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Naoki Watanabe

Publications and source records attributed to Naoki Watanabe.

At least 55 records · Page 3Linked to original sources
PubMed2004

Actin polymerization-driven molecular movement of mDia1 in living cells.

mDia1, a Rho effector, belongs to the Formin family of proteins, which shares the conserved tandem FH1-FH2 unit structure. Formins including mDia1 accelerate actin nucleation while interacting with actin filament fast-growing ends. Here our single-molecule imaging revealed fast directional movement of mDia1 FH1-FH2 for tens of microns in living cells. The movement of mDia1 FH1-FH2 was blocked by actin-perturbing drugs, and the speed of mDia1 FH1-FH2 movement appeared to correlate with actin elongation rates. In vitro, mDia1 FH1-FH2 associated persistently with the growing actin barbed end. mDia1 probably moves processively along the growing end of actin filaments in cells, and Formins may be a molecular motility machinery that is independent from motor proteins.

Actin Cytoskeleton↗
PubMed2004

Survivin enhances Fas ligand expression via up-regulation of specificity protein 1-mediated gene transcription in colon cancer cells.

Cancer cells are thought to possess mechanisms for evading the host's immune surveillance system. Survivin, a member of the inhibitor-of-apoptosis family overexpressed by cancer cells, inhibits Fas-mediated apoptosis induced by immune cells. In addition, cancer cells express Fas ligand (FasL) on their surfaces as a counterattack against immune cells. Mechanisms by which cancer cells express FasL, including involvement of survivin, are unclear. In the present study, we demonstrated that survivin up-regulated FasL expression and investigated how this might occur. Quantitative immunostaining showed correlation between survivin and FasL protein expression in colon cancer tissues (r=0.79). FasL expression was up-regulated in LS180 colon cancer cells transfected with the survivin gene. Transfectants showed increased cytotoxicity against a Fas-sensitive human T leukemia cell line, Jurkat. In contrast, FasL expression was down-regulated in SW480 cells transfected with a small inhibitory RNA to prevent survivin expression. Survivin gene transfectants showed increased DNA binding of transcription factor specificity protein 1 (Sp1) to the FasL promoter, and up-regulation of Sp1 phosphorylation at serine and threonine residues; the total amount of Sp1 was unchanged. Thus, survivin enables cancer cells not only to suppress immune cell attack by inhibiting Fas-mediated apoptotic signaling, but to attack immune cells by induction of FasL.

Adjuvants, Immunologic↗
PubMed2004

Expression of survivin mRNA and livin mRNA in non-small-cell lung cancer.

It has been suggested that suppression of apoptosis may contribute to the development and progression of cancer. Anti-apoptotic survivin and livin genes are highly expressed in cancer cells and transformed cells, but show little or no expression in normal differentiated tissues. However, there are no available data concerning livin expression in non-small-cell lung cancer (NSCLC). We therefore measured livin mRNA and survivin mRNA expression in 38 NSCLC cancer samples and 15 paired non-cancerous lung tissue samples using a quantitative reverse transcription-polymerase chain reaction (RT-PCR). While both mRNAs showed higher expression in cancers than non-cancerous tissues (P < 0.001), livin mRNA and survivin mRNA expression did not correlate with one another. When a cut-off value for positivity was set at the mean + S.D. for expression values in non-cancerous tissues, positivity rates for livin mRNA and survivin mRNA expression were 76.3% (29 of 38) and 36.8% (14 of 38) in lung cancers and 6.7% (1 of 15) and 0% (0 of 15), respectively, in paired non-cancerous lung tissue samples. Livin mRNA and survivin mRNA expression in tumors were up-regulated in 23 of 31 (74.2%) early-stage NSCLC patients and 11 of 31 (35.5%), respectively. Expression of both mRNAs in tumors varied independently of tumor histology. These results support the possibility that the livin gene may play a role in NSCLC development and increased expression of livin mRNA may serve as a new target for lung cancer treatment as well as survivin.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Mutations of the p53 gene and loss of heterozygosity at chromosome 17p13.1 are associated with increased survivin expression in breast cancer.

Expression of survivin, a member of the inhibitor-of-apoptosis (IAP) family, is elevated in fetal tissues and in various human cancers originating in the breast, lung, prostate, colon, pancreas, and stomach. Since overexpression of the survivin gene has been linked to poor patient survival in several cancers, survivin may be an important prognostic marker. Mechanisms up-regulating survivin gene expression in cancer are poorly understood. Recently, wild-type p53 was found to repress expression of the survivin gene by binding to the survivin promoter, thereby inhibiting promoter activity. Further, loss of heterozygosity (LOH) at 17p13 distal to the p53 gene is associated with more aggressive behavior of breast cancers. We therefore tested the hypothesis that not only p53 gene mutation but also LOH at 17p13 can up-regulate survivin expression in breast cancer. Survivin mRNA expression was greater in cancers than in uninvolved tissues (p < 0.0001). Mutations of the p53 gene were detected in 5 of 25 tumors; higher survivin gene expression was evident in these. LOH at the D17S938 locus (17p13.1) was found in 10 of 25 tumors, and most of these also showed increased survivin gene expression. Thus expression of survivin may be regulated not only by p53 but additionally by a putative tumor suppressor gene located at 17p13 distal to the p53 gene.

Adult↗
PubMed2004

Survivin as a predictor of cis-diamminedichloroplatinum sensitivity in gastric cancer patients.

Survivin, a member of the inhibitor-of-apoptosis family, inhibits apoptosis by blocking caspase-3 and -7 activation. Gastric cancer, which is among the most intractable of malignant tumors, is known for resistance to various drugs, including cis-diamminedichloroplatinum (CDDP). Since this agent induces apoptosis via caspase-3 activation, survivin may mediate the drug resistance. We investigated survivin messenger RNA (mRNA) expression in gastric cancers and the relationship between expression and sensitivity to CDDP. Expression of the survivin gene was significantly up-regulated in gastric cancers compared to the tissues of normal mucosa, atrophic gastritis, and intestinal metaplasia (P < 0.0001) as assessed by a quantitative reverse transcription-polymerase chain reaction (RT-PCR), and was negatively associated with overall survival of patients who received CDDP-based chemotherapy. To investigate whether survivin is a resistance factor against CDDP-induced apoptosis, we transfected wild-type and dominant-negative mutants of the survivin gene into gastric cancer cells using a lipofection method. Overexpression of survivin protected MKN45 cells from CDDP-induced apoptosis. Expression of the dominant-negative mutant of the survivin gene sensitized NUGC-3 cells to drug-induced apoptosis. These results indicate that survivin may be pivotal in the development of gastric cancer and resistance to CDDP, and therefore controlling expression of the survivin gene may be therapeutically useful.

Adult↗
PubMed2004

[Nationwide surveillance of parenteral antibiotics containing meropenem activities against clinically isolated strains in 2002].

The antibacterial activity of meropenem (MEPM) and other parenteral antibiotics against clinical isolates of 899 strains of Gram-positive bacteria, 1500 strains of Gram-negative bacteria, and 158 strains of anaerobic bacteria obtained from 28 medical institutions during 2002 was measured. The results were as follows; 1. MEPM was more active than other carbapenem antibiotics against Gram-negative bacteria, especially against enterobacteriaceae and Haemophilus influenzae. MIC90 of MEPM against Pseudomonas aeruginosa was the lowest of the drugs tested. MEPM showed low cross-resistant rate against both imipenem-resistant P. aeruginosa and ciprofloxacin-resistant P. aeruginosa. MEPM was active against most of the species tested in Gram-positive and anaerobic bacteria, except for multi-drug resistant strains including methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE). 2. The proportion of extended-spectrum beta-lactamase (ESBL) strains was 3.1% (4 strains) in Escherichia coli and 1.9% (2 strains) in Klebsiella pneumoniae. Carbapenems including MEPM were active against these ESBL strains. In conclusion, the results from this surveillance study suggest that MEPM retains its potent and broad antibacterial activity and therefore is a clinically useful carbapenem; at present, 7 years after available for commercial use.

Bacteria↗
PubMed2003

A novel aspartate protease gene, ALP56, is related to morphological features of colorectal adenomas.

BACKGROUND AND AIMS: The recently identified aspartate protease gene ALP56 is up-regulated in human malignant tumors, including colorectal cancers, but the relationship remain unclear between ALP56 gene expression and clinicopathological findings, as well as when genetic alterations in ALP56 occur during the colorectal adenoma-carcinoma sequence. We therefore investigated expression of ALP56 mRNA in various human colorectal tissues. MATERIALS AND METHODS: We examined 18 colorectal adenomas 22 cancers, and 24 adjacent normal mucosal samples from patients undergoing conventional resection or endoscopic mucosal resection. Expression of ALP56 mRNA was determined by quantitative reverse-transcription polymerase chain reaction. RESULTS: Up-regulation of ALP56 gene transcription was observed in both adenomas and cancers compared to normal mucosa. ALP56 expression in exophytic adenomas was significantly greater than in flat adenomas. CONCLUSION: ALP56 may contribute to colorectal adenoma formation and to an exophytic growth pattern in these adenomas.

Adenoma↗
PubMed2003

A novel aspartic protease gene, ALP56, is up-regulated in human breast cancer independently from the cathepsin D gene.

Tumor cell invasion requires expression of degradative enzymes such as plasminogen activator, collagenase, and cathepsins. Cathepsin D, a lysosomal aspartic protease produced constitutively in human breast cancer cell lines, also has mitogenic activity in breast cancer cells. Additionally, high cathepsin D expression is associated with increased risk of metastasis in patients with node-negative breast cancer. Recently, a novel aspartic protease gene, ALP56 (aspartic-like protease 56kDa), has been identified. To examine possible interrelationships we quantitated ALP56 mRNA and cathepsin D mRNA in breast cancers using reverse transcription polymerase chain reaction. ALP56 mRNA expression was greater in cancers than in noncancerous tissues (p < 0.0001), as was expression of cathepsin D mRNA. ALP56 gene expression was dose-dependently down-regulated in T-47D breast cancer cells treated with estradiol, while cathepsin D was up-regulated. Expression of ALP56 mRNA in estrogen receptor (ER)-positive breast cancers was less than that in ER-negative cancers, and mRNA expression for ALP56 and cathepsin D did not correlate with one another. Thus ALP56 as well as cathepsin D may be a useful target molecule in breast cancer treatment.

Adult↗
PubMed2003

Analysis on distribution and genomic diversity of high-level antiseptic resistance genes qacA and qacB in human clinical isolates of Staphylococcus aureus.

High-level antiseptic resistance of Staphylococcus aureus is mediated by multidrug efflux pumps encoded by qacA and qacB genes. We investigated distribution and genomic diversity of these antiseptic resistance genes in a total of 522 clinical strains of S. aureus isolated recently in a Japanese hospital. The qacA/B gene was detected in 32.6% of methicillin-resistant S. aureus (MRSA) and 7.5% of methicillin-susceptible S. aureus (MSSA), whereas the low-level resistance gene smr, which was examined simultaneously, was detected at lower frequencies in both MRSA (3.3%) and MSSA (5.9%). Epidemiologic typing of S. aureus isolates suggested that higher prevalence of qacA/B in MRSA may be due to spread of a single predominant MRSA strain carrying qacA/B in the hospital. Restriction fragment length polymorphism (RFLP) analysis indicated higher prevalence of the qacB-type gene (59.3%) than the qacA-type gene (40.7%) among the qacA/B genes detected. Nucleotide sequencing analysis revealed the presence of two genetic variants in qacA (V1 and V2) and four variants in qacB (V1-V4) that differ from the qacA prototype in pSK1 by 1-5 nucleotides and 7-9 nucleotides, respectively. Although most strains with qacA-V1, qacA-V2, qacB-V3, and qacB-V4 showed high-level resistance to ethidium bromide (EB)(MIC > 100 microg/ml), all of the S. aureus isolates carrying qacB-V1 and qacB-V2 showed lower MICs of EB and some monovalent cationic antiseptic substances. By analysis of the genomic organization of the qacA/B downstream region, divergent forms of this region rearranged with an insertion of IS256 or IS257 were found primarily for qacB. The downstream region of qacA-V1 was suggested to be an evolutionary origin for other divergent forms. These findings indicated that both qacA and qacB are prevalent in recent clinical isolates, especially in MRSA, and these genes consist of variable genetic variants that may be responsible for different resistance levels against antiseptic substances.

Anti-Infective Agents, Local↗
PubMed2003

[Morita therapy in cultural context].

East is characterized by concepts of transcendence of ego structure, equality of mind to body and psychic structure of emptiness or nothingness. West is on the other hand characterized by concepts of ego strength, superiority of mind to body and psychic structure of fullness. Namely in the East ego is not strengthened but dispersed into relationships of a person with other persons, animated and in-animated others. There is no differentiation between mind and body. Also there is a traditional way of reaching a psychic state of emptiness or nothingness which is found in Zen-Buddhism. However in the West nothingness or emptiness has only negative meaning. West has also linear way of thinking that one lives by developing oneself towards God as progress whereas East has circular way of thinking like Nietzches word, "Eternal repeat of the sameness". Such traditional concepts of Eastern culture are reflected on our Japanese language. For example we would like to omit subject and object and propose to go to drink something, tea or coffee. We would like to keep the ambiguity in our expression so that we could avoid harming the others who actually wanted to go with us. Morita Therapy is based on the Eastern culture and has such cultural backgrounds. Indicated are the patients who have a tendency to be hypochondriacal and called "shinkeishitu". These patients have namely strong fear of death and also at the same time strong wish to live a full life. However the fear of death predominate and suppress the desire to live a full life which produces several neurotic symptoms like simple phobia, panic disorder, obsessive compulsive disorder, etc. For such patients we do absolute bed rest in order to let the patients discern the natural process of their inner self through paradoxical setting of lying down for 7 days that is usually unnatural. Patients are prescribed to lie down in bed except eating, face-washing and keeping hygiene. The bed rest induces at first boredom which would bring about paradoxically desire to live a full life. Also in the following work therapy period patients would not fixate their attention inwards, namely to their symptoms but learn to pay attention towards outwards even though they have still symptoms. In the body action we could acknowledge changes of our inner perception that is also possessed by other persons, other animated creatures and in-animated creatures as a form of "Inter-perceptivity". We do not only perceive the atmosphere established between us and others but also between us and outer nature. Patients learn that anxiety is not to be eliminated but to be accepted as it is. So we just accept and do "nothing" to eliminate anxiety. We address that Morita Therapy is not only indicated for "shinkeishitu" personality but also for other anxiety based disorders, such as cancer patients, traumatized patients, etc.

Anxiety Disorders↗
PubMed2003

[Activities of antimicrobial agents against 8,474 clinical isolates obtained from 37 medical institutions during 2000 in Japan].

A survey was conducted to determine the antimicrobial activity of fluoroquinolones and other antimicrobial agents against 8,474 clinical isolates obtained from 37 Japanese medical institutions in 2000. A total of 25 antimicrobial agents were used, comprising 4 fluoroquinolones, 13 beta-lactams, minocycline, chloramphenicol, clarithromycin, azithromycin, gentamicin, amikacin, sulfamethoxazole-trimethoprim, and vancomycin. A high resistance rate of over 85% against fluoroquinolones was exhibited by methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecium. Isolates showing resistance to fluoroquinolones among methicillin-resistant coagulase-negative Staphylococci, Enterococcus faecalis, and Pseudomonas aeruginosa from UTI accounted for 30-60%. However, many of the common pathogens were still susceptible to fluoroquinolones, such as Streptococcus pneumoniae (including penicillin-resistant isolates), Streptococcus pyogenes, methicillin-susceptible S. aureus (MSSA), methicillin-susceptible coagulase-negative Staphylococci, Moraxella catarrhalis, the Enterobacteriaceae family, and Haemophilus influenzae (including ampicillin-resistant isolates). About 85% of P. aeruginosa isolated from RTI were susceptible to fluoroquinolones. In conclusion, this survey of sensitivity to antimicrobial agents clearly indicated trend for increasing resistance to fluoroquinolones among MRSA, Enterococci, and P. aeruginosa isolated from UTI, although fluoroquinolones are still effective against other organisms and P. aeruginosa from RTI as has been demonstrated in previous studies.

Anti-Bacterial Agents↗
PubMed2003

[Nationwide sensitivity surveillance of ciprofloxacin and various parenteral antibiotics against bacteria isolated from patients with severe infections--the first Ciproxan IV special investigation in 2001].

The parenteral injection of ciprofloxacin (CPFX), a fluoroquinolone antimicrobial drug, was approved in September 2000 and a re-examination period of 6 years was set at that time. As a special investigation to apply for re-examination of this drug, it has been planned to conduct 3 nationwide surveillances during the re-examination period by collecting clinically isolated bacteria from patients with severe infections, to whom the drug was mainly indicated, and examining drug susceptibilities of the bacteria to various parenteral antimicrobial drugs including CPFX. This time, we determined the minimum inhibitory concentrations (MICs) of various parenteral antimicrobial drugs including CPFX against 1,220 strains isolated from patients with severe infections by the micro-liquid dilution method and compared susceptibilities of various clinically isolated bacteria to CPFX with those to other antimicrobial drugs. Gram-positive bacteria were less susceptible to CPFX than to carbapenems except 2 bacterial species, Enterococcus faecium and Enterococcus avium but susceptibilities of methicillin-susceptible Staphylococcus aureus (MSSA), Staphylococcus epidermidis and Enterococcus faecalis to CPFX were comparable to those to cefozopran. Susceptibility of Streptococcus pneumoniae to CPFX did not differ among ampicillin (ABPC)-susceptible Streptococcus pneumoniae (MIC of ABPC: < 0.25 microgram/ml), ABPC-intermediate S. pneumoniae (MIC of ABPC: 0.25-2 micrograms/ml) and ABPC-resistant S. pneumoniae (MIC of ABPC: > or = 4 micrograms/ml) MIC90 of CPFX: 1 microgram/ml) and a decrease in the antimicrobial activity seen among cephem and carbapenem antimicrobial drugs against penicillin-intermediate strains was not noted with CPFX. Gram-negative bacteria were susceptible to CPFX similarly to carbapenems and the MIC90 values of CPFX were in the range from < or = 0.063 to 2 micrograms/ml against strains except Stenotrophomonas maltophilia and Burkholderia cepacia. Pseudomonas aeruginosa was most susceptible to CPFX among the antibacterial drugs examined and the MIC90 was 2 micrograms/ml. CPFX also showed the lowest MIC90 value (0.5 microgram/ml) against beta-lactam-resistant P. aeruginosa among the drugs examined. When extended-spectrum beta-lactamase (ESBL) production and class B beta-lactamase production were examined in 439 strains of Enterobacteriaceae and 168 strains of glucose non-fermentative bacteria out of the Gram-negative bacteria collected this time, 3 strains (0.49%) producing ESBL and 7 strains (1.15%) producing class B beta-lactamase were found. The MIC range of CPFX to these 10 strains was between < or = 0.063 to 8 micrograms/ml and 5 strains among those showed susceptibilities (MIC of CPFX: 1 microgram/ml) based on the NCCLS breakpoint. CPFX also showed a satisfactory result concerning susceptibilities of major causal bacteria based on the report of the committee of Japan Society of Chemotherapy on the standard method for determination of susceptibility to antimicrobial agents, the breakpoint of pneumonia. Furthermore, susceptibilities of various bacteria isolated clinically from patients with severe infections this time did not differ much from the result of the nationwide surveillance which we conducted in 1997. Thus, it was concluded that the antimicrobial activity of CPFX was maintained in the post-marketing surveillance for its parenteral preparation.

Adolescent↗
PubMed2002

Cryptic t(12;15)(p13;q26) producing the ETV6-NTRK3 fusion gene and no loss of IGF2 imprinting in congenital mesoblastic nephroma with trisomy 11: fluorescence in situ hybridization and IGF2 allelic expression analysis.

In the present fluorescence in situ hybridization (FISH) study of six congenital mesoblastic nephromas (CMNs) using ETV6 and NTRK3 probes as well as a chromosome 15 painting probe, we identified a cryptic reciprocal translocation, t(12;15)(p13;q26), in one tumor, and an insertion, ins(12;15)(p13;q22q26), in another that were not previously identified by cytogenetic analysis. An interphase FISH study with the same probes detected the ETV6-NTRK3 fusion signal in all three cellular or mixed type tumors, but not in all three classical type tumors. Reverse transcriptase polymerase chain reaction (RT-PCR) analysis detected the ETV6-NTRK3 fusion transcript in the three cellular or mixed type tumors, but not in the three classical type tumors. FISH analysis using a chromosome 11-centromere probe detected trisomy or tetrasomy 11 in all three tumors with the ETV6-NTRK3 fusion signal. To clarify whether IGF2, a paternally expressed gene on chromosome 11, has a certain role in the tumorigenic process of CMN through a loss of imprinting (LOI), we studied IGF2 allelic expression. We found no LOI in two cellular or mixed type tumors or in two classical type tumors, and concluded that the role of the LOI of IGF2 is not essential for the development and progression of CMN with or without trisomy 11. Furthermore, we showed no rearrangements of the MLL gene, which is frequently rearranged in acute leukemia with +11 in the three CMN tumors with +11.

Alleles↗