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Biomedical subjects

T Kudo

Publications and source records attributed to T Kudo.

At least 325 records · Page 18Linked to original sources
PubMed1995

Effect of unilateral claustral lesion on intermittent light stimulation-induced convulsive response in D,L-allylglycine treated cats.

The effect of unilateral lesions of the claustrum was examined in cats treated with D,L-allylglycine. Prior to the lesion, intermittent light stimulation (ILS) induced (a) myoclonic jerking associated with generalized spike, or polyspike and wave discharge, maximal in the subcortical structures monitored and the cortical visual area, and (b) bisymmetrical generalized-onset tonic-clonic convulsions associated with sustained spike discharge in the motor cortex bilaterally. Subsequent to a unilateral lesion of the claustrum, ILS-induced electro-clinical manifestations of myoclonic jerking remained unchanged. However, the bisymmetrical convulsive pattern transformed into a partial onset secondarily generalized convulsive pattern beginning in the intact hemisphere. It is concluded that the claustrum plays an important role for access of visual afferents to the motor mechanism responsible for ILS-induced convulsive seizure.

Allylglycine↗
PubMed1995

Reverse correlation between P-glycoprotein expression and proliferative activity in endometrial adenocarcinoma.

Immunohistochemical study was employed using a monoclonal antibody (C219) to investigate P-glycoprotein expression in 23 normal endometria and 40 endometrial adenocarcinomas. P-glycoprotein immunopositivity was observed in the mid- to late-proliferative phase and the whole secretory phase of normal endometrium. In contrast, no P-glycoprotein was detected in endometrium of early proliferative phase nor post-menopausal endometrium. We also investigated the expression of P-glycoprotein in endometrial cancers to find 16 out of the 40 endometrial adenocarcinomas (40%) expressed P-glycoprotein. P-glycoprotein immunopositivity was often observed in gland growing parts but not in solid growing parts in a given tumor specimen. Proliferative activity of the tumor, as measured by PCNA labeling, was significantly higher in the P-glycoprotein-negative group than that in P-glycoprotein-positive group (P < 0.005). Thus, there was a strong reverse relation between P-glycoprotein expression and proliferative activity in endometrial adenocarcinomas.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

The beta 1,4-galactosyltransferase gene is post-transcriptionally regulated during differentiation of mouse F9 teratocarcinoma cells.

Mouse F9 teratocarcinoma cells converted into primitive endoderm and parietal endoderm-like cells when treated with retinoic acid (RA) and RA plus dibutyryl cyclic AMP (dbtcAMP), respectively. The carbohydrate chains of glycoconjugates are known to undergo rapid changes during F9 cell differentiation. The mechanism of gene regulation of beta 1,4-galactosyltransferase (beta 1,4GalT), one of the glycosyltransferases involved in the synthesis of carbohydrate structures, was explored during the differentiation of F9 cells. Northern blot analysis revealed that the amount of beta 1,4GalT mRNA increased approximately 1.5- and 6.5-fold in response to treatment with RA alone and RA plus dbtcAMP (RA/dbtcAMP), respectively, for 8 days. beta 1,4GalT specific activity also gradually increased up to 21-fold in response to treatment with RA/dbtcAMP for 8 days. The reason for the different rates of increase in mRNA and enzyme activity remains to be determined. The transcriptional activity of the beta 1,4GalT gene was measured during the course of RA/dbtcAMP-induced F9 cell differentiation in transient transfection experiments using 5'-upstream region DNA (1.8 kb) of the mouse beta 1,4GalT gene combined with luciferase cDNA. Although activity was slightly enhanced on the first day after induction, no significant rise in transcriptional activity was observed in the late stage of induction (3-6 days), when mRNA levels were greatly increased. This was further supported by the nuclear run-off assay which indicated that the rate of de novo synthesis of the beta 1,4GalT gene transcript in the RA/dbtcAMP-induced cells was almost the same as in undifferentiated F9 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Properties of glutamate dehydrogenase and its involvement in alanine production in a hyperthermophilic archaeon, Thermococcus profundus.

Thermococcus profundus, a hyperthermophilic archaeon, did not exhibit detectable glutamine synthetase activity, although the organism possessed an extraordinarily high level of glutamate dehydrogenase (GDH), the content of which reached over 10% of total soluble proteins. This GDH was purified to homogeneity. The enzyme had a molecular weight of 263,000 and was composed of six homogeneous subunits of molecular weight 43,000. The enzyme was extremely thermostable with a half life of 1 h at 90 degrees C. Circular dichroism (CD) spectra of the enzyme revealed gradual unfolding of alpha-helices upon exposure to increasing temperature. The enzyme reaction was strongly biased toward glutamate formation. T. profundus excreted L-alanine into the medium, and the concentration reached mM. High activity of alanine aminotransferase (AAT) was present in the cells, while no alanine dehydrogenase activity was detected. The alanine formation may be initiated by ammonia uptake by GDH followed by aminotransfer from glutamate to pyruvate by AAT.

Alanine↗
PubMed1995

Natronococcus amylolyticus sp. nov., a haloalkaliphilic archaeon.

The alpha-amylase-producing haloalkaliphilic archaeon Natronococcus sp. strain Ah-36T (T = type strain) was isolated previously from a Kenyan soda lake, Lake Magadi. Most cells of strain Ah-36T occurred in irregular clusters, and the colonies were orange-red. The polar lipids of this organism were composed of C20, C20 and C20, C25 derivatives of phosphatidylglycerol and phosphatidylglycerophosphate. Phosphatidylglycero-(cyclo-) phosphate, which is characteristic of Natronococcus occultus, was not detected. The complete nucleotide sequence of the 16S rRNA gene revealed that the closest relative of strain Ah-36T is N. occultus ATCC43101T (level of similarity, 96.4%), an extremely halophilic archaeon. However, strain Ah-36T did not exhibit a significant level of DNA homology to N. occultus ATCC43101T, which represents the only previously described species in the genus Natronococcus. We describe a new species for strain Ah-36T, for which we propose the name Natronococcus amylolyticus.

Archaea↗
PubMed1995

Can absence status epilepticus be of frontal lobe origin?

Five women with an unclassifiable nonconvulsive status epilepticus (NCSE) characterized by young age at onset, prolonged confusions, focal motor seizures, and both generalized spike-and-wave discharges and focal epileptic discharges on the EEG were studied with video-EEG monitoring. Electrographically, the NCSE originated from the left frontal lobe in 4 patients, and the left hemisphere with multifocal seizure discharges in 1 patient. Focal motor seizures seemed to originate from the left hemisphere in all 5 patients, particularly from its anterior part in 3 of them. Results show that the NCSE is complex partial status epilepticus of frontal lobe origin electroclinically mimicking absence status epilepticus once it reaches a full-blown phase.

Adult↗
PubMed1995

Low humoral responses to hepatitis C virus among pediatric renal transplant recipients.

Immunosuppressed patients infected with hepatitis C virus (HCV) are known to have a low prevalence of antibodies to the virus. We examined 12 HCV-infected renal transplant recipients and 18 immunocompetent patients in terms of viral markers. The renal patients had a lower prevalence of anti-C100-3 antibodies and lower titers of anti-p22 than the immunocompetents. Low titers of the antibodies seemed to be characteristic of HCV, because titers of anti-mumps and anti-cytomegalovirus antibodies were the same or even increased. Quantitation of HCV RNA showed approximately 200-fold more copies of mean HCV RNA in the sera of the kidney patients than in the immunocompetents. This indicates that the low humoral responsiveness to HCV is not due to the lower concentration of the virus. Immunosuppressive conditions seemed to suppress anti-HCV production with greater magnitude than other viral antibodies.

Adolescent↗
PubMed1995

Multiple genes encoding 2,3-dihydroxybiphenyl 1,2-dioxygenase in the gram-positive polychlorinated biphenyl-degrading bacterium Rhodococcus erythropolis TA421, isolated from a termite ecosystem.

Rhodococcus erythropolis TA421 was isolated from a termite ecosystem and is able to degrade a wide range of polychlorinated biphenyl (PCB) congeners. Genetic and biochemical analyses of the PCB catabolic pathway of this organism revealed that there are four different bphC genes (bphC1, bphC2, bphC3, and bphC4) which encode 2,3-dihydroxybiphenyl dioxygenases. As determined by Southern hybridization, none of the bphC genes exhibits homology to any other bphC gene. bphC1, bphC2, and bphC4 encode enzymes that have narrow substrate specificities and cleave the first aromatic ring in the meta position. In contrast, bphC3 encodes a meta cleavage dioxygenase with broad substrate specificity. Asturias et al. have shown that the closely related organism Rhodococcus globerulus P6 contains three different bphC genes (bphC1, bphC2, and bpHC3) which encode meta cleavage dioxygenases. The data suggest that there is a diverse family of bphC genes which encode PCB meta cleavage dioxygenases in members of the genus Rhodococcus.

Animals↗
PubMed1995

Purification and Properties of Extracellular Amylase from the Hyperthermophilic Archaeon Thermococcus profundus DT5432.

A hyperthermophilic archaeon, Thermococcus profundus DT5432, produced extracellular thermostable amylases. One of the amylases (amylase S) was purified to homogeneity by ammonium sulfate precipitation, DEAE-Toyopearl chromatography, and gel filtration on Superdex 200HR. The molecular weight of the enzyme was estimated to be 42,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The amylase exhibited maximal activity at pH 5.5 to 6.0 and was stable in the range of pH 5.9 to 9.8. The optimum temperature for the activity was 80(deg)C. Half-life of the enzyme was 3 h at 80(deg)C and 15 min at 90(deg)C. Thermostability of the enzyme was enhanced in the presence of 5 mM Ca(sup2+) or 0.5% soluble starch at temperatures above 80(deg)C. The enzyme activity was inhibited in the presence of 5 mM iodoacetic acid or 1 mM N-bromosuccinimide, suggesting that cysteine and tryptophan residues play an important role in the catalytic action. The amylase hydrolyzed soluble starch, amylose, amylopectin, and glycogen to produce maltose and maltotriose of (alpha)-configuration as the main products. Smaller amounts of larger maltooligosaccharides were also produced with a trace amount of glucose. Pullulan; (alpha)-, (beta)-, and (gamma)-cyclodextrins; maltose; and maltotriose were not hydrolyzed.

Journal Article↗
PubMed1995

Effect of retinoids on fetal lung development in the rat.

We investigated the effect of retinoids on fetal lung development in the rat. The concentration of retinyl palmitate increased rapidly to a peak on day 17 of gestation and decreased to a minimum on day 21 of gestation; there was a slight increase after birth. Retinoid acid receptor (RAR)-alpha and -beta mRNA were detected in all samples obtained from perinatal and adult rat lung, and only a trace of RAR-gamma mRNA was detected in the fetuses on days 15, 17 and 19 of gestation and in the adults by reverse transcriptase-polymerase chain reaction. After a maternal retinol deficiency of 28 days' duration, fetal body and lung weights were significantly lower than those of controls; the concentrations of retinyl palmitate and phosphatidylcholine (PC) in the lung after a maternal retinol deficiency of 14, 21, or 28 days were significantly lower than those of controls. Expression of RAR-beta mRNA in the group with 28-day retinol deficiency was lower than in controls, that of RAR-alpha mRNA was increased and that of RAR-gamma mRNA was not influenced by retinol deficiency. The rate of choline incorporation into PC in fetal lung explants was significantly higher in the group treated with retinoic acid (RA) than in controls. RA enhanced the effect of epidermal growth factor on choline incorporation and prevented that of dexamethasone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Effects of epidermal growth factor on glucose metabolism in neonatal rats.

Epidermal growth factor (EGF) may play a key role in fetal growth. We have investigated the effects of EGF on glucose metabolism, the main source of energy during the early neonatal period. When compared to control, EGF treatment increased hepatic glycogen, plasma insulin, and the proportion of B cells in the islets of Langerhans, but decreased the concentration of plasma glucagon. Thus, the insulin-to-glucagon molar ratio in plasma was increased in the EGF-treated group. These data suggest that EGF shifts glucose metabolism from catabolism towards anabolism during the early neonatal period by controlling the pancreatic endocrine system. This effect may help the neonate in adapting to the extrauterine environment after birth.

Animals↗
PubMed1995

Characterization of a mutation responsible for an alkali-sensitive mutant, 18224, of alkaliphilic Bacillus sp. strain C-125.

An alkali-sensitive mutant, 18224, of the alkaliphilic Bacillus sp. strain C-125 was characterized. The nucleotide sequence of the PvuI-NlaIV DNA fragment that recovers the alkaliphily of 18224 has been cloned from the mutant and sequenced. Comparison of the nucleotide sequences of the corresponding regions found a G to A substitution in the mutant. The mutation resulted in an amino acid substitution from 82Gly to Glu of the putative ORF3 product, which consisted a gene cluster of at least four tandemly located open reading frames. The ORF3 product was deduced to be an 112 amino acid polypeptide with hydrophobic properties, which was expressed using an in vitro translation system.

Alkalies↗
PubMed1995

Establishment of a new extrahepatic bile duct carcinoma cell line, TFK-1.

A new human extrahepatic bile duct carcinoma cell line (TFK-1) was established from a surgically resected tumor specimen, which was histologically diagnosed as partly papillary adenocarcinoma and partly differentiated tubular adenocarcinoma. The tumor cells cultured in RPMI-1640 medium supplemented with 10% FBS grew as monolayers showing epithelial-like morphology with a population doubling time of 37 hr during exponential growth at passage 40. Chromosome number was distributed in the range of 72 to 76, with a modal number of 73. Tumor markers (CEA, CA19-9, ST-439, DUPAN-2) were negative in culture supernatant and plasma of SCID mice grafted with TFK-1 cells. Though no point mutation at 12 codon of K-ras was detected, expression of c-erb B-2 product and MUC1 antigen was positive. TFK-1 is the third cell line established from extrahepatic bile duct carcinomas in the world literature, and should provide useful information on various aspects of this type of neoplasm.

Adenocarcinoma↗
PubMed1995

RS-22A, B and C: new macrolide antibiotics from Streptomyces violaceusniger. I. Taxonomy, fermentation, isolation and biological activities.

Three novel 36-membered macrolide antibiotics, RS-22A, B and C produced by Streptomyces violaceusniger have been isolated. These antibiotics were purified from an acetone extract of the mycelia followed by butanol extraction, centrifugal partition chromatography and HPLC. RS-22A, B, C showed antimicrobial activity against fungi and Gram-positive bacteria.

Anti-Bacterial Agents↗
PubMed1995

[Quantitative analysis of myocardial tracer distribution in patients with ischemic heart disease: comparison of 201T1 and 123I-15-(p-iodophenyl)-3-methylpentadecanoic acid (BMIPP)].

Quantitative assessment of myocardial tracer uptake in stress-delayed thallium and resting BMIPP imagings were performed in 24 patients with coronary artery disease. Each distribution was displayed on the bull's eye polar map and % uptake of each distribution was calculated as a mean value in 9 myocardial segments on the polar map. Redistribution index (% delayed uptake minus % stress uptake on thallium images) and discordance index (% delayed thallium uptake minus % BMIPP uptake) were also calculated. Each parameter was compared to the visual uptake score and wall motion score on contract left ventriculography. Excellent correlations were obtained between % uptake and the uptake score in each tracer. The % thallium and BMIPP uptake also correlated with regional wall motion score. Furthermore, a significant correlation was observed between redistribution and discordance indexes in the mildly hypoperfused segments. These data indicate that the quantitative analysis of thallium and BMIPP distributions seems to be valuable to understand relationship between perfusion and regional wall motion. The discordant BMIPP uptake may represent asynergic but viable segments. However, several important factors, such as attenuation factor should be also taken into consideration for such quantitative analysis.

Aged↗