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Hideki Sugimoto

Publications and source records attributed to Hideki Sugimoto.

At least 19 recordsLinked to original sources
PubMed2006

Subacute combined degeneration of the spinal cord concomitant with gastric cancer.

We report a rare case of subacute combined degeneration of the spinal cord concomitant with gastric cancer. A 67-year-old man was admitted because of posterior column symptoms, pyramidal tract sign and peripheral neuropathy with severe hyperchromic anemia. He was treated with mecobalamin 1 mg IM, after which his anemia and neurological signs recovered. He was diagnosed as having subacute combined degeneration with pernicious anemia. Subsequent stomach biopsy revealed gastric cancer, and the patient underwent gastrectomy. It is a well known association that chronic atrophic gastritis is associated with gastric cancer or subacute combined degeneration. Our findings suggest that in this case subacute combined degeneration and gastric cancer are independent of each other; rather, both resulted from chronic atrophic gastritis.

Aged↗
PubMed2006

Autoimmune thrombocytopenic purpura, autoimmune hemolytic anemia and gastric cancer appeared in a patient with myasthenia gravis.

We report a case of myasthenia gravis (MG) associated with autoimmune thrombocytopenic purpura (AITP) and autoimmune hemolytic anemia (AIHA), and after that gastric cancer appeared. A 51-year-old man began to suffer from fluctuated muscle weakness in 1985. Muscle weaknesses became exacerbated, and he was admitted to our hospital in 1989. He was diagnosed as MG associated with AITP. After a thymectomy (hyperplasia), prednisolone therapy was started, subsequently his condition was satisfactory. In March 1995, he developed severe anemia and icterus. He was diagnosed as Evans' syndrome (AIHA and AITP) with MG. High-doses of immunoglobulin administration improved the anemia, but thrombocytopenia continued. In November 2002, he suffered marked petechia; the platelet count decreased to 1000/microl. Methylprednisolone pulse therapy and platelet transfusion were started. Gastrofiberscopy was performed and biopsy specimens revealed signet cell-type adenocarcinoma. On December 19, 2002, subtotal gastrectomy and splenectomy were performed. After that, his condition has remained satisfactory, without MG symptoms or thrombocytopenia. This is the first such case report in the literature.

Anemia, Hemolytic, Autoimmune↗
PubMed2006

Extrathymic tumors in patients with myasthenia gravis: a 35-year retrospective study.

OBJECTIVE: Autoimmune diseases are frequently associated with malignant tumor. In addition, prolonged immunosuppression may favor the development of malignancy. While the coincidence of myasthenia gravis and extrathymic tumor has been reported, the risk and features of these tumors are not well understood. REVIEW SUMMARY: We treated 305 patients with myasthenia gravis from 1968-2003, including 48 thymoma cases. Two hundred twenty-nine patients had undergone thymectomy and 76 had not. We examined cancer risk, tumor characteristics, and associations to medications. We encountered 9 cases of extrathymic tumor. Cancer risk in the thymoma cases was 6.3% and 2.3% in the nonthymoma cases, a statistically insignificant difference. Azathioprine was administered to only 14 in this series of patients; however, 2 patients developed cancer. CONCLUSIONS: Cancer risk in patients with myasthenia gravis is 2.6%, similar to that of the general population in Japan. We neurologists need to be aware that prolonged immunosuppression may favor the development of malignancy.

Adult↗
PubMed2006

[A case of primary HIV infection presenting as mononeuritis multiplex].

A 34-year-old man presented with gait disturbance. He had a low grade fever and diarrhea for a few days prior to admission. Two weeks after he started to have diarrhea, he developed gait disturbance with a left foot drop. The cerebrospinal fluid obtained on admission showed pleocytosis (30/microl) and increased protein. The motor nerve conduction velocities (MCV) of the left peroneal nerve and the tibial nerve were slow, but the right peroneal and tibial MCVs were within normal limits. A test for human immunodeficiency virus (HIV) antibody was positive. The Western blot was positive with bands of gp160 and p24, confirming HIV infection. Seroconversion-related neuropathy of HIV was diagnosed. Acute HIV infection should be included in the differential diagnosis of mononeuritis multiplex. Before full-fledged AIDS development, it is important to find early stage of HIV infection in patients, so that we can treat them more effectively by means of anti-HIV drugs.

Adult↗
PubMed2005

Mononuclear five-coordinate molybdenum(IV) and -(V) monosulfide complexes coordinated with dithiolene ligands: reversible redox of Mo(V)/Mo(IV) and irreversible dimerization of [MoVS]- cores to a dinuclear [MoV2(mu-S)2]2- Core.

A mononuclear five-coordinate molybdenum(IV) monosulfide complex, (Et4N)2[MoS(L)2] (L = cyclohexene-1,2-dithiolate) (1), was obtained and characterized by IR, UV-vis spectroscopic methods, and X-ray crystallography. 1 was oxidized by an equivalent ferrocenium cation to give the corresponding mononuclear molybdenum(V) complex, (Et4N)[MoS(L)2] (2), which was stable for a few minutes under a lower concentration than 0.3 mM and then further dimerized to (Et4N)2[Mo(L)2]2(mu-S)2 (3).

Journal Article↗
PubMed2005

A new series of molybdenum-(IV), -(V), and -(VI) dithiolate compounds as active site models of molybdoenzymes: preparation, crystal structures, spectroscopic/electrochemical properties and reactivity in oxygen atom transfer.

A new set of molybdenum-(IV), -(V), and -(VI) compounds containing 3,6-dichloro-1,2-benzenedithiolate (bdtCl2) were isolated and characterised by crystallographic and other spectroscopic techniques as active site models of arsenite oxidase, one of the molybdoenzymes. MoO2 compounds were prepared in high yields by reaction of MoO2Cl2 with bdtCl2, related dithiolene and thiocatecholate in methanol at low temperature. The bdtCl2 ligand particularly stabilised the MoO compounds with oxidation numbers of +4 and +5 as well as the MoO2 compound with an oxidation number of +6. The compounds (Et4N)2[MoVIO2(bdtCl2)2], (Et4N)2[MoIVO(bdtCl2)2] and (Et4N)[MoVO(bdtCl2)2] were successfully isolated, whereas (Et3NH)2[MoO2(thiocatecholate)2] gradually decomposed in acetonitrile. A distorted octahedral structure similar to that of was suggested for the structure of the active site of the oxidised form of arsenite oxidase on the basis of a comparison of their bond distances and angles. The bond distances and angles around the molybdenum(IV) atom in were similar to those around the molybdenum(IV) centre in the reduced form of arsenite oxidase. The reversible / couple exhibited a more positive redox potential than common MoO dithiolene compounds. Underwent an irreversible proton-coupled reduction process to yield. An oxygen atom transfer reaction of with triphenylphosphine afforded and triphenylphosphine oxide, and proceeded in second order as v=-d/dt[MoO2]=k[MoO2][PPh3]. The structures and properties of the oxo-bridged dinuclear compound (Et4N)2[MoVIO2(bdtCl2)]2(micro-O), a dimer of bdtCl2 and were also characterised.

Binding Sites↗
PubMed2005

Dioxo-molybdenum(VI) and mono-oxo-molybdenum(IV) complexes supported by new aliphatic dithiolene ligands: new models with weakened Mo=O bond characters for the arsenite oxidase active site.

The cis-dioxo-molybdenum(VI) complexes, [MoO2(L(H))2]2- (1b), [MoO2(L(S))(2)]2- (2b), and [MoO2(L(O))2]2- (3b) (L(H) = cyclohexene-1,2-dithiolate, L(S) = 2,3-dihydro-2H-thiopyran-4,5-dithiolate, and L(O) = 2,3-dihydro-2H-pyran-4,5-dithiolate), with new aliphatic dithiolene ligands were prepared and investigated by infrared (IR) and UV-vis spectroscopic and electrochemical methods. The mono-oxo-molybdenum(IV) complexes, [MoO(L(H))2]2- (1a), [MoO(L(S))2]2- (2a), and [MoO(L(O))2]2- (3a), were further characterized by X-ray crystal structural determinations. The IR and resonance Raman spectroscopic studies suggested that these cis-dioxo molybdenum(VI) complexes (1b-3b) had weaker Mo=O bonds than the common Mo(VI)O2 complexes. Complexes 1b-3b also exhibited strong absorption bands in the visible regions assigned as charge-transfer bands from the dithiolene ligands to the cis-MoO2 cores. Because the oxygen atoms of the cis-Mo(VI)O2 cores are relatively nucleophilic, these complexes were unstable in protic solvents and protonation might occur to produce Mo(VI)O(OH), as observed with the oxidized state of arsenite oxidase.

Binding Sites↗
PubMed2005

Cytochrome c-crown ether complexes as supramolecular catalysts: cold-active synzymes for asymmetric sulfoxide oxidation in methanol.

A series of supramolecular complexes of various cytochrome c proteins with 18-crown-6 derivatives behave as cold-active synzymes in the H2O2 oxidation of racemic sulfoxides. This interesting behavior contrasts with native functionality, where the employed proteins act as electron transfer carriers. ESI-MS. UV, CD, and Raman spectroscopic characterizations reveal that four or five 18-crown-6 molecules strongly bind to the surface of the cytochrome c and also that nonnatural low-spin hexacoordinate heme structures are induced in methanol. Significantly, crown ether complexation can convert catalytically inactive biological forms to catalytically active artificial forms. Horse heart, pigeon breast, and yeast cytochromes c all stereoselectively oxidize (S)-isomers of methyl tolyl sulfoxide and related sulfoxides upon crown ether complexation. These supramolecular catalysts show the highest efficiency and enantiomer selectivity at -40 degrees C in the H202-dependent sulfoxide oxidation, while oxidative decomposition of the heme moieties predominantly occurs at room temperature. The oxidation reactivity of the employed sulfoxides is apparently related to steric constraints and electrochemical oxidation potentials of their S=O bonds. Among the cytochrome c complexes, yeast cytochrome c demonstrates the lowest catalytic activity and degradation reactivity. It has a significantly different protein sequence, suggesting that crown ether complexation effectively activates heme coordination but may additionally alter the native backbone structure. The proper combination of cytochrome c proteins, 18-crown-6 receptors, and external circumstances can be used to successfully generate "protein-based supramolecular catalysts" exhibiting nonbiological reactivities.

Animals↗
PubMed2004

Bone density in myasthenia gravis patients receiving long-term prednisolone therapy.

Osteoporosis is an adverse effect of prednisolone therapy, although no study has been conducted on myasthenia gravis patients receiving high-dose prednisolone. We measured bone density in 36 patients (26 females and 10 males) who had undergone long-term prednisolone administration, and found a decrease in bone density in 31% of female patients and osteoporosis in only 11.5% (three cases). This frequency is lower than the presumptive rate of the general population in Japan (22.6%). No osteoporosis was detected in male patients. In conclusion, prednisolone-treated patients with myasthenia gravis have an acceptable risk of bone loss if prophylactic medication is administered.

Absorptiometry, Photon↗
PubMed2003

Luminescent lanthanide complexes with stereocontrolled tris(2-pyridylmethyl)amine ligands: chirality effects on lanthanide complexation and luminescence properties.

A series of tris(2-pyridylmethyl)amines including one and two asymmetric centers were synthesized in a stereo-controlled fashion as potential ligands of lanthanide cations. The reaction of chiral pyridylethyl methanesulfonates and bis(pyridylmethyl)amines occurred via an S(N)2 mechanism with complete inversion of asymmetric centers and gave the stereocontrolled tris(2-pyridylmethyl)amines, the stereochemical purity of which was ascertained by GPC, NMR, X-ray, and polarimetry experiments. They formed stable Tb(3+) and Eu(3+) complexes having 1:1, 1:2, and 1:3 stoichiometry (metal:ligand) in CH(3)CN solutions. NMR and UV titration experiments revealed that their complexation behaviors were rarely influenced by ligand chirality but significantly affected by the nature of the counteranion and the concentration ratio of metal to ligand. The Tb(3+) and Eu(3+) complexes with these tripodal ligands exhibited characteristic luminescence spectra upon excitation for pyridine chromophores (260 nm), the intensities of which were largely dependent on the ligand chirality. The meso isomer of the disubstituted tripods particularly exhibited the enhanced terbium luminescence ca. three times more than its diastereomer and un- and monosubstituted tripods. Direct excitation at the lanthanide center had similar chirality effects on the luminescence profiles, indicating that the stereochemistry of the employed ligand largely influenced the lanthanide emitting processes. Since the ligand chirality finely modified the local coordination environments around the lanthanide center, the use of stereocontrolled ligands is applicable in design of the luminescent lanthanide complexes.

Journal Article↗
PubMed2003

Chemical activation of cytochrome c proteins via crown ether complexation: cold-active synzymes for enantiomer-selective sulfoxide oxidation in methanol.

Supramolecular complexation with 18-crown-6 significantly converted catalytically inactive cytochrome c (biological form) to catalytically active synzyme (artificial form). Although a family of cytochrome c proteins does not work as enzymes in nature, crown ether complexation modified their heme coordination structures and functionally activated them to promote the asymmetric oxidation of racemic sulfoxides at low temperature. Horse heart, pigeon breast, and yeast cytochrome c proteins were demonstrated to form supramolecular complexes with 18-crown-6 in methanol, which effectively oxidized (S)-isomers of naphthyl methyl sulfoxide, methyl tolyl sulfoxide, isopropyl phenyl sulfoxide, benzyl methyl sulfoxide, and 4-methylsulfenyl acetophenone at -40 degrees C. Because horse heart and pigeon breast cytochromes c exhibited more efficient and higher enantiomer-selective activities than yeast cytochrome c, a proper combination of cytochrome c and crown ether offers a new class of cold-active synzymes promoting nonbiological asymmetric oxidation.

Crown Ethers↗
PubMed2003

Lysine-containing proteins in maize endosperm: a major contribution from cytoskeleton-associated carbohydrate-metabolizing enzymes.

We measured fresh weight, dry weight, total protein, and the amounts of several individual proteins during endosperm development in three varieties of maize ( Zea mays L.): W64A wild-type (WT) and opaque-2 (o2), and sweet corn (SW). By 28 days after pollination (DAP), fresh weight was much higher in WT and SW than in o2, but o2 had a higher dry weight and thus a much lower water content. By 28 DAP, protein concentration [mg (g tissue(-1))] was highest in o2 and lowest in WT, while the protein content (microg seed(-1)) was lowest in o2. The storage proteins, alpha- and gamma-zeins, were low initially, but by 28 DAP they comprised over 50% of the total protein in WT and SW, but only about 30% in o2. In all varieties, the cytoskeleton proteins, actin, tubulin and eEF1alpha, sedimented with the protein bodies at 30 g to 27,000 g in tissue homogenized in cytoskeleton-stabilizing buffer. Other cytoskeleton-associated proteins increased during development, including UDP-glucose starch glucosyltransferase (UDP-GSGT, EC 2.4.1.11), sucrose synthase 1 (SuSy-1, EC 2.4.1.13) and fructose-1,6 bisphosphate aldolase (FBA, EC 4.1.2.13). At 28 DAP, these cytoskeleton-associated proteins combined make up 27% (WT), 23% (SW) and 33% (o2) of the total protein. These proteins are all rather high (5-11%) in lysine, and so they contribute about 75% (WT), 67% (o2), and 51% (SW) of the total endosperm lysine. We conclude that efforts to elevate the levels of these proteins could make a significant contribution to the nutritional value of corn.

Actins↗
PubMed2003

Relapse of ocular symptoms after remission of myasthenia gravis--a comparison of relapsed and complete remission cases.

Extended thymectomy and high-dose alternate-day prednisolone administration may increase the chance of remission in myasthenia gravis (MG) patients. In cases of remission, ocular symptoms sometimes reappear after a gradual decrease or discontinuation of prednisolone administration. We compared relapsed patients with those who experienced complete remission. We found that the period from onset of MG to thymectomy and initiation of prednisolone administration was longer in the relapsed cases, which suggests that early thymectomy and administration of prednisolone can lead to a superior outcome in MG patients.

Adolescent↗