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T Kurihara

Publications and source records attributed to T Kurihara.

At least 91 records · Page 5Linked to original sources
PubMed2000

[A case report of Bickerstaff's brainstem encephalitis with positive anti GQ 1 b, GT 1 a, GM 1 ganglioside antibodies].

Patient was an 18-year-old female student. After she had symptoms of common cold for 3 days, she developed somnolence, diplopia, dysarthria, urinary disturbance and ataxia. On admission neurological examination revealed coma with mydriasis, ophthalmoplegia, ptosis and weakness of the upper limbs. Light reflex, corneal reflex and oculocephalic test were all negative. Deep tendon reflexes were brisk and extensor toe signs were positive bilaterally. She did not have nuchal rigidity. Laboratory test revealed normal cerebrospinal fluid with negative myelin basic protein. Brain MRI, brainstem evoked potentials presented no abnormality. EMG revealed normal conduction velocity and no conduction block. EEG had diffuse theta and delta slowing. Culture of the stool represented no Campylobacter jejuni. At the fifth day of admission consciousness level improved, and other neurological findings disappeared in about 6 weeks. She had anti GQ 1 b, GT 1 a(IgG, IgM) and anti GM 1(IgM) antibodies in the serum. We made a diagnosis of Bickerstaff's brainstem encephalitis from these neurological symptoms and clinical course. The main lesion was present in the brainstem from midbrain to medulla oblongata in the midline. High titer of anti GT 1a antibody may be related to the ophthalmoplegia as noted in Miller Fisher syndrome. As a result of EMG and stool culture, it denied the complication of Guillain-Barré syndrome. We had no proof of the reason of the presentation of anti GM 1 antibody.

Adolescent↗
PubMed2000

[Proposal of postgraduate training program in neurology].

In order to improve the postgraduate training in neurology in Japan, practical program is proposed. It consists of 5 years. The first 2 years include internal medicine for 16 months, pediatrics for 2 months, neurosurgery for 2 months, emergency medicine for 2 months, and anesthesiology for 2 months. The next 3 years include neurology training in the ward and out-patient clinic in the University Hospital for one year followed by another year of neurology ward training at the affiliated hospital where they are exposed to see more acute neurological cases. In addition to these clinical training, they will study basic neurological sciences in neuroanatomy, and neurophysiology in the evening in the form of small group seminars and they are assigned to read EEG every week and attend EEG reading sessions. EMG, muscle biopsy, and sural nerve biopsy will be done under supervision when they are in charge of such cases who require those examinations. The last year program includes neurological consultation from the other departments, out-patient clinic, setting up neurological conferences, and elective course for 3 months. It is recommended that Japanese Neurological Society informs us several institutes where they can offer pediatric neurology training, and neuropathology training in several districts in Japan, since they have difficulty in getting training in these two specialties in many Japanese hospitals.

Education, Medical, Graduate↗
PubMed1999

Novel related cDNAs (C184L, C184M, and C184S) from developing mouse brain encoding two apparently unrelated proteins.

Three related cDNAs (C184L, C184M, and C184S) were isolated from a developing mouse brain cDNA library. C184S is the 5'-end portion and C184M is the 3'-end portion, respectively, of C184L. C184S and C184M have open reading frames of 199 amino acids (ORF1) and 189 amino acids (ORF2), respectively; C184L has both ORF1 and ORF2 (dicistronic structure), but seems to translate only ORF1. Southern blot analysis suggests that all of the three related mRNAs are transcribed from the same single gene. The intervening region of C184L cDNA between ORF1 and ORF2 contained a promoter sequence for C184M mRNA, which is transcribed from the corresponding genomic sequence. Very recently, a cDNA encoding human homologue of ORF1 (human autoantigen p27) and a cDNA encoding a different mouse isoform of ORF2 (mammary tumor virus receptor) were reported. Our results indicate that the mRNAs encoding these apparently unrelated proteins are transcribed within an adjacent or overlapping area on the genome, suggesting the same origin of the two transcription units.

Aging↗
PubMed1999

DL-2-Haloacid dehalogenase from Pseudomonas sp. 113 is a new class of dehalogenase catalyzing hydrolytic dehalogenation not involving enzyme-substrate ester intermediate.

DL-2-Haloacid dehalogenase from Pseudomonas sp. 113 (DL-DEX 113) catalyzes the hydrolytic dehalogenation of D- and L-2-haloalkanoic acids, producing the corresponding L- and D-2-hydroxyalkanoic acids, respectively. Every halidohydrolase studied so far (L-2-haloacid dehalogenase, haloalkane dehalogenase, and 4-chlorobenzoyl-CoA dehalogenase) has an active site carboxylate group that attacks the substrate carbon atom bound to the halogen atom, leading to the formation of an ester intermediate. This is subsequently hydrolyzed, resulting in the incorporation of an oxygen atom of the solvent water molecule into the carboxylate group of the enzyme. In the present study, we analyzed the reaction mechanism of DL-DEX 113. When a single turnover reaction of DL-DEX 113 was carried out with a large excess of the enzyme in H(2)(18)O with a 10 times smaller amount of the substrate, either D- or L-2-chloropropionate, the major product was found to be (18)O-labeled lactate by ionspray mass spectrometry. After a multiple turnover reaction in H(2)(18)O, the enzyme was digested with trypsin or lysyl endopeptidase, and the molecular masses of the peptide fragments were measured with an ionspray mass spectrometer. No peptide fragments contained (18)O. These results indicate that the H(2)(18)O of the solvent directly attacks the alpha-carbon of 2-haloalkanoic acid to displace the halogen atom. This is the first example of an enzymatic hydrolytic dehalogenation that proceeds without producing an ester intermediate.

Esters↗
PubMed1999

A nifS-like gene, csdB, encodes an Escherichia coli counterpart of mammalian selenocysteine lyase. Gene cloning, purification, characterization and preliminary x-ray crystallographic studies.

Selenocysteine lyase is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that catalyzes the exclusive decomposition of L-selenocysteine to L-alanine and elemental selenium. An open reading frame, named csdB, from Escherichia coli encodes a putative protein that is similar to selenocysteine lyase of pig liver and cysteine desulfurase (NifS) of Azotobacter vinelandii. In this study, the csdB gene was cloned and expressed in E. coli cells. The gene product was a homodimer with the subunit Mr of 44,439, contained 1 mol of PLP as a cofactor per mol of subunit, and catalyzed the release of Se, SO2, and S from L-selenocysteine, L-cysteine sulfinic acid, and L-cysteine, respectively, to yield L-alanine; the reactivity of the substrates decreased in this order. Although the enzyme was not specific for L-selenocysteine, the high specific activity for L-selenocysteine (5.5 units/mg compared with 0.019 units/mg for L-cysteine) supports the view that the enzyme can be regarded as an E. coli counterpart of mammalian selenocysteine lyase. We crystallized CsdB, the csdB gene product, by the hanging drop vapor diffusion method. The crystals were of suitable quality for x-ray crystallography and belonged to the tetragonal space group P43212 with unit cell dimensions of a = b = 128.1 A and c = 137.0 A. Consideration of the Matthews parameter Vm (3.19 A3/Da) accounts for the presence of a single dimer in the crystallographic asymmetric unit. A native diffraction dataset up to 2.8 A resolution was collected. This is the first crystallographic analysis of a protein of NifS/selenocysteine lyase family.

Animals↗
PubMed1999

Role of lysine 39 of alanine racemase from Bacillus stearothermophilus that binds pyridoxal 5'-phosphate. Chemical rescue studies of Lys39 --> Ala mutant.

The lysine residue binding with the cofactor pyridoxal 5'-phosphate (PLP) plays an important role in catalysis, such as in the transaldimination and abstraction of alpha-hydrogen from a substrate amino acid in PLP-dependent enzymes. We studied the role of Lys39 of alanine racemase (EC 5.1.1.1) from Bacillus stearothermophilus, the PLP-binding residue of the enzyme, by replacing it site-specifically with alanine and characterizing the resultant K39A mutant enzyme. The mutant enzyme turned out to be inherently inactive, but gained an activity as high as about 0.1% of that of the wild-type enzyme upon addition of 0.2 M methylamine. The amine-assisted activity of the mutant enzyme depended on the pKa values and molecular volumes of the alkylamines used. A strong kinetic isotope effect was observed when alpha-deuterated D-alanine was used as a substrate in the methylamine-assisted reaction, but little effect was observed using its antipode. In marked contrast, only L-enantiomer of alanine showed a solvent isotope effect in deuterium oxide in the methylamine-assisted reaction. These results suggest that methylamine serves as a base not only to abstract the alpha-hydrogen from D-alanine but also to transfer a proton from water to the alpha-position of the deprotonated (achiral) intermediate to form D-alanine. Therefore, the exogenous amine can be regarded as a functional group fully representing Lys39 of the wild-type enzyme. Lys39 of the wild-type enzyme probably acts as the base catalyst specific to the D-enantiomer of alanine. Another residue specific to the L-enantiomer in the wild-type enzyme is kept intact in the K39A mutant.

Alanine↗
PubMed1999

Humanization of a mouse neutralizing monoclonal antibody against tumor necrosis factor-alpha (TNF-alpha).

An anti-human tumor necrosis factor-alpha (TNF-alpha) monoclonal antibody, designated as 3B10, inhibits the biological activity of human TNF-alpha. In the present study, we constructed humanized version of the antibody by grafting its complementarity-determining regions (CDRs) onto a human antibody, HBS-1. Using a molecular model of mouse 3B10, framework residues affecting the CDR conformation were identified. Thus, these residues were also introduced into the framework together with the CDRs in a stepwise manner, depending on the degree of the possible importance of the residues. As a result, one humanized version (h3B10-9) which possesses nine mouse framework residues showed the same binding activity as that of the chimeric version. This humanized anti-TNF-alpha antibody is expected to be less immunogenic and thus more suitable for possible clinical use.

Amino Acid Sequence↗
PubMed1999

Primary anorectal malignant melanoma: report of a case.

Primary anorectal malignant melanoma is a fairly uncommon but highly malignant disease. This disease is sometimes mistaken for such benign conditions as either a hemorrhoid or rectal polyp. We herein describe a case of early primary malignant melanoma of the anal canal. In this case, magnetic resonance (MR) imaging was found to be useful for diagnosing the melanotic melanoma. We especially emphasize the usefulness of a fat-saturation MR image in distinguishing melanotic melanoma from other rectal tumors.

Aged↗
PubMed1999

Basaloid carcinoma of the thymus.

A 58-year-old man was found to have a basaloid carcinoma of the thymus, initially detected as an abnormal shadow on chest radiograph. The patient underwent resection followed by radiotherapy, and has survived 25 months without recurrence. Although this rare tumor may be related to multilocular thymic cyst, its pathogenesis is obscure. We discuss clinicopathologic features of our case and others.

Carcinoma, Transitional Cell↗
PubMed1999

Active immunization of combined beta1-adrenoceptor and M2-muscarinic receptor peptides induces cardiac hypertrophy in rabbits.

BACKGROUND: The high prevalence of patients with dilated cardiomyopathy (DCM) with anti-beta1-adrenoceptor and/or anti-M2-muscarinic receptor autoantibodies in their sera has been observed. However, the pathophysiological role of these autoantibodies in the development of cardiomyopathy is unknown. We previously reported an experimental model of early-stage DCM-like cardiomyopathy induced by immunizing rabbits for 1 year with synthetic peptides corresponding to the sequence of the second extracellular loop of either beta1-adrenoceptor or M2-muscarinic receptor. Because approximately half the sera of patients with DCM that recognize one of the two receptor sequences also recognize the second sequence, a model was created in rabbits simultaneously immunized with the synthetic peptides corresponding to the second extracellular loop of the beta1-adrenoceptor and M2-muscarinic receptor. METHODS AND RESULTS: All rabbits (n = 8) immunized with both peptides had a high titer of both anti-beta1-adrenoceptor and anti-M2-muscarinic receptor autoantibodies in their sera, whereas none of the sera from control rabbits injected with saline (n = 9) was positive. No significant cross-reaction with peptides other than those used for immunization was found. The weight of the hearts of immunized rabbits increased significantly. The hearts of immunized rabbits showed marked concentric left ventricular hypertrophy with mild inflammatory cell infiltration. In these rabbits, mild or moderate interstitial fibrosis was also observed. In electron micrographs, immunized rabbits showed focal myofibrillar lysis, loss of myofilament, and a marked increase in the number of mitochondria and deposition of dense granules in both sarcoplasm and myofibrils. Conversely, one of the control rabbits showed scant mononuclear cell infiltration. However, in this control rabbit, no significant alteration was found by electron microscopy. CONCLUSION: Our results showed the coexistence of both anti-beta1-adrenoceptor and anti-M2-muscarinic receptor autoantibodies in the sera has pathophysiological importance, shown by their ability to induce cardiac hypertrophy in rabbits.

Amino Acid Sequence↗
PubMed1999

Gene structure and amino acid sequence of Latimeria chalumnae (coelacanth) myelin DM20: phylogenetic relation of the fish.

The structure of Latimeria chalumnae (coelacanth) proteolipid protein/DM20 gene excluding exon 1 was determined, and the amino acid sequence of Latimeria DM20 corresponding to exons 2-7 was deduced. The nucleotide sequence of exon 3 suggests that only DM20 isoform is expressed in Latimeria. The structure of proteolipid protein/DM20 gene is well preserved among human, dog, mouse, and Latimeria. Southern blot analysis indicates that Latimeria DM20 gene is a single-copy gene. When the amino acid sequences of DM20 were compared among various species, Latimeria was more similar to tetrapods than other fishes including lungfish, confirming the previous finding by immunoreactivity (Waehneldt and Malotka 1989 J. Neurochem. 52:1941-1943). However, when phylogenetic trees were constructed from the DM20 sequences, lungfish was clearly the closest to tetrapods. Latimeria was situated outside of lungfish by the maximum likelihood method. The apparent similarity of Latimeria DM20 to tetrapod proteolipid protein/DM20 is explained by the slow amino acid substitution rate of Latimeria DM20.

Amino Acid Sequence↗
PubMed1999

Multiple sclerosis with extensive lesions left hemiplegia, mental dysfunction and retrobulbar neuritis.

Multiple sclerosis (MS) is usually diagnosed on the basis of the typical clinical course, with remission and exacerbation in multiple parts of the central nervous system (CNS). Recently, magnetic resonance imaging (MRI) has made a large contribution to the diagnosis of patients with MS. But it is difficult to make a definite diagnosis due to clinical variability of the disease and variable MRI findings. We report the case of a 26-year-old woman who developed progressive left hemiplegia, mental dysfunction, and had extensive bilateral cerebral white matter lesions diagnosed by brain MRI. Complete recovery from the left hemiplegia followed the use of corticosteroid, and her brain MRI findings also improved after medication. Early in the clinical course it was difficult to differentiate between multiple sclerosis and granulomatous angiitis of the CNS. After recovery from the first episode of left hemiplegia and mental dysfunction, she developed acute visual disturbance five months after her first admission. Readmission followed and her retrobulbar neuritis was successfully treated by methylpredonisolone pulse therapy. In summary, she experienced two episodes of neurological deficit, had left hemiplegia and mental dysfunction associated with multiple lesions in bilateral cerebral white matter in brain MRI, and the left retrobulbar neuritis with delay of P100 by visual evoked potential study. Due to these two episodes we concluded that she had multiple sclerosis. Though the initial diagnosis was difficult, prompt treatment and close follow-up was important, since multiple sclerosis and granulomatous angiitis of the CNS can both recur.

Adult↗
PubMed1999

Cytochemical energy-filtering transmission electron microscopy of mitochondrial free radical formation in paraquat cytotoxicity.

The generation of oxygen free radicals was investigated using cytochemistry and its energy-filtering transmission electron microscopy in reference to the toxic mediator for the herbicide paraquat. When isolated intact mitochondria from rat livers were incubated in a medium containing paraquat and NADH, a mitochondrial NADH-quinone oxidoreductase activity generated superoxide anions to cause the destruction of mitochondria which resulted in cell death. The superoxide anions were immediately converted into hydrogen peroxide, which then formed cerium perhydroxide deposits in the presence of cerium ions and precipitated on the outer surface of the mitochondrial outer membrane. This localization was also specifically identified by energy spectral imaging and image-electron energy loss spectral analyses. Precipitation reaction was scavenged by the addition of either cytochrome c or catalase and inhibited by dicoumarol (an inhibitor of NAD(P)H-quinone oxidoreductases). These cytochemical energy-filtering transmission electron microscopic results indicated that paraquat generated free radicals from the outer membrane of mitochondria.

Animals↗
PubMed1999

Management of malignant pericardial effusion resulting from recurrent cancer with local instillation of aclarubicin hydrochloride.

To determine the efficacy of aclarubicin hydrochloride in local control of malignant pericardial effusion, the authors carried out a trial of pericardial drainage with local administration of this agent in five patients, whose effusions had produced cardiac tamponade. All patients were women, and their primary cancers, all initially treated surgically, had arisen in the breast (two patients), or lung (three patients). Mean patient age was 54.2 years (range, 43-62). In four patients, improvement permitted removal of the drainage catheter. Two patients (40%) had a complete remission of the malignant pericardial effusion. The other three patients were difficult to evaluate because nonpericardial metastases limited their survival. All patients, however, showed disappearance of malignant cells from the pericardial sac with no cytopathologically demonstrable recurrence. In our few patients, intrapericardial aclarubicin appeared to be highly effective against malignant pericardial effusion.

Aclarubicin↗
PubMed1999

Cold-active serine alkaline protease from the psychrotrophic bacterium Shewanella strain ac10: gene cloning and enzyme purification and characterization.

The gene encoding serine alkaline protease (SapSh) of the psychrotrophic bacterium Shewanella strain Ac10 was cloned in Escherichia coli. The amino acid sequence deduced from the 2,442-bp nucleotide sequence revealed that the protein was 814 amino acids long and had an estimated molecular weight of 85,113. SapSh exhibited sequence similarities with members of the subtilisin family of proteases, and there was a high level of conservation in the regions around a putative catalytic triad consisting of Asp-30, His-65, and Ser-369. The amino acid sequence contained the following regions which were assigned on the basis of homology to previously described sequences: a signal peptide (26 residues), a propeptide (117 residues), and an extension up to the C terminus (about 250 residues). Another feature of SapSh is the fact that the space between His-65 and Ser-369 is approximately 150 residues longer than the corresponding spaces in other proteases belonging to the subtilisin family. SapSh was purified to homogeneity from the culture supernatant of E. coli recombinant cells by affinity chromatography with a bacitracin-Sepharose column. The recombinant SapSh (rSapSh) was found to have a molecular weight of about 44,000 and to be highly active in the alkaline region (optimum pH, around 9.0) when azocasein and synthetic peptides were used as substrates. rSapSh was characterized by its high levels of activity at low temperatures; it was five times more active than subtilisin Carlsberg at temperatures ranging from 5 to 15 degreesC. The activation energy for hydrolysis of azocasein by rSapSh was much lower than the activation energy for hydrolysis of azocasein by the subtilisin. However, rSapSh was far less stable than the subtilisin.

Amino Acid Sequence↗
PubMed1999

Chmadrin: a novel Ki-67 antigen-related perichromosomal protein possibly implicated in higher order chromatin structure.

A novel perichromosomal protein, which we have named chmadrin, was identified from rat kangaroo PtK2 cells. The deduced amino acid sequence revealed structural homologies in several limited regions to the Ki-67 antigen (pKi-67). The subcellular localization of chmadrin was found to be similar to that of pKi-67 throughout the cell cycle, that is, predominantly nucleolar during interphase and perichromosomal in the mitotic phase. In addition, a certain population of the protein was found to be localized in heterochromatic foci in interphase nuclei. Transient expression analysis of the truncated proteins corresponding to the conserved regions clearly demonstrated the structural basis for the characteristic cellular localization. Residues 494-778, which show extensive similarity to the corresponding region of pKi-67, were efficiently targeted to nucleoli, whereas a repetitive structure found at the C-terminal portion, whose similarity to pKi-67 is weak, was localized precisely to mitotic chromosomes. The C-terminal portion was designated the 'LR domain' since several LR (leucine and arginine) pairs commonly appear in chmadrin and pKi-67. When overproduced in the interphase nuclei, the LR domain induced the formation of aberrant heterochromatin as a structural constituent. These are the first empirical data suggesting the involvement of perichromosomal proteins in the organization of chromatin structure.

Amino Acid Sequence↗
PubMed1999

[Characteristics of myocardial ischemia in patients with chronic renal failure and its relation to cardiac sympathetic activity].

In order to clarify the characteristics of myocardial ischemia in patients with chronic renal failure (CRF), we performed exercise stress myocardial perfusion imaging with 99mTc-MIBI in 36 patients with CRF. In 18 patients myocardial imaging with 123I-MIBG (MIBG) and 201Tl was performed at rest to evaluate myocardial sympathetic activities: cardiac uptake of MIBG normalized by myocardial perfusion (Uptake Ratio, UR) and myocardial washout rate of MIBG (WO). Exercise-induced perfusion abnormality was observed in 25 patients, and coronary angiography was performed in 19 of them. Among 25 diseased coronary arteries, 18 developed perfusion abnormalities in the myocardial segments which were supplied by each coronary artery. However in 5 patients without coronary artery stenosis and 2 patients with left anterior descending coronary artery disease, transient perfusion abnormalities were observed in the inferior segments. In 6 of them, MIBG imaging was obtained (Group A). MIBG imaging was also performed in 5 patients with transient inferior perfusion abnormality with coronary artery stenosis which supplied the inferior wall (Group B), and 7 patients without perfusion abnormality (Group C). In the patients of Group B, inferior UR was significantly lower than in Group C (0.58 +/- 0.07 vs. 0.68 +/- 0.08, p = 0.0485) and inferior WO was more accelerated than in Group C (18.6 +/- 7.7 vs. 12.1 +/- 6.0%, NS). However anterior UR and Wo levels were identical with those in Group C. In Group A, inferior UR (0.43 +/- 0.05) was significantly lower than in Group B and C, and WO in Group A (27.2 +/- 8.3%) was accelerated significantly compared to that in Group C. Besides in Group A, anterior UR was significantly smaller and WO was greater than in Group B and C. These findings suggested that in some patients with CRF, myocardial ischemia could arise without coronary artery stenosis, and this phenomenon might be related to abnormalities of cardiac sympathetic activity.

Aged↗