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Y Yoshida

Publications and source records attributed to Y Yoshida.

At least 559 records · Page 31Linked to original sources
PubMed1997

[A case of pulmonary arteriovenous fistula presenting as multiple brain abscesses after a sustained period without treatment].

A 64-year-old man was admitted to our hospital with multiple brain abscesses accompanied by pulmonary arteriovenous fistula (PAVF). He had been diagnosed with PAVF eight years previously, but had refused any treatment despite a developing exertional dyspnea. Rendu-Osler-Weber disease was diagnosed as well because the patient exhibited teleangiectasis of the nasopharyngeal mucosa and persistent gastro-intestinal bleeding. Despite administration of antibiotics and corticosteroids the abscesses perforated into the lateral ventricle. The natural history of this rare disease is still incompletely understood. Thus, the time at which treatment should be commenced remains unclear. However the natural course of PAVF is unsatisfactory, and it appears that treatment by surgery and/or embolization should be considered in all cases.

Arteriovenous Fistula↗
PubMed1997

[An adult case of Williams-Campbell syndrome associated with pulmonary hypertension and a severe decrease in ventilatory response].

Williams-Campbell syndrome is a unique form of bronchiectasis caused by a congenital defect in bronchial cartilage, and is rare in Japan. A 34-year-old man was admitted to our hospital with a fever, and a productive cough. Arterial blood gas analysis revealed severe type II-respiratory failure. Many thin-walled cystic shadows (5-60 mm in diameter) were present in the entire lung field. Pulmonary function tests revealed obstructive impairment. Bronchograms demonstrated cystic bronchiectasis, with ballooning on inspiration and collapse on expiration, characteristic of Williams-Campbell syndrome. Despite severe hypoxia, he did not suffer from dyspnea. We examined ventilatory response to hypercapnea (HCVR) and hypoxia (HVR), and both HCVR and HVR were abnormal. In addition, the mean pulmonary artery pressure was 26 mmHg, indicating pulmonary hypertension.

Adult↗
PubMed1997

[Relationships between resting behavior and health locus of control among elementary schoolgirls].

PURPOSE: To clarify the effects of Internal Health Locus of Control (IHLC) on the practice of resting behavior. Resting has recently gained attention because of overwork and stressful social situations. We investigated daily preventive health behaviors and Health Locus of Control (HLC) in children and their mothers over three years from 1991. This paper reports on the relationships between resting and IHLC among elementary schoolgirls. METHODS: The subjects of this study in 1991 were public elementary schoolgirls in their 3rd year (8-9 years old) and their mothers. Three years, later in 1994, we investigated the same children and their mothers, with 104 girls answering questionnaires in both studies. The resting behavior data was obtained from the question "Do you rest or take a nap when you are very tired?". We used Parcel & Meyer's Children's HLC Scales for children and Horige's Japanese version of Health Locus of Control (JHLC) Scales for mothers. Only the data concerning IHLC was extrapolated for this study. RESULTS: 1. The data for resting behavior for 1991 in the 3rd grade did not coincide with that for 1994 in the 6th grade. On the whole rest was taken more frequently in the 3rd grade than in the 6th grade. 2. Perceived health state had a significant association with resting behavior. 3. Girls who perceived rest was relating directly to their personal health, took a rest more often than those who did not perceive a personal application for rest. 4. IHLC data distribution shows a marked difference between grades. Scores were significantly higher in the 6th grade than in the 3rd grade. This rising tendency of internality seems to be a developmental change. 5. IHLC scores of 1991 3rd graders classified their 3rd grade behavior patterns. The 3rd grade (1991) "usually taking a rest" group scored significantly higher than the other groups. 1991 IHLC scores classified their 1994 6th grade behavior patterns. The 6th grade (1994) "usually taking a rest" group also scored significantly higher than the other groups. 6. The data for resting behavior of the girls did not coincide with that of their mothers. There were no correlations between the girls's IHLC scores and their mothers's IHLC scores. CONCLUSION: This study revealed some significant relationships between resting behaviors and IHLC scores among the schoolgirls. It seems that girls who had high IHLC tendency in the 3rd grade were growing up with this tendency. Perhaps in the interest of self-care, they elected to rest to keep healthy when they were tired.

Adult↗
PubMed1997

Tooth pulp neurons in the caudal medulla oblongata of the cat.

The medulla oblongata caudal to the obex was explored for neurons responsive to tooth pulp (TP) stimulation in cats. Four different subclasses of TP neurons were found. The latter included TP specific (TPS) neurons, trigeminal wide dynamic range (trigeminal WDR) neurons with TP input, trigeminal subnucleus reticularis ventralis (trigeminal SRV) neurons with TP input and convergent reticular formation (convergent RF) neurons with TP input. TPS neurons were located in the dorsal marginal rim of the trigeminal subnucleus caudalis, i.e., in the marginal layer or the outer zone of substantia gelatinosa. WDR neurons with TP input were found in the neck region of medullary dorsal horn which corresponds to the lateral part of subnucleus reticularis dorsalis (SRD). Trigeminal SRV neurons with TP input were located in the lateral part of SRV. Convergent RF neurons with TP input were found in the middle third of the caudal bulbar RF consisting of SRD and SRV. Both TPS neurons and WDR neurons with TP input included trigeminothalamic neurons as evidenced by the antidromic activation from the nucleus ventralis posteromedialis of the contralateral thalamus. A significant proportion of both trigeminal SRV and convergent RF neurons with TP input were antidromically activated by stimulation of the nucleus centralis lateralis of the contralateral thalamus. The former two subclasses may subserve the sensory-discriminative aspect of toothache, while the latter two subclasses, the emotional-motivational aspect.

Animals↗
PubMed1996

Insulin suppresses the induction of CYP2B1 and CYP2B2 gene expression by phenobarbital in adult rat cultured hepatocytes.

The effect of insulin on the phenobarbital (PB)-induced gene expression of CYP2B1 and CYP2B2 (CYP2B1/2B2) in adult rat hepatocytes was investigated. Insulin, which has been regarded as an essential hormone for primary hepatocytes, was found to strongly suppress the induction of CYP2B1/2B2 gene expression in hepatocytes cultured on EHS-gel. Although the induction by PB was not seen in monolayer hepatocytes cultured on type I collagen under standard culture conditions, the induced expression of the CYP2B1/2B2 gene was observed in monolayer hepatocytes by removing insulin from the medium. Further, we succeeded in maintaining the prolonged induction of CYP2B1/2B2 by PB in monolayer hepatocytes by using a medium containing dexamethasone but not insulin. Since the PB-induced UDP-glucuronosyltransferase gene expression was not reduced by insulin, the suppressive effect of insulin was considered to be specific to the CYP2B1/2B2 gene. These results demonstrate that insulin in media masks the PB-induced expression of the CYP2B1/2B2 gene in conventional monolayer hepatocytes and that the use of insulin-free media with primary hepatocytes provides a useful tool for investigating the molecular mechanism of CYP2B1/2B2 gene expression.

Animals↗
PubMed1996

Genomic structure and promoter activity of the mouse polysialic acid synthase gene (mST8Sia II). Brain-specific expression from a TATA-less GC-rich sequence.

The mouse ST8Sia II (mST8Sia II/STX) gene encodes a neural cell adhesion molecule-specific polysialic acid synthase whose expression is regulated during the developmental stages of mouse brain. To elucidate the molecular mechanism by which the expression is tissue-specifically and developmentally regulated, we isolated the complete genomic DNA and characterized the promoter of the gene for mST8Sia II. The gene encoding mST8Sia II was found to span about 80 kilobases and to be composed of six exons. Primer extension and S1 nuclease protection analyses revealed that the transcription started from 167 nucleotides upstream of the translational initiation site. Promoter analyses of the 5'-flanking region of the mST8Sia II gene using a luciferase gene reporter system revealed strong promoter activity in retinoic acid-induced differentiated P19 cells, which highly express the mST8Sia II gene. Deletion analyses demonstrated that the minimal promoter activity detected for the proximal region 325 base pairs upstream from the translational initiation codon (-158 to +167) could be modulated by various sequences within the 9. 5-kilobase 5'-flanking region. The minimal promoter was embedded in a GC-rich domain (74%, GC content), in which two Sp1 binding motifs as well as a long purine-rich region were found, but it lacked TATA and CAAT boxes. The positive regulatory region located between -159 and -659 contained two additional Sp1 binding motifs and a long pyrimidine-rich region. We also found that the minimal promoter region of the mST8Sia II gene was sufficient for expression of a reporter gene in mST8Sia II gene-expressing neural differentiated P19 cells but not in nonexpressing ones. Thus the TATA-less GC-rich minimal promoter region of mST8Sia II probably controls the cell type-specific expression of the mST8Sia II gene.

3T3 Cells↗
PubMed1996

Molecular cloning and expression of a fifth type of alpha2,8-sialyltransferase (ST8Sia V). Its substrate specificity is similar to that of SAT-V/III, which synthesize GD1c, GT1a, GQ1b and GT3.

The cDNAs encoding a new alpha2,8-sialyltransferase (ST8Sia V) were cloned from a mouse brain cDNA library by means of a polymerase chain reaction-based method using the nucleotide sequence information on mouse ST8Sia I (GD3 synthase) and mouse ST8Sia III (Siaalpha2,3Galbeta1,4GlcNAcalpha2,8-sialyltransferase ), both of which exhibit activity toward glycolipids. The predicted amino acid sequence of ST8Sia V shows 36.1% and 15.0% identity to those of mouse ST8Sia I and III, respectively. The recombinant protein A-fused ST8Sia V expressed in COS-7 cells exhibited an alpha2, 8-sialyltransferase activity toward GM1b, GD1a, GT1b, and GD3, and synthesized GD1c, GT1a, GQ1b, and GT3, respectively. The apparent Km values for GM1b, GD1a, GT1b and GD3 were 1.1, 0.082, 0.070, and 0.28 mM, respectively. However, ST8Sia V did not exhibit activity toward GM3. Thus, the substrate specificity of ST8Sia V is different from those of ST8Sia I and III, both of which exhibit activity toward GM3. Transfection of the ST8Sia V gene into COS-7 cells, which express GD1a as a major glycolipid, led to the expression of determinants for monoclonal antibody 4F10, which recognizes GT1a and GQ1b, suggesting that ST8Sia V exhibits activity toward gangliosides GD1a and/or GT1b in vivo. The expression of the ST8Sia V gene was tissue- and developmental stage-specific, and was clearly different from those of other alpha2,8-sialyltransferase genes. The ST8Sia V gene was strongly expressed in the brain and weakly in other tissues such as the liver. In addition, its expression was greater in the adult than fetal brain. These results strongly indicate that ST8Sia V is a candidate for SAT-V, the alpha2,8-sialyltransferase involved in GD1c, GT1a, GQ1b, and GT3 synthesis.

Amino Acid Sequence↗
PubMed1996

Comparison of results of intracoronary implantation of the Plamaz-Schatz stent with conventional balloon angioplasty in chronic total coronary arterial occlusion.

We compared angiographic and clinical outcomes after successful revascularization of chronic total coronary arterial occlusion with the placement of the Palmaz-Schatz stent (43 patients) and conventional balloon angioplasty (53 patients). After the procedure, the coronary stent led to a greater minimal lumen diameter than conventional balloon angioplasty (2.6 vs 1.7 mm, p < 0.001), resulting in a smaller residual stenosis (6.5% vs 36.7%, p < 0.001). At 6-month follow-up, there was no significant difference in late loss between the groups, resulting in a larger minimal lumen diameter at follow-up in the stent group (1.8 vs 1.1 mm, p < 0.001). The incidence of restenosis was lower in the stent group (27.9% vs 56.6%, p < 0.005). The frequency of the combination of myocardial infarction and coronary artery bypass graft surgery tended to be less in the stent group (2.3% vs 11.3%, P = 0.09). Placement of the Palmaz-Schatz stent improved left ventricular ejection fraction by 26% in patients who had reduced left ventricular function (p < 0.05), but conventional balloon angioplasty did not. Thus, placement of the Palmaz-Schatz stent provided a wider lumen than did conventional balloon angioplasty and, therefore, reduced the incidence of restenosis in chronic total coronary arterial occlusion. The lower restenosis rate of coronary stenting would be beneficial for long-term clinical outcome in patients with chronic total occlusion.

Aged↗
PubMed1996

Inhibition of thymidylate synthase and thymidine kinase by okadaic acid in regenerating rat liver after partial hepatectomy.

The effects of okadaic acid, a potent and specific inhibitor of protein phosphatases 1 and 2A, on liver regeneration after partial (70%) hepatectomy were investigated. The injection of okadaic acid (25 micrograms/kg body weight) inhibited the increases in the activities of thymidylate synthase and thymidine kinase in regenerating rat liver at 24 hr after partial hepatectomy, with a concomitant reduction in DNA content. Northern blot analysis showed that the suppression of thymidylate synthase and thymidine kinase activities was caused by comparable decreases in their mRNA levels. The protein levels of thymidylate synthase and thymidine kinase were confirmed by immunoblotting assay to be proportional to the activity and mRNA levels. These findings suggest that okadaic acid-sensitive protein phosphatases are involved in transcriptional control of the dTMP-synthesizing enzymes during liver regeneration.

Animals↗
PubMed1996

Annual changes in colorectal carcinoma incidence in Japan. Analysis of survey data on incidence in Aomori Prefecture.

BACKGROUND: In recent years, the mortality rate for colorectal carcinoma in Japan has rapidly been increasing, and there are indications that it may surpass that of gastric carcinoma, with colorectal carcinoma fast becoming one of the main targets of cancer treatment in Japan. METHODS: Eight thousand three hundred and eighty-six case records of colorectal carcinoma (4479 males and 3907 females; 4691 colon carcinoma cases and 3695 rectal carcinoma cases), diagnosed over 18 years from 1974 to 1991 in Aomori Prefecture, were analyzed. RESULTS: Age-adjusted incidence for colorectal carcinoma per 100,000 population were 12.6 and 8.7 for males and females, respectively, in 1974. The corresponding rates were 20 and 13.6, respectively, in 1980, and 42.5 and 25.6, respectively, in 1991. Among patients with colon carcinoma, a higher proportion have sigmoid colon carcinoma. The degree of increase in the incidence of sigmoid colon carcinoma was almost the same as that of right-sided colon carcinoma. By birth cohort analysis, among those born in 1934 or earlier, the incidence at the same age was higher in the younger population. CONCLUSION: It is possible that the age-adjusted incidence of colorectal carcinoma in Japan will soon resemble that of the white population in the United States, in a manner similar to that of Japanese-Americans.

Adult↗
PubMed1996

Biosynthesis and expression of polysialic acid on the neural cell adhesion molecule is predominantly directed by ST8Sia II/STX during in vitro neuronal differentiation.

We have reported recently that ST8Sia II/STX as well as ST8Sia IV/PST-1 is a neural cell adhesion molecule (NCAM)-specific polysialic acid (PSA) synthase (Kojima, N., Tachida, Y., Yoshida, Y., and Tsuji, S. (1996) J. Biol. Chem. 271, 19457-19463). To investigate which of two PSA synthase (ST8Sia II and IV) are involved in the biosynthesis of PSA associated with NCAM, the expressions of PSA, PSA synthase activity, and the genes of two PSA synthases during in vitro neuronal differentiation of mouse embryonal carcinoma P19 cells were determined. PSA was not expressed on undifferentiated cells (day 0) or cell aggregates (days 1-3) induced with retinoic acid. Expression of PSA began after cell aggregates had been dissociated and re-plated on a dish (day 4) and increased up to day 7. The expression of the mouse ST8Sia II gene was negligible in both undifferentiated and aggregated cells, it beginning at day 4, then dramatically increasing, and reaching the maximum level at days 6-7. On the other hand, transcription of the ST8Sia IV gene remained at a very low level throughout the entire period, a significant increase in its expression during differentiation not being observed. PSA synthase activity was not detected in undifferentiated or aggregated P19 cells, it increasing in parallel with ST8Sia II gene expression during differentiation. In addition, the cells at day 7 were stained with an anti-mouse ST8Sia II antiserum. Similar up-regulation of the ST8Sia II gene were observed during the differentiation of rat MNS-8 cells, which were derived from E-12 rat neuroepithelium of the neural tube and shown to differentiate into neurons. These results indicate that ST8Sia II predominantly directs PSA expression during neuronal differentiation rather than ST8Sia IV.

Animals↗
PubMed1996

Characterization of mouse ST8Sia II (STX) as a neural cell adhesion molecule-specific polysialic acid synthase. Requirement of core alpha1,6-linked fucose and a polypeptide chain for polysialylation.

We previously showed that mouse ST8Sia II (STX) exhibits polysialic acid (PSA) synthase activity in vivo as well as in vitro (Kojima, N., Yoshida, Y., and Tsuji, S. (1995) FEBS Lett. 373, 119-122, 1995). In this paper, we reported that the neural cell adhesion molecule (NCAM) was specifically polysialylated by a single enzyme, ST8Sia II. PSA-expressing Neuro2a cells (N2a-STX) were established by stable transfection of the mouse ST8Sia II gene. Only the 140- and 180-kDa isoforms of NCAM in N2a-STX cells were specifically polysialylated in vivo, although other membrane proteins of N2a-STX were polysialylated in vitro. A recombinant soluble mouse ST8Sia II synthesized PSA on a recombinant soluble NCAM fused with the Fc region of human IgG1 (NCAM-Fc) as well as fetuin. However, NCAM-Fc served as a 1500-fold better acceptor for ST8Sia II than fetuin. Treatment of NCAM-Fc with Charonia lampas alpha-fucosidase, which is able to cleave alpha1,6-linked fucose, clearly reduced the polysialylation of NCAM-Fc by ST8Sia II. PSA was not synthesized on the N-glycanase-treated NCAM-Fc polypeptide or the free N-glycans of NCAM-Fc. When fetuin and its glycopeptide and N-glycans of fetuin were used as substrates for ST8Sia II, PSA was found to be synthesized on native fetuin and its glycopeptide but not on free N-glycans. These results strongly suggested that core alpha1, 6-fucose on N-glycans as well as the antennary structures of N-glycans and the polypeptide regions are required for the polysialylation by ST8Sia II. Furthermore, oligo and single alpha2, 8-sialylated glycoproteins were no longer polysialylated by mouse ST8Sia II. Therefore, the single enzyme, ST8Sia II, directly transferred all alpha2,8-sialic acid residues on the alpha2,3-linked sialic acids of N-glycans of specific NCAM isoforms to yield PSA-NCAM. Polysialylation did not require any initiator alpha2, 8-sialyltransferase but did depend on the carbohydrate and protein structures of NCAM.

Animals↗
PubMed1996

Sterol 14-demethylase P450 activity expressed in rat gonads: contribution to the formation of mammalian meiosis-activating sterol.

Sterol 14-demethylase P450 (P45014DM)-dependent formation of 4,4-dimethylcholesta-8,14,24-trienol, that has been reported for a mammalian meiosis-activating sterol, in rat ovaries was confirmed. Transient elevation of ovarian P45014DM activity, that might be related to the female sexual cycle of rat, was observed. The P45014DM activity of immature ovaries was induced by pregnant mare's serum gonadotropin. These facts suggest the contribution of ovarian P45014DM to the gonadotropin-dependent formation of the meiosis-activating sterol, and provide a clue to understanding the mechanism how gonadotropins initiate the resumption of meiosis of mammalian oocytes. It was also found that rat testicular P45014DM participated in the production of 4,4-dimethylcholesta-8,24-dienol that was reported for another meiosis-activated sterol isolated from bull testes.

Animals↗
PubMed1996

Molecular cloning and genomic analysis of mouse Galbeta1, 3GalNAc-specific GalNAc alpha2,6-sialyltransferase.

cDNA and genomic clones encoding mouse Galbeta1, 3GalNAc-specific GalNAc alpha2,6-sialyltransferase (ST6GalNAc II) were isolated, and the structure organization of the gene was determined. The predicted amino acid sequence is 57.4% identical to the chick ST6GalNAc II sequence but 33.8% identical to the chick ST6GalNA I (GalNAc alpha2, 6-sialyltransferase) sequence. The ST6GalNAc II gene is constitutively expressed in various mouse tissues but highly expressed in lactating mammary gland and adult testis. The gene contains nine exons spanning about 25 kilobases of genomic DNA and encodes a messenger RNA of 1995 nucleotides. Primer extension and S1 nuclease protection analysis of submaxillary gland mRNA showed that the transcription of the ST6GalNAc II gene starts from 68 nucleotides upstream from the translation start site. Characterization of 5'-flanking genomic regions indicated that the Galbeta1,3GalNAc-specific GalNAc alpha2,6-sialyltransferase promoter is embedded in a G+C-rich domain and contains no TATA or CAAT box but has putative binding sites for transcription factors Sp1 and AP-2. Transient transfection experiments involving luciferase reporter genes demonstrated promoter activity in NIH3T3 cells.

3T3 Cells↗
PubMed1996

Isolation and characterization of vascular smooth muscle inositol 1,4,5-trisphosphate receptor.

myo-Inositol 1,4,5-trisphosphate (InsP3) receptor of porcine aorta was purified to near homogeneity and its biochemical properties were compared with those of cerebellar InsP3 receptor of the same animal species. The aortic InsP3 receptor consisted of equal amounts of two polypeptides with slightly differing molecular masses of around 240 kDa and was found to possess a single population of InsP3-binding site (Kd of 1.2 nM). The InsP3 receptor purified from porcine cerebellum was also comprised of two polypeptides. However, the molecular mass was slightly but definitely larger, being 250 kDa, and the amounts of the two polypeptides were not equal. The aortic InsP3 receptor cross-reacted with polyclonal antibody specific to type 1 InsP3 receptor as did the cerebellar InsP3 receptor. The aortic InsP3 receptor bound to calmodulin-Sepharose in a Ca(2+)-dependent manner, while the cerebellar InsP3 receptor did not. Reverse transcriptase-PCR analysis revealed two splicing variants of the type 1 InsP3 receptor in porcine aortic smooth muscle distinct from those of the type 1 InsP3 receptor of porcine cerebellum. The possible relevance of this difference to difference in calmodulin-binding property was discussed.

Amino Acid Sequence↗