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High Accumulation (high + accumulation)
Selected AbstractsPhysiological responses of Matricaria chamomilla to cadmium and copper excessENVIRONMENTAL TOXICOLOGY, Issue 1 2008Jozef Ková Abstract Physiological responses of Matricaria chamomilla plants exposed to cadmium (Cd) and copper (Cu) excess (3, 60, and 120 ,M for 7 days) with special emphasis on phenolic metabolism were studied. Cu at 120 ,M reduced chamomile growth, especially in the roots where it was more abundant than Cd. Notwithstanding the low leaf Cu amount (37.5 ,g g,1 DW) in comparison with Cd (237.8 ,g g,1 DW) at 120 ,M, it caused reduction of biomass accumulation, Fv/Fm ratio and soluble proteins. In combination with high accumulation of phenolics, strong reduction of proteins and high GPX activity in the roots, this supports severe redox Cu properties. In terms of leaf phenylalanine ammonia-lyase (PAL) activity, it seems that Cd had a stimulatory effect during the course of the experiment, whereas Cu was found to stimulate it after 7-day exposure. The opposite trend was visible in the roots, where Cd had a stimulatory effect at high doses but Cu mainly at the highest dose. This supports the assumption of different PAL time dynamics under Cd and Cu excess. A dose of 60 and 120 ,M Cu led to 2- and 3-times higher root lignin accumulation while the same Cd doses increased it by 33 and 68%, respectively. A Cu dose of 120 ,M can be considered as limiting for chamomile growth under conditions of present research, while resistance to high Cd doses was confirmed. However, PAL and phenolics seemed to play an important role in detoxification of Cd- and Cu-induced oxidative stress. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. [source] Expression of MsPG3-GFP fusions in Medicago truncatula,hairy roots' reveals preferential tip localization of the protein in root hairsFEBS JOURNAL, Issue 2 2003Ignacio D. Rodríguez-Llorente Tip growth is a specialized type of polar growth where new cell wall is deposited in a localized region of the cell, the growing tip. These cells show a characteristic zonation, with a high accumulation of secretory vesicles containing cell wall components at the tip, followed by an organelle-enriched zone. MsPG3 is a Medicago sativa polygalacturonase gene isolated in our laboratory, specifically expressed during the interaction of this plant with its symbiotic partner Sinorhizobium meliloti and which might participate in tip growth processes during symbiosis. We have used MsPG3-GFP fusions to study in vivo protein transport processes and localization during root hair growth. Different MsPG3-GFP fusions were expressed in Medicago truncatula,hairy roots' following a protocol developed for this study and also tested by transient expression in onion epidermal cells. Preferential accumulation of an MsPG3-GFP fusion protein in the tip of the growing root hair at different developmental stages was found, confirming the delivery of MsPG3 to the newly synthesized cell wall. This indicates that this protein may participate in tip growth processes during symbiosis and, in addition, that this fusion could be a useful tool to study this process in plants. [source] Blood ribavirin concentration in high-dose ribavirin for adenovirus-induced haemorrhagic cystitis , a case reportJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 1 2008M. Homma PhD Summary Blood ribavirin concentration was monitored after the administration of high-dose oral ribavirin in a case of adenovirus-induced haemorrhagic cystitis post-stem-cell transplantation. Combination use of intravenous gamma immunoglobulin (15 g/3 days) and high-dose ribavirin (RBV; 9000 mg/4 days) provided plasma ribavirin concentration of 24·3 ,m and achieved virus eradication. High level of erythrocyte ribavirin (1085 ,m; mostly as phosphorylated metabolites) with long half-life (15 days) caused severe anaemia, which required several blood transfusions for 2 weeks after the cessation of the ribavirin treatment. It was suggested that blood transfusion and intensive haemoglobin level monitoring is necessary for at least 4 weeks after the RBV, because of the high accumulation of phosphorylated ribavirin in erythrocytes even after stopping ribavirin administration. [source] Reduction of Acrylamide Formation in Potato Chips by Low-temperature Vacuum FryingJOURNAL OF FOOD SCIENCE, Issue 8 2004C. Granda ABSTRACT: Potatoes and other foods that have a high content of the amino acid asparagine and a high accumulation of reducing sugars are subject to the formation of acrylamide upon frying. The objectives of this research were (1) to analyze the level of acrylamide formed during deep-fat frying of potato chips and (2) to evaluate means of reducing acrylamide in potato chips by using different potato cultivars and vacuum frying. Several potato cultivars were used in this research, including Innovator (I), NDTX 4930,5W (N), ATX 854 04,8W (ATw), Atlantic (A), Shepody (S), ATX847806,2Ru (ATr), and White-Rose (W). An electric bench-top (atmospheric conditions)-type fryer was used to fry the potatoes. Three temperatures were used: 150 °C, 165 °C, and 180 °C. The vacuum frying experiments were performed at 118 °C, 125 °C, and 140 °C and a vacuum pressure of 10 Torr. The potatoes were sliced (1.5-mm thick) and fried for different lengths of times. For potatoes fried at 165 °C (for 4 min) at atmospheric conditions, the acrylamide contents were 5021 ± 55 ppb (W), 552 ± 25 ppb (I), 358 ± 50 ppb (N), 397 ± 25 ppb (ATw), 646 ± 55 ppb (A), 466 ± 15 ppb(S), and 537 ± 14 ppb (ATr). Vacuum frying reduced acrylamide formation by 94%. Results showed that both cultivar and modified frying systems can play an important role in reducing acrylamide formation in fried potatoes. As the frying temperature decreased from 180 °C to 165 °C, acrylamide content in potato chips reduced by 51% during traditional frying and by 63% as the temperature decreased from 140 °C to 125 °C in vacuum frying. Increased frying time increased acrylamide formation during traditional frying for all temperatures and frying methods analyzed. However, the effect on acrylamide concentration was greater for the traditional frying than the vacuum frying. Keywords: acrylamide, vacuum, frying, potato, temperature [source] Synthesis and biological evaluation of [carboxyl - 11C]eprosartanJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 8 2009Ola Åberg Abstract Essential hypertension occurs in approximately 25% of the adult population and one cause of hypertension is primary aldosteronism. Targeting the angiotensin II AT1 receptor using PET and an appropriate tracer may offer a diagnostic method for adrenocortical tissue. This report describes the synthesis of the selective AT1 receptor antagonist [carboxyl - 11C]eprosartan 10, 4-[2-butyl-5-((E)-2-carboxy-3-thiophen-2-yl-propenyl)-imidazol-1-ylmethyl]-[carboxyl - 11C]benzoic acid, and its precursor (E)-3-[2-butyl-3-(4-iodo-benzyl)-3H -imidazol-4-yl]-2-thiophen-2-ylmethyl-acrylic acid 9. 11C-carboxylation of the iodobenzyl moiety was performed using a palladium-mediated reaction with [11C]carbon monoxide in the presence of tetra- n -butyl-ammonium hydroxide in a micro-autoclave using a temperature gradient from 25 to 140°C over 5,min. After purification by semipreparative HPLC, [carboxyl - 11C]eprosartan 10 was obtained in 37,54% decay-corrected radiochemical yield (from [11C]carbon monoxide) with a radiochemical purity >95% within 35,min of the end of bombardment (EOB). A 5-µAh bombardment gave 2.04,GBq of 10 (50% rcy from [11C]carbon monoxide) with a specific activity of 160,GBq,µmol,1 at 34,min after EOB. Frozen-section autoradiography shows specific binding in kidney, lung and adrenal cortex. In vivo experiments in rats demonstrate a high accumulation in kidney, liver and intestinal wall. Copyright © 2009 John Wiley & Sons, Ltd. [source] Physiological Performance of Asymptomatic and Yellow Leaf Syndrome-affected Sugarcanes in VenezuelaJOURNAL OF PHYTOPATHOLOGY, Issue 1 2002M. L. IZAGUIRRE-MAYORAL Serological analyses revealed the presence of the sugarcane yellow leaf virus (ScYLV) in asymptomatic (S,) and symptomatic (S+) yellow leaf syndrome-affected sugarcane plants of the cultivars PR.692176, C.323,68, V.64,10, V.71,47, V.75,6, SP.72,2086, SP.72,1210, SP.74,2005, C.323,68, B.80,549 and B.82,363. Tests for the presence of the sugarcane yellows phytoplasma, carried out by Dr P. Jones (IACR-Rothamsted), gave negative results in all cultivars. Physiological analyses were performed in the top visible dewlap (TVD) leaf of S, and S+ plants of the cultivar PR.692176. All plants were at the second ratoon and flowering. When compared with S, plants, the S+ plants showed: (a) a marked reduction in the area of the leaf and internodes; (b) a high accumulation of total reducing sugars (TRS), glucans and ,-amino-N in the leaf blade and of TRS in the corresponding leaf sheath; (c) a decrease in the chlorophyll, phosphorus and nitrogen content in the leaf; (d) the disappearance of the leaf diurnal fluctuations in TRS accumulation and export as well as the daily oscillations of TRS and glucans between dawn and dusk; and (e) major ultrastructural alterations in the companion cells of the phloem, including the accumulation of ScYLV particles in the cytoplasm. In S, plants, none of the growth and physiological alterations described above were observed, in spite of the high density of ScYLV particles in the cytoplasm. The location of S, and S+ plants close to each other without a discernible pattern of distribution in plots subjected to optimal irrigation and fertilization rule out the possibility that environmental conditions underlay the appearance of symptoms. In plots under severe drought for 3 months, however, all S, plants become S+. Symptom expression did not affect the acid phosphatase activity in the rhizosphere of S+ plants. [source] Dissecting the components of quinine accumulation in Plasmodium falciparumMOLECULAR MICROBIOLOGY, Issue 5 2008Cecilia P. Sanchez Summary Although quinine, the active ingredient of chinchona bark, has been used in the treatment of malaria for several centuries, there is little information regarding the interactions of this drug with the human malaria parasite Plasmodium falciparum. To better understand quinine's mode of action and the mechanism underpinning reduced responsiveness, we have investigated the factors that contribute to quinine accumulation by parasites that differ in their susceptibility to quinine. Interestingly, passive distribution, in accordance with the intracellular pH gradients, and intracellular binding could account for only a small fraction of the high amount of quinine accumulated by the parasites investigated. The results of trans -stimulation kinetics suggest that high accumulation of quinine is brought about by a carrier-mediated import system. This import system seems to be weakened in parasites with reduced quinine susceptibility. Other data show that polymorphisms within PfCRT are causatively linked with an increased verapamil-sensitive quinine efflux that, depending on the genetic background, resulted in reduced quinine accumulation. The polymorphisms within PfMDR1 investigated did not affect quinine accumulation. Our data are consistent with the model that several factors, including acidotropic trapping, binding to intracellular sites and carrier-mediated import and export transport systems, contribute to steady-state intracellular quinine accumulation. [source] Loss of cytosolic fructose-1,6-bisphosphatase limits photosynthetic sucrose synthesis and causes severe growth retardations in rice (Oryza sativa)PLANT CELL & ENVIRONMENT, Issue 12 2008SANG-KYU LEE ABSTRACT During photosynthesis, triose-phosphates (trioseP) exported from the chloroplast to the cytosol are converted to sucrose via cytosolic fructose-1,6-bisphosphatase (cFBPase). Expression analysis in rice suggests that OscFBP1 plays a major role in the cytosolic conversion of trioseP to sucrose in leaves during the day. The isolated OscFBP1 mutants exhibited markedly decreased photosynthetic rates and severe growth retardation with reduced chlorophyll content, which results in plant death. Analysis of primary carbon metabolites revealed both significantly reduced levels of sucrose, glucose, fructose and starch in leaves of these mutants, and a high accumulation of sucrose to starch in leaves of rice plants. In the oscfbp1 mutants, products of glycolysis and the TCA cycle were significantly increased. A partitioning experiment of 14C-labelled photoassimilates revealed altered carbon distributions including a slight increase in the insoluble fraction representing transitory starch, a significant decrease in the neutral fraction corresponding to soluble sugars and a high accumulation of phosphorylated intermediates and carboxylic acid fractions in the oscfbp1 mutants. These results indicate that the impaired synthesis of sucrose in rice cannot be sufficiently compensated for by the transitory starch-mediated pathways that have been found to facilitate plant growth in the equivalent Arabidopsis mutants. [source] Effects of citraconylation on enzymatic modification of human proinsulin using trypsin and carboxypeptidase BBIOTECHNOLOGY PROGRESS, Issue 4 2009Young-Jin Son Abstract Insulin is a polypeptide hormone which is produced by the ,-cell of pancreas and controls the blood glucose level in the human body. Enzymatic modification of human proinsulin using trypsin and carboxypeptidase B generally causes high accumulation of insulin derivatives, leading to more complicated purification processes. A simple method including citraconylation and decitraconylation in the enzymatic modification process was developed for the reduction of a major derivative, des-threonine human insulin. Addition of 3.0 g citraconic anhydride per g protein into the reaction solution led to the citraconylation of lysine residues in human proinsulin and reduction of relative des-threonine insulin content from 13.5 to 1.0%. After the enzymatic hydrolysis of the citraconylated proinsulin, 100% of lysine residues can be decitraconylated and restored by adjusting pH to 2,3 at 25 °C. Combination of hydrogen peroxide addition and citraconylation of proinsulin expressed in recombinant Escherichia coli remarkably improved the conversion yield of insulin from 52.7 to 77.7%. Consequently, citraconylation of lysine residues blocked the unexpected cleavage of human proinsulin by trypsin, minimized the formation of des-threonine insulin and hence increased the production yield of active insulin. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Hydrogenation for Low Trans and High Conjugated Fatty AcidsCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 1 2005Eun Seok Jang ABSTRACT Hydrogenated vegetable oils contain of trans fatty acids. Because of the increased health concern about trans fatty acids, new hydrogenations have been studied to seek ways for substantial reduction of the trans fatty acids in the hydrogenated vegetable oils. This paper reviews new hydrogenation processes such as electrocatalytic hydrogenation, precious catalyst hydrogenation, and supercritical fluid state hydrogen, which have shown promising results for the reduction of trans fatty acids below the level of 8%. This paper also reviews the recently introduced hydeogenation technique for high accumulation of conjugated linoleic acids, beneficiary functional components. The hydrogenated vegetable oils with high quantity conjugated linoleic acid might provide the possibility for the utilization of hydrogenated oils as health-prompting food ingredients. [source] | |||||||||||||