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971.
972.
A cDNA clone, pAUK1, with an open reading frame (ORF) coding for a hypothetical 164-amino-acid protein was isolated from an Arabidopsis thaliana (L.) Heynh cDNA library. The clone was attached, tail to tail, to the 3′ end of A. thaliana hexokinase cDNA. An almost identical sequence had been previously described as the 5′ untranslated region (5′ UTR) of A. thaliana calmodulin cDNA (ACaM-2). Sequence comparison with three additional A. thaliana truncated cDNA clones which appear in a database (GenBank) supports the conclusion that pAUKl is identical to the 5′ UTR of ACaM-2 and that the 5′ UTR of ACaM-2 is an independent cDNA artificially linked to A. thaliana calmodulin cDNA. 相似文献
973.
Summary Fluorescence microscopy offers some distinct advantages over other techniques for studying ion transport processes in situ with plant cells. However, the use of this technology in plant cells has been limited by our lack of understanding the mechanisms that influence the subcellular distribution of dyes after loading with the lipophilic precursors. In this study, the subcellular distribution of 5-(and 6-)carboxydichlorofluorescein (CDCF), carboxy-SNAFL-1, and carboxy-SNARF-1 was compared to that of 2,7-bis-(2-carboxyethyl)-5-(and 6-)carboxyfluorescein (BCECF) after incubation of maize roots with their respective lipophilic precursors. Previously, we reported that incubation of roots with BCECF-acetomethyl ester (BCECF-AM) led to vacuolar accumulation of this dye. Similar results were found when roots were incubated with CDCF-diacetate. In contrast, carboxy-SNAFL-1 appeared to be confined to the cytoplasm based on the distribution of fluorescence and the excitation spectra of the dye in situ. On the other hand, incubation of roots with carboxy-SNARF-1-acetoxymethyl acetate yielded fluorescence throughout the cell. When the cytoplasm of epidermal cells was loaded with the BCECF acid by incubation at pH 4 in the absence of external Ca, the dye was retained in the cytoplasm at least 3 h after the loading period. This result indicated that vacuolar accumulation of BCECF during loading of BCECF-AM was not due to transport of BCECF from cytoplasm to vacuole. The esterase activities responsible for the production of either carboxy-SNAFL-1 or BCECF from their respective lipophilic precursor by extracts of roots were compared. The characterization of esterase activities was consistent with the subcellular distribution of these dyes in root cells. The results of these experiments suggest that in maize root epidermal cells the subcellular distribution of these fluorescein dyes may be determined by the characteristics of the esterase activities responsible for hydrolysis of the lipophilic precursor.Abbreviations BCECF (BCECF-AM)
2,7-bis-(2-carboxyethyl)-5-(and 6-)carboxyfluorescein (its acetoxymethyl ester)
- BTB
bis-trispropane
- CDCF (CDCF-DA)
5-(and 6-)carboxy-2,7-dichlorofluorescein (its diacetate derivative)
- DAPI
4,6-diamidino-2 phenylindole dihydrochloride
- DMSO
dimethylsulfoxide
- HEPES
N-[2-hydroxyethyl] piperazine-N-[2-ethanesulfonic acid]
- MES
2-[N-morpholino]ethane-sulfonic acid
- SNAFL-1 (SNAFL-1-DA)
carboxyl SNAFL-1 (its diacetate)
- SNARF-1 (SNARF-1-AM)
carboxyl SNARF-1 (its acetoxymethyl acetate) 相似文献
974.
Alexandra M. Birrell Annemarie Hennessy Adrian Gillin John Horvath David Tiller 《Journal of medical primatology》1996,25(4):287-293
Abstract: Baboons are widely used in biomedical research. Although it is widely held that Papio hamadryas breed well in captivity, each established colony has a different reproductive success often hypothesised to be due to husbandry practices. The National Baboon Colony in Australia is a unique colony that houses Papio hamadryas to mimic that structure seen in the wild. In this article; we have analysed their reproductive parameters and neonatal outcomes. The success of the colony husbandry practices was demonstrated by lack of maternal mortality, low foetal morbidity, and known maternal and paternal linage. 相似文献
975.
Benoît F. Morel Meghan A. Burke Jayant Kalagnanam Susan A. McCarthy David J. Tweardy Penelope A. Morel 《Bulletin of mathematical biology》1996,58(3):569-594
The cytokines are the information superhighway of the immune system. They are an important component of the integrated behavior
of the system. In order to be able to have a good understanding of the immune system, we must be able to model the effect
of cytokines and their combined effect. This work is a step in that direction. We study the combined effect of two cytokines:
interleukin-2 (IL-2) and interleukin-4 (IL-4) on some cells of the immune system.
Interleukin-2 and interleukin-4 are important growth and differentiation factors for B and T cells. Interleukin-4 antagonizes
the effect of interleukin-2 on B cells and some T cells while it synergizes with interleukin-2 on other T cells. We build
a mathematical model of the interaction of both cytokines on T and B cells as a building block toward a model of the Th1/Th2
cross-regulation. The response of a given cell to the combination of interleukin-2 and interleukin-4 is shown to involve competing
dynamical effects which can lead to either antagnostic or synergistic combined effect.
Author to whom correspondence should be addressed at Department of Engineering and Public Policy. Work supported by NIH grant
nv: Ai31427. 相似文献
976.
Katherine J. Devonald Winthrop J. Harewood David A. Ellwood Andrew F. Phippard 《Journal of medical primatology》1996,25(5):339-345
Normal biometric ranges for fetal growth in a captive breeding baboon (Papio hamadryas) colony are described. Measurements include crown-rump length, biparietal diameter, binocular distance, head circumference, abdominal circumference, femur length and amniotic fluid index. The pattern of fetal growth is compared with other baboon subspecies and man. The uses and limitations of such data for breeding colony management and optimum utilisation of experimentally derived data are discussed. 相似文献
977.
Charles H. A. Snijders Rob A. Samson Ellen S. Hoekstra Thérèse Quellet J. David Miller Petra C. E. M. de Rooij-van der Goes A. J. M. Baar A. E. J. Dubois Henk F. Kauffman 《Mycopathologia》1996,135(2):119-128
In the European coastal dunes, marram grass (Ammophila arenaria) is planted in order to control sand erosion. In the years 1986 to 1991, workers on the Wadden islands in the Netherlands planting marram grass showed lesions of skin and mucous membranes, suggesting a toxic reaction. Fusarium culmorum dominated the mycoflora of those marram grass culms that were used for planting. This plant material had been cut and stored for more than one week in the open. The Fusarium toxin deoxynivalenol (DON) was detected in the suspect marram grass culms. Isolated F. culmorum strains were able to produce DON in vitro in liquid culture as well as in experimentally inoculated wheat heads. Pathogenicity tests, toxin test as well as RAPD analysis showed that the F. culmorum strains were not specialized for marram grass but may form part of the West-European F. culmorum population infecting cereals and grasses. Storage on old sand-dunes with plant debris may have led to the high occurrence of F. culmorum and contamination with DON. Marram grass culms should be obtained from young plantings on dunes on the seaward slopes and cut culms should not be stored. 相似文献
978.
The killing of Candida species by human neutrophils in a long-term 24-h assay and possible synergy with fluconazole (FCZ) for killing was investigated. The test medium (TM) consisted of RPMI-1640, penicillin and streptomycin (P/S), and 10% fresh autologous serum. TM alone was highly fungistatic for Candida species compared to TM without serum. When neutrophils were cocultured in TM with Candida species for 24 h the inoculum colony-forming units (CFU) were always significantly reduced (killing) by 58 to 99%. FCZ was tested over a range of 1–500 g/ml, and though almost always fungistatic itself, it synergized with neutrophils for significantly increased killing of C. albicans (isolate Sh27) (P<0.01) and C. albicans (isolate 94-20) (P<0.05). Killing of non-albicans Candida species was so efficient in the absence of FCZ that demonstration of synergy with FCZ was difficult. 相似文献
979.
Anticryptococcal activity of human serum and apotransferrin in RPMI 1640 was studied in vitro. The effects of varying concentrations of FeCl3 on this activity was investigated. Possible synergy of serum and apotransferrin with fluconazole was also measured. The fungistatic activity of human serum, whether lyophilized, stored at 4 °C, fresh frozen or purchased from commercial sources vs. Cryptococcus neoformans was comparable. There was no significant loss of fungistatic activity after freezing and thawing the serum up to 10 times. The fungistatic activity of human serum was similar when tested in different tissue culture media with the exception of Medium 199. The addition of apotransferrin (2.0 or 0.2 mg/ml) to RPMI 1640 had an inhibitory effect on cryptococcal growth. This effect was reversed by 20 M of FeCl3 at both apotransferrin concentrations. By contrast, addition of FeCl3 to human serum and RPMI 1640 did not reverse inhibition of growth. Fluconazole synergized with the human serum preparations described, but not with pooled commercial serum, for fungicidal activity. Synergistic activity of fluconazole and human serum was not affected by the addition of FeCl3. Apotransferrin did not show any synergistic fungicidal activity with fluconazole. 相似文献
980.