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Biomedical subjects

Y Tamai

Publications and source records attributed to Y Tamai.

At least 145 records · Page 8Linked to original sources
PubMed1992

[Favorable prognoses in 24 adult patients with acute leukemia, surviving over five years since 1985].

Since 1985 we have experienced 24 leukemia cases with long-term survival, who were treated with one of three types of postremission therapy. Of them, 20 patients were physically fit for ordinary work and returned to their work as workers or housewives during long-term follow-up period. Two housewives gave birth. We have devised three types of postremission therapy; 1) multidrug combination therapy with gradually longer intermissions (January 1980-March 1983); 2) controlled randomized clinical trial by the Japanese Foundation for the Multidisciplinary Treatment of Cancer, April 1983-March 1985-March 1988). In a group who underwent multidrug combination therapy without prednisolone, 12 of 20 patients who achieved complete remission have shown continued complete remission, as of November 1991, including seven 5-year survivors. These results indicate that improvement of postremission therapy makes it possible for adult patients with acute leukemia to survive 5 years or longer.

Adolescent↗
PubMed1992

[Bleeding time].

Bleeding time indicates the interaction of the platelets with the damaged vessel wall and the subsequent formation of the primary hemostatic plug. Bleeding time has been widely used in the diagnosis of bleeding disorders, especially thrombocytopenia, abnormalities in platelet function, vascular disorders, and von Willebrand's disease. There are a number of methods to perform the bleeding time test, but there are significant problems concerning sensitivity, specificity, and reproducibility. To study the inhibitory effects of monoclonal antibodies (anti-vWF, anti-GPIb, and anti-GPIIb/IIIa) on primary hemostasis, these antibodies were infused to normal pigs. Anti-vWF and anti-GPIb antibodies markedly prolonged the bleeding time and inhibited hemostatic plug formation. The anti-GPIIb/IIIa antibody completely inhibited ADP-and collagen-induced platelet aggregation, but no or only mild prolongation of bleeding time was observed. The quantitative bleeding time which measures both the time and the amount of blood loss is useful in the diagnosis of hemorrhagic disorders and in judging the efficacy of the treatment. It will provide important information to understand the mechanism of primary hemostasis.

Animals↗
PubMed1992

Inhibitory effects of (1E,3E,5E,7E)-5-hydroxy-4-(8-phenyl-1,3,5,7- octatetraenyl)-2(5H)-furanone on proliferation of human malignant tumor cells.

A butenolide compound (1E,3E,5E,7E)-5-hydroxy-4-(8-phenyl-1,3,5,7- octatetraenyl)-2(5H)-furanone (KNK-41), was shown to have strong anti-tumor activity. KNK-41 inhibited the proliferation of various kinds of human malignant tumor cells, such as HeLa (cervical carcinoma), HGC-27 (gastric cancer), PANC-1 (pancreatic cancer) and GOTO (neuroblastoma). Flow cytometric analysis indicated that KNK-41 caused an arrest in G0/G1 phase of the cell cycle. However, it scarcely affected DNA synthesis and the level of c-myc mRNA. These results suggest that the growth-inhibitory effect of KNK-41 is the result of G0/G1 arrest and not of the suppression of DNA synthesis and/or c-myc expression.

4-Butyrolactone↗
PubMed1991

Sequence of EndoA gene encoding mouse cytokeratin and its methylation state in the CpG-rich region.

A genomic clone obtained from mouse liver DNA using a mouse cytokeratin EndoA cDNA probe revealed the complete sequence of the EndoA gene. The gene is divided into nine exons and the exon-intron pattern has been conserved compared to that of other type-II cytokeratin-encoding genes. The 5' upstream, 3' downstream and first and third introns contain potential regulatory sequences, including polyoma virus enhancer motifs (PEA1 and PEA3) and AP-1 elements. The 5' regions upstream of the EndoA, EndoB and Ck8 genes contain homologous sequences surrounding the TATA boxes. In addition, a CpG dinucleotide cluster region was located around the first exon. This CpG cluster region was found to be hypomethylated in endodermal PYS-2 cells, retinoic acid-treated F9 cells, and F9 embryonal carcinoma cells, but hypermethylated in BALB/C 3T3 fibroblast cells that do not express EndoA. These findings may provide a clue to understanding the molecular mechanisms of EndoA gene expression.

Animals↗
PubMed1991

The promoter of the endo A cytokeratin gene is activated by a 3' downstream enhancer.

Mouse cytokeratin EndoA is an intermediate filament subunit of the type II cytokeratin class which initiates expression in trophectoderm cells of blastocyst during embryogenesis. To identify the regulatory elements of the endo A gene, we constructed a series of CAT expression vectors and transfected them into PYS-2 cells. We found an enhancer element locating 1 kb downstream from the endo A gene which acts on both the endo A and SV40 promoters. This enhancer consists of six direct repeated sequences with homology to the PEA3 motif in polyoma virus alpha enhancer core. In undifferentiated F9 embryonal carcinoma cells, expression of the construct containing the enhancer was not detected. These results indicate that one of the regulatory mechanisms of endo A gene expression is the 3' downstream enhancer.

Animals↗
PubMed1991

Miniature manipulator with microelectrode for chronic recording of single units from freely-moving animals.

We report a simple recording and stimulating system, a miniature manipulator with a microelectrode (MMM) that can be mounted on animal's skull. The system consists of a miniature manipulator and a microelectrode which are used in one body. Several MMMs can be implanted simultaneously into the brain as the part of the manipulator is small. With this device, recording of single units from several different cortices is possible from awake and unrestricted animals.

Animals↗
PubMed1991

Molecular cloning and sequencing of plasma membrane H(+)-ATPase gene from the salt-tolerant yeast Zygosaccharomyces rouxii.

A plasma membrane H(+)-ATPase gene from the salt-tolerant yeast Zygosaccharomyces rouxii was isolated by probing the genomic DNA library with a labeled DNA fragment derived from the Saccharomyces cerevisiae H(+)-ATPase gene (PMA1) and the nucleotide sequence of a cloned gene was determined. The gene encoded a polypeptide of molecular weight 100,060 that consisted of 920 amino acid residues. The deduced amino acid sequence was 83% homologous to that of S. cerevisiae H(+)-ATPase and was highly similar to the conserved sequences in the plasma membrane ATPase family comprising yeast plasma membrane H(+)-ATPases. The peptide motifs involved in the ATPase functions were found in the Z. rouxii H(+)-ATPase sequence. The result of Northern analysis indicated that the size of the transcript of the Z. rouxii H(+)-ATPase gene was the same as that of S. cerevisiae PMA1.

Amino Acid Sequence↗
PubMed1991

Anti-5-hydroxytryptamine3 effect of galanolactone, diterpenoid isolated from ginger.

It has been reported that an acetone extract of ginger and its fractions have anti-5-HT (5-hydroxytryptamine; serotonin) effects. In the present study, guinea pig ileum, rat stomach fundus and rabbit aortic strips are used in order to determine the constituents of fraction 2 which are responsible for anti-5-HT effect and to examine their pharmacological properties. The analysis of fraction 2-3 indicated that galanolactone, a diterpenoid, is one of the active constituents. In guinea pig ileum, galanolactone inhibited contractile responses to 5-HT with a pIC50 value 4.93. pIC50 value of galanolactone against the response to 2-methyl-5-HT, a selective 5-HT3 agonist, in the presence of methysergide at 1 x 10(-5) M was 5.10. pIC50 values of ICS 205-930, a selective 5-HT3 antagonist, were 5.30 and 7.49, respectively. The concentration-response curve of 5-HT was shown as a biphasic curve and galanolactone caused a selective shift to the right of the second phase. In the same preparations, the pIC50 value of galanolactone and ICS 205-930 against the response to carbamylcholine (CCh) was 4.45 and 4.46. The inhibitory effect of galanolactone on the 5-HT response in the stomach fundus and aortic strips was less than that in the ileum. In addition, in the thoracic aorta precontracted with 50 mM K+, the relaxing effect of galanolactone was about 1/10 of that of papaverine. These results suggest that the anti-5-HT effect of galanolactone, a diterpenoid isolated from ginger, is related to antagonism of 5-HT3 receptors.

Animals↗
PubMed1991

[Imaging analysis of antiulcer action and the active constituent of Atractylodis rhizoma].

Examination of the sizes of gastric mucosal injury has been conducted by visual means. However, the human visual-eye examination may sometimes involve personal biases and errors. In order to reduce these errors, automated analytical apparatuses have been developed. The equipment is generally expensive. In the present study, a low-cost imaging analytical method to examine the antiulcer action of drugs is reported. By using our imaging analytical method, an antiulcer effect of herbal medicine was examined on hydrochloric acid-ethanol induced gastric mucosal injury. Acetone extract of Atractylodis Rhizoma was found to have antiulcer action. In addition, the examination of fractions of the acetone extract, obtained through column chromatography, indicated that atractylon, at 17.5 mg/kg, p.o. significantly inhibits gastric mucosal injury.

Animals↗
PubMed1991

Isolation and fundamental characteristics of a phospholipase B inhibitor from autolyzed Torulaspora delbrueckii.

Phospholipase B inhibitor was found in the autolyzate of yeast cells, Torulaspora delbrueckii. The inhibitor was purified to homogeneity by ethanol precipitation, gel filtration with Sephadex G-10, ion-exchange chromatography with DEAE-Sephacel, and gel filtration with Asahipak GS-320. On thin-layer chromatography the purified inhibitor was detected with the Hanes-Isherwood reagent, which is used to detect phosphorus. The activity of the inhibitor was not affected by heat treatment at 100 degrees C for 1 h. Heating at 100 degrees C for 1 h in 1 M HCl and 1 M NaOH lowered activity to 76 and 80% of the original values, respectively, but heating at 110 degrees C for 24 h in 6 M HCl completely abolished activity. The inhibitor was highly soluble in water, but practically insoluble in alcohol, acetone, ether, and chloroform. The degree of inhibition of enzyme activity was not proportional to the concentration of inhibitor. The inhibitor inhibited both membrane-bound and water-soluble phospholipase B activity from T. delbrueckii at the same level; however, the inhibitor did not inhibit the activity of phospholipase A2 from snake venom (Naja naja).

Chemical Precipitation↗
PubMed1991

Identification and characterization of a thermolabile antigen (TLAb, glyceraldehyde-3-phosphate dehydrogenase) in Saccharomyces cerevisiae.

Five thermolabile antigens (TLAa, TLAb, TLAc, TLAd, and TLAe) have been purified from Saccharomyces cerevisiae. Recently, we reported that TLAa was identical with yeast enolase (EC 4.2.1.11). In this paper, TLAb was identified as yeast glyceraldehyde-3-phosphate dehydrogenase (GAPDH, EC 1.2.1.12) on the following bases: (1) Mr, N-terminal amino acid sequence, and isomer number of TLAb were the same as those of GAPDH; (2) anti-TLAb serum was reactive to GAPDH in the Ouchterlony test and in sodium dodecyl sulfate-polyacrylamide gel electrophoresis immunoblotting; and (3) TLAb possessed GAPDH enzyme activity which was inhibited by anti-TLAb serum. The effect of various growth conditions on the proportion of three TLAb isoproteins (TLAb-1, TLAb-2, and TLAb-3) was examined. The proportion of two TLAb isoproteins (TLAb-1 and TLAb-2) changed depending on the cell growth phase the carbon sources, and sodium chloride shock. It is concluded that environmental stress has a differential effect on the biosynthesis of TLAb isoproteins.

Amino Acid Sequence↗
PubMed1990

Projections from eye movement-evoking cerebral cortices to the striatum and claustrum in the cat.

Projection fields in the striatum and claustrum from eye movement-evoking cerebral cortices (EMECs) in the cat were investigated using the WGA-HRP tracing method under electrophysiological guidance to place WGA-HRP in the appropriate sites. The EMECs in the frontal cortex, which are located in the medial wall under the cruciate sulcus (CRUo), the medial and lateral banks of the presylvian sulcus the the knee portion of the coronal sulcus (CORo), projected to the rostral part of the striatum. The EMEC in the temporal cortex, which is located in the ventral bank of the anterior ectosylvian sulcus, projected to the middle part of the striatum. Concerning the EMECs in the frontal cortex, the medially situated CRUo projected to the dorsomedial portion of the striatum, and the laterally situated CORo projected to the ventrolateral portion of the striatum. The dorsal half of the claustrum had reciprocal connections with all of the EMECs.

Animals↗
PubMed1990

Antiulcer action of Sophora flavescens root and an active constituent. I.

The effect of a methanol extract of Sophora flavescens root was examined on gastric ulcers induced in rats by HCl/ethanol in order to substantiate its reputed protective properties. Oral doses of 1 g/kg completely suppressed ulceration. Results suggest that oral administration of 50 mg/kg of vexibinol, a flavanol found in the extract, inhibited ulceration more effectively than spizofurone at 100 mg/kg.

Animals↗
PubMed1990

Vasodilatory active principles of Sophora flavescens root.

Flavanones vexibinol and kurarinone were isolated from an ethyl acetate extract of Sphora flavescens roots and assayed using isolated rabbit and rat thoracic aorta helical strips. These compounds inhibited KCl and norepinephrine maximum contractions in a concentration-dependent manner in the rat but only KCl contractions in the rabbit. Vexibinol and kurarinone weakly inhibited histamine- and serotonin-induced contractions in the rabbit. The results suggest that these flavanones may inhibit Ca2+ influx through a voltage-dependent Ca2+ channel.

Animals↗
PubMed1990

The antiulcer action of sophora and the active constituent in Sophora. II. The antiulcer action of vexibinol.

The inhibitory effect of vexibinol, one of the flavanols found in Sophora, on gastric ulcers induced by HCl-ethanol has been reported previously. In the present study, the effect of vexibinol was examined in various experimental ulcer models in order to determine the mechanism of its antiulcer action. The results indicated that the oral administration of vexibinol at 25-50 mg/kg significantly inhibited the development of ulcers induced by HCl-ethanol, 0.6 N HCl 0.2 N NaOH, absolute ethanol and 1% NH3. In addition, an intraduodenal administration of vexibinol at 300 mg/kg significantly inhibited Shay's ulcer. Further, intraduodenal administration at 300 mg/kg significantly inhibited acid secretion caused by 2-deoxy-D-glucose. These results suggest that vexibinol has not only gastric mucosal protective action but also an inhibitory effect on the secretion of gastric acids.

Animals↗
PubMed1990

Antianoxic action and active constituents of atractylodis lanceae rhizoma.

The screening test was carried out to identify new drugs from natural products for the KCN-induced anoxia model in mice. Acetone extract of Atractylodis Lanceae Rhizoma (Atractylodes lancea DC. var. Chinensis Kitamura) had a significant effect in the KCN-induced anoxia model and therefore the extract was selected for further study in order to identify the active principles. The result showed that beta-eudesmol was the active component in Atractylodis Lanceae Rhizoma.

Animals↗
PubMed1990

Anti-ulcer effect in rats of bitter cardamon constituents.

The effects of bitter cardamon (the fruit of Alpinia oxphylla), used as a medicine and a condiment, on HCl/ethanol-induced gastric lesions in rats were examined. The acetone extract at 50 mg/kg, p.o. significantly inhibited gastric lesions by 57.0%. An analysis of the active constituents in the acetone extract was performed using column chromatography. Nootkatone at 20 mg/kg, p.o. significantly inhibited gastric lesion. These results suggest that nootkatone, the sesquiterpenoid is an important constituent in stomach medications containing bitter cardamon.

Animals↗