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Biomedical subjects

Y Hashimoto

Publications and source records attributed to Y Hashimoto.

At least 415 records · Page 23Linked to original sources
PubMed1998

Functional alteration of guanine nucleotide binding proteins (Gs and Gi) in psoriatic epidermis.

Psoriatic involved epidermis has been characterized by a defective beta-adrenergic adenylate cyclase response. It is also characterized by increased cholera toxin- and forskolin-induced cyclic AMP accumulations. Due to the fact that receptor signals are transduced to adenylate cyclase through guanine nucleotides binding proteins (G-proteins), that affect cholera toxin- and forskolin-induced cyclic AMP accumulations, possible alterations of G-proteins of psoriatic involved and perilesional uninvolved epidermis by using toxin-catalyzed ADP-ribosylation and immunoblot analyses was investigated. Cholera toxin catalyzes ADP-ribosylation of stimulatory guanine nucleotides binding protein (Gs) in either trimeric (inactive) or monomeric (active) form, while islet activating protein (IAP) catalyzes ADP ribosylation of inhibitory guanine nucleotide binding protein (Gi) in only trimeric (inactive) form. Results indicate that although the psoriatic involved epidermis shows increased cholera toxin- and IAP-catalyzed ADP-ribosylations, the amounts of immunoreactive Gs alpha or Gi alpha are not significantly altered. The increase in IAP-catalyzed ADP-ribosylation indicates increased inactive Gi, explaining the increased forskolin-induced cyclic AMP accumulation. The increase in cholera toxin-catalyzed ADP-ribosylation of Gs explains the increased cholera toxin-induced cyclic AMP accumulation in the psoriatic involved epidermis.

Adenosine Diphosphate Ribose↗
PubMed1998

Epidermal cell kinetics of pig skin in vivo following UVB irradiation: apoptosis induced by UVB is enhanced in hyperproliferative skin condition.

We investigated the effects of ultraviolet B (UVB) irradiation on pig epidermal sunburn cell (apoptotic cell) formation. Expression of p53 tumor suppressor gene product, p21 (WAF1/CIP1), and proliferating cell nuclear antigen (PCNA) was also determined immunohistochemically. Apoptotic cells appeared at 12 h and reached a peak at 48 h following 2 MED-UVB irradiation. The formation of sunburn cells was confirmed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) method. p53-positive cells, and p21-positive cells appeared at 6 h, and 12 h, respectively, following the UVB-irradiation. The peak of p53-positive cells was observed at 24 h, and that of p21-positive cells was at 48 h. No expression of TUNEL-, p53-, or p21-positive cells was detected in non-irradiated epidermis. The increase in PCNA-positive cells was observed at 24 h and reached its peak at 96 h following the UVB-irradiation. Flow cytometric analyses indicated a decrease in S-phase cells at 24 h, that was followed by their increase at 96 h. Cells in G2/M phase were also considerably decreased at 6 h and 48 h following the UVB-irradiation, and was followed by their increase thereafter. The [3H]thymidine uptake and mitotic counts remained low up until 48 h, and then both parameters increased reaching their peaks at 72 96 h. Effects of UVB irradiation were also determined in tape stripping-induced hyperproliferative epidermis. The numbers of UVB-induced apoptotic cells and PCNA positive cells were markedly enhanced in the tape stripping-treated epidermis, while the numbers of p53- and p21-positive cells were not significantly altered. No induction of apoptosis, p53, or p21 was observed by tape stripping alone. Our results indicate that UVB irradiation induces G1 arrest, prolonged S, and G2/M block of epidermal keratinocytes as well as apoptosis. These processes provide a G1 check point and the elimination of possibly hazardous cells carrying DNA damage, respectively. Our results also indicate that the UVB-induced apoptotic process is enhanced in hyperproliferative skin condition suggesting that apoptosis is closely associated with cell cycle progression.

Animals↗
PubMed1998

Interleukin-10 production during and after upper abdominal surgery.

STUDY OBJECTIVE: To evaluate the influence of major abdominal surgery on the plasma levels of interleukin-10 (IL-10). DESIGN: Prospective study. SETTING: University hospital. PATIENTS: 10 ASA physical status I and II patients undergoing upper abdominal surgery. INTERVENTIONS: All patients received combined general-epidural anesthesia with isoflurane and nitrous oxide, after insertion of an epidural catheter at T8-T9 dosed with 1.5% lidocaine. MEASUREMENTS AND MAIN RESULTS: Plasma interleukin-6 (IL-6), interleukin-8 (IL-8), and IL-10 levels were determined with an enzyme-linked immunosorbent assay at preanesthesia, 0, 2, and 4 hours during surgery, and at the end of surgery, followed by sampling on the morning of postoperative days 1 (POD1) and 3 (POD3). Before anesthesia and at 0 hours of surgery, IL-10 was not detected. In all ten patients, the plasma levels of IL-10 showed significant elevations and achieved their maximal value 4 hours after the skin incision (p < 0.05 vs. baseline). The plasma IL-10 levels returned to preanesthesia levels on POD3. The plasma levels of IL-6 and IL-8 also increased in the perioperative period. The peak cytokine levels correlated (r = 0. 915, p = 0.0001 for IL-6 vs. IL-8; r = 0.82, p = 0.025 for IL-6 vs. IL-10; and r = 0.641, p = 0.06 for IL-8 vs. IL-10). The peak plasma IL-10 levels significantly correlated with the amount of intraoperative blood loss (r = 0.69, p < 0.05). CONCLUSIONS: In patients undergoing major abdominal surgery, plasma IL-10 levels were elevated during and after operation. IL-10 may modulate the inflammatory responses in the perioperative period.

Abdomen↗
PubMed1998

Effects of intestinal and hepatic metabolism on the bioavailability of tacrolimus in rats.

PURPOSE: Tacrolimus, an immunosuppressive agent, has poor and variable bioavailability following oral administration in clinical use. We investigated the contribution of intestinal metabolism to the first pass effect of tacrolimus in rats. METHODS: Tacrolimus was administered intravenously, intraportally or intraintestinally to rats. Blood samples were collected over a 240-min period, and blood tacrolimus concentrations were measured. The extraction ratios of tacrolimus in the intestine and liver were investigated. In addition, the metabolism of tacrolimus in the everted sacs of the small intestine was examined. RESULTS: The rate of absorption of tacrolimus in the intestine was rapid, and tacrolimus was almost completely absorbed after intestinal administration. The bioavailability of tacrolimus was about 40% and 25% after intraportal and intraintestinal administration, respectively. indicating that tacrolimus is metabolized in both the intestine and the liver. In addition, tacrolimus was significantly metabolized in the everted sacs of the rat intestine. CONCLUSIONS: The present study suggested that the metabolism of tacrolimus in the intestine contributes to its extensive and variable first pass metabolism following the oral administration.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Effects of fosfomycin and imipenem/cilastatin on nephrotoxicity and renal excretion of vancomycin in rats.

PURPOSE: The effects of fosfomycin and imipenem/cilastatin on the nephrotoxicity of vancomycin were studied in rats, and those on the renal handling of vancomycin were also investigated in perfused kidneys. METHODS: The protective effects of fosfomycin and imipenem/cilastatin on vancomycin nephrotoxicity were evaluated by increases in plasma concentration of creatinine and urea nitrogen in rats. The urinary excretion of vancomycin was measured and analyzed kinetically in the perfused rat kidney. RESULTS: The nephrotoxicity induced by vancomycin (500 mg/kg, i.v.) was inhibited almost completely by co-administration of fosfomycin or imipenem/cilastatin. In the perfused rat kidney, the excretion ratio of vancomycin was less than those of p-aminohippurate and cimetidine, and greater than that of arbekacin, suggesting the secretion and reabsorption of vancomycin in renal tubules. The tissue/perfusate ratios of unbound vancomycin were not significantly changed by co-treatment with fosfomycin or imipenem/cilastatin. Imipenem/cilastatin significantly decreased the excretion ratio of vancomycin. Fosfomycin also decreased vancomycin excretion ratio, although this effect was not significant. CONCLUSIONS: The renal handling of vancomycin was different from those of organic anions and cations and an aminoglycoside antibiotic. The protective effects of fosfomycin and imipenem/cilastatin against the nephrotoxicity of vancomycin might be partly due to the change in renal handling of vancomycin, probably in its tubular secretion/ reabsorption, in rats.

Animals↗
PubMed1998

A panel set for epitope analysis of myeloperoxidase (MPO)-specific antineutrophil cytoplasmic antibody MPO-ANCA using recombinant hexamer histidine-tagged MPO deletion mutants.

A major target protein of antineutrophil cytoplasmic antibody with a perinuclear staining pattern (P-ANCA) has been identified as myeloperoxidase (MPO). Recombinant deletion mutants of MPO, eight fragments of the heavy-chain subunit, and two fragments of the light chain subunit were expressed in E. coli using a pQE expression vector. The recombinant hexamer histidine-tagged fragments were partially purified as the denatured proteins on a Ni2+-charged nitrirotriacetic acid column. The recombinant fragments were reacted with a rabbit polyclonal antibody to human MPO in Western blotting. In addition, the reactivities of the proteins with MPO-ANCA-positive sera of four patients with renal diseases were examined by Western blotting. The profile of the reactivity showed that different sera recognized different sets of fragments of the heavy chain, whereas no serum reacted with the fragments of the light chain. These results indicate that the sera of patients with MPO-ANCA-positive diseases showed varied reactivities with the different fragments. Furthermore, an ELISA system using a set of the fragments completely purified by Sephacryl S-200HR column chromatography was established. The panel set is useful for subclassification of MPO-ANCA-related diseases.

Animals↗
PubMed1998

Most of CD30+ anaplastic large cell lymphoma of B cell type show a somatic mutation in the IgH V region genes.

Relationship and histogenesis of Hodgkin's disease (HD) and anaplastic large cell lymphoma (ALCL) still remain unclear. Recently, Reed-Sternberg cells or Hodgkin cells in HD with B cell phenotype (B-HD) are considered to originate from germinal center B cells, ALCLs of B cell phenotype (B-ALCL) are involved in diffuse large B cell lymphoma (DLBCL) as anaplastic variant, but an origin of tumor cells of B-ALCL has not been elucidated. We have therefore investigated somatic mutation of the lg heavy chain (IgH) genes among 17 cases of B-ALCL to clarify whether there is a difference in characteristic and origin of tumor cells between B-ALCL, B-HD and DLBCL. Amplificates of IgH variable (V) region of 10 cases by the polymerase chain reaction method were sequenced and compared with reported germ line configurations. Nine cases (90%) with heavily somatic mutations were found. A case with an out-of-frame rearrangement and a case with 9 base pairs insertion were included. The mutation pattern revealed the tumor cells were selected for antibody expression and discriminated from B-HD. These findings suggest the tumor cells of B-ALCL are derived from germinal center or postgerminal center (memory and effector) B cells and an origin of B-ALCL is not different from DLBCL.

Adult↗
PubMed1998

Lyme disease with facial nerve palsy: rapid diagnosis using a nested polymerase chain reaction-restriction fragment length polymorphism analysis.

A 64-year-old woman with Lyme disease and manifesting facial nerve palsy had been bitten by a tick on the left frontal scalp 4 weeks previously. Erythema migrans appeared on the left forehead, accompanied by left facial paralysis. Nested polymerase chain reaction-restriction fragment length polymorphism analysis (nested PCR-RFLP) was performed on DNA extracted from a skin biopsy of the erythema on the left forehead. Borrelia flagellin gene DNA was detected and its RFLP pattern indicated that the organism was B. garinii, Five weeks later, B. garinii was isolated by conventional culture from the erythematous skin lesion, but not from the cerebrospinal fluid. After treatment with ceftriaxone intravenously for 10 days and oral administration of minocycline for 7 days, both the erythema and facial nerve palsy improved significantly. Nested PCR and culture taken after the lesion subsided, using skin samples obtained from a site adjacent to the original biopsy, were both negative. We suggest that nested PCR-RFLP analysis might be useful for the rapid diagnosis of Lyme disease and for evaluating therapy.

Adult↗
PubMed1998

An immunohistochemical study of bcl-2 and p53 protein expression in pancreatic carcinomas.

BACKGROUND: Only a few articles have examined the relationship between bcl-2 expression and clinical findings or bcl-2 expression and p53 expression in pancreatic carcinomas. METHODS: We investigated bcl-2 protein and p53 protein expression by means of immunohistochemical methods. RESULTS: The immunostaining for bcl-2 was positive in 16 (20%) of 81 cases of pancreatic carcinoma. There were no significant correlations between bcl-2 expression and the age, gender, region of sampling, or clinical stage of the patients. Bcl-2 protein was detected more frequently in histologically high-grade pancreatic carcinomas (grade III, 31%; grade II, 14%; grade I, 0%); however, there was no significant difference in prognosis between patients with and without bcl-2 protein expression. Immunostaining for the p53 protein was positive in 45 (56%) of 81 cases of pancreatic carcinoma. There was no significant correlation between bcl-2 protein expression and p53 protein expression. CONCLUSION: Bcl-2 was often detected in histologically high-grade pancreatic carcinomas, although there was no significant correlation between bcl-2 expression and the prognosis.

Adenocarcinoma↗
PubMed1998

Inhibition of cell growth in culture by quinones.

Quinones were studied for their growth inhibitory effect on cultured malignant cells. HCT-15 cells derived from human colon carcinoma were used for these experiments. Quinones used were arbutin in the benzoquinone group, juglone and lawsone in the naphthaquinone group, alizarin, emodin, 1,8-dihydroxyanthraquinone, and anthraquinone in the anthraquinone group, and xanthone. Cultured cells were incubated with various concentrations of the quinones for four days in a 5% CO2 incubator, after which cell numbers were counted and significance of differences was analyzed by Student's t test. Anthraquinones and naphthaquinones used in these experiments were more effective than the monocyclic quinone. The 50% suppression dose was less than 12.5 micrograms/ml for them. The number of OH groups seemed to play an important role in the degree of the cell growth inhibition: anthraquinones with 2 or 3 OH groups were more effective than those with no OH group like, 9,10-dioxoanthracene and xanthone. In fact, anthraquinones with no OH group and xanthone were not significantly effective. Flow cytometric histograms revealed a specific pattern; that is, lawsone and juglone in the naphthaquinone group and alizarin and 1,8-dihydroxy-anthraquinone in the anthraquinone group blocked mainly the S phase, and emodin in the anthraquinone group blocked the G1 to S phase of the cell cycle.

Anthraquinones↗
PubMed1998

Effect of gold on survival of tumor-bearing mice.

Sodium aurothiomalate (monogold monosodium mono-hydrogen sulfidobutanedioate), an anti-rheumatoid gold agent, was injected s.c. every other day for three times or given in drinking water daily for two weeks to Balb/C mice that were inoculated with syngeneic Meth/A cells i.p. As the control, cisplatinum was injected s.c. Survival curve was then observed and significance was determined by Wilcoxon's method. Statistically significant effects on survivals was obtained by 30 mg/kg/day s.c. or 75 mg/kg/day p.o. of gold. A dose of less than 12.5 mg/kg/day s.c. adversely affected the survival. Cisplatinum was significantly effective at the dose of 12.5 mg/kg/day, but markedly toxic at the dose of 125 mg/kg and adversely effective at 6 mg/kg/day s.c. The range of dose effectiveness of cisplatinum on survival was narrower than that of gold. Gold was effective when given s.c. or p.o. No significant toxicity of gold was observed at doses up to 125 mg/kg/day.

Administration, Oral↗
PubMed1998

Anti-tumor effect of methanol extracts from red and white wines.

Crude methanol extracts of red and white wines were added to diethyl ether in order to divide them into the anthocyanin fraction (insoluble in diethyl ether) and fractions containing other flavonoids and their derivatives (soluble in diethyl ether). However, the white wine did not contain anthocyanins (all of the methanol extract was soluble in diethyl ether). When HCT-15 cells, derived from human colon cancer or AGS cells, derived from human gastric cancer, were cultured with these fractions, the anthocyanin fraction from the red wine and the non-anthocyanic substances extracted from red and white wines suppressed the growth of the cells, and the suppression rate by the anthocyanin fraction was significantly higher than that of the other fractions. Thin-layer chromatographic analysis revealed mostly delphinidin in the anthocyanin fraction. The other fractions contained mostly flavonoids and their derivatives. The sugars in all fractions were mainly glucose, fucose, and fructose. Flow cytometric study suggested that the anthocyanin fraction blocked mostly S, G2, and M phase, and the non-anthocyanic flavonoids also blocked these phases, although the histographic pattern varied depending on the fractions. Methanol insoluble but water soluble fractions (mostly free sugars) of red and white wines did not show such suppressive effects.

Anthocyanins↗
PubMed1998

Effects of thiopental on airway calibre in dogs: direct visualization method using a superfine fibreoptic bronchoscope.

Induction of anaesthesia with thiopental sometimes causes bronchospasm. Although the mechanism by which thiopental induces bronchospasm may involve cholinergic stimulation, direct spastic effect and histamine release, the spastic effects of thiopental have not been comprehensively defined. In this study, we have assessed the effect of thiopental on in vivo airway smooth muscle tone using direct visualization method with a superfine fibreoptic bronchoscope as previously reported. Twenty-one mongrel dogs were anaesthetized with pentobarbital (30 mg kg-1) and paralysed with pancuronium (200 micrograms kg-1 h-1). The trachea was intubated with a tube that had a second lumen for insertion of the bronchoscope (od: 2.2 mm) to continuously measure bronchial cross-sectional area. The tip of the bronchoscope was placed between the second and third bronchial bifurcation of the right lung. The dogs were allocated to three groups of seven: group T, A+T, H+T. In group T, thiopental 0 (saline), 0.1, 1.0 and 10 mg kg-1 was given i.v. In group A+T, saline i.v., 5 min later atropine 0.1 mg kg-1 i.v., and 5 min later thiopental 10 mg kg-1 was administered. In group H+T, bronchoconstriction was produced with histamine 10 micrograms kg-1 i.v. followed by infusion at 500 micrograms kg-1 h-1. Thirty minutes later, thiopental 0, 1.0 and 10 mg kg-1 were given. Arterial blood sampling was performed for measurement of plasma catecholamines and histamine. In group T, thiopental significantly reduced bronchial cross-sectional area (maximally by 28.7 (5.6% at 0.5 min after thiopental 10 mg kg-1), which returned to the baseline in 3 min, while any changes in plasma concentrations of catecholamines and histamine were not observed except norepinephrine level at 1 min following thiopental 10 mg kg-1 i.v. Atropine pretreatment completely prevented thiopental-induced bronchospasm in group A+T. In group H+T, thiopental 10 mg kg-1 transiently but significantly decreases bronchial cross-sectional area. Therefore, the present study indicates that the mechanism of thiopental bronchospasm may result from cholinergic nerve stimulation.

Anesthetics, Intravenous↗
PubMed1998

A streptavidin-based neoglycoprotein carrying more than 140 GT1b oligosaccharides: quantitative estimation of the binding specificity of murine sialoadhesin expressed on CHO cells.

We prepared a streptavidin-based neoglycoprotein which carries more than 140 GT1b oligosaccharides. GT1b oligosaccharides were covalently coupled to streptavidin by reductive amination, yielding a monomer form of streptavidin carrying 13 oligosaccharides. The monomer form of glycosylated streptavidin was polymerized with biotinylated-bovine serum albumin, which yielded a polymer carrying more than 140 oligosaccharides. Both the monomer and the polymer bound to Chinese hamster ovary cells expressing murine sialoadhesin. The relative binding potencies determined with the polymer, monomer, and free GT1b oligosaccharides were 3,500, 83, and 1, respectively, indicating that an increase in the number of oligosaccharide ligands is critical for high avidity. The high avidity of the polymer enabled us to develop a sensitive and quantitative binding assay, and the assay was applied to characterization of the binding specificity of sialoadhesin. The polymer binding was inhibited by various gangliosides, the order of the inhibitory potencies being GM3 (IC50 = 40 microM) > GD1a (100 microM) > sialylparagloboside (120 microM) > GT1b (310 microM) > GM2 (640 microM) > GM4 (2,100 microM) > GD1b>LacCer = GM1 = paragloboside (no inhibition). These results indicate that the binding specificity is comparable to that reported, i.e. the determinant structure is NeuAcalpha2-3Galbeta1-linked to either 3GalNAc, 3(4)GlcNAc, or 4Glc, and that the oligosaccharide structure on the polymer is properly presented to sialoadhesin on the cell surface. To determine the precise requirement of the NeuAc structure for binding, NeuAc of GM3 was converted into various derivatives, the inhibitory potencies of which were examined; i.e. GM3 containing NeuAc, IC50 = 40 microM; C7- or C8-aldehyde, 500 microM; C7- or C8-alcohol, 700 microM; C1-alcohol, 2,000 microM; C1-amide, 2,200 microM; and NeuGc,>3,000 microM. These results confirmed the requirement of the hydroxyl group at C9 and/or C8, the carboxyl group at C1, and the methyl group of the N-acetyl residue of NeuAc in a quantitative manner. Thus, this streptavidin-based neoglycoprotein is a useful multivalent glycoprobe, which exhibits high affinity and specificity to murine sialoadhesin on the cell surface.

Animals↗
PubMed1998

Kinetic characterization of lysine-specific metalloendopeptidases from Grifola frondosa and Pleurotus ostreatus fruiting bodies.

Two zinc-metalloendopeptidases, GFMEP (accession number P81054) and POMEP (accession number P81055), from the fruiting bodies of two edible mushrooms, Grifola frondosa and Pleurotus ostreatus, respectively, specifically hydrolyze peptidyl-lysine bonds (-X-Lys-) in polypeptides. To understand detailed substrate specificities and kinetic characters of these enzymes, we have synthesized various intramolecularly quenched fluorescent peptide substrates and determined their kinetic constants with these substrates. Each synthesized fluorogenic peptide has a fluorescent residue, tryptophan, at its carboxyl terminus and a quenching group, dinitrophenyl (Dnp), at its amino terminus. Quenching of the Trp fluorescence in an intact substrate is relieved on hydrolysis of the -X-Lys- bond, giving rise to a continuous increase in fluorescence. The octapeptide substrate, Dnp-Ser-Thr-Ala-Thr-Lys-Leu-Ser-Trp, was an efficient substrate for both enzymes, the kcat/Km values being 9.8 x 10(6) and 7.0 x 10(5) M-1.s-1 for GF- and POMEP, respectively. Peptides with aspartic acid adjacent to the Lys residue were found to be poor substrates for both enzymes. Neither the shortest peptide, Dnp-Thr-Lys-Trp, nor peptides with substitution of L-Arg, L-ornithine, or D-Lys for Lys were hydrolyzed by either enzyme. These results confirmed the strict specificities of GF- and POMEP toward the peptide bond, -X-Lys-. Substitution of Co2+ for Zn2+ enhanced the activity, while the Km values were comparable. All peptides not hydrolyzed by either enzyme had inhibitory effects on GFMEP activity. The active site structure is discussed in relation to these observations.

2,4-Dinitrophenol↗