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T Nukada

Publications and source records attributed to T Nukada.

At least 55 records · Page 3Linked to original sources
PubMed1990

A validation study on the reproducibility of transcranial Doppler velocimetry.

The transcranial Doppler method for the measurement of intracranial arterial blood flow velocity is a useful noninvasive technique with a number of applications. The present study validated the reproducibility of this method for repeated measurements of flow velocity in the middle cerebral and basilar arteries. Fifteen healthy volunteers were studied. Measurements were made twice by one examiner and once by another in a single day and again by the first examiner on another day. The reproducibility was evaluated by calculating the correlation coefficient (r) and the coefficient of variation (CV) of the difference between the values obtained from each pair of measurements. Although depending on the examiner, the time interval between the examinations and the vessels studied some differences were noted in the reproducibility, both the r (0.69-0.95) and CV (6.7%-19.5%) values in the whole study were good enough to warrant the applicability of this method for the repeated measurements of the intracranial arterial blood flow velocity in future studies.

Cerebral Arteries↗
PubMed1989

[Assessment of reproducibility of transcranial Doppler velocimetry].

In recent years, transcranial Doppler velocimetry has been widely used as a noninvasive method for measurement of blood flow velocity in basal cerebral arteries. As for the reproducibility of this method, however, there have been only few reports so far. In the present study, we attempted to evaluate the reproducibility of this method by changing the examiners and the timing of the examination. Fifteen healthy volunteers were investigated by using a pulsed wave Doppler ultrasound device with a 2 MHz transducer. Both peak and mean spatial frequencies calculated from the frequency spectrum of the Doppler signals from the middle cerebral artery (MCA) and the basilar artery (BA) were used as blood flow parameters for assessing the reproducibility. The arterial blood pressure and the end-tidal carbon dioxide partial pressure (PECO2) were also monitored during the ultrasonic examinations. The intra- and inter-observer reproducibilities were evaluated by obtaining the coefficient of variation (CV) of the differences and/or analyzing the correlation between the values from the two measurements by the same examiner and by two separate examiners, respectively. The intraobserver reproducibility in separate days was also evaluated. Both in the mean arterial blood pressure and in PECO2, no significant changes were observed between the two measurements in each subjects. In the present examination, the CV and r values ranged from 6.7 to 19.5% and from 0.69 to 0.95, respectively, showing good reproducibility of the transcranial Doppler method for measurement of blood flow velocity, though some differences were observed as follows. The intraobserver reproducibility was better than the interobserver reproducibility.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Total synthesis of X hapten, III3 Fuc alpha-nLc4 Cer.

Total synthesis of O-beta-D-galactopyranosyl-(1----4)-O-[alpha-L- fucopyranosyl- (1----3)]-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-(1----3)-O-beta- D- galactopyranosyl- (1----4)-O-beta-D-glucopyranosyl-(1----1)-2-N-tetracosanoyl-(2S,3R ,4E)- sphingenine was achieved by use of the key glycosyl donors O-(2,3,4,6-tetra-O-acetyl-beta-D- galactopyranosyl)-(1----4)-O-[(2,3,4-tri-O-acetyl-alpha-L-fucopyranosyl) - (1----3)]-O-(2- acetamido-6-O-acetyl-2-deoxy-beta-D-glucopyranosyl)-(1----3)-O-(2,4,6-tr i-O- acetyl- beta-D-galactopyranosyl)-(1----4)-2,3,6-tri-O-acetyl-alpha-D-glucopyrano syl trichloroacetimidate and fluoride, as well as key glycosyl acceptor 3-O-benzoyl-2-N-tetracosanoyl- (2S,3R,4E)-sphingenine, in an unambiguous manner.

Carbohydrate Conformation↗
PubMed1987

Functional expression of cloned cDNA encoding the alpha-subunit of adenylate cyclase-stimulating G-protein.

Cloned cDNA encoding the alpha-subunit of the adenylate cyclase-stimulating G-protein (Gs), carried by a simian virus 40 vector, has been introduced into the cyc- variant of S49 lymphoma cells by electroporation. In contrast to untransfected cys- cells, clones transformed with the cDNA exhibit an increase in intracellular cyclic AMP concentration in response to a beta-adrenergic agonist.

Adenylyl Cyclases↗
PubMed1986

Synthesis of a heptasaccharide hapten related to a biantennary glycan chain of human chorionic gonadotropin of a choriocarcinoma patient. A convergent approach.

Synthesis of the heptasaccharide hapten 8-methoxycarbonyloctyl O-beta-D-galactopyranosyl-(1----4)-O-(2-acetamido-2-deoxy-beta-D- glucopyranosyl)-(1----2)-O-[beta-D-galactopyranosyl-(1----4)-O-(2-acetam ido-2- deoxy-beta-D-glucopyranosyl)-(1----4)]-O-alpha-D-mannopyranosyl-(1----3) -O- [alpha-D-mannopyranosyl-(1----6)]-beta-D-mannopyranoside is described, by use of the known, protected glycosyl acceptor 8-ethoxy-carbonyloctyl O-(2,3,4,6-tetra-O-benzyl-alpha-D-mannopyranosyl)-(1----6)-2,4-di-O-benz yl-beta - D-mannopyranoside, and the key glycopentaosyl donors O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-(1----4)-O-(2-acetami do-3,6- di-O-acetyl-2-deoxy-beta-D-glucopyranosyl)-(1----2)-O-[(2,3,4,6-tetra-O- acetyl-beta-D-galactopyranosyl)-(1----4)-O-(2-acetamido-3,6-di-O-acetyl- 2- deoxy-beta-D-glucopyranosyl)-(1----4)]-3,6-di-O-benzyl-alpha-D-mannopyra nosyl trichloroacetimidate (5) and the corresponding fluoride 7, which, in turn, were prepared in 5 steps from allyl 3,6-di-O-benzyl-alpha-D-mannopyranoside in 35 and 22% overall yields, respectively. In model experiments, the key glycosyl donors 5 and 7 were also treated with the simple glycosyl acceptor 8-ethoxycarbonyloctanol, to give 8-methoxycarbonyloctyl O-beta-D-galactopyranosyl-(1----4)-O-(2-acetamido-2-deoxy-beta-D- glucopyranosyl)-(1----2)-O-[beta-D-galactopyranosyl-(1----4)-O-(2-acetam ido-2- deoxy-beta-D-glucopyranosyl)-(1----4)]-alpha (and beta)-D-mannopyranoside.

Choriocarcinoma↗
PubMed1986

Synthesis of a heptasaccharide hapten related to an anomalous biantennary glycan-chain of human chorionic gonadotropin of a patient with choriocarcinoma. A stepwise approach.

A stereocontrolled synthesis of a heptasaccharide hapten, 8-methoxycarbonyloctyl 3-O-[2,4-di-O-(2-acetamido-2-deoxy-4-O-beta-D-galactopyranosyl-beta-D- glucopyranosyl)-alpha-D-mannopyranosyl]-6-O-alpha-D-mannopyranosyl-beta- D-mannopyranoside (2), is described employing the lactosaminyl donor 3,6-di-O-acetyl-2-deoxy-2-phthalimido-4-O-(2,3,4, 6-tetra-O-acetyl-beta-D-galactopyranosyl)-beta-D-glucopyranosyl bromide and the mannotriosyl glycosyl acceptor 8-ethoxycarbonyloctyl 2,4-di-O-benzyl-3-O-(3,6-di-O-benzyl-alpha-D-mannopyranosyl)-6-O-(2,3, 4,6-tetra-O-benzyl-alpha-D-mannopyranosyl)-beta-D-mannopyranoside, the reaction of which gave the biantennary structure 8-ethoxycarbonyloctyl 2,4-di-O-benzyl-3-O-(3,6- di-O-benzyl-2,4-di-O-[3,6-di-O-acetyl-2-deoxy-2-phthalimido-4-O-(2,3, 4,6-tetra-O-benzyl-alpha-D-mannopyranosyl)-beta-D-mannopyranoside (9), as well as a monoglycosylated product, 8-ethoxycarbonyloctyl 2,4-di-O-benzyl-3-O-(3,6-di-O-benzyl-4-O-[3,6- di-O-acetyl-2-deoxy-2-phthalimido-4-O-(2,3,4,6- tetra-O-benzyl-alpha-D-mannopyranosyl)-beta-D-mannopyranoside. The diglycosylated product 9 was transformed into 2, and the structure was confirmed by 1H-n.m.r. data.

Amino Acid Sequence↗
PubMed1986

Primary structure of the alpha-subunit of bovine adenylate cyclase-inhibiting G-protein deduced from the cDNA sequence.

The primary structure of the alpha-subunit of the adenylate cyclase-inhibiting G-protein (Gi) has been deduced from the nucleotide sequence of cloned DNA complementary to the bovine cerebral mRNA encoding the polypeptide. A much higher degree of amino acid sequence homology is observed between the alpha-subunits of Gi and transducin (68%) than between those of Gi and the adenylate cyclase-stimulating G-protein (Gs) (43%) or between those of transducin and Gs (42%).

Adenylyl Cyclase Inhibitors↗
PubMed1986

Primary structure of the alpha-subunit of bovine adenylate cyclase-stimulating G-protein deduced from the cDNA sequence.

The primary structure of the alpha-subunit of the adenylate cyclase-stimulating G-protein (Gs) has been deduced from the nucleotide sequence of cloned DNA complementary to the bovine cerebral mRNA encoding the polypeptide. Comparison of the amino acid sequences of the alpha-subunits of Gs and transducin reveals that some of the highly conserved regions show sequence homology with elongation factor-Tu and ras p21 proteins and correspond to functional regions of guanine nucleotide-binding proteins.

Adenylyl Cyclases↗
PubMed1985

Primary structure of the beta-subunit of bovine transducin deduced from the cDNA sequence.

DNA complementary to the bovine retinal mRNA coding for the beta-subunit of transducin has been cloned by screening a cDNA library with oligodeoxyribonucleotide probes. Nucleotide sequence analysis of the cloned cDNA has revealed that this polypeptide consists of 340 amino acid residues (including the initiating methionine). Furthermore, cDNA hybridizable with a transducin beta-subunit cDNA probe has been cloned from a library derived from bovine brain poly(A)+ RNA. Comparison of the cloned cDNAs, in conjunction with blot hybridization analysis and S1 nuclease mapping of poly(A)+ RNA from bovine retina, brain and liver, suggests that the mRNAs coding for the beta-subunits of transducin and other guanine nucleotide binding proteins have the same protein-coding sequence but partly different 5'-noncoding sequences.

Amino Acid Sequence↗
PubMed1983

Myoclonus in a case of suspected progressive rubella panencephalitis.

Predominantly unilateral myoclonus induced by movement of the affected parts in a 21-year-old Japanese man with suspected progressive rubella panencephalitis appeared in the course of treatment for epilepsy with anticonvulsant drugs after five years. Antirubella antibody levels in the serum and CSF were elevated and IgM antibody against rubella was found in the serum. An EEG recorded while the patient was awake showed diffuse 3- to 4-Hz theta activity with high voltage. The neurological symptoms are progressing slowly.

Adult↗
PubMed1983

Muscarinic receptors in porcine caudate nucleus. I. Enhancement by nickel and other cations of [3H]cis-methyldioxolane binding to guanyl nucleotide-sensitive sites.

Muscarinic acetylcholine receptors in the synaptic membrane fraction of porcine caudate nucleus were characterized by using a radiolabeled agonist, [3H]cis-methyldioxolane [( 3H]CD) and an antagonist, [3H]quinuclidinyl benzilate [( 3H]QNB). Scatchard analysis of the specific binding of [3H]CD gave a single equilibrium dissociation constant of 8.1 nM when a concentration of less than 80 nM [3H]CD was used. The binding capacity was 390 fmoles/mg of protein and corresponded to about 10% of the binding sites of [3H]QNB. Agonist/[3H]CD competition binding experiments indicated that [3H]CD was selectively bound to the sites with a high affinity for agonists. [3H]CD binding was inhibited by Na+, K+, Mg2+, and Ca2+ with the half-maximal effect at 10-50 mM. Nickel ion showed biphasic effects on [3H]CD binding: a 2- to 3-fold enhancement of binding at 0.1-10 mM and inhibition above 10 mM. Other cations, including Co2+, Mn2+, and Zn2+, at 1 mM also increased [3H]CD binding by a factor of 1.5-1.8. Among 18 cations examined, only Cd2+, Hg2+, and Cu2+ caused significant inhibition of [3H]CD binding at 1 mM. [3H]CD binding was decreased to about 20% of the control value in the presence of guanylyl-5'-imidodiphosphate (GppNHp), GTP, and GDP with the half-maximal effect at 1.3, 32, and 45 microM, respectively. [3H]CD binding in the presence of Ni2+ was decreased by GppNHp to a level obtained in the presence of GppNHp alone. The increase caused by Ni2+ in [3H]CD binding was due to the increase in the maximal binding capacity (Bmax) without changes in the affinity for [3H]CD. We conclude that Ni2+ increases the proportion of a muscarinic receptor subclass (or state) that is sensitive to guanyl nucleotide.

Animals↗
PubMed1983

Muscarinic receptors in porcine caudate nucleus. II. Different effects of N-ethylmaleimide on [3H]cis-methyldioxolane binding to heat-labile (guanyl nucleotide-sensitive) sites and heat-stable (guanyl nucleotide-insensitive) sites.

Heat treatment of membranes from porcine caudate nucleus (50 degrees for 7 min) caused a marked decrease in [3H]cis-methyldioxolane [( 3H]CD) binding without affecting seriously the binding of [3H]3-quinuclidinyl benzilate [( 3H]QNB). Approximately 20% of the [3H]CD binding at 5 nM [3H]CD remained after the heat treatment. The remaining binding was not affected by 0.1 mM guanylyl-5'-imidodiphosphate (GppNHp) or by nickel or other cations at concentrations below 10 mM. Treatment of the membranes with trypsin (30 micrograms/mg of protein) at 20 degrees for 20 min also caused a marked decrease in [3H]CD binding without affecting seriously the binding of [3H]QNB. About 20% of the original [3H]CD binding remained in the presence of trypsin at a high concentration of protein (90 micrograms/mg). N-Ethylmaleimide (NEM) affected [3H]CD binding in two different ways: (a) preincubation of the membranes with NEM caused a marked reduction in heat- and GppNHp-sensitive [3H]CD binding, and (b) treatment with NEM caused an enhancement of heat-, GppNHp-, and trypsin-insensitive [3H]CD binding. Neither of the NEM effects required the coexistence of agonists. The concentration of NEM required for the first effect was 10 times lower than that for the second effect, indicating the existence of two NEM-binding sites with different affinities for NEM. The equilibrium dissociation constant (Kd) for [3H]CD after NEM treatment was 33 nM and was not affected by GppNHp, Ni2+, or heat treatment; the Kd was only 4 times higher than that (8 nM) without NEM treatment. These findings indicated the existence of two kinds of [3H]CD binding sites with high affinities for agonists: one is sensitive to guanyl nucleotide and is abolished by NEM and the other is induced by NEM and insensitive to guanyl nucleotide.

Animals↗