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Y Okawa

Publications and source records attributed to Y Okawa.

At least 19 recordsLinked to original sources
PubMed2006

[Aortic valve replacement in elderly patients with small aortic annulus; is the indexed effective orifice area important?].

We sought to determine whether the small indexed effective orifice area (EOAI) increased mortality and morbidity after aortic valve replacement (AVR) in patients over 75 years of age. From May 1999 to July 2005, 77 patients underwent isolated AVR for aortic stenosis. They were divided into 3 groups (S-EOAI : EOAI < or = 0.7 cm2/m2, M-EOAI : 0.7 cm2/m2 <EOAI < or = 0.85 cm2/ m2, L-EOAI : 0.85cm2/m2 <EOAI) for evaluation. We examined the body surface area (BSA), EOAI, and the left ventricular (LV) mass index (LVMI). We found that patients with S-EOAI had less symptomatic improvement (p <0.05, vs L-EOAI) and LV mass regression (p< 0.01, vs L-EOAI). But, their average New York Heart Association (NYHA) class was improved significantly (2.3 +/- 0.8 vs 1.8 +/- 0.7 : preoperative vs postoperative, p=0.001). Furthermore, severe patient-prosthesis mismatch (PPM) had no significant negative impacts on the freedom of valve-related complications (75.1% : S-EOAI group vs 92.0% : L-EOAI group) and the 5-year survival (84.9% : S-EOAI group vs 87.8% : L-EOAI group). In elderly patients, the average NYHA class was 1.9 +/- 0.6 postoperatively (p<0.0001 vs preoperative) and the LVMI showed significant regression (p<0.0001) despite an average EOAI of 0.73 +/- 0.13 cm2/m2. It is important to consider whether the benefits of avoiding PPM overcome the drawbacks of other complicated techniques. In this study, we found that moderate PPM (0.7 cm2/m2 < or = EOAI) is acceptable to elderly patients.

Aged↗
PubMed2006

[Effects of dexmedetomidine hydrochloride on postoperative sedation in cardiovascular surgery].

BACKGROUND: Postoperative assessment of brain damage in cardiovascular surgery is often obscured by sedatives. Therefore, early postoperative detection of brain attack and its treatment are also hampered. A newly approved sedative, dexmedetomidine hydrochloride has weak analgesic effect and no respiratory depressive effect. These characteristics allow early assessment of brain damage after surgery. In this report, we compared 2 sedatives, propofol and dexmedetomidine hydrochloride, in cardiovascular settings. SUBJECT AND METHODS: Both sedatives were initiated right after admission to the intensive care unit (ICU), followed by titrimetric method targeting for the sedation agitation scale (SAS) from 1 to 4. Thirty-five cases were included in dexmedetomidine hydrochloride group (DEX group) and 16 cases were included in propofol group (Prop group). RESULTS: Preoperative and operative demographic data were the same between the 2 groups. Conversion rate to another sedatives, and incidence of vasopressor or hypotensor use were both in the same proportion in both groups. Intubated time was the same in both groups. Both systolic and diastolic blood pressures were kept lower in DEX group than Prop group until 8 hours after ICU admission. Other hemodynamic measurements, heart rate, pulmonary artery pressure and cardiac index showed no statistical difference. SAS and Ramsay score were better in DEX group early after ICU admission, and remained better until 10 hours later. CONCLUSION: Dexmedetomidine hydrochloride has no major hemodynamic nor other side effects after cardiovascular surgery. Dexmedetomidine hydrochloride could be used as an effective agent for postoperative sedation and analgesia in cardiovascular settings.

Aged↗
PubMed2005

Invasive phenotype and apoptosis induction of Plesiomonas shigelloides P-1 strain to Caco-2 cells.

AIMS: The mechanism of the host cell invasion of Plesiomonas shigelloides and its capability to induce apoptosis were investigated. METHODS AND RESULTS: We performed a time course experiment on the bacterial adherence and invasion of the P. shigelloides P-1 strain into Caco-2 cells using an invasion assay and flow cytometry. The adherence of P. shigelloides to the Caco-2 cells was almost completed within 10 min after the infection. Thereafter, P. shigelloides starts internalization within the Caco-2 cells, which was completed within 60 min after the infection. Based on the invasion assay using nocodazole, cytochalasin D, and genistein, it became clear that the mechanism of the internalization depended on the signal transduction followed by the rearrangement of the cytoskeletal protein. Based on the DNA laddering and TUNEL methods, the cytotoxicity of the Caco-2 cells by the invasion of P. shigelloides occurred through the induction of apoptosis. CONCLUSIONS: This work demonstrated that the mechanism of invasion of P. shigelloides into Caco-2 cells and the invasion of P. shigelloides induces apoptotic cell death. SIGNIFICANCE AND IMPACT OF THE STUDY: This work revealed the virulence factor, which may be important for understanding of the pathogenesis of P. shigelloides.

Apoptosis↗
PubMed2001

Purification and identification of monoubiquitin-phosphoglycerate mutase B complex from human colorectal cancer tissues.

Ubiquitin-conjugated proteins in human colorectal cancer tissues were analyzed by the immunoprecipitation with the antibody FK2 against conjugated ubiquitin followed with SDS-PAGE. In these immunoprecipitable proteins, a 38-kDa protein was abundant in the tumor regions but almost absent in the adjacent normal regions in 17/26 patients, thus we attempted to purify it. Using immunoaffinity chromatography with the antibody FK2 followed by gel filtration and SDS-PAGE, approximately 10 pmol of this protein was separated from 34 g of the pooled cancerous tissue and transferred onto a PVDF membrane. The 38-kDa protein was further digested with Achromobacter protease I, resulting in several peptide fragments. Amino acid sequences of these peptides showed complete sequence identity to those derived from either ubiquitin or phosphoglycerate mutase-B, suggesting that the 38-kDa protein is monoubiquitinated phosphoglycerate mutase-B, whose calculated mass is 37,369 Da. Western blot using an antibody against phosphoglycerate mutase-B revealed the presence of the 38-kDa protein in the anti-ubiquitin immunoprecipitates derived from the tumor regions, but not from normal counterparts. In addition, part of non-ubiquitinated phosphoglycerate mutase-B (29 kDa) was also found in the anti-ubiquitin immunoprecipitates, whose levels were higher in the tumor regions than in the adjacent normal regions. These results suggest that monoubiquitination of phosphoglycerate mutase-B as well as formation of a noncovalent complex containing ubiquitin and phosphoglycerate mutase-B increases in colorectal cancer and novel modification of phosphoglycerate mutase-B might have a pathophysiological role.

Aged↗
PubMed2001

Identification and characterization of the human serotonin-4 receptor gene promoter.

The human serotonin-4 (5-HT(4)) receptor gene expression is highly regulated in various tissues. We isolated the human 5-HT(4) receptor gene containing the 5'-flanking region and characterized its promoter. By 5'-RACE (5'-rapid amplification of the cDNA ends) and inverse PCR, multiple transcription initiation sites were identified. The most 5' one (assigned to +1) was 5135 bp upstream to the translation start site. The 500-bp 5'-flanking region contained potential binding sites for transcription factor Sp-1, AP-2, AP-4, and GATA. However, this region lacked TATA- and CAAT-boxes. Transient transfection analyses in human choriocarcinoma T3M-3 (5-HT(4) receptor-positive) and HepG2 (5-HT(4) receptor-negative) cells revealed that the region (-210 to -105) is necessary for the basic and cell-type specific 5-HT(4) receptor gene expression. In addition, untranslated exon 1 contained negative (+112 to +182) as well as positive (+1 to +111) modulators, indicating that exon 1 plays a regulatory role in the 5-HT(4) receptor gene expression.

Base Sequence↗
PubMed2001

Isolation of ubiquitin-E2 (ubiquitin-conjugating enzyme) complexes from erythroleukaemia cells using immunoaffinity techniques.

A variety of ubiquitin-associated (or conjugated) proteins, including substrates and enzymes for the ubiquitin system, are present in eukaryotic cells. In the present study we developed a simple method for their isolation, consisting of immunoaffinity chromatography using the monoclonal antibody FK2, which recognizes the conjugated ubiquitin molecule. Using this method followed by gel filtration, we isolated multi-ubiquitinated proteins with high molecular masses (>30 kDa) and also ubiquitinthioester-linked and mono-ubiquitinated forms of ubiquitin-conjugating (E2) enzymes, UbcH7 and UBE2N, together with mono-, di- and tri-ubiquitin molecules, from the cytoplasmic extract of heat-shock-treated K562 erythroleukaemia cells. We also demonstrated that the FK2 antibody was capable of precipitating a ubiquitin-UbcH7 thioester, but not free UbcH7, which enabled the measurement of the respective cellular levels separately. The immunoprecipitable ubiquitin-UbcH7 thioester was found only when the cells were treated with heat-shock. These results suggest the usefulness of the immunoaffinity techniques for identifying and analysing the cellular enzyme/protein-ubiquitin complexes.

Amino Acid Sequence↗
PubMed2001

Clinical studies of bioabsorbable poly-L-lactide sternal coaptation pins.

BACKGROUND: Median sternotomy has become the most commonly used incision in cardiac surgery. Since sternal dehiscence, however, is a major complication, we used bioabsorbable poly-L-lactide (P-L-LA) sternal coaptation pins for sternal closure to prevent it. METHODS: From February 1998 to October 1999, 99 patients (64 men, 35 women; mean age, 63+/-1.2 years) underwent median sternotomy for cardiac surgery using sternal coaptation pins. Nineteen patients had diabetes mellitus and seven had renal failure. In closure, two sternal pins were inserted into the bone marrow of the sternum, one into the manubrium, the other into the body, and the sternum was sutured with five stainless steel wires. RESULTS: Five patients died in the hospital. The causes of death were cardiac failure in two patients, respiratory problem in two and perforation of the stomach in one. The average length of hospitalization was 2 4.5+/-2.5 days. Sternal dehiscence occurred in one patient and mediastinitis in four. There was no bleeding from the bone marrow and no complication related to the use of the sternal pins. CONCLUSIONS: P-L-LA sternal pins were easy to insert and may be effective in preventing dehiscence of the sternum.

Absorbable Implants↗
PubMed2000

Calpain inhibitor inhibits secretory granule maturation and secretion of GH.

Clathrin- and AP-1-coated buds are present on immature secretory granules of endocrine cells that mature into clathrin-uncoated granules. The mechanism of clathrin and adaptor protein uncoating has remained obscure. Benzyloxycarbonyl-L-leucyl-L-leucinal (ZLLal), a calpain inhibitor, reduced growth hormone (GH) secretion with intracellular accumulation, in a GH-secreting rat pituitary tumor cell. Pulse and chase demonstrated that ZLLal retarded the turnover of clathrin (Clt.H) and adaptins. ZLLal-treatment co-immunoprecipitated the increased amounts of GH with Clt.H and adaptins compared to control cells, suggesting the intracellular accumulation of immature secretory granules. Clt.H and adaptins were limited-proteolyzed by m-calpain in vitro, indicating that calpain may be involved partly in the maturation of secretory granules in endocrine cells via the process of clathrin uncoating.

Adaptor Protein Complex alpha Subunits↗
PubMed2000

Comparison of standard coronary artery bypass grafting and minimary invasive direct coronary artery bypass grafting. Early and mid-term result.

OBJECTIVES: We studied indications and problems involved in minimally invasive coronary artery bypass grafting (MIDCAB). METHODS: We compared patients profiles, graft patency, stenosis severity, morbidity, mortality, long-term survival and freedom from cardiac accidents in 174 patients undergoing elective standard coronary artery bypass grafting (CABG) and 128 undergoing between January 1996 and March 1999. RESULTS: No statistically difference was seen in gender, diabetes mellitus, renal failure, cerebrovascular accident, multi-vessel disease ratios, or left main trunk stenosis between 2 groups. Internal thoracic artery graft patency was 97% (114/118) and the rate of anastomotic stenosis (> 50%) was 9% (10/118) compared to 96% (213/221) in the MIDCAB group. The 3-year survival rate was 91% in the MIDCAB group and 92% in the CABG group and freedom from cardiac accidents, most involving pericutaneus transluminal coronary angioplasty retreatment, was 66% in the MIDCAB group and 88% in the CABG group. CONCLUSION: Although patency and stenosis incidence did not differ between 2 groups, freedom from cardiac accidents was lower in the MIDCAB group.

Aged↗
PubMed1999

Calpain inhibitor causes accumulation of ubiquitinated P-glycoprotein at the cell surface: possible role of calpain in P-glycoprotein turnover.

P-glycoprotein (Pgp) is a plasma-membrane glycoprotein that confers multi-drug resistance (MDR) on cells and displays ATP-driven drug pumping. The possible contribution of calpain-mediated proteolytic pathways to the functional regulation of the Pgp molecule was evaluated using K562/DXR, MDR cells. N-Acetyl-L-leucyl-L-leucyl-norleucinal was effluxed by Pgp, but N-benzyloxycarbonyl-L-leucyl-L-leucinal (zLLal), an inhibitor of calpain, retarded the degradation of Pgp leading to accumulation of the molecule largely at the cell surface membrane. Treatment with brefeldin A did not obstruct the zLLal-induced Pgp accumulation. NH4Cl increased the cytoplasmic Pgp level, with a slight to significant decrease at the cell surface membrane. Ubiquitin-ELISA and western blot analysis confirmed that the Pgp molecule, which accumulated mainly at the cell surface, was ubiquitinated. However, lactacystin did not show any accumulation of Pgp in either the cytoplasm or the cell surface membrane, suggesting that the proteasome did not participate in the phenomenon. Additionally, the Pgp was limitedly proteolyzed by calpain into two 98 kDa and 69 kDa, fragments within one minute. Despite the increased accumulation of Pgp at the cell surface after treatment with calpain inhibitor, the cytoplasmic doxorubicin level of the cells treated with a calpain inhibitor was higher than that of non-treated cells and approached that of parental cells. These results indicated that calpain involved Pgp turnover and that calpain inhibition induced ubiquitinated Pgp-accumulation mainly at the cell surface membrane with a reduction in its own functions suggesting that the modulation of Pgp-turnover involves MDR-reversal by another approach.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed1998

Structural and immunochemical characterization of beta-1,2-linked mannobiosyl phosphate residue in the cell wall mannan of Candida glabrata.

A mannan of Candida glabrata IFO 0622 digested by Arthrobacter exo-alpha-mannosidase and a beta-1,2-linked mannobiose obtained from the parent mannan by acid treatment was analyzed using 13C nuclear magnetic resonance spectroscopy. The results show that the beta-1, 2-linked mannobiosyl residue is esterified to a phosphate group through position C-1 in the alpha-configuration, Manbeta1- 2Manalpha1-HPO3-. The results of immunochemical assays of these mannans using the commercial antigenic factor sera of the genus Candida (Candida Check, Iatron) indicate that the main recognition site of serum no. 6 in this kit is the mannotetraosyl side-chain Manbeta1-2Manalpha1- 2Manalpha1-2Man in C. glabrata mannan and also suggest that the phosphate-containing unit (such as Manbeta1- 2Manalpha1-HPO3- in this mannan) behaves as one of the antigenic determinants of serum no. 6, but not of serum no. 5. Therefore, the present and previous findings indicate that serum no. 5 recognizes relatively longer beta-1,2-linked oligomannosyl side-chains, Manbeta1-[2Manbeta1-]n 2Man (n = 1-6), attached to the phosphate groups previously observed in the cell wall mannans of Candida albicans, Candida stellatoidea, and Candida tropicalis.

Agglutination↗
PubMed1998

Transverse colonic stenosis.

A 3-year child presented with episodic lower abdominal pain; during the eighth attack, a mass was palpable in the left upper quadrant, and a barium enema revealed a stenotic area in the transverse colon. This was resected and an uneventful postoperative course followed. Subsequently, the child has remained symptom-free. instruments are no longer in use.

Colon↗
PubMed1998

Synthesis of Escherichia coli O9a polysaccharide requires the participation of two domains of WbdA, a mannosyltransferase encoded within the wb* gene cluster.

WbdA (previously MtfA) is one of the mannosyltransferases encoded within the Escherichia coli O9a wb* gene cluster. It is composed of two domains of similar size, connected by an alpha-helix chain. Elimination of the C-terminal half by transposon insertion or gene deletion caused synthesis of an altered structural O-polysaccharide consisting only of alpha-1,2-linked mannose. O9a polysaccharide synthesis was restored by the C-terminal half of WbdA in trans. No membrane incorporation of mannose from GDP mannose was observed in a strain carrying only the gene for truncated WbdA. For mannose incorporation, it was necessary to introduce both wbdB and wbdC genes into the strain. Therefore, it is likely that the N-terminal half of truncated WbdA synthesizes the altered O-polysaccharide together with other mannosyltransferases which participate in the initial reactions of the O9a polysaccharide synthesis. Both N- and C-terminal domains of WbdA are required for the synthesis of the complete E. coli O9a polysaccharide. The chi sequence location between the two domains and homology plot analyses of the wbdA and the WbdA protein suggested that the wbdA gene might have arisen by fusion of two independent genes.

Conserved Sequence↗
PubMed1998

Further characterization of the 5'-flanking promoter region of the human beta1-adrenergic receptor gene.

Further characterization of the 5'-flanking promoter region of the human beta1-adrenergic receptor (AR) gene was attempted. The transcription initiation sites, determined by the primer extension and the rapid amplification of the 5'-cDNA end, are multiple in a spanning about 30 nucleotides (-289 to -261 relative to the translation start site). There exist inverted CCAAT boxes, multiple binding sites for transcription factor Sp1 and AP-2 nearby transcription initiation sites, however, this region lacks a typical TATA box. In order to localize the regulatory region for the basal transcription of the human beta1-AR gene, a variety of 5'-flanking sequence/chloramphenicol acetyltransferase reporter gene fusion constructs was prepared and transiently expressed in HeLa cells. Functional analyses reveal negatively (-3813 to -2925 and -1772 to -796) as well as positively (-2925 to -1772) regulatory regions, in addition to the region (-796 to -87) being necessary for the basic expression of the human beta1-AR gene.

Amino Acid Sequence↗
PubMed1998

[Eighty cases of minimally invasive direct coronary artery bypass grafting].

Between March 1996 and November 1997, 80 patients with a mean age of 70 years (45-89) have undergone minimally invasive direct coronary artery bypass grafting via anterior minithoracotomy or subxiphoid incision with left internal thoracic artery and right epigastric artery using local coronary occlusion on a beating heart. Cardiac-related hospital mortality was 2.5% (2/80). Routine angiographic assessment of anastomotic patency showed an overall patency. rate of 94.6%, but demonstrated the severe stenosis at the anastomotic site in 8 patients. Further study is required to establish the efficacy of minimally invasive direct coronary artery bypass grafting and combination therapy with PTCA.

Aged↗
PubMed1997

NMR assignment of the galactomannan of Candida lipolytica.

The chemical structure of the cell wall galactomannan of Candida lipolytica was analyzed using two-dimensional NMR techniques without chemical fragmentation. The H-1-H-2-correlated cross-peaks of the galactomannan indicated that it consists of an alpha-1,6-linked mannan backbone moiety with side chains. A sequential NMR assignment of the side chains through nuclear Overhauser effect (NOE) cross-peaks indicated that the triose side chain contains an alpha-1,2-linked galactopyranose unit at the non-reducing terminal. The structure was significantly different from the galactomannan of Trichophyton. The molar ratio of the side chains calculated from the H-1 signal dimensions indicated that ca. 45% of the backbone alpha-1,6-linked mannose units are not substituted with side chains and are responsible for the reactivity of the galactomannan with factor 9 serum.

Candida↗
PubMed1997

Amended structure of side chains in a cell wall mannan from Candida albicans serotype A strain grown in yeast extract-Sabouraud liquid medium under acidic conditions: detection of the branched side chains corresponding to antigenic factor 4.

In a previous study, we reported the excess production of alpha-1,3-linked mannose residues with the complete disappearance of beta-1,2-linked mannose residues in cell wall mannans of Candida albicans serotype A strain cells, which were grown in yeast extract-Sabouraud liquid medium at pH 2.0. In the present study, we examined the immunochemical reactivity of the same mannan of NIH A-207 with an enzyme-linked immunosorbent assay (ELISA) using several antisera to antigenic factors of the genus Candida (FAbs) and the structure of the mannan by two-dimensional homonuclear Hartmann-Hahn analysis. The ELISA showed that the mannan reacts to FAb 4 but not to FAbs 13b and 34, which are reported to be antibody factors against linear side chains containing an alpha-1,3-linked mannose residue. In the Hartmann-Hahn analysis, we found two branched side chains, Man alpha 1-2Man alpha 1-3[Man alpha 1-6]Man alpha 1-(2Man alpha 1-)(2)2Man and Man alpha 1-3[Man alpha 1-6]Man alpha 1-(2Man alpha 1-)(2)2Man, instead of the previously reported linear side chains. The branched side chains are oversynthesized under acidic conditions.

Antibodies, Fungal↗