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81.
82.
Microtubule Depolymerization Inhibits Ethanol-Induced Enhancement of GABAA Responses in Stably Transfected Cells 总被引:1,自引:0,他引:1
Valerie J. Whatley Susan J. Brozowski †Karen L. Hadingham †Paul J. Whiting ‡ R. Adron Harris 《Journal of neurochemistry》1996,66(3):1318-1321
Abstract: We studied whether microtubule organization is important for actions of ethanol on GABAA ergic responses by testing the effects of microtubule depolymerization on ethanol enhancement of GABA action in mouse L(tk− ) cells stably transfected with GABAA receptor α1 β1 γ2L subunits. The microtubule-disrupting agents colchicine, taxol, and vinblastine completely blocked ethanol-induced enhancement of muscimol-stimulated chloride uptake. β-Lumicolchicine, a colchicine analogue that does not disrupt microtubules, had no effect on ethanol action. Colchicine did not alter the potentiating actions of flunitrazepam or pentobarbital on muscimol-stimulated chloride uptake. Thus, colchicine specifically inhibited the potentiating action of ethanol. From these findings, we conclude that intact microtubules are required for ethanol-induced enhancement of GABAA responses and suggest that a mechanism involving microtubules produces posttranslational modifications that are necessary for ethanol sensitivity in this cell system. 相似文献
83.
84.
Lisa M. Vogler Sumner W. Jones Glen E. Jensen R. Gary Brewer Karen J. Brewer 《Inorganica chimica acta》1996,250(1-2):155-162
A number of osmium and ruthenium complexes of the tridentate ligands 2,2′:6′,2″-terpyridine (tpy) and 2,3,5,6-tetrakis(2-pyridyl)pyrazine (tpp) have been prepared and characterized by our laboratory. All these complexes possess metal based oxidations and ligand based reductions localized on each polyazine ligand. Polymetallic complexes bridged by the tpp ligand exhibit two sequential tpp based reductions prior to the reduction of other polyazine ligands in these complexes. The spectroscopy of these complexes is dominated by ligand based π-π* transitions in the ultraviolet and MLCT (metal-to-ligand charge transfer) bands terminating on each polyzine ligand in the visible. For the complexes reported herein the lowest lying optical transitionis a M → BL CT band. For most of the complexes reported, occupation of this excited state gives rise to an observable emission at room temperature. For ruthenium complexes of these tridentate ligands, the presence of a low-lying LF state shortens the excited state lifetimes of these chromophores. This gives rise to ruthenium complexes that display shorter excited state lifetimes than the analogous osmium based systems. Incorporation of tpp based chromophores into polymetallic frameworks leads to the production of bimetallic species with long-lived excited states, 100 ns at room temperature. This makes these chromophores good candidates for the development of stereochemically defined supramolecular complexes. It is possible to measure an electrochemical HOMO-LUMO energy gap and a correlation between this electrochemically measured energy gap and the spectroscopic energy associated with this HOMO→LUMO transition are reported herein (HOMO== highest occupied molecular orbital, LUMO = lowest unoccupied molecular orbital). 相似文献
85.
Fetal cells in maternal blood: recovery by charge flow separation 总被引:11,自引:0,他引:11
S. S. Wachtel David Sammons Michael Manley Gwendolyn Wachtel Garland Twitty Joseph Utermohlen Owen P. Phillips Lee P. Shulman Douglas J. Taron U. R. Müller Peter Koeppen Teresa M. Ruffalo Karen Addis Richard Porreco Joyce Murata-Collins Natalie B. Parker Loris McGavran 《Human genetics》1996,98(2):162-166
Fetal blood cells can be recovered from the maternal circulation by charge flow separation (CFS), a method that obviates the
risks associated with amniocentesis and chorionic villus sampling. By CFS, we processed blood samples from 13 women carrying
male fetuses, 2 carrying fetuses with trisomy 21, and 1 who had delivered a stillborn infant with trisomy 18. On average more
than 2000 fetal nucleated red blood cells were recovered per 20-ml sample of maternal blood. Recovery of fetal cells was confirmed
by fluorescence in situ hybridization with probes for chromosomes Y, 18 and 21. After culturing of CFS-processed cells, amplification
by the polymerase chain reaction revealed Y-chromosomal DNA in clones from four of six women bearing male fetuses, but not
in clones from three women bearing female fetuses.
Received: 8 January 1996 / Revised: 22 March 1996 相似文献
86.
Giorgio Crosta Franco Brunetta Maria Luisa Ortelli Antonio Cavallo Roberto Bertolini 《Aerobiologia》1996,12(1):133-137
In the last 2 years we have conducted an aerobiological monitoring program ofCryptomeria japonica, a plant belonging to the family of Taxodiaceae that sometimes causes pollinosis in the period from February to April. Throughout 1994, we checked the incidence of its sensitization and the clinical effects in 85 subjects with correlated seasonal symptoms, who gave a positive skin prick test (SPT) for Betulaceae and/or Corylaceae. Twenty-five patients (29.4%; 19 M; 6 F; mean age, 38.8 years) all with oculorhinitis, were SPT positive to an allergenic extract ofCryptomeria. RAST confirmed this positivity in 44% of the cases. No patients showed monosensitization forCryptomeria to either SPT or RAST. Two subjects gave a positive result on specific nasal provocation. RAST inhibition showed no cross-reaction betweenCryptomeria and birch pollen. During the pollen season each patient made a list, scoring symptoms and specifying any drugs used, so we could correlate these elements with aerobiological observations. The pollen concentration probably exceeded the allergizing threshold forCryptomeria on 8 days during 3 months of recording. The intensity and duration of symptoms seemed to be mainly influenced by sensitization to Betulaceae and Corylaceae. It is thus possible that a combination of minor pollinosis may produce seasonal symptoms in allergic patients. 相似文献
87.
Marcella Carcupino Anna Maria Fausto Maria Luisa Bernardino Ortega Marzio Zapparoli Massimo Mazzini 《Zoomorphology》1996,116(3):103-110
Spermatophore development and ultrastructure of the mature sperm of Craterostigmus tasmanianus were studied using light and electron microscopy. In C. tasmanianus, as in the Scolopendromorpha, the spermatophore develops within the vas deferens. The latter consists of three parts, each
with a different morphology. The first may be involved in guiding the sperm to roll up into typical ring-like structures,
while the other two, which show an evident secretory activity, secrete the acellular wall of the spermatophores. The ultrastructure
of mature spermatozoa showed that a very close similarity exists between Craterostigmomorpha and Lithobiomorpha, especially
regarding the organization of the connecting piece. Based on this similarity, we consider the Craterostigmomorpha together
with the Scolopendromorpha, Geophilomorpha and Lithobiomorpha (=Pleurostigmophora) to be the sister group of the Scutigeromorpha.
Accepted: 2 June 1996 相似文献
88.
Diel vertical migration of zooplankton in the Northeast Atlantic 总被引:7,自引:0,他引:7
Acoustic Doppler current profiler (ADCP) data collected duringAugustSeptember 1991 reveal the diel migration of zooplanktonin the northeast Atlantic (5060 相似文献
89.
Karen van Zee Dawn A. Baertlein Steve E. Lindow Nicholas Panopoulos Tony H. H. Chen 《Plant molecular biology》1996,30(1):207-211
The bacterial ice nucleation gene inaZ confers production of ice nuclei when transferred into transgenic plants. Conditioning of the transformed plant tissue at temperatures near 0°C greatly increased the ice nucleation activity in plants, and maximum ice nucleation activity was achieved only after low-temperature conditioning for about 48 h. Although the transgenic plants contain similar amounts of inaZ mRNA at both normal and low temperatures, low temperatures are required for accumulation of INAZ protein. We propose that the stability of the INAZ protein and thus ice nucleation activity in the transgenic plants is enhanced by low-temperature conditioning. 相似文献
90.
Jos M. Torn Luisa Moysset Inmaculada Claparols Esther Simn 《Physiologia plantarum》1996,98(2):413-418
The effects of photoperiod and end-of-day phytochrome control on somatic embryogenesis and polyamine (PA) content in Araujia sericifera petals have been studied. Petals from immature flowers were cultured under 16- and 8-h photoperiods. Far red (FR), red (R) and FR followed by R light treatments were applied at the end of the photoperiods for three weeks. The number of somatic embryos, callus weight and the levels of free and bound PAs in the cultured petal explants were determined 40 days after the beginning of light treatments. Long day (LD) promoted somatic embryogenesis but did not have any significant effect on PA content. Short day (SD) reduced somatic embryogenesis and enhanced total PAs, mainly in the form of bound spermidine. End-of-day FR treatment increased PA content and inhibited somatic embryogensis under LD but had no significant effect under SD. This effect of FR on PA levels was cancelled by R and was independent of the presence of silver thiosulphate in the medium. End-of-day R treatment reduced the total PA content under SD. However, end-of-day R increased or reduced somatic embryogenesis under SD depending on the presence or absence of silver in the medium. The results suggest a photoperiodic control of somatic embryogenesis and PA content in A. sericifera. The effects of end-of-day R and FR treatments depend on the length of the photoperiod. This finding and the FR/R photoreversibility of end-of-day treatments indicate that phytochrome may be involved in both somatic embryogenesis and accumulation of PA. 相似文献