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Biomedical subjects

Yutaka Suto

Publications and source records attributed to Yutaka Suto.

8 recordsLinked to original sources
PubMed2005

Cu(I)-catalyzed direct enantioselective cross aldol-type reaction of acetonitrile.

Direct catalytic enantioselective cross aldol-type reaction of an acetate surrogate was developed using Cu alkoxide-chiral phosphine complexes as catalysts. Chemoselective activation and deprotonation of the donor substrate (acetonitrile) by the soft metal alkoxide in a strongly donating solvent (HMPA) are key to success in this reaction. Useful chemical yields and promising enantioselectivities are produced using either DTBM-SEGPHOS or a tuned BIPHEP as a chiral ligand. [reaction: see text]

Journal Article↗
PubMed2004

Myasthenia gravis with thymus hyperplasia and pure red cell aplasia.

A case of myasthenia gravis (MG) with thymus hyperplasia and pure red cell aplasia (PRCA) is reported. A 57-year-old woman was diagnosed as having MG and was treated with thymectomy 26 years ago. The histology of the resected thymus was thymic lymphoid follicular hyperplasia. She developed rapidly progressive anemia and a bone marrow examination revealed PRCA. Her hematological results improved with oral administration of cyclosporine A. Cases of MG, thymoma and PRCA have been reported in the literature. We report the first case of MG without thymoma and PRCA.

Cyclosporine↗
PubMed2004

[A case of hemichorea with hyperglycemia presenting with low signal intensity in the striatum on T2*-weighted gradient-echo magnetic resonance imaging].

A 76-year-old woman was admitted to our hospital with chorea in her left arm and leg. She also suffered from poorly controlled diabetes. Her arm and leg flexed and shook, and these movements were worsened by stress and disappeared during sleep. Neurological examinations were otherwise normal. The blood glucose level was 232 mg/dl and glycosylated hemoglobin A1c was 13.9%. Magnetic resonance (MR) showed high signal intensity on T1-weighted images (T1-WI) in the right striatum, and low signal intensity on T2-weighted images (T2-WI). T2*-weighted gradient-echo magnetic resonance imaging showed low signal intensity that gradually became even lower, suggesting petechial hemorrhage. SPECT showed normal blood flow in the right striatum under these conditions, and gradually decreased. The patient's diabetes was controlled with insulin, and the hemichorea improved on treatment with tiapride up to 75 mg per day, haloperidol up to 2.25 mg per day. Hemichorea with hyperglycemia is a disorder that is associated with poorly controlled diabetes, old age, and high signal intensity on T1-weighted MR imaging in the striatum contralateral to the hemichorea. The pathophysiology of the hemichorea is presumed to be ischemic changes in the striatum associated with hyperglycemia and hyperviscosity. The MR findings in our patient suggest petechial hemorrhage following ischemic change, although petechial hemorrhage has not been reported in similar cases in the recent literature. The striatal hyperactivity may be associated with the onset of hemichorea in our patient.

Aged↗
PubMed2003

Direct catalytic aldol-type reactions using RCH2CN.

[reaction: see text] A copper fluoride-catalyzed cyanomethylation that can be applied to a wide range of ketones and aldehydes was developed using TMSCH(2)CN as a nucleophile. The reaction was extended to a conceptually more advanced copper alkoxide-catalyzed direct addition of alkylnitriles to aldehydes, which can act as a surrogate direct catalytic aldol reaction of esters. These reactions can be applied to the first catalytic enantioselective cyanomethylation of ketones and direct catalytic enantioselective cyanomethylation of aldehydes.

Journal Article↗
PubMed2003

A new method for the catalytic aldol reaction to ketones.

A new method for the catalytic aldol reaction to ketones, using CuF.3PPh3.2EtOH complex as the catalyst and (EtO)3SiF as the additive, is described. The reaction can be applied to a wide range of ketones and trimethylsilyl enolates. On the basis of mechanistic studies, a working hypothesis for the catalytic cycle is proposed, in which the dynamic ligand exchange mediated by copper silicates produces the active copper enolate. Moreover, the present reaction can be extended to the catalytic enantioselective reaction using tol-BINAP as a chiral ligand.

Journal Article↗
PubMed2002

Dramatic switching of protein kinase C agonist/antagonist activity by modifying the 12-ester side chain of phorbol esters.

A dramatic switching of PKC agonist and antagonist activity was observed by modification of the hydrophilicity of the 12-ester side chain of phorbol. Thus, phorbol ester 4 that contains a glycol at the 12-ester chain demonstrated a pure and significant antagonist ability of PKC; however, 3 that contains an alkanol at the 12-ester chain demonstrated a potent PKC agonist activity. On the basis of the structural difference between 3 and 4 and results of the partition assay in the Hela cell/PBS buffer system, we propose that 4 acts as a translocation poison of the PKC-phorbol ester complex. The approach of controlling the agonist/antagonist activity of phorbol esters by the nature (i.e., hydrophilicity, charge, and rigidity, etc.) of the 12-ester chain may be very useful for developing selective PKC inhibitors and a potential pharmaceutical compound for anticancer therapies.

Cell Membrane↗