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Biomedical subjects

Y Tamai

Publications and source records attributed to Y Tamai.

At least 19 recordsLinked to original sources
PubMed1992

Inhibitory effect of 5-hydroxy-4-(2-phenyl-(E)-ethenyl)-2(5H)-furanone, a novel synthesized retinoid, on azoxymethane-induced intestinal carcinogenesis in rats.

Modifying effects of 5-hydroxy-4-(2-phenyl-(E)-ethenyl)-2(5H)-furanone, a novel synthesized retinoid (KYN-54), on intestinal carcinogenesis were examined in a rat model using azoxymethane (AOM). A total of ninety male F344 rats, 6 weeks old, were divided into 4 groups. Group 1 (20 rats) was fed a diet containing KYN-54 at a concentration of 0.02% for 3 weeks, during which time 2 s.c. injections of azoxymethane (15 mg/kg) were applied and then kept on a basal diet until the end of the experiment (1 year). Group 2 (30 rats) was given azoxymethane as in group 1 and fed the basal diet throughout, without synthetic retinoid exposure. Group 3 (20 rats) was administered KYN-54 at the commencement of the experiment, but not given the carcinogen. Group 4 (20 rats) received a basal diet alone throughout the experiment and served as a control. Intestinal tumors were seen in groups 1 and 2, their incidence and average number in group 1 (74%, 1.07 +/- 0.87) being significantly less than in group 2 (39%, 0.56 +/- 0.78) (P < 0.02 and P < 0.05, respectively). These results suggest that the synthetic retinoid might be a promising chemopreventive agent for intestinal neoplasia.

4-Butyrolactone↗
PubMed1992

Sensory response of cortical neurons in the anterior ectosylvian sulcus, including the area evoking eye movement.

The deep cortical tissue in the caudal portion of the anterior ectosylvian sulcus (AES) of cats anesthetized with alpha-chloralose was explored to examine the sensory response properties of neurons in this area, which is known to contain an area evoking eye movement. Of 873 neurons isolated, 262 (30.0%) were multimodal, i.e. responsive to two or more of the stimulus modalities of visual, auditory, or somatic. The ratio of multimodal neurons to total neurons in the eye-movement-evoking area was significantly larger than this ratio in other areas; 79 (39.5%) of 200 neurons in the eye-movement-evoking area were multimodal, while 183 (27.2%) of 673 neurons in other areas were multimodal. Neuronal minimal latency in response to visual stimulation was widely and bimodally distributed, showing two peaks at 35 ms and 60 ms, whereas latencies to auditory and somatic stimulation were narrowly distributed, with one peak at 10 ms and 15 ms, respectively. There was no remarkable difference either between unimodal neurons and multimodal neurons or between the neurons in the eye-movement-evoking area and those in other areas in distribution of latency. That there was a significant difference in ratio of multimodal to total neurons between the eye movement area and other areas suggests that some convergence or integration of different kinds of sensory input in relation to eye movement might be carried out in the caudal portion of the AES.

Animals↗
PubMed1992

Postremission therapy without prednisolone improves survival in adults with acute leukemia.

This prospective randomized clinical trial was to clarify whether postremission therapy without prednisolone (PSL) was more effective than therapy with PSL in improving the 5-year survival of adults with acute leukemia. Thirty consecutive adult patients with newly achieved complete remission were randomized to receive postremission therapy either with or without PSL between September 1985 and September 1988. The patients ranged from 16 to 57 years in age. Patients treated without PSL had a significantly better 5-year survival rate than those receiving PSL according to Kaplan-Meier analysis (53.5% vs 15.3%, p < 0.05). In the group treated without PSL, eight out of 15 patients were alive at 72 months, and seven patients maintained their first complete remission at 72 months. Among patients with acute lymphoblastic leukemia (ALL) who were treated without PSL the median duration of remission was 24 months, and the survival rate at 72 months was 50.0%. On the other hand, the median survival was only 13 months for the 5 patients with ALL treated with PSL. Thus, it is desirable that adults with acute leukemia are treated by postremission therapy without PSL.

Acute Disease↗
PubMed1992

Characteristic distribution of glycolipids in gadoid fish nerve tissues and its bearing on phylogeny.

Glycolipids were isolated from nerve tissues of gadoid fishes including Alaskan pollack and Pacific cod. Their chemical structures were determined by gas-liquid chromatography and gas chromatography-mass spectrometry, and their constituents were analyzed in detail and compared with those of glycolipids from other fish groups. The results revealed that gadoid fish nerve membranes contain peculiar glycolipid molecular species that are distinctly different from those in other teleostean fishes and higher vertebrates. The mole percentage ratio of the four major glycolipids (cerebroside-sulfatide-galactosylglyceride-sulfogalactosylglyce ride) was 48:12:25:15, indicating profound accumulation of glycoglycerolipids. Galactosylglyceride and sulfogalactosylglyceride were primarily of the diacyl type (greater than 90%), the major fatty acids being 16:0 and 18:1. An abundance of glucocerebroside (25 to 55% of cerebroside) and its fatty acid ester (37 to 47% of ester cerebroside) was noted. Cerebroside and sulfatide were characterized by the absence of hydroxy and odd numbered fatty acids, and 24:1 acid was a predominant component of both glucocerebroside and galactocerebroside. Subcellular fractionation revealed that myelin membranes comprised such unusual glycolipid constituents as those seen in whole nerve tissues. A vertebrate whose nerve membranes consist of such peculiar glycolipid molecules has not previously been reported. The characteristics of the glycolipid composition in gadoid fishes are discussed in relation to myelin functions, physicochemical properties of nerve membranes, and the phylogenic significance of this fish group.

Animals↗
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↗