Science.gov

Sample records for 13co2 excretion tmax

  1. Impact of oceanic circulation changes on atmospheric δ13CO2

    NASA Astrophysics Data System (ADS)

    Menviel, L.; Mouchet, A.; Meissner, K. J.; Joos, F.; England, M. H.

    2015-12-01

    δ13CO2 measured in Antarctic ice cores provides constraints on oceanic and terrestrial carbon cycle processes linked with millennial-scale and glacial/interglacial changes in atmospheric CO2. However, the interpretation of δ13CO2 is not straightforward. Using two Earth system models of intermediate complexity we perform a set of sensitivity experiments in which the formation rates of North Atlantic Deep Water (NADW), North Pacific Deep Water (NPDW), Antarctic Bottom Water (AABW) and Antarctic Intermediate Water (AAIW) are varied. We study the impact of these circulation changes on atmospheric δ13CO2 as well as on the oceanic δ13C distribution. In general, we find that the formation rates of AABW, NADW, NPDW and AAIW are negatively correlated with changes in δ13CO2: namely strong oceanic ventilation decreases atmospheric δ13CO2. However, since large scale ocean circulation reorganizations also impact nutrient utilization and the Earth's climate the relationship between atmospheric δ13CO2 levels and ocean ventilation rate is not unequivocal. In both models atmospheric δ13CO2 is very sensitive to changes in AABW formation rates: increased AABW formation enhances the upwelling of low δ13C waters to the surface and decreases atmospheric δ13CO2. By contrast, the impact of NADW changes on atmospheric δ13CO2 is less robust and might be model dependent.

  2. Biosynthesis of Nudicaulins: A (13) CO2 -pulse/chase labeling study with Papaver nudicaule.

    PubMed

    Tatsis, Evangelos C; Eylert, Eva; Maddula, Ravi Kumar; Ostrozhenkova, Elena; Svatoš, Aleš; Eisenreich, Wolfgang; Schneider, Bernd

    2014-07-21

    Nudicaulins are unique alkaloids responsible for the yellow color of the petals of some papaveraceaous plants. To elucidate the unknown biosynthetic origin of the skeleton, a (13) CO2 -pulse/chase experiment was performed with growing Papaver nudicaule plants. (13) C NMR analysis revealed more than 20 multiple (13) C-enriched isotopologues in nudicaulins from the petals of (13) CO2 -labeled plants. The complex labeling pattern was compared with the isotopologue composition of a kaempferol derivative that was isolated from petals of the same (13) CO2 -labeled plants. The deconvolution of the labeling profiles indicated that the nudicaulin scaffold is assembled from products or intermediates of indole metabolism, the phenylpropanoid pathway, and the polyketide biosynthesis. Naringenin-type compounds and tryptophan/tryptamine are potential substrates for the condensation reaction finally generating the aglycone skeleton of nudicaulins.

  3. 13CO2 as a universal metabolic tracer in isotopologue perturbation experiments.

    PubMed

    Römisch-Margl, Werner; Schramek, Nicholas; Radykewicz, Tanja; Ettenhuber, Christian; Eylert, Eva; Huber, Claudia; Römisch-Margl, Lilla; Schwarz, Christine; Dobner, Maria; Demmel, Norbert; Winzenhörlein, Bernhard; Bacher, Adelbert; Eisenreich, Wolfgang

    2007-01-01

    A tobacco plant was illuminated for 5h in an atmosphere containing (13)CO(2) and then maintained for 10 days under standard greenhouse conditions. Nicotine, glucose, and amino acids from proteins were isolated chromatographically. Isotopologue abundances of isolated metabolites were determined quantitatively by NMR spectroscopy and mass spectrometry. The observed non-stochastic isotopologue patterns indicate (i) formation of multiply labeled photosynthetic carbohydrates during the (13)CO(2) pulse phase followed by (ii) partial catabolism of the primary photosynthetic products, and (iii) recombination of the (13)C-labeled fragments with unlabeled intermediary metabolites during the chase period. The detected and simulated isotopologue profiles of glucose and amino acids reflect carbon partitioning that is dominated by the Calvin cycle and glycolysis/glucogenesis. Retrobiosynthetic analysis of the nicotine pattern is in line with its known formation from nicotinic acid and putrescine via aspartate, glyceraldehyde phosphate and alpha-ketoglutarate as basic building blocks. The study demonstrates that pulse/chase labeling with (13)CO(2) as precursor is a powerful tool for the analysis of quantitative aspects of plant metabolism in completely unperturbed whole plants.

  4. NMR determination of photorespiration in intact leaves using in vivo 13CO 2 labeling

    NASA Astrophysics Data System (ADS)

    Cegelski, Lynette; Schaefer, Jacob

    2006-01-01

    Solid-state 13C NMR measurements of intact soybean leaves labeled by 13CO 2 lead to the conclusion that photorespiration is 17% of photosynthesis for a well-watered and fertilized plant. This is the first direct assessment of the level of photorespiration in a functioning plant. A 13C{ 31P} rotational-echo double-resonance (REDOR) measurement tracked the incorporation of 13C label into intermediates in the Calvin cycle as a function of time. For labeling times of 5 min or less, the isotopic enrichment of the Calvin cycle depends on the flux of labeled carbon from 13CO 2, relative to the flux of unlabeled carbon from glycerate returned from the photorespiratory cycle. Comparisons of these two rates for a fixed value of the 13CO 2 concentration indicate that the ratio of the rate of photosynthesis to the rate of photorespiration of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in soybean leaves is 5.7. This translates into a photorespiratory CO 2 loss that is 21% of net CO 2 assimilation, about 80% of the value estimated from Rubisco kinetics parameters. The ratio of rates is reduced at low external CO 2 concentrations, as measured by net carbon assimilation rates. The carbon assimilation was determined from 13C-label spin counts converted into total carbon by the REDOR-determined isotopic enrichments of the Calvin cycle. The net carbon assimilation rates indicate that the rate of decarboxylation of glycine is not directly proportional to the oxygenase activity of Rubisco as is commonly assumed.

  5. NMR determination of photorespiration in intact leaves using in vivo 13CO2 labeling.

    PubMed

    Cegelski, Lynette; Schaefer, Jacob

    2006-01-01

    Solid-state 13C NMR measurements of intact soybean leaves labeled by 13CO2 lead to the conclusion that photorespiration is 17% of photosynthesis for a well-watered and fertilized plant. This is the first direct assessment of the level of photorespiration in a functioning plant. A 13C{31P} rotational-echo double-resonance (REDOR) measurement tracked the incorporation of 13C label into intermediates in the Calvin cycle as a function of time. For labeling times of 5 min or less, the isotopic enrichment of the Calvin cycle depends on the flux of labeled carbon from 13CO2, relative to the flux of unlabeled carbon from glycerate returned from the photorespiratory cycle. Comparisons of these two rates for a fixed value of the 13CO2 concentration indicate that the ratio of the rate of photosynthesis to the rate of photorespiration of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in soybean leaves is 5.7. This translates into a photorespiratory CO2 loss that is 21% of net CO2 assimilation, about 80% of the value estimated from Rubisco kinetics parameters. The ratio of rates is reduced at low external CO2 concentrations, as measured by net carbon assimilation rates. The carbon assimilation was determined from 13C-label spin counts converted into total carbon by the REDOR-determined isotopic enrichments of the Calvin cycle. The net carbon assimilation rates indicate that the rate of decarboxylation of glycine is not directly proportional to the oxygenase activity of Rubisco as is commonly assumed.

  6. Interaction of 13 CO 2 and bicarbonate with human hemoglobin preparations.

    PubMed

    Morrow, J S; Keim, P; Visscher, R B; Marshall, R C; Gurd, F R

    1973-05-01

    Formation of (13)C-resonances attributable to carbamino derivatives has been observed in human erythrocyte hemolysate preparations equilibrated with (13)CO(2) at 33 degrees . Carbamino formation is most marked in deoxyhemoglobin and at alkaline pH, and is very largely inhibited by the addition of 2,3-diphosphoglycerate or conversion to oxyhemoglobin. The prominent carbamino resonance at 30.0 ppm upfield of CS(2) is visible in the spectrum of packed, deoxygenated erythrocytes equilibrated in (13)CO(2). This chemical shift falls close to that observed with sperm-whale myoglobin and within 2 ppm upfield of that seen with simple amino acids and peptides. The bicarbonate-carbonate resonance near 33 ppm is broad in the hemoglobin preparations, which always contain some carbonic anhydrase, but becomes narrow in the presence of the carbonic anhydrase inhibitor, acetazolamide. The nuclear magnetic resonance condition of intermediate exchange rate with dissolved CO(2) (68.4 ppm) obtains in the absence of inhibitor. The process has marked consequences in reducing the spin-lattice relaxation time, T(1), of the bicarbonate resonance by more than 10 times. The deoxyhemoglobin carbamino resonance has a T(1) value of 700 msec, indistinguishable from that of the protein carbonyl resonance envelope.

  7. Ecological and Molecular Study of Soil Chemoautotrophic Microorganisms via the Sequestration of Atmospheric 13CO2

    NASA Astrophysics Data System (ADS)

    Hart, K. M.; Kelleher, B.; Allen, C.; Simpson, A.

    2009-05-01

    Soil Organic Matter (SOM) is the most complicated biomaterial on Earth and stores significantly more carbon than is currently present in the atmosphere [1]. It has been recently reported that humic material in SOM is a highly complex mixture of microbial and plant biopolymers and not a distinct chemical fraction as previously thought [2]. Furthermore, it has been reported that the microbial biomass contribution to SOM is not comprised of mainly humic materials and that in fact the contribution to SOM by soil microorganisms has been seriously underestimated [3]. Therefore, the question arises if we underestimate microbial biomass in soil do we also underestimate carbon sequestration by soil microbes? Soil microorganisms consist of a large range of diverse species with soil bacteria contributing a large proportion of the biomass content. Autotrophs are organisms that can produce organic compounds from CO2 as the sole carbon source, using either light (photoautotroph) or inorganic reactions (chemoautotroph) as the energy source. The aim of this project is to enrich chemoautotrophic soil microbes with carbon-13 (13C) sequestered as 13CO2. Once labeled, these target microbes can be differentiated from other microbes using techniques such as Stable Isotope Probing (SIP) and carbon NMR. This enrichment is facilitated via incubation in a custom built environmental chamber and the controlled introduction of 13CO2. Before introduction of 13CO2 the chambers capabilities had to be fully characterized to ensure that it was fit for purpose. Mixed cultures of soil chemoautotrophic microorganisms were propagated from different soils and data collected using the environmental chamber demonstrated that CO2 fluctuations mimicked the natural activity of actively growing chemoautotrophic cultures. Therefore using this soil slurry approach, a mixed culture of soil autotrophs will be exposed to 13CO2 prior to the harvesting of the microbial biomass. Ion chromatographic analysis of the

  8. Tracing photosynthetic carbon in leaves with nanoSIMS after 13CO2 labelling

    NASA Astrophysics Data System (ADS)

    Dannoura, Masako; Takeuchi, Miyuki; Kominami, Yuji; Takanashi, Satoru; Kenichi, Yoshimura; Ataka, Mioko

    2015-04-01

    To understand the carbon allocation of the tree and forest ecosystem, it is important to consider the residence time of carbon in different pools at suitable time scales. For example the carbon used for respiration will stay a few minutes to a few days in the tree, the carbon used for storage or structure of leaves will stay months to years, and the carbon used for wood structure, it will stay over the whole lifespan of the tree. The leaves are the entrance of carbon in trees where it can be used for foliage growth and maintenance or exported to the other organs or the other forest ecosystem compartments. Tracing carbon isotope using NanoSIMS technique is one of useful methods to estimate where and how long the carbon stay in the tree organs. In this study, 13CO2 pulse labelling were conducted and 13C was measured by IRMS to see the amount of C remaining in the leaves with time.NanoSIMS was used to localize where the labelled C remained within the leaf tissue. Twice labelling were done on branches of Quercus serrata at FFPRI(Forest and Forest Products research Institute) in Kyoto, Japan. The first labelling was in 30 April 2012 when the leaves start flushing and the second one was in 29 May 2012 when the leaves were completely deployed. For both labelling experiment, one branch was selected and covered with transparent plastic bag. CO2 concentration was recorded with IRGA and air temperature inside the chamber was monitored. Then 13CO2 was injected into the bag, and after 1 hour, the bag was removed and the branch was again exposed to ambient air. Leaves were collected before and 10-12 times after labelling and their isotope compositions were measured by IRMS. The leaf collected just after labelling and 6 days after labelling were used for NanoSIMS observation. Samples for nanoSIMS were preserved in glutaraldehyde and then embed in epoxy resin. The sliced sample were placed on the silicon wafer and observed by NanoSIMS 50L(Cameca, France). The 13C was highest just

  9. 13C Tracking after 13CO2 Supply Revealed Diurnal Patterns of Wood Formation in Aspen.

    PubMed

    Mahboubi, Amir; Linden, Pernilla; Hedenström, Mattias; Moritz, Thomas; Niittylä, Totte

    2015-06-01

    Wood of trees is formed from carbon assimilated in the photosynthetic tissues. Determining the temporal dynamics of carbon assimilation, subsequent transport into developing wood, and incorporation to cell walls would further our understanding of wood formation in particular and tree growth in general. To investigate these questions, we designed a (13)CO2 labeling system to study carbon transport and incorporation to developing wood of hybrid aspen (Populus tremula × tremuloides). Tracking of (13)C incorporation to wood over a time course using nuclear magnetic resonance spectroscopy revealed diurnal patterns in wood cell wall biosynthesis. The dark period had a differential effect on (13)C incorporation to lignin and cell wall carbohydrates. No (13)C was incorporated into aromatic amino acids of cell wall proteins in the dark, suggesting that cell wall protein biosynthesis ceased during the night. The results show previously unrecognized temporal patterns in wood cell wall biosynthesis, suggest diurnal cycle as a possible cue in the regulation of carbon incorporation to wood, and establish a unique (13)C labeling method for the analysis of wood formation and secondary growth in trees.

  10. A joint global carbon inversion system using both CO2 and 13CO2 atmospheric concentration data

    NASA Astrophysics Data System (ADS)

    Chen, Jing M.; Mo, Gang; Deng, Feng

    2017-03-01

    Observations of 13CO2 at 73 sites compiled in the GLOBALVIEW database are used for an additional constraint in a global atmospheric inversion of the surface CO2 flux using CO2 observations at 210 sites (62 collocated with 13CO2 sites) for the 2002-2004 period for 39 land regions and 11 ocean regions. This constraint is implemented using prior CO2 fluxes estimated with a terrestrial ecosystem model and an ocean model. These models simulate 13CO2 discrimination rates of terrestrial photosynthesis and ocean-atmosphere diffusion processes. In both models, the 13CO2 disequilibrium between fluxes to and from the atmosphere is considered due to the historical change in atmospheric 13CO2 concentration. This joint inversion system using both13CO2 and CO2 observations is effectively a double deconvolution system with consideration of the spatial variations of isotopic discrimination and disequilibrium. Compared to the CO2-only inversion, this 13CO2 constraint on the inversion considerably reduces the total land carbon sink from 3.40 ± 0.84 to 2.53 ± 0.93 Pg C year-1 but increases the total oceanic carbon sink from 1.48 ± 0.40 to 2.36 ± 0.49 Pg C year-1. This constraint also changes the spatial distribution of the carbon sink. The largest sink increase occurs in the Amazon, while the largest source increases are in southern Africa, and Asia, where CO2 data are sparse. Through a case study, in which the spatial distribution of the annual 13CO2 discrimination rate over land is ignored by treating it as a constant at the global average of -14. 1 ‰, the spatial distribution of the inverted CO2 flux over land was found to be significantly modified (up to 15 % for some regions). The uncertainties in our disequilibrium flux estimation are 8.0 and 12.7 Pg C year-1 ‰ for land and ocean, respectively. These uncertainties induced the unpredictability of 0.47 and 0.54 Pg C year-1 in the inverted CO2 fluxes for land and ocean, respectively. Our joint inversion system is therefore

  11. Decoding Biosynthetic Pathways in Plants by Pulse-Chase Strategies Using 13CO2 as a Universal Tracer †

    PubMed Central

    Bacher, Adelbert; Chen, Fan; Eisenreich, Wolfgang

    2016-01-01

    13CO2 pulse-chase experiments monitored by high-resolution NMR spectroscopy and mass spectrometry can provide 13C-isotopologue compositions in biosynthetic products. Experiments with a variety of plant species have documented that the isotopologue profiles generated with 13CO2 pulse-chase labeling are directly comparable to those that can be generated by the application of [U-13C6]glucose to aseptically growing plants. However, the application of the 13CO2 labeling technology is not subject to the experimental limitations that one has to take into account for experiments with [U-13C6]glucose and can be applied to plants growing under physiological conditions, even in the field. In practical terms, the results of biosynthetic studies with 13CO2 consist of the detection of pairs, triples and occasionally quadruples of 13C atoms that have been jointly contributed to the target metabolite, at an abundance that is well above the stochastic occurrence of such multiples. Notably, the connectivities of jointly transferred 13C multiples can have undergone modification by skeletal rearrangements that can be diagnosed from the isotopologue data. As shown by the examples presented in this review article, the approach turns out to be powerful in decoding the carbon topology of even complex biosynthetic pathways. PMID:27429012

  12. Adaptation of the NDIR technology to 13CO2 breath tests under increased inspiratory O2 concentrations.

    PubMed

    Vogt, Josef A; Wachter, Ulrich; Mehring, Jürgen; Radermacher, Peter; Georgieff, Michael; Fischer, Heinz; Hölscher, Uvo; Moede, Michael; Fabinski, Walter

    2009-07-01

    Nondispersive infrared spectroscopy (NDIR) allows the continuous analysis of respiratory gases. Due to its high selectivity, simple and robust setup, and small footprint, it is also used to support (13)CO(2) breath tests to assess bacterial growth in the stomach, gut, or liver function. CO(2) NDIR signals, however, are biased by oxygen in the gas matrix. This complicates NDIR-based breath tests, if the inspired oxygen concentration has to be adjusted to the subject's requirements, or hyperoxia-induced effects were studied. To avoid the oxygen-induced bias, a "dilution" approach was developed: expired gas is mixed with N(2) to lower the oxygen content down to the usual range of 15-20%. Accuracy and precision were tested using synthetic gas mixtures with increasing (13)CO(2)-to-(12)CO(2) ratios ((13)CO(2)/(12)CO(2)), either based on synthetic air with approximately 20% volume O(2) or on pure O(2). For samples with delta(13)C values smaller than 300 (or (13)CO(2)/(12)CO(2) smaller than 0.003), the dilution does not significantly increase the bias in the (13)CO(2)/(12)CO(2) determination, and the within-run imprecision is smaller than 1 delta(13)C. The practical use of this approach was validated in a pig study using a sepsis model reflecting a clinical situation that requires an increased oxygen concentration for respiration. The N(2) dilution eliminated the high bias in NDIR measurement, thus allowing the determination of the impact of oxygenation on glucose oxidation in patients ventilated with increased oxygen.

  13. Constraining Ecosystem Gross Primary Production and Transpiration with Measurements of Photosynthetic 13CO2 Discrimination

    NASA Astrophysics Data System (ADS)

    Blonquist, J. M.; Wingate, L.; Ogeé, J.; Bowling, D. R.

    2011-12-01

    The stable carbon isotope composition of atmospheric CO2 (δ13Ca) can provide useful information on water use efficiency (WUE) dynamics of terrestrial ecosystems and potentially constrain models of CO2 and water fluxes at the land surface. This is due to the leaf-level relationship between photosynthetic 13CO2 discrimination (Δ), which influences δ13Ca, and the ratio of leaf intercellular to atmospheric CO2 mole fractions (Ci / Ca), which is related to WUE and is determined by the balance between C assimilation (CO2 demand) and stomatal conductance (CO2 supply). We used branch-scale Δ derived from tunable diode laser absorption spectroscopy measurements collected in a Maritime pine forest to estimate Ci / Ca variations over an entire growing season. We combined Ci / Ca estimates with rates of gross primary production (GPP) derived from eddy covariance (EC) to estimate canopy-scale stomatal conductance (Gs) and transpiration (T). Estimates of T were highly correlated to T estimates derived from sapflow data (y = 1.22x + 0.08; r2 = 0.61; slope P < 0.001) and T predictions from an ecosystem model (MuSICA) (y = 0.88x - 0.05; r2 = 0.64; slope P < 0.001). As an alternative to estimating T, Δ measurements can be used to estimate GPP by combining Ci / Ca estimates with Gs estimates from sapflow data. Estimates of GPP were determined in this fashion and were highly correlated to GPP values derived from EC (y = 0.82 + 0.07; r2 = 0.61; slope P < 0.001) and GPP predictions from MuSICA (y = 1.10 + 0.42; r2 = 0.50; slope P < 0.001). Results demonstrate that the leaf-level relationship between Δ and Ci / Ca can be extended to the canopy-scale and that Δ measurements have utility for partitioning ecosystem-scale CO2 and water fluxes.

  14. Method for tracing simulated CO2 leak in terrestrial environment with a 13CO2 tracer

    NASA Astrophysics Data System (ADS)

    Moni, Christophe; Rasse, Daniel

    2013-04-01

    Facilities for the geological storage of carbon dioxide (CO2) as part of carbon capture and storage (CCS) schemes will be designed to prevent any leakage from the defined 'storage complex'. However, developing regulations and guidance throughout the world (e.g. the EC Directive and the USEPA Vulnerability Evaluation Framework) recognize the importance of assessing the potential for environmental impacts from CO2 storage. RISCS, a European (FP7) project, aims to improve understanding of those impacts that could plausibly occur in the hypothetical case that unexpected leakage occurs. As part of the RISCS project the potential impacts that an unexpected CO2 leaks might have on a cropland ecosystems was investigated. A CO2 exposure field experiment based on CO2 injection at 85 cm depth under an oats culture was designed. To facilitate the characterization of the simulated leaking zone the gas used for injection was produced from natural gas and had a δ13C of -46‰. The aim of the present communication is to depict how the injected gas was traced within the soil-vegetation-atmosphere continuum using 13CO2 continuous cavity ring-down spectrometry (CRDS). Four subsurface experimental injection plots (6m x 3m) were set up. In order to test the effects of different intensity of leakage, the field experiment was designed as to create a longitudinal CO2 gradient for each plot. For this purpose gas supply pipes were inserted at one extremity of each plot at the base of a 45 cm thick layer of sand buried 40 cm below the surface under the clayey plough layer of Norwegian moraine soils. Soil CO2 concentration and isotopic signature were punctually recorded: 1) in the soil at 20 cm depth at 6 positions distributed on the central transect, 2) at the surface following a (50x50 cm) grid sampling pattern, and 3) in the canopy atmosphere at 10, 20, 30 cm along three longitudinal transects (seven sampling point per transect). Soil CO2 fluxes and isotopic signature were finally

  15. Raman spectroscopic investigation of 13CO 2 labeling and leaf dark respiration of Fagus sylvatica L. (European beech).

    PubMed

    Keiner, Robert; Gruselle, Marie-Cécile; Michalzik, Beate; Popp, Jürgen; Frosch, Torsten

    2015-03-01

    An important issue, in times of climate change and more extreme weather events, is the investigation of forest ecosystem reactions to these events. Longer drought periods stress the vitality of trees and promote mass insect outbreaks, which strongly affect ecosystem processes and services. Cavity-enhanced Raman gas spectrometry was applied for online multi-gas analysis of the gas exchange rates of O2 and CO2 and the labeling of Fagus sylvatica L. (European beech) seedlings with (13)CO2. The rapid monitoring of all these gases simultaneously allowed for the separation of photosynthetic uptake of CO2 by the beech seedlings and a constant (12)CO2 efflux via respiration and thus for a correction of the measured (12)CO2 concentrations in course of the labeling experiment. The effects of aphid infestation with the woolly beech aphid (Phyllaphis fagi L.) as well as the effect of a drought period on the respirational gas exchange were investigated. A slightly decreased respirational activity of drought-stressed seedlings in comparison to normally watered seedlings was found already for a low drought intensity. Cavity-enhanced Raman gas monitoring of O2, (12)CO2, and (13)CO2 was proven to be a powerful new tool for studying the effect of drought stress and aphid infestation on the respirational activity of European beech seedlings as an example of important forest species in Central Europe.

  16. Influence of C4 vegetation on 13CO2 discrimination and isoforcing in the upper Midwest, United States

    NASA Astrophysics Data System (ADS)

    Griffis, T. J.; Baker, J. M.; Sargent, S. D.; Erickson, M.; Corcoran, J.; Chen, M.; Billmark, K.

    2010-12-01

    Agricultural crops with a C4 photosynthetic pathway rapidly expanded across North America as early as 800 A.D. Their distribution continues to expand globally as demands for food and biofuel production increase. These systems are highly productive, having a significant impact on carbon and water exchange between the land and atmosphere. Here, we investigate the relative impact of agricultural C4 vegetation on the 13CO2 photosynthetic discrimination and atmospheric isotopic forcing in the upper Midwest, United States. We address three questions: (1) What is the relative importance of C3 and C4 species to the CO2 budget? (2) How do these different photosynthetic pathways influence the photosynthetic discrimination within this heterogeneous landscape? (3) To what extent does land use change (i.e., a change in C4 crops) impact atmospheric isotopic forcing and the isotopic signature of the atmosphere? These questions are addressed using measurements obtained from the University of Minnesota tall tower (244 m) trace gas observatory (TGO) over the growing seasons of 2007 and 2008 and are supported with scaled-up values of discrimination and isotopic forcing based on ecosystem-scale eddy flux observations and high-resolution land use data. Our land use analyses indicate that local and regional C4 production was higher by 10% in 2007 due to increased demand for biofuel. The 2007 growing season was also characterized by moderate drought as a consequence of low antecedent soil water content. Isotopic flux ratio measurements from TGO provide evidence that the increase in C4 land use and drier soil conditions of 2007 had a significant impact on the growing season 13CO2 photosynthetic discrimination, which ranged from 11.5 to 14.8 in 2007 and 12.4‰ to 17.4‰ in 2008. Isotopic partitioning indicated that C4 species accounted for about 20 to 40% of the growing season gross photosynthetic CO2 exchange. The isoforcing analysis revealed that C3 discrimination dominated the

  17. Tracking the oxidative kinetics of carbohydrates, amino acids and fatty acids in the house sparrow using exhaled 13CO2.

    PubMed

    McCue, M D; Sivan, O; McWilliams, S R; Pinshow, B

    2010-03-01

    Clinicians commonly measure the (13)CO(2) in exhaled breath samples following administration of a metabolic tracer (breath testing) to diagnose certain infections and metabolic disorders. We believe that breath testing can become a powerful tool to investigate novel questions about the influence of ecological and physiological factors on the oxidative fates of exogenous nutrients. Here we examined several predictions regarding the oxidative kinetics of specific carbohydrates, amino acids and fatty acids in a dietary generalist, the house sparrow (Passer domesticus). After administering postprandial birds with 20 mg of one of seven (13)C-labeled tracers, we measured rates of (13)CO(2) production every 15 min over 2 h. We found that sparrows oxidized exogenous amino acids far more rapidly than carbohydrates or fatty acids, and that different tracers belonging to the same class of physiological fuels had unique oxidative kinetics. Glycine had a mean maximum rate of oxidation (2021 nmol min(-1)) that was significantly higher than that of leucine (351 nmol min(-1)), supporting our prediction that nonessential amino acids are oxidized more rapidly than essential amino acids. Exogenous glucose and fructose were oxidized to a similar extent (5.9% of dose), but the time required to reach maximum rates of oxidation was longer for fructose. The maximum rates of oxidation were significantly higher when exogenous glucose was administered as an aqueous solution (122 nmol min(-1)), rather than as an oil suspension (93 nmol min(-1)), supporting our prediction that exogenous lipids negatively influence rates of exogenous glucose oxidation. Dietary fatty acids had the lowest maximum rates of oxidation (2-6 nmol min(-1)), and differed significantly in the extent to which each was oxidized, with 0.73%, 0.63% and 0.21% of palmitic, oleic and stearic acid tracers oxidized, respectively.

  18. On-line analysis of the (13)CO(2) labeling of leaf isoprene suggests multiple subcellular origins of isoprene precursors.

    PubMed

    Karl, T; Fall, R; Rosenstiel, T N; Prazeller, P; Larsen, B; Seufert, G; Lindinger, W

    2002-10-01

    Isoprene (2-methyl-1,3-butadiene) is the most abundant biogenic hydrocarbon released from vegetation, and there is continuing interest in understanding its biosynthesis from photosynthetic precursors in leaf chloroplasts. We used on-line proton-transfer-reaction mass spectrometry (PTR-MS) to observe the kinetics of (13)C-labeling of isoprene following exposure to (13)CO(2) and then the loss of (13)C after a return to normal (12)CO(2) in oak ( Quercus agrifolia Nee) and cottonwood (Populus deltoides Barr.) leaves. Assignments of labeled isoprene species were verified by gas chromatography-mass spectrometry. For the first time, it was possible to observe the half-lives of individually (13)C-labeled isoprene species during these transitions, and to trace some of the label to a C3 fragment that contained the two isoprene carbons derived from pyruvate via the deoxyxylulose-5-phosphate (DOXP) pathway. At steady state (under (13)CO(2)), approximately 80% of isoprene carbon was labeled, with fully labeled isoprene as the major species (approx. 60%). The source of the unlabeled C is suggested to be extrachloroplastic, but not from photorespiratory carbon. After a transfer to (12)CO(2), (13)C-labeling persisted in one isoprene carbon for several hours; this persistence was much more pronounced in (i) leaves inhibited by fosmidomycin, a specific inhibitor of the DOXP pathway, and (ii) in sun leaves which have higher ratios of soluble sugars to starch. From the mass 41-44 fragment data, and labeling predicted from the DOXP pathway in chloroplasts, precursors may arise from cytosolic pyruvate/phospho enolpyruvate equivalents transported into the chloroplast; this idea was supported by an indirect measure of pyruvate labeling. Other sources of cytosolic isoprene precursors (i.e. dimethylallyl diphosphate or pentose phosphate) could not be excluded. The data obtained shed light on the half-lives of photosynthetic metabolites, exchanges of carbon between cellular pools, and

  19. Comparing ∆Tmax Determination Approaches for Granier-Based Sapflow Estimations

    PubMed Central

    Rabbel, Inken; Diekkrüger, Bernd; Voigt, Holm; Neuwirth, Burkhard

    2016-01-01

    Granier-type thermal dissipation probes are common instruments for quantifying tree water use in forest hydrological studies. Estimating sapflow using Granier-type sapflow sensors requires determining the maximum temperature gradient (∆Tmax) between the heated probe and the reference probe below. ∆Tmax represents a state of zero sap flux, which was originally assumed to occur each night leading to a ∆Tmax determination on a daily basis. However, researchers have proven that, under certain conditions, sapflow may continue throughout the night. Therefore alternative approaches to determining ∆Tmax have been developed. Multiple ∆Tmax approaches are now in use; however, sapflow estimates remain imprecise because the empirical equation that transfers the raw temperature signal (∆T) to sap flux density (Fd) is strongly sensitive to ∆Tmax. In this study, we analyze the effects of different ∆Tmax determination approaches on sub-daily, daily and (intra-)seasonal Fd estimations. On this basis, we quantify the uncertainty of sapflow calculations, which is related to the raw signal processing. We show that the ∆Tmax determination procedure has a major influence on absolute ∆Tmax values and the respective sap flux density computations. Consequently, the choice of the ∆Tmax determination approach may be a significant source of uncertainty in sapflow estimations. PMID:27916949

  20. Evaluating the Community Land Model in a pine stand with shading manipulations and 13CO2 labeling

    DOE PAGES

    Mao, Jiafu; Ricciuto, Daniel M.; Thornton, Peter E.; ...

    2016-02-03

    Carbon partitioning and flow through ecosystems regulates land surface atmosphere CO2 exchange and thus is a key, albeit uncertain component of mechanistic models. The Partitioning in Trees and Soil (PiTS) experiment-model project tracked C partitioning through a young Pinus taeda stand following pulse-labeling with 13CO2 and two levels of shading. The field component of this project provided process-oriented data that was used to evaluate and improve terrestrial biosphere model simulations of rapid shifts in carbon partitioning and hydrological dynamics under varying environmental conditions. Here we tested the performance of the Community Land Model version 4 (CLM4) in capturing short-term carbonmore » and water dynamics in relation to manipulative shading treatments, and the timing and magnitude of carbon fluxes through various compartments of the ecosystem. To constrain CLM4 to closely simulate pretreatment conditions, we calibrated select model parameters with the pretreatment observational data. Compared to CLM4 simulations with default parameters, CLM4 with calibrated model parameters was better able to simulate pretreatment vegetation carbon pools, light response curves, and other initial states and fluxes of carbon and water. Over a 3-week treatment period, the calibrated CLM4 generally reproduced the impacts of shading on average soil moisture at 15-95 cm depth, transpiration, relative change in stem carbon, and soil CO2 efflux rate, although some discrepancies in the estimation of magnitudes and temporal evolutions existed. CLM4, however, was not able to track the progression of the 13CO2 label from the atmosphere through foliage, phloem, roots or surface soil CO2 efflux, even when optimized model parameters were used. This model bias arises, in part, from the lack of a short-term non-structural carbohydrate storage pool and progressive timing of within-plant transport, thus indicating a need for future work to improve the allocation routines in CLM4

  1. Evaluating the Community Land Model in a pine stand with 13CO2 labeling and shading manipulations

    NASA Astrophysics Data System (ADS)

    Mao, J.; Ricciuto, D. M.; Thornton, P. E.; Warren, J. M.; King, A. W.; Shi, X.; Iversen, C. M.; Norby, R. J.

    2015-05-01

    Carbon allocation and flow through ecosystems regulate land surface-atmosphere CO2 exchange and thus is a key, albeit uncertain, component of mechanistic models. The Partitioning in Trees and Soil (PiTS) experiment-model project tracked carbon allocation through a young Pinus taeda stand following pulse-labeling with 13CO2 and two levels of shading. The field component of this project provided process-oriented data that was used to evaluate and improve terrestrial biosphere model simulations of rapid shifts in carbon allocation and hydrological dynamics under varying environmental conditions. Here we tested the performance of the Community Land Model version 4 (CLM4) in capturing short-term carbon and water dynamics in relation to manipulative shading treatments, and the timing and magnitude of carbon fluxes through various compartments of the ecosystem. For CLM4 to closely simulate pretreatment conditions, we calibrated select model parameters with pretreatment observational data. Compared to CLM4 simulations with default parameters, CLM4 with calibrated model parameters was able to better simulate pretreatment vegetation carbon pools, light response curves, and other initial states and fluxes of carbon and water. Over a 3 week treatment period, the calibrated CLM4 generally reproduced the impacts of shading on average soil moisture at 15-95 cm depth, transpiration, relative change in stem carbon, and soil CO2 efflux rate, although some discrepancies in the estimation of magnitudes and temporal evolutions existed. CLM4, however, was not able to track the progression of the 13CO2 label from the atmosphere through foliage, phloem, roots or surface soil CO2 efflux, even when optimized model parameters were used. This model bias arises, in part, from the lack of a short-term non-structural carbohydrate storage pool and progressive timing of within-plant transport, thus indicating a need for future work to improve the allocation routines in CLM4. Overall, these types

  2. Unraveling carbohydrate transport mechanisms in young beech trees (Fagus sylvatica f. purpurea) by 13CO2 efflux measurements from stem and soil

    NASA Astrophysics Data System (ADS)

    Thoms, Ronny; Muhr, Jan; Keitel, Claudia; Kayler, Zachary; Gavrichkova, Olga; Köhler, Michael; Gessler, Arthur; Gleixner, Gerd

    2016-04-01

    Transport mechanisms of soluble carbohydrates and diurnal CO2 efflux from tree stems and surrounding soil are well studied. However, the effect of transport carbohydrates on respiration and their interaction with storage processes is largely unknown. Therefore, we performed a set of 13CO2 pulse labeling experiments on young trees of European beech (Fagus sylvatica f. purpurea). We labeled the whole tree crowns in a closed transparent plastic chamber with 99% 13CO2 for 30 min. In one experiment, only a single branch was labeled and removed 36 hours after labeling. In all experiments, we continuously measured the 13CO2 efflux from stem, branch and soil and sampled leaf and stem material every 3 h for 2 days, followed by a daily sampling of leaves in the successive 5 days. The compound specific δ 13C value of extracted soluble carbohydrates from leaf and stem material was measured by high-performance liquid chromatography linked with an isotope ratio mass spectrometer (HPLC-IRMS). The 13CO2 signal from soil respiration occurred only few hours after labeling indicating a very high transport rate of carbohydrates from leaf to roots and to the rhizosphere. The label was continuously depleted within the next 5 days. In contrast, we observed a remarkable oscillating pattern of 13CO2 efflux from the stem with maximum 13CO2 enrichment at noon and minima at night time. This oscillation suggests that enriched carbohydrates are respired during the day, whereas in the night the enriched sugars are not respired. The observed oscillation in stem 13CO2 enrichment remained unchanged even when only single branches were labelled and cut right afterwards. Thus, storage and conversion of carbohydrates only occurred within the stem. The δ13C patterns of extracted soluble carbohydrates showed, that a transformation of transitory starch to carbohydrates and vice versa was no driver of the oscillating 13CO2 efflux from the stem. Carbohydrates might have been transported in the phloem to

  3. 13C Tracking after 13CO2 Supply Revealed Diurnal Patterns of Wood Formation in Aspen1

    PubMed Central

    Mahboubi, Amir; Linden, Pernilla; Moritz, Thomas

    2015-01-01

    Wood of trees is formed from carbon assimilated in the photosynthetic tissues. Determining the temporal dynamics of carbon assimilation, subsequent transport into developing wood, and incorporation to cell walls would further our understanding of wood formation in particular and tree growth in general. To investigate these questions, we designed a 13CO2 labeling system to study carbon transport and incorporation to developing wood of hybrid aspen (Populus tremula × tremuloides). Tracking of 13C incorporation to wood over a time course using nuclear magnetic resonance spectroscopy revealed diurnal patterns in wood cell wall biosynthesis. The dark period had a differential effect on 13C incorporation to lignin and cell wall carbohydrates. No 13C was incorporated into aromatic amino acids of cell wall proteins in the dark, suggesting that cell wall protein biosynthesis ceased during the night. The results show previously unrecognized temporal patterns in wood cell wall biosynthesis, suggest diurnal cycle as a possible cue in the regulation of carbon incorporation to wood, and establish a unique 13C labeling method for the analysis of wood formation and secondary growth in trees. PMID:25931520

  4. Evaluating the Community Land Model in a pine stand with shading manipulations and 13CO2 labeling

    NASA Astrophysics Data System (ADS)

    Mao, J.; Ricciuto, D. M.; Thornton, P. E.; Warren, J. M.; King, A. W.; Shi, X.; Iversen, C. M.; Norby, R. J.

    2016-02-01

    Carbon allocation and flow through ecosystems regulates land surface-atmosphere CO2 exchange and thus is a key, albeit uncertain, component of mechanistic models. The Partitioning in Trees and Soil (PiTS) experiment-model project tracked carbon allocation through a young Pinus taeda stand following pulse labeling with 13CO2 and two levels of shading. The field component of this project provided process-oriented data that were used to evaluate terrestrial biosphere model simulations of rapid shifts in carbon allocation and hydrological dynamics under varying environmental conditions. Here we tested the performance of the Community Land Model version 4 (CLM4) in capturing short-term carbon and water dynamics in relation to manipulative shading treatments and the timing and magnitude of carbon fluxes through various compartments of the ecosystem. When calibrated with pretreatment observations, CLM4 was capable of closely simulating stand-level biomass, transpiration, leaf-level photosynthesis, and pre-labeling 13C values. Over the 3-week treatment period, CLM4 generally reproduced the impacts of shading on soil moisture changes, relative change in stem carbon, and soil CO2 efflux rate. Transpiration under moderate shading was also simulated well by the model, but even with optimization we were not able to simulate the high levels of transpiration observed in the heavy shading treatment, suggesting that the Ball-Berry conductance model is inadequate for these conditions. The calibrated version of CLM4 gave reasonable estimates of label concentration in phloem and in soil surface CO2 after 3 weeks of shade treatment, but it lacks the mechanisms needed to track the labeling pulse through plant tissues on shorter timescales. We developed a conceptual model for photosynthate transport based on the experimental observations, and we discussed conditions under which the hypothesized mechanisms could have an important influence on model behavior in larger-scale applications

  5. Multiscale observations of CO2, 13CO2, and pollutants at Four Corners for emission verification and attribution.

    PubMed

    Lindenmaier, Rodica; Dubey, Manvendra K; Henderson, Bradley G; Butterfield, Zachary T; Herman, Jay R; Rahn, Thom; Lee, Sang-Hyun

    2014-06-10

    There is a pressing need to verify air pollutant and greenhouse gas emissions from anthropogenic fossil energy sources to enforce current and future regulations. We demonstrate the feasibility of using simultaneous remote sensing observations of column abundances of CO2, CO, and NO2 to inform and verify emission inventories. We report, to our knowledge, the first ever simultaneous column enhancements in CO2 (3-10 ppm) and NO2 (1-3 Dobson Units), and evidence of δ(13)CO2 depletion in an urban region with two large coal-fired power plants with distinct scrubbing technologies that have resulted in ∆NOx/∆CO2 emission ratios that differ by a factor of two. Ground-based total atmospheric column trace gas abundances change synchronously and correlate well with simultaneous in situ point measurements during plume interceptions. Emission ratios of ∆NOx/∆CO2 and ∆SO2/∆CO2 derived from in situ atmospheric observations agree with those reported by in-stack monitors. Forward simulations using in-stack emissions agree with remote column CO2 and NO2 plume observations after fine scale adjustments. Both observed and simulated column ∆NO2/∆CO2 ratios indicate that a large fraction (70-75%) of the region is polluted. We demonstrate that the column emission ratios of ∆NO2/∆CO2 can resolve changes from day-to-day variation in sources with distinct emission factors (clean and dirty power plants, urban, and fires). We apportion these sources by using NO2, SO2, and CO as signatures. Our high-frequency remote sensing observations of CO2 and coemitted pollutants offer promise for the verification of power plant emission factors and abatement technologies from ground and space.

  6. Precise measurements of the total concentration of atmospheric CO2 and 13CO2/12CO2 isotopic ratio using a lead-salt laser diode spectrometer.

    PubMed

    Croizé, Laurence; Mondelain, Didier; Camy-Peyret, Claude; Delmotte, Marc; Schmidt, Martina

    2008-04-01

    We have developed a tunable diode laser spectrometer, called SIMCO (spectrometer for isotopic measurements of CO(2)), for determining the concentrations of (12)CO(2) and (13)CO(2) in atmospheric air, from which the total concentration of CO(2) and the isotopic composition (expressed in delta units) delta(13)CO(2) are calculated. The two concentrations are measured using a pair of lines around 2290.1 cm(-1), by fitting a line profile model, taking into account the confinement narrowing effect to achieve a better accuracy. Using the Allan variance, we have demonstrated (for an integration time of 25 s) a precision of 0.1 ppmv for the total CO(2) concentration and of 0.3[per thousand] for delta(13)CO(2). The performances on atmospheric air have been tested during a 3 days campaign by comparing the SIMCO instrument with a gas chromatograph (GC) for the measurement of the total CO(2) concentration and with an isotopic ratio mass spectrometer (MS) for the isotopic composition. The CO(2) concentration measurements of SIMCO are in very good agreement with the GC data with a mean difference of Delta(CO(2))=0.16+/-1.20 ppmv for a comparison period of 45 h and the linearity of the concentration between the two instruments is also very good (slope of correlation: 0.9996+/-0.0003) over the range between 380 and 415 ppmv. For delta(13)CO(2), the comparison with the MS data shows a larger mean difference of Delta(delta(13)CO(2))=(-1.9+/-1.2)[per thousand], which could be partly related to small residual fluctuations of the overall SIMCO instrument response.

  7. Partitioning net ecosystem carbon exchange into net assimilation and respiration using 13CO2 measurements: A cost-effective sampling strategy

    NASA Astrophysics Data System (ADS)

    OgéE, J.; Peylin, P.; Ciais, P.; Bariac, T.; Brunet, Y.; Berbigier, P.; Roche, C.; Richard, P.; Bardoux, G.; Bonnefond, J.-M.

    2003-06-01

    The current emphasis on global climate studies has led the scientific community to set up a number of sites for measuring the long-term biosphere-atmosphere net CO2 exchange (net ecosystem exchange, NEE). Partitioning this flux into its elementary components, net assimilation (FA), and respiration (FR), remains necessary in order to get a better understanding of biosphere functioning and design better surface exchange models. Noting that FR and FA have different isotopic signatures, we evaluate the potential of isotopic 13CO2 measurements in the air (combined with CO2 flux and concentration measurements) to partition NEE into FR and FA on a routine basis. The study is conducted at a temperate coniferous forest where intensive isotopic measurements in air, soil, and biomass were performed in summer 1997. The multilayer soil-vegetation-atmosphere transfer model MuSICA is adapted to compute 13CO2 flux and concentration profiles. Using MuSICA as a "perfect" simulator and taking advantage of the very dense spatiotemporal resolution of the isotopic data set (341 flasks over a 24-hour period) enable us to test each hypothesis and estimate the performance of the method. The partitioning works better in midafternoon when isotopic disequilibrium is strong. With only 15 flasks, i.e., two 13CO2 nighttime profiles (to estimate the isotopic signature of FR) and five daytime measurements (to perform the partitioning) we get mean daily estimates of FR and FA that agree with the model within 15-20%. However, knowledge of the mesophyll conductance seems crucial and may be a limitation to the method.

  8. A new automatic chamber system for measuring soil surface CO2 and its isotopic (13CO2) effluxes in New Jersey Pinelands

    NASA Astrophysics Data System (ADS)

    Xu, M.

    2006-05-01

    A new automatic chamber system was developed to measure soil surface CO2 efflux with 16 pairs of chambers at hourly interval in an oak forest in New Jersey Pinelands. The trench method was applied to separate root respiration from the total soil respiration. I found that soil temperature and moisture alternatively control root and soil heterotrophic respiration in different seasons based on the data collected in about 3 years. The isotopic flux of soil 13CO2 was also measured at hourly interval using the chamber system with a new laser-based stable carbon isotope analyzer.

  9. Biogenic volatile organic compounds (BVOCs) emission of Scots pine under drought stress - a 13CO2 labeling study to determine de novo and pool emissions under different treatments

    NASA Astrophysics Data System (ADS)

    Lüpke, M.

    2015-12-01

    Plants emit biogenic volatile organic compounds (BVOCs) to e.g. communicate and to defend herbivores. Yet BVOCs also impact atmospheric chemistry processes, and lead to e.g. the built up of secondary organic aerosols. Abiotic stresses, such as drought, however highly influence plant physiology and subsequently BVOCs emission rates. In this study, we investigated the effect of drought stress on BVOCs emission rates of Scots pine trees, a de novo and pool emitter, under controlled climate chamber conditions within a dynamic enclosure system consisting of four plant chambers. Isotopic labeling with 13CO2 was used to detect which ratio of emissions of BVOCs derives from actual synthesis and from storage organs under different treatments. Additionally, the synthesis rate of the BVOCs synthesis can be determined. The experiment consisted of two campaigns (July 2015 and August 2015) of two control and two treated trees respectively in four controlled dynamic chambers simultaneously. Each campaign lasted for around 21 days and can be split into five phases: adaptation, control, dry-out, drought- and re-watering phase. The actual drought phase lasted around five days. During the campaigns two samples of BVOCs emissions were sampled per day and night on thermal desorption tubes and analyzed by a gas chromatograph coupled with a mass spectrometer and a flame ionization detector. Additionally, gas exchange of water and CO2, soil moisture, as well as leaf and chamber temperature was monitored continuously. 13CO2 labeling was performed simultaneously in all chambers during the phases control, drought and re-watering for five hours respectively. During the 13CO2 labeling four BVOCs emission samples per chamber were taken to identify the labeling rate on emitted BVOCs. First results show a decrease of BVOCs emissions during the drought phase and a recovery of emission after re-watering, as well as different strength of reduction of single compounds. The degree of labeling with 13

  10. Carbon transfer, partitioning and residence time in the plant-soil system: a comparison of two 13CO2 labelling techniques

    NASA Astrophysics Data System (ADS)

    Studer, M. S.; Siegwolf, R. T. W.; Abiven, S.

    2014-03-01

    Various 13CO2 labelling approaches exist to trace carbon (C) dynamics in plant-soil systems. However, it is not clear if the different approaches yield the same results. Moreover, there is no consistent way of data analysis to date. In this study we compare with the same experimental setup the two main techniques: pulse and continuous labelling. We evaluate how these techniques perform to estimate the C transfer time, the C partitioning along time and the C residence time in different plant-soil compartments. We used identical plant-soil systems (Populus deltoides × nigra, Cambisol soil) to compare the pulse labelling approach (exposure to 99 atom % 13CO2 for three hours, traced for eight days) with a continuous labelling (exposure to 10 atom % 13CO2, traced for 14 days). The experiments were conducted in climate chambers under controlled environmental conditions. Before label addition and at four successive sampling dates, the plant-soil systems were destructively harvested, separated into leaves, petioles, stems, cuttings, roots and soil and soil microbial biomass was extracted. The soil CO2 efflux was sampled throughout the experiment. To model the C dynamics we used an exponential function to describe the 13C signal decline after pulse labelling. For the evaluation of the 13C distribution during the continuous labelling we applied a logistic function. Pulse labelling is best suited to assess the minimum C transfer time from the leaves to other compartments, while continuous labelling can be used to estimate the mean transfer time through a compartment, including short-term storage pools. The C partitioning between the plant-soil compartments obtained was similar for both techniques, but the time of sampling had a large effect: shortly after labelling the allocation into leaves was overestimated and the soil 13CO2 efflux underestimated. The results of belowground C partitioning were consistent for the two techniques only after eight days of labelling, when the

  11. Carbon transfer, partitioning and residence time in the plant-soil system: a comparison of two 13CO2 labelling techniques

    NASA Astrophysics Data System (ADS)

    Studer, M. S.; Siegwolf, R. T. W.; Abiven, S.

    2013-10-01

    Various 13CO2 labelling approaches exist to trace carbon (C) dynamics in plant-soil systems. However, it is not clear if the different approaches yield the same results. Moreover, there is no consistent way of data analysis to date. In this study we compare with the same experimental setup the two main techniques: the pulse and the continuous labelling. We evaluate how these techniques perform to estimate the C transfer velocity, the C partitioning along time and the C residence time in different plant-soil compartments. We used identical plant-soil systems (Populus deltoides x nigra, Cambisol soil) to compare the pulse labelling approach (exposure to 99 atom% 13CO2 for three hours, traced for eight days) with a continuous labelling (exposure to 10 atom% 13CO2, traced for 14 days). The experiments were conducted in climate chambers under controlled environmental conditions. Before label addition and at four successive sampling dates, the plant-soil systems were destructively harvested, separated into leaves, petioles, stems, cuttings, roots and soil and the microbial biomass was extracted from the soil. The soil CO2 efflux was sampled throughout the experiment. To model the C dynamics we used an exponential function to describe the 13C signal decline after pulse labelling. For the evaluation of the 13C distribution during the continuous labelling we suggest to use a logistic function. Pulse labelling is best suited to assess the maximum C transfer velocity from the leaves to other compartments. With continuous labelling, the mean transfer velocity through a compartment, including short-term storage pools, can be observed. The C partitioning between the plant-soil compartments was similar for both techniques, but the time of sampling had a large effect: shortly after labelling the allocation into leaves was overestimated and the soil 13CO2 efflux underestimated. The results of belowground C partitioning were consistent for the two techniques only after eight days of

  12. Effects of waterlogging on carbon assimilate partitioning in the Zoigê alpine wetlands revealed by 13CO2 pulse labeling.

    PubMed

    Gao, Jun-Qin; Gao, Ju-Juan; Zhang, Xue-Wen; Xu, Xing-Liang; Deng, Zhao-Heng; Yu, Fei-Hai

    2015-03-23

    Waterlogging has been suggested to affect carbon (C) turnover in wetlands, but how it affects C allocation and stocks remains unclear in alpine wetlands. Using in situ (13)CO2 pulse labelling, we investigated C allocation in both waterlogged and non-waterlogged sites in the Zoigê wetlands on the Tibetan Plateau in August 2011. More than 50% of total (13)C fixed by photosynthesis was lost via shoot respiration. Shoots recovered about 19% of total (13)C fixed by photosynthesis at both sites. Only about 26% of total fixed (13)C was translocated into the belowground pools. Soil organic C pool accounted for 19% and roots recovered about 5-7% of total fixed (13)C at both sites. Waterlogging significantly reduced soil respiration and very little (13)C was lost via soil respiration in the alpine wetlands compared to that in grasslands. We conclude that waterlogging did not significantly alter C allocations among the C pools except the (13)CO2 efflux derived from soil respiration and that shoots made similar contributions to C sequestration as the belowground parts in the Zoigê alpine wetlands. Therefore, changes in waterlogging due to climate change will not affect C assimilate partitioning but soil C efflux.

  13. 13CO2/12CO2 ratio analysis in exhaled air by lead-salt tunable diode lasers for noninvasive diagnostics in gastroenterology

    NASA Astrophysics Data System (ADS)

    Stepanov, Eugene V.; Zyrianov, Pavel V.; Miliaev, Valerii A.; Selivanov, Yurii G.; Chizhevskii, Eugene G.; Os'kina, Svetlana; Ivashkin, Vladimir T.; Nikitina, Elena I.

    1999-07-01

    An analyzer of 13CO2/12CO2 ratio in exhaled air based on lead-salt tunable diode lasers is presented. High accuracy of the carbon isotope ratio detection in exhaled carbon dioxide was achieved with help of very simple optical schematics. It was based on the use of MBE laser diodes operating in pulse mode and on recording the resonance CO2 absorption at 4.2 micrometers . Special fast acquisition electronics and software were applied for spectral data collection and processing. Developed laser system was tested in a clinical train aimed to assessment eradication efficiency in therapy of gastritis associated with Helicobacter pylori infection. Data on the 13C-urea breath test used for P.pylori detection and obtained with tunable diode lasers in the course of the trail was compared with the results of Mass-Spectroscopy analysis and histology observations. The analyzer can be used also for 13CO2/12CO2 ratio detection in exhalation to perform gastroenterology breath test based on using other compounds labeled with stable isotopes.

  14. Riverine GHG emissions: one year of CO2, 13CO2 and CH4 flux measurements on Vistula river in Krakow, southern Poland

    NASA Astrophysics Data System (ADS)

    Jasek, Alina; Wachniew, Przemyslaw; Zimnoch, Miroslaw

    2013-04-01

    Terrestrial surface waters are generally considered to be sources of carbon dioxide and methane, because respiration of organic matter via aerobic and anaerobic pathways causes supersaturation of surface waters with respect to CO2 and CH4, respectively. In rivers, these processes are influenced by such anthropogenic factors as changes of land-use, wastewater and alteration of river channels. The research object is Vistula, the largest Polish river. It has the length of 1047 km and annual runoff of 6.2x1010m3. The urban section of Vistula in Krakow receives large amounts of organic matter from highly urbanized catchment and point discharges of urban waste waters within the city limits. The river was sampled regularly at three points: the entrance to the city, the center and the point where Vistula leaves the agglomeration. A floating chamber coupled with Picarro G2101-i analyzer was applied to quantify CO2, 13CO2 and CH4 fluxes leaving the surface of the river. A floating chamber was equipped with sensors to measure air pressure, temperature and humidity inside the chamber and the temperature of water. The chamber was equipped with a set of floats and an anchor. The measurements started in October 2011, and were repeated with approximately monthly frequency. Physicochemical properties of water (temperature, conductivity, pH, CO2 partial pressure over the water surface and alkalinity) were also measured during each measurement campaign. In addition, at each site short-term variability of the measured fluxes was also investigated. Additionally, short-term variability of the measured fluxes of CO2, 13CO2 and CH4 were performed in all three sites. The results indicate that fluxes of CO2 released from the river are comparable with the soil emissions of this gas measured in Krakow area. The δ13CO2 signature of riverine CO2 flux allowed to identify decomposition of C3 organic matter as the major source of this gas. No distinct seasonal variability of the CO2 emission and

  15. Seasonal variations of the amount of carbon allocated to respiration after in situ 13CO2 pulse labelling of trees (Invited)

    NASA Astrophysics Data System (ADS)

    Epron, D.; Dannoura, M.; Ngao, J.; Plain, C.; Berveller, D.; Chipeaux, C.; Gerant, D.; Bosc, A.; Maillard, P.; Loustau, D.; Damesin, C.; Cats Project (Anr-07-Blan-0109)

    2010-12-01

    Soil and trunk respiration are the major sources of carbon from forest ecosystems to the atmosphere and they account for a large fraction of total ecosystem respiration. The amount of photosynthate allocated to respiration affects the growth of the tree and the potential for carbon sequestration of forest ecosystems. This study, aiming at understanding patterns of carbon allocation to respiration among species and seasons, consisted in pure 13CO2 labelling of the entire crown of three different tree species (beech, oak and pine) at distinct phenological stages between Sept 2008 and Feb 2010. 13C was then tracked for several weeks in soil and trunk CO2 efflux at high temporal resolution using tuneable diode laser absorption spectrometry (Plain et al. 2009). Recovery of 13C in trunk and soil CO2 efflux was observed a few couple of hours after the beginning of the labelling in oak and beech. There is a rapid transfer of 13C belowground with a maximum occurring within 2 to 4 days after labelling. Label was recovered at the same time in the respiration and in the biomass of both fine roots and microbes. Maximum recovery occurred earlier in beech and oak, while it happened later in Pine. Indeed, the velocity of phloem transport, calculated as the difference of time lags in 13C recovery in trunk respiration at different height, was around 0.10-0.2m/h in pine and around 0.2-1.2 m/h in oak and beech, reflecting difference in phloem anatomy between angiosperm and gymnosperm. The cumulated amount of label recovered in soil CO2 efflux 20 days after labelling varied among the seasons in all species, from 1 to 16% in beech, 2 to 11% in oak and 1 to 11% in pine. For all species, allocation to soil respiration was greater in early summer compared to spring, late summer and autumn. A compartmental analysis is further conducted to characterise functional pools of labelled substrates and storage compounds that contribute to both trunk and soil respiration. [Plain C, Gérant D

  16. 13CO2/12CO2 isotope ratio analysis in human breath using a 2 μm diode laser

    NASA Astrophysics Data System (ADS)

    Sun, Mingguo; Cao, Zhensong; Liu, Kun; Wang, Guishi; Tan, Tu; Gao, Xiaoming; Chen, Weidong; Yinbo, Huang; Ruizhong, Rao

    2015-04-01

    The bacterium H. pylori is believed to cause peptic ulcer. H. pylori infection in the human stomach can be diagnosed through a CO2 isotope ratio measure in exhaled breath. A laser spectrometer based on a distributed-feedback semiconductor diode laser at 2 μm is developed to measure the changes of 13CO2/12CO2 isotope ratio in exhaled breath sample with the CO2 concentration of ~4%. It is characterized by a simplified optical layout, in which a single detector and associated electronics are used to probe CO2 spectrum. A new type multi-passes cell with 12 cm long base length , 29 m optical path length in total and 280 cm3 volume is used in this work. The temperature and pressure are well controlled at 301.15 K and 6.66 kPa with fluctuation amplitude of 25 mK and 6.7 Pa, respectively. The best 13δ precision of 0.06o was achieved by using wavelet denoising and Kalman filter. The application of denoising and Kalman filter not only improved the signal to noise ratio, but also shorten the system response time.

  17. IRAM 30 m Large Scale Survey of 12CO(2-1) and 13CO(2-1) Emission in the Orion Molecular Cloud

    NASA Astrophysics Data System (ADS)

    Berné, O.; Marcelino, N.; Cernicharo, J.

    2014-11-01

    Using the IRAM 30 m telescope, we have surveyed a 1 × 0.°8 part of the Orion molecular cloud in the 12CO and 13CO (2-1) lines with a maximal spatial resolution of ~11'' and spectral resolution of ~0.4 km s-1. The cloud appears filamentary, clumpy, and with a complex kinematical structure. We derive an estimated mass of the cloud of 7700 M ⊙ (half of which is found in regions with visual extinctions AV below ~10) and a dynamical age for the nebula of the order of 0.2 Myr. The energy balance suggests that magnetic fields play an important role in supporting the cloud, at large and small scales. According to our analysis, the turbulent kinetic energy in the molecular gas due to outflows is comparable to turbulent kinetic energy resulting from the interaction of the cloud with the H II region. This latter feedback appears negative, i.e., the triggering of star formation by the H II region is inefficient in Orion. The reduced data as well as additional products such as the column density map are made available online (http://userpages.irap.omp.eu/~oberne/Olivier_Berne/Data).

  18. CO, NOx and 13CO2 as tracers for fossil fuel CO2: results from a pilot study in Paris during winter 2010

    NASA Astrophysics Data System (ADS)

    Lopez, M.; Schmidt, M.; Delmotte, M.; Colomb, A.; Gros, V.; Janssen, C.; Lehman, S. J.; Mondelain, D.; Perrussel, O.; Ramonet, M.; Xueref-Remy, I.; Bousquet, P.

    2013-08-01

    Measurements of the mole fraction of the CO2 and its isotopes were performed in Paris during the MEGAPOLI winter campaign (January-February 2010). Radiocarbon (14CO2) measurements were used to identify the relative contributions of 77% CO2 from fossil fuel consumption (CO2ff from liquid and gas combustion) and 23% from biospheric CO2 (CO2 from the use of biofuels and from human and plant respiration: CO2bio). These percentages correspond to average mole fractions of 26.4 ppm and 8.2 ppm for CO2ff and CO2bio, respectively. The 13CO2 analysis indicated that gas and liquid fuel contributed 70% and 30%, respectively, of the CO2 emission from fossil fuel use. Continuous measurements of CO and NOx and the ratios CO/CO2ff and NOx/CO2ff derived from radiocarbon measurements during four days make it possible to estimate the fossil fuel CO2 contribution over the entire campaign. The ratios CO/CO2ff and NOx/CO2ff are functions of air mass origin and exhibited daily ranges of 7.9 to 14.5 ppb ppm-1 and 1.1 to 4.3 ppb ppm-1, respectively. These ratios are consistent with different emission inventories given the uncertainties of the different approaches. By using both tracers to derive the fossil fuel CO2, we observed similar diurnal cycles with two maxima during rush hour traffic.

  19. Production of hyperpolarized 13CO2 from [1-13C]pyruvate in perfused liver does reflect total anaplerosis but is not a reliable biomarker of glucose production

    PubMed Central

    Moreno, Karlos X.; Moore, Christopher L.; Burgess, Shawn C.; Sherry, A. Dean; Malloy, Craig R.

    2015-01-01

    In liver, 13CO2 can be generated from [1-13C] pyruvate via pyruvate dehydrogenase or anaplerotic entry of pyruvate into the TCA cycle followed by decarboxylation at phosphoenolpyruvate carboxykinase (PEPCK), the malic enzyme, isocitrate dehydrogenase, or α-ketoglutarate dehydrogenase. The purpose of this study was to determine the relative importance of these pathways in production of hyperpolarized (HP) 13CO2 after administration of hyper-polarized pyruvate in livers supplied with a fatty acid plus substrates for gluconeogenesis. Isolated mouse livers were perfused with a mixture of thermally-polarized 13C-enriched pyruvate, lactate and octanoate in various combinations prior to exposure to HP pyruvate. Under all perfusion conditions, HP malate, aspartate and fumarate were detected within ~ 3 s showing that HP [1-13C]pyruvate is rapidly converted to [1-13C]oxaloacetate which can subsequently produce HP 13CO2 via decarboxylation at PEPCK. Measurements using HP [2-13C]pyruvate allowed the exclusion of reactions related to TCA cycle turnover as sources of HP 13CO2. Direct measures of O2 consumption, ketone production, and glucose production by the intact liver combined with 13C isotopomer analyses of tissue extracts yielded a comprehensive profile of metabolic flux in perfused liver. Together, these data show that, even though the majority of HP 13CO2 derived from HP [1-13C]pyruvate in livers exposed to fatty acids reflects decarboxylation of [4-13C]oxaloacetate (PEPCK) or [4-13C]malate (malic enzyme), the intensity of the HP 13CO2 signal is not proportional to glucose production because the amount of pyruvate returned to the TCA cycle via PEPCK and pyruvate kinase is variable, depending upon available substrates. PMID:26543443

  20. Carbon Allocation of 13CO2-labeled Photoassimilate in Larix gmelinii Saplings - A Physiological Basis for Isotope Dendroclimatology in Eastern Siberia.

    NASA Astrophysics Data System (ADS)

    Kagawa, A.; Sugimoto, A.; Maximov, T. C.

    2006-12-01

    Tree-ring density and widths have been successfully used to reconstruct summer temperatures in high- northern latitudes, although a discrepancy between tree-growth and temperature has been found for recent decades. The so-called "reduced sensitivity" of tree rings to summer temperatures has been observed especially strongly in northern Siberia (Briffa et al., 1998) and drought stress (increased water use efficiency) arose from global warming and/or increasing CO2 are suggested as causes (Barber et al. 2000, Saurer et al. 2004). By using carbon isotope ratio as an indicator of drought stress and ring-width/density as indicators of growth, we can clarify how drought stress caused by recent global warming affects wood formation of Siberian trees. However, isotope dendroclimatology is still in its infancy and our understanding of basic physiological processes of isotope signal transfer from leaves to tree rings is insufficient. In order to understand translocation, storage, and allocation of photoassimilate to different organs of trees, we pulse- labeled ten L. gmelinii growing in a continuous permafrost zone with stable 13CO2. We studied seasonal course of carbon allocation patterns of photoassimilate among needles, branches, stem and roots and also how spring, summer, and autumn photoassimilate is later used for both earlywood and latewood formation. About half of the carbon in new needles was derived from stored material. The starch pool in non- needle parts, which can be used for xylem formation, drew about 43 percent of its carbon from previous year's photoassimilate, suggesting that carbon storage is the key mechanism behind autocorrelation in (isotope) dendroclimatology. Analysis of intra-annual 13C of the tree rings formed after the labeling revealed that earlywood contained photoassimilate from the previous summer and autumn as well as from the current spring. Latewood was mainly composed of photoassimilate from the current year's summer/autumn, although it

  1. Quantifying protein synthesis and degradation in Arabidopsis by dynamic 13CO2 labeling and analysis of enrichment in individual amino acids in their free pools and in protein.

    PubMed

    Ishihara, Hirofumi; Obata, Toshihiro; Sulpice, Ronan; Fernie, Alisdair R; Stitt, Mark

    2015-05-01

    Protein synthesis and degradation represent substantial costs during plant growth. To obtain a quantitative measure of the rate of protein synthesis and degradation, we supplied (13)CO2 to intact Arabidopsis (Arabidopsis thaliana) Columbia-0 plants and analyzed enrichment in free amino acids and in amino acid residues in protein during a 24-h pulse and 4-d chase. While many free amino acids labeled slowly and incompletely, alanine showed a rapid rise in enrichment in the pulse and a decrease in the chase. Enrichment in free alanine was used to correct enrichment in alanine residues in protein and calculate the rate of protein synthesis. The latter was compared with the relative growth rate to estimate the rate of protein degradation. The relative growth rate was estimated from sequential determination of fresh weight, sequential images of rosette area, and labeling of glucose in the cell wall. In an 8-h photoperiod, protein synthesis and cell wall synthesis were 3-fold faster in the day than at night, protein degradation was slow (3%-4% d(-1)), and flux to growth and degradation resulted in a protein half-life of 3.5 d. In the starchless phosphoglucomutase mutant at night, protein synthesis was further decreased and protein degradation increased, while cell wall synthesis was totally inhibited, quantitatively accounting for the inhibition of growth in this mutant. We also investigated the rates of protein synthesis and degradation during leaf development, during growth at high temperature, and compared synthesis rates of Rubisco large and small subunits of in the light and dark.

  2. Short-term Fate of Carbon in two Woody Species Under Contrasting Resources Availability: Insights From a 13CO2 Pulse Labeling Approach

    NASA Astrophysics Data System (ADS)

    Mambelli, S.; Dawson, T. E.; Bird, J. A.; Torn, M. S.; Gaudinski, J. B.

    2003-12-01

    In response to the environment, plants adjust allocation patterns to maintain a functional balance between the activities of roots and shoots such that belowground resources are acquired in approximate balance with aboveground resources. Changes in allocation driven by changes in environmental conditions may affect the amount of carbon stored in plant tissues, released by the root system, and ultimately sequestered into the soil. The aim of this study was to quantify the allocation belowground of recently fixed carbon in contrasting species and resources availability. We tested the hypothesis that carbon limitation and high nitrogen supply both negatively affect carbon transport to roots, causing a reduction of the carbon flow into the soil rhizosphere. Two woody species, a conifer (Pinus Ponderosa) and a deciduous tree (Acer Rubrum) were grown in a greenhouse under a factorial of light and nitrogen regimes (full light/shade and limited/excess nitrogen). At the stage of full leaf expansion plants were pulse-labeled by addition of 13CO2 and harvested after 0, 7 and 30 days. During the experiment the treatments affected the pattern of plant biomass allocation. Shade negatively influenced belowground growth and Maple showed a more conservative response than Pine. High supply of nitrogen also reduced allocation to roots but only when plants were grown under light. Preliminary results show that the initial amount of recently fixed carbon into the rhizosphere was in general higher under Pine. However, after 7 and 30 days, the new soil carbon pool increased only in the rhizosphere of carbon limited Pine seedlings. These findings suggest that belowground respiration was negatively affected or, alternatively, that the exudates released were less easily decomposable

  3. Measuring and modelling the intra-day variability of the 13CO2 & 12CO2 vertical soil profile production in a Scots pine forest

    NASA Astrophysics Data System (ADS)

    Longdoz, Bernard; Goffin, Stéphanie; Parent, Florian; Plain, Caroline; Epron, Daniel; Wylock, Christophe; Haut, Benoit; Aubinet, Marc; Maier, Martin

    2015-04-01

    Vertical profile of CO2 production (Ps) and transport, as well as their isotopic discrimination (13CO2/12CO2) should be considered to improve the soil CO2 efflux (Fs) mechanistic understanding and especially its short-term temporal variations. In this context, we propose a new methodology able to measure continuously and simultaneously Fs, the vertical soil CO2 concentration ([CO2]) profile and their respective isotopic signature (δFs and δCO2) [1]. The Ps of the different soil layers and their isotopic signature (δPs) can then be determined from these measurements by an approach considering diffusion as the only gas transport. A field campaign was conducted with this device at the Scots Pine Hartheim forest (Germany). The results [2] show (i) a Ps dependence on local temperature specific for each layer, (ii) an enrichment of δPs with soil drought, (iii) Fs and [CO2] large intra-day fluctuations non explained by the soil temperature and moisture. These fluctuations can be generated by other processes creating Ps and/or transport variability. To investigate about the nature of these processes, some sensitivity analyses have been performed with a soil CO2 model simulating both production and transport. The impacts of the introduction of advection, dispersion and phloem pressure concentration wave (through dependence of Ps on vapour pressure deficit) on intra-day Fs and [CO2] variations have been quantified. We conclude that these variations are significantly better represented when the phloem pressure wave expression is included in the simulations. The study of the processes related to CO2 production seems to be a better option than an investigation about transport to explain the intra-day Fs variability.

  4. Effects of season and nitrogen supply on the partitioning of recently fixed carbon in understory vegetation using a 13CO2 pulse labeling technique

    NASA Astrophysics Data System (ADS)

    Hasselquist, Niles; Metcalfe, Daniel; Högberg, Peter

    2013-04-01

    Vegetation research in boreal forests has traditionally been focused on trees, with little attention given to understory vegetation. However, understory vegetation has been identified as a key driver for the functioning of boreal forests and may play an important role in the amount of carbon (C) that is entering and leaving these forested ecosystems. We conducted a large-scale 13C pulse labeling experiment to better understand how recently fixed C is allocated in the understory vegetation characteristic of boreal forests. We used transparent plastic chambers to pulse label the understory vegetation with enriched 13CO2 in the early (June) and late (August) growing seasons. This study was also replicated across a nitrogen (N) fertilization treatment to better understand the effects of N availability on C allocation patterns. We present data on the amount of 13C label found in different components of the understory vegetation (i.e. leaves, stems, lichens, mosses, rhizomes and fine roots) as well as CO2 efflux. Additionally, we provide estimates of C residence time (MRT) among the different components and examine how MRT of C is affected by seasonality and N availability. Seasonality had a large effect on how recently fixed C is allocated in understory vegetation, whereas N fertilization influenced the MRT of C in the different components of ericaceous vegetation. Moreover, there was a general trend that N additions increased the amount of 13C in CO2 efflux compared to the amount of 13C in biomass, suggesting that N fertilization may lead to an increase in the utilization of recently fixed C, whereas N-limitation promotes the storage of recently fixed C.

  5. Comparison of TTP and Tmax estimation techniques in perfusion-weighted MR datasets for tissue-at-risk definition

    NASA Astrophysics Data System (ADS)

    Forkert, Nils Daniel; Kaesemann, Philipp; Fiehler, Jens; Thomalla, Götz

    2012-03-01

    Acute stroke is a major cause for death and disability among adults in the western hemisphere. Time-resolved perfusion-weighted (PWI) and diffusion-weighted (DWI) MR datasets are typically used for the estimation of tissue-at-risk, which is an important variable for acute stroke therapy decision-making. Although several parameters, which can be estimated based on PWI concentration curves, have been proposed for tissue-at-risk definition in the past, the time-to-peak (TTP) or time-to-max (Tmax) parameter is used most frequently in recent trials. Unfortunately, there is no clear consensus which method should be used for estimation of Tmax or TTP maps. Consequently, tissue-at-risk estimations and following treatment decision might vary considerably with the method used. In this work, 5 PWI datasets of acute stroke patients were used to calculate TTP or Tmax maps using 10 different estimation techniques. The resulting maps were segmented using a typical threshold of +4s and the corresponding PWI-lesions were calculated. The first results suggest that the TTP or Tmax method used has a major impact on the resulting tissue-at-risk volume. Numerically, the calculated volumes differed up to a factor of 3. In general, the deconvolution-based Tmax techniques estimate the ischemic penumbra rather smaller compared to direct TTP based techniques. In conclusion, the comparison of different methods for TTP or Tmax estimation revealed high variations regarding the resulting tissue-at-risk volume, which might lead to different therapy decisions. Therefore, a consensus how TTP or Tmax maps should be calculated seems necessary.

  6. The global carbon cycle over the last millennium: implications of the latest Law Dome and South Pole firn and ice core records of CO2 and δ13CO2

    NASA Astrophysics Data System (ADS)

    Trudinger, C. M.; Rubino, M.; Etheridge, D. M.; Raupach, M. R.; Harman, I. N.

    2012-12-01

    The Law Dome δ 13CO2 ice core record has recently been revised and merged with new firn and ice core measurements. Here we present calculations with a globally-aggregated carbon cycle model looking at both natural variability and the industrial perturbation in CO2 and δ 13CO2. We investigate the use of observations of CO2, {}13CO2 and {}14CO2 to calibrate the Simple Carbon-Climate Model (SCCM), including the implications of the slightly lower preindustrial δ 13C levels in the latest record. We also present a Kalman filter double deconvolution that uses CO2 and δ 13CO2 measurements to infer net fluxes of CO2 between the atmosphere, land and oceans, focussing on decadal variability over the industrial period and century-scale variations back to 1000 AD. We will compare the results of the double deconvolution with calculations of SCCM forced with temperature variations to improve our understanding of the sensitivity of land and ocean carbon fluxes to climate on different timescales.

  7. The effect of physical back-diffusion of 13CO2 tracer on the coupling between photosynthesis and soil CO2 efflux in grassland.

    PubMed

    Burri, Susanne; Sturm, Patrick; Baur, Thomas; Barthel, Matti; Knohl, Alexander; Buchmann, Nina

    2014-01-01

    Pulse labelling experiments provide a common tool to study short-term processes in the plant-soil system and investigate below-ground carbon allocation as well as the coupling of soil CO(2) efflux to photosynthesis. During the first hours after pulse labelling, the measured isotopic signal of soil CO(2) efflux is a combination of both physical tracer diffusion into and out of the soil as well as biological tracer release via root and microbial respiration. Neglecting physical back-diffusion can lead to misinterpretation regarding time lags between photosynthesis and soil CO(2) efflux in grassland or any ecosystem type where the above-ground plant parts cannot be labelled in gas-tight chambers separated from the soil. We studied the effects of physical (13)CO(2) tracer back-diffusion in pulse labelling experiments in grassland, focusing on the isotopic signature of soil CO(2) efflux. Having accounted for back-diffusion, the estimated time lag for first tracer appearance in soil CO(2) efflux changed from 0 to 1.81±0.56 h (mean±SD) and the time lag for maximum tracer appearance from 2.67±0.39 to 9.63±3.32 h (mean±SD). Thus, time lags were considerably longer when physical tracer diffusion was considered. Using these time lags after accounting for physical back-diffusion, high nocturnal soil CO(2) efflux rates could be related to daytime rates of gross primary productivity (R(2)=0.84). Moreover, pronounced diurnal patterns in the δ(13)C of soil CO(2) efflux were found during the decline of the tracer over 3 weeks. Possible mechanisms include diurnal changes in the relative contributions of autotrophic and heterotrophic soil respiration as well as their respective δ(13)C values. Thus, after accounting for physical back-diffusion, we were able to quantify biological time lags in the coupling of photosynthesis and soil CO(2) efflux in grassland at the diurnal time scale.

  8. In situ 13CO2 pulse labelling of field-grown eucalypt trees revealed the effects of potassium nutrition and throughfall exclusion on phloem transport of photosynthetic carbon.

    PubMed

    Epron, Daniel; Cabral, Osvaldo Machado Rodrigues; Laclau, Jean-Paul; Dannoura, Masako; Packer, Ana Paula; Plain, Caroline; Battie-Laclau, Patricia; Moreira, Marcelo Zacharias; Trivelin, Paulo Cesar Ocheuze; Bouillet, Jean-Pierre; Gérant, Dominique; Nouvellon, Yann

    2016-01-01

    Potassium (K) is an important limiting factor of tree growth, but little is known of the effects of K supply on the long-distance transport of photosynthetic carbon (C) in the phloem and of the interaction between K fertilization and drought. We pulse-labelled 2-year-old Eucalyptus grandis L. trees grown in a field trial combining K fertilization (+K and -K) and throughfall exclusion (+W and -W), and we estimated the velocity of C transfer by comparing time lags between the uptake of (13)CO2 and its recovery in trunk CO2 efflux recorded at different heights. We also analysed the dynamics of the labelled photosynthates recovered in the foliage and in the phloem sap (inner bark extract). The mean residence time of labelled C in the foliage was short (21-31 h). The time series of (13)C in excess in the foliage was affected by the level of fertilization, whereas the effect of throughfall exclusion was not significant. The velocity of C transfer in the trunk (0.20-0.82 m h(-1)) was twice as high in +K trees than in -K trees, with no significant effect of throughfall exclusion except for one +K -W tree labelled in the middle of the drought season that was exposed to a more pronounced water stress (midday leaf water potential of -2.2 MPa). Our results suggest that besides reductions in photosynthetic C supply and in C demand by sink organs, the lower velocity under K deficiency is due to a lower cross-sectional area of the sieve tubes, whereas an increase in phloem sap viscosity is more likely limiting phloem transport under drought. In all treatments, 10 times less (13)C was recovered in inner bark extracts at the bottom of the trunk when compared with the base of the crown, suggesting that a large part of the labelled assimilates has been exported out of the phloem and replaced by unlabelled C. This supports the 'leakage-retrieval mechanism' that may play a role in maintaining the pressure gradient between source and sink organs required to sustain high

  9. Investigating the impact of light and water status on the exchange of COS, 13CO2, CO18O and H218O from bryophytes

    NASA Astrophysics Data System (ADS)

    Gimeno, Teresa; Royles, Jessica; Ogee, Jerome; Jones, Samuel; Burlett, Regis; West, Jason; Sauze, Joana; Wohl, Steven; Genty, Bernard; Griffiths, Howard; Wingate, Lisa

    2016-04-01

    Terrestrial surfaces are often covered by photoautotrophic communities that play a significant role in the biological fixation of C and N at the global scale. Bryophytes (mosses, liverworts and hornworts) are key members in these communities and are especially adapted to thrive in hostile environments, by growing slowly and surviving repeated dehydration events. Consequently, bryophyte communities can be extremely long-lived (>1500yrs) and can serve as valuable records of historic climate change. In particular the carbon and oxygen isotope compositions of mosses can be used as powerful proxies describing how growing season changes in atmospheric CO2 and rainfall have changed in the distant past over the land surface. Interpreting the climate signals of bryophyte biomass requires a robust understanding of how changes in photosynthetic activity and moisture status regulate the growth and isotopic composition of bryophyte biomass. Thus theoretical models predicting how changes in isotopic enrichment and CO2 discrimination respond to dehydration and rehydration are used to tease apart climatic and isotopic source signals. Testing these models with high resolution datasets obtained from new generation laser spectrometers can provide more information on how these plants that lack stomata cope with water loss. In addition novel tracers such as carbonyl sulfide (COS) can also be measured at high resolution and precision (<5ppt) and used to constrain understanding of diffusional and enzymatic limitations during dehydration and rehydration events in the light and the dark. Here, we will present for the first time simultaneous high-resolution chamber measurements of COS, 13CO2, CO18O and H218O fluxes by a bryophyte species (Marchantia sp.) in the light and during the dark, through complete desiccation cycles. Our measurements consistently reveal a strong enrichment dynamic in the oxygen isotope composition of transpired water over the dessication cycle that caused an increase

  10. Tracing of recently assimilated carbon in respiration at high temporal resolution in the field with a tuneable diode laser absorption spectrometer after in situ 13CO2 pulse labelling of 20-year-old beech trees.

    PubMed

    Plain, Caroline; Gerant, Dominique; Maillard, Pascale; Dannoura, Masako; Dong, Yanwen; Zeller, Bernd; Priault, Pierrick; Parent, Florian; Epron, Daniel

    2009-11-01

    The study of the fate of assimilated carbon in respiratory fluxes in the field is needed to resolve the residence and transfer times of carbon in the atmosphere-plant-soil system in forest ecosystems, but it requires high frequency measurements of the isotopic composition of evolved CO2. We developed a closed transparent chamber to label the whole crown of a tree and a labelling system capable of delivering a 3-h pulse of 99% 13CO2 in the field. The isotopic compositions of trunk and soil CO2 effluxes were recorded continuously on two labelled and one control trees by a tuneable diode laser absorption spectrometer during a 2-month chase period following the late summer labelling. The lag times for trunk CO2 effluxes are consistent with a phloem sap velocity of about 1 m h(-1). The isotopic composition (delta13C) of CO2 efflux from the trunk was maximal 2-3 days after labelling and declined thereafter following two exponential decays with a half-life of 2-8 days for the first and a half-life of 15-16 days for the second. The isotopic composition of the soil CO2 efflux was maximal 3-4 days after labelling and the decline was also well fitted with a sum of two exponential functions with a half-life of 3-5 days for the first exponential and a half-life of 16-18 days for the second. The amount of label recovered in CO2 efflux was around 10-15% of the assimilated 13CO2 for soil and 5-13% for trunks. As labelling occurred late in the growing season, substantial allocation to storage is expected.

  11. Using eddy covariance of CO2, 13CO2 and CH4, continuous soil respiration measurements, and PhenoCams to constrain a process-based biogeochemical model for carbon market-funded wetland restoration

    NASA Astrophysics Data System (ADS)

    Oikawa, P. Y.; Baldocchi, D. D.; Knox, S. H.; Sturtevant, C. S.; Verfaillie, J. G.; Dronova, I.; Jenerette, D.; Poindexter, C.; Huang, Y. W.

    2015-12-01

    We use multiple data streams in a model-data fusion approach to reduce uncertainty in predicting CO2 and CH4 exchange in drained and flooded peatlands. Drained peatlands in the Sacramento-San Joaquin River Delta, California are a strong source of CO2 to the atmosphere and flooded peatlands or wetlands are a strong CO2 sink. However, wetlands are also large sources of CH4 that can offset the greenhouse gas mitigation potential of wetland restoration. Reducing uncertainty in model predictions of annual CO2 and CH4 budgets is critical for including wetland restoration in Cap-and-Trade programs. We have developed and parameterized the Peatland Ecosystem Photosynthesis, Respiration, and Methane Transport model (PEPRMT) in a drained agricultural peatland and a restored wetland. Both ecosystem respiration (Reco) and CH4 production are a function of 2 soil carbon (C) pools (i.e. recently-fixed C and soil organic C), temperature, and water table height. Photosynthesis is predicted using a light use efficiency model. To estimate parameters we use a Markov Chain Monte Carlo approach with an adaptive Metropolis-Hastings algorithm. Multiple data streams are used to constrain model parameters including eddy covariance of CO2, 13CO2 and CH4, continuous soil respiration measurements and digital photography. Digital photography is used to estimate leaf area index, an important input variable for the photosynthesis model. Soil respiration and 13CO2 fluxes allow partitioning of eddy covariance data between Reco and photosynthesis. Partitioned fluxes of CO2 with associated uncertainty are used to parametrize the Reco and photosynthesis models within PEPRMT. Overall, PEPRMT model performance is high. For example, we observe high data-model agreement between modeled and observed partitioned Reco (r2 = 0.68; slope = 1; RMSE = 0.59 g C-CO2 m-2 d-1). Model validation demonstrated the model's ability to accurately predict annual budgets of CO2 and CH4 in a wetland system (within 14% and 1

  12. Quantifying Protein Synthesis and Degradation in Arabidopsis by Dynamic 13CO2 Labeling and Analysis of Enrichment in Individual Amino Acids in Their Free Pools and in Protein1[OPEN

    PubMed Central

    Fernie, Alisdair R.; Stitt, Mark

    2015-01-01

    Protein synthesis and degradation represent substantial costs during plant growth. To obtain a quantitative measure of the rate of protein synthesis and degradation, we supplied 13CO2 to intact Arabidopsis (Arabidopsis thaliana) Columbia-0 plants and analyzed enrichment in free amino acids and in amino acid residues in protein during a 24-h pulse and 4-d chase. While many free amino acids labeled slowly and incompletely, alanine showed a rapid rise in enrichment in the pulse and a decrease in the chase. Enrichment in free alanine was used to correct enrichment in alanine residues in protein and calculate the rate of protein synthesis. The latter was compared with the relative growth rate to estimate the rate of protein degradation. The relative growth rate was estimated from sequential determination of fresh weight, sequential images of rosette area, and labeling of glucose in the cell wall. In an 8-h photoperiod, protein synthesis and cell wall synthesis were 3-fold faster in the day than at night, protein degradation was slow (3%–4% d−1), and flux to growth and degradation resulted in a protein half-life of 3.5 d. In the starchless phosphoglucomutase mutant at night, protein synthesis was further decreased and protein degradation increased, while cell wall synthesis was totally inhibited, quantitatively accounting for the inhibition of growth in this mutant. We also investigated the rates of protein synthesis and degradation during leaf development, during growth at high temperature, and compared synthesis rates of Rubisco large and small subunits of in the light and dark. PMID:25810096

  13. Photosynthetic Gas Exchange and Discrimination against 13CO2 and C18O16O in Tobacco Plants Modified by an Antisense Construct to Have Low Chloroplastic Carbonic Anhydrase.

    PubMed Central

    Williams, T. G.; Flanagan, L. B.; Coleman, J. R.

    1996-01-01

    The physiological role of chloroplastic carbonic anhydrase (CA) was examined by antisense suppression of chloroplastic CA (on average 8% of wild type) in Nicotiana tabacum. Photosynthetic gas-exchange characteristics of low-CA and wild-type plants were measured concurrently with short-term, on-line stable isotope discrimination at varying vapor pressure deficit (VPD) and light intensity. Low-CA and wild-type plants were indistinguishable in the responses of assimilation, transpiration, stomatal conductance, and intercellular CO2 concentration to changing VPD or light intensity. At saturating light intensity, low-CA plants had lower discrimination against 13CO2 than wild-type plants by 1.2 to 1.8[per mille (thousand) sign]. Consequently, tissue of the low-CA plants was higher in 13C than the control plants. It was calculated that low-CA plants had chloroplast CO2 concentrations 13 to 22 [mu]mol mol-1 lower than wild-type plants. Discrimination against C18O16O in low-CA plants was 20% of that of the wild type, confirming a role of chloroplastic CA in the mechanism of discrimination against C18O16O ([delta]C18O16O). As VPD increased, stomatal closure caused a reduction in chloroplastic C02 concentration, and since VPD and chloroplastic CO2 concentration act in opposing directions on [delta]C18O16O, no effect of VPD was seen on [delta]C18O16O. PMID:12226395

  14. Short-term carbon dynamics in a temperate heathland upon six years of exposure to elevated CO2 concentration, drought and warming: Evidence from an in-situ 13CO2 pulse-chase experiment

    NASA Astrophysics Data System (ADS)

    Ambus, P.; Reinsch, S.; Sárossy, Z.; Egsgaard, H.; Jakobsen, I.; Michelsen, A.; Schmidt, I.; Nielsen, P.

    2013-12-01

    An in-situ 13CO2 pulse-labeling experiment was carried out in a temperate heathland (8 oC MAT, 610 mm MAP) to study the impact on short-term carbon (C) allocation as affected by elevated CO2 concentration (+120 ppm), prolonged summer droughts (ca. -43 mm) and warming (+1 oC). The study was carried out six years after the climate treatments were initiated and took place in the early growing season in May in vegetation dominated by grasses, mainly Deschampsia flexuosa. Newly assimilated C (13C from the pulse-label) was traced into vegetation, soil and soil microorganisms and belowground respiration 1, 2 and 8 days after pulse-labeling. The importance of the microbial community in C utilization was investigated using 13C enrichment patterns in different microbial functional groups on the basis of phospholipid fatty acid (PLFA) profiles. Climate treatments did not affect microorganism abundance in soil or rhizosphere fractions in terms of total PLFA-C concentration. Elevated CO2 significantly reduced the abundance of gram-negative bacteria (17:0cy), but did not affect the abundance of decomposers (fungi and actinomycetes) in rhizosphere fractions. Drought favored the bacterial community in rhizosphere fractions whereas warming reduced the abundance of gram-negative bacteria (19:0cy) and changed the actinomycetes community (10Me16:0, 10Me18:0). Fastest and highest utilization of recently assimilated C was observed in rhizosphere associated gram-negative bacteria followed by gram-positive bacteria. The utilization of recently assimilated C by the microbial community was faster under elevated CO2 conditions compared to ambient. The 13C assimilation by green plant tissue and translocation to roots was significantly reduced by the extended summer drought. Under elevated CO2 conditions we observed an increased amount of 13C in the litter fraction. The assimilation of 13C by vegetation was not changed when the climate factors were applied in combination. The total amount of

  15. Virus excretion in smallpox

    PubMed Central

    Sarkar, J. K.; Mitra, A. C.; Mukherjee, M. K.; De, S. K.

    1973-01-01

    Throat swabs of 34 of 328 family contacts of 52 smallpox cases, examined 4-8 days after the onset of the disease in the family, were positive for variola virus. The log titre of virus per swab ranged from 2 to 3.95. A higher proportion of unvaccinated than of vaccinated contacts excreted the virus. Only 4 of the virus-positive contacts developed clinical smallpox; this occurred 5-7 days after their swabs were examined. Excretion of virus in the throats of these contacts, a few of whom were in the incubation period of the disease, suggests the possibility that they could have spread the infection. This possibility, if kept in mind, may help in tracing the source of infection or in determining the incubation period in a few instances when difficulty is experienced. PMID:4359679

  16. Hepatobiliary excretion of berberine.

    PubMed

    Tsai, Pi-Lo; Tsai, Tung-Hu

    2004-04-01

    Berberine is a bioactive herbal ingredient isolated from the roots and bark of Berberis aristata or Coptis chinensis. To investigate the detailed pharmacokinetics of berberine and its mechanisms of hepatobiliary excretion, an in vivo microdialysis coupled with high-performance liquid chromatography was performed. In the control group, rats received berberine alone; in the drug-treated group, 10 min before berberine administration, the rats were injected with cyclosporin A (CsA), a P-glycoprotein (P-gp) inhibitor; quinidine, both organic cation transport (OCT) and P-gp inhibitors; SKF-525A (proadifen), a cytochrome P450 inhibitor; and probenecid to inhibit the glucuronidation. The results indicate that berberine displays a linear pharmacokinetic phenomenon in the dosage range from 10 to 20 mg kg(-1), since a proportional increase in the area under the concentration-time curve (AUC) of berberine was observed in this dosage range. Moreover, berberine was processed through hepatobiliary excretion against a concentration gradient based on the bile-to-blood distribution ratio (AUC(bile)/AUC(blood)); the active berberine efflux might be affected by P-gp and OCT since coadministration of berberine and CsA or quinidine at the same dosage of 10 mg kg(-1) significantly decreased the berberine amount in bile. In addition, berberine was metabolized in the liver with phase I demethylation and phase II glucuronidation, as identified by liquid chromatography/tandem mass spectrometry. Also, the phase I metabolism of berberine was partially reduced by SKF-525A treatment, but the phase II glucuronidation of berberine was not obviously affected by probenecid under the present study design.

  17. Mathematical formulation of Tmax-Tstop method for LM-OSL and its experimental validation on α-Al2O3:C

    NASA Astrophysics Data System (ADS)

    Soni, Anuj; Mishra, D. R.

    2016-05-01

    A mathematical formulation and its experimental validation on α-Al2O3:C for evaluating the number of OSL components has been described. The method consists of various partial bleaching steps of LM-OSL curve and as a result, the peak position (Tmax) of the resultant curve shifts if the system contains multiple components. However, for single component system the peak position of the resultant curve doesn't change on partial bleaching for a phosphor obeying first order kinetics. The method has been theoretically formulated for single and multiple component system with different order of kinetics and validated experimentally on the commercial α-Al2O3:C OSL phosphor. The slope of the curve between shift in Tmax and bleaching time gives the number of the OSL components and measure of their closeness in terms of photoionization cross-section. Based on this result, the photoionization cross-section of the two embedded peaks in the LM-OSL curve of α-Al2O3:C were found to be 1.51 × 10-18 cm2 and 5.02 × 10-19 cm2 using CW-OSL and NL-OSL method.

  18. Quantifying the effect of Tmax extreme events on local adaptation to climate change of maize crop in Andalusia for the 21st century

    NASA Astrophysics Data System (ADS)

    Gabaldon, Clara; Lorite, Ignacio J.; Ines Minguez, M.; Lizaso, Jon; Dosio, Alessandro; Sanchez, Enrique; Ruiz-Ramos, Margarita

    2015-04-01

    Extreme events of Tmax can threaten maize production on Andalusia (Ruiz-Ramos et al., 2011). The objective of this work is to attempt a quantification of the effects of Tmax extreme events on the previously identified (Gabaldón et al., 2013) local adaptation strategies to climate change of irrigated maize crop in Andalusia for the first half of the 21st century. This study is focused on five Andalusia locations. Local adaptation strategies identified consisted on combinations of changes on sowing dates and choice of cultivar (Gabaldón et al., 2013). Modified cultivar features were the duration of phenological phases and the grain filling rate. The phenological and yield simulations with the adaptative changes were obtained from a modelling chain: current simulated climate and future climate scenarios (2013-2050) were taken from a group of regional climate models at high resolution (25 km) from the European Project ENSEMBLES (http://www.ensembles-eu.org/). After bias correcting these data for temperature and precipitation (Dosio and Paruolo, 2011; Dosio et al., 2012) crop simulations were generated by the CERES-maize model (Jones and Kiniry, 1986) under DSSAT platform, previously calibrated and validated. Quantification of the effects of extreme Tmax on maize yield was computed for different phenological stages following Teixeira et al. (2013). A heat stress index was computed; this index assumes that yield-damage intensity due to heat stress increases linearly from 0.0 at a critical temperature to a maximum of 1.0 at a limit temperature. The decrease of crop yield is then computed by a normalized production damage index which combines attainable yield and heat stress index for each location. Selection of the most suitable adaptation strategy will be reviewed and discussed in light of the quantified effect on crop yield of the projected change of Tmax extreme events. This study will contribute to MACSUR knowledge Hub within the Joint Programming Initiative on

  19. Preparation of an amorphous sodium furosemide salt improves solubility and dissolution rate and leads to a faster Tmax after oral dosing to rats.

    PubMed

    Nielsen, Line Hagner; Gordon, Sarah; Holm, René; Selen, Arzu; Rades, Thomas; Müllertz, Anette

    2013-11-01

    crystalline free acid, respectively. The promising properties of the amorphous salt in vitro were further evaluated in an in vivo study, where solid dosage forms of the amorphous salt, amorphous and crystalline free acid and a solution of furosemide were administered orally to rats. The amorphous salt exhibited a significantly faster Tmax compared to the solution and amorphous and crystalline free acid. Cmax for the solution was significantly higher compared to the three furosemide forms. No significant difference was found in AUC and absolute bioavailability for the solution, crystalline free acid and the two amorphous forms of furosemide. It can be concluded that the higher IDR and higher apparent solubility of the amorphous salt resulted in a faster Tmax compared to the amorphous and crystalline free acid.

  20. Copiea - excretion rates of salamaders

    EPA Pesticide Factsheets

    Stoichiometry of excreta and excretion rates of a stream-dwelling plethodontid salamander in Cincinnati, OH, USAThis dataset is associated with the following publication:Milanovich , J., and M. Hopton. Stoichiometry of excreta in larval stream salamanders: implications regarding the ecological roles of salamanders. FUNCTIONAL ECOLOGY. Blackwell Publishing, Malden, MA, USA, 00, (2012).

  1. Urinary zinc excretion in infancy.

    PubMed

    Sievers, E; Oldigs, H D; Dörner, K; Schaub, J

    1990-03-01

    In view of the conflicting data on urinary Zn excretion in infancy we investigated the possible influence of contamination, collecting methods, nutrition (human milk versus formula) and longitudinal changes during the first 16 weeks of life. Methodical investigation showed that special attention is necessary to avoid contamination due to the use of Zn-containing baby creams in the genital region. The sampling device for collection should include the smallest area of skin possible and the use of Zn-containing baby creams has to be avoided both during the collection and at least 24 hours prior to urine collection. Previous fractional urine sampling of the collecting method to be evaluated proves that erroneously high values are not obtained at the beginning of collection. Midstream urinary samples reduce the possibility of contamination. Increased urinary excretion was shown in pre-term infants under theophylline or coffeine medication. The median daily urinary Zn excretion in healthy breast-fed term infants declined significantly from 0.063 (0.027-0.111) mg per kg body weight at the age of 2 weeks to 0.018 (0.004-0.059) mg per kg body weight at the age of 16 weeks. Comparable values for formula-fed term infants were 0.029 (0.025-0.063) mg per kg body weight initially and 0.025 (0.007-0.059) mg per kg body weight at the end of the study. These values can be used as reference values for the urinary Zn excretion of healthy infants.

  2. Cholesterol excretion and colon cancer.

    PubMed

    Broitman, S A

    1981-09-01

    Populations consuming diets high in fat and cholesterol exhibit a greater incidence of colon cancer than those consuming less fat and cholesterol. Lowering elevated serum cholesterol levels experimentally or clinically is associated with increased large-bowel tumorigenesis. Thus, cholesterol lost to the gut, either dietary or endogenously synthesized, appears to have a role in large-bowel cancer. Whether the effect(s) is mediated by increases in fecal bile acid excretion or some other mechanism is not clear.

  3. Human pharmacology of ayahuasca: subjective and cardiovascular effects, monoamine metabolite excretion, and pharmacokinetics.

    PubMed

    Riba, Jordi; Valle, Marta; Urbano, Gloria; Yritia, Mercedes; Morte, Adelaida; Barbanoj, Manel J

    2003-07-01

    The effects of the South American psychotropic beverage ayahuasca on subjective and cardiovascular variables and urine monoamine metabolite excretion were evaluated, together with the drug's pharmacokinetic profile, in a double-blind placebo-controlled clinical trial. This pharmacologically complex tea, commonly obtained from Banisteriopsis caapi and Psychotria viridis, combines N,N-dimethyltryptamine (DMT), an orally labile psychedelic agent showing 5-hydroxytryptamine2A agonist activity, with monoamine oxidase (MAO)-inhibiting beta-carboline alkaloids (harmine, harmaline, and tetrahydroharmine). Eighteen volunteers with prior experience in the use of psychedelics received single oral doses of encapsulated freeze-dried ayahuasca (0.6 and 0.85 mg of DMT/kg of body weight) and placebo. Ayahuasca produced significant subjective effects, peaking between 1.5 and 2 h, involving perceptual modifications and increases in ratings of positive mood and activation. Diastolic blood pressure showed a significant increase at the high dose (9 mm Hg at 75 min), whereas systolic blood pressure and heart rate were moderately and nonsignificantly increased. Cmax values for DMT after the low and high ayahuasca doses were 12.14 ng/ml and 17.44 ng/ml, respectively. Tmax (median) was observed at 1.5 h after both doses. The Tmax for DMT coincided with the peak of subjective effects. Drug administration increased urinary normetanephrine excretion, but, contrary to the typical MAO-inhibitor effect profile, deaminated monoamine metabolite levels were not decreased. This and the negligible harmine plasma levels found suggest a predominantly peripheral (gastrointestinal and liver) site of action for harmine. MAO inhibition at this level would suffice to prevent first-pass metabolism of DMT and allow its access to systemic circulation and the central nervous system.

  4. Salt excretion in Suaeda fruticosa.

    PubMed

    Labidi, Nehla; Ammari, Manel; Mssedi, Dorsaf; Benzerti, Maali; Snoussi, Sana; Abdelly, C

    2010-09-01

    Suaeda fruticosa is a perennial "includer" halophyte devoid of glands or trichomes with a strong ability of accumulating and sequestrating Na(+) and Cl(-). We were interested in determining whether leaf cuticle salt excretion could be involved as a further mechanism in salt response of this species after long-term treatment with high salinity levels. Seedlings had been treated for three months with seawater (SW) diluted with tap water (0, 25, 50 and 75% SW). Leaf scanning electron microscopy revealed a convex adaxial side sculpture and a higher accumulation of saline crystals at the lamina margin, with a large variability on repartition and size between treatments. No salt gland or salt bladder was found. Threedimensional wax decorations were the only structures found on leaf surface. Washing the leaf surface with water indicated that sodium and chloride predominated in excreted salts, and that potassium was poorly represented. Optimal growth of whole plant was recorded at 25% SW, correlating with maximum Na(+) and Cl(-) absolute secretion rate. The leaves of plants treated with SW retained more water than those of plants treated with tap water due to lower solute potential, especially at 25% SW. Analysis of compatible solute, such as proline, total soluble carbohydrates and glycinebetaine disclosed strong relationship between glycinebetaine and osmotic potential (r = 0.92) suggesting that tissue hydration was partly maintained by glycinebetaine accumulation. Thus in S. fruticosa , increased solute accumulation associated with water retention, and steady intracellular ion homeostasis confirms the "includer" strategy of salt tolerance previously demonstrated. However, salt excretion at leaf surface also participated in conferring to this species a capacity in high salinity tolerance.

  5. Mercury excretion and intravenous ascorbic acid.

    PubMed

    Dirks, M J; Davis, D R; Cheraskin, E; Jackson, J A

    1994-01-01

    We tested the hypothesis that intravenous ascorbic acid increases urinary excretion of mercury in subjects with low mercury levels from dental amalgam, food, and other sources. From 89 adult volunteers we selected 28 subjects with the highest mercury excretions (2 to 14 micrograms/24 h). We administered intravenous infusions of 500 ml lactated Ringer's solution with and without addition of 750 mg of ascorbic acid/kg body weight, up to 60 g ascorbic acid. Average mercury excretion during the 24 h after infusion of ascorbic acid was 4.0 +/- 0.5 micrograms (mean +/- SEM), which was not significantly more than after infusion of Ringer's solution alone (3.7 +/- 0.5 micrograms). Lead excretion was similarly unaffected. If ascorbic acid administered intravenously benefits some persons with suspected adverse reactions to mercury, the benefit in subjects similar to ours appears unrelated to short-term enhanced excretion of mercury or lead.

  6. The effects of uphill vs. level-grade high-intensity interval training on VO2max, Vmax, V(LT), and Tmax in well-trained distance runners.

    PubMed

    Ferley, Derek D; Osborn, Roy W; Vukovich, Matthew D

    2013-06-01

    Uphill running represents a frequently used and often prescribed training tactic in the development of competitive distance runners but remains largely uninvestigated and unsubstantiated as a training modality. The purpose of this investigation included documenting the effects of uphill interval training compared with level-grade interval training on maximal oxygen consumption (VO2max), the running speed associated with VO2max (Vmax), the running speed associated with lactate threshold (V(LT)), and the duration for which Vmax can be sustained (Tmax) in well-trained distance runners. Thirty-two well-trained distance runners (age, 27.4 ± 3.8 years; body mass, 64.8 ± 8.9 kg; height, 173.6 ± 6.4 cm; and VO2max, 60.9 ± 8.5 ml·min(-1)·kg(-1)) received assignment to an uphill interval training group (G(Hill) = 12), level-grade interval training group (G(Flat) = 12), or control group (G(Con) = 8). G(Hill) and G(Flat) completed 12 interval and 12 continuous running sessions over 6 weeks, whereas G(Con) maintained their normal training routine. Pre- and posttest measures of VO2max, Vmax, V(LT), and Tmax were used to assess performance. A 3 × 2 repeated measures analysis of variance was performed for each dependent variable and revealed a significant difference in Tmax in both G(Hill) and G(Flat) (p < 0.05). With regard to running performance, the results indicate that both uphill and level-grade interval training can induce significant improvements in a run-to-exhaustion test in well-trained runners at the speed associated with VO2max but that traditional level-grade training produces greater gains.

  7. Urinary Excretion of Antidiuretic Hormone in Man

    NASA Technical Reports Server (NTRS)

    Miller, M.

    1972-01-01

    It is shown that urinary excretion of ADH can be detected readily and quantitated accurately. The ADH excretion in normal subjects is inhibited following the administration of a water load and stimulated following water deprivation. It appears that measurement of ADH excretion in man provides a means of quantitating alterations in neurohypophyseal ADH secretion. By determining not only the basal excretion of ADH but also the response to such physiological influences as water loading and dehydration, it becomes possible to study the dynamics of ADH release. Thus, the ability to extract ADH efficiently from urine combined with a sensitive and specific technique for determination of ADH concentration allows the exploration of regulatory systems for ADH control in the normal state as well as the etiological role of altered ADH secretion in clinical disorders of water balance.

  8. Absorption, metabolism, and excretion of cider dihydrochalcones in healthy humans and subjects with an ileostomy.

    PubMed

    Marks, Serena C; Mullen, William; Borges, Gina; Crozier, Alan

    2009-03-11

    The phloretin-O-glycosides, phloretin-2'-O-glucoside and phloretin-2'-O-(2''-O-xylosyl)glucoside, are thought to be unique to apples and apple products. To investigate the metabolism and bioavailability of these compounds, nine healthy and five ileostomy human subjects consumed 500 mL of Thatchers Redstreak apple cider containing 46 micromol of phloretin-O-glycosides. Over the ensuing 24 h period, plasma, urine, and ileal fluid were collected prior to analysis by high-performance liquid chromatography-mass spectrometry (HPLC-MS). The sole metabolite present in quantifiable amounts in plasma was phloretin-2'-O-glucuronide, which reached a peak concentration (C(max)) of 73 nmol/L and 0.6 h after ingestion (T(max)) with the healthy subjects, and statistically similar values were obtained with the ileostomy volunteers. Phloretin-2'-O-glucuronide was also detected in urine along with two additional phloretin-O-glucuronides and a phloretin-O-glucuronide-O-sulfate. The quantity of phloretin metabolites excreted in urine represented 5.0 + or - 0.9% of intake in healthy volunteers and 5.5 + or - 0.6% in ileostomy volunteers. The similarity in the excretion levels of the two groups and the rapid plasma T(max) indicate absorption of the dihydrochalcones in the small intestine. Of the two major phloretin-O-glycosides in cider, only phloretin-2'-O-(2''-O-xylosyl)glucoside was recovered in ileal fluid in quantities corresponding to 22% of intake. The absence of phloretin-2'-O-glucoside in ileal fluid suggests that it is more readily absorbed than phloretin-2'-O-(2''-O-xylosyl)glucoside. Phloretin-2'-O-glucuronide, two other phloretin-O-glucuronides, one phloretin-O-glucuronide-O-sulfate, two phloretin-O-sulfates, and the aglycone phloretin were also detected in the ileal fluid. This implies that the wall of the small intestine contains beta-glycosidase, sulfuryltransferase, and UDP-glucuronosyltransferase activities and that, as well as being absorbed, sizable amounts of the

  9. Bioavailability, tissue distribution, and excretion characteristics of the novel carbonic anhydrase inhibitor tolsultazolamide in rats

    PubMed Central

    Wang, Jin-da; Shi, Yong-ping; Yin, Jing; Pan, Zhi-yuan; Cui, Wen-yu; Zhang, Yan-fang; Wang, Hai

    2014-01-01

    Aim: Tolsultazolamide, a novel carbonic anhydrase inhibitor, is designed for the prophylaxis and treatment of acute mountain sickness. The aim of this study was to investigate the pharmacokinetics, tissue distribution, and excretion characteristics of tolsultazolamide and the sex difference in pharmacokinetics in rats. Methods: For pharmacokinetic study, rats were intravenously injected tolsultazolamide at 1 and 2 mg/kg or orally administered tolsultazolamide at 20, 40, or 80 mg/kg) in a pharmacokinetic study. The concentrations of tolsultazolamide in plasma were determined with high-performance liquid chromatography, with a liquid–liquid extraction. For tissue distribution study, tolsultazolamide (80 mg/kg) was orally administered to overnight fasted rats (six per group and three per sex). Samples were collected from the brain, heart, lung, liver, spleen, muscle, kidney, stomach, fat, intestines, pancreas and sexual gland. For excretion study, tolsultazolamide (40 mg/kg) was orally administered to 6 rats (three per sex). The urine, feces, and bile samples were collected at 24, 48, and 72 h. Results: After its intravenous administration, tolsultazolamide was rapidly eliminated from the plasma, with T1/2 of about 60–90 min. The AUC0–t and the initial concentration (C0) values were proportional to the intravenous doses. After its oral administration, tolsultazolamide showed dose-independent pharmacokinetic characteristics, with Tmax and T1/2 of approximately 2 h and 5–7 h, respectively, and good oral absolute bioavailability of about 60%. Tolsultazolamide was distributed widely in various tissues. The highest tolsultazolamide levels were detected in the stomach, intestine, spleen, lung, and kidney. Total excretion of unchanged tolsultazolamide in the urine, feces, and bile was less than 2%. The Cmax and AUC of tolsultazolamide were significantly higher in female rats than those in male rats. Clearance and volume of distribution were greater in male rats than

  10. Excreting and non-excreting grasses exhibit different salt resistance strategies

    PubMed Central

    Moinuddin, Muhammad; Gulzar, Salman; Ahmed, Muhammad Zaheer; Gul, Bilquees; Koyro, Hans-Werner; Khan, Muhammad Ajmal

    2014-01-01

    The combination of traits that makes a plant successful under saline conditions varies with the type of plant and its interaction with the environmental conditions. Knowledge about the contribution of these traits towards salt resistance in grasses has great potential for improving the salt resistance of conventional crops. We attempted to identify differential adaptive response patterns of salt-excreting versus non-excreting grasses. More specifically, we studied the growth, osmotic, ionic and nutrient (carbon/nitrogen) relations of two salt-excreting (Aeluropus lagopoides and Sporobolus tremulus) and two non-excreting (Paspalum paspalodes and Paspalidium geminatum) perennial C4 grasses under non-saline and saline (0, 200 and 400 mM NaCl) conditions. Growth and relative growth rate decreased under saline conditions in the order P. geminatum > S. tremulus = A. lagopoides > P. paspalodes. The root-to-shoot biomass allocation was unaffected in salt-excreting grasses, increased in P. paspalodes but decreased in P. geminatum. Salt-excreting grasses had a higher shoot/root Na+ ratio than non-excreting grasses. K+, Ca2+ and Mg2+ homoeostasis remained undisturbed among test grasses possibly through improved ion selectivity with rising substrate salinity. Salt-excreting grasses increased leaf succulence, decreased ψs and xylem pressure potential, and accumulated proline and glycinebetaine with increasing salinity. Higher salt resistance of P. paspalodes could be attributed to lower Na+ uptake, higher nitrogen-use efficiency and higher water-use efficiency among the test species. However, P. geminatum was unable to cope with salt-induced physiological drought. More information is required to adequately document the differential strategies of salt resistance in salt-excreting and non-excreting grasses. PMID:24996428

  11. Enhancement of radiopharmaceutical excretion by chemical interventions

    SciTech Connect

    Oster, Z.H.; Som, P.; Brill, A.B.; Sacker, D.F.; Atkins, H.L.

    1982-01-01

    The goal was to find methods of decreasing the radiation dose after radionuclide studies, by giving a compound that will increase the rate of excretion of the radionuclide. Sprague - 1 Dawley rats were given Tc-99m pertechnetate, Ga-67 citrate or Tl-201 chloride intravenously followed at intervals of 1 to 24 hours by one of the following compounds: desferroxamine (DFO), 2,3-dimercapto-1-propanol (BAL), triethylene tetraamine hexaacetic acid (TETHA), stannous tartarate, bleomycin (BLEO), 2,3-dimercaptosuccinic acid (DMSA), diethylene-triaminepentaacetic acid (DTPA), DTPA+SnCl.2H/sub 2/O, dihydroxybenzoic acid (DHB), and ferric-cyanoferrate (IT)(Prussian blue, PB). All the agents except PB are chelators. Some of these agents enhance excretion through the urinary tract (DFO), while most are excreted through the bile. PB was shown to increase Cs excrection through the G.I. tract. (ACR)

  12. Clinical study of urinary excretion of Ga-67

    SciTech Connect

    Nakano, S.; Hasegawa, Y.; Ibuka, K.; Hashizume, T.; Noguchi, A.; Kojima, J.; Sasakuma, F.; Ishigami, S. )

    1990-04-01

    Ga-67 urinary excretion was examined in 59 patients. The 72-hour urinary excretion rate ranged from 4.3 to 67.8% of the injected dose. Within the first 24 hours, 60.9% of the 72-hour urinary excretion was excreted. There was no significant difference in the Ga-67 urinary excretion rate between males and females, nor between the Ga-67 positive and negative cases. A significant negative correlation was found between the 72-hour Ga-67 urinary excretion rate and the unsaturated iron binding capacity. Notably, four patients with hyperferremia, which was considered secondary to leukemia and/or chemotherapy or liver cirrhosis, excreted more than 46.8% of Ga-67 within 72 hours. A significant negative correlation was also found between the 72-hour Ga-67 urinary excretion rate and age. Urinary excretion of Ga-67 may be related to the glomerular filtration rate, which decreases with age.

  13. The excretion of pethidine and its derivatives.

    PubMed

    ASATOOR, A M; LONDON, D R; MILNE, M D; SIMENHOFF, M L

    1963-04-01

    The excretion of pethidine and its metabolite norpethidine is increased in acid urine and decreased in alkaline urine. Excretion of these two bases is the main route of removal of pethidine from the body if the urine is highly acid. If the urine is alkaline, excretion of the hydrolysis products meperidinic and normeperidinic acids, both as free acids and as conjugates, is the more important means of elimination of the drug. Acidification of the urine with ammonium chloride is indicated in the therapy of cases of pethidine poisoning in patients with reduced metabolic breakdown of the drug by the microsomal enzyme systems within liver cells. Reversed-phase chromatography of the dinitrophenyl derivative of norpethidine may prove to be of forensic importance in the diagnosis of pethidine poisoning or of pethidine addiction. Norpethidine can be detected in the urine by this method for at least 3 days after the last dose of pethidine. Analytical sensitivity is increased by acidification of the urine which produces a temporary rise of the excretion rate.

  14. Urate excretion by the cat kidney.

    PubMed

    Kim, Y K; Jung, D K; Jung, J S; Lee, S H

    1992-08-01

    1. The renal handling of urate by the cat kidney was investigated during continuous infusion of urate. 2. Fractional urate excretion (FE(UA)) in cats was 0.57 +/- 0.04, indicating net reabsorption of urate. In contrast, FE(UA) in rabbits was 1.76 +/- 0.08, reflecting net secretion of urate. 3. Fractional PAH excretion (FE(PAH)) was 3.94 +/- 0.26 in cats and 4.12 +/- 0.76 in rabbits, showing net secretion in both species. 4. FE(UA) in cats was dependent on urine flow, but was independent of plasma urate concentration. 5. The urate excretion in cats was enhanced by probenecid, but was insensitive to PAH and PZA. 6. The PAH excretion in cats was reduced by probenecid, but was unaltered by urate and PZA. 7. These results indicate that urate is handled in the cat kidney by a unique transport system which is distinct from that for organic anions.

  15. Urinary beta-aminoisobutyric acid excretion in thalassaemia

    PubMed Central

    Fessas, Ph.; Koniavitis, A.; Zeis, P. M.

    1969-01-01

    The quantity of beta-aminoisobutyric acid (BAIB) excreted in the urine of patients with an intact spleen suffering from thalassaemia major appears to be proportional to the number of the circulating normoblasts and inversely proportional to the haemoglobin level. After splenectomy only minute amounts of BAIB are excreted. Transfusion constantly, but temporarily, reduces urinary excretion of beta-aminoisobutyric acid. Other anaemic but non-thalassaemic patients may excrete low levels. Images PMID:5776546

  16. Urinary beta-aminoisobutyric acid excretion in thalassaemia.

    PubMed

    Fessas, P; Koniavitis, A; Zeis, P M

    1969-03-01

    The quantity of beta-aminoisobutyric acid (BAIB) excreted in the urine of patients with an intact spleen suffering from thalassaemia major appears to be proportional to the number of the circulating normoblasts and inversely proportional to the haemoglobin level. After splenectomy only minute amounts of BAIB are excreted. Transfusion constantly, but temporarily, reduces urinary excretion of beta-aminoisobutyric acid. Other anaemic but non-thalassaemic patients may excrete low levels.

  17. [Secret excretion from the mouse mammary gland].

    PubMed

    Tolkunov, Iu A; Balakina, G B; Markov, A G

    2000-02-01

    Histological studies revealed that the mammary gland nipple have smooth muscle fibres along the nipple channel. These fibres infiltrate the connective tissue parallel to the skin. The ring muscles are not obvious. Delays in the milk excretion in mice may be due to specifics of allocation and functioning of the nipple smooth muscles. To obtain milk, a mechanical action upon the nipple and a synchronised release of oxitocin into the blood are necessary.

  18. Breath hydrogen excretion in infants with colic.

    PubMed

    Miller, J J; McVeagh, P; Fleet, G H; Petocz, P; Brand, J C

    1989-05-01

    Breath hydrogen excretion as an index of incomplete lactose absorption was measured in 118 healthy infants who were either breast fed or given a formula feed containing lactose, some of whom had colic. Infants with colic (n = 65) were selected on the basis of the mother's report of a history of inconsolable crying lasting several hours each day. Infants in the control group (n = 53) were not reported to cry excessively by their mothers. Breath samples were collected using a face mask sampling device preprandially, and 90 and 150 minutes after the start of a feed. Normalised breath hydrogen concentrations were higher in the group with colic than in the control group at each time point. The median maximum breath hydrogen concentration in the colic group was 29 ppm, and in the control group 11 ppm. The percentage of infants with incomplete lactose absorption (breath hydrogen concentration more than 20 ppm) in the colic group was 62% compared with 32% in the control group. The clinical importance of the observed association between increased breath hydrogen excretion and infantile colic remains to be determined. Increased breath hydrogen excretion indicative of incomplete lactose absorption may be either a cause or an effect of colic in infants.

  19. Urinary excretion of arsenic following rice consumption.

    PubMed

    Meharg, A A; Williams, P N; Deacon, C M; Norton, G J; Hossain, M; Louhing, D; Marwa, E; Lawgalwi, Y; Taggart, M; Cascio, C; Haris, P

    2014-11-01

    Patterns of arsenic excretion were followed in a cohort (n = 6) eating a defined rice diet, 300 g per day d.wt. where arsenic speciation was characterized in cooked rice, following a period of abstinence from rice, and other high arsenic containing foods. A control group who did not consume rice were also monitored. The rice consumed in the study contained inorganic arsenic and dimethylarsinic acid (DMA) at a ratio of 1:1, yet the urine speciation was dominated by DMA (90%). At steady state (rice consumption/urinary excretion) ∼40% of rice derived arsenic was excreted via urine. By monitoring of each urine pass throughout the day it was observed that there was considerable variation (up to 13-fold) for an individual's total arsenic urine content, and that there was a time dependent variation in urinary total arsenic content. This calls into question the robustness of routinely used first pass/spot check urine sampling for arsenic analysis.

  20. [Effect of electroacupuncture on the urine flow, sodium excretion and potassium excretion in the conscious dog].

    PubMed

    Lin, M Z; Wei, Z Y

    1989-01-01

    Unanesthetized dogs with chronic ureteral and gastric fistulae were infused with 0.8% NaCl solution into the stomach at a constant rate for maintaining a state of saline loading. In these animals, there was a steady renal excretion of water, sodium and potassium. However, after a 20-minute unilateral electroacupuncture of the points corresponding to "Sanyinjao" and "Zhaohai" in human leg as described in Traditional Chinese Medicine caused a marked increase in urine flow and urinary sodium excretion, but had no significant effect on urinary potassium excretion. In another group of normal unanesthetized dogs (without saline loading), the effect of electroacupuncture mentioned above no longer appeared. Owing to the facts that electroacupuncture merely increased the water and sodium excretion of kidneys in saline-loading unanesthetized dogs, and had no effect in normal unanesthetized dogs, it is concluded that the effects of electroacupuncture on the urine flow and sodium excretion in saline-loading unanesthetized dogs is an action of normalization by acupuncture.

  1. Excretion of trazodone in breast milk.

    PubMed Central

    Verbeeck, R K; Ross, S G; McKenna, E A

    1986-01-01

    The excretion of breast milk was studied in six lactating women following the oral administration of a single trazodone tablet (50 mg). The milk/plasma ratio of trazodone based on area under the plasma and milk curves was small: 0.142 +/- 0.045 (mean +/- s.d.). Assuming that the babies would drink 500 ml 12 h-1, they would be exposed to less than 0.005 mg kg-1 as compared to 0.77 mg kg-1 for the mothers. It is concluded that exposure of babies to trazodone via breast milk is very small. PMID:3768252

  2. Nitrogen metabolism and excretion during aestivation.

    PubMed

    Ip, Y K; Chew, S F

    2010-01-01

    In this chapter, up-to-date information on nitrogen metabolism and excretion in various aestivators is presented. Although aestivation involves long-term fasting and corporal torpor, adaptive responses with regard to excretory nitrogen metabolism exhibited by aestivators during aestivation differ from those exhibited by nonaestivators undergoing fasting or immobilization. Special efforts were made to address current issues pertaining to excretory nitrogen metabolism and related phenomena in aestivators. Adaptations exhibited by aestivators were discussed in relation to the induction, maintenance, and arousal phases of aestivation. For the induction phase, we included topics like urea as an internal induction signal for aestivation, alteration in the permeability of the skin to ammonia, and changes in rate of ammonia production and urea synthesis. For the maintenance phase, the emphasis was on protein synthesis and degradation, ammonia production, and urea synthesis and accumulation. For the arousal phase, the focus was on rehydration, urea excretion, and phenomena related to feeding. Adaptations exhibited by aestivators specifically to each of these three phases of aestivation are essential to the understanding of the overall aestivation process, but, at present, only limited information is available on excretory nitrogen metabolism in animals during the induction or arousal phases of aestivation. Therefore, future efforts should be made to identify adaptive responses particular to each of the three phases of aestivation in various aestivators.

  3. Urinary oxalate excretion in urolithiasis and nephrocalcinosis

    PubMed Central

    Neuhaus, T.; Belzer, T.; Blau, N.; Hoppe, B.; Sidhu, H.; Leumann, E.

    2000-01-01

    AIMS—To investigate urinary oxalate excretion in children with urolithiasis and/or nephrocalcinosis and to classify hyperoxaluria (HyOx).
METHODS—A total of 106 patients were screened. In those in whom the oxalate: creatinine ratio was increased, 24 hour urinary oxalate excretion was measured. Liver biopsy and/or genomic analysis was performed if primary hyperoxaluria (PH) was suspected. Stool specimens were examined for Oxalobacter formigenes in HyOx not related to PH type 1 or 2 (PH1, PH2) and in controls.
RESULTS—A total of 21 patients screened had HyOx (>0.5 mmol/24 h per 1.73 m2); they were classified into five groups. Eleven had PH (PH1 in nine and neither PH1 nor PH2 in two). Six had secondary HyOx: two enteric and four dietary. Four could not be classified. Seven patients had concomitant hypercalciuria. Only one of 12 patients was colonised with O formigenes compared to six of 13controls.
CONCLUSIONS—HyOx is an important risk factor for urolithiasis and nephrocalcinosis in children, and can coexist with hypercalciuria. A novel type of PH is proposed. Absence of O formigenes may contribute to HyOx not related to PH1.

 PMID:10735843

  4. Lorry drivers' work stress evaluated by catecholamines excreted in urine.

    PubMed Central

    van der Beek, A J; Meijman, T F; Frings-Dresen, M H; Kuiper, J I; Kuiper, S

    1995-01-01

    OBJECTIVES--To evaluate lorry drivers' work stress by measurement of adrenaline and noradrenaline excreted in the urine, and to find out which factors in their working situation are related to the excretion rates of these catecholamines. METHODS--The urinary excretion of adrenaline and noradrenaline of 32 lorry drivers, who also had loading and unloading activities to perform, was studied for one working day and one rest day. Each driver was asked to provide six urine samples on both days. RESULTS--For all samples, except the first (overnight) sample, the excretion rates of both catecholamines on the working day were higher than those on the rest day. Hierarchical multiple regression analyses were carried out to find out which factors in the drivers' working situation were related to the excretion rate of the working day. The excretion rate of adrenaline on the rest day, age, and psychosomatic complaints were positively related to the excretion rate on the working day (all P < 0.05). Body mass index and physical workload during loading and unloading were positively related to noradrenaline excretion rate (both P < 0.01). Psychosocial job strain did not significantly contribute to the proportion of variance explained in the excretion rates of both catecholamines. CONCLUSIONS--The excretion rates of adrenaline and, especially, noradrenaline on the working day were higher than those found in earlier studies among professional drivers and insufficient recovery took place after the work was ended. The only association between excretion rate on the working day and work stressors was found for noradrenaline and physical workload. The drivers' sympathoadrenal medullary reactivity to everyday work demands shows the characteristics of sustained activation. PMID:7670621

  5. Excretion of drugs in human breast milk

    SciTech Connect

    Welch, R.M.; Findlay, J.W.

    1981-01-01

    The present report briefly discusses some of the morphological, physiological, and compositional aspects of animal and human breast milk and how these characteristics might be important for the accumulation of drugs and foreign compounds. In addition, a study is described confirming the presence of caffeine, codeine, morphine, phenacetin, acetaminophen, and salicylic acid in the breast milk of a lactating mother following oral administration of a combination analgesic containing aspirin, phenacetin, caffeine, and codeine. Although the study is limited to one subject, it has provided critically needed data on the rates of appearance in, and elimination of these drugs from, breast milk. A similar amount of information is presented on phenacetin, also a component of the analgesic mixture, which has not been previously reported to enter human milk. The distribution of these drugs between the slightly more acidic breast milk and the relatively neutral plasma is consistent with their weakly basic, acidic, or relatively neutral properties. In general, the study shows that codeine and morphine milk concentrations are higher than, salicylic acid milk levels are much lower than, and phenacetin, caffeine, and acetaminophen milk concentrations are relatively similar to their respective plasma levels. It is projected, from estimated steady-state milk concentrations of the drugs and their metabolites studied, that very low percentages of the therapeutic dosages (less than 0.7%) would be excreted in mother's milk, too low an amount to be clinically significant to the infant.

  6. Excretion of Δ9-Tetrahydrocannabinol in Sweat

    PubMed Central

    Huestis, Marilyn A.; Scheidweiler, Karl B.; Saito, Takeshi; Fortner, Neil; Abraham, Tsadik; Gustafson, Richard A.; Smith, Michael L.

    2008-01-01

    Sweat testing is a noninvasive technique for monitoring drug exposure over a 7-day period in treatment, criminal justice, and employment settings. We evaluated Δ9-tetrahydrocannabinol (THC) excretion in 11 daily cannabis users after cessation of drug use. PharmChek® sweat patches worn for 7 days were analyzed for THC by gas chromatography-mass spectrometry (GC/MS). The limit of quantification (LOQ) for the method was 0.4 ng THC/patch. Sweat patches worn the first week of continuously monitored abstinence had THC above the United States Substance Abuse Mental Health Services Administration’s proposed cutoff concentration for federal workplace testing of 1 ng THC/patch. Mean ± S.E.M. THC concentrations were 3.85 ± 0.86 ng THC/patch. Eight of 11 subjects had negative patches the second week and one produced THC positive patches for four weeks of monitored abstinence. We also tested daily and weekly sweat patches from 7 subjects who were administered oral doses of up to 14.8 mg THC/day for five consecutive days. In this oral THC administration study, no daily or weekly patches had THC above the LOQ; concurrent plasma THC concentrations were all less than 6.1 μg/L. In conclusion, using proposed federal cutoff concentrations, most daily cannabis users will have a positive sweat patch in the first week after ceasing drug use and a negative patch after subsequent weeks, although patches may remain positive for four weeks or more. Oral ingestion of up to 14.8 mg THC daily does not produce a THC positive sweat patch test. PMID:17481836

  7. Biliary excretion of TT virus (TTV).

    PubMed

    Nakagawa, N; Ikoma, J; Ishihara, T; Yasui-Kawamura, N; Fujita, N; Iwasa, M; Kaito, M; Watanabe, S; Adachi, Y

    2000-08-01

    A novel DNA virus (TT virus; TTV) was isolated from a patient with post-transfusion hepatitis of unknown etiology. If TTV replicates in the liver, TTV may appear in the bile. In the present study, to clarify whether fecal-oral infection occur via biliary excretion, the presence of TTV DNA was assessed in paired serum and bile samples collected from 28 patients with obstructive jaundice without parenchymal liver disease. TTV DNA was detected by polymerase chain reaction (PCR) using semi-nested primers, and quantified by Real Time Detection PCR (RTD-PCR). The nucleotide sequence of isolates TTV DNAs was also determined and the sequences were compared between serum and bile samples. Among 28 patients, 7 were positive for TTV DNA in both samples, and 3 and 2 were positive in serum and bile respectively. Of 7 patients positive for TTV DNA in both samples, the TTV DNA titer was higher in serum of 4 patients and in bile of 1 patient. Among 7 patients positive for TTV DNA in serum and bile, 6 had the same sequence in both samples. Multiple distinct types of TTV DNA clones were isolated from serum in 2 patients and from bile in 4 patients. In conclusion, TTV DNA is detected frequently in bile from patients with obstructive jaundice, suggesting a fecal-oral route of infection and high prevalence of asymptomatic TTV carriers. TTV DNA was detected only in serum from some patients, suggesting that replication of TTV may occur in other organs as well as in the liver.

  8. Gababuline induces delta-aminolevulinic acid excretion by cyanobacteria

    SciTech Connect

    Freeman, L.; Guikema, J.A.

    1986-04-01

    Gabaculine (5-amino-1,3-cyclohexadienylcarboxylic acid) was examined as an inhibitor of Chl biosynthesis in the cyanobacterium, Anacystis nidulans. At 20 ..mu..M, it blocked the synthesis of both Chl and phycocyanin. Similar results were obtained using aminooxyacetic acid. Because gabaculine is well established as an inhibitor of aminotransferase activity, the authors expected it to cause an inhibition of ..delta..-aminolevulinic acid (ALA) synthesis. However, an excretion of ALA was observed instead. Concentrated cell cultures were incubated in the presence of gabaculine, and the spent media was examined for ALA excretion using modified Ehrlick's reagent. Gabaculine induced ALA excretion in normal cultures, and in those stressed by iron or phosphate deficiency. Nitrate deficiency depressed the extent of ALA excretion. These results suggest that, in cyanobacteria, gabaculine inhibits CHl biosynthesis at a site after ALA formation.

  9. Ammonia excretion in mytilid mussels is facilitated by ciliary beating.

    PubMed

    Thomsen, J; Himmerkus, N; Holland, N; Sartoris, F J; Bleich, M; Tresguerres, M

    2016-08-01

    The excretion of nitrogenous waste products in the form of ammonia (NH3) and ammonium (NH4 (+)) is a fundamental process in aquatic organisms. For mytilid bivalves, little is known about the mechanisms and sites of excretion. This study investigated the localization and the mechanisms of ammonia excretion in mytilid mussels. An Rh protein was found to be abundantly expressed in the apical cell membrane of the plicate organ, which was previously described as a solely respiratory organ. The Rh protein was also expressed in the gill, although at significantly lower concentrations, but was not detectable in mussel kidney. Furthermore, NH3/NH4 (+) was not enriched in the urine, suggesting that kidneys are not involved in active NH3/NH4 (+) excretion. Exposure to elevated seawater pH of 8.5 transiently reduced NH3/NH4 (+) excretion rates, but they returned to control values following 24 h acclimation. These mussels had increased abundance of V-type H(+)-ATPase in the apical membranes of plicate organ cells; however, NH3/NH4 (+) excretion rates were not affected by the V-type H(+)-ATPase specific inhibitor concanamycin A (100 nmol l(-1)). In contrast, inhibition of ciliary beating with dopamine and increased seawater viscosity significantly reduced NH3 excretion rates under control pH (8.0). These results suggest that NH3/NH4 (+) excretion in mytilid mussels takes place by passive NH3 diffusion across respiratory epithelia via the Rh protein, facilitated by the water current produced for filter feeding, which prevents accumulation of NH3 in the boundary layer. This mechanism would be energy efficient for sessile organisms, as they already generate water currents for filter feeding.

  10. Renal sodium excretion in sons of hypertensive parents.

    PubMed

    Turner, S T; Reilly, S L

    1993-09-01

    The objective of this study was to evaluate whether renal excretion of sodium is impaired and whether tubular reabsorption of sodium is increased in normotensive white men with a familial predisposition to develop essential hypertension. We compared 11 normotensive sons of two hypertensive parents (SOHT) with 11 normotensive sons of two normotensive parents (SONT); renal sodium handling was assessed after 1 week of low-sodium diet (10 mmol/d) and after 1 week of high-sodium diet (200 mmol/d). The SOHT were on average 5.5 years older than the SONT (46.9 +/- 5.2 [SD] vs 41.4 +/- 4.1, P = .012). On the sixth day of each diet, mean urinary sodium excretion did not differ between the two groups (12.9 +/- 6.3 vs 12.7 +/- 6.7 mmol/d on low-sodium diet, P = .930; 197 +/- 25 vs 200 +/- 27 mmol/d on high-sodium diet, P = .817). On the seventh day of each diet, baseline means for filtered load of sodium, absolute excretion of sodium, fractional excretion of sodium (an index of total tubular sodium reabsorption), and fractional excretion of lithium (an inverse index of proximal tubular sodium reabsorption) also did not differ between the groups. To assess renal sodium handling under non-steady-state conditions, we infused 2 L normal saline intravenously over a 2-hour period. The means for absolute excretion of sodium, fractional excretion of sodium, and fractional excretion of lithium increased from baseline, but the increases did not differ in magnitude between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Fecal and urinary excretion of six iodothyronines in the rat

    SciTech Connect

    DiStefano, J.J. III; Sapin, V.

    1987-11-01

    Fecal and urinary excretion rates of six iodothyronines were assessed in the rat maintained under normal steady state physiological conditions, to gain a more comprehensive understanding of the mechanisms of control of normal thyroid hormone economy and metabolism. Groups of young adult male rats were injected with trace doses of T4, T3, rT3, 3,3'-diiodothyronine (T2), 3',5'-T2, or 3'-monoiodothyronine, each labeled with /sup 125/I, and feces and urine were collected separately for up to 10 days. Pooled fecal pellets were homogenized in saline, extracted in ethanol, evaporated under vacuum, and reconstituted in NaOH. Fecal extracts and urine were chromatographed on Sephadex G25 columns under conditions providing quantitative separations of components of interest. A new technique was also developed, based on a model of the in vitro extraction and measurement process, to correct chromatographic results for possible variable recoveries and possible artifactious degradation of radioactively labeled components. No iodothyronines or their conjugates were excreted in urine; all radioactivity was in the form of iodide. In feces, about 30% of the (/sup 125/I)T3 injected was excreted as T3; and 24% of the (/sup 125/I)T4 injected was excreted as T4, plus 4% as T3. Together, these results imply that about 24% of endogenous T4 production is excreted as T4 and 76% is irreversibly metabolized; and for T3, about 30% of endogenous T3 production is excreted as T3 and 70% is degraded. For the nonhormonal iodothyronines, about 6% of injected monoiodothyronine, 3% of injected 3',5'-T2, 2% of injected 3,3'-T2, and less than 1% of injected rT3 were excreted in feces as such, indicating that these substances are nearly completely deiodinated in vivo. Very little (1-7%) iodide was excreted as such in feces, which also were devoid of measurable conjugates.

  12. Ammonia excretion in the freshwater planarian Schmidtea mediterranea.

    PubMed

    Weihrauch, Dirk; Chan, Ainsely C; Meyer, Heiko; Döring, Carmen; Sourial, Mary; O'Donnell, Michael J

    2012-09-15

    In aquatic invertebrates, metabolic nitrogenous waste is excreted predominately as ammonia. Very little is known, however, of the underlying mechanisms of ammonia excretion, particularly in freshwater species. Our results indicate that in the non-parasitic freshwater planarian Schmidtea mediterranea, ammonia excretion depends on acidification of the apical unstirred layer of the body surface and consequent ammonia trapping. Buffering of the environment to a pH of 7 or higher decreased the excretion rate. Inhibitor experiments suggested further that the excretion mechanism involves the participation of the V-type H(+)-ATPase and carbonic anhydrase and possibly also the Na(+)/K(+)-ATPase and Na(+)/H(+) exchangers. Alkalinization (pH 8.5, 2 days) of the environment led to a 1.9-fold increase in body ammonia levels and to a downregulation of V-ATPase (subunit A) and Rh-protein mRNA. Further, a 2 day exposure to non-lethal ammonia concentrations (1 mmol l(-1)) caused a doubling of body ammonia levels and led to an increase in Rh-protein and Na(+)/K(+)-ATPase (α-subunit) mRNA expression levels. In situ hybridization studies indicated a strong mRNA expression of the Rh-protein in the epidermal epithelium. The ammonia excretion mechanism proposed for S. mediterranea reveals striking similarities to the current model suggested to function in the gills of freshwater fish.

  13. Active hydrogen excretion and sodium absorption through isolated frog skin.

    PubMed

    Ehrenfeld, J; Garcia-Romeu, F

    1977-07-01

    The in vitro skin of Rana esculenta was studied in open-circuit conditions. It was shown that when the external face is bathed in a 2-meq solution of NaCl, sodium is absorbed at a significantly higher rate than chloride. The ionic balance is maintained by excretion of hydrogen. With a mucosal solution of 2 meq Na2SO4 the equation relating sodium absorption to proton excretion is JnH+ = (-25 +/- 7) - (0.73 +/- 0.04) JnNa+. The correlation between the two variables is highly significant. Hydrogen excretion obeys saturation kinetics in relation to the sodium concentration of the mucosal solution. Maximum excretion occurs at a sodium concentration of 4 meq. When the mucosal solution is a 115-meq solution of Na2SO4 the net flux of sodium is 2.3 times higher than that of hydrogen. The balance is maintained by absorption of SO42-. The effects of various substances on the Na+ext/H+int exchange were studied. With a mucosal solution of 2 meq Na2SO4 and short-circuit conditions it was shown that the hydrogen excretion is active and nearly the same as in open circuit, the short-circuit current is equal (to within 8%) to the sum of the sodium and hydrogen net fluxes, and the correlation between the movements of the two ions is low. A model relating the active proton excretion with the sodium transport mechanism is proposed.

  14. Species differences in biliary excretion of benzo(a)pyrene

    SciTech Connect

    Weyand, E.H.; Bevan, D.R.

    1986-05-01

    Biliary excretion of benzo(a)pyrene (B(a)P) was investigated in rats, hamsters, and guinea pigs following intratracheal administration. (/sup 3/H)-B(a)P, in amounts of approximately 150 ng or 350 ..mu..g, was instilled into lungs and amounts of radioactivity excreted in bile were monitored for six hrs following administration. Differences in biliary excretion of (/sup 3/H)-B(a)P and/or metabolites among species were observed at low doses but not at high doses. Six hours after instillation of a low dose of B(a)P, 70, 54, and 62% of the dose was excreted in bile of rats, hamsters, and guinea pigs, respectively. Upon administration of the higher dose of B(a)P, approximately 50% of the dose was excreted in bile in six hrs by all species. Thus, rats and guinea pigs exhibit differences in biliary excretion of low and high doses of B(a)P whereas hamsters do not. Profiles of phase II metabolites in rats and hamsters were similar at both low and high doses, with the majority of metabolites being glucuronides and thioether conjugates. However, differences in relative amounts of these conjugates were observed between the two doses, with a shift towards a greater proportion of glucuronides at the higher dose. Metabolites in bile from guinea pigs were primarily thioether conjugates, which accounted for 88% of metabolites at the low dose and 95% at the high dose.

  15. Isotopic Labeling of Red Cabbage Anthocyanins with Atmospheric 13-CO2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Isotopic labeling of plants provides a unique opportunity for understanding metabolic processes. A significant challenge of isotopic labeling during plant growth is that isotopes must be administered without disrupting plant development and at sufficient levels for mass spectral analysis. We describ...

  16. Plasma disposition and faecal excretion of oxfendazole, fenbendazole and albendazole following oral administration to donkeys.

    PubMed

    Gokbulut, Cengiz; Akar, Ferda; McKellar, Quintin A

    2006-07-01

    Fenbendazole (FBZ), oxfendazole (fenbendazole sulphoxide, FBZSO), and albendazole (ABZ) were administered orally to donkeys at 10mg/kg bodyweight. Blood and faecal samples were collected from 1 to 120 h post-treatment. The plasma and faecal samples were analysed by high performance liquid chromatography (HPLC). The parent molecule and its sulphoxide and sulphone (FBZSO(2)) metabolites did not reach detectable concentrations in any plasma samples following FBZ administration. ABZ was also not detected in any plasma samples, but its sulphoxide and sulphone metabolites were detected, demonstrating that ABZ was completely metabolised by first-pass mechanisms in donkeys. Maximum plasma concentrations (C(max)) of FBZSO (0.49microg/mL) and FBZSO(2) (0.60microg/mL) were detected at (t(max)) 5.67 and 8.00h, respectively, following administration of FBZSO. The area under the curve (AUC) of the sulphone metabolite (10.33microg h/mL) was significantly higher than that of the parent drug FBZSO (5.17microg h/mL). C(max) of albendazole sulphoxide (ABZSO) (0.08g/mL) and albendazole sulphone (ABZSO(2)) (0.04microg/mL) were obtained at 5.71 and 8.00h, respectively, following ABZ administration. The AUC of the sulphoxide metabolite (0.84microg h/mL) of ABZ was significantly higher than that of the sulphone metabolite (0.50microg h/mL). The highest dry-faecal concentrations of parent molecules were detected at 32, 34 and 30h for FBZSO, FBZ and ABZ, respectively. The sulphide metabolite was significantly higher than the parent molecule after FBZSO administration. The parent molecule was predominant in the faecal samples following FBZ administration. After ABZ administration, the parent molecule was significantly metabolised, probably by gastrointestinal microflora, to its sulphoxide metabolite (ABZSO) that showed a similar excretion profile to the parent molecule in the faecal samples. The AUC of the parent FBZ was significantly higher than that of FBZSO and ABZ in faeces. It is

  17. [Trans-intestinal cholesterol excretion (TICE): a new route for cholesterol excretion].

    PubMed

    Blanchard, Claire; Moreau, François; Cariou, Bertrand; Le May, Cédric

    2014-10-01

    The small intestine plays a crucial role in dietary and biliary cholesterol absorption, as well as its lymphatic secretion as chylomicrons (lipoprotein exogenous way). Recently, a new metabolic pathway called TICE (trans-intestinal excretion of cholesterol) that plays a central role in cholesterol metabolism has emerged. TICE is an inducible way, complementary to the hepatobiliary pathway, allowing the elimination of the plasma cholesterol directly into the intestine lumen through the enterocytes. This pathway is poorly characterized but several molecular actors of TICE have been recently identified. Although it is a matter of debate, two independent studies suggest that TICE is involved in the anti-atherogenic reverse cholesterol transport pathway. Thus, TICE is an innovative drug target to reduce -cardiovascular diseases.

  18. Contribution of dietary oxalate to urinary oxalate excretion

    NASA Technical Reports Server (NTRS)

    Holmes, R. P.; Goodman, H. O.; Assimos, D. G.

    2001-01-01

    BACKGROUND: The amount of oxalate excreted in urine has a significant impact on calcium oxalate supersaturation and stone formation. Dietary oxalate is believed to make only a minor (10 to 20%) contribution to the amount of oxalate excreted in urine, but the validity of the experimental observations that support this conclusion can be questioned. An understanding of the actual contribution of dietary oxalate to urinary oxalate excretion is important, as it is potentially modifiable. METHODS: We varied the amount of dietary oxalate consumed by a group of adult individuals using formula diets and controlled, solid-food diets with a known oxalate content, determined by a recently developed analytical procedure. Controlled solid-food diets were consumed containing 10, 50, and 250 mg of oxalate/2500 kcal, as well as formula diets containing 0 and 180 mg oxalate/2500 kcal. Changes in the content of oxalate and other ions were assessed in 24-hour urine collections. RESULTS: Urinary oxalate excretion increased as dietary oxalate intake increased. With oxalate-containing diets, the mean contribution of dietary oxalate to urinary oxalate excretion ranged from 24.4 +/- 15.5% on the 10 mg/2500 kcal/day diet to 41.5 +/- 9.1% on the 250 mg/2500 kcal/day diet, much higher than previously estimated. When the calcium content of a diet containing 250 mg of oxalate was reduced from 1002 mg to 391 mg, urinary oxalate excretion increased by a mean of 28.2 +/- 4.8%, and the mean dietary contribution increased to 52.6 +/- 8.6%. CONCLUSIONS: These results suggest that dietary oxalate makes a much greater contribution to urinary oxalate excretion than previously recognized, that dietary calcium influences the bioavailability of ingested oxalate, and that the absorption of dietary oxalate may be an important factor in calcium oxalate stone formation.

  19. Glucocorticoids increase salt appetite by promoting water and sodium excretion.

    PubMed

    Thunhorst, Robert L; Beltz, Terry G; Johnson, Alan Kim

    2007-09-01

    Glucocorticoids [e.g., corticosterone and dexamethasone (Dex)], when administered systemically, greatly increase water drinking elicited by angiotensin and sodium ingestion in response to mineralocorticoids [e.g., aldosterone and deoxycorticosterone acetate (DOCA)], possibly by acting in the brain. In addition, glucocorticoids exert powerful renal actions that could influence water and sodium ingestion by promoting their excretion. To test this, we determined water and sodium intakes, excretions, and balances during injections of Dex and DOCA and their coadministration (DOCA+Dex) at doses commonly employed to stimulate ingestion of water and sodium. In animals having only water to drink, Dex treatment greatly increased water and sodium excretion without affecting water intake, thereby producing negative water and sodium balances. Similar results were observed when Dex was administered together with DOCA. In animals having water and saline solution (0.3 M NaCl) to drink, Dex treatment increased water and sodium excretion, had minimal effects on water and sodium intakes, and was associated with negative water and sodium balances. DOCA treatment progressively increased sodium ingestion, and both water and sodium intakes exceeded their urinary excretion, resulting in positive water and sodium balances. The combination of DOCA+Dex stimulated rapid, large increases in sodium ingestion and positive sodium balances. However, water excretion outpaced total fluid intake, resulting in large, negative water balances. Plasma volume increased during DOCA treatment and did not change during treatment with Dex or DOCA+Dex. We conclude that increased urinary excretion, especially of water, during glucocorticoid treatment may explain the increased ingestion of water and sodium that occurs during coadministration with mineralocorticoids.

  20. Urinary calcium excretion in postmenopausal African American women

    PubMed Central

    Aloia, John F.; Shieh, Albert; Mikhail, Mageda; Islam, Shahidul

    2015-01-01

    Aim: The objective of this study was to develop a reference range for urine calcium excretion (both 24-hour and fasting) for African American women compared to White women. In addition, the variables that determine urine calcium excretion were identified. Material: Data were analyzed for baseline studies of healthy postmenopausal volunteers who participated in seven separate studies conducted at one site. Methods: Some studies included fasting urine Ca/Cr and others 24-hour urine calcium excretion. 24-hour urine calcium was considered with and without correction for urinary creatinine excretion. Calcium was measured initially by atomic absorption spectrophotometry and more recently by an automated method (ADVIA 2400 Chemistry System). Results: Participants were considered healthy based on history and physical and routine laboratory studies. Those screened who had a history of nephrolithiasis were excluded. A reference range for 24-hour urine calcium and fasting urine calcium/creatinine was developed. Reference intervals of 11 – 197 mg/24-hour urine calcium excretion and of 0.007 – 0.222 of fasting Ca/Cr were found for African American women compared to 21 – 221 mg/24 hours and 0.019 – 0.264 in White women, respectively. Urine creatinine excretion was higher in African Americans consistent with their higher muscle mass. Conclusion: Urine calcium excretion is lower in postmenopausal African American than White women. The reference range developed should be considered in the diagnosis of hypocalciuric states and may also be useful in the diagnosis of hypercalciuria. PMID:26226948

  1. Homeostatic control of manganese excretion in the neonatal rat

    SciTech Connect

    Ballatori, N.; Miles, E.; Clarkson, T.W.

    1987-05-01

    Previous studies in neonatal and suckling animals showed that immature animals have a greatly diminished capacity to excrete manganese and therefore were considered to be unable to regulate tissue manganese concentrations. In contrast, the present studies indicate that suckling rats have the capacity to excrete excess manganese at rates nearly comparable to those of adults. Eight- to 10-day-old rats given a tracer dose of /sup 54/MnCl/sub 2/ (essentially carrier free), either via gavage or by intraperitoneal injection showed little elimination of the /sup 54/Mn until the 18-19th day of life, when there was an abrupt increase in the rate of the metal's excretion. However, when manganese was given in doses of 1 and 10 mg/kg, the young animals excreted from 30-70% of the dose in only 4 days, at which time a new rate of excretion was achieved. This enhanced rate of excretion remained constant until the 18-19th day of life, when it was again accelerated. Biliary excretion of manganese, the primary route for the elimination of the metal, was only 30-60% lower in 14-day-old rats compared with adults at doses ranging from tracer to 10 mg /sup 54/Mn/kg. For both the 14-day-old and adult rats, an apparent biliary transport maximum was reached at a dose of 10 mg Mn/kg. These studies indicate that the excretory pathways for manganese are well developed in the neonatal rat. The avid retention of tracer quantities of manganese by the neonate may be a consequence of the scarcity of this essential trace metal in its diet.

  2. Effects of polybrominated biphenyls on the excretion of steroids.

    PubMed

    Willett, L B; Schanbacher, F L; Moorhead, P D

    1983-05-01

    When polybrominated biphenyls (fireMaster BP-6, PBB) are ingested by cattle, they have been shown to alter hepatic enzyme systems, and produce renal lesions with chronic high exposure. These changes provide mechanisms for alteration of the metabolism and clearance of steroid hormones that might then affect reproductive function. This study was conducted to examine the effects of PBB on the excretion of radiolabel from injected estradiol-17 beta and progesterone. Toxicity was induced by dosing two Holstein cows with 25 g of fireMaster BP-6/d for 39 or 50 d. Single iv injections of 35 microCi [4-14C] progesterone and 400 microCi [2,4,6,7-3H] estradiol-17 beta were given on d -5, 10, 30 and 38 or 48 relative to dosing. Last injections were given when animals were terminally toxic. Clinical signs and necropsy findings confirmed the typical toxic syndrome and renal lesions. Excretion of 14C was primarily in feces, while 3H appeared in both urine and feces. As toxicosis developed, the excretion of steroids in feces was delayed as anorexia reduced mass and rate of passage of feces. This had little effect on the amount of steroid excreted and the rate of urinary excretion was affected only minimally. Recovery of both radiolabels declined 10 to 20% by d 30 of dosing as excretion rate was reduced from pre-PBB dosing. Excretion declined sharply when animals were moribund. Despite developing toxicosis, both animals continued to have estrous cycles with normal periodicity.

  3. Urinary Sodium and Potassium Excretion and CKD Progression.

    PubMed

    He, Jiang; Mills, Katherine T; Appel, Lawrence J; Yang, Wei; Chen, Jing; Lee, Belinda T; Rosas, Sylvia E; Porter, Anna; Makos, Gail; Weir, Matthew R; Hamm, L Lee; Kusek, John W

    2016-04-01

    CKD is a major risk factor for ESRD, cardiovascular disease, and premature death. Whether dietary sodium and potassium intake affect CKD progression remains unclear. We prospectively studied the association of urinary sodium and potassium excretion with CKD progression and all-cause mortality among 3939 patients with CKD in the Chronic Renal Insufficiency Cohort Study. Urinary sodium and potassium excretion were measured using three 24-hour urine specimens, and CKD progression was defined as incident ESRD or halving of eGFR. During follow-up, 939 CKD progression events and 540 deaths occurred. Compared with the lowest quartile of urinary sodium excretion (<116.8 mmol/24 h), hazard ratios (95% confidence intervals) for the highest quartile of urinary sodium excretion (≥194.6 mmol/24 h) were 1.54 (1.23 to 1.92) for CKD progression, 1.45 (1.08 to 1.95) for all-cause mortality, and 1.43 (1.18 to 1.73) for the composite outcome of CKD progression and all-cause mortality after adjusting for multiple covariates, including baseline eGFR. Additionally, compared with the lowest quartile of urinary potassium excretion (<39.4 mmol/24 h), hazard ratios for the highest quartile of urinary potassium excretion (≥67.1 mmol/24 h) were 1.59 (1.25 to 2.03) for CKD progression, 0.98 (0.71 to 1.35) for all-cause mortality, and 1.42 (1.15 to 1.74) for the composite outcome. These data indicate that high urinary sodium and potassium excretion are associated with increased risk of CKD progression. Clinical trials are warranted to test the effect of sodium and potassium reduction on CKD progression.

  4. Quantitative studies of human urinary excretion of uropontin.

    PubMed

    Min, W; Shiraga, H; Chalko, C; Goldfarb, S; Krishna, G G; Hoyer, J R

    1998-01-01

    Uropontin is the urinary form of osteopontin, an aspartic acid-rich phosphorylated glycoprotein. Uropontin has been previously shown to be a potent inhibitor of the nucleation, growth and aggregation of calcium oxalate crystals and the binding of these crystals to renal epithelial cells. Quantitative data defining the excretion of this protein are necessary to determine its role in urinary stone formation. In the present studies, we determined uropontin excretion rates of normal humans. Urine samples were obtained under conditions of known dietary intake from young adult human volunteers with no history, radiographic or laboratory evidence of renal disease. Urinary concentrations of uropontin were measured by a sensitive ELISA employing an affinity purified polyclonal antiserum to uropontin. Thirteen normal subjects ingested a constant diet providing 1 gram of calcium, 1 gram of phosphorus, 150 mEq of sodium and 1 gram of protein per kilogram of body wt per day during an eight day study period. The relationship of urinary volume to uropontin excretion was assessed by varying fluid intake on the last four days of the study to change the mean urine volume/24 hr by > 500 ml. Urine collected in six hour aliquots for eight days was analyzed for uropontin by ELISA, and for calcium, and creatinine. Daily uropontin excretion of 13 individual subjects was 3805 +/- 1805 micrograms/24 hr (mean +/- 1 SD). The mean urinary levels (1.9 micrograms/ml) detected in the present study are sufficient for inhibition of crystallization; our previous studies have demonstrated that the nucleation, growth and aggregation of calcium oxalate crystals and their binding to renal cells in vitro are inhibited by this concentration of purified uropontin. In contrast to the regular pattern of diurnal variation of calcium excretion seen in most subjects, uropontin excretion showed no regularity of diurnal variation and was not directly related to either calcium or creatinine excretion or changes in

  5. Changes in parasite transmission stage excretion after pheasant release.

    PubMed

    Villanúa, D; Acevedo, P; Höfle, U; Rodríguez, O; Gortázar, C

    2006-09-01

    The production of parasite transmission stages was investigated in the faeces of 77 farm-bred ring-necked pheasants (Phasianus colchicus). Coccidian oocysts (Eimeria sp.), and nematode eggs (Heterakis sp., and Capillaria-like eggs) were recovered before and after release but all birds were treated prior to release. Treatment with fenbendazole significantly reduced the abundance of transmission-stage excretion for all parasites, and reduced the prevalence in the case of Eimeria sp. and Heterakis sp. Nonetheless, a significant increase in the excretion abundance for all parasites and in the prevalence of Eimeria sp. and Heterakis sp. was found after release. Eggs of Ascaridia sp. were found only after releasing, suggesting infection ocurred in the wild. A negative relationship was found between the pheasant body condition and Heterakis excretion abundance and a higher abundance of Capillaria sp. eggs in female birds. No significant relationship was found between parasite excretion abundance and pheasant survival. Despite this, results suggest that an increase in the excretion of parasite transmission stages follows the release of captive pheasants into the wild. This can in part explain restocking failures, but also means that autochtonous free-living birds may become exposed to new and potentially harmful pathogens. To avoid these risks it is proposed that improved prophylactic measures should be taken.

  6. Systemic lanthanum is excreted in the bile of rats.

    PubMed

    Damment, Stephen J P; Pennick, Michael

    2007-06-15

    Lanthanum carbonate is a non-calcium-based oral phosphate binder for the control of hyperphosphataemia in patients with chronic kidney disease Stage 5. As part of its pre-clinical safety evaluation, studies were conducted in rats to determine the extent of absorption and routes of excretion. Following oral gavage of a single 1500 mg/kg dose, the peak plasma lanthanum concentration was 1.04+/-0.31 ng/mL, 8 h post-dose. Lanthanum was almost completely bound to plasma proteins (>99.7%). Within 24h of administration of a single oral dose, 97.8+/-2.84% of the lanthanum was recovered in the faeces of rats. Comparing plasma exposure after oral and intravenous administration of lanthanum yielded an absolute oral bioavailability of 0.0007%. Following intravenous administration of lanthanum chloride (0.3 mg/kg), 74.1+/-5.82% of the dose (96.9+/-0.50% of recovered lanthanum) was excreted in faeces in 42 days, and in bile-duct cannulated rats, 10.0+/-2.46% of the dose (85.6+/-2.97% of recovered lanthanum) was excreted in bile in 5 days. Renal excretion was negligible, with <2% of the intravenous dose recovered in urine. These studies demonstrate that lanthanum undergoes extremely low intestinal absorption and that absorbed drug is predominantly excreted in the bile.

  7. Urine excretion strategy for stem cell-generated embryonic kidneys.

    PubMed

    Yokote, Shinya; Matsunari, Hitomi; Iwai, Satomi; Yamanaka, Shuichiro; Uchikura, Ayuko; Fujimoto, Eisuke; Matsumoto, Kei; Nagashima, Hiroshi; Kobayashi, Eiji; Yokoo, Takashi

    2015-10-20

    There have been several recent attempts to generate, de novo, a functional whole kidney from stem cells using the organogenic niche or blastocyst complementation methods. However, none of these attempts succeeded in constructing a urinary excretion pathway for the stem cell-generated embryonic kidney. First, we transplanted metanephroi from cloned pig fetuses into gilts; the metanephroi grew to about 3 cm and produced urine, although hydronephrosis eventually was observed because of the lack of an excretion pathway. Second, we demonstrated the construction of urine excretion pathways in rats. Rat metanephroi or metanephroi with bladders (developed from cloacas) were transplanted into host rats. Histopathologic analysis showed that tubular lumina dilation and interstitial fibrosis were reduced in kidneys developed from cloacal transplants compared with metanephroi transplantation. Then we connected the host animal's ureter to the cloacal-developed bladder, a technique we called the "stepwise peristaltic ureter" (SWPU) system. The application of the SWPU system avoided hydronephrosis and permitted the cloacas to differentiate well, with cloacal urine being excreted persistently through the recipient ureter. Finally, we demonstrated a viable preclinical application of the SWPU system in cloned pigs. The SWPU system also inhibited hydronephrosis in the pig study. To our knowledge, this is the first report showing that the SWPU system may resolve two important problems in the generation of kidneys from stem cells: construction of a urine excretion pathway and continued growth of the newly generated kidney.

  8. Urine excretion strategy for stem cell-generated embryonic kidneys

    PubMed Central

    Yokote, Shinya; Matsunari, Hitomi; Iwai, Satomi; Yamanaka, Shuichiro; Uchikura, Ayuko; Fujimoto, Eisuke; Matsumoto, Kei; Nagashima, Hiroshi; Kobayashi, Eiji; Yokoo, Takashi

    2015-01-01

    There have been several recent attempts to generate, de novo, a functional whole kidney from stem cells using the organogenic niche or blastocyst complementation methods. However, none of these attempts succeeded in constructing a urinary excretion pathway for the stem cell-generated embryonic kidney. First, we transplanted metanephroi from cloned pig fetuses into gilts; the metanephroi grew to about 3 cm and produced urine, although hydronephrosis eventually was observed because of the lack of an excretion pathway. Second, we demonstrated the construction of urine excretion pathways in rats. Rat metanephroi or metanephroi with bladders (developed from cloacas) were transplanted into host rats. Histopathologic analysis showed that tubular lumina dilation and interstitial fibrosis were reduced in kidneys developed from cloacal transplants compared with metanephroi transplantation. Then we connected the host animal’s ureter to the cloacal-developed bladder, a technique we called the “stepwise peristaltic ureter” (SWPU) system. The application of the SWPU system avoided hydronephrosis and permitted the cloacas to differentiate well, with cloacal urine being excreted persistently through the recipient ureter. Finally, we demonstrated a viable preclinical application of the SWPU system in cloned pigs. The SWPU system also inhibited hydronephrosis in the pig study. To our knowledge, this is the first report showing that the SWPU system may resolve two important problems in the generation of kidneys from stem cells: construction of a urine excretion pathway and continued growth of the newly generated kidney. PMID:26392557

  9. Lowering urinary oxalate excretion to decrease calcium oxalate stone disease

    PubMed Central

    Knight, John; Assimos, Dean G.

    2016-01-01

    Dietary modifications should be considered as a first line approach in the treatment of idiopathic calcium oxalate nephrolithiasis. The amounts of oxalate and calcium consumed in the diet are significant factors in the development of the disease due to their impact on urinary oxalate excretion. There are a number of strategies that can be employed to reduce oxalate excretion. The consumption of oxalate-rich foods should be avoided and calcium intake adjusted to 1000–1200 mg/day. To encourage compliance it should be emphasized to patients that they be vigilant with this diet as a deviation in any meal or snack could potentially result in significant stone growth. The evidence underlying these two modifications is outlined and other strategies to reduce urinary oxalate excretion are reviewed. PMID:26614109

  10. Excretion of technetium 99m hexakismethoxyisobutylisonitrile in milk.

    PubMed

    Rubow, S M; Ellmann, A; le Roux, J; Klopper, J

    1991-01-01

    The amount of radioactivity excreted in breast milk following the administration of technetium 99m hexakismethoxyisobutylisonitrile (99mTc-MIBI) to a patient referred for cold spot myocardial scintigraphy was determined. During the first 24 h after administration, only 41.2 kBq 99mTc (0.0084% of the injected dose) was excreted in 448 ml milk with the highest concentration of 0.49 kBq/ml in the first sample. The images obtained show a high concentration of 99mTc-MIBI in the lactating breasts contrary to the very small percentage excreted in the milk. Comparison with various recommendations regarding nursing after administration of radiopharmaceuticals seems to indicate that the administration of 99mTc-MIBI does not necessitate an interruption of breast-feeding.

  11. Quantitation of phosphorus excretion in sheep by compartmental analysis

    SciTech Connect

    Schneider, K.M.; Boston, R.C.; Leaver, D.D.

    1987-04-01

    The control of phosphorus excretion in sheep has been examined by constructing a kinetic model that contains a mechanistic set of connections between blood and gastrointestinal tract. The model was developed using experimental data from chaff-fed sheep and gives an accurate description of the absorption and excretion of /sup 32/P phosphorus in feces and urine of the ruminating sheep. These results indicated the main control site for phosphorus excretion in the ruminating sheep was the gastrointestinal tract, whereas for the non-ruminating sheep fed the liquid diet, control was exerted by the kidney. A critical factor in the induction of adaptation of phosphorus reabsorption by the kidney was the reduction in salivation, and since this response occurred independently of marked changes in the delivery of phosphorus to the kidney, a humoral factor may be involved in this communication between salivary gland and kidney.

  12. Reduction in urinary prostaglandin excretion in the premenstrual syndrome.

    PubMed

    Piccoli, A; Modena, F; Calò, L; Cantaro, S; Avogadro, A; Nardo, G; Cerutti, R

    1993-12-01

    The purpose of the present work was to study some factors involved in renal handling of salt and water in the premenstrual syndrome (PMS), in which salt and water retention is frequently observed. In 18 women with PMS and in 18 healthy women we studied the levels of cyclic adenosine monophosphate, aldosterone, prostaglandin E2, prostaglandin F2 alpha and kallikrein in urinary samples collected during the luteal phase. There was no difference between the two groups regarding sodium, aldosterone and kallikrein urinary excretion. In the PMS group there was a significant reduction in urinary excretion of cyclic adenosine monophosphate, prostaglandin E2 and prostaglandin F2 alpha with respect to the control group. At multivariate analysis sodium urinary excretion proved not to be the same as the model validated in healthy women. There may be different renal handling of water and electrolytes during the luteal phase of the menstrual cycle in women with PMS.

  13. Dynamics of renal electrolyte excretion in growing mice.

    PubMed

    Schmidt, Katharina; Ripper, Maria; Tegtmeier, Ines; Humberg, Evelyn; Sterner, Christina; Reichold, Markus; Warth, Richard; Bandulik, Sascha

    2013-01-01

    Genetically modified mice represent important models for elucidating renal pathophysiology, but gene deletions frequently cause severe failure to thrive. In such cases, the analysis of the phenotype is often limited to the first weeks of life when renal excretory function undergoes dramatic physiological changes. Here, we investigated the postnatal dynamics of urinary ion excretion in mice. The profiles of urinary electrolyte excretion of mice were examined from birth until after weaning using an automated ion chromatography system. Postnatally, mice grew about 0.4 g/day, except during two phases with slower weight gain: (i) directly after birth during adaptation to extrauterine conditions (P0-P2) and (ii) during the weaning period (P15-P21), when nutrition changed from mother's milk to solid chow and water. During the first 3 days after birth, remarkable changes in urinary Na(+), Ca(2+), Mg(2+), and phosphate concentrations occurred, whereas K(+) and Cl(-) concentrations hardly changed. From days 4-14 after birth, Na(+), Ca(2+), Mg(2+), K(+), and Cl(-) concentrations remained relatively stable at low levels. Urinary concentrations of creatinine, NH4(+), phosphate, and sulfate constantly increased from birth until after weaning. Profiles of salt excretion in KCNJ10(-/-) mice exemplified the relevance of age-dependent analysis of urinary excretion. In conclusion, the most critical phases for analysis of renal ion excretion during the first weeks of life are directly after birth and during the weaning period. The age dependence of urinary excretion varies for the different ions. This should be taken into consideration when the renal phenotype of mice is investigated during the first weeks of life.

  14. Increased urinary excretion of thioether in new rubber workers

    PubMed Central

    Kilpikari, I; Savolainen, H

    1982-01-01

    ABSTRACT Urinary excretion of thioether before starting work and in the early work period in a rubber factory was measured in urine samples collected after one, two to four, and five or more months of starting work. The study population consisted of 84 new workers. The urinary excretion of thioether decreased after one month's exposure and increased thereafter up to five months. Measurement of urinary thioethers in groups of new workers is therefore informative of exposure to alkylating agents only after several months from starting work. This effect may be mediated by the induction of the pertinent metabolic pathway. PMID:7138800

  15. [Microalbuminuria and urinary albumin excretion in clinical practice].

    PubMed

    Tagle, Rodrigo; González, Fernando; Acevedo, Mónica

    2012-06-01

    Microalbuminuria is a new tool in the management of patients with diabetes mellitus or hypertension. Microalbuminuria is an easily measured biomarker in a urine sample. Urinary albumin to creatinine ratio in first morning urine sample correlates with 24 hours urinary albumin excretion, but it is easier to obtain, and can identify hypertensive or diabetic patients with high risk for cardiovascular events. Therapeutic interventions such as renin angiotensin system blockade have demonstrated their usefulness in reducing urinary albumin excretion in clinical studies. It would be advisable to incorporate urinary albumin to creatinine ratio to the routine clinical monitoring of patients with cardiovascular risk, such as those with hypertension and diabetes mellitus.

  16. Episodic hypoglycemia with psi-hydroxy fatty acid excretion.

    PubMed

    Colle, E; Mamer, O A; Montgomery, J A; Miller, J D

    1983-02-01

    We present case histories of two young children with episodes of hypoglycemia, elevation of SGOT, low insulin levels, increased urinary excretion of psi-hydroxy fatty acids (5-hydroxyhexanoic, 7-hydroxyoctanoic and 9-hydroxydecanoic), traces of the corresponding psi-ketoacids and elevations of urinary adipic, suberic, and sebacic acids. The ratio of psi-hydroxy fatty acids to 3-hydroxybutyric in the urine of these patients is higher than in patients of similar ages with similar illnesses. These acids persisted while the patients were well. Increased urinary psi-hydroxy fatty acids could be reproduced by a load of medium chain triglycerides without precipitating other clinical symptoms. Three children with hypoglycemia were found not to excrete measurable amounts of these unusual acids while ill. A medium chain triglyceride load in one of these children after recovery failed to elicit psi-hydroxy acid excretion. Small amounts of urinary 5-hydroxyhexanoic acid only were found in two patients with acute Reye's syndrome and in three of five severely ill children with starvation ketonuria. In this last group, no urinary psi-hydroxyacids could be detected after recovery. Normal children do not excrete measurable amounts (less than 1 mg/g creatinine) of these psi-hydroxyacids.

  17. INFLUENCE OF DIETARY ARSENIC ON URINARY ARSENIC METABOLITE EXCRETION

    EPA Science Inventory

    Influence of Dietary Arsenic on Urinary Arsenic Metabolite Excretion

    Cara L. Carty, M.S., Edward E. Hudgens, B.Sc., Rebecca L. Calderon, Ph.D., M.S.P.H., Richard Kwok, M.S.P.H., Epidemiology and Biomarkers Branch/HSD, NHEERL/US EPA; David J. Thomas, Ph.D., Pharmacokinetics...

  18. Biliary excretion in dogs: evidence for a molecular weight threshold.

    PubMed

    Yang, Xinning; Gandhi, Yash A; Morris, Marilyn E

    2010-04-16

    Molecular weight (MW) is known as an important factor of biliary excretion in rats, guinea pigs, rabbits and humans. The objective of this study was to evaluate the relationship between the biliary excretion and MW of drugs in dogs. Data on the percentage of dose excreted into bile as parent drug (PD(b)) in dogs were collected from the literature for 134 compounds. Receiver operating characteristic (ROC) curve analysis was utilized to determine whether a MW threshold exists for PD(b). A MW threshold of 375-400 Da was established for anions in dogs, which is similar with the cutoff value observed in rats (400 Da) but lower than the one in humans (475 Da). No MW threshold was found for cations or cations/neutral compounds. A molecular volume threshold of 300A(3) was also determined for anions in dogs, which corresponds to a MW of 394 Da. In conclusion, our analysis suggested the presence of a MW cutoff for anions in dogs, which may be related with the molecular size of a compound. This represents the first report of the influence of MW or molecular volume as a determinant of biliary excretion for a structurally diverse set of compounds in dogs.

  19. Increased leukotriene E4 excretion in systemic mastocytosis.

    PubMed

    Butterfield, Joseph H

    2010-06-01

    Cysteinyl leukotrienes such as LTE(4) are produced by mast cells, neutrophils, eosinophils, and macrophages. LTE(4) levels have not been reported in systemic mastocytosis, a disorder with a large increase in mast cell numbers. Urinary LTE(4) from patients referred for symptoms potentially due to mast cell degranulation or systemic mastocytosis was measured by a commercial cysteinyl leukotriene enzyme immunoassay kit. The diagnosis of systemic mastocytosis was established using current World Health Organization criteria. Compared with a control group of patients with various potential mast cell-related symptoms (e.g., "spells"), patients with systemic mastocytosis had a significant (P=.01) increase in urinary LTE(4) excretion, whether expressed as LTE(4) ng/g creatinine or as LTE(4) ng/24h. There was a moderate correlation of LTE(4) ng/24h with excretion of N-methyl histamine and serum tryptase but not with urinary 11beta-prostaglandin F(2alpha) (11beta-PGF(2alpha)) excretion. LTE(4) excretion is increased in patients with systemic mastocytosis and potentially contributes to clinical symptoms.

  20. Renal Regulation of Acid-Base Balance: Ammonia Excretion.

    ERIC Educational Resources Information Center

    Tanner, George A.

    1984-01-01

    Describes an experiment which demonstrates changes in ammonia excretion and urine pH that occur in response to metabolic acidosis (induced by ammonium chloride ingestion) or metabolic alkalosis (produced by sodium bicarbonate ingestion). List of materials needed and background information are included. Typical results are provided and discussed.…

  1. Predicting nitrogen excretion in commercial grazing system dairy farms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improving nitrogen (N) management on dairy farms is best facilitated through management of dairy cow feed N intakes (NI), due to strong associations between NI, feed N use efficiencies (NUE, proportion of NI secreted as milk N) and manure N excretion (Nex). Milk urea N (MUN) has also been used as an...

  2. Urinary Albumin Excretion and Vascular Function in Rheumatoid Arthritis

    PubMed Central

    2016-01-01

    Rheumatoid arthritis (RA) is associated with significant cardiovascular (CV) morbidity and mortality. Increased urinary albumin excretion is a marker of CV risk. There are only few data on urinary albumin excretion in RA patients. Aim of the present study was to investigate urinary albumin excretion in RA patients and analyze, whether there is an association between urinary albumin excretion and vascular function as measured by the augmentation index (AIx). In a total of 341 participants (215 with RA, 126 without RA) urinary albumin-creatinine ratio (ACR) was determined and the AIx was measured. The Kolmogorov-Smirnov-test was used to cluster patient groups whose distributions of ACR can be considered to be equal. A crude analysis showed a median ACR of 6.6 mg/g in the RA group and 5.7 mg/g in patients without RA (P > 0.05). In order to account for diabetes (DM) we formed 4 distinct patient groups. Group 1: RA-/DM- (n = 74); group 2: RA+/DM- (n = 195); group 3: RA-/DM+ (n = 52); group 4: RA+/DM+ (n = 20). Clustering of these groups revealed two distinct patient groups: those without RA and DM, and those with either RA or DM or both. The latter group showed statistically significant higher ACR (median 8.1 mg/g) as the former (median 4.5 mg/g). We found no significant correlation between AIx and ACR. Urinary albumin excretion in patients with RA or DM or both is higher than in subjects without RA and DM. This can be seen as a sign of vascular alteration and increased CV risk in these patients. PMID:26955238

  3. Increased Renal Solute Excretion in Rats Following Space Flight

    NASA Technical Reports Server (NTRS)

    Wade, Charles E.; Moore, A. L.; Morey-Holton, E.

    1995-01-01

    Following space flight a diuresis, due to an increase in free water clearance, has been suggested in humans. To assess the effects of space flight on renal function, rats were flown in space for 14 days. Rats were divided into three groups; vivarium controls (V;n=6; housed 2/shoe box cage), flight controls (FC;n=6; group housed in a flight cage), and flight animals (F;n=6). Upon landing all animals were placed into individual metabolic cages. Urine was collected daily for 7 days and every other day for 14 days. Urine output was increased (p less than 0.05; ANOVA) following flight for 3 days. On postflight day 1, flow rates were, V=6.8 plus or minus 0.9, FC=8.711.8 and F=16.6 plus or minus 2.7 microliter/min. Excretion rates of Na+ and K+ were increased, resulting in an increased osmotic excretion rate (V=7.9 plus or minus 0.9, FC=6.1 plus or minus 0.7 and F=13.5 plus or minus 0.7 uOsm/min). Creatinine excretion rate was increased over the first two postflight days. In the absence of changes in plasma creatinine, Na+, or K+ (samples obtained immediately post flight from similar rats compared to Day 14), GFR was increased following space flight. The increased excretion of solute was thus the result of increased delivery and decreased reabsorption. Osmotic clearance was increased (V=28, FC=27 and F=51 microliter/min), while free water clearance was decreased post flight (V=-21,FC=-18 and F=-34 microliter/min). In rats, the postflight diuresis is the result of an increase in solute (osmotic) excretion with an accompanying reduction in free water clearance.

  4. Impairment of renal sodium excretion in tropical residents - phenomenological analysis

    NASA Astrophysics Data System (ADS)

    Arthur, S. K.; Aryee, P. A.; Amuasi, J.; Hesse, I. F. A.; Affram, R. K.

    There is evidence of impaired renal sodium excretion in salt-sensitive African Blacks. A decreased rate of renal sodium chloride (NaCl) excretion, low plasma renin activity and a tendency to elevated blood pressure are the hallmarks of salt sensitivity. Recent evidence indicates that increased proximal and distal tubular fluid reabsorption in some tropical residents may explain the impaired sodium excretion in these people. In this study of a cohort population, we speculated that subjects selected from that population might be salt-sensitive. We therefore measured the sodium balance in 10 normotensive male subjects over 10 consecutive days, after they had ingested a normal or a high amount of sodium, as NaCl (salt) in their diet. We quantified their renal sodium excretion rate by phenomenological analysis of their sodium balance data. We also measured plasma renin activity for 7 consecutive days in a separate group of 6 male and 4 female subjects in order to assess the state of their renin/angiotensin system. We selected all our subjects from a cohort population of 269 subjects randomly selected from a community known to have a high prevalence of primary hypertension. Our data on two separate groups of subjects from the same cohort population revealed delayed renal sodium excretion with t1/2 of about 5 days, compared to published data for normal individuals with t1/2 of less than 24 h. Also, plasma renin activity levels were low. Hence, our subjects are salt-sensitive. Quantification of their renal impairment is important for various reasons: it heightens one's appreciation of the problem of salt retention in African Blacks who are salt-sensitive and it also underlines the importance of the need for further research into the benefits of dietary salt restriction for reducing cardiovascular mortality in African populations, as has been done in some Western countries.

  5. Intake and urinary excretion of sodium chloride under varying conditions of effort and environment heat

    NASA Technical Reports Server (NTRS)

    Zohar, E.; Adar, R.; Tennenbaum, J.; Kesten, M.

    1982-01-01

    Intake and urinary excretion of sodium were investigated in a group of young, healthy and acclimated men. The sodium excretions of workers and of machinists in the engine rooms of a ship were also investigated.

  6. The effect of lithium salts on the urinary excretion of α-oxoglutarate in man

    PubMed Central

    Bond, P. A.; Jenner, F. A.; Lee, C. R.; Lenton, Elizabeth; Pollitt, R. J.; Sampson, Gwyneth A.

    1972-01-01

    1. Lithium ions in therapeutic doses cause an increase in the renal excretion of α-oxoglutarate and glutaric acid. 2. The excretion is probably due to reduced renal tubular reabsorption. 3. Neither citrate, lactate nor pyruvate excretion rises. PMID:5084816

  7. Efficient production of ectoine using ectoine-excreting strain.

    PubMed

    Zhang, Ling-hua; Lang, Ya-jun; Nagata, Shinichi

    2009-07-01

    Halophilic bacteria strain Halomonas salina DSM 5928 was found to excrete ectoine, suggesting its potential in the development of a new method of ectoine production. We performed HPLC and LC-MS analyses that showed that Halomonas salina DSM 5928 excreted ectoine under constant extracellular osmolarity. Medium adopting monosodium glutamate as a sole source of carbon and nitrogen was beneficial for ectoine synthesis. The total concentration of ectoine was not affected by NaCl concentration in the range 0.5-2 mol l(-1). The total concentration of ectoine and productivity in a 10-l fermentor with 0.5 mol l(-1) NaCl were 6.9 g l(-1) and 7.9 g l(-1) d(-1), respectively. These findings show that Halomonas salina DSM 5928 efficiently produces ectoine at relatively low NaCl concentration. This research also indicates the potential application of free or immobilized cells for continuous culture to produce ectoine.

  8. Urinary selenium excretion in patients with cervical uterine cancer.

    PubMed

    Navarrete, M; Gaudry, A; Revel, G; Martínez, T; Cabrera, L

    2001-02-01

    In this work, we report on a relationship between urinary selenium and the development of cervical uterine cancer. A simple chemical method was developed to concentrate trace amounts of selenium from relatively large urine samples by use of small activated carbon filters. When these filters are irradiated with thermal neutrons, selenium can be determined either by 77mSe (t1/2 = 17.5 s) or 75Se (t1/2 = 120 d). In this article, we report the results for 82 urine samples from women with cervical uterine cancer in several stages of development and from healthy controls. These results show a statistically significant increase of selenium excretion in cancer patients as compared to controls. Urinary selenium excretion is highest for patients in the intermediate stages of the disease.

  9. Altered amino acid excretion in children with autism.

    PubMed

    Evans, Craig; Dunstan, R Hugh; Rothkirch, Tony; Roberts, Tim K; Reichelt, Karl L; Cosford, Robyn; Deed, Gary; Ellis, Libby B; Sparkes, Diane L

    2008-02-01

    Autism is a complex and life-long behavioural disorder of unknown aetiology. Recent reports have indicated the involvement of digestive tract dysfunction and possible complications from inadequate nutrition. In this study, 34 autistic children (12 untreated and 22 receiving therapeutic treatments related to digestive function and nutritional uptake) and 29 control subjects (all 5-15 years of age) were investigated to determine whether there were any anomalies in the urinary excretion of amino acids, glucose, sucrose, arabinose and tartaric acid using GC/FID and GC/MS analysis techniques. Significantly lower relative urinary levels of essential amino acids were revealed for both the untreated (mean +/- SEM, 32.53 +/- 3.09%) and treated (31.98 +/- 2.87%) autistic children compared with the controls (37.87 +/- 1.50%). There were no significant differences in measured excretions of sugars or tartaric acid. It was concluded that the untreated autistic children had evidence of altered metabolic homeostasis.

  10. Metabolism and excretion of orally administered arsenobetaine in the hamster

    SciTech Connect

    Yamauchi, H.; Kaise, T.; Yamamura, Y.

    1986-03-01

    Arsenobetaine, one of the trimethylarsenic compounds (TMA), occurs abundantly in seafoods. The urinary excretion pattern of arsenic in man following oral ingestion of TMA contained in fishes once only indicates that the most portion of the TMA is excreted in urine. These experiments in humans have used fish arsenic but no authentic arsenobetaine. From previous experiments in mice, rats and rabbits using/sup 73/As-labeled arsenobetaine, it was reported that arsenobetaine is not converted in vivo into any other chemical species of arsenic. The metabolic and excretory patterns of arsenic compounds in the hamster seem to be similar to those in humans. In the present study, the authors examined arsenobetaine-treated hamsters for what chemical species of arsenic this arsenic compound (arsenobetaine) would be metabolized into in vivo and also for its excretory patterns in urine and feces with time.

  11. Moderate alcohol consumption and urinary excretion of magnesium and calcium.

    PubMed

    Rylander, R; Mégevand, Y; Lasserre, B; Amstutz, W; Granbom, S

    2001-01-01

    The aim of this study was to evaluate the magnesium (Mg) status of male subjects consuming moderate amounts of alcohol (n = 14) in comparison with that of a group of non-consumers of alcohol (n = 10). Plasma ionized Mg levels and total erythrocyte Mg content were determined as well as the excretion of Mg in urine before and after an oral loading test. Intake of Mg via food and water was estimated using a one-week dietary records. The results showed a significantly higher, alcohol dose-related excretion of Mg and Ca (calcium) in the urine after the oral Mg load among consumers of alcohol. Although the study is based on a small number of subjects with differences in smoking habits, it is suggested that alcohol consumption even in moderate amounts could contribute to Mg deficiency.

  12. III. Quantitative aspects of phosphorus excretion in ruminants.

    PubMed

    Bravo, David; Sauvant, Daniel; Bogaert, Catherine; Meschy, François

    2003-01-01

    Ruminant phosphorus excretion and metabolism were studied through a database. Faecal endogenous phosphorus is the main pathway of phosphorus excretion and averages 0.85 of total faecal phosphorus. The remaining 0.15 is unabsorbed dietary phosphorus. Faecal endogenous phosphorus is mainly unabsorbed phosphorus, with saliva being the major source, and is correlated to factors influencing saliva secretion (DM intake, physical dietary characteristics and dietary phosphorus content). Another source of faecal endogenous phosphorus is rumen microbial phosphorus that escaped solubilisation during post-rumen digestion. All factors stimulating microbial growth would increase phosphorus uptake by the rumen microbes and consequently the faecal endogenous phosphorus. Understanding the determinants of faecal endogenous phosphorus flow will help to precise the determination of net phosphorus requirements for maintenance. The role of plasma phosphorus in urinary phosphorus loss is discussed.

  13. Results of a quality assurance exercise for urinary glycosaminoglycan excretion.

    PubMed

    Brimble, A; Pennock, C; Stone, J

    1990-03-01

    Urine samples collected from four patients with a mucopolysaccharide storage disease (MPS) and two non-MPS patients were distributed to up to 33 laboratories as a test of their ability to detect abnormal glycosaminoglycan excretion. Seven national reference laboratories made a correct diagnostic assignment to all samples analysed. Qualitative turbidity and spot tests were shown to be unreliable. Failure to identify the excretion pattern occurred when reliance was placed on one-dimensional electrophoresis or thin layer chromatography as the sole method for glycosaminoglycan identification. Two-dimensional electrophoresis appeared to be the method of choice provided that staff had adequate experience in interpretation. Clinically unacceptable delays in analysis were common, with 80% of laboratories taking longer than 10 days to issue a report.

  14. Salivary excretion of rabies virus by healthy vampire bats.

    PubMed Central

    Aguilar-Setien, A.; Loza-Rubio, E.; Salas-Rojas, M.; Brisseau, N.; Cliquet, F.; Pastoret, P. P.; Rojas-Dotor, S.; Tesoro, E.; Kretschmer, R.

    2005-01-01

    Salivary excretion of rabies virus was evaluated in 14 adult vampire bats (Desmodus rotundus) intramuscularly injected with a large dose (10(6) MICLD50) of vampire rabies virus variant CASS88. Saliva samples were obtained from surviving bats every other day for 30 days, then weekly for 2 months, and finally 1 and 2 years later. Rabies virus was isolated in murine neuroblastoma cells and in randomly selected cases by PCR. Rabies virus was not detected in the saliva of any of the 11 animals that succumbed (somewhat early) to rabies challenge, nor in the control bats. In contrast, virus was detected early, and only once (days 6, 6 and 21) in each of the three animals that survived rabies challenge and remained healthy for at least 2 years after challenge. At that time even vigorous dexamethasone and cyclosporine administration failed to provoke further viral excretion. PMID:15966107

  15. Salivary excretion of rabies virus by healthy vampire bats.

    PubMed

    Aguilar-Setien, A; Loza-Rubio, E; Salas-Rojas, M; Brisseau, N; Cliquet, F; Pastoret, P P; Rojas-Dotor, S; Tesoro, E; Kretschmer, R

    2005-06-01

    Salivary excretion of rabies virus was evaluated in 14 adult vampire bats (Desmodus rotundus) intramuscularly injected with a large dose (10(6) MICLD50) of vampire rabies virus variant CASS88. Saliva samples were obtained from surviving bats every other day for 30 days, then weekly for 2 months, and finally 1 and 2 years later. Rabies virus was isolated in murine neuroblastoma cells and in randomly selected cases by PCR. Rabies virus was not detected in the saliva of any of the 11 animals that succumbed (somewhat early) to rabies challenge, nor in the control bats. In contrast, virus was detected early, and only once (days 6, 6 and 21) in each of the three animals that survived rabies challenge and remained healthy for at least 2 years after challenge. At that time even vigorous dexamethasone and cyclosporine administration failed to provoke further viral excretion.

  16. Plasma pharmacokinetics, faecal excretion and efficacy of pyrantel pamoate paste and granule formulations following per os administration in donkeys naturally infected with intestinal strongylidae.

    PubMed

    Gokbulut, Cengiz; Aksit, Dilek; Smaldone, Giorgio; Mariani, Ugo; Veneziano, Vincenzo

    2014-09-15

    The plasma disposition, faecal excretion and efficacy of two formulations of pyrantel pamoate in donkeys were examined in a controlled trial. Three groups of seven donkeys received either no medication (control) or pyrantel paste or granule formulations at horse dosage of 20mg/kg B.W. (equals 6.94 mg/kg PYR base) of body weight. Heparinized blood and faecal samples were collected at various times between 1 and 144 h after treatment. The samples were analysed by high-performance liquid chromatography. The last detectable plasma concentration (tmax) of paste formulation was significantly earlier (36.00 h) compared with granule formulation (46.29 h). Although, there was no significant difference on terminal half lives (t1/2: 12.39 h vs. 14.86 h), tmax (14.86 h vs. 14.00) and MRT (24.80 h vs. 25.44 h) values; the Cmax (0.09 μg/ml) AUC (2.65 μgh/ml) values of paste formulation were significantly lower and smaller compared with those of granule formulation (0.21 μg/ml and 5.60 μgh/ml), respectively. The highest dry faecal concentrations were 710.46 μg/g and 537.21 μg/g and were determined at 48 h for both paste and granule formulation of PYR in donkeys, respectively. Pre-treatment EPG of 1104, 1061 and 1139 were observed for the control, PYR paste and PYR granule groups, respectively. Pre-treatment EPG were not significantly different (P>0.1) between groups. Post-treatment EPG for both PYR treatment groups were significantly different (P<0.001) from the control group until day 35. Following treatments the PYR formulations were efficient (>95% efficacy) until day 28. In all studied donkeys, coprocultures performed at day-3 revealed the presence of Cyathostomes, S. vulgaris. Faecal cultures performed on different days from C-group confirmed the presence of the same genera. Coprocultures from treated animals revealed the presence of few larvae of Cyathostomes.

  17. A Micropuncture Study of Potassium Excretion by the Remnant Kidney

    PubMed Central

    Bank, Norman; Aynedjian, Hagop S.

    1973-01-01

    In order to study the mechanism of enhanced potassium excretion by the remaining nephrons of the remnant kidney, micropuncture and clearance experiments were carried out in rats after surgical ablation of 3/4 of the total renal mass. The potassium intake in all animals was approximately 5 meq/day. Animals were studied 24 h and 10-14 days after 3/4 nephrectomy. Balance measurements in the chronic animals before micropuncture study indicated that 24 h K+ excretion by the remnant kidney was equal to that of the two kidneys before ablation of renal mass. Measurements of distal tubular inulin and potassium concentrations revealed progressive reabsorption of potassium in this segment of the nephron in both the 24-h and chronic 3/4-nephrectomized rats, as well as in normal control rats. A large increase in tubular fluid potassium content occurred between the end of the distal tubule and the final urine in the 3/4-nephrectomized rats, but not in the normal controls. These observations suggest that the segment of the nephron responsible for enhanced potassium excretion by remaining nephrons was the collecting duct. In additional experiments, potassium was completely eliminated from the diet of chronic 3/4-nephrectomized rats before micropuncture study. In these animals, no addition of K+ occurred beyond the distal tubules. Normal rats infused with 0.15 M KCl to acutely elevate serum K+ concentration, demonstrated reabsorption of K+ in the distal tubule and a large addition of K+ to the urine beyond the distal tubule. We conclude that the collecting duct is the major site of regulation of urinary potassium excretion in normal rats and is responsible for the adaptation to nephron loss by the remnant kidney. PMID:4703232

  18. Steroid hormone excretion is enhanced by sucrose feeding to rats

    SciTech Connect

    Kruger, T.C.; Hsu, H.; Saunders, J.P.; Kim, S.S.; Given-Proctor, J.; Ahrens, R.A.

    1986-03-01

    The hypothesis tested was that feeding rats sucrose rather than invert sugar (50:50 mixture of glucose and fructose) or cornstarch would result in a more rapid excretion of intravenously injected 1,2-/sup 3/H aldosterone or 1,2,6,7-/sup 3/H cortisol. The three carbohydrate sources provided 45% of dietary energy when fed, respectively, to one of three groups of 10 male, Sprague Dawley rats. After 4 or 8 weeks of ad lib feeding of the three diets 5 ..mu..CI of /sup 3/H-labeled hormones were injected intravenously and % recovery in urine and feces was measured for 4 days by liquid scintillation counting. Nearly 90% of the /sup 3/H injected as 1,2-/sup 3/H aldosterone was recovered over 4 days in the excreta of the sucrose fed rats. This recovery of /sup 3/H from aldosterone was significantly greater (P < 0.01) than when invert sugar (65%) or cornstarch (60%) were fed. The recovery of /sup 3/H from intravenously injected 1,2,6,7-/sup 3/H cortisol followed a similar pattern. The authors anticipate that the excretion of all metabolic end products and xenobiotics excreted as glucuronides would be enhanced by sucrose feeding. Oxocarbonium ions from the glucose portion of sucrose digestion in the mammalian small intestine are thought to compete with oxocarbonium ions from the glucuronic acid portion of glucuronide hydrolysis. Such competition may slow glucuronide hydrolysis and promote glucuronide excretion, including the glucuronides derived from aldosterone and cortisol.

  19. Mechanism of Impaired Water Excretion in the Hypothyroid Rat

    PubMed Central

    Emmanouel, Dimitrios S.; Lindheimer, Marshall D.; Katz, Adrian I.

    1974-01-01

    The ability to excrete an oral water load and the renal diluting mechanism were studied in hypothyroid rats and in age-matched euthyroid controls. Hypothyroid animals excreted a significantly smaller fraction of a 50-ml/kg oral water load than controls, demonstrating the same limited ability to excrete free water as thyroid-deficient man. During hypotonic (0.45%) saline infusion, absolute sodium delivery to the diluting segment and free water clearance were markedly lower in hypothyroid rats. However, both fractional distal sodium delivery and fractional free water clearance were similar in hypothyroid and control animals, suggesting that the reduced absolute free water formation in hypothyroid rats was due to decreased net distal delivery. In support of this hypothesis was the observation that fractional distal sodium reabsorption was equal or higher in thyroid-deficient rats, which indicates that the sodium reabsorptive capacity of the diluting segment was preserved in these animals. The results cannot be attributed to incomplete suppression of antidiuretic hormone (ADH) since they were identical in diabetes insipidus rats, nor to different rates of non-ADH-dependent backflux of filtrate since tissue osmolality and solute concentrations in the cortex, medulla, and papilla were similar in hypothyroid and control rats of both Sprague-Dawley and Brattleboro strains. The functional integrity of the diluting segment in hypothyroid rats was further demonstrated in experiments in which distal delivery was increased by contralateral nephrectomy or by administration of carbonic anhydrase inhibitors which decrease proximal sodium reabsorption. In both studies, fractional free water clearance increased markedly reaching levels significantly greater than in euthyroid controls. These results demonstrate that the impaired ability of the hypothyroid rat to excrete a water load is not due to incomplete suppression of ADH or decreased reabsorptive capacity of the diluting segment

  20. Microalbumin excretion in patients with positive exercise electrocardiogram tests.

    PubMed

    Horton, R C; Gosling, P; Reeves, C N; Payne, M; Nagle, R E

    1994-10-01

    Thirty-three subjects underwent exercise electrocardiogram testing, 20 had a history of myocardial infarction and 13 were age-matched volunteers. Exercise electrocardiograms were positive in 15 subjects, negative in 12 and anomalous in six. Urinary microalbumin excretion was measured at rest, 30 and 60 min after exercise. Urinary microalbumin excretion was expressed as the albumin-creatinine ratio in mg.mmol-1. In the positive exercise electrocardiogram group median albumin-creatinine ratio increased from 1.0 mg.mmol-1 (95% CI 0.94-1.49) at rest to 2.0 mg.mmol-1 (95% CI 1.51-3.94) 30 min after exercise, whilst in the negative electrocardiogram group median resting and 30 min post exercise albumin-creatinine ratio values of 0.85 (95% CI 0.53-1.32) and 1.80 (95% CI 0.63-2.32) mg.mmol-1 respectively were not significantly different. These results suggest that exercise-induced myocardial ischaemia is associated with increased urinary microalbumin excretion.

  1. Biliary excretion of iron and ferritin in idiopathic hemochromatosis

    SciTech Connect

    Hultcrantz, R.; Angelin, B.; Bjoern-Rasmussen, E.E.; Ewerth, S.; Einarsson, K.

    1989-06-01

    The role of biliary excretion of iron and ferritin in iron overload was studied and evaluated. Ten patients with idiopathic hemochromatosis and two groups of controls (14 gallstone patients and 16 healthy subjects) were included. Liver tissue (obtained by percutaneous or operative biopsy) was investigated with light microscopy and transmission electron microscopy in combination with x-ray microanalysis. Fasting bile samples were obtained through duodenal aspiration or at cholecystectomy. Iron was determined in liver tissue and bile using atomic absorption spectroscopy, and ferritin was determined in serum and bile with a radioimmunoassay technique. All patients with hemochromatosis had iron-positive staining as seen in light microscopy. Electron microscopy showed iron-containing proteins in the lysosomes and cytosol of liver parenchymal cells, and this observation was supported by x-ray microanalysis. Hepatic iron concentration was increased about eightfold in the patients with hemochromatosis (p less than 0.001). Biliary iron concentration, expressed per millimole of bile acid, was increased about twofold (p less than 0.05) and biliary ferritin concentration about fivefold (p less than 0.001) in hemochromatosis. Four of the patients with hemochromatosis were reexamined after completed treatment with venesection; this resulted in normalized biliary concentrations of iron and ferritin. We conclude that biliary secretion of ferritin occurs in humans and that both iron and ferritin excretion are enhanced in hepatic iron overload. The apparently limited capacity of biliary iron excretion may be of importance for the hepatic iron accumulation in hemochromatosis.

  2. A proteolytic modification of AIM promotes its renal excretion

    PubMed Central

    Yamazaki, Tomoko; Sugisawa, Ryoichi; Hiramoto, Emiri; Takai, Ryosuke; Matsumoto, Ayaka; Senda, Yoshie; Nakashima, Katsuhiko; Nelson, Peter S.; Lucas, Jared M.; Morgan, Andrew; Li, Zhenghua; Yamamura, Ken-ichi; Arai, Satoko; Miyazaki, Toru

    2016-01-01

    Apoptosis inhibitor of macrophage (AIM, encoded by cd5l) is a multi-functional circulating protein that has a beneficial role in the regulation of a broad range of diseases, some of which are ameliorated by AIM administration in mice. In blood, AIM is stabilized by association with IgM pentamers and maintains its high circulating levels. The mechanism regulating the excessive accumulation of blood AIM remains unknown, although it is important, since a constitutive increase in AIM levels promotes chronic inflammation. Here we found a physiological AIM-cleavage process that induces destabilization of AIM and its excretion in urine. In blood, IgM-free AIM appeared to be cleaved and reduced in size approximately 10 kDa. Cleaved AIM was unable to bind to IgM and was selectively filtered by the glomerulus, thereby excreted in urine. Amino acid substitution at the cleavage site resulted in no renal excretion of AIM. Interestingly, cleaved AIM retained a comparable potency with full-length AIM in facilitating the clearance of dead cell debris in injured kidney, which is a key response in the recovery of acute kidney injury. Identification of AIM-cleavage and resulting functional modification could be the basis for designing safe and efficient AIM therapy for various diseases. PMID:27929116

  3. Excreted Cytoplasmic Proteins Contribute to Pathogenicity in Staphylococcus aureus

    PubMed Central

    Ebner, Patrick; Rinker, Janina; Nguyen, Minh Thu; Popella, Peter; Nega, Mulugeta; Luqman, Arif; Schittek, Birgit; Di Marco, Moreno; Stevanovic, Stefan

    2016-01-01

    Excretion of cytoplasmic proteins in pro- and eukaryotes, also referred to as “nonclassical protein export,” is a well-known phenomenon. However, comparatively little is known about the role of the excreted proteins in relation to pathogenicity. Here, the impact of two excreted glycolytic enzymes, aldolase (FbaA) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), on pathogenicity was investigated in Staphylococcus aureus. Both enzymes bound to certain host matrix proteins and enhanced adherence of the bacterial cells to host cells but caused a decrease in host cell invasion. FbaA and GAPDH also bound to the cell surfaces of staphylococcal cells by interaction with the major autolysin, Atl, that is involved in host cell internalization. Surprisingly, FbaA showed high cytotoxicity to both MonoMac 6 (MM6) and HaCaT cells, while GAPDH was cytotoxic only for MM6 cells. Finally, the contribution of external FbaA and GAPDH to S. aureus pathogenicity was confirmed in an insect infection model. PMID:27001537

  4. Urinary excretion of morphine and biosynthetic precursors in mice

    PubMed Central

    Grobe, Nadja; Lamshöft, Marc; Orth, Robert G.; Dräger, Birgit; Kutchan, Toni M.; Zenk, Meinhart H.; Spiteller, Michael

    2010-01-01

    It has been firmly established that humans excrete a small but steady amount of the isoquinoline alkaloid morphine in their urine. It is unclear whether it is of dietary or endogenous origin. There is no doubt that a simple isoquinoline alkaloid, tetrahydropapaveroline (THP), is found in human and rodent brain as well as in human urine. This suggests a potential biogenetic relationship between both alkaloids. Unlabeled THP or [1,3,4-D3]-THP was injected intraperitoneally into mice and the urine was analyzed. This potential precursor was extensively metabolized (96%). Among the metabolites found was the phenol-coupled product salutaridine, the known morphine precursor in the opium poppy plant. Synthetic [7D]-salutaridinol, the biosynthetic reduction product of salutaridine, injected intraperitoneally into live animals led to the formation of [7D]-thebaine, which was excreted in urine. [N-CD3]-thebaine was also administered and yielded [N-CD3]-morphine and the congeners [N-CD3]-codeine and [N-CD3]-oripavine in urine. These results show for the first time that live animals have the biosynthetic capability to convert a normal constituent of rodents, THP, to morphine. Morphine and its precursors are normally not found in tissues or organs, presumably due to metabolic breakdown. Hence, only that portion of the isoquinoline alkaloids excreted in urine unmetabolized can be detected. Analysis of urine by high resolution-mass spectrometry proved to be a powerful method for tracking endogenous morphine and its biosynthetic precursors. PMID:20421505

  5. Plasma pharmacokinetics and urinary excretion of hexamethylene bisacetamide metabolites.

    PubMed

    Egorin, M J; Zuhowski, E G; Cohen, A S; Geelhaar, L A; Callery, P S; Van Echo, D A

    1987-11-15

    In order to further understand the clinical toxicities of hexamethylene bisacetamide (HMBA) and to allow appropriate in vitro studies, we developed a suitable gas chromatographic assay and quantified plasma concentrations and urinary excretion of four metabolites which we had previously identified in urine of patients receiving 5-day HMBA infusions at 4.8-43.2 g/m2/day. 6-Acetamidohexanoic acid (AcHA) was the major plasma metabolite and reached steady state concentration (Css) by 24 h. AcHA Css increased from 0.12 +/- 0.02 (SD) mM at 4.8 g/m2/day to 0.72 mM at 43.2 g/m2/day. The Css AcHA:Css HMBA ratio decreased with increasing HMBA dosage. At dosages below 24 g/m2/day plasma Css of N-acetyl-1,6-diaminohexane (NADAH), the initial metabolite of HMBA, were below the limit of detection of our assay. With HMBA infusions of 24, 33.6, and 43.2 g/m2/day, Css of NADAH were 0.16 +/- 0.05, 0.14 +/- 0.06, and 0.19 +/- 0.04 mM, respectively. Css NADAH:Css HMBA ratios at 24, 33.6, and 43.2 g/m2/day were 0.18 +/- 0.06, 0.08 +/- 0.02, and 0.31 +/- 0.05, respectively. Plasma Css of 1,6-diaminohexane and 6-aminohexanoic acid were below the limit of detection of our assay. Each patient's urinary excretion of NADAH, AcHA, and 1,6-diaminohexane was consistent from day to day. The fraction of dose excreted in urine as AcHA was not affected by HMBA dosage and accounted for 12.7 +/- 3.9% of the daily dose. The percentage of daily HMBA dose accounted for by excretion of NADAH decreased with increasing HMBA dosage (10.8 +/- 6.0% at 4.8 g/m2/day to 4.2 +/- 1.2% at 33.6 g/m2/day). Urinary excretion of 1,6-diaminohexane always accounted for less than 3% of the daily dose. Our results indicate that: (a) plasma concentrations of AcHA alone cannot explain the degree of acidosis observed with toxic doses of HMBA; (b) NADAH is present in plasma at concentrations that we have found to cause differentiation in vitro; and (c) the probable rate-limiting step in HMBA metabolism is the initial

  6. Estimation of nutrient excretion factors of broiler and layer chickens in Japan.

    PubMed

    Ogino, Akifumi; Murakami, Hitoshi; Yamashita, Takahiro; Furuya, Motohiro; Kawahara, Hirofumi; Ohkubo, Takako; Osada, Takashi

    2017-04-01

    We estimated the nitrogen (N), phosphorus (P), potassium (K) and magnesium (Mg) excretion factors of broiler and layer chickens in Japan, using two approaches and the latest data available. In the top-down approach, we determined the nutrient amounts in the feeds and those in the products (i.e. the liveweight gain, eggs), and the national nutrient excretions were determined as the difference between these amounts. We then calculated the nutrient excretion factors by dividing the national excretions by the number of animals. In the bottom-up approach, we calculated the amounts of nutrients in the feed and product per head using productivity parameters (feed conversion ratio, etc.). The differences between these amounts were considered the nutrient excretion factors. The average nutrient excretion factors of broilers (g/day/head) estimated using the top-down and bottom-up approaches were: N, 1.40 and 1.87; P, 0.36, 0.50; K, 0.54, 0.77; Mg, 0.13, 0.18, respectively. The excretion factors obtained by the top-down approach can be used to calculate the national/regional excretions. The two approaches resulted in almost the same excretion factors for layers, and the average nutrient excretion factors of layers (g/day/head) estimated were: N, 2.20; P, 0.55; K, 0.68; Mg, 0.23. The estimated excretion factors for N (only) are smaller than the reported factors.

  7. Chlordecone impaired biliary excretion: In vivo and in vitro correlates

    SciTech Connect

    Rochelle, L.G.

    1989-01-01

    The focus of this research was to investigate mechanisms of impaired biliary excretion localized to the bile canaliculus. Two modes of chlordecone (CD) action were investigated: (1) direct effects on organic anion transport at the bile canaliculus; and/or (2) general membrane perturbation, indirectly affecting anion transport proteins. Bile canaliculi-enriched fractions (BCEF) were isolated from rat livers in order to characterize effects of CD on this domain of the plasma membranes. CD inhibited the initial rate leading to a peak Na{sup +}-stimulated ({sup 3}H)L-glutamate uptake in BCEF CD inhibition of the initial or Na{sup +}-gradient driven phase of ({sup 3}H)L-glutamate uptake suggested that CD was affecting maintenance of the Na{sup +}-gradient by the BCEF membrane vesicles. In vivo PG anion excretion was inhibited as well as in vitro ({sup 3}H)L-glutamate transport at 24 hr following in vivo CD treatment of rats. Seventy-two hr following CD treatment, rats recovered to control PG excretion levels. PG excretory performance was regained in 72 hr pretreated rats despite an increase in liver CD concentration. Liver CD concentrations in 24 hr pretreated rats were approximately 50% of the concentrations in 72 hr pretreated rats. At low CD concentrations, there was no evidence of general membrane perturbation in terms of immobilization of the lipid electron spin resonance probe, 16-doxyl stearate, in BCEF. Mobility of 16-doxyl stearate in BCEF was reduced at in vitro CD concentrations of 0.20 {mu}mol/mg protein or greater. CD did reduce hepatobiliary permeability to ({sup 14}C)mannitol in 24 and 72 hr pretreated rats; perhaps restricting movement through membrane aqueous pores.

  8. Diurnal nitrogen excretion rhythm of the functionally ureogenic gobiid fish Mugilogobius abei.

    PubMed

    Kajimura, Makiko; Iwata, Katsuya; Numata, Hideharu

    2002-02-01

    This study was performed to determine the daily periodicity of urea excretion in the ureogenic gobiid fish Mugilogobius abei. In 20% seawater, urea excretion of all the fish examined showed daily periodic changes under a 12-h light-dark cycle, and some showed a free-running rhythm under constant darkness. This is the first report of a circadian rhythm in urea excretion in fishes. Daily variations in urea excretion under light-dark cycles were also observed under various conditions, i.e. exposure to water ammonia, confinement/non-confinement and solitary/group. Due to the daily variations in urea excretion, urea contents in tissues changed periodically, whereas enzyme activities related to urea synthesis did not change significantly. The index of urea permeability as determined by changes in body urea contents after 2-h immersion of 25 mM urea solution was high during the peak of daily variation in urea excretion. Locomotor activity and urea excretion showed clear daily variations under light-dark cycles, both of which were diurnal. Furthermore, daily variations in urea excretion were maintained even when the diurnal pattern in the locomotor activity was disturbed. These results suggest that periodic urea excretion was mediated by periodic enhancement of permeability for urea at excretion sites.

  9. Testosterone urinary excretion rate increases during hypergravity in male monkeys

    NASA Technical Reports Server (NTRS)

    Strollo, F.; Barger, L.; Fuller, C.

    2000-01-01

    Real and simulated microgravity impairs T secretion both in animals and in the human. To verify whether hypergravity might enhance T secretion as a consequence of an opposite mechanical effect, 6 male monkeys were centrifuged at 2 G for 3 weeks after a 1 G stabilization period lasting 3 weeks and then taken back to 1 G for 1 week and urine were collected daily for T excretion measurement. Significantly higher level were observed during the initial 2 G phase as compared to pre- and post centrifugation periods and the trend was the same during the remaining 2 G period. This may reflect changes in testicular perfusion rather than endocrine adaptation per se.

  10. Hereditary Orotic Aciduria and the Excretion of Orotidine.

    PubMed

    Nyhan, William L; Gangoiti, Jon A

    2016-12-01

    Objective Orotic aciduria and deficiency of uridine monophosphate synthetase have been observed in a patient, studied over 10 years, who had no megaloblastic anemia. Excretion of orotic acid and orotidine were 8.24 and 0.52 mmol/mol of creatinine. The ratio of 15.85 differed appreciably from that of 6 patients reported with no megaloblastic anemia. Methods The analysis of orotidine by gas chromotography mass spectrometry was conducted. Conclusion Patients with orotic aciduria with and without megaloblastic anemia cannot be distinguished by ratio of orotic acid to orotidine.

  11. Radiation dosimetry from breast milk excretion of radioiodine and pertechnetate

    SciTech Connect

    Hedrick, W.R.; Di Simone, R.N.; Keen, R.L.

    1986-10-01

    Measurements were made of the activity in samples of breast milk obtained from a patient with postpartum thyroiditis following administration of (/sup 123/I)sodium iodide and subsequently (99mTc)pertechnetate 24 hr later. Both /sup 123/I and 99mTc were found to be excreted exponentially with an effective half-life of 5.8 hr and 2.8 hr, respectively. Less than 10% of the activity was incorporated into breast-milk protein. After administration of (/sup 123/I)sodium iodide breast feeding should be discontinued for 24-36 hr to reduce the absorbed dose to the child's thyroid.

  12. Kinetics of excretion in milk of some antimastitis drugs.

    PubMed

    Aureli, P; Dominici, S; Ferrini, A M; Lepri, M L

    1990-01-01

    A study on the kinetics of excretion in milk of some antimastitis drugs is described. The five antibiotic molecules used were detected by confronting two methods: the Galesloot-Hassing method which, even though specific for the detection of penicillin in milk, is officially used for the detection of antibiotic residues in general; and the M. luteus paper disk assay, which uses M. luteus ATCC 9341 as test microorganism. The obtained results show that withdrawal times for the assayed molecules are longer than those declared and that M. luteus is more efficient for the detection of kanamycin residues.

  13. [Hepatoduodenal circulation and excretion of the new GABA derivative citrocard].

    PubMed

    Tiurenkov, I N; Perfilova, V N; Smirnova, L A; Riabukha, A F; Suchkov, E A; Lebedeva, S A

    2013-01-01

    Pharmacokinetic investigation of a new gamma-aminobutyric acid (GABA) derivative cirtocard showed that, upon the intravenous introduction, the drug is determined in high concentrations in organs of elimination--the liver and kidneys. The tissue accessibility amounts to 1.341 for the liver and 4.053 for the kidneys and the separation factor is 1.041 for the liver and 4.486 for the kidneys. The study of drug excretion showed that cirtocard is determined in the urine for 48 h, its nephritic clearance being 0.047 L/h and extra-nephritic clearance, 0.33 L/h. For the unchanged substance, a large significance ofhepatoduodenal circulation is low probable, since no more than 1 - 2% of the introduced dose was isolated with bile over entire experiment. It is established that the removal of the unchanged substance does not exceed 10% of the introduced dose. There is high probability of hepatoduodenal circulation and excretion of the preparation in the form of metabolites.

  14. High Salt Diet Affects Renal Sodium Excretion and ERRα Expression.

    PubMed

    Wang, Dan; Wang, Yang; Liu, Fu-Qiang; Yuan, Zu-Yi; Mu, Jian-Jun

    2016-04-01

    Kidneys regulate the balance of water and sodium and therefore are related to blood pressure. It is unclear whether estrogen-related receptor α (ERRα), an orphan nuclear receptor and transcription factor highly expressed in kidneys, affects the reabsorption of water and sodium. The aim of this study was to determine whether changes in the expressions of ERRα, Na⁺/K⁺-ATPase and epithelial sodium channel (ENaC) proteins affected the reabsorption of water and sodium in kidneys of Dahl salt-sensitive (DS) rats. SS.13BN rats, 98% homologous to the DS rats, were used as a normotensive control group. The 24 h urinary sodium excretion of the DS and SS.13BN rats increased after the 6-week high salt diet intervention, while sodium excretion was increased in DS rats with daidzein (agonist of ERRα) treatment. ERRα expression was decreased, while β- and γ-ENaC mRNA expressions were increased upon high sodium diet treatment in the DS rats. In the chromatin immunoprecipitation (CHIP) assay, positive PCR signals were obtained in samples treated with anti-ERRα antibody. The transcriptional activity of ERRα was decreased upon high salt diet intervention. ERRα reduced the expressions of β- and γ-ENaC by binding to the ENaC promoter, thereby increased Na+ reabsorption. Therefore, ERRα might be one of the factors causing salt-sensitive hypertension.

  15. Possible parameters in the urinary excretion of tritium

    SciTech Connect

    Cawley, C.N.; Lewis, B.A.; Cannon, L.A.

    1985-11-01

    Because of its mobility in both physical and biological systems, tritium is interesting both as a tracer and as an issue in health physics. Because tritium is extremely difficult to contain, it is one of the major radionuclides of concern if released to the environment from nuclear facilities. Relatively very large releases are tolerated because the beta particle has low energy and, therefore, the radioisotope is not a health hazard unless deposited internally. Moreover, on release to the environment, tritium enters the hydrologic cycle and is diluted and dispersed widely through the hydrosphere. It is likely that tritium uptake and loss in humans is more complex than generally believed and may be more functionally related to physiological processes, such as the bicarbonate and electrolyte balances, than to ambient environmental conditions such as temperature. Despite the many uncertainties in the analyses of experimental data on tritium contamination and excretion, it is likely that further investigations will establish both a better understanding of the tritium health hazard and the physiological processes governing excretion and, perhaps, its indefinite recycling through metabolic pools.

  16. Longitudinal fecal steroid excretion in maned wolves (Chrysocyon brachyurus).

    PubMed

    Velloso, A L; Wasser, S K; Monfort, S L; Dietz, J M

    1998-10-01

    This study used a fecal steroid monitoring technique to evaluate reproductive cycles in male (4) and female (15) maned wolves, endangered South American canids. A radiolabeled testosterone infusion on a male revealed a fast and predominantly fecal route of excretion for this steroid. Testosterone was also excreted as eight unidentified metabolites, which was not the primary form of this steroid quantified in our assays. Fecal steroid concentrations (estradiol, E2; progestins, P; testosterone, T) in males and acyclic, nonpregnant (pseudo-pregnant), and pregnant females were monitored over four breeding seasons (October-January). Significant differences were detected between longitudinal P profiles of cyclic and acyclic females during estrus, luteal phase, and after birth/end of pseudo-pregnancy. Concentrations of P were also significantly higher in pregnant, compared to nonpregnant females, from proestrus to the end of the pregnant luteal phase. Although levels of T were higher in males than in females throughout the breeding season, no cyclicity in male fecal T concentrations was detected. Values of fecal P, T, and the ratio P/T were useful for differentiating gender and detecting pregnancy in females. Similarities to available data on other canids and the management and conservation implications of these findings were discussed.

  17. Enhancement of anammox by the excretion of diel vertical migrators

    PubMed Central

    Bianchi, Daniele; Babbin, Andrew R.; Galbraith, Eric D.

    2014-01-01

    Measurements show that anaerobic ammonium oxidation with nitrite (anammox) is a major pathway of fixed nitrogen removal in the anoxic zones of the open ocean. Anammox requires a source of ammonium, which under anoxic conditions could be supplied by the breakdown of sinking organic matter via heterotrophic denitrification. However, at many locations where anammox is measured, denitrification rates are small or undetectable. Alternative sources of ammonium have been proposed to explain this paradox, for example through dissimilatory reduction of nitrate to ammonium and transport from anoxic sediments. However, the relevance of these sources in open-ocean anoxic zones is debated. Here, we bring to attention an additional source of ammonium, namely, the daytime excretion by zooplankton and micronekton migrating from the surface to anoxic waters. We use a synthesis of acoustic data to show that, where anoxic waters occur within the water column, most migrators spend the daytime within them. Although migrators export only a small fraction of primary production from the surface, they focus excretion within a confined depth range of anoxic water where particle input is small. Using a simple biogeochemical model, we suggest that, at those depths, the source of ammonium from organisms undergoing diel vertical migrations could exceed the release from particle remineralization, enhancing in situ anammox rates. The contribution of this previously overlooked process, and the numerous uncertainties surrounding it, call for further efforts to evaluate the role of animals in oxygen minimum zone biogeochemistry. PMID:25288743

  18. The pharmacokinetics, urinary and biliary excretion of pipecuronium bromide.

    PubMed

    Wierda, J M; Szenohradszky, J; De Wit, A P; Zentai, G; Agoston, S; Kakas, M; Kleef, U W; Meijer, D K

    1991-11-01

    The pharmacodynamics and -kinetics of pipecuronium were studied in 12 patients, six of whom received 100 micrograms kg-1 for laryngectomy (Group L), and six who underwent choledochotomy after insertion of the T-drain and were given 50 micrograms kg-1 (Group C). Onset time and clinical duration were 2.3 and 109 min and 2.8 and 39 min in Groups L and C, respectively. All patients could be sufficiently reversed with neostigmine. Terminal half-lives were 101.5 min (Group L) and 179 min (Group C) in a three-exponent decay; the distribution volumes at steady state 0.339 l kg-1 (Group L) and 0.506 l kg-1 (Group C); the plasma clearance 3.4 ml kg-1 min-1 (Group L) and 2.5 ml kg-1 min-1 (Group C). Within 24 h, 38.6% and 37% were excreted unchanged in the urine and 4.4% and 1% as 3-desacetyl pipecuronium in Groups L and C, respectively. Within 24 h only 2% was excreted into the bile in Group C. Distribution volume and terminal half-life in Group C were positively correlated with pre-operative serum aminotransferase levels (P less than 0.005).

  19. Enhancement of anammox by the excretion of diel vertical migrators

    NASA Astrophysics Data System (ADS)

    Bianchi, Daniele; Babbin, Andrew R.; Galbraith, Eric D.

    2014-11-01

    Measurements show that anaerobic ammonium oxidation with nitrite (anammox) is a major pathway of fixed nitrogen removal in the anoxic zones of the open ocean. Anammox requires a source of ammonium, which under anoxic conditions could be supplied by the breakdown of sinking organic matter via heterotrophic denitrification. However, at many locations where anammox is measured, denitrification rates are small or undetectable. Alternative sources of ammonium have been proposed to explain this paradox, for example through dissimilatory reduction of nitrate to ammonium and transport from anoxic sediments. However, the relevance of these sources in open-ocean anoxic zones is debated. Here, we bring to attention an additional source of ammonium, namely, the daytime excretion by zooplankton and micronekton migrating from the surface to anoxic waters. We use a synthesis of acoustic data to show that, where anoxic waters occur within the water column, most migrators spend the daytime within them. Although migrators export only a small fraction of primary production from the surface, they focus excretion within a confined depth range of anoxic water where particle input is small. Using a simple biogeochemical model, we suggest that, at those depths, the source of ammonium from organisms undergoing diel vertical migrations could exceed the release from particle remineralization, enhancing in situ anammox rates. The contribution of this previously overlooked process, and the numerous uncertainties surrounding it, call for further efforts to evaluate the role of animals in oxygen minimum zone biogeochemistry.

  20. Oxalic acid excretion after intravenous ascorbic acid administration.

    PubMed

    Robitaille, Line; Mamer, Orval A; Miller, Wilson H; Levine, Mark; Assouline, Sarit; Melnychuk, David; Rousseau, Caroline; Hoffer, L John

    2009-02-01

    Ascorbic acid is frequently administered intravenously by alternative health practitioners and, occasionally, by mainstream physicians. Intravenous administration can greatly increase the amount of ascorbic acid that reaches the circulation, potentially increasing the risk of oxalate crystallization in the urinary space. To investigate this possibility, we developed gas chromatography mass spectrometry methodology and sampling and storage procedures for oxalic acid analysis without interference from ascorbic acid and measured urinary oxalic acid excretion in people administered intravenous ascorbic acid in doses ranging from 0.2 to 1.5 g/kg body weight. In vitro oxidation of ascorbic acid to oxalic acid did not occur when urine samples were brought immediately to pH less than 2 and stored at -30 degrees C within 6 hours. Even very high ascorbic acid concentrations did not interfere with the analysis when oxalic acid extraction was carried out at pH 1. As measured during and over the 6 hours after ascorbic acid infusions, urinary oxalic acid excretion increased with increasing doses, reaching approximately 80 mg at a dose of approximately 100 g. We conclude that, when studied using correct procedures for sample handling, storage, and analysis, less than 0.5% of a very large intravenous dose of ascorbic acid is recovered as urinary oxalic acid in people with normal renal function.

  1. [Basic mechanisms: absorption and excretion of cholesterol and other sterols].

    PubMed

    Cofan Pujol, Montserrat

    2014-01-01

    Cholesterol is of vital importance for vertebrate cell membrane structure and function. It is obvious that adequate regulation of cholesterol homeostasis is essential. Hypercholesterolemia promotes atherosclerosis and thereby represents a major risk factor for cardiovascular disease. The liver has been considered the major site of control in maintenance of cholesterol homeostasis. The liver facilitates clearance of (very) low density lipoprotein particles and cholesterol-containing chylomicron remnants, synthesizes cholesterol, synthesizes and secretes (nascent) high density lipoprotein particles, secretes cholesterol and bile salts to bile, and is involved in reverse cholesterol transport. In recent years, however, the importance of the intestine in many aspects of cholesterol physiology is increasingly recognized. It has become apparent that direct secretion of cholesterol from the blood compartment into the intestine, or transintestinal cholesterol excretion, plays a major role in disposal of cholesterol via the feces. This review will discuss current knowledge on the physiology of cholesterol homeostasis, with emphasis on cholesterol absorption, cholesterol synthesis and fecal excretion, and therapeutic options for hypercholesterolemia.

  2. High Salt Diet Affects Renal Sodium Excretion and ERRα Expression

    PubMed Central

    Wang, Dan; Wang, Yang; Liu, Fu-Qiang; Yuan, Zu-Yi; Mu, Jian-Jun

    2016-01-01

    Kidneys regulate the balance of water and sodium and therefore are related to blood pressure. It is unclear whether estrogen-related receptor α (ERRα), an orphan nuclear receptor and transcription factor highly expressed in kidneys, affects the reabsorption of water and sodium. The aim of this study was to determine whether changes in the expressions of ERRα, Na+/K+-ATPase and epithelial sodium channel (ENaC) proteins affected the reabsorption of water and sodium in kidneys of Dahl salt-sensitive (DS) rats. SS.13BN rats, 98% homologous to the DS rats, were used as a normotensive control group. The 24 h urinary sodium excretion of the DS and SS.13BN rats increased after the 6-week high salt diet intervention, while sodium excretion was increased in DS rats with daidzein (agonist of ERRα) treatment. ERRα expression was decreased, while β- and γ-ENaC mRNA expressions were increased upon high sodium diet treatment in the DS rats. In the chromatin immunoprecipitation (CHIP) assay, positive PCR signals were obtained in samples treated with anti-ERRα antibody. The transcriptional activity of ERRα was decreased upon high salt diet intervention. ERRα reduced the expressions of β- and γ-ENaC by binding to the ENaC promoter, thereby increased Na+ reabsorption. Therefore, ERRα might be one of the factors causing salt-sensitive hypertension. PMID:27043552

  3. Effect of chloroquine on the urinary excretion of ciprofloxacin.

    PubMed

    Ilo, Cajetan E; Ezejiofor, Ndidi A; Agbakoba, Nneka; Brown, Sinye A; Maduagwuna, Chinonye A; Agbasi, Patrick U; Orisakwe, Orish E; Orisakweph, Orish E

    2008-01-01

    Ciprofloxacin is an inexpensive antibacterial, whereas chloroquine is an inexpensive antimalarial. The coadministration of chloroquine and ciprofloxacin is easily encountered because both drugs are commonly prescribed to patients in the tropics. Five healthy male volunteers aged 19 to 31 years who were not taking any of the prescribed medications and who had no sensitivity to either ciprofloxacin or chloroquine each received 500 mg ciprofloxacin orally with 250 mL of water, and after a 2-week washout period, 500 mg ciprofloxacin plus 600 mg chloroquine was administered orally with 250 mL of water after providing informed consent. A urine sample (7 mL) was collected just before taking the drug at 8:00 AM representing 0 hour and continued afterward at 1, 2, 4, 8, 12, and 24 hours the next day. The samples were stored at -20 degrees C until analyzed. The minimum inhibitory concentrations by diffusion through agar technique were used for the assay of urine ciprofloxacin. The rate of ciprofloxacin excretion and cumulative urine ciprofloxacin were significantly increased. The coadministration of chloroquine increased the cumulative urinary concentration and excretion rate of ciprofloxacin.

  4. Rapid Hepatobiliary Excretion of Micelle-Encapsulated/Radiolabeled Upconverting Nanoparticles as an Integrated Form

    PubMed Central

    Seo, Hyo Jung; Nam, Sang Hwan; Im, Hyung-Jun; Park, Ji-yong; Lee, Ji Youn; Yoo, Byeongjun; Lee, Yun-Sang; Jeong, Jae Min; Hyeon, Taeghwan; Who Kim, Ji; Lee, Jae Sung; Jang, In-Jin; Cho, Joo-Youn; Hwang, Do Won; Suh, Yung Doug; Lee, Dong Soo

    2015-01-01

    In the field of nanomedicine, long term accumulation of nanoparticles (NPs) in the mononuclear phagocyte system (MPS) such as liver is the major hurdle in clinical translation. On the other hand, NPs could be excreted via hepatobiliary excretion pathway without overt tissue toxicity. Therefore, it is critical to develop NPs that show favorable excretion property. Herein, we demonstrated that micelle encapsulated 64Cu-labeled upconverting nanoparticles (micelle encapsulated 64Cu-NOTA-UCNPs) showed substantial hepatobiliary excretion by in vivo positron emission tomography (PET) and also upconversion luminescence imaging (ULI). Ex vivo biodistribution study reinforced the imaging results by showing clearance of 84% of initial hepatic uptake in 72 hours. Hepatobiliary excretion of the UCNPs was also verified by transmission electron microscopy (TEM) examination. Micelle encapsulated 64Cu-NOTA-UCNPs could be an optimal bimodal imaging agent owing to quantifiability of 64Cu, ability of in vivo/ex vivo ULI and good hepatobiliary excretion property. PMID:26494465

  5. Tissue Distribution, Excretion, and Hepatic Biotransformation of Microcystin-LR in Mice

    DTIC Science & Technology

    1990-07-09

    Distribution, Excretion, and Hepatic Biotiansformation of Microcystin -LR in Mice 12. PERSONAL AUTHOR(S) Nancy A. Robinson, Judith G. Pace, Charles F...number) The distribution, excretion, and hepatic metabolism of [3H] microcystin -LR ([3H]MCYST-LR, sublethal, i.v.) were measured in mice. Plasma...Distribution, Excretion, and Hepatic Biotransformation of Microcystin -LR in Mice 𔃼 Nancy A. Robinson, Judith G. Pace, Charles F. Matson, George A. Miura, and

  6. Effects of feeding and confinement on nitrogen metabolism and excretion in the gulf toadfish Opsanus beta

    PubMed

    Walsh; Milligan

    1995-01-01

    In order to elucidate further the cues for, and the biochemical mechanisms of, the transition to ureogenesis in the gulf toadfish Opsanus beta, experiments on the effects of feeding (i.e. nitrogen loading) were carried out. Baseline nitrogen excretion rates were first measured on solitary toadfish in large water volumes (i.e. unconfined conditions). These nitrogen excretion rates were higher, and had a higher proportion as ammonia (61 %), than previously published 'control' measurements. Feeding of unconfined toadfish elevated total nitrogen excretion approximately threefold, with little change in the proportion of urea versus ammonia. During the first 24 h of confinement of unfed toadfish, absolute levels of urea excretion remained constant while ammonia excretion rates fell to near zero, so that toadfish became 90 % ureotelic. When fed prior to confinement, urea excretion rates remained constant for the first 24 h, and the bulk of the nitrogen was excreted as ammonia (80 %); excretion of the excess dietary nitrogen took up to 48 h to complete. If pre-adapted to confinement and then fed, toadfish excreted only about 55 % of their nitrogenous waste as ammonia, and excretion of excess dietary nitrogen was completed by 24 h. Elevations of hepatic glutamine synthetase (GNS) activities accompanied confinement and were shown to be almost exclusively in the cytosolic compartment and to be correlated with a decrease in the ratio of hepatic levels of glutamate:glutamine. These GNS activity increases also appear to account in part for the decrease in the percentage of ammoniotely in toadfish under conditions of nitrogen loading after confinement. However, additional means of regulating total nitrogen excretion (e.g. changes in protein turnover rates) and the degree of ureogenesis versus ammoniogenesis (e.g. N-acetylglutamate stimulation of carbamoylphosphate synthetase) must be postulated to account fully for changes in nitrogen excretion rates and activation of ureogenesis

  7. Biliary excretion of diazepam in rats: influence of the route of administration and dosage.

    PubMed

    Phillips, R; Plaa, G L

    1981-01-01

    The biliary excretion of diazepam metabolites was found in rats. Equivalent dosages of diazepam were administered orally and intraperitoneally. The biliary excretion was dose-dependent and was greater following intraperitoneal administration. After intravenous administration, a greater percentage of the diazepam dosage administered was excreted into the bile. Repetitive intravenous administrations yielded results which approached those observed after intraperitoneally administered dosages given as a bolus.

  8. Measurement of urinary mercury excretion by atomic absorption in health and disease

    PubMed Central

    Taylor, Andrew; Marks, Vincent

    1973-01-01

    Taylor, A., and Marks, V. (1973).British Journal of Industrial Medicine,30, 293-296. Measurement of urinary excretion by atomic absorption in health and disease. Excretion of mercury was measured by a cold-vapour atomic absorption technique on samples of urine from five groups of people having varying exposure to mercury. Serial investigations of up to 14 days were carried out on eight subjects to determine the temporal relationship between exposure and excretion. Subjects with no exposure excreted 0-10 μg mercury per gramme creatinine. Similar values were found in laboratory staff and men assembling hollow cathode lamps. Excretion of mercury by dental workers was significantly increased. No correlation between exposure and excretion of mercury was seen in the subjects investigated. The significance of measuring urinary excretion in the detection of mercury intoxication is discussed. The suggestion is made that urinary mercury excretion of more than 20 μg/g creatinine or 40 μg mercury per 24 hours should be considered evidence of recent or remote exposure to mercury. It is concluded that measurement of urinary mercury excretion is important in revealing those persons who may ultimately develop symptoms of toxicity. PMID:4723792

  9. EVALUATION OF PRESSOR ASSAY, PLASMA RENIN ACTIVITY, AND ALDOSTERONE EXCRETION IN RENAL VASCULAR HYPERTENSION.

    DTIC Science & Technology

    KIDNEYS, *DIAGNOSTIC AGENTS, HYPERTENSION , DISEASES, BLOOD PRESSURE , BLOOD CIRCULATION, DIAGNOSIS(MEDICINE), EXCRETION, THERAPY, SURGERY, CORTICOSTEROID AGENTS, PEPTIDE HYDROLASES, ENZYMES, BLOOD PLASMA, BLOOD VESSELS.

  10. Excretion and biotransformation of carboxymethyl-cysteine in rat, dog, monkey and man.

    PubMed

    Turnbull, L B; Teng, L; Kinzie, J M; Pitts, J E; Pinchbeck, F M; Bruce, R B

    1978-10-01

    1. Following an oral dose of S-carboxymethyl [35S]cysteine monkey (rhesus and African green), rat, dog, and man excreted 77,88,95, and 100% respectively of the 35S radioactivity in urine and 7.0, 2.5, 0.7, and 0.3% in faeces during a 3 to 4 day period. 2. The principal drug-related components excreted were unchanged carboxymethylcysteine, dicarboxymethyl sulphide and inorganic sulphate. 3. Rat, dog, and man excreted primarily dicarboxymethyl sulphide and unchanged carboxymethylcysteine and no inorganic sulphate (rat, 7%). 4. Monkey excreted largely inorganic sulphate, moderate amounts of dicarboxymethyl sulphide and a trace of unchanged drug.

  11. Elevated urinary excretion of beta-aminoisobutyric acid and exposure to inorganic lead.

    PubMed

    Farkas, W R; Fischbein, A; Solomon, S; Buschman, F; Borek, E; Sharma, O K

    1987-01-01

    beta-Aminoisobutyric acid (beta-AIB), a normal degradation product of thymine, a constituent of DNA and, to a lesser extent, of transfer RNA, is excreted in low levels in human urine. We found that a group of iron workers occupationally exposed to inorganic lead excreted high levels of urinary beta-AIB. Elevated urinary excretion of beta-AIB was also observed in marmosets, Callithrix jacchus, that received lead acetate in drinking water. Our results suggest that increased urinary excretion of beta-AIB could stem from damage to DNA on exposure to lead.

  12. Colestilan decreases weight gain by enhanced NEFA incorporation in biliary lipids and fecal lipid excretion[S

    PubMed Central

    Sugimoto-Kawabata, Kanami; Shimada, Hiroshi; Sakai, Kaoru; Suzuki, Kazuo; Kelder, Thomas; Pieterman, Elsbet J.; Cohen, Louis H.; Havekes, Louis M.; Princen, Hans M.; van den Hoek, Anita M.

    2013-01-01

    Bile acid sequestrants (BASs) are cholesterol-lowering drugs that also affect hyperglycemia. The mechanism by which BASs exert these and other metabolic effects beyond cholesterol lowering remains poorly understood. The present study aimed to investigate the effects of a BAS, colestilan, on body weight, energy expenditure, and glucose and lipid metabolism and its mechanisms of action in high-fat-fed hyperlipidemic APOE*3 Leiden (E3L) transgenic mice. Mildly insulin-resistant E3L mice were fed a high-fat diet with or without 1.5% colestilan for 8 weeks. Colestilan treatment decreased body weight, visceral and subcutaneous fat, and plasma cholesterol and triglyceride levels but increased food intake. Blood glucose and plasma insulin levels were decreased, and hyperinsulinemic-euglycemic clamp analysis demonstrated improved insulin sensitivity, particularly in peripheral tissues. In addition, colestilan decreased energy expenditure and physical activity, whereas it increased the respiratory exchange ratio, indicating that colestilan induced carbohydrate catabolism. Moreover, kinetic analysis revealed that colestilan increased [3H]NEFA incorporation in biliary cholesterol and phospholipids and increased fecal lipid excretion. Gene expression analysis in liver, fat, and muscle supported the above findings. In summary, colestilan decreases weight gain and improves peripheral insulin sensitivity in high-fat-fed E3L mice by enhanced NEFA incorporation in biliary lipids and increased fecal lipid excretion. PMID:23434610

  13. Excretion of Glycolate, Mesotartrate and Isocitrate Lactone by Synchronized Cultures of Ankistrodesmus braunii1

    PubMed Central

    Chang, Wei-Hsein; Tolbert, N. E.

    1970-01-01

    Fixation of 14CO2 by synchronized cultures of Ankistrodesmus braunii was highest for young growing cells, low for mature cells, and lowest for dividing cells. The amount of 14C excreted during photosynthesis followed the same trend. Cells at the end of the growing phase, after 10 hours of a 16-hour light phase, excreted nearly 35% of the total 14C fixed as one product, glycolate. Dividing cells from the dark phase, when tested in the light, excreted only 4% as much glycolate-14C as the young growing cells. Dividing cells also excreted as much mesotartrate as glycolate and also some isocitrate lactone and an unidentified acid. None of these excreted acids were found inside the cells in significant amounts. Methods for isolation and identification of the excreted acids are present. With 14C-labeled algae, it was shown that the excretion of glycolate was light-dependent and inhibited by 1,1-dimethyl-3-(p-chlorophenyl) urea. The excretion of labeled mesotartrate, isocitrate lactone, and an unknown acid, but not glycolate, also occurred in the dark. The excreted mesotartrate was predominantly carboxyl-labeled even after long periods of 14CO2 fixation. Since glycolate is known to be uniformly labeled, glycolate could not be the precursor of the carboxyl-labeled mesotartrate. The reason for the specific excretion of glycolate, mesotartrate, and isocitrate lactone is not known, but the metabolism of all three acids by the algae may be limited and each can form dilactides or lactones by dehydration. In this context isocitrate lactone was excreted rather than the free acid. PMID:16657471

  14. Marine, freshwater and aerially acclimated mangrove rivulus (Kryptolebias marmoratus) use different strategies for cutaneous ammonia excretion

    PubMed Central

    Cooper, Christopher A.; Wilson, Jonathan M.

    2013-01-01

    Rhesus (Rh) glycoproteins are ammonia gas (NH3) channels known to be involved in ammonia transport in animals. Because of the different osmoregulatory and ionoregulatory challenges faced by teleost fishes in marine and freshwater (FW) environments, we hypothesized that ammonia excretion strategies would differ between environments. Also, we hypothesized that cutaneous NH3 volatilization in air-acclimated fish is facilitated by base secretion. To test these hypotheses, we used the skin of the euryhaline amphibious mangrove rivulus (Kryptolebias marmoratus). The skin excretes ammonia and expresses Rh glycoproteins. Serosal-to-mucosal cutaneous ammonia flux was saturable (0–16 mmol/l ammonia, Km of 6.42 mmol/l). In FW, ammonia excretion increased in response to low mucosal pH but decreased with pharmacological inhibition of Na+/H+ exchangers (NHE) and H+ ATPase. Conversely, in brackish water (BW), lowering the mucosal pH significantly decreased ammonia excretion. Inhibitors of NHE also decreased ammonia excretion in BW fish. Immunofluorescence microscopy demonstrated that both the Rh isoform, Rhcg1, and NHE3 proteins colocalized in Na+/K+ ATPase expressing mitochondrion-rich cells in the gills, kidney, and skin. We propose that the mechanisms of cutaneous ammonia excretion in FW K. marmoratus are consistent with the model for branchial ammonia excretion in FW teleost fish. NH4+ excretion appeared to play a stronger role in BW. NH4+ excretion in BW may be facilitated by apical NHE and/or diffuse through paracellular pathways. In aerially acclimated fish, inhibition of NHE and H+ ATPase, but not the Cl−/HCO3− exchanger, significantly affected cutaneous surface pH, suggesting that direct base excretion is not critical for NH3 volatilization. Overall, K. marmoratus use different strategies for excreting ammonia in three different environments, FW, BW, and air, and Rh glycoproteins and NHE are integral to all. PMID:23389109

  15. Marine, freshwater and aerially acclimated mangrove rivulus (Kryptolebias marmoratus) use different strategies for cutaneous ammonia excretion.

    PubMed

    Cooper, Christopher A; Wilson, Jonathan M; Wright, Patricia A

    2013-04-15

    Rhesus (Rh) glycoproteins are ammonia gas (NH(3)) channels known to be involved in ammonia transport in animals. Because of the different osmoregulatory and ionoregulatory challenges faced by teleost fishes in marine and freshwater (FW) environments, we hypothesized that ammonia excretion strategies would differ between environments. Also, we hypothesized that cutaneous NH(3) volatilization in air-acclimated fish is facilitated by base secretion. To test these hypotheses, we used the skin of the euryhaline amphibious mangrove rivulus (Kryptolebias marmoratus). The skin excretes ammonia and expresses Rh glycoproteins. Serosal-to-mucosal cutaneous ammonia flux was saturable (0-16 mmol/l ammonia, K(m) of 6.42 mmol/l). In FW, ammonia excretion increased in response to low mucosal pH but decreased with pharmacological inhibition of Na(+)/H(+) exchangers (NHE) and H(+) ATPase. Conversely, in brackish water (BW), lowering the mucosal pH significantly decreased ammonia excretion. Inhibitors of NHE also decreased ammonia excretion in BW fish. Immunofluorescence microscopy demonstrated that both the Rh isoform, Rhcg1, and NHE3 proteins colocalized in Na(+)/K(+) ATPase expressing mitochondrion-rich cells in the gills, kidney, and skin. We propose that the mechanisms of cutaneous ammonia excretion in FW K. marmoratus are consistent with the model for branchial ammonia excretion in FW teleost fish. NH(4)(+) excretion appeared to play a stronger role in BW. NH(4)(+) excretion in BW may be facilitated by apical NHE and/or diffuse through paracellular pathways. In aerially acclimated fish, inhibition of NHE and H(+) ATPase, but not the Cl(-)/HCO(3)(-) exchanger, significantly affected cutaneous surface pH, suggesting that direct base excretion is not critical for NH(3) volatilization. Overall, K. marmoratus use different strategies for excreting ammonia in three different environments, FW, BW, and air, and Rh glycoproteins and NHE are integral to all.

  16. [Amoxicillin and its excretion into bronchial secretion (author's transl)].

    PubMed

    Weingärtner, L; Richter, I; Patsch, R; Thiemann, H H; Brömme, W; Baum, W; Vorwald, U

    1977-02-01

    Various dates on amoxicillin (resorption, distribution, elimination, tissue passage, urinary excretion) are presented. The bacterial spectrum is more fully discussed. Amoxicillin is compared with ampicillin. Dosage and therapeutical results are presented. Within repeated bronchoscopic examinations necessary on account of bronchopulmonary affections determination of germs were done in 88 children. At the same time examination of ampicillin levels in bronchial secretions were performed after amoxicillin therapy with different high doses (3 x 125 mg to 3 x 750 mg) for 7 days. It could be shown that good antibiotic levels could be found in secretion specimens above all obtained 2 to 4 hours after the last amoxicillin administration. They could be found too, if there did not exist any purulent secretion or stronger inflammation. There are relations between the amount of dosage, the level in secretion as well as the influence on germs.

  17. Excretion of artifactual endogenous digitalis-like factors

    SciTech Connect

    Kelly, R.A.

    1986-07-01

    Radioimmunoassays have been used to detect digoxin-like immunoreactive factors (DLF) in the plasma and urine of hypertensive patients and rats with deoxycorticosterone acetate (DOCA)-salt hypertension. DLF, partially purified from DOCA-HS urine by antidigoxin antibody immunoaffinity chromatography, was found to have a molecular weight <2000. When DOCA-HS rats were switched to the low-sodium chow, DLF excretion dropped precipitously. No measurable DLF was detected in the plasma of rats eating either chow. However, >95% of the urinary DLF could be attributed to a contaminant in the standard laboratory chow. These data document the importance of excluding nonspecific compounds and exogenous sources of DLF when sensitive radioligand and biologic assays are used to detect endogenous inhibitors of the sodium pump.

  18. Excretion of chloroquine and desethylchloroquine in human milk.

    PubMed Central

    Ogunbona, F A; Onyeji, C O; Bolaji, O O; Torimiro, S E

    1987-01-01

    The excretion of chloroquine and the major metabolite, desethylchloroquine, in breast milk was investigated in eleven lactating mothers following a single oral dose of chloroquine (600 mg base). The average milk to plasma concentration ratio at the 24th hour was 6.6 +/- 2.4 for chloroquine and 1.5 +/- 0.6 for desethylchloroquine in five of the volunteers. In five other volunteers the elimination half-life of chloroquine in milk was 8.8 +/- 4.7 days which was longer than that in saliva (3.9 +/- 1.0 days) from the same volunteers. The maximum daily dose of the drug that the infant can receive from breastfeeding was about 0.7% of the maternal start dose of the drug in malaria chemotherapy. It is, therefore, suggested that it is safe for mothers to breastfeed their infants when undergoing treatment for malaria with chloroquine. PMID:3580253

  19. Excretion of chloroquine and desethylchloroquine in human milk.

    PubMed

    Ogunbona, F A; Onyeji, C O; Bolaji, O O; Torimiro, S E

    1987-04-01

    The excretion of chloroquine and the major metabolite, desethylchloroquine, in breast milk was investigated in eleven lactating mothers following a single oral dose of chloroquine (600 mg base). The average milk to plasma concentration ratio at the 24th hour was 6.6 +/- 2.4 for chloroquine and 1.5 +/- 0.6 for desethylchloroquine in five of the volunteers. In five other volunteers the elimination half-life of chloroquine in milk was 8.8 +/- 4.7 days which was longer than that in saliva (3.9 +/- 1.0 days) from the same volunteers. The maximum daily dose of the drug that the infant can receive from breastfeeding was about 0.7% of the maternal start dose of the drug in malaria chemotherapy. It is, therefore, suggested that it is safe for mothers to breastfeed their infants when undergoing treatment for malaria with chloroquine.

  20. Urinary albumin excretion in patients with renovascular hypertension.

    PubMed

    Růzicka, M; Stríbrná, J; Englis, M; Lánská, V; Skibová, J; Peregrin, J

    1992-01-01

    Twenty-four hour urinary excretion of albumin (UEalb), IgG and beta-2 microglobulin was investigated at a 3 hour-interval in a control group (C) of healthy subjects, in 30 patients with renovascular hypertension (RVH), and in 16 patients with essential hypertension (EH). Mean UEalb in RVH was significantly higher than in C. A significant direct correlation was demonstrated between diastolic blood pressure and UEalb (p < 0.01). Microalbuminuria (MA) > or = 30 micrograms.min-1 was found in about 18% of RVH patients; it was higher than 16.7 micrograms.min-1 in approx. 31%. These results did not substantially differ from those obtained in patients with EH. The cause for increased UEalb in hypertensive patients may be functional, haemodynamic changes, or structural ones. In either case, MA indicates renal injury, and these patients should be given increased attention when monitoring their blood pressure and when selecting antihypertensive drugs.

  1. Urinary excretion of parabens in pregnant Japanese women.

    PubMed

    Shirai, Sayaka; Suzuki, Yayoi; Yoshinaga, Jun; Shiraishi, Hiroaki; Mizumoto, Yoshifumi

    2013-01-01

    Urinary excretion of free and total (free plus conjugated) forms of methyl, ethyl, n-propyl and n-butyl parabens (MP, EP, PP and BP, respectively) and their metabolite p-hydroxybenzoic acid were measured for 111 pregnant Japanese women. Frequent detection of parabens and their metabolite indicated that exposure takes place daily for pregnant Japanese women. The estrogenic potency of PP was 20 times higher than those of the other 3 parabens for the present subjects when both abundance in the urine and the relative estrogenic activity of each compound was considered. Detection of free parabens suggested dermal exposure, probably from their inclusion in personal care products. No statistical association was found between the anogenital index (birth weight-adjusted AGD) of male offspring and the concentrations of any parabens in the urine of the mothers suggesting that the parabens were not apparently estrogenically active at the exposure level of the present subjects.

  2. Bone resorption and mineral excretion in rats during spaceflight

    NASA Technical Reports Server (NTRS)

    Cann, C. E.; Adachi, R. R.

    1983-01-01

    Bone resorption was measured directly in flight and synchronous control rats during COSMOS 1129. Continuous tracer administration techniques were used, with replacement of dietary calcium with isotopically enriched Ca-40 and measurement by neutron activation analysis of the Ca-48 released by the skeleton. There is no large change in bone resorption in rats at the end of 20 days of spaceflight as has been found for bone formation. Based on the time course of changes, the measured 20-25 percent decrease in resorption is probably secondary to a decrease in total body calcium turnover. The excretion of sodium, potassium, and zinc all increase during flight, sodium and potassium to a level four to five times control values.

  3. Serum protein adsorption and excretion pathways of metal nanoparticles

    PubMed Central

    Vinluan, Rodrigo D; Zheng, Jie

    2015-01-01

    While the synthesis of metal nanoparticles (NPs) with fascinating optical and electronic properties have progressed dramatically and their potential biomedical applications were also well demonstrated in the past decade, translation of metal NPs into the clinical practice still remains a challenge due to their severe accumulation in the body. Herein, we give a brief review on size-dependent material properties of metal NPs and their potential biomedical applications, followed by a summary of how structural parameters such as size, shape and charge influence their interactions with serum protein adsorption, cellular uptake and excretion pathways. Finally, the future challenges in minimizing serum protein adsorption and expediting clinical translation of metal NPs were also discussed. PMID:26377047

  4. Urinary potassium excretion and sodium sensitivity in blacks.

    PubMed

    Aviv, Abraham; Hollenberg, Norman K; Weder, Alan

    2004-04-01

    Based on racial differences in urinary potassium excretion and responses to diuretics, we present a model suggesting that a major cause of sodium sensitivity in blacks is an augmented activity of the Na-K-2Cl cotransport in the thick ascending limb of Henle's loop. This would result in an increased ability to conserve not only sodium but also water, and an upward and rightward shift in the operating point of tubuloglomerular feedback, which may cause an increase in the glomerular capillary hydraulic pressure and predilection to glomerular injury with and without hypertension. In this sense, the biological implication of sodium sensitivity in blacks and in humans in general has ramifications above and beyond salt-evoked increase in blood pressure.

  5. Fecal Calprotectin Excretion in Preterm Infants during the Neonatal Period

    PubMed Central

    Rougé, Carole; Butel, Marie-José; Piloquet, Hugues; Ferraris, Laurent; Legrand, Arnaud; Vodovar, Michel; Voyer, Marcel; de la Cochetière, Marie-France; Darmaun, Dominique; Rozé, Jean-Christophe

    2010-01-01

    Background Fecal calprotectin has been proposed as a non-invasive marker of intestinal inflammation in inflammatory bowel disease in adults and children. Fecal calprotectin levels have been reported to be much higher in both healthy full-term and preterm infants than in children and adults. Objective To determine the time course of fecal calprotectin (f-calprotectin) excretion in preterm infants from birth until hospital discharge and to identify factors influencing f-calprotectin levels in the first weeks of life, including bacterial establishment in the gut. Methodology F-calprotectin was determined using an ELISA assay in 147 samples obtained prospectively from 47 preterm infants (gestational age, and birth-weight interquartiles 27–29 weeks, and 880–1320 g, respectively) at birth, and at 2-week intervals until hospital discharge. Principal Findings Although median f-calprotectin excretion was 138 µg/g, a wide range of inter- and intra-individual variation in f-calprotectin values (from day 3 to day 78) was observed (86% and 67%, respectively). In multivariate regression analysis, f-calprotectin correlated negatively with ante and per natal antibiotic treatment (p = 0.001), and correlated positively with the volume of enteral feeding (mL/kg/d) (p = 0.009), the need to interrupt enteral feeding (p = 0.001), and prominent gastrointestinal colonization by Clostridium sp (p = 0.019) and Staphylococcus sp (p = 0.047). Conclusion During the first weeks of life, the high f-calprotectin values observed in preterm infants could be linked to the gut bacterial establishment. PMID:20552029

  6. Ammonia Production, Excretion, Toxicity, and Defense in Fish: A Review

    PubMed Central

    Ip, Yuen K.; Chew, Shit F.

    2010-01-01

    Many fishes are ammonotelic but some species can detoxify ammonia to glutamine or urea. Certain fish species can accumulate high levels of ammonia in the brain or defense against ammonia toxicity by enhancing the effectiveness of ammonia excretion through active NH4+transport, manipulation of ambient pH, or reduction in ammonia permeability through the branchial and cutaneous epithelia. Recent reports on ammonia toxicity in mammalian brain reveal the importance of permeation of ammonia through the blood–brain barrier and passages of ammonia and water through transporters in the plasmalemma of brain cells. Additionally, brain ammonia toxicity could be related to the passage of glutamine through the mitochondrial membranes into the mitochondrial matrix. On the other hand, recent reports on ammonia excretion in fish confirm the involvement of Rhesus glycoproteins in the branchial and cutaneous epithelia. Therefore, this review focuses on both the earlier literature and the up-to-date information on the problems and mechanisms concerning the permeation of ammonia, as NH3, NH4+ or proton-neutral nitrogenous compounds, across mitochondrial membranes, the blood–brain barrier, the plasmalemma of neurons, and the branchial and cutaneous epithelia of fish. It also addresses how certain fishes with high ammonia tolerance defend against ammonia toxicity through the regulation of the permeation of ammonia and related nitrogenous compounds through various types of membranes. It is hoped that this review would revive the interests in investigations on the passage of ammonia through the mitochondrial membranes and the blood–brain barrier of ammonotelic fishes and fishes with high brain ammonia tolerance, respectively. PMID:21423375

  7. Pharmacokinetics, pharmacodynamics, metabolism, distribution, and excretion of carfilzomib in rats.

    PubMed

    Yang, Jinfu; Wang, Zhengping; Fang, Ying; Jiang, Jing; Zhao, Frances; Wong, Hansen; Bennett, Mark K; Molineaux, Christopher J; Kirk, Christopher J

    2011-10-01

    Carfilzomib [(2S)-N-[(S)-1-[(S)-4-methyl-1-[(R)-2-methyloxiran-2-yl]-1-oxopentan-2-ylcarbamoyl]-2-phenylethyl]-2-[(S)-2-(2-morpholinoacetamido)-4-phenylbutanamido]-4-methylpentanamide, also known as PR-171] is a selective, irreversible proteasome inhibitor that has shown encouraging results in clinical trials in multiple myeloma. In this study, the pharmacokinetics, pharmacodynamics, metabolism, distribution, and excretion of carfilzomib in Sprague-Dawley rats were characterized. After intravenous administration, the plasma concentration of carfilzomib declined rapidly in a biphasic manner. Carfilzomib displayed high plasma clearance [195-319 ml/(min · kg)], a short-terminal half-life (5-20 min), and rapid and wide tissue distribution in rats. The exposure to carfilzomib (C(max) and area under the curve) increased dose proportionally from 2 to 4 mg/kg but less than dose proportionally from 4 to 8 mg/kg. The high clearance was mediated predominantly by extrahepatic metabolism through peptidase cleavage and epoxide hydrolysis. Carfilzomib was excreted mainly as metabolites resulting from peptidase cleavage. Carfilzomib and its major metabolites in urine and bile accounted for approximately 26 and 31% of the total dose, respectively, for a total of 57% within 24 h postdose. Despite the high systemic clearance, potent proteasome inhibition was observed in blood and a variety of tissues. Together with rapid and irreversible target binding, the high clearance may provide an advantage in that "unnecessary" exposure to the drug is minimized and potential drug-related side effects may be reduced.

  8. Alkali absorption and citrate excretion in calcium nephrolithiasis

    NASA Technical Reports Server (NTRS)

    Sakhaee, K.; Williams, R. H.; Oh, M. S.; Padalino, P.; Adams-Huet, B.; Whitson, P.; Pak, C. Y.

    1993-01-01

    The role of net gastrointestinal (GI) alkali absorption in the development of hypocitraturia was investigated. The net GI absorption of alkali was estimated from the difference between simple urinary cations (Ca, Mg, Na, and K) and anions (Cl and P). In 131 normal subjects, the 24 h urinary citrate was positively correlated with the net GI absorption of alkali (r = 0.49, p < 0.001). In 11 patients with distal renal tubular acidosis (RTA), urinary citrate excretion was subnormal relative to net GI alkali absorption, with data from most patients residing outside the 95% confidence ellipse described for normal subjects. However, the normal relationship between urinary citrate and net absorbed alkali was maintained in 11 patients with chronic diarrheal syndrome (CDS) and in 124 stone-forming patients devoid of RTA or CDS, half of whom had "idiopathic" hypocitraturia. The 18 stone-forming patients without RTA or CDS received potassium citrate (30-60 mEq/day). Both urinary citrate and net GI alkali absorption increased, yielding a significantly positive correlation (r = 0.62, p < 0.0001), with the slope indistinguishable from that of normal subjects. Thus, urinary citrate was normally dependent on the net GI absorption of alkali. This dependence was less marked in RTA, confirming the renal origin of hypocitraturia. However, the normal dependence was maintained in CDS and in idiopathic hypocitraturia, suggesting that reduced citrate excretion was largely dietary in origin as a result of low net alkali absorption (from a probable relative deficiency of vegetables and fruits or a relative excess of animal proteins).

  9. Relationship between endogenous 3-methylhistidine excretion and body composition.

    PubMed

    Lukaski, H C; Mendez, J; Buskirk, E R; Cohn, S H

    1981-03-01

    Fourteen healthy men (aged 20-30 yr) consumed two isocaloric, isonitrogenous diets in the sequence of a 4-day meat diet (MD) followed by a 7-day meal-free diet (MFD). Urinary 3-methylhistidine (3MH) excretion during the MD (513 +/- 21 mumol . day-1, mean +/- SE) was significantly higher (P less than 0.01) than day 3 of the MFD (230 +/- 10 mumol . day-1), after which the mean daily 3MH output was constant with a mean coefficient of variation of 4.5%. There was no change in fat-free body mass (FFBM) determined by densitometry at the start (62.3 +/- 1.8 kg) and the end (62.2 +/- 1.9 kg) of the 11-day dietary period. Mean muscle mass (MM) calculated from measurements of total-body potassium and nitrogen was 23.4 +/- 1.3 kg. Endogenous 3MH excretion was related more closely to MM (r = 0.91, P less than 0.001) than to FFBM measured by densitometry (r = 0.81, P less than 0.001). Only a low correlation coefficient (r = 0.33, P less than 0.05) was observed between 3MH and the nonmuscle component of FFBM. Urinary creatinine output also was correlated significantly with 3MH (r = 0.87; P less than 0.001) and MM (r = 0.79; P less than 0.01). It is concluded that because endogenous 3MH is significantly related to MM in man, it can be used as a marker to study in vivo total-body muscle protein degradation provided that the necessary dietary restrictions are observed.

  10. Increased Salivary Nitrite and Nitrate Excretion in Rats with Cirrhosis.

    PubMed

    Mahmoodi, Somayeh; Rahmatollahi, Mahdieh; Shahsavari, Fatemeh; Shafaroodi, Hamed; Grayesh-Nejad, Siyavash; Dehpour, Ahmad R

    2015-11-01

    Increased nitric oxide (NO) formation is mechanistically linked to pathophysiology of the extrahepatic complications of cirrhosis. NO is formed by either enzymatic or non-enzymatic pathways. Enzymatic production is catalyzed by NO synthase (NOS) while entero-salivary circulation of nitrate and nitrite is linked to non-enzymatic formation of NO under acidic pH in the stomach. There is no data on salivary excretion of nitrate and nitrite in cirrhosis. This study was aimed to investigate salivary levels of nitrate and nitrite in a rat model of biliary cirrhosis. Cirrhosis was induced by bile duct ligation (BDL). Four weeks after the operation, submandibular ducts of anesthetized BDL and control rats were cannulated with polyethylene microtube for saliva collection. Assessment of pH, nitrite and nitrate levels was performed in our research. We also investigated NOS expression by real time RT-PCR to estimate eNOS, nNOS and iNOS mRNA levels in the submandibular glands. Salivary pH was significantly lower in BDL rats in comparison to control animals. We also observed a statistically significant increase in salivary levels of nitrite as well as nitrate in BDL rats while there was no elevation in the mRNA expression of nNOS, eNOS, and iNOS in submandibular glands of cirrhotic groups. This indicates that an increased salivary level of nitrite/nitrate is less likely to be linked to increased enzymatic production of NO in the salivary epithelium. It appears that nitrate/nitrite can be transported from the blood stream by submandibular glands and excreted into saliva as entero-salivary circulation, and this mechanism may have been exaggerated during cirrhosis.

  11. Renal excretion in coho salmon (Oncorhynchus kisutch) after acute exposure to 3-trifluoromethyl-4-nitrophenol

    USGS Publications Warehouse

    Hunn, J.B.; Allen, J.L.

    1975-01-01

    COHO SALMON (ONCORHYNCHUS KISUTCH) EXPOSED TO AN ACUTE, SUBLETHAL CONCENTRATION OF 3-TRIFLUOROMETHLY 1-4 NITROPHENOL (TFM) EXHIBITED AN INCREASED OUTPUT OF URINE WHEN COMPARED WITH CONTROLS, BUT THE URINARY EXCRETION OF NA, K, CA, MG AND C1 WAS NOT AFFECTED. ABOUT 35 TIMES MORE CONJUGATED TFM THAN FREE TFM WAS EXCRETED DURING THE 24-HOUR STUDY PERIOD.

  12. Renal function in sick very low birthweight infants: 4. Glucose excretion.

    PubMed Central

    Wilkins, B H

    1992-01-01

    Renal glucose excretion was measured on 239 occasions in a sample of 36 infants of 25.5-33 weeks' gestation, birth weight 720-2000 g, between the ages of 0.5 and 32 days. Glucose was invariably present in urine from the first day. Fractional glucose excretion varied widely from 0.1% to 90% of filtered glucose and glucose excretion rate was up to 15.5 mmol/kg/day and was higher in the most immature infants, especially below 28 weeks' gestation. The highest values were in association with hyperglycaemia between 5 and 15 days but there was no consistent plasma glucose threshold with frequent glucose spillage at normal blood glucose concentrations. There was some correlation with sodium excretion in the first week suggesting that in the absence of hyperglycaemia with a normal filtered glucose load, glucose excretion is caused by proximal tubular immaturity. PMID:1444549

  13. Influence of magnesium on the absorption and excretion of calcium and oxalate ions.

    PubMed

    Berg, W; Bothor, C; Pirlich, W; Janitzky, V

    1986-01-01

    In two test series additional oxalic acid excretion in urine was induced in healthy test persons by administering a spinach diet. This additional excretion could be markedly reduced by magnesium administration. Calcium and citrate excretions are largely unaffected by magnesium administration. Magnesium excretions, however, are clearly increased. The calcium oxalate crystallization rates in the 5-or 7-hour urines reveal a behavior parallel to that of the oxalic acid excretion profile. In the control urines, the crystal picture is characterized by numerous medium-sized whewellite crystals. In contrast, in the test series weddellite crystals are reduced in size and frequency after magnesium administration. New aspects of magnesium effects must be discussed; above all the possible absorption changes resulting from gastrointestinal diseases.

  14. Speciation of mercury excreted in feces from individuals with amalgam fillings.

    PubMed

    Engqvist, A; Colmsjö, A; Skare, I

    1998-01-01

    Investigators established methods for the analysis of total mercury (Hg-total), oxidized mercury and mercury bound to sulfhydryl groups (Hg-S), mercury vapor (Hg0), and mercury from amalgam particles (APs) in fecal samples. Two individuals consumed mercury as a mercury-cysteine complex mercury vapor, and mercury from amalgam particles, and the cumulative excretion of mercury in feces was followed. Investigators found that 80% of the mercury from amalgam particles and mercury bound to sulfhydryl groups was excreted, but only 40% of the mercury vapor was excreted. Speciation of mercury excreted in feces from 6 individuals with a moderate loading of amalgam fillings showed that most of the mercury originating from the fillings consisted of oxidized mercury, which was probably bound to sulfhydryl-containing compounds. The proportion of amalgam particles in fecal samples from these individuals was low, and it did not exceed 26% of the total amount of mercury excreted.

  15. Effect of demographics on excretion of key urinary factors related to kidney stone risk

    PubMed Central

    Perinpam, Majuran; Ware, Erin B.; Smith, Jennifer A.; Turner, Stephen T.; Kardia, Sharon L.R.; Lieske, John C.

    2015-01-01

    Objective To investigate the effect of demographics including age and sex on excretion of four key urinary factors (calcium (Ca), magnesium (Mg), oxalate (Ox) and uric acid (UA)) related to kidney stone risk. Methods Twenty-four hour urine samples were collected from non-Hispanic white sibships in Rochester, MN. Height, weight, blood pressure, serum creatinine and cystatin C (CC) were measured. Diet was assessed using the Viocare food frequency questionnaire. Effects of demographics and dietary elements on urinary excretions were evaluated in univariate, multivariate, and interaction models that included age, sex, and body mass index (BMI). Results Samples were available from 709 individuals. In multivariate models, sex was a significant predictor of all four urinary factors, age was significant for all but UA excretion, and serum creatinine was significant only for Ca and Mg excretion (p<0.05). BMI or weight positively correlated with Mg, Ox and UA excretion (p<0.05). Use of a thiazide diuretic (lower) and dietary protein (higher) were associated with Ca excretion, while dietary Ca was associated with higher Mg excretion. Urinary UA excretion increased with animal protein intake and CC estimated glomerular filtration rate (eGFR), and was lower with concurrent loop diuretic use. Significant interaction effects on urinary UA excretion were observed for loop diuretic use and sex, eGFR and sex, age and animal protein intake, and BMI and eGFR (p<0.05). Conclusions Age and sex influence excretion of key urinary factors related to kidney stone risk, and should be taken into account when evaluating kidney stone patients. PMID:26206452

  16. Excretion of the dipeptidyl peptidase-4 inhibitor linagliptin in rats is primarily by biliary excretion and P-gp-mediated efflux.

    PubMed

    Fuchs, Holger; Runge, Frank; Held, Heinz-Dieter

    2012-04-11

    Linagliptin is a selective, competitive dipeptidyl peptidase-4 (DPP-4) inhibitor, recently approved in the USA, Japan and Europe for the treatment of type 2 diabetes. It has non-linear pharmacokinetics and, unlike other DPP-4 inhibitors, a largely non-renal excretion route. It was hypothesised that P-glycoprotein (P-gp)-mediated intestinal transport could influence linagliptin bioavailability, and might contribute to its elimination. Two studies evaluated the role of P-gp-mediated transport in the bioavailability and intestinal secretion of linagliptin in rats. In the bioavailability study, male Wistar rats received single oral doses of linagliptin, 1 or 15 mg/kg, plus either the P-gp inhibitor, zosuquidar trihydrochloride, or vehicle. For the intestinal secretion study, rats underwent bile duct cannulation, and urine, faeces, and bile were collected. At the end of the study, gut content was sampled. Inhibition of intestinal P-gp increased the bioavailability of orally administered linagliptin, indicating that this transport system plays a role in limiting the uptake of linagliptin from the intestine. This effect was dependent on linagliptin dose, and could play a role in its non-linear pharmacokinetics after oral dosing. Systemically available linagliptin was mainly excreted unchanged via bile (49% of i.v. dose), but some (12%) was also excreted directly into the gut independently of biliary excretion. Thus, direct excretion of linagliptin into the gut may be an alternative excretion route in the presence of liver and renal impairment. The primarily non-renal route of excretion is likely to be of benefit to patients with type 2 diabetes, who have a high prevalence of renal insufficiency.

  17. Intercomparison of two cavity ring-down spectroscopy analyzers for atmospheric 13CO2 / 12CO2 measurement

    NASA Astrophysics Data System (ADS)

    Pang, Jiaping; Wen, Xuefa; Sun, Xiaomin; Huang, Kuan

    2016-08-01

    Isotope ratio infrared spectroscopy (IRIS) permits continuous in situ measurement of CO2 isotopic composition under ambient conditions. Previous studies have mainly focused on single IRIS instrument performance; few studies have considered the comparability among different IRIS instruments. In this study, we carried out laboratory and ambient measurements using two Picarro CO2δ13C analyzers (G1101-i and G2201-i (newer version)) and evaluated their performance and comparability. The best precision was 0.08-0.15 ‰ for G1101-i and 0.01-0.04 ‰ for G2201-i. The dependence of δ13C on CO2 concentration was 0.46 ‰ per 100 ppm and 0.09 ‰ per 100 ppm, the instrument drift ranged from 0.92-1.09 ‰ and 0.19-0.37 ‰, and the sensitivity of δ13C to the water vapor mixing ratio was 1.01 ‰ / % H2O and 0.09 ‰ / % H2O for G1101-i and G2201-i, respectively. The accuracy after correction by the two-point mixing ratio gain and offset calibration method ranged from -0.04-0.09 ‰ for G1101-i and -0.13-0.03 ‰ for G2201-i. The sensitivity of δ13C to the water vapor mixing ratio improved from 1.01 ‰ / % H2O before the upgrade of G1101-i (G1101-i-original) to 0.15 ‰ / % H2O after the upgrade of G1101-i (G1101-i-upgraded). Atmospheric δ13C measured by G1101-i and G2201-i captured the rapid changes in atmospheric δ13C signals on hourly to diurnal cycle scales, with a difference of 0.07 ± 0.24 ‰ between G1101-i-original and G2201-i and 0.05 ± 0.30 ‰ between G1101-i-upgraded and G2201-i. A significant linear correlation was observed between the δ13C difference of G1101-i-original and G2201-i and the water vapor concentration, but there was no significant correlation between the δ13C difference of G1101-i-upgraded and G2201-i and the water vapor concentration. The difference in the Keeling intercept values decreased from 1.24 ‰ between G1101-i-original and G2201-i to 0.36 ‰ between G1101-i-upgraded and G2201-i, which indicates the importance of consistency among different IRIS instruments.

  18. Carbon assimilation and turnover in grassland vegetation using an in situ (13)CO(2) pulse labelling system.

    PubMed

    Ostle, N; Ineson, P; Benham, D; Sleep, D

    2000-01-01

    A mobile laboratory was developed to administer a controlled flow of (13)C labelled CO(2) at ambient concentrations ( approximately 350 ppm) in the field. The stable isotope delivery (SID) system consists of an isotope-mixing unit with flow control to a series of 12 independent labelling chambers. In-line CPU controlled infrared gas analysers allow automated measurement of chamber CO(2) concentrations and gas flow management. A preliminary experiment was established on an upland pasture located at the NERC Soil Biodiversity experimental site, Sourhope, UK, in August 1999. The objective of this investigation was to determine the magnitude of pulse-derived C incorporation into a typical upland plant community. To achieve this, the SID system was deployed to pulse-label vegetation with CO(2) enriched with (13)C (50 atom %) at ambient concentrations ( approximately 350 ppm) on two consecutive days in August 1999. Samples of headspace CO(2), shoot and root were taken on four occasions over a period of 28 days after (13)C labelling. These materials were then prepared for (13)C/(12)C ratio determination by continuous-flow/combustion/isotope ratio mass spectrometry (CF-C-IRMS). Results showed that pulse derived CO(2)-C was assimilated at a rate of 128 +/- 32 microg g shoot-C hour(-1). Dynamic samplings showed that pulse-derived (13)C concentrations in the labelled plant tissues declined by 77.4 +/- 6% after 48 hours. The rapid decline in (13)C concentrations in plant matter was the result of C loss from the plant in the form of respired CO(2) and root exudates, and dilution by subsequent unlabelled C assimilates. This novel system offers considerable potential for in situ tracer investigations.

  19. The effect of sex, height and time of day on the excretion of glycosaminoglycans and the consequences.

    PubMed

    Poulsen, J H; Vaeth, M

    1982-02-01

    A diurnal rhythm in the excretion of glycosaminoglycan-derived uronic acid with an increased excretion during daytime has been found in adults. Due to this rhythm a 24-h excretion was established as the optimum measurement of glycosaminoglycan turnover in tissue. Neither the excretion of uronic acid nor the uronic acid/creatinine ratio in the morning urine could predict the 24-h excretion of glycosaminoglycans as estimated by a statistical model. This model may also be of general interest in similar clinical problems. Compared with males, females had a lower excretion of glycosaminoglycans. Part of this discrepancy reflected a sex-difference in height, which was shown to be positively correlated with the excretion. On the other hand, the uronic acid/creatinine ratio was not influenced by height or sex. Body mass, age and urine output did not influence the ratio or the excretion of uronic acid.

  20. Nitrogen dioxide exposure and urinary excretion of hydroxyproline and desmosine

    SciTech Connect

    Adgate, J.L.; Reid, H.F.; Morris, R.; Helms, R.W.; Berg, R.A.; Hu, P.C.; Cheng, P.W.; Wang, O.L.; Muelenaer, P.A.; Collier, A.M. )

    1992-09-01

    The relationship between average and peak personal exposure to nitrogen dioxide and urinary excretion of hydroxyproline and desmosine was investigated in a population of preschool children and their mothers. Weekly average personal nitrogen dioxide exposures for subjects who resided in homes with one or more potential nitrogen dioxide source (e.g., a kerosene space heater, gas stove, or tobacco smoke) ranged between 16.3 and 50.6 ppb (30.6 and 95.1 micrograms/m3) for children and between 16.9 and 44.1 ppb (12.8 and 82.9 micrograms/m3) for mothers. In these individuals, the hydroxyproline-to-creatinine and desmosine-to-creatinine ratios were unrelated to personal nitrogen dioxide exposure--even though continuous monitoring documented home nitrogen dioxide concentration peaks of 100-475 ppb lasting up to 100 h in duration. Significantly higher hydroxyproline-to-creatinine and desmosine-to-creatinine ratios were observed in children, compared with mothers (p < .001 and .003, respectively).

  1. Excretion of caffeine and its primary degradation products into bile.

    PubMed

    Holstege, A; Kurz, M; Weinbeck, M; Gerok, W

    1993-01-01

    Caffeine, widely consumed in beverages, is known to alter several biliary parameters that can affect gallstone pathogenesis. To address the question whether methylxanthines can act on the luminal side of biliary epithelial cells, we measured caffeine and its primary demethylation products in human bile. Eight patients had an external biliary drainage due to bile duct or gallbladder disease. Two of the patients suffered from histologically confirmed liver cirrhosis. The levels of caffeine, paraxanthine, theobromine, and theophylline were monitored over 10 h in plasma and bile before and after a prior oral dose of caffeine (5 mg/kg b. wt.). Methylxanthines were enriched by an organic extraction procedure and separated by reversed-phase high-performance liquid chromatography. Time-concentration curves in bile paralleled the time-course of methylxanthine levels in blood plasma. Accordingly, values in bile and blood plasma were highly correlated for each methylxanthine measured. Within 1 h after the oral test dose, peak levels of caffeine were obtained in both fluids. Biliary concentrations were either almost equal (caffeine) or lower (dimethylxanthines) than their respective values in blood plasma. The results of our study indicate that minor amounts of caffeine and its primary degradation products are excreted via the bile allowing local interference with epithelial cell metabolism of bile ducts and gallbladder.

  2. Persistence of urinary excretion products of benzo(a)pyrene

    SciTech Connect

    Uziel, M.; Haglund, R.; White, D.A.

    1988-01-01

    Persistence of DNA-adducts has been observed in a variety of experimental circumstances and has been suggested as one potential mechanism for explaining the long-term delay before expression of proliferative disease. In this concept, a stable DNA-adduct, which is a remnant of a prior exposure in a nondividing cell, would not express the genotoxic effect until the cells were stimulated to divide, and thus explain the long-term delay in expression of cancer. An alternative view of the observation of persistent DNA-adducts, described in this communication, is the continuing replenishment of DNA adducts by formation and turnover of these adducts from exposure to a constant supply of the ultimate carcinogenic species derived from a prior exposure. It is of interest to note that virtually all experiments where ''persistent'' adducts have been observed have been high dose exposures. During the course of experiments designed to develop improved methods for detection of DNA adducts and related derivatives derived from polynuclear aromatic hydrocarbons (PAH), we observed that there was a continuous excretion of urinary derivatives of the injected benzo(a)pyrene (BaP) beyond the initial burst of detoxification. This report describes the time dependent distribution of those derivatives in blood, urine, feces, and at the site of injection. 11 refs., 5 figs., 4 tabs.

  3. Organic Acid Excretion in Penicillium ochrochloron Increases with Ambient pH

    PubMed Central

    Vrabl, Pamela; Fuchs, Viktoria; Pichler, Barbara; Schinagl, Christoph W.; Burgstaller, Wolfgang

    2012-01-01

    Despite being of high biotechnological relevance, many aspects of organic acid excretion in filamentous fungi like the influence of ambient pH are still insufficiently understood. While the excretion of an individual organic acid may peak at a certain pH value, the few available studies investigating a broader range of organic acids indicate that total organic acid excretion rises with increasing external pH. We hypothesized that this phenomenon might be a general response of filamentous fungi to increased ambient pH. If this is the case, the observation should be widely independent of the organism, growth conditions, or experimental design and might therefore be a crucial key point in understanding the function and mechanisms of organic acid excretion in filamentous fungi. In this study we explored this hypothesis using ammonium-limited chemostat cultivations (pH 2–7), and ammonium or phosphate-limited bioreactor batch cultivations (pH 5 and 7). Two strains of Penicillium ochrochloron were investigated differing in the spectrum of excreted organic acids. Confirming our hypothesis, the main result demonstrated that organic acid excretion in P. ochrochloron was enhanced at high external pH levels compared to low pH levels independent of the tested strain, nutrient limitation, and cultivation method. We discuss these findings against the background of three hypotheses explaining organic acid excretion in filamentous fungi, i.e., overflow metabolism, charge balance, and aggressive acidification hypothesis. PMID:22493592

  4. Reduction in fecal excretion of Giardia cysts: effect of cholestasis and diet.

    PubMed

    Erlandsen, Stanley

    2005-12-01

    Bile is a major growth factor for the proliferation of Giardia spp. trophozoites in the small intestine and, at high concentrations, stimulates encystment of trophozoites. This report demonstrates that surgical cholestasis to interrupt the flow of bile from liver to intestine or the use of bile-binding resins in the diet can both dramatically decrease the fecal excretion of Giardia muris cysts. Cholestasis produced a 3 log reduction in excretion of G. muris cysts within 24 hr of surgery and a 4 log reduction after 3 days. Sham controls showed no difference in cyst excretion from presurgical control values. Two isocaloric diets were studied: a control diet (N) of Purina mouse chow containing 5% celufil and an experimental diet (CR) containing 5% cholestyramine, a resin that binds bile. Compared with the N diet, the CR diet was associated with reductions in cyst excretion of 3 logs within 1 day. Despite lowered excretion of G. muris cysts in mice fed the cholestyramine diet, the trophozoite recovery from the duodenum was similar with both diets. Cyclic feeding of the CR diet and the N diet at 3-day intervals produced significant oscillations (changes of 3-4 logs) in fecal cyst shedding. The significant reductions in fecal excretion of cysts observed with agents that bind bile suggests that diets capable of binding bile might be a therapeutic means to minimize the fecal excretion of cysts and thereby may help to reduce the risk of spreading giardiasis through fecal-oral contamination.

  5. Effects of chronic lithium administration on renal acid excretion in humans and rats

    PubMed Central

    Weiner, I. David; Leader, John P.; Bedford, Jennifer J.; Verlander, Jill W.; Ellis, Gaye; Kalita, Priyakshi; Vos, Frederiek; de Jong, Sylvia; Walker, Robert J.

    2014-01-01

    Abstract Lithium therapy's most common side effects affecting the kidney are nephrogenic diabetes insipidus (NDI) and chronic kidney disease. Lithium may also induce a distal renal tubular acidosis. This study investigated the effect of chronic lithium exposure on renal acid–base homeostasis, with emphasis on ammonia and citrate excretion. We compared 11 individuals on long‐term lithium therapy with six healthy individuals. Under basal conditions, lithium‐treated individuals excreted significantly more urinary ammonia than did control subjects. Following an acute acid load, urinary ammonia excretion increased approximately twofold above basal rates in both lithium‐treated and control humans. There were no significant differences between lithium‐treated and control subjects in urinary pH or urinary citrate excretion. To elucidate possible mechanisms, rats were randomized to diets containing lithium or regular diet for 6 months. Similar to humans, basal ammonia excretion was significantly higher in lithium‐treated rats; in addition, urinary citrate excretion was also significantly greater. There were no differences in urinary pH. Expression of the critical ammonia transporter, Rhesus C Glycoprotein (Rhcg), was substantially greater in lithium‐treated rats than in control rats. We conclude that chronic lithium exposure increases renal ammonia excretion through mechanisms independent of urinary pH and likely to involve increased collecting duct ammonia secretion via the ammonia transporter, Rhcg. PMID:25501430

  6. Comparative Study on Trace Element Excretions between Nonanuric and Anuric Patients Undergoing Continuous Ambulatory Peritoneal Dialysis

    PubMed Central

    Xiang, Siyun; Yao, Ying; Wan, Yunan; Liang, Wangqun; Meng, Ruiwei; Jin, Qiman; Wu, Nannan; Xu, Fangyi; Ying, Chenjiang; Zuo, Xuezhi

    2016-01-01

    Few studies have been reported on alterations of trace elements (TE) in peritoneal dialysis patients. Our objective was to investigate and assess the characteristics of daily TE excretions in continuous ambulatory peritoneal dialysis (CAPD) patients. This cross-sectional study included 61 CAPD patients (nonanuric/anuric: 45/16) and 11 healthy subjects in Wuhan, China between 2013 and 2014. The dialysate and urine of patients and urine of healthy subjects were collected. The concentrations of copper (Cu), zinc (Zn), selenium (Se), molybdenum (Mo), and arsenic (As) in dialysate and urine were determined using inductively coupled plasma mass spectrometer (ICP-MS). Various clinical variables were obtained from automatic biochemical analyzer. Daily Cu, Zn, Se, and Mo excretions in nonanuric patients were higher than healthy subjects, while arsenic excretion in anuric patients was lower. A strong and positive correlation was observed between Se and Mo excretion in both dialysate (β = 0.869, p < 0.010) and urine (β = 0.968, p < 0.010). Furthermore, the clinical variables associated with Se excretion were found to be correlated with Mo excretion. Our findings indicated that nonanuric CAPD patients may suffer from deficiency of some essential TEs, while anuric patients are at risk of arsenic accumulation. A close association between Se and Mo excretion was also found. PMID:27999390

  7. Effect of sodium taurolithocholate on bile flow and bile acid excretion

    PubMed Central

    Javitt, Norman B.; Emerman, Sidney

    1968-01-01

    Sodium taurolithocholate and sodium taurocholenate were infused intravenously into rats and hamsters. Each bile acid salt was given alone or in combination with varying amounts of a primary bile salt, either sodium taurocholate or sodium taurochenodeoxycholate. Bile flow, total bile acid salt excretion, and the excretion of sodium taurolithocholate were quantitatively determined. In addition, mannitol excretion in bile was determined at various flow rates. Sodium taurolithocholate was found to be rapidly excreted in bile in concentrations greater than its aqueous solubility. When the endogenous excretion rate of bile salt or the infusion of primary bile salt was less than the molar amount of administered sodium taurolithocholate, cholestasis always occurred. Increasing molar amounts of primary bile salt prevented cholestasis and enhanced the excretion rate of sodium taurolithocholate. Infusion of sodium taurocholenate, a nonhemolytic bile salt, caused an effect on bile flow and bile acid salt excretion qualitatively similar to sodium taurolithocholate. The induction of cholestasis can be attributed to the physical properties of these poorly water soluble bile salts. The reduction in bile flow could not be shown to be related to water reabsorption from the biliary tree since there was no increase in mannitol concentration in bile during cholestasis. Reduction in bile flow may be related to obstruction of segments of the biliary tree by precipitates of sodium taurolithocholate and possibly to a decrease in water entry into the biliary tree during infusion of this bile acid salt. PMID:5645847

  8. Are hummingbirds facultatively ammonotelic? Nitrogen excretion and requirements as a function of body size.

    PubMed

    McWhorter, Todd J; Powers, Donald R; Martínez Del Rio, Carlos

    2003-01-01

    Most birds are uricotelic. An exception to this rule may be nectar-feeding birds, which excrete significant amounts of ammonia under certain conditions. Although ammonia is toxic, because it is highly water soluble its excretion may be facilitated in animals that ingest and excrete large amounts of water. Bird-pollinated plants secrete carbohydrate- and water-rich floral nectars that contain exceedingly little protein. Thus, nectar-feeding birds are faced with the dual challenge of meeting nitrogen requirements while disposing of large amounts of water. The peculiar diet of nectar-feeding birds suggests two hypotheses: (1) these birds must have low protein requirements, and (2) when they ingest large quantities of water their primary nitrogen excretion product may be ammonia. To test these hypotheses, we measured maintenance nitrogen requirements (MNR) and total endogenous nitrogen losses (TENL) in three hummingbird species (Archilochus alexandri, Eugenes fulgens, and Lampornis clemenciae) fed on diets with varying sugar, protein, and water content. We also quantified the form in which the by-products of nitrogen metabolism were excreted. The MNR and TENL of the hummingbirds examined were exceptionally low. However, no birds excreted more than 50% of nitrogen as ammonia or more nitrogen as ammonia than urates. Furthermore, ammonia excretion was not influenced by either water or protein intake. The smallest species (A. alexandri) excreted a significantly greater proportion (>25%) of their nitrogenous wastes as ammonia than the larger hummingbirds ( approximately 4%). Our results support the hypothesis that nectar-feeding birds have low protein requirements but cast doubt on the notion that they are facultatively ammonotelic. Our data also hint at a possible size-dependent dichotomy in hummingbirds, with higher ammonia excretion in smaller species. Differences in proportionate water loads and/or postrenal modification of urine may explain this dichotomy.

  9. The effect of ethanol on the urinary excretion and differential metabolism of folate compounds

    SciTech Connect

    Eisenga, B.H.

    1989-01-01

    In rats chronically fed ethanol and folate-containing diets for 12 weeks, urinary folate excretion was increased. However, no significant tissue depletion was noted unless rats were fed folate deficient diets. In rats fed folate-deficient diets urinary folate excretion was dramatically decreased at two weeks, when tissue folate stores were replete. After 16 weeks of diet treatment, the urinary excretion of an intraperitoneal dose of {sup 3}H-PteGlu was not altered in folate-deficient rats. Although acute ethanol administration (oral or intravenous) increased endogenous folate excretion that of {sup 3}H-PteGlu was not significantly altered, nor was the fractional excretion of {sup 3}H-label. To clarify this effect, the metabolism of {sup 3}H-PteGlu was studied. HPLC analysis of urine showed extensive metabolism of {sup 3}H-PteGlu to other folate substrates. Oral ethanol-treatment increased the fractional excretion of endogenous 5-CH{sub 3}-H{sub 4}PteGlu with no increase in urinary excretion or fractional excretion of other {sup 3}H-labeled derivatives. After infusion of tritium labeled 5-CH{sub 3}-H{sub 4}PteGlu, ethanol treatment increased the fractional excretion of endogenous and {sup 3}H-5-CH{sub 3}-H{sub 4}PteGlu, but not that of other folates. There was rapid uptake of {sup 3}H-label by the kidney with only 10% of the urinary {sup 3}H-label as {sup 3}H-5-CH{sub 3}-H{sub 4}PteGlu.

  10. Systematic review focusing on the excretion and protection roles of sweat in the skin.

    PubMed

    Peng, Yan; Cui, Xiao; Liu, Yanhua; Li, Yaoyin; Liu, Jian; Cheng, Biao

    2014-01-01

    The skin excretes substances primarily through sweat glands. Several conditions have been demonstrated to be associated with diminished sweating. However, few studies have concentrated on the metabolism and excretion of sweat. This review focuses on the relationship between temperature and the thermoregulatory efficacy of sweat, and then discusses the excretion of sweat, which includes the metabolism of water, minerals, proteins, vitamins as well as toxic substances. The potential role of sweat secretion in hormone homeostasis and the effects on the defense system of the skin are also clarified.

  11. Excretion of lead as a mechanism for survival in Chrissia halyi (Ferguson, 1969)

    SciTech Connect

    Prasuna, G.; Zeba, M.; Khan, M.A.

    1996-12-31

    In general organisms develop or use a number of mechanisms to overcome the adverse influence of such toxicants as heavy metals. These mechanisms may be avoidance, immobilization, excretion and mechanisms involving enzymatic changes. Tolerant organisms may possess certain storage organs which are particularly involved in heavy metal immobilization as suggested by Hopkin and Martin (1985). Chrissia halyi (Crustacea, Ostracoda) were observed to be surviving in waters which are highly polluted with lead. Besides they were found feeding voraciously on contaminated blue green algae, and excreting large pellets. Therefore the present work has been taken up to see the lead in the excreted pellets. 10 refs., 1 tab.

  12. Infant botulism with prolonged faecal excretion of botulinum neurotoxin and Clostridium botulinum for 7 months.

    PubMed

    Derman, Y; Korkeala, H; Salo, E; Lönnqvist, T; Saxen, H; Lindström, M

    2014-02-01

    In Finland in April 2010, a 3-month old baby was diagnosed with type A infant botulism. He excreted botulinum neurotoxin and/or Clostridium botulinum in his faeces until November 2010. Five months of excretion was after clinical recovery and discharge from hospital. C. botulinum isolates recovered from the household dust in the patient's home were genetically identical to those found in the infant's stool samples. Long-term faecal excretion of C. botulinum may pose a possible health risk for the parents and others in close contact with the infant.

  13. Pseudouridine and beta-aminoisobutyric acid excretion in urine: diagnostic and prognostic value.

    PubMed

    Kvist, E; Sjølin, K E

    1990-01-01

    The sex- and age-related urinary excretion of pseudouridine/creatinine and beta-aminoisobutyric acid/creatinine was studied in 77 healthy subjects (24 children and 53 adults, 27 of whom were women). The highest values were found in the youngest children. We compared the excretion ratios of pseudouridine/creatinine and beta-aminoisobutyric acid/creatinine in women and men and found no significant differences between them. The excretion patterns may be helpful in the diagnosis of patients with urinary tract tumours and in predicting patients at risk of recurrences.

  14. Renal excretion of plasma soluble melanins by healthy human adults.

    PubMed

    Hegedus, Z L; Nayak, U

    1993-01-01

    The soluble melanins of blood plasma form in vivo and in vitro from dopa, catecholamines, catechol, hydroquinone, homogentisic acid, 3-hydroxykynurenine, 3-hydroxyanthranilic acid, p-aminophenol, p-phenylenediamine and other structurally related end(ex)ogenous compounds by oxidative polymerization. The mean quantity of natural melanins in normal plasma is 1.61 +/- 0.10 (standard deviation) mg/ml, (n = 20) and in uraemic plasma 2.72 +/- 0.38 mg/ml, (n = 16). The plasma melanins (approximately 3%), are associated with proteins (approximately 85%), mucoproteins (approximately 0.25%), lipids (approximately 0.4%), as soluble lipofuscins, and probably are associated with proteins without lipids as soluble melanoproteins. Fluorescence, UV-VIS and IR spectroscopies and the melanin isolation method show the presence of soluble melanins in the urine of healthy people. Soluble melanins can also be formed in vitro in the urine by oxidative polymerization of the precursors. In most of the urine samples we studied, melanins were present in larger amounts than the urinary proteins, indicating that the kidneys can selectively excrete the melanin components of the lipofuscins, and that the solubility of melanins does not depend upon combination with proteins. The quantities of purified melanins precipitated with 6 N HCl at 110 degrees C during 72 h from urine samples collected during 24 h periods ranged from 0.1460 g to 3.7627 g (mean 1.1303 +/- 1.1739 g, n = 8) and the plasma clearance rates ranged from 0.06 ml/min to 1.56 ml/min (mean 0.48 +/- 0.48 ml/min, n = 8). From the individual 24 h urine samples we obtained from 9 to 216 mg/dl of precipitated melanins while the individual plasma samples contained from 145 to 175 mg/dl.

  15. Free phytosterols facilitate excretion of endogenous cholesterol in gerbils.

    PubMed

    Hayes, K C; Pronczuk, Andrzej; Wijendran, Vasuki; Beer, Michael

    2005-05-01

    To determine whether phytosterols (PST) facilitate excretion of whole body cholesterol and whether dietary fat or enhancing gallbladder contraction with curcumin might influence this process, four experiments were conducted in gerbils. In Experiment 1, naive gerbils received cholesterol-free purified diets with 30% energy from fat and 0% or 0.75% free PST from tall oil for 4 weeks. In Experiment 2, body cholesterol pools were expanded by feeding a diet containing 0.3% cholesterol for 3 weeks. Subsequently, PST was provided in either fat-free or normal-fat diets without cholesterol for only 2 h each morning, followed by a low-fat diet for the rest of the day and food restriction overnight. In Experiment 3, gerbils were preloaded with cholesterol, followed by either PST alone or PST+curcumin to enhance gallbladder contraction. In Experiment 4, curcumin or curcumin+PST were fed with 30% as fat and 0.15% cholesterol throughout the study. Because of the small whole body cholesterol pool in Experiment 1, the impact of PST was limited. When whole body cholesterol was expanded in Experiments 2 and 3, subsequent reductions of liver esterified cholesterol by PST were significant. In the presence of dietary fat, PST caused a greater reduction (23%) than in a fat-free diet (8%) compared to respective controls. Curcumin (Experiments 3 and 4) proved ineffective in reducing liver or plasma cholesterol pools, and the 3:1 ratio between PST/diet cholesterol was less effective at blocking cholesterol absorption than a 5:1 ratio previously employed. Thus, free PST removed whole body cholesterol, which was enhanced by concomitant fat intake, but was unaffected by a gallbladder contracting agent.

  16. High sodium intake increases the urinary excretion of L-3,4-dihydroxyphenylalanine but fails to alter the urinary excretion of dopamine and amine metabolites in Wistar rats.

    PubMed

    Vieira-Coelho, M A; Pestana, M; Soares-da-Silva, P

    1996-12-01

    1. The present study has examined the daily urinary excretion of L-DOPA, dopamine and its metabolites (DOPAC, 3-MT and HVA) during normal salt (NS) and high salt(HS) diets. 2. Daily urinary excretion of L-DOPA, DA, DOPAC, 3-MT and HVA during the 4-day period of NS diet averaged, respectively, 7.6 +/- 0.4, 71 +/- 5, 217 +/- 22, 570 +/- 90 and 1217 +/- 110 nmol/kg/day. The slight increase in the urinary excretion of DA, DOPAC and 3-MT (16% to 42% increase), when rats were fed a HS diet, did not achieve statistical significance. 3. In contrast, the urinary levels of L-DOPA during the HS diet period (11 +/- 1 nmol/kg/day) were found to be significantly higher than during the NS diet period; the maximal increase in the urinary excretion of L-DOPA (93% increase) was observed in the first day and then a progressive decline was observed towards the end of the HS intake period. 4. During the first 5 days of the HS intake period, the urine output of noradrenaline (NA) was found to increase (27% to 83%) and then to progressively decline to baseline values (13.5 +/- 0.7 nmol/ kg/day). Urinary excretion of adrenaline (AD) during the HS intake period was found to increase (72% to 146%); the mean daily urinary excretion of AD during the NS diet period averaged 2.5 +/- 0.4 nmol/ kg/day. NS and DA contents in the kidney of rats on a NS diet were not significantly different from that of rats in a HS diet. 6. It is concluded that long-term HS intake in Wistar rats fail to change the urinary excretion of DA and of its metabolites (DOPAC, 3-MT and HVA). Furthermore, the discrepant profile in the urinary excretion of L-DOPA and DA during HS intake might be related to a reduction in the tubular uptake of the amino acid, rather than reflecting a decrease in its decarboxylation.

  17. The quantitative relationship of urinary peptide hydroxyproline excretion to collagen degradation

    PubMed Central

    Weiss, Phillip H.; Klein, LeRoy

    1969-01-01

    To determine the quantitative relationship of urinary hydroxyproline peptide excretion to collagen breakdown, known quantities of radioactive hydroxyproline peptides were administered to unlabeled animals and excertion of radioactivity in respiratory carbon dioxide, urine, and feces was measured. The major routes of excretion of collagen peptide metabolites were respiratory carbon dioxide (75%) and urine, as hydroxyproline-containing peptides (25%). Since the predominant urine hydroxyproline peptide linkage is proly-hydroxyproline, L-prolyl-L-hydroxyproline-3H was administered to unlabeled animals. Greater than 80% of the administered dipeptide was excreted in urine, suggesting that this peptide linkage is not hydrolyzed to a significant extent in vivo. These data suggest that urinary hydroxyproline excretion is a “fairly” sensitive indicator of collagen breakdown and can be used at the clinical level to quantitate changes in collagen breakdown. PMID:5765022

  18. Emulsifier formation with Acinetobacter: search for an excretion-reduced mutant of Acinetobacter calcoaceticus 69-V.

    PubMed

    Müller, R H; Babel, W

    1986-01-01

    After growth on acetate three groups of Acinetobacter strains could be identified with respect to the excretion of a bioemulsifier. Mutants of A. calcoaceticus 69-V were selected which produced reduced amounts of emulsifier.

  19. Excretion of Water and Electrolytes During the Osmotic Diuresis of Dogs with Experimental Diabetes Insipidus,

    DTIC Science & Technology

    ELECTROLYTES(PHYSIOLOGY), *BODY FLUIDS, ELECTROLYTES(PHYSIOLOGY), EXCRETION, PITUITARY HORMONES , OSMOSIS, TRANSPORT PROPERTIES, MEMBRANES(BIOLOGY...BLOOD PLASMA, DIABETES, WATER, SECRETION, SODIUM, POTASSIUM, URINE, CELLS(BIOLOGY), KIDNEY FUNCTION TESTS, BIOLOGICAL ABSORPTION.

  20. Grazing and excretion by zooplankton in the Peru upwelling system during April 1977

    NASA Astrophysics Data System (ADS)

    Dagg, M.; Cowles, T.; Whitledge, T.; Smith, S.; Howe, S.; Judkins, D.

    1980-01-01

    Rates of ingestion and excretion by adult females of the copepods Calanus chilensis, Eucalanus inermis, and Centropages brachiatus were measured in natural seawater during a cruise in the Peru upwelling system during April 1977. Simultaneously, zooplankton samples were collected for later determination of the abundance and distribution of these and other species. For these three organisms, feeding, and excretion rates of individuals are combined with information on the animal concentrations to estimate the grazing stress on the phytoplankton at each station, and to estimate the excretory nitrogen produced at each station. Comparison of grazing stresses with measured rates of primary production indicates that these large copepods were harvesting less than 5% of the daily phytoplankton production. Comparison of the nitrogen excretion rates with the amounts of excreted nitrogen in the water column indicates that less than 3% of the ambient excretory nitrogen was produced daily by these copepods. The importance of the abundant small zooplankton in the system is suggested.

  1. ENVIRONMENTAL FOOTPRINT OF PHARMACEUTICALS - THE SIGNIFICANCE OF FACTORS BEYOND DIRECT EXCRETION TO SEWERS

    EPA Science Inventory

    The combined excretion of active pharmaceutical ingredients (APIs) via urine and feces is considered the primary route by which APIs from human pharmaceuticals enter the environment. Disposal of unwanted, leftover medications by flushing into sewers has been considered a secondar...

  2. Evidence that auxin-induced growth of soybean hypocotyls involves proton excretion

    SciTech Connect

    Rayle, D.L.; Cleland, R.E.

    1980-09-01

    The role of H/sup +/ excretion in auxin-induced growth of soybean hypocotyl tissues has been investigated, using tissues whose cuticle was rendered permeable to protons or buffers by scarification (scrubbing). Indoleacetic acid induces both elongation and H/sup +/ excretion after a lag of 10 to 12 minutes. Cycloheximide inhibits growth and causes the tissues to remove protons from the medium. Neutral buffers (pH 7.0) inhibit auxin-induced growth of scrubbed but not intact sections; the inhibition increases as the buffers strength is increased. Both live and frozen-thawed sections, in the absence of auxin, extend in response to exogenously supplied protons. Fusicoccin induces both elongation and H/sup +/ excretion at rates greater than does auxin. These results indicate that H/sup +/ excretion is involved in the initiation of auxin-induced elongation in soybean hypocotyl tissue.

  3. Ammonium and phosphate excretion in three common echinoderms from Philippine coral reefs.

    PubMed

    Dy; Yap

    2000-08-30

    The ammonium and phosphate excretion and oxygen consumption of three species of echinoderms (Tripneustes gratilla, Protoreaster nodosus and Ophiorachna incrassata) commonly encountered in Philippine coral reefs were investigated in relation to time of day (i.e. daytime between 10:00 and 12:00 h vs. nighttime between 22:00 and 24:00 h) and their recent feeding history (i.e. recently-collected vs. short-term starvation for 3+/-1 days). The experiment used whole organism incubations and followed a nested hierarchical design. Ammonium excretion rates were 1447+/-310 nmolg(-1) DWh(-1) (mean+/-S.E., n=24) for T. gratilla, 361+/-33 for O. incrassata and 492+/-38 for P. nodosus. Ammonium excretion differed significantly among species, time of incubation and recent feeding history. Interaction between species and recent feeding history was also significant. The organisms excreted more ammonium during daytime except for starved specimens of O. incrassata. In addition, animals that were starved in the laboratory for a few days had a tendency to excrete more ammonium than recently-collected specimens. Phosphate excretion rates were 25+/-13 nmolg(-1) DWh(-1) for T. gratilla, 10+/-2 for O. incrassata and 4+/-1 for P. nodosus. There were no significant differences in phosphate excretion among the three species of echinoderms, their recent feeding history and time of day. Oxygen consumption rates were 286+/-24 µg O(2)g(-1) DWh(-1) for T. gratilla, 64+/-3 for O. incrassata and 54+/-3 for P. nodosus. Oxygen consumption differed significantly among species and recent feeding history but differed only slightly with time of incubation. There was a significant correlation between oxygen consumption and ammonium excretion (r=0.48, P=0.018), and between oxygen consumption and phosphate excretion (r=0.41, P=0.047) for T. gratilla. The nutrient excretion by tropical echinoderms is another pathway by which inorganic nutrients are regenerated in coral reef communities. However, the quantity

  4. K+ excretion: the other purpose for puddling behavior in Japanese Papilio butterflies.

    PubMed

    Inoue, Takashi A; Ito, Tetsuo; Hagiya, Hiroshi; Hata, Tamako; Asaoka, Kiyoshi; Yokohari, Fumio; Niihara, Kinuko

    2015-01-01

    To elucidate the purpose of butterfly puddling, we measured the amounts of Na+, K+, Ca2+, and Mg2+ that were absorbed or excreted during puddling by male Japanese Papilio butterflies through a urine test. All of the butterflies that sipped water with a Na+ concentration of 13 mM absorbed Na+ and excreted K+, although certain butterflies that sipped solutions with high concentrations of Na+ excreted Na+. According to the Na+ concentrations observed in naturally occurring water sources, water with a Na+ concentration of up to 10 mM appears to be optimal for the health of male Japanese Papilio butterflies. The molar ratio of K+ to Na+ observed in leaves was 43.94 and that observed in flower nectars was 10.93. The Na+ amount in 100 g of host plant leaves ranged from 2.11 to 16.40 mg, and the amount in 100 g of flower nectar ranged from 1.24 to 108.21 mg. Differences in host plants did not explain the differences in the frequency of puddling observed for different Japanese Papilio species. The amounts of Na+, K+, Ca2+, and Mg2+ in the meconium of both male and female butterflies were also measured, and both males and females excreted more K+ than the other three ions. Thus, the fluid that was excreted by butterflies at emergence also had a role in the excretion of the excessive K+ in their bodies. The quantities of Na+ and K+ observed in butterfly eggs were approximately 0.50 μg and 4.15 μg, respectively; thus, female butterflies required more K+ than male butterflies. Therefore, female butterflies did not puddle to excrete K+. In conclusion, the purpose of puddling for male Papilio butterflies is not only to absorb Na+ to correct deficiencies but also to excrete excessive K+.

  5. Urinary excretion of phytoestrogens and risk of breast cancer among Chinese women in Shanghai.

    PubMed

    Dai, Qi; Franke, Adrian A; Jin, Fan; Shu, Xiao-Ou; Hebert, James R; Custer, Laurie J; Cheng, Jiarong; Gao, Yu-Tang; Zheng, Wei

    2002-09-01

    Although the majority of ecological and experimental studies have suggested a potential role of phytoestrogens in breast cancer prevention, findings from epidemiological studies have been inconsistent. Part of the inconsistencies may be attributable to the difficulty in measuring intake levels of phytoestrogens. Overnight urine samples from 250 incident breast cancer cases and their individually matched controls were analyzed for urinary excretion rates of isoflavonoids, mammalian lignans, and citrus flavonoids. The study subjects were a subset of the participants in the Shanghai Breast Cancer Study, a large population-based case-control study conducted in Shanghai from 1996-1998. To minimize potential influence of treatment on the exposure of interest, urine samples from breast cancer cases were collected before cancer therapy. Urinary excretion of total isoflavonoids and mammalian lignans was substantially lower in breast cancer cases than in controls. The median excretion rate of total isoflavonoids was 13.97 nmol/mg creatinine in cases and 23.09 in controls (P = 0.01), and the median excretion rate of total lignans was 1.77 in cases and 4.16 in controls (P < 0.01). The risk of breast cancer was reduced with increasing excretion of total isoflavonoids (P for trend, 0.04) and total lignans (P for trend, <0.01), with adjusted odds ratios of 0.62 (95% confidence interval, 0.39-0.99) and 0.40 (95% confidence interval, 0.24-0.64) observed for the highest versus the lowest tertile of total isoflavonoid and lignan excretion, respectively. The adjusted odds ratio was 0.28 (95% confidence interval, 0.15-0.50) for women who had a high excretion rate of both total lignans and isoflavonoids compared with those with a low excretion of both groups of phytoestrogens. No association was observed with citrus flavonoids. The results from this study suggest that high intake of certain phytoestrogens may reduce the risk of breast cancer.

  6. Associations of ambulatory blood pressure with urinary caffeine and caffeine metabolite excretions.

    PubMed

    Guessous, Idris; Pruijm, Menno; Ponte, Belén; Ackermann, Daniel; Ehret, Georg; Ansermot, Nicolas; Vuistiner, Philippe; Staessen, Jan; Gu, Yumei; Paccaud, Fred; Mohaupt, Markus; Vogt, Bruno; Pechère-Bertschi, Antoinette; Pechère-Berstchi, Antoinette; Martin, Pierre-Yves; Burnier, Michel; Eap, Chin B; Bochud, Murielle

    2015-03-01

    Intake of caffeinated beverages might be associated with reduced cardiovascular mortality possibly via the lowering of blood pressure. We estimated the association of ambulatory blood pressure with urinary caffeine and caffeine metabolites in a population-based sample. Families were randomly selected from the general population of Swiss cities. Ambulatory blood pressure monitoring was conducted using validated devices. Urinary caffeine, paraxanthine, theophylline, and theobromine excretions were measured in 24 hours urine using ultrahigh performance liquid chromatography tandem mass spectrometry. We used mixed models to explore the associations of urinary excretions with blood pressure although adjusting for major confounders. The 836 participants (48.9% men) included in this analysis had mean age of 47.8 and mean 24-hour systolic and diastolic blood pressure of 120.1 and 78.0 mm Hg. For each doubling of caffeine excretion, 24-hour and night-time systolic blood pressure decreased by 0.642 and 1.107 mm Hg (both P values <0.040). Similar inverse associations were observed for paraxanthine and theophylline. Adjusted night-time systolic blood pressure in the first (lowest), second, third, and fourth (highest) quartile of paraxanthine urinary excretions were 110.3, 107.3, 107.3, and 105.1 mm Hg, respectively (P trend <0.05). No associations of urinary excretions with diastolic blood pressure were generally found, and theobromine excretion was not associated with blood pressure. Anti-hypertensive therapy, diabetes mellitus, and alcohol consumption modify the association of caffeine urinary excretion with systolic blood pressure. Ambulatory systolic blood pressure was inversely associated with urinary excretions of caffeine and other caffeine metabolites. Our results are compatible with a potential protective effect of caffeine on blood pressure.

  7. K+ Excretion: The Other Purpose for Puddling Behavior in Japanese Papilio Butterflies

    PubMed Central

    2015-01-01

    To elucidate the purpose of butterfly puddling, we measured the amounts of Na+, K+, Ca2+, and Mg2+ that were absorbed or excreted during puddling by male Japanese Papilio butterflies through a urine test. All of the butterflies that sipped water with a Na+ concentration of 13 mM absorbed Na+ and excreted K+, although certain butterflies that sipped solutions with high concentrations of Na+ excreted Na+. According to the Na+ concentrations observed in naturally occurring water sources, water with a Na+ concentration of up to 10 mM appears to be optimal for the health of male Japanese Papilio butterflies. The molar ratio of K+ to Na+ observed in leaves was 43.94 and that observed in flower nectars was 10.93. The Na+ amount in 100 g of host plant leaves ranged from 2.11 to 16.40 mg, and the amount in 100 g of flower nectar ranged from 1.24 to 108.21 mg. Differences in host plants did not explain the differences in the frequency of puddling observed for different Japanese Papilio species. The amounts of Na+, K+, Ca2+, and Mg2+ in the meconium of both male and female butterflies were also measured, and both males and females excreted more K+ than the other three ions. Thus, the fluid that was excreted by butterflies at emergence also had a role in the excretion of the excessive K+ in their bodies. The quantities of Na+ and K+ observed in butterfly eggs were approximately 0.50 μg and 4.15 μg, respectively; thus, female butterflies required more K+ than male butterflies. Therefore, female butterflies did not puddle to excrete K+. In conclusion, the purpose of puddling for male Papilio butterflies is not only to absorb Na+ to correct deficiencies but also to excrete excessive K+. PMID:25955856

  8. Excretion masses and environmental occurrence of antibiotics in typical swine and dairy cattle farms in China.

    PubMed

    Zhou, Li-Jun; Ying, Guang-Guo; Liu, Shan; Zhang, Rui-Quan; Lai, Hua-Jie; Chen, Zhi-Feng; Pan, Chang-Gui

    2013-02-01

    This paper evaluated the excretion masses and environmental occurrence of 11 classes of 50 antibiotics in six typical swine and dairy cattle farms in southern China. Animal feeds, wastewater and solid manure samples as well as environmental samples (soil, stream and well water) were collected in December 2010 from these farms. Twenty eight antibiotics, including tetracyclines, bacitracin, lincomycin, sulfonamides, fluoroquinolones, ceftiofur, trimethoprim, macrolides, and florfenicol, were detected in the feeds, animal wastes and receiving environments. The normalized daily excretion masses per swine and cattle were estimated to be 18.2mg/day/swine and 4.24 mg/day/cattle. Chlortetracycline (11.6 mg/day/swine), bacitracin (3.81 mg/day/swine), lincomycin (1.19 mg/day/swine) and tetracycline (1.04 mg/day/swine) were the main contributors to the normalized daily excretion masses of antibiotics per swine, while chlortetracycline (3.66 mg/day/cattle) contributed 86% of the normalized daily excretion masses of antibiotics per cattle. Based on the survey of feeds and animal wastes from the swine farms and interview with the farmers, antibiotics excreted by swine were mainly originated from the feeds, while antibiotics excreted by dairy cattle were mainly from the injection route. If we assume that the swine and cattle in China excrete the same masses of antibiotics as the selected livestock farms, the total excretion mass by swine and cattle per annum in China could reach 3,080,000 kg/year and 164,000 kg/year. Various antibiotics such as sulfonamides, tetracyclines, fluroquinolones, macrolides, trimethoprim, lincomycin and florfenicol were detected in well water, stream and field soil, suggesting that livestock farms could be an important pollution source of various antibiotics to the receiving environments.

  9. Iodine Excretion in 24-hour Urine Collection and Its Dietary Determinants in Healthy Japanese Adults

    PubMed Central

    Katagiri, Ryoko; Asakura, Keiko; Uechi, Ken; Masayasu, Shizuko; Sasaki, Satoshi

    2016-01-01

    Background Since seaweed is a common component of the Japanese diet, iodine intake in Japanese is expected to be high. However, urinary iodine excretion, measured using 24-hour urine samples, and its dietary determinants are not known. Methods Apparently healthy adults aged 20 to 69 years living in 20 areas throughout Japan were recruited in February and March, 2013. Urinary iodine excretion was evaluated using 24-hour urine collected from 713 subjects (362 men and 351 women), and the difference among age groups was assessed. The association between dietary intake of food groups and urinary iodine excretion was assessed among 358 subjects who completed a semi-weighed 4-day diet record (DR) and urine collection. The correlations between iodine intake and iodine excretion were also evaluated, and correlation coefficients were calculated for iodine intake in the DR of the overlapping day or the DR 1 day before and after urine collection. Results Median iodine excretion in 24-hour urine was 365 µg, and excretion was significantly higher in older subjects. Iodine intake estimated by the DRs was significantly correlated with urinary iodine excretion when DRs and urine collection were obtained on the same day (r = 0.37). After adjustment for confounding factors, iodine excretion was significantly associated with intakes of kelp and soup stock from kelp and fish. Conclusions Although multiple measurements for urinary iodine are required to confirm our results, this study showed the current iodine status of healthy Japanese adults. The results suggest that kelp and fish are the main contributors to Japanese iodine status measured by 24-hour urine. PMID:27374137

  10. The effects of unsaturated dietary fats on absorption, excretion, synthesis, and distribution of cholesterol in man

    PubMed Central

    Grundy, Scott M.; Ahrens, E. H.

    1970-01-01

    Cholesterol balance studies were carried out in 11 patients with various types of hyperlipoproteinemia to determine the mechanism by which unsaturated fats lower plasma cholesterol. Unsaturated fats produced no increase in fecal endogenous neutral steroids in 10 of 11 patients and no decrease in absorption of exogenous cholesterol in 5 patients who received cholesterol in the diet. In 8 of 11 patients no changes occurred in excretion of bile acids during the period on unsaturated fat when plasma cholesterol was declining. However, in 3 of 11 patients small but significant increases in bile acid excretion were found during this transitional period; in 2 others increases also occurred after plasma cholesterol had become constant at lower levels on unsaturated fat. Since the majority of patients showed no change in cholesterol or bile acid excretions during the transitional period, we propose that when excretion changes did occur they were probably not the cause of the plasma cholesterol change. Furthermore, turnover data and specific activity curves suggested that cholesterol synthesis was not influenced by exchange of dietary fats. Thus, excluding changes in excretion and synthesis, we conclude that it is most likely that unsaturated fats cause plasma cholesterol to be redistributed into tissue pools. We have also examined the possibility that cholesterol which is redistributed into tissues could be secondarily excreted as neutral steroids or bile acids. In at least 5 of 11 patients excretion patterns were consistent with this explanation. However, we cannot rule out that excretion changes may have been due to alterations in transit time, to changes in bacterial flora, or to transitory changes in absorption or synthesis of cholesterol or bile acids. Our conclusion that unsaturated fats cause a redistribution of cholesterol between plasma and tissue pools points to the necessity in future to explore where cholesterol is stored, to what extent stored cholesterol can

  11. Controlled exercise effects on chromium excretion of trained and untrained runners consuming a constant diet

    SciTech Connect

    Anderson, R.A.; Bryden, N.A.; Polansky, M.M.; Deuster, P.A.

    1986-03-05

    To determine if degree of training effects urinary Cr losses, Cr excretion of 8 adult trained and 5 untrained runners was determined on rest days and following exercise at 90% of maximal oxygen uptake on a treadmill to exhaustion with 30 second exercise and 30 second rest periods. Subjects were fed a constant daily diet containing 9 ..mu..g of Cr per 1000 calories to minimize changes due to diet. Maximal oxygen consumption of the trained runners was in the good or above range based upon their age and that of the untrained runners was average or below. While consuming the control diet, basal urinary Cr excretion of subjects who exercise regularly was significantly lower than that of the sedentary control subjects, 0.09 +/- 0.01 and 0.21 +/- 0.03 ..mu..g/day (mean +/- SEM), respectively. Daily urinary Cr excretion of trained subjects was significantly higher on the day of a single exercise bout at 90% of maximal oxygen consumption compared to nonexercise days, 0.12 +/- 0.02 and 0.09 +/- 0.01 ..mu..g/day, respectively. Urinary Cr excretion of 5 untrained subjects was not altered following controlled exercise. These data demonstrate that basal urinary Cr excretion and excretion in response to exercise are related to maximal oxygen consumption and therefore degree of fitness.

  12. Screening of alginate lyase-excreting microorganisms from the surface of brown algae.

    PubMed

    Wang, Mingpeng; Chen, Lei; Zhang, Zhaojie; Wang, Xuejiang; Qin, Song; Yan, Peisheng

    2017-12-01

    Alginate lyase is a biocatalyst that degrades alginate to produce oligosaccharides, which have many bioactive functions and could be used as renewable biofuels. Here we report a simple and sensitive plate assay for screening alginate lyase-excreting microorganisms from brown algae. Brown algae Laminaria japonica, Sargassum horneri and Sargassum siliquatrum were cultured in sterile water. Bacteria growing on the surface of seaweeds were identified and their capacity of excreting alginate lyase was analyzed. A total of 196 strains were recovered from the three different algae samples and 12 different bacterial strains were identified capable of excreting alginate lyases. Sequence analysis of the 16S rRNA gene revealed that these alginate lyase-excreting strains belong to eight genera: Paenibacillus (4/12), Bacillus (2/12), Leclercia (1/12), Isoptericola (1/12), Planomicrobium (1/12), Pseudomonas (1/12), Lysinibacillus (1/12) and Sphingomonas (1/12). Further analysis showed that the LJ-3 strain (Bacillus halosaccharovorans) had the highest enzyme activity. To our best knowledge, this is the first report regarding alginate lyase-excreting strains in Paenibacillus, Planomicrobium and Leclercia. We believe that our method used in this study is relatively easy and reliable for large-scale screening of alginate lyase-excreting microorganisms.

  13. Reliability of Urinary Excretion Rate Adjustment in Measurements of Hippuric Acid in Urine

    PubMed Central

    Nicolli, Annamaria; Chiara, Federica; Gambalunga, Alberto; Carrieri, Mariella; Bartolucci, Giovanni Battista; Trevisan, Andrea

    2014-01-01

    The urinary excretion rate is calculated based on short-term, defined time sample collections with a known sample mass, and this measurement can be used to remove the variability in urine concentrations due to urine dilution. Adjustment to the urinary excretion rate of hippuric acid was evaluated in 31 healthy volunteers (14 males and 17 females). Urine was collected as short-term or spot samples and tested for specific gravity, creatinine and hippuric acid. Hippuric acid values were unadjusted or adjusted to measurements of specific gravity, creatinine or urinary excretion rate. Hippuric acid levels were partially independent of urinary volume and urinary flow rate, in contrast to specific gravity and creatinine, which were both highly dependent on the hippuric acid level. Accordingly, hippuric acid was independent on urinary specific gravity and creatinine excretion. Unadjusted and adjusted values for specific gravity or creatinine were generally closely correlated, especially in spot samples. Values adjusted to the urinary excretion rate appeared well correlated to those unadjusted and adjusted to specific gravity or creatinine values. Thus, adjustment of crude hippuric acid values to the urinary excretion rate is a valid procedure but is difficult to apply in the field of occupational medicine and does not improve the information derived from values determined in spot urine samples, either unadjusted or adjusted to specific gravity and creatinine. PMID:25019265

  14. Hyperuricemia in acute gastroenteritis is caused by decreased urate excretion via ABCG2

    PubMed Central

    Matsuo, Hirotaka; Tsunoda, Tomoyuki; Ooyama, Keiko; Sakiyama, Masayuki; Sogo, Tsuyoshi; Takada, Tappei; Nakashima, Akio; Nakayama, Akiyoshi; Kawaguchi, Makoto; Higashino, Toshihide; Wakai, Kenji; Ooyama, Hiroshi; Hokari, Ryota; Suzuki, Hiroshi; Ichida, Kimiyoshi; Inui, Ayano; Fujimori, Shin; Shinomiya, Nariyoshi

    2016-01-01

    To clarify the physiological and pathophysiological roles of intestinal urate excretion via ABCG2 in humans, we genotyped ABCG2 dysfunctional common variants, Q126X (rs72552713) and Q141K (rs2231142), in end-stage renal disease (hemodialysis) and acute gastroenteritis patients, respectively. ABCG2 dysfunction markedly increased serum uric acid (SUA) levels in 106 hemodialysis patients (P = 1.1 × 10−4), which demonstrated the physiological role of ABCG2 for intestinal urate excretion because their urate excretion almost depends on intestinal excretion via ABCG2. Also, ABCG2 dysfunction significantly elevated SUA in 67 acute gastroenteritis patients (P = 6.3 × 10−3) regardless of the degree of dehydration, which demonstrated the pathophysiological role of ABCG2 in acute gastroenteritis. These findings for the first time show ABCG2-mediated intestinal urate excretion in humans, and indicates the physiological and pathophysiological importance of intestinal epithelium as an excretion pathway besides an absorption pathway. Furthermore, increased SUA could be a useful marker not only for dehydration but also epithelial impairment of intestine. PMID:27571712

  15. Excretion of glutamic acid in Citrobacter intermedius C3 associated with plasmid deoxyribonucleic acid.

    PubMed Central

    Jofre, J; Prieto, M J; Tomás, J; Parés, R

    1979-01-01

    Several mutants of Citrobacter intermedius C3 lacking both the ability to synthesize proline and the ability to excrete glutamic acid were isolated by treatment with nitrosoguanidine. No revertants for either characteristic were obtained from these mutants. The ability to excrete glutamic acid was transferred to those mutants with very high frequencies in mating experience by using auxotropic excreting strains as donors. Moreover, the ability to synthesize proline was transferred together with the ability to excrete glutamic acid when an excreting strain was used as donor. The transconjugants showed a rapid spontaneous curing of both genetic markers. It was shown by two different methods that a band of covalently closed circular deoxyribonucleic acid is present in the cesium chloride gradients corresponding to the wild type and excretor mutants. Nonexcretor mutants described herein lacked such a band. Pro + transformants that were also excretors were obtained with plasmid deoxyribonucleic acid isolated either from wild type or from an excretor mutant. These data strongly indicate that glutamic acid excretion in C. intermedius C3 is related to the presence of extrachromosomal deoxyribonucleic acid. PMID:457593

  16. Tissular localization and excretion of intravenously administered silica nanoparticles of different sizes

    NASA Astrophysics Data System (ADS)

    Xie, Guangping; Sun, Jiao; Zhong, Gaoren

    2012-01-01

    The nanotoxicology as a new subdiscipline of nanotechnology needs to be studied in vivo. To do so, it is essential to understand certain pharmacological information of the nanoparticles in vivo. Silica nanoparticles (SiNPs) have been developed for a number of biomedical uses; however, research on their tissular localization and excretion has been limited. In this study, we analyzed the localization of intravenously administered SiNPs with sizes of 20 and 80 nm in liver and spleen and quantitatively investigated the excretion of SiNPs through urine and feces. The results of the tissular localization study showed that the SiNPs were located in liver evenly; however, they were mainly accumulated in the white pulp of spleen. The quantitative excretory assay found the renal excretion being the main excretion pathway of SiNPs and indicated that the accumulated excretory rate of 80 nm SiNPs through urine was higher than that of 20 nm SiNPs because of the higher hemoconcentration. Further analysis of radioactive substances in the excreta showed the convincing confirmatory evidence that the SiNPs of both the sizes of 20 and 80 nm could be excreted through urine. These results provide important information on in vivo distribution and excretion of SiNPs.

  17. Influence of cellulose fibre length on faecal quality, mineral excretion and nutrient digestibility in cat.

    PubMed

    Prola, L; Dobenecker, B; Mussa, P P; Kienzle, E

    2010-06-01

    In dogs, faeces quality and nutrients digestibility were affected by different types of cellulose (Wichert et al., 2002). In this study, it was investigated whether there are comparable effects of cellulose type in cats. Seven adult, healthy cats were fed a moist commercial complete cat food with three different cellulose type added at a level of 4% for a 1 week period. Faeces quality was between 1 and 3 on the scale used from 1 to 5. The addition of long fibre cellulose resulted in significantly firmer faeces. Addition of cellulose decreased the digestibility of dry matter and energy, whereas the impact on protein and fat digestibility was not significant. The type of cellulose affected faecal bulk and faecal water excretion. Faecal excretion of sodium and potassium was exponentially correlated to faecal water, faecal bulk and to a lesser extent to faecal dry matter excretion. Faecal calcium, magnesium and phosphorus excretion showed an exponential correlation to faecal dry matter excretion. A weaker correlation existed in all three elements to faecal bulk, whereas the effect of faecal water excretion was small. Results suggest a remarkable likeness between cats and dogs with regard to the digestive physiology of major minerals.

  18. African swine fever virus excretion patterns in persistently infected animals: a quantitative approach.

    PubMed

    de Carvalho Ferreira, H C; Weesendorp, E; Elbers, A R W; Bouma, A; Quak, S; Stegeman, J A; Loeffen, W L A

    2012-12-07

    The continuing circulation of African swine fever (ASF) in Russia and in the Trans-Caucasian countries has led to increased efforts in characterizing the epidemiology of ASF. For a better insight in epidemiology, quantitative data on virus excretion is required. Until now, excretion data has mainly focused on the initial stages of the disease. In our study we have studied ASF virus (ASFV) excretion dynamics in persistently infected animals. For this purpose, virus excretion through different routes was quantified over 70 days after infection. Three virus isolates of moderate virulence were used: the Brazil'78, the Malta'78 (a low and a high inoculation dose) and the Netherlands'86 isolate. For each isolate or dose, 10 animals were used. All (Brazil'78 group), or three animals per group were inoculated and the other animals served as contact animals. It was shown that dose (Malta'78 low or high) or infection route (inoculated or naturally infected) did not influence the ASFV excretion (p>0.05). Nasal, ocular and vaginal excretions showed the lowest ASFV titres. Virus was consistently present in the oropharyngeal swabs, showing two peaks, for up to 70 days. Virus was occasionally present in the faeces, occasionally with very high titres. Viral DNA persisted in blood for up to 70 days. The results presented in this study show that a high proportion of persistently infected animals shed virus into the environment for at least 70 days, representing a possible risk for transmission and that should be considered in future epidemiological analysis of ASF.

  19. The urinary excretion of pyridinoline and deoxypyridinoline during rheumatoid arthritis therapy with infliximab.

    PubMed

    Ostanek, Lidia; Pawlik, Andrzej; Brzosko, Iwona; Brzosko, Marek; Sterna, Rozalia; Droździk, Marek; Gawrońska-Szklarz, Barbara

    2004-06-01

    Rheumatoid arthritis is a systemic disease that causes inflammation and joint destruction. As a result of pathological destruction in bone and cartilage, crosslinks in collagen are resorbed more rapidly. This causes a rise in circulating collagen crosslink levels and their urinary excretion. In RA, apart from the crosslink resorption at the site of inflamed joints, there may be increased resorption due to general bone loss associated with disease activity. The aim of this study was to evaluate the influence of therapy with infliximab on urinary excretion of pyridinoline (PYD) and deoxypyridinoline (DPYR) as a markers of collagen degradation and its correlation with clinical and biochemical parameters of disease activity. Seventeen patients with active rheumatoid arthritis treated with infliximab were recruited into the study. The therapy resulted in the reduction in the symptoms of RA and urinary excretion of PYD and DPYR. The urinary excretion of PYD correlated with a number of swollen joints, morning stiffness, CRP and ESR. The urinary excretion of DPYR correlated during infliximab therapy with the number of swollen and tender joints and morning stiffness. The measurement of urinary excretion of PYR and DPYR may give insight into bone metabolism and help us to better understand the actual changes in bone and cartilage caused by RA and its treatment.

  20. Effects of foods rich in polyphenols on nitrogen excretion in rats.

    PubMed

    Shahkhalili, Y; Finot, P A; Hurrell, R; Fern, E

    1990-04-01

    The extent to which tea, cocoa and carob (foods rich in polyphenols) influence fecal nitrogen (N) excretion was investigated in rats. The studies took into account the methylxanthine contents of tea and cocoa as well as the poor digestibility of cocoa nitrogen. Balance measurements indicated that all three food sources significantly increased fecal nitrogen excretion relative to methylxanthine-matched control diets (p less than 0.01). In the case of cocoa, virtually all the increase could be attributed to the poor digestibility of cocoa protein itself (estimated to be only 28-30% of total N in cocoa powder). There appeared to be no other effects. With extracts of tea and carob, however, the increased excretion of N in feces resulted either from a decreased digestibility of other dietary protein, through interaction with their polyphenols, or from a stimulation of the excretion of endogenous (body) nitrogen. With respect to the latter possibility, a preliminary investigation with the stable isotope of nitrogen (15N) showed that tea produced a marked increase in the excretion of endogenous nitrogen. These studies, therefore, indicate that foods rich in polyphenols have varying effects on N excretion in feces and that, in the case of tea at least, the loss of endogenous nitrogen may be a major contributing factor.

  1. Effects of a high protein intake on renal acid excretion in bodybuilders.

    PubMed

    Manz, F; Remer, T; Decher-Spliethoff, E; Höhler, M; Kersting, M; Kunz, C; Lausen, B

    1995-03-01

    Bodybuilders often prefer a high protein diet to achieve maximum skeletal muscle hypertrophy. In this study the effect of a high protein diet on renal acid load and renal handling of proton excretion was studied comparing dietary intake and urinary ionograms in 37 male bodybuilders and 20 young male adults. Energy intake (+ 7%), protein intake (128 vs 88 g/d/1.73 m2), and renal net acid excretion (95 vs 64 mmol/d/1.73 m2) were higher in the bodybuilders than in the controls, however, urine-pH was only slightly lower (5.83 vs 6.12). In the bodybuilders renal ammonium excretion was higher at any given value of urine pH than in the controls. In a regression analysis protein intake proved to be an independent factor modulating the ratio between urine-pH and renal ammonium excretion. The concomitant increase of renal net acid excretion and maximum renal acid excretion capacity in periods of high protein intake appears to be a highly effective response of the kidney to a specific food intake leaving a large renal surplus capacity for an additional renal acid load.

  2. Does hypercalcaemia or calcium antagonism affect human melatonin secretion or renal excretion?

    PubMed

    Wikner, J; Wetterberg, L; Röjdmark, S

    1997-05-01

    Patients with primary hyperparathyroidism have higher serum melatonin concentrations during active disease than after surgical cure. Whether this is caused by hypercalcaemia per se, increased parathyroid hormone secretion or other mechanisms is unknown. We decided to elucidate whether exogenous hypercalcaemia influences melatonin secretion. For this purpose, eight healthy volunteers were infused with calcium and saline on separate days and in random order (experiment A). Hypercalcaemia inhibited nocturnal melatonin secretion by 20% but left urinary melatonin excretion unaffected. If exogenous hypercalcaemia inhibits melatonin secretion, it is reasonable to assume that calcium channel blockers such as verapamil might have the opposite effect. This was investigated in experiment B, in which eight healthy subjects were treated on separate occasions with oral verapamil and placebo. Verapamil did not affect nocturnal melatonin secretion but increased melatonin excretion by 145%. As 6-sulphatoxy-melatonin is the main melatonin metabolite excreted by the kidneys, it was considered important to find out whether verapamil would also influence the excretion of 6-sulphatoxy-melatonin. This was investigated in experiment C, in which eight healthy volunteers were treated, on separate occasions, with oral verapamil and placebo. In this experiment also, verapamil increased urinary melatonin excretion significantly (by 67%), but left excretion of 6-sulphatoxy-melatonin unaffected. These findings imply that verapamil influences the renal and/or hepatic handling of melatonin.

  3. Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion.

    PubMed

    Weiner, I David; Mitch, William E; Sands, Jeff M

    2015-08-07

    Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance.

  4. Renal electrolyte excretion and renin release during calcium and parathormone infusions in conscious rabbits.

    PubMed Central

    Peart, W S; Roddis, S A; Unwin, R J

    1986-01-01

    Following a random block experimental design in each case, three repeated measurement studies were carried out in three different groups of conscious rabbits, to investigate the renal effects of increasing doses of intravenous calcium chloride (CaCl2) and bovine parathyroid hormone (PTH). In the first study, each rabbit received either CaCl2 (0.15, 0.3, 0.5 or 1.0 mg kg-1 min-1) or vehicle alone (control) for 160 min. In the second study, rabbits were given either PTH (0.15 microgram kg-1 min-1), CaCl2 (1.0 mg kg-1 min-1), PTH plus CaCl2 (0.15 microgram kg-1 min-1 and 1.0 mg kg-1 min-1, respectively) or vehicle alone; PTH was infused for just over 60 min. In the third study, a much smaller dose (0.05 mg kg-1 min-1) of CaCl2 was infused for 100 min. CaCl2 infusion produced a striking fall in fractional excretion of sodium of at least 50% (P less than 0.01), but this was not dose related, being almost maximal at the smaller doses infused. Although this effect was evident in the absence of any changes in total plasma calcium concentration at the lower doses of CaCl2, renal calcium excretion was increased between 2- and 20-fold (P less than 0.01) at all doses infused. Fractional excretion of chloride doubled at the two higher doses of CaCl2 (P less than 0.01), but potassium excretion was unchanged. There were no consistent alterations in mean arterial blood pressure, effective renal plasma flow, glomerular filtration rate or plasma renin activity (PRA); total plasma calcium concentration was consistently elevated only during infusion of the high dose by just under 1 mmol l-1. PTH infusion had no measured effect on fractional excretion of sodium or renal calcium excretion, but doubled fractional potassium excretion (P less than 0.05). Heart rate and PRA increased (P less than 0.01 and less than 0.05, respectively), the latter by 50%, but systemic pressure and renal haemodynamics were not significantly affected. By contrast, PTH infused with CaCl2 produced a 4-fold rise

  5. Nitrogen and phosphorus retention and excretion in late-gestation dairy heifers.

    PubMed

    Hill, S R; Knowlton, K F; James, R E; Pearson, R E; Bethard, G L; Pence, K J

    2007-12-01

    The objectives of this study were to evaluate the effects of limit feeding diets containing concentrates or by-products in place of forages on manure and nutrient excretion in growing, gravid heifers. Eighteen Holstein heifers confirmed pregnant were grouped by due date and fed 1 of 3 diets (n = 6 per treatment) for the last 14 wk of pregnancy. Diets were high forage, fed ad libitum (HF); by-product based (BP), fed at the same rate as HF-fed heifers; or low forage (LF), fed at 86% of the HF diet. Diets were designed to supply equal quantities of P, N, and metabolizable energy. Total collection of feces and urine was conducted in wk 14, 10, 6, and 2 prepartum. The HF ration was 90.7% forage, 13.7% crude protein (CP), and contained orchardgrass hay, corn silage, corn grain, soybean meal 44%, and a vitamin-mineral premix. The BP diet was 46.2% forage and 14.0% CP, with 70% of the grain mix space replaced with soybean hulls and cottonseed hulls in a 1:1 ratio, with intake limited to 93% of the dry matter intake (DMI) of HF. The LF ration was 45.3% forage and 17.8% CP, with intake limited to 86% of the DMI of HF. The effect of diet was analyzed with repeated measures, using preplanned contrasts to compare HF with BP and LF with HF and BP. As designed, heifers fed HF and BP had greater DMI than the heifers limit-fed LF, and there was no effect of diet on average daily gain or BW. Intake and digestibility of N were lower, and fecal N excretion was higher, in heifers fed HF and BP than heifers fed LF. Mean feces excretion on both a wet and dry basis was greater for HF heifers compared with BP heifers and less for LF heifers than for HF and BP heifers. Despite differences in urinary output, diet had no effect on urea N excretion, but there was a trend for heifers fed HF and BP rations to excrete less urinary N compared with those fed LF. Compared with HF and BP heifers, LF heifers tended to have lower fecal P excretion and had higher urinary P excretion. Measured manure and

  6. Evaluation of urinary porphyrin excretion in neonates born to mothers exposed to airborne hexachlorobenzene.

    PubMed Central

    Ozalla, Dolores; Herrero, Carmen; Ribas-Fitó, Núria; To-Figueras, Jordi; Toll, Agustí; Sala, Maria; Grimalt, Joan; Basagaña, Xavier; Lecha, Màrius; Sunyer, Jordi

    2002-01-01

    The existence of a link between hexachlorobenzene (HCB) and porphyria cutanea tarda has been known for a long time. However, the epidemiologic data on effects on health caused by prenatal exposure have not provided convincing evidence that HCB alters porphyrin metabolism. Our objectives were to analyze urinary porphyrin excretion and HCB in maternal serum and fetal cord blood in neonates born in a village (Flix) near a chlorinated solvent factory, to detect possible adverse effects in urinary porphyrin excretion caused by prenatal exposure, and to assess their relationship with HCB blood levels. We conducted a cross-sectional study in the Porphyria Unit at a tertiary care facility in Barcelona, Spain, and the Pediatric Unit of the Móra d'Ebre Hospital, the reference hospital of the study area. We included in the study all neonates (n = 68) born in Móra d'Ebre Hospital 1997-1999 and their mothers. We obtained 68 urine specimens of singleton neonates on the third day after birth to test for urinary porphyrin excretion. We obtained 52 fetal cord blood and 56 maternal serum samples for HCB analysis. Total urinary porphyrins were quantified using spectrofluorometry. Porphyrin profile was determined by HPLC. Serum HCB was analyzed by gas chromatography coupled with electron capture detection. In total population, median HCB levels were 1.08 ng/mL in cord blood and 3.31 ng/mL in maternal serum. Total urinary porphyrin concentration was 37.87 micromol/mol creatinine. Coproporphyrin I and coproporphyrin III were the major porphyrins excreted. We found no positive relationship between urinary porphyrin excretion and HCB levels. However, we observed an association between maternal smoking and coproporphyrin excretion. Although high environmental levels of HCB are reported in the town of Flix, we found no alteration in urinary porphyrin excretion. PMID:11836151

  7. Effect of microsomal enzyme inducers on the biliary excretion of triiodothyronine (T(3)) and its metabolites.

    PubMed

    Vansell, Nichole R; Klaassen, Curtis D

    2002-02-01

    It has been postulated that inducers of UDP-glucuronosyltransferase (UGT) decrease circulating thyroid hormone concentrations by increasing their biliary excretion. The inducers pregnenolone-16 alpha-carbonitrile (PCN), 3-methylcholanthrene (3MC), and Aroclor 1254 (PCB) are each effective at reducing serum thyroxine concentrations. However, only PCN treatment produces a marked increase in serum levels of thyroid-stimulating hormone (TSH), whereas 3MC and PCB cause little to no increase in TSH. Excessive TSH elevation is considered the primary stimulus for thyroid tumor development in rats, yet the mechanism by which enzyme induction leads to TSH elevation is not fully understood. Whereas PCN, 3MC, and PCB all increase microsomal UGT activity toward T(4), only PCN causes an increase in T(3)-UGT activity in vitro. The purpose of this study was to determine whether PCN, which increases serum TSH, causes an increase in the glucuronidation and biliary excretion of T(3) in vivo. Male rats were fed control diet or diet containing PCN (1000 ppm), 3MC (250 ppm), or PCB (100 ppm) for 7 days. Animals were then given [(125)I]-T(3), i.v., and bile was collected for 2 h. Radiolabeled metabolites in bile were analyzed by reverse-phase HPLC with gamma-detection. The biliary excretion of total radioactivity was increased up to 75% by PCN, but not by 3MC or PCB. Of the T(3) excreted into bile, approximately 75% was recovered as T(3)-glucuronide, with remaining amounts represented as T(3)-sulfate, T(2)-sulfate, T(3), and T(2). Biliary excretion of T(3)-glucuronide was increased up to 66% by PCN, while neither 3MC nor PCB altered T(3)-glucuronide excretion. These findings indicate that PCN increases the glucuronidation and biliary excretion of T(3) in vivo, and suggest that enhanced elimination of T(3) may be the mechanism responsible for the increases in serum TSH caused by PCN.

  8. Roles of P-glycoprotein, Bcrp, and Mrp2 in biliary excretion of spiramycin in mice.

    PubMed

    Tian, Xianbin; Li, Jun; Zamek-Gliszczynski, Maciej J; Bridges, Arlene S; Zhang, Peijin; Patel, Nita J; Raub, Thomas J; Pollack, Gary M; Brouwer, Kim L R

    2007-09-01

    The multidrug resistance proteins P-glycoprotein (P-gp), breast cancer resistance protein (Bcrp), and multidrug resistance-associated protein 2 (Mrp2) are the three major canalicular transport proteins responsible for the biliary excretion of most drugs and metabolites. Previous in vitro studies demonstrated that P-gp transported macrolide antibiotics, including spiramycin, which is eliminated primarily by biliary excretion. Bcrp was proposed to be the primary pathway for spiramycin secretion into breast milk. In the present study, the contributions of P-gp, Bcrp, and Mrp2 to the biliary excretion of spiramycin were examined in single-pass perfused livers of male C57BL/6 wild-type, Bcrp-knockout, and Mrp2-knockout mice in the presence or absence of GF120918 (GW918), a P-gp and Bcrp inhibitor. Spiramycin was infused to achieve steady-state conditions, followed by a washout period, and parameters governing spiramycin hepatobiliary disposition were recovered by using pharmacokinetic modeling. In the absence of GW918, the rate constant governing spiramycin biliary excretion was decreased in Mrp2(-) knockout mice (0.0013 +/- 0.0009 min(-1)) relative to wild-type mice (0.0124 +/- 0.0096 min(-1)). These data are consistent with the approximately 8-fold decrease in the recovery of spiramycin in the bile of Mrp2-knockout mice and suggest that Mrp2 is the major canalicular transport protein responsible for spiramycin biliary excretion. Interestingly, biliary recovery of spiramycin in Bcrp-knockout mice was increased in both the absence and presence of GW918 compared to wild-type mice. GW918 significantly decreased the rate constant for spiramycin biliary excretion and the rate constant for basolateral efflux of spiramycin. In conclusion, the biliary excretion of spiramycin in mice is mediated primarily by Mrp2 with a modest P-gp component.

  9. Waste nitrogen metabolism and excretion in zebrafish embryos: effects of light, ammonia, and nicotinamide.

    PubMed

    Bucking, Carol; Lemoine, Christophe M R; Walsh, Patrick J

    2013-08-01

    Bony fish primarily excrete ammonia as adults however the persistence of urea cycle genes may reflect a beneficial role for urea production during embryonic stages in protecting the embryo from toxic effects of ammonia produced from a highly nitrogenous yolk. This study aimed to examine the dynamic scope for changes in rates of urea synthesis and excretion in one such species (zebrafish, Danio rerio) by manipulating the intrinsic developmental rate (by alteration of light:dark cycles), as well as by direct chemical manipulation via ammonia injection (to potentially activate urea production) and nicotinamide exposure (to potentially inhibit urea production). Continuous dark exposure delayed development in embryos as evidenced by delayed appearance of hallmark anatomical features (heartbeat, eye pigmentation, body pigmentation, lateral line, fin buds) at 30 and 48 hr post-fertilization, as well by a lower hatching rate compared to embryos reared in continuous light. Both ammonia and urea excretion were similarly effected and were generally higher in embryos continuously exposed to light. Ammonia injection resulted in significant increases (up to fourfold) of urea N excretion and no changes to ammonia excretion rates along with modest increases in yolk ammonia content during 2-6 hr post-injection. Nicotinamide (an inhibitor of urea synthesis in mammals) reduced the ammonia-induced increase in urea excretion and led to retention of ammonia in the yolk and body of the embryo. Our results indicate that there is a relatively rapid and large scope for increases in urea production/excretion rates in developing embryos. Potential mechanisms for these increases are discussed.

  10. Factors Altering Pyruvate Excretion in a Glycogen Storage Mutant of the Cyanobacterium, Synechococcus PCC7942

    PubMed Central

    Benson, Phoebe J.; Purcell-Meyerink, Diane; Hocart, Charles H.; Truong, Thy T.; James, Gabriel O.; Rourke, Loraine; Djordjevic, Michael A.; Blackburn, Susan I.; Price, G. D.

    2016-01-01

    Interest in the production of carbon commodities from photosynthetically fixed CO2 has focused attention on cyanobacteria as a target for metabolic engineering and pathway investigation. We investigated the redirection of carbon flux in the model cyanobacterial species, Synechococcus elongatus PCC 7942, under nitrogen deprivation, for optimized production of the industrially desirable compound, pyruvate. Under nitrogen limited conditions, excess carbon is naturally stored as the multi-branched polysaccharide, glycogen, but a block in glycogen synthesis, via knockout mutation in the gene encoding ADP-glucose pyrophosphorylase (glgC), results in the accumulation of the organic acids, pyruvate and 2-oxoglutarate, as overflow excretions into the extracellular media. The ΔglgC strain, under 48 h of N-deprivation was shown to excrete pyruvate for the first time in this strain. Additionally, by increasing culture pH, to pH 10, it was possible to substantially elevate excretion of pyruvate, suggesting the involvement of an unknown substrate/proton symporter for export. The ΔglgC mutant was also engineered to express foreign transporters for glucose and sucrose, and then grown photomixotrophically with exogenous organic carbon supply, as added 5 mM glucose or sucrose during N- deprivation. Under these conditions we observed a fourfold increase in extracellular pyruvate excretion when glucose was added, and a smaller increase with added sucrose. Although the magnitude of pyruvate excretion did not correlate with the capacity of the ΔglgC strain for bicarbonate-dependent photosynthetic O2 evolution, or with light intensity, there was, however, a positive correlation observed between the density of the starter culture prior to N-deprivation and the final extracellular pyruvate concentration. The factors that contribute to enhancement of pyruvate excretion are discussed, as well as consideration of whether the source of carbon for pyruvate excretion might be derived from

  11. Clinical significance of the fractional excretion of anions in metabolic acidosis.

    PubMed

    Kim, H Y; Han, J S; Jeon, U S; Joo, K W; Earm, J H; Ahn, C; Kim, S; Lee, J S; Kim, G H

    2001-06-01

    The fractional excretion of anions has been proposed as a new index for the differential diagnosis of metabolic acidosis, identifying the properties of the conjugate base by examining the renal handling of the anion. Here, we investigated clinical significance of the fractional excretion of anions in pathophysiologic diagnosis of metabolic acidosis by measuring urine ammonium (NH4+) excretion, the ratio of A plasma anion gap/delta plasma HCO3- concentration (deltaAG/deltaHCO3-), and fractional excretion of anions in three different groups of metabolic acidosis: acid overproduction (8 patients with lactic acidosis, 8 with diabetic ketoacidosis, 3 with hippuric acidosis following glue sniffing), acid underexcretion (10 patients with chronic renal failure) and normal controls (10 normal volunteers who underwent 3-day NH4Cl loading). As expected, urine NH4+ excretion was higher in overproduction acidosis than in acid-loaded normal controls (88.1 +/- 12.3 vs. 54.0 +/- 3.7 mmol/day, p < 0.05), and it was lower in chronic renal failure than in acid-loaded normal controls (12.8 +/- 1.7 vs. 54.0 +/- 3.7 mmol/day, p < 0.05). The fractional excretion of anions had no difference between overproduction acidosis and chronic renal failure (41.2 +/- 42.8% vs. 41.0 +/- 8.1%). However, the fractional excretion of anions showed significant differences between the subgroups in acid overproduction (lactic acidosis, 4.7 +/- 0.3%; diabetic ketoacidosis, 45.8 +/- 3.1%; hippuric acidosis, 126.0 +/- 14.4%; p < 0.05). The ratio of plasma deltaAG/deltaHCO3- also exhibited significant differences between the subgroups in acid overproduction (lactic acidosis, 1.5 +/- 0.1; diabetic ketoacidosis, 1.0 +/- 0.1; hippuric acidosis, 0.3 +/- 0.1; p < 0.05). There was an inverse linear correlation between the fractional excretion of anions and the ratio of plasma deltaAG/deltaHCO3- (r2 =-0.89, p < 0.05). In conclusion, determination of the fractional excretion of anions may provide a useful clue to the

  12. Nitrogen excretion at different stages of growth and its association with production traits in growing pigs.

    PubMed

    Shirali, M; Doeschl-Wilson, A; Knap, P W; Duthie, C; Kanis, E; van Arendonk, J A M; Roehe, R

    2012-06-01

    The objectives of this study were to determine nitrogen loss at different stages of growth and during the entire growing period and to investigate the associations between nitrogen excretion and production traits in growing pigs. Data from 315 pigs of an F(2) population which originated from crossing Pietrain sires with a commercial dam line were used. Nitrogen retention was derived from protein retention as measured using the deuterium dilution technique during different stages of growth (60 to 90 kg, 90 to 120 kg, and 120 to 140 kg). Pigs were fed ad libitum with 2 pelleted diets containing 17% (60 to 90 kg) and 16.5% (90 to 120 and 120 to 140 kg) CP. Average daily nitrogen excretion (ADNE) within each stage of growth was calculated on the basis of the accumulated difference between average daily nitrogen intake (ADNI) and average daily nitrogen retention (ADNR). Least ADNE, nitrogen excretion per BW gain (NEWG) and total nitrogen excretion (TNE) were observed during growth from 60 to 90 kg. In contrast, the greatest ADNE, NEWG, and TNE were found during growth from 120 to 140 kg. Statistical analyses indicated that gender, housing type, the ryanodine receptor 1 (RYR1) gene, and batch influenced nitrogen excretion (P < 0.05), but the degree and direction of influences differed between growth stages. Gender differences showed that gilts excreted less nitrogen than barrows (P < 0.05), which was associated with decreased feed conversion ratio (FCR; feed:gain) and lipid:protein gain ratio. Single-housed pigs showed reduced nitrogen excretion compared with group-housed pigs (P < 0.05). In comparison to other genotypes, pigs carrying genotype NN (homozygous normal) at the RYR1 locus had the least nitrogen excretion (P < 0.05) at all stages of growth except from 60 to 90 kg. The residual correlations indicated that NEWG and TNE have large positive correlations with FCR (r = 0.99 and 0.91, respectively) and moderate negative correlations with ADG (r = -0.53 and -0

  13. Longitudinal gonadal steroid excretion in free-living male and female meerkats (Suricata suricatta).

    PubMed

    Moss, A M; Clutton-Brock, T H; Monfort, S L

    2001-05-01

    Slender-tailed meerkats (Suricata suricatta) are small, diurnal, cooperatively breeding mongooses of the family Herpestidae. A prerequisite to fully understanding the mating system of meerkats is the development of a normative reproductive-endocrine database. This study examined longitudinal gonadal steroid excretion in all adult and juvenile individuals of both sexes within a social group of free-living meerkats sampled across an entire breeding season. The specific objectives of this study were to (1) validate noninvasive (fecal and urinary) gonadal steroid hormone monitoring techniques in male (testosterone) and female (estrogens, progestagens) meerkats; (2) test the feasibility of using these noninvasive methods under field conditions; (3) characterize the endocrine correlates associated with the female reproductive cycle, including estrus, gestation, and postpartum estrus; (4) examine longitudinal androgen excretion in males; and (5) determine whether social status (i.e., dominant versus subordinate) affected gonadal steroid excretion. In females, the results demonstrated the physiological validity of noninvasive monitoring in meerkats by corresponding excretory hormone concentrations to major reproductive events (i.e., estrous, pregnancy, parturition). Hormone excretory patterns during estrous intervals suggested possible mechanisms whereby reproductive suppression may operate in female meerkats. In males, androgen excretion did not correspond to changes in reproductive and aggressive behaviors, suggesting that dominance, and hence breeding access to females, was not regulated strictly by gonadal steroid production. The consistency in androgen excretion among male meerkats indicated that reproductive suppression may be mediated by behavioral (i.e., intermale aggression) rather than physiological (i.e., depressed spermatogenesis) mechanisms.

  14. Predicting nutrient excretion of aquatic animals with metabolic ecology and ecological stoichiometry: a global synthesis.

    PubMed

    Vanni, Michael J; McIntyre, Peter B

    2016-12-01

    The metabolic theory of ecology (MTE) and ecological stoichiometry (ES) are both prominent frameworks for understanding energy and nutrient budgets of organisms. We tested their separate and joint power to predict nitrogen (N) and phosphorus (P) excretion rates of ectothermic aquatic invertebrate and vertebrate animals (10,534 observations worldwide). MTE variables (body size, temperature) performed better than ES variables (trophic guild, vertebrate classification, body N:P) in predicting excretion rates, but the best models included variables from both frameworks. Size scaling coefficients were significantly lower than predicted by MTE (<0.75), were lower for P than N, and varied greatly among species. Contrary to expectations under ES, vertebrates excreted both N and P at higher rates than invertebrates despite having more nutrient-rich bodies, and primary consumers excreted as much nutrients as carnivores despite having nutrient-poor diets. Accounting for body N:P hardly improved upon predictions from treating vertebrate classification categorically. We conclude that basic data on body size, water temperature, trophic guild, and vertebrate classification are sufficient to make general estimates of nutrient excretion rates for any animal taxon or aquatic ecosystem. Nonetheless, dramatic interspecific variation in size-scaling coefficients and counter-intuitive patterns with respect to diet and body composition underscore the need for field data on consumption and egestion rates. Together, MTE and ES provide a powerful conceptual basis for interpreting and predicting nutrient recycling rates of aquatic animals worldwide.

  15. Gas transfer in dogfish: a unique model of CO2 excretion.

    PubMed

    Gilmour, K M; Perry, S F

    2010-04-01

    Carbonic anhydrase (CA) is a zinc metalloenzyme that catalyzes the reversible hydration-dehydration reactions of CO(2). It is present in high abundance in the cytoplasm of vertebrate red blood cells, where it contributes to CO(2) excretion. A membrane-bound CA isoform (CA IV) is also present in the lungs of mammals and reptiles, but plays little role in CO(2) excretion. The gills of teleost fish appear to lack plasma-accessible CA activity. In elasmobranchs, however, evidence gathered using a variety of physiological, biochemical and molecular approaches suggests that CA IV is present in the gills, and that at least in dogfish, this CA IV makes a significant contribution to CO(2) excretion by catalyzing the dehydration of plasma HCO(3)(-). The contribution of CA IV to CO(2) excretion is favoured by unusually high relative plasma buffering that aids in the provision of protons for HCO(3)(-) dehydration. Moreover, reduced emphasis on HCO(3)(-) flux through the red blood cell may reflect the occurrence of a slower turnover cytosolic CA in dogfish. This model of CO(2) excretion, in which HCO(3)(-) dehydration in the red blood cell catalyzed by cytosolic CA and HCO(3)(-) dehydration in the plasma catalyzed by membrane-bound CA IV are of comparable importance, has been described for the dogfish. Further work is required to determine whether it applies to elasmobranch fish as a group.

  16. Circadian rhythm of catecholamine excretion in rats after phase shift of light-dark cycle.

    PubMed

    Sudo, A; Miki, K

    1995-01-01

    To clarify the time course of circadian rhythm adaptation to a phase shift of the light-dark (LD) cycle, urinary excretion of catecholamines was measured in rats before and after a 12-hour or 6-hour phase delay of a 12-hour light and 12-hour dark schedule. In rats under a basal condition, distinct circadian rhythms in catecholamine excretion were observed, especially in adrenaline excretion. During the 1st and 2nd days after a 12-hour phase delay, the acrophase and amplitude of adrenaline rhythm remained almost unchanged, but thereafter the acrophase was retarded and the amplitude was reduced. The acrophase once again became constant after 5 or 6 days, but the ratio of amplitude to mesor in the circadian rhythm of adrenaline excretion and the ratio of light-period to 24-hour noradrenaline excretion were readjusted to the new LD schedule on 11th or 12th day. IN the 6-hour phase delay of the LD cycle, similar findings were observed, and the results suggested adaptation on the 5-6th day. It is considered that the circadian rhythms of the sympathetic adrenomedullary function are restored, at the latest, 12 days after a 12-hour delay of the LD cycle, and 6 days after a 6-hour delay, suggesting that rats need approximately 1 day to adapt to a 1-hour phase shift.

  17. Renal Expression and Urinary Excretion of Na-K-2Cl Cotransporter in Obstructive Nephropathy

    PubMed Central

    2017-01-01

    Renal damage due to urinary tract obstruction accounts for up to 30% of acute kidney injury in paediatrics and adults. Bilateral ureteral obstruction (BUO) is associated with polyuria and reduced urinary concentrating capacity. We investigated the renal handling of water and electrolytes together with the renal expression and the urinary excretion of the Na-K-Cl cotransporter (NKCC2) after 1 (BUO-1), 2 (BUO-2), and 7 (BUO-7) days of release of BUO. Immunoblotting and immunohistochemical studies showed that NKCC2 expression was upregulated in apical membranes both from BUO-2 and from BUO-7 rats. The apical membrane expression, where NKCC2 is functional, may be sufficient to normalize water, potassium, sodium, and osmolytes tubular handling. NKCC2 abundance in homogenates and mRNA levels of NKCC2 was significantly decreased in almost all groups suggesting a decrease in the synthesis of the transporter. Urinary excretion of NKCC2 was increased in BUO-7 groups. These data suggest that the upregulation in the expression of NKCC2 in apical membranes during the postobstructive phase of BUO could contribute to improving the excretion of sodium and consequently also the excretion of potassium, osmolytes, and water. Moreover, the increase in urinary excretion of NKCC2 in BUO-7 group could be a potential additional biomarker of renal function recovery. PMID:28164127

  18. Factors that explain excretion of enteric pathogens by persons without diarrhea.

    PubMed

    Levine, Myron M; Robins-Browne, Roy M

    2012-12-01

    Excretion of enteropathogens by subjects without diarrhea influences our appreciation of the role of these pathogens as etiologic agents. Characteristics of the pathogens and host and environmental factors help explain asymptomatic excretion of diarrheal pathogens by persons without diarrhea. After causing acute diarrhea followed by clinical recovery, some enteropathogens are excreted asymptomatically for many weeks. Thus, in a prevalence survey of persons without diarrhea, some may be excreting pathogens from diarrheal episodes experienced many weeks earlier. Volunteer challenges with Vibrio cholerae O1, enterotoxigenic Escherichia coli (ETEC), enteropathogenic E. coli, Campylobacter jejuni, and Giardia lamblia document heterogeneity among enteropathogen strains, with some inexplicably not eliciting diarrhea. The immune host may not manifest diarrhea following ingestion of a pathogen but may nevertheless asymptomatically excrete. Some human genotypes render them less susceptible to symptomatic or severe diarrheal infection with certain pathogens such as Vibrio cholerae O1 and norovirus. Pathogens in stools of individuals without diarrhea may reflect recent ingestion of inocula too small to cause disease in otherwise susceptible hosts or of animal pathogens (eg, bovine or porcine ETEC) that do not cause human illness.

  19. Metabolism and excretion of novel pulmonary-targeting docetaxel liposome in rabbits

    PubMed Central

    Wang, Jie; Zhang, Li; Wang, Lijuan; Liu, Zhonghong

    2017-01-01

    Our study aims to determine the metabolism and excretion of novel pulmonary-targeting docetaxel liposome (DTX-LP) using the in vitro and in vivo animal experimental models. The metabolism and excretion of DTX-LP and intravenous DTX (DTX-IN) in New Zealand rabbits were determined with ultraperformance liquid chromatography tandem mass spectrometry. We found DTX-LP and DTX-IN were similarly degraded in vitro by liver homogenates and microsomes, but not metabolized by lung homogenates. Ultra-performance liquid chromatography tandem mass spectrometry identified two shared DTX metabolites. The unconfirmed metabolite Mun differed structurally from all DTX metabolites identified to date. DTX-LP likewise had a similar in vivo metabolism to DTX-IN. Conversely, DTX-LP showed significantly diminished excretion in rabbit feces or urine, approximately halving the cumulative excretion rates compared to DTX-IN. Liposomal delivery of DTX did not alter the in vitro or in vivo drug metabolism. Delayed excretion of pulmonary-targeting DTX-LP may greatly enhance the therapeutic efficacy and reduce the systemic toxicity in the chemotherapy of non-small cell lung cancer. The identification of Mun may further suggest an alternative species-specific metabolic pathway. PMID:28066140

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

    PubMed

    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.

  1. PLasma half-life and urinary excretion of cyclophosphamide in children.

    PubMed

    Sladek, N E; Priest, J; Doeden, D; Mirocha, C J; Pathre, S; Krivit, W

    1980-01-01

    The plasma half-life and urinary excretion of cyclophosphamide were determined in 13 children who had various malignancies and/or who were being prepared for bone marrow transplantation. Disappearance from the plasma following iv infusion over a 1-2 hour period was first-order. Urinary excretion was maximal during the first 8 hours after administration and was essentially complete in 24 hours. The plasma half-life in children not receiving known inducers of hepatic microsomal mixed-function oxygenase activity or cyclophosphamide in the 3-week period prior to each determination ranged from 145 to 390 minutes. These values are lower than those ordinarily found in adult patients. The fraction of the total dose excreted in the urine as the parent compound ranged from 4% to 27%. Repeated administration of cyclophosphamide at approximately 30-60 day intervals did not appear to alter its plasma half-life but did appear to increase its urinary excretion. Daily administration of cyclophosphamide (approximately 50 mg/kg/day x 2 or 4) significantly decreased its plasma half-life and urinary excretion suggesting that it may reversibly induce its own metabolism.

  2. The effect of modified citrus pectin on urinary excretion of toxic elements.

    PubMed

    Eliaz, Isaac; Hotchkiss, Arland T; Fishman, Marshall L; Rode, Dorena

    2006-10-01

    This study was undertaken to evaluate the effect of modified citrus pectin (MCP) on the urinary excretion of toxic elements in healthy individuals. MCP is a reduced molecular weight pectin (weight-average molar mass = 15,400) that is mostly linear homogalacturonan with a 3.8% degree of esterification and approximately 10% rhamnogalacturonan II based on the presence of 2-keto-3-deoxy-octonic acid. Subjects ingested 15 g of MCP (PectaSol, EcoNugenics Inc., Santa Rosa, California 95407) each day for 5 days and 20 g on day 6. Twenty-four hour urine samples were collected on day 1 and day 6 for comparison with baseline. The urine samples were analysed for toxic and essential elements. In the first 24 h of MCP administration the urinary excretion of arsenic increased significantly (130%, p < 0.05). On day 6, urinary excretion was increased significantly for cadmium (150%, p < 0.05). In addition, lead showed a dramatic increase in excretion (560%, p < 0.08). This pilot trial provides the first evidence that oral administration of MCP increases significantly the urinary excretion of toxic metals in subjects with a 'normal' body load of metals. It is suggested that systemic chelation of toxic metals by MCP may in part be attributable to the presence of rhamnogalacturonan II, which has been shown previously to chelate metals.

  3. Renal function, aldosterone, and vasopressin excretion following repeated long-distance running.

    PubMed

    Wade, C E; Dressendorfer, R H; O'Brien, J C; Claybaugh, J R

    1981-04-01

    Renal and endocrine responses were studied in 10 male runners during a 20-day 500-km race. Overnight urine and prerun blood samples were taken prior to running on days 1, 2, 5, 8, 14, 17, and 20. Day 13 followed 70 h of rest. Urine flow rate, osmotic clearance, tubular free water reabsorption, urinary vasopressin excretion rate, and body weight were not significantly changed. Creatinine clearance was constant except for an elevation on day 5. Plasma osmolality was elevated on days 2, 14, and 17. Plasma sodium was increased (P less than 0.05) on days 2 and 13 but reduced on day 20. The percentage of filtered sodium excreted was significantly reduced on all nights following running and elevated on recovery day 13. Urinary aldosterone excretion rate was significantly elevated 162, 117, and 97% on days 5, 8, and 20 and returned to control levels on day 13 after 70 h of rest. These data suggest that in response to repeated long-distance running normal fluid balance is regained within 12 h. However, it is necessary to conserve sodium for at least 24 h after exercise as evidenced by the decrease in the percent filtered sodium excreted and continued elevation of aldosterone excretion.

  4. Kinetics of Rituximab Excretion into Urine and Peritoneal Fluid in Two Patients with Nephrotic Syndrome

    PubMed Central

    Schwarz, Anke; Wagner, A. D.; Haller, Hermann; Schiffer, Mario

    2017-01-01

    Clinical observations suggest that treatment of Rituximab might be less effective in patients with nephrotic range proteinuria when compared to nonnephrotic patients. It is conceivable that the reason for this is that significant amounts of Rituximab might be lost in the urine in a nephrotic patient and that these patients require a repeated or higher dosage. However, this has not been systematically studied. In this case report we describe two different patients with nephrotic range proteinuria receiving Rituximab. The first patient received Rituximab for therapy resistant cryoglobulinemic membranoproliferative glomerulonephritis and the other for second line treatment of Felty's syndrome. We employed flow cytometry to determine the amount of Rituximab excretion in both urine and peritoneal fluid specimens in these patients following administration of Rituximab. We found that a significant amount of Rituximab is lost from the circulation by excretion into the urine. Furthermore we saw a close correlation of the excretion of Rituximab to the excretion of IgG molecules suggesting selectivity of proteinuria as the determining factor of Rituximab excretion. Further larger scale clinical studies could have the potential to evaluate an optimal cut-off value of IgG urinary loss before a possible administration of Rituximab therefore contributing to a more individualized treatment approach in patients with nonselective and nephrotic range proteinuria. PMID:28243475

  5. Excretion of berberine and its metabolites in oral administration in rats.

    PubMed

    Ma, Jing-Yi; Feng, Ru; Tan, Xiang-Shan; Ma, Chao; Shou, Jia-Wen; Fu, Jie; Huang, Min; He, Chi-Yu; Chen, Shuo-Nan; Zhao, Zhen-Xiong; He, Wen-Yi; Wang, Yan; Jiang, Jian-Dong

    2013-11-01

    Berberine (BBR) has been confirmed to show extensive bioactivities for the treatments of diabetes and hypercholesterolemia in clinic. However, there are few pharmacokinetic studies to elucidate the excretions of BBR and its metabolites. Our research studied the excretions of BBR and its metabolites in rats after oral administration (200 mg/kg). Metabolites in bile, urine, and feces were detected by liquid chromatography coupled to ion trap time-of-flight mass spectrometry; meanwhile, a validated liquid chromatography coupled with tandem mass spectrometry method was developed for their quantifications. Sixteen metabolites, including 10 Phase I and six Phase II metabolites were identified and clarified after dosing in vivo. Total recovered rate of BBR was 22.83% (19.07% of prototype and 3.76% of its metabolites) with 9.2 × 10(-6) % in bile (24 h), 0.0939% in urine (48 h), and 22.74% in feces (48 h), respectively. 83% of BBR was excreted as thalifendine (M1) from bile, whereas thalifendine (M1) and berberrubine (M2) were the major metabolites occupying 78% of urine excretion. Most of BBR and its metabolites were found in feces containing 84% of prototype. In summary, we provided excretion profiles of BBR and its metabolites after oral administration in rats in vivo.

  6. Urinary Excretion of Neutrophil Gelatinase-Associated Lipocalin in Diabetic Rats

    PubMed Central

    Arellano-Buendía, Abraham Said; García-Arroyo, Fernando Enrique; Cristóbal-García, Magdalena; Loredo-Mendoza, María Lilia; Tapia-Rodríguez, Edilia; Sánchez-Lozada, Laura Gabriela; Osorio-Alonso, Horacio

    2014-01-01

    Recent studies suggest that tubular damage precedes glomerular damage in the progression of diabetic nephropathy. Therefore, we evaluated oxidative stress and urinary excretion of tubular proteins as markers of tubular dysfunction. Methods. Diabetes was induced in rats by streptozotocin administration (50 mg/kg). Oxidative stress was assessed by measuring the activity of catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD); additionally, expression levels of 3-nitrotyrosine (3-NT), 4-hydroxynonenal (4-HNE), and oxidized protein (OP) were quantified. Whole glomerular filtration rate (GFR) was measured. Urinary excretion of neutrophil gelatinase-associated lipocalin (uNGAL), osteopontin (uOPN), and N-acetyl-β-D-glucosaminidase (uNAG) was also determined. Results. Diabetic rats showed an increase in uNGAL excretion 7 days following induction of diabetes. Diuresis, proteinuria, albuminuria, creatinine clearance, and GFR were significantly increased by 30 days after induction. Furthermore, there was an increase in both CAT and SOD activity, in addition to 3-NT, 4-HNE, and OP expression levels. However, GPx activity was lower. Serum levels of NGAL and OPN, as well as excretion levels of uNGAL, uOPN, and uNAG, were increased in diabetics. Tubular damage was observed by 7 days after diabetes induction and was further aggravated by 30 days after induction. Conclusion. The tubular dysfunction evidenced by urinary excretion of NGAL precedes oxidative stress during diabetes. PMID:25243053

  7. Distribution and excretion of 2,4,5,2',4',5'-hexabromobiphenyl, the major component of Firemaster BP-6.

    PubMed

    Matthews, H B; Kato, S; Morales, N M; Tuey, D B

    1977-10-01

    The intestinal absorption, distribution, and excretion of the major component of Firemaster BP-6,2,4,5,2',4',5'-hexabromobiphenyl, has been studied in the male rat. This polybrominated biphenyl was readily absorbed from the intestine, initially distributed throughout the body, and eventually stored primarily in the adipose tissue, was not subject to appreciable metabolism, and was excreted almost exclusively in the feces and at a very slow rate. Approximately 90% of an oral dose was absorbed from the intestine, and extrapolation of the rate of excretion to infinity indicates that less than 10% of the total dose would ever be excreted.

  8. Effect of 14 days of bed rest on urine metabolite excretion and plasma enzyme levels

    NASA Technical Reports Server (NTRS)

    Pace, N.; Grunbaum, B. W.; Kodama, A. M.; Rahlmann, D. F.; Newsom, B. D.

    1974-01-01

    After 1 week of ambulatory base-line measurement, a group of 8 men 19-26 years of age remained continuously recumbent for 14 days. Studies were continued for 1 week following the prolonged recumbency. Urine excretion rates for a number of constituents were determined 2 days before bed rest, on day 14 of bed rest, and day 6 after bed rest. Blood plasma samples were also obtained at these times, and analyzed for several enzymes. On day 14 of bed rest significant increases were observed in urine excretion of total osmotically-active substances, magnesium, calcium, phosphate, creatinine, hydroxyproline, and 17-OH corticosteroids. A decrease occurred in urinary glucose excretion. Plasma levels of alkaline phosphatase and LDH-3 were depressed, while plasma GPT was elevated. Many of these changes persisted on day 6 after bed rest, and are interpreted as concomitants of the disuse atrophy of the musculoskeletal system that characterizes prolonged bed rest and weightlessness.

  9. Examining the Proportion of Dietary Phosphorus From Plants, Animals, and Food Additives Excreted in Urine.

    PubMed

    St-Jules, David E; Jagannathan, Ram; Gutekunst, Lisa; Kalantar-Zadeh, Kamyar; Sevick, Mary Ann

    2017-03-01

    Phosphorus bioavailability is an emerging topic of interest in the field of renal nutrition that has important research and clinical implications. Estimates of phosphorus bioavailability, based on digestibility, indicate that bioavailability of phosphorus increases from plants to animals to food additives. In this commentary, we examined the proportion of dietary phosphorus from plants, animals, and food additives excreted in urine from four controlled-feeding studies conducted in healthy adults and patients with chronic kidney disease. As expected, a smaller proportion of phosphorus from plant foods was excreted in urine compared to animal foods. However, contrary to expectations, phosphorus from food additives appeared to be incompletely absorbed. The apparent discrepancy between digestibility of phosphorus additives and the proportion excreted in urine suggests a need for human balance studies to determine the bioavailability of different sources of phosphorus.

  10. Effects of water extract of Hibiscus sabdariffa, Linn (Malvaceae) 'Roselle' on excretion of a diclofenac formulation.

    PubMed

    Fakeye, T O; Adegoke, A O; Omoyeni, O C; Famakinde, A A

    2007-01-01

    The effect of beverages prepared from the dried calyx of the flowers of Hibiscus sabdariffa on the excretion of diclofenac was investigated using a controlled study in healthy human volunteers. A high pressure liquid chromatographic method was used to analyse the 8 h urine samples collected after the administration of diclofenac with 300 mL (equivalent to 8.18 mg anthocyanins) of the beverage administered daily for 3 days. An unpaired two-tailed t-test was used to analyse for significant difference observed in the amount of diclofenac excreted before and after administration of the beverage. There was a reduction in the amount of diclofenac excreted and the wide variability observed in the control with the water beverage of Hibiscus sabdariffa (p < 0.05). There is an increasing need to counsel patients against the use of plant beverages with drugs.

  11. Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

    NASA Astrophysics Data System (ADS)

    Kiko, Rainer; Hauss, Helena; Buchholz, Friedrich; Melzner, Frank

    2016-04-01

    Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs) that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ). At depth, the animals experience reduced temperature and oxygen partial pressure (pO2) and an increased carbon dioxide partial pressure (pCO2) compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2, and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply could fuel bacterial anaerobic ammonium oxidation - a major loss process for fixed nitrogen in the ocean considerably. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2) does not result in a down-regulation of ammonium excretion. We exposed calanoid copepods from the Eastern Tropical North Atlantic (ETNA; Undinula vulgaris and Pleuromamma abdominalis) and euphausiids from the Eastern Tropical South Pacific (ETSP; Euphausia mucronata) and the ETNA (Euphausia gibboides) to different temperatures, carbon dioxide and oxygen levels to study their survival, respiration and excretion rates at these conditions. An increase in temperature by 10 °C led to an approximately 2-fold increase of the respiration and excretion rates of U. vulgaris (Q10, respiration = 1.4; Q10, NH4-excretion = 1.6), P. abdominalis (Q10, respiration = 2.0; Q10, NH4-excretion = 2.4) and

  12. A membrane vesicle-based assay to enable prediction of human biliary excretion.

    PubMed

    Colombo, Federico; Poirier, Hugo; Rioux, Nathalie; Montecillo, Maria Arias; Duan, Jianmin; Ribadeneira, Maria D

    2013-10-01

    1. Prediction of biliary excretion is a challenge due to the lack of in vitro assays. Our laboratory previously demonstrated a highly significant correlation between in vitro IC50 values against mrp2 using rat canalicular liver plasma membrane vesicles and in vivo biliary excretion (Colombo et al., 2012). This study explores the possibility of predicting in vivo biliary excretion in human using membrane vesicles prepared from MDCKII cells transfected with human ABCC2. 2. In vitro MRP2 activity was determined by measuring the ATP-dependent uptake of 5(6)-carboxy-2',7'-dichlorofluorescein (CDCF) in inside-out membrane vesicles isolated from MDCK-ABCC2 cells. CDCF uptake was time- and concentration-dependent (Km of 4.0 ± 1.2 µM and a Vmax of 7.8 ± 0.9 pmol/mg/min) and inhibited by benzbromarone and MK-571 with IC50 values of 1.2 and 7.6 µM, respectively. 3. A significant linear correlation (r(2 )= 0.790) between the in vitro IC50 values from the described MRP2 assay and in vivo biliary excretion in humans was observed using 11 well-documented drugs covering low to high biliary excretions. 4. This study demonstrates, for the first time, that inhibition of CDCF uptake in MDCKII-ABCC2 vesicles not only provides a screening assay to assess MRP2 drug-drug interaction potential, but is also predictive of human MRP2-mediated biliary excretion.

  13. Dietary and Lifestyle Factors and Medical Conditions Associated with Urinary Citrate Excretion

    PubMed Central

    Taylor, Eric N.; Curhan, Gary C.

    2013-01-01

    Summary Background and objectives Lower urinary citrate excretion is a risk factor for nephrolithiasis and associated with metabolic acidosis and higher prevalence of hypertension and insulin resistance. This study sought to quantify the independent predictors of urinary citrate excretion in population-based cohorts. Design, setting, participants, & measurements A cross-sectional study of 2561 individuals from the Health Professionals Follow-Up Study and Nurses’ Health Studies I and II who provided two 24-hour urine collections was conducted. Dietary data were ascertained from the semiquantitative food frequency questionnaire. Lifestyle and disease data were derived from responses to biennial questionnaires. Multivariable linear regression was used to quantify the predictors of urinary citrate excretion. Results After adjusting for age, urinary creatinine, dietary, and other factors, higher intake of nondairy animal protein (per 10 g/d; −20 mg/d; 95% confidence interval [−29 to −11]), higher body mass index (per 1 kg/m2; −4 mg/d; [−6 to −2]), and history of nephrolithiasis (−57 mg/d; [−79 to −36]), hypertension (−95 mg/d; [−119 to −71]), gout (−104 mg/d; [−155 to −54]), and thiazide use (−34 mg/d; [−68 to −1]) were independently associated with lower 24-hour urinary citrate excretion. Higher intake of potassium (per 1000 mg/d; 53 mg/d; [33 to 74]), higher urinary sodium (per 100 mEq/d; 56 mg/d; [31 to 80]), and history of diabetes (61 mg/d; [21 to 100]) were independently associated with higher citrate excretion. Conclusions Several dietary and lifestyle factors and medical conditions are independently associated with urinary citrate excretion. PMID:23449767

  14. Excretion and measurement of corticosterone and testosterone metabolites in bank voles (Myodes glareolus).

    PubMed

    Sipari, Saana; Ylönen, Hannu; Palme, Rupert

    2017-03-01

    The bank vole is a commonly used model species in behavioral and ecophysiological studies. Thus, presenting a validated method for noninvasive monitoring of corticosterone and testosterone secretion is of high relevance. Here, we evaluated the effect of time of day and an ACTH challenge test on measured fecal corticosterone (FCM) and testosterone (FTM) metabolites in both sexes. Furthermore, we performed radiometabolism experiments for both steroids and sexes to study metabolism and excretion of (3)H-corticosterone and (3)H-testosterone. FCM and FTM were analysed with a 5α-pregnane-3β,11β,21-triol-20-one enzyme immunoassay (EIA) and a testosterone (measuring 17β-hydroxyandrostanes) EIA, respectively. Males had significantly higher FCM levels than females and their main excretion route was via the feces (∼72%), whereas females excreted nearly equal portions in both feces and urine. For testosterone the main excretion route was via the feces in both sexes (∼80%). The time course of excretion was similar in both sexes, but for the first time a significant difference between injected steroids was found: Corticosterone was excreted faster than testosterone, both in urine (median of peak levels: 4h vs 6h) and feces (6h vs 8h). Several metabolites were present in the feces and the tested EIAs reacted with some of them. Time of day had a significant effect on measured fecal steroid metabolites. As expected, males had significantly higher FTM levels than females. ACTH administration significantly increased FCM values; peaks were observed 4-8h after injection. In conclusion, both tested EIAs proved suited for a noninvasive measurement of glucocorticoids and androgens in bank voles.

  15. Dietary hydroxypropyl methylcellulose increases excretion of saturated and trans fats by hamsters fed fast food diets.

    PubMed

    Yokoyama, Wallace; Anderson, William H K; Albers, David R; Hong, Yun-Jeong; Langhorst, Marsha L; Hung, Shao-Ching; Lin, Jiann-Tsyh; Young, Scott A

    2011-10-26

    In animal studies, hydroxypropyl methylcellulose (HPMC) intake results in increased fecal fat excretion; however, the effects on dietary saturated fatty acids (SATs) and trans-fatty acids (TRANS) remain unknown. This study investigated the effect of HPMC on digestion and absorption of lipids in male Golden Syrian hamsters fed either freeze-dried ground pizza (PZ), pound cake (PC), or hamburger and fries (BF) supplemented with dietary fiber from either HPMC or microcrystalline cellulose (MCC) for 3 weeks. We observed greater excretion of SATs and TRANS by both diets supplemented with HPMC or MCC as compared to the feed. SAT, TRANS, and unsaturated fatty acids (UNSAT) contents of feces of the PZ diet supplemented with HPMC were 5-8 times higher than diets supplemented with MCC and tended to be higher in the PC- and BF-HPMC supplemented diets as well. We also observed significant increases in fecal excretion of bile acids (2.6-3-fold; P < 0.05), sterols (1.1-1.5-fold; P < 0.05), and unsaturated fatty acids (UNSAT, 1.7-4.5-fold; P < 0.05). The animal body weight gain was inversely correlated with the excretion of fecal lipid concentrations of bile acids (r = -0.56; P < 0.005), sterols (r = -0.48; P < 0.005), SAT (r = -0.69; P < 0.005), UNSAT (r = -0.67; P < 0.005), and TRANS (r = -0.62; P < 0.005). Therefore, HPMC may be facilitating fat excretion in a biased manner with preferential fecal excretion of both TRANS and SAT in hamsters fed fast food diets.

  16. Modelling phosphorus intake, digestion, retention and excretion in growing and finishing pigs: model description.

    PubMed

    Symeou, V; Leinonen, I; Kyriazakis, I

    2014-10-01

    Low phosphorus (P) digestibility combined with intensive pig production can increase P diffuse pollution and environmental load. The aim of this paper was to develop a deterministic, dynamic model able to represent P digestion, retention and ultimately excretion in growing and finishing pigs of different genotypes, offered access to diets of different composition. The model represented the limited ability of pig endogenous phytase activity to dephosphorylate phytate as a linear function of dietary calcium (Ca). Phytate dephosphorylation in the stomach by exogenous microbial phytase enzymes was expressed by a first order kinetics relationship. The absorption of non-phytate P from the lumen of the small intestine into the blood stream was set at 0.8 and the dephosphorylated phytate from the large intestine was assumed to be indigestible. The net efficiency of using digested P was set at 0.94 and assumed to be independent of BW, and constant across genotype and sex. P requirements for both maintenance and growth were made simple functions of body protein mass, and hence functions of animal genotype. Undigested P was assumed to be excreted in the feaces in both soluble and insoluble forms. If digestible P exceeded the requirements for P then the excess digestible P was excreted through the urinary flow; thus the model represented both forms of P excretion (soluble and insoluble) into the environment. Using a UK industry standard diet, model behaviour was investigated for its predictions of P digestibility, retention and excretion under different levels of inclusion of microbial phytase and dietary Ca, and different non-phytate P : phytate ratios in the diet, thus covering a broad space of potential diet compositions. Model predictions were consistent with our understanding of P digestion, metabolism and excretion. Uncertainties associated with the underlying assumptions of the model were identified. Their consequences on model predictions, as well as the model

  17. Excretion and metabolism of milnacipran in humans after oral administration of milnacipran hydrochloride.

    PubMed

    Li, Fanying; Chin, Christina; Wangsa, Julie; Ho, John

    2012-09-01

    The pharmacokinetics, excretion, and metabolism of milnacipran were evaluated after oral administration of a 100-mg dose of [¹⁴C]milnacipran hydrochloride to healthy male subjects. The peak plasma concentration of unchanged milnacipran (∼240 ng/ml) was attained at 3.5 h and was lower than the peak plasma concentration of radioactivity (∼679 ng Eq of milnacipran/ml) observed at 4.3 h, indicating substantial metabolism of milnacipran upon oral administration. Milnacipran has two chiral centers and is a racemic mixture of cis isomers: d-milnacipran (1S, 2R) and l-milnacipran (1R, 2S). After oral administration, the radioactivity of almost the entire dose was excreted rapidly in urine (approximately 93% of the dose). Approximately 55% of the dose was excreted in urine as unchanged milnacipran, which contained a slightly higher proportion of d-milnacipran (∼31% of the dose). In addition to the excretion of milnacipran carbamoyl O-glucuronide metabolite in urine (∼19% of the dose), predominantly as the l-milnacipran carbamoyl O-glucuronide metabolite (∼17% of the dose), approximately 8% of the dose was excreted in urine as the N-desethyl milnacipran metabolite. No additional metabolites of significant quantity were excreted in urine. Similar plasma concentrations of milnacipran and the l-milnacipran carbamoyl O-glucuronide metabolite were observed after dosing, and the maximum plasma concentration of l-milnacipran carbamoyl O-glucuronide metabolite at 4 h after dosing was 234 ng Eq of milnacipran/ml. Lower plasma concentrations (<25 ng Eq of milnacipran/ml) of N-desethyl milnacipran and d-milnacipran carbamoyl O-glucuronide metabolites were observed.

  18. Sex and age differences in mercury distribution and excretion in methylmercury-administered mice

    SciTech Connect

    Hirayama, K.; Yasutake, A.

    1986-01-01

    Sex differences in mercury distribution and excretion after single administration of methylmercury chloride (MMC, 5 mg/kg were studied in mice. A sex difference in urinary mercury excretion was found in sexually mature mice (age of 7 wk) of C57BL/6N and BALB/cA strains. Males showed higher mercury levels in urine than females, though no significant difference was found in fecal mercury levels 24 h post exposure to MMC. The higher urinary excretion rates in males accounted for significant lowering of mercury levels in the brain, liver, and blood, but not in the kidney, which showed higher values. At 5 min, however, the sex difference was found only in the kidney, showing higher levels in males. Changes in mercury distribution with time were studied in C57BL/6N mice. The brain mercury increased in both sexes up to 3 d, and decreased only in males on d 5. Liver and blood mercury decreased with time in both sexes, and these were constantly higher in females than in males. Renal mercury in males decreased to similar levels to females on d 3. The sex differences at various ages were studied with C57BL/6N mice 24 h after dosing. Two-week-old mice did not show significant sex differences in the mercury distribution and excretion, and their urinary mercury levels were much lower as compared to the older mice. Urinary mercury excretion in both sexes increased at 4 wk of age and then decreased at 45 wk of age. At 4, 7, 10, and 45 wk of age, males showed higher urinary mercury levels than females. From these findings, it has been suggested that urinary mercury excretion may be related to sex hormones, especially androgens.

  19. Dynamics of pregnancy-associated polyomavirus urinary excretion: a prospective longitudinal study.

    PubMed

    McClure, Gloria B; Gardner, J Suzette; Williams, Jason T; Copeland, Christina M; Sylvester, Sarah K; Garcea, Robert L; Meinerz, Natalie M; Groome, Lynn J; Vanchiere, John A

    2012-08-01

    Asymptomatic polyomaviruria of pregnancy has been documented in point prevalence studies, but little attention has been given to the dynamics of polyomavirus excretion during pregnancy because of its benign course. We tested the hypothesis that the frequency and/or magnitude of polyomavirus excretion would increase as pregnancy progresses. Urine specimens were obtained prospectively from 179 healthy women during uncomplicated pregnancies and 37 healthy non-pregnant women. Real-time polymerase chain reaction was used to determine BK virus (BKV) and JC virus (JCV) viral loads in urine, blood, and rectal and vaginal swabs collected during routine obstetric and gynecologic clinic visits. Asymptomatic urinary shedding of BKV and/or JCV was observed in 384 (48.0%) of 800 specimens from 100 (55.8%) pregnant women. BKV excretion was more common in pregnant than non-pregnant women (41.3% vs. 13.5%, P = 0.0026). The frequency of JCV excretion was no different in pregnant compared to non-pregnant women. The frequency and magnitude of polyomavirus shedding did not vary with gestational age. Post-partum shedding of BKV, but not JCV, rapidly decreased to undetectable levels. Pregnancy-associated BKV excretion begins early in pregnancy and terminates rapidly post-partum. Neither the frequency nor magnitude of BKV or JCV shedding increased with pregnancy progression. Further study into the host factors that regulate pregnancy-associated BKV excretion may allow identification of the host factors that predict susceptibility to BKV-associated diseases in immune compromised patients.

  20. [Studies on the absorption, excretion and distribution of aclacinomycin A: absorption, excretion and distribution of aclacinomycin A in mice, rabbits and dogs by photometric assay (author's transl)].

    PubMed

    Iguchi, H; Matsushita, Y; Ohmori, K; Hirano, S; Kiyosaki, T; Hori, S; Tone, H; Oki, T

    1980-02-01

    An anthracycline antitumor antibiotic, aclacinomycin A, was given to mice, rabbits or dogs intravenously to study the pharmacokinetics by photometric assay based on the absorption of anthracycline ring. The drug was rapidly eliminated from the blood in these animals. Drug levels were much higher in the blood cells than in the plasma. Tissue levels in dogs were 50 approximately 100 times higher than the blood levels, which showed the drug was rapidly transferred from the blood to tissues after administration. Higher levels were observed in the lungs, spleen and lymph nodes, where the drug was present as aclacinomycin A itself and the glycoside-type metabolites that were biologically active. The active form was also detected in the pancreas, heart, thymus, bone marrow and gastrointestinal tract. In the liver and kidneys, biologically inactive aglycone-type metabolites were observed. About 2 approximately 4% of the drug given to rabbits or dogs was recovered in the urine by 72 hours after administration, in which only 10% of the excreted drug was active form in rabbits but about 65% in dogs. The rest was inactive aglycone-type metabolites that were excreted almost in the conjugated form. Biliary excretion also contributed to the total clearance of the drug. Aclacinomycin A was absorbed even by oral administration in rabbits and dogs. Tissue distribution of the drug orally given to dogs was similar to that in intravenous administration, except that higher levels of active form were detected in the gastrointestinal tract and of inactive form in the liver.

  1. Relative bioavailability of sodium cromoglycate to the lung following inhalation, using urinary excretion

    PubMed Central

    Aswania, O A; Corlett, S A; Chrystyn, H

    1999-01-01

    Aims To determine if a urinary excretion method, previously described for salbutamol, could also indicate the relative bioavailability of sodium cromoglycate to the lung following inhalation from a metered dose inhaler. Method Inhaled (INH), inhaled+oral charcoal (INHC), oral (ORAL) and oral+oral charcoal (ORALC) 20 mg doses of sodium cromoglycate were given via a randomised cross-over design to 11 healthy volunteers trained on how to use a metered dose inhaler. Urine samples were collected at 0.0, 0.5, 1.0 and up to 24 h post dosing and the sodium cromoglycate urinary concentration was measured using a high performance liquid chromatographic method. Results No sodium cromoglycate was detected in the urine up to 24 h following ORALC dosing. A mean (s.d.) of 3.6 (4.3) μg, 10.4 (10.9) μg and 83.7 (71.1) μg of the ORAL dose was excreted, in the urine, during the 0.5, 1.0 and 24 h post dose collection periods, respectively. Following INH dosing, the renal excretion was significantly higher (P < 0.01) with 32.9 (14.5) μg, 61.2 (28.3) μg and 305.6 (82.3) μg excreted, respectively. The SCG excreted at 0.5, 1.0 and 24 h collection periods following INHC dosing were 26.3 (8.4) μg, 49.3 (18.1) μg and 184.9 (98.4) μg, respectively. There was no significant difference between the excretion rate of sodium cromoglycate following INHC when compared with INH dosing in the first 0.5 and 1.0 h. Conclusions The urinary excretion of sodium cromoglycate in the first 0.5 h post inhalation can be used to compare the relative lung deposition of two inhaled products or of the same product using different inhalation techniques. This represents the relative bioavailability of sodium cromoglycate to the lung following inhalation. Similar 24 h urinary excretion of sodium cromoglycate can be use to compare the total dose delivered to the body from two different inhalation products/inhalation methods. This represents the relative bioavailability of sodium cromoglycate to the body

  2. Abnormal urinary excretion of polyamines in HHH syndrome (hyperornithinemia associated with hyperammonemia and homocitrullinuria).

    PubMed

    Shimizu, H; Maekawa, K; Eto, Y

    1990-01-01

    The HHH syndrome (hyperornithinemia associated with hyperammonemia and homocitrullinuria) is characterized by a very rare genetic defect of ornithine transport in mitochondrial membrane. We first demonstrated that a patient with HHH syndrome excreted about 6 times higher amount of polyamines in urine than the control when supplemented with high protein diets and ornithine loading. Each urinary polyamine fraction measured by HPLC method in HHH syndrome appears to be increased, as compared with those of the control. These data suggest that increased urinary excretion of polyamines in this syndrome is closely related to overflowing of plasma polyamine due to an ornithine transport defect in the mitochondrial membrane.

  3. D-penicillamine does not increase urinary bismuth excretion in patients treated with tripotassium dicitrato bismuthate.

    PubMed

    Nwokolo, C U; Pounder, R E

    1990-10-01

    Twenty-four urinary bismuth excretion was measured in five patients who had been treated with tripotassium dicitrato bismuthate, before and after single 1 g oral dose of D-penicillamine. Before dosing with D-penicillamine, the median 24 h urinary bismuth output was 55 micrograms 24 h-1 (range 17-156 micrograms 24 h-1) and following dosing with D-penicillamine the median 24 h urinary bismuth output was 53 micrograms 24 h-1 (range 12-156 micrograms 24 h-1). D-penicillamine does not facilitate the urinary excretion of bismuth, hence it is unsuitable for use as an oral chelator in patients with bismuth intoxication.

  4. Single dose povidone-iodine on thyroid functions and urinary iodine excretion.

    PubMed

    Yilmaz, Deniz; Teziç, H Tahsin; Zorlu, Pelin; Firat, Serap; Bilaloğlu, Eriş; Kutlu, Alev Oğuz

    2003-08-01

    The effect of single dose povidone-iodine on serum thyrotropin and thyroxine levels and urinary iodine excretion in 30 preterm, 40 full-term newborns and 50 infants at Dr. Sami Ulus Children's Hospital was studied. There was no significant change of thyroid function in any of the groups (p>0.05). Urinary iodine excretion in preterm and full-term groups elevated significantly (p<0.05). The authors conclude that patients who receive single dose povidone-iodine for skin disinfection are not at risk for thyroid disorders.

  5. Intrarenal role of angiotensin II in controlling sodium excretion during dehydration in dogs.

    PubMed

    Trippodo, N C; Hall, J E; Lohmeier, T E; Guyton, A C

    1977-05-01

    1. The intrarenal role of angiotensin II in controlling sodium excretion was examined in anaesthetized, dehydrated dogs by infusing the angiotensin II antagonist Sar1-Ile8-angiotensin II directly into the renal artery. Comparisons were made with dehydrated dogs receiving only sodium chloride solution intrarenally. 2. Intrarenal angiotensin II blockade resulted in significant increases in urinary sodium excretion and urine flow rate. 3. The results indicate that during the high-renin state of dehydration endogenous angiotensin II has intrarenal effects which lead to salt and water retention.

  6. Neurogenic hypertension associated with an excessively high excretion rate of catecholamine metabolites.

    PubMed Central

    Funck-Brentano, C; Pagny, J Y; Menard, J

    1987-01-01

    A 60 year old hypertensive patient suffered several cerebral infarctions. A phaeochromocytoma was suspected because the excretion rates of vanillylmandelic acid and its methoxy derivatives were raised and the patient had hypertensive crises. No tumour was found, however, by 131mI-iodobenzylguanidine scintigraphy and computed tomography of the abdomen. Moreover, the enhanced orthostatic plasma catecholamine response suggested that the high excretion rates of catecholamine metabolites were more likely to be caused by the syndrome of raised catecholamines after cerebrovascular accidents than a phaeochromocytoma. A phaeochromocytoma should not be diagnosed within several months of cerebral infarction without first excluding the possibility of a hyperadrenergic state induced by cerebral infarction. PMID:3593621

  7. Assessment of urinary excretion of antimalarial drugs in large-scale chemotherapeutic eradication projects

    PubMed Central

    Bruce-Chwatt, L. J.

    1959-01-01

    Assessment of the urinary excretion of an antimalarial drug is a useful means of checking the amount of drug administered and the regularity of intake. The author describes the various methods available for the qualitative and quantitative estimation of antimalarial drugs in urine and discusses their relative merits, with special reference to their suitability for use in the field. He points out the difficulties involved in estimating the urinary excretion of antimalarials in large-scale chemotherapeutic eradication projects and stress the importance of simplifying testing techniques as far as possible. PMID:13805135

  8. Urinary excretion of dietary Maillard reaction products in healthy adult female cats.

    PubMed

    van Rooijen, C; Bosch, G; Butré, C I; van der Poel, A F B; Wierenga, P A; Alexander, L; Hendriks, W H

    2016-01-01

    During processing of foods, the Maillard reaction occurs, resulting in the formation of advanced Maillard reaction products (MRP). Varying amounts of MRP have been found in commercially processed pet foods. Dietary MRP can be absorbed and contribute to the endogenous pool of MRP and possibly the etiology of age-related diseases. The aim of the present study was to determine urinary excretion of dietary MRP in cats fed commercial moist and dry foods. A pilot study with 10 cats, conducted to determine the adaptation time required for stable urinary excretion of MRP when changing to a diet with contrasting MRP content, showed an adaptation time of 1 d for all components. In the main study, 6 commercially processed dry and 6 moist diets were fed to 12 adult female cats in 2 parallel randomized, 36-d Latin square designs. The 24-h urine was collected quantitatively using modified litter boxes, and fructoselysine (FL), carboxymethyllysine (CML), and lysinoalanine (LAL) were analyzed using ultra high performance liquid chromatography (UHPLC) - mass spectrometer. Daily urinary excretion of FL and CML showed a positive relationship with daily intake in the dry ( = 0.03 and < 0.01, respectively) and moist ( < 0.01) foods. For LAL, no significant relationship was observed. Urinary recovery (% ingested) showed a negative relationship with daily intake for FL, CML, and LAL in the dry foods ( < 0.01, < 0.01, and = 0.08, respectively) and for CML and LAL in the moist foods ( < 0.01). The observed increase in urinary excretion with increasing dietary intake indicates that dietary MRP were absorbed from the gastrointestinal tract of cats and excreted in the urine. The adaptation time with change in diet indicates a likely effective excretion of MRP. Minimum apparent absorption of FL, CML, and LAL was found to range between 8% and 23%, 25% and 73%, and 6% and 19%, respectively. The observed decrease in urinary recovery suggests a limiting factor in digestion, absorption, metabolism

  9. Fecal excretion pattern of bile acids in rats fed high fat diets and neomycin in induced colon tumorigenesis.

    PubMed

    Panda, S K; Broitman, S A

    1999-09-06

    Neomycin augments colon tumorigenesis in 1,2 - dimethylhydrazine treated rats fed polyunsaturated fat diet and decreases fecal cholic acid excretion, while it inhibits tumorigenesis with increased cholic acid and decreased deoxycholic acid excretions in rats fed high cholesterol diet. Participation of other fecal bile acids seems to be insignificant in relation to colon carcinogenesis.

  10. Phytate utilization and phosphorus excretion by broiler chickens fed diets containing cereal grains varying in phytate and phytase content

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poor digestibility of phytate P by poultry leads to supplementation of poultry diets with inorganic P thereby increasing feed costs and also increasing the excretion of P by the birds. In order to quantify phytate utilization and P excretion by poultry, eighty, 12 day-old, male broiler chicks, weig...

  11. Bioaccessibility and excretion of arsenic in Niu Huang Jie Du Pian pills

    SciTech Connect

    Koch, Iris; Sylvester, Steven; Lai, Vivian W.-M.; Owen, Andrew; Reimer, Kenneth J. Cullen, William R.

    2007-08-01

    Traditional Chinese medicines (TCMs) often contain significant levels of potentially toxic elements, including arsenic. Niu Huang Jie Du Pian pills were analyzed to determine the concentration, bioaccessibility (arsenic fraction soluble in the human gastrointestinal system) and chemical form (speciation) of arsenic. Arsenic excretion in urine (including speciation) and facial hair were studied after a one-time ingestion. The pills contained arsenic in the form of realgar, and although the total arsenic that was present in a single pill was high (28 mg), the low bioaccessibility of this form of arsenic predicted that only 4% of it was available for absorption into the bloodstream (1 mg of arsenic per pill). The species of arsenic that were solubilized were inorganic arsenate (As(V)) and arsenite (As(III)) but DMAA and MMAA were detected in urine. Two urinary arsenic excretion peaks were observed: an initial peak several (4-8) hours after ingestion corresponding to the excretion of predominantly As(III), and a larger peak at 14 h corresponding predominantly to DMAA and MMAA. No methylated As(III) species were observed. Facial hair analysis revealed that arsenic concentrations did not increase significantly as a result of the ingestion. Arsenic is incompletely soluble under human gastrointestinal conditions, and is metabolized from the inorganic to organic forms found in urine. Bioaccessible arsenic is comparable to the quantity excreted. Facial hair as a bio-indicator should be further tested.

  12. Organic Anion Transporter 5 Renal Expression and Urinary Excretion in Rats with Vascular Calcification

    PubMed Central

    Hazelhoff, María Herminia; Bulacio, Romina Paula; Torres, Adriana Mónica

    2013-01-01

    It has been described renal damage in rats with vascular calcification. The organic anion transporter 5 (Oat5) is only expressed in kidney, and its urinary excretion was proposed as potential early biomarker of renal injury. The aim of this study was to evaluate the Oat5 renal expression and its urinary excretion in an experimental model of vascular calcification in comparison with traditional markers of renal injury. Vascular calcification was obtained by the administration of an overdose of vitamin D3 (300,000 IU/kg, b.w., i.m.) to male Wistar rats. Oat5 urinary abundance was evaluated by Western blotting. Traditional markers of renal injury, such as creatinine and urea plasma levels, urinary protein levels, and urinary alkaline phosphatase (AP) activity, were determined using commercial kits. Histology was assessed by hematoxylin/eosin staining. Oat5 renal expression was evaluated by Western blotting and by immunohistochemistry. An increased expression of Oat5 in renal homogenates, in apical membranes, and in its urinary excretion was observed in rats with vascular calcification. The traditional parameters used to evaluate renal function were not modified, with the exception of histology. It is possible to postulate the urinary excretion of Oat5 as a potential noninvasive biomarker of renal injury associated with vascular calcification. PMID:24199190

  13. Urinary excretion of orally administered oxalic acid in saccharin and o-phenylphenol-fed NMRI mice.

    PubMed

    Salminen, E; Salminen, S

    1986-01-01

    Both saccharin and o-phenylphenol have been suggested to be carcinogenic to the urinary bladder in experimental animals, but the mechanism has remained unclear. The aim of this study was to investigate the effects of dietary saccharin and o-phenylphenol on the urinary excretion of dietary oxalic acid. Male NMRI mice were gradually adapted to either 3% o-phenylphenol or 5% saccharin in their diet. Having being adapted to these diets for 1 week or after consuming them for 3 months, the animals were fasted for 6 h and given a 2.5-microCi oral dose of U-14C-oxalic acid. Dosed animals were kept in metabolism cages for 48 h to monitor urinary and fecal excretion of the label. Adaptation to dietary o-phenylphenol appeared to increase the urinary excretion of orally administered U-14C-oxalic acid when food and water were available during urinary and fecal collections. Adaptation to dietary saccharin had little effect on urinary oxalate levels when compared to control animals. These results indicate that changes in urinary oxalate levels should be more carefully studied in connection with potential urinary bladder carcinogens to avoid the possibility of bladder irritation by increased urinary oxalate excretion.

  14. Lanthanum carbonate reduces urine phosphorus excretion: evidence of high-capacity phosphate binding.

    PubMed

    Pennick, Michael; Poole, Lynne; Dennis, Kerry; Smyth, Michael

    2012-01-01

    The effectiveness of phosphate binders can be assessed by evaluating urinary phosphorus excretion in healthy volunteers, which indicates the ability of the phosphate binder to reduce gastrointestinal phosphate absorption. Healthy volunteers were enrolled into one of five separate randomized trials; four were open label and one double blind. Following a screening period of ≤28 days, participants received differing tablets containing lanthanum carbonate [LC, 3000 mg/day of elemental lanthanum (in one study other doses were also used)]. Participants received a standardized phosphate diet and remained in the relevant study center throughout the duration of each treatment period. The end point in all studies was the reduction in urinary phosphorus excretion. Reductions in mean 24-h urinary phosphorus excretion in volunteers receiving a lanthanum dose of 3000 mg/day were between 236 and 468 mg/day over the five separate studies. These data in healthy volunteers can be used to estimate the amount of reduction of dietary phosphate absorption by LC. The reduction in 24-h urinary phosphorus excretion per tablet was compared with published data on other phosphate binders. Although there are limitations, evidence suggests that LC is a very effective phosphate binder in terms of binding per tablet.

  15. Pb and Cd accumulation and phyto-excretion by salt cedar (Tamarix smyrnensis Bunge).

    PubMed

    Kadukova, Jana; Manousaki, Eleni; Kalogerakis, Nicolas

    2008-01-01

    The accumulation and excretion of lead (Pb) and cadmium (Cd) by salt cedar (Tamarix smyrnensis Bunge) were investigated in this study. Tamarix smyrnensis plants were exposed to the mixtures of Pb and Cd and high salinity for 10 wk. Subsequently, Pb and Cd uptake was quantified in the shoots and roots of the plants by ICP-AES. In addition, physiological parameters such as biomass production, shoot length, plant appearance, and chlorophyll content were examined. The roots accumulated the highest amount of Pb. Salinity was found to not have an important effect on Pb translocation to the leaves. Cd was translocated into the aerial part in a higher portion than Pb. Cd content in leaves of T. smyrnensis increased with the increasing salinity. The visible toxicity symptoms, if present, were connected only to the high salinity. The excretion of Pb and Cd by salt glands was observed and quantified. T. smyrnensis excreted a significant amount of metals on the leaf surface. This characteristic of salt cedar plants can be viewed as a novel phytoremediation process for the remediation of sites contaminated with heavy metals that we have termed "phyto-excretion."

  16. Urinary trimethylselenonium excretion by the rat: effect of level and source of selenium-75

    SciTech Connect

    Nahapetian, A.T.; Janghorbani, M.; Young, V.R.

    1983-02-01

    The purpose of this study was to explore in rats the urinary metabolites of selenium (Se), by using (/sup 75/Se)selenomethionine, (/sup 75/Se)selenocystine, and (/sup 75/Se)selenite, and to assess the effects of low and high levels of Se intake on trimethylselenonium ion (TMSe) excretion in urine. Male adult rats were adapted for 6 weeks to a commercial rat laboratory stock diet (0.25 ppm Se). They were then starved for 24 hours and given an oral dose of either low (16 micrograms Se/kg body weight) or high (1500 micrograms Se/kg body weight) Se as the test Se compounds. Appearance of radioactivity in TMSe and non-TMSe Se metabolites in urine was monitored for 48 hours. About 40% of the /sup 75/Se dose was excreted in urine. TMSe was the major urinary Se metabolite at high, and a minor urinary Se metabolite at low dose levels of Se and for all three Se test compounds. At least 80% of urinary /sup 75/Se and 26-42% of the orally administered /sup 75/Se were excreted as non-TMSe Se metabolites in urine under the latter condition. It is hypothesized that at a requirement intake of Se either a trace or no TMSe is excreted in urine, and it becomes a major excretory metabolite of Se when the dietary trace mineral intake exceeds a requirement level, probably serving as a means of detoxification.

  17. Reduction of Escherichia coli O157:H7 excretion in sheep by oral lactoferrin administration.

    PubMed

    Yekta, M Atef; Cox, E; Goddeeris, B M; Vanrompay, D

    2011-06-02

    Ruminants are an important reservoir of Escherichia coli O157:H7, therefore reducing E. coli O157:H7 excretion by these animals could play a key role in reducing human infections. The present study investigates the potential of bovine lactoferrin, a natural antimicrobial-immunomodulatory protein of milk, to prevent colonization and excretion of E. coli O157:H7 in sheep. The effect of two different doses of lactoferrin (1.5 g or 0.15 g per 12h) was evaluated on colonization of sheep intestine and faecal excretion of the NCTC12900 strain. Hereto, lactoferrin was orally administered to sheep during 30 consecutive days and sheep were experimentally infected with E. coli O157:H7 on the second day of the lactoferrin administration. Interestingly, both lactoferrin dosages significantly reduced the number of E. coli O157:H7 in faeces as well as the duration of faecal excretion. The high dose group showed a significantly higher antibody response against EspA and EspB, two structural proteins of the bacterial type III secretion system (TTSS), than the colonization control group. The results suggest that oral lactoferrin administration could be used to prevent persistent colonization of sheep with E. coli O157:H7.

  18. Urinary folate excretion in chronic ethanol- and diet-treated rats

    SciTech Connect

    Collins, T.D.; McMartin, K.E.; Bairnsfather, L.

    1986-03-05

    Acute ethanol treatment of rats produces a marked increase in urinary folate excretion, which accumulates in correlation with the duration of ethanol treatment. In order to study the role of excess urinary folate excretion in the development of folate deficiency by chronic ethanol feeding, groups of male Sprague-Dawley rats were maintained for four months on one of the following liquid diets: ethanol, pair-fed control, ethanol minus folic acid, and pair-fed control minus folic acid. A fifth group was provided a control chow diet ad libitum. Blood ethanol levels were generally maintained between 80-150 mg/dl at various times of the day. Decrease in plasma and tissue folate levels occurred within four weeks in all liquid diet groups compared to chow rats and within two weeks for urinary folate levels. Greater effects were generally observed in both folate-deficient groups than in the control or ethanol group. Acute ethanol treatment of rats from the various diet groups produced increases in urinary folate excretion in all groups except the ethanol minus folic acid diet group. When the folate system of rats are compromised by dietary deprivation and/or chronic ethanol treatment, these results suggest that urinary folate excretion is greatly reduced as a conservation measure.

  19. Corticosterone excretion patterns and affiliative behavior over development in ravens (Corvus corax)

    PubMed Central

    Stöwe, Mareike; Bugnyar, Thomas; Schloegl, Christian; Heinrich, Bernd; Kotrschal, Kurt; Möstl, Erich

    2015-01-01

    Averse effects of social stress may be buffered by the presence of social allies, which mainly has been demonstrated in mammals and recently also in birds. However, effects of socio-positive behavior prior to fledging in relation to corticosterone excretion in altricial birds have not been investigated yet. We here monitored corticosterone excretion patterns in three groups of hand raised juvenile ravens (n=5, 6 and 11) in the nest, post-fledging (May–July) and when ravens would be independent from their parents (September–November). We related these corticosterone excretion patterns to socio-positive behavior. Behavioral data were collected via focal sampling in each developmental period considered. We analyzed amounts of excreted immunoreactive corticosterone metabolites (CM) using enzyme immuno assays. We collected fecal samples in each developmental period considered and evaluated the most appropriate assay via an isolation stress experiment. Basal CM was significantly higher during the nestling period than post-fledging or when birds were independent. The time nestlings spent allopreening correlated negatively with mean CM. Post-fledging, individuals with higher CM levels sat close to (distance <50 cm) conspecifics more frequently and tended to preen them longer. When birds were independent and a stable rank hierarchy was established, dominant individuals were preened significantly longer than subordinates. These patterns observed in ravens parallel those described for primates, which could indicate that animal species living in a complex social environment may deal with social problems in a similar way that is not restricted to mammals or primates. PMID:18022623

  20. Possible involvement of P-glycoprotein in the biliary excretion of grepafloxacin.

    PubMed

    Zhao, Ying Lan; Cai, Shao Hui; Wang, Li; Kitaichi, Kiyoyuki; Tatsumi, Yasuaki; Nadai, Masayuki; Yoshizumi, Hideo; Takagi, Kenji; Takagi, Kenzo; Hasegawa, Takaaki

    2002-03-01

    1. In the present study, we have examined the effects of the quinolones norfloxacin (NFLX), enoxacin (ENX), ofloxacin (OFLX), tosufloxacin (TFLX), lomefloxacin (LFLX), sparfloxacin (SPFX) and grepafloxacin (GPFX) on the efflux of doxorubicin from mouse leukaemia P388/ADR cells expressing P-glycoprotein. The relationship between their partition coefficients (hydrophobicity) and effluxing potencies was also elucidated. 2. Both TFLX and SPFX strongly increased the intracellular accumulation of doxorubicin (5 micromol/L) in P388/ADR cells, but had no effect on P388/S cells not expressing P-glycoprotein. The rank of order of the potency of the quinolones (TFLX > SPFX > GPFX > NFLX) was not related directly to their hydrophobicity. These results suggest that some quinolones can reverse anticancer drug resistance. 3. Because GPFX is more highly excreted into the bile than other known quinolones, the effects of doxorubicin (10 mg/kg) or the well-known inhibitors of P-glycoprotein, namely cyclosporine A (10 mg/kg) and erythromycin (100 mg/kg), on the biliary excretion of GPFX at steady state was studied in rats. 4. Doxorubicin, cyclosporine A and erythromycin significantly decreased the biliary clearance of GPFX. Cyclosporine A and erythromycin had a much stronger inhibitory effect on the biliary excretion of GPFX than doxorubicin. These results suggest the possibility that GPFX is, at least in part, excreted into the bile by a P-glycoprotein-mediated transport mechanism.

  1. Cytostatic drugs are without significant effect on digitoxin plasma level and renal excretion.

    PubMed

    Kuhlmann, J; Wilke, J; Rietbrock, N

    1982-11-01

    In three patients with malignant lymphoma who received 0.5 mg digitoxin before and 24 hr after combination therapy with cyclophosphamide, Oncovin, procarbazine, and prednisone (COPP) or cyclophosphamide, Oncovin, and prednisone (COP), plasma glycoside concentrations and renal excretion were measured 0 to 168 hr after digitoxin and the areas under plasma concentration-time curves *(AUCs) were calculated. In 10 patients receiving 0.1 mg digitoxin, daily plasma glycoside concentration and daily renal excretion were measured before and after COPP, COP, or cyclophosphamide, Oncovin, cytosine-arabinoside, and prednisone (COAP) treatment schemes. In contrast to previous reports on digoxin, cytostatic drug therapy does not lead to a reduction in steady-state digitoxin plasma levels and daily renal excretion. During cytostatic therapy attainment of peak digitoxin level was delayed after a single dose, showing that the rate of digitoxin absorption was reduced, but that the AUCs and renal excretion of digitoxin (parameters of the extent of digitoxin absorption) were not diminished. Since the absorption rate is not clinically relevant in patients on long-term glycoside therapy, our results indicate that digitoxin is preferable to digoxin in such patients.

  2. Pattern of Salmonella excretion in amphibians and reptiles in a vivarium.

    PubMed

    Pfleger, Silvia; Benyr, Gerald; Sommer, Regina; Hassl, Andreas

    2003-01-01

    During a period of about three years the faeces of five species of amphibians (35 individuals) and of 23 species of reptiles (103 individuals) living in one vivarium with terrariums imitating different types of ecosystems were examined for salmonellae. From 54 out of 376 faecal samples Salmonella spp. was isolated (= 14%). Twenty-one different Salmonella strains were found. Salmonellae could be isolated about twice as often from animals kept under arid or mesic conditions than from animals living in humid or aquatic environments although this was not statistically significant. Statistically significant for the rate of Salmonella excretion was the animals' diet and the class the animals are belonging to. Animals feeding on mice (p = 0.04) and reptiles in general (p = 0.04) were more commonly excreting Salmonella. Duration of stay was also a significant factor (p = 0.0005), whereby the relative risk for Salmonella excretion increased with the factor 2.91 per year during the investigation period. Salmonella strains were not necessarily transferred among animals living in the same terrarium or among the inhabitants of different terrariums. The pattern of Salmonella excretion was generally fragmentary. The outsides as well as the insides of the walls of the terrariums were also tested for salmonellae several times, but salmonellae have never been isolated.

  3. Predicting when biliary excretion of parent drug is a major route of elimination in humans.

    PubMed

    Hosey, Chelsea M; Broccatelli, Fabio; Benet, Leslie Z

    2014-09-01

    Biliary excretion is an important route of elimination for many drugs, yet measuring the extent of biliary elimination is difficult, invasive, and variable. Biliary elimination has been quantified for few drugs with a limited number of subjects, who are often diseased patients. An accurate prediction of which drugs or new molecular entities are significantly eliminated in the bile may predict potential drug-drug interactions, pharmacokinetics, and toxicities. The Biopharmaceutics Drug Disposition Classification System (BDDCS) characterizes significant routes of drug elimination, identifies potential transporter effects, and is useful in understanding drug-drug interactions. Class 1 and 2 drugs are primarily eliminated in humans via metabolism and will not exhibit significant biliary excretion of parent compound. In contrast, class 3 and 4 drugs are primarily excreted unchanged in the urine or bile. Here, we characterize the significant elimination route of 105 orally administered class 3 and 4 drugs. We introduce and validate a novel model, predicting significant biliary elimination using a simple classification scheme. The model is accurate for 83% of 30 drugs collected after model development. The model corroborates the observation that biliarily eliminated drugs have high molecular weights, while demonstrating the necessity of considering route of administration and extent of metabolism when predicting biliary excretion. Interestingly, a predictor of potential metabolism significantly improves predictions of major elimination routes of poorly metabolized drugs. This model successfully predicts the major elimination route for poorly permeable/poorly metabolized drugs and may be applied prior to human dosing.

  4. Fluid electrolyte excretion during different hypokinetic body positions of trained subjects

    NASA Astrophysics Data System (ADS)

    Zorbas, Yan G.; Naexu, Konstantin A.; Federenko, Youri F.

    The aim of this study was to evaluate the effect of different body positions on renal excretion of fluid and electrolytes after exposure to 364 days of decreased number of steps per day (hypokinesia, HK). The studies were performed on 18 endurance trained male volunteers aged 19-24 years who had an average of VO 2max 67 ml/kg body/min. All volunteers were divided into three equal groups: the 1st group subjected to 12 h orthostatic position (OP) and 12 h clinostatic position (CP)/day, the 2nd group exposed to 8 h orthostatic position and 14 h clinostatic position/day, and the 3rd group submitted to 10 h orthostatic position and 16 h clinostatic position/day for 364 days. For the simulation of the hypokinetic effect all volunteers were kept under an average of 3000 steps/day for 364 days. Diuresis and the concentrations of sodium, potassium, chloride, calcium and magnesium as well as excretion of creatine were determined in 24-h urine samples. By the end of the hypokinetic period all volunteers, regardless of their body position during HK, manifested a significant increase in renal excretion of fluid and electrolytes as compared to prehypokinetic period values. It was concluded that prolonged restriction of motor activity induced a significant increase in renal excretion of fluid and electrolytes in endurance trained subjects regardless to their body position and duration thereof per day.

  5. Prediction of nitrogen excretion by beef cattle: a meta-analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reliable estimates of nitrogen (N) excretion in the urine and feces of beef cattle are essential for developing cost-effective and environmentally sound nutrient management plans. A meta-analysis dataset was compiled that included data for starting live BW, DMI, N intake, dietary CP concentration, u...

  6. The involvement of multidrug and toxin extrusion protein 1 in the distribution and excretion of berberine.

    PubMed

    Xiao, Ling; Xue, Yaru; Zhang, Cuifeng; Wang, Le; Lin, Yunfei; Pan, Guoyu

    2017-03-16

    1. Berberine (BBR), an isoquinoline alkaloid, has demonstrated multiple clinical pharmacological actions. As a substrate of multiple transporters in the liver, BBR is rarely excreted into the bile but can be found in the urine. The purpose of the present study was to investigate the role of multidrug and toxin extrusion protein 1 (MATE1) in the transport of BBR in the liver and kidney. 2. Using human MATE1 (hMATE1)-transfected HEK293 cells, BBR was shown to be a substrate of hMATE1 (Km = 4.28 ± 2.18 μM). In primary rat hepatocytes, pH-dependent uptake and efflux studies suggested that the transport of BBR was driven by the exchange of H(+) and involved Mate1. In rats, we found that pyrimethamine (PYR), an inhibitor of Mate1, increased hepatic and renal distribution of BBR and decreased systematic excretion of BBR. 3. These findings indicated that BBR is a substrate of MATE1 and that hepatic and renal Mate1 promote excretion of BBR into bile and urine, respectively. In conclusion, Mate1 plays a key role in the distribution and excretion of BBR, and we speculate that drug-drug interactions (DDIs) caused by MATE1 may occur between BBR and other co-administered drugs.

  7. Increased urinary excretion of platelet activating factor in mice with lupus nephritis

    SciTech Connect

    Macconi, D.; Noris, M.; Benfenati, E.; Quaglia, R.; Pagliarino, G. ); Remuzzi, G. Ospedali Riuniti di Bergamo )

    1991-01-01

    Platelet activating factor (PAF) is present in urine from humans and experimental animals in normal conditions. Very little is known about changes in PAF urinary excretion under pathologic conditions and no data are available about the origin of PAF in the urine. In the present study we explored the possibility that immunologic renal disease is associated with an increase in PAF urinary excretion using gas chromatography-mass spectrometry technique. To clarify the renal or extrarenal origin of urinary PAF we evaluated whether exogenously administered PAF (1-(1{prime},2{prime}-{sup 3}H)alkyl) is filtered through the glomerulus and excreted in the urine. The results show that: (1) urine from mice with lupus nephritis in the early phase of the disease contained amounts of PAF comparable to those excreted in normal mouse urine, (2) PAF levels increased when animals started to develop high grade proteinuria, (3) after intravenous injection of ({sup 3}H) PAF In nephritic mice, a negligible amount of ({sup 3}H) ether lipid, corresponding to ({sup 3}H)1-alkyl -2-acyl-3-phosphocholine (alkyl-2-acyl-GPC), was recovered from the 24 h urine extract.

  8. Faecal bacterial profile, nitrogen excretion and mineral absorption in healthy dogs fed supplemental oligofructose.

    PubMed

    Beynen, A C; Baas, J C; Hoekemeijer, P E; Kappert, H J; Bakker, M H; Koopman, J P; Lemmens, A G

    2002-10-01

    In a cross-over trial, five healthy dogs were fed a dry food without or with 1% (w/w) oligofructose to assess any oligofructose-induced effects on the faecal bacterial profile, nitrogen excretion and mineral absorption. The diets were given for a period of 3 weeks. Oligofructose feeding significantly raised the number of Bifidobacteria, Streptococci and Clostridia in faeces. The numbers of faecal anaerobic and aerobic bacteria were raised after ingestion of oligofructose. The faecal pH was unchanged. There was no effect of oligofructose feeding on the route of nitrogen excretion which was associated with a lack of effect on faecal ammonium and urinary urea excretion. It is suggested that the absence or presence of an effect of oligofructose on urinary and faecal nitrogen excretion depends on the background composition of the diet, in particular the content of non-digestible, fermentable carbohydrates. In the diets used, the content of non-digestible, fermentable carbohydrates was not measured. Both apparent magnesium and calcium absorption were significantly raised by oligofructose feeding, but phosphorus absorption was unaffected. The data presented may contribute to the qualification of the use of oligofructose in dog foods.

  9. Increased urinary excretion of beta-aminoisobutyric acid in a Danish family.

    PubMed

    Sjølin, K E

    1988-08-01

    During collection of a control material for determination of urinary excretion of beta-aminoisobutyric acid (beta-AIB), female high excretors were found in four generations in a Danish family. The heredity seemed to be sex related and dominant, unlike previous communications about genetically conditioned high excretors of beta-AIB.

  10. A new paradigm for ammonia excretion in aquatic animals: role of Rhesus (Rh) glycoproteins.

    PubMed

    Wright, Patricia A; Wood, Chris M

    2009-08-01

    Ammonia excretion at the gills of fish has been studied for 80 years, but the mechanism(s) involved remain controversial. The relatively recent discovery of the ammonia-transporting function of the Rhesus (Rh) proteins, a family related to the Mep/Amt family of methyl ammonia and ammonia transporters in bacteria, yeast and plants, and the occurrence of these genes and glycosylated proteins in fish gills has opened a new paradigm. We provide background on the evolution and function of the Rh proteins, and review recent studies employing molecular physiology which demonstrate their important contribution to branchial ammonia efflux. Rhag occurs in red blood cells, whereas several isoforms of both Rhbg and Rhcg occur in many tissues. In the branchial epithelium, Rhcg appears to be localized in apical membranes and Rhbg in basolateral membranes. Their gene expression is upregulated during exposure to high environmental ammonia or internal ammonia infusion, and may be sensitive to synergistic stimulation by ammonia and cortisol. Rhcg in particular appears to be coupled to H(+) excretion and Na(+) uptake mechanisms. We propose a new model for ammonia excretion in freshwater fish and its variable linkage to Na(+) uptake and acid excretion. In this model, Rhag facilitates NH(3) flux out of the erythrocyte, Rhbg moves it across the basolateral membrane of the branchial ionocyte, and an apical "Na(+)/NH (+)(4) exchange complex" consisting of several membrane transporters (Rhcg, V-type H(+)-ATPase, Na(+)/H(+) exchanger NHE-2 and/or NHE-3, Na(+) channel) working together as a metabolon provides an acid trapping mechanism for apical excretion. Intracellular carbonic anhydrase (CA-2) and basolateral Na(+)/HCO (-)(3) cotransporter (NBC-1) and Na(+)/K(+)-ATPase play indirect roles. These mechanisms are normally superimposed on a substantial outward movement of NH(3) by simple diffusion, which is probably dependent on acid trapping in boundary layer water by H(+) ions created by

  11. Decrease in Urinary Creatinine Excretion in Early Stage Chronic Kidney Disease

    PubMed Central

    Tynkevich, Elena; Flamant, Martin; Haymann, Jean-Philippe; Metzger, Marie; Thervet, Eric; Boffa, Jean-Jacques; Vrtovsnik, François; Houillier, Pascal; Froissart, Marc; Stengel, Bénédicte

    2014-01-01

    Background Little is known about muscle mass loss in early stage chronic kidney disease (CKD). We used 24-hour urinary creatinine excretion rate to assess determinants of muscle mass and its evolution with kidney function decline. We also described the range of urinary creatinine concentration in this population. Methods We included 1072 men and 537 women with non-dialysis CKD stages 1 to 5, all of them with repeated measurements of glomerular filtration rate (mGFR) by 51Cr-EDTA renal clearance and several nutritional markers. In those with stage 1 to 4 at baseline, we used a mixed model to study factors associated with urinary creatinine excretion rate and its change over time. Results Baseline mean urinary creatinine excretion decreased from 15.3±3.1 to 12.1±3.3 mmol/24 h (0.20±0.03 to 0.15±0.04 mmol/kg/24 h) in men, with mGFR falling from ≥60 to <15 mL/min/1.73 m2, and from 9.6±1.9 to 7.6±2.5 (0.16±0.03 to 0.12±0.03) in women. In addition to mGFR, an older age, diabetes, and lower levels of body mass index, proteinuria, and protein intake assessed by urinary urea were associated with lower mean urinary creatinine excretion at baseline. Mean annual decline in mGFR was 1.53±0.12 mL/min/1.73 m2 per year and that of urinary creatinine excretion rate, 0.28±0.02 mmol/24 h per year. Patients with fast annual decline in mGFR of 5 mL/min/1.73 m2 had a decrease in urinary creatinine excretion more than twice as big as in those with stable mGFR, independent of changes in urinary urea as well as of other determinants of low muscle mass. Conclusions Decrease in 24-hour urinary creatinine excretion rate may appear early in CKD patients, and is greater the more mGFR declines independent of lowering protein intake assessed by 24-hour urinary urea. Normalizing urine analytes for creatininuria may overestimate their concentration in patients with reduced kidney function and low muscle mass. PMID:25401694

  12. Evaluation of solids, nitrogen, and phosphorus excretion models for lactating dairy cows.

    PubMed

    Hollmann, M; Knowlton, K F; Hanigan, M D

    2008-03-01

    Monitoring or accurately predicting manure quantities and nutrient concentrations is important for dairy farms facing strict environmental regulations. The objectives of this project were to determine the daily out-flow of manure nutrients from a free-stall barn using mass balance and to compare results with published excretion models. The project was conducted at the free-stall facility housing the lactating cow herd of the Virginia Tech Dairy Center in 2005. The herd consisted of 142 (+/-8.9) Holstein and Jersey cows with a mean body weight of 568 (+/-6.2) kg and average milk yield of 29.8 (+/-1.7) kg/d with 3.18% (+/-0.07) true protein and 3.81% (+/-0.13) milk fat on 18 sampling days. The intakes of dry matter (DM), N, and P were estimated from the formulated ration. Daily consumption averaged 21.7 (+/-0.27) kg of DM with 17.7% (+/-0.26) crude protein and 0.46% (+/-0.03) P. Approximately 110 (+/- 27.9) kg/d of sawdust was used as bedding; its contribution to manure flow was subtracted. The alleys in the free-stall barn were flushed every 6 h with recycled wastewater, and the slurry was collected. On 18 sampling days the volumes and constituents of the flushwater and the flushed manure were determined for a 6-h flush cycle and extrapolated to daily values. Net daily flow of solids and nutrients in manure were calculated as the differences between masses in flushed slurry and flushwater. Nitrogen and P excretion were also calculated from dietary inputs and milk output. The flow was compared with the American Society of Agricultural Engineers' (ASAE) standards. Each cow produced 5.80 kg/d of total solids (remainder after drying at 105 degrees C). The ASAE standard predicted DM (remainder after drying at 60 degrees C) excretion of 8.02 to 8.53 kg/d per cow. Recovery of P amounted to 74.8 g/d per cow. Overall, 102% of intake P was recovered; 75.1% in the manure outflow and 26.9% in milk. About 285 g/d and 148 g/d of N per cow were recaptured in manure and milk

  13. The effect of phenobarbital on the metabolism and excretion of thyroxine in rats

    SciTech Connect

    McClain, R.M.; Levin, A.A.; Posch, R.; Downing, J.C.

    1989-06-15

    The effect of phenobarbital on thyroid function and the metabolism and biliary excretion of thyroxine in rats was determined. Phenobarbital, administered for 2 weeks at a dose of 100 mg/kg/day, resulted in an increase in hepatic and thyroid gland weights, decreased circulating levels of T4, T3 and rT3, and increased TSH levels in male and female rats. After 3 months of treatment liver and thyroid weights were still increased; however, hormone values were not as markedly affected indicating that the rats had partially compensated for the effect on thyroid function. In thyroidectomized rats the plasma clearance of thyroxine was increased with phenobarbital. In bile duct cannulated phenobarbital-treated male rats the hepatic uptake at 4 hr was markedly increased. Bile flow was increased and the 4-hr cumulative biliary excretion of administered radioactivity was increased by 42%. Most of the increase in the excretion (76%) was accounted for by an increase in the excretion of thyroxine-glucuronide in phenobarbital-treated rats. Hepatic thyroxine-glucuronyltransferase activity in phenobarbital-treated rats expressed as picomoles per milligram of protein was increased by 40%; enzyme activity per gram of liver was increased by about twofold which, coupled with increased hepatic weight, resulted in about a threefold increase in total hepatic thyroxine-glucuronyltransferase activity in phenobarbital-treated rats as compared to that of controls. Qualitatively similar effects on metabolism, excretion, and enzyme induction were noted in female rats; however, the magnitude of increase was less than that observed in male rats. It is concluded that the effect of phenobarbital on thyroid function in rats is primarily a result of its effects on the hepatic disposition of thyroid hormone.

  14. Effects of dietary protein level on growth performance and nitrogen excretion of dairy heifers

    PubMed Central

    Zhang, Bin; Wang, Chong; Liu, He; Liu, Jianxin; Liu, Hongyun

    2017-01-01

    Objective Protein supplementation is costly and can result in excess nitrogen (N) excretion. The objective of this study was to evaluate the effects of feeding different levels of dietary protein on average daily gain, body size, rumen fermentation, and nitrogen excretion of 8 to 10 month-old Holstein heifers. Methods Thirty-six Holstein heifers were divided into 12 blocks according to age (273±6.2 d) and were randomly assigned to diets containing a low (10.2% dry matter [DM]), medium (11.9% DM), or high (13.5% DM) level of dietary crude protein (CP). All diets contained approximately 70% roughage and 30% concentrate with similar dietary metabolizable energy (ME) content (2.47 Mcal/kg). Results Dry matter intake did not differ among the treatments, and average daily gain increased with the increasing dietary protein, 0.79, 0.95, 0.97 kg/d for low, medium, and high group, respectively. Body height increased linearly with increasing dietary CP but no other significant differences in body dimensions were found among the treatments. The increased ratios of dietary CP improved the rate of rear teat length growth remarkably (p<0.05). There was no difference in rumen pH or ruminal major volatile fatty acid (acetate, propionate, and butyrate) concentration among the 3 diets, but rumen ammonia-N concentration increased with the higher dietary CP (p<0.05). Increasing N intake led to increased total N excretion; urinary N excretion was significantly increased (p<0.05) but fecal N excretion was similar among the treatments. Conclusion These data suggest that the diet containing 11.9% CP (ME 2.47 Mcal/kg) could meet the maintenance and growth requirements of 9 to 11 month-old Holstein heifers gaining approximately 0.9 kg/d. PMID:27554361

  15. Excretion of Eimeria alabamensis oocysts in grazing calves and young stock.

    PubMed

    Svensson, C

    2000-03-01

    The aims of the present study were to investigate the excretion of Eimeria alabamensis oocysts by young cattle during their first grazing season and during the first 16 days of their second grazing period. In trial 1, nine first-season grazing heifers were studied and found to have become infected with E. alabamensis shortly after turnout. The next grazing period they were turned out on to a permanent pasture together with two first-season grazing calves. Faecal samples were collected before turnout and then daily from day 3 to day 16. The second-season grazing heifers excreted insignificant numbers of E. alabamensis oocysts, whereas one of the two first-season grazing calves excreted up to 703,000 oocysts/g of faeces (OPG), indicating that the pasture was contaminated. In trial 2, faecal samples were collected from 12 calves before their first turnout in May, daily from day 2 to day 20 after turnout and then once a week until the end of September. The calves grazed pastures used in previous years by first-season grazing calves. Nine of the calves developed clinical E. alabamensis coccidiosis 4-7 days after turnout and excreted more than 950,000 OPG on days 9-10. By day 17 the oocyst excretion had decreased below 900 OPG and remained low throughout the rest of the grazing season. The results of the two studies indicate that reinfections with E. alabamensis are of little clinical importance in calves grazing contaminated pastures, and that young stock infected with E. alabamensis during their first grazing season may be used to cleanse contaminated pastures without risk of developing clinical coccidiosis.

  16. Excretion pathways and ruminal disappearance of glyphosate and its degradation product aminomethylphosphonic acid in dairy cows.

    PubMed

    von Soosten, D; Meyer, U; Hüther, L; Dänicke, S; Lahrssen-Wiederholt, M; Schafft, H; Spolders, M; Breves, G

    2016-07-01

    From 6 balance experiments with total collection of feces and urine, samples were obtained to investigate the excretion pathways of glyphosate (GLY) in lactating dairy cows. Each experiment lasted for 26d. The first 21d served for adaptation to the diet, and during the remaining 5d collection of total feces and urine was conducted. Dry matter intake and milk yield were recorded daily and milk and feed samples were taken during the sampling periods. In 2 of the 6 experiments, at the sampling period for feces and urine, duodenal contents were collected for 5d. Cows were equipped with cannulas at the dorsal sac of the rumen and the proximal duodenum. Duodenal contents were collected every 2h over 5 consecutive days. The daily duodenal dry matter flow was measured by using chromium oxide as a volume marker. All samples (feed, feces, urine, milk and duodenal contents were analyzed for GLY and aminomethylphosphonic acid (AMPA). Overall, across the 6 experiments (n=32) the range of GLY intake was 0.08 to 6.67mg/d. The main proportion (61±11%; ±SD) of consumed GLY was excreted with feces; whereas excretion by urine was 8±3% of GLY intake. Elimination via milk was negligible. The GLY concentrations above the limit of quantification were not detected in any of the milk samples. A potential ruminal degradation of GLY to AMPA was derived from daily duodenal GLY flow. The apparent ruminal disappearance of GLY intake was 36 and 6%. In conclusion, the results of the present study indicate that the gastrointestinal absorption of GLY is of minor importance and fecal excretion represents the major excretion pathway. A degradation of GLY to AMPA by rumen microbes or a possible retention in the body has to be taken into account.

  17. Sex-related differences in urinary excretion of egualen sodium in rats.

    PubMed

    Sato, M; Suzaka, H; Miyazaki, H

    2000-01-01

    Egualen sodium (sodium 3-ethyl-7-isopropyl-1-azulenesulfonate 1/3 hydrate) is a new antiulcer drug. There has been no difference observed in absorption between male and female rats, the relative amount of metabolites in male plasma has been higher than that in females, and the excretion ratios of metabolites in males have been significantly higher than those in females. However, the plasma concentration profile of total radioactivity in males has been higher than that in females. To clarify this discrepancy, the renal clearances and plasma concentrations of the unchanged drug and its metabolites were determined. The renal clearance of the unchanged drug in males was 21 times lower than that in females, and the urinary excretions in males and females were 2.1 and 39.5% of dose, respectively. This indicates that the major factor in the sex-related difference observed in the plasma concentration of total radioactivity is due to the difference in the renal clearance of the unchanged drug between the sexes. The results of treatments with probenecid in normal and gonadectomized rats revealed that egualen sodium was mainly excreted into urine by secretion through the renal tubule. Furthermore, the results of treatments with testosterone in rats revealed that the excretion of egualen sodium was highly affected by androgens. These facts indicated that the sex-related difference observed in the plasma concentration of total radioactivity can be attributed to the inhibition of renal tubular secretion of the unchanged drug by androgens. This is the first example of sex-related differences in both metabolism and excretion.

  18. Excretion of Human Immunodeficiency Virus Type 1 through Polarized Epithelium by Immunoglobulin A▿

    PubMed Central

    Wright, Alison; Lamm, Michael E.; Huang, Yung T.

    2008-01-01

    Human immunodeficiency virus (HIV) is transmitted primarily sexually across mucosal surfaces. After infection, HIV propagates initially in the lamina propria below the polarized epithelium and causes extensive destruction of mucosal T cells. Immunoglobulin A (IgA) antibodies, produced in the lamina propria and then transcytosed across the mucosal epithelium into the lumen, can be the first line of immune defense against HIV. Here, we used IgA monoclonal antibodies against HIV envelope proteins to investigate the abilities of polarized primate and human epithelial cells to excrete HIV virions from the basolateral to the apical surface via polymeric Ig receptor (pIgR)-mediated binding and the internalization of HIV-IgA immune complexes. African green monkey kidney cells expressing pIgR demonstrated HIV excretion that was dependent on the IgA concentration and the exposure time. Matched IgG antibodies with the same variable regions as the IgA antibodies and IgA antibodies to non-HIV antigens had no HIV excretory function. A mixture of two IgA anti-bodies against gp120 and gp41 showed a synergistic increase in the level of HIV excreted. The capacity for HIV excretion correlated with the ability of IgA antibodies to bind HIV and of the resulting immune complexes to bind pIgR. Consistent with the epithelial transcytosis of HIV-IgA immune complexes, the colocalization of HIV proteins and HIV-specific IgA was detected intracellularly by confocal microscopy. Our results suggest the potential of IgA antibodies to excrete HIV from mucosal lamina propria, thereby decreasing the viral burden, access to susceptible cells, and the chronic activation of the immune system. PMID:18829757

  19. D-glucaric acid excretion in critical care patients--comparison with 6 beta-hydroxycortisol excretion and serum gamma-glutamyltranspeptidase activity and relation to multiple drug therapy.

    PubMed Central

    Heinemeyer, G; Roots, I; Lestau, P; Klaiber, H R; Dennhardt, R

    1986-01-01

    The incidence of increased drug metabolism activity as a consequence of multiple drug therapy at a surgical intensive care ward has been studied non-invasively by determinations of daily urinary D-glucaric acid (GA) excretion rates. Among 165 randomly selected patients, GA excretion was stimulated in 76 cases (= 46%). Exploratory data analysis showed that increases in GA excretion are primarily due to administration of barbiturates (pentobarbitone, Nembutal), miconazole (Daktar) and, to a lesser extent, neuroleptics. Surprisingly, the large number of simultaneously administered additional drugs failed to increase GA excretion. Urinary 6 beta-hydroxycortisol (6 beta-OHF) and 17-hydroxycorticosteroid (17-OHCS) excretion rates were correlated in 34 patients with GA excretion; patients not receiving known enzyme inducers showed low GA values but high 6 beta-OHF and 17-OHCS values, however, with a ratio of 6 beta-OHF/17-OHCS in the normal range. Patients receiving high dose pentobarbitone treatment failed to exhibit significantly increased 6 beta-OHF and 17-OHCS or 6 beta-OHF/17-OHCS values. Miconazole treatment resulted in a significantly increased ratio of 6 beta-OHF/17-OHCS. gamma-Glutamyltranspeptidase activity in serum showed no correlation with GA excretion (n = 91). PMID:2868749

  20. Excretion is Faster Than Diagenesis for Nutrient Recycling in Lake Michigan Benthos

    NASA Astrophysics Data System (ADS)

    Aguilar, C.; Cuhel, R. L.

    2013-12-01

    Regeneration of phytoplankton growth nutrients including ammonium (NH4+) and phosphate (HPO4=) occurs in aquatic systems worldwide through biogeochemical processes of diagenesis. Organic matter falling to the bottom accumulates in sediments, and bacterial decomposition removes oxygen from the sub-surface. Anaerobic metabolism is energetically inefficient, and bacteria a few cm below the surface respire or ferment organic matter into carbon dioxide or organic acids, excreting nitrogen (NH4+) or phosphorus inorganic 'waste'. Subsurface production of bacterial metabolic products often leads to sharp gradients in porewater concentrations of NH4+ and HPO4=, which drive diffusive flux out of the sediments into overlying water. Aquatic systems with totally aerobic water overlying anoxic sediment (e.g., Lake Michigan) have muted efflux of certain inorganic nutrients arising from organic matter decomposition. For example, NH4+ is oxidized to nitrate in the upper few mm of surficial sediments by nitrifying bacteria. Strong subsurface porewater gradients, especially of redox- or geochemically-reactive compounds, often decline to low values well below the sediment-water interface, indicating transformation by sediment bacterial populations, or by purely geochemical processes such as calcium hydroxyphosphate (apatite) precipitation. For these, little flux to the water column occurs. In Lake Michigan, neither NH4+ nor HPO4= escapes substantially from the biogeochemical barriers between their diagenetic sources and overlying waters, either before or after ecosystem alteration by invasive quagga mussels (QM). Silicate and total CO2 evade unimpeded in the same cores. The organic matter deposited from the water column is also the nutrition of benthic bivalve filter feeders such as QM in Lake Michigan, or the Asian Clam in San Francisco Bay. In animal metabolism for energy production, only the carbon component is oxidized through respiration, with NH4+ (from protein) and HPO4= (from

  1. Response of urinary purine derivatives excretion to different levels of ruminal glucose infusion in heifers.

    PubMed

    Dickhoefer, Uta; Ahnert, Sandra; Schoof, Hartwig; Moritz, Niels; Susenbeth, Andreas

    2015-01-01

    This study investigated the response of urinary purine derivatives (PD) excretion to increasing levels of intraruminal glucose infusion to evaluate how well this indicator reflects induced changes in microbial crude protein flow. Four rumen-cannulated heifers (482 ± 25 kg body weight) were fed at maintenance energy level with a basal diet (on fresh matter basis) of 4 kg/d hay, 1.5 kg/d concentrate and 60 g/d minerals in two equal meals. The trial comprised a control period (Control I) without glucose infusion followed by four consecutive periods in which all animals received 125 g, 250 g, 500 g or 1000 g/d of glucose, respectively. For this, daily dosages of glucose and urea (90 g/d during all periods) were divided into three portions that were dissolved in water and directly administered into the rumen during morning and afternoon feedings and once during noon. After the highest glucose dosage, a second control period was carried out (Control II). Urinary PD excretion increased with glucose infusion of 125 g/d (71.4 mmol/d) and 1000 g/d (74.2 mmol/d) over the level at Control I (53.9 mmol/d (standard error of the mean (SEM) 3.4; p = 0.012). After withdrawing glucose infusion, PD excretion (79.0 mmol/d) did not return to Control I level (p = 0.001). In contrast, faecal nitrogen (N) excretions linearly increased with incremental glucose infusion (p < 0.001) from 33.9 g/d at Control I to 39.7 g/d (SEM 0.5) at 1000 g/d of glucose and were similar in Control I and II (p = 0.086). The contradicting responses in the excretions of faecal N and urinary PD to increasing glucose infusions highlight the limited accuracy of the PD excretion as a non-invasive indicator when incremental dosages of rapidly fermentable carbohydrates are supplied.

  2. Potassium citrate decreases urine calcium excretion in patients with hypocitraturic calcium oxalate nephrolithiasis.

    PubMed

    Song, Yan; Hernandez, Natalia; Shoag, Jonathan; Goldfarb, David S; Eisner, Brian H

    2016-04-01

    Two previous studies (<10 patients each) have demonstrated that alkali therapy may reduce urine calcium excretion in patients with calcium oxalate nephrolithiasis. The hypothesized mechanisms are (1) a decrease in bone turnover due to systemic alkalinization by the medications; (2) binding of calcium by citrate in the gastrointestinal tract; (3) direct effects on TRPV5 activity in the distal tubule. We performed a retrospective review of patients on potassium citrate therapy to evaluate the effects of this medication on urinary calcium excretion. A retrospective review was performed of a metabolic stone database at a tertiary care academic hospital. Patients were identified with a history of calcium oxalate nephrolithiasis and hypocitraturia who were on potassium citrate therapy for a minimum of 3 months. 24-h urine composition was assessed prior to the initiation of potassium citrate therapy and after 3 months of therapy. Patients received 30-60 mEq potassium citrate by mouth daily. Inclusion criterion was a change in urine potassium of 20 mEq/day or greater, which suggests compliance with potassium citrate therapy. Paired t test was used to compare therapeutic effect. Twenty-two patients were evaluated. Mean age was 58.8 years (SD 14.0), mean BMI was 29.6 kg/m(2) (SD 5.9), and gender prevalence was 36.4% female:63.6% male. Mean pre-treatment 24-h urine values were as follows: citrate 280.0 mg/day, potassium 58.7 mEq/day, calcium 216.0 mg/day, pH 5.87. Potassium citrate therapy was associated with statistically significant changes in each of these parameters-citrate increased to 548.4 mg/day (p < 0.0001), potassium increased to 94.1 mEq/day (p < 0.0001), calcium decreased to 156.5 mg/day (p = 0.04), pH increased to 6.47 (p = 0.001). Urine sodium excretion was not different pre- and post-therapy (175 mEq/day pre-therapy versus 201 mEq/day post-therapy, p = NS). Urinary calcium excretion decreased by a mean of 60 mg/day on potassium citrate therapy-a nearly 30

  3. Diurnal fluctuations in nematode egg excretion in naturally and in experimentally infected chickens.

    PubMed

    Wongrak, Kalyakorn; Gauly, Matthias; Daş, Gürbüz

    2015-03-15

    We investigated whether nematode egg excretion through feces of naturally or experimentally infected chickens follow certain patterns within a day, which may allow determining the most appropriate sampling time for the highest parasite egg concentration. Feces samples (n=864) from chickens (n=36) with naturally occurring mixed nematode infections (trials N1, N2) or with an experimental Ascaridia galli infection (E) were collected quantitatively every 4h for four consecutive days. Number of eggs per gram of feces (EPG) was determined, and accumulative egg output (AEO) at each sampling time as well as total number of eggs excreted within 24h (eggs per day, EPD) were then estimated. At the end of the collection period, the hens were necropsied and their worm burdens determined. Naturally infected hens harbored Heterakis gallinarum (100%), Capillaria spp. (95.7%) and A. galli (91.3%). The experimental A. galli infection produced patent infections in all the birds. In general, both fecal egg concentration (EPG) and the amount of feces increased (P<0.05) sharply from the early morning to early-noon (10:00 a.m.) and remained at a high level until evenings which thereafter decreased to their initial levels during the night both in naturally and experimentally infected birds. This resulted in a more apparent increase or a decrease in AEO at the corresponding time points, respectively, and led to much higher egg excretions during the daytime than the nights. Despite the apparent within day fluctuations in egg excretion, neither EPG (P=0.704) nor AEO (P=0.499) nor EPD (P=0.149) was significantly different among the four collection days. Similarly, there was no significant interaction (P>0.05) between effects of sampling hours and days on EPG and AEO, suggesting the existence of repeatable diurnal fluctuations within each day. Although an association between climatic parameters (e.g., ambient temperature and relative humidity) and the nematode egg excretion was quantified, a

  4. A synergistic effect of oxytocin and vasopressin on sodium excretion in the neurohypophysectomized rat.

    PubMed Central

    Balment, R J; Brimble, M J; Forsling, M L; Kelly, L P; Musabayane, C T

    1986-01-01

    1. Renal function and the effect of oxytocin and vasopressin replacement have been examined in anaesthetized male neurohypophysectomized rats. 2. Rates of urine flow were higher but sodium excretion markedly lower in neurohypophysectomized rats than in intact animals receiving hypotonic saline infusion (33.8 +/- 2.3 vs. 27.0 +/- 0.7 ml and 472 +/- 84 vs. 1946 +/- 124 mumol respectively for the third to sixth hour of study). 3. In intact animals, mean arterial blood pressure stabilized at 106 mmHg. Haematocrit (46%) remained stable but glomerular filtration rates declined slightly over the 8 h of study to 2.5 +/- 0.2 ml/h. These values in neurohypophysectomized rats did not differ significantly from those in intact rats. 4. Although plasma corticosterone levels (54 +/- 13 ng/ml) did not differ significantly from those in intact rats, neurohypophysectomy was associated with greatly reduced aldosterone concentration (0.12 +/- 0.03 vs. 0.76 +/- 0.04 ng/ml). Trace levels of vasopressin (0.17 +/- 0.03 microunit/ml) were found in neurohypophysectomized rat plasma. 5. Oxytocin administration at 15 microunits/min, which produced plasma hormone levels of 1.62 +/- 0.19 microunit/ml, had no detectable effect on sodium excretion but increased urine flow. Arginine vasopressin administration (12 microunits/min) inducing plasma levels of 1.24 +/- 0.08 microunit/ml, reduced urine flow by 80% and produced a small increase in sodium excretion. 6. Concurrent administration of oxytocin (15 microunits/min) potentiated the natriuretic response to vasopressin (12 microunits/min). Total sodium excretion during the 3 h combined hormone infusion (1256 +/- 149 mumol) greatly exceeded that in animals receiving vasopressin alone (549 +/- 132 mumol) and approached that observed in intact animals (1946 +/- 124 mumol). Combined hormone administration at the lower rate of 5 microunits/min oxytocin and 4 microunits/min vasopressin produced a similar large increment in sodium excretion. 7. It is

  5. Tissue dosimetry, metabolism and excretion of pentavalent and trivalent monomethylated arsenic in mice after oral administration

    PubMed Central

    Hughes, Michael F.; Devesa, Vicenta; Adair, Blakely M.; Styblo, Miroslav; Kenyon, Elaina M.; Thomas, David J.

    2008-01-01

    Exposure to monomethylarsonic acid (MMA(V)) and monomethylarsonous acid (MMA(III)) can result from their formation as metabolites of inorganic arsenic and by the use of the sodium salts of MMA(V) as herbicides. This study compared the disposition of MMA(V) and MMA(III) in adult female B6C3F1 mice. Mice were gavaged po with MMA(V), either unlabeled or labeled with 14C at two dose levels (0.4 or 40 mg As/kg). Other mice were dosed po with unlabeled MMA(III) at one dose level (0.4 mg As/kg). Mice were housed in metabolism cages for collection of excreta and sacrificed serially over 24 h for collection of tissues. MMA(V)-derived radioactivity was rapidly absorbed, distributed and excreted. By 8 h post-exposure, 80% of both doses of MMA(V) were eliminated in urine and feces. Absorption of MMA(V) was dose dependent; that is, there was less than a 100-fold difference between the two dose levels in the area under the curves for the concentration-time profiles of arsenic in blood and major organs. In addition, urinary excretion of MMA(V)-derived radioactivity in the low dose group was significantly greater (P < 0.05) than in the high dose group. Conversely, fecal excretion of MMA(V)-derived radioactivity was significantly greater (P < 0.05) in the high dose group than in the low dose group. Speciation of arsenic by hydride generation-atomic absorption spectrometry in urine and tissues of mice administered MMA(V) or MMA(III) found that methylation of MMA(V) was limited while the methylation of MMA(III) was extensive. Less than 10% of the dose excreted in urine of MMA(V)-treated mice was in the form of methylated products, whereas it was greater than 90% for MMA(III)-treated mice. In MMA(V)-treated mice, 25% or less of the tissue arsenic was in the form of dimethylarsenic, whereas in MMA(III)-treated mice, 75% or more of the tissue arsenic was in the form of dimethylarsenic. Based on urinary analysis, administered dose of MMA(V) did not affect the level of its metabolites

  6. Prevalence of Eimeria bovis and Eimeria zuernii in German cattle herds and factors influencing oocyst excretion.

    PubMed

    Bangoura, Berit; Mundt, Hans-Christian; Schmäschke, Ronald; Westphal, Bernhard; Daugschies, Arwid

    2011-08-01

    The present study was designed to investigate the prevalence of the pathogenic coccidia species E. bovis and E. zuernii in shed-reared animals in German dairy and fattening facilities.Samples were obtained from 65 cattle farms distributed randomly across all the regions of Germany, regardless of the occurrence of clinical problems. The samples were obtained rectally. Faecal consistency and the total number of oocysts per gram of faeces (OPG) were determined for Eimeria spp., along with the separate OPG values for Eimeria (E.) bovis and E. zuernii. A questionnaire was completed for each farm to record information about herd size and management together with individual animal data. Eimeria oocysts, regardless of the kind of Eimeria spp., were detected in 62 of these farms, which gives a prevalence of 95.4 %. The farm prevalence of the pathogenic species was 76.9 % for E. bovis and 83.1 % for E. zuernii. The average oocyst excretion level was 2,950 OPG in terms of total Eimeria spp. oocyst excretion, 700 OPG for E. bovis and 1,500 OPG for E. zuernii.The number of oocysts excreted could not be correlated significantly with farm type or farm management but depended on the floor type which influences the infection pressure, on the age of the calves and the time after rehousing. In general, higher oocyst excretion rates were found in calves kept on litter compared to rearing on slatted floor. Younger calves and calves sampled early after housing shed higher amounts of oocysts than older calves and calves stabled a longer period before sampling, respectively. Furthermore, there was a positive correlation between OPG and the observation of diarrhoea, defined as observation of a loose to liquid faecal consistency. Excretion of E. zuernii oocysts was more closely linked to the occurrence of diarrhoea than E. bovis oocyst excretion. This study confirms that the pathogenic coccidia E. bovis and E. zuernii are ubiquitous in German cattle populations and a significant cause of

  7. 40 CFR Table Jj-3 to Subpart Jj of... - State-Specific Volatile Solids (VS) and Nitrogen (N) Excretion Rates for Cattle

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) and Nitrogen (N) Excretion Rates for Cattle JJ Table JJ-3 to Subpart JJ of Part 98 Protection of... Volatile Solids (VS) and Nitrogen (N) Excretion Rates for Cattle State Volatile solids excretion rate (kg VS/day/1000 kg animal mass) Dairy cows Dairy heifers Feedlot steer Feedlot heifers Nitrogen...

  8. 40 CFR Table Jj-3 to Subpart Jj of... - State-Specific Volatile Solids (VS) and Nitrogen (N) Excretion Rates for Cattle

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) and Nitrogen (N) Excretion Rates for Cattle JJ Table JJ-3 to Subpart JJ of Part 98 Protection of... REPORTING Manure Management Pt. 98, Subpt. JJ, Table JJ-3 Table JJ-3 to Subpart JJ of Part 98—State-Specific Volatile Solids (VS) and Nitrogen (N) Excretion Rates for Cattle State Volatile solids excretion rate...

  9. Genetic manipulation of a metabolic enzyme and a transcriptional regulator increasing succinate excretion from unicellular cyanobacterium.

    PubMed

    Osanai, Takashi; Shirai, Tomokazu; Iijima, Hiroko; Nakaya, Yuka; Okamoto, Mami; Kondo, Akihiko; Hirai, Masami Y

    2015-01-01

    Succinate is a building block compound that the U.S. Department of Energy (DOE) has declared as important in biorefineries, and it is widely used as a commodity chemical. Here, we identified the two genes increasing succinate production of the unicellular cyanobacterium Synechocystis sp. PCC 6803. Succinate was excreted under dark, anaerobic conditions, and its production level increased by knocking out ackA, which encodes an acetate kinase, and by overexpressing sigE, which encodes an RNA polymerase sigma factor. Glycogen catabolism and organic acid biosynthesis were enhanced in the mutant lacking ackA and overexpressing sigE, leading to an increase in succinate production reaching five times of the wild-type levels. Our genetic and metabolomic analyses thus demonstrated the effect of genetic manipulation of a metabolic enzyme and a transcriptional regulator on succinate excretion from this cyanobacterium with the data based on metabolomic technique.

  10. L-carnitine enhances excretion of propionyl coenzyme A as propionylcarnitine in propionic acidemia.

    PubMed Central

    Roe, C R; Millington, D S; Maltby, D A; Bohan, T P; Hoppel, C L

    1984-01-01

    Treatment with L-carnitine greatly enhanced the formation and excretion of short-chain acylcarnitines in three patients with propionic acidemia and in three normal controls. The use of fast atom bombardment mass spectrometry and linked scanning at constant magnetic (B) to electric (E) field ratio identified the acylcarnitine as propionylcarnitine in patients with propionic acidemia. The normal children excreted mostly acetylcarnitine. Propionic acidemia and other organic acidurias are characterized by the intramitochondrial accumulation of short-chain acyl-Coenzyme A (CoA) compounds. The substrate specificity of the carnitine acetyltransferase enzyme and its steady state nature appears to facilitate elimination of propionyl groups while restoring the acyl-CoA:free CoA ratio in the mitochondrion. We suggest that L-carnitine may be a useful therapeutic approach for elimination of toxic acyl CoA compounds in several of these disorders. PMID:6725560

  11. Genetic manipulation of a metabolic enzyme and a transcriptional regulator increasing succinate excretion from unicellular cyanobacterium

    PubMed Central

    Osanai, Takashi; Shirai, Tomokazu; Iijima, Hiroko; Nakaya, Yuka; Okamoto, Mami; Kondo, Akihiko; Hirai, Masami Y.

    2015-01-01

    Succinate is a building block compound that the U.S. Department of Energy (DOE) has declared as important in biorefineries, and it is widely used as a commodity chemical. Here, we identified the two genes increasing succinate production of the unicellular cyanobacterium Synechocystis sp. PCC 6803. Succinate was excreted under dark, anaerobic conditions, and its production level increased by knocking out ackA, which encodes an acetate kinase, and by overexpressing sigE, which encodes an RNA polymerase sigma factor. Glycogen catabolism and organic acid biosynthesis were enhanced in the mutant lacking ackA and overexpressing sigE, leading to an increase in succinate production reaching five times of the wild-type levels. Our genetic and metabolomic analyses thus demonstrated the effect of genetic manipulation of a metabolic enzyme and a transcriptional regulator on succinate excretion from this cyanobacterium with the data based on metabolomic technique. PMID:26500619

  12. Clinical features of two cases of Legionnaires' disease with persistence of Legionella urinary antigen excretion.

    PubMed

    Higa, Futoshi; Fujita, Jiro; Koide, Michio; Haranaga, Shusaku; Tateyama, Masao

    2008-01-01

    The advantages of diagnosing legionellosis by urinary antigen detection are widely recognized, and include early detection, rapidity of testing, and ease of specimen collection. However, the persistence of Legionella urinary antigen excretion has been suggested in some selected patients, although the clinical features of these patients have not yet been clearly described. Here, we describe the clinical features of two patients with Legionnaires' disease with persistence of Legionella urinary antigen excretion (117 days and 247 days). One patient had an underlying disease, adult T-cell leukemia, and the other patient had ulcerative colitis and was receiving oral corticosteroids. Unusual clinical and radiological findings as well as a review of the literature are presented.

  13. A new model of reverse cholesterol transport: enTICEing strategies to stimulate intestinal cholesterol excretion.

    PubMed

    Temel, Ryan E; Brown, J Mark

    2015-07-01

    Cardiovascular disease (CVD) remains the largest cause of mortality in most developed countries. Although recent failed clinical trials and Mendelian randomization studies have called into question the high-density lipoprotein (HDL) hypothesis, it remains well accepted that stimulating the process of reverse cholesterol transport (RCT) can prevent or even regress atherosclerosis. The prevailing model for RCT is that cholesterol from the artery wall must be delivered to the liver where it is secreted into bile before leaving the body through fecal excretion. However, many studies have demonstrated that RCT can proceed through a non-biliary pathway known as transintestinal cholesterol excretion (TICE). The goal of this review is to discuss the current state of knowledge of the TICE pathway, with emphasis on points of therapeutic intervention.

  14. Experimental Aujeszky's disease in pigs: excretion, survival and transmission of the virus.

    PubMed

    Donaldson, A I; Wardley, R C; Martin, S; Ferris, N P

    1983-11-19

    Airborne Aujeszky's disease virus was recovered from looseboxes containing groups of pigs infected with virus strains from England, Northern Ireland and Denmark from days 1 to 7 after infection. Pigs sampled individually excreted most airborne virus on days 2 and 3 after infection. On a 24 hour basis the maximum amount of airborne virus excreted per pig was log10 5.3 TCID50. Subclinical infection was transmitted from a clinically affected group of pigs to a seronegative group held in separate looseboxes when air was drawn through ducting connecting one box with the other. Tissues taken from pigs killed at varying times after infection showed that the main sites of virus replication were in the head and neck region. Aujeszky's disease virus was detected for up to 40 days in a range of tissues taken from pigs at the acute stage of disease and stored at -20 degrees C.

  15. Comparison of the absorption, excretion, and metabolism of suxibuzone and phenylbutazone in humans.

    PubMed

    Yasuda, Y; Shindo, T; Mitani, N; Ishida, N; Oono, F; Kageyama, T

    1982-05-01

    The absorption, excretion, and metabolism of a single oral dose of suxibuzone, a new nonsteroidal anti-inflammatory agent, in healthy male volunteers were compared with those of phenylbutazone. After oral administration of either suxibuzone or phenylbutazone, phenylbutazone, oxyphenbutazone, and gamma-hydroxyphenylbutazone were found in the plasma; phenylbutazone was the main metabolite of suxibuzone and phenylbutazone. In the urine, p-gamma-dihydroxyphenylbutazone and several glucuronide conjugates also were found. Spectrometric and/or enzymatic analysis showed that these glucuronide conjugates were suxibuzone glucuronide, 4-hydroxymethylphenylbutazone glucuronide, 4-hydroxymethyloxyphenbutazone glucuronide, oxyphenbutazone glucuronide, and phenylbutazone glucuronides (two types: O-glucuronide and C-4-glucuroxide) after suxibuzone administration, and oxyphenbutazone glucuronide and phenylbutazone glucuronide after phenylbutazone administration. The conjugates specific to suxibuzone administration, suxibuzone glucuronide, 4-hydroxymethylphenylbutazone glucuronide, and 4-hydroxymethyloxyphenbutazone glucuronide, were excreted in the first 6 hr urine. These findings and the pharmacokinetics of these metabolites in the plasma and urine show that suxibuzone is a prodrug of phenylbutazone.

  16. Regulatory Mutations of Inositol Biosynthesis in Yeast: Isolation of Inositol-Excreting Mutants

    PubMed Central

    Greenberg, Miriam L.; Reiner, Barry; Henry, Susan A.

    1982-01-01

    The enzyme inositol-1-phosphate synthase (I-1-P synthase), product of the INO1 locus, catalyzes the synthesis of inositol-1-phosphate from the substrate glucose-6-phosphate. The activity of this enzyme is dramatically repressed in the presence of inositol. By selecting for mutants which overproduce and excrete inositol, we have identified mutants constitutive for inositol-1-phosphate synthase as well as a mutation in phospholipid biosynthesis. Genetic analysis of the mutants indicates that at least three loci (designated OPI1, OPI2 and OPI4) direct inositol-mediated repression of I-1-P synthase. Mutants of these loci synthesize I-1-P synthase constitutively. Three loci are unlinked to each other and to INO1, the structural gene for the enzyme. A mutant of a fourth locus, OPI3, does not synthesize I-1-P synthase constitutively, despite its inositol excretion phenotype. This mutant is preliminarily identified as having a defect in phospholipid synthesis. PMID:7047296

  17. No evidence of rat hepatitis E virus excretion into urine of rats.

    PubMed

    Li, Tian-Cheng; Yoshizaki, Sayaka; Ami, Yasushi; Suzaki, Yuriko; Johne, Reimar; Wakita, Takaji

    2016-08-31

    To investigate whether rat hepatitis E virus (rat HEV) is excreted into the urine of rats, we infected three Wistar and six nude rats with rat HEV and examined the rat HEV RNA in serum, fecal and urine samples. We detected rat HEV RNA in the serum and fecal samples of all rats but not in the urine. Our results suggest that in rats, rat HEV is not transmitted via urine.

  18. Discontinuous ammonia excretion and glutamine storage in littoral Oniscidea (Crustacea: Isopoda): testing tidal and circadian models.

    PubMed

    Nakamura, Maya; Wright, Jonathan C

    2013-01-01

    A key evolutionary development facilitating land colonization in terrestrial isopods (Isopoda: Oniscidea) is the intermittent liberation of waste nitrogen as volatile ammonia. Intermittent ammonia release exploits glutamine (Gln) as an intermediary nitrogen store. Here, we explore the relationship between temporal patterns of ammonia release and Gln accumulation in three littoral oniscideans from Southern California. Results are interpreted in terms of water availability, habitat, activity patterns, and ancestry. A two-way experimental design was used to test whether ammonia excretion and Gln accumulation follow a tidal or diel periodicity. Ammonia excretion was studied in the laboratory using chambers with or without available seawater and using an acid trap to collect volatile ammonia. Ligia occidentalis releases ammonia directly into seawater and accumulates Gln during low tide (48.9 ± 6.5 μmol g⁻¹ at low tide, 24.1 ± 3.0 μmol g⁻¹ at high tide), indicating that excretion is tidally constrained. Alloniscus perconvexus and Tylos punctatus can excrete ammonia directly into seawater or utilize volatilization. Both species burrow in sand by day and show a diel excretory pattern, accumulating Gln nocturnally (31.8 ± 2.7 μmol g⁻¹ at dawn and 21.8 ± 2.3 μmol g⁻¹ at dusk for A. perconvexus; 85.7 ± 15.1 μmol g⁻¹ at dawn and 25.4 ± 2.9 μmol g⁻¹ at dusk for T. punctatus) and liberating ammonia diurnally. Glutaminase shows higher activity in terrestrial (0.54-0.86 U g⁻¹) compared to intertidal (0.25-0.31 U g⁻¹) species, consistent with the need to generate high PNH₃ for volatilization. The predominant isoform in Armadillidium vulgare is phosphate dependent and maleate independent; phosphate is a plausible regulator in vivo.

  19. Urinary excretion of cortisol from rhesus monkeys (Macaca mulatta) habituated to restraint

    NASA Technical Reports Server (NTRS)

    Wade, C. E.; Ortiz, R. M.

    1997-01-01

    Use of monkeys in research has often required that they be restrained in a chair. However, chair restraint can elicit an initial neuroendocrine stress response. Also, inactivity associated with restraint can induce muscular atrophy. We proposed that prior habituation of monkeys to chair restraint would attenuate these neuroendocrine responses without causing substantial muscle wasting. Four rhesus monkeys (Macaca mulatta) were trained and habituated to a restraint chair specifically designed for spaceflight. During the study, monkeys were placed in metabolic cages for 7 days (prerestraint, Phase I), placed in a chair restraint for 18 days (Phase II), and then returned to their metabolic cages for 5 days (postrestraint, Phase III). Urine was collected between 0700-1100 daily, and measurements of cortisol, creatinine, and electrolyte concentrations were adjusted for hourly excretion rates. Body weights of the monkeys did not change between start of the prerestraint and postrestraint phases (10.3 +/- 0.8 vs. 10.3 +/- 0.9 kg, respectively). During the 3 phases, mean excretion rate of cortisol did not change (24.1 +/- 10.3, 26.7 +/- 7.7, and 19.3 +/- 5.8 microg/h, respectively). Mean excretion rate of creatinine (37.3 +/- 7.5, 37.5 +/- 12.2, and 36.9 +/- 17.1 mg/h, respectively), Na+ (3.3 +/- 1.2, 3.2 +/- 1.2, 2.2 +/- 1.8 mmol/h, respectively), and K+ (5.3 +/- 1.8, 5.4 +/- 1.6, and 4.3 +/- 2.8 mmol/h, respectively) were also not altered. Lack of an increase in excreted urinary cortisol suggested that prior habituation to chair restraint attenuated neuroendocrine responses reported previously. Also, the chair restraint method used appeared to allow adequate activity, because the monkeys did not have indices of muscle wasting.

  20. Vitamin D repletion does not alter urinary calcium excretion in healthy postmenopausal women

    PubMed Central

    Penniston, Kristina L.; Jones, Andrea N.; Nakada, Stephen Y.; Hansen, Karen E.

    2009-01-01

    Objective To evaluate, in a posthoc analysis of a previous study, whether vitamin D repletion in postmenopausal women with insufficient vitamin D increases urinary calcium excretion, as vitamin D therapy might contribute to hypercalciuria and calcium stones in susceptible individuals, and the effect of vitamin D on the risk of urolithiasis warrants attention. Subjects and methods We recruited 18 women at ≥ 5 years after menopause who had vitamin D insufficiency (serum 25(OH)-vitamin D, 16–24 mg/dL). We excluded women with a history of urolithiasis and kidney disease. Women had one calcium absorption study when vitamin D-insufficient, received vitamin D therapy, and completed a second calcium absorption study when vitamin D-replete. We fed subjects meals that mirrored the nutrient composition from self-reported 7-day diet diaries. To measure calcium absorption, we collected urine for 24 h during both visits. Results We achieved vitamin D repletion in all women (25(OH)-vitamin D before and after treatment, 22 and 63 mg/dL, respectively; P < 0.001). The mean calcium intake was 832 mg/day. Residual urine specimens were available for 16 women, allowing a measurement of 24-h urinary calcium. Calcium excretion did not change after vitamin D therapy (212 before vs 195 mg/day after; P = 0.60). Of four women with hypercalciuria (> 247 mg/day), calcium excretion decreased in three (377–312 mg/day, not significant). Conclusion Vitamin D supplementation did not increase the urinary calcium excretion in healthy postmenopausal women. Many stone formers are at risk of premature bone loss, vitamin D insufficiency, or both. Based on the present results we suggest a study of patients with hypercalciuria and nephrolithiasis to determine the risks of vitamin D therapy. PMID:19389005

  1. Relative lung and systemic bioavailability of sodium cromoglycate inhaled products using urinary drug excretion post inhalation.

    PubMed

    Aswania, Osama; Chrystyn, Henry

    2002-05-01

    The relative lung and systemic bioavailability of sodium cromoglycate following inhalation by different methods have been determined using a urinary excretion pharmacokinetic method. On three separate randomised study days, 7 days apart, subjects inhaled (i) 4x5 mg from an Intal metered dose inhaler (MDI), (ii) 4x5 mg from an MDI attached to a large volume spacer (MDI+SP) and (iii) 20 mg from an Intal Spinhaler (DPI). Urine samples were provided at 0, 0.5, 1, 2, 5 and 24 h post dose. The mean (S.D.) amount of sodium cromoglycate excreted in the urine during the first 30 min post inhalation was 38.1 (27.5), 222.3 (120.3) and 133.1 (92.2) microg following MDI, MDI+SP and DPI, respectively. The mean ratio (90% confidence interval) of these amounts excreted in the urine over the first 30 min for MDI+SP vs. MDI, DPI vs. MDI and MDI+SP vs. DPI was 801.0 (358.0, 1244; p<0.002)%, 457.0 (244.0, 670.0; p<0.02)% and 262.4 (110.2, 414.5)%, respectively. Similarly for the 24 h cumulative amount of sodium cromoglycate excreted over the 24 h post inhalation the ratios were 375.4 (232.9, 517.9; p<0.005)%, 287.5 (183.4, 391.6; p<0.02)% and 211.4 (88.3, 334.5)%, respectively. The results highlight better lung deposition of sodium cromoglycate from a metered dose inhaler attached to a large volume spacer.

  2. Lamprey parasitism of sharks and teleosts: high capacity urea excretion in an extant vertebrate relic.

    PubMed

    Wilkie, Michael P; Turnbull, Steven; Bird, Jonathan; Wang, Yuxiang S; Claude, Jaime F; Youson, John H

    2004-08-01

    We observed 10 sea lampreys (Petromyzon marinus) parasitizing basking sharks (Cetorhinus maximus), the world's second largest fish, in the Bay of Fundy. Due to the high concentrations of urea in the blood and tissues of ureosmotic elasmobranchs, we hypothesized that sea lampreys would have mechanisms to eliminate co-ingested urea while feeding on basking sharks. Post-removal urea excretion rates (J(Urea)) in two lampreys, removed from separate sharks by divers, were initially 450 ( approximately 9000 micromol N kg-1 h-1) and 75 times ( approximately 1500 micromol N kg-1 h-1) greater than basal (non-feeding) rates ( approximately 20 micromol N kg-1 h-1). In contrast, J(Urea) increased by 15-fold after parasitic lampreys were removed from non-ureosmotic rainbow trout (Oncorhynchus mykiss). Since activities of the ornithine urea cycle (OUC) enzymes, carbamoyl phosphate synthetase III (CPSase III) and ornithine carbamoyl transferase (OCT) were relatively low in liver and below detection in intestine and muscle, it is unlikely that the excreted urea arose from de novo urea synthesis. Measurements of arginase activity suggested that hydrolysis of dietary arginine made a minor contribution to J(Urea.). Post-feeding ammonia excretion rates (J(Amm)) were 15- to 25-fold greater than basal rates in lampreys removed from both basking sharks and rainbow trout, suggesting that parasitic lampreys have a high capacity to deaminate amino acids. We conclude that the sea lamprey's ability to penetrate the dermal denticle armor of sharks, to rapidly excrete large volumes of urea and a high capacity to deaminate amino acids, represent adaptations that have contributed to the evolutionary success of these phylogenetically ancient vertebrates.

  3. Correlation between sodium and potassium excretion in 24- and 12-h urine samples.

    PubMed

    Mill, J G; Silva, A B T da; Baldo, M P; Molina, M C B; Rodrigues, S L

    2012-09-01

    Low-sodium and high-potassium diets have been recommended as an adjunct to prevention and treatment of hypertension. Analysis of these nutrients in 24-h urine has been considered the reference method to estimate daily intake of these minerals. However, 24-h urine collection is difficult in epidemiological studies, since urine must be collected and stored in job environments. Therefore, strategies for shorter durations of urine collection at home have been proposed. We have previously reported that collecting urine during a 12-h period (overnight) is more feasible and that creatinine clearance correlated strongly with that detected in 24-h samples. In the present study, we collected urine for 24 h divided into two 12-h periods (from 7:00 am to 7:00 pm and from 7:00 pm to 7:00 am next day). A sample of 109 apparently healthy volunteers aged 30 to 74 years of both genders working in a University institution was investigated. Subjects with previous myocardial infarction, stroke, renal insufficiency, and pregnant women were not included. Significant (P < 0.001) Spearman correlation coefficients (r s) were found between the total amount of sodium and potassium excreted in the urine collected at night and in the 24-h period (r s = 0.76 and 0.74, respectively). Additionally, the 12-h sodium and potassium excretions (means ± SD, 95% confidence interval) corresponded to 47.3 ± 11.2%, 95%CI = 45.3-49.3, and 39.3 ± 4.6%, 95%CI = 37.3-41.3, respectively, of the 24-h excretion of these ions. Therefore, these findings support the assumption that 12-h urine collected at night can be used as a reliable tool to estimate 24-h intake/excretion of sodium and potassium.

  4. Comparative effects of chelating agents on distribution, excretion, and renal toxicity of inorganic mercury in rats

    SciTech Connect

    Kojima, S.; Shimada, H.; Kiyozumi, M. )

    1989-06-01

    The effects of three chelating agents, sodium N-benzyl-D-glucamine dithiocarbamate(NBG-DTC), 2,3-dimercaptopropanol(BAL), and D-penicillamine(D-PEN), on the distribution, excretion, and renal toxicity of inorganic mercury were compared in rats exposed to HgCl2. Rats were injected i.p. with 203HgCl2 (300 micrograms of Hg and 2 microCi of 203Hg/kg) and 30 min or 24 h later they were injected with a chelating agent (a quarter of an LD50). The injection of the chelating agents significantly enhanced the biliary and urinary excretions of mercury. BAL was the most effective for removal of mercury from the body at 30 min after mercury treatment. The extent of enhancing effect of the chelating agents for removal of mercury at 24 h after mercury was in the order NBG-DTC = BAL greater than D-PEN. The injection of BAL at 24 h after mercury treatment caused the redistribution of mercury to the heart and lung. NBG-DTC did not result in the redistribution of mercury to the heart, lung, and brain. Urinary excretion of protein and AST significantly increased 24-48 h after mercury treatment and decreased to the control values 72 h after mercury. The injection of the chelating agents at 30 min after mercury treatment significantly decreased the urinary excretion of protein and AST. In rats pretreated with mercury 24 h earlier, the chelating agents significantly decreased the urinary protein at 48 h after mercury treatment, but did not decrease the urinary AST. The results of this study indicate that the chelating agents are effective in removing mercury from the body, resulting in the protective effect against the mercury-induced renal damage.

  5. Urinary excretion of uranium in adult inhabitants of the Czech Republic.

    PubMed

    Malátová, Irena; Bečková, Věra; Kotík, Lukáš

    2016-02-01

    The main aim of this study was to determine and evaluate urinary excretion of uranium in the general public of the Czech Republic. This value should serve as a baseline for distinguishing possible increase in uranium content in population living near legacy sites of mining and processing uranium ores and also to help to distinguish the proportion of the uranium content in urine among uranium miners resulting from inhaled dust. The geometric mean of the uranium concentration in urine of 74 inhabitants of the Czech Republic was 0.091 mBq/L (7.4 ng/L) with the 95% confidence interval 0.071-0.12 mBq/L (5.7-9.6 ng/L) respectively. The geometric mean of the daily excretion was 0.15 mBq/d (12.4 ng/d) with the 95% confidence interval 0.12-0.20 mBq/d (9.5-16.1 ng/d) respectively. Despite the legacy of uranium mines and plants processing uranium ore in the Czech Republic, the levels of uranium in urine and therefore, also human body content of uranium, is similar to other countries, esp. Germany, Slovenia and USA. Significant difference in the daily urinary excretion of uranium was found between individuals using public supply and private water wells as a source of drinking water. Age dependence of daily urinary excretion of uranium was not found. Mean values and their range are comparable to other countries, esp. Germany, Slovenia and USA.

  6. Urinary trimethylselenonium excretion by the rat: effect of level and source of /sup 75/Se

    SciTech Connect

    Nahapetian, A.T.; Janghorbani, M.; Young, V.R.

    1983-02-01

    The purpose of this study was to explore in rats the urinary metabolites of selenium (Se), by using (/sup 75/Se)selenomethionine, (/sup 75/Se)selenocystine, and (/sup 75/Se)selenite, and to assess the effects of low and high levels of Se intake on trimethylselenonium ion (TMSe) excretion in urine. Male adult rats were adapted for 6 weeks to a commercial rat laboratory stock diet (0.25 ppm Se). They were then starved for 24 hours and given an oral dose of either low (16 micrograms Se/kg body weight) or high (1500 micrograms Se/kg body weight) Se as the test Se compounds. Appearance of radioactivity in TMSe and non-TMSe Se metabolites in urine was monitored for 48 hours. About 40% of the /sup 75/Se dose was excreted in urine. TMSe was the major urinary Se metabolite (57-69% of urinary /sup 75/Se and 16-25% of oral /sup 75/Se dose) at high, and a minor urinary Se metabolite (10% of urinary /sup 75/Se and 3-4% of oral /sup 75/Se dose) at low dose levels of Se and for all three Se test compounds. At least 80% of urinary /sup 75/Se and 26-42% of the orally administered /sup 75/Se were excreted as non-TMSe Se metabolites in urine under the latter condition. It is hypothesized that at a requirement intake of Se either a trace or no TMSe is excreted in urine, and it becomes a major excretory metabolite of Se when the dietary trace mineral intake exceeds a requirement level, probably serving as a means of detoxification.

  7. Increased Klk9 Urinary Excretion Is Associated to Hypertension-Induced Cardiovascular Damage and Renal Alterations

    PubMed Central

    Blázquez-Medela, Ana M.; García-Sánchez, Omar; Quirós, Yaremi; Blanco-Gozalo, Victor; Prieto-García, Laura; Sancho-Martínez, Sandra M.; Romero, Miguel; Duarte, Juan M.; López-Hernández, Francisco J.; López-Novoa, José M.; Martínez-Salgado, Carlos

    2015-01-01

    Abstract Early detection of hypertensive end-organ damage and secondary diseases are key determinants of cardiovascular prognosis in patients suffering from arterial hypertension. Presently, there are no biomarkers for the detection of hypertensive target organ damage, most outstandingly including blood vessels, the heart, and the kidneys. We aimed to validate the usefulness of the urinary excretion of the serine protease kallikrein-related peptidase 9 (KLK9) as a biomarker of hypertension-induced target organ damage. Urinary, plasma, and renal tissue levels of KLK9 were measured by the Western blot in different rat models of hypertension, including angiotensin-II infusion, DOCA-salt, L-NAME administration, and spontaneous hypertension. Urinary levels were associated to cardiovascular and renal injury, assessed by histopathology. The origin of urinary KLK9 was investigated through in situ renal perfusion experiments. The urinary excretion of KLK9 is increased in different experimental models of hypertension in rats. The ACE inhibitor trandolapril significantly reduced arterial pressure and the urinary level of KLK9. Hypertension did not increase kidney, heart, liver, lung, or plasma KLK9 levels. Hypertension-induced increased urinary excretion of KLK9 results from specific alterations in its tubular reabsorption, even in the absence of overt nephropathy. KLK9 urinary excretion strongly correlates with cardiac hypertrophy and aortic wall thickening. KLK9 appears in the urine in the presence of hypertension as a result of subtle renal handling alterations. Urinary KLK9 might be potentially used as an indicator of hypertensive cardiac and vascular damage. PMID:26469898

  8. Effects of kefir on coccidial oocysts excretion and performance of dairy goat kids following weaning.

    PubMed

    Daş, Gürbüz; Ataşoğlu, Cengiz; Akbağ, Hande Işıl; Tölü, Cemil; Yurtman, Ismail Yaman; Savaş, Türker

    2012-06-01

    The aim of this study was to investigate effects of kefir, a traditional source of probiotic, on coccidial oocysts excretion and on the performance of dairy goat kids following weaning. Twin kids were randomly allocated to one of two groups at weaning. Kids of the first group received 20 ml of kefir daily for 6 weeks (KEF), while kids in the control group were given a placebo (CON). Individual faecal samples were regularly (n = 18 per kid) taken to quantify the number of coccidial oocysts per gram of faeces (OpG). There were no differences between the groups in terms of body weight development (P > 0.05) and feed consumption. Kids of both groups were not able to consume enough feed to meet their nutrient requirements during the first 3 weeks following weaning. KEF had a lower frequency of OpG positive samples than CON (P = 0.043). Kefir did not affect the maximum oocyst excretion and age of the kids at the highest oocyst excretion (P > 0.05). KEF shed numerically 35% lower coccidial oocysts than the controls, which corresponded to a statistical tendency (P = 0.074) in lowering Log-OpG in comparison to CON. While KEF had a lower frequency of OpG positive samples and tended to shed lower OPG by around one-third, the frequency of diarrhea, level of highest oocyst excretion, and performance of the kids remained unaffected. Therefore, it is concluded that overall effects of kefir do not have a significant impact on sub-clinical infection and performance in weaned kids under relatively high-hygienic farming conditions.

  9. Sodium and potassium urinary excretion and dietary intake: a cross-sectional analysis in adolescents

    PubMed Central

    Gonçalves, Carla; Abreu, Sandra; Padrão, Patrícia; Pinho, Olívia; Graça, Pedro; Breda, João; Santos, Rute; Moreira, Pedro

    2016-01-01

    Background Hypertension is the leading cause for heart disease and stroke, for mortality and morbidity worldwide, and a high sodium-to-potassium intake ratio is considered a stronger risk factor for hypertension than sodium alone. Objective This study aims to evaluate sodium and potassium urinary excretion, and assess the food sources of these nutrients in a sample of Portuguese adolescents. Design A cross-sectional study with a sample of 250 Portuguese adolescents. Sodium and potassium excretion were measured by one 24-h urinary collection, and the coefficient of creatinine was used to validate completeness of urine collections. Dietary sources of sodium and potassium were assessed using a 24-h dietary recall. Results Valid urine collections were provided by 200 adolescents (118 girls) with a median age of 14.0 in both sexes (p=0.295). Regarding sodium, the mean urinary excretion was 3,725 mg/day in boys and 3,062 mg/day in girls (p<0.01), and 9.8% of boys and 22% of girls met the World Health Organization (WHO) recommendations for sodium intake. Concerning potassium, the mean urinary excretion was 2,237 mg/day in boys and 1,904 mg/day in girls (p<0.01), and 6.1% of boys and 1.7% of girls met the WHO recommendations for potassium intake. Major dietary sources for sodium intake were cereal and cereal products (41%), meat products (16%), and milk and milk products (11%); and for potassium intake, main sources were milk and milk products (21%), meat products (17%), and vegetables (15%). Conclusions Adolescents had a high-sodium and low-potassium diet, well above the WHO recommendations. Health promotion interventions are needed in order to decrease sodium and increase potassium intake. PMID:27072344

  10. Biliary albumin excretion induced by bile salts in rats is a pathological phenomenon

    SciTech Connect

    Ohta, M.; Kitani, K.; Kanai, S. )

    1989-09-01

    The bile to plasma 125I-albumin concentration ratio (B/P ratio) was examined before and during various bile salt infusions in male Wistar rats that had previously received iv injection of 125I-albumin. Endogenous rat albumin and IgG concentrations in the bile were also determined by a single radial immunodiffusion method. Taurocholate (TC) infusion (1.0 mumol/min/100 g body wt) significantly increased the bile flow rate in the first hr but the flow began to decline in the second hr. The B/P ratio as well as rat albumin (and IgG) excretion into the bile significantly increased as early as 15 min after the start of TC infusion, and the increase became more pronounced in the second hr, when the bile flow began to decrease. Infusion of taurochenodeoxycholate (TCDC, 0.4 mumol/min/100 g) caused a reduction in bile flow 15 min after the start of infusion but the B/P ratio increased 40 times at its peak compared with the basal value before the bile salt infusion. Simultaneous infusion of tauroursodeoxycholate (TUDC, 0.6 mumol/min/100 g) and TCDC not only abolished the cholestasis induced by TCDC but maintained stable choleresis as long as for 2 hr. During this choleretic period, the B/P ration never exceeded the basal value. The choleresis induced by either taurodehydrocholate (TDHC) or bucolome was not accompanied by enhanced albumin excretion. In rats given TDHC infusion, albumin excretion started to increase only after the bile flow began to decline following the initial choleretic period. The enhanced excretion of albumin induced by TC and TCDC is therefore suggested to be caused not by the choleresis per se but by a possible concomitant increase in the communication between sinusoids and bile canaliculi, which eventually leads to cholestasis.

  11. Renal metabolism and urinary excretion of platelet-activating factor in the rat

    SciTech Connect

    Noris, M.; Perico, N.; Macconi, D.; Nanni, V.; Dadan, J.; Peterlongo, F.; Remuzzi, G. )

    1990-11-15

    The origin of platelet-activating factor (PAF) in the urine remains ill defined. The present study documents that (3H)PAF (3.5 mu Ci) injected into the renal artery of isolated control rat kidney preparations perfused at constant pressure with a cell-free medium containing 1% bovine serum albumin (BSA) was excreted in negligible amounts (0.034%) in the urine, whereas 6% was retained by the kidney. When kidneys were perfused with a BSA-free medium, 0.029 and 71% of the total radioactivity added to the perfusate was recovered in the urine and in the renal tissue, respectively. (3H)PAF urine excretion in proteinuric kidneys from adriamycin-treated rats was still negligible (0.015%). Analysis of the renal tissue-retained radioactivity in control and proteinuric kidneys perfused with 1% BSA indicated metabolism into long chain acyl-sn-glycero-3-phosphorylcholine species, lyso-PAF, glycerols, and intact PAF. Thin layer chromatography analysis of (3H)glycerol fraction in these renal extracts showed two major components comigrating with 1-O-alkylglycerol and 1-O-alkyl-2-fatty acylglycerol. Isolated proximal tubules, but not glomeruli from nephrotic rats exposed to increasing concentrations of BSA (0-4%), had a higher PAF uptake than control tubules for BSA concentrations ranging from 0 to 0.1%. Our findings in the isolated perfused kidneys indicate that, in normal conditions, circulating PAF is excreted in the urine in negligible amounts and that the altered glomerular permeability to proteins does not affect this excretion rate. Moreover, analysis of renal tissue radioactivity documented that the renal metabolism of PAF is comparable in control and nephrotic kidneys.

  12. Endogenous 6-Hydroxymelatonin Excretion and Subsequent Risk of Breast Cancer: A Prospective Study

    DTIC Science & Technology

    2005-03-01

    Epidemiologia e Prevenzione 46:359-363; 1991. Bojkowski CJ. Arendt J. Shih MC. Markey SP. Melatonin secretion in humans assessed by measuring its...urinary 6-hydroxymelatonin excretion. Clinica Chimica Acta. 150(3):221-5, 1985. Mawson AR. Breast cancer in female flight attendants. Lancet. 352(9128...expected cases in a dynamic cohort. Epidemiologia e Prevenzione. 18(60): 164-9; 1994. Muti P, Celentano E, Panico S, Berrino F. Measurement of cutaneous

  13. Endogenous 6-Hydroxylmelatonin Excretion and Subsequent Risk of Breast Cancer: A Prospective Study

    DTIC Science & Technology

    2006-03-01

    D, Zarini E. Progettazione di uno studio prospettico con banca biologica. Epidemiologia e Prevenzione 46:359-363; 1991. Bojkowski CJ. Arendt J...melatonin levels and urinary 6-hydroxymelatonin excretion. Clinica Chimica Acta. 150(3):221-5, 1985. Mawson AR. Breast cancer in female flight...computer program to calculate expected cases in a dynamic cohort. Epidemiologia e Prevenzione.18(60):164-9; 1994. Muti P, Celentano E, Panico S

  14. Endogenous 6-Hydroxymelatonin Excretion and Subsequent Risk of Breast Cancer: A Prospective Study

    DTIC Science & Technology

    2008-03-01

    biologica. Epidemiologia e Prevenzione 46:359-363; 1991. 15 Bojkowski CJ. Arendt J. Shih MC. Markey SP. Melatonin secretion in humans assessed by...Danforth DN. Tamarkin L. The correlation between human plasma melatonin levels and urinary 6-hydroxymelatonin excretion. Clinica Chimica Acta. 150(3...women. J Clin Epidemiol 44:1055-60; 1991. Micheli A, Krogh V. A computer program to calculate expected cases in a dynamic cohort. Epidemiologia e

  15. Endogenous 6-Hydroxymelatonin Excretion and Subsequent Risk of Breast Cancer: A Prospective Study

    DTIC Science & Technology

    2007-03-01

    Zarini E. Progettazione di uno studio prospettico con banca biologica. Epidemiologia e Prevenzione 46:359-363; 1991. Bojkowski CJ. Arendt J. Shih...levels and urinary 6-hydroxymelatonin excretion. Clinica Chimica Acta. 150(3):221-5, 1985. Mawson AR. Breast cancer in female flight attendants...program to calculate expected cases in a dynamic cohort. Epidemiologia e Prevenzione.18(60):164-9; 1994. Muti P, Celentano E, Panico S, Berrino F

  16. [SUBSTANTIATION OF SURGICAL APPROACH IN IATROGENIC INJURIES OF THE BILE-EXCRETING DUCTS].

    PubMed

    Maistrenko, N A; Romashchenko, P N; Pryadko, A S; Aliev, A K

    2015-01-01

    The results of examination and treatment were analyzed in 51 patients with iatrogenic injuries of the bile-excreting ducts. Patients were divided into 5 groups according to international classification (EAES, 2013). It depended on the time of detection, the nature and scale of damage of the bile ducts, mechanism of injury, development of infectious and septic complications. Injuries of the main bile duct were detected intraoperatively (n = 14). The complete intersection was in 10 patients (the first group) and the edge intersection--in 4 cases (the second group). Iatrogenic injuries of the bile-excreting ducts were revealed in 37 patients in postoperative period. There were the complete intersections in 28 cases (the third group) and the edge intersections--in 7 cases (the fifth group). Injuries of additional bile ducts were determined in 2 patients (the fifth group). An analysis of the main qualifying features of iatrogenic injuries of the bile-excreting ducts allowed defining indications to reconstructive-restorative surgery in 60.8% patients, restorative operations--in 29.4%, an external drainage--in 5.8% and reclipping of additional bile ducts in relaparoscopy--in 3.9%. The rational surgical approach allowed obtaining perfect results in 65.8% and good, satisfactory results in immediate and long-term period with low postoperative lethality of 1.95%. The study of diagnostics results and treatment of the patients with iatrogenic injuries of the bile- excreting ducts indicated about reasonability of assessment of main factors, which are based on iatrogenic injuries according to the EAES classification. An individual program of examination and more rational variant of surgery could be chosen due to this approach, which provides minimization of negative results and good quality of life.

  17. [Pyridinoline and deoxypyridinoline excretion in urine of healthy children--dependence on age].

    PubMed

    Marowska, J; Lukaszkiewicz, J; Kobylińska, M; Matusik, H; Tałajko, A; Lebiedowski, M; Olszaniecka, M; Madej, M; Lorenc, R S

    1993-11-01

    Pyridinoline (Pyr) and deoxypyridinoline (DPyr) are crosslinking compounds of bone collagen. Their urinary excretion is considered to be the first sensitive and specific marker of bone resorption in a number of metabolic bone diseases in adults. Application of crosslinks measurements to evaluate bone turnover rate in pediatric patients is so far limited because of lack of reference values. Therefore, the aim of our study was to determine urinary excretion of Pyr and DPyr in healthy children aged 3-18 yrs, and to evaluate the possible relationship between the levels of both compounds and body height, weight, BMC, and BMD. Pyr and DPyr levels were determined in first void urine samples obtained from 249 children (124 boys, 125 girls). Urine aliquots were hydrolysed, Pyr and DPyr extracted on CF1 cellulose, and analysed by HPLC with fluorimetric detection. Bone mineral content (BMC) and density (BMD) were measured with Lunar DPX-L apparatus in 205 children (104 boys, 101 girls) from the same population, aged over 5.5 yrs. In prepubertal children, a tendency towards lowering of urinary Pyr and DPyr levels with advancing age was shown. At puberty, urinary excretion of both crosslinks markedly decreased. This phenomenon was observed at various calendar age in girls as compared to boys, reflecting sex-dependent differences. Significant negative correlation (p < 0.0001) between urinary Pyr and DPyr levels and calendar age, body height and weight, BMC and BMD, were also found. The obtained results suggest that references values for Pyr and DPyr excretion in growing children should be related to calendar age, sex, and--in case of adolescents--phase of puberty.

  18. Effects of dairy cow diet forage proportion on duodenal nutrient supply and urinary purine derivative excretion.

    PubMed

    Moorby, J M; Dewhurst, R J; Evans, R T; Danelón, J L

    2006-09-01

    Four mature Holstein-Friesian dairy cows were used in a 4 x 4 Latin square change-over design experiment made up of four 4-wk periods to investigate the relationship between microbial protein flow to the duodenum and excretion of purine derivatives (PD) in the urine. Four dietary treatments based on ad libitum access to ryegrass silage were offered, with a standard dairy concentrate included at different forage:concentrate (F:C) ratios, calculated on a dry matter basis: 80:20, 65:35, 50:50, and 35:65. Feed intakes increased as the proportion of concentrate in the diet increased, despite a concurrent decrease in silage intake. Increased feed intake led to increased nutrient flow to the duodenum. Milk yields increased as the diet F:C ratio decreased, with cows offered the 35:65 diet yielding nearly 8 kg/d more milk than cows offered the 80:20 diet; the concentrations of milk fat decreased and milk protein increased with a decreasing F:C ratio. Purine derivative excretion in the urine increased with an increasing proportion of concentrate in the diet, and there was a strong linear relationship between total PD excretion (allantoin and uric acid) and microbial N flow to the duodenum: microbial N (g/d) = 19.9 + 0.689 x total PD (mmol/d); R = 0.887. This strengthens the case for using PD excretion as a noninvasive marker of microbial protein flow from the rumen in dairy cows.

  19. Storage excretion in the Indian apple snail, Pila globosa (Swainson), during aestivation.

    PubMed

    Athawale, Madhura S; Reddy, S Raghupathi Rami

    2002-11-01

    Uric acid accumulates in several tissues of the Indian apple snail, P. globosa, during aestivation. This accumulation is particularly high in the foot muscle and reproductive organs. Since the kidney, a tiny organ in the snail, has only a limited capacity to store uric acid, extrarenal tissues are used as storage depots of uric acid during aestivation. It is suggested that the aestivating snail, faced with a cleidoic situation, resorts to storage excretion, a phenomenon well documented in insects.

  20. Secretion of melatonin and 6-sulfatoxymelatonin urinary excretion in functional dyspepsia

    PubMed Central

    Chojnacki, Cezary; Poplawski, Tomasz; Klupinska, Grażyna; Blasiak, Janusz; Chojnacki, Jan; Reiter, Russel J

    2011-01-01

    AIM: To evaluate blood concentration of melatonin and urinary excretion of its metabolite, 6-sulfatoxymelatonin (6-OHMS), in functional dyspepsia (FD). METHODS: Ninety individuals were enrolled in the study: 30 in each study group: patients with postprandial distress syndrome (PDS), epigastric pain syndrome (EPS), and controls. Blood samples were drawn at 02:00 and 09:00 h and 24-h urine collection was performed. Serum melatonin and urinary 6-OHMS concentrations were measured by enzyme-linked immunosorbent assay. RESULTS: Serum melatonin concentration at night and in the morning was significantly (P < 0.001) higher in PDS patients [at 02:00 h-93.3 pg/mL, quartile range (QR): 79.8-116.2; at 09.00 h-14.3 pg/mL, QR: 7.06-19.0] than in EPS (57.2 pg/mL, QR: 42.6-73.1; 8.1 pg/mL, QR: 4.1-9.3) and control patients (57.7 pg/mL, QR: 51.2-62.5; 8.1 pg/mL, QR: 5.4-10.3). A similar relationship was observed for urinary 6-OHMS excretion. Patients with severe PDS symptoms had a higher melatonin concentration than these with moderate syndromes, whereas patients with severe EPS had a lower urinary 6-OHMS excretion than patients with moderate symptoms. CONCLUSION: Evaluation of melatonin serum concentrations and 24-h urinary 6-OHMS excretion are useful methods for differential diagnosis of various clinical forms of FD. PMID:21677834

  1. Urinary corticosteroid excretion predicts left ventricular mass and proteinuria in chronic kidney disease.

    PubMed

    McQuarrie, Emily P; Freel, E Marie; Mark, Patrick B; Fraser, Robert; Patel, Rajan K; Dargie, Henry G; Connell, John M C; Jardine, Alan G

    2012-09-01

    Blockade of the MR (mineralocorticoid receptor) in CKD (chronic kidney disease) reduces LVMI [LV (left ventricular) mass index] and proteinuria. The MR can be activated by aldosterone, cortisol and DOC (deoxycorticosterone). The aim of the present study was to explore the influence of mineralocorticoids on LVMI and proteinuria in patients with CKD. A total of 70 patients with CKD and 30 patients with EH (essential hypertension) were recruited. Patients underwent clinical phenotyping; biochemical assessment and 24 h urinary collection for THAldo (tetrahydroaldosterone), THDOC (tetrahydrodeoxycorticosterone), cortisol metabolites (measured using GC-MS), and urinary electrolytes and protein [QP (proteinuira quantification)]. LVMI was measured using CMRI (cardiac magnetic resonance imaging). Factors that correlated significantly with LVMI and proteinuria were entered into linear regression models. In patients with CKD, significant predictors of LVMI were male gender, SBP (systolic blood pressure), QP, and THAldo and THDOC excretion. Significant independent predictors on multivariate analysis were THDOC excretion, SBP and male gender. In EH, no association was seen between THAldo or THDOC and LVMI; plasma aldosterone concentration was the only significant independent predictor. Significant univariate determinants of proteinuria in patients with CKD were THAldo, THDOC, USod (urinary sodium) and SBP. Only THAldo excretion and SBP were significant multivariate determinants. Using CMRI to determine LVMI we have demonstrated that THDOC is a novel independent predictor of LVMI in patients with CKD, differing from patients with EH. Twenty-four hour THAldo excretion is an independent determinant of proteinuria in patients with CKD. These findings emphasize the importance of MR activation in the pathogenesis of the adverse clinical phenotype in CKD.

  2. [Ecogenetic aspects of the study of phenotypes and levels of beta-aminoisobutyric acid excretion].

    PubMed

    Spitsyn, V A; Afanas'eva, I S; Alekseeva, N V

    1993-11-01

    The levels of excretion of beta-aminoisobutyric acid (BAIB) in urea were examined in five groups. The distribution of BAIB concentration revealed the existence of high and low excretors in each group. Asbestosis patients had the lowest frequency of high excretors. The BAIB concentration among high excretors was similar for all the groups. The BAIB levels of low excretors varied. The most alike were two children groups, asbestosis patients and the workers from the town Asbest.

  3. Metabolism, excretion and avoidance of cyanogenic glucosides in insects with different feeding specialisations.

    PubMed

    Pentzold, Stefan; Zagrobelny, Mika; Bjarnholt, Nanna; Kroymann, Juergen; Vogel, Heiko; Olsen, Carl Erik; Møller, Birger Lindberg; Bak, Søren

    2015-11-01

    Cyanogenic glucosides (CNglcs) are widespread plant defence compounds releasing toxic hydrogen cyanide when hydrolysed by specific β-glucosidases after plant tissue damage. In contrast to specialist herbivores that have mechanisms to avoid toxicity from CNglcs, it is generally assumed that non-adapted herbivores are negatively affected by CNglcs. Recent evidence, however, implies that the defence potential of CNglcs towards herbivores may not be as effective as previously anticipated. Here, performance, metabolism and excretion products of insects not adapted to CNglcs were analysed, including species with different degrees of dietary specialisation (generalists, specialists) and different feeding modes (leaf-snipping lepidopterans, piercing-sucking aphids). Insects were reared either on cyanogenic or acyanogenic plants or on an artificial cyanogenic diet. Lepidopteran generalists (Spodoptera littoralis, Spodoptera exigua, Mamestra brassicae) were compared to lepidopteran glucosinolate-specialists (Pieris rapae, Pieris brassicae, Plutella xylostella), and a generalist aphid (Myzus persicae) was compared to an aphid glucosinolate-specialist (Lipaphis erysimi). All insects were tolerant to cyanogenic plants; in lepidopterans tolerance was mainly due to excretion of intact CNglcs. The two Pieris species furthermore metabolized aromatic CNglcs to amino acid conjugates (Cys, Gly, Ser) and derivatives of these, which is similar to the metabolism of benzylglucosinolates in these species. Aphid species avoided uptake of CNglcs during feeding. Our results imply that non-adapted insects tolerate plant CNglcs either by keeping them intact for excretion, metabolizing them, or avoiding uptake.

  4. Cortisol-mediated synchronization of circadian rhythm in urinary potassium excretion

    NASA Technical Reports Server (NTRS)

    Moore-Ede, M. C.; Schmelzer, W. S.; Kass, D. A.; Herd, J. A.

    1977-01-01

    Conscious chair-acclimatized squirrel monkeys (Saimiri sciureus) studied with lights on (600 lx) from 0800 to 2000 hr daily (LD 12:12) display a prominent circadian rhythm in renal potassium excretion. The characteristics of this rhythm were reproduced in adrenalectomized monkeys by infusing 5 mg cortisol and 0.001 mg aldosterone, or 5 mg cortisol alone, between 0800 and 0900 kr daily. When the timing of cortisol administration (with or without aldosterone) was phase-delayed by 8 hr, the urinary potassium rhythm resynchronized by 80% of the cortisol phase shift, but only after a transient response lasting 3-4 days. With the same daily dose of adrenal steroids given as a continuous infusion throughout each 24 hr, urinary potassium excretion showed free-running oscillations no longer synchronized to the light-dark cycle. These results indicate that the circadian rhythm of plasma cortisol concentration acts as an internal mediator in the circadian timing system, synchronizing a potentially autonomous oscillation in renal potassium excretion to environmental time cues and to other circadian rhythms within the animal.

  5. Feeding and excretion in the Afghan pika (Ochotona rufescens rufescens), a new laboratory animal.

    PubMed

    Matsuzawa, T; Nakata, M; Tsushima, M

    1981-10-01

    Food and water intake and the excretion of urine and faecal pellets during the day (0500-2100) and at night (2100-0500) were observed in Afghan pikas, rats and guineapigs fed appropriate diets. Urine composition was observed in these species after they had been fed the pika diet for 4 weeks. Rats ate more at night than did pikas or guineapigs. The pikas excreted numerous small, hard faeces and soft faeces, the latter being reingested. On the pika diet all species gained about 10% in bodyweight. Food consumption was similar to that shown by each species on its own diet. All animals fed the pika diet excreted alkaline urine. Chloride concentration in pika urine was similar to that of the rat and was significantly higher than that of the guineapig. The ratio of sodium to potassium in pika urine was 2.8 and 1.7 fold that of the rat and guineapig respectively. Osmolality of pika urine was slightly higher than that of the rat, and was 3.8 fold that of the guineapig.

  6. Renal excretion profiles of psilocin following oral administration of psilocybin: a controlled study in man.

    PubMed

    Hasler, Felix; Bourquin, Daniel; Brenneisen, Rudolf; Vollenweider, Franz X

    2002-09-05

    In a clinical study eight volunteers received psilocybin (PY) in psychoactive oral doses of 212+/-25 microg/kg body weight. To investigate the elimination kinetics of psilocin (PI), the first metabolite of PY, urine was collected for 24 h and PI concentrations were determined by high-performance liquid chromatography with column switching and electrochemical detection (HPLC-ECD). Sample workup included protection of the unstable PI with ascorbic acid, freeze-drying, and extraction with methanol. Peak PI concentrations up to 870 microg/l were measured in urine samples from the 2-4 h collection interval. The PI excretion rate in this period was 55.5+/-33.8 microg/h. The limit of quantitation (10 microg/L) was usually reached 24 h after drug administration. Within 24 h, 3.4+/-0.9% of the applied dose of PY was excreted as free PI. Addition of beta-glucuronidase to urine samples and incubation for 5 h at 40 degrees C led to twofold higher PI concentrations, although 18+/-7% of the amount of unconjugated PI was decomposed during incubation. We conclude that in humans PI is partially excreted as PI-O-glucuronide and that enzymatic hydrolysis extends the time of detectability for PI in urine samples.

  7. Protein intake and urinary excretion of protein-derived metabolites in aging female vegetarians and nonvegetarians.

    PubMed

    Kunkel, M E; Beauchene, R E

    1991-08-01

    Relationships among age, protein intake, and urinary excretion of protein-derived metabolites were studied in 125 vegetarian and nonvegetarian women ages 40-92. There were 63 women in the vegetarian (AV) group and 62 women in the nonvegetarian (NV) group. Average daily intakes of energy and total animal and vegetable protein were calculated from 7-day dietary records. Twenty-four-hour urine samples were analyzed for total nitrogen, urea, creatinine, hydroxyproline, and inorganic sulfate. Energy intakes for the two groups were similar. AVs consumed less total and animal protein and more vegetable protein than NVs, even though both groups consumed more than the RDA for protein. No significant differences existed between the groups in the urinary excretion of total nitrogen, urea nitrogen, hydroxyproline, or inorganic sulfate. Energy and protein intakes and total nitrogen excretion were lower in older AVs than in younger AVs, while those of NVs increased between 40 and 55 years of age, and decreased among the older NV women. The relationship between these variables and age in NVs was more accurately described by polynomial rather than linear regression models.

  8. Ammonium excretion in two benthic cnidarians: Alcyonium digitatum (Linnaeus, 1758) and Urticina felina (Linnaeus, 1767)

    NASA Astrophysics Data System (ADS)

    Migné, A.; Davoult, D.

    1997-05-01

    As part of an evaluation of nitrogen fluxes between the water column and a macrobenthic community of the Strait of Dover (eastern English Channel), ammonium excretion was measured throughout the year in two common cnidarians (the octocoral Alcyonium digitatum and the sea anemone Urticina felina) which together accounted for 37% of the biomass. Mean ammonium excretion rates were 6.48 (±2.44 s.d.) μg N g -1 h -1 (ash-free dry weight) for A. digitatum and 4.12 (±l.38 s.d.) μg N g -1 h -1 for U. felina. Seasonal variations were observed in the excretion of A. digitatum, whereas such variations were less pronounced in U. felina. These trends are discussed in relation to temperature, food availability, nutritional state and nutritional habits of the two species. The results of this and a previous study indicate a nitrogen production of 18.9 g N m -2 y -1 for the entire benthic community.

  9. Oral intake of ranitidine increases urinary excretion of N-nitrosodimethylamine.

    PubMed

    Zeng, Teng; Mitch, William A

    2016-06-01

    The H2-receptor antagonist, ranitidine, is among the most widely used pharmaceuticals to treat gastroesophageal reflux disease and peptic ulcers. While previous studies have demonstrated that amines can form N-nitrosamines when exposed to nitrite at stomach-relevant pH, N-nitrosamine formation from ranitidine, an amine-based pharmaceutical, has not been demonstrated under these conditions. In this work, we confirmed the production of N-nitrosodimethylamine (NDMA), a potent carcinogen, by nitrosation of ranitidine under stomach-relevant pH conditions in vitro We also evaluated the urinary NDMA excretion attributable to ingestion of clinically used ranitidine doses. Urine samples collected from five female and five male, healthy adult volunteers over 24-h periods before and after consumption of 150mg ranitidine were analyzed for residual ranitidine, ranitidine metabolites, NDMA, total N-nitrosamines and dimethylamine. Following ranitidine intake, the urinary NDMA excreted over 24h increased 400-folds from 110 to 47 600ng, while total N-nitrosamines increased 5-folds. NDMA excretion rates after ranitidine intake equaled or exceeded those observed previously in patients with schistosomiasis, a disease wherein N-nitrosamines are implicated as the etiological agents for bladder cancer. Due to metabolism within the body, urinary NDMA measurements represent a lower-bound estimate of systemic NDMA exposure. Our results suggest a need to evaluate the risks attributable to NDMA associated with chronic consumption of ranitidine, and to identify alternative treatments that minimize exposure to N-nitrosamines.

  10. Extracellular carbonic anhydrase in the dogfish, Squalus acanthias: a role in CO2 excretion.

    PubMed

    Gilmour, K M; Perry, S F; Bernier, N J; Henry, R P; Wood, C M

    2001-01-01

    In Pacific spiny dogfish (Squalus acanthias), plasma CO(2) reactions have access to plasma carbonic anhydrase (CA) and gill membrane-associated CA. The objectives of this study were to characterise the gill membrane-bound CA and investigate whether extracellular CA contributes significantly to CO(2) excretion in dogfish. A subcellular fraction containing membrane-associated CA activity was isolated from dogfish gills and incubated with phosphatidylinositol-specific phospholipase C. This treatment caused significant release of CA activity from its membrane association, a result consistent with identification of the dogfish gill membrane-bound CA as a type IV isozyme. Inhibition constants (K(i)) against acetazolamide and benzolamide were 4.2 and 3.5 nmol L(-1), respectively. Use of a low dose (1.3 mg kg(-1) or 13 micromol L(-1)) of benzolamide to selectively inhibit extracellular CA in vivo caused a significant 30%-60% reduction in the arterial-venous total CO(2) concentration difference, a significant increase in Pco(2) and an acidosis, without affecting blood flow or ventilation. No effect of benzolamide on any measure of CO(2) excretion was detected in rainbow trout (Oncorhynchus mykiss). These results indicate that extracellular CA contributes substantially to CO(2) excretion in the dogfish, an elasmobranch, and confirm that CA is not available to plasma CO(2) reactions in rainbow trout, a teleost.

  11. Aedes aegypti Rhesus glycoproteins contribute to ammonia excretion by larval anal papillae.

    PubMed

    Durant, Andrea C; Chasiotis, Helen; Misyura, Lidiya; Donini, Andrew

    2017-02-15

    In larval Aedes aegypti, transcripts of the Rhesus-like glycoproteins AeRh50-1 and AeRh50-2 have been detected in the anal papillae, sites of ammonia (NH3/NH4(+)) excretion; however, these putative ammonia transporters have not been previously localized or functionally characterized. In this study, we show that the AeRh50s co-immunolocalize with apical V-type H(+)-ATPase as well as with basal Na(+)/K(+)-ATPase in the epithelium of anal papillae. The double-stranded RNA-mediated knockdown of AeRh50-1 and AeRh50-2 resulted in a significant reduction in AeRh50 protein abundance in the anal papillae, and this was coupled to decreased ammonia excretion. The knockdown of AeRh50-1 resulted in decreased hemolymph [NH4(+)] and pH whereas knockdown of AeRh50-2 had no effect on these parameters. We conclude that the AeRh50s are important contributors to ammonia excretion at the anal papillae of larval A. aegypti, which may be the basis for their ability to inhabit areas with high ammonia levels.

  12. Stereoselectivity in bioaccumulation and excretion of epoxiconazole by mealworm beetle (Tenebrio molitor) larvae.

    PubMed

    Lv, Xiaotian; Liu, Chen; Li, Yaobin; Gao, Yongxin; Wang, Huili; Li, Jianzhong; Guo, Baoyuan

    2014-09-01

    Stereoselectivity in bioaccumulation and excretion of stereoisomers of epoxiconazole by mealworm beetle (Tenebrio molitor) larvae through dietary exposure was investigated. Liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method that use a ChiralcelOD-3R[cellulosetris-Tris-(3, 5-dichlorophenyl-carbamate)] chromatography column was applied to carry out chiral separation of the stereoisomers. Wheat bran was spiked with racemic epoxiconazole at two dose levels of 20mg/kg and 2mg/kg (dry weight) to feed T. molitor larvae. The results showed that both the doses of epoxiconazole were taken up by Tenebrio molitor larvae rapidly at the initial stages. There was a significant trend of stereoselective bioaccumulation in the larvae with a preferential accumulation of (-)-epoxiconazole in the 20mg/kg dose. The stereoselectivity in bioaccumulation in the 2mg/kg dosage was not obvious compared to the 20mg/kg group. Results of excretion indicated an active excretion is an important pathway for the larvae to eliminate epoxiconazole which was a passive transport process with non stereoselectivity. The faster elimination might be the reason for the low accumulation of epoxiconazole, as measured by bioaccumulation factor (BAF).

  13. Phytoplankton uptake and excretion of assimilated nitrate in a small Canadian shield lake.

    PubMed

    Chan, H K; Campbell, N E

    1978-06-01

    Nitrate uptake in the epilemnetic waters of a small eutrophic Canadian Shield lake was studied by using a 15N method during summer stratification. Concurrent with inhibition of primary production, 3-(3,4-dichlorophenyl)-1,1-dimethylurea inhibited NO3- assimilation. Nitrate up to 1 mg of N/liter did not affect the rate of primary production during 3 h of incubation. The NO3- fertilizer added to the lake weekly was consumed through algal assimilation in about 3 days. Excretion of the photoassimilated NO3- as dissolved organic nitrogen represented a significant portion of the nutrient incorporated by the cells. Only 40% of the NO3- -15N which disappeared could be accounted for in the particulate fraction. Although the rest was presumably excreted, only 15% of the 15N label was accounted for as cationic dissolved organic nitrogen by isotope assays. These excreted organic forms were predominantly serine and glycine in the dissolved free amino acid fraction. Bacteria as well as algae might be expected to contribute to and modify the extracellular nitrogen pool.

  14. Effects of porcine hemoglobin on serum lipid content and fecal lipid excretion in rats.

    PubMed

    Hosomi, Ryota; Fukunaga, Kenji; Nishiyama, Toshimasa; Yoshida, Munehiro

    2014-03-01

    The purpose of this study was to elucidate the effects of dietary hemoglobin on serum and liver lipid contents in rats, and the ability of hemoglobin hydrolysates to disrupt lipid absorption. After rats had been fed on casein- or porcine hemoglobin-containing diets for 4 weeks, their serum and liver lipid contents and fecal cholesterol, bile acid, and nitrogen excretion were measured. To elucidate the mechanism of lipid absorption by dietary hemoglobin, we also examined lipase activity, micellar solubility of cholesterol, and bile acid binding activity in the presence of hemoglobin hydrolysates. Dietary hemoglobin decreased serum and liver triglyceride and cholesterol contents and increased fecal fatty acid, cholesterol, and bile acid excretion. In addition, hemoglobin hydrolysates inhibited lipase activity compared with casein hydrolysates in an in vitro study. These results suggested that the hypolipidemic effect of hemoglobin is mediated by increased fecal lipid excretion, and that decreased lipase activity by hemoglobin is at least partially responsible for this result. The observed effects were documented with an 8 g/kg hemoglobin diet, which is lower than in other studies; therefore. hemoglobin may be useful in the prevention of lifestyle-related diseases.

  15. Impacts of active urea secretion into pars recta on urine concentration and urea excretion rate

    PubMed Central

    Layton, Anita T; Bankir, Lise

    2013-01-01

    It has been observed experimentally that early distal tubular urea flow exceeds urea delivery by the proximal convoluted tubule to the pars recta and loop of Henle. Moreover, the fractional excretion of urea in the urine may exceed values compatible with the reabsorption known to occur in the proximal convoluted tubule in the cortex. A likely explanation for these observations is that urea may be actively secreted into the pars recta, as proposed in a few studies. However, this hypothesis has yet to be demonstrated experimentally. In this study, we used a mathematical model of the renal medulla of the rat kidney to investigate the impacts of active urea secretion in the intrarenal handling of urea and in the urine concentrating ability. The model represents only the outer and inner medullary zones, with the actions taking place in the cortex incorporated via boundary conditions. Blood flow in the model vasculature is divided into plasma and red blood cell compartments. We compared urea flow rates and other related model variables without and with the hypothetical active urea secretion in the pars recta. The simulation suggests that active urea secretion induces a “urea-selective” improvement in urine concentrating ability by enhancing the efficiency of urea excretion without requiring a higher urine flow rate, and with only modest changes in the excretion of other solutes. These results should encourage experimental studies in order to assess the existence of an active urea secretion in the rodent kidney. PMID:24058732

  16. Pyridoxic acid excretion during low vitamin B-6 intake, total fasting, and bed rest

    NASA Technical Reports Server (NTRS)

    Coburn, S. P.; Thampy, K. G.; Lane, H. W.; Conn, P. S.; Ziegler, P. J.; Costill, D. L.; Mahuren, J. D.; Fink, W. J.; Pearson, D. R.; Schaltenbrand, W. E.

    1995-01-01

    Vitamin B-6 metabolism in 10 volunteers during 21 d of total fasting was compared with results from 10 men consuming a diet low only in vitamin B-6 (1.76 mumol/d) and with men consuming a normal diet during bed rest. At the end of the fast mean plasma concentrations of vitamin B-6 metabolites and urinary excretion of 4-pyridoxic acid tended to be higher in the fasting subjects than in the low-vitamin B-6 group. The fasting subjects lost approximately 10% of their total vitamin B-6 pool and approximately 13% of their body weight. The low-vitamin B-6 group lost only approximately 4% of their vitamin B-6 pool. Compared with baseline, urinary excretion of pyridoxic acid was significantly increased during 17 wk of bed rest. There was no increase in pyridoxic acid excretion during a second 15-d bed rest study. These data suggest the possibility of complex interactions between diet and muscle metabolism that may influence indexes that are frequently used to assess vitamin B-6 status.

  17. Recent advances in understanding trans-epithelial acid-base regulation and excretion mechanisms in cephalopods

    PubMed Central

    Hu, Marian Y; Hwang, Pung-Pung; Tseng, Yung-Che

    2015-01-01

    Cephalopods have evolved complex sensory systems and an active lifestyle to compete with fish for similar resources in the marine environment. Their highly active lifestyle and their extensive protein metabolism has led to substantial acid-base regulatory abilities enabling these organisms to cope with CO2 induced acid-base disturbances. In convergence to teleost, cephalopods possess an ontogeny-dependent shift in ion-regulatory epithelia with epidermal ionocytes being the major site of embryonic acid-base regulation and ammonia excretion, while gill epithelia take these functions in adults. Although the basic morphology and excretory function of gill epithelia in cephalopods were outlined almost half a century ago, modern immunohistological and molecular techniques are bringing new insights to the mechanistic basis of acid-base regulation and excretion of nitrogenous waste products (e.g. NH3/NH4+) across ion regulatory epithelia of cephalopods. Using cephalopods as an invertebrate model, recent findings reveal partly conserved mechanisms but also novel aspects of acid-base regulation and nitrogen excretion in these exclusively marine animals. Comparative studies using a range of marine invertebrates will create a novel and exciting research direction addressing the evolution of pH regulatory and excretory systems. PMID:26716070

  18. Effects of cytostatic drugs on plasma level and renal excretion of beta-acetyldigoxin.

    PubMed

    Kuhlmann, J; Zilly, W; Wilke, J

    1981-10-01

    Mucosal defects decrease digoxin absorption in patients with malabsorption syndromes. Since the intestinal mucosa can be damaged by cytostatic drugs, we investigated their effects on digoxin plasma levels and urinary digoxin excretion. In six patients with malignant lymphoma who received 0.8 mg beta-acetyldigoxin before and 24 hr after treatment with a combination of cyclophosphamide, oncovin, procarbazine, and prednisone (COPP) or cyclophosphamide, oncovin, and prednisone (COP), plasma digoxin concentrations were measured 0 to 8 hr after the dose and areas under the plasma concentration-time curves were calculated. In 15 patients on 0.3 mg of beta-acetyldigoxin daily, plasma glycoside concentrations and renal excretion were measured daily before and after COPP, COP, cyclophosphamide, oncovin, cytosine-arabinosine, and prednisone (COAP), or adriamycin, bleomycin, and prednisone (ABP) treatment schemes. The diminished steady-state glycoside plasma concentrations and daily renal glycoside excretion during the 24 to 168 hr after the cytostatic drug established reversible impairment of digoxin absorption. The delayed time to peak after a single dose of digoxin during cytostatic drug therapy shows that extent and rate of digoxin absorption are reduced. To maintain adequate control of digoxin therapy in patients treated with cytostatic drugs, plasma levels should be monitored.

  19. Human Excretion of Polybrominated Diphenyl Ether Flame Retardants: Blood, Urine, and Sweat Study

    PubMed Central

    Genuis, Shelagh K.; Birkholz, Detlef

    2017-01-01

    Commonly used as flame retardants, polybrominated diphenyl ethers (PBDEs) are routinely detected in the environment, animals, and humans. Although these persistent organic pollutants are increasingly recognized as having serious health implications, particularly for children, this is the first study, to our knowledge, to investigate an intervention for human elimination of bioaccumulated PBDEs. Objectives. To determine the efficacy of blood, urine, and perspiration as PBDE biomonitoring mediums; assess excretion of five common PBDE congeners (28, 47, 99, 100, and 153) in urine and perspiration; and explore the potential of induced sweating for decreasing bioaccumulated PBDEs. Results. PBDE congeners were not found in urine samples; findings focus on blood and perspiration. 80% of participants tested positive in one or more body fluids for PBDE 28, 100% for PBDE 47, 95% for PBDE 99, and 90% for PBDE 100 and PBDE 153. Induced perspiration facilitated excretion of the five congeners, with different rates of excretion for different congeners. Conclusion. Blood testing provides only a partial understanding of human PBDE bioaccumulation; testing of both blood and perspiration provides a better understanding. This study provides important baseline evidence for regular induced perspiration as a potential means for therapeutic PBDE elimination. Fetotoxic and reproductive effects of PBDE exposure highlight the importance of further detoxification research. PMID:28373979

  20. Excretion of cytoplasmic proteins in Staphylococcus is most likely not due to cell lysis.

    PubMed

    Ebner, Patrick; Rinker, Janina; Götz, Friedrich

    2016-02-01

    The excretion of cytoplasmic proteins (ECP) is a long-known phenomenon in bacteria and eukaryotes. So far, it was not possible to associate either a signal peptide-dependent or a signal peptide-independent pathway to ECP. Nevertheless 25% of the proteins found in Staphylococcus aureus supernatants were cytoplasmic proteins. Because the excreted proteins do not possess a common motive, the most widespread opinion is that ECP is due to cell lysis. This explanation seems to be too easy since several indications imply that there exists a yet unknown mechanism for ECP. Certainly, the up-regulation of autolysins as well as decreased peptidoglycan cross-linking increased ECP. However, in recent years, several evidences arose that cell lysis is not the only reason for ECP. It seems that ECP is a part of the normal cell cycle of S. aureus as it turned out that ECP with several model proteins occurs mainly during cell growth. It has common features as proteins secreted via the Sec translocon and finally the excretion site is the cross wall of dividing cells.

  1. Biological Monitoring of Human Exposure to Neonicotinoids Using Urine Samples, and Neonicotinoid Excretion Kinetics

    PubMed Central

    Harada, Kouji H.; Tanaka, Keiko; Sakamoto, Hiroko; Imanaka, Mie; Niisoe, Tamon; Hitomi, Toshiaki; Kobayashi, Hatasu; Okuda, Hiroko; Inoue, Sumiko; Kusakawa, Koichi; Oshima, Masayo; Watanabe, Kiyohiko; Yasojima, Makoto; Takasuga, Takumi; Koizumi, Akio

    2016-01-01

    Background Neonicotinoids, which are novel pesticides, have entered into usage around the world because they are selectively toxic to arthropods and relatively non-toxic to vertebrates. It has been suggested that several neonicotinoids cause neurodevelopmental toxicity in mammals. The aim was to establish the relationship between oral intake and urinary excretion of neonicotinoids by humans to facilitate biological monitoring, and to estimate dietary neonicotinoid intakes by Japanese adults. Methodology/Principal Findings Deuterium-labeled neonicotinoid (acetamiprid, clothianidin, dinotefuran, and imidacloprid) microdoses were orally ingested by nine healthy adults, and 24 h pooled urine samples were collected for 4 consecutive days after dosing. The excretion kinetics were modeled using one- and two-compartment models, then validated in a non-deuterium-labeled neonicotinoid microdose study involving 12 healthy adults. Increased urinary concentrations of labeled neonicotinoids were observed after dosing. Clothianidin was recovered unchanged within 3 days, and most dinotefuran was recovered unchanged within 1 day. Around 10% of the imidacloprid dose was excreted unchanged. Most of the acetamiprid was metabolized to desmethyl-acetamiprid. Spot urine samples from 373 Japanese adults were analyzed for neonicotinoids, and daily intakes were estimated. The estimated average daily intake of these neonicotinoids was 0.53–3.66 μg/day. The highest intake of any of the neonicotinoids in the study population was 64.5 μg/day for dinotefuran, and this was <1% of the acceptable daily intake. PMID:26731104

  2. Recent advances in understanding trans-epithelial acid-base regulation and excretion mechanisms in cephalopods.

    PubMed

    Hu, Marian Y; Hwang, Pung-Pung; Tseng, Yung-Che

    2015-01-01

    Cephalopods have evolved complex sensory systems and an active lifestyle to compete with fish for similar resources in the marine environment. Their highly active lifestyle and their extensive protein metabolism has led to substantial acid-base regulatory abilities enabling these organisms to cope with CO2 induced acid-base disturbances. In convergence to teleost, cephalopods possess an ontogeny-dependent shift in ion-regulatory epithelia with epidermal ionocytes being the major site of embryonic acid-base regulation and ammonia excretion, while gill epithelia take these functions in adults. Although the basic morphology and excretory function of gill epithelia in cephalopods were outlined almost half a century ago, modern immunohistological and molecular techniques are bringing new insights to the mechanistic basis of acid-base regulation and excretion of nitrogenous waste products (e.g. NH3/NH4 (+)) across ion regulatory epithelia of cephalopods. Using cephalopods as an invertebrate model, recent findings reveal partly conserved mechanisms but also novel aspects of acid-base regulation and nitrogen excretion in these exclusively marine animals. Comparative studies using a range of marine invertebrates will create a novel and exciting research direction addressing the evolution of pH regulatory and excretory systems.

  3. Collagen cross-link excretion during space flight and bed rest

    NASA Technical Reports Server (NTRS)

    Smith, S. M.; Nillen, J. L.; Leblanc, A.; Lipton, A.; Demers, L. M.; Lane, H. W.; Leach, C. S.; LeBlanc, A. (Principal Investigator)

    1998-01-01

    Extended exposure to weightlessness results in bone loss. However, little information exists as to the precise nature or time course of this bone loss. Bone resorption results in the release of collagen breakdown products, including N-telopeptide and the pyridinium (PYD) cross-links, pyridinoline and deoxypyridinoline. Urinary pyridinoline and deoxypyridinoline are known to increase during bed rest. We assessed excretion of PYD cross-links and N-telopeptide before, during, and after long (28-day, 59-day, and 84-day) Skylab missions, as well as during short (14-day) and long (119-day) bed-rest studies. During space flight, the urinary cross-link excretion level was twice those observed before flight. Urinary excretion levels of the collagen breakdown products were also 40-50% higher, during short and long bed rest, than before. These results clearly show that the changes in bone metabolism associated with space flight involve increased resorption. The rate of response (i.e. within days to weeks) suggests that alterations in bone metabolism are an early effect of weightlessness. These studies are important for a better understanding of bone metabolism in space crews and in those who are bedridden.

  4. Model for antiorthostatic hypokinesia - Head-down tilt effects on water and salt excretion

    NASA Technical Reports Server (NTRS)

    Deavers, D. R.; Musacchia, X. J.; Meininger, G. A.

    1980-01-01

    Water and electrolyte excretion was investigated in antiorthostatic hypokinetic and orthostatic hypokinetic and control rats in metabolic cages. Significant (t test, P less than 0.05) diuresis, natriuresis, and kaliuresis occurred in the antiorthostatic hypokinetic subjects but did not occur in either the orthostatic hypokinetic or controls. Recovery from antiorthostatic hypokinesia was characterized by retention of water, sodium, and potassium. Patterns of changes in body weight and food and water consumption were virtually identical in antiorthostatic and orthostatic hypokinetic rats and thus could not account for the differences in renal handling of water and electrolytes. Also, differences in ingestion of food and water in controls could not account for differences in excretion of water and electrolytes between these and antiorthostatic hypokinetic rats. It was concluded that the antiorthostatic position was responsible for the diuresis and natriuresis and that the antiorthostatic hypokinetic rat appears to be a good model for the study of water and elecrolyte excretion during conditions such as bed rest, water immersion, and exposure to weightlessness.

  5. Melatonin secretion and excretion in patients with obstructive sleep apnea syndrome.

    PubMed

    Wikner, J; Svanborg, E; Wetterberg, L; Röjdmark, S

    1997-11-01

    Melatonin (MT) secretion and excretion were investigated in patients with obstructive sleep apnea syndrome (OSAS). Nine men, mean age 55.1 years, mean body mass index 31.2, with a previously confirmed diagnosis of moderate to severe OSAS, were tested on two occasions: immediately before initiation of continuous positive airway pressure (CPAP) treatment and again after at least 4 weeks of continuous nocturnal use of CPAP. Serum MT concentrations were determined every second hour between 2000 and 0800 hours. Urine was collected between 2200 and 0700 hours for determination of urinary MT excretion. Sleep apnea recordings included ear oximetry, respiration and body movements, body position, and breathing sounds. Nine healthy male controls were tested on one occasion. We found that the MT secretion, as reflected by the area under the curve (AUC), among the OSAS patients did not differ from that found in healthy controls (MT AUC 1.68 vs. 1.92 nmol/l x h). Sleep apnea recordings were normalized during CPAP treatment. Moreover, the excessive daytime sleepiness disappeared in all patients. Neither MT secretion (MT AUC 1.68 vs. 1.56 nmol/l x h) nor urinary excretion of MT (0.122 vs. 0.108 nmol/9 h) changed significantly as a result of the CPAP treatment.

  6. Circadian rhythm of water balance and aldosterone excretion in the whitebellied sunbird Nectarinia talatala.

    PubMed

    Fleming, P A; Gray, D A; Nicolson, S W

    2004-05-01

    Nectarivorous whitebellied sunbirds, Nectarinia talatala, demonstrate distinct circadian patterns in osmoregulatory parameters. We recorded intake of a 1 mol/l sucrose solution which enabled calculation of total water gain, and collected cloacal fluid for measurements of volume, osmolality and aldosterone concentration. These variables were assessed hourly over 12 h of photophase, and averaged over the 12-h scotophase period. Overnight, when sunbirds were in negative water balance, aldosterone concentrations and outputs were significantly higher than diurnal levels, reflecting a shut-down of cloacal fluid production. Early morning was marked by a high rate of osmotic excretion, disproportionate to water gain or cloacal fluid output, followed by steady intake and cloacal fluid output during the morning and early afternoon. Reduced water flux (decreased feeding and cloacal fluid output) during mid-afternoon was accompanied by a paradoxical decline in osmotic excretion, whilst a significant increase in the discrepancy between water intake and output was recorded as the birds effectively stored water before the scotophase. These patterns of intake and excretion may be informative in explaining drinking and foraging behaviour in the field.

  7. Selenium absorption, distribution, and excretion in white sturgeon orally dosed with l-selenomethionine.

    PubMed

    Tashjian, Diran H; Hung, Silas S O

    2006-10-01

    The usefulness of a newly developed, combined technique consisting of esophageal intubation, dorsal aortic cannulation, and urinary catheterization to deliver Se orally and to monitor Se uptake, accumulation, and excretion in white sturgeon (Acipenser transmontanus) was explored. Groups of five yearling sturgeon (1-2 kg) each were intubated with 0 (sham), 250, 500, or 1,000 microg Se/kg body weight in the form of L-selenomethionine, an ecologically relevant organic form of Se. Selenium concentrations in whole blood, plasma, and red blood cells did not change in the sham group but began to rise within 2 h postintubation in the other groups, and levels remained near maximum concentrations throughout the 48-h sampling period. Average urinary Se excretion rates over the entire 48-h period were 0.05, 0.46, 0.61, and 2.15 microg Se/kg/h in sturgeon intubated with 0, 250, 500, and 1,000 microg Se/kg, respectively. Selenium excretion rates were highest within the first 6 h in all treatment groups except the sham group. Selenium concentrations in the liver were positively correlated with the intubated Se dosage.

  8. Turnover and urinary excretion of free and acetylated MS-222 rainbow trout, Salmo gairdneri

    USGS Publications Warehouse

    Hunn, J.B.; Schoettger, R.A.; Willford, W.A.

    1968-01-01

    Rainbow trout (Salmo gairdneri) anesthetized in 100 mg/liter of M.S. 222 at 12 C excreted the drug in free and acetylated forms via the urine during a 24-hr recovery period in freshwater. Of the M.S. 222 excreted, 77-96% was acetylated. Blood levels of free drug in anesthetized trout approximated 75% of the anesthetic concentration, but the amount of acetylated M.S. 222 was relatively insignificant. The blood and urine were cleared of the two fractions of M.S. 222 in 8 and 24 hr respectively. Low levels of aromatic amines of natural origin occurred in blood and urine and were subtracted from measurements of M.S. 222. Intraperitoneal injections of 10-100 mg/kg of M.S. 222 did not induce anesthesia; however, the 24-hr pattern of drug excretion was similar to that observed after anesthesia by immersion. Only 15-21 % of the injected dose was found in the urine, suggesting a second route of drug elimination.

  9. Observation of changes in urinary excretion of thorium in humans following ingestion of a therapeutic soil.

    PubMed

    Höllriegl, V; Greiter, M; Giussani, A; Gerstmann, U; Michalke, B; Roth, P; Oeh, U

    2007-01-01

    The study investigated the changes in urinary thorium excretion by humans following ingestion of a therapeutic soil, which contains about 10 ppm of thorium. This well-known healing earth in Germany has been considered as an alternative medicine for diarrhoea and gastric hyper-acidity. Six adult volunteers ingested this therapeutic soil in varying quantities for 1-15 days at levels approximating those described in the package insert of the medicine (10-60 g of soil per day). The subjects ingested about 0.1-0.6 mg of thorium daily, which is 100-600 times higher than the normal daily intake of about 1 microg thorium in Germany. All 24-h urine samples collected from the subjects during pre-ingestion, ingestion and post-ingestion periods of the soil were analyzed for (232)Th using inductively coupled plasma mass spectrometry (ICP-MS). The measured excretion values varied in a wide range. Apparently, the high thorium amounts administered did not increase the (232)Th excretion in urine as expected, suggesting that this soil ingestion will not result in a considerably higher and harmful uptake of thorium into the human body.

  10. Organic Anion Transporter 5 (Oat5) Urinary Excretion Is a Specific Biomarker of Kidney Injury: Evaluation of Urinary Excretion of Exosomal Oat5 after N-Acetylcysteine Prevention of Cisplatin Induced Nephrotoxicity.

    PubMed

    Bulacio, Romina Paula; Anzai, Naohiko; Ouchi, Motoshi; Torres, Adriana Mónica

    2015-08-17

    Cisplatin is a commonly used chemotherapeutic agent. Its main side-effect is nephrotoxicity. It was reported that the organic anion transporter 5 (Oat5) urinary excretion is elevated, implying renal perturbation, when no modifications of traditional markers of renal damage are still observed in cisplatin-induced acute kidney injury (AKI). It was also demonstrated that Oat5 is excreted in urine by the exosomal pathway. This study was designated to demonstrate the specific response of the urinary excretion of exosomal Oat5 to kidney injury independently of other cisplatin toxic effects, in order to strengthen Oat5 urinary levels as a specific biomarker of AKI. To accomplish that aim, we evaluated if urinary excretion of exosomal Oat5 returns to its basal levels when cisplatin renal damage is prevented by the coadministration of the renoprotective compound N-acetylcysteine. Four days after cisplatin administration, AKI was induced in cisplatin-treated male Wistar rats (Cis group), as it was corroborated by increased urea and creatinine plasma levels. Tubular damage was also observed. In cotreated animals (Cis + NAC group), plasma urea and creatinine concentrations tended to return to their basal values, and tubular damage was improved. Urinary excretion of exosomal Oat5 was notably increased in the Cis group, but when renal injury was ameliorated by N-acetylcysteine coadministration, that increase was undetected. So, in this work we observed that urinary excretion of exosomal Oat5 was only increased if renal insult is produced, demonstrating its specificity as a renal injury biomarker.

  11. Catecholamine excretion and circadian blood pressure profile in patients with pheochromocytoma.

    PubMed

    Dabrowska, Elzbieta; Lewandowski, Jacek; Jedrusik, Piotr; Symonides, Bartosz; Wocial, Bozena; Lapinski, Mariusz; Gaciong, Zbigniew

    2006-08-01

    Circadian blood pressure (BP) rhythm is often disturbed in patients with secondary forms of hypertension. The aim of the present article was to investigate changes in circadian BP profile parameters using two-step statistical approach by Fourier analysis in relation to day and night urinary catecholamine excretion in 35 patients with pheochromocytoma (mean age 42+/-19 years). Twenty-four-hour ambulatory BP measurements (ABPM) were obtained using the SpaceLabs 90,207 monitor. Daytime and night-time urine collection was obtained in all patients to determine circadian catecholamine excretion. Fourier analysis was applied to estimate measures of BP circadian rhythm in ABPM, including the highest (Max) and lowest (Min) systolic (SBP) and diastolic (DBP) BP values, norad (ampSBP, ampDBP), and early acrophase (APSBP, APDBP). The Fourier indices of circadian BP rhythm were: MaxSBP 153+/-28 mm Hg, MaxDBP 99+/-16 mm Hg, MinSBP 117+/-17 mm Hg, MinDBP 69+/-11 mm Hg, ampSBP 18+/-8 mm Hg, ampDBP 14+/-5 mm Hg, APSBP 10+/-5 (h), and APDBP 11+/-3 (h). Urine noradrenaline (NA), adrenaline (A), and dopamine (DA) excretion during the day (d) and night (n) were: dNA 103.5+/-89.8 microg/14 h, nNA 52+/-70.8 microg/10 h, dA 13.2+/-17.9 microg/14 h; nA 6.13+/-9.6 microg/10 h, dD 181.8+/-87.3 microg/14 h, and nD 89.3+/-59.8 microg/10 h. A positive correlation was observed between urine dNa excretion and MaxDBP (r=0.37, P<0.05), and urine nNA and urine dA excretion were correlated with APDBP (r=0.47, r=0.35, respectively, both P<0.05). Thus, in addition to the effect on mean 24-h BP values, catecholamines released by tumor may also disturb circadian BP rhythm in patients with pheochromocytoma.

  12. The alkaline tide and ammonia excretion after voluntary feeding in freshwater rainbow trout.

    PubMed

    Bucking, Carol; Wood, Chris M

    2008-08-01

    We investigated the potential acid-base and nitrogenous waste excretion challenges created by voluntary feeding in freshwater rainbow trout, with particular focus on the possible occurrence of an alkaline tide (a metabolic alkalosis created by gastric HCl secretion during digestion). Plasma metabolites (glucose, urea and ammonia) were measured at various time points before and after voluntary feeding to satiation (approximately 5% body mass meal of dry commercial pellets), as was the net flux of ammonia and titratable alkalinity to the water from unfed and fed fish. Arterial blood, sampled by indwelling catheter, was examined for post-prandial effects on pH, plasma bicarbonate and plasma CO2 tension. There was no significant change in plasma glucose or urea concentrations following feeding, whereas plasma ammonia transiently increased, peaking at threefold above resting values at 12 h after the meal and remaining elevated for 24 h. The increased plasma ammonia was correlated with an increase in net ammonia excretion to the water, with fed fish significantly elevating their net ammonia excretion two- to threefold between 12 and 48 h post feeding. These parameters did not change in unfed control fish. Fed fish likewise increased the net titratable base flux to the water by approximately threefold, which resulted in a transition from a small net acid flux seen in unfed fish to a large net base flux in fed fish. Over 48 h, this resulted in a net excretion of 13 867 micromol kg(-1) more base to the external water than in unfed fish. The arterial blood exhibited a corresponding rise in pH (between 6 and 12 h) and plasma bicarbonate (between 3 and 12 h) following feeding; however, no respiratory compensation was observed, as PaCO2 remained constant. Overall, there was evidence of numerous challenges created by feeding in a freshwater teleost fish, including the occurrence of an alkaline tide, and its compensation by excretion of base to the external water. The possible

  13. 5-HIAA excretion is not associated with bone metabolism in carcinoid syndrome patients.

    PubMed

    van Dijk, S C; de Herder, W W; Kwekkeboom, D J; Zillikens, M C; Feelders, R A; van Schaik, R H N; van Driel, M; van Leeuwen, J P T M

    2012-06-01

    In patients with a carcinoid syndrome and neuroendocrine tumors of the digestive tract (carcinoids), elevated circulating serotonin (5-hydroxytryptamine, 5-HT) levels can be demonstrated. It can be hypothesized that bone metabolism will be affected in these patients, since serotonin receptors are expressed on bone cells and serotonin effects on bone have been demonstrated. However, to date, no data are available on bone metabolism parameters in patients with neuroendocrine tumors of the digestive tract (carcinoids). In the current retrospective study we have measured serum bone formation markers P1CP (pro-collagen type I C-terminal), and osteocalcin, and the bone resorption marker NTx (collagen breakdown product N-terminal), in a group of 61 carcinoid patients with increased circulating serotonin levels as demonstrated by increased excretion of the serotonin breakdown product, 5-hydroxy indole acetic acid (5-HIAA), in the urine (>50 μmol/24 h, so-called "hyper-secretors") and a control group of 23 carcinoid patients, without increased 5-HIAA excretion (so-called non-secretors). The 24-h urinary excretion of 5-HIAA reflects the 24-h production of serotonin. Measurements of markers of bone metabolism were performed in serum samples obtained before the start of medical treatment. The hypersecretor group had on average a 10-fold higher urinary 5-HIAA excretion than the control (non-secretor) group. No significant differences in bone metabolism parameters could be demonstrated between hyper-secretors and controls (non-secretors). Correlation and regression analyses could not demonstrate significant age- and sex-adjusted correlations between urinary 5-HIAA excretion and any of the markers for bone turnover. A limitation is that the exposure time to elevated levels of serotonin is unknown, which might have been too short to induce effects on bone metabolism. Treatment of human pre-osteoblasts SV-HFO with serotonin didn't change alkaline phosphatase activity throughout

  14. Bicarbonate promotes BK-α/β4-mediated K excretion in the renal distal nephron.

    PubMed

    Cornelius, Ryan J; Wen, Donghai; Hatcher, Lori I; Sansom, Steven C

    2012-12-01

    Ca-activated K channels (BK), which are stimulated by high distal nephron flow, are utilized during high-K conditions to remove excess K. Because BK predominantly reside with BK-β4 in acid/base-transporting intercalated cells (IC), we determined whether BK-β4 knockout mice (β4KO) exhibit deficient K excretion when consuming a high-K alkaline diet (HK-alk) vs. high-K chloride diet (HK-Cl). When wild type (WT) were placed on HK-alk, but not HK-Cl, renal BK-β4 expression increased (Western blot). When WT and β4KO were placed on HK-Cl, plasma K concentration ([K]) was elevated compared with control K diets; however, K excretion was not different between WT and β4KO. When HK-alk was consumed, the plasma [K] was lower and K clearance was greater in WT compared with β4KO. The urine was alkaline in mice on HK-alk; however, urinary pH was not different between WT and β4KO. Immunohistochemical analysis of pendrin and V-ATPase revealed the same increases in β-IC, comparing WT and β4KO on HK-alk. We found an amiloride-sensitive reduction in Na excretion in β4KO, compared with WT, on HK-alk, indicating enhanced Na reabsorption as a compensatory mechanism to secrete K. Treating mice with an alkaline, Na-deficient, high-K diet (LNaHK) to minimize Na reabsorption exaggerated the defective K handling of β4KO. When WT on LNaHK were given NH(4)Cl in the drinking water, K excretion was reduced to the magnitude of β4KO on LNaHK. These results show that WT, but not β4KO, efficiently excretes K on HK-alk but not on HK-Cl and suggest that BK-α/β4-mediated K secretion is promoted by bicarbonaturia.

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

    EPA Science Inventory

    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...

  16. Combined laboratory and epidemiological study of the effect of load on the excretion of Beta aminoisobutyric acid

    SciTech Connect

    Farkas, W.R.; Fischbein, A.; Sharma, O.K.S.

    1987-01-01

    Beta Aminoisobutyric Acid (BAIB) is the end product of the catabolism of thymine. BAIB is actively secreted and is a common component of human urine. Since lead has not been reported to degrade DNA we were surprised to find elevated amounts of BAIB in the urine of workers who had lead poisoning. To further study this phenomenon a group of 26 males engaged in demolition work which exposed them to lead was compared to a control group of 40 male hospital workers with regard to BAIB excretion. The exposed workers excreted an average of 19.26 nmoles of BAIB per ..mu..mole creatinine. The value for the control group was 6.02. In order to determine the effect of lead on BAIB excretion under controlled conditions, the authors exposed marmosets to different doses of lead and monitored the lead poisoning via the blood level of zinc protoporphyrin. They found a strong correlation between exposure to lead and excretion of BAIB.

  17. Prolonged excretion of a low-pathogenicity H5N2 avian influenza virus strain in the Pekin duck

    PubMed Central

    Carranza-Flores, José Manuel; Padilla-Noriega, Luis; Loza-Rubio, Elizabeth

    2013-01-01

    H5N2 strains of low-pathogenicity avian influenza virus (LPAIV) have been circulating for at least 17 years in some Mexican chicken farms. We measured the rate and duration of viral excretion from Pekin ducks that were experimentally inoculated with an H5N2 LPAIV that causes death in embryonated chicken eggs (A/chicken/Mexico/2007). Leghorn chickens were used as susceptible host controls. The degree of viral excretion was evaluated with real-time reverse transcriptase-polymerase chain reaction (RRT-PCR) using samples from oropharyngeal and cloacal swabs. We observed prolonged excretion from both species of birds lasting for at least 21 days. Prolonged excretion of LPAIV A/chicken/Mexico/2007 is atypical. PMID:23820212

  18. [Effect of the protein-free calf-blood-extract (Solcoseryl) on the excretion of estrogens in chronic placental insufficiency].

    PubMed

    Herre, H D; Kyank, H; Adomssent, S; Wilken, H P

    1976-01-01

    In a double blind study the action of Solcoseryl was tested in 31 patients during late pregnancy with chronic placental insufficiency. Under treatment with Solcoseryl a significant increase in urinary estrogen excretion occurred in relation to the placebo-group.

  19. Plasma levels, tissue distribution, and excretion of radioactivity after single-dose administration of (3H)-oleic acid added to D-004, a lipid extract of the fruit of Roystonea regia, in rats

    PubMed Central

    Pérez, L. Yohani; Menéndez, Roberto; Más, Rosa; González, Rosa M.

    2006-01-01

    , and urine samples of rats that did not receive (3H)-oleic acid were used as controls. Excretion was expressed as the percentage of the radioactivity excreted via each route with respect to the total radioactive dose administered to each rat. Results: A total of 50 rats were included in the experiment (mean age, 4 weeks; mean weight, 310 g). Absorption was rapid; mean Cmax was 195.56 (31.12) μgEq/mL, and mean Tmax was 2 hours. Thereafter, a biphasic decay of TR was found: a rapid first phase (t1/2α, 1.33 hours), followed by a slower second elimination phase (t1/2β, 36.07 hours). Radioactivity was rapidly and broadly distributed throughout the tissues, with more accumulating in the prostate than elsewhere. In the first 8 hours, accumulation of TR was greatest in the prostate, followed by the liver, small intestine, and plasma. Subsequently, TR increased in the small intestine, while it decreased in the liver and plasma. In contrast, over the periods of 24 and 144 hours after administration, TR increased in the adipose tissue, while it decreased in the other tissues and plasma. During those intervals, TR was greatest in the prostate, followed by adipose tissue. Mean peak radioactivity in the prostate (562.41 μgEq/g) was reached at 4 hours and decreased slowly thereafter. The prostate had the highest values of t1/2β and cumulative AUC compared with the other tissues and plasma. Mean (SD) TR was similar in feces (33.48% [4.90%]) and urine (28.96% [5.32%]), with total excretion being 62.40% (5.90%) of the administered dose. Conclusions: In this experimental study, after single-dose administration of oral D-004 radiolabeled with (3H)-oleic acid in rats, TR was rapidly and widely distributed across the tissues, with the prostate having the highest accumulation of radioactivity. Excretion of TR was limited, with similar amounts being excreted in feces and urine. The broad distribution of radiolabeled oleic acid and/or its metabolites suggests (SD) pharmacokinetic

  20. Zea mays L. extracts modify glomerular function and potassium urinary excretion in conscious rats.

    PubMed

    Velazquez, D V O; Xavier, H S; Batista, J E M; de Castro-Chaves, C

    2005-05-01

    Diuretic and uricosuric properties have traditionally been attributed to corn silk, stigma/style of Zea mays L. Although the diuretic effect was confirmed, studies of the plant's effects on renal function or solute excretion were lacking. Thus, we studied the effects of corn silk aqueous extract on the urinary excretion of water, Na+, K+, and uric acid. Glomerular and proximal tubular function and Na+ tubular handling were also studied. Conscious, unrestrained adult male rats were housed in individual metabolic cages (IMC) with continuous urine collection for 5 and 3 h, following two protocols. The effects of 25, 50, 200, 350, and 500 mg/kg body wt. corn silk extract on urine volume plus Na+ and K+ excretions were studied in water-loaded conscious rats (2.5 ml/100 g body wt.) in the IMC for 5 h (Protocol 1). Kaliuresis was observed with doses of 350 (100.42 +/- 22.32-120.28 +/- 19.70 microEq/5 h/100 g body wt.; n = 13) and 500 mg/kg body wt. (94.97+/- 29.30-134.32 +/- 39.98 microEq/5h/100 g body wt.; n = 12; p<0.01), and the latter dose resulted in diuresis as well (1.98 +/- 0.44-2.41 +/- 0.41 ml/5 h/100 g body wt.; n = 12; p<0.05). The effects of a 500 mg/kg body wt. dose of corn silk extract on urine volume, Na+, K+ and uric acid excretions, and glomerular and proximal tubular function, were measured respectively by creatinine (Cler) and Li+ (ClLi) clearances and Na+ tubular handling, in water-loaded rats (5 ml/100 g body wt.) in the IMC for 3 h (Protocol 2). Clcr (294.6 +/- 73.2, n = 12, to 241.7 +/- 48.0 microl/ min/100 g body wt.; n = 13; p<0.05) and the Na+ filtered load (41.9 +/- 10.3, n = 12, to 34.3 +/- .8, n = 13, p<0.05) decreased and ClLi and Na+ excretion were unchanged, while K+ excretion (0.1044 +/- 0.0458, n=12, to 0.2289 +/- 0.0583 microEq/min/100 body wt.; n = 13; p<0.001) increased. For Na+ tubular handling, the fractional proximal tubular reabsorption (91.5 +/- 3.5, n = 12, to 87.5 +/- 3.4%; n = 13; p<0.01) decreased, and both fractional distal

  1. Urinary excretion rates of natural estrogens and androgens from humans, and their occurrence and fate in the environment: a review.

    PubMed

    Liu, Ze-Hua; Kanjo, Yoshinori; Mizutani, Satoshi

    2009-09-01

    Endocrine disrupting compounds (EDCs) are pollutants with estrogenic or androgenic activities at very low concentrations and are emerging as a major concern for water quality. For sewage of municipal wastewater treatment plants in cities, one of the most important sources of EDCs are natural estrogens and natural androgens (NEAs) excreted from humans. Therefore, estrogenic/androgenic potencies or relative binding affinity of the NEAs were first outlined from different sources, and data of urinary excretion rates of NEAs were summarized. To evaluate their estrogenic activities, their excretion rates of estrogen equivalent (EEQ) or testosterone (T) equivalent (TEQ) were also calculated. Based on our summary, the total excretion rates of EEQ by estrone (E1), 17beta-estradiol (E2), and estriol (E3) only accounted for 66-82% of the total excretion rate of EEQ among four different groups, and the other corresponding natural estrogens contributed 18-34%, which meant that some of the other natural estrogens may also exist in wastewater with high estrogenic activities. Based on the contribution ratio of individual androgens to the total excretion rate of TEQ, five out of 12 natural androgens, T, dihydrotestosterone (DHT), androsterone (AD), 5beta-androstanediol (beta-ADL), and androstenediol (ANL) were evaluated as the priority natural androgens, which may exist in wastewater with high androgenic activities. Published data on occurrence and fate of the NEAs including natural estrogen conjugates in the environment were also summarized here.

  2. Human urinary excretion profile after smoking and oral administration of ( sup 14 C)delta 1-tetrahydrocannabinol

    SciTech Connect

    Johansson, E.; Gillespie, H.K.; Halldin, M.M. )

    1990-05-01

    The urinary excretion profiles of delta 1-tetrahydrocannabinol (delta 1-THC) metabolites have been evaluated in two chronic and two naive marijuana users after smoking and oral administration of ({sup 14}C)delta 1-THC. Urine was collected for five days after each administration route and analyzed for total delta 1-THC metabolites by radioactivity determination, for delta 1-THC-7-oic acid by high-performance liquid chromatography, and for cross-reacting cannabinoids by the EMIT d.a.u. cannabinoid assay. The average urinary excretion half-life of {sup 14}C-labeled delta 1-THC metabolites was calculated to be 18.2 +/- 4.9 h (+/- SD). The excretion profiles of delta 1-THC-7-oic acid and EMIT readings were similar to the excretion profile of {sup 14}C-labeled metabolites in the naive users. However, in the chronic users the excretion profiles of delta 1-THC-7-oic acid and EMIT readings did not resemble the radioactive excretion due to the heavy influence from previous Cannabis use. Between 8-14% of the radioactive dose was recovered in the urine in both user groups after oral administration. Lower urinary recovery was obtained both in the chronic and naive users after smoking--5 and 2%, respectively.

  3. Daily Intake of Magnesium and its Relation to Urinary Excretion in Korean Healthy Adults Consuming Self-Selected Diets.

    PubMed

    Choi, Mi-Kyeong; Weaver, Connie M

    2017-03-01

    Magnesium (Mg) is an essential nutrient as a structural constituent of bone and regulator of >300 enzymes. However, studies on intake and urinary excretion of Mg are limited. The purpose of this study was to evaluate Mg intake and its relation to 24-h urinary excretion in healthy adults. Anthropometric measurements and dietary intake by the 24-h recall method were conducted in 80 adults aged 21-69 (average 44.3) years. Urine was collected for 24 h on the day following the dietary survey. Dietary assessment and 24-h urine collection were repeated 3 days later. Daily intake and urinary excretion of Mg were analyzed using Can-Pro and ICP-OES, respectively. The statistical analysis was conducted using SAS program. Mg intake of the subjects was 319 ± 129 mg/day for men and 277 ± 94 mg/day for women and the proportion of subjects who did not meet the estimated average requirement was 50 and 67.5 % for men and women, respectively. Urinary Mg excretion was 30.3 % of the daily Mg intake. Urinary Mg excretion was not significantly correlated with the daily Mg intake. Korean adults are not meeting the recommended intake of Mg, but its urinary excretion suggests homeostasis is not compromised.

  4. Effect of metoprolol on 24-hour urinary excretion of adrenal steroids and kallikrein in patients with essential hypertension.

    PubMed Central

    Fritschka, E.; Gotzen, R.; Kittler, R.; Schöneshöfer, M.

    1984-01-01

    Treatment of fifteen patients with essential hypertension over four weeks using the beta 1-adrenoceptor blocking agent, metoprolol, resulted in a decrease in 24 h urinary excretion of kallikrein and aldosterone along with a decrease in plasma renin activity. There was no significant change in 24 h excretion rates of the free adrenal steroids deoxycorticosterone, 18-OH-deoxycorticosterone, corticosterone, cortisol or 18-OH-corticosterone during treatment, which were not significantly different from excretion rates of normal males, thus excluding inhibitory effects of adrenal steroids on urinary kallikrein activity. A positive correlation was found between plasma renin activity and urinary excretion of kallikrein during the control period and after 2 weeks on metoprolol, supporting the assumption of a preserved link between the renin-angiotensin-aldosterone system and the renal excretion of kallikrein in these patients. The decrease in kallikrein excretion during beta 1-adrenoceptor blockade in patients with essential hypertension may be explained by a reduction in sympathetic tone and by reduced activity of the renin-aldosterone system. PMID:6367871

  5. Ammonia excretion in Caenorhabditis elegans: Physiological and molecular characterization of the rhr-2 knock-out mutant.

    PubMed

    Adlimoghaddam, Aida; O'Donnell, Michael J; Kormish, Jay; Banh, Sheena; Treberg, Jason R; Merz, David; Weihrauch, Dirk

    2016-05-01

    Previous studies have shown the free living soil nematode Caenorhabditis elegans (N2 strain) to be ammonotelic. Ammonia excretion was suggested to take place partially via the hypodermis, involving the Na(+)/K(+)-ATPase (NKA), V-ATPase (VAT), carbonic anhydrase, NHX-3 and a functional microtubule network and at least one Rh-like ammonia transporter RHR-1. In the current study, we show that a second Rh-protein, RHR-2, is highly expressed in the hypodermis, here also in the apical membrane of that tissue. To further characterize the role of RHR-2 in ammonia excretion, a knock-out mutant rhr-2 (ok403), further referred to as ∆rhr-2, was employed. Compared to wild-type worms (N2), this mutant showed a lower rate of ammonia excretion and a lower hypodermal H(+) excretion rate. At the same time rhr-1, nka, vat, and nhx-3 showed higher mRNA expression levels when compared to N2. Also, in contrast to N2 worms, ∆rhr-2 did not show enhanced ammonia excretion rates when exposed to a low pH environment, suggesting that RHR-2 represents the apical NH3 pathway that allows ammonia trapping via the hypodermis in N2 worms. A hypothetical model for the mechanism of hypodermal ammonia excretion is proposed on the basis of data in this and previous investigations.

  6. Amorphous Silica Based Nanomedicine with Safe Carrier Excretion and Enhanced Drug Efficacy

    NASA Astrophysics Data System (ADS)

    Zhang, Silu

    With recent development of nanoscience and nanotechnology, a great amount of efforts have been devoted to nanomedicine development. Among various nanomaterials, silica nanoparticle (NP) is generally accepted as non-toxic, and can provide a versatile platform for drug loading. In addition, the surface of the silica NP is hydrophilic, being favorable for cellular uptake. Therefore, it is considered as one of the most promising candidates to serve as carriers for drugs. The present thesis mainly focuses on the design of silica based nanocarrier-drug systems, aiming at achieving safe nanocarrier excretion from the biological system and enhanced drug efficacy, which two are considered as most important issues in nanomedicine development. To address the safe carrier excretion issue, we have developed a special type of selfdecomposable SiO2-drug composite NPs. By creating a radial concentration gradient of drug in the NP, the drug release occurred simultaneously with the silica carrier decomposition. Such unique characteristic was different from the conventional dense SiO2-drug NP, in which drug was uniformly distributed and can hardly escape the carrier. We found that the controllable release of the drug was primarily determined by diffusion, which was caused by the radial drug concentration gradient in the NP. Escape of the drug molecules then triggered the silica carrier decomposition, which started from the center of the NP and eventually led to its complete fragmentation. The small size of the final carrier fragments enabled their easy excretion via renal systems. Apart from the feature of safe carrier excretion, we also found the controlled release of drugs contribute significantly to the drug efficacy enhancement. By loading an anticancer drug doxorubicin (Dox) to the decomposable SiO 2-methylene blue (MB) NPs, we achieved a self-decomposable SiO 2(MB)-Dox nanomedicine. The gradual escape of drug molecules from NPs and their enabled cytosolic release by optical

  7. Increasing urinary calcium excretion after ceftriaxone and cephalothin therapy in adults: possible association with urolithiasis.

    PubMed

    Otunctemur, Alper; Ozbek, Emin; Polat, Emre Can; Cekmen, Mustafa; Dursun, Murat; Cakir, Suleyman Sami

    2014-04-01

    In children, stone formation after ceftriaxone (CTRX) therapy by increasing calcium excretion was showed in the literature. In this study, we investigated the effect of CTRX, cephalothin (CP) and ampicillin (AS) therapy on urinary calcium excretion in adults. 180 participants included in the study who divided into six equal groups. The groups were; (1) CTRX therapy in stone free patients, (2) CTRX therapy in patients who have urinary stone; (3) CP therapy in stone free patients, (4) CP therapy in patients with urinary stone, (5) AS therapy in stone free patients, (6) AS therapy in patients with urinary stone. The patients received 2 g/day intravenous CTRX, CP and AS for 5 days in all groups respectively. There were no significant differences in demographic characteristics and blood biochemistry between the groups. Before and 5 days after the antibiotic therapies, the participants were evaluated by 24-h urinary calcium to creatinine ratio. Results were compared between the groups statistically by ANOVA and Tukey test. After drug therapies in group 2 and 4, the excretion of calcium to creatinine ratio in 24-h urine was more than the other groups. We found that both groups of two drugs therapy with or without stones (groups 1, 2, 3, 4), have significantly increased calcium to creatinine ratio in 24-h urine (p < 0.05). We did not find statistically difference in groups 5 and 6, after AS therapy. As a result of the study, we suggest that the patients who have taken antibiotic therapy with CTRX or CP, have an increased risk for the urolithiasis. In addition, we think that these drugs should be used carefully especially in patients with urolithiasis.

  8. Urinary Sodium and Potassium Excretion and Carotid Atherosclerosis in Chinese Men and Women.

    PubMed

    Dai, Xiao-Wei; Wang, Cheng; Xu, Ying; Guan, Ke; Su, Yi-Xiang; Chen, Yu-Ming

    2016-10-01

    Limited studies have examined the association between sodium (Na) and potassium (K) levels and the risk of atherosclerosis. This study examined whether higher Na and Na/K levels and low K levels were independent risk factors for atherosclerosis. This community-based cross-sectional study included 3290 subjects (1067 men and 2223 women) 40 to 75 years of age in Guangzhou, China, between 2011 and 2013. Urinary excretion of Na and K were measured from the first morning void, and creatinine-adjusted values were used. The intima-media thickness (IMT) of the carotid common artery and the carotid bifurcation was measured with high-resolution B-mode ultrasonography. Dietary K and Na intake and other covariates were obtained by face-to-face interviews. A significant positive association was seen between urinary Na excretion and carotid atherosclerosis after adjustment for age, sex, and other lifestyle covariates. The odds ratios (OR) and 95% confidence interval (CI) of the highest (vs. lowest) quartile of urinary Na were 1.32 (1.04-1.66) for carotid plaques, 1.48 (1.18-1.87) for increased common carotid artery IMT, and 1.55 (1.23-1.96) for increased carotid bifurcation IMT (all p-trend < 0.01). A similar positive association was observed between urinary Na/K levels and carotid plaque and increased IMT, and between dietary Na intake and increased bifurcation IMT. Regarding potassium data, we only found a significantly lower presence of carotid plaque (OR 0.72, 95% CI 0.57-0.91) for quartile 2 (vs. 1) of urinary K. Our findings suggest that higher levels of urinary excretion Na and Na/K are significantly associated with greater presence of carotid atherosclerosis in Chinese adults.

  9. SN2-Palmitate Reduces Fatty Acid Excretion in Chinese Formula-fed Infants

    PubMed Central

    Bar-Yoseph, Fabiana; Lifshitz, Yael; Cohen, Tzafra; Malard, Patrice; Xu, Chungdi

    2016-01-01

    ABSTRACT Objectives: Palmitic acid (PA) comprises 17% to 25% of human milk fatty acids, of which 70% to 75% are esterified to the SN2 position of the triglyceride (SN2-palmitate). In vegetable oils, which are commonly used in infant formulas, palmitate is primarily esterified to other positions, resulting in reduced calcium and fat absorption and hard stools. The aim of this study was to elucidate the effects of SN2-palmitate on nutrient excretion. Methods: In total, 171 Chinese infants were included (within 14 days of birth) in this multicenter study. Formula-fed infants were randomly assigned to receive either SN2-palmitate formula (INFAT, n = 57) or control formula (n = 57). The formulas (Biostime, China) differed only in their SN2 PA proportions. Stool was collected at 6 postnatal weeks. Results: The stool dry weight and fat content of the SN2-palmitate group were lower compared with the control group (dry weight 4.25 g vs 7.28 g, P < 0.05; fat 0.8 g vs 1.2 g, P < 0.05). The lipid component was also significantly lower for the SN2-palmitate group (0.79 g vs 1.19 g, P < 0.05). PA, representing ∼50% of the saponified fatty acids, was significantly lower in the SN2-palmitate group compared with the control group (0.3 g vs 0.7 g, P < 0.01). Breast-fed infants had a significantly lower stool dry weight, fat content, and saponified fat excretion compared with formula-fed infants (P < 0.01). Conclusions: Similar to breast milk, the SN2-palmitate infant formula primarily reduced calcium-saponified fat excretion. The results of this study further emphasize the nutritional importance of SN2-palmitate structured fat for infants. PMID:26334255

  10. Excretion of (3H)prednisolone in clinically normal and experimentally infected bovine udders

    SciTech Connect

    Geleta, J.N.; Shimoda, W.; Mercer, H.D.

    1984-08-01

    The excretion rate of (3H)prednisolone from clinically normal and experimentally infected udders of 10 lactating cows was studied. Each quarter of 6 cows was injected with a single dose of (3H)prednisolone mixed with non-radioactive prednisolone equivalent to 10 mg in 10 ml of peanut oil base. Each of the remaining 4 cows was given 40 mg of nonradioactive prednisolone and (3H)prednisolone in 60% ethanol IV. Control and postadministration samples of blood, milk, and urine were examined for radioactivity. The effects of (3H)prednisolone were evaluated in the same cows, first in clinically normal udders, then 2 weeks later in udders experimentally infected with Streptococcus agalactiae. Absorption and elimination of prednisolone were the same before and after induced infection. Within 3 hours after intramammary injection, 95% of the labeled prednisolone was absorbed systemically, less than 5% of this dose was recovered in milk, and 29% was excreted in urine. After IV injection of (3H)prednisolone, less than 0.2% of the total radioactivity was recovered in milk and less than 46% was excreted in urine. Clinical mastitis induced by S agalactiae was moderate. Circulating blood leukocytes and somatic cells in the milk of normal cows remained essentially unchanged. The leukocyte response to induced infection was rapid in blood and milk. Large numbers of leukocytes were noticed in the milk and a severe leukopenia occurred. Prednisolone treatment did not alter the number of somatic cells in milk or reduce the inflammatory response of experimentally infected cows.

  11. Branchial membrane-associated carbonic anhydrase activity maintains CO2 excretion in severely anemic dogfish.

    PubMed

    Gilmour, K M; Perry, S F

    2004-06-01

    Plasma CO(2) reactions in Pacific spiny dogfish (Squalus acanthias) have access to plasma and gill membrane-associated carbonic anhydrase (CA). Acute severe experimental anemia and selective CA inhibitors were used to investigate the role of extracellular CA in CO(2) excretion. Anemia was induced by blood withdrawal coupled to volume replacement with saline. Lowering hematocrit from 14.2 +/- 0.4% (mean +/- SE; N = 31) to 5.2 +/- 0.1% (N = 31) had no significant impact on arterial or venous CO(2) tensions (Pa(CO(2)) and Pv(CO(2)), respectively) over the subsequent 2 h. PCO(2) was maintained despite the reduction in red cell number and a significant 32% increase in cardiac output (V(b)), both of which have been found to cause Pa(CO(2)) increases in teleost fish. By contrast, treatment of anemic dogfish with the CA inhibitors benzolamide (1.3 mg/kg) or F3500 (50 mg/kg), to selectively inhibit extracellular CA, elicited rapid and significant increases in Pa(CO(2)) of 0.68 +/- 0.17 Torr (N = 6) and 0.53 +/- 0.11 Torr (N = 7), respectively, by 30 min after treatment. These findings provide a functional context in which extracellular CA in dogfish contributes substantially to CO(2) excretion. Additionally, the apparent lack of effect of V(b) changes on PCO(2) suggests that, in contrast to teleost fish, CO(2) excretion in dogfish does not behave as a diffusion-limited system.

  12. Passalurus ambiguus: new insights into copromicroscopic diagnosis and circadian rhythm of egg excretion.

    PubMed

    Rinaldi, Laura; Russo, Tamara; Schioppi, Mariangela; Pennacchio, Saverio; Cringoli, Giuseppe

    2007-08-01

    The present paper reports a study on the in vivo diagnosis and egg excretion rhythm of the pinworm Passalurus ambiguus in domesticated rabbits. Three copromicroscopic techniques were compared: the cellophane tape test, the McMaster technique, and the FLOTAC technique. Out of the 51 New Zealand White rabbit does examined, 42 (82.3%) resulted positive when examined with the FLOTAC technique, 39 (76.5%) with the cellophane tape test, and 29 (56.9%) with the McMaster technique. The agreement between the FLOTAC technique and the cellophane tape test was almost perfect (greater than 0.8); only moderate were the agreements (0.4) between the FLOTAC and the McMaster techniques and between the McMaster technique and the cellophane tape test. The results showed that the FLOTAC technique can be used for the quali-quantitative coprological diagnosis of P. ambiguus in rabbits due to its great sensitivity, as already shown for parasites of other animal species. The circadian rhythm of egg excretion by P. ambiguus was studied utilizing 42 individually caged rabbit does; fecal samples were collected from each cage every 6 h, i.e., at 6:00-12:00 hours, 12:00-18:00 hours, 18:00-24:00 hours, and 24:00-6:00 hours, and were analyzed by the FLOTAC technique. A circadian rhythm of P. ambiguus egg excretion was found, with significant lower values at 6:00-12:00 hours. In conclusion, the present study showed that the FLOTAC technique is the best copromicroscopic method for assessing P. ambiguus prevalence and intensity in rabbits and that the afternoon and evening hours are the best times for fecal sampling to perform the pinworm diagnosis.

  13. Urinary Sodium and Potassium Excretion and Carotid Atherosclerosis in Chinese Men and Women

    PubMed Central

    Dai, Xiao-Wei; Wang, Cheng; Xu, Ying; Guan, Ke; Su, Yi-Xiang; Chen, Yu-Ming

    2016-01-01

    Limited studies have examined the association between sodium (Na) and potassium (K) levels and the risk of atherosclerosis. This study examined whether higher Na and Na/K levels and low K levels were independent risk factors for atherosclerosis. This community-based cross-sectional study included 3290 subjects (1067 men and 2223 women) 40 to 75 years of age in Guangzhou, China, between 2011 and 2013. Urinary excretion of Na and K were measured from the first morning void, and creatinine-adjusted values were used. The intima-media thickness (IMT) of the carotid common artery and the carotid bifurcation was measured with high-resolution B-mode ultrasonography. Dietary K and Na intake and other covariates were obtained by face-to-face interviews. A significant positive association was seen between urinary Na excretion and carotid atherosclerosis after adjustment for age, sex, and other lifestyle covariates. The odds ratios (OR) and 95% confidence interval (CI) of the highest (vs. lowest) quartile of urinary Na were 1.32 (1.04–1.66) for carotid plaques, 1.48 (1.18–1.87) for increased common carotid artery IMT, and 1.55 (1.23–1.96) for increased carotid bifurcation IMT (all p-trend < 0.01). A similar positive association was observed between urinary Na/K levels and carotid plaque and increased IMT, and between dietary Na intake and increased bifurcation IMT. Regarding potassium data, we only found a significantly lower presence of carotid plaque (OR 0.72, 95% CI 0.57–0.91) for quartile 2 (vs. 1) of urinary K. Our findings suggest that higher levels of urinary excretion Na and Na/K are significantly associated with greater presence of carotid atherosclerosis in Chinese adults. PMID:27706075

  14. Increased urinary excretion of 8-hydroxydeoxyguanosine in engine room personnel exposed to polycyclic aromatic hydrocarbons

    PubMed Central

    Nilsson, R; Nordlinder, R; Moen, B; Ovrebo, S; Bleie, K; Skorve, A; Hollund, B; Tagesson, C

    2004-01-01

    Background: Previous investigations indicate that engine room personnel on ships are exposed to polycyclic aromatic hydrocarbons (PAH) from oil and oil products, with dermal uptake as the major route of exposure. Several PAH are known carcinogens and mutagens. Aims: To investigate the urinary excretion of a marker for oxidative DNA damage, 8-hydroxydeoxy-guanosine (8OHdG), in engine room personnel, and to study the association between 8OHdG and 1-hydroxypyrene (1OHP), a biological marker for PAH exposure. Methods: Urine samples were collected from engine room personnel (n = 36) on 10 Swedish and Norwegian ships and from unexposed controls (n = 34) with similar age and smoking habits. The exposure to oils, engine exhaust, and tobacco smoke 24 hours prior to sampling was estimated from questionnaires. The urinary samples were frozen for later analyses of 8OHdG and 1OHP by high performance liquid chromatography. Results: Excretion in urine of 8OHdG (adjusted to density 1.022) was similar for controls (mean 18.0 nmol/l, n = 33), and for those who had been in the engine room without skin contact with oils (mean 18.7 nmol/l, n = 15). Engine room personnel who reported skin contact with oil had increased excretion of 8OHdG (mean 23.2 nmol/l, n = 19). The difference between this group and the unexposed controls was significant. The urinary levels of ln 1OHP and ln 8OHdG were significantly correlated, and the association was still highly significant when the effects of smoking and age were accounted for in a multiple regression analysis. Conclusion: Results indicate that exposure to PAH or possibly other compounds from skin contact with oils in engine rooms may cause oxidative DNA damage. PMID:15258276

  15. Monitoring and managing urinary albumin excretion: practical advice for primary care clinicians.

    PubMed

    Bakris, George L; Kuritzky, Louis

    2009-07-01

    Albuminuria has a strong, continuous, direct, linear relationship with adverse cardiovascular (CV) outcomes and chronic kidney disease progression. Even at levels below the accepted upper limit of what is considered "normal" daily albumin excretion (< 30 mg/24 h), a relationship between albumin excretion level and adverse CV events is evident. Primary care clinicians (eg, physicians, nurse practitioners, physicians' assistants) are usually the first point of contact for patients at risk for CV and kidney disease. Hence, identifying and treating problematic albuminuria levels are important in primary care. Both the American Diabetes Association (ADA) and the National Kidney Foundation (NKF) endorse routine annual screening for microalbuminuria (small amounts of albumin in the urine). Once excess albumin excretion is detected, clinicians must employ aggressive CV risk reduction. To optimize outcomes, treatment of microalbuminuria often requires the combined skills of experts in primary care, cardiology, metabolic disease, and nephrology. Although blood pressure reduction usually improves microalbuminuria, agents that block the renin-angiotensin-aldosterone system (RAAS) are most efficacious. Renin-angiotensin-aldosterone system blockers (ie, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, direct renin inhibitors) may confer CV and kidney advantages in high-risk patients. Their effects on microalbuminuria reduction are greater than those associated with attaining guideline-recommended blood pressure goals. Effective RAAS blockade sometimes induces transient changes in creatinine and potassium, which merit consistent monitoring for the first 2 to 3 months of their use, but rarely necessitate discontinuation. This article also presents an approach to managing increases in creatinine and potassium that should fit comfortably in the hands of primary care clinicians.

  16. Urate excretion by the isolated perfused rat kidney and modification by drugs.

    PubMed

    MacDougall, M L; Wiegmann, T B

    1989-12-01

    Urate excretion in the isolated perfused rat kidney was studied over a wide range of perfusate urate concentrations (13.9-376.8 microM). Fractional excretion of urate (FEurate) averaged 57.9 +/- 2.0% (range, 58.5-59.6%), showed marked interanimal variability, but was not dependent on the perfusate-free urate concentration. In paired experiments, the effects of five drugs (probenecid, pyrazinoate, furosemide, salicylate, and oxonate) on FEurate were evaluated. A low concentration of pyrazinoate (0.2 mM) decreased FEurate (62.0 +/- 1.9 vs 53.8 +/- 2.4%, P less than 0.05), as did 0.8 mM pyrazinoate (59.5 +/- 2.4 vs 48.4 +/- 2.7%, P less than 0.05). Probenecid (1 mM) decreased FEurate (59.3 +/- 3.1 vs 52.0 +/- 2.5%, P less than 0.05) but 2.5 mM probenecid did not alter FEurate (48.0 +/- 6.3 vs 47.8 +/- 6.9%). Oxonate (0.1 mM) also decreased FEurate (75.8 +/- 4.2 vs 67.1 +/- 2.1%, P less than 0.05) while 0.2 mM oxonate had no effect (66.4 +/- 3.5 vs 61.5 +/- 4.6%). Neither salicylate nor furosemide affected FEurate, although both drugs caused a saliuresis and diuresis. Thus, urate transport in rat kidneys in vitro is not dependent on urate concentration, unlike man. Some drugs known to affect urate excretion in humans and rats did not have similar effects in isolated kidneys. Isolated organ studies provide additional information is understanding renal urate handling.

  17. The effect of ACTH upon faecal glucocorticoid excretion in the koala.

    PubMed

    Davies, Nicole; Gillett, Amber; McAlpine, Clive; Seabrook, Leonie; Baxter, Greg; Lunney, Daniel; Bradley, Adrian

    2013-10-01

    Environmental changes result in physiological responses of organisms, which can adversely affect population dynamics and reduce resistance to disease. These changes are expressed in chronic levels of stress. The measurement of glucocorticoid (GC) concentrations in faeces is a non-invasive method for monitoring stress in wildlife. The metabolism and excretion of steroids differ significantly between species and, as a consequence, non-invasive methods must be physiologically validated for each species. Koalas (Phascolarctos cinereus) are declining in numbers through much of their range. The role of chronic stress in koala populations has not been identified. Prior to the assessment of faecal GC concentrations in wild koala populations, the excretion timing and concentrations of GCs need to be determined. In this study, we assessed a method for identifying and measuring the concentrations of GC metabolites in faecal pellets of captive koalas following ACTH treatment. The results show that an elevation of plasma cortisol concentrations, using sustained release of ACTH, results in elevated concentrations of faecal cortisol/cortisol metabolites. Taking into account the excretion time lag, an increase in faecal cortisol metabolite concentrations corresponds to the release of GCs from the adrenal cortex as early as 36 h before faecal pellet collection. The calculations of steroid partitioning of plasma cortisol showed that the ACTH-stimulated values were significantly different from the control values for the concentrations of free, corticosteroid-binding globulin-bound and albumin-bound cortisol. This study validates the use of faecal cortisol analysis to assess the activity of the hypothalamo-pituitary-adrenocortical axis in freshly collected koala faecal pellets and indicates that the method should be suitable to assess the adrenocortical status of koalas in wild populations.

  18. The excretion and environmental effects of amoxicillin, ciprofloxacin, and doxycycline residues in layer chicken manure.

    PubMed

    Peng, Ping-cai; Wang, Yan; Liu, Long-yong; Zou, Yong-de; Liao, Xin-di; Liang, Juan-boo; Wu, Yin-bao

    2016-05-01

    The excretion rates and ecological risk to the environment of three commonly used veterinary antibiotics (VAs), amoxicillin, ciprofloxacin, and doxycycline, in layer hen manure during the application and withdrawal periods were investigated in a study consisting of a control group fed with VA-free basal diet and nine treatment groups consisted of three levels (200 mg/kg, 100 mg/kg, and 50 mg/kg) of amoxicillin (AMX), ciprofloxacin (CIP), or doxycycline (DOC). Each treatment group was replicated seven times with three layer hens per replication. Results of the study showed that the average excretion rates of AMX in the 200, 100, and 50 mg/kg groups were 67.88, 55.82, and 66.15%, respectively, while those for CIP and DOC were 47.84, 51.85, and 44.87% and 82.67, 94.39, and 95.72%, respectively. The concentrations of the above veterinary drugs in manure decreased sharply in the withdrawal period (7, 28, and 10 d, respectively), for AMX, DOC, and CIP. Neither AMX nor DOC was detected in the manure after the withdrawal period. In contrast to AMX and DOC, the excretion rate of CIP was significantly lower and thus had a longer residence time. Ecological risk study, estimated using hazard quotient values, showed that AMX in the 100 and 50 mg/kg groups posed no risk to the environment after d 1 of withdrawal, while CIP in the 50 mg/kg group posed no risk to the environment from d 5 of withdrawal. CIP in the 200 and 100 mg/kg groups required 10 d withdrawal in order to pose no risk to the environment. In contrast, DOC residue during withdrawal in the manure posed no risk to the environment, thus making it more environmentally safe.

  19. Arsenic drinking water exposure and urinary excretion among adults in the Yaqui Valley, Sonora, Mexico.

    PubMed

    Meza, Maria Mercedes; Kopplin, Michael J; Burgess, Jefferey L; Gandolfi, A Jay

    2004-10-01

    The objective of this study was to determine arsenic exposure via drinking water and to characterize urinary arsenic excretion among adults in the Yaqui Valley, Sonora, Mexico. A cross-sectional study was conducted from July 2001 to May 2002. Study subjects were from the Yaqui Valley, Sonora, Mexico, residents of four towns with different arsenic concentrations in their drinking water. Arsenic exposure was estimated through water intake over 24 h. Arsenic excretion was assessed in the first morning void urine. Total arsenic concentrations and their species arsenate (As V), arsenite (As III), monomethyl arsenic (MMA), and dimethyl arsenic (DMA) were determined by HPLC/ICP-MS. The town of Esperanza with the highest arsenic concentration in water had the highest daily mean intake of arsenic through drinking water, the mean value was 65.5 microg/day. Positive correlation between total arsenic intake by drinking water/day and the total arsenic concentration in urine (r = 0.50, P < 0.001) was found. Arsenic excreted in urine ranged from 18.9 to 93.8 microg/L. The people from Esperanza had the highest geometric mean value of arsenic in urine, 65.1 microg/L, and it was statistically significantly different from those of the other towns (P < 0.005). DMA was the major arsenic species in urine (47.7-67.1%), followed by inorganic arsenic (16.4-25.4%), and MMA (7.5-15%). In comparison with other reports the DMA and MMA distribution was low, 47.7-55.6% and 7.5-9.7%, respectively, in the urine from the Yaqui Valley population (except the town of Cocorit). The difference in the proportion of urinary arsenic metabolites in those towns may be due to genetic polymorphisms in the As methylating enzymes of these populations.

  20. Adult sea lamprey tolerates biliary atresia by altering bile salt composition and renal excretion

    PubMed Central

    Cai, Shi-Ying; Lionarons, Daniël A.; Hagey, Lee; Soroka, Carol J.; Mennone, Albert; Boyer, James L.

    2012-01-01

    The sea lamprey (Petromyzon marinus) is a genetically programmed animal model for biliary atresia as it loses its bile ducts and gallbladder during metamorphosis. However, in contrast to patients with biliary atresia or other forms of cholestasis who develop progressive disease, the post-metamorphosis lampreys grow normally to adult size. To understand how the adult lamprey thrives without the ability to secrete bile, we examined bile salt homeostasis in larval and adult lampreys. Adult livers were severely cholestatic with levels of bile salts >1 mM, but no evidence of necrosis, fibrosis, or inflammation. Interestingly, both larvae and adults had normal plasma levels (~10 μM) of bile salts. In larvae, petromyzonol sulfate (PZS) was the predominant bile salt, whereas the major bile salts in adult liver were sulfated C27 bile alcohols. Cytotoxicity assays revealed that PZS was highly toxic. Pharmacokinetic studies in free-swimming adults revealed that ~35% of intravenously injected bromosulfophthalein (BSP) was eliminated over a 72 hr period. Collection of urine and feces demonstrated that both endogenous and exogenous organic anions, including biliverdin, bile salts and BSP, were predominantly excreted via the kidney with minor amounts also detected in feces. Gene expression analysis detected marked up-regulation of orthologs of known organic anion and bile salt transporters in the kidney with lesser effects in the intestine and gills in adults compared to larvae. These findings indicate that adult lampreys tolerate cholestasis by altering hepatic bile salt composition, while maintaining normal plasma bile salt levels predominantly through renal excretion of bile products. Therefore, we conclude that strategies to accelerate renal excretion of bile salt and other toxins should be beneficial for patients with cholestasis. PMID:23175353

  1. Modelling phosphorus intake, digestion, retention and excretion in growing and finishing pig: model evaluation.

    PubMed

    Symeou, V; Leinonen, I; Kyriazakis, I

    2014-10-01

    A deterministic, dynamic model was developed, to enable predictions of phosphorus (P) digested, retained and excreted for different pig genotypes and under different dietary conditions. Before confidence can be placed on the predictions of the model, its evaluation was required. A sensitivity analysis of model predictions to ±20% changes in the model parameters was undertaken using a basal UK industry standard diet and a pig genotype characterized by British Society Animal Science as being of 'intermediate growth'. Model outputs were most sensitive to the values of the efficiency of digestible P utilization for growth and the non-phytate P absorption coefficient from the small intestine into the bloodstream; all other model parameters influenced model outputs by <10%, with the majority of the parameters influencing outputs by <5%. Independent data sets of published experiments were used to evaluate model performance based on graphical comparisons and statistical analysis. The literature studies were selected on the basis of the following criteria: they were within the BW range of 20 to 120 kg, pigs grew in a thermo-neutral environment; and they provided information on P intake, retention and excretion. In general, the model predicted satisfactorily the quantitative pig responses, in terms of P digested, retained and excreted, to variation in dietary inorganic P supply, Ca and phytase supplementation. The model performed well with 'conventional', European feed ingredients and poorly with 'less conventional' ones, such as dried distillers grains with solubles and canola meal. Explanations for these inconsistencies in the predictions are offered in the paper and they are expected to lead to further model development and improvement. The latter would include the characterization of the origin of phytate in pig diets.

  2. Effect of urinary excretion on the bladder tissue distribution of fluoroquinolones in rats.

    PubMed

    Izawa, Shigeru; Yamaoka, Makiko; Deguchi, Takashi

    2015-04-01

    The purpose of this study was to evaluate which of blood or urine has the greater effect on bladder tissue concentrations of fluoroquinolones important for the treatment of urinary tract infections by measuring concentrations of fluoroquinolones in the vesical tissue (chemically and immunohistochemically) and intravesical space (chemically). Thirty-minute incubation of isolated rat bladders with fluoroquinolones showed only a 1.9-fold difference in transferability among norfloxacin, levofloxacin, ciprofloxacin and sparfloxacin. Intravesical instillation of norfloxacin and sparfloxacin in rats yielded similar vesical tissue distributions. Thus, there were no large differences in vesical tissue transfer among the four fluoroquinolones. The bladder tissue/plasma concentration ratios of norfloxacin (high urinary excretion-type) and sparfloxacin (low urinary excretion-type) at 1 h after a single oral dose (10 mg/kg) to rats were 15.4 and 1.3, respectively. The bladder tissue/plasma concentration ratios of norfloxacin after an intravenous injection (10 mg/kg) to ureter-catheterized and sham-operated rats were 1.36 and 57.8. Thus the bladder tissue distribution was significantly higher in the urine-exposed bladder. Immunohistochemical examination of the vesical tissue localization of norfloxacin in rats given a single intravenous dose revealed the presence of the drug-positive image in the cytoplasm of surface layer cells (both in umbrella and cover cells) of the bladder transitional epithelium. In conclusion, the results suggest that norfloxacin and other fluoroquinolones are excreted into urine and then transferred to the surface layer of the bladder transitional epithelium. Therefore, the urine levels have a greater effect on the vesicle tissue distribution of fluoroquinolones than the plasma levels in rats.

  3. Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

    NASA Astrophysics Data System (ADS)

    Kiko, R.; Hauss, H.; Buchholz, F.; Melzner, F.

    2015-10-01

    Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs) that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ). At depth, the animals experience reduced temperature and oxygen partial pressure (pO2) and an increased carbon dioxide partial pressure (pCO2) compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2 and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply considerably fuels bacterial anaerobic ammonium oxidation - a major loss process for fixed nitrogen in the ocean. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2) does not result in a downregulation of ammonium excretion. Here we show that exposure to OMZ conditions can result in strong depression of respiration and ammonium excretion in calanoid copepods and euphausiids from the Eastern Tropical North Atlantic and the Eastern Tropical South Pacific. These physiological responses need to be taken into account when estimating DVM-mediated fluxes of carbon and nitrogen into OMZs.

  4. Comparative microRNA profiling in relation to urinary albumin excretion in newly diagnosed hypertensive patients.

    PubMed

    Parthenakis, F I; Marketou, M E; Kontaraki, J E; Maragoudakis, F; Maragkoudakis, S; Nakou, H; Roufas, K; Patrianakos, A; Chlouverakis, G; Malliaraki, N; Vardas, P E

    2016-11-01

    Microalbuminuria is an established early marker of endothelial dysfunction and damage. MicroRNAs (miRNAs) are emerging as essential modulators of cardiovascular physiology and disease. In the present study, we sought an association between the differential expression of related miRNAs in the peripheral blood mononuclear cells of untreated patients with newly diagnosed essential hypertension and the levels of urinary albumin excretion. We assessed the expression of the miRNAs miRNA-1, miRNA-133a, miRNA-26b, miRNA-208b, miRNA-499 and miRNA-21 in consecutive subjects with untreated newly diagnosed essential hypertension (aged 62.5±9.7 years) and with no indications of other organic heart disease. MiRNA expression levels in peripheral blood mononuclear cells were quantified by real-time reverse transcription-polymerase chain reaction. The prevalence of microalbuminuria was 9.8%. miRNA-208b and miRNA-133a were independently correlated with 24-h urinary albumin excretion. More specifically, a strong association was found between the gene expression levels of miRNA-208b in our patients' peripheral blood cells and urinary albumin (r=0.72, P<0.001). A similar association was found for miRNA-133a (r=0.372, P<0.001). In conclusion, miRNA-208b and miRNA-133a show distinct profiling in peripheral blood cells isolated from untreated patients with recently diagnosed essential hypertension. Their gene expression levels reveal a strong correlation with urinary albumin excretion levels. Our findings provide new perspectives on the development of a new generation of biomarkers for the better monitoring of end-organ damage in hypertension.

  5. Urinary isothiocyanate excretion, brassica consumption, and gene polymorphisms among women living in Shanghai, China.

    PubMed

    Fowke, Jay H; Shu, Xiao-Ou; Dai, Qi; Shintani, Ayumi; Conaway, C Clifford; Chung, Fung-Lung; Cai, Qiuyin; Gao, Yu-Tang; Zheng, Wei

    2003-12-01

    Alternative measures of Brassica vegetable consumption (e.g., cabbage) may clarify the association between Brassica and cancer risk. Brassica isothiocyanates (ITCs) are excreted in urine and may provide a sensitive and food-specific dietary biomarker. However, the persistence of ITCs in the body may be brief and dependent on the activity of several Phase II enzymes, raising questions about the relationship between a single ITC measure and habitual dietary patterns. This study investigates the association between urinary ITC excretion and habitual Brassica consumption, estimated by a food frequency questionnaire, among healthy Chinese women enrolled in the Shanghai Breast Cancer Study. Participants (n = 347) completed a validated food frequency questionnaire querying habitual dietary intake during the prior 5 years and provided a fasting first-morning urine specimen. Genetic deletion of glutathione S-transferases (GSTM1/GSTT1), and single nucleotide substitutions in GSTP1 (A313G) and NAD(P)H:quinone oxidoreductase 1 (NQO1: C609T), were identified from blood DNA. Urinary ITC excretion levels were marginally higher with the GSTT1-null or GSTP1-G/G genotypes (P = 0.07, P = 0.05, respectively). Mean habitual Brassica intake was 98.3 g/day, primarily as bok choy, and Brassica intake significantly increased across quartile categories of ITC levels. The association between habitual Brassica intake and urinary ITC levels was stronger among women with GSTT1-null or GSTP1-A/A genotypes, or NQO1 T-allele, and the interaction was statistically significant across GSTP1 genotype. In conclusion, a single urinary ITC measure, in conjunction with markers of Phase II enzyme activity, provides a complementary measure of habitual Brassica intake among Shanghai women.

  6. Nocturnal 6-hydroxymelatonin sulfate excretion in female workers exposed to magnetic fields

    SciTech Connect

    Juutilainen, J; Stevens, Richard G. ); Anderson, Larry E. ); Hansen, Norman H.; Kilpelainen, M; Kumlin, T; Laitinen, J T.; Sobell, Eugene; Wilson, Bary W. )

    2000-03-15

    The objective of this study was to determine whether daytime occupational exposure to extremely low frequency magnetic fields (MFs) suppresses nocturnal melatonin production. Sixty female volunteers were recruited. Thirty-nine worked in a garment factory, and 21 office workers served as a reference group. Exposure assessment was based on the type of sewing machine used and MF measurements around each type of machine. Eye-level MF flux density was used to classify the operators to higher (> 1 microT) and lower (0.3-1 microT) exposure categories. A third group of factory workers had diverse MF exposures from other sources. The reference group had average exposure of about 0.15 microT. Urine samples were collected on Friday and Monday for three consecutive weeks. Melatonin production was assessed as urinary 6-hydroxymelatonin sulfate (6-OHMS) excretion. The ratio of Friday morning/Monday morning 6-OHMS was used to test the hypothesis that melatonin production is suppressed after 4 days of occupational MF exposure with significant recovery during the weekend. Possible chronic suppression of melatonin production was evaluated by studying exposure-related differences in the Friday values by multivariate regression analysis. The Monday/Friday ratios were close to 1.0, suggesting that there is no increase in melatonin production over the weekend. The average 6-OHMS excretion on Friday was lower among the factory workers than in the reference group, but no monotonous dose-response was observed. Multivariate regression analysis identified MF exposure, smoking, and age as significant explanatory variables associated with decreased 6-OHMS excretion.

  7. Role of renal medullary adenosine in the control of blood flow and sodium excretion.

    PubMed

    Zou, A P; Nithipatikom, K; Li, P L; Cowley, A W

    1999-03-01

    This study determined the levels of adenosine in the renal medullary interstitium using microdialysis and fluorescence HPLC techniques and examined the role of endogenous adenosine in the control of medullary blood flow and sodium excretion by infusing the specific adenosine receptor antagonists or agonists into the renal medulla of anesthetized Sprague-Dawley rats. Renal cortical and medullary blood flows were measured using laser-Doppler flowmetry. Analysis of microdialyzed samples showed that the adenosine concentration in the renal medullary interstitial dialysate averaged 212 +/- 5.2 nM, which was significantly higher than 55.6 +/- 5.3 nM in the renal cortex (n = 9). Renal medullary interstitial infusion of a selective A1 antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; 300 pmol. kg-1. min-1, n = 8), did not alter renal blood flows, but increased urine flow by 37% and sodium excretion by 42%. In contrast, renal medullary infusion of the selective A2 receptor blocker 3, 7-dimethyl-1-propargylxanthine (DMPX; 150 pmol. kg-1. min-1, n = 9) decreased outer medullary blood flow (OMBF) by 28%, inner medullary blood flows (IMBF) by 21%, and sodium excretion by 35%. Renal medullary interstitial infusion of adenosine produced a dose-dependent increase in OMBF, IMBF, urine flow, and sodium excretion at doses from 3 to 300 pmol. kg-1. min-1 (n = 7). These effects of adenosine were markedly attenuated by the pretreatment of DMPX, but unaltered by DPCPX. Infusion of a selective A3 receptor agonist, N6-benzyl-5'-(N-ethylcarbonxamido)adenosine (300 pmol. kg-1. min-1, n = 6) into the renal medulla had no effect on medullary blood flows or renal function. Glomerular filtration rate and arterial pressure were not changed by medullary infusion of any drugs. Our results indicate that endogenous medullary adenosine at physiological concentrations serves to dilate medullary vessels via A2 receptors, resulting in a natriuretic response that overrides the tubular A1 receptor

  8. Renal excretion in channel catfish following injection of quinaldine sulphate or 3-trifluoromethyl-4-nitrophenol

    USGS Publications Warehouse

    Allen, J.L.; Hunn, J.B.

    1977-01-01

    Channel catfish, Ictalurus punctatus Rafinesque, injected intraperitoneally with 2-methyl-quinoline sulphate (QdSO4) or 3-trifluoromethyl-4-nitrophenol (TFM) eliminate most of the dose of these compounds by extra-renal routes. Patterns of renal excretion of Na+, K+, Ca2+, Mg2+, and Cl- (pEq kg-1 h-1) appeared to be associated with the 'stress' of the urine collection technique rather than with the elimination of either compound. Concentrations of Na+, K+, Ca2+, Mg2+, and Cl- (mEq/1) were determined in urine, plasma and gall bladder bile.

  9. Abnormal circadian rhythm and cortisol excretion in autistic children: a clinical study

    PubMed Central

    Lakshmi Priya, Malarveni Damodaran; Geetha, Arumugam; Suganya, Vijayashankar; Sujatha, Sridharan

    2013-01-01

    Aim To determine the circadian rhythm alteration of cortisol excretion and the level of corticosteroids in children with different grades of autism severity. Methods The study included 45 children with different grades of autism severity (low [LFA], medium [MFA], and high functioning autism [HFA]), 15 in each group, and 45 age/sex-matched children with typical development. The urinary levels of free cortisol (at three phases of 24-hour cycle), corticosteroids, vanilylmandelic acid, and 5-hydroxyindole acetic acid were determined. Results Alteration in the pattern of cortisol excretion (Phases I, II, and III) was observed in children with LFA (Phase I: 43.8 ± 4.43 vs 74.30±8.62, P = 0.000; Phase II: 21.1±2.87 vs 62±7.68, P < 0.001; Phase III: 9.9 ± 1.20 vs 40 ± 5.73, P < 0.001) and MFA (Phase I: 43.8 ± 4.43 vs 52.6±7.90, P < 0.001; Phase II: 21.1±2.87 vs 27.4±4.05, P < 0.001; Phase III: 9.9 ± 1.20 vs 19 ± 2.50, P < 0.001) compared to the control group. The corticosteroids excretion levels were higher in all the groups of children with autism than in the control group. The level of 5-hydroxyindole acetic acid was significantly higher in children with LFA (8.2±1.48 vs 6.8±0.85, P < 0.001) and MFA (8.2±1.48 vs 7.4± 0.89, P = 0.001) and not significantly higher in children with HFA than in the control group. The changes were correlated with degrees of severity of the disorder. Conclusion These data suggest that altered cortisol excretion pattern and high level of corticosteroids in urine may probably be a consequence of altered hypothalamic-pituitary-adrenal axis function, which may contribute to the pathogenesis and affect the severity of autism. PMID:23444244

  10. Faecal nitrogen excretion as an approach to estimate forage intake of wethers.

    PubMed

    Kozloski, G V; Oliveira, L; Poli, C H E C; Azevedo, E B; David, D B; Ribeiro Filho, H M N; Collet, S G

    2014-08-01

    Data from twenty-two digestibility trials were compiled to examine the relationship between faecal N concentration and organic matter (OM) digestibility (OMD), and between faecal N excretion and OM intake (OMI) by wethers fed tropical or temperate forages alone or with supplements. Data set was grouped by diet type as follows: only tropical grass (n = 204), only temperate grass (n = 160), tropical grass plus supplement (n = 216), temperate grass plus supplement (n = 48), tropical grass plus tropical legume (n = 60) and temperate grass with ruminal infusion of tannins (n = 16). Positive correlation between OMD and either total faecal N concentration (Nfc, % of OM) or metabolic faecal N concentration (Nmetfc, % of OM) was significant for most diet types. Exceptions were the diet that included a tropical legume, where both relationships were negative, and the diet that included tannin extract, where the correlation between OMD and Nfc was not significant. Pearson correlation and linear regressions between OM intake (OMI, g/day) and faecal N excretion (Nf, g/day) were significant for all diet types. When OMI was estimated from the OM faecal excretion and Nfc-based OMD values, the linear comparison between observed and estimated OMI values showed intercept different from 0 and slope different from 1. When OMI was estimated using the Nf-based linear regressions, the linear comparison between observed and estimated OMI values showed neither intercept different from 0 nor slope different from 1. Both linear comparisons showed similar R(2) values (i.e. 0.78 vs. 0.79). In conclusion, linear equations are suitable for directly estimating OM intake by wethers, fed only forage or forage plus supplements, from the amount of N excreted in faeces. The use of this approach in experiments with grazing wethers has the advantage of accounting for individual variations in diet selection and digestion processes and precludes the use of techniques to estimate forage

  11. Effects of substituted dithiocarbamates on distribution and excretion of inorganic mercury in mice

    SciTech Connect

    Gale, G.R.; Atkins, L.M.; Smith, A.B.; Jones, M.M.

    1985-02-01

    Diethyldithiocarbamate (DDTC) and six of its N,N-disubstituted congeners were evaluated for their relative efficacies in mobilizing and promoting excretion of mercury (Hg/sup + +/) using mice which had been given /sup 203/Hg/sup + +/; D-penicillamine (PEN) was used as a positive control compound. While none was as effective as PEN when compared on a molar dose basis, significant activity as assessed by reduction of whole body /sup 203/Hg burden, was observed following treatment with three of the analogs. The order of effectiveness was PEN greater than N-methyl-N-dithiocarboxyglucamine (MDCG) greater than di(carboxymethyl)dithiocarbamate (DCDC) greater than di(hydroxyethyl)dithiocarbamate (DHDC).

  12. Effects of dietary fibre on serum lipid levels and fecal bile acid excretion.

    PubMed Central

    Kay, R M

    1980-01-01

    Epidemiologic studies have suggested that dietary fibre protects humans against coronary heart disease, but interpretation of the data is confounded by coexisting differences in both dietary and environmental variables. The hypocholesterolemic action of dietary fibre varies: in general mucilaginous fibres such as pectin and oat bran are more effective than particulate fibres such as wheat bran. Although the mechanism of action of mucilaginous fibres is not completely understood, there is evidence that they induce small increases in the fecal excretion of bile acids and neutral steroids that are not fully compensated for by de novo cholesterol synthesis. PMID:6257368

  13. Two Cases of Hypophosphatemia with Increased Renal Phosphate Excretion in Legionella Pneumonia

    PubMed Central

    Watanabe, Shuhei; Kono, Keiji; Fujii, Hideki; Nakai, Kentaro; Goto, Shunsuke; Nishi, Shinichi

    2016-01-01

    We encountered 2 cases of hypophosphatemia due to Legionella pneumonia. Both cases showed increased urinary phosphate excretion and renal tubular dysfunction, which ameliorated with recovery from Legionella pneumonia. Serum fibroblast growth factor-23 level was suppressed, whereas serum 1,25(OH)2 vitamin D and parathyroid hormone levels were normal. Delayed elevation of serum 1,25(OH)2 vitamin D levels was observed with improvement in renal tubular function. These findings suggested hypophosphatemia might be mediated by renal tubular dysfunction. PMID:27066493

  14. Use of In Vitro Absorption, Distribution, Metabolism, and Excretion (ADME) Data in Bioaccumulation Assessments for Fish

    SciTech Connect

    Nichols, John W.; Erhardt, Susan; Dyer, Scott; James, Margaret O.; Moore, Margo; Plotzke, Kathleen; Segner, Helmut; Schultz, Irvin R.; Thomas, Karluss; Vasiluk, Luba; Weisbrod, Anne V.

    2007-11-01

    A scientific workshop was held in 2006 to discuss the use of in vitro Absorption, Distribution, Metabolism, and Excretion (ADME) data in chemical bioaccumulation assessments for fish. Computer-based (in silico) modeling tools are widely used to estimate chemical bioaccumulation. These in silico methods have inherent limitations that result in inaccurate estimates for many compounds. Based on a review of the science workshop participants concluded that two factors, absorption and metabolism, represent the greatest sources of uncertainty in current bioaccumulation models. Both factors can be investigated experimentally using in vitro test systems.

  15. Urinary potassium excretion and risk of developing hypertension: the prevention of renal and vascular end-stage disease study.

    PubMed

    Kieneker, Lyanne M; Gansevoort, Ron T; Mukamal, Kenneth J; de Boer, Rudolf A; Navis, Gerjan; Bakker, Stephan J L; Joosten, Michel M

    2014-10-01

    Previous prospective cohort studies on the association between potassium intake and risk of hypertension have almost exclusively relied on self-reported dietary data, whereas repeated 24-hour urine excretions, as estimate of dietary uptake, may provide a more objective and quantitative estimate of this association. Risk of hypertension (defined as blood pressure ≥140/90 mm Hg or initiation of blood pressure-lowering drugs) was prospectively studied in 5511 normotensive subjects aged 28 to 75 years not using blood pressure-lowering drugs at baseline of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study. Potassium excretion was measured in two 24-hour urine specimens at baseline (1997-1998) and midway during follow-up (2001-2003). Baseline median potassium excretion was 70 mmol/24 h (interquartile range, 57-85 mmol/24 h), which corresponds to a dietary potassium intake of ≈91 mmol/24 h. During a median follow-up of 7.6 years (interquartile range, 5.0-9.3 years), 1172 subjects developed hypertension. The lowest sex-specific tertile of potassium excretion (men: <68 mmol/24 h; women: <58 mmol/24 h) had an increased risk of hypertension after multivariable adjustment (hazard ratio, 1.20; 95% confidence interval, 1.05-1.37), compared with the upper 2 tertiles (Pnonlinearity=0.008). The proportion of hypertension attributable to low potassium excretion was 6.2% (95% confidence interval, 1.7%-10.9%). No association was found between the sodium to potassium excretion ratio and risk of hypertension after multivariable adjustment. Low urinary potassium excretion was associated with an increased risk of developing hypertension. Dietary strategies to increase potassium intake to the recommended level of 90 mmol/d may have the potential to reduce the incidence of hypertension.

  16. Development and validation of a UPLC-MS/MS method to monitor cephapirin excretion in dairy cows following intramammary infusion.

    PubMed

    Ray, Partha; Knowlton, Katharine F; Shang, Chao; Xia, Kang

    2014-01-01

    Cephapirin, a cephalosporin antibiotic, is used by the majority of dairy farms in the US. Fecal and urinary excretion of cephapirin could introduce this compound into the environment when manure is land applied as fertilizer, and may cause development of bacterial resistance to antibiotics critical for human health. The environmental loading of cephapirin by the livestock industry remains un-assessed, largely due to a lack of appropriate analytical methods. Therefore, this study aimed to develop and validate a cephapirin quantification method to capture the temporal pattern of cephapirin excretion in dairy cows following intramammary infusion. The method includes an extraction with phosphate buffer and methanol, solid-phase extraction (SPE) clean-up, and quantification using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The LOQ values of the developed method were 4.02 µg kg(-1) and 0.96 µg L(-1) for feces and urine, respectively. This robust method recovered >60% and >80% cephapirin from spiked blank fecal and urine samples, respectively, with acceptable intra- and inter-day variation (<10%). Using this method, we detected trace amounts (µg kg(-1)) of cephapirin in dairy cow feces, and cephapirin in urine was detected at very high concentrations (133 to 480 µg L(-1)). Cephapirin was primarily excreted via urine and its urinary excretion was influenced by day (P = 0.03). Peak excretion (2.69 mg) was on day 1 following intramammary infusion and decreased sharply thereafter (0.19, 0.19, 0.08, and 0.17 mg on day 2, 3, 4, and 5, respectively) reflecting a quadratic pattern of excretion (Quadratic: P = 0.03). The described method for quantification of cephapirin in bovine feces and urine is sensitive, accurate, and robust and allowed to monitor the pattern of cephapirin excretion in dairy cows. This data will help develop manure segregation and treatment methods to minimize the risk of antibiotic loading to the environment from dairy

  17. Magnesium, zinc, arsenic, selenium and platinum urinary excretion from cancer patients of Antofagasta region, Chile: multi-metal approach

    PubMed Central

    Pizarro, I; Rivera, L; Ávila, J; Cortés, P

    2016-01-01

    Objectives To evaluate the short-term 24 h urinary excretion of platinum, arsenic, selenium, magnesium and zinc in patients with lung cancer and with cancer other than lungs treated with cisplatin or/and carboplatin from Antofagasta, Chile. Design Urine measurements of Pt and Se were made by inductively coupled plasma optical emission spectrometry, As by hydride-generation atomic absorption spectrometry and Mg and Zn by means of flame furnace atomic absorption spectrometry. Setting All samples were provided by the Oncological Centre of Antofagasta Regional Hospital (Region of Antofagasta, Chile). Participants Ninety 24-h urine samples from cancer patients after the infusion of Pt-base drugs and 10 24-h urine samples from cancer patients not treated with metal-base drugs. Main outcome measures Concentrations of Pt, Se, As, Zn and Mg coming from 24-h urine samples. Results Pt excreted was not significantly different between patients with lung and other cancers treated with cisplatin. The excretion of Mg, Zn and Se was greater than As. Then, Pt favours the excretion of essential elements. For lung and other types of cancers treated with drugs without Pt, excretion of Mg, Zn and Se was also greater than that of As, suggesting antagonism Mg-Zn-Se–anti-cancer drug relationship. Conclusions The amounts of Mg, Zn and Se excreted were greater than for As either with or without Pt-containing drugs, suggesting antagonist Mg-Zn-Se–anti-cancer drug relationships. The excretion of As, Mg, Zn and Se is induced by Pt. Knowledge obtained can contribute to understanding the arsenic cancer mechanism and the As-Mg-Zn-Se-Pt inter-element association for lung cancer and other types of cancer. PMID:27757244

  18. Urinary excretion of LH and testosterone from male rats during exposure to increased gravity: post-spaceflight and centrifugation

    NASA Technical Reports Server (NTRS)

    Ortiz, R. M.; Wade, C. E.; Morey-Holton, E.

    2000-01-01

    A dissociation between plasma luteinizing hormone (LH) and testosterone (T) appears to exist during exposure to altered gravity. The pulsatile nature of LH release and the diurnal variability of T secretion may mask or bias the effects of altered gravity on the pituitary-gonadal axis when analyzing plasma concentrations. Therefore, we examined the relationship between the excretion of urinary LH and T in male Sprague-Dawley rats during exposure to increased gravity upon return to Earth following a 14-day spaceflight (n = 6) and by 12 days of centrifugation at 2g (n = 8). Excreted LH and T were elevated on the first 3 days postflight. Excreted T was elevated between Days 1 and 8 of centrifugation; however, excreted LH was reduced on Days 2 and 3 compared with control animals. Excreted LH and T were significantly correlated (R = 0.731 and 0.706, respectively) in postspaceflight and centrifuged animals. Correlation curves had similar slopes (0.0213 and 0.023, respectively), but different y-intercepts (-1.43 and 3.32, respectively). The sustained increase in excreted T during centrifugation suggests that the pituitary-gonadal axis in postspaceflight animals may adapt quicker to increased gravity. The upward shift in the correlation curve exhibited by the centrifuged animals suggests that the sensitivity of LH-induced T release is increased in these animals. The previous dissociation between plasma LH and T during altered gravity was not observed in the present study in which excreted LH and T were measured.

  19. The course of phosphorus excretion in growing pigs fed continuously increasing phosphorus concentrations after a phosphorus depletion.

    PubMed

    Rodehutscord, M; Faust, M; Pfeffer, E

    1999-01-01

    A balance study was performed in order to quantify the effect of continuously increased phosphorus (P) intake on faecal and urinary P excretion. The aim was to quantify the level of intake where regulatory P excretion becomes relevant for comparative digestibility measurements on P, and when the pig adapts its urinary P excretion to increased P intake. Phosphorus intake of growing pigs was continuously increased on a daily basis starting at a marginal level and P excretion via faeces and urine was continuously followed for 92 days. Two semi-synthetic diets were prepared with different proportions of Na2HPO4 resulting in 2.4 (diet 1) and 6.3 (diet 2) g P/kg DM. Concentration of Ca was adapted to achieve a Ca supply approximately 3.1 fold the digestible P supply. Six castrated male crossbred pigs (31 kg BW) were kept individually in metabolism crates after they had undergone a 14 d P depletion period during which they were fed diet 1 solely. Pigs received 1.04kg of diet 1 per day throughout the experiment, and each day the amount of feed and P supplied to pigs from diet 2 was increased by 12 g and 69 mg, respectively. ME supply was approximately 2.4 fold maintenance and average daily BW gain of pigs during the entire experiment was 690 +/- 30 g. While intake increased linearly, faecal excretion of P and Ca increased non-linearly and could be best described by third order polynomial functions. The proportion of ingested P not excreted via faeces followed a quadratic type of curve with a maximum of 81% at 25 days on experiment and P intake of 4.0 g/d. Thereafter, the proportion decreased continuously. The digestibility of P from diet 2, determined by the slope ratio technique, was constant and not affected by P intake up to a P intake of 5 g/d. Renal P excretion did not exceed inevitable losses until day 60 and increased exponentially thereafter when body P reserves were restored. It is concluded, that an adaptation to surplus P supply occurred earlier on the

  20. Biotransformation of acrolein in rat: excretion of mercapturic acids after inhalation and intraperitoneal injection.

    PubMed

    Linhart, I; Frantík, E; Vodicková, L; Vosmanská, M; Smejkal, J; Mitera, J

    1996-01-01

    Biotransformation of acrolein (ACR) was studied in vivo in the rat following inhalation and ip administration. The major and minor urinary metabolites were 3-hydroxypropylmercapturic acid (HPMA) and 2-carboxyethylmercapturic acid (CEMA), respectively. Male Wistar rats were exposed to ACR, 23, 42, 77 and 126 mg/m3, for 1 hr. The sum of mercapturic acids HPMA and CEMA excreted within 24 hr after the exposure amounted to 0.87 +/- 0.12, 1.34 +/- 0.5, 2.81 +/- 1.15, and 7.13 +/- 1.56 mumol/kg, i.e., 10.9 +/- 1.5, 13.3 +/- 5.0, 16.7 +/- 6.9, and 21.5 +/- 4.8% of the estimated absorbed dose, respectively. The dose estimate was based on reported values of minute respiratory volume and respiratory tract retention and was corrected for the ACR-induced changes in minute respiratory volume. In the relevant dose range (8.9 to 35.7 mumol/kg) the portion of mercapturic acids excreted was nearly constant for ip exposed rats. The sum of HPMA and CEMA amounted to 29.1 +/- 6.5% of the dose. These results indicate that the deficiency in rat lung metabolism of ACR to acrylic acid previously observed is not compensated by the other detoxication pathway in vivo, mercapturic acid formation. The health hazard arising from inhalation of ACR is likely to be higher than that from other routes of exposure.

  1. Absorption, Distribution, Metabolism and Excretion of 3-MCPD 1-Monopalmitate after Oral Administration in Rats.

    PubMed

    Gao, Boyan; Liu, Man; Huang, Guoren; Zhang, Zhongfei; Zhao, Yue; Wang, Thomas T Y; Zhang, Yaqiong; Liu, Jie; Yu, Liangli

    2017-03-15

    Fatty acid esters of monochloropropane 1,2-diol (3-MCPD) are processing-induced toxicants and have been detected in several food categories. This study investigated the absorption, distribution, metabolism, and excretion of 3-MCPD esters in Sprague-Dawley (SD) rats using 3-MCPD 1-monopalmitate as the probe compound. The kinetics of 3-MCPD 1-monopalmitate in plasma was investigated using SD rats, and the results indicated that 3-MCPD 1-monopalmitate was absorbed directly in vivo and metabolized. Its primary metabolites in the liver, kidney, testis, brain, plasma, and urine were tentatively identified and measured at 6, 12, 24, and 48 h after oral administration. Structures were proposed for eight metabolites. 3-MCPD 1-monopalmitate was converted to free 3-MCPD, which formed the phase II metabolites. All of the metabolites were chlorine-related chemical components; most of them existed in urine, reflecting the excretion pattern of 3-MCPD esters. Understanding the metabolism of 3-MCPD esters in vivo is critical for assessing their toxicities.

  2. Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats

    PubMed Central

    Cheema-Dhadli, Surinder; Chong, Chee Keong; Kim, Namhee; Kamel, Kamel S

    2010-01-01

    When the concentration of sodium (Na+) in arterial plasma (PNa) declines sufficiently to inhibit the release of vasopressin, water will be excreted promptly when the vast majority of aquaporin 2 water channels (AQP2) have been removed from luminal membranes of late distal nephron segments. In this setting, the volume of filtrate delivered distally sets the upper limit on the magnitude of the water diuresis. Since there is an unknown volume of water reabsorbed in the late distal nephron, our objective was to provide a quantitative assessment of this parameter. Accordingly, rats were given a large oral water load, while minimizing non-osmotic stimuli for the release of vasopressin. The composition of plasma and urine were measured. The renal papilla was excised during the water diuresis to assess the osmotic driving force for water reabsorption in the inner medullary collecting duct. During water diuresis, the concentration of creatinine in the urine was 13-fold higher than in plasma, which implies that ~8% of filtered water was excreted. The papillary interstitial osmolality was 600 mOsm/L > the urine osmolality. Since 17% of filtered water is delivered to the earliest distal convoluted tubule micropuncture site, we conclude that half of the water delivered to the late distal nephron is reabsorbed downstream during water diuresis. The enormous osmotic driving force for the reabsorption of water in the inner medullary collecting duct may play a role in this reabsorption of water. Possible clinical implications are illustrated in the discussion of a case example. PMID:21468191

  3. Effects of temperature on oxygen consumption and ammonia—N excretion of Chlamys farreri

    NASA Astrophysics Data System (ADS)

    Yang, Hong-Sheng; Zhang, Tao; Wang, Ping; He, Yi-Chao; Zhang, Fu-Sui

    1998-06-01

    Effects of temperature on oxygen consumption rate (OCR) and ammonia—N excretion rate of scallop Chlamys farreri (1.7 6.2 cm in shell height) were studied in laboratory from Dec. 30,1996 to Jan. 28,1997. Under the controlled conditions of ambient water temperature 10 31°C and salinity 32, the concentrations of dissolved oxygen and ammonia—N were determined by the Winkle method and the hypobromite method, respectively. Results showed that the OCR ranged from 1.20 mg/g (DW) · h to 5.76 mg/g (DW) · h. The OCR increased with temperature from 10°C to 23°C, but at 28°C the OCR of mature individuals decreased, and that of different size scallops reduced at 31°C. The ammonia—N excretion rate ranged from 113.03 μg NH4-N/g (DW) · h to 486.63 μg NH4-N/g (DW) · h, and increased with temperature from 10°C to 31°C.

  4. Lactococcus lactis catalyses electricity generation at microbial fuel cell anodes via excretion of a soluble quinone.

    PubMed

    Freguia, Stefano; Masuda, Masaki; Tsujimura, Seiya; Kano, Kenji

    2009-09-01

    Lactococcus lactis is a gram-positive, normally homolactic fermenter that is known to produce several kinds of membrane associated quinones, which are able to mediate electron transfer to extracellular electron acceptors such as Fe(3+), Cu(2+) and hexacyanoferrate. Here we show that this bacterium is also capable of performing extracellular electron transfer to anodes by utilizing at least two soluble redox mediators, as suggested by the two-step catalytic current developed. One of these two mediators was herein suggested to be 2-amino-3-dicarboxy-1,4-naphthoquinone (ACNQ), via evaluation of standard redox potential, ability of the bacterium to exploit the quinone when exogenously provided, as well as by high performance liquid chromatography coupled with UV spectrum analysis. During electricity generation, L. lactis slightly deviated from its normal homolactic metabolism by excreting acetate and pyruvate in stoichiometric amounts with respect to the electrical current. In this metabolism, the anode takes on the role of electron sink for acetogenic fermentation. The finding that L. lactis self-catalyses anodic electron transfer by excretion of redox mediators is remarkable as the mechanisms of extracellular electron transfer by pure cultures of gram-positive bacteria had previously never been elucidated.

  5. Effect of penicillin on fatty acid synthesis and excretion in Streptococcus mutans BHT

    SciTech Connect

    Brissette, J.L.; Pieringer, R.A.

    1985-03-01

    Treatment of exponentially growing cultures of Streptococcus mutans BHT with growth-inhibitory concentrations (0.2 microgram/ml) of benzylpenicillin stimulates the incorporation of (2-/sup 14/C) acetate into lipids excreted by the cells by as much as 69-fold, but does not change the amount of /sup 14/C incorporated into intracellular lipids. At this concentration of penicillin cellular lysis does not occur. The radioactive label is incorporated exclusively into the fatty acid moieties of the glycerolipids. During a 4-hr incubation in the presence of penicillin, the extracellular fatty acid ester concentration increases 1.5 fold, even though there is no growth or cellular lysis. An indication of the relative rate of fatty acid synthesis was most readily obtained by placing S. mutans BHT in a buffer containing /sup 14/C-acetate. Under these nongrowing conditions free fatty acids are the only lipids labeled, a factor which simplifies the assay. The addition of glycerol to the buffer causes all of the nonesterified fatty acids to be incorporated into glycerolipid. The cells excrete much of the lipid whether glycerol is present or not. Addition of penicillin to the nongrowth supporting buffer system does not stimulate the incorporation of (/sup 14/C)-acetate into fatty acids.

  6. Tissue accumulation and urinary excretion of Cr in chromium picolinate (CrPic)-supplemented lambs.

    PubMed

    Dallago, Bruno Stéfano Lima; Lima, Bárbara Alcântara Ferreira; Braz, Shélida Vasconcelos; Mustafa, Vanessa da Silva; McManus, Concepta; Paim, Tiago do Prado; Campeche, Aline; Gomes, Edgard Franco; Louvandini, Helder

    2016-05-01

    Chromium (Cr) concentrations in liver, kidney, spleen, heart, lymph node, skeletal muscle, bone, testis and urine of lambs were measured to trace the biodistribution and bioaccumulation of Cr after oral supplementation with chromium picolinate (CrPic). Twenty-four Santa Inês lambs were treated with four different concentrations of CrPic: placebo, 0.250, 0.375 and 0.500 mg of CrPic/animal/day for 84 days. The basal diet consisted of Panicum maximum cv Massai hay and concentrate. Cr concentrations were measured by ICP-MS measuring (52)Cr as collected mass. There was a positive linear relationship between dose administered and the accumulation of Cr in the heart, lungs and testis. Urinary excretion of Cr occurred in a time and dose-dependent manner, so the longer or more dietary Cr provided, the greater excretion of the element. As some non-carcass components (such as lungs or heart) are added to bone and visceral meal to feed animals, there is a risk of bioaccumulation and biomagnification due to Cr offered as CrPic in the diet.

  7. Cerebral regulation of renal sodium excretion in sheep infused intravenously with hypertonic NaCl.

    PubMed Central

    Chodobski, A; McKinley, M J

    1989-01-01

    1. The natriuretic response to intravenous infusion of 2 M-NaCl was investigated in six conscious sheep. This hypertonic NaCl load resulted in relatively small, physiological (2-3 mmol l-1) increases in plasma Na+ concentration and was followed by a natriuresis with a maximum mean urinary sodium excretion 5 times higher than pre-infusion values. 2. Intravenous infusion of isotonic NaCl, delivering the same Na+ load as hypertonic NaCl infusion, did not induce natriuresis. This suggested, therefore, that with the hypertonic sodium load administered in the present study, the rise in plasma Na+ and/or tonicity rather than increase in blood volume is important in evoking the natriuretic response. 3. Intracerebroventricular infusion of low-Na+ artificial cerebrospinal fluid (CSF) reduced CSF Na+ concentration, decreased plasma vasopressin (AVP) levels and caused a copious water diuresis. This was associated with excessive loss of water and large increases in plasma Na+ concentration and osmolality. 4. The natriuresis induced by intravenous hypertonic NaCl load could be blocked by lowering CSF Na+ concentration in situations where water diuresis was either prevented or reduced by intravenous infusion of AVP or by delayed intracerebroventricular infusion of low-Na+ CSF, respectively. 5. The results of the present study provide further evidence that renal sodium excretion can be controlled by the central nervous system. PMID:2621619

  8. Temporal dynamics of seed excretion by wild ungulates: implications for plant dispersal

    PubMed Central

    Picard, Mélanie; Papaïx, Julien; Gosselin, Frédéric; Picot, Denis; Bideau, Eric; Baltzinger, Christophe

    2015-01-01

    Dispersal is a key process in metapopulation dynamics as it conditions species’ spatial responses to gradients of abiotic and biotic conditions and triggers individual and gene flows. In the numerous plants that are dispersed through seed consumption by herbivores (endozoochory), the distance and effectiveness of dispersal is determined by the combined effects of seed retention time in the vector’s digestive system, the spatial extent of its movements, and the ability of the seeds to germinate once released. Estimating these three parameters from experimental data is therefore crucial to calibrate mechanistic metacommunity models of plant–herbivore interactions. In this study, we jointly estimated the retention time and germination probability of six herbaceous plants transported by roe deer (Capreolus capreolus), red deer (Cervus elaphus), and wild boar (Sus scrofa) through feeding experiments and a Bayesian dynamic model. Retention time was longer in the nonruminant wild boar (>36 h) than in the two ruminant species (roe deer: 18–36 h, red deer: 3–36 h). In the two ruminants, but not in wild boar, small and round seeds were excreted faster than large ones. Low germination probabilities of the excreted seeds reflected the high cost imposed by endozoochory on plant survival. Trait-mediated variations in retention time and germination probability among animal and plant species may impact plant dispersal distances and interact with biotic and abiotic conditions at the release site to shape the spatial patterns of dispersed plant species. PMID:26257875

  9. A global database of nitrogen and phosphorus excretion rates of aquatic animals

    DOE PAGES

    Vanni, Michael J.; McIntyre, Peter B.; Allen, Dennis; ...

    2017-03-06

    Though their importance varies greatly among species and ecosystems, animals can be important in modulating ecosystem-level nutrient cycling. Nutrient cycling rates of individual animals represent valuable data for testing the predictions of important frameworks such as the Metabolic Theory of Ecology (MTE) and ecological stoichiometry (ES). They also represent an important set of functional traits that may reflect both environmental and phylogenetic influences. Over the past two decades, studies of animal-mediated nutrient cycling have increased dramatically, especially in aquatic ecosystems. Here we present a global compilation of aquatic animal nutrient excretion rates. The dataset includes 10,534 observations from freshwater andmore » marine animals of N and/or P excretion rates. Furthermore, these observations represent 491 species, including most aquatic phyla. Coverage varies greatly among phyla and other taxonomic levels. The dataset includes information on animal body size, ambient temperature, taxonomic affiliations, and animal body N:P. We used this data set to test predictions of MTE and ES, as described in Vanni and McIntyre (2016; Ecology DOI: 10.1002/ecy.1582).« less

  10. High fluid intake increases urine free cortisol excretion in normal subjects.

    PubMed

    Mericq, M V; Cutler, G B

    1998-02-01

    To test the hypothesis that increased fluid intake increases the urine free cortisol, we prescribed 5 liters of fluid intake per day or a normal fluid intake according to a randomized cross-over design in six normal volunteers. Each period lasted 5 days, with a 2-day washout period of normal fluid intake between the two periods. Urine free cortisol, 17-hydroxycorticosteroids, and creatinine were measured daily during each study period, and the average value over each 5-day period was calculated for each subject. High fluid intake caused a significant increase in the mean urine free cortisol [126 +/- 33 (SD) vs. 77 +/- 18 micrograms/day, P < 0.005]. The frequency of urine free cortisol results that exceeded the upper normal limit of 95 micrograms/day was also much higher during high fluid intake (23/30 vs. 6/30, P < 0.005). By contrast, urine 17-hydroxycorticosteroids (high fluid vs. normal fluid: 5.3 +/- 1.5 vs. 5.0 +/- 1.7 mg/day, respectively, P = not significant) and urine creatinine (1.51 +/- 0.48 vs. 1.45 +/- 0.37 g/day, P = not significant) did not differ between the two study periods. We conclude that high fluid intake (5 liters/day) increases free cortisol excretion without an increase in urine 17-hydroxycorticosteroids. Thus, mild to moderate increases in urine cortisol excretion may not indicate hypercortisolism in individuals who have a high fluid intake and urine volume.

  11. Urinary Excretion of Phenolic Acids by Infants and Children: A Randomised Double-Blind Clinical Assay

    PubMed Central

    Uberos, J.; Fernández-Puentes, V.; Molina-Oya, M.; Rodríguez-Belmonte, R.; Ruíz-López, A.; Tortosa-Pinto, P.; Molina-Carballo, A.; Muñoz-Hoyos, A.

    2012-01-01

    Objectives: The present study, which is part of the ISRCTN16968287 clinical assay, is aimed at determining the effects of cranberry syrup or trimethoprim treatment for UTI. Methods: This Phase III randomised clinical trial was conducted at the San Cecilio Clinical Hospital (Granada, Spain) with a study population of 192 patients, aged between 1 month and 13 years. Criteria for inclusion were a background of recurrent UTI, associated or otherwise with vesico-ureteral reflux of any degree, or renal pelvic dilatation associated with urinary infection. Each child was randomly given 0.2 mL/Kg/day of either cranberry syrup or trimethoprim (8 mg/mL). The primary and secondary objectives, respectively, were to determine the risk of UTI and the levels of phenolic acids in urine associated with each intervention. Results: With respect to UTI, the cranberry treatment was non-inferior to trimethoprim. Increased urinary excretion of ferulic acid was associated with a greater risk of UTI developing in infants aged under 1 year (RR 1.06; CI 95% 1.024–1.1; P = 0.001). Conclusions: The results obtained show the excretion of ferulic acid is higher in infants aged under 1 year, giving rise to an increased risk of UTI, for both treatment options. PMID:23641168

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

    PubMed

    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.

  13. The Kinetics of Urinary Fumonisin B1 Excretion in Humans Consuming Maize-Based Diets

    PubMed Central

    Riley, Ronald T.; Torres, Olga; Showker, Jency L.; Zitomer, Nicholas C.; Matute, Jorge; Voss, Kenneth A.; Gelineau-van Waes, Janee; Maddox, Joyce R.; Gregory, Simon G.; Ashley-Koch, Allison E.

    2013-01-01

    Fumonisins (FB) are mycotoxins found in maize. The purpose of this study was to 1) determine the relationship between FB1, FB2 and FB3 intake and urinary excretion in humans, 2) validate a method to isolate urinary FB on C18-SPE cartridges for international shipment, and 3) test the method using samples from Guatemala. Volunteers (n=10) consumed 206 grams/day of tortillas and biscuits prepared from masa flour and a product containing maize flour. Volunteers estimated their daily urine output and samples were analyzed for FB1, FB2 and FB3 and hydrolyzed FB1. Only FB1 was detected in urine suggesting lower absorption of FB2 and FB3. Excretion was highly variable peaking soon after consumption began and decreasing rapidly after consumption stopped. Within five days after consumption ended FB1 was not detected in urine. In a study with eight volunteers, the average total urinary FB1 was 0.5% of the intake. FB1 was detected in 61% (107/177) of the samples collected in Guatemala. The results support the use of urinary FB1 to assess ongoing exposure in population based studies. However, relating the FB1 concentration in urine to dietary intake of FB by individual subjects will be complicated due to inter-individual variability and the rapidity of clearance. PMID:22815244

  14. Bioassay data and a retention-excretion model for systemic plutonium

    SciTech Connect

    Leggett, R.W.

    1984-05-01

    The estimation of systemic burdens from urinalyses has been the most common and useful method of quantifying occupational exposures to plutonium. Problems arise in using this technique, however, because of inadequate modeling of human retention, translocation, and excretion of this element. Present methods for estimating the systemic burden from urinalyses were derived to a large extent from patterns observed in the first few months after exposure, but there is now evidence that these same patterns do not persist over long periods. In this report we collect and discuss data needed for the interpretation of bioassay results for Pu. These data are used to develop a model that describes the movement, retention, and excretion of systemic Pu in the human body in terms of explicitly identified anatomical compartments. This model may be used in conjunction with existing models and/or case-specific information concerning the translocation of Pu from the respiratory or gastrointestinal tract or from wounds to the bloodstream. Attention is restricted to the behavior of Pu after it has gained access to the bloodstream. There remain significant uncertainties concerning some aspects of the movement of Pu, particularly its translocation from the liver. An attempt has been made to construct the model in such a way as to elucidate those areas needing further attention. 98 references, 18 figures, 16 tables.

  15. Molecular mechanism of 1,1-dichloroethylene toxicity: excreted metabolites reveal different pathways of reactive intermediates.

    PubMed

    Reichert, D; Werner, H W; Metzler, M; Henschler, D

    1979-07-11

    The excretion and biotransformation of [14C] 1,1-dichloroethylene (vinylidene chloride, VDC) after administration of a single oral dose has been investigated in female rats. Seventy-two hours after a dose of 0.5, 5.0, and 50.0 mg/kg, 1.26, 9.70, 16.47%, respectively, are exhaled as unchanged VDC, and 13.64, 11.35, 6.13% as 14CO2. The main pathway of elimination is through renal excretion with 43.55, 53.88, 42.11% of the administered radioactivity. Through the biliary system, 15.74, 14.54, 7.65% of the activity are eliminated. The isolation of the main metabolites of VDC from 24 h urine is accomplished through the combined application of solvent extraction, ion exchange chromatography and thin layer chromatography. Then gas chromatography and mass spectrometry are used for their identification. Three metabolites have been identified: thiodiglycolic acid, N-acetyl-S-(2-carboxymethyl)cysteine and methyl-thio-acetylaminoethanol. In addition, three smaller unidentified radioactive peaks have been found. Thiodiglycolic acid is the main metabolite in VDC metabolism. The simultaneous formation of an ethanolamine- and a cysteine-conjugation product points to different reaction pathways of the postulated intermediate reactive epoxide; ethanolamine probably originates from membrane lipids, which react with VDC-epoxide and/or its derivatives. This pathway could explain, in part, the parenchyma damaging effect of VDC.

  16. Optimized siRNA-PEG conjugates for extended blood circulation and reduced urine excretion in mice.

    PubMed

    Iversen, Frank; Yang, Chuanxu; Dagnæs-Hansen, Frederik; Schaffert, David H; Kjems, Jørgen; Gao, Shan

    2013-01-01

    Some of the main concerns with in vivo application of naked small interfering RNA are rapid degradation and urinary excretion resulting in a short plasma half-life. In this study we investigated how conjugation of polyethylene glycol (PEG) with variable chain length affects siRNA pharmacokinetics and biodistribution. The PEG chains were conjugated to chemically stabilized siRNA at the 5' terminal end of the passenger strand using click chemistry. The siRNA conjugate remained functionally active and showed significantly prolonged circulation in the blood stream after intravenous injection. siRNA conjugated with 20kDa PEG (PEG20k-siRNA) was most persistent, approximately 50% PEG20k-siRNA remained 1h post-injection, while the uncoupled siRNA was rapidly removed >90% at 15min. In vivo fluorescent imaging of the living animal showed increased concentration of siRNA in peripheral tissue and delayed urine excretion when coupled to PEG 20k. Biodistribution studies by northern blotting revealed equal distribution of conjugated siRNA in liver, kidney, spleen and lung without significant degradation 24 h post-injection. Our study demonstrates that PEG conjugated siRNA can be applied as a delivery system to improve siRNA bioavailability in vivo and may potentially increase the efficiency of siRNA in therapeutic applications.

  17. [Functional status of the bile excretion system and upper gastrointestinal tract in patients with duodenal ulcer].

    PubMed

    Razarenova, T G; Koshel', A P; Klokov, S S; Dibina, T V

    2010-01-01

    The research of functional condition of biliary tract in 35 patients suffered from gastroduodenal ulcers compared with 30 almost healthy patients was conducted. Disorders of motor function were found out in 13.2% patients in control group. The motor-evacuative function of biliary tract conformed to average scores of healthy patients group in only 8.6% cases. The accelerated gallbladder empting (11.4%), the hypermotoric biliary dyskinesia with the absence of latent period of biliary excretion (17.1%), the hypomotoric dysfunction of biliary tract (34.3%) were found out in the rest cases. The separate group of patients were patients with distortion of biliary excretion that was consisted in periodic increase and decrease of gall bladder volume during the contraction. We concluded that motor-evacuative function of biliary tract doesn't depend on the type of pathological process in the stomach or duodenum but correlates with gastric evacuation contents, the rate of cholagogic meal advancement along the duodenum and acid-productive function of the stomach.

  18. Excretion of ammonium by a nifL mutant of Azotobacter vinelandii fixing nitrogen.

    PubMed Central

    Bali, A; Blanco, G; Hill, S; Kennedy, C

    1992-01-01

    A mutation in the gene upstream of nifA in Azotobacter vinelandii was introduced into the chromosome to replace the corresponding wild-type region. The resulting mutant, MV376, produced nitrogenase constitutively in the presence of 15 mM ammonium. When introduced into a nifH-lacZ fusion strain, the mutation permitted beta-galactosidase production in the presence of ammonium. The gene upstream of nifA is therefore designated nifL because of its similarity to the Klebsiella pneumoniae nifL gene in proximity to nifA, in mutant phenotype, and in amino acid sequence of the gene product. The A. vinelandii nifL mutant MV376 excreted significant quantities of ammonium (approximately 10 mM) during diazotrophic growth. In contrast, ammonium excretion during diazotrophy was much lower in a K. pneumoniae nifL deletion mutant (maximum, 0.15 mM) but significantly higher than in NifL+ K. pneumoniae. The expression of the A. vinelandii nifA gene, unlike that of K. pneumoniae, was not repressed by ammonium. PMID:1622243

  19. Absorption, distribution, and excretion of 8-methoxypsoralen in HRA/Skh mice

    SciTech Connect

    Muni, I.A.; Schneider, F.H.; Olsson, T.A. III; King, M.

    1984-12-01

    The tissue distribution and excretion of (/sup 3/H)8-methoxypsoralen (8-MOP), a well-accepted therapeutic agent for the treatment of psoriasis, was studied in hairless HRA/Skh female mice. Mice were given single oral doses of 6 mg of (/sup 3/H)8-MOP or 5-(/sup 14/C)8-MOP/kg in corn oil. Radiochemical analyses of tissues and excreta were accomplished by liquid scintillation counting. The 8-MOP appeared to be rapidly absorbed through the gastrointestinal tract, where the tritium levels were highest, followed by skin, blood, and liver; levels were lowest in fat (adipose tissue). In female HRA/Skh mice which had not been irradiated with UVA (320-400 nm), 84% of the carbon-14 and 58% of the tritium were recovered in the urine and feces within 24 hours of oral administration of 5-(/sup 14/C)8-MOP or (/sup 3/H)8-MOP, respectively. Animals that were exposed to UVA and received (3H)8-MOP excreted approximately 12% less tritium in the urine and feces compared with the animals which received no UVA.

  20. Effect of hyperosmotic solutions on salt excretion and thirst in rats

    NASA Technical Reports Server (NTRS)

    Schoorlemmer, G. H.; Johnson, A. K.; Thunhorst, R. L.

    2000-01-01

    We investigated urinary changes and thirst induced by infusion of hyperosmotic solutions in freely moving rats. Intracarotid infusions of 0.3 M NaCl (4 ml/20 min, split between both internal carotid arteries) caused a larger increase in excretion of Na(+) and K(+) than intravenous infusions, indicating that cephalic sensors were involved in the response to intracarotid infusions. Intravenous and intracarotid infusions of hyperosmotic glycerol or urea (300 mM in 150 mM NaCl) had little or no effect, suggesting the sensors were outside the blood-brain barrier (BBB). Intracarotid infusion of hypertonic mannitol (300 mM in 150 mM NaCl) was more effective than intravenous infusion, suggesting that cell volume rather than Na(+) concentration of the blood was critical. Similarly, intracarotid infusion (2 ml/20 min, split between both sides), but not intravenous infusion of hypertonic NaCl or mannitol caused thirst. Hyperosmotic glycerol, infused intravenously or into the carotid arteries, did not cause thirst. We conclude that both thirst and electrolyte excretion depend on a cell volume sensor that is located in the head, but outside the BBB.

  1. Bioconcentration and excretion of diazinon, IBP, malathion and fenitrothion by carp.

    PubMed

    Tsuda, T; Aoki, S; Kojima, M; Harada, H

    1990-01-01

    1. Bioconcentration and excretion of diazinon, IBP, malathion and fenitrothion were studied for carp (Cyprinus carpio L.). 2. The concentrations of these pesticides in muscle and viscera of the carp reached plateaus in 12-48 hr exposure. 3. The average values of bioconcentration factors (BCF) for diazinon were 20.9 in muscle, 60.0 in liver, 111.1 in kidney and 32.2 in gallbladder over the 168 hr exposure period. Similarly, those values were 4.3-26.7 for IBP, 2.7-17.3 for malathion, and 36.0-157.1 for fenitrothion. 4. The excretion rate constants of malathion (hr-1) were 0.13 for muscle, 0.12 for liver, 0.08 for kidney and 0.06 for gallbladder. Those of diazinon, IBP and fenitrothion (g.ng-1.hr-1) were 0.002-0.024 for muscle, 0.001-0.020 for liver, 0.0004-0.004 for kidney and 0.002-0.023 for gallbladder, respectively.

  2. Excretion of lead and its biological activity several years after termination of exposure

    PubMed Central

    Přerovská, I.; Teisinger, J.

    1970-01-01

    Přerovská, and Teisinger, J. (1970).Brit. J. industr. Med.,27, 352-355. Excretion of lead and its biological activity several years after termination of exposure. A group of 27 persons who had been treated some years previously for chronic lead poisoning at our clinic, and who had not come into occupational contact with lead since, was examined. Half of them had had no occupational exposure to lead for 3 to 5 years and the others for 8 to 17 years. In most of these persons there is still an increased lead excretion, originating from an increased deposit in the bones. The mobilization test after calcium versenate (CaEDTA) injection was greater than 0·350 mg/24 hours. The values found for haemoglobin, punctate basophilia, coproporphyrin and ALA in urine were normal, but there was, in all cases, a decreased ALA-D activity. This finding suggests biological activity of such negligible lead flow many years after termination of exposure. PMID:5488694

  3. Preventive obesity agent montmorillonite adsorbs dietary lipids and enhances lipid excretion from the digestive tract

    PubMed Central

    Xu, Pengfei; Dai, Shu; Wang, Jing; Zhang, Jun; Liu, Jin; Wang, Fang; Zhai, Yonggong

    2016-01-01

    Western diets are typically high in fat and are associated with long-term complications such as obesity and hepatic steatosis. Because of the enjoyable taste of high-fat diets (HFDs), we are interested in determining how to decrease lipid absorption and enhance lipid excretion from the digestive tract after the consumption of eating fatty foods. Montmorillonite was initially characterized as a gastrointestinal mucosal barrier protective agent for the treatment of diarrhoea. Dietary lipid adsorbent- montmorillonite (DLA-M) was isolated and purified from Xinjiang montmorillonite clay via the water extraction method. Here, we show that DLA-M has an unexpected role in preventing obesity, hyperlipidaemia and hepatic steatosis in HFD-fed rats. Interestingly, combined application of polarized light microscopy and lipid staining analyses, showed that DLA-M crystals have dietary lipid-adsorbing ability in vitro and in vivo, which enhances lipid excretion via bowel movements. In summary, our results indicate that DLA-M prevent HFD-induced obesity. This novel dietary lipid-adsorbing agent can help prevent obesity and its comorbidities. PMID:26891902

  4. [Effect of positive pressure respiration on diurnal catecholamine excretion by patients with obstructive sleep apnea].

    PubMed

    Cieślicki, J; Wocial, B; Koziej, M; Pałasiewicz, G; Zieliński, J

    1996-02-01

    The aim of the study was to investigate effects of CPAP treatment on diurnal catecholamine excretion in urine in patients with obstructive sleep apnea (OSA). 12 males with severe OSA (mean AHI = 63) were measured in 3 separate 8 hour samples by fluorimetric method. NA levels were higher in OSA patients in all urine samples than in obese, mildly hypertensive males (control group = C). In C group patients NA levels were significantly lower at night than during the day contrary to OSA patients in whom NA levels dropped insignificantly during sleep. In OSA patients NA levels during sleep correlated with severity of apneas (r = 0.42) and night hypoxaemia (r = -0.46). CPAP treatment resulted in significant fall in NA levels during sleep (p < 0.01). A levels did not change after CPAP treatment. We conclude that abnormally high NA level during sleep in OSA patients may be related to sleep fragmentation and hypoxia. CPAP treatment restores normal circadian rhythm of NA excretion.