WorldWideScience

Sample records for absorption distribution metabolism

  1. The absorption, distribution, metabolism and excretion of procyanidins.

    Zhang, Liang; Wang, Yijun; Li, Daxiang; Ho, Chi-Tang; Li, Junsong; Wan, Xiaochun

    2016-03-16

    Procyanidins (PAs) are polyphenols in plant food that have many health benefits, including cancer prevention, cardiovascular protection and diabetes prevention. PAs have been known to have low oral bioavilability. In this review, we summarize the published results on the ADME (absorption, distribution, metabolism and excretion) of PAs in vivo and in vitro. After oral administration, in the stomach the decomposition of PAs is highly dependent on the pH value of gastric juice, which is also affected by food intake. In the small intestine, PA polymers and oligomers with DP > 4 are not directly absorbed in vivo, but minor PA monomers and dimers could be detected in the plasma. Methylated and glucuronidated PA dimers and monomers are the main metabolites of PAs in plasma. In the colon, PAs are catabolized by colonic microflora into a series of low molecular weight phenolic acids, such as phenyl valerolactone, phenylacetic acids and phenylpropionic acids. We reviewed the degradation of PAs in gastric digestion, the absorption of PAs in the small intestine and the metabolic pathway of PAs by colonic microflora. To clearly explain the in vivo pharmacokinetics of PAs, a systematic comparative analysis on previously published data on PAs was conducted. PMID:26814915

  2. Identification of Absorption, Distribution, Metabolism, and Excretion (ADME) Genes Relevant to Steatosis Using a Differential Gene Expression Approach

    Absorption, distribution, metabolism, and excretion (ADME) parameters represent important connections between exposure to chemicals and the activation of molecular initiating events of Adverse Outcome Pathways (AOPs) in cellular, tissue, and organ level targets. ADME parameters u...

  3. Determination of drug-like properties of a novel antileishmanial compound: In vitro absorption, distribution, metabolism, and excretion studies

    Mondal Susanta

    2009-01-01

    Full Text Available In drug discovery research, the compounds should not only to be potent and selective but also must possess acceptable pharmacokinetic properties such as absorption, distribution, metabolism, and excretion (ADME to increase success rate in clinical studies. Objective: Exploration of drug-like properties of 2-(2-methylquinolin-4-ylamino-N-phenyl acetamide, a potent antileishmanial compound by performing some in vitro ADME experiments along with validation of such studies. Materials and Methods: Experimental protocols were established and validated for stability (in PBS pH7.4, simulated gastric and intestinal fluid, solubility, permeability, distribution coefficient (Log D, plasma protein binding and metabolism by rat liver microsomes by using spectrophotometer or HPLC. Methods were considered valid if the results of the standard compounds matched with reported results or within acceptable range or with proper ranking (high-medium-low. Results: The compound was found to be stable (>95% remaining in all stability studies and aqueous solubility was 299.7 ± 6.42 μM. The parallel artificial membrane permeability assay (PAMPA indicated its medium permeability (Log Pe = -5.53 ± 0.01. The distribution coefficients (Log D in octanol/PBS and cyclohexane/PBS systems were found to be 0.54 and -1.33, respectively. The plasma protein binding study by the equilibrium dialysis method was observed to be 78.82 ± 0.13% while metabolism by Phase-I enzymes for 1 hour at 37°C revealed that 36.07 ± 4.15% of the compound remained after metabolism. Conclusion: The methods were found to be very useful for day-to-day ADME studies. All the studies with the antileishmanial compound ascertained that the compound bears optimum pharmacokinetic properties to be used orally as a potential drug for the treatment of leishmaniasis.

  4. Studies on absorption, distribution, excretion and metabolism of 3H-1α-hydroxycholecalciferol in vitamin D deficient rats

    The absorption, distribution, excretion and metabolism of 2-3H-1α-OH-D3 (4.2 Ci/mmol) were studied in vitamin D deficient rats in comparison with the normal rats after oral or intravenous dosing. (1) Maximum blood level of administered radioactivity was observed at 8 hours after oral administration with apparent half life of 3.8 days. This blood level was higher than that in normal rat. (2) As in the normal rat, administered radioactivity was distributed relatively high in the liver, while any other specific distribution or accumulation was not observed in the another tissues, which was consistent to the finding in the normal rat. The tissue levels of the radioactivity were higher than these in the normal rat. (3) Urinary excretion of administered radioactivity was significantly higher, fecal and biliary excretion was significantly lower than that in the normal rat after intravenous dosing. (4) Relative percentage of 3H-1α, 25-(OH)2-D3 content to 3H-1α-OH-D3 content in tissues and blood was higher than that in the normal one. Above results suggest that in the vitamin D deficient state, the tissue accumulation of 1α-OH-D3 was significantly augmented than in the normal rat, thus resulting increased bioavailability of its active metabolite, 1α, 25-(OH)2-D3. (author)

  5. Evaluation of in vitro absorption, distribution, metabolism, and excretion (ADME) properties of mitragynine, 7-hydroxymitragynine, and mitraphylline.

    Manda, Vamshi K; Avula, Bharathi; Ali, Zulfiqar; Khan, Ikhlas A; Walker, Larry A; Khan, Shabana I

    2014-05-01

    Mitragyna speciosa (kratom) is a popular herb in Southeast Asia, which is traditionally used to treat withdrawal symptoms associated with opiate addiction. Mitragynine, 7-hydroxymitragynine, and mitraphylline are reported to be the central nervous system active alkaloids which bind to the opiate receptors. Mitraphylline is also present in the bark of Uncaria tomentosa (cat's claw). Several therapeutic properties have been reported for these compounds but limited information is available on the absorption and distribution properties. This study focuses on evaluating the absorption, distribution, metabolism, and excretion (ADME) properties of these compounds and their effect on major efflux transporter P-glycoprotein, using in vitro methods. Quantitative analysis was performed by the Q-TOF LC-MS system. Mitragynine was unstable in simulated gastric fluid with 26 % degradation but stable in simulated intestinal fluid. 7-Hydroxymitragynine degraded up to 27 % in simulated gastric fluid, which could account for its conversion to mitragynine (23 %), while only 6 % degradation was seen in simulated intestinal fluid. Mitraphylline was stable in simulated gastric fluid but unstable in simulated intestinal fluid (13.6 % degradation). Mitragynine and 7-hydroxymitragynine showed moderate permeability across Caco-2 and MDR-MDCK monolayers with no significant efflux. However, mitraphylline was subjected to efflux mediated by P-glycoprotein in both Caco-2 and MDR-MDCK monolayers. Mitragynine was found to be metabolically stable in both human liver microsomes and S9 fractions. In contrast, both 7-hydroxymitragynine and mitraphylline were metabolized by human liver microsomes with half-lives of 24 and 50 min, respectively. All three compounds exhibited high plasma protein binding (> 90 %) determined by equilibrium dialysis. Mitragynine and 7-hydroxymitragynine inhibited P-glycoprotein with EC50 values of 18.2 ± 3.6 µM and 32.4 ± 1.9 µM, respectively

  6. The absorption, distribution, metabolism and elimination of β-(p-chlorophenyl)-GABA (Baclofen), 4

    Distribution of 14C-baclofen was studied according to the autoradiography of a whole body in SD-JCL male rats after oral administration of 14C-baclofen (100 μCi/kg). Distribution of radioactivity in kidney and liver was already apparent 15 min after administration. Radioactivity in kidney and liver was increased distribution of radioactivity in skeletal muscle was apparent 1 hr after administration. Radio and activity in various tissues decreased 3 hrs after administration. Distribution of radioactivity in brain and spinal cord remained low at any time after administration. Distribution of radioactivity of 14C-baclofen in autoradiography was consistent with that in tracer study (Yamamoto et al 1977). (auth.)

  7. A proteomics approach to the study of absorption, distribution, metabolism, excretion, and toxicity.

    Nordvarg, Helena; Flensburg, John; Rönn, Ola; Ohman, Johan; Marouga, Rita; Lundgren, Bo; Haid, Daniel; Malmport, Eva; Goscinski, Jan; Hörnsten, Lena; Scigelova, Michaela; Bourin, Stephanie; Garberg, Per; Woffendin, Gary; Fenyö, David; Bergling, Hélène; Forsberg, Erik

    2004-12-01

    A proteomics approach was used to identify liver proteins that displayed altered levels in mice following treatment with a candidate drug. Samples from livers of mice treated with candidate drug or untreated were prepared, quantified, labeled with CyDye DIGE Fluors, and subjected to two-dimensional electrophoresis. Following scanning and imaging of gels from three different isoelectric focusing intervals (3-10, 7-11, 6.2-7.5), automated spot handling was performed on a large number of gel spots including those found to differ more than 20% between the treated and untreated condition. Subsequently, differentially regulated proteins were subjected to a three-step approach of mass spectrometry using (a) matrix-assisted laser desorption/ionization time-of-flight mass spectrometry peptide mass fingerprinting, (b) post-source decay utilizing chemically assisted fragmentation, and (c) liquid chromatography-tandem mass spectrometry. Using this approach we have so far resolved 121 differentially regulated proteins following treatment of mice with the candidate drug and identified 110 of these using mass spectrometry. Such data can potentially give improved molecular insight into the metabolism of drugs as well as the proteins involved in potential toxicity following the treatment. The differentially regulated proteins could be used as targets for metabolic studies or as markers for toxicity. PMID:15585823

  8. Absorption, distribution, metabolism, and excretion of macitentan, a dual endothelin receptor antagonist, in humans.

    Bruderer, Shirin; Hopfgartner, Gérard; Seiberling, Michael; Wank, Janine; Sidharta, Patricia N; Treiber, Alexander; Dingemanse, Jasper

    2012-09-01

    Macitentan is a tissue-targeting, dual endothelin receptor antagonist, currently under phase 3 investigation in pulmonary arterial hypertension. In this study the disposition and metabolism of macitentan were investigated following administration of a single oral 10 mg dose of (14)C-macitentan to six healthy male subjects. The total radioactivity in matrices was determined using liquid scintillation counting. The proposed structure of metabolites was based on mass spectrometry characteristics and, when available, confirmed by comparison with reference compounds. Mean (± SD) cumulative recovery of radioactivity from faeces and urine was 73.6% (± 6.2%) of the administered radioactive dose, with 49.7% (± 3.9%) cumulative recovery from urine, and 23.9% (± 4.8%) from faeces. In plasma, in addition to parent macitentan, ACT-132577, a pharmacologically active metabolite elicited by oxidative depropylation and the carboxylic acid metabolite ACT-373898 were identified. In urine, four entities were identified, with the hydrolysis product of ACT-373898 as the most abundant one. In faeces, five entities were identified, with the hydrolysis product of macitentan and ACT-132577 as the most abundant one. Concentrations of total radioactivity in whole blood were lower compared to plasma, which indicates that macitentan and its metabolites poorly bind to or penetrate into erythrocytes. PMID:22458347

  9. Absorption, distribution, metabolism, and excretion of the novel antibacterial prodrug tedizolid phosphate.

    Ong, Voon; Flanagan, Shawn; Fang, Edward; Dreskin, Howard J; Locke, Jeffrey B; Bartizal, Kenneth; Prokocimer, Philippe

    2014-08-01

    Tedizolid phosphate is a novel antibacterial prodrug with potent activity against Gram-positive pathogens. In vitro and in vivo studies demonstrated that the prodrug is rapidly converted by nonspecific phosphatases to the biologically active moiety tedizolid. Single oral dose radiolabeled (14)C-tedizolid phosphate kinetic studies in human subjects (100 µCi in 204 mg tedizolid phosphate free acid) confirmed a rapid time to maximum tedizolid concentration (Tmax, 1.28 hours), a long terminal half-life (10.6 hours), and a Cmax of 1.99 µg/ml. Metabolite analysis of plasma, fecal, and urine samples from rats, dogs, and humans confirmed that tedizolid is the only measurable metabolite in plasma after intravenous (in animals only) or oral administration and that tedizolid sulfate is the major metabolite excreted from the body. Excellent mass balance recovery was achieved and demonstrated that fecal excretion is the predominant (80-90%) route of elimination across species, primarily as tedizolid sulfate. Urine excretion accounted for the balance of drug elimination but contained a broader range of minor metabolites. Glucuronidation products were not detected. Similar results were observed in rats and dogs after both intravenous and oral administration. The tedizolid metabolites showed less potent antibacterial activity than tedizolid. The observations from these studies support once daily dosing of tedizolid phosphate and highlight important metabolism and excretion features that differentiate tedizolid phosphate from linezolid. PMID:24875463

  10. Absorption and Metabolism of Xanthophylls

    Eiichi Kotake-Nara

    2011-06-01

    Full Text Available Dietary carotenoids, especially xanthophylls, have attracted significant attention because of their characteristic biological activities, including anti-allergic, anti-cancer, and anti-obese actions. Although no less than forty carotenoids are ingested under usual dietary habits, only six carotenoids and their metabolites have been found in human tissues, suggesting selectivity in the intestinal absorption of carotenoids. Recently, facilitated diffusion in addition to simple diffusion has been reported to mediate the intestinal absorption of carotenoids in mammals. The selective absorption of carotenoids may be caused by uptake to the intestinal epithelia by the facilitated diffusion and an unknown excretion to intestinal lumen. It is well known that β-carotene can be metabolized to vitamin A after intestinal absorption of carotenoids, but little is known about the metabolic transformation of non provitamin A xanthophylls. The enzymatic oxidation of the secondary hydroxyl group leading to keto-carotenoids would occur as a common pathway of xanthophyll metabolism in mammals. This paper reviews the absorption and metabolism of xanthophylls by introducing recent advances in this field.

  11. Absorption, distribution, metabolism and excretion of selenium following oral administration of elemental selenium nanoparticles or selenite in rats

    Löschner, Katrin; Hadrup, Niels; Hansen, Marianne;

    2014-01-01

    A suspension of nanoparticles of BSA-stabilized red amorphous elemental selenium (Se) or an aqueous solution of sodium selenite was repeatedly administered by oral gavage for 28 days at 0.05 mg/kg bw/day (low dose) or at 0.5 mg/kg bw/day (high dose) as Se to female rats. Prior to administration......, the size distribution of the Se nanoparticles was characterized by dynamic light scattering and transmission electron microscopy, which showed that the particles’ mean diameter was 19 nm and ranged in size from 10-80 nm. Following administration of the high dose of Se nanoparticles or selenite the...... concentration of Se was determined by ICP-MS in liver, kidney, urine, feces, stomach, lungs, plasma at µg/g level and in brain and muscle tissue at sub-µg/g level. In order to test if any elemental Se was present in liver, kidney or feces, an in situ derivatization selective to elemental Se was made by...

  12. The colon: Absorptive, seccretory and metabolic functions.

    Cummings, J G

    1975-01-01

    The role which the human colon fulfils in digestion and metabolism remains largely undocumented. Its capacity to conserve water and electrolytes is well known although how this is controlled is uncertain. In the animal kingdom, calcium and magnesium absorption from the colon are improtant as are absorption and synthesis of vitamins. The abundant microflora of the human colon gives it unique properties. Dietary residue is metabolised forming short-chain fatty acids, hydrogen, carbon dioxide and methane; whilst 20% of urea synthesised in man is broken down in the colon to ammonia, which is reabsorbed, and carbonic acid. The microflora also degrades a wide variety of organic compounds including food additives, drugs, bile salts, and cholesterol which may be relevant to the development of colon cancer. Regional differences in colonic function also exist making interpretation of data from this relatively inaccessible organ more difficult. PMID:1205009

  13. Absorption and metabolism of the absorption enhancer didecanoylphosphatidylcholine in rabbit nasal epithelium in vivo

    Vermehren, C.; Johansen, P.B.; Hansen, Harald S.

    1997-01-01

    The absorption enhancer, didecanoylphosphatidylcholine (DDPC), improves the nasal absorption of human growth hormone in rabbits. We elucidated the uptake and the metabolism of 1,2-di[1-C]decanoyl-L-3-phosphatidylcholine and 1,2-didecanoyl-L-3-phosphatidyl[N-methyl-H]choline in rabbit nasal mucosa...

  14. Absorption and metabolic fate of bioactive dietary benzoxazinoids in humans

    Adhikari, Khem B; Laursen, Bente B; Gregersen, Per L;

    2013-01-01

    Scope Benzoxazinoids, which are natural compounds recently identified in mature whole grain cereals and bakery products, have been suggested to have a range of pharmacological properties and health-protecting effects. There are no published reports concerned with the absorption and metabolism of...... bioactive benzoxazinoids in humans. Methods and results The absorption, metabolism, and excretion of ten different dietary benzoxazinoids were examined by LC-MS/MS by analyzing plasma and urine from 20 healthy human volunteers after daily intake of 143 μmol of total benzoxazinoids from rye bread and rye...... benzoxazinoids with abundant HBOA-Glc (219 nmol × μmol−1 of creatinine). The sulfate and glucuronide conjugates of 2-hydroxy-1,4-benzoxazin-3-one (HBOA) and 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) were detected in plasma and urine, indicating substantial phase II metabolism. Direct absorption of lactam...

  15. Absorption and metabolism of benzoic acid in growing pigs

    Kristensen, N B; Nørgaard, J V; Wamberg, S; Engbæk, M; Fernández, J A; Zacho, H D; Poulsen, H D

    2009-01-01

    Dietary benzoic acid (BA) supplementation causes a pronounced reduction in urinary pH but only small changes in blood pH. The present study aimed to investigate the portal absorption profile, hepatic metabolism of BA, and renal excretion of hippuric acid (HA) underlying the relatively small impact...

  16. Absorption Measure Distribution in Mrk 509

    Adhikari, T. P.; Różańska, A.; Sobolewska, M.; Czerny, B.

    2015-12-01

    In this paper we model the observed absorption measure distribution (AMD) in Mrk 509, which spans three orders of magnitude in ionization level with a single-zone absorber in pressure equilibrium. AMD is usually constructed from observations of narrow absorption lines in radio-quiet active galaxies with warm absorbers. We study the properties of the warm absorber in Mrk 509 using recently published broadband spectral energy distribution observed with different instruments. This spectrum is an input in radiative transfer computations with full photoionization treatment using the titan code. We show that the simplest way to fully reproduce the shape of AMD is to assume that the warm absorber is a single zone under constant total pressure. With this assumption, we found theoretical AMD that matches the observed AMD determined on the basis of the 600 ks reflection grating spectrometer XMM-Newton spectrum of Mrk 509. The softness of the source spectrum and the important role of the free-free emission breaks the usual degeneracy in the ionization state calculations, and the explicit dependence of the depths of AMD dips on density open a new path to the density diagnostic for the warm absorber. In Mrk 509, the implied density is of the order of 108 cm-3.

  17. Docking mode of delvardine and its analogues into the p66 domain of HIV-1 reverse transcriptase: screening using molecular mechanics-generalized born/surface area and absorption, distribution, metabolism and excretion properties

    Dipankar Sengupta; Deeptak Verma; Pradeep K Naik

    2007-12-01

    Delvardine and its structural derivatives are important non-nucleoside HIV-1 reverse transcriptase inhibitors (NNRTIs). In this work, 15 delvardine analogues were studied. A free energy-of-binding (FEB) expression was developed in the form of an optimized linear combination of van der Waal (vdW), electrostatic, solvation and solvent-accessible surface area (SASA) energy terms. The solvation energy terms estimated by generalized born/surface area (GB/SA) play an important role in predicting the binding affinity of delvardine analogues. Out of 15 derivatives, substitution of CH3 with H at the Y and R positions, as well as substitution of SO2CH3 with only CH2 at the Z position in S2, S8 and S12 analogues, were found to be the most potent (glide score = –7.60, –8.06 and –7.44; pIC50 = 7.28, 7.37 and 7.64) in comparison with the template delvardine (which is used currently as the drug candidate). All the three analogues also passed the absorption, distribution, metabolism and excretion (ADME) screening and Lipinski’s rule of 5, and have the potential to be used for second-generation drug development. The work demonstrates that dock molecular mechanics-generalized born/surface area (MM–GB/SA–ADME) is a promising approach to predict the binding activity of ligands to the receptor and further screen for a successful candidate drug in a computer-aided rational drug design.

  18. Gastrointestinal absorption and metabolism of capsaicin and dihydrocapsaicin in rats

    Kawada, T.; Suzuki, T.; Takahashi, M.; Iwai, K.

    1984-03-15

    Gastrointestinal absorption of capsaicin and dihydrocapsaicin was studied in rats in vivo and in situ. Rapid absorption of capsaicin or dihydrocapsaicin from stomach and small intestine occurred in vivo. About 85% of the dose was absorbed in the gastrointestinal tract within 3 hr. In situ, within 60 min after the administration of capsaicin and dihydrocapsaicin into stomach, jejunum, and ileum, about 50, 80, and 70% of the respective dose had disappeared from the lumen. When 2,4-dinitrophenol or NaCN was added, no significant reduction in uptake of (/sup 3/H)dihydrocapsaicin was observed in the jejunum. These results suggested that capsaicin and its analogs were absorbed by a nonactive process in jejunum. (/sup 3/H)Dihydrocapsaicin was mainly absorbed via the portal system but not a mesenteric lymphangial one. The radioactivity in the portal blood was composed of 85% of (/sup 3/H)dihydrocapsaicin and 15% of its metabolite (8-methyl nonanoic acid) bound to the albumin fraction. Dihydrocapsaicin-hydrolyzing enzyme activity was found in jejunal tissue. These results suggest that capsaicin and its analogs partly received a first-pass effect, i.e., metabolism of a compound following first absorption in the gastrointestinal tract. It is concluded that capsaicin and its analogs are readily transported to the portal vein through the gastrointestinal tract by a nonactive process and partly metabolized during absorption.

  19. Gastrointestinal absorption and metabolism of capsaicin and dihydrocapsaicin in rats

    Gastrointestinal absorption of capsaicin and dihydrocapsaicin was studied in rats in vivo and in situ. Rapid absorption of capsaicin or dihydrocapsaicin from stomach and small intestine occurred in vivo. About 85% of the dose was absorbed in the gastrointestinal tract within 3 hr. In situ, within 60 min after the administration of capsaicin and dihydrocapsaicin into stomach, jejunum, and ileum, about 50, 80, and 70% of the respective dose had disappeared from the lumen. When 2,4-dinitrophenol or NaCN was added, no significant reduction in uptake of [3H]dihydrocapsaicin was observed in the jejunum. These results suggested that capsaicin and its analogs were absorbed by a nonactive process in jejunum. [3H]Dihydrocapsaicin was mainly absorbed via the portal system but not a mesenteric lymphangial one. The radioactivity in the portal blood was composed of 85% of [3H]dihydrocapsaicin and 15% of its metabolite (8-methyl nonanoic acid) bound to the albumin fraction. Dihydrocapsaicin-hydrolyzing enzyme activity was found in jejunal tissue. These results suggest that capsaicin and its analogs partly received a first-pass effect, i.e., metabolism of a compound following first absorption in the gastrointestinal tract. It is concluded that capsaicin and its analogs are readily transported to the portal vein through the gastrointestinal tract by a nonactive process and partly metabolized during absorption

  20. Plant root absorption and metabolic fate of technetium in plants

    In this series of studies with TcO4-, root absorption characteristics and tissue distributions are discussed and the chemical fate of Tc in plants is described and compared with that of Selenium and Sulphur. Vegetable and agricultural species used included the carrot, cabbage, lettuce, pea, mustard, radish, leek, bunch and bulb onion, soybean, alfalfa and garlic. (UK)

  1. First-pass metabolism limits the intestinal absorption of enteral alpha-ketoglutarate in young pigs

    Our results in a previous study indicated that the portal absorption of intragastrically fed alpha-ketoglutarate (AKG) was limited in young pigs. Our aim was to quantify the net portal absorption, first-pass metabolism, and whole-body flux of enterally infused AKG. In study 1, we quantified the net ...

  2. Numerical calculations of the ray trace, absorption distribution and absorption efficiency of the laser beam in spherical symmetric plasmas

    The computer code ''ABS'', which can calculate the absorption rate and distribution of the laser light in spherical symmetric plasmas has been developed. The dependences of the absorption rate and distribution on the focusing position and their wavelength dependences were obtained. It was found that with a shorter wavelength laser light, the absorption nonuniformity on the fusion pellets will be reduced as well as the absorption rate will increase. (author)

  3. Interplay of metabolism and transport in determining oral drug absorption and gut wall metabolism: a simulation assessment using the "Advanced Dissolution, Absorption, Metabolism (ADAM)" model.

    Darwich, A S; Neuhoff, S; Jamei, M; Rostami-Hodjegan, A

    2010-11-01

    Bioavailability of orally administered drugs can be influenced by a number of factors including release from the formulation, dissolution, stability in the gastrointestinal (GI) environment, permeability through the gut wall and first-pass gut wall and hepatic metabolism. Although there are various enzymes in the gut wall which may contribute to gut first pass metabolism, Cytochrome P450 (CYP) 3A has been shown to play a major role. The efflux transporter P-glycoprotein (P-gp; MDR1/ABCB1) is the most extensively studied drug efflux transporter in the gut and might have a significant role in the regulation of GI absorption. Although not every CYP3A substrate will have a high extent of gut wall first-pass extraction, being a substrate for the enzyme increases the likelihood of a higher first-pass extraction. Similarly, being a P-gp substrate does not necessarily pose a problem with the gut wall absorption however it may reduce bioavailability in some cases (e.g. when drug has low passive permeability). An on-going debate has focused on the issue of the interplay between CYP3A and P-gp such that high affinity to P-gp increases the exposure of drug to CYP3A through repeated cycling via passive diffusion and active efflux, decreasing the fraction of drug that escapes first pass gut metabolism (F(G)). The presence of P-gp in the gut wall and the high affinity of some CYP3A substrates to this transporter are postulated to reduce the potential for saturating the enzymes, thus increasing gut wall first-pass metabolism for compounds which otherwise would have saturated CYP3A. Such inferences are based on assumptions in the modelling of oral drug absorption. These models should be as mechanistic as possible and tractable using available in vitro and in vivo information. We review, through simulation, this subject and examine the interplay between gut wall metabolism and efflux transporters by studying the fraction of dose absorbed into enterocytes (F(a)) and F(G) via

  4. Modelling the Absorption Measurement Distribution (AMD) for Mrk 509

    Adhikari, T.; Rozanska, A.; Sobolewska, M.; Czerny, B.

    2015-07-01

    Absorption Measurement Distribution (AMD) measures the distribution of absorbing column over a range of ionization parameters of the X-ray absorbers in Seyfert galaxies. In this work, we modeled the AMD in Mrk 509 using its recently published broad band Spectral Energy Distribution (SED). This SED is used as an input for radiative transfer computations with full photoionization treatment using the photoionization codes Titan and Cloudy. Assuming a photoionized medium with a uniform total pressure (gas+radiation), we reproduced the discontunity in the observed AMD distribution which is usually described as the region of thermal instability of the absorber. We also studied the structure and properties of the warm absorber in Mrk 509.

  5. Intestinal triacylglycerol synthesis in fat absorption and systemic energy metabolism.

    Yen, Chi-Liang Eric; Nelson, David W; Yen, Mei-I

    2015-03-01

    The intestine plays a prominent role in the biosynthesis of triacylglycerol (triglyceride; TAG). Digested dietary TAG is repackaged in the intestine to form the hydrophobic core of chylomicrons, which deliver metabolic fuels, essential fatty acids, and other lipid-soluble nutrients to the peripheral tissues. By controlling the flux of dietary fat into the circulation, intestinal TAG synthesis can greatly impact systemic metabolism. Genes encoding many of the enzymes involved in TAG synthesis have been identified. Among TAG synthesis enzymes, acyl-CoA:monoacylglycerol acyltransferase 2 and acyl-CoA:diacylglycerol acyltransferase (DGAT)1 are highly expressed in the intestine. Their physiological functions have been examined in the context of whole organisms using genetically engineered mice and, in the case of DGAT1, specific inhibitors. An emerging theme from recent findings is that limiting the rate of TAG synthesis in the intestine can modulate gut hormone secretion, lipid metabolism, and systemic energy balance. The underlying mechanisms and their implications for humans are yet to be explored. Pharmacological inhibition of TAG hydrolysis in the intestinal lumen has been employed to combat obesity and associated disorders with modest efficacy and unwanted side effects. The therapeutic potential of inhibiting specific enzymes involved in intestinal TAG synthesis warrants further investigation. PMID:25231105

  6. Reconstructing absorption and scattering distributions in quantitative photoacoustic tomography

    Quantitative photoacoustic tomography is a novel hybrid imaging technique aiming at estimating optical parameters inside tissues. The method combines (functional) optical information and accurate anatomical information obtained using ultrasound techniques. The optical inverse problem of quantitative photoacoustic tomography is to estimate the optical parameters within tissue when absorbed optical energy density is given. In this paper we consider reconstruction of absorption and scattering distributions in quantitative photoacoustic tomography. The radiative transport equation and diffusion approximation are used as light transport models and solutions in different size domains are investigated. The simulations show that scaling of the data, for example by using logarithmic data, can be expected to significantly improve the convergence of the minimization algorithm. Furthermore, both the radiative transport equation and diffusion approximation can give good estimates for absorption. However, depending on the optical properties and the size of the domain, the diffusion approximation may not produce as good estimates for scattering as the radiative transport equation. (paper)

  7. Effect of randomization of mixtures of butter oil and vegetable oil on absorption and lipid metabolism in rats

    Becker, C.; Lund, Pia; Hølmer, Gunhild Kofoed

    2001-01-01

    dietary fats compared. Data on the fate of such lipids beyond the bloodstream is rather scarce and animal model studies are needed. Aim of the study To compare the metabolism of butter oil and mixtures of butter and rapeseed oil, native or randomized, in a model. The regiospecific fatty acid distribution...... present in dietary fats was followed through absorption, chylomicron formation, and deposition in adipose tissue and in different liver lipids (triacylglycerols, phospholipids, and cholesterol esters). Methods Rats were fed for 6 weeks from weaning either butter oil (BO), a butteroil- rapeseed oil mixture...... 65:35 w/w (BR) or a randomized mixture of BR (tBR). Half of the animals were used for organ analysis, the rest for a postprandial study with the same fats and isolation of chylomicrons. The regiospecific distribution of the fatty acids present in the dietary fats was followed during metabolism by...

  8. Percutaneous absorption and metabolism of tritiated oil. I

    The chemical and radiolytic interaction of tritium with oils produces a variety of tritiated compounds. To understand the metabolic behavior and possible dosimetric consequences of tritiated oil contamination, the course of urinary tritium activity in hairless rats exposed to tritiated pump oils has been investigated. The contaminated oil was applied on the animals' skin, and the excretion of tritium in urine was assayed for 112 days, allowing for the measurement of long-term tritium retention and excretion in the body. Tritiated oil deposited on the skin provides an input of OBT (organic-bound tritium) and HTO to the body. The excretion of HTO was found to be biphasic with exponential function half-lives of 3.3 ± 0.4 days and 25.5 ± 3.5 days. Elevated levels of OBT were noticed in the urine. The excretion of OBT was analyzed in terms of fast, slow and long-term components. OBT had a much shorter effective time constant than HTO. The half-lives for these components were 1.0 ± 0.1 day, 5.4 ± 0.6 days, and 31.4 ± 1.9 days, respectively. The long-term retention of tritium in the body is attributed to metabolism and the assimilation of tritiated compounds into the body. (Author) (3 figs., 3 tabs., 11 refs.)

  9. Replacing lactose from calf milk replacers : effects on digestion and post-absorptive metabolism

    Gilbert, M.S.

    2015-01-01

    Summary PhD thesis Myrthe S. Gilbert Replacing lactose from calf milk replacers – Effects on digestion and post-absorptive metabolism Veal calves are fed milk replacer (MR) and solid feed. The largest part of the energy provided to veal calves originates from

  10. Viscous Food Matrix Influences Absorption and Excretion but Not Metabolism of Blackcurrant Anthocyanins in Rats

    Walton, M.C.; Hendriks, W.H.; Broomfield, A.M.; McGhie, T.K.

    2009-01-01

    The aim of the present study was to investigate the effect of a simultaneous intake of food and anthocyanins (ACNs) on ACN absorption, metabolism, and excretion. Blackcurrant ACNs (BcACNs) were dissolved in water with or without the addition of oatmeal and orally administered to rats, providing appr

  11. A mathematical model for the absorption and metabolism of formaldehyde vapour by humans

    Epidemiological studies of occupational exposure to formaldehyde gas (HCHO) have suggested possible links between concentration and duration of exposure, and elevated risks of leukaemia and other cancers at sites distant from the site of contact. Formaldehyde is a highly water soluble gas which, when inhaled, reacts rapidly at the site of contact and is quickly metabolised by enzymes in the respiratory tissue. Inhaled formaldehyde is almost entirely absorbed in the respiratory tract and, for formaldehyde induced toxicity to occur at distant sites, HCHO must enter the blood and be transported to systemic tissues via the circulatory system. A mathematical model describing the absorption and removal of inhaled formaldehyde in the nasal tissue is therefore formulated to predict the proportion of formaldehyde entering into the blood. Accounting for the spatial distribution of the formaldehyde concentration and the metabolic activity within the mucosa, the concentration of formaldehyde in the mucus, the epithelium and the blood has been determined and was found to attain a steady-state profile within a few seconds of exposure. The increase of the formaldehyde concentration in the blood was predicted to be insignificant compared with the existing pre-exposure levels in the body, indicating that formaldehyde is rapidly removed in the nasal tissue. The results of the model thus suggest that it is highly unlikely that following inhalation by the nose, formaldehyde itself will cause toxicity at sites other than the initial site of contact in the respiratory tract

  12. Compartmentation of glycogen metabolism revealed from 13C isotopologue distributions

    Marin de Mas Igor

    2011-10-01

    Full Text Available Abstract Background Stable isotope tracers are used to assess metabolic flux profiles in living cells. The existing methods of measurement average out the isotopic isomer distribution in metabolites throughout the cell, whereas the knowledge of compartmental organization of analyzed pathways is crucial for the evaluation of true fluxes. That is why we accepted a challenge to create a software tool that allows deciphering the compartmentation of metabolites based on the analysis of average isotopic isomer distribution. Results The software Isodyn, which simulates the dynamics of isotopic isomer distribution in central metabolic pathways, was supplemented by algorithms facilitating the transition between various analyzed metabolic schemes, and by the tools for model discrimination. It simulated 13C isotope distributions in glucose, lactate, glutamate and glycogen, measured by mass spectrometry after incubation of hepatocytes in the presence of only labeled glucose or glucose and lactate together (with label either in glucose or lactate. The simulations assumed either a single intracellular hexose phosphate pool, or also channeling of hexose phosphates resulting in a different isotopic composition of glycogen. Model discrimination test was applied to check the consistency of both models with experimental data. Metabolic flux profiles, evaluated with the accepted model that assumes channeling, revealed the range of changes in metabolic fluxes in liver cells. Conclusions The analysis of compartmentation of metabolic networks based on the measured 13C distribution was included in Isodyn as a routine procedure. The advantage of this implementation is that, being a part of evaluation of metabolic fluxes, it does not require additional experiments to study metabolic compartmentation. The analysis of experimental data revealed that the distribution of measured 13C-labeled glucose metabolites is inconsistent with the idea of perfect mixing of hexose

  13. Absorption and metabolism of triclosan after application to the skin of B6C3F1 mice.

    Fang, Jia-Long; Vanlandingham, Michelle; Gamboa da Costa, Gonçalo; Beland, Frederick A

    2016-05-01

    Triclosan is used as an antimicrobial agent in personal care products, household items, medical devices, and clinical settings. Humans can receive lifelong exposures to triclosan; however, data on the toxicity and carcinogenicity after topical application are lacking. This study determined the absorption, distribution, metabolism, and excretion of triclosan after application to the skin of B6C3F1 mice. [(14) C(U)]triclosan (10 or 100 mg triclosan/kg body weight) was administered topically to mice in two separate experiments: a vehicle selection experiment using propylene glycol, ethanol, and a generic cosmetic cream, and a toxicokinetic experiment. Mice were killed up to 72 h after triclosan administration, and excreta and tissues were analyzed for radioactivity. Ethanol had the best properties of the vehicles evaluated. Maximum absorption was obtained at approximately 12 h after dosing. Radioactivity appeared in the excreta and in all tissues examined, with the highest levels in the gall bladder and the lowest levels in the brain. Triclosan was metabolized to triclosan sulfate, triclosan glucuronide, 2,4-dichlorophenol, and hydroxytriclosan. The metabolite profile was tissue-dependent and the predominant route of excretion was fecal. The AUC0-∞ and the Cmax of plasma and liver in females were greater than those in males. Slightly lower absorption was observed in mice with Elizabethan collars. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 609-623, 2016. PMID:25410937

  14. Microbiota regulate intestinal absorption and metabolism of fatty acids in the zebrafish.

    Semova, Ivana; Carten, Juliana D; Stombaugh, Jesse; Mackey, Lantz C; Knight, Rob; Farber, Steven A; Rawls, John F

    2012-09-13

    Regulation of intestinal dietary fat absorption is critical to maintaining energy balance. While intestinal microbiota clearly impact the host's energy balance, their role in intestinal absorption and extraintestinal metabolism of dietary fat is less clear. Using in vivo imaging of fluorescent fatty acid (FA) analogs delivered to gnotobiotic zebrafish hosts, we reveal that microbiota stimulate FA uptake and lipid droplet (LD) formation in the intestinal epithelium and liver. Microbiota increase epithelial LD number in a diet-dependent manner. The presence of food led to the intestinal enrichment of bacteria from the phylum Firmicutes. Diet-enriched Firmicutes and their products were sufficient to increase epithelial LD number, whereas LD size was increased by other bacterial types. Thus, different members of the intestinal microbiota promote FA absorption via distinct mechanisms. Diet-induced alterations in microbiota composition might influence fat absorption, providing mechanistic insight into how microbiota-diet interactions regulate host energy balance. PMID:22980325

  15. Effects of heat stress on dynamic absorption process, tissue distribution and utilization efficiency of vitamin C in broilers

    The experiment was conducted to determine the effects of heat stress on ascorbic acid nutritional physiology of broilers with radioisotope technology. 3H-Vc was fed to broilers and then the blood, liver, kidney, breast muscle, and excreta were sampled to determine the dynamic absorption process, the tissue distribution and the utilization efficiency of vitamin C. The results indicated that the absorption, metabolism and mobilization of supplemented vitamin C in broilers with heat stress was faster than that in broilers without heat stress. However, the utilization efficiency of supplemented vitamin C in broilers with heat stress was not higher than that of broilers without heat stress

  16. Review of OPFRs in animals and humans: Absorption, bioaccumulation, metabolism, and internal exposure research.

    Hou, Rui; Xu, Yiping; Wang, Zijian

    2016-06-01

    Due to their widespread use, organophosphate flame retardants (OPFRs) are commonly detected in various environmental matrices and have been identified as emerging contaminants. Considering the adverse effects of OPFRs, many researchers have paid their attention on the absorption, bioaccumulation, metabolism and internal exposure processes of OPFRs in animals and humans. In this article, we first review the diverse absorption routes of OPFRs by animals and humans (e.g., inhalation, ingestion, dermal absorption and gill absorption). Bioaccumulation and biomagnification potentials of OPFRs in different types of organisms and food webs are also summarized, based on quite limited available data and results. For metabolism, we review the Phase-I and Phase-II metabolic processes for each type of OPFRs (chlorinated OPFRs, alkyl-OPFRs and aryl-OPFRs) in the animals and humans, as well as toxicokinetic information and putative exposure biomarkers on OPFRs. Finally, we highlight gaps in our knowledge and critical directions for future internal exposure studies of OPFRs in animals and humans. PMID:27010170

  17. Effect of randomization of mixtures of butter oil and vegetable oil on absorption and lipid metabolism in rats

    Becker, C.; Lund, Pia; Hølmer, Gunhild Kofoed

    2001-01-01

    present in dietary fats was followed through absorption, chylomicron formation, and deposition in adipose tissue and in different liver lipids (triacylglycerols, phospholipids, and cholesterol esters). Methods Rats were fed for 6 weeks from weaning either butter oil (BO), a butteroil- rapeseed oil mixture......Background The nutritional effect of the regiospecific distribution of fatty acids in edible fats is currently discussed due to an increased use of interesterification of fats for human consumption. However, disagreeing results have been reported which may be due to the varying composition of the...... dietary fats compared. Data on the fate of such lipids beyond the bloodstream is rather scarce and animal model studies are needed. Aim of the study To compare the metabolism of butter oil and mixtures of butter and rapeseed oil, native or randomized, in a model. The regiospecific fatty acid distribution...

  18. Systemic absorption of topical steroids. Metabolic effects as an index of mild hypercortisolism.

    Garden, J M; Freinkel, R K

    1986-09-01

    This study was undertaken to determine whether the commonly used treatment of psoriasis with potent topical glucocorticoids results in hypercortisolism and whether metabolic changes might provide a means for monitoring pharmacologic effects of excessive systemic absorption of glucocorticoids. Plasma cortisol, glucose, and insulin and circulating polymorphonuclear leukocytes were assessed under controlled conditions in five otherwise healthy patients with psoriasis (40% to 85% involvement) treated with topical desoximetasone, without occlusion. In all patients, there were rapid and sustained suppression of endogenous cortisol production, twofold to threefold increases in fasting insulin levels indicating insulin resistance, and elevated levels of polymorphonuclear leukocytes. Two patients also experienced reduced glucose tolerance. These findings suggest that application of potent corticosteroids to large areas of diseased skin results in sufficient systemic absorption to cause not only adrenal suppression but some degree of hypercortisolism with greater frequency and rapidity than has been suggested. Prospective monitoring of insulin-glucose relationships as a sensitive index of the metabolic effects of glucocorticoids may provide a means of assessing excess systemic absorption that is not predictable on the basis of adrenal suppression or circulating levels of the drug. Such prediction could have particular relevance in anticipating adverse clinical effects in the treatment of chronic skin disorders with potent topical glucocorticoids. PMID:3527074

  19. Metabolism and gastrointestinal absorption of neptunium and protactinium in adult baboons

    Ralston, L.G.; Cohen, N.; Bhattacharyya, M.H.; Larsen, R.P.; Ayres, L.; Oldham, R.D.; Moretti, E.S.

    1985-01-01

    The metabolism of neptunium and protactinium was studied in adult female baboons following intravenous injection and intragastric intubation. Immediately following intravenous injection (10/sup -1/ to 10/sup -10/ mg Np per kg body wt), neptunium cleared rapidly from blood, deposited primarily in the skeleton (54 +- 5%) and liver (3 +- 0.2%), and was excreted predominantly via urine (40 +- 3%). For the first year post injection, neptunium was retained with a biological half-time of approx.100 days in liver and 1.5 +- 0.2 yr in bone. In comparison, injected protactinium (10/sup -9/ mg/kg) was retained in blood in higher concentrations and was initially eliminated in urine to a lesser extent (6 +- 3%). In vivo measurements indicated that protactinium was retained in bone (65 +- 0.3%) with a half-time of 3.5 +- 0.6 yr. Differences in the physicochemical states of the neptunium or protactinium solutions injected did not alter the metabolic behavior of these nuclides. The gastrointestinal absorption value for neptunium in two fasted baboons, sacrificed at 1 day post administration, was determined to be 0.92 +- 0.04%. Of the total amount of neptunium absorbed, 52 +- 3% was retained in bone, 6 +- 2% was in liver, and 42 +- 0.1% was excreted in urine. A method was developed to estimate GI absorption values for both nuclides in baboons which were not sacrificed. Absorption values calculated by this method for neptunium and protactinium in fasted baboons were 1.8 +- 0.8% and 0.65 +- 0.01%, respectively. Values for fed animals were 1 to 2 orders of magnitude less than those for fasted animals. 14 refs., 3 figs., 4 tabs. (DT)

  20. The metabolism and gastrointestinal absorption of neptunium and protactinium in adult baboons

    The metabolism of neptunium and protactinium was studied in adult female baboons following intravenous injection and intragastric intubation. Neptunium-239, Np-237, and Pa-233 were prepared as either citrate-buffer, nitrate, or bicarbonate solutions with oxidation states of (V) and (VI). Samples of blood, urine, feces and autopsy tissues were measured by gamma spectrometry. Retention of neptunium and protactinium was determined in vivo using whole and partial body gamma-scintillation spectrometry with [NaI-CsI(T1)] detectors. Fed and fasted baboons were administered solutions of Np(VI) bicarbonate (10/sup -8/ to 10/sup -1/ mg/kg) and Pa(V) citrate-buffer (10/sup -9/ mg/kg) by gavage. The gastrointestinal absorption value for neptunium in two fasted baboons, sacrificed at 1 day post administration, was determined to be 0.92 +- 0.04%. Of the total amount of neptunium absorbed, 52 +- 3% was retained in bone, 6 + 2% was in liver, and 42 +- 0.1% was excreted in urine. The metabolism of neptunium followed oral and iv administrations was found to be similar. This observation was also true for baboons which had received oral and iv doses of protactinium. A method was developed to estimate GI absorption values for both nuclides in baboons, which were not sacrificed, by comparison of activities present in bioassay samples after injection and gavage. Absorption values calculated by this method for neptunium and protactinium in fasted baboons were 1.8 +- 0.8% and 0.65 +- 0.01%, respectively. Values for fed animals were 1 to 2 orders of magnitude less than those for fasted animals. Further experiments are currently underway to evaluate this assay technique

  1. Lipid metabolizing enzyme activities modulated by phospholipid substrate lateral distribution.

    Salinas, Dino G; Reyes, Juan G; De la Fuente, Milton

    2011-09-01

    Biological membranes contain many domains enriched in phospholipid lipids and there is not yet clear explanation about how these domains can control the activity of phospholipid metabolizing enzymes. Here we used the surface dilution kinetic theory to derive general equations describing how complex substrate distributions affect the activity of enzymes following either the phospholipid binding kinetic model (which assumes that the enzyme molecules directly bind the phospholipid substrate molecules), or the surface-binding kinetic model (which assumes that the enzyme molecules bind to the membrane before binding the phospholipid substrate). Our results strongly suggest that, if the enzyme follows the phospholipid binding kinetic model, any substrate redistribution would increase the enzyme activity over than observed for a homogeneous distribution of substrate. Besides, enzymes following the surface-binding model would be independent of the substrate distribution. Given that the distribution of substrate in a population of micelles (each of them a lipid domain) should follow a Poisson law, we demonstrate that the general equations give an excellent fit to experimental data of lipases acting on micelles, providing reasonable values for kinetic parameters--without invoking special effects such as cooperative phenomena. Our theory will allow a better understanding of the cellular-metabolism control in membranes, as well as a more simple analysis of the mechanisms of membrane acting enzymes. PMID:21108012

  2. Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro.

    Manwaring, John; Rothe, Helga; Obringer, Cindy; Foltz, David J; Baker, Timothy R; Troutman, John A; Hewitt, Nicola J; Goebel, Carsten

    2015-09-01

    Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis-Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte Km and Vmax values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and Cmax was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. PMID:26028483

  3. Effect of phytohormones on absorption and distribution of ions in salt-stressed bean plants

    Zofia Starck

    2014-02-01

    Full Text Available Bean plant seedlings grown in water culture were treated for 5 days either with NaCl or with 7-times concentrated nutrient solution (diminished water potential by 3-103 hPa in both cases. Control and stressed plants were treated for 24 hrs with zeatin and GA,. NaCl-stress reduced distinctly ion absorption rate (K, Ca and P. Zeatin and GA3 promoted potassium uptake, but only in NaCI-treated plants. These hormones diminished Na accumulation in metabolically active organs but increased P- and Ca-content. In plants grown under both kind of stresses zeatin and GA3 partially reestablished the ratio of the main mono- to divalent cations, which increased in the leaves and apical part of the stressed plants. ABA introduced into the nutrient solution caused inhibition of the ion uptake (K, Ca, Mg and P. similar to that caused by NaCl-stress. The above reported results seem to confirm the supposition, that hormones act as an important factor contributing to regulation of both uptake and distribution of ions. In this way growth substances may also participate in the regulation of transport of various substances (among others - assimilates in the whole plant.

  4. Animal metabolism

    Studies on placental transport included the following: clearance of tritiated water as a baseline measurement for transport of materials across perfused placentas; transport of organic and inorganic mercury across the perfused placenta of the guinea pig in late gestation; and transport of cadmium across the perfused placenta of the guinea pig in late gestation. Studies on cadmium absorption and metabolism included the following: intestinal absorption and retention of cadmium in neonatal rats; uptake and distribution of an oral dose of cadmium in postweanling male and female, iron-deficient and normal rats; postnatal viability and growth in rat pups after oral cadmium administration during gestation; and the effect of calcium and phosphorus on the absorption and toxicity of cadmium. Studies on gastrointestinal absorption and mineral metabolism included: uptake and distribution of orally administered plutonium complex compounds in male mice; gastrointestinal absorption of 144Ce in the newborn mouse, rat, and pig; and gastrointestinal absorption of 95Nb by rats of different ages. Studies on iodine metabolism included the following: influence of thyroid status and thiocyanate on iodine metabolism in the bovine; effects of simulated fallout radiation on iodine metabolism in dairy cattle; and effects of feeding iodine binding agents on iodine metabolism in the calf

  5. Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro

    Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis–Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte Km and Vmax values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and Cmax was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. - Highlights: • An entirely in silico/in vitro approach to predict in vivo exposure to dermally applied hair dyes • Skin penetration and epidermal conversion assessed in human skin explants and Ha

  6. Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro

    Manwaring, John, E-mail: manwaring.jd@pg.com [Procter & Gamble Inc., Mason Business Center, Mason, OH 45040 (United States); Rothe, Helga [Procter & Gamble Service GmbH, Sulzbacher Str. 40, 65823 Schwalbach am Taunus (Germany); Obringer, Cindy; Foltz, David J.; Baker, Timothy R.; Troutman, John A. [Procter & Gamble Inc., Mason Business Center, Mason, OH 45040 (United States); Hewitt, Nicola J. [SWS, Erzhausen (Germany); Goebel, Carsten [Procter & Gamble Service GmbH, Sulzbacher Str. 40, 65823 Schwalbach am Taunus (Germany)

    2015-09-01

    Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis–Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte K{sub m} and V{sub max} values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and C{sub max} was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. - Highlights: • An entirely in silico/in vitro approach to predict in vivo exposure to dermally applied hair dyes • Skin penetration and epidermal conversion assessed in human

  7. Polarized Synchrotron Emissivities and Absorptivities for Relativistic Thermal, Power-Law, and Kappa Distribution Functions

    Pandya, Alex; Chandra, Mani; Gammie, Charles F

    2016-01-01

    Synchrotron emission and absorption determine the observational appearance of many astronomical systems. In this paper, we describe a numerical scheme for calculating synchrotron emissivities and absorptivities in all four Stokes parameters for arbitrary gyrotropic electron distribution functions, building on earlier work by Leung, Gammie, and Noble. We use this technique to evaluate the emissivities and the absorptivities for a thermal (Maxwell-J\\"uttner), isotropic power-law, and isotropic kappa distribution function. The latter contains a power-law tail at high particle energies that smoothly merges with a thermal core at low energies, as is characteristic of observed particle spectra in collisionless plasmas. We provide fitting formulae and error bounds on the fitting formulae for use in codes that solve the radiative transfer equation. The numerical method and the fitting formulae are implemented in a compact C library called ${\\tt symphony}$. We find that: the kappa distribution has a source function th...

  8. Distribution of hydrogen-metabolizing bacteria in alfalfa field soil

    H2 evolved by alfalfa root nodules during the process of N2 fixation may be an important factor influencing the distribution of soil bacteria. To test this hypothesis under field conditions, over 700 bacterial isolates were obtained from fallow soil or from the 3-mm layer of soil surrounding alfalfa (Medicago sativa L.) root nodules, alfalfa roots, or bindweed (Convolvulus arvensis L.) roots. Bacteria were isolated under either aerobic or microaerophilic conditions and were tested for their capacity to metabolize H2. Isolates showing net H2 uptake and 3H2 incorporation activity under laboratory conditions were assigned a Hup+ phenotype, whereas organisms with significant H2 output capacity were designated as a Hout+ phenotype. Under aerobic isolation conditions two Hup+ isolates were obtained, whereas under microaerophilic conditions five Hup+ and two Hout+ isolates were found. The nine isolates differed on the basis of 24 standard bacteriological characteristics or fatty acid composition. Five of the nine organisms were isolated from soil around root nodules, whereas the other four were found distributed among the other three soil environments. On the basis of the microaerophilic isolations, 4.8% of the total procaryotic isolates from soil around root nodules were capable of oxidizing H2, and 1.2% could produce H2. Two of the Hup+ isolates were identified as Rhizobium meliloti by root nodulation tests, but the fact that none of the isolates reduced C2H2 under the assay conditions suggested that the H2 metabolism traits were associated with various hydrogenase systems rather than with nitrogenase activity

  9. Absorption and initial metabolism of 75Se-l-selenomethionine

    Grosse Ruse, Mareile; Søndergaard, Lasse R.; Ditlevsen, Susanne;

    2015-01-01

    -SeMet). Scanning started simultaneously to the ingestion of 75Se-SeMet and lasted 120 min. We generated time-activity curves from two-dimensional regions of interest in the stomach, small intestine and liver. During scanning, blood samples were collected at 10-min intervals to generate plasma time-activity curves....... A four-compartment model, augmented with a delay between the liver and plasma, was fitted to individual participants’ data. The mean rate constant for 75Se-SeMet transport was 2·63 h–1 from the stomach to the small intestine, 13·2 h–1 from the small intestine to the liver, 0·261 h–1 from the liver...... to the plasma and 0·267 h–1 from the stomach to the plasma. The delay in the liver was 0·714 h. Gamma camera imaging provides data for use in compartmental modelling of 75Se-SeMet absorption and metabolism in humans. In clinical settings, the obtained rate constants and the delay in the liver may be useful...

  10. Analytical algorithm to determine the spherical particle size distribution from spectral absorption measurements

    Zhao, Jian-Qi; Li, Jiangnan

    2015-11-01

    A modified anomalous diffraction theory (MADT) by including the effects of reflection and refraction is proposed. With respect to MADT, an analytical technique for retrieval of spherical particle size distribution (PSD), based on absorption was developed. Also, an MADT transform pair between the size distribution and the absorption spectrum was constructed. This provides a new tool to study the related particle optical properties. By Gaver-Stehfest inversion method, the derived complex-inversion formula is finally converted into the new real-inversion formula so that the measured absorption data can be applied directly. The inversion experiments show that the use of extended precision instead of double precision arithmetic can produce more reliable results at the expense of CPU time. The effects of complex refractive index on retrieval of PSD were examined. Also it was found that an appropriate reduction of the truncation number with the smoothing technique improved the anti-noise ability for the algorithm.

  11. Automated low energy photon absorption equipment for measuring internal moisture and density distributions of wood samples

    Automated equipment for measuring the moisture and density distributions of wood samples was developed. Using a narrow beam of gamma rays, the equipment scans the wood samples, which are placed on the moving belt. The moisture measurement is based on the 241Am photon absorption technique (59.5 keV), where the difference of the linear absorption coefficients of the moist and dry wood is measured. The method requires no knowledge of the thickness of the specimen. The density estimation method is based on the measurement of the linear attenuation coefficient of wood. Comprehensive software including image processing was developed for treatment of the numerical values of the measurements. (author)

  12. Absorption of electron cyclotron waves by super-thermal electron velocity distribution in Tokamak plasmas

    We consider a Tokamak plasma in which the distribution of electron velocities in the direction paralletl to the magnetic field has a monotonically decreasing superthermal tail. A fully three-dimensional ray-tracing code is used to calculate the absorption of the extraordinary mode in the nonrelativistic limit. The results indicate that small tails (tail fraction <= 0.5%) can significantly affect wave absorption at low densities. In a high-density plasma where the extraordinary mode cutoff is present, tail electrons can cause substantial absorption. The use of a gyrotron with frequency much less than the central electron cyclotron frequency with an outside launch position is found to be verg effective in the presence of tail electrons. (author)

  13. Distribution of radiosodium in the various organs of Sorghum after root absorption

    The kinetics of Na22 migration corroborate the distribution pattern of the non-radioactive element after root absorption: the sodium content of the leaf laminae is very low whereas a building-up is observed in the conductive tissues, particularly in the roots. After absorption, sodium seems to be rapidly translocated to all the organs, then moves downwards to accumulate in the roots; this phenomenon may be a way, for the plant, to fight sodium intoxication. The absorption of radiosodium is independent of the specific activity of the nutrient solution and appears to be related to its volumic activity. Thus, sodium is not taken up selectively by the roots of Sorghum; its translocation mechanism is therefore of the passive type

  14. Distribution fitting 12. Sampling distribution of compounds abundance from plant species measured by instrumentation. Application to plants metabolism classification

    Jäntschi, Lorentz; Bolboacă, Sorana D.; Sestraş, Radu E.

    2011-01-01

    A series of ten plant species belonging to Magnoliopsida - Dicotyledons class were analyzed in terms of chemical compounds distribution of abundance, starting from the assumption that these distributions should give a picture of similarities and differences between plants metabolism. From a pool of theoretical distributions, log-normal distribution was selected giving the best accuracy with the modeled phenomena and agreement with the observed data. From obtained lognormal distributions stati...

  15. Polarized Synchrotron Emissivities and Absorptivities for Relativistic Thermal, Power-law, and Kappa Distribution Functions

    Pandya, Alex; Zhang, Zhaowei; Chandra, Mani; Gammie, Charles F.

    2016-05-01

    Synchrotron emission and absorption determine the observational appearances of many astronomical systems. In this paper, we describe a numerical scheme for calculating synchrotron emissivities and absorptivities in all four Stokes parameters for arbitrary gyrotropic electron distribution functions, building on earlier work by Leung, Gammie, and Noble. We use this technique to evaluate the emissivities and the absorptivities for a thermal (Maxwell–Jüttner), isotropic power-law, and an isotropic kappa distribution function. The latter contains a power-law tail at high particle energies that smoothly merges with a thermal core at low energies, as is characteristic of observed particle spectra in collisionless plasmas. We provide fitting formulae and error bounds on the fitting formulae for use in codes that solve the radiative transfer equation. The numerical method and the fitting formulae are implemented in a compact C library called symphony. We find that the kappa distribution has a source function that is indistinguishable from a thermal spectrum at low frequency and transitions to the characteristic self-absorbed synchrotron spectrum, \\propto {ν }5/2, at high frequency; the linear polarization fraction for a thermal spectrum is near unity at high frequency; and all distributions produce O(10%) circular polarization at low frequency for lines of sight sufficiently close to the magnetic field vector.

  16. Distribution and metabolism of carbofuran in paddy rice

    A study was conducted to evaluate slow release formulations of carbofuran in aquatic systems. Laboratory, greenhouse and field experiments in rice paddy were carried out to determine the behaviour and fate of the important systemic insecticide carbofuran after application of new formulations. The release rates into water and the residues in the plant and soil were determined. Metabolites were identified by gas chromatography/mass spectrometry. Carbon-14 labelled carbofuran was used for the experiments. The results showed that the cellulose based (hydroxyethyl-cellulose) formulations released the active ingredient carbofuran at a significantly slow rate, compared to commercial formulations, but that the concentration of carbofuran in water and plants was high enough to protect the plants against insects. Recovery of the applied insecticide in the rice paddy was only about 30%. Most of it was lost by evaporation, which could be confirmed in laboratory and glass house experiments. The radioactivity found in grain and straw was 0.03% and 0.2%, respectively. The distribution of carbofuran in soil at different layers was: 0-5 cm: 17%, 5-15 cm: 7%, 15-25 cm: 4%, 25-40 cm: 2%. Less than 10% of the total radioactivity could be extracted from plants (Soxhlet extraction with acetonitrile and methanol); thus, most of the carbofuran was metabolized and bound to the plant/grain constituents. It was concluded that by using different natural polymers, and some combinations of them for formulations, release rates of carbofuran in aquatic systems could be slowed down. Simple formulation procedures and low prices would also permit application of formulations in less developed countries. 5 refs, 6 figs, 4 tabs

  17. Comparative absorption, distribution, and excretion of titanium dioxide and zinc oxide nanoparticles after repeated oral administration

    Cho, Wan-Seob; Kang, Byeong-Cheol; Lee, Jong Kwon; Jeong, Jayoung; Che, Jeong-Hwan; Seok, Seung H

    2013-01-01

    BACKGROUND:The in vivo kinetics of nanoparticles is an essential to understand the hazard of nanoparticles. Here, the absorption, distribution, and excretion patterns of titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles following oral administration were evaluated.METHODS:Nanoparticles were orally administered to rats for 13 weeks (7 days/week). Samples of blood, tissues (liver, kidneys, spleen, and brain), urine, and feces were obtained at necropsy. The level of Ti or Zn in each sam...

  18. Effects of gastric bypass surgery on glucose absorption and metabolism during a mixed meal in glucose-tolerant individuals

    Jacobsen, Siv H; Bojsen-Møller, Kirstine N; Dirksen, Carsten;

    2013-01-01

    after RYGB is rapid entry of glucose into the systemic circulation due to modified gastrointestinal anatomy, causing hypersecretion of insulin and other hormones influencing glucose disappearance and endogenous glucose production. METHODS: We determined glucose absorption and metabolism and the rate of...... RYGB. Endogenous glucose production was similar before and after surgery. Postoperative glucagon secretion increased and showed a biphasic response after RYGB. Adipose tissue basal rate of lipolysis was higher after RYGB. CONCLUSIONS/INTERPRETATION: A rapid rate of absorption of ingested glucose into...... lipolysis before and 3 months after RYGB in obese glucose-tolerant individuals using the double-tracer technique during a mixed meal. RESULTS: After RYGB, the postprandial plasma glucose profile changed, with a higher peak glucose concentration followed by a faster return to lower than basal levels. These...

  19. Recent discoveries on absorption of dietary fat: Presence, synthesis, and metabolism of cytoplasmic lipid droplets within enterocytes.

    D'Aquila, Theresa; Hung, Yu-Han; Carreiro, Alicia; Buhman, Kimberly K

    2016-08-01

    Dietary fat provides essential nutrients, contributes to energy balance, and regulates blood lipid concentrations. These functions are important to health, but can also become dysregulated and contribute to diseases such as obesity, diabetes, cardiovascular disease, and cancer. Within enterocytes, the digestive products of dietary fat are re-synthesized into triacylglycerol, which is either secreted on chylomicrons or stored within cytoplasmic lipid droplets (CLDs). CLDs were originally thought to be inert stores of neutral lipids, but are now recognized as dynamic organelles that function in multiple cellular processes in addition to lipid metabolism. This review will highlight recent discoveries related to dietary fat absorption with an emphasis on the presence, synthesis, and metabolism of CLDs within this process. PMID:27108063

  20. X-ray absorption of the Hg distribution in metal-halide lamps

    Nimalasuriya, T; Zhu, X; Ridderhof, E J; Haverlag, M; Denisova, N; Stoffels, W W; Mullen, J J A M van der [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)

    2008-01-21

    Spatial temperature profiles of metal-halide lamps have been acquired using x-ray absorption of the Hg density distribution. The temperature profiles were determined by combining the measured absorption of the spatially resolved Hg density with the wall temperature. The data analysis of x-ray absorption is extensive. After the necessary image reconstruction, the line integrated density profile needs to be Abel inverted. The solution from the Abel inversion is stabilized with the Tikhonov regularization parameter. The previous method for x-ray absorption developed in our group has been modified and improved by utilizing the following: (1) a larger outer bulb, (2) the corrections for x-ray scattering on the lamp materials, (3) an optimum value of Tikhonov regularization parameter {mu}, and (4) employing a higher degree of polynomials used for the Abel inversion. For a similar lamp as reported previously by Zhu, we found an axis temperature of 6200 K instead of 5200 K. The higher temperature is similar to what is found using optical spectroscopic methods. Typical results from a metal-halide lamp with and without salts are shown.

  1. X-ray absorption of the Hg distribution in metal-halide lamps

    Spatial temperature profiles of metal-halide lamps have been acquired using x-ray absorption of the Hg density distribution. The temperature profiles were determined by combining the measured absorption of the spatially resolved Hg density with the wall temperature. The data analysis of x-ray absorption is extensive. After the necessary image reconstruction, the line integrated density profile needs to be Abel inverted. The solution from the Abel inversion is stabilized with the Tikhonov regularization parameter. The previous method for x-ray absorption developed in our group has been modified and improved by utilizing the following: (1) a larger outer bulb, (2) the corrections for x-ray scattering on the lamp materials, (3) an optimum value of Tikhonov regularization parameter μ, and (4) employing a higher degree of polynomials used for the Abel inversion. For a similar lamp as reported previously by Zhu, we found an axis temperature of 6200 K instead of 5200 K. The higher temperature is similar to what is found using optical spectroscopic methods. Typical results from a metal-halide lamp with and without salts are shown

  2. Investigation into the flux distribution of central carbon metabolism in Corynebacterium glutamicum using principal component analysis

    Shang Chuanyu

    2015-01-01

    Full Text Available Central carbon metabolism is the main source of energy required by organisms and it provides precursors for other in vivo metabolic processes. The flux flowing through the pathways involved in central carbon metabolism characterizes its biological function and genetic readout between species or environments. In recent years, using a 13C tracer technique, researchers have measured the flux of central carbon metabolism in Corynebacterium glutamicum under a variety of nutritional and environmental changes or genetic modifications. However, there is no integrated and comparative analysis of these measured flux values. In this study, the flux values of central carbon metabolism in Corynebacterium glutamicum that were obtained in other recent studies were consolidated. A preliminary examination of the distribution characteristics of flux values in each metabolic pathway was conducted and the regression relationship between different fluxes was investigated. The principal components of the flux vector were further extracted and aggregated based on the components, and the general features of flux distribution of central carbon metabolism as well as the influence of environmental and genetic factors on the flux distribution were determined. This study provides a foundation for further investigation into the flux distribution and regulation characteristics of central carbon metabolism.

  3. MAMMALIAN METABOLISM AND DISTRIBUTION OF PERFLUOROOCTYL ETHANOL (8-2 TELOMER ALCOHOL) AND ITS OXIDATION METABOLITES

    Perfluorinated compounds have been shown to be globally distributed, bioaccumulative, persistent and potentially toxic. It has been hypothesized that many precursor fluorinated compounds, including the telomer alcohols, degrade or metabolize to the common metabolite PFOA.

  4. Extensive gut metabolism limits the intestinal absorption of excessive supplemental dietary glutamate loads in infant pigs

    Glutamate (Glu) is a major intestinal oxidative fuel, key neurotransmitter, and may be a useful dietary supplement to augment health of the infant gut. We quantified the metabolic fate of various supplemental dietary Glu intakes in young pigs surgically implanted with vascular, intraduodenal (ID), o...

  5. Absorption and Metabolism Characteristics of Triptolide as Determined by a Sensitive and Reliable LC-MS/MS Method

    Xiaomei Gong

    2015-05-01

    Full Text Available In this research, a sensitive and reliable LC-MS/MS method was developed and applied to determine the concentration of triptolide in rat plasma, microsomes, and cell incubation media. The absolute oral bioavailability of triptolide is 63.9% at a dose of 1 mg·kg−1. In vitro, the bidirectional transport of triptolide across Caco-2 cells was studied. A markedly higher transport of triptolide across Caco-2 cells was observed in the basolateral-to-apical direction and was abrogated in the presence of the P-gp inhibitor, verapamil. The result indicated that P-gp might be involved in the absorption of triptolide in intestinal. The metabolic stability was also investigated using human liver microsome incubation systems in vitro. In HLMs, incubations with an initial triptolide concentration of 1 μM resulted in an 82.4% loss of substrate over 60 min, and the t1/2 was 38 min, which indicated that triptolide was easily metabolized in human liver microsomes. In conclusion, the absolute oral bioavailability of triptolide in plasma, transport across Caco-2 cell monolayers, and metabolic stability in human liver microsomes were systematically investigated by using a sensitive and reliable LC-MS/MS method.

  6. Effect of dietary calcium and phosphorus on intestinal calcium absorption and vitamin D metabolism

    To understand better dietary regulation of intestinal calcium absorption, a quantitative assessment of the metabolites in plasma and duodenum of rats given daily doses of radioactive vitamin D3 and diets differing in calcium and phosphorus content was made. All known vitamin D metabolites were ultimately identified by high-pressure liquid chromatography. In addition to the known metabolites (25-hydroxyvitamin D3, 24,25-dihydroxyvitamin D3, 1,25-dihydroxyvitamin D3, 25,26-dihydroxyvitamin D3, and 1,24,25-trihydroxyvitamin D3), several new and unidentified metabolites were found. In addition to 1,25-dihydroxyvitamin D3 and 1,24,25-trihydroxyvitamin D3, the levels of some of the unknown metabolites could be correlated with intestinal calcium transport. However, whether or not any of these metabolites plays a role in the stimulation of intestinal calcium absorption by low dietary calcium or low dietary phosphorus remains unknown

  7. Conservation of bubble size distribution during gas reactive absorption in bubble column reactors

    P. L.C. LAGE

    1999-12-01

    Full Text Available Conservation of the bubble size distribution function was applied to the reactive absorption of carbon dioxide in a bubble column reactor. The model developed was solved by the method of characteristics and by a Monte Carlo method. Simulations were carried out using simplified models for the liquid phase and for the gas-liquid mass transfer. Predictions of gas holdup and outlet gas composition showed that the concept of a mean bubble diameter is not applicable when the bubble size distribution is reasonably polydispersed. In these cases, the mass mean velocity and the numerical mean velocity of the bubbles are very different. Therefore, quantification of the polydispersion of bubbles was shown to be essential to gas-phase hydrodynamics modeling.

  8. Biochemical mechanisms involved in the Omega fatty acids digestion, absorption and metabolism

    Léa Silvia Sant´Ana

    2004-01-01

    Lipids consist of a broad group of compounds that are very different from one another and fatty acids are the substances present in greater quantity. The inadequate ingestion of these substances has an influence on the incidence of various diseases, such as coronary heart disease, some types of cancer, immune diseases and rheumatoid arthritis. In order to understand the role of lipids in the animal body it is necessary to know the food lipid composition, as well the absorption and digestion m...

  9. Absorption, distribution and excretion of the colour fraction of Caramel Colour IV in the rat.

    Selim, S; Chappel, C I; Schoenig, G P

    1992-05-01

    Caramel Colour IV prepared from [U-14C]glucose was ultrafiltered in order to isolate the high molecular weight colour fraction (HMCF). The colour fraction that was non-permeable to a 10,000-Da porosity membrane, contained 84% of the colour, 22% of the solids and 24% of the radioactivity of the [14C]Caramel Colour IV. The absorption, distribution and excretion of [14C]HMCF were evaluated in male rats after administration of single or multiple oral doses of the material at a dosage level of 2.5 g/kg body weight. Rats on the multiple oral dosage regimen were given unlabelled HMCF in their drinking water for 13 days before the administration of a bolus dose of [14C]HMCF on day 14. On both dosage regimens, the predominant route of excretion was by way of the faeces. Less than 3% of the administered radioactivity was excreted in the urine and only a negligible amount was found in the expired air. More than 99% of the administered radioactivity was excreted within 96 hr. The principal tissues in which radioactivity was found were the mesenteric lymph nodes, liver, kidney and tissues of the gastro-intestinal tract. No major differences were observed in the absorption, distribution or excretion patterns between the single and multiple oral dose regimens. PMID:1644386

  10. Stress modification of the kinetic of 137Cs absorption and primary pattern of intercompartments distribution

    The kinetic of 137Cs absorption by pea seedlings and the possibility of alteration of the qualitative and quantitative characteristics of this process were investigated. Gamma irradiation of dry seeds of pea at doses of 25-50 Gy brings about a global change in the kinetic and concentration curves of the active and passive 137Cs uptake by the plant roots. The first and second phases of the kinetic curve, which mirror the passive stage of absorption, and the type of the concentration curve in general, were changed. The level of radionuclide accumulation at this passive stage and the retention for the apoplast-symplast passage increase significantly. Changes in the Michaelis-Menten parameters of the concentration curves were also observed. The changes mirror changes in the radionuclide distribution in the symplast-apoplast system. The time of 137Cs retention for the root-stem transition increased from 0.5 min to 1 min. This investigation suggests that the cation exchange capacity of the parts and structures of a plant is among the main factors which determine the primary intercompartment distribution of 137Cs as nonbiogenous mineral elements

  11. Absorption, metabolism and excretion of diethylene glycol (DEG) in rat and dog

    DEG is a major industrial chemical with considerable consumer exposure. Ingestion of DEG by children and dogs is a common occurrence. DEG metabolism has been reported to proceed with the cleavage of the ether bond, forming oxalic acid and other two-carbon products. DEG toxicity is attributed to the effect of oxalic acid on the kidneys. In the present work the fate of [14C]DEG was studied in rats following iv, oral and dermal administration, and in dogs following oral administration. Dermal doses were poorly (10%) absorbed in 72 h of exposure, but oral doses were well absorbed (ca. 80%) and excreted within 24 h. In each case absorbed DEG was excreted unchanged (>50%) and as a single metabolite (10-30%). The metabolite was isolated and characterized by 13C-NMR and by chemical synthesis as 2-(hydroxy)ethoxyacetic acid. Neither oxalic acid nor other two-carbon metabolites were detected. There was no persistence of DEG or its metabolites in kidney or other organs examined. It is speculated that previous studies of the metabolism and toxicity of DEG have been confounded by the presence of ethylene glycol, which is metabolized to oxalic acid to account for much of the toxicity of commercial grades of DEG

  12. Prevalence and gender distribution of the metabolic syndrome

    Ogbera Anthonia O

    2010-01-01

    Full Text Available Abstract Background The Metabolic syndrome (MetS is a cardiovascular risk factor of public health significance and of recent has become a topical issue. The prevalence of diabetes mellitus (DM is on the increase and with this scenario, a possible increase in burden of DM which may be largely attributed to cardiovascular complications is expected. The objective of this report is to determine the prevalence of the MetS and compare gender characteristics in subjects with type 2 DM. Methods Subjects with type 2 DM were recruited from an urban hospital for the study. Clinical data was obtained by interviewing the patients and referring to their Case folders. The anthropometric indices and blood pressure measurements were documented. Laboratory parameters analysed for included total cholesterol, high density and low density cholesterol, triglyceride and glycosylated haemoglobin. Statistical analysis included usage of Student's t test and chi square. Results 963 patients with type 2 DM aged between 35-85 years were recruited for the study. The main outcome measures included the prevalence of the metabolic syndrome and the gender differences of its components. The prevalence of the metabolic syndrome was 86%. The frequency of occurrence of the MetS was similar for men (83% and women (86% and increased with age in both sexes. The prevalence of MetS increased from 11% among participants aged 20 through 29 years to 89% in participants aged 70 through 79. In our patients with DM, the commonest occurring and least detected MetS defining parameters are central obesity and elevated triglyceride levels respectively. The components of the MetS that differed significantly in both sexes was HDL-C. The combination of the components of the MetS were comparable in both genders and 5.8% of the subjects with the MetS had all components of the MetS. Conclusion The prevalence of the MetS in type 2DM is high in both genders and increases with age thus posing a potential

  13. Estimation of the Intestinal Absorption and Metabolism Behaviors of 2- and 3-Monochloropropanediol Esters.

    Kaze, Naoki; Watanabe, Yomi; Sato, Hirofumi; Murota, Kaeko; Kotaniguchi, Miyako; Yamamoto, Hiroshi; Inui, Hiroshi; Kitamura, Shinichi

    2016-08-01

    The regioisomers of the di- and mono-oleate of monochloropropanediol (MCPD) have been synthesized and subsequently hydrolyzed with pancreatic lipase and pancreatin to estimate the intestinal digestion and absorption of these compounds after their intake. The hydrolysates were analyzed by HPLC using a corona charged aerosol detection system, which allowed for the separation and detection of the different regioisomers of the MCPD esters. The hydrolysates were also analyzed by GC-MS to monitor the free MCPD. The results indicated that the two acyl groups of 2-MCPD-1,3-dioleate were smoothly hydrolyzed by pancreatic lipase and pancreatin to give free 2-MCPD. In contrast, the hydrolysis of 3-MCPD-1,2-dioleate proceeded predominantly at the primary position to produce 3-MCPD-2-oleate. 2-MCPD-1-oleate and 3-MCPD-1-oleate were further hydrolyzed to free 2- and 3-MCPD by pancreatic lipase and pancreatin, although the hydrolysis of 3-MCPD-2-oleate was 80 % slower than that of 3-MCPD-1-oleate. The intestinal absorption characteristics of these compounds were evaluated in vitro using a Caco-2 cell monolayer. The results revealed that the MCPD monooleates, but not the MCPD dioleates, were hydrolyzed to produce the free MCPD in the presence of the Caco-2 cells. The resulting free MCPD permeated the Caco-2 monolayer most likely via a diffusion mechanism because their permeation profiles were independent of the dose. Similar permeation profiles were obtained for 2- and 3-MCPDs. PMID:27023203

  14. Invariability of Central Metabolic Flux Distribution in Shewanella oneidensis MR-1 Under Environmental or Genetic Perturbations

    Tang, Yinjie; Martin, Hector Garcia; Deutschbauer, Adam; Feng, Xueyang; Huang, Rick; Llora, Xavier; Arkin, Adam; Keasling, Jay D.

    2009-04-21

    An environmentally important bacterium with versatile respiration, Shewanella oneidensis MR-1, displayed significantly different growth rates under three culture conditions: minimal medium (doubling time {approx} 3 hrs), salt stressed minimal medium (doubling time {approx} 6 hrs), and minimal medium with amino acid supplementation (doubling time {approx}1.5 hrs). {sup 13}C-based metabolic flux analysis indicated that fluxes of central metabolic reactions remained relatively constant under the three growth conditions, which is in stark contrast to the reported significant changes in the transcript and metabolite profiles under various growth conditions. Furthermore, ten transposon mutants of S. oneidensis MR-1 were randomly chosen from a transposon library and their flux distributions through central metabolic pathways were revealed to be identical, even though such mutational processes altered the secondary metabolism, for example, glycine and C1 (5,10-Me-THF) metabolism.

  15. Gills as a glutathione-dependent metabolic barrier in Pacific oysters Crassostrea gigas: Absorption, metabolism and excretion of a model electrophile.

    Trevisan, Rafael; Mello, Danielle F; Delapedra, Gabriel; Silva, Danilo G H; Arl, Miriam; Danielli, Naissa M; Metian, Marc; Almeida, Eduardo A; Dafre, Alcir L

    2016-04-01

    The mercapturic acid pathway (MAP) is a major phase II detoxification route, comprising the conjugation of electrophilic substances to glutathione (GSH) in a reaction catalyzed by glutathione S-transferase (GST) enzymes. In mammals, GSH-conjugates are exported from cells, and the GSH-constituent amino acids (Glu/Gly) are subsequently removed by ectopeptidases. The resulting Cys-conjugates are reabsorbed and, finally, a mercapturic acid is generated through N-acetylation. This pathway, though very well characterized in mammals, is poorly studied in non-mammalian biological models, such as bivalve mollusks, which are key organisms in aquatic ecosystems, aquaculture activities and environmental studies. In the present work, the compound 1-chloro-2,4-dinitrobenzene (CDNB) was used as a model electrophile to study the MAP in Pacific oysters Crassostrea gigas. Animals were exposed to 10μM CDNB and MAP metabolites were followed over 24h in the seawater and in oyster tissues (gills, digestive gland and hemolymph). A rapid decay was detected for CDNB in the seawater (half-life 1.7h), and MAP metabolites peaked in oyster tissues as soon as 15min for the GSH-conjugate, 1h for the Cys-conjugate, and 4h for the final metabolite (mercapturic acid). Biokinetic modeling of the MAP supports the fast CDNB uptake and metabolism, and indicated that while gills are a key organ for absorption, initial biotransformation, and likely metabolite excretion, hemolymph is a possible milieu for metabolite transport along different tissues. CDNB-induced GSH depletion (4h) was followed by increased GST activity (24h) in the gills, but not in the digestive gland. Furthermore, the transcript levels of glutamate-cysteine ligase, coding for the rate limiting enzyme in GSH synthesis, and two phase II biotransformation genes (GSTpi and GSTo), presented a fast (4h) and robust (∼6-70 fold) increase in the gills. Waterborne exposure to electrophilic compounds affected gills, but not digestive gland

  16. Enhancement of light absorption in polyazomethines due to plasmon excitation on randomly distributed metal nanoparticles

    Wróbel, P.; Antosiewicz, T. J.; Stefaniuk, T.; Ciesielski, A.; Iwan, A.; Wronkowska, A. A.; Wronkowski, A.; Szoplik, T.

    2015-05-01

    In photovoltaic devices, metal nanoparticles embedded in a semiconductor layer allow the enhancement of solar-toelectric energy conversion efficiency due to enhanced light absorption via a prolonged optical path, enhanced electric fields near the metallic inclusions, direct injection of hot electrons, or local heating. Here we pursue the first two avenues. In the first, light scattered at an angle beyond the critical angle for reflection is coupled into the semiconductor layer and confined within such planar waveguide up to possible exciton generation. In the second, light is trapped by the excitation of localized surface plasmons on metal nanoparticles leading to enhanced near-field plasmon-exciton coupling at the peak of the plasmon resonance. We report on results of a numerical experiment on light absorption in polymer- (fullerene derivative) blends, using the 3D FDTD method, where exact optical parameters of the materials involved are taken from our recent measurements. In simulations we investigate light absorption in randomly distributed metal nanoparticles dispersed in polyazomethine-(fullerene derivative) blends, which serve as active layers in bulkheterojunction polymer solar cells. In the study Ag and Al nanoparticles of different diameters and fill factors are diffused in two air-stable aromatic polyazomethines with different chemical structures (abbreviated S9POF and S15POF) mixed with phenyl-C61-butyric acid methyl ester (PCBM) or [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM). The mixtures are spin coated on a 100 nm thick Al layer deposited on a fused silica substrate. Optical constants of the active layers are taken from spectroscopic ellipsometry and reflectance measurements using a rotating analyzer type ellipsometer with auto-retarder performed in the wavelength range from 225 nm to 2200 nm. The permittivities of Ag and Al particles of diameters from 20 to 60 nm are assumed to be equal to those measured on 100 to 200 nm thick metal films.

  17. Effects of Hyperglycemia and Effects of Ketosis on Cerebral Perfusion, Cerebral Water Distribution, and Cerebral Metabolism

    Glaser, Nicole; Ngo, Catherine; Anderson, Steven; Yuen, Natalie; Trifu, Alexandra; O’Donnell, Martha

    2012-01-01

    Diabetic ketoacidosis (DKA) may cause brain injuries in children. The mechanisms responsible are difficult to elucidate because DKA involves multiple metabolic derangements. We aimed to determine the independent effects of hyperglycemia and ketosis on cerebral metabolism, blood flow, and water distribution. We used magnetic resonance spectroscopy to measure ratios of cerebral metabolites (ATP to inorganic phosphate [Pi], phosphocreatine [PCr] to Pi, N-acetyl aspartate [NAA] to creatine [Cr], ...

  18. Distribution of genetic polymorphisms of genes encoding drug metabolizing enzymes & drug transporters - a review with Indian perspective

    Gurusamy Umamaheswaran

    2014-01-01

    Full Text Available Phase I and II drug metabolizing enzymes (DME and drug transporters are involved in the absorption, distribution, metabolism as well as elimination of many therapeutic agents, toxins and various pollutants. Presence of genetic polymorphisms in genes encoding these proteins has been associated with marked inter-individual variability in their activity that could result in variation in drug response, toxicity as well as in disease predisposition. The emergent field pharmacogenetics and pharmacogenomics (PGx is a promising discipline, as it predicts disease risk, selection of proper medication with regard to response and toxicity, and appropriate drug dosage guidance based on an individual′s genetic make-up. Consequently, genetic variations are essential to understand the ethnic differences in disease occurrence, development, prognosis, therapeutic response and toxicity. For that reason, it is necessary to establish the normative frequency of these genes in a particular population before unraveling the genotype-phenotype associations. Although a fair amount of allele frequency data are available in Indian populations, the existing pharmacogenetic data have not been compiled into a database. This review was intended to compile the normative frequency distribution of the variants of genes encoding DMEs (CYP450s, TPMT, GSTs, COMT, SULT1A1, NAT2 and UGTs and transporter proteins (MDR1, OCT1 and SLCO1B1 with Indian perspective.

  19. Effects of glucose, fructose and 5-hydroxymethyl-2-furaldehyde on the presystemic metabolism and absorption of glycyrrhizin in rabbits.

    Hou, Y C; Ching, H; Chao, P D L; Tsai, S Y; Wen, K C; Hsieh, P H; Hsiu, S L

    2005-02-01

    Our previous study reported that co-administration of honey significantly increased the serum levels of glycyrrhetic acid (GA) after oral administration of glycyrrhizin (GZ) in rabbits. The components of honey are sucrose, glucose, fructose and 5-hydroxymethyl-furaldehyde (HMF). To clarify the causative component(s) in honey that altered the metabolic pharmacokinetics of GZ, rabbits were given GZ (150 mg kg(-1)) with and without glucose (5 g/rabbit), fructose (5 g/rabbit) and HMF (1 mg kg(-1)), respectively, in crossover designs. An HPLC method was used to determine concentrations of GZ and GA in serum as well as GA and 3-dehydroglycyrrhetic acid (3-dehydroGA) in faeces suspension. A noncompartment model was used to calculate the pharmacokinetic parameters and analysis of variance was used for statistical comparison. Our results indicated that the area under curve (AUC) of GA was significantly increased by 29% when HMF was coadministered, whereas the pharmacokinetics of GZ and GA were not significantly altered by coadministration of glucose or fructose. An in-vitro study, using faeces to incubate GZ and GA individually, indicated that HMF significantly inhibited the oxidation of GA to 3-dehydroGA and this may explain the enhanced GA absorption in-vivo. It was concluded that HMF is the causative component in honey that affects the presystemic metabolism and pharmacokinetics of GZ in-vivo. PMID:15720790

  20. X-ray absorption of the Hg distribution in a commercial metal-halide lamp

    Nimalasuriya, T; Zhu, X; Ridderhof, E J; Beks, M L; Haverlag, M; Denisova, N; Stoffels, W W; Mullen, J J A M van der [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)], E-mail: T.Nimalasuriya@tue.nl

    2008-07-21

    The radial temperature profiles of a commercial metal-halide lamp and of lamps containing its individual components have been acquired using x-ray absorption of Hg density distribution. The temperature profiles were determined by combining the measured absorption of the spatially resolved Hg density with the wall temperature. The lamps studied were a commercial lamp, i.e. the Philips CDM-T 70 W/830, and identically shaped lamps containing NaI, DyI{sub 3} and TlI separately. It was found that the element Dy contracts the arc, Na broadens the arc while Tl causes the arc to have so-called 'shoulders'. Combined in the commercial lamp this leads to a wall-stabilized arc without contraction and 'shoulders'. A reproducibility test with identical lamps was also made and showed that the uncertainty in the temperature profile is about 8% for the absolute temperature and only 1.6% for the actual shape of the profile.

  1. Oral absorption and tissue distribution of a new squalenoyl anticancer nanomedicine

    Harivardhan Reddy, L.; Ferreira, Humberto; Dubernet, Catherine [Univ. Paris-Sud XI, Faculte de Pharmacie, UMR CNRS 8612, IFR 141 (France); Mouelhi, Sinda Lepetre; Desmaele, Didier [Universite Paris XI, Faculte de Pharmacie, UMR CNRS 8076 Biocis (France); Rousseau, Bernard [CEA, Bio Organic Chemistry and Labeled Compounds Division (France); Couvreur, Patrick [Univ. Paris-Sud XI, Faculte de Pharmacie, UMR CNRS 8612, IFR 141 (France)], E-mail: patrick.couvreur@u-psud.fr

    2008-05-15

    Recently, we had discovered that the linkage of nucleoside analogues to squalene, a precursor in the sterol biosynthesis, led to amphiphilic molecules, which self-organized in water as nanoassemblies of 100-300 nm in diameter, irrespective of the nucleoside analogue used. Thus, it was observed that the 4-(N)-trisnorsqualenoylgemcitabine (SQdFdC), the squalenoyl prodrug of the anticancer nucleoside analogue gemcitabine, was impressively more active than its parent compound gemcitabine, both in vitro and in vivo on experimental leukaemia. Since squalene, which is a natural constituent of shark liver and olive oil, is known to be absorbed orally, we investigated in this short note the absorption and tissue distribution of {sup 3}H-radiolabelled SQdFdC nanoassemblies comparatively to {sup 3}H-gemcitabine after oral administration to mice. Whereas gemcitabine was found to be rapidly absorbed (t{sub max} = 1 h), this compound underwent a rapid clearance from the plasma. Conversely, the SQdFdC nanoassemblies displayed slower absorption followed by the progressive tissue accumulation, and they exhibited a lower clearance rate. The accumulation of the SQdFdC nanoassemblies in tissues such as pancreas, thymus, lung, liver and spleen (except at 1 h post-administration) was similar to that of the gemcitabine, yet exhibited significantly greater penetration and retention into the stomach and intestinal tissues comparatively to gemcitabine. Thus, the SQdFdC nanoassemblies could be of potential interest in the treatment of gastrointestinal tumours by oral route.

  2. Untangling hyporheic residence time distributions and whole stream metabolisms using a hydrological process model

    Altenkirch, Nora; Mutz, Michael; Molkenthin, Frank; Zlatanovic, Sanja; Trauth, Nico

    2016-04-01

    The interaction of the water residence time in hyporheic sediments with the sediment metabolic rates is believed to be a key factor controlling whole stream metabolism. However, due to the methodological difficulties, there is little data that investigates this fundamental theory of aquatic ecology. Here, we report on progress made to combine numerical modeling with a series of manipulation to laboratory flumes overcoming methodological difficulties. In these flumes, hydraulic conditions were assessed using non-reactive tracer and heat pulse sensor. Metabolic activity was measured as the consumption and production of oxygen and the turnover of reactive tracers. Residence time and metabolic processes were modeled using a multicomponent reactive transport code called Min3P and calibrated with regard to the hydraulic conditions using the results obtained from the flume experiments. The metabolic activity was implemented in the model via Monod type expressions e.g. for aerobic respiration rates. A number of sediment structures differing in residence time distributions were introduced in both, the model and the flumes, specifically to model the biogeochemical performance and to validate the model results. Furthermore, the DOC supply and surface water flow velocity were altered to test the whole stream metabolic response. Using the results of the hydrological process model, a sensitivity analysis of the impact of residence time distributions on the metabolic activity could yield supporting proof of an existing link between the two.

  3. Do changes in the azimuthal distribution of maize leaves over time affect canopy light absorption?

    In maize canopies, when modelling the architecture and light regime one usually assumes leaf azimuths are distributed uniformly. Once we had demonstrated azimuthal re-orientation of maize leaves during the vegetative phase, we tested the weight of this hypothesis on the light absorbed daily by the canopy. We thus modelled the three-dimensional (3D) geometry of maize canopies with various plant densities and at different developmental stages using plant digitizing under field conditions. We simulated radiative transfer using a volume-based approach within actual and hypothetical canopies, obtained by simply rearranging leaf azimuths. Simulations indicated that changes to horizontal heterogeneity have little effect on daily light absorption efficiency. It is concluded that changes in leaf azimuths do not have to be taken into account in crop-functioning models. (author)

  4. Distribution, excretion, and metabolism of butylbenzyl phthalate in the rat

    The disposition of butylbenzyl phthalate (BBP), a widely used plasticizer, was evaluated after oral and iv administration to rats. Male Fischer-344 rats were dosed with [14C]BBP at 2, 20, 200, or 2000 mg/kg po or 20 mg/kg iv to determine the effects of dose on rates and routes of excretion. In 24 h, 61-74% of the dose was excreted in the urine and 13-19% in the feces at 2-200 mg/kg. At the 2000-mg/kg dose, 16% of the 14C was excreted in the urine and 57% in the feces. Urinary 14C was composed of monophthalate derivatives (MP: 10-42% of the dose) and glucuronides of these monophthalate derivatives (2-21% of the dose). At 4 h after iv administration of BBP (20 mg/kg), 53-58% of the dose was excreted in the bile of anesthetized rats. No parent compound was found in the bile, but monobutyl phthalate-glucuronide and monobenzyl phthalate-glucuronide (26% and 13% of the dose, respectively) and trace amounts of free monoesters (2% of the dose) and unidentified metabolites (14% of the dose) were present. Although BBP is an asymmetric diester with the potential of forming equal amounts of monbutyl phthalate (MBuP) and monobenzyl phthalate (MBeP), larger quantities of MBuP were formed (MBuP = 44% versus MBeP = 16% of the dose). The half-lives of BBP, MP, and total 14C in blood (20 mg/kg, iv) were 10 min, 5.9 h, and 6.3 h, respectively. This study indicates that BBP is rapidly metabolized and that the major route of excretion of metabolites is biliary. These metabolites are reabsorbed and ultimately eliminated in the urine

  5. Absorption, tissue distribution, and excretion of tritium-labeled ivermectin in cattle, sheep, and rat

    Tritium-labeled ivermectin was studied in cattle, sheep, and rat for absorption, tissue residue distribution, and excretion at doses of 0.3 mg/kg of body weight. The drug was absorbed by various dosing routes. By intraruminal and subcutaneous dosing routes, highest tissue residues were present in fat and liver of cattle, with half-lives of 6-8 and 4-5 days, respectively. Shorter half-lives (1-2 days) were observed in sheep and rat. The tissue residue distribution pattern was essentially the same for all species studied and similar in male and female rats. With doses of tritium-labeled avermectin B1a ranging from 0.06 to 7.5 mg/kg of body weight, plasma and tissue residue concentrations increased proportionally with the dose. When ivermectin was administered by various routes (ip, sc, iv, oral, and intraruminal), blood residue levels converged to 20-50 ppb 4 h after dosing and then depleted at similar rate regardless of the dosing route. Ivermectin was excreted primarily in the feces, with only less than 2% of the doses being eliminated in the urine in all three species studied

  6. Absorption and distribution of different form of nitrogen in sweet pepper

    The absorption and utilization of different form of nitrogen in sweet pepper were studied. The result showed that NH4+-N was favourable to growth of sweet pepper at seedling period and plant developing period and NO3--N was favourable at fruiting period. The utilization of the same form of nitrogen was quite different when N applied in different period. The utilization rate of nitrogen fertilizer dressed at fruiting was the highest (41.8%-45.8%), while that of the basal manure was the lowest (33.6%-36.7%). 75% of the nitrogen up taken from basal manure and fertilizer dressed in plant developing period was distributed in stems and leaves, more than 60% of nitrogen dressed in fruiting period was distributed in fruit. The analysis of fertilizer-N and soil-N in sweet pepper plant indicated that about 60% of plant-N was derived from soil-N and about 40% of plant-N was derived from fertilizer-N

  7. Comparing Spatial Distributions of Solar Prominence Mass Derived from Coronal Absorption

    Gilbert, Holly; Kilper, Gary; Alexander, David; Kucera, Therese

    2010-01-01

    In the present work we extend the use of this mass-inference technique to a sample of prominences observed in at least two coronal lines. This approach, in theory, allows a direct calculation of prominence mass and helium abundance and how these properties vary spatially and temporally. Our motivation is two-fold: to obtain a He(exp 0)/H(exp 0) abundance ratio, and to determine how the relative spatial distribution of the two species varies in prominences. The first of these relies on the theoretical expectation that the amount of absorption at each EUV wavelength is well-characterized. However, in this work we show that due to a saturation of the continuum absorption in the 625 A and 368 A lines (which have much higher opacity compared to 195 A-) the uncertainties in obtaining the relative abundances are too high to give meaningful estimates. This is an important finding because of its impact on future studies in this area. The comparison of the spatial distribution of helium and hydrogen presented here augments previous observational work indicating that cross-field diffusion of neutrals is an important mechanism for mass loss. Significantly different loss timescales for neutral He and H (helium drains much more rapidly than hydrogen) can impact prominence structure, and both the present and past studies suggest this mechanism is playing a role in structure and possibly dynamics. Section 2 of this paper contains a description of the observations and Section 3 summarizes the method used to infer mass along with the criteria imposed in choosing prominences appropriate for this study. Section 3 also contains a discussion of the problems due to limitations of the available data and the implications for determining relative abundances. We present our results in Section 4, including plots of radial-like scans of prominence mass in different lines to show the spatial distribution of the different species. The last section contains a discussion summarizing the importance

  8. Lithocholate metabolism during chemotherapy for gallstone dissolution. 2. Absorption and sulphation.

    Allan, R N; Thistle, J L; Hofmann, A F

    1976-01-01

    The amount of lithocholate input and the size of the total lithocholate exchangeable pool were measured using isotope dilution in three patients ingesting chenodeoxycholic acid for gallstone dissolution and two healthy control subjects. Because the specific activity decay curve was biexponential in appearance, input was calculated using a stochastic analysis employing the Stewart-Hamilton equation. By this method, the lithocholate input and the size of the exchangeable pool in gallstone patients during chenic acid ingestion was four to five times that observed in the healthy control subjects. It was calculated that about one-fifth of the newly formed lithocholate was absorbed in both gallstone patients and healthy control subjects. The extent of sulphation of absorbed lithocholate was then measured in seven gallstone patients whto had been ingesting chenodeoxycholic acid for gallstone dissolution by defining the chemical form of radioactivity in bile after intravenous administration of labelled lithocholate. Similar studies were carried out in eight healthy control subjects, but, in addition the extent of sulphation of injected lithocholylglycine and lithocholyltaurine was also defined. When lithocholate was injected, the majority of radioactivity in bile (50-60%) was present as sulphated conjugates, both in gallstone patients and healthy control subjects. The degree of sulphation was greater for glycine than taurine conjugates, and these findings, which suggested preferential sulphation of the glycine conjugates of lithocholate, were confirmed by showing that injected lithocholylglycine was sulphated to a much greater extent than injected lithocholyltaurine. These findings indicate that in patients receiving chenic acid there is effective sulphation of lithocholate, especially its glycine conjugates, despite a considerable increase in lithocholate absorption; they may provide an explanation for the lack of hepatotoxicity of chenic acid in man. PMID:955496

  9. Effects of guar gum and cellulose on glucose absorption, hormonal release and hepatic metabolism in the pig

    Nunes, C. S.; Malmlof, K.

    1992-01-01

    Six Large White pigs (mean body-weight 59 (SE 1.7) kg) were surgically fitted with permanent catheters in the portal vein, the brachiocephalic artery and the right hepatic vein, as well as with electromagnetic flow probes around the portal vein and the hepatic artery, and allowed to recover. The non-anaesthetized animals were given a basal non-fibre diet (diet A) alone or together with 60 g guar gum/kg (diet B) or 150 g purified cellulose/kg (diet C) by substitution for mica. The diets were given for weekly periods and according to a replicated 3 x 3 Latin square design. On the last day of each such adaptation period, test meals of 800 g were given before blood sampling. Sampling was continued for 8 h. Guar gum strongly reduced glucose apparent absorption without changing the absorption and the hepatic uptake profiles. Production rates of insulin, gastric inhibitory polypeptide and insulin-like growth factor-1 (IGF-1) were lowest after guar gum ingestion. However, the reductions in peripheral blood insulin levels caused by guar gum were not associated with a change in hepatic insulin extraction. IGF-1 appeared to be strongly secreted by the gut, whereas the liver had a net uptake of the peptide. Ingestion of guar gum increased the hepatic extraction coefficient of gut-produced IGF-1. Guar gum ingestion appeared also to decrease glucagon secretion. Cellulose at the level consumed had very few effects on the variables considered. It is suggested that the modulation of intestinal mechanisms by guar gum was sufficient to mediate the metabolic effects described.

  10. Metabolism

    ... also influenced by body composition — people with more muscle and less fat generally have higher BMRs. previous continue Things That Can Go Wrong With Metabolism Most of the time your metabolism works effectively ...

  11. Metabolism

    2008-01-01

    2008255 Serum adiponectin level declines in the elderly with metabolic syndrome.WU Xiaoyan(吴晓琰),et al.Dept Geriatr,Huashan Hosp,Fudan UnivShanghai200040.Chin J Geriatr2008;27(3):164-167.Objective To investigate the correlation between ser-um adiponectin level and metabolic syndrome in the elderly·Methods Sixty-one subjects with metabolic syndrome and140age matched subjects without metabolic

  12. A Proteomics Approach to the Study of Absorption, Distribution, Metabolism, Excretion, and Toxicity

    Nordvarg, Helena; Flensburg, John; Rönn, Ola; Öhman, Johan; Marouga, Rita; Lundgren, Bo; Haid, Daniel; Malmport, Eva; Goscinski, Jan; Hörnsten, Lena; Scigelova, Michaela; Bourin, Stephanie; Garberg, Per; Woffendin, Gary; Fenyö, David

    2004-01-01

    A proteomics approach was used to identify liver proteins that displayed altered levels in mice following treatment with a candidate drug. Samples from livers of mice treated with candidate drug or untreated were prepared, quantified, labeled with CyDye DIGE Fluors, and subjected to two-dimensional electrophoresis. Following scanning and imaging of gels from three different isoelectric focusing intervals (3–10, 7–11, 6.2–7.5), automated spot handling was performed on a large number of gel spo...

  13. Fertilizer N absorption and distribution by soybean from seedling to pod beginning

    The nitrogen assimilation and absorption by the soybean plant, especially the distribution of fertilizer N among different organs and nodes were studied during the period from seedling to pod beginning by using sand culture and staged 15N labeling method. Results were as follows: (1) total nitrogen accumulation during the five labeling experiments increased from 64.08 mg/plant in labeling experiment Ⅰ to 307.17 mg/plant in labeling experiment Ⅴ. (2) Fertilizer N accumulation in different organs exhibited different proportions during the period from seedling to pod beginning, with the highest in leaves (55.2%), 25.9% in roots and 18.9% in stems. (3) The accumulation and proportion of nodulations N increased gradually during the period from seedling to beginning, however for fertilizer N it was contrary, the soybean plant depended mainly on fertilizer-N before full bloom and then nodulations N during the period from full bloom to pod beginning. (4) Fertilizer N accumulation in leaves at different growing stages followed the order of growing leaves > newborn leaves > mature leaves. (5) Nitrogen composition of newborn leaves changed with that in total plant: fertilizer N was the primary nitrogen source from seedling to bloom beginning, and nodulations N was the primary nitrogen source from bloom beginning to pod beginning. (authors)

  14. Radio Through X-ray Spectral Energy Distributions of 38 Broad Absorption Line Quasars

    Gallagher, S C; Brandt, W N; Egami, E; Hines, D C; Priddey, R S

    2007-01-01

    We have compiled the largest sample of multiwavelength spectral energy distributions (SEDs) of Broad Absorption Line (BAL) quasars to date, from the radio to the X-ray. We present new Spitzer MIPS (24, 70, and 160 micron) observations of 38 BAL quasars in addition to data from the literature and public archives. In general, the mid-infrared properties of BAL quasars are consistent with those of non-BAL quasars of comparable luminosity. In particular, the optical-to-mid-infrared luminosity ratios of the two populations are indistinguishable. We also measure or place upper limits on the contribution of star formation to the far-infrared power. Of 22 (57%) upper limits, seven quasars have sufficiently sensitive constraints to conclude that star formation likely contributes little (<20%) to their far-infrared power. The 17 BAL quasars (45%) with detected excess far-infrared emission likely host hyperluminous starbursts with L_fir,SF=10^{13-14} L_sun. Mid-infrared through X-ray composite BAL quasar SEDs are pre...

  15. Remote sensing of vertical phytoplankton pigment distributions in the Baltic: new mathematical expressions. Part 3: Nonphotosynthetic pigment absorption factor:

    Bogdan Woźniak; Roman Majchrowski; Mirosława Ostrowska; Dariusz Ficek; Justyna Kunicka; Jerzy Dera

    2007-01-01

    This paper, part 3 of the description of vertical pigment distributions in the Baltic Sea, discusses the mathematical expression enabling the vertical distributions of the non-photosynthetic pigment absorption factor fa to be estimated. The factor fa is directly related to concentrations of the several groups of phytoplankton pigments and describes quantitatively the ratio of the light energy absorbed at given depths by photosynthetic pigments to the light energy absorbed by all the phytoplan...

  16. Reconstruction of combustion temperature and gas concentration distributions using line-of-sight tunable diode laser absorption spectroscopy

    Zhang, Zhirong; Sun, Pengshuai; Pang, Tao; Xia, Hua; Cui, Xiaojuan; Li, Zhe; Han, Luo; Wu, Bian; Wang, Yu; Sigrist, Markus W.; Dong, Fengzhong

    2016-07-01

    Spatial temperature and gas concentration distributions are crucial for combustion studies to characterize the combustion position and to evaluate the combustion regime and the released heat quantity. Optical computer tomography (CT) enables the reconstruction of temperature and gas concentration fields in a flame on the basis of line-of-sight tunable diode laser absorption spectroscopy (LOS-TDLAS). A pair of H2O absorption lines at wavelengths 1395.51 and 1395.69 nm is selected. Temperature and H2O concentration distributions for a flat flame furnace are calculated by superimposing two absorption peaks with a discrete algebraic iterative algorithm and a mathematical fitting algorithm. By comparison, direct absorption spectroscopy measurements agree well with the thermocouple measurements and yield a good correlation. The CT reconstruction data of different air-to-fuel ratio combustion conditions (incomplete combustion and full combustion) and three different types of burners (one, two, and three flat flame furnaces) demonstrate that TDLAS has the potential of short response time and enables real-time temperature and gas concentration distribution measurements for combustion diagnosis.

  17. Absorption and distribution of Zn by spring wheat in high zinc soil and effect of rhizosphere soil

    The isotope tracer technique was used to study the absorption and distribution of 65Zn by spring wheat in high zinc soil. The results showed that the distribution of 65Zn in the organs of spring wheat was in the order as stem leaf>grain>root>wheat husk; the specific activity of 65Zn and the transfer factor of 65Zn in the organs of spring wheat were in the order as root>grain>wheat husk>stem leaf. With added 65Zn increased, the absorption amount of 65Zn by spring wheat and the distribution of 65Zn in root increased. The 65Zn applied was enriched by rhizosphere soil of spring wheat

  18. Spatial Distribution of the Metabolically Active Microbiota within Italian PDO Ewes' Milk Cheeses

    De Pasquale, Ilaria; Di Cagno, Raffaella; Buchin, Solange; De Angelis, Maria; Gobbetti, Marco

    2016-01-01

    Italian PDO (Protected Designation of Origin) Fiore Sardo (FS), Pecorino Siciliano (PS) and Pecorino Toscano (PT) ewes’ milk cheeses were chosen as hard cheese model systems to investigate the spatial distribution of the metabolically active microbiota and the related effects on proteolysis and synthesis of volatile components (VOC). Cheese slices were divided in nine sub-blocks, each one separately subjected to analysis and compared to whole cheese slice (control). Gradients for moisture, an...

  19. Metabolism

    ... a particular food provides to the body. A chocolate bar has more calories than an apple, so ... More Common in People With Type 1 Diabetes Metabolic Syndrome Your Child's Weight Healthy Eating Endocrine System Blood ...

  20. Residue strength, water absorption and pore size distributions of recycled aggregate concrete after exposure to elevated temperatures

    Kou, Shi-Cong; Poon, Chi-Sun; Etxeberria Larrañaga, Miren

    2014-01-01

    In this paper, the effects of high temperature exposure of recycled aggregate concretes in terms of residual strengths, capillary water absorption capacity and pore size distribution are discussed. Two mineral admixtures, fly ash (FA) and ground granulated blast furnace (GGBS) were used in the experiment to partially replace ordinary Portland cement for concrete production. The water to cementitious materials ratio was maintained at 0.50 for all the concrete mixes. The replacement levels of n...

  1. Relationships between Body Fat Distribution, Epicardial Fat and Obstructive Sleep Apnea in Obese Patients with and without Metabolic Syndrome

    Carla Lubrano; Maurizio Saponara; Giuseppe Barbaro; Palma Specchia; Eliana Addessi; Daniela Costantini; Marta Tenuta; Gabriella Di Lorenzo; Giuseppe Genovesi; Donini, Lorenzo M; Andrea Lenzi; Lucio Gnessi

    2012-01-01

    BACKGROUND: Obstructive sleep apnea (OSA) and metabolic syndrome, both closely related to obesity, often coexist in affected individuals; however, body mass index is not an accurate indicator of body fat and thus is not a good predictor of OSA and other comorbidities. The aim of this study was to investigate whether the occurrence of OSA could be associated with an altered body fat distribution and a more evident cardio metabolic risk independently from obesity and metabolic syndrome. METHODS...

  2. MID Max: LC–MS/MS Method for Measuring the Precursor and Product Mass Isotopomer Distributions of Metabolic Intermediates and Cofactors for Metabolic Flux Analysis Applications

    McCloskey, Douglas; Young, Jamey D.; Xu, Sibei;

    2016-01-01

    that takes advantage of additional scan types that maximizes the number of mass isotopomer distributions (MIDs) that can be acquired in a given experiment. The analytical method was found to measure the MIDs of 97 metabolites, corresponding to 74 unique metabolite-fragment pairs (32 precursor spectra...... and 42 product spectra) with accuracy and precision. The compounds measured included metabolic intermediates in central carbohydrate metabolism and cofactors of peripheral metabolism (e.g., ATP). Using only a subset of the acquired MIDs, the method was found to improve the precision of flux...

  3. Optical imaging of absorption and distribution of RITC-SiO2 nanoparticles after oral administration

    Lee CM

    2014-12-01

    Full Text Available Chang-Moon Lee,1 Tai Kyoung Lee,2–5 Dae-Ik Kim,1,6 Yu-Ri Kim,7 Meyoung-Kon Kim,7 Hwan-Jeong Jeong,2–5 Myung-Hee Sohn,2–5 Seok Tae Lim2–5 1Department of Biomedical Engineering, Chonnam National University, Yeosu, Jeollanam-Do, Republic of Korea; 2Department of Nuclear Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Jeollabuk-Do, Republic of Korea; 3Cyclotron Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Jeollabuk-Do, Republic of Korea; 4Biomedical Research Institute, Chonbuk National University Medical School and Hospital, Jeonju, Jeollabuk-Do, Republic of Korea; 5Molecular Imaging and Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Jeollabuk-Do, Republic of Korea; 6School of Electrical, Electronic Communication, and Computer Engineering, Chonnam National University, Yeosu, Jeollanam-Do, Republic of Korea; 7Department of Biochemistry and Molecular Biology, Korea University Medical School and College, Seounbuk-Gu, Seoul, Republic of Korea Purpose: In this study, we investigated the absorption and distribution of rhodamine B isothiocyanate (RITC-incorporated silica oxide nanoparticles(SiNPs (RITC-SiNPs after oral exposure, by conducting optical imaging, with a focus on tracking the movement of RITC-SiNPs of different particle size and surface charge. Methods: RITC-SiNPs (20 or 100 nm; positively or negatively charged were used to avoid the dissociation of a fluorescent dye from nanoparticles via spontaneous or enzyme-catalyzed reactions in vivo. The changes in the nanoparticle sizes and shapes were investigated in an HCl solution for 6 hours. RITC-SiNPs were orally administered to healthy nude mice at a dose of 100 mg/kg. Optical imaging studies were performed at 2, 4, and 6 hours after oral administration. The mice were sacrificed at 2, 4, 6, and 10 hours post-administration, and ex vivo imaging studies were performed

  4. Fiber-distributed multi-channel open-path H2S sensor based on tunable diode laser absorption spectroscopy

    Dong Chen; Wenqing Liu; Yujun Zhang; Jianguo Liu; Ruifeng Kan; Min Wang; Xi Fang; Yiben Cui

    2007-01-01

    Tunable diode laser based gas detectors are now being used in a wide variety of applications for safety and environmental interest. A fiber-distributed multi-channel open-path H2S sensor based on tunable diode laser absorption spectroscopy (TDLAS) is developed, the laser used is a telecommunication near infrared distributed feed-back (DFB) tunable diode laser, combining with wavelength modulation specby combining optical fiber technique. An on-board reference cell provides on-line sensor calibration and almost maintenance-free operation. The sensor is suitable for large area field H2S monitoring application.

  5. Spatial and temporal variations in NO(2) distributions over Beijing, China measured by imaging differential optical absorption spectroscopy.

    Lee, Hanlim; Kim, Young J; Jung, Jinsang; Lee, Chulkyu; Heue, Klaus-Peter; Platt, Ulrich; Hu, Min; Zhu, Tong

    2009-04-01

    During the CAREBEIJING campaign in 2006, imaging differential optical absorption spectroscopy (I-DOAS) measurements were made from 08:00 to 16:00 on September 9 and 10 over Beijing, China. Detailed images of the near-surface NO(2) differential slant column density (DSCD) distribution over Beijing were obtained. Images with less than a 30-min temporal resolution showed both horizontal and vertical variations in NO(2) distributions. For DSCD to mixing ratio conversion, path length along the lines of I-DOAS lines of sight was estimated using the light-extinction coefficient and Angstrom exponent data obtained by a transmissometer and a sunphotometer, respectively. Mixing ratios measured by an in-situ NO(2) analyzer were compared with those estimated by the I-DOAS instrument. The obtained temporal and spatial variations in NO(2) distributions measured by I-DOAS for the two days are interpreted with consideration of the locations of the major NO(x) sources and local wind conditions. I-DOAS measurements have been applied in this study for estimating NO(2) distribution over an urban area with multiple and distributed emission sources. Results are obtained for estimated temporal and spatial NO(2) distributions over the urban atmosphere; demonstrating the capability of the I-DOAS technique. We discuss in this paper the use of I-DOAS measurements to estimate the NO(2) distribution over an urban area with multiple distributed emission sources. PMID:19111964

  6. Spatial Distribution of the Metabolically Active Microbiota within Italian PDO Ewes' Milk Cheeses.

    De Pasquale, Ilaria; Di Cagno, Raffaella; Buchin, Solange; De Angelis, Maria; Gobbetti, Marco

    2016-01-01

    Italian PDO (Protected Designation of Origin) Fiore Sardo (FS), Pecorino Siciliano (PS) and Pecorino Toscano (PT) ewes' milk cheeses were chosen as hard cheese model systems to investigate the spatial distribution of the metabolically active microbiota and the related effects on proteolysis and synthesis of volatile components (VOC). Cheese slices were divided in nine sub-blocks, each one separately subjected to analysis and compared to whole cheese slice (control). Gradients for moisture, and concentrations of salt, fat and protein distinguished sub-blocks, while the cell density of the main microbial groups did not differ. Secondary proteolysis differed between sub-blocks of each cheese, especially when the number and area of hydrophilic and hydrophobic peptide peaks were assessed. The concentration of free amino acids (FAA) agreed with these data. As determined through Purge and Trap (PT) coupled with Gas Chromatography-Mass Spectrometry (PT-GC/MS), and regardless of the cheese variety, the profile with the lowest level of VOC was restricted to the region identified by the letter E defined as core. As shown through pyrosequencing of the 16S rRNA targeting RNA, the spatial distribution of the metabolically active microbiota agreed with the VOC distribution. Differences were highlighted between core and the rest of the cheese. Top and bottom under rind sub-blocks of all three cheeses harbored the widest biodiversity. The cheese sub-block analysis revealed the presence of a microbiota statistically correlated with secondary proteolysis events and/or synthesis of VOC. PMID:27073835

  7. A measurement plan of gas concentration and temperature distribution reconstruction based on the tunable diode laser absorption tomography

    Liu, Zhao-ran; Jin, Xing; Wang, Guang-yu; Song, Jun-ling

    2014-11-01

    Based on the tunable diode laser absorption tomography, gas concentration and temperature two-dimensional distribution reconstruction is realized using algebraic iterative reconstruction technique (ART). A measurement plan is proposed based on the beam splitting lens, and the corresponding beam arrangement is put forward. The beam splitting lenses are used in the plan to making one laser beam cross the measurement area repeatedly. Thus can raise the utilization ratio of laser beam and simplify the structure of measurement platform. A model for H2O vapor concentration and temperature distribution is assumed, and numerical simulation is utilized using two absorption transitions. The feasibility of the measurement plan is proved by the simulation experiment. The influences of initial beam angle, the number of beams and grids on the reconstructed results are analyzed numerically. A concept of phantom description method using in simulation experiments is proposed in order to getting closer to the real experiments. The phantom description method is used in the numerical simulation to evaluating concentration and temperature field reconstruction. Through this method, expected data is sampled from initial data, and reconstructed result is obtained by interpolation. The influence of random errors in projections on distribution reconstruction is also analyzed. The measurement plan can reconstruct the gas concentration and temperature distribution with a simplified measurement platform using beam splitting lenses. The feasibility of the phantom description method is also proved by the simulation experiment.

  8. Intramolecular stable isotope distributions detect plant metabolic responses on century time scales

    Schleucher, Jürgen; Ehlers, Ina; Augusti, Angela; Betson, Tatiana

    2014-05-01

    Plants respond to environmental changes on a vast range of time scales, and plant gas exchanges constitute important feedback mechanisms in the global C cycle. Responses on time scales of decades to centuries are most important for climate models, for prediction of crop productivity, and for adaptation to climate change. Unfortunately, responses on these timescale are least understood. We argue that the knowledge gap on intermediate time scales is due to a lack of adequate methods that can bridge between short-term manipulative experiments (e.g. FACE) and paleo research. Manipulative experiments in plant ecophysiology give information on metabolism on time scales up to years. However, this information cannot be linked to results from retrospective studies in paleo research, because little metabolic information can be derived from paleo archives. Stable isotopes are prominent tools in plant ecophysiology, biogeochemistry and in paleo research, but in all applications to date, isotope ratios of whole molecules are measured. However, it is well established that stable isotope abundance varies among intramolecular groups of biochemical metabolites, that is each so-called "isotopomer" has a distinct abundance. This intramolecular variation carries information on metabolic regulation, which can even be traced to individual enzymes (Schleucher et al., Plant, Cell Environ 1999). Here, we apply intramolecular isotope distributions to study the metabolic response of plants to increasing atmospheric [CO2] during the past century. Greenhouse experiments show that the deuterium abundance among the two positions in the C6H2 group of photosynthetic glucose depends on [CO2] during growth. This is observed for all plants using C3 photosynthesis, and reflects the metabolic flux ratio between photorespiration and photosynthesis. Photorespiration is a major C flux that limits assimilation in C3 plants, which encompass the overwhelming fraction of terrestrial photosynthesis and the

  9. Difference in the distribution pattern of substrate enzymes in the metabolic network of Escherichia coli, according to chaperonin requirement

    Niwa Tatsuya

    2011-06-01

    Full Text Available Abstract Background Chaperonins are important in living systems because they play a role in the folding of proteins. Earlier comprehensive analyses identified substrate proteins for which folding requires the chaperonin GroEL/GroES (GroE in Escherichia coli, and they revealed that many chaperonin substrates are metabolic enzymes. This result implies the importance of chaperonins in metabolism. However, the relationship between chaperonins and metabolism is still unclear. Results We investigated the distribution of chaperonin substrate enzymes in the metabolic network using network analysis techniques as a first step towards revealing this relationship, and found that as chaperonin requirement increases, substrate enzymes are more laterally distributed in the metabolic. In addition, comparative genome analysis showed that the chaperonin-dependent substrates were less conserved, suggesting that these substrates were acquired later on in evolutionary history. Conclusions This result implies the expansion of metabolic networks due to this chaperonin, and it supports the existing hypothesis of acceleration of evolution by chaperonins. The distribution of chaperonin substrate enzymes in the metabolic network is inexplicable because it does not seem to be associated with individual protein features such as protein abundance, which has been observed characteristically in chaperonin substrates in previous works. However, it becomes clear by considering this expansion process due to chaperonin. This finding provides new insights into metabolic evolution and the roles of chaperonins in living systems.

  10. Estrogenic activity of flavonoids in mice. The importance of estrogen receptor distribution, metabolism and bioavailability

    Breinholt, Vibeke; Hossaini, A.; Svendsen, Gitte W.; Brouwer, C.; Nielsen, S. E.

    2000-01-01

    The in vivo estrogenic potential of the flavonoids apigenin, kaempferol, genistein and equol was investigated in immature female mice. Genistein and equol, administered by gavage for 4 consecutive days [post-natal day (PND) 17-20, 100 mg/kg body weight], was found to significantly increase uterine...... lower potency. Bioavailability, metabolism, the ability to alter ER alpha distribution in the uterus and the estrogenic potential of parent compound and metabolites may thus contribute to the differences in in vivo estrogenicity of dietary flavonoids....

  11. Updated correlation of the absorption line blackbody distribution function for H2O based on the HITEMP2010 database

    The absorption line blackbody distribution function (ALBDF) was developed for use in global methods such as the SLW and FSK models that integrate the radiative transfer equation over the absorption coefficient rather than wavenumber. A widely used method of representing the ALBDF efficiently is a correlation in the form of a hyperbolic tangent function originally proposed by Denison and Webb. This paper reports on the generation of new coefficients to be used in the correlation for H2O using the recently released high temperature database, HITEMP2010. The updated correlation is valid for an expanded temperature range, from 400 to 3000 K, made possible by the new database. The accuracy of the new coefficients is tested and compared against the previous correlations through calculations of total emissivity and the Planck mean absorption coefficient. Solutions of the radiative transfer equation in homogeneous one-dimensional media have been performed with the SLW method using the updated ALBDF, and are compared to rigorous line-by-line calculations. The updated correlation performs very well in these calculations and shows excellent accuracy compared to the line-by-line benchmark predictions. Comparisons made with the previous coefficients show that updating the correlation was necessary in order to obtain accurate calculations. -- Highlights: ► HITEMP2010 was used to update the absorption line blackbody distribution function. ► Hyperbolic tangent form used previously was maintained. ► Temperature ceiling was extended from 2500 K up to 3000 K. ► Calculations using the updated correlation demonstrate its accuracy. ► Comparisons with the previous correlation demonstrate the need for an update

  12. Effect of quantum dot size and size distribution on the intersublevel transitions and absorption coefficients of III-V semiconductor quantum dot

    The intersublevel absorption peak energy and absorption coefficient of non-uniform quantum dot (QD) ensembles are calculated analytically. The effect of size variations and size distribution of QDs on their energy states is analyzed. The dots are considered as a quantum box with finite potential at the barriers and the size distribution described by a Gaussian function. The influence of the aspect ratio (base to height ratio) of the QDs on the optical transitions is studied. Our model predicts the dot size (height and base) accurately to determine the absorption peaks and corresponding absorption coefficient. We also compute the absorption coefficient of the QD with different size distributions to verify the results calculated using this model with the reported experimental and other theoretical results

  13. Reflectance, absorptance and transmittance spectra on sunflower (Helianthus annuus L.) as related to their metabolic age and stem position. Pt.2

    The results of a research carried out in order to study the reflectance, absorptance and transmittance spectra of sunflower leaves as related to their stem position are reported. Two sunflower hybrids, which differed for growth habitus (''Monica'', with low size, and ''Hysun-32'' with normal size) were used. Reflectance, absorptance and transmittance spectra were measured in vivo when the plants were in the phases of appearance of inflorescence and anthesis. The measures were taken with a portable spectroradiometer with an external integrating sphere. The radiation over the wavelength range from 400 to 1,100 mm was measured at intervals of 1 mm. Absorptance was calculated. The results have evidenced that leaf position, related to its metabolic age, influence the capacity of reflecting, absorbing and transmitting the radiation in the photosynthetically active region. In the PAR region the variations are different with the spectral band considered. The leaves in medium-high position, as compared to the top and bottom leaves, have lower reflectance and transmittance values and higher absorptance values. No difference emerged in the near infrared region

  14. Systemic, cerebral and skeletal muscle ketone body and energy metabolism during acute hyper-D-β-hydroxybutyratemia in post-absorptive healthy males

    Mikkelsen, Kristian H; Seifert, Thomas; Secher, Niels H; Grøndal, Thomas; van Hall, Gerrit

    2015-01-01

    CONTEXT: Ketone bodies are substrates during fasting and when on a ketogenic diet not the least for the brain and implicated in the management of epileptic seizures and dementia. Moreover, D-β-hydroxybutyrate (HOB) is suggested to reduce blood glucose and fatty acid levels. OBJECTIVES: The...... objectives of this study were to quantitate systemic, cerebral, and skeletal muscle HOB utilization and its effect on energy metabolism. DESIGN: Single trial. SETTING: Hospital. PARTICIPANT: Healthy post-absorptive males (n = 6). INTERVENTIONS: Subjects were studied under basal condition and three...... and dementia....

  15. Transmural distribution of metabolic abnormalities and glycolytic activity during dobutamine-induced demand ischemia.

    Jameel, Mohammad N; Wang, Xiaohong; Eijgelshoven, Marcel H J; Mansoor, Abdul; Zhang, Jianyi

    2008-06-01

    The heterogeneity across the left ventricular wall is characterized by higher rates of oxygen consumption, systolic thickening fraction, myocardial perfusion, and lower energetic state in the subendocardial layers (ENDO). During dobutamine stimulation-induced demand ischemia, the transmural distribution of energy demand and metabolic markers of ischemia are not known. In this study, hemodynamics, transmural high-energy phosphate (HEP), 2-deoxyglucose-6-phosphate (2-DGP) levels, and myocardial blood flow (MBF) were determined under basal conditions, during dobutamine infusion (DOB: 20 microg x kg(-1) x min(-1) iv), and during coronary stenosis + DOB + 2-deoxyglucose (2-DG) infusion. DOB increased rate pressure products (RPP) and MBF significantly without affecting the subendocardial-to-subepicardial blood flow ratio (ENDO/EPI) or HEP levels. During coronary stenosis + DOB + 2-DG infusion, RPP, ischemic zone (IZ) MBF, and ENDO/EPI decreased significantly. The IZ ratio of creatine phosphate-to-ATP decreased significantly [2.30 +/- 0.14, 2.06 +/- 0.13, and 2.04 +/- 0.11 to 1.77 +/- 0.12, 1.70 +/- 0.11, and 1.72 +/- 0.12 for EPI, midmyocardial (MID), and ENDO, respectively], and 2-DGP accumulated in all layers, as evidenced by the 2-DGP/PCr (0.55 +/- 0.12, 0.52 +/- 0.10, and 0.37 +/- 0.08 for EPI, MID, and ENDO, respectively; P ENDO). In the IZ the wet weight-to-dry weight ratio was significantly increased compared with the normal zone (5.9 +/- 0.5 vs. 4.4 +/- 0.4; P < 0.05). Thus, in the stenotic perfused bed, during dobutamine-induced high cardiac work state, despite higher blood flow, the subepicardial layers showed the greater metabolic changes characterized by a shift toward higher carbohydrate metabolism, suggesting that a homeostatic response to high-cardiac work state is characterized by more glucose utilization in energy metabolism. PMID:18424629

  16. Transmural Distribution of Metabolic Abnormalities and Glycolytic Activity during Dobutamine Induced Demand Ischemia

    Jameel, Mohammad N; Wang, Xiaohong; Eijgelshoven, Marcel H.J.; Mansoor, Abdul; Zhang, Jianyi

    2008-01-01

    The heterogeneity across the LV wall is characterized by higher rates of oxygen consumption, systolic thickening fraction, myocardial perfusion and lower energetic state in the subendocardial layers (ENDO). During dobutamine stimulation induced demand ischemia, the transmural distribution of energy demand and metabolic markers of ischemia are not known. In this study, hemodynamics, transmural high energy phosphate (HEP) and 2-deoxyglucose-6-phosphate (2DGP) levels and myocardial blood flow (MBF) were determined under basal conditions (B), during dobutamine infusion (DOB: 20 μg/kg/min iv.), and during coronary stenosis+DOB+2-deoxy-glucose (2DG) infusion. DOB increased rate pressure products (RPP) and MBF significantly without affecting subendocardial to subepicardial blood flow ratio (ENDO/EPI) or HEP levels. During coronary stenosis+DOB+2-deoxy-glucose (2DG) infusion RPP, ischemic zone (IZ) MBF and ENDO/EPI decreased significantly. IZ PCr/ATP decreased significantly (2.30 +/- 0.14, 2.06 +/- 0.13 and 2.04 +/- 0.11 to 1.77 +/- 0.12, 1.70 +/- 0.11 and 1.72 +/- 0.12; EPI, MID and ENDO, respectively) and 2DG6P accumulated in all layers as evidenced by the 2DG6P/PCr (0.55 +/- 0.12, 0.52 +/- 0.10 and 0.37 +/- 0.08; EPI, MID and ENDO respectively; pENDO). In the IZ the wet weight/dry weight ratio was significantly increased as compared to the normal zone (5.9 +/- 0.5 vs. 4.4 +/- 0.4; p<0.05). Thus, in stenotic perfused bed, during dobutamine induced high cardiac workstate, despite higher blood flow the subepicardial layers showed the greater metabolic changes that characterized by a shift toward higher carbohydrate metabolism suggesting a homeostatic responses to high cardiac workstate is characterized by more glucose utilization in energy metabolism. PMID:18424629

  17. Human microsomal cyttrochrome P450-mediated reduction of oxysophocarpine, an active and highly toxic constituent derived from Sophora flavescens species, and its intestinal absorption and metabolism in rat.

    Wu, Lili; Zhong, Wanping; Liu, Junjin; Han, Weichao; Zhong, Shilong; Wei, Qiang; Liu, Shuwen; Tang, Lan

    2015-09-01

    Oxysophocarpine (OSC), an active and toxic quinolizidine alkaloid, is highly valued in Sophora flavescens Ait. and Subprostrate sophora Root. OSC is used to treat inflammation and hepatitis for thousands of years in China. This study aims to investigate the CYP450-mediated reduction responsible for metabolizing OSC and to evaluate the absorption and metabolism of OSC in rat in situ. Four metabolites were identified, with sophocarpine (SC) as the major metabolite. SC formation was rapid in human and rat liver microsomes (HLMs and RLMs, respectively). The reduction rates in the liver are two fold higher than in the intestine, both in humans and rats. In HLMs, inhibitors of CYP2C9, 3A4/5, 2D6, and 2B6 had strong inhibitory effects on SC formation. Meanwhile, inhibitors of CYP3A and CYP2D6 had significant inhibition on SC formation in RLMs. Human recombinant CYP3A4/5, 2B6, 2D6, and 2C9 contributed significantly to SC production. The permeability in rat intestine and the excretion rates of metabolites were highest in the duodenum (pCYP3A inhibitor ketoconazole. In conclusion, the liver was the main organ responsible for OSC metabolism. First-pass metabolism via CYP3A4/5, 2B6, 2D6, and 2C9 may be the main reason for the poor OSC bioavailability. PMID:26045316

  18. The absorption, utilization and distribution of nitrate 15N and ammonium 15N in Populus Tomentosa seedlings

    Effects of different nitrogen sources (NO3-, NH4+) on the absorption, distribution and utilization of nitrogen on Populus tenement's seedlings (clone 50) was studied by using the 15N trace technique. Results showed that the Populus tenement's seedlings had the same nitrogen take up pattern: tissue nitrogen content grew up after fertilization, remarkbaly rising up after one week and reached peak after 28 days. Although the treatments are different, the tissue N content was about the same between 0.6g · plant-1. The maximum absorption of NO3-15N and NH4-15N was 0.26g · plant-1 and 0.12g · plant -1, which accounted for 39.15% and 19.95% of total nitrogen, respectively. The nitrogen use efficiency (NUE) of two nitrogen sources varied gignificantly. The maximum NUE of NO3-15N reached 25.83%, nearly twice of that of NH4-15N (12.03%). Hence we conclude that Populus tomentosa seedlings (clone 50) prefer to absorb NO3-. Nitrogen distribution rate changed obviously among different organs and the trend was leaf>root>stem. In the leaf, the distribution of NO3-15N was higher than that of NH4-15N. (authors)

  19. Gut Wall Metabolism. Application of Pre-Clinical Models for the Prediction of Human Drug Absorption and First-Pass Elimination.

    Jones, Christopher R; Hatley, Oliver J D; Ungell, Anna-Lena; Hilgendorf, Constanze; Peters, Sheila Annie; Rostami-Hodjegan, Amin

    2016-05-01

    Quantifying the multiple processes which control and modulate the extent of oral bioavailability for drug candidates is critical to accurate projection of human pharmacokinetics (PK). Understanding how gut wall metabolism and hepatic elimination factor into first-pass clearance of drugs has improved enormously. Typically, the cytochrome P450s, uridine 5'-diphosphate-glucuronosyltransferases and sulfotransferases, are the main enzyme classes responsible for drug metabolism. Knowledge of the isoforms functionally expressed within organs of first-pass clearance, their anatomical topology (e.g. zonal distribution), protein homology and relative abundances and how these differ across species is important for building models of human metabolic extraction. The focus of this manuscript is to explore the parameters influencing bioavailability and to consider how well these are predicted in human from animal models or from in vitro to in vivo extrapolation. A unique retrospective analysis of three AstraZeneca molecules progressed to first in human PK studies is used to highlight the impact that species differences in gut wall metabolism can have on predicted human PK. Compared to the liver, pharmaceutical research has further to go in terms of adopting a common approach for characterisation and quantitative prediction of intestinal metabolism. A broad strategy is needed to integrate assessment of intestinal metabolism in the context of typical DMPK activities ongoing within drug discovery programmes up until candidate drug nomination. PMID:26964996

  20. A one-dimensional, one-group absorption-production nodal method for neutron flux and power distributions calculations

    It is presented the absorption-production nodal method for steady and dynamical calculations in one-dimension and one group energy. It was elaborated the NOD1D computer code (in FORTRAN-IV language). Calculations of neutron flux and power distributions, burnup, effective multiplication factors and critical boron concentration were made with the NOD1D code and compared with results obtained through the CITATION code, which uses the finite difference method. The nuclear constants were produced by the LEOPARD code. (M.C.K.)

  1. SYNCHROTRON POLARIZATION AND SYNCHROTRON SELF-ABSORPTION SPECTRA FOR A POWER-LAW PARTICLE DISTRIBUTION WITH FINITE ENERGY RANGE

    We have derived asymptotic forms for the degree of polarization of the optically thin synchrotron and for synchrotron self-absorption (SSA) spectra assuming a power-law particle distribution of the form N(γ) ∼ γ–p with γ1 2, especially for a finite high-energy limit, γ2, in the case of an arbitrary pitch angle. The new results inferred concern more especially the high-frequency range x >> η2 with parameter η = γ2/γ1. The calculated SSA spectra concern instantaneous photon emission where cooling effects are not considered. They have been obtained by also ignoring likely effects such as Comptonization, pair creation and annihilation, as well as magnetic photon splitting. To that aim, in addition to the two usual absorption frequencies, a third possible one has been derived and expressed in terms of the Lambert W function based on the analytical asymptotic form of the absorption coefficient, αν, for the high-frequency range ν >> ν2 (with ν2 the synchrotron frequency corresponding to γ2). We have shown that the latter frequency may not have realistic applications in astrophysics, except in the case of an adequate set of parameters allowing one to neglect Comptonization effects. More detailed calculations and discussions are presented.

  2. Phosphate absorption and distribution in flue-cured tobacco under different ozone consistency by using 32P

    The absorption and distribution of phosphate in flue-cured tobacco under different ozone consistencies was studied by using 32P. The results showed that the percentage of root of whole tobacco plant assimilating 32p reduced as growing, but in stem it increased as growing in the sand culture. Root and stem of flue-cured tobacco assimilating 32P varied little in the whole growing period in the solution culture. Distribution situation in leaf with two consistencies was in the order of lower leaf>cutters leaf>upper leaf, and the ratio of radioactivity showed root>stem>lower leaf>cutters leaf>upper leaf. However, flue-cured tobacco assimilating phosphate in the two consistencies showed significantly positive correlation with length of growth period. Assimilating phosphate in the solution culture was more and faster than in the low ozone consistency culture

  3. Do changes in the azimuthal distribution of maize leaves over time affect canopy light absorption?

    Drouet, J.L.; Moulia, B.; Bonhomme, R

    1999-01-01

    Pour les couverts de maïs, les modèles d’architecture des plantes et de transferts radiatifs utilisent classiquement l’hypothèse d’une répartition aléatoire des feuilles en azimut. Ayant précédemment mis en évidence des ré-orientations azimutales des feuilles de maïs au cours de la phase végétative, nous avons testé le poids de cette hypothèse sur l’absorption journalière de lumière par le couvert. Pour cela, nous avons modélisé la géométrie en trois dimensions (3D) de couverts de maïs de den...

  4. Effective utilization of quantum-cascade distributed-feedback lasers in absorption spectroscopy

    Kosterev, A. A.; Curl, R. F.; Tittel, F. K.; Gmachl, C.; Capasso, F.; Sivco, D. L.; Baillargeon, J. N.; Hutchinson, A. L.; Cho, A. Y.

    2000-01-01

    A variable duty cycle quasi-cw frequency scanning technique was applied to reduce thermal effects resulting from the high heat dissipation of type I quantum-cascade lasers. This technique was combined with a 100-m path-length multipass cell and a zero-air background-subtraction technique to enhance detection sensitivity to a parts-in-10(9) (ppb) concentration level for spectroscopic trace-gas detection of CH4, N2O, H2O, and C2H5OH in ambient air at 7.9 micrometers. A new technique for analysis of dense high resolution absorption spectra was applied to detection of ethanol in ambient air, yielding a 125-ppb detection limit.

  5. Influence of food tannins on certain aspects of iron metabolism : Part 1 -- Absorption and excretion in normal and anemic rats

    Studies on absorption and excretion of iron by isotopic and non-isotopic methods in normal and hemolytic anemic rats indicate that dietary food tannins at a dose of 0.5 mg/kg body wt/day tend to increase iron excretion in normal rats but more iron is absorbed or retained in tannin-fed anemic rats and absorption of iron is comparable to that in normal control. Both in vivo and in vitro tannin at a high dose (2.0 mg/kg body wt/day) inhibits the iron absorption in experimental animals. The interference of food tannins (0.5 kg/mg body wt/day) with absorption of iron (59Fe) varies with plant species from which tannin has been prepared. Normal iron balance in tannin-fed (0.5 mg/kg body wt/day) anemic rats may result from increased assimilation of tannin-bound iron in intestinal mucosa, and absorbed tannin appears to remove unabsorbed iron. (auth.)

  6. Imazamox Absorption, Translocation and Metabolism in Red Lentil (Lens culinaris Medic.) and Dry Bean (Phaseolus vulgaris L.)

    Imazamox is an imidazolinone herbicide used to control many grasses and broadleaf weeds in leguminous crops such as soybeans, alfalfa and dry beans; however, imazamox cannot be used on red lentils because of unacceptable injury. Studies were conducted to compare imazamox absorption, translocation a...

  7. An X-ray Absorption Fine Structure study of Au adsorbed onto the non-metabolizing cells of two soil bacterial species

    Song, Zhen; Kenney, Janice P.L.; Fein, Jeremy B.; Bunker, Bruce A. (Notre)

    2015-02-09

    Gram-positive and Gram-negative bacterial cells can remove Au from Au(III)-chloride solutions, and the extent of removal is strongly pH dependent. In order to determine the removal mechanisms, X-ray Absorption Fine Structure (XAFS) spectroscopy experiments were conducted on non-metabolizing biomass of Bacillus subtilis and Pseudomonas putida with fixed Au(III) concentrations over a range of bacterial concentrations and pH values. X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) data on both bacterial species indicate that more than 90% of the Au atoms on the bacterial cell walls were reduced to Au(I). In contrast to what has been observed for Au(III) interaction with metabolizing bacterial cells, no Au(0) or Au-Au nearest neighbors were observed in our experimental systems. All of the removed Au was present as adsorbed bacterial surface complexes. For both species, the XAFS data suggest that although Au-chloride-hydroxide aqueous complexes dominate the speciation of Au in solution, Au on the bacterial cell wall is characterized predominantly by binding of Au atoms to sulfhydryl functional groups and amine and/or carboxyl functional groups, and the relative importance of the sulfhydryl groups increases with increasing pH and with decreasing Au loading. The XAFS data for both microorganism species suggest that adsorption is the first step in the formation of Au nanoparticles by bacteria, and the results enhance our ability to account for the behavior of Au in bacteria-bearing geologic systems.

  8. Mass balance approaches for estimating the intestinal absorption and metabolism of peptides and analogues: theoretical development and applications

    Sinko, P. J.; Leesman, G. D.; Amidon, G. L.

    1993-01-01

    A theoretical analysis for estimating the extent of intestinal peptide and peptide analogue absorption was developed on the basis of a mass balance approach that incorporates convection, permeability, and reaction. The macroscopic mass balance analysis (MMBA) was extended to include chemical and enzymatic degradation. A microscopic mass balance analysis, a numerical approach, was also developed and the results compared to the MMBA. The mass balance equations for the fraction of a drug absorbed and reacted in the tube were derived from the general steady state mass balance in a tube: [formula: see text] where M is mass, z is the length of the tube, R is the tube radius, Pw is the intestinal wall permeability, kr is the reaction rate constant, C is the concentration of drug in the volume element over which the mass balance is taken, VL is the volume of the tube, and vz is the axial velocity of drug. The theory was first applied to the oral absorption of two tripeptide analogues, cefaclor (CCL) and cefatrizine (CZN), which degrade and dimerize in the intestine. Simulations using the mass balance equations, the experimental absorption parameters, and the literature stability rate constants yielded a mean estimated extent of CCL (250-mg dose) and CZN (1000-mg dose) absorption of 89 and 51%, respectively, which was similar to the mean extent of absorption reported in humans (90 and 50%). It was proposed previously that 15% of the CCL dose spontaneously degraded systematically; however, our simulations suggest that significant CCL degradation occurs (8 to 17%) presystemically in the intestinal lumen.(ABSTRACT TRUNCATED AT 250 WORDS).

  9. The absorption distribution and utilization of N in different nitrogen forms by american ginsengs

    NH4+ and NO3- uptake by 2,3,4-year old Panax quinquefolium and their distribution in the plants were studied with 15N tracer in both soil and water cultures. The results showed that P. quinquefolium can absorb both NH4+ and NO3- from sprouting stage to leaf expansion stage, but the absorbing capacity for NH4+ was twice as that for NO3-, and during this period more fertilizer was distributed in stem and leaves than in roots. During the stage of root growth, however, the plants absorbed the both forms of fertilizer well, and more fertilizer was distributed in root than in stem and leaves. Of the total nitrogen content absorbed by P. quinquefolium cultured in soil, more than 80% was from soil, about 5% was from fertilizer, and the rest was from original root. It is concluded that improving fertility of soil and culturing strong root are keys to improve yield and quality of P. quinquefolium

  10. Intestinal absorption and postabsorptive metabolism of linoleic acid in rats with short-term bile duct ligation

    Minich, DM; Havinga, R; Stellaard, F; Vonk, RJ; Kuipers, F; Verkade, HJ

    2000-01-01

    We investigated in bile duct-ligated (BDL) and sham-operated control rats whether the frequent presence of essential fatty acid deficiency in cholestatic liver disease could be related to linoleic acid malabsorption, altered linoleic acid metabolism, or both. In plasma of BDL rats, the triene-to-tet

  11. Quantitative autoradiography of 14C-D-glucose metabolism of normal and traumatized rat brain using micro-absorption photometry

    It could be shown using 14C-glucose as energy-providing substrate for brain tissue metabolism that for bolus type application a retarded and even channelling of the substrate into the metabolic process takes place. The presence of tracer in the tissue was established using autoradiography. A linear correlation between the amount of tissue-incorporated 14C section thickness and exposure time could be established by means of densitometric measurement of brain sections of various thicknesses, by applying various 14C-activities and by different exposure times. From these correlations direct conclusions may be made regarding the specific activity of the tissue provided that exposure time and section thickness of the sample are known. Comparative studies between cortex and narrow and between traumatized and non-traumatized brain tissue show that the rate of metabolism in brain cortex is markedly higher than in the marrow and that 14C-incorporation is higher in traumatized tissue than in non-traumatized tissue. Whilst the difference in rate of metabolism between brain cortex and marrow can be clearly related to the differing cell count/unit surface area for cortex and marrow, the different energy conversion rates for functionally damaged and normal brain tissue is a specific characteristic of injury. Apart from the fact that an increased 14C-deposition is in no way indicative of an increased metabolic activity, the possibility of quantifying 14C-tissue content provides a basis for estimating therapeutic effects e.g. in the treatment of trauma-caused brain edema. (orig.)

  12. Metabolism and distribution of 3,4-epithiobutanenitrile in the rat

    Brocker, E.R.; Benn, M.H.; Luethy, J.; von Daeniken, A.

    1984-03-01

    The metabolism and distribution of (2-/sup 14/C)- and /sup 35/S-labelled 3,4-epithiobutanenitrile (4ETN), a thiirane occurring naturally in cruciferous vegetables, was studied in the rat. A dose of c. 11 mg 4ETN/kg body weight was rapidly transformed into water-soluble compounds and was mainly excreted in the urine, irrespective of the route of administration (oral or ip). The main metabolite in the urine was identified by gas chromatography-mass spectrometry as a mercapturic acid derivative. Low residual radioactivity demonstrated in organs 72 hr after administration was consistent with an earlier report that the thiirane may function as a weak biological alkylating agent.

  13. Aerosol particle number size distributions and particulate light absorption at the ZOTTO tall tower (Siberia), 2006-2009

    Heintzenberg, J.; Birmili, W.; Otto, R.; Andreae, M. O.; Mayer, J.-C.; Chi, X.; Panov, A.

    2011-08-01

    This paper analyses aerosol particle number size distributions, particulate absorption at 570 nm wavelength and carbon monoxide (CO) measured between September 2006 and January 2010 at heights of 50 and 300 m at the Zotino Tall Tower Facility (ZOTTO) in Siberia (60.8° N; 89.35° E). Average number, surface and volume concentrations are broadly comparable to former studies covering shorter observation periods. Fits of multiple lognormal distributions yielded three maxima in probability distribution of geometric mean diameters in the Aitken and accumulation size range and a possible secondary maximum in the nucleation size range below 25 nm. The seasonal cycle of particulate absorption shows maximum concentrations in high winter (December) and minimum concentrations in mid-summer (July). The 90th percentile, however, indicates a secondary maximum in July/August that is likely related to forest fires. The strongly combustion derived CO shows a single winter maximum and a late summer minimum, albeit with a considerably smaller seasonal swing than the particle data due to its longer atmospheric lifetime. Total volume and even more so total number show a more complex seasonal variation with maxima in winter, spring, and summer. A cluster analysis of back trajectories and vertical profiles of the pseudo-potential temperature yielded ten clusters with three levels of particle number concentration: Low concentrations in Arctic air masses (400-500 cm-3), mid-level concentrations for zonally advected air masses from westerly directions between 55° and 65° N (600-800 cm-3), and high concentrations for air masses advected from the belt of industrial and population centers in Siberia and Kazakhstan (1200 cm-3). The observational data is representative for large parts of the troposphere over Siberia and might be particularly useful for the validation of global aerosol transport models.

  14. Toxic metals distribution in different components of Pakistani and imported cigarettes by electrothermal atomic absorption spectrometer.

    Kazi, T G; Jalbani, N; Arain, M B; Jamali, M K; Afridi, H I; Sarfraz, R A; Shah, A Q

    2009-04-15

    It was extensively investigated that a significant flux of toxic metals, along with other toxins, reaches the lungs through smoking. In present study toxic metals (TMs) (Al, Cd, Ni and Pb) were determined in different components of Pakistani local branded and imported cigarettes, including filler tobacco (FT), filter (before and after normal smoking by a single volunteer) and ash by electrothermal atomic absorption spectrometer (ETAAS). Microwave-assisted digestion method was employed. The validity and accuracy of methodology were checked by using certified sample of Virginia tobacco leaves (ICHTJ-cta-VTL-2). The percentages (%) of TMs in different components of cigarette were calculated with respect to their total contents in FT of all branded cigarettes before smoking, while smoke concentration has been calculated by subtracting the filter and ash contents from the filler tobacco content of each branded cigarette. The highest percentage (%) of Al was observed in ash of all cigarettes, with range 97.3-99.0%, while in the case of Cd, a reverse behaviour was observed, as a range of 15.0-31.3% of total contents were left in the ash of all branded cigarettes understudy. PMID:18657905

  15. Toxic metals distribution in different components of Pakistani and imported cigarettes by electrothermal atomic absorption spectrometer

    It was extensively investigated that a significant flux of toxic metals, along with other toxins, reaches the lungs through smoking. In present study toxic metals (TMs) (Al, Cd, Ni and Pb) were determined in different components of Pakistani local branded and imported cigarettes, including filler tobacco (FT), filter (before and after normal smoking by a single volunteer) and ash by electrothermal atomic absorption spectrometer (ETAAS). Microwave-assisted digestion method was employed. The validity and accuracy of methodology were checked by using certified sample of Virginia tobacco leaves (ICHTJ-cta-VTL-2). The percentages (%) of TMs in different components of cigarette were calculated with respect to their total contents in FT of all branded cigarettes before smoking, while smoke concentration has been calculated by subtracting the filter and ash contents from the filler tobacco content of each branded cigarette. The highest percentage (%) of Al was observed in ash of all cigarettes, with range 97.3-99.0%, while in the case of Cd, a reverse behaviour was observed, as a range of 15.0-31.3% of total contents were left in the ash of all branded cigarettes understudy

  16. Absorption, distribution and utilization of radioactive phosphorus in healthy and root (wilt) diseased coconut palms

    Radioactive KH2P32O4 was fed to coconut leaves and palms under laboratory and field conditions. In healthy palms the absorption of phosphorus by roots and its accumulation in spindle and first fully opened leaves was found to be significantly higher till 9th hr as compared to that of diseased palms, but at later stages the reverse pattern was observed. The time required for 32P to reach the spindle (top-most leaf) situated at 9.5 m height in both diseased and healthy palm was found to be 3 hr only. In contrast to the leaves, the activity of 32P differed insignificantly in stem and roots of healthy and diseased palms and also the native P remained higher in the stem and roots of former palms as compared to latter. The analysis of total different fractions of phosphorus and entry of 32P in the different forms of organic phosphorus indicated that although total P was more in the case of diseased palms but the organic phosphorus especially the nucleic acid P was significantly less as compared to healthy ones. This revealed less utilization of absorbed P in the synthesis of P-constituted organic substances in diseased palms. (auth.)

  17. Common variants near MC4R in relation to body fat, body fat distribution, metabolic traits and energy expenditure

    Kring, Sofia Inez Iqbal; Holst, C; Toubro, Søren;

    2010-01-01

    Common variants near melanocortin receptor 4 (MC4R) have been related to fatness and type 2 diabetes. We examined the associations of rs17782313 and rs17700633 in relation to body fat, body fat distribution, metabolic traits, weight development and energy expenditure.......Common variants near melanocortin receptor 4 (MC4R) have been related to fatness and type 2 diabetes. We examined the associations of rs17782313 and rs17700633 in relation to body fat, body fat distribution, metabolic traits, weight development and energy expenditure....

  18. Luminescent liposome labeling technology with PKH-26 solution and absorption and distribution assessment of lipid multilammelar vesicles and small liposomes in liver following intravenous administration

    This study examined the possibility to form liposomal compositions containing PKH-26 fluorescent dye and to use those compositions in order to assess absorption and tissue distribution of the liposomes in rat liver. Liposomal compositions consisted of egg lecithin and cholesterol (Sigma) in a 7:5 ratio, respectively. The dye was incorporated into the lipid layer while preparing multilammelar vesicles with the extruder. The obtained labeled liposomal compositions allowed to quantitatively assess how the vesicles are absorbed by the liver and visualize the dye distribution in different liver cells. The study presents the data on the absorption and distribution of the dye in the liver, according to the size of the lipid vesicles, 1, 2 and 24 hours after the intravenous administration. Key words : luminescent labeling, absorption of the liposomes, visualization of the liposomes, liposomal distribution in the cells, PKH -26, liver

  19. Uptake, tissue distribution and metabolism of the insecticide endosulfan in Jenynsia multidentata (Anablepidae, Cyprinodontiformes)

    The study reports the accumulation, distribution and metabolism of technical endosulfan in Jenynsia multidentata. Adult females were exposed to acute sublethal concentrations (0.072, 0.288 and 1.4 μg L-1). After 24 h, fish were sacrificed and gills, liver, brain, intestine and muscle were removed. Results show that both isomers of technical-grade endosulfan (α- and β-) are accumulated in fish tissues and biotransformation to endosulfan sulfate occurs at all concentrations tested. Significantly differences in endosulfan accumulation were only found at 1.4 μg L-1 but not between the lowest concentrations. However a similar distribution pattern was observed at all exposure levels where liver, intestine and brain had the highest levels of α-, β-endosulfan and endosulfan sulfate. Moreover, liver and brain showed the highest endosulfan sulfate:α-endosulfan ratios due to high biotransfomation capacity. J. multidentata demonstrated to be a sensitive species under exposure to technical endosulfan and, therefore, could be used to assess aquatic pollution. - Highlights: → Acute exposure of Jenynsia multidentata to technical-grade endosulfan. → Endosulfan bioaccumulation in different organs of Jenynsia multidentata. → Technical-grade endosulfan biotransformation to endosulfan sulfate. - Endosulfan is accumulated in organs of J. multidentata as well as biotransformed to endosulfan sulfate, which relative abundance points out the time from exposure.

  20. Uptake, tissue distribution and metabolism of the insecticide endosulfan in Jenynsia multidentata (Anablepidae, Cyprinodontiformes)

    Ballesteros, M.L., E-mail: mlballesteros@efn.uncor.edu [Universidad Nacional de Cordoba, Facultad de Ciencias Exactas Fisicas y Naturales, Catedra Diversidad Animal II, Av. Velez Sarsfield 299, 5000 Cordoba (Argentina); Universidad Nacional de Mar del Plata, Facultad de Ciencias Exactas y Naturales, Laboratorio de Ecotoxicologia, Funes 3350, 7600 Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Gonzalez, M. [Universidad Nacional de Mar del Plata, Facultad de Ciencias Exactas y Naturales, Laboratorio de Ecotoxicologia, Funes 3350, 7600 Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Wunderlin, D.A. [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Universidad Nacional de Cordoba-CONICET, Facultad de Ciencias Quimicas, Dto. Quimica Organica-CIBICI, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Bistoni, M.A. [Universidad Nacional de Cordoba, Facultad de Ciencias Exactas Fisicas y Naturales, Catedra Diversidad Animal II, Av. Velez Sarsfield 299, 5000 Cordoba (Argentina); Miglioranza, K.S.B. [Universidad Nacional de Mar del Plata, Facultad de Ciencias Exactas y Naturales, Laboratorio de Ecotoxicologia, Funes 3350, 7600 Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)

    2011-06-15

    The study reports the accumulation, distribution and metabolism of technical endosulfan in Jenynsia multidentata. Adult females were exposed to acute sublethal concentrations (0.072, 0.288 and 1.4 {mu}g L{sup -1}). After 24 h, fish were sacrificed and gills, liver, brain, intestine and muscle were removed. Results show that both isomers of technical-grade endosulfan ({alpha}- and {beta}-) are accumulated in fish tissues and biotransformation to endosulfan sulfate occurs at all concentrations tested. Significantly differences in endosulfan accumulation were only found at 1.4 {mu}g L{sup -1} but not between the lowest concentrations. However a similar distribution pattern was observed at all exposure levels where liver, intestine and brain had the highest levels of {alpha}-, {beta}-endosulfan and endosulfan sulfate. Moreover, liver and brain showed the highest endosulfan sulfate:{alpha}-endosulfan ratios due to high biotransfomation capacity. J. multidentata demonstrated to be a sensitive species under exposure to technical endosulfan and, therefore, could be used to assess aquatic pollution. - Highlights: > Acute exposure of Jenynsia multidentata to technical-grade endosulfan. > Endosulfan bioaccumulation in different organs of Jenynsia multidentata. > Technical-grade endosulfan biotransformation to endosulfan sulfate. - Endosulfan is accumulated in organs of J. multidentata as well as biotransformed to endosulfan sulfate, which relative abundance points out the time from exposure.

  1. Cachectin/tumor necrosis factor: production, distribution, and metabolic fate in vivo

    A highly specific radioreceptor assay for cachectin/tumor necrosis factor (TNF) was utilized to measure the time course of lipopolysaccharide (LPS)-induced hormone production in rabbits. Cachectin/TNF bioactivity was monitored in the same serum samples by measuring lipoprotein lipase (LPL) suppression in 3T3-L1 cells. Cachectin/TNF is produced in large quantities by LPS-treated rabbits without priming by bacillus Calmette Guerin, C. parvum, or other agents. Nanomolar concentrations of the hormone are achieved, with peak levels occurring at 2 hr postinjection; the hormone is rapidly cleared thereafter. In separate studies, mice were used to assess the distribution and metabolic fate of cachectin/TNF. Radioiodinated hormone is cleared from the plasma with a half-life of 6 to 7 min. Studies of the tissue distribution of label after injection demonstrate that liver, kidneys, skin, and gastrointestinal tract take up most of the hormone. Electrophoretic analysis of tissues recovered from injected animals suggests that the hormone is very rapidly degraded after binding

  2. [Studies on the remote measurement of the distribution of city gaseous pollutant by mobile passive differential optical absorption spectroscopy].

    Wu, Feng-cheng; Li, Ang; Xie, Pin-hua; Xu, Jin; Shi, Peng; Qin, Min; Wang, Man-hua; Wang, Jie; Zhang, Yong

    2011-03-01

    An optical remote sensing method based on passive differential optical absorption spectroscopy for the measurement of the distribution of city gaseous pollutant was studied. The passive DOAS system, which was installed in a car, successively measures the interested area (such as city, industrial area) and the column density was obtained by DOAS fitting process using the zenith scattered sunlight. The mobile DOAS was applied to measurement in Shenzhen City during the continuous six days and got the distribution of SO2, NO2 in this paper. It showed that the pollution in the west is higher than in the east. The average concentration in the west is 2.0 times higher than the eastern for SO2 and 3.6 times for NO2. And comparison of the values between mobile DOAS and the point instrument was carried out in Baguang site. There was an agreement between the two instruments, the correlation coefficient was 0.86 for SO2, while 0.57 for NO2. The results indicate that this optical remote sensing method based on passive DOAS is an effective means of rapidly determining the distribution of city gaseous pollutant. PMID:21595196

  3. Absorption, distribution and utilization of soil-applied 10B in apple trees

    10B utilization rate was 7.0% and 10B distribution rate in roots, trunks and newly emerged organs of pot cultured apple tree (cv. 'liao fu'/Malus ptunifolia Borkh.) was 24.4%, 46.6% and 29.0%, respectively, in one month after soil-application of 10B during shoot rapid growth period. As the aerial newly emerged organs were concerned, Bdff% in long shoots and its leaves were higher than that in other shoots and leaves, suggesting that long shoots and its leaves had stronger ability of up taking 10B. At beginning of boron application, total boron amount and Bdff% in leaves increased fast, but 10B accumulating speed in shoot, particularly in its cortex, was higher than that in leaves in the later growing season, indicating that distribution center changed with growing period. The reserved boron in root and trunk played a mediative role in boron supply to newly emerged organs, a part of reserved mobile boron could transport to newly emerged organs when roots could not absorb any boron. With soil-applied 10B of 2μg·g-1 in autumn, Bdff% in soil was found less than 5% in the spring of the third year, but Bdff% in newly emerged organs was still 20%∼30%, which suggested that a part of reserved 10B could be reused

  4. Investigations on temperature distribution of satellite surfaces affected by solar absorptivity

    Liu, Y.; Pan, X. X.; Li, G. H.; Liu, X.; Jiang, L. X.

    2010-09-01

    Based on the Monte Carlo ray-tracing method, the network coefficients of thermal network model describing the radiation heat transfer among satellite surfaces is solved by considering the surface material optical characters. It is superiority to the conventional Gebhart's method in view of the grey body and the diffuse reflection assumptions. The zone leveling method is used to discrete the governing equations and the solar absorpivity is separated and considered to be an important correction parameter. Effects of the solar incidence round angle, the zenith angle and the ratio of absorpivity to emissivity (RAE) on temperature distribution are numerically simulated and discussed in detail. The higher or the lower the RAE may be lead to the alternative heating and cooling tend with a larger heating or cooling velocity of main body surfaces than the solar array surfaces. Furthermore, maximum temperature of main body is almost larger than solar arrays. Under the same RAE, solar incidence angle make a great effect on the uniform character of temperature distribution.

  5. Effects of the soil aeration on nutrient absorption, 14C-assimilates distribution and storage root yield in sweet potato

    Using Ipomoea batatas (L.) Lam. cv Lushu7 and Xushu18 as materials, the effect of the soil aeration on mineral nutrition absorption, 14C-assimilates distribution in storage roots and storage root yield were studied. The results showed that the improved soil aeration could increase the content of potassium, calcium, manganese, boron and zinc in leaves, increase the content of potassium and calcium in storage roots, decrease the content of manganese, boron and zinc in storage roots, improve the transportation of 14C-assimilates, increase the starch content of storage roots and significantly increase the storage root yield. The role of mineral elements on improving the transportation of 14C-assimilates was discussed

  6. A study of the absorption and distribution of isotope-labelling tracer 65Zn in Typha latifolia

    The result of the study of the absorption and distribution of 65Zn in Typha latifoliate shows that Typha has a very powerful capacity of absorbing 65Zn. The 65Zn absorbed and accumulated by the root and rhizome of Typha was much greater than that transferred to the leaf. The capacity of absorbing 65Zn of the organs of Typha is as follows: root>rhizome>leaf. The research also shows that the quantity of 65Zn absorbed by Typha increased with the time. Moreover, the quantity of zinc absorbed by Typha increased with the concentration of 65Zn in the culture solution. But the rate of absorbing 65Zn of Typha declined after 24 hor for the concentration of 65Zn in culture solution beyond 200 mg·kg-1

  7. Topographical body fat distribution links to amino acid and lipid metabolism in healthy obese women [corrected].

    Francois-Pierre J Martin

    Full Text Available Visceral adiposity is increasingly recognized as a key condition for the development of obesity related disorders, with the ratio between visceral adipose tissue (VAT and subcutaneous adipose tissue (SAT reported as the best correlate of cardiometabolic risk. In this study, using a cohort of 40 obese females (age: 25-45 y, BMI: 28-40 kg/m(2 under healthy clinical conditions and monitored over a 2 weeks period we examined the relationships between different body composition parameters, estimates of visceral adiposity and blood/urine metabolic profiles. Metabonomics and lipidomics analysis of blood plasma and urine were employed in combination with in vivo quantitation of body composition and abdominal fat distribution using iDXA and computerized tomography. Of the various visceral fat estimates, VAT/SAT and VAT/total abdominal fat ratios exhibited significant associations with regio-specific body lean and fat composition. The integration of these visceral fat estimates with metabolic profiles of blood and urine described a distinct amino acid, diacyl and ether phospholipid phenotype in women with higher visceral fat. Metabolites important in predicting visceral fat adiposity as assessed by Random forest analysis highlighted 7 most robust markers, including tyrosine, glutamine, PC-O 44∶6, PC-O 44∶4, PC-O 42∶4, PC-O 40∶4, and PC-O 40∶3 lipid species. Unexpectedly, the visceral fat associated inflammatory profiles were shown to be highly influenced by inter-days and between-subject variations. Nevertheless, the visceral fat associated amino acid and lipid signature is proposed to be further validated for future patient stratification and cardiometabolic health diagnostics.

  8. Pharmacokinetics, distribution, metabolism, and excretion of the dual reuptake inhibitor [(14)C]-nefopam in rats.

    Yu, Jian; Solon, Eric; Shen, Helen; Modi, Nishit B; Mittur, Aravind

    2016-11-01

    1. This study examined the pharmacokinetics, distribution, metabolism, and excretion of [(14)C] nefopam in rats after a single oral administration. Blood, plasma, and excreta were analyzed for total radioactivity, nefopam, and metabolites. Metabolites were profiled and identified. Radioactivity distribution was determined by quantitative whole-body autoradiography. 2. The pharmacokinetic profiles of total radioactivity and nefopam were similar in male and female rats. Radioactivity partitioned approximately equally between plasma and red blood cells. A majority of the radioactivity was excreted in urine within 24 hours and mass balance was achieved within 7 days. 3. Intact nefopam was a minor component in plasma and excreta. Numerous metabolites were identified in plasma and urine generated by multiple pathways including: hydroxylation/oxidation metabolites (M11, M22a and M22b, M16, M20), some of which were further glucuronidated (M6a to M6c, M7a to M7c, M8a and M8b, M3a to M3d); N-demethylation of nefopam to metabolite M21, which additionally undergoes single or multiple hydroxylations or sulfation (M9, M14, M23), with some of the hydroxylated metabolites further glucuronidated (M2a to M2d). 4. Total radioactivity rapidly distributed with highest concentrations found in the urinary bladder, stomach, liver, kidney medulla, small intestine, uveal tract, and kidney cortex without significant accumulation or persistence. Radioactivity reversibly associated with melanin-containing tissues. PMID:26927982

  9. Absorption and metabolism of bisphenol A, a possible endocrine disruptor, in the aquatic edible plant, water convolvulus (Ipomoea aquatica).

    Noureddin, Imadeddin M; Furumoto, Toshio; Ishida, Yutaka; Fukui, Hiroshi

    2004-06-01

    Water convolvulus, a vegetable, absorbed bisphenol A (BPA), an endocrine disruptor, from the medium. One week later, no BPA could be detected in the plant, indicating that BPA had been metabolized in the plant. BPA monoglucoside was detected as the BPA base at ca. 10% in the roots, some in the stems, but none in the leaves. (2)H-NMR analyses of MeOH extracts and hydrolyzates of the plant treated with BPA-d(16) showed the presence of metabolites (ca. 7% and 26%, respectively, as BPA equivalents) other than the glucoside. Over 50% of BPA might be polymerized and/or tightly bound in the plant residues. PMID:15215615

  10. Mass spectrometric methods for studying nutrient mineral and trace element absorption and metabolism in humans using stable isotopes: a review

    Mass spectrometric methods for determining stable isotopes of nutrient minerals and trace elements in human metabolic studies are described and discussed. The advantages and disadvantages of the techniques of electron ionization, fast atom bombardment, thermal ionization, and inductively coupled plasma and gas chromatography mass spectrometry are evaluated with reference to their accuracy, precision, sensitivity, and convenience, and the demands of human nutrition research. Examples of specific applications are described and the significance of current developments in mass spectrometry are discussed with reference to present and probable future research needs. (Author)

  11. Human Vitamin B12 Absorption and Metabolism are Measured by Accelerator Mass Spectrometry Using Specifically Labeled 14C-Cobalamin

    There is need for an improved test of human ability to assimilate dietary vitamin B12. Assaying and understanding absorption and uptake of B12 is important because defects can lead to hematological and neurological complications. Accelerator mass spectrometry (AMS) is uniquely suited for assessing absorption and kinetics of 14C-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of carbon-14 (14C) in microliter volumes of biological samples, with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B12 in the range of normal dietary intake. The B12 used was quantitatively labeled with 14C at one particular atom of the DMB moiety by exploiting idiosyncrasies of Salmonellametabolism. In order to grow aerobically on ethanolamine, S. entericamust be provided with either pre-formed B12 or two of its precursors: cobinamide and dimethylbenzimidazole (DMB). When provided with 14C-DMB specifically labeled in the C2 position, cells produced 14C-B12 of high specific activity (2.1 GBq/mmol, 58 mCi/mmol) and no detectable dilution of label from endogenous DMB synthesis. In a human kinetic study, a physiological dose (1.5 mg, 2.2 KBq/59 nCi) of purified 14C-B12 was administered and showed plasma appearance and clearance curves consistent with the predicted behavior of the pure vitamin. This method opens new avenues for study of B12 assimilation

  12. Tissue distribution and metabolism of guanosine in rats following intraperitoneal injection.

    Giuliani, P; Ballerini, P; Ciccarelli, R; Buccella, S; Romano, S; D'Alimonte, I; D' Alimonte, I; Poli, A; Beraudi, A; Peña, E; Jiang, S; Rathbone, M P; Caciagli, F; Di Iorio, P

    2012-01-01

    Guanosine has long been known as an endogenous purine nucleoside deeply involved in the modulation of several intracellular processes, especially G-protein activity. More recently, it has been reported to act as an extracellular signaling molecule released from neurons and, more markedly, from astrocytes either in basal conditions or after different kinds of stimulation including hypoxia. Moreover, in vivo studies have shown that guanosine plays an important role as both a neuroprotective and neurotrophic agent in the central nervous system. Specific high-affinity binding sites for this nucleoside have been found on membrane preparations from rat brain. The present study was undertaken to investigate the distribution and metabolic profiles of guanosine after administering the nucleoside to gain a better understanding of the biological effects of this potential drug candidate. Rats were given an intraperitonal (i.p.) injection of 2, 4, 8 or 16 mg/kg of guanosine combined with 0.05% of [3H]guanosine. Plasma samples were collected 7.5, 15, 30, 60 and 90 min after the guanosine-mixture administration and analyzed by either a liquid scintillation counter or by HPLC connected to a UV and to an on-line radiochemical detector to measure the levels of guanosine and its metabolic products guanine, xanthine and uric acid. The levels of guanosine, guanine and xanthine were also measured in brain, lung, heart, kidney and liver tissue homogenates at the defined time points after the injection of 8 mg/kg of the guanosine-mixture. We found that the levels of radioactivity in plasma increased linearly in a dose- and time-dependent manner. Guanosine was widely distributed in all tissues examined in the present study, at almost twice its usual levels. In addition, guanine levels dramatically increased in all the organs. Interestingly, enzymatic analysis of the plasma samples showed the presence of a soluble purine nucleoside phosphorylase, a key enzyme in the purine salvage pathway

  13. Characterization of penetration depth as a function of optical fiber separation at various absorption and scatter coefficients for a noninvasive metabolic sensor

    DeMilo, Charles; Brukilacchio, Thomas; Soller, Babs R.; Soyemi, Olusola

    2004-06-01

    A visible-near IR (500-1,000nm) fiber optic sensor is under development that is intended to non-invasively assess muscle metabolism through the measurement of tissue pH and oxygen partial pressure. These parameters are calculated from the spectra of hemoglobin and myoglobin in muscle. The sensor consists of transmit (illumination) fibers and receive (detection) fibers that are coupled to a spectrometer. Light from the probe must penetrate below the surface of the skin and into a 5-10mm thick layer of muscle. A study was conducted to quantify the relationship between transmit and receive fiber separation and sensor penetration depth below the surface of the skin. A liquid phantom was created to replicate the absorption (μa) and reduced scatter coefficient (μs') profiles typically found in human blood and tissue. The phantom consisted of a solution of Intralipid and India ink in the appropriate concentrations to achieve desired reduced scatter coefficient and absorption profiles. The reduced scatter coefficient of the liquid phantom was achieved to an accuracy of +/-10% compared to previously published data. A fixed illumination fiber and translatable detector fiber were placed in the liquid phantom, and the fiber separation was varied from 3-40mm. Values of μa and μs' varied from 0.03-0.40 cm-1 and 5.0-15.0 cm-1 respectively. Results from the experiment demonstrate a strong correlation between penetration depth and fiber separation. Additionally, it was found that penetration depth was not substantially influenced by absorption and scatter concentration. As signal-to-noise is an important parameter in many non-invasive biomedical applications, the relative signal as a function of fiber separation was determined to follow an exponential relationship.

  14. Human Vitamin B12 Absorption and Metabolism are Measured by Accelerator Mass Spectrometry Using Specifically Labeled 14C-Cobalamin

    Carkeet, C; Dueker, S R; Lango, J; Buchholz, B A; Miller, J W; Green, R; Hammock, B D; Roth, J R; Anderson, P J

    2006-01-26

    There is need for an improved test of human ability to assimilate dietary vitamin B{sub 12}. Assaying and understanding absorption and uptake of B{sub 12} is important because defects can lead to hematological and neurological complications. Accelerator mass spectrometry (AMS) is uniquely suited for assessing absorption and kinetics of {sup 14}C-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of carbon-14 ({sup 14}C) in microliter volumes of biological samples, with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B{sub 12} in the range of normal dietary intake. The B{sub 12} used was quantitatively labeled with {sup 14}C at one particular atom of the DMB moiety by exploiting idiosyncrasies of Salmonellametabolism. In order to grow aerobically on ethanolamine, S. entericamust be provided with either pre-formed B{sub 12} or two of its precursors: cobinamide and dimethylbenzimidazole (DMB). When provided with {sup 14}C-DMB specifically labeled in the C2 position, cells produced {sup 14}C-B{sub 12} of high specific activity (2.1 GBq/mmol, 58 mCi/mmol) and no detectable dilution of label from endogenous DMB synthesis. In a human kinetic study, a physiological dose (1.5 mg, 2.2 KBq/59 nCi) of purified {sup 14}C-B{sub 12} was administered and showed plasma appearance and clearance curves consistent with the predicted behavior of the pure vitamin. This method opens new avenues for study of B{sub 12} assimilation.

  15. Fast spatially resolved exhaust gas recirculation (EGR) distribution measurements in an internal combustion engine using absorption spectroscopy.

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E; Perfetto, Anthony; Geckler, Sam; Partridge, William P

    2015-09-01

    Exhaust gas recirculation (EGR) in internal combustion engines is an effective method of reducing NOx emissions while improving efficiency. However, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder non-uniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. A sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in the intake manifold. The study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz. PMID:26253286

  16. Remote sensing of vertical phytoplankton pigment distributions in the Baltic: new mathematical expressions. Part 3: Nonphotosynthetic pigment absorption factor:

    Bogdan Woźniak

    2007-12-01

    Full Text Available This paper, part 3 of the description of vertical pigment distributions in the Baltic Sea, discusses the mathematical expression enabling the vertical distributions of the non-photosynthetic pigment absorption factor fa to be estimated. The factor fa is directly related to concentrations of the several groups of phytoplankton pigments and describes quantitatively the ratio of the light energy absorbed at given depths by photosynthetic pigments to the light energy absorbed by all the phytoplankton pigments together (photosynthetic and photoprotecting. Knowledge of this factor is highly desirable in the construction of state-of-the-art "light-photosynthesis" models for remote-sensing purposes.    The expression enables fa to be estimated with considerable precision on the basis of two surface parameters (available from satellite observations: the total chlorophyll a concentration at the surfaceCa(0 and the spectral downward irradiance Ed(λ, 0 just below the sea surface. The expression is applicable to Baltic waters from the surface down to an optical depth of τ ≈ 5.    The verification of the model description of fa was based on 400 quasi-empirical values of this factor which were calculated on the basis of empirical values of the following parameters measured at the same depths: Ed(λ, z (or also PAR(z, apl(λ, z,and the concentrations of all the groups of phytoplankton pigments Ca(z and Cj(z (where j denotes in turn chl b, chl c, PSC, phyc, PPC. The verification shows that the errors in the values of the non-photosynthetic pigment absorption factor fa estimated using the modeldeveloped in this work are small: in practice they do not exceed 4%.    Besides the mathematical description of the vertical distribution of fa, this paper also discusses the range of variation of its values measured in the Baltic and its dependence on the trophic index of a basin and depth in the sea. In addition, the similarities and differences in the

  17. Estimating the geographical distribution of the prevalence of the metabolic syndrome in young Mexicans

    Miguel Murguía-Romero

    2012-09-01

    Full Text Available The geographical distribution of the metabolic syndrome (MetS prevalence in young Mexicans (aged 17-24 years was estimated stepwise starting from its prevalence based on the body mass index (BMI in a study of 3,176 undergraduate students of this age group from Mexico City. To estimate the number of people with MetS by state, we multiplied its prevalence derived from the BMI range found in the Mexico City sample by the BMI proportions (range and state obtained from the Mexico 2006 national survey on health and nutrition. Finally, to estimate the total number of young people with MetS in Mexico, its prevalence by state was multiplied by the share of young population in each state according to the National Population and Housing Census 2010. Based on these figures, we estimated the national prevalence of MetS at 15.8%, the average BMI at 24.1 (standard deviation = 4.2, and the prevalence of overweight people (BMI ≥25 of that age group at 39.0%. These results imply that 2,588,414 young Mexicans suffered from MetS in 2010. The Yucatan peninsula in the south and the Sonora state in the north showed the highest rates of MetS prevalence. The calculation of the MetS prevalence by BMI range in a sample of the population, and extrapolating it using the BMI proportions by range of the total population, was found to be a useful approach. We conclude that the BMI is a valuable public health tool to estimate MetS prevalence in the whole country, including its geographical distribution.

  18. Effects of different ratios of straw to N-fertilizer on growth of Malus hupehensis seedling and its absorption, distribution and utilization of nitrogen

    CUI Tong-Li; JIANG Yuan-Mao; PENG Fu-Tian; WEI Shao-Chong

    2012-01-01

    Aims The study was to explore the effects of different ratios of straw to N-fertilizer on growth of Malus hupehensis seedlings and 15 N absorption, distribution and utilization in them.Methods Using 15N trace technique, we measured growth parameters (plant height, basal stem diameter and dry weight) and 15N parameters (absorption, N derived from fertilizer, distribution and utilization) of two-year-old M.hupehensis seedlings and C/N ratio in soil organic matter under different straw-nitrogen ...

  19. Distribution and metabolism of carbofuran in paddy rice from controlled release formulations

    This study was conducted to evaluate slow release formulations of carbofuran in aquatic systems. Laboratory, greenhouse and field experiments in a rice paddy were carried out to determine the behaviour and fate of the important systemic insecticide carbofuran after application of new formulations. The release rates into water and the residues in the plant and soil were determined. Metabolites were identified by gas chromatography-mass spectrometry. Carbon-14 labelled carbofuran was used for the experiments. The results showed that the cellulose based (hydroxyethyl-cellulose) formulations released the active ingredient carbofuran at a significantly slower rate than commercial formulations, but that the concentration of carbofuran in water and plants was high enough to protect the plants against insects. Recovery of the insecticide in the rice paddy was only about 30%. Most was lost by changing the water in the paddy field, according to the usual cultivation practice, and by possible evaporation. The radioactivity found in grain and straw was 0.03% and 0.2%, respectively. The distribution of carbofuran in soil at different layers was: 0-5 cm: 17%; 5-15 cm: 7%; 15-25 cm: 4%; 25-40 cm: 2%. Less than 10% of the total radioactivity could be extracted from plants (Soxhlet extraction); thus, most of the carbofuran was metabolized and bound to the plant-grain constituents. (author). 4 refs, 5 figs, 4 tabs

  20. SVD identifies transcript length distribution functions from DNA microarray data and reveals evolutionary forces globally affecting GBM metabolism.

    Nicolas M Bertagnolli

    Full Text Available To search for evolutionary forces that might act upon transcript length, we use the singular value decomposition (SVD to identify the length distribution functions of sets and subsets of human and yeast transcripts from profiles of mRNA abundance levels across gel electrophoresis migration distances that were previously measured by DNA microarrays. We show that the SVD identifies the transcript length distribution functions as "asymmetric generalized coherent states" from the DNA microarray data and with no a-priori assumptions. Comparing subsets of human and yeast transcripts of the same gene ontology annotations, we find that in both disparate eukaryotes, transcripts involved in protein synthesis or mitochondrial metabolism are significantly shorter than typical, and in particular, significantly shorter than those involved in glucose metabolism. Comparing the subsets of human transcripts that are overexpressed in glioblastoma multiforme (GBM or normal brain tissue samples from The Cancer Genome Atlas, we find that GBM maintains normal brain overexpression of significantly short transcripts, enriched in transcripts that are involved in protein synthesis or mitochondrial metabolism, but suppresses normal overexpression of significantly longer transcripts, enriched in transcripts that are involved in glucose metabolism and brain activity. These global relations among transcript length, cellular metabolism and tumor development suggest a previously unrecognized physical mode for tumor and normal cells to differentially regulate metabolism in a transcript length-dependent manner. The identified distribution functions support a previous hypothesis from mathematical modeling of evolutionary forces that act upon transcript length in the manner of the restoring force of the harmonic oscillator.

  1. Absorption, metabolism, and effects at transcriptome level of a standardized French oak wood extract, Robuvit, in healthy volunteers: pilot study.

    Natella, Fausta; Leoni, Guido; Maldini, Mariateresa; Natarelli, Lucia; Comitato, Raffaella; Schonlau, Frank; Virgili, Fabio; Canali, Raffaella

    2014-01-15

    The consumption of wine and spirits, traditionally aged in oak barrels, exposes humans to roburin ingestion. These molecules belong to a class of ellagitannins (ETs), and their only known source is oak wood. Very little is currently known about roburin bioavailability and biological activity. We reported for the first time human absorption of roburins from a French oak wood (Quercus robur) water extract (Robuvit) by measuring the increase of total phenols (from 0.63 ± 0.06 to 1.26 ± 0.18 μg GAE equiv/mL plasma) and the appearance of roburin metabolites (three different glucoronidate urolithins and ellagic acid), in plasma, after 5 days of supplementation. Robuvit supplementation induced also the increase of plasma antioxidant capacity from 1.8 ± 0.05 to 1.9 ± 0.01 nmol Trolox equiv/mL plasma. Moreover, utilizing a combined ex vivo cell culture approach, we assessed the effect of Q. robur metabolites (present in human serum after supplementation) on gene expression modulation, utilizing an Affymetrix array matrix, in endothelial, neuronal, and keratinocyte cell lines. The functional analysis reveals that Robuvit metabolites affect ribosome, cell cycle, and spliceosome pathways. PMID:24354337

  2. Quantitative analysis of absorption, metabolism, and excretion of benzoxazinoids in humans after the consumption of high- and low-benzoxazinoid diets with similar contents of cereal dietary fibres: a crossover study

    Jensen, Bettina M.; B. Adhikari, Khem; Schnoor, Heidi J.;

    2016-01-01

    PURPOSE: Benzoxazinoids (BXs) are a group of wholegrain phytochemicals with potential pharmacological properties; however, limited information exists on their absorption, metabolism, and excretion in humans. The aim of this study was to investigate the dose-dependent uptake and excretion of dietary...

  3. Disposition of enalapril in the perfused rat intestine-liver preparation: absorption, metabolism and first-pass effect.

    Pang, K S; Cherry, W F; Ulm, E H

    1985-06-01

    A new procedure, namely the in situ perfused rat intestine-liver preparation, was introduced to examine the roles of the intestine and the liver in the elimination of enalapril, a new angiotensin-converting enzyme inhibitor. The in situ perfused rat intestine preparation was used to determine the rate and extent of enalapril absorption after an-intraduodenal dose. In the former technique, enalapril in blood perfusate (10 ml/min) was delivered via the superior mesenteric artery into the once-through perfused rat intestine-liver preparation, with sampling effected in reservoir, portal vein and hepatic vein. The ease of sampling, proximal and distal to the intestine and liver, allowed the direct estimation of the extraction ratios by the intestine and the liver. The steady-state intestinal extraction ratio of enalapril was small (0.04 +/- 0.066) compared to that for the liver (0.74 +/- 0.06), indicating that the liver was responsible for most of the hydrolytic conversion of enalapril to its pharmacologically active diacid metabolite, enalaprilat. Moreover, no trend in the values of the extraction ratios by both organs was apparent among the input concentrations of enalapril (0.55, 2.6 and 13.3 microM) used. Portal venous plasma consisted mainly of enalapril and was devoid of enalaprilat, whereas both enalapril and enalaprilat were detected in bile and hepatic venous plasma. With the latter technique, an intraduodenal injection of a tracer dose of [14C]enalapril (0.14-0.39 mumol) was made close to the pyloric sphinctor, whereas the intestine preparation was recirculated (7.5 ml/min) with blank perfusate.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2989498

  4. Concentration distribution of Nd{sup 3+} In Nd:Gd{sub 3}Ga{sub 5}O{sub 12} crystals studied by optical absorption method

    Sun, Dunlu; Zhang, Qingli; Wang, Zhaobing; Su, Jing; Gu, Changjiang; Wang, Aihua; Yin, Shaotang [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, HeFei 230031 (China)

    2005-07-01

    Nd:Gd{sub 3}Ga{sub 5}O{sub 12} crystals with different concentrations of Nd{sup 3+} were grown by Czochralski method, their absorption spectra were measured at room temperature. By using the optical absorption method, the effective distribution coefficient k{sub eff} for Nd{sup 3+} in GGG was fitted to be 0.40{+-}0.01, which is higher than that of Nd{sup 3+} in YAG. The 808nm absorption cross-section was calculated to be 4.0{+-}0.2 x 10{sup -20} cm{sup -2}. The lengthways and radial concentration distribution of Nd{sup 3+} in the crystals were also analyzed and discussed. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Regional distribution of xenobiotic metabolizing enzymes and DNA adducts in the respiratory tract - relationship to respiratory epithelial populations

    Specific regions from one-half of the nasal, tracheal, bronchial, and pulmonary airways of dogs were excised and analyzed for the presence of xenobiotic metabolizing enzymes. Substrates for different isozymes of cytochrome P-450, including benzo[a]pyrene (BaP), nitropyrene (NP), ethoxycoumarin, and ethoxyresorufin as well as selected Phase II enzymes were measured. Experiments were also conducted in which rats were exposed nose-only to dilute diesel exhaust (10 mg particles/m3) for up to 12 weeks. DNA adducts were measured in various regions of the respiratory tract after the 12-week exposure, using the highly sensitive 32P-postlabeling assay. The data indicate that there are significant differences in the metabolic capability and DNA adduct distribution along the respiratory tract. Quantitative differences that were noted along the respiratory tract are probably due to both differences in the capability of a given region to metabolize the organic chemicals associated with diesel exhaust and differences in the deposition patterns of the diesel exhaust. Differences in the metabolic capability, and therefore DNA adduct distribution, along the respiratory tracts of different species could explain, in part, why certain portions of the respiratory tract are more susceptible to tumor formation than are other portions

  6. Distribution and Metabolism of Bt-Cry1Ac Toxin in Tissues and Organs of the Cotton Bollworm, Helicoverpa armigera

    Zhuoya Zhao

    2016-07-01

    Full Text Available Crystal (Cry proteins derived from Bacillus thuringiensis (Bt have been widely used in transgenic crops due to their toxicity against insect pests. However, the distribution and metabolism of these toxins in insect tissues and organs have remained obscure because the target insects do not ingest much toxin. In this study, several Cry1Ac-resistant strains of Helicoverpa armigera, fed artificial diets containing high doses of Cry1Ac toxin, were used to investigate the distribution and metabolism of Cry1Ac in their bodies. Cry1Ac was only detected in larvae, not in pupae or adults. Also, Cry1Ac passed through the midgut into other tissues, such as the hemolymph and fat body, but did not reach the larval integument. Metabolic tests revealed that Cry1Ac degraded most rapidly in the fat body, followed by the hemolymph, peritrophic membrane and its contents. The toxin was metabolized slowly in the midgut, but was degraded in all locations within 48 h. These findings will improve understanding of the functional mechanism of Bt toxins in target insects and the biotransfer and the bioaccumulation of Bt toxins in arthropod food webs in the Bt crop ecosystem.

  7. Effects of antibodies induced by a conjugate vaccine on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone absorptive transport, metabolism, and proliferation of human lung cells.

    De Buck, Stefan S; Schellenberger, Mario T; Ensch, Corinne; Muller, Claude P

    2010-08-01

    One of the most abundant and potent lung carcinogen is the nicotine-derived tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The monoclonal antibody P9D5 induced with a NNK-conjugate vaccine was used to investigate the ability of NNK-specific antibodies to modulate NNK-induced adverse effects as well as its absorptive transport and metabolism in two lung cancer cell lines (Calu-3 and NCI-H82). Transport experiments in Calu-3 cells with a 50-fold molar excess of apical P9D5 increased the recovery of coadministered apical NNK, with a concomitant decrease in NNK transepithelial transport of more than 50% compared to controls. In contrast, basolateral P9D5 did neither influence transepithelial transport of NNK nor its disappearance from the apical compartment. Calu-3 cells were also found to reduce NNK to NNAL and a 65-fold molar excess of NNK-specific antibody inhibited this metabolic conversion by 46 and 54% compared to irrelevant control antibody after 48 and 72 hr, respectively. The biological relevance of NNK redistribution by antibody was demonstrated by reversion of NNK-induced cell proliferation in NCI-H82 cells. Repartitioning of tobacco carcinogens by antibody may reduce their early effective peak concentrations in susceptible target organs and thus relieve overloaded local DNA repair mechanisms and diminish carcinogen-induced cell proliferation. These in vitro data therefore suggest that a prophylactic antibody response may be associated with a reduced risk of cancer. PMID:19960439

  8. Absorption, Metabolism, and Excretion by Freely Moving Rats of 3,4-DHPEA-EDA and Related Polyphenols from Olive Fruits (Olea europaea

    Shunsuke Kano

    2016-01-01

    Full Text Available Absorption, metabolism, and excretion of 3,4-DHPEA-EDA, oleuropein, and hydroxytyrosol isolated from olive fruits were newly evaluated after oral and intravenous administration in freely moving rats cannulated in the portal vein, jugular vein, and bile duct. Orally administered 3,4-DHPEA-EDA, an important bioactive compound in olive pomace, was readily absorbed and metabolized to hydroxytyrosol, homovanillic acid, and homovanillyl alcohol, as shown by dose-normalized 4 h area under the curve (AUC0→4 h/Dose values of 27.7, 4.5, and 4.2 μM·min·kg/μmol, respectively, in portal plasma after oral administration. The parent compound 3,4-DHPEA-EDA was not observed in the portal plasma, urine, and bile after oral and intravenous administration. Additionally, hydroxytyrosol, homovanillic acid, and homovanillyl alcohol in the portal plasma after oral administration of hydroxytyrosol showed 51.1, 22.8, and 7.1 μM·min·kg/μmol AUC0→4 h/Dose, respectively. When oleuropein, a polar glucoside, was injected orally, oleuropein in the portal plasma showed 0.9 μM·min·kg/μmol AUC0→4 h/Dose. However, homovanillic acid was detected from oleuropein in only a small amount in the portal plasma. Moreover, the bioavailability of hydroxytyrosol and oleuropein for 4 hours was 13.1% and 0.5%, respectively. Because the amount of 3,4-DHPEA-EDA in olive fruits is about 2-3 times greater than that of hydroxytyrosol, the metabolites of 3,4-DHPEA-EDA will influence biological activities.

  9. Absorption, Metabolism, and Excretion by Freely Moving Rats of 3,4-DHPEA-EDA and Related Polyphenols from Olive Fruits (Olea europaea).

    Kano, Shunsuke; Komada, Haruna; Yonekura, Lina; Sato, Akihiko; Nishiwaki, Hisashi; Tamura, Hirotoshi

    2016-01-01

    Absorption, metabolism, and excretion of 3,4-DHPEA-EDA, oleuropein, and hydroxytyrosol isolated from olive fruits were newly evaluated after oral and intravenous administration in freely moving rats cannulated in the portal vein, jugular vein, and bile duct. Orally administered 3,4-DHPEA-EDA, an important bioactive compound in olive pomace, was readily absorbed and metabolized to hydroxytyrosol, homovanillic acid, and homovanillyl alcohol, as shown by dose-normalized 4 h area under the curve (AUC0→4 h/Dose) values of 27.7, 4.5, and 4.2 μM·min·kg/μmol, respectively, in portal plasma after oral administration. The parent compound 3,4-DHPEA-EDA was not observed in the portal plasma, urine, and bile after oral and intravenous administration. Additionally, hydroxytyrosol, homovanillic acid, and homovanillyl alcohol in the portal plasma after oral administration of hydroxytyrosol showed 51.1, 22.8, and 7.1 μM·min·kg/μmol AUC0→4 h/Dose, respectively. When oleuropein, a polar glucoside, was injected orally, oleuropein in the portal plasma showed 0.9 μM·min·kg/μmol AUC0→4 h/Dose. However, homovanillic acid was detected from oleuropein in only a small amount in the portal plasma. Moreover, the bioavailability of hydroxytyrosol and oleuropein for 4 hours was 13.1% and 0.5%, respectively. Because the amount of 3,4-DHPEA-EDA in olive fruits is about 2-3 times greater than that of hydroxytyrosol, the metabolites of 3,4-DHPEA-EDA will influence biological activities. PMID:26904279

  10. FluxSimulator: An R package to simulate isotopomer distributions in metabolic networks

    Binsl, Thomas W; Mullen, Katharine M.; Ivo H. M. van Stokkum; Jaap Heringa; van Beek, Johannes H G M

    2007-01-01

    The representation of biochemical knowledge in terms of fluxes (transformation rates) in a metabolic network is often a crucial step in the development of new drugs and efficient bioreactors. Mass spectroscopy (MS) and nuclear magnetic resonance spectroscopy (NMRS) in combination with 13C labeled substrates are experimental techniques resulting in data that may be used to quantify fluxes in the metabolic network underlying a process. The massive amount of data generated by spectroscopic exper...

  11. Identification of Absorption, Distribution, Metabolism, and Excretion (ADME) Genes Relevant to Steatosis Using a Systems Biology Approach

    Ensuring chemical safety and sustainability form a main priority of the U.S. Environmental Protection Agency. This entails efforts on multiple fronts to characterize the potential hazard posed by chemicals currently in use and those to be commercialized in the future. The use of ...

  12. Enabling the Distributed Generation Market of High Temperature Fuel Cell and Absorption Chiller Systems to Support Critical and Commercial Loads

    DiMola, Ashley M.

    Buildings account for over 18% of the world's anthropogenic Greenhouse Gas (GHG) emissions. As a result, a technology that can offset GHG emissions associated with buildings has the potential to save over 9 Giga-tons of GHG emissions per year. High temperature fuel cell and absorption chiller (HTFC/AC) technology offers a relatively low-carbon option for meeting cooling and electric loads for buildings while producing almost no criteria pollutants. GHG emissions in the state of California would decrease by 7.48 million metric tons per year if every commercial building in the State used HTFC/AC technology to meet its power and cooling requirements. In order to realize the benefits of HTFC/AC technology on a wide scale, the distributed generation market needs to be exposed to the technology and informed of its economic viability and real-world potential. This work characterizes the economics associated with HTFC/AC technology using select scenarios that are representative of realistic applications. The financial impacts of various input factors are evaluated and the HTFC/AC simulations are compared to the economics of traditional building utilities. It is shown that, in addition to the emissions reductions derived from the systems, HTFC/AC technology is financially preferable in all of the scenarios evaluated. This work also presents the design of a showcase environment, centered on a beta-test application, that presents (1) system operating data gathered using a custom data acquisition module, and (2) HTFC/AC technology in a clear and approachable manner in order to serve the target audience of market stakeholders.

  13. Growth against entropy in bacterial metabolism: the phenotypic trade-off behind empirical growth rate distributions in E. coli

    De Martino, Daniele; Capuani, Fabrizio; De Martino, Andrea

    2016-06-01

    The solution space of genome-scale models of cellular metabolism provides a map between physically viable flux configurations and cellular metabolic phenotypes described, at the most basic level, by the corresponding growth rates. By sampling the solution space of E. coli's metabolic network, we show that empirical growth rate distributions recently obtained in experiments at single-cell resolution can be explained in terms of a trade-off between the higher fitness of fast-growing phenotypes and the higher entropy of slow-growing ones. Based on this, we propose a minimal model for the evolution of a large bacterial population that captures this trade-off. The scaling relationships observed in experiments encode, in such frameworks, for the same distance from the maximum achievable growth rate, the same degree of growth rate maximization, and/or the same rate of phenotypic change. Being grounded on genome-scale metabolic network reconstructions, these results allow for multiple implications and extensions in spite of the underlying conceptual simplicity.

  14. Corticosterone metabolism in chicken tissues: evidence for tissue-specific distribution of steroid dehydrogenases

    Kučka, Marek; Vagnerová, Karla; Klusoňová, Petra; Mikšík, Ivan; Pácha, Jiří

    2006-01-01

    Roč. 147, č. 3 (2006), s. 377-383. ISSN 0016-6480 R&D Projects: GA AV ČR(CZ) IAA6011201; GA ČR(CZ) GA203/03/1062 Institutional research plan: CEZ:AV0Z50110509 Keywords : hydroxysteroid dehydrogenases * corticosterone metabolism * aves Subject RIV: CE - Biochemistry Impact factor: 2.487, year: 2006

  15. Analysis of the impact of controlled release formulations on oral drug absorption, gut wall metabolism and relative bioavailability of CYP3A substrates using a physiologically-based pharmacokinetic model

    Andres Olivares-Morales, Yoshiteru Kamiyama, Adam S Darwich, Leon Aarons, Amin Rostami-Hodjegan

    2015-01-01

    Controlled release (CR) formulations are usually designed to achieve similar exposure (AUC) levels as the marketed immediate release (IR) formulation. However, the AUC is often lower following CR compared to IR formulations. There are a few exceptions when the CR formulations have shown higher AUC. This study investigated the impact of CR formulations on oral drug absorption and CYP3A4-mediated gut wall metabolism. A review of the current literature on relative bioavailability (Frel) between ...

  16. Effects of the antituberculous drug ethambutol on zinc absorption, turnover and distribution in rats fed diet marginal and adequate in zinc

    King, A.B.; Schwartz, R.

    1987-04-01

    Ethambutol, (CH/sub 3/CH/sub 2/-CH(CH/sub 2/OH)-NH-CH/sub 2/)/sub 2/ (EMB), is an oral antituberculous agent that is administered therapeutically over extended time periods. It has chelating properties and may affect mineral metabolism. Male weanling Sprague-Dawley rats received 0, 400 or 600 mg EMB per kilogram body weight daily by gavage for 30 d. They were fed a casein-based diet with either adequate (49 ppm) or marginal (11 ppm) zinc. Both adequate-Zn (AZn) and marginal-Zn (MZn) rats receiving EMB showed alopecia and dose-dependent reductions in feed intake, weight gain and feed efficiency. None of these changes was seen in rats fed the MZn diet without EMB. Serum and tissue zinc levels were similar in rats not receiving EMB, regardless of the dietary zinc level. Serum zinc was consistently lower in AZn and MZn rats receiving EMB than in rats without EMB. Apparent zinc absorption, measured by /sup 65/Zn balance, was higher in AZn rats receiving EMB than in AZn rats without EMB. Thus, changes in absorption could not account for lower serum zinc levels in EMB-treated rats. However, /sup 65/Zn turnover was also higher in EMB groups. This suggests that EMB may have increased urinary zinc losses resulting in reduced circulating zinc and a consequent increase in zinc absorption.

  17. Absorption and metabolism of fructose and its relationship with human health%果糖的吸收代谢以及与健康的关系

    蔡雯雯; 李铎

    2016-01-01

    果糖是一种单糖,由于其甜度大于葡萄糖和蔗糖,近年来高果糖浓度的果葡糖浆被广泛用于食品工业中。因此,近年来果糖对人体健康的影响备受关注。本研究总结了果糖的主要食物来源、吸收和代谢,与相关疾病之间的关系,以及推荐摄入量。果糖和葡萄糖不同,它的主要代谢器官是肝,除部分代谢为葡萄糖外,主要代谢为脂肪酸,后者进一步合成甘油三酯。肝中甘油三酯沉积会增加脂肪肝的发病风险和胰岛素抵抗,其余甘油三酯可被转运至其他组织器官,增加胰岛素抵抗、肥胖和心血管系统疾病的发病风险。世界卫生组织建议在整个生命历程中减少游离糖摄入量,成人和儿童游离糖摄入量应减至摄入总能量的10%以内。如能进一步将其降至低于摄入总能量的5%,则对健康有更多益处。%Summary Fructose is a monosaccharide,which is greatly sweeter than glucose and sucrose.In recent years,high fructose corn syrup has been widely used in beverages and food industry globally.However,the effect of fructose on human health has received much attention in current years.In this review,we mainly discussed the food source, absorption and metabolism of fructose,relationship between fructose and metabolic disorders,and recommendation intake of total sugar. Crystalline fructose is dried,ground,and highly pure.Fructose is found in most fruits and vegetables either as a monosaccharide or as a unit of sucrose.The ratio of fructose to glucose in most natural food is approximately 1∶1 . Fructose has the lowest glycemic index of all natural sugars.High-fructose corn syrup (HFCS) is a mixture of fructose and glucose,which is widely used in food industry,added into soft drinks and baked foods for its palatability and good taste.HFCS-42,HFCS-55 and HFCS-90 are three kinds of HFCS,and the number for each HFCS represents the percentage of fructose in the syrup

  18. Regional distribution and variation of gamma-globulin absorption from the small intestine of the neonatal calf

    125I-labeled immunoglobulin (Ig)G1 in colostral whey was used to determine the region of maximum absorption of Ig from the small intestine of the neonatal calf and the variation in Ig absorption among calves at the intestinal level. In experiment 1, 5 segments (approx 5%, 35%, 60%, 80%, and 95% of the duodenocecal length) were formed in the small intestine of 9 colostrum-deprived calves shortly after birth. These segments were injected with colostral whey containing 125I-IgG1 4 hours after birth, and uptake, transfer, and absorption (defined as uptake plus transfer) were determined for each segment 2 hours later. Raw data were adjusted for the milligrams of IgG1 injected per gram of intestinal tissue to obtain the least squares mean (LSM) value. The LSM values for absorption of IgG1 from distal segments 3, 4, and 5 were significantly greater (P less than 0.05) than those values for proximal segments 1 and 2. The region of the maximum IgG1 absorption was the lower small intestine, 60% to 80% of the duodenocecal length. There was also an indication of independence between uptake and transfer in each of the segments. Significant differences (P less than 0.05) were present among calves in the LSM values for uptake and absorption, but not for transfer. In experiment 2, thoracic ducts of 8 newborn calves were cannulated 4 to 5 hours after birth. At 6 hours after birth, colostral whey with 125I-IgG1 was injected into an intestinal segment (approx 60% to 80% of the duodenocecal length)

  19. The evolution of control and distribution of adaptive mutations in a metabolic pathway.

    Wright, Kevin M; Rausher, Mark D

    2010-02-01

    In an attempt to understand whether it should be expected that some genes tend to be used disproportionately often by natural selection, we investigated two related phenomena: the evolution of flux control among enzymes in a metabolic pathway and properties of adaptive substitutions in pathway enzymes. These two phenomena are related by the principle that adaptive substitutions should occur more frequently in enzymes with greater flux control. Predicting which enzymes will be preferentially involved in adaptive evolution thus requires an evolutionary theory of flux control. We investigated the evolution of enzyme control in metabolic pathways with two models of enzyme kinetics: metabolic control theory (MCT) and Michaelis-Menten saturation kinetics (SK). Our models generate two main predictions for pathways in which reactions are moderately to highly irreversible: (1) flux control will evolve to be highly unequal among enzymes in a pathway and (2) upstream enzymes evolve a greater control coefficient then those downstream. This results in upstream enzymes fixing the majority of beneficial mutations during adaptive evolution. Once the population has reached high fitness, the trend is reversed, with the majority of neutral/slightly deleterious mutations occurring in downstream enzymes. These patterns are the result of three factors (the first of these is unique to the MCT simulations while the other two seem to be general properties of the metabolic pathways): (1) the majority of randomly selected, starting combinations of enzyme kinetic rates generate pathways that possess greater control for the upstream enzymes compared to downstream enzymes; (2) selection against large pools of intermediate substrates tends to prevent majority control by downstream enzymes; and (3) equivalent mutations in enzyme kinetic rates have the greatest effect on flux for enzymes with high levels of flux control, and these enzymes will accumulate adaptive substitutions, strengthening their

  20. Distribution of Metabolically Active Prokaryotes (Archaea and Bacteria) throughout the Profiles of Chernozem and Brown Semidesert Soil

    Semenov, M. V.; Manucharova, N. A.; Stepanov, A. L.

    2016-02-01

    The distribution of metabolically active cells of archaea and bacteria in the profiles of typical chernozems (Voronezh oblast) and brown semidesert soils (Astrakhan oblast) of natural and agricultural ecosystems was studied using the method of fluorescent in situ hybridization (FISH). The studied soils differed sharply in the microbial biomass and in the numbers of metabolically active cells of archaea and bacteria. The number of active bacterial cells was 3.5-7.0 times greater than that of archaea. In the arable chernozem, the numbers of active cells of archaea and bacteria were 2.6 and 1.5 times, respectively, lower than those in the chernozem under the shelterbelt. The agricultural use of the brown semidesert soil had little effect on the abundances of bacteria and archaea. The soil organic carbon content was the major factor controlling the numbers of metabolically active cells of both domains. However, the dependence of the abundance of bacteria on the organic matter content was more pronounced. The decrease in the organic carbon and total nitrogen contents down the soil profiles was accompanied by the decrease in the bacteria: archaea ratio attesting to a better adaptation of archaea to the permanent deficiency of carbon and nitrogen. The bacteria: archaea ratio can serve as an ecotrophic indicator of the state of soil microbial communities.

  1. Spatial and temporal distribution of genes involved in polyamine metabolism during tomato fruit development.

    Tsaniklidis, Georgios; Kotsiras, Anastasios; Tsafouros, Athanasios; Roussos, Peter A; Aivalakis, Georgios; Katinakis, Panagiotis; Delis, Costas

    2016-03-01

    Polyamines are organic compounds involved in various biological roles in plants, including cell growth and organ development. In the present study, the expression profile, the accumulation of free polyamines and the transcript localisation of the genes involved in Put metabolism, such as Ornithine decarboxylase (ODC), Arginine decarboxylase (ADC) and copper containing Amine oxidase (CuAO), were examined during Solanum lycopersicum cv. Chiou fruit development and maturation. Moreover, the expression of genes coding for enzymes involved in higher polyamine metabolism, including Spermidine synthase (SPDS), Spermine synthase (SPMS), S-adenosylmethionine decarboxylase (SAMDC) and Polyamine oxidase (PAO), were studied. Most genes participating in PAs biosynthesis and metabolism exhibited an increased accumulation of transcripts at the early stages of fruit development. In contrast, CuAO and SPMS were mostly expressed later, during the development stages of the fruits where a massive increase in fruit volume occurs, while the SPDS1 gene exhibited a rather constant expression with a peak at the red ripe stage. Although Put, Spd and Spm were all exhibited decreasing levels in developing immature fruits, Put levels maxed late during fruit ripening. In contrast to Put both Spd and Spm levels continue to decrease gradually until full ripening. It is worth noticing that in situ RNA-RNA hybridisation is reported for the first time in tomato fruits. The localisation of ADC2, ODC1 and CuAO gene transcripts at tissues such as the locular parenchyma and the vascular bundles fruits, supports the theory that all genes involved in Put biosynthesis and catabolism are mostly expressed in fast growing tissues. The relatively high expression levels of CuAO at the ImG4 stage of fruit development (fruits with a diameter of 3 cm), mature green and breaker stages could possibly be attributed to the implication of polyamines in physiological processes taking place during fruit ripening. PMID

  2. Analysis of the impact of controlled release formulations on oral drug absorption, gut wall metabolism and relative bioavailability of CYP3A substrates using a physiologically-based pharmacokinetic model.

    Olivares-Morales, Andrés; Kamiyama, Yoshiteru; Darwich, Adam S; Aarons, Leon; Rostami-Hodjegan, Amin

    2015-01-25

    Controlled release (CR) formulations are usually designed to achieve similar exposure (AUC) levels as the marketed immediate release (IR) formulation. However, the AUC is often lower following CR compared to IR formulations. There are a few exceptions when the CR formulations have shown higher AUC. This study investigated the impact of CR formulations on oral drug absorption and CYP3A4-mediated gut wall metabolism. A review of the current literature on relative bioavailability (Frel) between CR and IR formulations of CYP3A substrates was conducted. This was followed by a systematic analysis to assess the impact of the release characteristics and the drug-specific factors (including metabolism and permeability) on oral bioavailability employing a physiologically-based pharmacokinetic (PBPK) modelling and simulation approach. From the literature review, only three CYP3A4 substrates showed higher Frel when formulated as CR. Several scenarios were investigated using the PBPK approach; in most of them, the oral absorption of CR formulations was lower as compared to the IR formulations. However, for highly permeable compounds that were CYP3A4 substrates the reduction in absorption was compensated by an increase in the fraction that escapes from first pass metabolism in the gut wall (FG), where the magnitude was dependent on CYP3A4 affinity. The systematic simulations of various interplays between different parameters demonstrated that BCS class 1 highly-cleared CYP3A4 substrates can display up to 220% higher relative bioavailability when formulated as CR compared to IR, in agreement with the observed data collected from the literature. The results and methodology of this study can be employed during the formulation development process in order to optimize drug absorption, especially for CYP3A4 substrates. PMID:25444842

  3. Development and validation of an UPLC-MS/MS method for the quantification of ethoxzolamide in plasma and bioequivalent buffers: Applications to absorption, brain distribution, and pharmacokinetic studies

    Gao, Song; Zhao, Jing; Yin, Taijun; Ma, Yong; Xu, Beibei; Moore, Anthony N.; Dash, Pramod K.; Hu, Ming

    2015-01-01

    The purpose of this study is to develop and validate an UPLC-MS/MS method to quantify ethoxzolamide in plasma (EZ) and apply the method to absorption, brain distribution, as well as pharmacokinetic studies. A C18 column was used with 0.1% of formic acid in acetonitrile and 0.1% of formic acid in water as the mobile phases to resolve EZ. The mass analysis was performed in a triple quadrupole mass spectrometer using multiple reaction monitoring (MRM) with positive scan mode. The results show th...

  4. Metabolism and distribution of 14C- and 35S-labeled carbon disulfide in immature rats of different ages

    The metabolism and distribution of 14C- and 35S-CS2 was examined in 1-, 5-, 10-, 20-, 30-, and 40-day-old rats. During a 3-hr period following an ip dose of 14C-CS2, 58-83% of the dose was expired as CS2 and 4-9% was metabolized to expired CO2 depending on age. Thirty- and forty-day-old rats metabolized significantly more CS2 to CO2 and expired significantly less CS2 than 1- through 20-day-old rats. At the end of the measured expiration period, only biotransformation products of CS2, which were in part covalently bound, remained in tissues from rats of all ages. Tissue levels of 35S-CS2-derived radioactivity exceeded levels of 14C-CS2-derived radioactivity indicating that sulfur metabolites free from the carbon atom of CS2 were formed in rats as young as 1 day of age. The 35S-CS2-derived radioactivity per g of tissue and thus 35S covalently bound to tissue protein was significantly higher in 1- through 20-day-old rats than in 30- and 40-day-old rats. Twenty-four hr after dosing, up to 13 times more 35S-labeled metabolites were covalently bound in organs from 1-day-old rats than in similar organs from 40-day-old rats. The results showed that elimination of the biotransformation products of CS2, in particular the covalently binding sulfur metabolites, was prolonged in newborn rats in comparison to 40-day-old rats

  5. Sleep quality in middle-aged and elderly Chinese: distribution, associated factors and associations with cardio-metabolic risk factors

    Lin Xu

    2009-05-01

    Full Text Available Abstract Background Poor sleep quality has been associated with increased risk of heart disease, diabetes and mortality. However, limited information exists on the distribution and determinants of sleep quality and its associations with cardio-metabolic risk factors in Chinese populations. We aimed to evaluate this in the current study. Methods A cross-sectional survey conducted in 2005 of 1,458 men and 1,831 women aged 50–70 years from urban and rural areas of Beijing and Shanghai. Using a questionnaire, sleep quality was measured in levels of well, common and poor. Comprehensive measures of socio-demographical and health factors and biomarkers of cardio-metabolic disease were recorded. These were evaluated in association with sleep quality using logistic regression models. Results Half of the population reported good sleep quality. After adjusting for potential confounders, women and Beijing residents had almost half the probability to report good sleep quality. Good physical and mental health (good levels of self-rated health (OR 2.48; 95%CI 2.08 to 2.96 and no depression (OR 4.05; 95%CI 3.12 to 5.26 related to an increased chance of reporting good sleep quality, whereas short sleep duration ( Conclusion Levels of good sleep quality in middle-age and elderly Chinese were low. Gender, geographical location, self-rated health, depression and sleep quantity were major factors associated with sleep quality. Prospective studies are required to distil the factors that determine sleep quality and the effects that sleep patterns exert on cardio-metabolic health.

  6. Comparative study of absorption and distribution of dexamethasone 3H after percutaneous or oral administration in mice and rats

    Percutaneous absorption of dexamethasone in alcoholic solution in mice and rats was low. Permeability constant measured on mice was included between 1.05 and 1.39.10-5cm/h. Under the site of application, a retention appeared in subcutaneous tissue and skeletal muscles which explained local pharmacological action. In other tissues (plasma, liver, kidney, adrenals and muscles), level of corticoid remained very low. On the contrary after oral administration, dexamethasone was present everywhere, concentration was the highest in liver and kidney

  7. The ℓ-distribution method for modeling non-gray absorption in uniform and non-uniform gaseous media

    André, Frédéric

    2016-08-01

    The ℓ-distribution modeling is proposed for radiative heat transfer in uniform and non-uniform non-gray gaseous media. The method is partly based on the application of results from the k-moment method. It combines this technique with several concepts from probability theory: the notion of rank transmutation maps allows extending the k-moment method to an infinite number of k-moments; copula models appear naturally to extend the method from uniform to non-uniform gas paths. The ℓ-distribution approach is shown to provide results: (1) more accurate - up to three orders of magnitude - than usual k-distribution approaches in uniform media, (2) as precise as correlated-k models in non-uniform situations. All these results are obtained at a computational cost lower than k-distribution models. Differences and similarities between k- and ℓ-distribution methods are discussed.

  8. The distribution of 3H-(+-)noradrenaline in rabbit aortic strips after inhibition of the noradrenaline-metabolizing enzymes

    Rabbit aortic strips (nerve-free, reserpine pretreated or normal) whose noradrenaline-metabolizing enzymes were inhibited (by in vitro treatment with 0.5 mM pargyline for 30 min and by the presence of 0.1 mM U-0521) were exposed to 1.18 μM 3H-(+-)noradrenaline for 30 min (in most experiments). At the end of the incubation some strips were used for anlysis of radioactivity (i.e., of noradrenaline and its metabolites), while for others the efflux of radioactivity was determined during 240 min of wash out with amine-free solution. An estimate of the original distribution of the amine into the various extraneuronal and neuronal compartments of the tissue was obtained by compartmental analysis of the efflux curves. Extracellular amine distributes into 'compartment I + II' (characterized by a half time for efflux of 14C-sorbitol. The extraneuronal accumulation of noradrenaline is a quickly equilibrating process which involves compartments III and IV (with half times for efflux of 3 and 11 min, respectively). Compartment IV represents not only extraneuronally but also neuronally distributed noradrenaline. The neuronal accumulation of noradrenaline is a slowly equilibrating process which can be subdivided into axoplasmic and vesicular accumulation. The results support the view that the rate of relaxation (of strips initially exposed to noradrenaline and then washed out) is affected by the efflux of unchanged amine form extraneuronal and neuronal stores. (orig./GSE)

  9. Effect of lead in the laboratory mouse. 1. Influence of pregnancy upon absorption, retention, and tissue distribution of radiolabeled lead

    Whole-body retention and excretion following a single oral dose of radiolabeled lead (203Pb) in chronically lead-exposed pregnant BK:W mice were examined over 10-13 days. This was compared with values in similarly treated nonpregnant females and in ip injected females. Whole-body and bone retention were greater in injected than in orally dosed nonpregnant females; gastrointestinal absorption was estimated from this difference. Whole-body retention in the pups was measured at birth and at the end of the experiment. Whole-body retentions in pregnant females and in their pups at birth were significantly raised after treatment at Gestational Day 17, but not after treatment at Gestational Day 11, 14, 20, 23, or 26. Pup body burdens at birth were significantly and positively correlated with maternal retention. Measurement of radioactivity in bone, kidney, brain, heart, and liver of adults at the end of the experiments showed significantly increased levels in bone and kidney from females treated at Gestational Day 17 and in bone from females treated at Gestational Day 11. Lead excretion did not differ significantly among the groups but the total lead content of the femur was significantly raised in females treated at Gestational Days 17 and 26. Thus, these experiments provide evidence that lead absorption and retention in mice are markedly increased in the latter stages of pregnancy

  10. Excretion, distribution and metabolism of 1,2,4-trichlorobenzene in rats

    1,2,4-Trichlorobenzene (TCB) labeled with C-14 was given perorally to rats at a dosage of 50 mg/kg for excretion and distribution studies. About 66% and 17% of the oral dose was excreted in the urine and feces, respectively, within 7 days. Trapped radioactivity in the expired air amounted to 2.1% of the dose, but production of labeled carbon dioxide was negligible. Tissue residues were evenly distributed throughout the organs and tissues examined, except for the adipose tissue which consistently had a little higher concentration. The urinary, fecal and expiratory metabolites were identified. Free 2,4,5- and 2,3,5-trichlorophenol (TCP) and their conjugates were mainly detected in the urine. 5- or 6-sulfhydryl, methylthio, methylsulfoxide and methylsulfone derivatives of TCB were also detected as minor metabolites. Dichlorobenzenes and unchanged TCB were confirmed in the expired air. Reductive dechlorination seems to be catalysed by intestinal microflora enzymes. (orig.)

  11. PPARγ Pro12Ala and ACE ID polymorphisms are associated with BMI and fat distribution, but not metabolic syndrome

    Passaro Angela

    2011-12-01

    Full Text Available Abstract Background Metabolic Syndrome (MetS results from the combined effect of environmental and genetic factors. We investigated the possible association of peroxisome proliferator-activated receptor-γ2 (PPARγ2 Pro12Ala and Angiotensin Converting Enzyme (ACE I/D polymorphisms with MetS and interaction between these genetic variants. Methods Three hundred sixty four unrelated Caucasian subjects were enrolled. Waist circumference, blood pressure, and body mass index (BMI were recorded. Body composition was estimated by impedance analysis; MetS was diagnosed by the NCEP-ATPIII criteria. A fasting blood sample was obtained for glucose, insulin, lipid profile determination, and DNA isolation for genotyping. Results The prevalence of MetS did not differ across PPARγ2 or ACE polymorphisms. Carriers of PPARγ2 Ala allele had higher BMI and fat-mass but lower systolic blood pressure compared with Pro/Pro homozygotes. A significant PPARγ2 gene-gender interaction was observed in the modulation of BMI, fat mass, and blood pressure, with significant associations found in women only. A PPARγ2-ACE risk genotype combination for BMI and fat mass was found, with ACE DD/PPARγ2 Ala subjects having a higher BMI (p = 0.002 and Fat Mass (p = 0.002. Pro12Ala was independently associated with waist circumference independent of BMI and gender. Conclusions Carriers of PPARγ2 Ala allele had higher BMI and fat-mass but not a worse metabolic profile, possibly because of a more favorable adipose tissue distribution. A gene interaction exists between Pro12Ala and ACE I/D on BMI and fat mass. Further studies are needed to assess the contribution of Pro12Ala polymorphism in adiposity distribution.

  12. Effect of total pressure on the absorption line blackbody distribution function and radiative transfer in H2O, CO2, and CO

    The absorption spectrum has been generated for H2O, CO2, and CO at total pressures varying from 0.1 to 50 atm using the HITEMP 2010 spectroscopic database. From these spectra the absorption line blackbody distribution function (ALBDF) has been calculated at variable total pressure in order to understand the importance of accounting for pressure changes on this parameter. The ALBDF is used in the SLW solution method to the radiative transfer equation. ALBDF data for H2O, CO2, and CO are presented, revealing a shift in the ALBDF to lower values as total pressure increases. This shift is weaker at high temperature. The shift due to increase in mole fraction of H2O and CO2 was shown to be modest, and similar at different pressures. The ALBDF was shown to become less smooth as pressure increases. Total emissivity calculations are presented for variable total pressure, and it is seen that pressure changes account for a significant change in total emissivity. Total radiative flux and radiative flux divergence were calculated from line-by-line spectral integrations for one-dimensional layers of constant length and constant mass cases, showing that total pressure changes result in a significant impact on radiative transfer in a layer of gas. Radiative flux exiting a layer of gas can change by more than a factor of four over the pressure range investigated when the pressure change is the only variable considered. - Highlights: • The absorption spectrum is generated for H2O, CO2, and CO. • Temperature range is 400–3000 K, total pressure range from 0.1 atm to 50 atm. • The ALBDF is generated from the absorption spectrum. • The ALBDF is smoother, and decreases as total pressure is increased. • Pressure effect on radiative transfer is explored from line-by-line calculations

  13. Biological effects of 2-oxoglutarate with particular emphasis on the regulation of protein, mineral and lipid absorption/metabolism, muscle performance, kidney function, bone formation and cancerogenesis, all viewed from a healthy ageing perspective state of the art

    Harrison, Adrian Paul; Pierzynowski, S.G.

    of the Krebs cycle intermediate - alphaketoglutaric acid (AKG) in protecting elderly body systems from failing and degradation. The topics of paramount importance include impaied bone structure and strength, amino acid and mineral absorption, muscle performance, as well as highlighting the role of...... Krebs cycle intermediates in the debilitating changes that occur with end-stage renal failure and the regulation of the lipid metabolism. Finally, focus will be given to the role of 2-oxoglutarate as a potent protective factor in connection with the development of malignant cells in the body....

  14. Effect of multi-effect triazole on absorption of phosphorus and nitrogen and distribution of 14CO2-assimilates in rape plant

    By using tracer technique, the effects of Multi-Effect Triazole (MET) on uptake of 32P, 15N and distribution of 14CO2-assimilates in rape plant were studied. The experimental results showed that the foliar spraying of MET with the concentration of 150 ppm in three leaves stage could significantly increase 32P uptake by 75.34%∼101.08%, the utilization rate of base fertilizer 15NH4HCO3 by 9.10%. And the rate of photosynthesis increased by 7.44%∼31.40% in seedling stage, by 47.74% in initial flowering stage and by 47.93% in mature stage. The regulation effects of MET on distribution of 15N absorbed and 14CO2-assimilates were shown by increasing absorption of 15N and assimilates in seeds of rape plant

  15. Gastrointestinally distributed UDP-glucuronosyltransferase 1A10, which metabolizes estrogens and nonsteroidal anti-inflammatory drugs, depends upon phosphorylation.

    Basu, Nikhil K; Kubota, Shigeki; Meselhy, Meselhy R; Ciotti, Marco; Chowdhury, Bhabadeb; Hartori, Masao; Owens, Ida S

    2004-07-01

    Among gastrointestinal distributed isozymes encoded at the UGT1 locus, UDP-glucuronosyltransferase 1A10 (UGT1A10) metabolizes a number of important chemicals. Similar to broad conversion of phytoestrogens (Basu, N. K., Ciotti, M., Hwang, M. S., Kole, L., Mitra, P. S., Cho, J. W., and Owens, I. S. (2004) J. Biol. Chem. 279, 1429-1441), UGT1A10 metabolized estrogens and their derivatives, whereas UGT1A1, -1A3, -1A7, and -1A8 differentially exhibited reduced activity toward the same. UGT1A10 compared with UGT1A7, -1A8, and -1A3 generally exhibited high activity toward acidic nonsteroidal anti-inflammatory drugs and natural benzaldehyde derivatives, while UGT1A3 metabolized most efficiently aromatic transcinnamic acids known to be generated from flavonoid glycosides by microflora in the lower gastrointestinal tract. Finally UGT1A10, -1A7, -1A8, and -1A3 converted plant-based salicylic acids; methylsalicylic acid was transformed at high levels, and acetylsalicylic (aspirin) and salicylic acid were transformed at moderate to low levels. Atypically UGT1A10 transformed estrogens between pH 6 and 8 but acidic structures preferentially at pH 6.4. Furthermore evidence indicates UGT1A10 expressed in COS-1 cells depends upon phosphorylation; UGT1A10 versus its single, double, and triple mutants at three predicted protein kinase C phosphorylation sites incorporated [(33)P]-orthophosphate and showed a progressive decrease with no detectable label or activity for the triple T73A/T202A/S432G-1A10 mutant. Single and double mutants revealed either null/full activity or null/additive activity, respectively. Additionally UGT1A10-expressing cultures glucuronidated 17beta-[(14)C]estradiol, whereas cultures containing null mutants at protein kinase C sites showed no estrogen conversion. Importantly UGT1A10 in cells supported 10-fold higher glucuronidation of 17beta-estradiol than UGT1A1. In summary, our results suggest gastrointestinally distributed UGT1A10 is important for detoxifying

  16. ZINC ABSORPTION BY INFANTS

    Zinc is a vital mineral in human nutrition, and rare cases of overt zinc deficiency are well described in term and preterm infants. A variety of methods have been developed to assess zinc absorption, retention, and balance in humans, either using mass (metabolic) balance or stable isotope-based METH...

  17. Need for collection of quantitative distribution data for dosimetry and metabolic modeling

    Problems in radiation dose distribution studies in humans are discussed. Data show the effective half-times for 7Be and 75Se in the mouse, rat, monkey, dog, and human show no correlation with weight, body surface, or other readily apparent factor that could be used to equate nonhuman and human data. Another problem sometimes encountered in attempting to extrapolate animal data to humans involves equivalent doses of the radiopharmaceutical. A usual human dose for a radiopharmaceutical is 1 ml or 0.017 mg/kg. The same solution injected into a mouse in a convenient volume of 0.1 ml results in a dose of 4 ml/kg or 240 times that received by the human. The effect on whole body retention produced by a dose difference of similar magnitude for selenium in the rat shows the retention is at least twice as great with the smaller amount. With the development of methods for the collection of data throughout the body representing the fractional distribution of radioactivity versus time, not only can more realistic dose estimates be made, but also the tools will be provided for the study of physiological and biochemical interrelationships in the intact subject from which compartmental models may be made which have diagnostic significance. The unique requirement for quantitative biologic data needed for calculation of radiation absorbed doses is the same as the unique scientific contribution that nuclear medicine can make, which is the quantitative in vivo study of physiologic and biochemical processes. The technique involved is not the same as quantitation of a radionuclide image, but is a step beyond

  18. Distribution and association of hs-CRP with cardiovascular risk variables of metabolic syndrome in adolescent learners

    Megan A. Rensburg

    2011-12-01

    Full Text Available Objective: Metabolic syndrome (MetS and its associated cardiovascular risk are on the increase in children. High-sensitivity C-reactive protein (hs-CRP has emerged as a useful marker for inflammation associated with atherosclerosis and cardiovascular disease. Our aim was to determine the distribution of hs-CRP in an effort to identify the MetS variable that is critical in modulating plasma CRP levels in a population of South African adolescents. Design: A cross-sectional analytical study design was used for this investigation, where the dependent and independent variables were measured simultaneously.Methods: Anthropometric variables, blood pressure, fasting blood glucose and lipids were performed on 324 consenting learners aged 15–18 years from three different ethnic groups (Black, White and Coloured. The National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III for ages 15–18 year olds was used to define MetS.Results: The prevalence of MetS and obesity was 3.7% and 7.1%, respectively. The hs-CRP levels were significantly higher in subjects with a waist-circumference greater than the 90th percentile (p < 0.01 and in obese learners with MetS, but was lower in adolescents with normal weight and MetS. Median hs-CRP levels increased with an increasing number of metabolic abnormalities and exceeded 3 mg/L in 19% of adolescents. Gender and ethnic differences were observed.Conclusion: Our findings suggest that obesity and waist circumference appear to be major mediators of hs-CRP levels in South African adolescents.

  19. The H + OCS hot atom reaction - CO state distributions and translational energy from time-resolved infrared absorption spectroscopy

    Nickolaisen, Scott L.; Cartland, Harry E.

    1993-01-01

    Time-resolved infrared diode laser spectroscopy has been used to probe CO internal and translational excitation from the reaction of hot H atoms with OCS. Product distributions should be strongly biased toward the maximum 1.4 eV collision energy obtained from 278 nm pulsed photolysis of HI. Rotations and vibrations are both colder than predicted by statistical density of states theory, as evidenced by large positive surprisal parameters. The bias against rotation is stronger than that against vibration, with measurable population as high as v = 4. The average CO internal excitation is 1920/cm, accounting for only 13 percent of the available energy. Of the energy balance, time-resolved sub-Doppler line shape measurements show that more than 38 percent appears as relative translation of the separating CO and SH fragments. Studies of the relaxation kinetics indicate that some rotational energy transfer occurs on the time scale of our measurements, but the distributions do not relax sufficiently to alter our conclusions. Vibrational distributions are nascent, though vibrational relaxation of excited CO is unusually fast in the OCS bath, with rates approaching 3 percent of gas kinetic for v = 1.

  20. Metabolic fate (absorption, β-oxidation and deposition) of long-chain n-3 fatty acids is affected by sex and by the oil source (krill oil or fish oil) in the rat.

    Ghasemifard, Samaneh; Hermon, Karen; Turchini, Giovanni M; Sinclair, Andrew J

    2015-09-14

    The effects of krill oil as an alternative source of n-3 long-chain PUFA have been investigated recently. There are conflicting results from the few available studies comparing fish oil and krill oil. The aim of this study was to compare the bioavailability and metabolic fate (absorption, β-oxidation and tissue deposition) of n-3 fatty acids originating from krill oil (phospholipid-rich) or fish oil (TAG-rich) in rats of both sexes using the whole-body fatty acid balance method. Sprague-Dawley rats (thirty-six male, thirty-six female) were randomly assigned to be fed either a krill oil diet (EPA+DHA+DPA=1·38 mg/g of diet) or a fish oil diet (EPA+DHA+DPA=1·61 mg/g of diet) to constant ration for 6 weeks. The faeces, whole body and individual tissues were analysed for fatty acid content. Absorption of fatty acids was significantly greater in female rats and was only minimally affected by the oil type. It was estimated that most of EPA (>90 %) and more than half of DHA (>60 %) were β-oxidised in both diet groups. Most of the DPA was β-oxidised (57 and 67 % for female and male rats, respectively) in the fish oil group; however, for the krill oil group, the majority of DPA was deposited (82-83 %). There was a significantly greater deposition of DPA and DHA in rats fed krill oil compared with those fed fish oil, not due to a difference in bioavailability (absorption) but rather due to a difference in metabolic fate (anabolism v. catabolism). PMID:26234617

  1. NONLINEAR COLOR-METALLICITY RELATIONS OF GLOBULAR CLUSTERS. V. NONLINEAR ABSORPTION-LINE INDEX VERSUS METALLICITY RELATIONS AND BIMODAL INDEX DISTRIBUTIONS OF M31 GLOBULAR CLUSTERS

    Recent spectroscopy on the globular cluster (GC) system of M31 with unprecedented precision witnessed a clear bimodality in absorption-line index distributions of old GCs. Such division of extragalactic GCs, so far asserted mainly by photometric color bimodality, has been viewed as the presence of merely two distinct metallicity subgroups within individual galaxies and forms a critical backbone of various galaxy formation theories. Given that spectroscopy is a more detailed probe into stellar population than photometry, the discovery of index bimodality may point to the very existence of dual GC populations. However, here we show that the observed spectroscopic dichotomy of M31 GCs emerges due to the nonlinear nature of metallicity-to-index conversion and thus one does not necessarily have to invoke two separate GC subsystems. We take this as a close analogy to the recent view that metallicity-color nonlinearity is primarily responsible for observed GC color bimodality. We also demonstrate that the metallicity-sensitive magnesium line displays non-negligible metallicity-index nonlinearity and Balmer lines show rather strong nonlinearity. This gives rise to bimodal index distributions, which are routinely interpreted as bimodal metallicity distributions, not considering metallicity-index nonlinearity. Our findings give a new insight into the constitution of M31's GC system, which could change much of the current thought on the formation of GC systems and their host galaxies.

  2. Comparative study on intestinal metabolism and absorption in vivo of ginsenosides in sulphur-fumigated and non-fumigated ginseng by ultra performance liquid chromatography quadruple time-of-flight mass spectrometry based chemical profiling approach.

    Zhu, He; Shen, Hong; Xu, Jun; Xu, Jin-Di; Zhu, Ling-Ying; Wu, Jie; Chen, Hu-Biao; Li, Song-Lin

    2015-04-01

    Our previous study indicated that sulphur-fumigation of ginseng in post-harvest handling processes could induce chemical transformation of ginsenosides to generate multiple ginsenoside sulphur derivatives. In this study, the influence of sulphur-fumigation on intestinal metabolism and absorption in vivo of ginsenosides in ginseng was sequentially studied. The intestinal metabolic and absorbed profiles of ginsenosides in rats after intra-gastric (i.g.) administration of sulphur-fumigated ginseng (SFG) and non-fumigated ginseng (NFG) were comparatively characterized by a newly established ultra performance liquid chromatography quadruple time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) with electrospray ionization negative (ESI-) mode. A novel strategy based on the characteristic product ions and fragmentation pathways of different types of aglycones (saponin skeletons) and glycosyl moieties was proposed and successfully applied to rapid structural identification of ginsenoside sulphur derivatives and relevant metabolites. In total, 18 ginsenoside sulphur derivatives and 26 ginsenoside sulphur derivative metabolites in the faeces together with six ginsenoside sulphur derivatives in the plasma were identified in the SFG-administrated group but not in the NFG-administrated group. The results clearly demonstrated that the intestinal metabolic and absorbed profiles of ginsenosides in sulphur-fumigated and non-fumigated ginseng were quite different, which inspired that sulphur-fumigation of ginseng should not be recommended before the bioactivity and toxicity of the ginsenoside sulphur derivatives were systematically evaluated. PMID:24853104

  3. Epicardial fat thickness: distribution and association with diabetes mellitus, hypertension and the metabolic syndrome in the ELSA-Brasil study.

    Graeff, Daniela Bertol; Foppa, Murilo; Pires, Julio Cesar Gall; Vigo, Alvaro; Schmidt, Maria Ines; Lotufo, Paulo Andrade; Mill, Jose Geraldo; Duncan, Bruce Bartholow

    2016-04-01

    Epicardial fat thickness (EFT) has emerged as a marker of cardiometabolic risk, but its clinical use warrants proper knowledge of its distribution and associations in populations. We aimed to describe the distribution of EFT, its demographic correlates and independent associations with diabetes, hypertension and metabolic syndrome (MS) in free-living Brazilian adults. From the baseline echocardiography of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)-a cohort study of civil servants aged 35-74 years-EFT was measured from a randomly selected sample of 998 participants as the mean of two paraesternal windows obtained at end systole (EFTsyst) and end diastole (EFTdiast). From the 421 individuals free of diabetes, hypertension and MS, we defined EFT reference values and the EFTsyst 75th percentile cut-off. Median EFTsyst was 1.5 (IQR 0-2.6) mm; a large proportion (84 %) had EFTdiast = 0. EFT was higher in women and lower in blacks, and increased with age and BMI. Although EFT was higher in those with diabetes, hypertension, and MS, EFT associations were reduced when adjusted for age, sex and ethnicity, and were non-significant after adjusting for obesity measures. In conclusion, the amount of EFT in this large multiethnic population is smaller than reported in other populations. EFT reference values varied across demographic and clinical variables, EFT associations with cardiometabolic variables being largely explained by age, sex, ethnicity and central obesity. Although EFT can help identify individuals at increased cardiometabolic risk, it will likely have a limited additional role compared to current risk stratification strategies. PMID:26585750

  4. Absorption and tissue distribution of radioactivity in mussels (Mytilus Galloprovincialis) exposed to low concentrations of 14C-polychlorinated biphenyl

    Mussels (Mytilus galloprovincialis) were exposed for 144 h to an isomeric 14C polychlorinated biphenyl (PCB) mixture at an initial concentration of 4.6 μg l-1. Animals were sampled after 6, 12, 24, 72 and 144 h of exposure for sex differences in PCB tissue distribution. PCB was readily absorbed within 12 h and then slowly eliminated from the body with a biological half-time of 209 h. No sexual differences were observed except with mussels sampled at 12 h, where 14C activity was significantly higher (P14C activity measured in gills appeared to be related to the PCB water concentration. 14 refs.; 3 figs.; 1 table

  5. What do metabolic rates tell us about thermal niches? Mechanisms driving crayfish distributions along an altitudinal gradient.

    Stoffels, Rick J; Richardson, Adam J; Vogel, Matthew T; Coates, Simon P; Müller, Warren J

    2016-01-01

    Humans are rapidly altering thermal landscapes, so a central challenge to organismal ecologists is to better understand the thermal niches of ectotherms. However, there is much disagreement over how we should go about this. Some ecologists assume that a statistical model of abundance as a function of habitat temperature provides a sufficient approximation of the thermal niche, but ecophysiologists have shown that the relationship between fitness and temperature can be complicated, and have stressed the need to elucidate the causal mechanisms underlying the response of species to thermal change. Towards this end, we studied the distribution of two crayfishes, Euastacus woiwuru and Euastacus armatus, along an altitudinal gradient, and for both species conducted experiments to determine the temperature-dependence of: (1) aerobic scope (the difference between maximum and basal metabolic rate; purported to be a proxy of the thermal niche); and (2) burst locomotor performance (primarily fuelled using anaerobic pathways). E. woiwuru occupied cooler habitats than E. armatus, but we found no difference in aerobic scope between these species. In contrast, locomotor performance curves differed significantly and strongly between species, with peak locomotor performances of E. woiwuru and E. armatus occurring at ~10 and ~18 °C, respectively. Crayfish from different thermal landscapes may have similar aerobic thermal performance curves but different anaerobic thermal performance curves. Our results support a growing body of literature implying different components of ectotherm fitness have different thermal performance curves, and further challenge our understanding of the ecology and evolution of thermal niches. PMID:26440800

  6. Tunable diode laser absorption spectroscopy-based tomography system for on-line monitoring of two-dimensional distributions of temperature and H2O mole fraction

    To monitor two-dimensional (2D) distributions of temperature and H2O mole fraction, an on-line tomography system based on tunable diode laser absorption spectroscopy (TDLAS) was developed. To the best of the authors’ knowledge, this is the first report on a multi-view TDLAS-based system for simultaneous tomographic visualization of temperature and H2O mole fraction in real time. The system consists of two distributed feedback (DFB) laser diodes, a tomographic sensor, electronic circuits, and a computer. The central frequencies of the two DFB laser diodes are at 7444.36 cm−1 (1343.3 nm) and 7185.6 cm−1 (1391.67 nm), respectively. The tomographic sensor is used to generate fan-beam illumination from five views and to produce 60 ray measurements. The electronic circuits not only provide stable temperature and precise current controlling signals for the laser diodes but also can accurately sample the transmitted laser intensities and extract integrated absorbances in real time. Finally, the integrated absorbances are transferred to the computer, in which the 2D distributions of temperature and H2O mole fraction are reconstructed by using a modified Landweber algorithm. In the experiments, the TDLAS-based tomography system was validated by using asymmetric premixed flames with fixed and time-varying equivalent ratios, respectively. The results demonstrate that the system is able to reconstruct the profiles of the 2D distributions of temperature and H2O mole fraction of the flame and effectively capture the dynamics of the combustion process, which exhibits good potential for flame monitoring and on-line combustion diagnosis

  7. Tunable diode laser absorption spectroscopy-based tomography system for on-line monitoring of two-dimensional distributions of temperature and H2O mole fraction

    Xu, Lijun; Liu, Chang; Jing, Wenyang; Cao, Zhang; Xue, Xin; Lin, Yuzhen

    2016-01-01

    To monitor two-dimensional (2D) distributions of temperature and H2O mole fraction, an on-line tomography system based on tunable diode laser absorption spectroscopy (TDLAS) was developed. To the best of the authors' knowledge, this is the first report on a multi-view TDLAS-based system for simultaneous tomographic visualization of temperature and H2O mole fraction in real time. The system consists of two distributed feedback (DFB) laser diodes, a tomographic sensor, electronic circuits, and a computer. The central frequencies of the two DFB laser diodes are at 7444.36 cm-1 (1343.3 nm) and 7185.6 cm-1 (1391.67 nm), respectively. The tomographic sensor is used to generate fan-beam illumination from five views and to produce 60 ray measurements. The electronic circuits not only provide stable temperature and precise current controlling signals for the laser diodes but also can accurately sample the transmitted laser intensities and extract integrated absorbances in real time. Finally, the integrated absorbances are transferred to the computer, in which the 2D distributions of temperature and H2O mole fraction are reconstructed by using a modified Landweber algorithm. In the experiments, the TDLAS-based tomography system was validated by using asymmetric premixed flames with fixed and time-varying equivalent ratios, respectively. The results demonstrate that the system is able to reconstruct the profiles of the 2D distributions of temperature and H2O mole fraction of the flame and effectively capture the dynamics of the combustion process, which exhibits good potential for flame monitoring and on-line combustion diagnosis.

  8. Absorption and metabolism of volatile fatty acids by rumen and omasum Absorção e metabolismo de ácidos graxos voláteis pelo rúmen e omaso

    João Luiz Pratti Daniel

    2012-02-01

    Full Text Available Volatile fatty acids (VFA absorption and metabolic capacity of rumen and omasum were compared, in vitro. Fragments of rumen wall and omasum laminae were taken from eight adult crossbred bovines. An isolated fragment of the mucosa was fitted in a tissue diffusion chamber. Valeric acid and CrEDTA were added to ruminal fluid and placed on the mucosal side and buffer solution was placed on the serosal side. Fractional absorption rates were measured by exponential VFA:Cr ratio decay over time. Metabolism rate was determined as the difference between VFA absorbed and VFA which appeared on the serosal side over time. Mitotic index was higher in omasum (0.52% than in rumen epithelium (0.28%. VFA fractional absorption rate was higher in omasum (4.6%/h.cm² than in rumen (0.4%/h.cm². Acetate, propionate, butyrate, and valerate showed similar fractional absorption rates in both fragments. Percentage of metabolized acetate and propionate was lower than butyrate and valerate in both stomach compartments. In the rumen, individual VFA metabolism rates were similar (mean of 7.7 , but in the omasum, valerate (90.0 was more metabolized than butyrate (59.6 propionate (69.8 and acetate (51.7 . Correlation between VFA metabolism and mitotic index was positive in the rumen and in the omasum. In conclusion, VFA metabolism and absorption potential per surface of the omasum is higher than that of the rumen. Variations on rumen and omasum absorption capacities occur in the same way, and there are indications that factors capable of stimulating rumen wall proliferation are similarly capable of stimulating omasum walls.A capacidade de absorção e metabolismo de ácidos graxos voláteis (AGV pelo rúmen e omaso foi comparada, in vitro. Fragmentos da parede do rúmen e das lâminas do omaso foram coletados de oito bovinos mestiços adultos. Um fragmento isolado da mucosa foi colocado em uma câmara de difusão tecidual. Ácido valérico e CrEDTA foram adicionados ao fluido

  9. Study of Absorption and Distribution of Mercury in Nerium Oleander L. on Banks of the Valdeazogues River (Chillon Station- Ciudad Real)

    The main objective of this study is to determine the absorption and distribution of mercury in oleander (Nerium oleander L.) in the Valdeazogues river, located within the mining regions of Almaden (Ciudad Real). The results show that total mercury concentrations in soil range from 116,7 ±24,3 to 350,9 ± 68,6 mg kg-1 of Hg, but the readily available fraction (soluble + exchangeable) is very low (from 0,013 to 0,017 ± 0,257 ± 0,000 mg Hg kg-1: less than 0,16% of the total concentration of mercury measured directly on the soil sample).The distribution of mercury absorbed by N. oleander is not homogeneous throughout the aerial part. In general, the concentration is significantly higher in the leaves followed by stems and fruits. According to the results, although the concentration of mercury in the plant is not very high (Leaves: 0,282 ±0,014-1,022 ± 0,110 mg Kg-1; Stems: 0,087 ± 0,011-0,354 ± 0,046 mg Kg-1; Fruits: 0,030 ± 0,003-0,077 ± 0,009 mg Kg-1), oleander has a number of characteristics (high biomass, toxicity, non-edible) that could turn into a future candidate as phyto extraction of mercury in decontamination processes. (Author) 67 refs.

  10. Absorption, metabolism and excretion of flavanones from single portions of orange fruit and juice and effects of anthropometric variables and contraceptive pill use on flavanone excretion

    Brett, Gary M.; Hollands, Wendy; Needs, Paul W.; Teucher, Birgit; Dainty, Jack R.; Davis, Barry D.; Brodbelt, Jennifer S.; Kroon, Paul A.

    2012-01-01

    Oranges are rich sources of flavonoids that are bioactive and may protect against age-related diseases. The absorption of orange flavanones may be affected by factors such as processing and subject anthropometric variables, and the bioactivity of the absorbed phytochemicals depends on how they are metabolised during absorption. In a randomised cross-over study, twenty subjects consumed a single portion of orange fruit (150 g) or juice (300 g) that contained the flavanones narirutin and hesperidin, and an additional 109 subjects across a broad age range (18–80 years) consumed the juice. Flavanone metabolites were measured in regularly collected samples of plasma and urine. After consumption of fruit or juice, flavanone conjugates, but not the aglycones, were detected in plasma and urine. The flavanone conjugates were shown to include the 7- and 4′-O-monoglucuronides of naringenin, the 7- and 3′-O-monoglucuronides of hesperetin, two hesperetin diglucuronides and a hesperetin sulfo-glucuronide, but no aglycones or rutinosides. Analysis of the plasma pharmacokinetic and urinary excretion data on a dose-adjusted basis indicated no difference in absorption or excretion of either flavanone between the fruit and juice matrices. In the extended urinary excretion dataset the individual variation was very large (range 0–59 % urinary yield). There was a small but significant (P<0·05) decrease in the excretion of hesperetin (but not naringenin) with increasing age (P<0·05), but the effects of sex, BMI and contraceptive pill use were shown not to be associated with the variation in flavanone excretion. PMID:18710603

  11. A rapid method to derive horizontal distributions of trace gases and aerosols near the surface using multi-axis differential optical absorption spectroscopy

    Y. Wang

    2013-09-01

    Full Text Available We apply a novel experimental procedure for the rapid measurement of the average volume mixing ratios (VMRs and horizontal distributions of trace gases such as NO2, SO2, and HCHO in the boundary layer, which was recently suggested by Sinreich et al. (2013. The method is based on two-dimensional scanning multi-axis differential optical absorption spectroscopy (MAX-DOAS. It makes use of two facts (Sinreich et al. 2013: First, the light path for observations at 1° elevation angle traverses mainly air masses located close to the ground (typically 4. Thus, the average value of the trace gas VMR in the atmospheric layer between the surface and the altitude, for which this observation was sensitive, can be calculated. Compared to the originally proposed method, we introduce several important modifications and improvements: We apply the method only to measurements at 1° elevation angles, for which the uncertainties are especially small. Using only 1 elevation angle also allows an increased temporal resolution. We apply correction factors (and their uncertainties as function of the simultaneously modelled O4 absorption. In this way the correction factors can be directly determined according to the measured O4 dAMF. Finally, the method is extended to trace gases analysed at other wavelengths and also to the retrieval of the aerosol extinction. Depending on the atmospheric visibility, the typical uncertainty of the results ranges from about 15 to 30%. We apply the rapid method to observations of a newly developed ground-based multifunctional passive differential optical absorption spectroscopy (GM-DOAS instrument in the north-west outskirt near Hefei City in China. We report NO2, SO2, and HCHO VMRs and aerosol extinction for four azimuth angles and compare these results with those from simultaneous long-path DOAS observations. Good agreement is found (squares of the correlation coefficients for NO2, SO2, and HCHO were 0.92, 0.84, and 0.59, respectively

  12. Metabolic pathway analysis of Scheffersomyces (Pichia) stipitis. Effect of oxygen availability on ethanol synthesis and flux distributions

    Unrean, Pornkamol [King Mongkut' s Univ. of Technology Thonburi, Bangkok (Thailand). Biochemical Engineering and Pilot Plant Research and Development Unit; National Center for Genetik Engineering and Biotechnology (BIOTEC), Pathumtani (Thailand); Nguyen, Nhung H.A. [King Mongkut' s Univ. of Technology Thonburi, Bangkok (Thailand). Biochemical Engineering and Pilot Plant Research and Development Unit

    2012-06-15

    Elementary mode analysis (EMA) identifies all possible metabolic states of the cell metabolic network. Investigation of these states can provide a detailed insight into the underlying metabolism in the cell. In this study, the flux states of Scheffersomyces (Pichia) stipitis metabolism were examined. It was shown that increasing oxygen levels led to a decrease of ethanol synthesis. This trend was confirmed by experimental evaluation of S. stipitis in glucose-xylose fermentation. The oxygen transfer rate for an optimal ethanol production was 1.8 mmol/l/h, which gave the ethanol yield of 0.40 g/g and the ethanol productivity of 0.25 g/l/h. For a better understanding of the cell's regulatory mechanism in response to oxygenation levels, EMA was used to examine metabolic flux patterns under different oxygen levels. Up- and downregulation of enzymes in the network during the change of culturing condition from oxygen limitation to oxygen sufficiency were identified. The results indicated the flexibility of S. stipitis metabolism to cope with oxygen availability. In addition, relevant genetic targets towards improved ethanol-producing strains under all oxygenation levels were identified. These targeted genes limited the metabolic functionality of the cell to function according to the most efficient ethanol synthesis pathways. The presented approach is promising and can contribute to the development of culture optimization and strain engineers for improved lignocellulosic ethanol production by S. stipitis. (orig.)

  13. Modeling the effects of commonly used drugs on human metabolism.

    Sahoo, Swagatika; Haraldsdóttir, Hulda S; Fleming, Ronan M T; Thiele, Ines

    2015-01-01

    Metabolism contributes significantly to the pharmacokinetics and pharmacodynamics of a drug. In addition, diet and genetics have a profound effect on cellular metabolism with respect to both health and disease. In the present study, we assembled a comprehensive, literature-based drug metabolic reconstruction of the 18 most highly prescribed drug groups, including statins, anti-hypertensives, immunosuppressants and analgesics. This reconstruction captures in detail our current understanding of their absorption, intracellular distribution, metabolism and elimination. We combined this drug module with the most comprehensive reconstruction of human metabolism, Recon 2, yielding Recon2_DM1796, which accounts for 2803 metabolites and 8161 reactions. By defining 50 specific drug objectives that captured the overall drug metabolism of these compounds, we investigated the effects of dietary composition and inherited metabolic disorders on drug metabolism and drug-drug interactions. Our main findings include: (a) a shift in dietary patterns significantly affects statins and acetaminophen metabolism; (b) disturbed statin metabolism contributes to the clinical phenotype of mitochondrial energy disorders; and (c) the interaction between statins and cyclosporine can be explained by several common metabolic and transport pathways other than the previously established CYP3A4 connection. This work holds the potential for studying adverse drug reactions and designing patient-specific therapies. PMID:25345908

  14. Absorption and metabolization of orally administered D-[α-15N]lysine and L-[α-15N]lysine with regard to the metabolism of intestinal bacteria

    Absorption of D-[α-15N]lysine and L-[α-15N]lysine following oral single pulse-labelling at a dosage of 5 mg 15N'/kg body weight was compared in four subjects aged 4 to 14 months. The wastages of 15N' in the feces ranged from 0.3 to 5% of the input implying comparably high absorption rates of both the lysine enantiomers. Only about 7.6% of the 15N from the α-amino groups were found in the urine after loading with L-[α-15N]lysine. In contrast, about 80.2% of the 15N' dose from D-[α-15N]lysine were eliminated renally. However, 18.5% of the 15N' dose on an average were retained after D-[α-15N]lysine administration. This is certainly due to a partial desamination of D-lysine. The fecal bacteria isolated from the feces contained no or only small amounts of 15N' after D-[α-15N]lysine loading. Following L-[α-15N]lysine administration a measurable 15N enrichment of the fecal bacteria of up to 0.09 at.% excess was achieved in almost all cases. (author)

  15. Metabolic flux distributions in Corynebacterium glutamicum during growth and lysine overproduction. Reprinted from Biotechnology and Bioengineering, Vol. 41, Pp 633-646 (1993).

    Vallino, J J; Stephanopoulos, G

    2000-03-20

    The two main contributions of this article are the solidification of Corynebacterium glutamicum biochemistry guided by bioreaction network analysis, and the determination of basal metabolic flux distributions during growth and lysine synthesis. Employed methodology makes use of stoichiometrically based mass balances to determine flux distributions in the C. glutamicum metabolic network. Presented are a brief description of the methodology, a thorough literature review of glutamic acid bacteria biochemistry, and specific results obtained through a combination of fermentation studies and analysis-directed intracellular assays. The latter include the findings of the lack of activity of glyoxylate shunt, and that phosphoenolpyruvate carboxylase (PPC) is the only anaplerotic reaction expressed in C. glutamicum cultivated on glucose minimal media. Network simplifications afforded by the above findings facilitated the determination of metabolic flux distributions under a variety of culture conditions and led to the following conclusions. Both the pentose phosphate pathway and PPC support significant fluxes during growth and lysine overproduction, and that flux partitioning at the glucosa-6-phosphate branch point does not appear to limit lysine synthesis. PMID:10699864

  16. Fructose Consumption: Considerations for Future Research on Its Effects on Adipose Distribution, Lipid Metabolism, and Insulin Sensitivity in Humans12

    Stanhope, Kimber L.; Havel, Peter J.

    2009-01-01

    Results from a recent study investigating the metabolic effects of consuming fructose-sweetened beverages at 25% of energy requirements for 10 wk demonstrate that a high-fructose diet induces dyslipidemia, decreases insulin sensitivity, and increases visceral adiposity. The purpose of this review is to present aspects of the study design which may be critical for assessment of the metabolic effects of sugar consumption. Collection of postprandial blood samples is required to document the full...

  17. Distribution of metabolic activity and phosphate starvation response of lux-tagged Pseudomonas fluorescens reporter bacteria in the barley rhizosphere.

    Kragelund, L.; Hosbond, C; Nybroe, O

    1997-01-01

    The purpose of this study was to determine the metabolic activity of Pseudomonas fluorescens DF57 in the barley rhizosphere and to assess whether sufficient phosphate was available to the bacterium. Hence, two DF57 reporter strains carrying chromosomal luxAB gene fusions were introduced into the rhizosphere. Strain DF57-40E7 expressed luxAB constitutively, making bioluminescence dependent upon the metabolic activity of the cells under defined assay conditions. The DF57-P2 reporter strain resp...

  18. Absorption and distribution of xenobiotics.

    Standaert, F G

    1988-01-01

    Extrapolation of pharmacokinetic data between species has been simplified by the advent of more sensitive methods of analysis of chemicals in body tissues and by the capability of inexpensive computers to perform complex calculations. These new methods enable investigators to observe the rates at which target tissues reach equilibrium in different species and to develop mathematical models of these processes. The evaluation of physiological pharmacokinetics from classical or compartmental kin...

  19. METABOLISM OF IRON STORES

    Saito, Hiroshi

    2014-01-01

    ABSTRACT Remarkable progress was recently achieved in the studies on molecular regulators of iron metabolism. Among the main regulators, storage iron, iron absorption, erythropoiesis and hepcidin interact in keeping iron homeostasis. Diseases with gene-mutations resulting in iron overload, iron deficiency, and local iron deposition have been introduced in relation to the regulators of storage iron metabolism. On the other hand, the research on storage iron metabolism has not advanced since th...

  20. A rapid method to derive horizontal distributions of trace gases and aerosols near the surface using multi-axis differential optical absorption spectroscopy

    Wang, Y.; Li, A.; Xie, P. H.; Wagner, T.; Chen, H.; Liu, W. Q.; Liu, J. G.

    2014-06-01

    We apply a novel experimental procedure for the rapid measurement of the average volume mixing ratios (VMRs) and horizontal distributions of trace gases such as NO2, SO2, and HCHO in the boundary layer, which was recently suggested by Sinreich et al. (2013). The method is based on two-dimensional scanning multi-axis differential optical absorption spectroscopy (MAX-DOAS). It makes use of two facts (Sinreich et al., 2013): first, the light path for observations at 1° elevation angle traverses mainly air masses located close to the ground (typically DOAS) instrument in the north-west outskirts near Hefei in China. We report NO2, SO2, and HCHO VMRs and aerosol extinction for four azimuth angles and compare these results with those from simultaneous long-path DOAS observations. Good agreement is found (squares of the correlation coefficients for NO2, SO2, and HCHO were 0.92, 0.85, and 0.60, respectively), verifying the reliability of this novel method. Similar agreement is found for the comparison of the aerosol extinction with results from visibility meters. Future studies may conduct measurements using a larger number of azimuth angles to increase the spatial resolution.

  1. Absorption studies

    Absorption studies were once quite popular but hardly anyone does them these days. It is easier to estimate the blood level of the nutrient directly by radioimmunoassay (RIA). However, the information obtained by estimating the blood levels of the nutrients is not the same that can be obtained from the absorption studies. Absorption studies are primarily done to find out whether some of the essential nutrients are absorbed from the gut or not and if they are absorbed, to determine how much is being absorbed. In the advanced countries, these tests were mostly done to detect pernicious anaemia where vitamin B12 is not absorbed because of the lack of the intrinsic factor in the stomach. In the tropical countries, ''malabsorption syndrome'' is quire common. In this condition, several nutrients like fat, folic acid and vitamin B12 are not absorbed. It is possible to study absorption of these nutrients by radioisotopic absorption studies

  2. Exploring in vitro, in vivo metabolism of mogroside V and distribution of its metabolites in rats by HPLC-ESI-IT-TOF-MS(n).

    Xu, Feng; Li, Dian-Peng; Huang, Zhen-Cong; Lu, Feng-Lai; Wang, Lei; Huang, Yong-Lin; Wang, Ru-Feng; Liu, Guang-Xue; Shang, Ming-Ying; Cai, Shao-Qing

    2015-11-10

    Mogroside V, a cucurbitane-type saponin, is not only the major bioactive constituent of traditional Chinese medicine Siraitiae Fructus, but also a widely used sweetener. To clarify its biotransformation process and identify its effective forms in vivo, we studied its metabolism in a human intestinal bacteria incubation system, a rat hepatic 9000g supernatant (S9) incubation system, and rats. Meanwhile, the distribution of mogroside V and its metabolites was also reported firstly. Seventy-seven new metabolites, including 52 oxidation products formed by mono- to tetra- hydroxylation/dehydrogenation, were identified with the aid of HPLC in tandem with ESI ion trap (IT) TOF multistage mass spectrometry (HPLC-ESI-IT-TOF-MS(n)). Specifically, 14 metabolites were identified in human intestinal bacteria incubation system, 4 in hepatic S9 incubation system, 58 in faeces, 29 in urine, 14 in plasma, 34 in heart, 33 in liver, 39 in spleen, 39 in lungs, 42 in kidneys, 45 in stomach, and 51 in small intestine. The metabolic pathways of mogroside V were proposed and the identified metabolic reactions were deglycosylation, hydroxylation, dehydrogenation, isomerization, glucosylation, and methylation. Mogroside V and its metabolites were distributed unevenly in the organs of treated rats. Seven bioactive metabolites of mogroside V were identified, among which mogroside IIE was abundant in heart, liver, spleen and lung, suggesting that it may contribute to the bioactivities of mogroside V. Mogroside V was mainly excreted in urine, whereas its metabolites were mainly excreted in faeces. To our knowledge, this is the first report that a plant constituent can be biotransformed into more than 65 metabolites in vivo. These findings will improve understanding of the in vivo metabolism, distribution, and effective forms of mogroside V and congeneric molecules. PMID:26280925

  3. EXERCISE ENHANCING CALCIUM ABSORPTION MECHANISM

    Muliani

    2013-01-01

    Calcium has important role in many biological processes therefore calcium homeostasis should be maintained. Imbalance in calcium homeostasis would affects the bone metabolism, neuromuscular function, blood coagulation, cell proliferation and signal transduction. Homeostasis of calcium is maintained by three major organs: gastrointestinal tract, bone and kidney. Intestinal calcium absorption is the sole mechanism to supply calcium to the body. Calcium absorption controlled by calcitropic hormo...

  4. Absorption and Distribution of Foliar Applied Boron in Upland Cotton%陆地棉对叶面施硼的吸收和分配

    张君; 危常州; 梁远航; 李美宁; 董鹏

    2012-01-01

    In this paper we studied the absorption and distribution of foliar applied boron in upland cotton(Gossypium hirsutum L.) in a hydroponic experiment. The results showed that both boron concentration and uptake in different cotton plant organs were the greatest in the leaves, followed by the stem, and lowest in the roots, boron absorption in the cotton plants increased significantly after foliar boron application except in roots. Compared with the control treatment, boron concentration in roots decreased by 41.9% when boron was partially applied on the leaves and by 11.2% when boron was applied to all leaves. Stalk boron concentration in the partial application treatment decreased by 5.9% compared to the control, but boron concentration in cotton leaves increased by 149.1%, significantly greater than the control treatment. In the partial application treatment, the amount of boron that was transferred to untreated leaves was only 5.2%, showing that boron absorbed by leaves can be partially transferred to conductivity organs but hardly enters other leaves. In the whole plant boron application treatment, the absorption of boron increased by 22.5% in the stalk and 203.7% in leaves.%通过水培试验结合室内分析,研究陆地棉对叶面施硼的吸收和分配.结果表明:施硼显著提高植株体内的硼含量和硼吸收量;棉花各器官硼含量及硼吸收量顺序均为叶片>茎秆>根系;与根系营养吸硼处理相比,叶面施硼后棉花的根系含硼量显著降低,其中部分叶片施硼处理的棉花根系硼含量降低了41.9%,全株叶片施硼的根系硼含量降低11.2%;部分叶片施硼后棉花茎秆硼含量比根系营养吸硼处理降低了5.9%,叶片硼含量比根系营养吸硼处理增加149.1%,硼主要停留在施硼叶片中,被转移到不施硼叶片的硼含量只占5.2%,难以通过输导组织进入其他叶片;全株叶片施硼,进入茎秆的硼素比根系营养吸硼处理增加22.5%,但

  5. Effects of Substrate Complexing Light Rare Earth on Growth, Cd Absorption and Organ Distribution of Sweet Pepper (Capsicum annuum var. annuum)%Effects of Substrate Complexing Light Rare Earth on Growth, Cd Absorption and Organ Distribution of Sweet Pepper (Capsicum annuum var. annuum)

    2012-01-01

    [Objective] The aim was to research effects of substrate complexing light rare earth on growth, Cd absorption and organ distribution of sweet pepper to pro- vide references for development of rhizosphere regulation products in farmland seri- ously polluted. [Method] In the test, effects of substrate cakes (at the same size) and light rare earth (in different doses) on growth, Cd absorption and distribution of green peppers under stress from Cd were explored with a pot experiment. [Result] When 40 mg/kg of rare earth was added into a substrate cake, plant height of pep- per seedlings and the dry weight increased by 21.52% and 11.11%, compared with control group; when Cd was at 5.19 mg/kg (a highly graded pollution), the shoot biomass, olant biomass and dry weight of fruits all enhanced significantly, but root system changed little in the groups where substrate cakes were saved, compared with the group where the substrate cake was washed away. No matter RE was added into substrate cakes or not, root system was significantly inhibited by Cd stress (5.19 mg/kg), but RE at proper dose improved growth of green pepper and had little effect on fruit yielding. In addition, RE had little inhibition on Cd content in roots. RE at 10 mg/kg promoted Cd contents in stems and leaves, but reduced the content in fruits substantially. The regressive equation of Cd content and rare dose in leaves was as follows: y=4E-05x%0.009 6x+0.655 6, FF=0.542 6; the regression equations of Cd content in root, stem and fruit did not make sense. [Conclusion] The experiment lays foundation for further research on heavy metals rhizosphere complexing controlling.

  6. FTO gene associated fatness in relation to body fat distribution and metabolic traits throughout a broad range of fatness

    Kring, Sofia I I; Holst, Claus; Zimmermann, Esther; Jess, Tine; Berentzen, Tina; Toubro, Søren; Hansen, Torben; Astrup, Arne; Pedersen, Oluf; Sørensen, Thorkild I A

    2008-01-01

    A common single nucleotide polymorphism (SNP) of FTO (rs9939609, T/A) is associated with total body fatness. We investigated the association of this SNP with abdominal and peripheral fatness and obesity-related metabolic traits in middle-aged men through a broad range of fatness present already in...

  7. Abdominal aortic calcification quantified by the Morphological Atherosclerotic Calcification Distribution (MACD) index is associated with features of the metabolic syndrome

    Barascuk, Natasha; Ganz, Melanie; Nielsen, Mads;

    2011-01-01

    death from cardiovascular disease (CVD). In this study we investigated associations of MACD and AC24 with traditional metabolic-syndrome associated risk factors at baseline and after 8.3 years follow-up, to identify biological parameters that may account for the differential performance of these indices...

  8. Establishing population distribution of drug-metabolizing enzyme activities for the use of salivary caffeine as a dynamic liver function marker in a Singaporean Chinese population.

    Chia, Hazel Yiting; Yau, Wai-Ping; Ho, Han Kiat

    2016-04-01

    The salivary paraxanthine/caffeine molar ratio has been proposed as a novel dynamic liver function test to guide dose adjustments of drugs hepatically cleared by CYP1A2. Its usability requires an established population norm as well as the factors influencing the ratio and actual concentrations. To address this knowledge gap, salivary caffeine and paraxanthine concentrations were measured at 4 h post caffeine dose in healthy Chinese individuals who had undergone 24 h of caffeine abstinence. The metabolic ratio was calculated and statistical analysis was performed. From the 52 participants (26 males; 30 regular caffeine consumers) recruited, the salivary paraxanthine/caffeine molar ratio was normally distributed with a mean and SD of 0.5 ± 0.2. No statistically significant factors (BMI, body weight, gender and regularity of caffeine intake) affecting the metabolic ratio were found. The caffeine concentration and total caffeine plus paraxanthine concentrations were lower in males than in females, and lower in regular caffeine consumers than in non-regular caffeine consumers. The 4 h salivary metabolic ratio (mean: 0.5) was generally not significantly different from the literature reported salivary, serum and plasma ratios measured at 4-9 h in healthy individuals (mean range 0.4-0.7) but was significantly higher than the literature reported 6 h plasma ratio and salivary ratios measured at 1-6 h in patients with liver disease or mild abnormal liver function tests (mean range 0.03-0.2). Overall, the population norm of the salivary metabolic ratio in a Singaporean Chinese population established in this study is distinct from individuals with liver disease or mild abnormal liver function tests and provides the benchmark for dosage adjustments of drugs metabolized by CYP1A2. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26862045

  9. 无机砷在植物体内的吸收和代谢机制%Absorption and metabolism mechanisms of inorganic arsenic in plants: A review

    刘艳丽; 徐莹; 杜克兵; 涂炳坤

    2012-01-01

    砷污染已成为全球非常突出且急需解决的环境问题,严重威胁人类健康和环境安全.在自然环境和土壤系统中,砷的存在形态相当复杂,但植物砷毒害主要源于As(Ⅴ)和As(Ⅲ)暴露.As(Ⅴ)通过Pi的吸收通道被植物根系吸收,并在还原酶(AR)作用下被快速还原为As(Ⅲ).As(Ⅲ)通过NIP蛋白通道进入植物体内,在砷甲基转移酶(ArsM)的作用下转化为甲基化砷或与谷胱甘肽(GSH)、植物螯合肽(PC)等多肽的巯基螯合封存在根部液泡或转运到地上部分,从而起到砷解毒的作用.同时,植物吸收的一部分砷也可外排到外部介质.本文以农作物尤其是水稻为主线,详述了As(Ⅴ)和As(Ⅲ)吸收、外排及As(Ⅴ)还原、As(Ⅲ)甲基化、螯合作用的最新研究进展,并提出了今后的研究重点.%Arsenic pollution seriously threatens human health and environment safety, being a very prominent environmental issue to be urgently solved in the world. In natural environment and soil systems, arsenic exists in complicated forms, but the plant arsenic poisoning is mainly from As ( Ⅴ) and As( Ⅲ) exposure. As(Ⅴ) can be absorbed by plant roots through Pi channel, and reduced rapidly to As( Ⅲ ) by arsenate reductase. As( Ⅲ ) can be transported into plants through NIP channel , and subsequently either transformed into methylated arsenic by arsenic methyltransferase or chelated with the thiol of GSH and PCs. These arsenic compounds can be sequestrated in root cell vacuoles or transported to plant aerial parts. Meanwhile, a part of absorbed arsenic can be discharged to external media. All of these can help to detoxify the arsenic in plants. This paper reviewed the latest research progress on the arsenic- resistance of crops, especially rice, with the focus on the mechanisms of As( Ⅴ) and As( Ⅲ ) absorption and excretion, As( Ⅴ) reduction, and As( Ⅲ) methylation and chelation. The major topics of future research on arsenic toxicity

  10. Precision-cut intestinal slices : alternative model for drug transport, metabolism, and toxicology research

    Li, Ming; de Graaf, Inge A M; Groothuis, Geny M M

    2016-01-01

    INTRODUCTION: The absorption, distribution, metabolism, excretion and toxicity (ADME-tox) processes of drugs are of importance and require preclinical investigation intestine in addition to the liver. Various models have been developed for prediction of ADME-tox in the intestine. In this review, pre

  11. Hypertriglyceridemia, Metabolic Syndrome, and Cardiovascular Disease in HIV-Infected Patients: Effects of Antiretroviral Therapy and Adipose Tissue Distribution

    van Wijk, Jeroen P. H.; Manuel Castro Cabezas

    2011-01-01

    The use of combination antiretroviral therapy (CART) in HIV-infected patients has resulted in a dramatic decline in AIDS-related mortality. However, mortality due to non-AIDS conditions, particularly cardiovascular disease (CVD) seems to increase in this population. CART has been associated with several metabolic risk factors, including insulin resistance, low HDL-cholesterol, hypertriglyceridemia and postprandial hyperlipidemia. In addition, HIV itself, as well as specific antiretroviral age...

  12. NON-INVASIVE ESTIMATION OF METABOLIC FLUX AND BLOOD FLOW IN WORKING MUSCLE: EFFECT OF BLOOD-TISSUE DISTRIBUTION

    Lai, Nicola; Saidel, Gerald M.; Iorio, Matthew; Cabrera, Marco E.

    2009-01-01

    Muscle oxygenation measurements by near infrared spectroscopy (NIRS) are frequently obtained in humans to make inferences about mechanisms of metabolic control of respiration in working skeletal muscle. However, these measurements have technical limitations that can mislead the evaluation of tissue processes. In particular, NIRS measurements of working muscle represent oxygenation of a mix of fibers with heterogeneous activation, perfusion and architecture. Specifically, the relative volume d...

  13. Influence of sulfur dioxide on metabolism and distribution of benzo[a]pyrene in isolated perfused rabbit lung

    An isolated perfused lung (IPL) preparation was used to investigate the effects of SO2 (1 to 2 ppM) on the metabolism of benzo[a]pyrene (BaP), a ubiquitous potent carcinogen that has been associated with the increased incidence of human brochiogenic carcinoma in occupational and urban populations. [14C]BaP, with and without crude air particulate (CAP), was administered intracheally to the IPL in conjunction with SO2 or after pretreatment of the whole animal with SO2. Metabolites were isolated from serial blood samples up to 3 h after the administration of [14C]BaP to the IPL. Metabolites were also isolated from lung tissue, washout fluid, macrophage, and trachea and bronchi at the end of the perfusion at 180 min. Patterns of BaP metabolites were determined by thin-layer and high-performance liquid chromatography and liquid scintillation counting. SO2 given in conjunction with BaP on the IPL or given to the whole animal followed by BaP on the IPL, in comparison with BaP only on the IPL, resulted in a twofold increase in the total rate of appearance of metabolites of BaP in the blood with changes in the metabolic pattern. SO2 given in conjunction with BaP and CAP on the IPL, in comparison with BaP plus SO2 on the IPL, resulted in a threefold decrease in the total rate of appearance of metabolites of BaP in the blood with changes in the metabolic pattern

  14. Revealing differences in metabolic flux distributions between a mutant strain and its parent strain Gluconacetobacter xylinus CGMCC 2955.

    Cheng Zhong

    Full Text Available A better understanding of metabolic fluxes is important for manipulating microbial metabolism toward desired end products, or away from undesirable by-products. A mutant strain, Gluconacetobacter xylinus AX2-16, was obtained by combined chemical mutation of the parent strain (G. xylinus CGMCC 2955 using DEC (diethyl sulfate and LiCl. The highest bacterial cellulose production for this mutant was obtained at about 11.75 g/L, which was an increase of 62% compared with that by the parent strain. In contrast, gluconic acid (the main byproduct concentration was only 5.71 g/L for mutant strain, which was 55.7% lower than that of parent strain. Metabolic flux analysis indicated that 40.1% of the carbon source was transformed to bacterial cellulose in mutant strain, compared with 24.2% for parent strain. Only 32.7% and 4.0% of the carbon source were converted into gluconic acid and acetic acid in mutant strain, compared with 58.5% and 9.5% of that in parent strain. In addition, a higher flux of tricarboxylic acid (TCA cycle was obtained in mutant strain (57.0% compared with parent strain (17.0%. It was also indicated from the flux analysis that more ATP was produced in mutant strain from pentose phosphate pathway (PPP and TCA cycle. The enzymatic activity of succinate dehydrogenase (SDH, which is one of the key enzymes in TCA cycle, was 1.65-fold higher in mutant strain than that in parent strain at the end of culture. It was further validated by the measurement of ATPase that 3.53-6.41 fold higher enzymatic activity was obtained from mutant strain compared with parent strain.

  15. Selenium metabolism in cancer cell lines - determination of cellular uptake, distribution and identification of metabolites by LC-ICPMS

    Full text: Selenium is an essential element and has shown cancer protective properties. The mechanism behind this cancer preventive effect has yet to be determined. The purpose of this study is to identify the metabolic conversions of selenium compounds carried out by the cancer cell and generates a credible hypothesis explaining the cancer preventive effect. Liver cancer cells were incubated for 24 hours with Se-methylselenocysteine or selenomethionine. The medium was removed and the cells lysed in 50 % methanol. Total selenium content was determined for the three samples, medium, supernatant and pellet fraction. Separation of the metabolites was accomplished by HPLC-ICPMS. (author)

  16. VISUALIZATION OF TISSUE DISTRIBUTION AND METABOLISM OF BENZO[A]PYRENE IN EARLY EMBRYONIC MEDAKA (ORYZIAS LATIPES)

    Fish early life stages are highly sensitive to exposure to persistent bioaccumulative toxicants (PBTs). The factors that contribute to this are unknown, but may include the distribution of PBTs to sensitive tissues during critical stages of development. Multiphoton laser scannin...

  17. Distribution and phylogenies of enzymes of the Embden-Meyerhof-Parnas pathway from archaea and hyperthermophilic bacteria support a gluconeogenic origin of metabolism

    Ron S. Ronimus

    2003-01-01

    Full Text Available Enzymes of the gluconeogenic/glycolytic pathway (the Embden-Meyerhof-Parnas (EMP pathway, the reductive tricarboxylic acid cycle, the reductive pentose phosphate cycle and the Entner-Doudoroff pathway are widely distributed and are often considered to be central to the origins of metabolism. In particular, several enzymes of the lower portion of the EMP pathway (the so-called trunk pathway, including triosephosphate isomerase (TPI; EC 5.3.1.1, glyceraldehyde-3-phosphate dehydrogenase (GAPDH; EC 1.2.1.12/13, phosphoglycerate kinase (PGK; EC 2.7.2.3 and enolase (EC 4.2.1.11, are extremely well conserved and universally distributed among the three domains of life. In this paper, the distribution of enzymes of gluconeogenesis/glycolysis in hyperthermophiles—microorganisms that many believe represent the least evolved organisms on the planet—is reviewed. In addition, the phylogenies of the trunk pathway enzymes (TPIs, GAPDHs, PGKs and enolases are examined. The enzymes catalyzing each of the six-carbon transformations in the upper portion of the EMP pathway, with the possible exception of aldolase, are all derived from multiple gene sequence families. In contrast, single sequence families can account for the archaeal and hyperthermophilic bacterial enzyme activities of the lower portion of the EMP pathway. The universal distribution of the trunk pathway enzymes, in combination with their phylogenies, supports the notion that the EMP pathway evolved in the direction of gluconeogenesis, i.e., from the bottom up.

  18. Preclinical assessment of the distribution,metabolism, and excretion of S-propargyl-cysteine, a novel H2S donor, in Sprague-Dawley rats

    Yuan-ting ZHENG; Yi-zhun ZHU; Wei-min CAI; Jian-hua ZHU; Guo MA; Qing ZHU; Ping YANG; Bo TAN; Jin-lian ZHANG; Hai-xing SHEN; Jia-lin XU

    2012-01-01

    Aim:To study the distribution,metabolism and excretion of S-propargyl-cysteine (SPRC),a novel hydrogen sulfide (H2S) donor,after oral administration in rats.Methods:Adult Sprague-Dawley rats were used.The tissue distribution of [35S] SPRC-derived radioactivity was measured using a liquid scintillation counter.The plasma protein binding of SPRC was examined using 96-well equilibrium dialysis.The excretion of SPRC in urine,bile and feces was analyzed using the LC-MS/MS method.The major metabolites in rat biomatrices were identified using MRM information-dependent,acquisition-enhanced product ion (MRM-IDA-EPI) scans on API 4000QTrap system.Results:After oral administration of [35S] SPRC at a dose of 75 mg/kg,[35S] SPRC-derived radioactivity displayed broad biological distribution in various tissues of rats,including its target organs (heart and brain) with the highest in kidney.On the other hand,the binding of SPRC to human,rat and dog plasma protein was low.Only 2.18%±0.61% and 0.77%±0.61% of the total SPRC administered was excreted unchanged in the bile and urine.However,neither intact SPRC nor its metabolites were detected in rat feces.The major metabolic pathway in vivo (rat bile,urine,and plasma) was N-acetylation.Conclusion:The preliminary results suggest that SPRC possesses acceptable pharmacokinetic properties in rats.

  19. Association among heterogeneity of intratumoral anti-CD20 antibody distribution, glucose metabolism and therapeutic response in radioimmunotherapy for B-cell lymphoma

    Full text of publication follows. Aim: in Zevalin therapy for CD20 positive low-grade lymphoma, heterogeneity of intratumoral anti-CD20 antibody distribution as well as status of lesional glucose metabolism prior to therapy may affect tumor response. The aim of this study was to evaluate association of heterogeneity of intratumoral In-111 Zevalin (In-Zevalin), accumulation of F-18 FDG (FDG), and therapeutic response in patients receiving Zevalin therapy. Methods: 16 patients with CD20 positive B-cell non-Hodgkin's lymphoma who underwent Y-90 Zevalin therapy after imaging with In-Zevalin SPECT/CT and FDG PET/CT were enrolled. Patients received In-Zevalin, followed by SPECT/CT scanning at 48 hours after administration. SUVmax of FDG of lesions was measured on PET/CT while lesion accumulation of In-Zevalin as %ID/g and SUVmax of In-Zevalin (In-Zevalin SUVmax) was measured on SPECT/CT. To evaluate heterogeneity of anti-CD20 antibody distribution, skewness and kurtosis of voxel distribution were calculated by placing there-dimensional volumes of interest (3-D VOIs) on SPECT/CT images. As another intratumoral heterogeneity index, cumulative SUVmax-volume histograms describing percentage of total tumor volume above thresholds of In-Zevalin SUVmax (AUC-CSH) were calculated by placing 3-D VOIs. All lesions (n=42) were classified into responders and non-responders lesion-by-lesion on pre- and post-therapeutic CT images. Results: by lesion-based analysis, a positive correlation was observed between FDG SUVmax and accumulation of In-Zevalin. Accumulation of In-Zevalin was 0.0022 ± 0.0009 and 0.0024 ± 0.0008 %ID/g (n.s.), and 2.74 ± 1.43 and 3.29 ± 1.47 SUVmax (n.s.) for responders and non-responders, respectively. In contrast, voxel distribution of In-Zevalin demonstrated skewness of 0.58 ± 0.16 and 0.73 ± 0.24 (p<0.05), kurtosis of 2.39 ± 0.32 and 2.78 ± 0.53 (p<0.02), and AUC-CSH of 0.37 ± 0.04 and 0.34 ± 0.05 (p<0.05) for responders and non

  20. Dermal absorption of phthalate diesters in rats

    This study examined the extent of dermal absorption of a series of phthalate diesters in the rat. Those tested were dimethyl, diethyl, dibutyl, diisobutyl, dihexyl, di(2-ethylhexyl), diisodecyl, and benzyl butyl phthalate. Hair from a skin area (1.3 cm in diameter) on the back of male F344 rats was clipped, the [14C]phthalate diester was applied in a dose of 157 mumol/kg, and the area of application was covered with a perforated cap. The rat was restrained and housed for 7 days in a metabolic cage that allowed separate collection of urine and feces. Urine and feces were collected every 24 hr, and the amount of 14C excreted was taken as an index of the percutaneous absorption. At 24 hr, diethyl phthalate showed the greatest excretion (26%). As the length of the alkyl side chain increased, the amount of 14C excreted in the first 24 hr decreased significantly. The cumulative percentage dose excreted in 7 days was greatest for diethyl, dibutyl, and diisobutyl phthalate, about 50-60% of the applied 14C; and intermediate (20-40%) for dimethyl, benzyl butyl, and dihexyl phthalate. Urine was the major route of excretion of all phthalate diesters except for diisodecyl phthalate. This compound was poorly absorbed and showed almost no urinary excretion. After 7 days, the percentage dose for each phthalate that remained in the body was minimal and showed no specific tissue distribution. Most of the unexcreted dose remained in the area of application. These data show that the structure of the phthalate diester determines the degree of dermal absorption. Absorption maximized with diethyl phthalate and then decreased significantly as the alkyl side chain length increased

  1. Modelling of absorption, distribution and physicochemical properties of AT1 receptor antagonists / Modelovanie absorpcie, distribúcie a fyzikálnochemických vlastnosti antagonistov AT1 receptorov

    Ježko Pavol

    2015-12-01

    Full Text Available The theoretical chemistry methods were used to elucidate absorption, distribution and physicochemical properties of AT1 receptor antagonists and dual angiotensin II and endothelin A receptor antagonist (PS-433540. Computed partition coefficients (ALOGPS method studied for drugs varied between 2.98 and 6.66. Neutral compounds are described as lipophilic drugs. Telmisartan is a drug with the highest lipophilicity. The neutral forms of the studied AT1 receptor antagonists are practically insoluble in water, and their computed solubilities is in interval between 2.04 and 22.65 mg/l (ALOGpS method. The calculated pKa values for tetrazolyle moiety are in the range 3.92-5.00 and for carboxylic moiety 3.12-5.50. Telmisartan (polar surface area = 72.95 A and irbesartan (polar surface area = 87.14 A belong to the AT1 receptor antagonists with increased absorption.

  2. Distribution and metabolism of dimethylsulfoniopropionate (DMSP) and phylogenetic affiliation of DMSP-assimilating bacteria in northern Baffin Bay/Lancaster Sound

    Motard-CôTé, J.; Levasseur, M.; Scarratt, M. G.; Michaud, S.; Gratton, Y.; Rivkin, R. B.; Keats, K.; Gosselin, M.; Tremblay, J.-É.; Kiene, R. P.; Lovejoy, C.

    2012-02-01

    We determined the distribution and bacterial metabolism of dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS) in the two dominant surface water masses in northern Baffin Bay/Lancaster Sound during September 2008. Concentrations of particulate DMSP (DMSPp; 5-70 nmol L-1) and the DMSPp:Chl a ratios (15-229 nmol μg-1) were relatively high, suggesting the presence of DMSP-rich phytoplankton taxa. Photosynthetic picoeukaryotes and total prokaryotes were tenfold and threefold more abundant in Baffin Bay surface water (BBS) than in Arctic surface water (AS), respectively. Heterotrophic bacterial production (0.07-2.5 μC L-1 d-1) and bacterial turnover rate constants for dissolved DMSP (DMSPd) were low (0.03-0.11 h-1) compared with the values previously reported in warmer and more productive environments. Nonetheless, a relatively large proportion (12%-31%) of the DMSP metabolized by the bacteria was converted into DMS. Additionally, between 40% and 65% of the total bacterial cells incorporated sulfur from DMSPd, with Gammaproteobacteria and non-Roseobacter Alphaproteobacteria (AlfR-) contributing proportionally more to total DMSP-incorporating cells. The contribution of AlfR- to the total prokaryotic community was 50% higher in BBS than in AS, while the bacterial rate constants for DMSPd turnover were 78% higher in BBS than in AS. These results show that the two different Arctic water masses host specific microbial assemblages that result in distinct affinity for DMSP.

  3. Disappearance and distribution of 14C-chlorfenvinphos and some of its metabolities in the carrot plants

    The pot experiments in glasshouse on residues of chlorfenvinphos in carrot plants have been carried out. A granular preparation containing 10% 14C-chlorfenvinphos was used at the seed time of the variety Lenka. The radioactivity was determined separately in the leaves, in the scraped roots and in the exodermis being scraped off. In the early consumption stage the residues of chlorfenvinphos were still fairly high, in the roots prepared for consumption being 0.21-0.67 mg/kg depending on the dose applied. In the stage of full ripeness no residues of chlorfenvinphos have been detected in the scraped roots. Some amounts of 2 metabolities, 2,4-dichlorophenacyl chloride and 2,4-dichloroacetophenone, have been found mainly in the leaves and in root exodermis. Considering, however, the amount of chlorfenvinphos residues determined in the early consumption stage as well as the rate of their disappearance, also in field investigations, the application of this compound for carrot plant protection seems to be non-advisable. (author)

  4. Metabolism and toxicology of the uranium compounds

    Three important points to be considered in the metabolic behaviour of uranium are: 1) ionic behaviour which depends only on its chemical characteristics; 2) behaves in the organism as a unique element and has no metabolism similar to others like for example Sr-90 and Ba-140 which are akin to Ca; and 3) metabolism is identical for the three isotopes of uranium and has no isotopic effect. The metabolic decomposition undergoes three phases namely: 1) absorption of the components up to the blood streams; 2) distribution through the blood into the organs; and 3) elimination. The mode of entry in the organism is through inhalation, ingestion, wounds, absorption through the skin, and entry by the eyes. Uranium decomposes in the blood after its entry, disperses in the extracellular medium and deposits in the different organs of the body. However, it has no definite fixation and the different compartments are always in equilibrium with each other. Elimination of contamination is through the feces and urine. In case of massive absorption, that is either acute or sub-acute toxicity, the following are the subsequent effects: a) clinical effects major lesion in the kidneys whatever the mode of entry may be and feebleness of the muscles, apathy and nausea are noted; b) lesions in the renal region-yellowish gray in the medular and critical region; c) biological effects-appearance of proteinuria and catalysuria, cellular wastes in the urine and a change in the capacity to reabsorb Na+, Cl-, and glucose. The lethal dose is 1 mg U-nat/kg.wt. The dose provoking renal lesion is 0.1mg U/kg.wt. The maximum permissible dose is: a) annual dose 40 mg U-nat/yr; b) Inhalation 2.5 mg/day; c) Ingestion 150 mg/2 days consecutive (soluble = 4.7x10-1 μCi, insoluble = 3.4x10-2 μCi

  5. [Distribution and speciation of Pb in Arabidopsis thaliana shoot and rhizosphere soil by in situ synchrotron radiation micro X-ray fluorescence and X-ray absorption near edge structure].

    Shen, Ya-Ting

    2014-03-01

    In order to investigate plant reacting mechanism with heavy metal stress in organ and tissue level, synchrotron radiation micro X-ray fluorescence (micro-SRXRF) was used to determine element distribution characteristics of K, Ca, Mn, Fe, Cu, Zn, Pb in an Arabidopsis thaliana seedling grown in tailing dam soil taken from a lead-zinc mine exploration area. The results showed a regular distribution characters of K, Ca, Fe, Cu and Zn, while Pb appeared not only in root, but also in a leaf bud which was beyond previously understanding that Pb mainly appeared in plant root. Pb competed with Mn in the distribution of the whole seedling. Pb may cause the increase of oxidative stress in root and leaf bud, and restrict Mn absorption and utilization which explained the phenomenon of seedling death in this tailing damp soil. Speciation of Pb in Arabidopsis thaliana and tailing damp rhizosphere soil were also presented after using PbL3 micro X-ray absorption near edge structure (micro-XANES). By comparison of PbL3 XANES peak shape and peak position between standard samples and rhizosphere soil sample, it was demonstrated that the tailing damp soil was mainly formed by amorphous forms like PbO (64.2%), Pb (OH)2 (28.8%) and Pb3O4 (6.3%) rather than mineral or organic Pb speciations. The low plant bioavailability of Pb demonstrated a further research focusing on Pb absorption and speciation conversion is needed, especially the role of dissolve organic matter in soil which may enhance Pb bioavailability. PMID:25208420

  6. Distribution of Cold ($\\lesssim 300$K) Atomic Gas in Galaxies: Results from the GBT HI Absorption Survey Probing the Inner Halos ($\\rho<20$kpc) of Low-z Galaxies

    Borthakur, Sanchayeeta

    2016-01-01

    We present the Green Bank Telescope absorption survey of cold atomic hydrogen ($\\lesssim 300$K) in the inner halo of low-redshift galaxies. The survey aims to characterize the cold gas distribution and to address where condensation - the process where ionized gas accreted by galaxies condenses into cold gas within the disks of galaxies - occurs. Our sample consists of 16 galaxy-quasar pairs with impact parameters of $\\le$ 20kpc. We detected an HI absorber associated with J0958+3222 (NGC 3067) and HI emission from six galaxies. We also found two \\ion{Ca}{2} absorption system in the archival SDSS data associated with galaxies J0958+3222 and J1228+3706, although the sample was not selected based on the presence of metals in absorption. Our detection rate of HI absorbers with optical depths of $\\ge 0.06$ is $\\sim$7\\%. We also find that cold HI phase ($\\lesssim$300K) is 44($\\pm$18)\\% of the total atomic gas in the sightline probing J0958+3222. We find no correlation between the peak optical depth and impact parame...

  7. Effect of colchicine on rat small intestinal absorptive cells. II. Distribution of label after incorporation of [3H]fucose into plasma membrane glycoproteins

    By means of radioautography the influence was tested of various periods (5, 15, 30, 40 min, 2 hr) of pretreatment with colchicine, administered intraperitoneally to rats at a dosage of 0.5 mg/100 g of body weight, on the intracellular pathway of [3H]fucose in absorptive cells of the small intestine. Administration of colchicine for 30 min and longer time intervals causes delay in the insertion of [3H]fucose into the oligosaccharide chains of glycoconjugates in the Golgi apparatus, and results in redistribution of the label apparent over the different portions of the plasma membrane. In controls, at 2 and 4 hr after administration of [3H]fucose the apical plasma membrane is strongly labeled. Colchicine causes equalization of the reaction of apical and basolateral regions of the plasma membrane: the number of silver grains attributable to the apical plasma membrane is reduced; following treatment with colchicine, apical portions of the plasma membrane comprise 31.6 +/- 1.8% of the silver grains, 38.6 +/- 3.8% are attributable to basolateral membrane regions. The colchicine-induced equalization of the density of label of apical and basolateral regions of the plasma membrane, in addition to the occurrence of basolateral microvillus borders, suggests microtubules to be important in the maintenance of the polar organization of small intestinal absorptive cells

  8. Absorption Of Dietary Lipid Components

    Abdulkadir Hurşit

    2015-01-01

    Although the digestion and absorption of lipids that are necessary for the survival of living organisms are well known in general terms, nevertheless how different lipids to be digested, how it is distributed into the bloodstream, and how to be used by the cells, are unknown issues by most non specialist people. In recent years, knowledge of lipid digestion and absorption has expanded considerably. More insight has been gained in the mechanism of action of H + pump as a transport system in fa...

  9. Long-Term Impacts of Foetal Malnutrition Followed by Early Postnatal Obesity on Fat Distribution Pattern and Metabolic Adaptability in Adult Sheep.

    Khanal, Prabhat; Johnsen, Lærke; Axel, Anne Marie Dixen; Hansen, Pernille Willert; Kongsted, Anna Hauntoft; Lyckegaard, Nette Brinch; Nielsen, Mette Olaf

    2016-01-01

    We aimed to investigate whether over- versus undernutrition in late foetal life combined with obesity development in early postnatal life have differential implications for fat distribution and metabolic adaptability in adulthood. Twin-pregnant ewes were fed NORM (100% of daily energy and protein requirements), LOW (50% of NORM) or HIGH (150%/110% of energy/protein requirements) diets during the last trimester. Postnatally, twin-lambs received obesogenic (HCHF) or moderate (CONV) diets until 6 months of age, and a moderate (obesity correcting) diet thereafter. At 2½ years of age (adulthood), plasma metabolite profiles during fasting, glucose, insulin and propionate (in fed and fasted states) tolerance tests were examined. Organ weights were determined at autopsy. Early obesity development was associated with lack of expansion of perirenal, but not other adipose tissues from adolescence to adulthood, resulting in 10% unit increased proportion of mesenteric of intra-abdominal fat. Prenatal undernutrition had a similar but much less pronounced effect. Across tolerance tests, LOW-HCHF sheep had highest plasma levels of cholesterol, urea-nitrogen, creatinine, and lactate. Sex specific differences were observed, particularly with respect to fat deposition, but direction of responses to early nutrition impacts were similar. However, prenatal undernutrition induced greater metabolic alterations in adult females than males. Foetal undernutrition, but not overnutrition, predisposed for adult hypercholesterolaemia, hyperureaemia, hypercreatinaemia and hyperlactataemia, which became manifested only in combination with early obesity development. Perirenal expandability may play a special role in this context. Differential nutrition recommendations may be advisable for individuals with low versus high birth weights. PMID:27257993

  10. Long-Term Impacts of Foetal Malnutrition Followed by Early Postnatal Obesity on Fat Distribution Pattern and Metabolic Adaptability in Adult Sheep.

    Prabhat Khanal

    Full Text Available We aimed to investigate whether over- versus undernutrition in late foetal life combined with obesity development in early postnatal life have differential implications for fat distribution and metabolic adaptability in adulthood. Twin-pregnant ewes were fed NORM (100% of daily energy and protein requirements, LOW (50% of NORM or HIGH (150%/110% of energy/protein requirements diets during the last trimester. Postnatally, twin-lambs received obesogenic (HCHF or moderate (CONV diets until 6 months of age, and a moderate (obesity correcting diet thereafter. At 2½ years of age (adulthood, plasma metabolite profiles during fasting, glucose, insulin and propionate (in fed and fasted states tolerance tests were examined. Organ weights were determined at autopsy. Early obesity development was associated with lack of expansion of perirenal, but not other adipose tissues from adolescence to adulthood, resulting in 10% unit increased proportion of mesenteric of intra-abdominal fat. Prenatal undernutrition had a similar but much less pronounced effect. Across tolerance tests, LOW-HCHF sheep had highest plasma levels of cholesterol, urea-nitrogen, creatinine, and lactate. Sex specific differences were observed, particularly with respect to fat deposition, but direction of responses to early nutrition impacts were similar. However, prenatal undernutrition induced greater metabolic alterations in adult females than males. Foetal undernutrition, but not overnutrition, predisposed for adult hypercholesterolaemia, hyperureaemia, hypercreatinaemia and hyperlactataemia, which became manifested only in combination with early obesity development. Perirenal expandability may play a special role in this context. Differential nutrition recommendations may be advisable for individuals with low versus high birth weights.