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71.
R F Troxler H S Belford F G Oppenheim 《Biochemical and biophysical research communications》1983,111(1):239-246
RNA was isolated from a human submandibular gland and separated into poly A-enriched and poly A-deficient fractions by chromatography on oligo (dT) cellulose. Both of these RNA fractions stimulated methionine incorporation into polypeptides in a reticulocyte lysate translation system. Two in vitro translation products templated by poly A-enriched mRNA were isolated by immunoprecipitation with immune serum directed against human salivary anionic proline-rich protein I. These polypeptides were shown to be precursors of proline-rich proteins on the basis of Mr, affinity for the antiserum, and preferential incorporation of proline. This study is the first to demonstrate cell-free translation of the mRNAs for human proline-rich salivary protein precursors. 相似文献
72.
B J Baum R F Troxler H M Kagan J A Grasso B Faris C Franzblau 《Biochemical and biophysical research communications》1973,53(4):1350-1356
L-Azetidine-2-car?ylic acid (AZA), the lower homologue of proline, was incorporated into hemoglobin in rabbit reticulocytes in vitro. Hydrolysis of [14C] AZA-hemolobin with 3 N p-toluenesulfonic acid and subsequent amino acid analysis resulted in recovery of 90% of the initial radioactivity in fractions containing added free AZA standard. An additional 6% of the radioactivity eluted with homoserine, a known degradation product of AZA. After tryptic digestion of [14C] AZA-hemoglobin, less than 9% of radioactivity eluted near added free AZA standard, while 91% of radioactivity was located in tryptic peptides elsewhere on the chromatogram. These data provide the first demonstration of AZA incorporation into a mammalian protein. 相似文献
73.
Breithaupt Joshua L. Smoak Joseph M. Sanders Christian J. Troxler Tiffany G. 《Ecosystems》2019,22(4):844-858
Ecosystems - Mangrove wetlands are some of the most important locations of organic carbon (OC) sequestration and storage in the world on a per area basis. The high stocks of soil OC are driven by... 相似文献
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Silva Celio Heinz Troxler Silke S Durka Jaroslav Chládek Johannes H Wildhaber Felix H Sennhauser Claus W Heizmann Alexander Moeller 《Nitric oxide》2006,15(3):226-232
3-Nitrotyrosine (3-NT) is considered as a marker of oxidative stress, which occurs during inflammation. Since 3-NT levels in exhaled breath condensate (EBC) are very low, we applied a specific and sensitive gas chromatography-negative ion chemical ionization-mass spectrometry (GC-NICI-MS) method and high performance liquid chromatography (HPLC) with electrochemical detection for the analysis of free 3-NT in EBC. A total of 42 children (aged 5-17 years) were enrolled in this study, including children with asthma (n=12), cystic fibrosis (n=12), and healthy controls (n=18). Additionally, 14 healthy non-smoking adults (aged 18-59 years) were included. An EcoScreen system was used for the collection of EBC samples. Free 3-NT levels in EBC ranged from 0.54-6.8 nM. Median (interquartile range) concentrations (nM) were similar in all groups: 1.46 (0.97-2.49) in healthy adults, 2.51 (1.22-3.51) in healthy children, 1.46 (0.88-2.02) in children with asthma, and 1.97 (1.37-2.35) in CF children, respectively (p=0.24, Kruskall-Walis test). No difference was found between the children with airway disease and age-matched healthy controls. In healthy subjects, there was no effect of age on 3-NT concentrations. HPLC analyses provided similar concentration ranges for EBC 3-NT when compared with GC-NICI-MS. Our study has clearly demonstrated that free 3-NT in EBC fails as a marker for oxidative stress in children with stable CF and asthma. 相似文献
77.
Historically, the Florida Everglades was characterized by a corrugated landscape of shorter hydroperiod, elevated sawgrass (Cladium jamaicense) ridges and longer hydroperiod, deep water slough communities. Drainage and compartmentalization of the Everglades have fundamentally altered this pattern, and sawgrass ridge communities have expanded at the expense of deep water slough communities throughout much of the landscape. In this study we provide a simple isotopic and nutrient characterization of major components of the slough ecosystem to elucidate physiological and nutrient differences among species and to suggest pathways for organic matter decomposition that contribute to peat development in deep water sloughs. We examined carbon (C) and nitrogen (N) isotopes and C, N and phosphorus (P) concentrations of the floating-leaved macrophytes Nymphaea odorata and Nymphoides aquatica, the emergent macrophyte Eleocharis elongata, and the submerged species Utricularia foliosa and Utricularia purpurea, as well as soil and flocculent material from the southern Water Conservation Area 3-A. Flocculent material and soils had the highest N content (4.5 ± 0.2%) and U. foliosa and N. odorata had the highest P content (0.13 ± 0.01% to 0.12 ± 0.01%). The range for δ15N average ± SE values was 5.81 ± 0.29‰ (U. foliosa) to −1.84 ± 0.63‰ (N. odorata), while the range for δ13C values was −23.83 ± 0.12‰ (N. odorata) to −29.28 ± 0.34‰ (U. purpurea). Differences of up to 10‰ in C isotopic values of U. foliosa and N. odorata suggest fundamental physiological differences between these species. Along a degradation continuum, enrichment of 13C and 15N and extent of decomposition was negatively related to phosphorus concentrations. A two end-member 13C mixing model suggested that Utricularia species were the primary organic source for flocculent materials, whereas organic matter derived from root decomposition of N. odorata contributed to the progressively enriched δ13C values found with depth in soils. These results illustrate the fundamentally important roles of Nymphaea and Utricularia species in ecosystem dynamics of deep water sloughs. 相似文献
78.
Troxler T Hoyer D Langenegger D Neumann P Pfäffli P Schoeffter P Sorg D Swoboda R Hurth K 《Bioorganic & medicinal chemistry letters》2007,17(14):3983-3987
A novel class of non-peptide somatostatin receptor ligands bearing the octahydrobenzo[g]quinoline (obeline) structural element has been identified. SAR studies have been performed that led to the discovery of derivatives with high affinity (pK(d) r sst(1) > or = 9) and selectivity (> or = 150-fold for h sst(1) over h sst(2)-h sst(5)) for somatostatin receptor subtype sst(1). In a functional assay, the compounds act as antagonists at human recombinant sst(1) receptors. 相似文献
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The differential accumulation or loss of carbon and nutrients during decomposition can promote differentiation of wetland
ecosystems, and contribute to landscape-scale heterogeneity. Tree islands are important ecosystems because they increase ecological
heterogeneity in the Everglades landscape and in many tropical landscapes. Only slight differences in elevation due to peat
accumulation allow the differentiation of these systems from the adjacent marsh. Hydrologic restoration of the Everglades
landscape is currently underway, and increased nutrient supply that could occur with reintroduction of freshwater flow may
alter these differentiation processes. In this study, we established a landscape-scale, ecosystem-level experiment to examine
litter decomposition responses to increased freshwater flow in nine tree islands and adjacent marsh sites in the southern
Everglades. We utilized a standard litterbag technique to quantify changes in mass loss, decay rates, and phosphorus (P),
nitrogen (N) and carbon (C) dynamics of a common litter type, cocoplum (Chrysobalanus icaco L.) leaf litter over 64 weeks. Average C. icaco leaf degradation rates in tree islands were among the lowest reported for wetland ecosystems (0.23 ± 0.03 yr−1). We found lower mass loss and decay rates but higher absolute mass C, N, and P in tree islands as compared to marsh ecosystems
after 64 weeks. With increased freshwater flow, we found generally greater mass loss and significantly higher P concentrations
in decomposing leaf litter of tree island and marsh sites. Overall, litter accumulated N and P when decomposing in tree islands,
and released P when decomposing in the marsh. However, under conditions of increased freshwater flow, tree islands accumulated
more P while the marsh accumulated P rather than mineralizing P. In tree islands, water level explained significant variation
in P concentration and N:P molar ratio in leaf tissue. Absolute P mass increased strongly with total P load in tree islands
(r
2 = 0.81). In the marsh, we found strong, positive relationships with flow rate. Simultaneous C and P accumulation in tree
island and mineralization in adjacent marsh ecosystems via leaf litter decomposition promotes landscape differentiation in
this oligotrophic Everglades wetland. However, results of this study suggest that variation in flow rates, water levels and
TP loads can shift differential P accumulation and loss leading to unidirectional processes among heterogeneous wetland ecosystems.
Under sustained high P loading that could occur with increased freshwater flow, tree islands may shift to litter mineralization,
further degrading landscape heterogeneity in this system, and signaling an altered ecosystem state. 相似文献