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  • 1
    ISSN: 1432-1440
    Keywords: Prostaglandin E receptor ; EP4 subtype ; THP-1 ; Cyclic AMP ; Phorbol myristate acetate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We isolated a cDNA clone encoding the human prostaglandin (PG) E receptor EP4 subtype and examined the gene expression in human blood cells. Northern blot analysis revealed that the EP4 gene is expressed at a high level in peripheral blood mononuclear cells, and at lower levels in cultured human blood cell lines, THP-1 and U937 (monocytoid cell lines), MOLT-4 and Jurkat (T-cell lines), and Raji (B-cell line). To examine regulation of the EP4 gene expression in the immune system, we studied the effects of phorbol 12-myristate 13-acetate (PMA) on these cell lines. Gene expression was upregulated in THP-1, U937, and Raji cells by PMA, and was downregulated in MOLT-4 and Jurkat cells. In THP-1 cells the effects of PMA were further analyzed, and the upregulation of the EP4 gene was shown to be followed by an increase in PGE2 binding sites and in PGE2-induced cAMP accumulation. In the striking contrast, other PGE receptor subtypes (EP1, EP2 and EP3) and other prostanoid receptors (IP and DP) were shown not to be upregulated by PMA. Therefore, this is the first demonstration of a highly specific upregulation of the EP4 subtype in THP-1 cells treated with PMA, suggesting the importance of the EP4 subtype in the immune system. In the present study we also clarified that EP4 gene expression is regulated differently among human monocytoid and lymphoid lineage cells, thus leading to the better understanding of the regulatory mechanisms for the human EP4 gene expression in the immune system.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1440
    Keywords: Key words Prostaglandin E receptor ; EP4 subtype ; THP-1 ; Cyclic AMP ; Phorbol myristate acetate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  We isolated a cDNA clone encoding the human prostaglandin (PG) E receptor EP4 subtype and examined the gene expression in human blood cells. Northern blot analysis revealed that the EP4 gene is expressed at a high level in peripheral blood mononuclear cells, and at lower levels in cultured human blood cell lines, THP-1 and U937 (monocytoid cell lines), MOLT-4 and Jurkat (T-cell lines), and Raji (B-cell line). To examine regulation of the EP4 gene expression in the immune system, we studied the effects of phorbol 12-myristate 13-acetate (PMA) on these cell lines. Gene expression was upregulated in THP-1, U937, and Raji cells by PMA, and was downregulated in MOLT-4 and Jurkat cells. In THP-1 cells the effects of PMA were further analyzed, and the upregulation of the EP4 gene was shown to be followed by an increase in PGE2 binding sites and in PGE2-induced cAMP accumulation. In the striking contrast, other PGE receptor subtypes (EP1, EP2 and EP3) and other prostanoid receptors (IP and DP) were shown not to be upregulated by PMA. Therefore, this is the first demonstration of a highly specific upregulation of the EP4 subtype in THP-1 cells treated with PMA, suggesting the importance of the EP4 subtype in the immune system. In the present study we also clarified that EP4 gene expression is regulated differently among human monocytoid and lymphoid lineage cells, thus leading to the better understanding of the regulatory mechanisms for the human EP4 gene expression in the immune system.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1573-1561
    Keywords: Tsetse fly ; sex stimulant ; pheromone ; hydrocarbon ; methylalkanes ; gas chromatography ; Diptera ; biting fly
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Study of lipids from male and female laboratory-reared flies led to the demonstration of a potent contact sex stimulant in extracts and cuticular hydrocarbons of the female tsetse fly Glossina tachinoides (Westwood) against conspecific males. Thin-layer and column chromatography indicated that extracts contained hydrocarbons and saponifiable lipids. Biological activity was found in the alkanes from females, including prominent branched-chain alkanes that were detected by gas chromatography (GC). The alkanes were separated and collected by preparative gas chromatography (GC), and only the 37-carbon region showed biological activity. GC–mass spectrometry showed the major peak contained a mixture of isomeric 11,23-, 13,25- plus a minor amount of 11,21-dimethylheptatriacontane. Two racemic isomers were synthesized, and bioassays showed that the greatest activity was possessed by the 11,23- isomer with somewhat less activity in 13,25-dimethyl heptatria-contane. Dose–response data showed ED50 at 5 μg per decoy with solvent-washed males, nonspecific females, or corks as decoys. These alkanes released sexual activity in males that comprised most of the behaviors released by a female fly of the same species.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1573-1561
    Keywords: Mosquito ; Culex pipiens fatigans ; Diptera ; Culicidae ; oviposition ; attractant ; pheromone ; chiral chromatography ; acetoxyhexadecanolide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract 6-Acetoxy-5-hexadecanolide (Ia) in the oviposition attractant pheromone released from egg apical droplets of the mosquitoCulex pipiens fatigans Wied. is shown to be the (−)-(5R,6S)- enantiomer. Identification was by chromatography of the 6-trifluoroacetoxy derivatives of the natural pheromone and of the synthetic (−)-(5R,6S)- (Ib) and (+)-(5S,6R)- (IIb) enantiomers on a capillary column having a chiral stationary phase comprising a derivative of (1S,3S)-chrysanthemic acid. The synthetic (−)-(5R,6S)- enantiomer (Ia) attracted oviposition of four fold more mosquito egg rafts than the control (P 〈 0.01) whereas for the (5S,6R)- enantiomer (IIa) there was no statistically significant oviposition attraction.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1573-1561
    Keywords: Enantiomers ; bark beetle ; pheromone ; Dendroctonus frontalis ; Coleoptera ; Scolytidae ; southern pine beetle ; electrophysiology ; olfaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In laboratory and field bioassays, the response ofDendroctonus frontalis was significantly greater to the mixture of (1S, 5R)-(−)-frontalin andalpha-pinene than to (1R,5S)-(+)-frontalin andalpfa-pinene. Electro-physiological studies revealed that antennal olfactory receptor cells were significantly more responsive to (1S, 5R)-(−)-frontalin than to (1R, 5S)-(+)-frontalin. Both enantiomers stimulated the same olfactory cells which suggests that each cell possesses at least two types of enantiomer-specific acceptors.
    Type of Medium: Electronic Resource
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