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S Nagai

Publications and source records attributed to S Nagai.

At least 55 records · Page 3Linked to original sources
PubMed2000

Inhibition of Wnt signaling by ICAT, a novel beta-catenin-interacting protein.

Wnt signaling has an important role in both embryonic development and tumorigenesis. beta-Catenin, a key component of the Wnt signaling pathway, interacts with the TCF/LEF family of transcription factors and activates transcription of Wnt target genes. Here, we identify a novel beta-catenin-interacting protein, ICAT, that was found to inhibit the interaction of beta-catenin with TCF-4 and represses beta-catenin-TCF-4-mediated transactivation. Furthermore, ICAT inhibited Xenopus axis formation by interfering with Wnt signaling. These results suggest that ICAT negatively regulates Wnt signaling via inhibition of the interaction between beta-catenin and TCF and is integral in development and cell proliferation.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Comprehensive gene expression profile of a normal human liver.

To investigate the gene expression profile of a normal human liver, we performed serial analysis of gene expression (SAGE), which allows the quantitative and simultaneous analysis of thousands of genes expressed in tissue. Polyadenylated RNA was obtained from a bulk normal human liver sample and SAGE was performed. Reverse transcriptase-polymerase chain reaction (RT-PCR) was also performed in each of 3 different normal liver samples to evaluate the validity of the profile in each individual. A total of 30,982 tags were sequenced, 8,596 of which were unique. The genes highly expressed in the normal liver were those encoding plasma proteins (>21.8% of total transcripts), cytoplasmic proteins (>8.6%), enzymes (>4.8%), protease inhibitors (>1.7%), complements (>1.1%), and coagulation factors (>0.75%). About 13.9% of all transcripts encoded genes not reported in GenBank thus far. This study identifies candidate genes to be examined in relation to various human liver diseases, including viral hepatitis, liver cirrhosis, and hepatocellular carcinoma.

Adult↗
PubMed2000

Interleukin-4 and breast cancer.

IL-4 is a pleiotropic cytokine produced by T lymphocytes which acts on various cells of such as T and B lymphocytes, monocytes, fibroblast, endothelial cells, macrophages and some others. IL-4 was originally described as a B cell growth factor, and now known to provide potent anti-tumor activity against various tumors, including breast cancer. IL-4 can induce apoptosis in cultured breast cancer cells. In addition, it has been clarified that IL-4 plays an important role in the regulation of estrogen synthesis enzymes including 17beta-HSD and 3beta-HSD. These findings imply that IL-4 is a key enzyme not only for Th2 type immune reactions but also for tumor cell growth itself in human breast cancer.

Apoptosis↗
PubMed2000

HLA-DQB1*0601 is primarily associated with the susceptibility to cardiac sarcoidosis.

Cardiac sarcoidosis occurs in 1-5% of sarcoidosis patients. We previously reported a significant increase of the uncommon TNFA (tumor necrosis factor alpha) allele, TNFA2 with cardiac sarcoidosis in Japanese. In order to precisely localize the susceptible locus for cardiac sarcoidosis within the HLA region, genetic polymorphisms of classical HLA genes, non-classical HLA class II genes such as HLA-DMA and -DMB genes and several genes involved in the class I-mediated antigen presentation pathway (TAP1, TAP2, LMP2 and LMP7) were investigated. Further, association analyses using four polymorphic microsatellite markers located around the TAP1 and TNFA genes were also carried out. As a result, HLA-DQB1*0601 was found to be the most significantly associated allele, being more significantly increased than TNFA2. No significant increase of the DR52-associated DRB1 alleles (DRB1*03, 05, 06 and 08), which was suggested to be primarily associated with lung sarcoidosis, was observed in cardiac sarcoidosis. A primary role of DQB1*0601 in determination of the susceptibility to cardiac sarcoidosis was supported by association analysis using four polymorphic microsatellite markers, in which only the TAP1 microsatellite locus, the nearest marker to the DQB1 gene among the microsatellites tested, displayed a significant positive association with cardiac sarcoidosis. On the other hand, the HLA-DQB1*0501-DQA1*0101-DRB1*0101-B7 haplotype showed a negative association with the disease, as similarly observed in lung sarcoidosis. Thus, molecular mechanism for controlling the development of the disease related to HLA molecules are different between cardiac and lung sarcoidosis, whereas those for conferring a resistant trait may be similar to each other.

Alleles↗
PubMed2000

Interstitial lung disease in polymyositis and dermatomyositis.

Interstitial lung disease (ILD) is common in patients with polymyositis (PM) and dermatomyositis (DM), and is a major cause of morbidity. Although its cause is unknown, it is known to be closely associated with autoimmune disorders. Its manifestation has been found to be quite heterogeneous, as demonstrated by the differences among PM/DM patients in their immunologic profiles and histopathologic findings, which suggest variations in immunopathogenetic mechanisms. We review the clinicopathologic and immunologic findings in ILD associated with PM/DM, and discuss recent advances in classification, autoantibodies, and treatment. The most critical issues are to clarify the immunopathogenesis of severe forms of ILD, such as rapidly progressive ILD associated with amyopathic DM, and to establish the most appropriate therapy.

Dermatomyositis↗
PubMed2000

Smoking-related interstitial lung diseases.

Interstitial lung diseases (ILDs) encompass diverse clinicopathological disease entities ranging from idiopathic interstitial pneumonia (IIP) to interstitial pneumonia accompanied by collagen vascular diseases and diseases related to smoking, drug reactions, occupational environments, infections, and malignancies. Our focus is on the smoking-related interstitial lung diseases. Specifically, we focus on reports suggesting that chronic smoking is deeply involved in the disease pathogenesis and on reports suggesting that chronic smoking may influence the clinical course in terms of either disease severity or progression. Pulmonary Langerhans' cell granulomatosis (PLCG), desquamative interstitial pneumonia (DIP), respiratory bronchiolitis with interstitial lung diseases (RB-ILD), interstitial pneumonia associated with rheumatoid arthritis, acute respiratory distress syndrome (ARDS), and idiopathic pulmonary fibrosis (IPF) are covered.

Comorbidity↗
PubMed2000

Isolation and characterization of mini-Tn5Km2 insertion mutants of enterohemorrhagic Escherichia coli O157:H7 deficient in adherence to Caco-2 cells.

Adherence of enterohemorrhagic Escherichia coli (EHEC) to intestinal epithelium is essential for initiation of the infection. To identify genes involved in adherence, an EHEC O157:H7 strain (O157Sakai) was mutagenized by mini-Tn5Km2, where Km refers to kanamycin resistance, and 4,677 insertion mutants were screened for their ability to form microcolonies (MC) on Caco-2 cells. The less adherent mutants were divided into three groups: those with no adherent ability (designated as class 1 mutants, n = 10), those less adherent than the wild type (class 2 mutants, n = 16), and those unable to form MC but which adhered in a diffuse manner (class 3 mutants, n = 1). The sites of insertion in class 1 mutants were all found within genes of the locus for enterocyte effacement (LEE) thought to be required for type III protein secretion. Indeed, the class 1 mutants failed to secrete type III secreted proteins such as EspA and Tir into the culture medium. The insertions in class 2 mutants were outside the LEE, and all the mutants except one were able to secrete type III proteins into the culture medium. The class 3 mutant had the insertion in the tir gene in the LEE and was deficient in Tir and intimin expression, suggesting that in the absence of intimin-Tir, O157Sakai can still adhere to Caco-2 cells but in a diffused manner. This was confirmed by construction of a nonpolar eae (encoding intimin) mutant. Examination of the eae mutant together with O157Sakai and one of the class 1 mutants for the ability to form MC revealed that EHEC initially adhered diffusely at 1.5 h after infection. Following washing out of the nonadherent bacteria, while wild-type EHEC bacteria developed MC for another 2 to 3 h on Caco-2 cells, the eae mutant diffusely adhered throughout the infection without forming MC. MC with O157Sakai but not the diffusely adherent eae mutant could evoke F-actin condensation beneath the bacterium. Our results suggest that EHEC encodes additional adherence-associated loci and that the type III secreted proteins are involved in the initial diffuse adherence, while the intimin-Tir interaction is required for the subsequent development of MC.

Adhesins, Bacterial↗
PubMed2000

Glucocorticoid-induced contractility and F-actin content of human lung fibroblasts in three-dimensional culture.

Fibroblast contractility plays a useful role in the wound healing process but contributes to architectural distortion in the lungs. Glucocorticoids (GCs) have been reported to reduce dermal fibroblast contractility, which may result in delaying wound healing, but the effects on lung fibroblasts are unknown. In this study, we examined how human lung fibroblast contractility is altered in the presence of GCs. Lung fibroblast cell lines (n = 5) were established from normal parts of surgically resected lung tissue. The effects of GCs on contractility were investigated with a type I collagen gel contraction assay. Filamentous actin (F-actin) content was detected by confocal microscopy and measured with a fluorescent phalloidin binding assay. GCs augmented fibroblast contraction in a concentration-dependent manner, with an approximate EC(50) of 1.8 x 10(-8) M, whereas other steroid derivatives had no effects. GC contractility needed de novo protein synthesis. The GC-induced increase in contractility was found to be consistent with an increase in F-actin content. In conclusion, lung fibroblast contractility was enhanced with GCs through an upregulation of lung fibroblast F-actin.

Actins↗
PubMed2000

The potential of various lipopolysaccharides to release IL-8 and G-CSF.

Lipopolysaccharide (LPS) derived from Pseudomonas aeruginosa is less cytotoxic than that from Escherichia coli. But P. aeruginosa induces a prominent sustained lung inflammation as in cystic fibrosis and diffuse panbronchiolotis. The present study examined the potential for several LPSs obtained from E. coli and P. aeruginosa to release neutrophil chemotactic activity (NCA) from lung cells. LPSs differently stimulated A549 cells, BEAS-2B cells, and lung fibroblasts to release NCA [P. aeruginosa > E. coli 0127:B8 (Difco) > E. coli 055:B5 (Sigma) > E. coli 026:B6 (Sigma)]. E. coli 0127:B8 (Sigma) and 0111:B4 (Sigma) did not stimulate these cells. NCA was chemotactic by checkerboard analysis. Molecular-sieve column chromatography revealed three chemotactic peaks. The release of NCA was inhibited by cycloheximide and lipoxygenase inhibitors. Experiments with blocking antibodies suggested that much of the NCA was secondary to the release of interleukin (IL)-8 and granulocyte colony-stimulating factor (G-CSF). Thus we examined the concentrations of IL-8 and G-CSF and found that the potency of the various LPSs to stimulate NCA closely paralleled the potency in releasing IL-8 and G-CSF. But a difference among LPSs to stimulate A549 cells was observed. Finally, the release of IL-6 showed similar results. These data suggest that P. aeruginosa LPS may stimulate lung cells to release more NCA than E. coli LPSs, leading to sustained lung inflammation.

Antibodies↗
PubMed2000

Airflow limitation in Japanese smokers: significance of serum neutrophil elastase/alpha(1)-proteinase inhibitor ratio and FEV(1) (%pred) adjusted by pack-years.

BACKGROUND: In spite of the known role of cigarette smoking in the development of airflow limitation (AL), fewer than 20% of smokers actually develop chronic obstructive pulmonary disease (COPD). OBJECTIVES: We examined how smoking histories and indices in blood are related to the degree of AL in asymptomatic smokers in order to determine whether they can predict the development of AL. METHODS: Spirometry and peripheral blood tests were examined in 433 Japanese asymptomatic current smokers at the initial examination. Forced expiratory volume in 1 s (FEV(1)) was measured periodically for 2 or more years (2-13 years) in 66 of the subjects. RESULTS: AL defined as an FEV(1)/vital capacity of less than 0.7, was found in 11.3% (49 of 433) of the smokers. Pack-years of smoking, serum amounts of alpha(1)-proteinase inhibitor, and serum procollagen III peptide activities were correlated with the degree of AL. Fifteen percent (10 of 66) of subjects underwent rapid declines in FEV(1) that were found to be related not with smoking amounts or initial FEV(1), but with low FEV(1) (%pred) adjusted by pack-years and an elevated serum neutrophil elastase/alpha(1)-proteinase inhibitor ratio. These results suggest that smokers with a low FEV(1) out of proportion to pack-years are susceptible smokers at a high risk of developing COPD, and further, that increased proteinase burden relative to antiproteinase activity may contribute to the development of COPD. CONCLUSIONS: We conclude that the serum neutrophil elastase/alpha(1)-proteinase inhibitor ratio and FEV(1) (%pred) adjusted by pack-years can be reliable predictors of the development of COPD.

Adult↗
PubMed2000

Significance of the interleukin-1 receptor antagonist/interleukin-1 beta ratio as a prognostic factor in patients with pulmonary sarcoidosis.

BACKGROUND: Various factors such as serum angiotensin-converting enzyme (sACE) activity, bronchoalveolar lavage (BAL) fluid lymphocyte percent, CD4/CD8 ratio, and shadows on chest radiograph have been identified as indexes of disease activity in patients with sarcoidosis. However, it remains to be confirmed whether these factors can predict clinical outcomes. OBJECTIVE: To examine whether the interleukin-1 receptor antagonist (IL-1ra)/IL-1 beta ratio can predict the clinical course, we prospectively followed the clinical courses of 30 patients with pulmonary sarcoidosis 4 years after measurement of immunoreactive amounts of IL-1ra or IL-1 beta in the culture supernatants obtained from BAL fluid macrophages. METHODS: Immunoreactive amounts of IL-1ra or IL-1 beta were measured using ELISA. Changes in pulmonary function, sACE activity, and shadows on chest radiographs during observation periods were evaluated as markers of changes in disease activity. RESULTS: We found that the patients whose shadows on chest radiographs showed improvement had a higher molar IL-1ra/IL-1 beta ratio than the patients whose shadows persistently remained 4 years after BAL examination (p < 0.05). The molar ratio was found to be positively correlated with improvement of percent vital capacity (p < 0.05) and negatively correlated with the ratio of sACE activity at the time of the last observation to sACE activity at the time of BAL (sACE(LAST)/sACE(BAL), p < 0.01). The sACE(LAST)/sACE(BAL) ratio was significantly lower in patients whose shadows on chest radiographs decreased than in those whose shadows remained unchanged (p < 0.005). CONCLUSION: The IL-1ra/IL-1 beta ratio in the BAL fluid macrophage culture supernatants in patients with pulmonary sarcoidosis could be a useful marker in predicting the persistence of granulomatous lesions (chronicity).

Adult↗
PubMed2000

Familial pulmonary Mycobacterium avium complex disease.

We report two Japanese families affected by pulmonary Mycobacterium avium complex (MAC) disease, involving an older brother and younger sister in one family and two brothers in the second family. We investigated whether defects in the natural resistance-associated macrophage protein gene (NRAMP1) underlay susceptibility to MAC in these cases. All of the patients had computed tomographic findings of peripheral nodules and bronchiectasis. Pulse-field gel electrophoresis patterns of mycobacterial genomic DNA restriction fragments revealed that none of the MAC strains isolated from the patients was epidemiologically related to any of the others. Direct sequencing of the complementary DNA of the patients' NRAMP1 revealed a nonconservative missense mutation at codon 419 in one patient, which was heterozygous and was not seen in his affected sibling. No variations similar to those found in mice that show susceptibility to MAC were found. The results suggest an underlying genetic defect in host defense rather than exposure to an unusually virulent strain of MAC as the pathogenetic factor in MAC disease; however, alterations in the coding region of NRAMP1 do not appear to explain the susceptibility to MAC.

Adult↗
PubMed2000

Fibroblast contractility: usual interstitial pneumonia and nonspecific interstitial pneumonia.

The aim of this study was to compare the function of lung fibroblasts obtained from surgically biopsied specimens of patients with idiopathic pulmonary fibrosis/usual interstitial pneumonia (UIP; n = 5), nonspecific interstitial pneumonia (NSIP; n = 5), and normal parts of surgically resected lungs (control; n = 5). The results showed that (1) fibroblasts obtained from UIP showed increased contractility compared with those obtained from NSIP or controls (UIP, 72.7 +/- 6.21%; NSIP, 32.8 +/- 5.46; controls, 28.5 +/- 3.51, p < 0.01 in UIP versus NSIP or control); (2) this increase in contractility was consistent with enhanced F-actin content in fibroblasts; (3) conditioned media from UIP fibroblast cultures enhanced control fibroblast contractility, whereas those obtained from NSIP or controls did not; (4) the 180 and 25 kD products representing the contractility in conditioned media were identified as fibronectin (ED-A domain) and TGF-beta1 by immunoblots, respectively; (5) the UIP-conditioned media contained higher amounts of fibronectin or TGF-beta 1 (fibronectin: UIP 289 +/- 47.1 ng/ml, NSIP 121 +/- 23.0, control 118 +/- 16.0; TGF-beta1: UIP 798 +/- 119 pg/ml, NSIP 246 +/- 69.1, control 247 +/- 53.6, p < 0.01 in UIP versus NSIP or control); () the contractility positively correlated with the amount of either fibronectin (r = 0.867, p < 0.001, n = 15) or TGF-beta 1 (r = 0.939, p < 0.001, n = 15), respectively. Thus, UIP fibroblasts showed greater contractility than did NSIP fibroblasts and up-regulated control fibroblasts.

Actins↗
PubMed2000

Bradykinin stimulates lung fibroblasts to release neutrophil and monocyte chemotactic activity.

Activation of the kallikrein-kinin system in lung injury has long been recognized. However, the effects of bradykinin (BK) on human lung fibroblasts (HLF) remain to be elucidated. We determined whether BK stimulates HLF to release chemotactic activity for neutrophils and monocytes (NCA and MCA, respectively). We evaluated HLF supernatant fluids for chemotactic activity through a blind-well chamber technique. HLF released NCA and MCA in a dose- and time-dependent manner in response to BK. The release of chemotactic activity was inhibited by lipoxygenase inhibitors and cycloheximide. Molecular sieve column chromatography revealed that both NCA and MCA had multiple chemotactic peaks. NCA was inhibited by a leukotriene (LT) B(4) receptor antagonist and by antibodies to interleukin (IL)-8 and granulocyte colony-stimulating factor (G-CSF). MCA was attenuated by the LTB(4) receptor antagonist and by antibodies to monocyte chemoattractant protein-1 (MCP-1), granulocyte-macrophage colony-stimulating factor (GM-CSF), and transforming growth factor (TGF)-beta. Both the LTB(4) receptor antagonist and these antibodies inhibited chemotactic activity of the molecular weights corresponding to MCP-1, GM-CSF, and TGF-beta, separated by column chromatography. The concentrations of IL-8, G-CSF, MCP-1, GM-CSF, and TGF-beta in supernatant fluids increased significantly in a time-dependent manner in response to BK. The receptors responsible for the release of NCA, MCA, and individual chemokines included both BKB(1) and BKB(2) receptors. These data suggest that BK may stimulate lung fibroblasts to release inflammatory cytokines, which may modulate lung inflammation.

Binding, Competitive↗
PubMed2000

Hypertrophic cardiomyopathy as a manifestation of cardiac sarcoidosis.

The present study aimed to clarify whether cardiac sarcoidosis causes changes that mimic hypertrophic cardiomyopathy. Eighty-two consecutive patients (35 men, 47 women), who were referred to the Department of Cardiovascular Medicine, with a diagnosis of pulmonary and/or ocular sarcoidosis (average age, 49.5 years, range 20-74), underwent detailed clinical, electrocardiographic, and echocardiographic evaluations; in some patients, right and left heart catheterization, selective coronary artery cineangiography, and right and left endomyocardial biopsies were performed. Over a 15-month period of observation, 6 of these 82 patients (7.3%) were found to have echocardiographic abnormalities: increased thickness of the interventricular septum was found in 4 patients, asymmetric septal hypertrophy in 2, localized septal hypertrophy in 1 and apical hypertrophy in 1 patient. One patient had an 'ace-of-spades' deformity of the left ventricle. Cardiac sardoidosis can mimic, and even present as, hypertrophic cardiomyopathy.

Adult↗
PubMed2000

[A modified technique for insertion of the laryngeal mask airway in children].

We modified the technique for laryngeal mask airway (LMA) insertion in children. This modification involves inserting a two-thirds inflated LMA with its lumen facing laterally toward left and then rotating it 90 degrees clockwise as it passes downwards into position behind the larynx. Then the cuff is inflated fully. We conducted a survey on the use of LMA in ten consecutive children for minor superficial surgery. After slow induction, anesthesia was maintained with 3.0% of end-tidal sevoflurane concentration in 100% oxygen for 5 minutes before insertion of LMA. No muscle relaxant was used. Successful insertion was judged by the clinical integrity of the airway. The standard LMA insertion technique or another airway device was applied when three trials had failed. Traumatic insertion was observed by the attachment of blood clots to the surface of the removed LMA. A satisfactory airway was achieved in all of the children who participated in the survey. There were no significant differences in vital signs between pre- and post-insertion. Only one child was found to have attachment of blood clots on the surface of the removed LMA. We conclude that our technique would be one recommended method in pediatric practice.

Anesthesia, Inhalation↗
PubMed1999

Serial analysis of gene expression in human monocyte-derived dendritic cells.

Dendritic cells (DCs) are professional antigen-presenting cells in the immune system and can be generated in vitro from hematopoietic progenitor cells in the bone marrow, CD34(+) cord blood cells, precursor cells in the peripheral blood, and blood monocytes by culturing with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-4, and tumor necrosis factor-alpha. We have performed serial analysis of gene expression (SAGE) in DCs derived from human blood monocytes. A total of 58,540 tag sequences from a DC complementary DNA (cDNA) library represented more than 17,000 different genes, and these data were compared with SAGE analysis of tags from monocytes (Mo) and GM-CSF-induced macrophages (M open diamond). Many of the genes that were differentially expressed in DCs were identified as genes encoding proteins related to cell structure and cell motility. Interestingly, the highly expressed genes in DCs encode chemokines such as TARC, MDC, and MCP-4, which preferentially chemoattract Th2-type lymphocytes. Although DCs have been considered to be very heterogeneous, the identification of specific genes expressed in human Mo-derived DCs should provide candidate genes to define subsets of, the function of, and the maturation stage of DCs and possibly also to diagnose diseases in which DCs play a significant role, such as autoimmune diseases and neoplasms. This study represents the first extensive gene expression analysis in any type of DCs.

Antigen Presentation↗