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111.
Johannes D. Veldhuis Patricia Klase Laurence M. Demers 《Prostaglandins & other lipid mediators》1982,23(3):319-327
Granulosa cells isolated from mature Graafian follicles of swine produced significant quantities of immunoreactive 6-keto-PGF1α under chemically defined conditions in vitro. Luteinizing hormone elicited a dose-dependent stimulation of 6-keto-PGF1α accumulation, but follicle stimulating hormone, prolactin, L-epinephrine, estradiol-17B, or PGE2 were devoid of effect. The time-dependent in vitro production of 6-keto-PGF1α by ovarian cells was susceptible to inhibition by indomethacin, U-51506, cycloheximide, and actinomycin D. These observations implicate granulosa cells in the specific and hormonally regulated production of prostacyclin. 相似文献
112.
Hans Bisgaard Johannes Kristensen Jrgen Sndergaard 《Prostaglandins & other lipid mediators》1982,23(6):797-801
Using a laser-Doppler-flowmeter the microvascular response to LTC4 and LTD4 was measured. Intradermal injection of 1 Ug LTC4 and LTD4 caused an increase in the microvascular cutaneous bloodflow. The increase in flow was equal to that caused by histamine in equimolar amounts. Blocking the triple-response did not change the response. The values measured after injection of histamine and leucotrienes were about 10–15 times the values found in undisturbed skin and represents probably a maximally dilated vascular bed. Injection of the leucotrienes caused a slight sensation of pain. 相似文献
113.
Johannes L. Bos 《Molecular & general genetics : MGG》1981,181(4):420-423
Summary The omega locus controls the polarity of recombination and transmission of genetic markers in the 21S ribosomal RNA region in yeast mtDNA. Polarity is observed in crosses between omega+ and omega- strains. These two strains differ by the presence of an intervening sequence in the 21S ribosomal RNA gene of omega+ strains. Mutations of the omega- allele, omega neutral (omegan), can eliminate the polarity effect. We have made DNA:RNA hybrids containing ribosomal RNA from an omegan strain and mtDNA from Saccharomyces carlsbergensis (identical to omega- in the nucleotide sequence of the omega region). These hybrids contain no mismatch at the omega region detectable by digestion with S1 nuclease. We conclude that omegan differs from omega- only in a point mutation or analogous small alteration and that the omegan mutation can result either m a Cr phenotype (omeganCr) or in the phenotypic suppression of pre-existing Cr mutations (omeganCs). All results can be explained by a model which postulates interaction in the ribosome between the Cr and omegan regions of the ribosomal RNA and interference of the omegan mutation with splicing of the precursor ribosomal RNA in omega+ strains. The mechanism of omega-directed polarity is discussed.Abbreviations rRNA
ribosomal RNA
- bp
base pair(s)
- kb
kilo base pair(s) 相似文献
114.
Synopsis Triggerfishes construct nests by excavating depressions in sand. Eggs are laid in an adhesive mass and anchored with rubble. A photograph of a newly-hatched embryo is included. 相似文献
115.
A polymorphism for an isozyme of a presumed arylesterase, esterase-16 (EC 3.1.1.2), has been detected in kidney, heart, and spleen of the house mouse, Mus musculus, by means of isoelectric focusing and by disc electrophoresis. Three phenotypes can be distinguished: the ES-16A phenotype (IEP 5.9) was found in C57BL/10Sn and many other laboratory inbred strains; the ES-16B phenotype (IEP 6.1) was found in M. m. molossinus; and the ES-16C phenotype (IEP 5.9; very weak activity) was found in Peru-Coppock. Esterase-16 is strongly inhibited by 10?3 m p-chloromercuribenzoate, but not by 2·10?4 m bis-p-nitrophenyl phosphate or by 10?3 m Diamox. It stains well with indoxyl acetate and other indigogenic substrates but only weakly with α-naphthyl acetate. Esterase-16 is completely insoluble in water. It is apparently governed by a structural gene locus, Es-16, with three alleles, Es-16 a , Es-16b, and Es-16 c, respectively. Es-16 is closely linked to Car-1 and Car-2 on chromosome 3. Typing of 94 animals of the backcross (C57BL/10Sn × M. m. mol.) F1 × M. m. mol. revealed a recombination frequency of 8.51±2.9%. 相似文献
116.
Johannes Boonstra Paul T. Van Der Saag Wouter H. Moolenaar Siegfried W. De Laat 《Experimental cell research》1981,131(2):452-455
Nerve growth factor (NGF) induces neuronal differentiation of rat pheochromocytoma cells (PC12). Here we show that NGF causes a stimulation of Na+,K+-pump mediated K+ influx, with a maximum at 30 min after addition of NGF. The stimulation of the Na+,K+-pump is completely blocked by the Na+-flux inhibitor amiloride (0.2 mM) and can be mimicked by the Na+ ionophore monensin. These results suggest that NGF causes a rapid enhancement of Na+ influx leading to an activation of the Na+,K+-pump, a mechanism similar to the action of other growth factors. 相似文献
117.
Labeled mevalonate is incorporated into terpenes and hop bitter compounds by Humulus lupulus. The role of mevalonate as a precursor for the prenyl (3-methyl-but-2-enyl) side chain of the hop bitter compounds is discussed. 相似文献
118.
Configurational assignments for the tertiary alcoholic centers of four branched-chain 3-C-nitromethylglycopyranosides, namely, methyl 2-benzamido-4,6-O-benzylidene-2-deoxy-3-C-nitromethyl-α-D-allopyranoside (1), benzyl 2-acetamido-4,6-O-benzylidene-2-deoxy-3-C-nitromethyl-α-D-glucopyranoside (4), benzyl 2-acetamido-4,6-O-benzylidene-2-deoxy-3-C-nitromethyl-α-D-allopyranoside (5), and methyl 4,6-O-benzylidene-3-C-nitromethyl-2-O-p-tolylsulfonyl-α-D-glucopyranoside (8), were made on the basis of the downfield chemical shifts of their identifiable protons per molar equivalent of added Eu(fod)3, as compared with those of model compounds, of known configuration, having a close structural relationship. In some cases, the assignments were corroborated by the position of the acetyl resonances in the unshifted 60-MHz p.m.r. spectra of the corresponding O-acetyl derivatives. 相似文献
119.
120.
Zusammenfassung An Totalpräparaten der Antennengeißel von Arbeiterin und Drohne vonApis mellifera carnica wurden Zahl und Verteilung aller Sensillen und Setae ermittelt. Dabei ließen sich anhand des cuticularen Baues folgende Sensillentypen unterscheiden: S. placodeum, S. ampullaceum, S. coeloconicum, S. campaniforme und 5 Haarsensillen S. trichodeum A, B1, B2, C, D, sowie 4 Setatypen (A 1–3, B), die wahrscheinlich nicht innerviert sind. Die Benennungen der Sensillen wurde den bisher gebrauchten Bezeichnungen gegenübergestellt. Sensillenzahl und -Verteilung, Sinneszellzahl und Funktion der Sensillen wurden anhand von Literaturangaben zusammengestellt und diskutiert. Bemerkenswert ist der starke Dimorphismus zwischen Arbeiterin und Drohne in der relativen Sensillenzahl für die einzelnen Sensillentypen und in der Gesamtzahl der Sinneszellen. So sind bei der Arbeiterin die wahrscheinlich olfaktorischen S. trichodea A und die mechanorezeptorischen S. trichodea B 1 wesentlich stärker vertreten. Die Drohne hat keine S. basiconica und im übrigen wesentlich mehr S. placodea als die Arbeiterin. Insgesamt hat die Drohne eine ca. 2-fach größere Geißeloberfläche und etwa 5-mal soviele Sinneszellen wie die Arbeiterin. Die Arbeiterinnengeißel hat auf ihrer Rückseite eine porenplattenfreie Zone, die dicht mit nichtinnervierten Setae besetzt ist. Bei der Drohne findet man stattdessen eine porenplattenärmere Zone mit einer geringeren Zahl von Setae. Charakteristische Verteilungsmuster bestehen auch für alle anderen Sensillen und Setae.
Number and distribution of the sensilla on the antennal flagellum of the honeybee (Apis mellifera L.)
Summary Number and distribution of sensilla and setae on the antennal flagellum of the honeybeeApis mellifera carnica were determined on whole antennal preparations. The following types of sensilla were distinguished according to their cuticular structure: Sensillum placodeum, S. ampullaceum, S. coeloconicum, S. basiconicum, S. campaniforme and 5 hair sensilla S.trichodeum A, B1, B2, C, D, as well as 4 types of probably non-innervated setae (A1–3, B). The names used here for the different types were compared with the previously used terms. Number and distribution of sensilla, the number of sensory cells and the function of the sensilla were discussed with respect to the data available from the literature. There is a notable dimorphism between the worker and drone with respect to the relative number of sensilla of each type and to the total number of sensory cells. The worker has far more of the presumably olfactory S. trichodea A and of the mechanoreceptive S. trichodea B1. The drone lacks the S. basiconica and has far more S. placodea than the worker. The flagellum surfarce of the drone is twice as large as that of the worker and has 5 times as many sensory cells. The worker flagellum has a poreplate-free zone on the side facing the head which is densely packed with non-innervated setae. In the corresponding zone the drone has a lower density of poreplates than elsewhere on its antennal flagellum. All other sensilla and setae are also characteristically distributed.相似文献