with that of non-myeloma hematological malignant cell lines and a hepatocellular carcinoma cell line. KMS-18 produced higher levels of ammonia in medium than the other cell lines examined. This new cell line may prove helpful in analyzing the role and biological mechanisms of the t(4;14)(p16.3;q32.3) translocation in myeloma and also in investigating hyperammonemia in cases with myeloma.

Ammonia↗

PubMed1998

Activation-induced cell death in human peripheral blood lymphocytes after stimulation with silicate in vitro.

Silica and related substances such as silicate have been proven to possess "adjuvant effects". We have previously reported a finding of polyclonal human T cell activation induced by silicate as a superantigen in vitro. In this study, we observed activation-induced cell death in human lymphocytes after stimulation with chrysotile, a kind of silicate. Apoptotic cells were detected flow cytometrically using the TUNEL assay, and the maximum appearance of TUNEL positive cells occurred on day 4 of incubation. Simultaneously the manifestation of small-sized cells in the specimens increased implying apoptosis. Fas expression on lymphocytes increased to day 3 of incubation with chrysotile, and then spontaneously decreased on day 4 when remarkable apoptosis could be detected. Based on these results it is conceivable that activation-induced cell death occurred through Fas-Fas ligand interaction in lymphocytes after stimulation with silicate in a concentration with which no acute cytotoxicity has been detected. Whether and how the repeated apoptosis in definite clones of lymphocytes causes the induction of sFas synthesis need clarification.

Asbestos, Serpentine↗

PubMed1998

Clinical study on arthroplasties for osteoarthritic hip by quantitative gait analysis. Comparison between total hip arthroplasty and bipolar endoprosthetic arthroplasty.

The present study was undertaken to serially observe gait of patients after hip arthroplasty, using quantitative gait analysis, and to compare it between patients after total hip arthroplasty (THA) and those after bipolar endoprosthetic arthroplasty (BEA). The subjects were 53 women with unilateral osteoarthritis of the hip. Thirty-one of them underwent THA (mean age: 59.5 years) and 22 underwent BEA (mean age: 58.0 years). The stance time and characteristic parameters calculated from the vertical component of floor reaction force (FRF) were analyzed by use of FRF plate. The stance time, which indirectly represents the walking speed, tended to decrease for one year after THA and for 3 years after BEA. The decrease in this parameter was greater on the unaffected side than on the affected side. The deceleration effect and the weighing-off effect are indicators useful for observation of gait recovery. Significant differences in these indicators between the unaffected and affected sides were seen for one year after THA and 3 years after BEA. This indicates that cadence and balance of the gait recovers earlier after THA than after BEA.

Acceleration↗

PubMed1998

[Retrospective analysis of elderly patients > or = 60 years of age with acute leukemia].

A retrospective analysis was performed on 76 consecutive elderly patients with acute leukemia aged 60 years or more (48 men, 28 women). Forty patients were 60-69 years old, 28 were 70-79 years old and 8 were > or = 80 years old. There were 55 patients with acute myelogenous leukemia (AML), 13 acute lymphoblastic leukemia (ALL) and 8 AML from myelodysplastic syndrome (MDS/AML). Patients were treated with the JALSG protocol, CAG regimen, or low-dose Ara-C regimen for AML, and DVP/M-CHOP protocol for ALL. The complete remission (CR) rates were 52.7% (29 of 55) in AML, 61.5% (8 of 13) in ALL, and 0% in MDS/AML. The median CR durations were 226, 85, 0 days, and the median survivals were 204, 177, 99 days, respectively. CR rates were 65.3% for the JALSG protocol, 62.5% for the CAG regimen and 25.0% for low-dose Ara-C regimen. According to age, CR was obtained 62.5% in patients aged 60-69 years and 33.3% in patients over 70 years old. Our results indicated that patients aged 60-69 years should be treated with intensive chemotherapy.

Aclarubicin↗