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Biomedical subjects

T Aoki

Publications and source records attributed to T Aoki.

At least 19 recordsLinked to original sources
PubMed1995

Cupric ion blocks NF kappa B activation through inhibiting the signal-induced phosphorylation of I kappa B alpha.

A transcription factor NF kappa B, which regulates expression of various cellular genes involved in immune responses and viral genes including HIV, is sequestered in the cytoplasm as a complex with an inhibitory protein I kappa B. Various extracellular signals induce phosphorylation and rapid degradation of I kappa B alpha to release NF kappa B. Cu2+ was found to inhibit the activation of NF kappa B induced by TNF-alpha, TPA, or H2O2. Deoxycholate treatment of the cytoplasmic extract prepared from cells stimulated by TNF-alpha in the presence of Cu2+ resulted in the release of NF kappa B from I kappa B alpha, indicating that Cu2+ interferes with the dissociation of the NF kappa B-I kappa B complex. Neither phosphorylation nor degradation of I kappa B alpha was observed upon TNF-alpha stimulation in the presence of Cu2+. These results indicate that Cu2+ inhibits the release of NF kappa B by blockade of a signal leading to the phosphorylation of I kappa B alpha.

Animals↗
PubMed1995

Novel zinc chelators with dual activity in the inhibition of the kappa B site-binding proteins HIV-EP1 and NF-kappa B.

Both HIV-EP1 (also called PRDII-BF1 or MBP-1), a zinc finger protein, and NF-kappa B, a Rel family protein, bind to kappa B site present in the enhancer of multiple cellular and viral genes involved in immune function and inflammatory response including HIV-1 LTR and human interferon beta gene. When cells are exposed to extracellular stimuli such as virus or phorbol ester, the activity of both HIV-EP1 and NF-kappa B is induced. Thus, kappa B site-directed transcription could be regulated by two distinct proteins in a cooperative way. Novel heterocyclic compounds comprising (dimethylamino)pyridine and histidine units, i.e., 1-4, have been designed and synthesized, aiming at inhibition of these kappa B site-binding proteins to discriminate their functions. These compounds exhibited remarkable zinc-binding capability as revealed by NMR study. Compounds 1 and 2 showed a marked inhibitory effect on the DNA binding activity of HIV-EP1 by removing zinc without interfering with the DNA binding activity of NF-kappa B. Since it has been demonstrated that zinc somehow influences the DNA binding of NF-kappa B, the effect of these heterocyclic compounds and their zinc complexes on NF-kappa B was examined. Zinc complexes of 3 and 4 exhibited the inhibitory effect on the DNA binding of NF-kappa B and/or homodimeric complexes of p50 and p65 subunits of NF-kappa B without affecting HIV-EP1. Thus, it became possible to inhibit either one of the two kappa B site-binding proteins without inhibiting the other.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1995

Discordant expression and variable numbers of neighboring GGA- and GAA-rich triplet repeats in the 3' untranslated regions of two groups of messenger RNAs encoded by the rat polymeric immunoglobulin receptor gene.

An unusual S1-nuclease sensitive microsatellite (STMS) has been found in the single copy, rat polymeric immunoglobulin receptor gene (PIGR) terminal exon. In Fisher rats, elements within or beyond the STMS are expressed variably in the 3' untranslated regions (3'UTRs) of two 'Groups' of PIGR-encoded hepatic mRNAs (pIg-R) during liver regeneration. STMS elements include neighboring constant regions (a 60-bp d[GA]-rich tract with a chi-like octamer, followed by 15 tandem d[GGA] repeats) that merge directly with 36 or 39 tandem d[GAA] repeats (Fisher or Wistar strains, respectively) interrupted by d[AA] between their 5th-6th repeat units. The Wistar STMS is flanked upstream by two regions of nearly contiguous d[CA] or d[CT] repeats in the 3' end of intron 8; and downstream, by a 283 bp 'unit' containing several inversions at its 5' end, and two polyadenylation signals at its 3' end. The 283 nt unit is expressed in Group 1 pIg-R mRNAs; but it is absent in the Group 2 family so that their GAA repeats merge with their poly A tails. In contrast to genomic sequence, GGA triplet repeats are amplified (n > or = 24-26), whereas GAA triplet repeats are truncated variably (n < or = 9-37) and expressed uninterruptedly in both mRNA Groups. These results suggest that 3' end processing of the rat PIGR gene may involve misalignment, slippage and premature termination of RNA polymerase II. The function of this unusual processing and possible roles of chi-like octamers in quiescent or extrahepatic tissues are discussed.

Animals↗
PubMed1995

Stage-specific isoforms of complex II (succinate-ubiquinone oxidoreductase) in mitochondria from the parasitic nematode, Ascaris suum.

Complex II from mitochondria of the adult parasitic nematode, Ascaris suum, exhibits high fumarate reductase activity and plays a key role in the anaerobic electron transport observed in these organelles. In contrast, mitochondria isolated from free living second stage larvae (L2) of A. suum show much lower fumarate reductase activity than those from adults, whereas succinate dehydrogenase activities of mitochondria in both stages are comparable. In the present study, biochemical and antigenic properties of the partially purified enzymes from both larval and adult mitochondria were compared. Larval complex II eluted from the DEAE-Cellulofine column chromatography at a lower salt concentration than adult enzyme, whereas the apparent molecular size of both enzyme complexes estimated by gel permeation column chromatography was the same. The fumarate reductase activity of larval complex II was less than 3% of that of adult enzyme, and the Km values for substrates were significantly different between the two complexes. The flavoprotein subunit of larval complex II could be distinguished from that of adult complex II by two-dimensional gel electrophoresis and peptide mapping. The antibody against the smallest subunit (small subunit of cytochrome b558) of the adult enzyme did not cross-react with that of the larval enzyme. These results suggest that larval complex II differs from adult enzyme and is more similar to aerobic mammalian enzymes with low fumarate reductase activity. This is the first direct indication of the two different stage-specific forms of mitochondrial complex II.

Animals↗
PubMed1995

Gene rearrangement studies on lymphoma of the lung: report of a case.

We describe herein how true lymphoma of the lung was differentiated from pseudolymphoma in a 45-year-old woman presenting with pulmonary infiltrates. Although segmental resection revealed typical histologic findings of pseudolymphoma of the lung and immunohistochemical studies did not demonstrate a monoclonal proliferation, Southern blot analysis of the frozen tissue revealed rearrangements in the heavy and light chains of the immunoglobulin gene, with no T-cell receptor gene rearrangement suggestive of a lymphoproliferative disorder. These findings indicate that the identification of gene rearrangement may be utilized to distinguish between true lymphoma and pseudolymphoma.

Blotting, Southern↗
PubMed1995

Analysis of zinc and other elements in rat pancreas, with studies in acute pancreatitis.

Determination of the concentration of certain elements makes it possible to investigate the physiology of the pancreas. We used X-ray fluorescence to determine the concentrations of zinc and other elements in the pancreas of normal (control) rats and those with cerulein-induced pancreatitis. Ten elements (Zn, Ni, Fe, P, Ca, Cl, S, K, Ti, and Mn) were detected in controls. In the early stage of acute pancreatitis, the pancreatic concentrations of Zn, Ni, Fe, and P were significantly decreased (P < 0.05) and those of Ca and Cl were significantly increased (P < 0.05), compared with control levels. However, levels of S, K, and Ti did not differ significantly from the control values. Mn was detected in only some samples. The serum levels of Zn and Fe were significantly elevated (P < 0.05) in acute pancreatitis. These observations indicate that Zn and these other nine elements could play an important role in acute pancreatitis.

Acute Disease↗
PubMed1995

Immunoelectron microscopic analysis of chondroitin sulfates during calcification in the rat growth plate cartilage.

The proximal growth plate cartilage of rat tibia was fixed in the presence of ruthenium hexamine trichloride (RHT) in order to preserve proteoglycans in the tissue. Quantitative changes of chondroitin sulfates during endochondral calcification were investigated by immunoelectron microscopy using mouse monoclonal antibodies 1-B-5, 2-B-6, and 3-B-3, which recognize unsulfated, 4-sulfated, and 6-sulfated chondroitin sulfates, respectively. The content of chondroitin-4-sulfate in the cartilage matrix increased from the proliferative zone to the calcifying zone, while that of unsulfated chondroitin sulfate decreased. Chondroitin-6-sulfate remained constant from the proliferative zone to the upper hypertrophic zone, then decreased in the calcifying zone. The immunoreaction to each antibody increased conspicuously in the cartilagenous core of metaphysial bone trabeculae. The changes of sulfation in chondroitin sulfate chains of proteoglycans may play an important role in inducing and/or promoting calcification in growth plate cartilage.

Animals↗
PubMed1995

Temperature-modulated platelet and lymphocyte interactions with poly(N-isopropylacrylamide)-grafted surfaces.

Temperature-responsive semitelechelic poly(N-isopropylacrylamide) (PIPAAm) bearing a carboxyl end group has been chemically immobilized on aminated polystyrene particle surfaces via condensation reaction. PIPAAm-grafted particles were uniformly suspended in aqueous media at lower temperatures. With increasing temperature, PIPAAm-grafted particles aggregated and precipitated. Such reversible changes in particle colloidal behaviour was correlated to temperature-modulated hydrophilic/hydrophobic changes of particle surfaces modified by PIPAAm hydration/dehydration with temperature changes. Interactions between platelets and PIPAAm-grafted surfaces were studied by monitoring cytoplasmic free Ca2+ concentration ([Ca2+]i) changes in platelets using intracellularly-trapped Ca2+ indicator dye, Fura 2, at various temperatures. Although changes in [Ca2+]i in platelets in contact with PIPAAm-grafted particles were not observed below the critical temperature of PIPAAm, significant changes in [Ca2+]i in platelets were induced by contact with particles above this critical temperature. Furthermore, temperature-modulated cell adsorption/desorption control by PIPAAm-grafted particles was investigated using a particle aggregation assay in the presence of lymphocytes. Below the critical temperature of PIPAAm, mixed suspensions were completely homogeneous due to minimal interaction between lymphocytes and hydrated particles. In contrast, aggregated precipitates were observed by increasing the suspension temperature above the critical temperature of PIPAAm resulting from strong hydrophobic interactions between particles with lymphocytes. These precipitates are reversibly resuspended in cold buffer. The feasibility of cell activation/inactivation or cell attachment/detachment control by temperature-modulated surface changes is attractive for suspension cell culture and drug delivery at targeted sites in vivo.

Acrylic Resins↗
PubMed1995

Determining the optimal dose of lansoprazole injection by 24-hour intragastric pH monitoring.

Two studies were performed on healthy adult males using 24-h intragastric pH monitoring to investigate the acid secretion inhibitory effects of the proton pump inhibitor lansoprazole in its injectable form (lansoprazole injection). In the first study (study 1), eight subjects received 30 mg once daily and 30 mg twice daily of lansoprazole injection by the crossover method. In the second study (study 2), 12 subjects received 15 and 30 mg twice daily of lansoprazole injection and 20 mg twice daily of a histamine H2-receptor antagonist using the crossover method. The results of study 1 showed that 30 mg once daily of lansoprazole injection was not able to achieve sufficient suppression of acid secretion, and the results of study 2 suggested that the effectiveness of the three treatment regimens studied in suppressing gastric acid secretion can be ranked as follows: lansoprazole 30 mg twice daily > lansoprazole 15 mg twice daily > H2-receptor antagonist 20 mg twice daily.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1995

Inhibitory effects of intravenous lansoprazole on gastric acid hypersecretion in patients with postoperative stress.

The inhibitory effects of intravenous lansoprazole on gastric acid hypersecretion caused by stress after surgical invasion were studied in patients who underwent surgery under general anesthesia for gastrointestinal diseases. Patients in this study received either 15 mg or 30 mg of lansoprazole by slow intravenous injection twice daily for 3 days (six injections). The total number of patients studied was 82, with 41 patients in each group. Intragastric pH was measured every 8 h after the start of administration, and the inhibitory effects of intravenous lansoprazole on postoperative gastric acid secretion were evaluated using four grades: excellent, good, fair, and poor. In the 15-mg group, 65.8% (25 of 38 patients) were classified as good or excellent, and in the 30-mg group, 75.7% (28 of 37 patients) were good or excellent. No adverse effects directly attributable to the administration of lansoprazole were observed.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1995

Intravenous administration of lansoprazole: a preliminary study of dose ranging and efficacy in upper gastrointestinal bleeding.

Using 24-h pH monitoring, we studied the optimal dose and mode of administration of lansoprazole (LAN) injection in healthy adult male volunteers in three tests of antisecretory effect. We followed this with a dose-finding study, using the drug's suppressive effect on increased gastric acid secretion due to surgical stress as the indicator. Finally, we conducted a pilot study to determine the optimal mode of administration and efficacy of the drug in patients with haemorrhage from the upper gastrointestinal tract. Twenty-four-hour intragastric pH monitoring established the order of potency of the different regimens: LAN 30 mg b.d. > LAN 15 mg b.d.; and LAN 30 mg b.d., intravenous drip infusion = LAN 30 mg b.d., bolus injection. Lansoprazole 30 mg b.d. appeared to be slightly more effective than LAN 15 mg b.d. in suppressing increased gastric acid secretion due to post-operative stress and in haemostasis in patients with upper gastrointestinal bleeding. No severe adverse effects were observed in either study.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1995

RAPD analysis of Aeromonas salmonicida and Aeromonas hydrophila.

The randomly amplified polymorphic DNA (RAPD) technique was used to analyse the genetic differentiation of 13 strains of Aeromonas salmonicida subsp. salmonicida, and seven strains of Aer. hydrophila. Reproducible profiles of genomic DNA fingerprints were generated by polymerase chain reaction (PCR) using a single randomly designed primer. The RAPD profiles of all the non-motile aeromonads, Aer. salmonicida subsp. salmonicida were identical. However, profiles of the motile aeromonads, Aer. hydrophila differed between isolates. These findings reveal genomic homogeneity in Aer. salmonicida subsp. salmonicida and genetic variety in Aer. hydrophila strains.

Aeromonas↗
PubMed1995

Intramuscular myxoma with fibrous dysplasia: a report of two cases with a review of the literature.

Two cases are reported of a rare association of intramuscular myxoma with fibrous dysplasia in a 70 and 40 year old Japanese woman, respectively. One of them had a solitary intramuscular myxoma, and the other patient suffered from two intramuscular tumors that had been initially misdiagnosed as myxoid liposarcoma. Only 24 cases of this kind of association have been recorded in the literature. This association should be taken into consideration to avoid inappropriate treatment, when cases of myxoid soft tissue tumor with a bone lesion are encountered.

Adult↗
PubMed1995

Angiomyofibroblastoma of the vulva: a clinicopathologic study of seven cases.

A clinicopathologic and immunohistochemical review was made of seven cases of angiomyofibroblastoma. The patients were middle-aged women who had a slowly growing mass, measuring 1.5-6 cm in maximum dimension, located subcutaneously in the vulva. The tumors were well-demarcated and characterized by well-vascularized, alternating hypercellular and hypocellular edematous areas composed of bland, plump spindle- or oval-shaped stromal cells frequently aggregated around small blood vessels. An epithelioid appearance of the stromal cells was seen in two cases. Immunohistochemically, the stromal cells were consistently positive for vimentin and desmin, but negative for muscle specific actin, alpha-smooth muscle actin, myosin, cytokeratins, S-100 protein or von Willebrand factor. Ultrastructurally, the plump stromal cells had a small amount of peripherally located rough endoplasmic reticulum, numerous pinocytotic vesicles and abundant intermediate filaments, on which immunogold probes for desmin were localized, whereas fine filaments were few and there were no electron dense plaques. Thus, while the proliferating stromal cells expressed an immunohistochemical profile of peculiar myoid differentiation, ultrastructural findings differed from those of smooth muscle cells or those seen in typical myofibroblasts. At 1-4 years after surgery, there was no evidence of recurrence.

Adult↗
PubMed1995

A new cis-acting element for RNA replication within the 5' noncoding region of poliovirus type 1 RNA.

Mouse cells expressing the human poliovirus receptor (PVR-mouse cells) as well as human HeLa cells are susceptible to poliovirus type 1 Mahoney strains and produce a large amount of progeny virus at 37 degrees C. However, the virus yield is markedly reduced at 40 degrees C in PVR-mouse cells but not in HeLa cells. The reduction in virus yield at 40 degrees C appears to be due to a defective initiation process in positive-strand RNA synthesis (K. Shiroki, H. Kato, S. Koike, T. Odaka, and A. Nomoto, J. Virol. 67:3989-3996, 1993). To gain insight into the molecular mechanisms involved in this detective process, naturally occurring heat-resistant (Hr)-mutants which show normal growth ability in PVR-mouse cells even at 40 degrees C were isolated from a virus stock of the Mahoney strain and their mutation sites that affect the phenotype were identified. The key mutation was a change from adenine (A) to guanine (G) at nucleotide position (nt) 133 within the 5' noncoding region of the RNA. This mutation also gave an Hr phenotype to the viral plus-strand RNA synthesis in PVR-mouse cells. Mutant Mahoney strains with a single point mutation at nt 133 (A to G, C, or T or deletion) were investigated for their ability to grow in PVR-mouse cells at 40 degrees C. Only the mutant carrying G at nt 133 showed an Hr growth phenotype in PVR-mouse cells. These results suggest that a host cellular factor(s) interacts with an RNA segment around nt 133 of the plus-strand RNA or the corresponding region of the minus-strand RNA, contributing to efficiency of plus-strand RNA synthesis.

Animals↗
PubMed1995

In vivo effects of endothelin A- and B-receptor antagonists in guinea pigs.

Endothelin (ET)-1, a novel 21-amino acid constrictor peptide, has been recently reported to have a potential pathophysiological role in asthma. We hypothesized that ET-1 might affect guinea pig lung via different ET receptor subtypes, i.e., ETA and ETB, in vivo. To test this hypothesis, we investigated the effects of ET-1 on airways in anesthetized, open-chest, mechanically ventilated [frequency (f) = 1 Hz; tidal volume (VT) = 9 ml/kg; positive end-expiratory pressure (PEEP) = 4 cmH2O] guinea pigs in the absence or the presence of ETA and ETB selective antagonists, i.e., BQ-123 and BQ-788, respectively. We affixed alveolar capsules to the lungs to measure alveolar pressure and calculated the elastance of lung (EL) and the resistance of lung (RL), tissue (Rti), and airway (R(aw)) under control conditions and after intravenous administration of ET-1 (10(-8) mol/kg). ET-1 induced a concentration-dependent increase in RL, Rti, R(aw), and EL.BQ-123 (2 mg/kg) partially blocks delta RL and delta R(aw) during ET-1 induced constriction, while delta Rti and delta EL were not significantly affected. BQ-788 (2 mg/kg) significantly inhibited delta RL, delta Rti, delta R(aw), and delta EL during ET-1-induced constriction. The combination of BQ-123 and BQ-788 completely ablated the response to ET-1. These data suggest that both ET receptor subtypes, i.e., ETA and ETB, may have physiological roles in guinea pig airways in response to ET-1, a potential mediator of asthma.

Airway Resistance↗