Publications by authors named "Nagata R"

The practical synthesis of a series of tricyclic indole-2-carboxylic acids, 7-chloro-3-arylaminocarbonylmethyl-1,3,4,5-tetrahydrobenz[cd]indole-2-carboxylic acids, as a new class of potent NMDA-glycine antagonists is described. The synthetic route to the key intermediate 12a comprises a regioselective iodination of 4-chloro-2-nitrotoluene, modified Reissert indole synthesis, Jeffery's Heck-type reaction with allyl alcohol, Wittig-Horner-Emmons reaction, and iodination at the indole C-3 position. The key step in the route is an intramolecular cyclization of 12a to give the tricyclic indole structure.

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To develop an experimental model of thromboembolic stroke without intracranial surgery, an autologous blood clot was delivered to the middle cerebral artery (MCA) via the internal carotid artery in cynomolgus monkeys. Male cynomolgus monkeys, in which a chronic catheter had been earlier implanted in the left internal carotid artery, were used. The clot was flushed into the internal carotid artery under sevofluorane anesthesia.

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Transferrin was isolated from plasma of the ascidian Halocynthia roretzi by ion-exchange chromatography. The molecular weight of the plasma transferrin was determined to be 52K by SDS-polyacrylamide gel electrophoresis and gel filtration. Ascidian plasma transferrin was found to bind one mole of iron ion per mole of protein.

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The effects of ropinirole (4-[2-(dipropylamino)ethyl]-2-indolinone monohydrochloride), a nonergoline dopamine receptor agonist with a high affinity for native dopamine D(2)-like receptors, on Parkinsonism induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), 2.5 mg/animal in common marmosets were examined and compared to the effects of bromocriptine. Ropinirole (0.

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Mutant human lysozymes (Ile56Thr & Asp67His) have been reported to form amyloid deposits in the viscera. From the standpoint of understanding the mechanism of amyloid formation, we searched for conditions of amyloid formation in vitro using hen egg lysozyme, which has been extensively studied from a physicochemical standpoint. It was found that the circular dichroism spectra in the far-ultraviolet region of the hen egg lysozyme changed to those characteristic of a beta-structure from the native alpha-helix rich spectrum in 90% ethanol solution.

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The introduction in Japan of New GCP regulations, as well as the internationalization of clinical trials under the ICH process (International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use), has meant that the system is now faced with a number of serious challenges. This is shown by the dramatic decrease in registration of new drugs. Identifying the actors in the new context is essential.

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Ropinirole (4-[2-(dipropylamino)ethyl]-2-indolinone monohydrochloride) a nonergoline dopamine receptor agonist with high affinity for native dopamine D(2)-like receptors in human caudate tissue, was tested with respect to the stimulation of postsynaptic brain dopamine receptors in standard preclinical models of Parkinson's disease. Additionally, in these animal models the antiparkinsonian activity of ropinirole was compared to that of bromocriptine. The ED(50)s (95% confidence limits) of ropinirole and bromocriptine on the turning behavior in 6-OHDA-lesioned rats were 20.

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Synthetic phenylurea derivatives such as N-phenyl-N'-(4-pyridyl)urea (4PU) and N-(2-chloro-4-pyridyl)-N'-phenylurea (4PU30) have strong cytokinin activities. Using tritiated 4PU30 as a probe, we found the presence of a cytokinin-specific binding protein (CSBP) with high affinity for 4PU30 (Ka for 4PU30 = 4 x 10(10) M-1) in the soluble fraction of etiolated mung bean seedlings. We purified CSBP by the use of 4PU-Sepharose 4B, an affinity gel ligated with 4PU.

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We previously demonstrated that amino acid residues Gln62 (P3), Phe63 (P2), Leu64 (P1), and Phe67 (P3') in the primary binding loop of Erythrina variegata chymotrypsin inhibitor (ECI), a member of the Kunitz inhibitor family, are involved in its strong inhibitory activity toward chymotrypsin [Iwanaga et al. (1998) J. Biochem.

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One of the challenging issues in modern biomedical science is the increasing number of osteoporosis patients due to the expansion of elderly populations. Among aging-related pathogenic changes, alterations in bone function and skeletal pathogenesis is a particularly important issue of concern. Osteoporosis is one of the most serious bone-related pathogenic states, as it causes serious loss of quality of life.

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Synthetic urea derivatives such as N-phenyl-N'-(4-pyridyl)urea (4PU) and N-(2-chloro-4-pyridyl)-N'-phenylurea (4PU30) have strong cytokinin activities. Using tritiated 4PU30 as a probe, we previously established the presence of a cytokinin-specific binding protein (CSBP) of high affinity (Ka for 4PU30 = 4x10(10) M(-1)) in the soluble fraction of etiolated mung bean seedlings [Nagata, R., Kawachi, E.

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Complementary DNA fragments encoding cynomolgus monkey CYP1A2 were amplified by the reverse transcriptase-polymerase chain reaction (RT-PCR) method from the liver total RNA of a 3-methylcholanthrene (3-MC)-treated cynomolgus monkey. The nucleotide sequence determined was 1630 bp long and contained an open reading frame for a polypeptide of 516 residues. The nucleotide and the deduced amino acid sequences of cynomolgus monkey CYP1A2 showed 95.

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It has been recognized that bone trace element composition analysis provides clues when analyzing bone-related physiological conditions. Increasing numbers of bone-related genetic diseases have been identified recently. In this study, we have analyzed bone trace element composition in a genetic mutant animal model.

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Complementary DNA of marmoset CYP1A2 was isolated by means of screening the cDNA library and reverse-transcriptase polymerase chain reaction. The deduced amino acid sequence of marmoset CYP1A2 consisted of 516 residues and showed 88.2 and 90.

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Clinical features of epiretinal membranes were examined in 22 eyes of 13 patients with Terson syndrome who were treated with pars plana vitrectomy. The shape and localization of the epiretinal membranes were intraoperatively evaluated and correlated with the presence or absence of posterior vitreous detachment (PVD). Patients with complete PVD, but with no membrane found during surgery, were followed postoperatively.

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An antigenicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was conducted in Hartley guinea pigs and BALB/cAnN mice. The following results were obtained. No active systemic anaphylaxis reactions were found in guinea pigs immunized by subcutaneous injection of NS-21 alone or in combination with Freund's complete adjuvant (FCA).

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A 26-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1, 1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was conducted in Sprague-Dawley rats. Male and female rats were given the drug orally for 26 weeks at doses of 0 (control), 5, 50 and 500 mg/kg. After discontinuation of the treatment, a 9-week recovery test was also conducted.

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Northern blot and immunoblot analyses indicated that considerable levels of CYP2B, CYP2C, CYP2D, CYP2E, and CYP3A were expressed in the liver of untreated marmosets. CYP1A was also expressed but to lesser extents. CYP3A mRNA was also detectable in the small intestine of untreated marmoset; the amount was increased by treatment with polychlorinated biphenyl.

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A cytokinin isolated from the fluid endosperm of Cocos mucifera L. (coconut milk), accounting for more than 20% of the total cytokinin activity, was structurally analyzed by NMR techniques, mass spectrometry, and sugar analysis by high performance liquid chromatography (HPLC). The planar structure of the cytokinin was deduced from its NMR and mass spectrometric data.

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A monoclonal antibody was developed, using cultured subepithelial fibroblasts of rat duodenal villi as the antigenic material, by in vitro immunization. Hybridomas were selected on cryosections of rat brain and small intestine using indirect immunofluorescence techniques. The monoclonal antibody, termed 8E1, was very useful to label GFAP-positive astrocytes in the adult rat brain, subepithelial fibroblasts of intestinal villi and Thuneberg's fibroblast-like interstitial cells associated with the myenteric plexus layer.

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Single-dose and repeated dose toxicity studies of prulifloxacin, a new antibacterial agent, were conducted in aged beagle dogs. I. A single-dose toxicity study Prulifloxacin was administered orally to aged female dogs at a single dose of 2500 and 5000 mg/kg.

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A major cytokinin found in coconut milk was isolated by using the tobacco callus growth-promoting assay as a guide during purification. The structure of the factor was determined to be 14-O-(3-O-[beta-D-galactopyranosyl-(1-->2)-alpha-D-galactopyranosyl-(1-- >3)- alpha-L-arabinofuranosyl]-4-O-(alpha-L-arabinofuranosyl)-beta-D- galactopyranosyl)-trans-zeatin riboside [G3A2-ZR] by various NMR techniques, including heteronuclear multiple bond connectivity by 2D multiple quantum NMR (HMBC), as well as mass spectroscopy and sugar analysis. The optimum concentration of G3A2-ZR for cytokinin activity in the tobacco callus assay was estimated to be 5 x 10(-6) M, so that G3A2-ZR is one order of magnitude more potent than 1,3-diphenylurea and one order less potent than zeatin riboside.

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A novel glucose sensor employing ferrocene-modified glucose oxidase is fabricated using the screen printing technique. Glucose oxidase is covalently bound to the electron mediator ferrocenecarboxylic acid in order to obtain higher enzyme activity. The ferrocene-glucose oxidase shows an increased catalytic current because the ferrocene acts as an electron transfer relay between the active centre of the enzyme and the gold electrode.

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This study was conducted to characterize the opiate dependence potential of a number of opiate and non-opiate psychoactive drugs in morphine-dependent cynomolgus monkeys (Macaca fascicularis). In addition, the agonist/antagonist profiles of buprenorphine and butorphanol were directly compared. Six male cynomolgus monkeys were maintained on morphine (3.

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A series of tricyclic quinoxalinediones, 5,6-dihydro-1H-pyrrolo[1,2,3-de]quinoxaline-2,3-diones and 6,7-dihydro-1H,5H-pyrido[1,2,3-de]quinoxaline-2,3-diones, were synthesized and was evaluated for their affinity for the glycine binding site of the NMDA receptor using a [3H]-5,7-dichlorokynurenic acid binding assay. The six-membered ring-fused tricyclic quinoxalinedione 18g (Ki = 9.9 nM) displayed high affinity for the glycine site.

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