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T Nakano

Publications and source records attributed to T Nakano.

At least 199 records · Page 11Linked to original sources
PubMed2000

Identification and characterization of a novel protein inhibitor of type 1 protein phosphatase.

We have isolated human cDNA for a novel type 1 protein phosphatase (PP1) inhibitory protein, named inhibitor-4 (I-4), from a cDNA library of germ cell tumors. I-4, composed of 202 amino acids, is 44% identical to a PP1 inhibitor, inhibitor-2 (I-2). I-4 conserves functionally important structure of I-2 and exhibited similar biochemical properties. I-4 inhibited activity of the catalytic subunit of PP1 (PP1C), specifically with an IC(50) of 0.2 nM, more potently than I-2 with an IC(50) of 2 nM. I-4 weakly inhibited the activity of myosin-associated phosphates (PP1M). However, the level of inhibition of PP1M was increased during preincubation of PP1M with I-4, suggesting that the inhibition is caused by interaction of I-4 with PP1C in such a manner that it competes with the M subunit of PP1M. Gel overlay experiments showed that I-4 binds PP1C directly. Three I-4 peptides containing the N-terminal residues 1-123, 1-131, and 1-142 all showed strong binding ability to PP1C but did not show PP1 inhibitory activity, whereas an I-2 peptide (residues 1-134), lacking the corresponding C-terminal residues, potently inhibited PP1C activity as previously reported. Removal of the 18 N-terminal amino acid residues from I-4 dramatically reduced the PP1 binding activity with a correlated loss of inhibitory activity, whereas removal of the 10 N-terminal residues had only a little effect. The two peptides GST-I-4(19-131) and GST-I-4(132-202) showed ability to bind to PP1C, albeit very weakly. These results strongly suggest a multiple-point interaction between I-4 and PP1C, which is thought to cause the inhibition of I-4 which is stronger than the inhibition of I-2.

Amino Acid Sequence↗
PubMed2000

Analysis of deletion mutations of the rpsL gene in the yeast Saccharomyces cerevisiae detected after long-term flight on the Russian space station Mir.

Using the yeast Saccharomyces cerevisiae on board the Russian space station Mir, we studied the effects of long-term space flight on mutation of the bacterial ribosomal protein L gene (rpsL) cloned in a yeast-Escherichia coli shuttle vector. The mutation frequencies of the cloned rpsL gene on the Mir and the ground (control) yeast samples were estimated by transformation of E. coli with the plasmid DNAs recovered from yeast and by assessment of the conversion of the rpsL wild-type phenotype (Sm(S)) to its mutant phenotype (Sm(R)). After a 40-day space flight, some part of space samples gave mutation frequencies two to three times higher than those of the ground samples. Nucleotide sequence analysis showed no apparent difference in point mutation rates between the space and the ground mutant samples. However, the greater part of the Mir mutant samples were found to have a total or large deletion in the rpsL sequence, suggesting that space radiation containing high-linear energy transfer (LET) might have caused deletion-type mutations.

Base Sequence↗
PubMed2000

High growth fraction at 9 grays of radiotherapy is associated with a good prognosis for patients with cervical squamous cell carcinoma.

BACKGROUND: MIB-1, a murine monoclonal antibody, recognizes the Ki-67 antigen of routinely processed paraffin sections after microwave treatment. Cycling cells are positive for MIB-1 in their nucleus, and quiescent cells are negative for MIB-1. The MIB-1 labeling index represents the growth fraction of the cell population. METHODS: A total of 150 cervical biopsy specimens were taken from 75 consecutive patients with cervical squamous cell carcinomas before radiotherapy (RT) and at 9 grays (Gy) of RT and were investigated to analyze the correlation between the MIB-1 labeling index or the deltaMIB-1 labeling index and patient prognosis or local disease control. The deltaMIB-1 index was calculated as the MIB-1 index at 9 Gy minus the MIB-1 index before RT. RESULTS: The mean MIB-1 index was 38% (range, 11-67%) before RT and 54% (range, 15-85%) at 9 Gy. The MIB-1 index at 9 Gy was related to prognosis, including overall survival (P = 0.025), disease free survival (P = 0. 024), and metastasis free survival (P = 0.045). Patients who had a deltaMIB-1 index > 20% showed a trend toward a higher disease free survival rate compared with patients who had a deltaMIB-1 index < 20% (P = 0.093). Neither the MIB-1 index nor the deltaMIB-1 index was associated with local disease control. CONCLUSIONS: The high growth fraction at 9 Gy is regarded as a predictive factor for a good prognosis in patients with cervical squamous cell carcinoma patients who undergo RT alone.

Adult↗
PubMed2000

Phosphorylation of CPI-17, an inhibitor of myosin phosphatase, by protein kinase N.

CPI-17 is a phosphorylation-dependent inhibitory protein for smooth muscle myosin phosphate. Phosphorylation at Thr(38), in vitro, by protein kinase C or Rho-kinase enhances the inhibitory potency toward myosin phosphatase. Phosphorylation of CPI-17 by protein kinase N (PKN), a fatty acid- and Rho-activated serine/threonine kinase, and its effect on smooth muscle myosin phosphatase activity were investigated. CPI-17 was phosphorylated by GST-PKN-CAT, a constitutively active GST-fusion fragment of PKN, to 1.46 mol of P/mol of CPI-17, in vitro. The K(m) value of CPI-17 for PKN was 0.96 microM. Phosphorylation of PKN dramatically increased the inhibitory effect of CPI-17 on myosin phosphatase activity. The major and inhibitory phosphorylation site was identified as Thr(38) using a point mutant of CPI-17 and a phosphorylation-state specific antibody. Thus, CPI-17 is a substrate of PKN and might be involved in the Ca(2+) sensitization of smooth muscle contraction as a downstream effector of Rho and/or arachidonic acid.

Animals↗
PubMed2000

Synthesis and biological activity of 4'-methoxy derivatives of abscisic acid.

Replacing the 4'-carbonyl group of abscisic acid with a methoxy group does not affect the abscisic acid (ABA)-like activities of the product in barley aleurone protoplasts, although the reduction of ABA to 4'-hydroxyl derivatives significantly reduces the ABA-like activity of the products. This suggests that methoxy derivatives of abscisic acid might be used to produce probes for ABA binding proteins.

Abscisic Acid↗
PubMed2000

Progesterone receptor is a favorable prognostic factor of radiation therapy for adenocarcinoma of the uterine cervix.

PURPOSE: The prognostic significance of the expression of estrogen receptors (ER) and progesterone receptors (PgR) in adenocarcinoma of the uterine cervix has been controversial. Hence, the relationship between the expression of the hormone receptors and clinical outcome was evaluated for patients with adenocarcinoma treated with radiation therapy alone. MATERIALS AND METHODS: This study involved 66 patients with cervical adenocarcinoma consisting of 44 adenocarcinomas and 22 adeno-squamous cell carcinomas. They received radiation therapy at the National Institute of Radiological Sciences Hospital between 1962 and 1993. The mean age of the patients was 62. 0 +/- 12.0 years (range, 36-82 years). The numbers of patients with Stage I, II, III, and IV diseases were 7, 17, 27, and 15, respectively. Their ER and PgR statuses were investigated immunohistochemically using biopsy specimens excised from the cervical tumors before radiation therapy. RESULTS: ER staining was positive in 12 patients (19%). ER status did not correlate with the 5-year cause-specific, local-control, and disease-free survivals. PgR staining was positive in 12 patients (19%). The disease-free survival rate of PgR-positive patients was significantly higher than that of PgR-negative patients (p = 0.044). Although PgR status did not reach statistical significance in relation to the 5-year cause-specific survival and local-control survival, the better survival was due to less local recurrence rather than to less distant metastasis. CONCLUSION: The present study suggested that PgR status was associated with prognosis after radiation therapy for adenocarcinoma of the uterine cervix.

Adenocarcinoma↗
PubMed2000

Survivin initiates cell cycle entry by the competitive interaction with Cdk4/p16(INK4a) and Cdk2/cyclin E complex activation.

Survivin is observed uniquely in tumor cells and developmental cells, which undergo either inappropriate or programmed cell growth. In the current study, we investigated the influence of Survivin on cell cycle. Overexpression of Survivin resulted in accelerated S phase shift, resistance to G1 arrest, and activated Cdk2/Cyclin E complex leading Rb phosphorylation. In addition, nuclear translocation of Survivin followed by an interaction with Cdk4 was detected. Interestingly, Survivin nuclear translocation coincided with S phase shift, and prevention of nuclear transport suppressed Survivin nuclear translocation and S phase shift. Further, we also observed that Survivin competitively interacted with the Cdk4/p16(INK4a) complex in a cell free system and in vivo. These results suggest that Survivin initiates the cell cycle entry as a result of nuclear translocation followed by an interaction with Cdk4.

Amino Acid Sequence↗
PubMed2000

ESOP-1, a secreted protein expressed in the hematopoietic, nervous, and reproductive systems of embryonic and adult mice.

To isolate soluble factors expressed in early phases of hematopoietic differentiation, we applied the signal sequence trap method to the in vitro murine hematopoietic differentiation system, in which ES cells are cocultured with OP-9 stroma cells. This strategy allowed us to isolate cDNA for a secreted protein, ESOP-1, of 160 amino acids, the sequence of which shows 64% identity with human ESOP-1/MD-2. ESOP-1 mRNA was highly expressed in the mouse embryos at 7.5 days after coitus. Expression of the ESOP-1 mRNA and protein was shown in the embryonic and adult hematopoietic system. In addition, the ESOP-1 protein was found in the yolk sac-blood islands, the developing nervous system, and the adult reproductive system. These results suggest that ESOP-1 may play some roles in the development or maintenance of hematopoietic, nervous, and reproductive systems.

Amino Acid Sequence↗
PubMed2000

Phosphorylation of CPI-17, an inhibitory phosphoprotein of smooth muscle myosin phosphatase, by Rho-kinase.

Phosphorylation of CPI-17 by Rho-associated kinase (Rho-kinase) and its effect on myosin phosphatase (MP) activity were investigated. CPI-17 was phosphorylated by Rho-kinase to 0.92 mol of P/mol of CPI-17 in vitro. The inhibitory phosphorylation site was Thr(38) (as reported previously) and was identified using a point mutant of CPI-17 and a phosphorylation state-specific antibody. Phosphorylation by Rho-kinase dramatically increased the inhibitory effect of CPI-17 on MP activity. Thus, CPI-17 as a substrate of Rho-kinase could be involved in the Ca(2+) sensitization of smooth muscle contraction as a downstream effector of Rho-kinase.

Animals↗
PubMed2000

Expression of p27 and p53 in cervical squamous cell carcinoma patients treated with radiotherapy alone: radiotherapeutic effect and prognosis.

BACKGROUND: The p27/Kip1 gene inhibits a variety of cyclin-cyclin-dependent kinase complexes and regulates cell growth. The p53 gene acts as a tumor suppressor gene, controlling entry into the S-phase of the cell cycle. METHODS: A total of 202 biopsy specimens obtained from 77 patients with squamous cell carcinoma of the cervix before and during radiotherapy (RT) was investigated for expression of p27 and p53 in conventionally fixed and processed histologic specimens using an immunohistochemical method. DNA samples exhibiting high p53 overexpression were analyzed for detection of the wild-type or mutant-type of p53 by polymerase chain reaction-single strand conformation polymorphism analysis. RESULTS: Carcinoma cells and degenerated or swollen carcinoma cells after RT that were positive for p27 and p53 showed intranuclear reactivity. Degenerated or swollen carcinoma cells after RT with 27 Gy showed stronger p53 positivity than carcinoma cells before RT. The mean p27 labeling index was decreased significantly after 27 Gy; conversely, the mean p53 labeling index was increased significantly after 27 Gy of RT. A high p27 labeling index before RT was associated significantly with good disease free and metastasis free survival. A high p53 labeling index before RT was associated with poor overall survival. Both samples examined before RT showed no mutations of p53 (exons 5-8). Four of 5 samples showed mutations in exon 5 or 7 of the p53 gene after 27 Gy of RT. CONCLUSIONS: The high p27 expression and low p53 expression in carcinoma cells before RT are regarded as predictive factors for good prognosis of patients with cervical squamous cell carcinoma treated with RT alone. The mean p27 and p53 indices change in an inverse fashion during the period between the initiation of RT and the period after 27 Gy of RT. RT induces the mutant-type p53 oncogene after 27 Gy.

Adult↗
PubMed2000

Prevalence, predictive factors, and screening for psychologic distress in patients with newly diagnosed head and neck cancer.

BACKGROUND: High levels of distress are a concern regarding patients with head and neck cancer. Early detection of and intervention for such distress are needed to predict patients' adaptation to treatment or rehabilitation, but few studies have investigated the detection of their distress in a patient population of significant size. METHODS: The authors examined 107 consecutive patients with head and neck cancer to assess their psychologic distress (adjustment disorders or major depression) or other psychiatric problems by structured psychiatric interview before the initial cancer treatment. They also evaluated predictive factors for psychologic distress and assessed the ability of a self-rating questionnaire (Hospital Anxiety and Depression Scale, HADS) to screen for distress. RESULTS: Of 107 subjects, 18 (16.8%) had an adjustment disorder or major depression. Thirty-six (33.6%), 7 (6. 5%), and 35 (32.7%) met criteria for alcohol dependence, alcohol abuse, and nicotine dependence, respectively. Logistic regression analysis revealed that having advanced stage cancer (odds ratio, 5. 77; 95% confidence interval [CI], 1.41-39.7; P = 0.03) and living alone (odds ratio, 4.83; 95% CI, 1.04-22.2; P = 0.04) were significantly associated with having psychologic distress. The optimal cutoff point for the HADS screening for psychologic distress was 15. This cutoff point gave 72.2% sensitivity and 81.4% specificity. CONCLUSIONS: Head and neck cancer patients who have advanced disease or live alone should be assessed so that psychologic distress can be detected and intervention made. HADS is a useful clinical instrument to screen for their distress.

Adjustment Disorders↗
PubMed2000

X-rays vs. carbon-ion tumor therapy: cytogenetic damage in lymphocytes.

PURPOSE: To measure chromosomal aberrations in peripheral blood lymphocytes from cancer patients treated with X-rays or carbon ions (C-ions). METHODS AND MATERIALS: Blood samples from patients diagnosed for esophageal or uterine cervical cancer were obtained before, during, and at the end of the radiation treatment. The novel technique of interphase chromosome painting was used to detect aberrations in prematurely condensed chromosomes 2 and 4. The fraction of aberrant lymphocytes was measured as a function of the dose to the tumor volume. For comparison, blood samples were also exposed in vitro to X-rays or to carbon ions accelerated at the HIMAC. RESULTS: C-ions were more efficient than X-rays in the induction of chromosomal aberrations in vitro. In patients with similar pathologies, tumor positions, and radiation field sizes, however, C-ions induced a lower fraction of aberrant lymphocytes than X-rays during the treatment. The initial slope of the dose-response curve for the induction of chromosomal aberrations during the treatment was correlated to the relative decrease in the number of white blood cells and lymphocytes during the treatment. CONCLUSION: C-ions induce a lower level of cytogenetic damage in lymphocytes than X-rays, reducing the risk of bone marrow morbidity.

Aged↗
PubMed2000

Increased platelet aggregability in response to shear stress in acute myocardial infarction and its inhibition by combined therapy with aspirin and cilostazol after coronary intervention.

Although antiplatelet therapy with a specific inhibitor of phosphodiesterase-3 cilostazol improves stent patency compared with use of aspirin (ASA) alone, the specific role of cilostazol on platelet aggregation in patients with acute myocardial infarction (AMI) is less well understood. Thirty-six patients with AMI who were successfully treated with primary angioplasty were randomized to 3 antiplatelet regimens: ASA alone (n = 12), ASA + ticlopidine (n = 12), and ASA + cilostazol (n = 12). We measured shear stress-induced platelet aggregation (SIPA) using a modified cone-plate viscometer on admission and on day 7, and evaluated the inhibitory effects of combination therapy with ASA + cilostazol on SIPA. Compared with cases of stable coronary artery disease, significant increases in SIPA and plasma von Willebrand factor activity were observed in patients with AMI before they received antiplatelet therapy. On day 7 after primary angioplasty, ASA did not inhibit SIPA (65 +/- 15% vs 57 +/- 11%, p = 0.086), whereas both combination therapies of ASA + ticlopidine and ASA + cilostazol significantly inhibited SIPA in patients with AMI (ASA + ticlopidine: 61 +/- 15% vs 45 +/- 13%, p <0. 0001; ASA + cilostazol: 64 +/- 14% vs 43 +/- 9%, p <0.005). There was a significant correlation of SIPA with adenosine diphosphate (ADP)-induced platelet aggregation (r = 0.412, p = 0.003) and with plasma von Willebrand factor activity (r = 0.461, p = 0.0008). These data suggest that patients with AMI have increased platelet aggregability in response to high shear stress. Combined antiplatelet therapy with ASA + cilostazol appears to be as effective as therapy with ASA + ticlopidine for reducing SIPA in patients with AMI who are undergoing primary angioplasty.

Aged↗
PubMed2000

Asymmetry in the nonmesonic weak decay of polarized (5)(Lambda)He hypernuclei

We have measured the asymmetric emission of protons from the nonmesonic decay of polarized (5)(Lambda)He produced by the (pi(+), K+) reaction. (5)(Lambda)He is an s-shell hypernucleus and its polarization is due to the Lambda. One expects to obtain direct information on the elementary weak Lambda-->p-->np process. The asymmetry parameter has been determined to be 0.24+/-0.22. The implication of the result is discussed.

Journal Article↗
PubMed2000

Survivin initiates procaspase 3/p21 complex formation as a result of interaction with Cdk4 to resist Fas-mediated cell death.

Caspase 3 is an essential death factor for the Fas-mediated cell death, and its inactivation in cells is initiated by an interaction with p21 on mitochondria or with IAP family member ILP. Survivin is also a member of IAP family and is specifically expressed during embryogenesis and in tumor cells and suppresses cell death signaling. In our current study, we demonstrated that Survivin translocation into the nucleus is dependent on Fas stimulation and cell proliferation. Survivin also interacts with the cell cycle regulator Cdk4, leading to Cdk2/Cyclin E activation and Rb phosphorylation. As a result of Survivin/Cdk4 complex formation, p21 is released from its complex with Cdk4 and interacts with mitochondrial procaspase 3 to suppress Fas-mediated cell death. Here, we propose that Survivin supports procaspase 3/p21 complex formation as a result of interaction with Cdk4 resulting in suppression of cell death signaling.

Caspase 3↗
PubMed2000

Protease activity of CND41, a chloroplast nucleoid DNA-binding protein, isolated from cultured tobacco cells.

CND41 is a 41 kDa DNA-binding protein isolated from chloroplast nucleoids of cultured tobacco cells. The presence of the active domain of aspartic protease in the deduced amino acid sequence of CND41 suggests that it has proteolytic activity. To confirm this, CND41 was highly purified from cultured tobacco cells and its proteolytic activity was characterized with fluorescein isothiocyanate-labeled hemoglobin as the substrate. The purified CND41 had strong proteolytic activity at an acidic pH (pH 2-4). This activity was inhibited by various chemicals, including the nucleoside triphosphates, NADPH, Fe(3+) and sodium dodecyl sulfate.

Adenosine Triphosphate↗
PubMed2000

Characterization of hematopoietic lineage-specific gene expression by ES cell in vitro differentiation induction system.

The continuous generation of mature blood cells from hematopoietic progenitor cells requires a highly complex series of molecular events. To examine lineage-specific gene expression during the differentiation process, we developed a novel method combining LacZ reporter gene analysis with in vitro hematopoietic differentiation induction from mouse embryonic stem cells. For a model system using this method, we chose the erythroid and megakaryocytic differentiation pathways. Although erythroid and megakaryocytic cells possess distinct functional and morphologic features, these 2 lineages originate from bipotential erythro-megakaryocytic progenitors and share common lineage-restricted transcription factors. A portion of the 5' flanking region of the human glycoprotein IIb (alphaIIb) integrin gene extending from base -598 to base +33 was examined in detail. As reported previously, this region is sufficient for megakaryocyte-specific gene expression. However, previous reports that used human erythro-megakaryocytic cell lines suggested that one or more negative regulatory regions were necessary for megakaryocyte-specific gene expression. Our data clearly showed that an approximately 200-base enhancer region extending from -598 to -400 was sufficient for megakaryocyte-specific gene expression. This experimental system has advantages over those using erythro-megakaryocytic cell lines because it recapitulates normal hematopoietic cell development and differentiation. Furthermore, this system is more efficient than transgenic analysis and can easily examine gene expression with null mutations of specific genes.

Animals↗