Publications by authors named "Ichikawa J"

Various 1,1-difluoro-1-alkenes such as monosubstituted 1,1-difluoro-1-alkenes, 2-bromo-1,1-difluoro-1-alkenes, and 3,3-difluoroallylic alcohols are synthesized in two simple steps from 1-trifluoromethylvinylsilane: (i) its SN2' reaction with nucleophiles to construct 2,2-difluorovinylsilanes and (ii) the subsequent substitution of electrophiles for the vinylic silyl group. The combination of these two processes allows a one-pot synthesis of the functionalized 1,1-difluoro-1-alkenes starting from 1-trifluoromethylvinylsilane, which functions as a CF2=C(-)-CH2+ synthon.

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Phencyclidine (PCP) is an N-methyl-D-aspartate (NMDA) glutamate receptor channel noncompetitive antagonist that produces some of the symptoms of schizophrenia, including delusions, hallucinations, and negative symptoms as well as cognitive impairment. Thus, administration of PCP to rodents and nonhuman primates has been suggested to provide a potential animal model for schizophrenia. There have been some reports that 7-14 days of PCP administration can bring about enduring impairments in working memory in rodents but not all studies have been consistent in this regard.

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Background/purpose: The utility of hepatectomy for patients with metastatic liver tumors from gastrointestinal stromal tumors (GISTs) was evaluated in the present study.

Methods: Between 1989 and 2001, ten patients with liver metastases from GIST (four men and six women; age, 34-77 years) underwent hepatectomy at our hospital. All patients underwent complete resection of the primary tumor and hepatectomy with or without microwave coagulation therapy (MCT) for all detectable hepatic tumors.

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o-Cyano-beta,beta-difluorostyrenes react with organolithiums selectively at the cyano carbon to generate the corresponding sp(2) nitrogen anions, which in turn undergo intramolecular replacement of the vinylic fluorine to afford 3-fluoroisoquinolines. Similarly, the reaction of beta,beta-difluoro-o-isocyanostyrenes with organomagnesiums or -lithiums generates the corresponding sp(2) carbanions on the isocyano carbon. Subsequent cyclization via substitution of the fluorine leads to 3-fluoroquinolines.

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(+/-)-([1-(2,5-Dimethoxy-4-iodophenyl)-aminopropane]-hydrochloride) (DOI) (2.5 mg/kg), a 5-HT(2A/2C) agonist, significantly potentiated D-amphetamine (AMPH) (1 mg/kg)-induced dopamine (DA) release in rat medial prefrontal cortex (mPFC) and nucleus accumbens (NAC). This effect of DOI was completely prevented by M100907 (1 mg/kg), a selective 5-HT(2A) antagonist, which by itself had no effect on basal and AMPH-induced DA release in either region.

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Rationale: Atypical, but not typical, antipsychotic drugs (APDs), produce preferential increases in dopamine (DA) and acetylcholine (ACh) release in rat medial prefrontal cortex (mPFC) compared to the nucleus accumbens (NAC). The increase in DA release has been attributed, in part, to their greater serotonin (5-HT)(2A) relative to D(2) receptor occupancy, while the basis for the increase in ACh has not yet been determined. Loxapine, a dibenzoxazepine congener of clozapine, is generally considered to be a typical APD because it produces significant extrapyramidal symptoms (EPS) in humans, at generally recommended clinical doses (60-100 mg/day), and catalepsy in rodents, although several studies have found it to be effective at lower doses which do not produce significant EPS.

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Background And Study Aims: Gastric carcinoid tumors are a rare disease. Previously, total gastrectomy was regarded as the treatment of choice. However, differences in biological malignancy have recently led to the increased use of endoscopic mucosal resection (EMR) for treatment.

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Behavioral evidence suggests that muscarinic/cholinergic inhibition of brain dopaminergic activity may be a useful principle for developing novel antipsychotic drugs (APDs). Thus, oxotremorine, a muscarinic agonist, attenuates amphetamine-induced locomotor activity in rodents, an effect also produced by a wide variety of proven APDs, whereas scopolamine, a muscarinic antagonist, has the opposite effect. Since atypical APDs such as clozapine, olanzapine, risperidone, ziprasidone and quetiapine, increase brain acetylcholine as well as dopamine (DA) release in a region-specific manner, their effects on cholinergic and dopaminergic neurotransmission may also contribute to various actions of these drugs.

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Preferential increases in both cortical dopamine (DA) and acetylcholine (ACh) release have been proposed to distinguish the atypical antipsychotic drugs (APDs) clozapine, olanzapine, risperidone and ziprasidone from typical APDs such as haloperidol. Although only clozapine and ziprasidone are directly acting 5-HT(1A) agonists, WAY100635, a selective 5-HT(1A) antagonist, partially attenuates these atypical APD-induced increases in cortical DA release that may be due to combined 5-HT(2A) and D(2) blockade. However, WAY100635 does not attenuate clozapine-induced cortical ACh release.

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The combination of M100907, a putative antipsychotic drug (APD) and serotonin (5-HT)(2A) antagonist, and the typical APD haloperidol, can enhance dopamine (DA) release in rat medial prefrontal cortex (mPFC), an effect which has been postulated to be of value to improve cognition and negative symptoms. The present study demonstrated that another putative APD and 5-HT(2A/2C) antagonist, SR46349-B (10 mg/kg, but not 1-3 mg/kg) alone, but not M100907 (0.1 and 3 mg/kg) alone, increased mPFC DA release, whereas neither drug alone affected nucleus accumbens (NAC) DA release.

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Combined serotonin (5-HT)(2A) and dopamine (DA) D(2) blockade has been shown to contribute to the ability of atypical antipsychotic drugs (APDs) to increase DA release in rat medial prefrontal cortex (mPFC). We provide additional support for this hypothesis by examining the effect of the selective 5-HT(2A) antagonist M100907 plus haloperidol, a potent D(2) antagonist APD, on DA release in the mPFC and nucleus accumbens (NAC). Haloperidol (0.

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The atypical antipsychotic drugs (APDs) clozapine, olanzapine, risperidone, and ziprasidone preferentially increase dopamine (DA) release in rat medial prefrontal cortex (mPFC). These effects have been shown to depend upon potent 5-HT(2A) relative to weak D(2) antagonism, and 5-HT(1A) agonism as well. Atypical APDs also increase acetylcholine (ACh) release in the mPFC, but not the nucleus accumbens (NAC) or striatum (STR), whereas typical APDs such as haloperidol, S(-)-sulpiride and thioridazine do not produce either effect in the mPFC.

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The role of acetylcholine (ACh) in the action of antipsychotic drugs (APDs) was studied by microdialysis, without AChesterase inhibition, to facilitate the interpretation of any observed drug effects. The atypical APDs, clozapine (2.5-20 mg/kg), olanzapine (10 mg/kg), risperidone (1 mg/kg), and ziprasidone (3 mg/kg) significantly increased ACh release in rat medial prefrontal cortex (mPFC), whereas the typical APDs, haloperidol (0.

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The beta-hetero-substituted vinylphosphonates 1a-c on treatment with LDA or LTMP were readily lithiated at the alpha-position of the phosphono group, and the resulting alpha-lithiovinylphosphonates were trapped with various electrophiles to afford the corresponding alpha-functionalized vinylphosphonates 2-14 in 55-96% yields. The Friedel-Crafts reaction of alpha-(silyl)- or alpha-(germyl)phosphonoketene dithioacetals 2, 9, or 4 with acid chlorides gave alpha-acylated phosphonoketene dithioacetals 15-19 in 53-91% yields. The palladium-catalyzed cross-coupling reaction of beta-ethoxy-alpha-(tributylstannyl)vinylphosphonate 13 with a variety of organic halides (R = acyl, allyl, aryl, etc.

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alpha-Ester-substituted 1,3-dienylphosphonates 7 and 8, prepared by the Knoevenagel condensation, underwent intramolecular [2 + 2] cycloaddition in the presence of Lewis acid to form bicyclo[4.2.0] (26-57% yield) and bicyclo[3.

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The role of intracellular Ca2+ stores and capacitative Ca2+ entry on EGF-induced cell proliferation was investigated in mouse mammary epithelial cells. We have previously demonstrated that EGF enhances Ca2+ mobilization (release of Ca2+ from intracellular Ca2+ stores) and capacitative Ca2+ entry correlated with cell proliferation in mouse mammary epithelial cells. To confirm their role on EGF-induced cell cycle progression, we studied the effects of 2,5-di-tert-butylhydroquinone (DBHQ), a reversible inhibitor of the Ca2+ pump of intracellular Ca2+ stores, and SK&F 96365, a blocker of capacitative Ca2+ entry, on mitotic activity induced by EGF.

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[reaction: see text] 3-Fluoro-5-methylene-2-cyclopentenone is treated with appropriate nucleophiles and Lewis acids to undergo regioselective 1,2-addition, exocyclic 1,4-addition, and endocyclic 1,4-addition, leading to 3-substituted 4-methylene-2-cyclopentenones, 5-substituted 3-fluoro-2-cyclopentenones, and 3-substituted 5-methylene-2-cyclopentenones in good yields, respectively.

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Most patients with ampullary carcinoma have obstructive jaundice without cholangitis. We experienced a patient with ampullary carcinoma who presented with obstructive jaundice and cholangitis, probably because of an accompanying periampullary choledochoduodenal fistula. A 77-year-old Japanese man had jaundice, high fever, and upper abdominal pain and was diagnosed, at another hospital, with obstructive cholangitis.

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(+/-)-1-(2,5-Dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI, 1.25, 2.5 and 5 mg/kg), a serotonin (5-HT)2A/2C agonist, produced an inverted U-shaped increase in DA release in rat medial prefrontal cortex (mPFC) with a significant effect only at 2.

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Atypical antipsychotic drugs (APDs), all of which are relatively more potent as serotonin (5-HT)(2A) than dopamine D(2) antagonists, may improve negative symptoms and cognitive dysfunction in schizophrenia, in part, via increasing cortical dopamine release. 5-HT(1A) agonism has been also suggested to contribute to the ability to increase cortical dopamine release. The present study tested the hypothesis that clozapine, olanzapine, risperidone, and perhaps other atypical APDs, increase dopamine release in rat medial prefrontal cortex (mPFC) via 5-HT(1A) receptor activation, as a result of the blockade of 5-HT(2A) and D(2) receptors.

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Effects of epidermal growth factor (EGF) on the intracellular Ca(2+) ([Ca(2+)](i)) responses to nucleotides, Ca(2+) release from thapsigargin-sensitive stores and capacitative Ca(2+) entry were investigated in cultured mouse mammary epithelial cells. EGF treatment induced proliferation of mammary epithelial cells. We checked for mitotic activity by immunocytochemistry with an anti-PCNA (proliferating cell nuclear antigen) antibody, which stains nuclei of the cells in S-phase of cell cycle.

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Pseudomonas aeruginosa is an opportunistic pathogen that plays a major role in lung function deterioration in cystic fibrosis patients. To identify critical host responses during infection, we have used high-density DNA microarrays, consisting of 1,506 human cDNA clones, to monitor gene expression in the A549 lung pneumocyte cell line during exposure to P. aeruginosa.

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Developmental changes in capacitative Ca(2+) entry and Ca(2+) release from intracellular stores were measured using fura-2 fluorescence method during the pregnancy period (day 3-;18) in mouse mammary epithelial cells. Ca(2+) release was identified with the transient intracellular Ca(2+) ([Ca(2+)](i)) increase induced by thapsigargin addition in a Ca(2+)-free solution. Capacitative Ca(2+) entry was measured by the transient [Ca(2+)](i) increase induced by re-addition of extracellular Ca(2+) after depletion of Ca(2+) stores by thapsigargin.

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