Search PubMed⌕ Search

Biomedical subjects

S Ueno

Publications and source records attributed to S Ueno.

At least 289 records · Page 16Linked to original sources
PubMed1992

[Unsuspected painless subacute thyroiditis detected by radiogallium scintigraphy].

Two cases of painless subacute thyroiditis were presented in whom fever, fatigue and arthralgia except for thyroidal pain and swelling were complained. Until a intense uptake of the thyroid was found on radiogallium scintigraphy, the examinations of the thyroid had not been done. Laboratory data showed increased erythrocyte sedimentation rate, C-reactive protein and serum alkaline phosphatase, and mild leukocytosis. Skeletal, hepatic and biliary diseases were denied. In patients who have fever, increased erythrocyte sedimentation rate and serum alkaline phosphatase elevation without apparent sources, thyroid function should be evaluated because subacute thyroiditis can be associated with elevation of the serum alkaline phosphatase.

Gallium Radioisotopes↗
PubMed1991

New mutant gene (transthyretin Arg 58) in cases with hereditary polyneuropathy detected by non-isotope method of single-strand conformation polymorphism analysis.

Single-strand conformation polymorphism (SSCP) was analyzed to detect a mutation in the transthyretin (TTR) gene from the mother and son showing polyneuropathy with carpal tunnel syndrome. DNA segments containing TTR coding sequence were amplified by polymerase chain reaction, heat denatured and electrophoresed on a neutral polyacrylamide gel. The single-stranded DNA fragments in the gel were transferred to a nylon membrane and hybridized with biotinylated TTR cDNA probe, followed with chemiluminescent DNA detection. The mobility shift was found in the fragments of exon 3 from the patients' DNA. Sequencing analyses of the exon 3 confirmed a T----G base change, resulting in a Leu 58----Arg substitution. TTR Arg 58 is the first mutant TTR gene that has been detected by SSCP analysis. The rapid and sensitive detection of new mutations at various sites on the TTR gene is hereafter possible by the present method in the facilities for non-radioactive experiments.

Adult↗
PubMed1991

[CT appearance of small renal angiomyolipoma].

Twenty-six small renal angiomyolipomas (AML) in 21-patients, detected incidentally by ultrasonography, were evaluated with CT. Conventional CT findings of AML were classified into three types by the degree of the fatty areas in the mass. Type 1 is a mainly fat density mass like a lipoma observed in 7 lesions (26.9%). Type 2 is a fatty mass intermixed with areas of tissue density and found in 15 lesions (57.7%). Type 3 is a mass without fatty portion and observed in 4 lesions (15.4%). These latter lesions were indistinguishable from renal cell carcinoma on CT. It is important to diagnose a small lesion of the kidney as AML correctly for proper treatment.

Adult↗
PubMed1991

Secretion of sphingolipid hydrolase activator precursor, prosaposin.

Sphingolipid hydrolases are activated by activator proteins or saposins. The precursor protein has been expected from the studies on the cDNA for saposins. Here we demonstrate that prosaposin occurs in various kinds of human secretory fluids such as cerebrospinal fluid, semen, milk, pancreatic juice, and bile. However, mature type saposins were not detected in these fluids. In human milk the amount of prosaposin changed during the lactating period; it became high in concentration within a few days after delivery, decreased during the transitional milk lactating stage, and then increased again toward the mature milk lactating stage. Prosaposin was released from human platelets in response to stimulation by thrombin, but mature saposins were not. From the time course of the release of prosaposin induced by thrombin and from the fact that weak platelet agonists, ADP, epinephrine, and collagen, did not cause the release of prosaposin, prosaposin secretion from platelets seemed to be from lysosome like granules. We postulate that some prosaposin works as a precursor for saposins in the lysosomes and the other serves as an extracellular protein with other specific roles.

Adenosine Diphosphate↗
PubMed1991

Neoplastic epithelial cells express alpha-subunit of muscle nicotinic acetylcholine receptor in thymomas from patients with myasthenia gravis.

We studied the expression of mRNAs coding for the alpha-subunit of the muscle nicotinic acetylcholine receptor (AChR) in thymomas from patients with myasthenia gravis (MG). Northern blot analysis failed to detect the expression, but amplification of mRNAs derived from thymomas by reverse transcription and polymerase chain reaction produced the DNA fragments containing the nucleotide sequence coding for part of the alpha-subunit. We further revealed that the alpha-subunit mRNA was derived from neoplastic epithelial cells of thymoma. Our results support the hypothesis that AChR expressed in thymoma is a candidate for the primary antigen which induces autoimmune responses to muscle AChR. The close relationship between MG and thymoma may be at least in part explained by this hypothesis.

Amino Acid Sequence↗
PubMed1991

Isolation and identification of alpha-(beta-alanyl)hypusine from bovine brain.

A unique dipeptide was isolated from bovine brain using five steps of ion-exchange chromatography. Its acid hydrolysate contained equimolar amounts of beta-alanine and hypusine. The structure of the peptide was elucidated as alpha-(beta-alanyl)hypusine using dansylation technique. About 1 mumol of the compound was isolated from 1090 g of bovine brain.

Animals↗
PubMed1991

Immunohistochemical demonstration of keratin in ameloblastoma as an indication of tumor differentiation.

Keratin expression was studied immunohistochemically in 27 ameloblastomas using polyclonal antibody against wide-spectrum keratins (TTL) and monoclonal antibodies against lower- and higher-molecular-weight keratins (PKK1 and KL1), respectively, to clarify the tumor differentiation. Reactions with TTL and KL1 antibodies were generally positive in the stellate cells of the follicular or acanthomatous ameloblastomas. Cell nests of the basal cell type were positive for PKK1. On the other hand, the reactions with TTL or KL1 in the plexiform type were generally weak or absent. From these facts, it was concluded that the follicular, as well as acanthomatous, ameloblastoma is liable to undergo squamous differentiation, whereas the plexiform ameloblastoma remains in primitive stage of tumor differentiation.

Ameloblastoma↗
PubMed1991

Cytochemical studies of transitional area between retina and optic nerve.

We have investigated the fine structural features of the transitional area between retina and optic nerve with special emphasis on the identification of Müller cells using the cytochemical method for detecting the localization of G6Pase activity, which is specific to the endoplasmic reticulum (ER) of Müller cells in the guinea pig retina. This cytochemical method enabled us to differentiate Müller cells from astrocytes or other cells easily and also allowed topographical, three dimensional analysis by high voltage electron microscopy because of the high contrast of the reaction products. Our study demonstrates that Müller cells are a major constitutional element of intermediary tissue of Kuhnt, which is considered to be the possible site of barrier between optic nerve and retina. These findings may indicate that Müller cells contribute to the barrier function in this region of the eye.

Animals↗
PubMed1991

Kinetic properties of T-type Ca2+ currents in isolated rat hippocampal CA1 pyramidal neurons.

1. T-type Ca2+ channels producing a transient inward current were studied in pyramidal neurons acutely isolated from the ventral portion of rat hippocampal CA1 region. Membrane currents were recorded by the suction-pipette technique, which allows for internal perfusion under a single-electrode voltage clamp. 2. In all cells superfused with external solution containing 10 mM Ca2+, the T-type Ca2+ current was evoked by step depolarization to potentials more positive than -60 mV from a holding potential of -100 mV and reached a peak in the current-voltage relationship around -30 mV at 20-22 degrees C. 3. Activation and inactivation processes of T-type Ca2+ current were highly potential dependent, and the latter was fitted by a single exponential function. 4. Steady-state inactivation of T-type Ca2+ current could be fitted by a Boltzmann's equation with a slope factor of 6.0 and a half-inactivated voltage of -79 mV. 5. Recovery from inactivation of T-type Ca2+ current was not a single exponent. The major component of recovery (60-90% of total) was voltage sensitive with a time constant of 215 ms at -100 mV. 6. Amplitude of the T-type Ca2+ current depended on the external Ca2+ concentration. The ratio of peak amplitude in the individual current-voltage relationships of Ca2+, Ba2+, and Sr2+ currents passing through T-type Ca2+ channel was 1.0:0.85:1.32. The current kinetics were much the same. 7. All kinetic properties, including activation and inactivation, as well as the amplitude of T-type Ca2+ current, were temperature sensitive with Q10 (temperature coefficient) values of 1.7-2.5.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Combined cytochemical detection of Müller-cell-specific enzyme activity and permeability tracers.

A combination of cytochemical methods in one tissue section was studied in order to detect the contribution of Müller cells to the blood-ocular barrier. Applications are shown for the detection of Müller cells and peroxidatic enzymes. The following advantages of the present method were demonstrated: superior sensitivity of glucose-6-phosphatase (G6Pase) activity, which allows the detection of these cells even in the coagulated retina. The reaction products showed no deleterious change after a subsequent reaction. These factors, and the contrasting reaction products of G6Pase and the enzymatic tracers (especially those of horseradish peroxidase) allow the distinction of Müller cells and the functional barrier site.

Animals↗
PubMed1991

Purification and characterization of the vascular permeability factor produced by Bacillus cereus.

Purification of an extracellular protein exhibiting the vascular permeability activity produced by Bacillus cereus was performed by ammonium sulfate precipitation followed by chromatography on DE-32 cellulose, Sephadex G-100, and Sephadex G-75. The purified protein was found to be electrophoretically and antigenically almost homogeneous although it contained a trace of contaminant. The molecular weight of the protein was calculated to be 45,000 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The purified protein showed vascular permeability activity and mouse lethal toxicity, and caused fluid accumulation in ligated mouse intestinal loops, whereas it did not show any hemolytic and lecithinase activities. From these findings, the purified protein is suggested to be an enterotoxin (or a diarrheagenic toxin) responsible for diarrhea caused by B. cereus in a diarrheal-type food poisoning.

Animals↗
PubMed1991

[DNA tests for mutant genes coding for transthyretins Gly42, Arg50 and Cys114 in Japanese cases of familial amyloid polyneuropathy].

Four different genes encoding variant transthyretins (TTR) have been known in Japanese cases with familial amyloidotic polyneuropathy (FAP); TTR Met30, Gly42, Arg50 and Cys114. First three mutant genes can be detected by restriction fragment length polymorphism using NsiI, Cfr13I and MvaI, respectively. Since a single base change responsible for TTR Cys114 produces no new restriction site, RFLP is not directly applicable for the detection of this gene. In this study, TTR Cys114 gene was amplified by polymerase chain reaction using mismatch primer to produce a new restriction site for HgiAI. The enzyme digestion of the product resulted in the appearance of extra fragments in the presence of the normal fragment. The accurate detections of all the four mutant genes are hereafter possible by these procedures.

Amyloidosis↗
PubMed1991

Role of histamine in motion sickness in Suncus murinus.

The levels of histamine (HA) and tele-methylhistamine (t-MH) were determined in five brain regions of Suncus murinus (suncus) and the effects of motion stimulus or drugs influencing the turnover of these amines were studied to elucidate the role of histamine in motion sickness. Shaking the animals for 2 min increased HA contents in telencephalon and diencephalon without significantly changing the t-MH levels. alpha-Fluoromethylhistidine (alpha-FMH), which is presumed to deplete the neuronal HA, tended to raise the HA levels. alpha-FMH slightly alleviated the vomiting response to motion stimulus and suppressed the HA increase in diencephalon caused by shaking. Compound 48/80, which releases HA from mast cells, did not alter the control HA levels, but effectively prevented the motion sickness and completely suppressed the motion-induced rises in HA levels. These results provide further evidence that brain HA plays an important role in the development of motion sickness.

Animals↗
PubMed1991

[Intracranial accumulation of 99mTc-phosphorous compound on bone scintigraphy].

Bone scintigrams of 99mTc-phosphorous compound in 4,579 cases were reviewed concerning the intracranial accumulation. Intracranial accumulations were demonstrated in 8 cases (0.17%). The lesions with intracranial accumulation were two cases of primary brain tumor (1 meningioma and 1 astrocytoma), five cases of metastatic brain tumor (1 rectal cancer, 1 gastric cancer, 1 uterine cervical cancer and 2 lung cancers) and one case of cerebral infarction. Calcification was detected in one of eight cases on CT scans. It is important to pay attention to the intracranial accumulation on routine bone scintigram because brain tumor or infarction may be detected.

Aged↗
PubMed1990

Further studies on D-3-aminoisobutyrate-pyruvate aminotransferase.

D-3-Aminoisobutyrate-pyruvate aminotransferase (EC 2.6.1.40, D-BAIB aminotransferase) participates in the metabolism of thymine. Recently we purified this enzyme from rat liver. We have studied D-BAIB aminotransferase further to clarify its physiological function. Among our findings were the following. (1) The enzyme activity was widely distributed in the organs of guinea pigs and rats. The kidney, liver, and lung showed high specific activities. (2) Using the livers of six vertebrates, differences between species were studied. Activity was detected in all species, the human liver showing the lowest activity among them. (3) Developmental study using rat liver showed that the activity was low at birth, increased sharply thereafter for 10 days, and then subsequently declined to the adult level. (4) Intraperitoneal injection of BAIB and beta-alanine in rats was performed to determine whether they induce activity of this aminotransferase. Only BAIB increased the activity of the aminotransferase in the liver significantly. (5) Subcellular distribution study of this aminotransferase in rat liver revealed that it is a mitochondrial enzyme.

Aging↗
PubMed1990

[Pathogenesis and prevention of gastrointestinal complications following transcatheter arterial embolization].

Prospective evaluation of gastrointestinal complications after transcatheter arterial embolization (TAE) was performed on 149 TAEs of 133 patients with endoscopy in order to evaluate whether the use of antiulcer medication can prevent such complications. In 21 of 141 TAEs (14%) there developed gastrointestinal complications. The incidence of complications with administration of H2-blocker was 30.4%, whereas the incidence with administration of PGE1 and without medication were 2.8% (p less than 0.01) and 9.0%, respectively. It has been suggested that such complications are mainly due to backflow of the embolic materials to the gastric artery. These findings indicates that decrease of gastric mucosal blood flow due to backflow of the embolic materials to the gastric artery cause the gastrointestinal complications.

Anti-Ulcer Agents↗
PubMed1990

Two novel variants of transthyretin identified in Japanese cases with familial amyloidotic polyneuropathy: transthyretin (Glu42 to Gly) and transthyretin (Ser50 to Arg).

Two mutant genes coding for two different variants of transthyretin were identified in two independent kindreds with familial amyloidotic polyneuropathy. A single base change from A to G was identified in exon 2 of transthyretin gene in two brothers from the first kindred. This base change led to replacement of glutamate by glycine at position 42 of 127-residue molecule. In a patient from the second kindred, T to G transversion in exon 3 of transthyretin gene led to replacement of Ser by Arg at position 50. The two mutants were discovered by randomly sequencing recombinant clones containing the entire length of each one of the four exons selectively amplified by polymerase chain reaction. The base change produced a new restriction site for Hae III and Cfr 13 I in the exon 2 and for Mva I in the exon 3, respectively. Restriction fragment length polymorphisms and allele-specific oligonucleotide hybridizations confirmed the base changes. The accurate detection of the new mutant genes is hereafter possible by these procedures.

Alleles↗