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Biomedical subjects

S Mizutani

Publications and source records attributed to S Mizutani.

At least 91 records · Page 5Linked to original sources
PubMed2000

Differentiation-associated expression and intracellular localization of cyclin-dependent kinase inhibitor p27KIP1 and c-Jun co-activator JAB1 in neuroblastoma.

Neuroblastoma is a unique pediatric cancer, which spontaneously regress in some infants and undergo maturation in older children. The cyclin-dependent kinase inhibitor p27KIP1 negatively control cell cycle progression and its expression is reported to be associated with differentiation and prognosis of some human cancers. To examine whether p27KIP1 is involved in differentiation of neuroblastomas, expression and localization of p27KIP1 in 30 cases of neuroblastic tumors were determined with immunohistochemistry. p27KIP1 was expressed in all cases, but staining intensity and intracellular localization varied in association with tumor differentiation. Primitive small round neuroblasts showed negative or only weak nuclear staining, while differentiating tumor cells displayed a novel, intense cytoplasmic positivity besides the nuclear staining, and mature ganglion cells showed intense positive reaction confined to the nucleus. A neuroblastoma cell line TGW was also immunostained positively for p27KIP1 in the cytoplasm after differentiation induction, and western blot analysis revealed an increase of p27KIP1 in these cells, corroborating the in vivo observations. JAB1, which is thought to bind p27KIP1 and transport it from the nucleus to the cytoplasm for proteasome/ubiquitin-mediated degradation, was found to be localized both in the cytoplasm and the nucleus in undifferentiated and differentiating tumors whereas located predominantly in the nucleus of differentiated tumor cells. These data indicate that the cytoplasmic localization of p27KIP1 in the process of differentiation is due to upregulation of p27KIP1 synthesis and subsequent degradation and suggest a role of p27KIP1 in differentiation of neuroblastoma.

Blotting, Western↗
PubMed2000

[Intrascrotal lipoma: a case report].

A 72-year-old male was admitted to our hospital with the complaint of right painless swelling of extratesticular scrotal content. Laboratory examinations were unremarkable. Under the diagnosis of an intrascrotal lipoma, the tumor was resected. The removed specimen weighed 115 g. Histopathological findings revealed lipoma. Other cases from the Japanese publications, together with our case, are reviewed.

Aged↗
PubMed2000

[Dysregulation of the genes controlling apoptosis in cancer development].

Apoptosis is a cellular self-destruction mechanism involved in a variety of biological events. Cancer is a disorder of autonomous cell proliferation and accumulation, which is associated with the failure to undergo apoptosis in response to appropriate stimuli. Inhibition of apoptosis may be a prerequisite or acquired biological feature of various cancer cells. Resistance to apoptosis is achieved either by an increase in apoptosis resistance or decrease in apoptosis sensitivity. Some of the hereditary cancer syndrome patients have mutations in the genes to induce apoptosis, eventually leading to inhibition of apoptosis and cancer development.

Apoptosis↗
PubMed2000

[Primary transitional cell carcinoma of prostate: a case report].

A 67-year-old male was admitted with a three-month history of voiding difficulty. Prostate specific antigen remained within the normal limit. Under the diagnosis of benign prostatic hypertrophy, transurethral resection of prostate was performed. Pathological examination of the resected specimens of the prostate revealed transitional cell carcinoma. Two courses of systemic M-VAC (methotrexate, vinblastine, doxorubicin, cisplatin) chemotherapy were performed, followed by cystoprostatourethrectomy, pelvic lymphadenectomy, and ileal conduit construction. Now one year has elapsed, with no clinical signs of recurrence.

Aged↗
PubMed2000

[A patient with gastric cancer with para-aortic lymph node metastases surviving for 9 years after effective preoperative chemotherapy and radical operation].

A 63-year-old male patient with type 3 advanced gastric cancer was referred to our hospital. Preoperative examination by CT-scan revealed swollen para-aortic lymph nodes and cancer invasion to the pancreas. The patient was treated pre-operatively with intravenous 5-FU, 500 mg/body/day, continuous infusion for 1 week. Immediately after the chemotherapy, the patient underwent total gastrectomy, splenctomy, left-adrenectomy and resection of the body and tail of the pancreas, along with para-aortic lymph node dissection. Microscopic examination revealed that the tumor was a moderately differentiated tubular adenocarcinoma, which displayed invasion to the pancreas with lymph node metastasis up to the level 3 lymph node. Histologically, the effect of preoperative chemotherapy showed a grade 2 effect on the main tumor, but a grade 3 chemotherapeutic effect was observed at the para-aortic lymph nodes. The patient has subsequently remained disease free for 9 years. In this case, it is considered that the preoperative chemotherapy by 5-FU and potentially curative radical operation yielded a good outcome.

Adenocarcinoma↗
PubMed2000

[Limits of nucleic acid amplification tests for diagnosis of smear negative pulmonary tuberculosis].

STUDY OBJECTIVES: To assess the usefulness of commercial kits of nucleic acid amplification test (NAAT) for diagnosis of smear negative (SN) pulmonary tuberculosis. DESIGN AND PATIENTS: Retrospective study of patients who were diagnosed as, or suspected of pulmonary tuberculosis during 3 years from January 1996 to December 1998 in Fukujuji Hospital which has 100 beds for tuberculosis patients. MEASUREMENTS AND RESULTS: 145 smear-negative culture-positive pulmonary tuberculosis patients are entered to our analysis. The DNA-based amplification test kit (Amplicor Mycobacterium Tuberculosis Test (AMPL), Roche Diagnostic Systems, Basel, Switzerland) detected 39.2% (20/51, 95% confidence interval (CI): 25.8-52.6%) of smear-negative culture-positive (SNCP) pulmonary tuberculosis cases. The RNA-based amplification test kit (Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (AMTDT), Gen-Probe Inc., San Diego, Calif., USA) detected 40.5% (15/37, 95% CI: 24.7-56.3%) of SNCP pulmonary tuberculosis cases. For both NAATs (AMPL and AMTDT), between two groups with and without the NAAT at diagnosis of SNCP pulmonary tuberculosis, there was statistical difference in culture-positive rate (proportion of positivity in sputum culture tests at diagnosis), but no statistical difference in maximum number of colony of Mycobacterium tuberculosis (MTB). When stratified for the culture-positive rate, adjusted sensitivity for SNCP patients was 44.2% (AMPL) and 40.4% (AMTDT) respectively. On the other hand, among 245 patients with sputum AMPL positive results during the 3 years, 8 were smear-negative culture-negative (SNCN), only one out of these 8 cases was judged as true active tuberculosis without treatment. Among 89 patients with sputum AMTDT positive results, 7 were SNCN, and 3 out of them were judged as true active tuberculosis without treatment. CONCLUSION: Usefulness of commercial NAAT kits (AMPL and AMTDT) to diagnosis SN pulmonary tuberculosis is limited in the point of sensitivity.

DNA, Bacterial↗
PubMed2000

[Metastatic bladder tumor disseminated lymphogenously from gastric cancer: a case report].

A 59-year-old man was referred to our clinic with a complaint of frequent urination, voiding pain, and macroscopic hematuria. He had undergone total gastrectomy for mucinous adenocarcinoma, 21 months earlier. Pelvic computed tomography revealed a thick bladder wall all around. There were no other metastatic sites except for paraaortic lymph nodes. Transurethral resection of the bladder tumor was performed. The specimen showed signet ring cell carcinoma and revealed the same pathological findings as the primary gastric cancer. We diagnosed him with metastastic bladder tumor lymphogenously disseminated from gastric cancer. Such lymphogenous metastases from gastric cancer at the entire bladder wall without other apparent lesions have rarely been reported in the Japanese literature.

Adenocarcinoma, Mucinous↗
PubMed1999

Clonal expansion of alphabeta-T lymphocytes with inverted Jbeta1 bias in familial hemophagocytic lymphohistiocytosis.

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare but fatal disease in infancy. There are no previous reports on the clonality of T cells in FHL patients. We analyzed here the clonality of alphabeta-T cells in 5 FHL patients using an inverse reverse transcriptase-polymerase chain reaction (RT-PCR) of the T-cell receptor variable region gene (TCR V), a joining region gene of the beta chain (Jbeta)-PCR, a single-strand conformation polymorphism (SSCP), and sequence analysis. A high frequency (15%) of Vbeta and Valpha families was observed in 3 of 5 and 4 of 4 patients examined, respectively. In 19 Vbeta repertoires, including all highly frequent Vbeta, the Jbeta-PCR analysis showed restricted usage of the Jbeta family, indicating a marked bias to Jbeta1 subsets (the mean rate of Jbeta1:Jbeta2 was 87:13 in 65% of the alphabeta-T cells) in widespread alphabeta-T cells (in all patients but 1). In all patients, the clonality of specific Vbeta-Jbeta fragment expanded was confirmed by SSCP and sequence analysis. These results suggest that the existence of clonal expansion and restricted Jbeta1 usage of T cells in FHL is genetically associated with the pathogenesis and the immunodysfunction of the disease. These results help to explain some of the abnormal functional behaviors of T cells in FHL and raise new questions regarding the mechanisms responsible for the restricted clonal diversity.

Amino Acid Sequence↗
PubMed1999

Structural organization of the 5'-end and chromosomal assignment of human placental leucine aminopeptidase/insulin-regulated membrane aminopeptidase gene.

Placental leucine aminopeptidase (P-LAP) which is identical with cystine aminopeptidase as oxytocinase was found to be a homologue of rat insulin-regulated membrane aminopeptidase (IRAP) by cDNA cloning. In this study, we confirmed 5'-end cDNA sequence of P-LAP and isolated genomic clones containing the upstream region of human P-LAP gene. The transcription initiation sites determined by primer extension located 478 and 480 bp upstream of the initiation methionine codon, 38 bp downstream of TATA box-like motif. The 5'-flanking region of human P-LAP gene contained DNA-binding motifs for several ubiquitous transcription factors such as SP1 and AP2. Chromosomal localization by fluorescence in situ hybridization showed that the gene was assigned to 5q14.2-q15 of the human chromosome. This study establishes the genetic basis for P-LAP gene research, thereby leading to better understanding of the molecular mechanism underlying the P-LAP gene.

Aminopeptidases↗
PubMed1999

Defective control of apoptosis and mitotic spindle checkpoint in heterozygous carriers of ATM mutations.

Ataxia telangiectasia (AT) carrier-derived lymphoblastoid cell lines (AT-LCLs/hetero) with suboptimal ATM protein expression were examined for the regulation of radiosensitivity, apoptosis, and mitotic spindle checkpoint in response to DNA-damaging agents. Although AT-LCLs/hetero showed intermediate radiation sensitivity, as determined by clonogenic assay, they were resistant to early-onset apoptosis, as much as AT patient-derived LCLs (AT-LCLs/homo). Furthermore, two of three AT-LCLs/hetero showed defective mitotic spindle checkpoint control in response to X-ray irradiation, which is a recently characterized biological feature in AT-LCLs/homo. Our findings indicate that carriers of ATM mutation have biological abnormalities due to haploinsufficiency of ATM protein or dominant-negative effect of mutant ATM protein. Thus, although it is still controversial whether ATM mutation carriers are at higher risk for cancer during adulthood, our findings based on in vitro biological indicators support the notion that at least some of such carriers are at a higher risk for cancer development than those without ATM mutation. Our findings may help to reevaluate epidemiological studies on cancer susceptibility in AT carriers.

Apoptosis↗
PubMed1999

Apoptosis inhibitory activity of cytoplasmic p21(Cip1/WAF1) in monocytic differentiation.

p21(Cip1/WAF1) inhibits cell-cycle progression by binding to G1 cyclin/CDK complexes and proliferating cell nuclear antigen (PCNA) through its N- and C-terminal domains, respectively. The cell-cycle inhibitory activity of p21(Cip1/WAF1) is correlated with its nuclear localization. Here, we report a novel cytoplasmic localization of p21(Cip1/WAF1) in peripheral blood monocytes (PBMs) and in U937 cells undergoing monocytic differentiation by in vitro treatment with vitamin D3 or ectopic expression of p21(Cip1/WAF1), and analyze the biological consequences of this cytoplasmic expression. U937 cells which exhibit nuclear p21(Cip1/WAF1) demonstrated G1 cell-cycle arrest and subsequently differentiated into monocytes. The latter event was associated with a cytoplasmic expression of nuclear p21(Cip1/WAF1), concomitantly with a resistance to various apoptogenic stimuli. Biochemical analysis showed that cytoplasmic p21(Cip1/WAF1) forms a complex with the apoptosis signal-regulating kinase 1 (ASK1) and inhibits stress-activated MAP kinase cascade. Expression of a deletion mutant of p21(Cip1/WAF1) lacking the nuclear localization signal (DeltaNLS-p21) did not induce cell cycle arrest nor monocytic differentiation, but led to an apoptosis-resistant phenotype, mediated by binding to and inhibition of the stress-activated ASK1 activity. Thus, cytoplasmic p21(Cip1/WAF1) itself acted as an inhibitor of apoptosis. Our findings highlight the different functional roles of p21(Cip1/WAF1), which are determined by its intracellular distribution and are dependent on the stage of differentiation.

Amino Acid Sequence↗
PubMed1999

Anti-tumor activity of antizyme which targets the ornithine decarboxylase (ODC) required for cell growth and transformation.

Anti-tumor activity of antizyme which targets the ornithine decarboxylase (ODC) required for cell growth and transformation Cell proliferation and transformation induced by growth factor stimulation or by carcinogens, viruses, or oncogenes are characterized by an associated increase in polyamine levels, which is mediated by increased polyamine biosynthesis and enhanced uptake of polyamines. Polyamine biosynthesis is catalyzed particularly, in the level of ornithine decarboxylase (ODC). The elevation of cellular polyamine levels on the other hand accelerates the induction of ornithine decarboxylase antizyme (antizyme), which is involved not only in ODC-degradation, but in the negative regulation of polyamine transport. Taking advantage of these characteristics of antizyme, the potential of antizyme as a factor having anti-cell growth and anti-tumor activity was investigated. We show that antizyme can induce cell death associated with a rapid decline of intracellular polyamine contents. The possible anti-tumor activities of ectopically expressed antizyme were tested in p21H-ras (Val 12)-transformed NIH3T3 cells and several human malignant cell lines including a line with loss of p53 expression, and they were shown to be as sensitive as nontransformed NIH3T3 cells in vitro. The in vivo anti-tumor activity was also tested using nude mice inoculated with H-ras transformed NIH3T3 cells that had been transfected with inducible antizyme expression vector and the results showed that antizyme expression in vivo blocks tumor formation in these mice. These results suggest that ectopic antizyme expression is of possible therapeutic benefit in the treatment of cancer, which is mediated by ODC inactivation and intracellular polyamine depletion.

3T3 Cells↗
PubMed1999

Clonal dissemination of T-lymphocytes in scid mice from familial hemophagocytic lymphohistiocytosis.

BACKGROUND: Although familial hemophagocytic lymphohistiocytosis (FHL) has been considered a disorder of T-cell dysfunction, there is no evidence of the clonal origin of T-cells in this disease. PROCEDURE: We engrafted mononuclear cells (MNCs) from five FHL patients into scid mice and examined the infiltration of human cells in mouse organs. The characterization of human cells that infiltrated in the mouse organs was then performed. RESULTS: A diffuse infiltration of human lymphoid cells was detected in scid mice treated with 1 x 10(6) MNCs from one of the five patients. These cells were positive for HLA-DR and CD3, but negative for CD4, CD8, CD20, and CD68, suggesting the infiltration of double negative (DN) T-cells. The MNCs from the other four patients induced murine lymphoma-like disease; T-cell lymphoma in one and lymphoma of unknown origin in three. The characterization of these human DN T-cells was performed. The analysis of the Vbeta repertoire showed no preferential usage of the Vbeta family in MNCs, while the dominant expression of Vbeta13 was detected in T-cells infiltrating in the spleen and lung. A Jbeta analysis showed the restricted usage of Jbeta1.2 for Vbeta13 in these cells, and the clonality of Vbeta13-Jbeta1.2 fragment was confirmed by a single-strand confirmation polymorphism analysis. The analysis of the Valpha repertoire showed that Valpha24 was exclusively used in these DN T-cells, but no usage of JalphaQ for Valpha24 was observed. CONCLUSIONS: A clonal expansion of T-cells was induced in scid mice by the engraftment of MNCs from an FHL patient. The infiltration of DN alphabeta T-cells bearing invariant Valpha24 T-cell receptor in mouse organs may provide a useful clue to the pathogenesis of FHL. In the patients whose MNCs induced murine lymphoma-like disease, some cytokines or unknown factors that stimulate the growth and the tumorigenicity of murine lymphocytes might be produced by the MNCs engrafted in scid mice. Further study is needed to confirm the validity of our experimental approach and the findings observed in scid mice by using more FHL samples.

Animals↗
PubMed1999

EBV infection induced transformation of benign T lymphoproliferative state in patient with chronic active EBV infection into malignant lymphoma: implication of EBV infection as additive oncogenic factor in tumorigenesis.

An 11-year-old girl with chronic EBV (Epstein-Barr virus) infection, who later developed malignant lymphoma in the lung, is reported. She had an increased number of V alpha2, V beta8, CD3, CD4, and HLADR positive activated lymphocytes (20-30% of total lymphocytes) in peripheral blood. One year later, she developed lymphoma in the lung, which was V alpha2, V beta8, CD3, CD4, HLADR and IL2Rbeta positive. At that time, the population in the peripheral blood increased up to 40%, but there was no evidence of lymphoma in the bone marrow. In situ hybridization revealed lymphoma cells were EBER-1 positive but gp350/220 and LMP mRNA negative. The EBV genome was detected in the tumor, but not in the peripheral T cells. Clonal analysis of the lymphoma cells revealed monoclonal rearrangement of the TcRbeta and gamma gene, however, investigation of the terminal repeat of EBV gene did not show the monoclonal pattern. These results indicate that infection of EBV into clonally activated T cells was related with transformation from benign lymphoproliferative disease to malignant lymphoma in this patient.

Child↗
PubMed1999

DNA damage-associated cell cycle and cell death control is differentially modulated by caffeine in clones with p53 mutations.

Caffeine is known to potentiate the cytotoxic effects of DNA damaging agents and increases the sensitivity of p53-deficient cells to X-irradiation (X-IR). We have analyzed the cell cycle and cell death control after X-IR in the absence or presence of caffeine in hematological cell lines with various configurations of the p53 gene; EBV-immortalized lymphoblastoid cells with heterozygous p53 mutation (wt/mt), human leukemia cell lines HL60 and KOPM28 with no and mutant p53 expression, respectively. These cell lines display an impaired G0/G1 checkpoint and G2 delay following X-IR, and resistance to apoptosis, which are in accordance with findings previously reported. When irradiated in combination with caffeine, all these cell lines overrode the G2 delay and accumulated at G0/G1. The cell cycle modifications in these cell lines correlated with the increase in radiation-induced p34Cdc2 kinase activity by caffeine. These cell cycle control modifications by caffeine, however, were not associated with enhancement of radiation-induced apoptosis or reduction of clonogenic growth activity in these cell lines. These results suggest that the cytocidal effect of caffeine may need to be verified independently of its cell cycle regulatory activities at least in some cases with p53 mutation.

Amino Acid Substitution↗
PubMed1999

Abnormalities of the p53 gene in juvenile myelomonocytic leukaemia.

Juvenile chronic myelomonocytic leukaemia (JMML) is a rare myeloproliferative disorder of childhood. Fewer than 30% of cases of JMML terminate in a blast crisis; however, its molecular mechanism is unknown. Since mutation and/or deletion of the p53 gene has been reported to be associated with disease progression in a wide variety of human cancers, including adult-type chronic myelogenous leukaemia, we studied the p53 gene in 20 patients with JMML (16 samples in chronic phase and seven at blast crisis). Exons 4-8 of the p53 gene, which cover all the hot spots of point mutations, were amplified by the polymerase chain reaction (PCR) method and subjected to mutation screening by single-strand conformation polymorphism analysis. No mobility shift of single-strand DNA of PCR products in polyacrylamide gel electrophoresis, indicating point mutations, was found in 19/20 patients. DNA of the remaining patient in the chronic phase failed to be amplified by PCR and Southern blot analysis with XbaI-digested genomic DNA revealed a gross rearrangement (presumed deletion) of the p53 gene. These data indicate that abnormalities of the p53 gene are rare in JMML and not responsible for acute transformation, but could be involved in the pathogenesis of some cases of JMML.

Blotting, Southern↗