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Biomedical subjects

M Suga

Publications and source records attributed to M Suga.

At least 91 records · Page 5Linked to original sources
PubMed1998

Endoscopic and pathological manifestations of the gastrointestinal tract in familial amyloidotic polyneuropathy type I (Met30).

OBJECTIVES: To evaluate the characteristic changes in the gastrointestinal tract in familial amyloidotic polyneuropathy (FAP) (Met30), both fibre gastroscopy and colonoscopy studies were performed in FAP (Met30) patients. Microscopic changes were also examined in autopsied and biopsied materials from patients with FAP, and compared with data from autopsied samples from patients with AL amyloidosis, and secondary amyloidosis patients. DESIGN: Endoscopic and histopathological study. SETTING: Kumamoto University Hospital, Kumamoto, Japan. SUBJECTS: Nine patients with FAP (Met30) underwent fibre gastroscopy and colonoscopy. Six autopsied and 23 biopsied gastrointestinal samples from FAP patients, four from autopsied amyloidosis (including two myeloma associated form), and two from autopsied secondary amyloidosis patients were examined for histopathological study. MAIN OUTCOME MEASURES: Fibre gastroscopy and colonoscopy were employed for macroscopic study. Congo red and H-E staining were performed for histopathological study. Macroscopic changes in the gastrointestinal tract and microscopic differences in the amyloid distribution pattern were compared between the different types of amyloidosis. RESULTS: Fibre gastroscopy and colonoscopy for nine FAP patients revealed that four showed a fine granular appearance in the duodenum, three showed lack of lustre, and two showed mucosal friability in the gastrointestinal tract; however, no macroscopic abnormality was observed in four other FAP patients. Histopathological examination of tissue from FAP patients revealed that, although a small amount of amyloid was recognized in the submucosa perivascular layer, a significant amount of amyloid was seen in and around the nerves of the gastrointestinal tract, but very little in Auerbach's nerve plexus. In total, the amount of deposited amyloid in the tissues was small compared with that in other types of systemic amyloidosis, such as AL and secondary amyloidosis. CONCLUSION: These results suggest that the major reason why FAP patients show such severe gastrointestinal symptoms, compared with other types of systemic amyloidosis, may be because of the deposition of a significant amount of amyloid in the nerves in the gastrointestinal tract.

Adult↗
PubMed1998

Nitric oxide and interstitial lung disease.

The role and significance of nitric oxide (NO) and its intermediates on interstitial lung diseases are discussed. NO itself has protective roles against lung injury; however, NO is converted to peroxynitrite through the reaction with the superoxide anion at the inflammation foci, resulting in various destructive effects against lung parenchyma. Increased production of NO and peroxynitrite play an important role in oxidative injury and remodeling associated with interstitial lung diseases.

Anti-Inflammatory Agents↗
PubMed1998

Influence of alcohol on branched-chain amino acid/tyrosine molar ratio in patients with cirrhosis.

We investigated whether the reduction of plasma tyrosine in alcoholic liver disease would affect the branched-chain amino acid/tyrosine molar ratio (BTR) measured using an enzymatic assay method in alcoholic cirrhosis. BTR values were higher in patients with compensated and decompensated alcoholic cirrhosis (5.68 +/- 2.29 and 3.28 +/- 0.75) due to reduction of the tyrosine level relative to those in patients with nonalcoholic cirrhosis (3.64 +/- 1.22 and 2.53 +/- 0.99). A decrease in tyrosine level and an increase in BTR value were observed after single ethanol administration to healthy subjects. As significant elevation of serum immunoreactive insulin levels followed elevation of serum glucose levels after alcohol loading, it was thought that insulin accelerated intrahepatic metabolism of aromatic amino acids, resulting in reduction of the tyrosine level. The same mechanism may be applied to tyrosine reduction in patients with alcoholic cirrhosis during heavy drinking.

Adult↗
PubMed1998

Significant correlation of nitric oxide synthase activity and p53 gene mutation in stage I lung adenocarcinoma.

Nitric oxide (NO) and its derivatives can directly cause DNA damage and mutation in vitro and may play a role in the multistage carcinogenic process. It has been reported that NO induces mutation in the p53 tumor suppressor gene; we therefore analyzed the relationship between NO synthase (NOS) activity and p53 gene status in early-stage lung adenocarcinoma. Surgical samples were classified into two categories: 14 lung adenocarcinomas with high NOS activity (>25 pmol/min/g tissue, category A), and 16 with low NOS activity (<25 pmol/min/g tissue, category B). A yeast functional assay for p53 mutations disclosed a red colony that corresponded to a mutation in the p53 gene in 8 cases (57.1%) in category A and 3 cases (18.8%) in category B, the frequency being significantly higher in the former (P<0.05). A p53 DNA sequence analysis revealed that 5 of the 8 p53 mutation-positive samples in category A had a G:C-to-T:A transversion, which is reported to be a major target of NO. The mechanism of carcinogenesis of adenocarcinoma is not fully understood, but these results suggest that an excess of endogenously formed NO may induce a p53 gene mutation containing mainly G:C-to-T:A transversion in the early stage of lung adenocarcinoma. Our results suggest that NO has potential mutagenic and carcinogenic activity, and may play important roles in human lung adenocarcinoma.

Adenocarcinoma↗
PubMed1998

Seasonal chronic cough with sputum eosinophilia caused by Trichosporon cutaneum (Trichosporon asahii).

The case of a 46-year-old man with a chronic cough with sputum eosinophilia (atopic cough) caused by Trichosporon cutaneum serotype II (Trichosporon asahii) is reported. The diagnosis was made with the inhalation challenge test with T. asahii antigen. He was admitted for the diagnosis and treatment of a severe nonproductive cough in the summer season. Although his sputum contained 13% eosinophils of nucleated cells, he did not have bronchial hyperresponsiveness to methacholine or a heightened bronchomotor tone. Bronchodilator therapy was not effective for his cough. His symptoms worsened on returning home, suggesting the existence of some etiologic agent in his house. A high titer of serum anti-Trichosporon antibody was detected and antigen provocation test with the Trichosporon extract was positive: the development of a cough 6 h later and a decrease in the cough threshold to inhaled capsaicin 48 h later (7.85 microM from 31.3 microM prechallenge). This is the first report on a chronic cough with sputum eosinophilia induced by T. cutaneum (T. asahii).

Chronic Disease↗
PubMed1998

Therapeutic effect of erythromycin on influenza virus-induced lung injury in mice.

Erythromycin (EM) is an antibiotic with potent antiinflammatory effects that is used for treating chronic lower respiratory tract infections. It has been shown that free radicals, such as the superoxide anion and nitric oxide (NO), are pathogenic molecules in viral disease. Much attention has been given to a critical role of NO in the pathologic events of various inflammatory diseases. In the present study, we evaluated the effects of EM on influenza-virus-induced pneumonia in mice infected with a lethal dose of influenza virus A/Kumamoto/Y5/67 (H2N2). The administration of EM at a dose of 3.3 mg/kg/d (intraperitoneally, from Days 1 to 6 after infection), significantly improved the survival rate of mice infected with influenza virus, and the survival rate of the virus-infected mice at Day 20 after infection increased in a dose-dependent fashion with EM administered to the animals, from 14% among controls to 42% among animals given EM at 1.0 mg/kg/d and 57% among those given EM at 3.3 mg/kg/d. The induction of interferon-gamma (IFN-gamma) in the mouse lung was inhibited by EM treatment on Day 6 after infection. Simultaneously, the number of inflammatory cells recovered in lung lavage fluid 6 d after virus infection was significantly reduced by the treatment with EM. The EM treatment resulted in a dose-dependent decrease in the level of nitrite/nitrate (metabolites of NO) in the serum and the NO synthase (NOS)-inducting potential in the lungs of the virus-infected mice. These results indicate that EM may have substantial therapeutic value for various acute inflammatory disorders such as influenza-virus-induced pneumonia, by inhibiting inflammatory-cell responses and suppressing NO overproduction in the lung.

Animals↗
PubMed1998

Free radicals in viral pathogenesis: molecular mechanisms involving superoxide and NO.

The importance of free radical molecular species in the pathogenesis of various viral diseases has been increasingly recognized in recent years. Oxygen radicals such as superoxide (O2-) and hydroxyl radical (.OH) have been implicated as possible pathogenic molecules in viral disease pathogenesis. Much attention has been given to another simple inorganic radical [nitric oxide (NO)] in the host's defense mechanism and pathogenesis of virus infection. The NO synthesis pathway, in particular, the inducible isoform of NO synthase (iNOS), is expressed in different viral diseases via induction of proinflammatory cytokines such as interferon-gamma. iNOS produces an excessive amount of NO for a long time compared with other constitutive isoforms of NOS (i.e., neuronal NOS and endothelial NOS). Recent studies indicate that NO and O2- are produced in excess during the host's defense responses against various intruding microbes. Reactive nitrogen oxide species such as peroxynitrite (ONOO-) and NOx (NO2 and N2O3) are produced in biological systems through the reaction of NO with either O2- or O2. Among these reactive nitrogen species, ONOO- and its biological actions are of considerable interest in that ONOO- causes oxidation and nitration of amino acid residues of proteins and guanine of DNA, lipid peroxidation, and DNA cleavage. Because the ONOO- is formed via a diffusion-limited fast reaction of NO and O2-, it may be a dominant nitrogen oxide species during the host's defense reactions, when both NO and O2- are produced in excess. Thus, understanding the role of NO and oxygen radical generation in virus infections will provide insight into not only viral pathogenesis but also the host-pathogen interaction in microbial infections at a molecular level.

Animals↗
PubMed1998

Expression of CD44 splicing isoforms in lung cancers: dominant expression of CD44v8-10 in non-small cell lung carcinomas.

We examined CD44 isoform expression in 138 frozen tissue samples, which included primary lung carcinomas, adjacent non-tumorous lung tissues and benign lung diseases, by both reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemical analyses. CD44v8-10 mRNA and protein were dominantly expressed in non-small cell lung carcinomas (NSCLC), while non-tumorous tissues principally expressed CD44s and small cell lung carcinomas (SCLC) expressed either CD44s or no detectable CD44. These results indicate that CD44v8-10 is the dominant splicing isoform in NSCLC and can be practically utilized as a diagnostic marker and therapeutical target in NSCLC.

Aged↗
PubMed1998

Measurement of serum monocyte chemoattractant protein-1 and its clinical application for estimating the activity of granuloma formation in sarcoidosis.

BACKGROUND AND AIM OF THE WORK: The role of monocyte chemoattractant protein-1 (MCP-1) in bronchoalveolar lavage fluids from sarcoidosis patients was previously reported. To study the role of MCP-1, we evaluated the serum MCP-1 and its clinical significance in sarcoidosis. METHODS: The serum MCP-1 level was measured in 47 patients with sarcoidosis and 10 normal healthy controls with the use of an enzyme-linked immunosorbent assay. The localization and mRNA expression of MCP-1 in sarcoid lymph nodes were evaluated by an immunohistochemical method using an anti-MCP-1 monoclonal antibody and an in situ hybridization technique to determine the cellular source(s) of MCP-1. RESULTS: Serum MCP-1 levels were significantly elevated in the sarcoidosis patients compared with the healthy controls (698.3 +/- 101.9 vs. less than 39 pg/ml, p < 0.001). A comparison of the patients' serum MCP-1 levels among standard radiographic stages revealed that the serum MCP-1 was significantly higher in early stages: stage 0 vs. III, and stage I vs. II. In addition, the serum MCP-1 levels were significantly correlated with the serum angiotensin converting enzyme levels (r = 0.539, p = 0.0006). MCP-1 expression was detected in macrophages peripheral to the epithelioid granuloma in sarcoid lymph nodes, by both immunohistochemistry and in situ hybridization. CONCLUSIONS: These data suggest that MCP-1 may be expressed by the macrophages in the granuloma throughout the body, and that the measurement of serum MCP-1 levels may have clinical value as an indicator in estimating the activity of granuloma formation throughout the body in sarcoidosis.

Adult↗
PubMed1997

Down regulation of a harmful variant protein by replacement of its normal protein.

To compensate for the hypoprotein and hypoalbuminemia of familial amyloidotic polyneuropathy (FAP) patients, 800 ml of fresh frozen plasma (FFP) was intravenously administered and change in total and variant transthyretin (TTR) levels were measured in the plasma. After injection of FFP, total plasma TTR levels were elevated and variant TTR levels decreased from 24 to 48 h, accompanied by an elevation of plasma total protein, albumin levels and TTR levels. To elucidate the mechanism of this phenomenon, a large amount of purified normal TTR from normal human plasma was intravenously injected in mice and FAP patients. By intravenous injection of 3 mg of the purified TTR to C57Black6, the expression of TTR mRNA decreased from 6 to 24 h post injection, and gradually increased up to 48 h post injection. After injecting 400 mg of normal TTR in each of 3 FAP patients, total plasma TTR levels were elevated and variant TTR levels decreased significantly from 24 to 48 h. These results suggested that down regulation of the harmful protein by replacement of its normal form of the protein occurred by this method. This phenomenon should be applied as the basis for one of the useful methods for decreasing the harmful proteins in the circulation.

Adult↗
PubMed1997

Activation of human neutrophil procollagenase by nitrogen dioxide and peroxynitrite: a novel mechanism for procollagenase activation involving nitric oxide.

The involvement of nitric oxide (NO) and its reactive intermediates such as nitrogen dioxide (NO2) and peroxynitrite (ONOO-) in the activation of matrix metallo-proteinase was investigated. The human neutrophil procollagenase (matrix metalloproteinase-8) (M(r), 85 kDa) was purified to homogeneity from human neutrophils by using column chromatography. After incubation of human neutrophil procollagenase with various nitrogen oxide-generating systems, collagenolytic activity in each reaction system was measured. In addition, neutrophil collagenase activity was determined by assessment of proteolysis of human alpha 1-protease inhibitor. NO was formed by the propylamine NONOate, and NO2 was generated by oxidation of NO with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (carboxy-PTIO). NO2, formed by NONOate and carboxy-PTIO, and the synthetic ONOO- exhibited strong activation of the procollagenase at 1-20 microM. Significant activation of the procollagenase was observed with use of authentic NO2 gas as well. Constant flux infusion of ONOO- into the procollagenase solution resulted in stronger procollagenase activation than did a bolus addition of ONOO- to the reaction mixture. However, NO showed only weak activating potential under the aerobic (ambient) condition; an NO concentration of more than 10 mM was needed for appreciable activation of the procollagenase. Of considerable importance was the fact that NO participates in activation of the neutrophil collagenase through its conversion to NO2 or ONOO- in human neutrophils. These results suggest that NO2 and ONOO- may be potent activators of human neutrophil procollagenase.

Benzoates↗
PubMed1997

Superoxide scavenging activity of erythromycin-iron complex.

We evaluated superoxide (O2-.) scavenging activity of erythromycin (EM) and of EM-iron complex by means of electron spin resonance spectroscopy, luminol-dependent chemiluminescence assay, and cytochrome c reduction assay. The EM-iron complex was produced by mixing EM with equal molar iron chloride and was stable in neutral buffer. The EM-iron complex reduced the amount of O2-. produced by xanthine oxidase/hypoxanthine without inhibiting the enzyme activity. It also reduced the amount of O2-. release from phorbor ester-stimulated human neutrophils and alveolar macrophages. EM alone showed few such effects. The scavenging activity of the complex was equal to that of L-ascorbic acid. These results in vitro suggest a possibility that the O2-.-scavenging effect of EM-iron complex contributes to the anti-inflammatory action of EM used in treating chronic inflammatory lung disease independent of its antimicrobial activity.

Erythromycin↗
PubMed1997

Activation of human matrix metalloproteinases by various bacterial proteinases.

Matrix metalloproteinases (MMPs) are zinc-containing proteinases that participate in tissue remodeling under physiological and pathological conditions. To test the involvement of bacterial proteinases in tissue injury during bacterial infections, we investigated the activation potential of various bacterial proteinases against precursors of MMPs (proMMPs) purified from human neutrophils (proMMP-8 and -9) and from human fibrosarcoma cells (proMMP-1). Each proMMP was subjected to treatment with a series of bacterial proteinases at molar ratios of 0.01-0.1 (bacterial proteinase to proMMP), and activities of MMPs generated were determined. Among six different bacterial proteinases, thermolysin family enzymes (family M4) such as Pseudomonas aeruginosa elastase, Vibrio cholerae proteinase, and thermolysin strongly activated all three proMMPs via limited proteolysis to generate active forms of the MMPs. N-terminal sequence analysis of the active MMPs revealed that cleavage occurred at the Val82-Leu83 and Thr90-Phe91 bonds of proMMP-1 and proMMP-9, respectively, which are located near the N terminus of the catalytic domain of MMPs. In contrast, Serratia 56-kDa proteinase and Pseudomonas alkaline proteinase, both of which are classified as members of the serralysin subfamily of zinc metalloproteinases (family M10), and Serratia 73-kDa thiol proteinase did not evidence proteolytic processing or activation of proMMP-1, -8, and -9 under these experimental conditions. These results indicate that bacterial proteinases may play an important role in tissue destruction and disintegration of extracellular matrix at the site of infections.

Amino Acid Sequence↗
PubMed1997

Alterations in cytokeratin expression by the alveolar lining epithelial cells in lung tissues from patients with idiopathic pulmonary fibrosis.

It is generally recognized that epithelial cytokeratins (CKs) are expressed in tissue-specific patterns and reflect differentiation, functional specialization, and pathological alterations of the cells. Differential epithelial cell types can thus be distinguished from each other by their selective expression of particular sets of CKs. To determine the characteristics of metaplastic and hyperplastic changes of alveolar-lining epithelial cells in the lungs of idiopathic pulmonary fibrosis (IPF), the expression of individual CKs was studied immunohistochemically using monospecific anti-CK monoclonal antibodies (anti-CKs 7, 8, 10, 13, 14, 16, 17, 18, 19). Biopsy specimens from 17 patients with IPF and normal lung tissues (NL) from seven patients with lung cancer were studied. In the IPF specimens, several kinds of altered epithelial cells were observed, which showed characteristic changes in CK expression compared with NL, especially CKs 8, 14, and 17. Hyperplastic type II cells expressed increased CKs 7, 8, and 19, but not CK 17; flattened or stratified squamous metaplastic cells expressed increased CKs 17 and 14, co-expressed with CKs 7, 8, and 19; bronchiolar metaplastic cells expressed increased CKs 7, 8, and 19, co-expressed with CKs 14 and 17; cuboidal metaplastic cells expressed increased CKs 7, 8, 17, and 19. The quantification of individual CKs in the tissues by enzyme-linked immunosorbent assay revealed increased expression of CKs 8, 14, and 17 in IPF lung tissues compared with NL. These results were consistent with the immunohistochemical observations. The hyperplastic and bronchiolar metaplastic phenotypes were characterized by their increased expression of simple CKs without CK alteration. The squamous metaplastic phenotype showed CK alterations, with the appearance of CKs 17 and 14. Epithelial cells are thus altered not only in shape, but possibly also in differentiation and function, with potential implications for the pathogenesis of IPF.

Aged↗
PubMed1997

A superfemale with primary Sjögren's syndrome which involved systemic organs.

A 52-year-old Japanese woman complicated by a sex chromosomal anomaly as a superfemale, a mosaic of XXXXX/XXXX/XXX/XX/XO, with mild mental retardation, was hospitalized for dry mouth, dry eyes, and proteinuria. The sialography of the right parotid gland showed a globular-type gland enlargement. A definite diagnosis of primary Sjögren's syndrome (SS) was made, and further examinations revealed not only typical sicca syndrome but also systemic extraglandular lymphocytic infiltration; interstitial pneumonitis, glomerular- and interstitial nephritis, superficial gastritis, thyroiditis, and a severe excitation conductive impairment of heart. We report a very rare case of superfemale with primary SS which involved systemic organs.

Bronchi↗
PubMed1997

Hypersensitivity pneumonitis.

There are 30 or more groups of hypersensitivity pneumonitis (HP), such as farmer's lung, bird fancier's disease, humidifier lung, air-conditioner disease, and summer-type HP. Regardless of the causative agent or its environmental setting, the pathogenesis and clinical manifestations of the groups are similar. Immune-complex formation and complement activation might play a role during the early inflammatory phase of the disease. Much evidence, however, supports a more important role of T-cell-mediated delayed-type hypersensitivity reaction than humoral hyperresponsiveness in the development of the disease. High-resolution CT findings, a striking increase in the number of T cells in bronchoalveolar lavage fluids, and the presence of specific IgG and IgA antibodies to the causative antigens in the patient's serum samples are helpful in differentiating HP from other interstitial lung diseases. Management and treatment involve avoidance of antigen exposure and occasional use of corticosteroid therapy.

Alveolitis, Extrinsic Allergic↗