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Biomedical subjects

H Ohbayashi

Publications and source records attributed to H Ohbayashi.

At least 19 recordsLinked to original sources
PubMed2001

TT virus is shown in the liver by in situ hybridization with a PCR-generated probe from the serum TTV-DNA.

BACKGROUND AND AIM: It has been a conflicting issue whether TT virus (TTV), a newly isolated DNA virus from a patient with liver injury of unknown cause, is a causative agent of acute and/or chronic hepatitis. TT Virus DNA titers were shown to be 10-100-fold greater in liver tissue than in serum, whereas the majority of TTV-positive cases had no biochemical or histological evidence of significant liver damage. We therefore attempted in situ hybridization to investigate whether TTV is hepatotropic. METHODS: Because of the marked divergence in TTV genome types, a template for TTV-DNA (coding region for N22 clone) was amplified and labeled with digoxigenin-dUTP by using hemi-nested PCR from the serum, then DNA probes were applied to the liver sections of the same case. After hybridization, the probes were visualized immunohistochemically. Besides TTV-DNA-negative cases, competitive inhibition experiments with unlabeled probes were performed to confirm the specificity. RESULTS: There were no positive signals in the negative controls, and the intensity of positive signals was markedly diminished in the competitive inhibition experiments. No cross-hybridization with different genotype probes also confirms the specificity. Under the optimal conditions, the positive signals were located in the cytoplasm of the hepatocytes in eight of nine TTV-DNA-positive cases. The signals were not seen in non-parenchymal cells of the liver. CONCLUSION: TT Virus is proved to be hepatotropic by in situ hybridization.

DNA, Viral↗
PubMed2001

Radiation therapy in combination with transcatheter arterial chemoembolization for hepatocellular carcinoma with extensive portal vein involvement.

AIM: The aim of this study was to examine the effectiveness and toxicity of radiation therapy in combination with transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) with extensive portal vein tumor thrombus (PVTT). METHODS: The combined therapy was performed in 24 HCC patients with extensive PVTT. External radiation targeted for PVTT (50 Gy in 2 Gy fractions) was performed in combination with repetitive TACE for intralobar lesions using 30-60 mg epirubicin every 3 months, and associations of the following variables with the survival rate were evaluated: gender, age, viral etiology, Child's class, performance status, extrahepatic metastasis, size and number of HCC, and location of PVTT. RESULTS: The local response confined to PVTT was complete response (CR) in four patients, partial response (PR) in eight patients, no change (NC) in eight patients, and progressive disease (PD) in four patients. By using the stepwise Cox's regression analysis, only Child's class was associated with the survival rate. The survival rates after 1 and 2 years were 73 and 21% in Child's A, 10 and 0% in Child B or C, and 61 and 21% in patients in whom the local response was CR or PR, and 19 and 9% in those in whom the local response was NC or PD, respectively. By using the multiple logistic regression analysis, Child's class was the only factor associated with the local response (P = 0.006). CONCLUSIONS: The combined therapy is feasible and may be useful to reverse PVTT in patients with good hepatic function reserve.

Antineoplastic Agents↗
PubMed2001

[The efficacy of a comprehensive smoking cessation class, combined with nicotine patch and gum replacement therapy].

A six-month comprehensive smoking cessation class was conducted in our hospital, and the results were evaluated after one year. To increase the rate of smoking cessation, a smoking cessation support team composed of a medical doctor, a pharmacist, nurses, a registered dietitian, and a physical therapist was formed. The team provided specialized lectures and comprehensive group counseling programs every two weeks for the first two months and every month for the next four months. Each participant's expired carbon monoxide concentration and body weight were measured at every attendance. The participant continued with beneficial behavioral treatment for smoking cessation for six months, with nicotine replacement therapy (NRT) for the first eight weeks. The protocol of our NRT consisted of both the routine use of nicotine patches (Nicotinell TTS) and the rescue use of nicotine gum (Nicorette). We first ascertained each participant's degree of nicotine dependence, using the Fagerström Tolerance Questionnaire score, and daily nicotine intake was estimated by a detailed questionnaire. We then divided the participants into two NRT groups according to their nicotine dependence. The higher nicotine dependence group consisted of those whose Fagerström Tolerance Questionnaire score was more than 5 points or whose estimated nicotine intake was more than 10 mg/day. This group they used Nicotinell TTS 30 (TTS 30) for the first four weeks, TTS 20 for the next two weeks, and TTS 10 for the last two. In the lower dependence group. TTS 20 and TTS 10 were each given for four weeks. Nicotine gum use was restricted to 4 pieces a day for the first week and reduced by one per day each subsequent week. As a result, there was an 81.3% smoking cessation rate after eight weeks, 70.3% after six months, and 58.2% after one year. In conclusion, two courses of routine nicotine patch use, with the addition of restricted rescue use of nicotine gum, can produce better longterm abstinence results than previously reported NRTs, suggesting that this may be one of the best ways to cease smoking. We also emphasize that intensive group counseling programs and lectures supported by doctors and medical teams, as well as a continuing behavioral treatment component, may be indispensable for enhancing longterm sustained abstinence rates.

Administration, Cutaneous↗
PubMed2000

Both inhalant and intravenous uroguanylin inhibit leukotriene C4-induced airway changes.

Uroguanylin, a well-known ligand of guanylyl cyclase C receptor in the gastrointestinal tissue, has recently been reported to have pulmonary effects. We investigated the inhibitory effects of uroguanylin against leukotriene C4-induced bronchoconstriction and airway microvascular leakage. Anesthetized guinea pigs, ventilated via a tracheal cannula in a plethysmograph box, were measured by pulmonary mechanics for 10 min after i.v. administering 2 microg/kg leukotriene C4. Airway microvascular leakage was assessed by extravasation of Evans blue dye into airway tissues. Both inhalant and i.v. pretreatment of uroguanylin significantly inhibited leukotriene C4-induced pulmonary changes in a dose-dependent manner, suggesting its effectiveness against an asthmatic condition.

Administration, Inhalation↗
PubMed2000

ZD-0892 AstraZeneca.

ZD-0892, a neutrophil elastase inhibitor, is under development by AstraZeneca as a potential treatment for chronic obstructive pulmonary disease (COPD) and peripheral vascular disease (PVD). It is in phase I clinical trials for these two indications [315489]. The compound was originally under investigation for the potential treatment of asthma, but development was discontinued for this indication [266604]. The compound is the follow-up to ZD-8321 (qv) [336599].

Animals↗
PubMed1999

Adrenomedullin inhibits ovalbumin-induced bronchoconstriction and airway microvascular leakage in guinea-pigs.

Human adrenomedullin is a potent vasodilator with bronchodilation properties. The effects of adrenomedullin on antigen-induced bronchoconstriction and airway microvascular leakage in guinea-pigs was investigated. The portion of the adrenomedullin molecule possessing these pulmonary active profiles was also examined, using two truncated adrenomedullin molecules: adrenomedullin (1-25) and adrenomedullin (22-52). Four weeks after sensitization with ovalbumin (0.1 mg x k(-1)), the guinea-pigs were anaesthetized and mechanically ventilated. Respiratory resistance, dynamic compliance and arterial blood pressure were monitored. Airway microvascular leakage was evaluated by extravasation of 20 mg x kg(-1) Evans blue into airway interstitial tissue. In order to enhance the pulmonary effects of adrenomedullin, the active production of endogenous nitric oxide was inhibited by coadministration of a nitric oxide synthase inhibitor, L-N(G)-nitroarginine methethyl ester (10 mg x kg(-1)). Intravenous pretreatment with adrenomedullin (10, 30 and 100 microg x mL(-1)) dose-dependently inhibited ovalbumin-induced bronchoconstriction and airway microvascular leakage in all airway segments. Inhaled adrenomedullin (100 microg.mL(-1), 1 min) also significantly inhibited pulmonary changes induced by ovalbumin inhalation (3 mg x mL (-1) , 3 min). These pulmonary profiles of adrenomedullin were enhanced by inhibiting the active production of endogenous nitric oxide. In conclusion, adrenomedullin has inhibitory effects on antigen-induced microvascular leakage and bronchoconstriction in guinea-pigs. These beneficial effects strongly related to its unique ring structure and N-terminal segment, making it a potential anti-asthma.

Adrenomedullin↗
PubMed1999

Granulocyte colony stimulating factor-producing diffuse malignant mesothelioma of pleura.

We report the rare case of a 61-year-old man with a diffuse malignant mesothelioma of mixed subtype which produced granulocyte colony-stimulating factor (G-CSF). The white blood cell (WBC) was elevated to 85,100/mm3 without any evidence of infection, and the G-CSF level in the pleural effusion was also increased at 13,200 pg/ml. The lobes of the lung were encased in a tumor. Histopathologically, the tumor cells were of a polymorphous morphology with an epithelial and sarcomatoid mixed pattern. Immunohistochemistry showed that the tumor cells were positive for vimentin, cytokeratin, epithelial membrane antigen, thrombomodulin, and G-CSF, and negative for carcinoembryonic antigen (CEA), CD34, and surfactant apoprotein-A.

Diagnosis, Differential↗
PubMed1998

Compared effects of natriuretic peptides on ovalbumin-induced asthmatic model.

We compared the effects of natriuretic peptides on antigen-induced bronchoconstriction and airway microvascular leakage in sensitized guinea pigs. Anesthetized male guinea pigs, ventilated via a tracheal cannula, were placed in a plethysmograph to measure pulmonary mechanics for 10 min after challenge with 1 mg/kg of ovalbumin, and then Evans blue dye was extravasated into airway tissue in order to indicate and evaluate microvascular leakage. Three separate intravenous pretreatments using atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) significantly inhibited the ovalbumin-induced bronchoconstriction and microvascular leakage in a dose-dependent manner. These inhibitory effects were mimicked by 8-bromoguanosine 3',5'-cyclic monophosphate. We showed that the rank order of inhibitory potencies, which were mediated by cyclic guanosine 3',5'-monophosphate, was BNP > or = ANP > or = CNP. These results gave us some clues for the clinical application of the natriuretic peptides.

Animals↗
PubMed1998

Effects of uroguanylin and guanylin against antigen-induced bronchoconstriction and airway microvascular leakage in sensitized guinea-pigs.

Uroguanylin and guanylin are isolated mainly from the gastrointestinal tract and are activators of guanylyl cyclase C receptor (GC-C), which mediates the production of intracellular cyclic guanosine 3',5'-monophosphate (cyclic GMP). The bronchodilator effects of agents that raise cyclic GMP levels, such as atrial natriuretic peptide, have been reported, and uroguanylin mRNA has recently been detected in extra-gastrointestinal tissues, including the lung, suggesting their role in pulmonary activity. In the first step of this study, we examined the relaxant effects of uroguanylin and guanylin on isolated tracheal smooth muscle of guinea-pigs, and measured tissue cyclic GMP levels by means of enzymeimmunoassay. Uroguanylin produced concentration-dependent relaxant effects on resting tone and significant elevated cyclic GMP levels. Guanylin produced the same, but less potent, effects. In this study, we first investigated the effects of uroguanylin and guanylin on antigen-induced bronchoconstriction and airway microvascular leakage in actively sensitized guinea-pigs. Anesthetized male guinea-pigs, ventilated via a tracheal cannula, were placed in a plethysmograph to measure pulmonary mechanics for 10 min after challenging with 1 mg/kg of ovalbumin. Evans blue dye was then extravasated into their airway tissues to measure microvascular leakage. Intravenous pretreatment with uroguanylin significantly inhibited ovalbumin-induced bronchoconstriction and microvascular leakage in a dose-dependent manner. These inhibitory effects were mimicked by 8-bromoguanosine 3', 5'-cyclic monophosphate. This study is the first to show that uroguanylin not only had a potent bronchodilatory effect but also inhibited microvascular leakage. These results encouraged us to continue the above experimental and clinical studies in bronchial asthma.

Airway Resistance↗
PubMed1998

Primary structure of a 120 kDa protein associated with the fucose sulfate glycoconjugate constituting the acrosome reaction-inducing substance of the sea urchin, Hemicentrotus pulcherrimus.

A fucose sulfate glycoconjugate (FSG), a natural acrosome reaction-inducer, was purified from the egg jelly of the sea urchin Hemicentrotus pulcherrimus. The FSG is composed primarily of four constituents: a 120 kDa protein, a 237 kDa protein, a 258 kDa protein, and a polysaccharide-containing protein. Among them, the 120 kDa protein was thought to play a critical role in the association of other FSG constituent proteins, and therefore was characterized from a structural point of view. The protein was isolated from the carboxymethylated FSG by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing conditions, and then digested with trypsin to obtain information regarding the primary structure. Based on the partial amino acid sequences of three internal peptides (FSG120KA: LHNNEYGYGDTAAGEPELAQEEID, FSG 120KG: AIDIPAETGHYGR, and FSG120KC: RPTFDLADAVDT) and the N-terminal peptide (LHNNEYGYGDTAAGEPELAQQEID) of the 120 kDa protein obtained from intact FSG, degenerate oligonucleotide primers were synthesized and used to amplify a 297 bp cDNA fragment. This fragment enabled us to obtain the full-length cDNA (3176 bp) by 5'- and 3'-rapid amplification of cDNA ends. The deduced amino acid sequence revealed that the 120 kDa protein is composed of 663 amino acid residues including 72 cysteine residues, and hence, about 40% is presumed to be carbohydrate by weight. The 120 kDa protein plays an important role in the association of FSG constituent proteins (258 and 237 kDa) through disulfide bonds.

Acrosome Reaction↗
PubMed1998

Neutral endopeptidase 3.4.24.11 inhibition potentiates the inhibitory effects of type-C natriuretic peptide on leukotriene D4-induced airway changes.

1. Microvascular leakage, a primary feature of inflammation, is well known for worsening the asthmatic condition. Gene expression of and a specific receptor for type-C natriuretic peptide (CNP), initially considered a neuropeptide, have been detected in the human vascular wall and secretion of CNP from vascular endothelial cells has recently been demonstrated. These facts suggest the presence of a vascular natriuretic peptide system and led us to expect that CNP may act beneficially on airway microvascular leakage in asthma. In the present study, we investigated the effects of CNP against leukotriene (LT) D4-induced airway microvascular leakage and bronchoconstriction and how these effects were potentiated by thiorphan, a potent neutral endopeptidase 3.4.24.11 (NEP) inhibitor. 2. Anaesthetized male guinea-pigs, ventilated via a tracheal cannula, were placed into a plethysmograph for 10 min, in order to measure pulmonary mechanics and mean blood pressure, after challenge with 2 micrograms/kg LTD4 and then the extravasation of 20 mg/kg Evans blue dye into airway tissue was investigated to indicate and evaluate microvascular leakage. 3. Intravenous administration of CNP (100, 300 and 1000 micrograms/kg) significantly inhibited the LTD4-induced microvascular leakage and bronchoconstriction in a dose-dependent manner. These inhibitory effects were enhanced by pretreatment with 20 mg/kg thiorphan, suggesting the important role of NEP in the pulmonary metabolism of CNP. 4. We believe that these results are encouraging for the further investigation of the therapeutic applications of exogenous CNP in asthma.

Animals↗
PubMed1998

Effects of cytokines and minocycline on subacute lung injuries induced by repeated injection of lipopolysaccharide.

Pathological changes were seen in the lungs of ddY mice one week after repeated intraperitoneal injections of lipopolysaccharide (LPS) of Klebsiella pneumoniae. The infiltration of polymorphonuclear cells (PMN), mainly neutrophils, and lymphocytes into the alveolar septum, the infiltration of PMN into perivascular areas and microthrombi were recognized in this murine model. The blood levels of TNF alpha and IL-1 alpha did not rise at this time, suggesting that the most important cytokine promoting inflammation one week after LPS stimulation was neither TNF alpha nor IL-1 alpha. In the lungs of mice administered minocycline together with LPS, lymphocyte infiltration of alveoli and perivascular areas as well as microthrombi were suppressed. The blood levels of TNF alpha, IL-1 alpha, IL-4 and IL-6 were elevated in these groups, suggesting the suppression of pathological changes to be associated with the anti-inflammatory effect of IL-6 and/or persistent elevation of TNF alpha and/or IL-1 alpha levels. In conclusion, subacute pathological changes in the lung were induced by repeated intraperitoneal injections of LPS to mice. These pathological changes were suppressed by minocycline, suggesting the anti-inflammatory effects of this antibiotic to be the result of stimulating certain cytokines.

Animals↗
PubMed1992

Enhancing effect of wortmannin on muscarinic stimulation of phospholipase D in rat pheochromocytoma PC12 cells.

Wortmannin, a specific inhibitor of myosin light chain kinase (MLCK), enhanced carbachol-induced formation of [3H]phosphatidylethanol ([3H]PEt), a marker of phospholipase D (PLD) activity, in [3H]palmitic acid-labeled PC12 cells. The apparent EC50 value was 1.5 microM, and the effect was maximal at 3 microM and slightly attenuated at higher concentration. Wortmannin alone had no significant effect on [3H]PEt formation. The enhancing effect of wortmannin was observed at the initial increasing phase of [3H]PEt formation but not at the subsequent plateau phase. Wortmannin enhanced also phorbol ester-induced PLD activation. Although the precise mechanism remains to be clarified, these results suggest that MLCK may be involved in PLD regulation in PC12 cells.

Androstadienes↗
PubMed1992

Carbohydrate binding specificity of immobilized Psathyrella velutina lectin.

The carbohydrate binding specificity of Psathyrella velutina lectin (PVL) was thoroughly investigated by analyzing the behavior of various complex-type oligosaccharides and human milk oligosaccharides on a PVL-Affi-Gel 10 column. Basically, the lectin interacts with the nonreducing terminal beta-N-acetylglucosamine residue, but does not show any affinity for the nonreducing terminal N-acetylgalactosamine or N-acetylneuraminic acid residue. Substitution of the terminal N-acetylglucosamine residues of oligosaccharides by galactose completely abolishes their affinity to the column. GlcNAc beta 1----3Gal beta 1----4sorbitol binds to the column, but GlcNAc beta 1----6Gal beta 1----4sorbitol is only retarded in the column. The behavior of degalactosylated N-linked oligosaccharides is quite interesting. Although all degalactosylated monoantennary sugar chain isomers are retarded in the column, those with the GlcNAc beta 1----2Man group interact more strongly with the column than those with the GlcNAc beta 1----4Man group or the GlcNAc beta 1----6Man group. The degalactosylated bi- and triantennary sugar chains bind to the column, but the tetraantennary ones are only retarded in the column. These results indicated that the binding affinity is not simply determined by the number of terminal N-acetylglucosamine residues. Addition of the bisecting N-acetylglucosamine residue reduces the affinity of oligosaccharides to the column, but addition of an alpha-fucosyl residue at the C-6 position of the proximal N-acetylglucosamine residue does not affect the behavior of oligosaccharides in the column. These results indicated that the binding specificity of PVL is quite different from those of other N-acetylglucosamine-binding lectins from higher plants, which interact preferentially with the GlcNAc beta 1----4 residue.

Basidiomycota↗
PubMed1990

Primary structure of a fucose-specific lectin obtained from a mushroom, Aleuria aurantia.

Aleuria aurantia lectin (AAL) is a protein composed of two identical subunits having no carbohydrate chain and shows sugar-binding specificity for L-fucose. Full-length cDNA encoding for the lectin has been isolated from a lambda gt11 library, screened with an antiserum directed against AAL. The cDNA clone contained 1,370 nucleotides and an open reading frame of 939 nucleotides encoding 313 amino acids. The amino-terminal sequence (residues 1-30) of the lectin isolated from the mushroom coincided with the deduced amino acid sequence starting from proline at the 2nd residue, indicating that the mature AAL consists of 312 amino acids. Its molecular weight is calculated to be 33,398. The deduced amino acid sequence shows that AAL includes six internal homologous regions, and has considerable homology with a hemagglutinin from a Gram-negative bacterium, Myxococcus xanthus, which forms a fruiting body. No significant homology was observed with higher plant or animal lectins. The recombinant AAL produced by Escherichia coli JM109 carrying the AAL expression plasmid pKA-1 [Fukumori, F. et al. (1989) FEBS Lett. 250, 153-156] was purified from the cell lysate by affinity chromatography using a fucose-starch column, and hundreds of milligrams of the lectin was obtained. The recombinant lectin showed the same biochemical characteristics and sugar binding specificity as did the natural AAL.

Amino Acid Sequence↗