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971.
Peter A. A. Harkes Leny Krijbolder Kees R. Libbenga Rommert Wijnsma Theodore Nsengiyaremge Robert Verpoorte 《Plant Cell, Tissue and Organ Culture》1985,4(3):199-214
Using the methods reported by De Fossard et al. (11) the influence of various media constituents on the growth and the alkaloid and anthraquinone production in Cinchona ledgeriana callus cultures was studied. Growth and indole alkaloid production (e.g. cinchonamine) was improved by higher auxin levels. The best growth was observed in the light, although many media resulted in no growth at all in the light. Anthraquinone production was highest at lower auxin levels. Quinoline alkaloid levels (e.g. quinidine) were highest in media with low auxin concentrations. Low and medium cytokinin concentration benefited the quinoline alkaloid production.From the results it was concluded that the pathways leading to the various secondary products, anthraquinones, indole alkaloids and quinoline alkaloids are, at least partly, regulated independently.Abbreviations used IAA
indol-acetic acid
- IBA
indol-butyric acid
- NAA
-naphtaleneacetic acid
- NOA
2-naphtoxy-acetic acid
- 2,4-D
2,4-dichlorophenoxy-acetic acid
- pCPA
parachlorophenoxy-acetic acid
- BA
benzyladenine 相似文献
972.
Theodore L. Taigen Kentwood D. Wells 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1985,155(2):163-170
Summary The metabolic demands of vocalization byHyla versicolor were determined by measuring oxygen consumption and whole body lactate content of calling animals. A stepwise multiple regression analysis identified both calling rate (calls/h) and call duration (s/call) as significant determinants of oxygen consumption during calling. These two variables accounted for 84% of the total variation in oxygen consumption observed in calling frogs. Aerobic metabolism
increased linearly with calling rate and call duration, reaching a peak value of 1.7 ml O2/(g·h) at the highest vocalization effort. For comparison, metabolic rates of the same individuals were also measured during short bouts of vigorous locomotor exercise
induced by mechanical stimulation. The mean value of
was only 62% of the peak
, and 5 of 13 frogs had rates of oxygen consumption during calling that exceeded their
. Whole body lactate levels were measured in two samples of calling frogs, one collected early in the evening (2100–2115 h) and the other 1.5 h later (2230–2245 h). The frogs in the second sample had significantly lower lactate levels (0.10 mg/g) than the frogs collected early in the evening (0.22 mg/g). Hence, vocalization does not entail the use of anaerobic metabolism, although lactate levels may be slightly elevated at the onset of an evening of calling. Calling rates of unrestrained frogs in a large chorus were measured at regular intervals during an evening. During the first half hour of calling, rates increased gradually from an initial mean value of 600 calls/h at 2030 h to nearly 1400 calls/h at 2100 h. These data indicate that acoustic advertisement byHyla versicolor is among the most energetically expensive activities regularly undertaken by any anuran, and indeed, is the most demanding yet measured in an ectothermic vertebrate.Abbreviations
resting rate of oxygen consumption
-
maximum rate of oxygen consumption
-
rate of oxygen consumption during forced exercise
-
rate of oxygen consumption during calling 相似文献
973.
Theodore Hymowitz 《Economic botany》1987,41(1):28-32
Events leading to the planting of the first soybeans in Illinois and the subsequent distribution of the seed throughout the United States are documented. In December 1850 theAuckland left Hong Kong for San Francisco. The ship came across a Japanese junk floundering on the sea. The Japanese crew was removed from the junk and placed on board theAuckland, which continued on to San Francisco. In March 1851 Dr. Benjamin Franklin Edwards obtained soybean seeds from the Japanese and brought the seeds to Alton, Illinois. Mr. John H. Lea of Alton planted the soybeans in his garden in summer 1851. These events took place 3 yr prior to the famous introduction of soybeans from Japan into the United States by the Perry Expedition. 相似文献
974.
Theodore Fotsis Haresh P. Shah Matti Härkönen Herman Adlercreutz 《Neurochemical research》1987,12(6):507-513
In the present study a method is described for the quantitative determination of the methylated metabolites of catechol estrogens in human urine. Following initial enzymatic hydrolysis the urine samples are extracted with ethyl acetate. The monomethyl ethers of catechol estrogens are then selectively fractionated with straight phase chromatography on Lipidex-5000 gel. Finally, samples are quantitated using enzymatic cycling with 17-estradiol dehydrogenase combined with fluorometry. The method is sensitive, reproducible and reasonably rapid for routine analysis and avoids the hazards of radioisotopes. Preliminary values of normal males and non-pregnant females are presented.Special Issue dedicated to Dr. O. H. Lowry. 相似文献
975.
Theodore A. Slotkin Frederic J. Seidler William L. Whitmore Christopher Lau Maria Salvaggio Donny F. Kirksey 《Journal of neurochemistry》1978,31(4):961-968
A fraction containing neurotransmitter storage vesicles was isolated from rat whole brain and brain regions, and the uptakes of [3H]norepinephrine and [3H]serotonin were determined in vitro. Norepinephrine uptake in vesicle preparations from corpus striatum was higher than in prep arations from cerebral cortex, and uptake in vesicles from the remainder (midbrain + brainstem + cerebellum) was intermediate. The Km for norepinephrine uptake was the same in the three brain regions, but the regions differed in maximal uptake capacity by factors which paralleled total catecholamine concentration rather than content of norepinephrine alone. Intracisternal administration of 6-hydroxydopamine, but not of 5,6-dihydroxytryptamine, reduced vesicular norepinephrine uptake, and pretreat-ment with desmethylimipramine (which protects specifically norepinephrine neurons but not dopamine neurons from the 6-hydroxydopamine) only partially prevented the loss of vesicular norepinephrine uptake. These studies indicate that uptake of norepinephrine by rat brain vesicle preparations occurs in vesicles from norepinephrine and dopamine neurons, but probably not in vesicles from serotonin neurons. Uptake of serotonin by brain vesicle preparations exhibited time, temperature and ATP-Mg2+ requirements nearly identical to those of norepinephrine uptake. The affinity of serotonin uptake matched that of serotonin for inhibition of norepinephrine uptake, and the maximal capacity was the same for serotonin as for norepinephrine. Norepinephrine, dopamine and reserpine inhibited serotonin uptake in a purely competitive fashion, with Kis similar to those for inhibition of norepinephrine uptake. Whereas 5,6-dihydroxytryptamine treatment reduced synaptosomal serotonin uptake but not vesicular serotonin uptake, 6-hydroxydopamine reduced vesicular serotonin uptake in the absence of reductions in synaptosomal serotonin uptake. Thus, in this preparation, serotonin appears to be taken up in vitro into catecholamine vesicles, rather than into serotonin vesicles. 相似文献
976.
John G. Haddad Chong Min Mike Mendelsohn Eduardo Slatopolsky Theodore J. Hahn 《Archives of biochemistry and biophysics》1977,182(2):390-395
A competitive protein-binding radioassay for 24,25-dihydroxyvitamin D [24,25-(OH)2D] in human serum has been developed. Whereas small amounts of [3H]24,25-(OH)2D must be biosynthesized in order to trace the efficiency of the extraction and chromatographic procedures, tritiated 25-hydroxyvitamin D3 ([3H]25-OHD3) can be used as the assay tracer. Since 25-OHD3 and 24,25-(OH)2D3 are equipotent in their competitive displacement of [3H]25-OHD3 from rat serum, 25-OHD3 can be used as the assay standard. Liquid-gel partition chromatography on small columns of Sephadex LH-20 can reliably isolate 24,25-(OH)2D by batch elution. The purity of biosynthesized [3H]24,25-(OH)2D3 and the 24,25-(OH)2D fraction isolated from serum was confirmed by high-pressure chromatography on 0.2 × 50 cm columns of 10-μm silica. Serum 24,25-(OH)2D levels averaged 16% of the serum 25-OHD concentrations in normal subjects. Since chronic hemodialysis patients, without kidneys, had normal serum 24,25-(OH)2D levels, significant extrarenal 25-hydroxycalciferol 24-hydroxylase activity occurs in these subjects. Since the present assay represents a reasonably simple extension of 25-OHD assay methodology, it should prove to be a useful technique in the analysis of clinical disorders of vitamin D metabolism. 相似文献
977.
Human Pb,human post-Pb,and nonhuman primate Pb proteins: Immunological and biochemical relationships
The isolation and characterization of a protein from human parotid saliva termed the "post-Pb protein" is described. By several criteria, this protein is closely related to the human Pb proteins. When reacted against antisera to human Pb protein in double diffusion, the post-Pb protein is found to be related to the Pb proteins by lines of identity. However, when the partial N-terminal amino acid sequences of the post-Pb protein and Pb proteins are compare, the sequences are not identical. Because of the similarity in size of the Pb and post-Pb proteins and because of the observed sequence differences, any product-precursor relationship between the Pb and post-Pb proteins is unlikely. The post-Pb protein probably is the product of a genetic locus different from the Pb locus. Two additional species of nonhuman primates (Papio papio and P. sphinx) have been found to have Pb proteins electrophoretically similar to these found in the rhesus monkey and differing from those in the human. The isolated Pb proteins of the rhesus monkey have been found to have close biochemical and immunological relationships to the human Pb proteins. 相似文献
978.
To investigate the potential molecular mediators of tissue-specific recruitment, we explored the influence of different cytokine challenges on gene expression regulation in five primary endothelial cells (ECs), representing two different phenotypes: iliac artery and aortic (macrovascular); lung, colon and dermal (microvascular). We challenged ECs with cytokines that elicit different patterns of inflammatory and immune responses in immune cells: tumor necrosis factor (TNF-alpha), interferon-gamma (IFN-gamma) or interleukin-4 (IL-4), and used microarrays containing approximately 40,000 unique cDNAs, to assess changes in differential gene expression relative to untreated cells. Five hundred and sixty three sequences changed by at least 2.5 fold in one or more of the 15 possible EC /cytokine combinations. The list included highly regulated adhesion molecules, chemokines, cytokines, metalloproteases, and IFN-gamma-induced genes. Overall, IFN-gamma caused the largest number of gene expression changes and its profile was least correlated with IL-4. In addition to clusters that were predominantly EC/cytokine specific, we also observed several clusters that were regulated by more than one cytokine across several ECs. Furthermore, we identified genes that were reciprocally expressed in response to different cytokines that could serve as markers of inflammatory and immune expression. These results confirm the importance of microenvironment in primary ECs that could have important applications in developing targeted therapies for vascular diseases. 相似文献
979.
Nicolas?P.?DolapsakisEmail author Triantafyllos?Tafas Theodore?J.?Abatzopoulos Stephanie?Ziller Athena?Economou-Amilli 《Journal of applied phycology》2005,17(1):39-49
There is continuous interest in many countries in maintaining and manipulating the rich ecological value of hypersaline ecosystems for aquaculture. The Megalon Embolon solar saltworks (northern Greece) were studied in sites of increasing salinity of 60–144 ppt to evaluate Dunaliella salina abundance and microalgal composition, in relation to physical and chemical parameters. Cluster and ordination analyses were performed based on the biotic and abiotic data matrices. Using fresh aliquots from 60 and 140 ppt salinity waters, phytoplankton performance was appraised with flask cultures in the laboratory by varying the inorganic PO4-P concentration at 23 °C and 30 °C. At the saltworks, among the most abundant microalgae identified were species of the genera Dunaliella, Chlamydomonas, Amphora, Navicula, and Nitzschia. Dunaliella salina populations were predominant comprising 5–22% of the total microalgal assemblages during spring, but only 0.3–1.0% during the summer, when grazing by Artemia parthenogenetica and Fabrea salina was intense. D. salina cell density in April–July was in the range of 0.4–12.5 × 106 L−1 with typical densities of 1.5–4.5 × 106 L−1. Overall, microalgal densities were high in salinities of ≥100 ppt when inorganic-P concentrations were ≥0.20 mg L−1 within saltworks waters. Multivariate analysis of species abundance showed that algal growth responses were primarily related to variation in salinity and inorganic-P concentrations, but also to NO3-N concentration. In the laboratory, experiments indicated effective fertilization and denser microalgal growth under high inorganic PO4-P applications (4.0 and 8.0 mg L−1) at 60 ppt salinity and 23 °C. The lower PO4-P applications (0.6–2.0 mg L−1) were more effective at 60 ppt salinity and 30 °C. At 140 ppt salinity, microalgal growth response was less obvious at any of the corresponding phosphorus concentrations or temperatures. In both salinity experiments, Dunaliella salina bloomed easily and was predominant among the microalgae. Our observations indicate that Dunaliella salina populations and the overall rich microalgal profile of the saltworks, along with their performance in laboratory mono–and mixed cultures hold promise for mass cultivation within the M. Embolon saltworks basins. 相似文献
980.
Friedlaender J Schurr T Gentz F Koki G Friedlaender F Horvat G Babb P Cerchio S Kaestle F Schanfield M Deka R Yanagihara R Merriwether DA 《Molecular biology and evolution》2005,22(6):1506-1517
Modern humans have occupied New Guinea and the nearby Bismarck and Solomon archipelagos of Island Melanesia for at least 40,000 years. Previous mitochondrial DNA (mtDNA) studies indicated that two common lineages in this region, haplogroups P and Q, were particularly diverse, with the coalescence for P considered significantly older than that for Q. In this study, we expand the definition of haplogroup Q so that it includes three major branches, each separated by multiple mutational distinctions (Q1, equivalent to the earlier definition of Q, plus Q2 and Q3). We report three whole-mtDNA genomes that establish Q2 as a major Q branch. In addition, we describe 314 control region sequences that belong to the expanded haplogroups P and Q from our Southwest Pacific collection. The coalescence dates for the largest P and Q branches (P1 and Q1) are similar to each other (approximately 50,000 years old) and considerably older than prior estimates. Newly identified Q2, which was found in Island Melanesian samples just to the east, is somewhat younger by more than 10,000 years. Our coalescence estimates should be more reliable than prior ones because they were based on significantly larger samples as well as complete mtDNA-coding region sequencing. Our estimates are roughly in accord with the current suggested dates for the first settlement of New Guinea-Sahul. The phylogeography of P and Q indicates almost total (female) isolation of ancient New Guinea-Island Melanesia from Australia that may have existed from the time of the first settlement. While Q subsequently diversified extensively in New Guinea-Island Melanesia, it has not been found in Australia. The only shared mtDNA haplogroup between Australia and New Guinea identified to date remains one minor branch of P. 相似文献