Search PubMed⌕ Search

Biomedical subjects

K Yano

Publications and source records attributed to K Yano.

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

Nuclear localization signals of the BRCA2 protein.

BRCA2 is a tumor suppressor gene whose germline mutations increase the lifetime risk of breast cancer. BRCA2 encodes a large nuclear protein involved in DNA repair, but the location of its functional domain has been unclear. Here, we report nuclear localization signals (NLSs) of the BRCA2 protein. By expressing various portions of the BRCA2 protein tagged with enhanced green fluorescent protein in HeLa cells, we show that the C-terminal domain is necessary for nuclear localization. Two regions in the C-terminal domain were identified with functional NLSs by site-directed mutagenesis analyses. The NLSs locate between the germline mutation found in the most downstream position and the polymorphic stop codon, suggesting that defects in the proper nuclear transport of the BRCA2 protein are causative of carcinogenesis. Our data thus provide a possible explanation for the high frequency of frame-shift and nonsense mutations in BRCA2 of hereditary breast cancer patients.

BRCA2 Protein↗
PubMed2000

Identification and characterization of human ZNF274 cDNA, which encodes a novel kruppel-type zinc-finger protein having nucleolar targeting ability.

A human cDNA encoding a novel zinc-finger protein, ZNF274, was identified by the "nuclear transportation trap" method (Ueki, N., Oda, T., Kondo, M., Yano, K., Noguchi, T., and Muramatsu, M., 1998, Nat. Biotechnol. 16: 1338-1342). Based on sequence analysis of the full-length cDNA, this novel gene has two alternative splicing forms, ZNF274a and ZNF274b, which encode putative proteins of 621 and 584 amino acids, respectively. ZNF274a contains five C2H2-type zinc-finger motifs, two KRAB-A (Kruppel-associated box) domains, and one leucine-rich domain. ZNF274b lacks the first KRAB-A domain at the N-terminus. ZNF274 mRNA is detected in various human tissues by Northern analysis. The ZNF274 gene is mapped distal to marker RP S28 1 in the human chromosome 19qter region, by RH mapping. The KRAB domains of ZNF274 exhibited transcription repressor activity when tested in GAL4 fusion protein assays. EGFP-ZNF274 fusion protein expressed in COS7 cells predominantly localized to the nucleoli. A series of deletion constructs revealed that a minimal domain consisting of the third and fourth zinc-fingers possesses nucleolar targeting ability. These results suggest that ZNF274 is a ubiquitous transcription repressor that plays a role in the nucleoli.

Alternative Splicing↗
PubMed2000

Ca(2+) binding and energy coupling in the calmodulin-myosin light chain kinase complex.

We have previously shown that 3 Ca(2+) ions are released cooperatively and 1 independently from the complex between (Ca(2+))4-calmodulin and skeletal muscle myosin light chain kinase or a peptide containing its core calmodulin-binding sequence. We now have found that three Ca(2+)-binding sites also function cooperatively in equilibrium Ca(2+) binding to these complexes. Replacement of sites I and II in calmodulin by a copy of sites III and IV abolishes these cooperative effects. Energy coupling-dependent increases in Ca(2+)-binding affinity in the mutant and native calmodulin complexes with enzyme are considerably less than in the peptide complexes, although the complexes have similar affinities. Ca(2+) binding to three sites in the native calmodulin-enzyme complex is enhanced; the affinity of the remaining site is slightly reduced. In the mutant enzyme complex Ca(2+) binding to one pair of sites is enhanced; the other pair is unaffected. In this complex reversal of enzyme activation occurs when Ca(2+) dissociates from the pair of sites with enhanced affinity; more rapid dissociation from the other pair has no effect, although both pairs participate in activation. Ca(2+)-independent interactions with calmodulin clearly play a major role in the enzyme complex, and appear to weaken Ca(2+)-dependent interactions with the core calmodulin-binding sequence.

Amino Acid Sequence↗
PubMed2000

Major complications during spasm provocation tests with an intracoronary injection of acetylcholine.

This study sought to clarify major complications associated with acetylcholine testing. Serious major complications, such as sustained ventricular tachycardia, shock, and cardiac tamponade were determined in 4 of 715 patients (0.56%), but no cases of death or irreversible complications occurred. The spasm provocation test using acetylcholine should be performed carefully, although it is considered a safe and reliable method.

Acetylcholine↗
PubMed2000

Interactions between cancer and bone marrow cells induce osteoclast differentiation factor expression and osteoclast-like cell formation in vitro.

Cancer cells metastasized to bone induce osteoclastogenesis for bone destruction. Coculture of either mouse melanoma B16 or breast cancer Balb/c-MC cells with mouse bone marrow cells (BMCs) induced osteoclast-like cells, which were not observed when cancer cells were segregated from BMCs. Osteoclast differentiation factor (ODF), also known as receptor activator of NF-kappaB ligand (RANKL), is a direct mediator of many osteotropic factors. Neither BMCs, B16 nor Balb/c-MC cells alone expressed ODF mRNA. However, coculture of these cancer cells with BMCs induced ODF expression, which was prevented by indomethacin. Moreover, the coculture with cancer cells inhibited secretion of osteoprotegerin/osteoclastogenesis inhibitory factor (OPG/OCIF), an inhibitory decoy receptor for ODF, from BMCs. Thus, enhanced osteoclastogenesis in the presence of cancer cells might be due to an increase in ODF activity. These results suggest that interactions between cancer cells and BMCs induce ODF expression and suppress OPG/OCIF level in metastatic foci resulting in pathological osteoclastogenesis for bone destruction.

Animals↗
PubMed2000

Distribution and serum concentration of sisomicin released from fibrin glue-sealed dacron graft in the rat and human.

We investigated whether or not fibrin glue (FG) used as a sealant in vascular prostheses to prevent leakage might be useful as a carrier of antibiotics for the prevention of local graft infection. Sisomicin (SISO) was incorporated into fibrin glue (SISO-FG) and evaluated as to its safety and pharmacokinetics. SISO (1.75 mg) -FG Dacron grafts were implanted subcutaneously in the anterior abdominal region of Sprague-Dawley rats, and then the changes in SISO concentrations in the serum and in the tissue around the implantation sites were compared with those same sites in rats that had had intravenous injection of SISO (1.75 mg). The serum SISO concentrations were significantly lower in the SISO-FG Dacron graft group than they were in the intravenous injection group. However, until 4 h after implantation the SISO concentrations in the tissues around the implantation sites were significantly higher in the SISO-FG Dacron group than they were in the iv injection group, and the peak concentrations during that time were 5.8 times higher for the SISO-FG Dacron group than they were for the intravenous injection group. The ratio of the area under the tissue concentration time curve of SISO (AUC tissue) after implantation of the SISO-FG Dacron graft to that after intravenous injection of SISO was 13.08. Therefore, FG was considered to control the release of SISO into the serum and to maintain a high SISO concentration in the tissue around the implantation site. Clinically, SISO (45 mg) -FG was applied directly to the Dacron grafts implanted in 10 patients who underwent prosthetic vascular reconstruction. No graft infection was observed in any of the patients who received SISO-FG Dacron grafts. The mean serum concentration of SISO was 0.65+/-0.17 microg/mL after 1 h and 0.33+/- 0.21 microg/mL after 3 h. The results of these clinical applications are in close correlation with those of the animal experiment and suggest that FG is useful as a carrier of SISO, allowing its controlled release for the prevention of local infection.

Aged↗
PubMed2000

Severity of residual stenosis of infarct-related lesion and left ventricular function after single-vessel anterior wall myocardial infarction: implication of ST-segment elevation in lead aVL of the admission electrocardiograms.

BACKGROUND: The relationship between the severity of chronic-phase stenosis of infarct-related lesions (IRLs) and chronic left ventricular function in anterior acute myocardial infarctions (AMI) has not been adequately investigated. HYPOTHESIS: This study investigated whether ST elevation in lead aVL of admission electrocardiogram (ECG) would be a determinant factor of the relationship between the severity of stenosis of the IRL and chronic left ventricular function after anterior wall AMI. METHODS: One month after AMI, the IRL was evaluated by coronary angiography in 98 patients with anterior AMI, and left ventricular ejection fraction (LVEF) was determined using multigated radionuclide angiocardiography. Patients were classified according to the severity of the IRL: patients with 100% occlusion (Group O), patients with 90 to 99% stenosis (Group H), and patients with < or =75% stenosis (Group L). Patients with ST elevation > or =0.1 mV in the aVL lead on their admission ECG were included in the ST-elevation group, and those with ST elevation <0.1 mV were included in the non-ST-elevation group. RESULTS: The LVEF was greater in the non-ST-elevation group than in the ST-elevation group (p<0.0001), and the LVEF in a whole group as follows: Group L LVEF>Group H LVEF>Group O LVEF (p = 0.0160). In the ST-elevation group, LVEF was higher in Group L than in the other groups (p = 0.0251). There were three independent predictors of a reduced LVEF: ST-elevation in aVL [odds ratio (OR): 3.38, p = 0.0044], IRL stenosis > or =90% (OR: 2.90, p = 0.0044), and the IRL occurring in the left anterior descending artery proximal to the first diagonal branch (OR: 6.31, p = 0.0024). CONCLUSION: Left ventricular function was preserved, regardless of the severity of residual stenosis, in patients without ST elevation in aVL if the IRL was not totally occluded. In patients with ST elevation in aVL, LVEF was lower in patients with more severe stenosis, even if the IRL was patent.

Adult↗
PubMed2000

Identification of Rad51 alteration in patients with bilateral breast cancer.

The human Rad51 gene, HsRAD51, is a homolog of RecA of Escherichia coli and functions in recombination and DNA repair. BRCA1 and BRCA2 proteins form a complex with Rad51, and these genes are thought to participate in a common DNA damage response pathway associated with the activation of homologous recombination and double-strand break repair. Additionally, we have shown that the pattern of northern blot analysis of the RadS gene is closely similar to those of the BRCA1 and BRCA2 genes. It is therefore possible that alterations of the Rad51 gene may be involved in the development of hereditary breast cancer. To investigate this possibility, we screened Japanese patients with hereditary breast cancer for Rad51 mutations and found a single alteration in exon 6. This was determined to be present in the germline in two patients with bilateral breast cancer, one with synchronous bilateral breast cancer and the other with synchronous bilateral multiple breast cancer. In both patients, blood DNAs showed a G-to-A transition in the second nucleotide of codon 150, which results in the substitution of glutamine for arginine. As this alteration was not present in any patients with breast or colon cancer examined, we assume that this missense alteration is likely to be a disease-causing mutation.

Blotting, Northern↗
PubMed2000

cDNA cloning of a novel human gene NAKAP95, neighbor of A-kinase anchoring protein 95 (AKAP95) on chromosome 19p13.11-p13.12 region.

A-kinase anchoring protein 95 (AKAP95) is a nuclear protein which binds to the regulatory subunit (RII) of cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) and to DNA. A novel nuclear human gene which shares sequence homology with the human AKAP95 gene was identified by a nuclear transportation trap method. By polymerase chain reaction (PCR)-based analysis with both a human/rodent monochromosomal hybrid cell panel and a radiation hybrid panel, the gene was mapped to the chromosome 19p13.11-p13.12 region between markers WI-4669 and CHLC.GATA27C12. Furthermore, alignment with genomic sequences revealed that the gene and human AKAP95 resided tandemly only approximately 250 bp apart from each other. We designated this gene as neighbor of AKAP95 (NAKAP95). The exon-intron structure of NAKAP95 and AKAP95 was conserved, indicating that they may have evolved by gene duplication. The predicted protein product of the NAKAP95 gene consists of 646 amino acid residues, and NAKAP95 and AKAP95 had an overall 40% similarity, both having a potential nuclear localizing signal and two C2H2 type zinc finger motifs. The putative RII binding motif in AKAP95 was not conserved in NAKAP95. A reverse transcription coupled (RT)-PCR experiment revealed that the NAKAP95 gene was transcribed ubiquitously in various human tissues.

Amino Acid Sequence↗
PubMed2000

Cardiac rupture and admission electrocardiography in acute anterior myocardial infarction: implication of ST elevation in aVL.

This study determines the usefulness of electrocardiography in the emergency room for assessing the risk of cardiac rupture after acute anterior myocardial infarction (MI). The presence of ST segment elevation on the admission 12-lead electrocardiography was evaluated in 325 consecutive anterior MI patients. A forward-stepwise logistic regression analysis for cardiac rupture was performed with the covariates of age, gender, hypertension, history of MI, reperfusion therapy by coronary angioplasty, and ST segment elevations in leads I, aVL, V1-V6. Cardiac rupture occurred in 16 patients, including 7 with left ventricular free wall rupture (FWR) and 9 with ventricular septal perforation (VSP). For FWR, ST elevation in lead aVL was the only independent predictor (odds ratio = 12.1, P = .0215). For VSP, female gender (odds ratio = 5.32, P = .0201) was the independent predictor. In conclusion, in patients with acute anterior MI, ST segment elevation in lead aVL on the admission electrocardiography is a significant risk factor for left ventricular FWR.

Adult↗
PubMed2000

Bioassay of bile acids using an enzyme-linked DNA aptamer.

A new analytical method for the detection of bile acids has been developed by adopting an alkaline phosphatase-linked DNA oligomer that binds to bile acids. A 5'-biotin-labeled DNA oligomer with a 40-nucleotide length that is defined by the in vitro selection method was connected with alkaline phosphatase through an avidin-biotin linkage and applied to an enzyme immunoassay format. Sample solutions were incubated with small aliquots for a cholic acid-immobilized agarose matrix, on which the alkaline phosphatase-linked DNA oligomer had been bound prior to carrying out the assay. The amount of the alkaline phosphatase-linked DNA oligomer dissociated from the cholic acid-immobilized agarose matrix, which was detected using a fluorogenic substrate for alkaline phosphatase, indicated the amount of bile acids in the samples. The results suggest that the DNA aptamer directly linked with the reporter enzyme is applicable as a detector ligand for the immunoassay format. A linear calibration range was obtained for cholic acid between 0.1 to 5 mmol l-1 with a limit of detection of 10 mumol l-1. The %RSD was 7 at 5 mmol l-1 of cholic acid.

Animals↗
PubMed2000

A mediator-type biosensor as a new approach to biochemical oxygen demand estimation.

A novel biosensor for the determination of biochemical oxygen demand (BOD) was developed using potassium hexacyanoferrate(III) [HCF(III)] as a mediator. The sensor element consists of a three-electrode system, with both working and counter electrodes compactly integrated as a disposable using etching and electroplating processes. Pseudomonas fluorescens biovar V (isolated from a wastewater treatment plant) was immobilized on the surface of the working electrode using poly(vinyl alcohol)-quaternized stilbazol (PVA-SbQ) photopolymer gel. Synthetic wastewater described by the Organization for Economic Cooperation and Development (OECD) was used as a standard solution instead of glucose-glutamic acid synthetic wastewater. The conditions of amperometric measurement were optimized at +600 mV (vs. Ag/AgCl) operating potential, namely 40 mM HCF(III) in a 0.1 M phosphate buffer (pH 7.0) at 20 degrees C. The sensor response was linear from 15 up to 200 mg O l-1 BOD. The response time was 15 min at 200 mg O l-1 BOD. To demonstrate the wide metabolic range of activity of the sensor, the sensor response to 14 substances in four categories of organic compounds was investigated. Further, it was shown that the response of this BOD sensor was not influenced in samples with low concentrations of dissolved oxygen under the measuring conditions used. For real wastewaters, the BOD values were determined using the sensor and compared favorably with those determined by the conventional BOD5 method.

Journal Article↗
PubMed2000

Combined latissimus dorsi musculocutaneous flap and free superior gluteal artery skin flap.

We used a combined superior gluteal artery skin flap and latissimus dorsi musculocutaneous flap to repair a massive tissue defect of the upper limb. This combined flap has several advantages in that the length can be more than 60 cm, it can be used as an auxilliary muscle (latissimus dorsi) and it can also be used as a sensory flap. This combined flap is useful for covering massive skin defects.

Adult↗
PubMed2000

A 15-year longitudinal follow-up study of heart rate and heart rate variability in healthy elderly persons.

BACKGROUND: Few researchers have conducted heart rate (HR) studies in healthy very elderly subjects aged 70 years or older, and there are no longitudinal follow-up studies in this population. The objective of this study was to evaluate long-term changes in HR and heart rate variability (HRV) with aging in healthy elderly persons by means of comparison between two Holter monitor recordings obtained at an interval of 15 years. METHODS: The study population consisted of 15 healthy elderly persons (10 women and 5 men) aged 64 to 80 years (mean 70 +/- 4.1) at the first recording, and 79 to 95 years old (mean 85 +/- 4.1 years) at the second recording 15 years later. Nighttime (midnight to 5 AM) and daytime (noon to 5 PM) HR and HRV were obtained, and paired t tests were performed to assess the differences in each parameter of nighttime and daytime HR and HRV between the two (15-year interval) Holter monitor recordings. RESULTS: The results of the t-test comparisons were as follows: there was a significant increase in minimal, maximal, and average HRs (nighttime, p < .01; daytime, p < .05, respectively). On the other hand, with regard to HRV, there was a significant nighttime decrease in the SDNN index (mean of standard deviations of normal RR intervals between adjacent QRS complexes resulting from sinus node depolarizations for all 5-minute segments) (p = .0086), and a significant daytime increase in the NN50 (number of adjacent normal RR intervals >50 milliseconds) per hour (p = .0425). Moreover, there was a significant decrease in the low-frequency (LF) component (nighttime, p = .0151; daytime, p = .0032), and a significant decrease in the LF/HF ratio (nighttime, p = .0270; daytime, p = .0371), but there was no significant change in the nighttime or daytime high-frequency (HF) component. CONCLUSIONS: HR increased with age over the 15-year period in the healthy elderly persons. As for concurrent changes in HRV, however, the parameters of sympathetic modulation decreased, and the parameters of parasympathetic modulation were unchanged or slightly increased.

Aged↗