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T Ueda

Publications and source records attributed to T Ueda.

At least 1,063 records · Page 59Linked to original sources
PubMed1990

Dynamic organization of ATP and birefringent fibrils during free locomotion and galvanotaxis in the plasmodium of Physarum polycephalum.

Directed migration by a cell is a good phenomenon for studying intracellular coordination. Dynamic organization of both ATP and birefringent fibrils throughout the cell was studied in the multinuclear ameboid cell of the Physarum plasmodium during free locomotion and galvanotaxis. In a directionally migrating plasmodium, waves of ATP as well as thickness oscillations propagated from just inside the advancing front to the rear, and ATP concentration was high at the front on the average. In a DC electric field, locomotion was inhibited more strongly, ATP concentration decreased more, and birefringent fibrils were formed more abundantly at the anodal than at the cathodal side. Inside the cell there were a few undulations in the distributions of ATP and birefringent fibrils. In short, birefringent fibrils become abundant where ATP concentration decreases. The possible mechanism of the coordination in the directed migration and the implications of the scaling law are discussed.

Adenosine Triphosphate↗
PubMed1990

Effect of chemical modifications of tryptophan residues on the folding of reduced hen egg-white lysozyme.

The effects of chemical modifications of Trp62 and Trp108 on the folding of hen egg-white lysozyme from the reduced form were investigated by means of the sulfhydryl-disulfide interchange reaction at pH 8 and 40 degrees C. The folding of reduced lysozyme was monitored by following the recovery of the original activity. Under the conditions employed, the apparent first-order rate constant for the folding of reduced lysozyme was not changed by the modifications of both Trp62 and Trp108 and the folding was completed within 30 min. However, the extent of the correct folding was changed by the modification of Trp62 but not by that of Trp108. Native and oxindolealanine108 lysozymes recovered 80 and 81% of their original activities after 30-min refolding, respectively, but Trp62-modified lysozymes recovered their activities to a lesser extent than native and oxindolealanine108 lysozymes. The recovered activities of Trp62-modified lysozymes after 30-min refolding were 63% for oxindolealanine62 lysozyme, 65% for delta 1-carboxamidomethylthiotryptophan62 lysozyme, and 52% for delta 1-carboxymethylthiotryptophan62 lysozyme. These results suggest that Trp62 is important for preventing the misfolding of reduced lysozyme, but that neither Trp62 nor Trp108 is involved in the rate-determining step (the slowest step) in the folding pathway. A decrease in the hydrophobic nature of Trp62 seems to increase the misfolding and thus to decrease the extent of the correct folding of reduced lysozyme. A mechanism for the involvement of Trp62 in the folding pathway of reduced lysozyme is proposed.

Amino Acid Sequence↗
PubMed1990

Oligoclonal immunoglobulin gene rearrangements in Philadelphia chromosome-positive common acute lymphoblastic leukemia.

The occurrence of more than two rearranged bands of immunoglobulin heavy chain (IgH) genes in B precursor acute lymphoblastic leukemia (ALL) has recently been documented. To elucidate the nature of such leukemias, we studied 30 patients with common ALL, including 6 patients with Philadelphia chromosome (Ph1)-positive ALL, by immunophenotyping and genotyping. In 10 of the 30, Southern blotting showed oligoclonal patterns of IgH gene arrangements, which were frequently detected in Ph1-positive ALL. In one patient of the 10, three rearranged bands of Ig kappa chain genes were detected. Ph1 abnormality and co-expression of myeloid associated antigens were found in 5 and 5 of the 10, respectively. Detection of multiple fragments of IgH genes would be suggestive of multipotent progenitor origin of these ALL.

Cloning, Molecular↗
PubMed1990

Synaptic vesicular glutamate uptake: modulation by a synaptosomal cytosolic factor.

We have demonstrated previously that L-glutamate is taken up into isolated synaptic vesicles in an ATP-dependent manner, supporting the neurotransmitter role of this acidic amino acid. We now report that a nerve terminal cytosolic factor inhibits the ATP-dependent vesicular uptake of glutamate in a dose-dependent manner. This factor appears to be a protein with a molecular weight greater than 100,000, as estimated by size exclusion chromatography, and is precipitated by ammonium sulfate (40% saturation). The inhibitory factor is inactivated by heating to 100 degrees C. Proteolytic digestion of the ammonium sulfate fraction by trypsin or chymotrypsin did not reduce, but rather increased slightly, the inhibition of glutamate uptake. Unlike the native factor, the digest retained inhibitory activity after heating, suggesting that proteolytic digestion may generate active fragments. The inhibition of ATP-dependent vesicular glutamate uptake is not species-specific, as the factor obtained from both rat and bovine brains produced an equal degree of inhibition of glutamate uptake into vesicles of each species. These observations raise the possibility that vesicular uptake of glutamate may be regulated by an endogenous factor in vivo.

Animals↗
PubMed1990

Synapsin I injected presynaptically into goldfish mauthner axons reduces quantal synaptic transmission.

1. Synapsin I was injected into a vertebrate presynaptic axon to analyze its action on quantal synaptic transmission. Two microelectrodes were used for simultaneous intracellular recording from pairs of identified neurons in the goldfish brain. The postsynaptic electrode was placed in a cranial relay neuron (CRN) within 100 microns of its synapse with the Mauthner neuron. The presynaptic electrode impaled the Mauthner axon (M-axon) 50-200 microns from the first electrode. 2. Spontaneous miniature excitatory postsynaptic potentials (mEPSPs) and evoked postsynaptic potentials (EPSPs) were recorded at steady states before and after synapsin I was microinjected into the presynaptic M-axon. Responses were digitized and subsequently analyzed by computer for quantal parameters. 3. In 12 experiments, injection of synapsin I resulted in a reduction in transmission. The decrease in EPSP amplitude began approximately 30 s after the injection, reached a plateau within 10 min, and appeared to be reversible and dose dependent. 4. Injection of synapsin I decreased quantal content (m), with no effect on postsynaptic receptor sensitivity or on amount of transmitter per quantum. Further analysis based on the simplest binomial model for quantal release revealed that synapsin I consistently reduced the number of quantal units available for release (n) although the probability of release (p) was either unchanged or slightly increased. Injected synapsin I may thus bind to presynaptic vesicles and prevent transmitter quanta from entering a pool subject to evoked release.

Animals↗
PubMed1990

Leuprorelin acetate depot: results of a multicentre Japanese trial. TAP-144-SR Study Group.

The clinical efficacy and safety of 3.75 or 7.5 mg leuprorelin acetate depot given subcutaneously once every 4 weeks was evaluated in a collaborative study of 81 patients with untreated prostatic cancer. Efficacy of treatment was assessed using criteria based on a meeting of the Prostatic Cancer Study Group funded by the Japanese Ministry of Health and Welfare and using National Prostatic Cancer Project criteria. Japanese criteria enabled evaluation of individual parameters, unlike the National Prostatic Cancer Project system which classified a patient as unevaluable if one evaluation parameter was unavailable. Leuprorelin acetate depot suppressed serum luteinizing hormone, follicle stimulating hormone and testosterone concentrations. Objective response rates of the prostate, bone metastases, serum prostatic acid phosphatase and soft tissue metastases, and subjective dysuria and pain responses were comparable to those found with conventional hormone therapy. Leuprorelin acetate depot was well tolerated, with no significant differences in response to the two doses.

Adult↗
PubMed1990

Ultraviolet action spectrum for intracellular free Ca2+ increase in human epidermal keratinocytes.

Effects of UV on normal human epidermal keratinocytes were studied by measuring the intracellular free Ca2+ concentration ([Ca2+]i) using fluorescence ratio imaging (fura-2-AM). Upon UV irradiation the [Ca2+]i increased sharply after a certain lag time, and the UV sensitivity was higher at lower temperatures. Statistically the distribution of [Ca2+]i became broader as the mean values became larger, and the number of affected cells increased sharply above a certain fluence (light intensity x time [photons/cm2]) at all wavelengths studied (200-400 nm). The action spectrum showed a single peak at about 230 nm and decreased gradually toward longer-wavelength UV regions.

Calcium↗
PubMed1990

Effects of environmental temperature on the population of T-cell subsets, the blastogenic responses of lymphocytes in blood and spleen and splenic NK cell activity in mice.

The population of T-cell subsets, the blastogenic responses of lymphocytes in blood and spleen and splenic NK cell activity were examined in mice transferred from 22 degrees C to 12 degrees C or 32 degrees C environments. The percentage of Thy-1.2 positive cells and Lyt-1.2 positive cells in the spleen decreased after the transfer. However the percentage of Lyt-2.2 positive cells in the spleen was not affected. Thy-1.2 and Lyt-1.2 positive cells in the blood also decreased. The percentage of Lyt-2.2 positive cells in the blood was not affected in mice exposed to 12 degrees C. However, Lyt-2.2 positive cells in the blood decreased on day 1 but increased on day 3 in mice exposed to 32 degrees C. Blastogenic responses of spleen lymphocytes to concanavalin A (Con A) and pokeweed mitogen (PWM) were suppressed in transferred mice, but responses to lipopolysaccharide (LPS) and phytohemagglutinin-P (PHA-P) were not affected in any group. Blastogenic responses of blood lymphocytes to Con A, PHA-P, and PWM tended to be weaker in transferred mice than in mice kept in the 22 degrees C environment. In particular the response to PWM in mice exposed to 12 degrees C was less than 8% of that in the 22 degrees C mice. Splenic NK cell activity decreased in transferred mice, but was not suppressed as much as in mice administered 5mg of cortisone acetate.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

The genetic code of a squid mitochondrial gene.

Cytochrome oxidase subunit I gene of a squid (Mollusca), Doryteuthis mitochondrial genome was sequenced. Comparison with the nucleotide sequence and the deduced amino acid sequence of other animal mitochondria suggests that the squid mitochondria has a variation in the genetic code; UGA codes for tryptophan, AUA for methionine and AGA/G for serine. This situation is similar to the case of Drosophila or Ascaris mitochondria.

Amino Acid Sequence↗
PubMed1990

[Moyamoya disease in fraternal twins].

The authors have reported here fraternal twins of moyamoya disease. The one has the onset at the age of two years and six months. Then he had suffered from multiple cerebral infarction and resulting in severe neurological deficits. Now he has right hemiparesis, left homonymous hemianopsia, aphasia and mental retardation. The encephalomyo synangiosis was done to the boy bilaterally at the age of five years. The other one has the onset at the age of five years and five months. He had good physical and neurological development. The Superficial temporal artery-Middle cerebral artery anastomosis and Encephalomyo synangiosis were done bilaterally. Now his development has no problems. The twins and their younger sister all have the same HLA type. The hereditary and environmental factors may be completely related to the pathogenesis of this disease.

Adult↗
PubMed1990

[Clinical and histological observation of HBV glomerulonephritis treated with interferon-beta].

Hepatitis B virus carriers, a 30-year-old man (case 1) and a 31-year-old man (case 2), associated with nephrotic syndrome were treated with interferon-beta. The nephrotic syndrome did not respond to corticosteroid therapy. Their HBs-Ag, HBe-Ag and HBc-Ab were positive. Renal biopsies revealed membranous glomerulonephritis in case 1 and mixed membranous and proliferative glomerulonephritis in case 2. Direct immunofluorescence studies showed strong granular staining of the GBM with IgG and using sandwich technique with anti-HBe antiserum, granular deposits were seen throughout the GBM. Patients were administrated mainly 3-6 x 10(6) IU/day interferon-beta intravenously for four weeks. After transitory elevation of serum transaminase, HBe-Ag and DNA-polymerase have disappeared with development of HBe-Ab (seroconversion) about six months after the end of interferon-beta administration. Then nephrotic syndrome has recovered in incomplete remission after a year and a half follow-up. The secondary renal biopsy in case 1 showed less intense deposits of HBe-Ag along GBM. These facts suggest that the improvement of proteinuria is associated with the decrease in HBV replication due to interferon therapy.

Adult↗
PubMed1990

[Clinical study of UFT chemotherapy in renal cancer. Kyushu University Cooperative Study Group of Renal Cancer].

Clinical effects of UFT chemotherapy for renal cancer were evaluated by 19 collaborating hospitals. UFT (300-600 mg/day) was administered for more than 3 months. Of the 30 patients entered in this study, 21 were evaluable for the antitumor effects of the drug. Of the 21 evaluable patients, complete response (CR) was obtained in 2 patients, partial response (PR) in 1, no change (NC) in 7, progressive disease (PD) in 11, respectively. The response rate was 0% in patients with primary lesion and 21.4% in nephrectomized patients with metastatic lesion. Responses were observed in the metastases of lung, pleura and mediastinal lymph node. The main side effects in 27 patients were gastrointestinal symptoms. No significant abnormality was noted on blood laboratory data. In one patient the drug was discontinued within 3 months because of gastrointestinal symptoms. These results suggested that UFT chemotherapy for advanced renal cancer was clinically effective.

Adult↗
PubMed1990

Molecular cloning and characterization of a novel type of regulatory protein (GDI) for the rho proteins, ras p21-like small GTP-binding proteins.

We have recently purified to near homogeneity a novel type of regulatory protein for the rho proteins, ras p21-like small GTP-binding proteins, from bovine brain cytosol. This regulatory protein, named GDP dissociation inhibitor for the rho proteins (rho GDI), regulates the GDP/GTP exchange reaction of the rho proteins by inhibiting the dissociation of GDP from them, and the subsequent binding of GTP to them. In the present studies, we have isolated the cDNA of rho GDI from a bovine brain cDNA library using oligonucleotide probes designed from the partial amino acid sequences of the purified rho GDI and determined its complete nucleotide and deduced amino acid sequences. The cDNA contains an open reading frame encoding a protein of 204 amino acids with a calculated Mr value of 23,421. This Mr value is similar to those of the purified rho GDI estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and sucrose density gradient ultra-centrifugation, both of which are about 27,000. The rho GDI cDNA is expressed in Escherichia coli and COS7 cells and the encoded protein exhibits rho GDI activity. The 1.9-kilobase rho GDI mRNA corresponding to the isolated cDNA is detected in various rat tissues by Northern blot analysis. Hydropathy analysis indicates that rho GDI is overall hydrophilic except for one hydrophobic region. Computer homology search has revealed that rho GDI is a novel protein that does not share a high amino acid sequence homology with any known protein.

Amino Acid Sequence↗
PubMed1990

[Double chambered right ventricle: surgical experience in a 60-year-old woman].

The patients reported as double chambered right ventricle are mainly children. A 60-year-old woman had been pointed out for her systolic cardiac murmur without any symptom. She was admitted to our hospital for her gradual onset of fatigue, lassitude. Cardiac catheterization data revealed a 105 mmHg peak-to-peak gradient within the right ventricular cavity with normal pulmonary pressures [20/5 (12) mmHg]. Right ventricular end-diastolic pressure was 4 mmHg. Right ventriculogram demonstrated double chambered right ventricle. Electrocardiogram showed neither right ventricular hypertrophy nor upright T wave in V3R. In order to release intraventricular pressure gradient and her symptom, the anomalous muscle bundles were resected through both the right atrium and the pulmonary artery. Surgical repair without right ventriculotomy is suitable for such an elder patient with double chambered right ventricle whose ventricular function may decrease.

Age Factors↗