Search PubMed⌕ Search

Biomedical subjects

T Nishida

Publications and source records attributed to T Nishida.

At least 145 records · Page 8Linked to original sources
PubMed2000

Regulation of connexin phosphorylation and cell-cell coupling in trabecular meshwork cells.

PURPOSE: To investigate the expression of functional gap junctions and the effect of protein kinase C (PKC) on such junctions in confluent cultures of bovine trabecular meshwork (TM) cells. METHODS: Expression of the gap junction protein connexin43 in TM cells was examined by immunofluorescence microscopy. Intercellular communication by gap junctions was assessed by observing the diffusion of fluorescent dye from an individual cell injected with lucifer yellow. The phosphorylation of connexin43 was evaluated by immunoblot analysis with a monoclonal antibody to this protein. RESULTS: Immunofluorescence staining revealed that connexin43 was localized to sites of contact between adjacent TM cells. Exposure of cells to the PKC activator phorbol 12-myristate 13-acetate (PMA; 10 nM, 1 hour) had no marked effect on the pattern of connexin43 immunofluorescence. Injection of a TM cell with lucifer yellow resulted in the spread of the dye into neighboring cells. Dye coupling was inhibited by PMA in a dose- and time-dependent manner, and this inhibition was prevented by pretreatment of cells with the PKC inhibitor bisindolylmaleimide I. Immunoblot analysis of control TM cell lysates yielded connexin43 bands corresponding to the nonphosphorylated protein (43 kDa) and three phosphorylated forms (47, 48, and 49 kDa). Cells exposed to PMA (10 nM, 1 hour) yielded an additional band corresponding to a 44-kDa form of phosphorylated connexin43 and showed a decrease in the intensity of the band corresponding to the nonphosphorylated protein and an increase in the intensity of the 47-kDa band. CONCLUSIONS: TM cells communicate with each other through gap junctions, and the communication is inhibited by PKC, probably, at least in part, through phosphorylation of connexin43.

Actins↗
PubMed2000

Multivessel coronary stenting: predictors of early and late outcome.

BACKGROUND: At present, only few data are available on the early and late outcome following multivessel coronary stenting. Of note, in these studies, the left anterior descending (LAD) artery was treated in less than 40% of cases. These patients may not fully represent the population commonly referred for surgical revascularization. METHODS: In-hospital and long-term (18 +/- 4 months) events were evaluated in 272 consecutive patients who had multivessel stent implantation including the LAD artery in each case. All clinical, angiographic, and procedural variables were analyzed to identify the predictors of acute and long-term major adverse coronary events. RESULTS: Eighteen patients (6.6%) had in-hospital major adverse coronary events (death 0.7%, coronary artery bypass grafting 0.4%, and myocardial infarction 6.3%). Acute and subacute stent thrombosis rates were 1.5 and 1.1%, respectively. At 18 +/- 4 months, event-free survival was 71%. Target lesion revascularization was performed in 54 (20%) patients (42 coronary angioplasty and 12 coronary artery bypass grafting). The jeopardy score was the predictor of in-hospital major adverse coronary events (p = 0.016, odds ratio 1.34, 95% confidence interval 1.05-1.69), and diabetes mellitus was the predictor of long-term major adverse coronary events (p = 0.027, odds ratio 2.80, 95 % confidence interval 1.12-6.96). CONCLUSIONS: Multivessel coronary stent implantation with treatment of the LAD artery in all instances is a safe procedure with low acute and long-term major adverse coronary events. The risk-benefit ratio must be assessed carefully for each patient, particularly taking into account the jeopardy score and the presence of diabetes mellitus.

Aged↗
PubMed2000

[Thoracoscopic resection for benign solitary fibrous tumor of the parietal pleura].

We have experienced thoracoscopic surgery for benign solitary fibrous tumor of the parietal pleura. A 46-year-old woman was admitted to our hospital because of chest abnormal shadow. Under thoracoscopy the tumor that was connected to the parietal pleura with a wide pedicle was completely resected with combined parietal resection of the pleura. Pathological diagnosis was a benign solitary fibrous tumor developed from the connective tissues under the parietal pleura. Thoracoscopic surgery is well indicated for a solitary fibrous tumor and wide excision of the tumor with combined resection of the pleura is important to prevent a local recurrence.

Female↗
PubMed2000

Coordinated reassembly of the basement membrane and junctional proteins during corneal epithelial wound healing.

PURPOSE: To characterize changes in the localizations of the basement membrane protein laminin-1 and of adhesion proteins of intercellular junctions during wound healing after epithelial ablation in the rat cornea. METHODS: Epithelial ablation was performed with an excimer laser. Rats were killed immediately, 12 hours, 24 hours, 3 days, or 4 weeks after ablation, and corneal cryosections were subjected to two-color immunofluorescence staining with antibodies to laminin-1 and antibodies to connexin43 for gap junctions, desmoglein 1 or 2 (desmoglein 1 + 2) for desmosomes, or E-cadherin for adherens junctions. Sections were also stained with antibodies to occludin for examination of tight junctions. RESULTS: Laminin-1 was detected in the basement membrane, connexin43 in the basal cell layer, desmoglein 1 + 2 in the wing cell layer, E-cadherin in all cell layers, and occludin in the wing and superficial cell layers of the intact corneal epithelium. Laminin-1 immunostaining was not detected at the leading edge of migrating epithelial cells until 24 hours after ablation. Expression of connexin43 and desmoglein 1 + 2 coincided with the reappearance of laminin-1, whereas that of E-cadherin and occludin was apparent regardless of the absence or presence of laminin-1. Epithelial remodeling was complete after 4 weeks. The basement membrane was re-established, and the expression patterns for all the adhesion proteins were identical with those characteristic of the intact cornea. CONCLUSIONS: Actively migrating epithelial cells no longer manifested gap junctions and desmosomes in the wounded area with no basement membrane. Re-establishment of the basement membrane coincided with reassembly of these intercellular junctions, suggesting that the presence of the basement membrane may be required for their reformation in the rat cornea.

Animals↗
PubMed2000

The influence of stenting on the behavior of amino-oleic acid-treated, glutaraldehyde-fixed porcine aortic valves in a sheep model.

BACKGROUND AND AIM OF THE STUDY: The durability of freehand-sewn aortic valve homografts used for valve replacement in humans is greater than for stented aortic homografts. In analogy with this, it is expected that the durability of a stentless heterograft will be superior to that of its stented counterpart. Our objective was to investigate the influence of stenting on amino-oleic acid (AOA)-treated, glutaraldehyde-fixed porcine aortic valve bioprostheses. METHODS: Twelve young sheep underwent implantation of porcine aortic valves in the pulmonary artery: six porcine aortic stentless valves (Freestyle) and six porcine aortic stented valves (Mosaic). In each series, three valves were explanted after three months, and three after six months. Valves were analyzed by gross inspection, radiography, histology, and transmission electron microscopy. Quantitative determination of calcium content was made with atomic absorption spectrometry. RESULTS: The porcine aortic stentless valve showed extensive calcification of its aortic wall portion, but had perfectly functioning, pliable cusps without calcification up to six months. The cusps of porcine aortic stented valves were also pliable and functioning without calcification up to six months. Only minimal calcification was seen in the aortic wall of the stented valves. At six months after implantation the cusps of stentless valves contained significantly less calcium than those of stented valves (2.7+/-1.2 microg/mg and 7.9+/-2.3 microg/mg, respectively; p = 0.011). However, the aortic wall from stentless valves contained significantly more calcium than that of stented valves (three-month explants: 39.2+/-14.4 versus 7.2+/-2.8 microg/mg; p <0.05; six-month explants: 49.3+/-14.0 versus 14.1+/-5.9 microg/mg; p <0.05). CONCLUSION: These data suggest that stenting does influence cuspal calcification of AOA-treated, glutaraldehyde-fixed porcine aortic valves.

Amino Acids↗
PubMed2000

Contemporary percutaneous treatment of saphenous vein graft stenosis: immediate and late outcomes.

PURPOSE: The aim of this study was to evaluate the immediate and long-term outcomes following percutaneous treatment of an unselected series of saphenous vein graft (SVG) lesions. METHODS AND RESULTS: Consecutive interventions on 129 saphenous vein graft lesions in 101 patients were reviewed. Stents were implanted in 114 lesions (88%), which included the use of polytetrafluoroethylene-covered stents in 22 lesions (17%) and abciximab in 20 patients (20%). Angiographic success was achieved in 125 lesions (97%). In-hospital major adverse cardiac events (MACE) occurred in 11 patients (11%), with myocardial infarction being the most frequent event. Treatment of degenerated SVG lesions and SVG lesions with larger reference diameters correlated with the incidence of in-hospital MACE [odds ratio (OR) = 7.69 and 2.65, respectively; 95% confidence interval (CI) = 1.80Eth 32.8 and 0.99Eth 7.10, respectively)]. Clinical follow-up was achieved in all patients at 25 +/- 21 months. Successful revascularization to all three distributions of the major coronary arteries negatively correlated [relative risk (RR) = 0.43; 95% CI = 0.20Eth 0.92)], while treatment of a degenerated SVG positively correlated (RR = 1.92; 95% CI = 1.05Eth 3.51) with the occurrence of follow-up MACE. A final effective blood supply to the anterior wall and a higher left ventricular ejection fraction was found to negatively correlate with the occurrence of follow-up death (RR = 0. 20 and 0.61, respectively; 95% CI = 0.06Eth 0.60 and 0.41Eth 0.90, respectively). CONCLUSION: Treatment of SVG lesions continues to be associated with a high incidence of myocardial infarction, particularly in cases of degenerated SVG lesions. An effective blood supply to the anterior wall and a higher left ventricular ejection fraction were protective for the occurrence of death during the follow-up period.

Aged↗
PubMed2000

Coronary stenting beyond standard indications. Immediate and follow-up results.

BACKGROUND: Coronary stent has become an accepted treatment modality for selected indications. However, the literature shows diverse results when indications for coronary stenting are different from those tested in large randomized trials. The purpose of this study was to determine immediate and follow-up clinical and angiographic results in patients treated with coronary stenting for indications not specifically tested in large randomized trials. METHODS: Coronary stents were implanted in a total of 2060 lesions (1757 patients) in seven groups with expanded indications: left main coronary lesions, calcified lesions, small vessels (< 3 mm in size), small vessels with diffuse disease, large vessels with diffuse disease, and bifurcation lesions treated with stents in both branches or with one stent implanted only in the major branch. Stents were implanted using high balloon pressure for final inflation and in most cases with intravascular ultrasound. Clinical follow-up was achieved in 96% of patients at a mean time of 12+/-7 months. RESULTS: Primary success (range 89-96%) and acute complications (range 5.7-13%) were comparable in all groups. At follow-up, the mortality rate was highest in the group of left main stenting (12.5%) but 20% of these patients had coronary stenting on non-elective basis. The restenosis rates ranged between 16-43%. The restenosis rate was highest in the group of bifurcation lesions with stent implantation in both vessels leading to a major adverse cardiac event (MACE) rate of 62% in this group. However, the survival rate at 1 and 2 years in the overall study group was 97 and 96%, and the event free survival was 76 and 74%, respectively. The procedure-related predictors of MACE were: final intravascular ultrasound result, use of stents with non-slotted tube morphology, final stent percent stenosis, and vessel size. CONCLUSIONS: Coronary stenting beyond standard indications is feasible, with acceptable primary success and complication rates. However, the overall MACE rates were relatively high (34-62%), in particular for the indication of bifurcation lesions with stents implanted in both vessels.

Age Factors↗
PubMed2000

The role of cytokine-induced neutrophil chemoattractant-1 in neutrophil-mediated remote lung injury after intestinal ischaemia/reperfusion in rats.

OBJECTIVE: Remote lung injury is induced by ischaemia/reperfusion (I/R) of the gastrointestinal tract and the liver following hypovolaemic shock. In the present study, the role of cytokine-induced neutrophil chemoattractant (CINC), a member of the interleukin (IL)-8 family, in neutrophil-mediated remote lung injury following intestinal I/R was investigated in anaesthetized rats. METHODOLOGY: The I/R group was subjected to 60 min of occlusion of the superior mesenteric artery with laparotomy, followed by 240 min of intestinal reperfusion. The sham-operated (sham) group was subjected to the same procedures with the exception of intestinal I/R. RESULTS: In the I/R group, the permeability index of the lung, the neutrophil count in pulmonary vascular lavage fluid and bronchoalveolar lavage fluid (BALF), lung myeloperoxidase activity and neutrophil oxidative production were all significantly greater than those in the sham group. Cytokine-induced neutrophil chemoattractant-1 levels in blood and BALF were significantly increased at 240 min after intestinal reperfusion. There was a significant relationship between neutrophils in BALF and CINC-1 level in BALE CONCLUSION: These findings suggest that intestinal reperfusion was associated with activation and accumulation of neutrophils in the lung and resulted in remote lung injury with increased microvascular permeability. Thus, CINC-1 in BALF may induce neutrophil migration from the pulmonary vessels to the interstitium and alveolar spaces in remote lung injury after intestinal I/R.

Animals↗
PubMed2000

Clinicopathological features of gastric stromal tumors.

Stromal tumors in the gastrointestinal (GI) tract consist of myogenic tumors, neurogenic tumors and gastrointestinal stromal tumors (GISTs). Mutations in the c-kit gene have been found in GISTs, and GISTs with c-kit mutations showed aggressive clinical behavior and histological features. In the present study, we classified stromal tumors into four groups according to histological differentiation and c-kit mutation: myogenic tumors, neurogenic tumors, c-kit mutation (-) GISTs and c-kit mutation (+) GISTs, and examined their clinicopathological importance and validity using data obtained from 125 patients with gastric stromal tumors. There was no difference in preoperative symptoms and signs among the four groups. GISTs with c-kit mutations were large and showed invasion into neighboring structures compared with the other tumors, indicating the clinically aggressive features of mutation (+) GISTs. In histological examinations, c-kit mutation (+) GISTs were higher in cellularity (P < 0.0001) and mitotic cell count (P = 0.0086), and showed frequent histological necrosis (P = 0.0058) and hemorrhage (P = 0.0170), and consequently, were higher in histological grade (P = 0.0001). In prognostic analyses, overall, cause-specific and disease-free survival of patients in the mutation (+) GIST group was the poorest among the four groups. No significant differences were found among the other three groups of myogenic tumors, neurogenic tumors and c-kit mutation (-) GISTs, indicating a similar aggressiveness in clinical presentation and histological features. Thus, this classification is considered to be clinically and pathologically important in the diagnosis of gastric stromal tumors.

Adult↗
PubMed1999

A functional and quantitative mutational analysis of p53 mutations in yeast indicates strand biases and different roles of mutations in DMBA- and BBN-induced tumors in rats.

In order to analyze the mutational events and to understand the biological significance of the p53 gene in chemical carcinogenesis, we applied a new yeast-based p53 functional assay to ovarian tumors induced by 7, 12-dimethylbenz[a]anthracene (DMBA), as well as to transitional cell carcinomas of the urinary bladder induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) in rats. The assay demonstrated that 15 of 19 DMBA induced tumors harbored clonal p53 mutations, which is consistent with the expectations of the "clonal expansion" hypothesis. The majority of the mutations were purine (AG) to pyrimidine (CT) transversions (12/19) on the non-transcribed (sense) strand (NTS), which is likely to be due to depurination created by DMBA adduct formation on the NTS. In contrast, we found no pyrimidine to purine [corrected] transversion on the NTS. After cessation of BBN treatment, BBN-induced multifocal lesions in the bladder contained heterogeneous p53 mutations at an early stage. In the later stage, however, clonal p53 mutations were identified in 4 out of 7 bladders analyzed, conforming with the concept of "field cancerization". The observed base substitutions were G-->A (1/6) or C -->T transitions (2/6), and mutations at T (3/6) on the NTS in clonal mutations, together with non-clonal mutations, showing a preference of C-->T to G-->A (17 vs. 0). Thus, preferential repair was found in the transcribed strand of the p53 gene, whether modified by DMBA or by BBN carcinogens. Very similar mutation patterns were observed between clonal and non-clonal mutations in the DMBA- and BBN-induced tumors, indicating that the rat yeast p53 functional assay can be a potential tool for the characterization of in vivo mutation patterns of p53, when modified by chemical carcinogens.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1999

Effect of c-kit mutation on prognosis of gastrointestinal stromal tumors.

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. Gain-of-function mutations in the juxtamembrane domain of the c-kit gene have been found in several GISTs. In this study, we examined the correlation between the presence of c-kit mutation and prognosis in 124 cases of GIST. DNA samples were extracted from paraffin sections. Exon 11 of the c-kit gene encoding the juxtamembrane domain and exon 17 encoding the kinase domain were amplified by PCR and sequenced. Most GISTs (89%) express the KIT protein, and missense mutations of exon 11 were found in 71 of 124 GISTs (57%). No mutations were detectable in exon 17. These 71 mutation-positive GISTs were larger in size and had more frequently invaded adjacent tissues than did the 53 mutation-negative GISTs. Histologically, the mutation-positive GISTs showed higher mitotic figures and more necrosis and hemorrhage. The patients with mutation-positive GISTs showed more frequent recurrences (P = 0.0005) and higher mortality (P = 0.0001) than did those with mutation-negative GISTs. The c-kit mutation was an independent prognostic factor for overall and cause-specific survival of the patients with GISTs. These results suggest that GISTs may be divided into mutation-positive and -negative subtypes. The prognosis was worse in patients with mutation-positive GISTs than in those with mutation-negative GISTs. Thus, mutation of the c-kit gene may be a good prognostic marker of GISTs.

Amino Acid Sequence↗
PubMed1999

Adenovirus-mediated local expression of human tissue factor pathway inhibitor eliminates shear stress-induced recurrent thrombosis in the injured carotid artery of the rabbit.

The main cause of acute coronary syndrome may be recurrent thrombosis, which is initiated by the activation of the extrinsic coagulation pathway. Tissue factor (TF) pathway inhibitor (TFPI) efficiently inhibits an early step in this pathway by the formation of a complex with factor VIIa, TF, and factor Xa. We determined whether local TFPI gene transfer can inhibit thrombosis in an injured artery without inducing systemic side effects. Balloon-injured rabbit carotid arteries were infected with an adenoviral vector that expressed either human TFPI (AdCATFPI) or bacterial beta-galactosidase (AdCALacZ). Two to 6 days after gene transfer, thrombosis was induced by the production of constant stenosis of the artery, and blood flow was measured continuously with an electromagnetic flow probe. A cyclic flow variation, which is thought to reflect the recurrent formation and dislodgment of mural thrombi, was observed in all AdCALacZ-infected arteries as well as in saline-infused arteries. In contrast, no cyclic flow variation was detectable in AdCATFPI-transfected arteries, even in the presence of epinephrine (1 microg. kg-1. min-1 infusion). Prothrombin time, activated partial thromboplastin time, and the ex vivo platelet aggregation induced by either adenosine diphosphate or collagen were unaltered in AdCATFPI-infected rabbits. We found that in vivo TFPI gene transfer into an injured artery completely inhibits the recurrent thrombosis induced by shear stress even in the presence of catecholamine, without affecting systemic coagulation status. Adenovirus-mediated local expression of TFPI may have the potential for the treatment of human thrombosis.

Adenoviridae↗
PubMed1999

Cultures in chimpanzees.

As an increasing number of field studies of chimpanzees (Pan troglodytes) have achieved long-term status across Africa, differences in the behavioural repertoires described have become apparent that suggest there is significant cultural variation. Here we present a systematic synthesis of this information from the seven most long-term studies, which together have accumulated 151 years of chimpanzee observation. This comprehensive analysis reveals patterns of variation that are far more extensive than have previously been documented for any animal species except humans. We find that 39 different behaviour patterns, including tool usage, grooming and courtship behaviours, are customary or habitual in some communities but are absent in others where ecological explanations have been discounted. Among mammalian and avian species, cultural variation has previously been identified only for single behaviour patterns, such as the local dialects of song-birds. The extensive, multiple variations now documented for chimpanzees are thus without parallel. Moreover, the combined repertoire of these behaviour patterns in each chimpanzee community is itself highly distinctive, a phenomenon characteristic of human cultures but previously unrecognised in non-human species.

Animals↗
PubMed1999

Up-regulation of integrin alpha5 by a C-terminus four-amino-acid sequence of substance P (phenylalanine-glycine-leucine-methionine- amide) synergistically with insulin-like growth factor-1 in SV-40 transformed human corneal epithelial cells.

We previously reported that substance P and insulin-like growth factor-1 (IGF-1) synergistically facilitate corneal epithelial migration in vivo and in vitro. We investigated whether the substance P-derived tetrapeptide (phenylalanine-glycine-leucine-methionine-amide, FGLM) can up-regulate the receptors for fibronectin and cellular adhesion to fibronectin matrix in the presence or absence of IGF-1 in cultured SV-40 transformed human corneal epithelial (HCE) cells. The combination of both FGLM and IGF-1 and substance P and IGF-1 significantly increased the number of cells adhered to the fibronectin matrix and the expression of integrin alpha5. The synergistic effect of FGLM and IGF-1 on the adhesion of HCE cells to the fibronectin matrix is partly carried through up-regulation of integrin alpha5 expression in HCE cells. These results showed that the four-amino-acid sequence at the C-terminus of substance P completely mimics the substance P molecule in terms of synergism with IGF-1 on adhesion of epithelial cells to the fibronectin matrix.

Antigens, CD↗
PubMed1999

Kupffer cell-mediated down regulation of rat hepatic CMOAT/MRP2 gene expression.

Lipopolysaccharides (LPS) induces intrahepatic cholestasis and canalicular multispecific organic anion transporter (CMOAT/MRP2) plays a central role in hepatic bilirubin transport. This study examined the role of Kupffer cell in LPS-induced cholestasis. Rats were injected intravenously with LPS. Kupffer cells were inactivated with gadolinium chloride (Gd). CMOAT/MRP2 mRNA expression was time- and dose-dependently decreased by LPS injection with a decrease in bile flow and an increase in serum bilirubin level. Gd pretreatment inhibited decrease in CMOAT/MRP2 mRNA and bile flow, and increase in serum bilirubin. Kupffer cell-conditioned medium decreased CMOAT/MRP2 expression. Addition of anti-IL-1 or anti-TNFalpha antibody restored CMOAT/MRP2 expression, whereas IL-1 and TNFalpha decreased the expression. MAP kinases were activated by addition of the conditioned medium, and addition of PD98059 or SB203580 restored CMOAT/MRP2 expression. These results suggest that LPS activates Kupffer cells to secrete IL-1 and TNFalpha, which in turn activate MAP kinases and decrease CMOAT/MRP2 expression.

Animals↗
PubMed1999

The Hsp70 homolog gene, Hsc70t, is expressed under translational control during mouse spermiogenesis.

Hsc70t is a member of the Hsp70 family of genes and is constitutively expressed after meiosis in mouse spermatogenesis. Immunohistochemistry and in situ hybridization techniques were used to examine the precise localization of the Hsc70t product during the various stages of spermatogenesis. A rabbit antiserum raised againstthe mouse Hsc70t-lacZ fusion protein detected the Hsc70t protein in the late spermatid-enriched fraction after two-dimensional Western blot analyses. On histological sections, the protein appears in the cytoplasm of spermatids as they progress from step 9 to the final step of spermatogenesis. An antisense RNA probe generated from the 3' untranslated region of Hsc70t cDNA detected Hsc70t mRNA in late round spermatids from step 7 onward with the signal disappearing in spermatids at step 15. Thus, Hsc70t mRNA first appears after meiosis in haploid cells but is not translated effectively until these cells progress to the transcriptionally inactive stage which coincides with chromatin condensation. These results establish that the synthesis of Hsc70t protein is under strict translational control.

Animals↗