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Sample records for extracellular potassium concentration

  1. Multistability in a neuron model with extracellular potassium dynamics

    Science.gov (United States)

    Wu, Xing-Xing; Shuai, J. W.

    2012-06-01

    Experiments show a primary role of extracellular potassium concentrations in neuronal hyperexcitability and in the generation of epileptiform bursting and depolarization blocks without synaptic mechanisms. We adopt a physiologically relevant hippocampal CA1 neuron model in a zero-calcium condition to better understand the function of extracellular potassium in neuronal seizurelike activities. The model neuron is surrounded by interstitial space in which potassium ions are able to accumulate. Potassium currents, Na+-K+ pumps, glial buffering, and ion diffusion are regulatory mechanisms of extracellular potassium. We also consider a reduced model with a fixed potassium concentration. The bifurcation structure and spiking frequency of the two models are studied. We show that, besides hyperexcitability and bursting pattern modulation, the potassium dynamics can induce not only bistability but also tristability of different firing patterns. Our results reveal the emergence of the complex behavior of multistability due to the dynamical [K+]o modulation on neuronal activities.

  2. Effects of extracellular potassium diffusion on electrically coupled neuron networks

    Science.gov (United States)

    Wu, Xing-Xing; Shuai, Jianwei

    2015-02-01

    Potassium accumulation and diffusion during neuronal epileptiform activity have been observed experimentally, and potassium lateral diffusion has been suggested to play an important role in nonsynaptic neuron networks. We adopt a hippocampal CA1 pyramidal neuron network in a zero-calcium condition to better understand the influence of extracellular potassium dynamics on the stimulus-induced activity. The potassium concentration in the interstitial space for each neuron is regulated by potassium currents, Na+-K+ pumps, glial buffering, and ion diffusion. In addition to potassium diffusion, nearby neurons are also coupled through gap junctions. Our results reveal that the latency of the first spike responding to stimulus monotonically decreases with increasing gap-junction conductance but is insensitive to potassium diffusive coupling. The duration of network oscillations shows a bell-like shape with increasing potassium diffusive coupling at weak gap-junction coupling. For modest electrical coupling, there is an optimal K+ diffusion strength, at which the flow of potassium ions among the network neurons appropriately modulates interstitial potassium concentrations in a degree that provides the most favorable environment for the generation and continuance of the action potential waves in the network.

  3. Primary afferent depolarization and changes in extracellular potassium concentration induced by L-glutamate and L-proline in the isolated spinal cord of the frog.

    Science.gov (United States)

    Vyklický, L; Vyskocil, F; Kolaj, M; Jastreboff, P

    1982-10-08

    To test the hypothesis that L-proline acts as an antagonist on glutamate receptors [17, 18], the interaction between L-glutamate and L-proline was studied in the isolated spinal cord of the frog. Glutamate at concentrations of 10(-6) -5 x 10(-3) mol/l depolarized the primary afferent fibres and increased extracellular potassium concentration, [K+]e, by 0.3-4 mmol/l. Repeated applications lead to inactivation of the response. L-Proline at 5 x 10(-3) -10(-2) mol/l, also depolarized the primary afferents and increased [K+]e by 0.5-2 mmol/l, but there was only a slight decrease of the effects after repeated application. The effects were additive when the amino acids were applied simultaneously. The effect of L-proline was still present when it was applied during inactivation of the glutamate receptors. This suggests that L-glutamate and L-proline act on different receptors.

  4. Elevated extracellular potassium ion concentrations suppress ...

    African Journals Online (AJOL)

    To address this question, we examined how elevations of [K+]o affect hippocampal oscillations in Scn1a mutant mouse, a mouse model of Dravet syndrome, a devastating genetic-epilepsy associated with gliosis, a major cause of dysregulated K+ homeostasis in epileptic brain. Methods: To this end, performing local field ...

  5. Concentration of Potassium in Plasma, Erythrocytes, and Muscle Tissue in Cows with Decreased Feed Intake and Gastrointestinal Ileus.

    Science.gov (United States)

    Schneider, S; Müller, A; Wittek, T

    2016-01-01

    Healthy cows consume large amounts of potassium and a sudden loss in appetite can lead to hypokalemia. The routine method to evaluate potassium homeostasis is the measurement of the extracellular potassium in plasma or serum, but this does not provide information about the intracellular potassium pool. To evaluate potassium homeostasis by comparing the extracellular and intracellular potassium concentration in cows with reduced feed intake and gastrointestinal ileus. Twenty cows 1-3 days postpartum (group 1) and 20 cows with gastrointestinal ileus (group 2). Observational cross-sectional study. Plasma potassium was measured by using an ion-sensitive electrode. Intracellular potassium was measured in erythrocytes and muscle tissue (muscle biopsy) by using inductively coupled plasma optical emission spectroscopy. Cows of group 1 did not have hypokalemia. Overall cows with gastrointestinal ileus were hypokalemic (mean ± SD, 2.9 mmol/L ± 0.78), but potassium concentration in erythrocytes and muscle tissue was not lower than in postpartum cows. Intracellular potassium in erythrocytes varied very widely; group 1: 3497-10735 mg/kg (5559 ± 2002 mg/kg), group 2: 4139-21678 mg/kg (7473 ± 4034 mg/kg). Potassium in muscle tissue did not differ between group 1 (3356 ± 735 mg/kg wet weight) and group 2 (3407 ± 1069 mg/kg wet weight). No association between extracellular and intracellular potassium concentrations was detected. That measurement of plasma potassium concentration is not sufficient to evaluate potassium metabolism of cows. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  6. Sodium and potassium concentrations in floral nectars in relation to ...

    African Journals Online (AJOL)

    Sodium and potassium concentrations have been measured in nectar from a variety of flowering plants visited by honey bees (Apis mellifera capensis). In 18 plant species the mean sodium concentration was 9,8 ± 1,4 mmol (± S.E.), and the mean potassium concentration was 18,7 ± 4,3 mmol. These results are compared ...

  7. Variable Potassium Concentrations: Which Is Right and Which Is Wrong?

    Science.gov (United States)

    Theparee, Talent; Benirschke, Robert C; Lee, Hong-Kee

    2017-05-01

    Reverse pseudohyperkalemia is a term used to describe in vitro, falsely elevated potassium concentrations in plasma specimens that occur in association with extreme leukocytosis and are commonly associated with hematologic malignant neoplasms. Tumor lysis syndrome is an in vivo lysis of tumor cells that leads to elevated levels of potassium, uric acid, phosphate, and lactate dehydrogenase, as well as decreased calcium concentrations. Herein, we report a case of a 66-year-old Caucasian man with stage IV mantle-cell lymphoma who has elevated levels of potassium, uric acid, and phosphorus, as well as a white blood cell (WBC) count greater than 100,000 cells per mm3. The patient initially was diagnosed as having tumor lysis syndrome. His subsequent potassium concentrations in whole blood remained elevated even after hemodialysis; however, his serum potassium concentrations were decreased. The patient then was diagnosed accurately as having reverse pseudohyperkalemia, and accurate potassium measurements were obtained via serum specimens. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Role of the activation gate in determining the extracellular potassium dependency of block of HERG by trapped drugs.

    Science.gov (United States)

    Pareja, Kristeen; Chu, Elaine; Dodyk, Katrina; Richter, Kristofer; Miller, Alan

    2013-01-01

    Drug induced long QT syndrome (diLQTS) results primarily from block of the cardiac potassium channel HERG (human-ether-a-go-go related gene). In some cases long QT syndrome can result in the lethal arrhythmia torsade de pointes, an arrhythmia characterized by a rapid heart rate and severely compromised cardiac output. Many patients requiring medication present with serum potassium abnormalities due to a variety of conditions including gastrointestinal dysfunction, renal and endocrine disorders, diuretic use, and aging. Extracellular potassium influences HERG channel inactivation and can alter block of HERG by some drugs. However, block of HERG by a number of drugs is not sensitive to extracellular potassium. In this study, we show that block of WT HERG by bepridil and terfenadine, two drugs previously shown to be trapped inside the HERG channel after the channel closes, is insensitive to extracellular potassium over the range of 0 mM to 20 mM. We also show that bepridil block of the HERG mutant D540K, a mutant channel that is unable to trap drugs, is dependent on extracellular potassium, correlates with the permeant ion, and is independent of HERG inactivation. These results suggest that the lack of extracellular potassium dependency of block of HERG by some drugs may in part be related to the ability of these drugs to be trapped inside the channel after the channel closes.

  9. Potassium concentration in bone of Beijing residents

    International Nuclear Information System (INIS)

    Lin Lianqing

    1994-01-01

    The author presents the measuring results of K concentration in bone ash samples of 65 residents in Beijing area by atomic absorption spectrum. The results indicate that the K concentrations in bone ash is logarithmic normal distribution, ranging level is 0.75-8.44 g/kg ash, the average and standard deviation is respectively 2.40 and 1.52 g/kg ash. The highest concentration (4.88 g/kg ash) appears in infantile stage (< 1y), the lowest concentration (1.59 g/kg ash) appears in young stage (2-5 y). The lower concentration (1.88 g/kg ash) appears in adolescence (11-20 y). The K concentration in wet bone as a percentage of weight is 0.067%. The specific activities of K-40 in bone is about 22 mBq/g wet bone. The total radioactivity of K-40 in whole bone is 220 Bq. The annual absorbed dose is received in adult bone from K-40 is estimated to be 95 μGy

  10. Changes in plasma potassium concentration during carbon dioxide pneumoperitoneum

    DEFF Research Database (Denmark)

    Perner, A; Bugge, K; Lyng, K M

    1999-01-01

    Hyperkalaemia with ECG changes had been noted during prolonged carbon dioxide pneumoperitoneum in pigs. We have compared plasma potassium concentrations during surgery in 11 patients allocated randomly to undergo either laparoscopic or open appendectomy and in another 17 patients allocated randomly...... to either carbon dioxide pneumoperitoneum or abdominal wall lifting for laparoscopic colectomy. Despite an increasing metabolic acidosis, prolonged carbon dioxide pneumoperitoneum resulted in only a slight increase in plasma potassium concentrations, which was both statistically and clinically insignificant....... Thus hyperkalaemia is unlikely to develop in patients with normal renal function undergoing carbon dioxide pneumoperitoneum for laparoscopic surgery....

  11. Sodium and potassium concentrations in floral nectars in relation to ...

    African Journals Online (AJOL)

    1989-08-03

    Aug 3, 1989 ... techniques (Instrumentation Laboratory Model IL 243). In order to examine ... mmol. Potassium and sugar concentrations were very poorly ... cations that the error in calculating its energy content would be .... mellifica adults (subspecies not named). .... consumption, and thoracic temperature during flight in a.

  12. Chaotic Dynamics Mediates Brain State Transitions, Driven by Changes in Extracellular Ion Concentrations

    DEFF Research Database (Denmark)

    Rasmussen, Rune; H. Jensen, Mogens; L. Heltberg, Mathias

    2017-01-01

    Previous studies have suggested that changes in extracellular ion concentrations initiate the transition from an activity state that characterizes sleep in cortical neurons to states that characterize wakeful- ness. However, because neuronal activity and extra- cellular ion concentrations...... are interdependent, isolating their unique roles during sleep-wake transitions is not possible in vivo. Here, we extend the Averaged-Neuron model and demonstrate that, although changes in extracellular ion concentrations occur concurrently, decreasing the conductance of calcium-dependent potassium channels initiates...... the transition from sleep to wakefulness. We find that sleep is governed by stable, self-sustained oscillations in neuronal firing patterns, whereas the quiet awake state and active awake state are both governed by irregular oscillations and chaotic dynamics; transitions between these separable awake states...

  13. Body water, extracellular water, body potassium, and exchangeable sodium in body builders using anabolic steroids

    International Nuclear Information System (INIS)

    Wang, J.; Colt, E.D.W.; Pierson, R.N. Jr.

    1986-01-01

    Nine competitive male body builders aged 21 to 34 who were determined to take anabolic steroids were studied before and 6 to 10 weeks after a training cycle which included steroid administration. A control group of nine subjects matched in age and duration of competitive career, but using only natural training methods were studied on a single occasion while in training. Total body potassium (TBK) by 40 K, total body water (TBW) by 3 H 2 O dilution, extracellular water (ECW) by 35 SO 4 dilution and zero time extrapolation, and exchangeable sodium by 24 Na dilution were measured before and after training. Intracellular water (ICW) was calculated from TBW - ECW. Initially steroid users had a greater skeletal muscle mass than control subjects, and obtained a further weight gain on steroids, all in skeletal muscle, based on parallel increases in TBK and ICW. Other body composition measurements did not change significantly. A single steroid user became ill taking steroids, decreased potassium by 5%, and increased extracellular water, changes which may represent the effects of hepatic dysfunction which occurred while on anabolic steroids

  14. Intraerythrocytic sodium and potassium concentrations during acute and chronic digitalization.

    Science.gov (United States)

    Pedersen, K E; Koldkjaer, O; Berndtz, N H; Hvidt, S; Kjaer, K; Midtskov, C; Sanchez, G

    1982-01-01

    To assess the cellular effects of digoxin, intraerythrocytic sodium and potassium concentrations were measured in 17 patients during the early phase of digitalization, in 45 patients on long-term therapy and in 64 non-digitalized control patients. Acute digitalization raised intraerythrocytic sodium from 11.6 +/- 0.4 to 16.7 +/- 1.0 mmol/l (mean +/- SEM) (p less than 0.01) and reduced intraerythrocytic potassium from 100.1 +/- 1.3 to 95.9 +/- 1.8 mmol/l (p less than 0.01). These changes were strongly correlated with the steady-state plasma digoxin concentration. During a few weeks of digoxin therapy, the intraerythrocytic cation composition normalized gradually. In patients on chronic treatment, neither intraerythrocytic sodium (11.3 +/- 0.3 mmol/l) nor potassium concentrations (100.0 +/- 0.6 mmol/l) differed significantly from the values of the control group (11.4 +/- 0.2 and 99.9 +/- 0.5 mmol/l, respectively). The changes in intraerythrocytic cation concentrations, induced by acute digitalization, seem to disappear during chronic administration of the drug.

  15. Neural synchronization via potassium signaling

    DEFF Research Database (Denmark)

    Postnov, Dmitry E; Ryazanova, Ludmila S; Mosekilde, Erik

    2006-01-01

    Using a relatively simple model we examine how variations of the extracellular potassium concentration can give rise to synchronization of two nearby pacemaker cells. With the volume of the extracellular space and the rate of potassium diffusion as control parameters, the dual nature of this reso...

  16. Tomato yield and potassium concentrations in soil and in plant petioles as affected by potassium fertirrigation

    Directory of Open Access Journals (Sweden)

    FONTES PAULO CEZAR REZENDE

    2000-01-01

    Full Text Available Tomato (Lycopersicon esculentum Mill. cv. Santa Clara was grown on a silt clay soil with 46 mg dm-3 Mehlich 1 extractable K, to evaluate the effects of trickle-applied K rates on fruit yield and to establish K critical concentrations in soil and in plant petioles. Six potassium rates (0, 48, 119, 189, 259 and 400 kg ha-1 K were applied in a randomized complete block design with four replications. Soil and plant K critical levels were determined at two plant growth stages (at the beginning of the second and fourth cluster flowering. Total, marketable and weighted yields increased with K rates, reaching their maximum of 86.4, 73.4, and 54.9 ton ha-1 at 198, 194, and 125 kg ha-1 K , respectively. At the first soil sampling date K critical concentrations in the soil associated with K rates for maximum marketable and weighted yields were 92 and 68 mg dm-3, respectively. Potassium critical concentrations in the dry matter of the petioles sampled by the beginning of the second and fourth cluster flowering time, associated with maximum weighted yield, were 10.30 and 7.30 dag kg-1, respectively.

  17. Stimulation of Suicidal Erythrocyte Death by Increased Extracellular Phosphate Concentrations

    Directory of Open Access Journals (Sweden)

    Jakob Voelkl

    2014-02-01

    Full Text Available Background/Aim: Anemia in renal insufficiency results in part from impaired erythrocyte formation due to erythropoietin and iron deficiency. Beyond that, renal insufficiency enhances eryptosis, the suicidal erythrocyte death characterized by phosphatidylserine-exposure at the erythrocyte surface. Eryptosis may be stimulated by increase of cytosolic Ca2+-activity ([Ca2+]i. Several uremic toxins have previously been shown to stimulate eryptosis. Renal insufficiency is further paralleled by increase of plasma phosphate concentration. The present study thus explored the effect of phosphate on erythrocyte death. Methods: Cell volume was estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, and [Ca2+]i from Fluo3-fluorescence. Results: Following a 48 hours incubation, the percentage of phosphatidylserine exposing erythrocytes markedly increased as a function of extracellular phosphate concentration (from 0-5 mM. The exposure to 2 mM or 5 mM phosphate was followed by slight but significant hemolysis. [Ca2+]i did not change significantly up to 2 mM phosphate but significantly decreased at 5 mM phosphate. The effect of 2 mM phosphate on phosphatidylserine exposure was significantly augmented by increase of extracellular Ca2+ to 1.7 mM, and significantly blunted by nominal absence of extracellular Ca2+, by additional presence of pyrophosphate as well as by presence of p38 inhibitor SB203580. Conclusion: Increasing phosphate concentration stimulates erythrocyte membrane scrambling, an effect depending on extracellular but not intracellular Ca2+ concentration. It is hypothesized that suicidal erythrocyte death is triggered by complexed CaHPO4.

  18. Photometric determination of phosphorus in zircon concentrate and potassium hexafluorozirconate

    International Nuclear Information System (INIS)

    Polonskaya, I.A.; Fominykh, N.L.

    1978-01-01

    A method for direct photometric phosphorus determination in the materials, containing considerable zirconium amounts is developed. Phosphorus is determined in a form of reduced heteropolyacid with the use of ascorbic acid and potassium antimonyltartrate in sulfuric acid medium. To remove zirconium effect, a graduation diagram is drawn at the background of zirconium, which is bound into a stable fluoride complex in the presence of H 3 BO 3 . Under the above conditions the coloring developes after 30-40 min and remains stable for 24 hrs. A proportional dependence between phosphorus concentration and optical density is observed in the range of 10-160 mg of Zr. The method sensitivity is 5x10 -5 %

  19. Temporal Profiles Dissociate Regional Extracellular Ethanol versus Dopamine Concentrations

    Science.gov (United States)

    2015-01-01

    In vivo monitoring of dopamine via microdialysis has demonstrated that acute, systemic ethanol increases extracellular dopamine in regions innervated by dopaminergic neurons originating in the ventral tegmental area and substantia nigra. Simultaneous measurement of dialysate dopamine and ethanol allows comparison of the time courses of their extracellular concentrations. Early studies demonstrated dissociations between the time courses of brain ethanol concentrations and dopaminergic responses in the nucleus accumbens (NAc) elicited by acute ethanol administration. Both brain ethanol and extracellular dopamine levels peak during the first 5 min following systemic ethanol administration, but the dopamine response returns to baseline while brain ethanol concentrations remain elevated. Post hoc analyses examined ratios of the dopamine response (represented as a percent above baseline) to tissue concentrations of ethanol at different time points within the first 25–30 min in the prefrontal cortex, NAc core and shell, and dorsomedial striatum following a single intravenous infusion of ethanol (1 g/kg). The temporal patterns of these “response ratios” differed across brain regions, possibly due to regional differences in the mechanisms underlying the decline of the dopamine signal associated with acute intravenous ethanol administration and/or to the differential effects of acute ethanol on the properties of subpopulations of midbrain dopamine neurons. This Review draws on neurochemical, physiological, and molecular studies to summarize the effects of acute ethanol administration on dopamine activity in the prefrontal cortex and striatal regions, to explore the potential reasons for the regional differences observed in the decline of ethanol-induced dopamine signals, and to suggest directions for future research. PMID:25537116

  20. Determination of potassium concentration in salt water for residual beta radioactivity measurements

    International Nuclear Information System (INIS)

    Suarez-Navarro, J.A.; Pujol, Ll.

    2004-01-01

    High interferences may arise in the determination of potassium concentration in salt water. Several analytical methods were studied to determine which method provided the most accurate measurements of potassium concentration. This study is relevant for radiation protection because the exact amount of potassium in water samples must be known for determinations of residual beta activity concentration. The fitting algorithm of the calibration curve and estimation of uncertainty in potassium determinations were also studied. The reproducibility of the proposed analytical method was tested by internal and external validation. Furthermore, the residual beta activity concentration of several Spanish seawater and brackish river water samples was determined using the proposed method

  1. Extracellular Bio-imaging of Acetylcholine-stimulated PC12 Cells Using a Calcium and Potassium Multi-ion Image Sensor.

    Science.gov (United States)

    Matsuba, Sota; Kato, Ryo; Okumura, Koichi; Sawada, Kazuaki; Hattori, Toshiaki

    2018-01-01

    In biochemistry, Ca 2+ and K + play essential roles to control signal transduction. Much interest has been focused on ion-imaging, which facilitates understanding of their ion flux dynamics. In this paper, we report a calcium and potassium multi-ion image sensor and its application to living cells (PC12). The multi-ion sensor had two selective plasticized poly(vinyl chloride) membranes containing ionophores. Each region on the sensor responded to only the corresponding ion. The multi-ion sensor has many advantages including not only label-free and real-time measurement but also simultaneous detection of Ca 2+ and K + . Cultured PC12 cells treated with nerve growth factor were prepared, and a practical observation for the cells was conducted with the sensor. After the PC12 cells were stimulated by acetylcholine, only the extracellular Ca 2+ concentration increased while there was no increase in the extracellular K + concentration. Through the practical observation, we demonstrated that the sensor was helpful for analyzing the cell events with changing Ca 2+ and/or K + concentration.

  2. Dependence of radiocaesium biological half-life in freshwater fish on water potassium concentration and temperature

    International Nuclear Information System (INIS)

    Carreiro, M.C.V.; Corisco, J.A.G.

    1998-01-01

    Short-term experiments (35-49 days) showed that the rate of cesium elimination from fish increases with increasing potassium concentration in water (the biological half-life decreases); this, however, is only true of the potassium concentration range of 0.35 to 3.5 ppm, whereas higher potassium concentrations do not seem to affect the elimination rate. Decrease in water temperature within the 20 degC to 5 degC range slows down the cesium elimination process. (P.A.)

  3. Evaluation of the potassium adsorption capacity of a potassium adsorption filter during rapid blood transfusion.

    Science.gov (United States)

    Matsuura, H; Akatsuka, Y; Muramatsu, C; Isogai, S; Sugiura, Y; Arakawa, S; Murayama, M; Kurahashi, M; Takasuga, H; Oshige, T; Yuba, T; Mizuta, S; Emi, N

    2015-05-01

    The concentration of extracellular potassium in red blood cell concentrates (RCCs) increases during storage, leading to risk of hyperkalemia. A potassium adsorption filter (PAF) can eliminate the potassium at normal blood transfusion. This study aimed to investigate the potassium adsorption capacity of a PAF during rapid blood transfusion. We tested several different potassium concentrations under a rapid transfusion condition using a pressure bag. The adsorption rates of the 70-mEq/l model were 76·8%. The PAF showed good potassium adsorption capacity, suggesting that this filter may provide a convenient method to prevent hyperkalemia during rapid blood transfusion. © 2015 International Society of Blood Transfusion.

  4. The influence of water potassium concentration on 137Cs excretion from fish

    International Nuclear Information System (INIS)

    Nasvit, O.J.

    1996-01-01

    Results are reported of the investigation on the peculiarities of 137 Cs release from carp (Cyprinus carpio L.) acclimatized to different potassium concentrations in water. The dynamics of radiocesium release are characterized by slow and fast components. The 137 Cs release rates observed in the experiments with different water potassium concentrations were markedly different from the point of view of middle-term radioecological predictions. 5 refs., 3 figs., 3 tabs

  5. Effect of elevated potassium ion concentrations on electrically evoked release of (/sup 3/H)acetylcholine in slices of rat hippocampus

    Energy Technology Data Exchange (ETDEWEB)

    Szerb, J C; Hadhazy, P; Dudar, J D [Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Physiology and Biophysics

    1978-01-01

    To establish the effect of raising the concentration of extracellular potassium ions on axonal conduction and transmitter release in a mammalian central pathway, the septohippocampal cholinergic tract, the rate of (/sup 3/H) acetylcholine release evoked by electrical stimulation was measured in rat hippocampal slices superfused with Krebs' solution containing 3-15 mM K/sup +/. The evoked release of (/sup 3/H) acetylcholine was abolished by the presence of tetrodotoxin or by the omission of Ca/sup 2 +/ in the superfusion medium, indicating that it originated from terminals depolarized by conducted action potentials. Potassium concentrations between 3 and 8 mM had no effect but 10-15 mM K/sup +/ reduced the rate of evoked release and decreased the size of the releasable pool of (/sup 3/H) acetylcholine. Decreasing the sodium content of the Krebs' solution to 97 mM or less had effects similar to those of elevated (K/sup +/). Elevated K/sup +/ (10-15 mM) reversibly reduced the size of compound action potentials in the fimbria and the alveus. The results suggest that extracellular potassium concentrations occurring under physiological conditions do not affect axonal conduction and transmitter release but that both are reduced in pathological states when extracellular (K/sup +/) above 8 mM occur.

  6. Concentrations of Uranium,Thorium and Potassium in Sweden

    International Nuclear Information System (INIS)

    Thunholm, Bo; Linden, Anders H.; Gustafsson, Bosse

    2005-04-01

    This report is largely a result of the Swedish contribution to an IAEA co-ordinated research programme (CRP) on the use of selected safety indicators in the assessment of radioactive waste disposal. The CRP was focusing on the assessment of the longterm safety of radioactive waste disposal by means of additional safety indicators based on data from natural systems with emphasis on description of existing data on radioactive elements and radionuclides. A major part of the work was focused on collecting data on geophysics as well as geochemistry and groundwater chemistry; mainly uranium (U), thorium (Th) and potassium (K). Data were interpreted resulting in maps and statistical description

  7. Concentrations of Uranium,Thorium and Potassium in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Thunholm, Bo; Linden, Anders H.; Gustafsson, Bosse [Geological Survey of Sweden, Uppsala (Sweden)

    2005-04-01

    This report is largely a result of the Swedish contribution to an IAEA co-ordinated research programme (CRP) on the use of selected safety indicators in the assessment of radioactive waste disposal. The CRP was focusing on the assessment of the longterm safety of radioactive waste disposal by means of additional safety indicators based on data from natural systems with emphasis on description of existing data on radioactive elements and radionuclides. A major part of the work was focused on collecting data on geophysics as well as geochemistry and groundwater chemistry; mainly uranium (U), thorium (Th) and potassium (K). Data were interpreted resulting in maps and statistical description.

  8. Estimation of natural potassium concentration in Romanian males by in vivo gamma-ray spectrometry measurements

    International Nuclear Information System (INIS)

    Mirela Angela Saizu

    2012-01-01

    At the Whole Body Monitoring Laboratory, from IFIN-HH, Bucharest, Romania, there were performed in vivo gamma-ray spectrometry measurements on 108 Romanian males in order to evaluate the mineral natural potassium content in human body, as total value and concentration. The measurements were performed with a shadow shield whole body counter, tilted chair geometry, based on a shielded NaI(Tl) scintillation detector of 12.5 cm (diameter) x 10 cm (height) crystal size. The results revealed a calculated value of the mean total body potassium (TBK) of 135.03 ± 2.94 g and a value of 1.9 ± 0.022 g of potassium/kg of body weight for the mean body potassium concentration, for the measured males. These values are similar with the values declared for the Reference Man, in ICRP23. Correlations between total body potassium, potassium concentration and age, weight and Body Build Index were investigated and peculiar conclusions were resulted. (author)

  9. Estimation of potassium concentration in coconut water by beta radioactivity measurement

    International Nuclear Information System (INIS)

    Reddy, P.J.; Narayani, K.; Bhade, S.P.D.; Anilkumar, S.; Kolekar, R.V.; Singh, Rajvir; Pradeepkumar, K.S.

    2014-01-01

    Potassium is widely distributed in soil, in all vegetable, fruits and animal tissues. Approximately half the radioactivity found in humans comes from 40 K. Potassium is an essential element in our diet since it is required for proper nerve and muscle function, as well as for maintaining the fluid balance of cells and heart rhythm. Potassium can enter the body mainly consuming fruits, vegetables and food. Tender coconut water is consumed widely as natural refreshing drink which is rich in potassium. The simple way to determine 40 K activity is by gamma ray spectrometry. However, the low abundance of this gamma photon makes the technique less sensitive compared to gross beta measurement. Many analytical methods are reported for potassium estimation which is time consuming and destructive in nature. A unique way to estimate 40 K by beta activity is by Cerenkov Counting technique using Liquid Scintillation Analyzer. Also much lower detection limit is achieved, allowing for greater precision. In this work, we have compared two methods to arrive at the potassium concentration in tender and matured coconut water by measuring 40 K. One is non-scintillator method based on measurement of the Cerenkov radiation generated from the high-energy β of 40 K. The second method is based on beta activity measurement using low background Gas flow counter

  10. An analysis of the potassium concentrations of soft drinks by HPGe gamma spectrometry

    International Nuclear Information System (INIS)

    Guillermo Espinosa; Jose-Ignacio Golzarri; Ilsa Hernandez-Ibinarriaga

    2009-01-01

    Potassium, in a variety of compounds, occurs in abundance in the Earth's crust, and is an essential nutrient for human health. A naturally occurring radioactive isotope of potassium, 40 K, is found in the food and water that we consume. This paper presents the results of a gamma spectrometry analysis of the 40 K concentrations of a selection of commercial soft drinks. The 40 K concentrations are used to calculate the overall potassium concentrations. The analysis was carried out using a hyper-pure germanium (HPGe) detector with Ortec R ASPEC-927 multichannel analyzer module and GammaVision R software. This system was chosen for its high resolution and automatic data processing. The carbonated soft drinks (sodas) Coca-Cola R , Coca-Cola Light R (sold as Diet Coke R in the USA and other countries), Coca-Cola Zero R , Pepsi R , Pepsi Light R , Pepsi Max R , Big Cola R , Lulu-Cola R , Manzana Lift R , Sprite R and Fanta R and the mineral waters Ciel R and Penafiel R were analyzed. These brands are all international registered trademarks. The products analyzed were manufactured and bottled in Mexico. The results show a great variety of potassium concentrations in the different soft drinks analyzed (from 128.0 to 1113.1 mg/L). The concentration of potassium in the sodas, in conjunction with the amounts drank by one person in a year (180 L/year), are high enough to warrant consideration by public health authorities and by people to whom high potassium intakes pose a risk. (author)

  11. Plasma potassium concentration and content changes after banana ingestion in exercised men.

    Science.gov (United States)

    Miller, Kevin C

    2012-01-01

    Individuals prone to exercise-associated muscle cramps (EAMCs) are instructed to eat bananas because of their high potassium (K(+)) concentration and carbohydrate content and the perception that K(+) imbalances and fatigue contribute to the genesis of EAMCs. No data exist about the effect of bananas on plasma K(+) concentration ([K(+)](p)) or plasma glucose concentration ([glucose](p)) after exercise in the heat. To determine whether ingesting 0, 1, or 2 servings of bananas after 60 minutes of moderate to vigorous exercise in the heat alters [K(+)](p) or [glucose](p) and whether changes in [K(+)](p) result from hypotonic fluid effluxes or K(+) ion changes. Crossover study. Laboratory. Nine euhydrated men (age = 27 ± 4 years, height = 180.3 ± 8.4 cm, mass = 84.9 ± 26.1 kg, urine specific gravity ≤ 1.006) without EAMCs volunteered. On 3 separate days, participants completed 60 minutes of moderate to vigorous cycling (temperature = 36.4°C ± 1.1°C, relative humidity = 19.4% ± 2.5%) and then ate 0 g (0 servings), 150 g (1 serving), or 300 g (2 servings) of bananas. Blood samples were collected at 3, 5, 15, 30, and 60 minutes postingestion. The [K(+)](p), changes in plasma K(+) content, plasma volume changes, and [glucose](p). The [K(+)](p) differed between conditions at 60 minutes; 2 servings (4.6 ± 0.3 mmol/L [conventional unit = 4.6 ± 0.3 mEq/L]) was greater than 1 serving (4.5 ± 0.2 mmol/L [conventional unit = 4.5 ± 0.2 mEq/L]) and 0 servings (4.4 ± 0.3 mmol/L [conventional unit = 4.4 ± 0.3 mEq/L]) (P banana ingestion on EAMCs is unknown; however, these data suggested bananas are unlikely to relieve EAMCs by increasing extracellular [K(+)] or [glucose](p). The increases in [K(+)](p) were marginal and within normal clinical values. The changes in [K(+)](p), plasma K(+) content, and [glucose](p) do not occur quickly enough to treat acute EAMCs, especially if they develop near the end of competition.

  12. GABA-mediated synchronization in the human neocortex: elevations in extracellular potassium and presynaptic mechanisms.

    Science.gov (United States)

    Louvel, J; Papatheodoropoulos, C; Siniscalchi, A; Kurcewicz, I; Pumain, R; Devaux, B; Turak, B; Esposito, V; Villemeure, J G; Avoli, M

    2001-01-01

    Field potential and extracellular [K(+)] ([K(+)](o)) recordings were made in the human neocortex in an in vitro slice preparation to study the synchronous activity that occurs in the presence of 4-aminopyridine (50 microM) and ionotropic excitatory amino acid receptor antagonists. Under these experimental conditions, negative or negative-positive field potentials accompanied by rises in [K(+)](o) (up to 4.1 mM from a baseline of 3.25 mM) occurred spontaneously at intervals of 3-27 s. Both field potentials and [K(+)](o) elevations were largest at approximately 1000 microm from the pia. Similar events were induced by neocortical electrical stimuli. Application of medium containing low [Ca(2+)]/high [Mg(2+)] (n=3 slices), antagonism of the GABA(A) receptor (n=7) or mu-opioid receptor activation (n=4) abolished these events. Hence, they represented network, GABA-mediated potentials mainly reflecting the activation of type A receptors following GABA release from interneurons. The GABA(B) receptor agonist baclofen (10-100 microM, n=11) reduced and abolished the GABA-mediated potentials (ID(50)=18 microM). Baclofen effects were antagonized by the GABA(B) receptor antagonist CGP 35348 (0.1-1 mM, n=6; ID(50)=0.19 mM). CGP 38345 application to control medium increased the amplitude of the GABA-mediated potentials and the concomitant [K(+)](o) rises without modifying their rate of occurrence. The GABA-mediated potentials were not influenced by the broad-spectrum metabotropic glutamate agonist (+/-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (100 microM, n=10), but decreased in rate with the group I receptor agonist (S)-3,5-dihydroxyphenylglycine (10-100 microM, n=9). Our data indicate that human neocortical networks challenged with 4-aminopyridine generate glutamatergic-independent, GABA-mediated potentials that are modulated by mu-opioid and GABA(B) receptors presumably located on interneuron terminals. These events are associated with [K(+)](o) elevations that may

  13. Role of lauric acid-potassium hydroxide concentration on bacterial contamination of spray washed broiler carcasses

    Science.gov (United States)

    A series of experiments were conducted to examine reductions in bacterial contamination of broiler carcasses washed in a spray cabinet with various concentrations of lauric acid (LA)-potassium hydroxide (KOH) solutions. Fifty eviscerated carcasses and 5 ceca were obtained from the processing line of...

  14. Statistical analysis of the potassium concentration obtained through

    International Nuclear Information System (INIS)

    Pereira, Joao Eduardo da Silva; Silva, Jose Luiz Silverio da; Pires, Carlos Alberto da Fonseca; Strieder, Adelir Jose

    2007-01-01

    The present work was developed in outcrops of Santa Maria region, southern Brazil, Rio Grande do Sul State. Statistic evaluations were applied in different rock types. The possibility to distinguish different geologic units, sedimentary and volcanic (acid and basic types) by means of the statistic analyses from the use of airborne gamma-ray spectrometry integrating potash radiation emissions data with geological and geochemistry data is discussed. This Project was carried out at 1973 by Geological Survey of Brazil/Companhia de Pesquisas de Recursos Minerais. The Camaqua Project evaluated the behavior of potash concentrations generating XYZ Geosof 1997 format, one grid, thematic map and digital thematic map files from this total area. Using these data base, the integration of statistics analyses in sedimentary formations which belong to the Depressao Central do Rio Grande do Sul and/or to volcanic rocks from Planalto da Serra Geral at the border of Parana Basin was tested. Univariate statistics model was used: the media, the standard media error, and the trust limits were estimated. The Tukey's Test was used in order to compare mean values. The results allowed to create criteria to distinguish geological formations based on their potash content. The back-calibration technique was employed to transform K radiation to percentage. Inside this context it was possible to define characteristic values from radioactive potash emissions and their trust ranges in relation to geologic formations. The potash variable when evaluated in relation to geographic Universal Transverse Mercator coordinates system showed a spatial relation following one polynomial model of second order, with one determination coefficient. The statistica 7.1 software Generalist Linear Models produced by Statistics Department of Federal University of Santa Maria/Brazil was used. (author)

  15. Metrological assessment of TDR performance for measurement of potassium concentration in soil solution

    Directory of Open Access Journals (Sweden)

    Isaac de M. Ponciano

    2016-04-01

    Full Text Available ABSTRACT Despite the growing use of the time domain reflectometry (TDR technique to monitoring ions in the soil solution, there are few studies that provide insight into measurement error. To overcome this lack of information, a methodology, based on the central limit theorem error, was used to quantify the uncertainty associated with using the technique to estimate potassium ion concentration in two soil types. Mathematical models based on electrical conductivity and soil moisture derived from TDR readings were used to estimate potassium concentration, and the results were compared to potassium concentration determined by flame spectrophotometry. It was possible to correct for random and systematic errors associated with TDR readings, significantly increasing the accuracy of the potassium estimation methodology. However, a single TDR reading can lead to an error of up to ± 18.84 mg L-1 K+ in soil solution (0 to 3 dS m-1, with a 95.42% degree of confidence, for a loamy sand soil; and an error of up to ± 12.50 mg L-1 of K+ (0 to 2.5 dS m-1 in soil solution, with a 95.06% degree of confidence, for a sandy clay soil.

  16. Solid contact potassium selective electrodes for biomedical applications – a review

    NARCIS (Netherlands)

    van de Velde, Lennart; d'Angremont, E.; Olthuis, Wouter

    2016-01-01

    Ion-selective electrodes (ISE) are used in several biomedical applications, including laboratory sensing of potassium concentration in blood and urine samples. For on-site determination of potassium concentration and usage in other applications such as determination of extracellular potassium

  17. Potassium Chloride Versus Voltage Clamp Contractures in Ventricular Muscle

    Science.gov (United States)

    Morad, M.; Reeck, S.; Rao, M.

    1981-01-01

    In frog ventricle, developed tension was markedly larger in response to depolarization caused by a voltage clamp step than to depolarization induced by high concentrations of potassium chloride. Measurement of extracellular potassium activity at the surface and at the depth of muscle during the development of contractures showed that the diffusion of potassium is much slower than the spread of depolarization through the cross section of muscle. These two observations suggest that competition between the depolarizing and the negative inotropic effects of an increase in the extracellular potassium ion concentration may determine the time course and magnitude of contractile tension in heart muscle.

  18. Determination of potassium concentration in organic samples by means of x-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Soto Moran, R.L.; Szgedi, S.

    1993-01-01

    By means of x-ray fluorescence analysis and the inner standard method using KH 2 PO 4 as the added chemical compound, potassium concentration of roots, stems , leaf, flowers and grains from Quinua (Chenopodium Quinoa Willd). which was previously treated with a nitrogen ed fertilizers has been determined taking into account the increasing effect the average atomic number due to used standard. Experimental errors are lower than 10 %

  19. 40K activities and potassium concentrations in tobacco samples of Mexican cigarettes

    International Nuclear Information System (INIS)

    Martinez, T.; Navarrete, M.; Cabrera, L.; Ramos, A.; Vazquez, K.; Juarez, F.

    2007-01-01

    Nine brands of tobacco cigarettes manufactured and distributed in the Mexican market were analyzed by γ-spectrometry to certify their nonartificial radioactive contamination. Since natural occurring radioactive materials (NORM) 40 K, 232 Th, 235 U, and 239 U (and decay products from the latter three nuclides) are the main sources for human radiation exposure, the aim of this work was to determine the activity of 40 K and potassium concentration. Averages of 40 K and potassium concentration were of 1.29 ± 0.18 Bq x g -1 , and 4.0 ± 0.57%. The annual dose equivalents to the whole body from ingestion and inhalation of 26 Bq 40 K were 0.23 μSv and 15.8 μSv, respectively. The corresponding 50 years committed dose equivalents was 0.23 μSv. The total committed dose to the lungs due to inhalation of 40 K in tobacco was 16 μSv. Potassium concentrations obtained in this work were in the same range of those obtained by INAA, so showing that the used technique is acute, reproducible, and accessible to laboratories equipped with low background scintillation detectors. (author)

  20. Cadmium, zinc, copper, sodium and potassium concentrations in rooster and turkey semen and their correlation.

    Science.gov (United States)

    Massanyi, Peter; Weis, Jan; Lukac, Norbert; Trandzik, Jozef; Bystricka, Judita

    2008-04-01

    The purpose of this study was to assess concentration of selected elements (cadmium, zinc, copper, sodium and potassium) in rooster and turkey semen and to find possible correlations between these elements. Samples were analyzed on the atomic absorption spectrophotometer. The analysis of cadmium showed that the concentration in rooster is 9.06 +/- 7.70 and in turkey 4.10 +/- 3.59 microg/mL. In zinc 5.25 +/- 1.96 microg/mL in rooster and 3.70 +/- 1.26 microg/mL in turkey were detected. Higher concentration of copper was found in rooster semen (6.79 +/- 6.42 microg/mL) in comparison with turkey semen (4.29 +/- 5.43 microg/mL). The level of sodium (3.96 +/- 1.02 microg/mL; 3.14 +/- 0.85 microg/mL) and potassium (2.88 +/- 0.65 microg/mL; 3.42 +/- 1.41 microg/mL) was very similar in both species. Correlation analysis detected high positive correlation between cadmium and zinc (r = 0.701) in rooster and between sodium and potassium (r = 0.899) in turkey semen.

  1. Comparative study of glycine single crystals with additive of potassium nitrate in different concentration ratios

    Energy Technology Data Exchange (ETDEWEB)

    Gujarati, Vivek P., E-mail: vivekgujarati@gmail.com; Deshpande, M. P., E-mail: vishwadeshpande@yahoo.co.in; Patel, Kamakshi R.; Chaki, S. H. [Department of Physics, Sardar Patel University, Vallabh Vidyanagar, Gujarat (India)

    2016-05-06

    Semi-organic crystals of Glycine Potassium Nitrate (GPN) with potential applications in Non linear optics (NLO) were grown using slow evaporation technique. Glycine and Potassium Nitrate were taken in three different concentration ratios of 3:1, 2:1 and 1:1 respectively. We checked the solubility of the material in distilled water at different temperatures and could observe the growth of crystals in 7 weeks time. Purity of the grown crystals was confirmed by Energy Dispersive X-ray Analysis (EDAX) and CHN analysis. GSN Powder X-ray diffraction pattern was recorded to confirm the crystalline nature. To confirm the applications of grown crystals in opto-electronics field, UV-Vis-NIR study was carried out. Dielectric properties of the samples were studied in between the frequency range 1Hz to 100 KHz.

  2. Effect of parental morphine addiction on extracellular glutamate concentration of dentate gyrus in rat offsprings

    Directory of Open Access Journals (Sweden)

    rahele Assaee

    2004-01-01

    Findings: In male offsprings of sham control1, sham control2, test1 and test2 basal and electrical stimulated of extracellular glutamate concentration of dentate gyrus were: 0.67±0.04, 1.11±0.1, and in female offsprings were 0.47±0.06, 0.88±0.05 (n=5. The basal and stimulated extra cellular glutamate concentration of dentate gyrus was decreased in both test1 and test2 offsprings. It was less in test1 than test2 offsprings. The glutamate concentration of dentate gyrus in female offsprings of test1 group was less than that of the male offsprings. conclusion: The results suggest that parental morphine addiction may cause learning deficiency through reduction of extracellular glutamate concentration in dentate gyrus so the side effects of parental morphine addiction in offsprings must be considered.

  3. Ion Concentration- and Voltage-Dependent Push and Pull Mechanisms of Potassium Channel Ion Conduction.

    Directory of Open Access Journals (Sweden)

    Kota Kasahara

    Full Text Available The mechanism of ion conduction by potassium channels is one of the central issues in physiology. In particular, it is still unclear how the ion concentration and the membrane voltage drive ion conduction. We have investigated the dynamics of the ion conduction processes in the Kv1.2 pore domain, by molecular dynamics (MD simulations with several different voltages and ion concentrations. By focusing on the detailed ion movements through the pore including selectivity filter (SF and cavity, we found two major conduction mechanisms, called the III-IV-III and III-II-III mechanisms, and the balance between the ion concentration and the voltage determines the mechanism preference. In the III-IV-III mechanism, the outermost ion in the pore is pushed out by a new ion coming from the intracellular fluid, and four-ion states were transiently observed. In the III-II-III mechanism, the outermost ion is pulled out first, without pushing by incoming ions. Increases in the ion concentration and voltage accelerated ion conductions, but their mechanisms were different. The increase in the ion concentrations facilitated the III-IV-III conductions, while the higher voltages increased the III-II-III conductions, indicating that the pore domain of potassium channels permeates ions by using two different driving forces: a push by intracellular ions and a pull by voltage.

  4. Extrarenal potassium adaptation: role of skeletal muscle

    International Nuclear Information System (INIS)

    Blachley, J.D.; Crider, B.P.; Johnson, J.H.

    1986-01-01

    Following the ingestion of a high-potassium-content diet for only a few days, the plasma potassium of rats rises only modestly in response to a previously lethal dose of potassium salts. This acquired tolerance, termed potassium adaptation, is principally the result of increased capacity to excrete potassium into the urine. However, a substantial portion of the acute potassium dose is not immediately excreted and is apparently translocated into cells. Previous studies have failed to show an increase in the content of potassium of a variety of tissues from such animals. Using 86 Rb as a potassium analogue, we have shown that the skeletal muscle of potassium-adapted rats takes up significantly greater amounts of potassium in vivo in response to an acute challenge than does that of control animals. Furthermore, the same animals exhibit greater efflux of 86 Rb following the termination of the acute infusion. We have also shown that the Na+-K+-ATPase activity and ouabain-binding capacity of skeletal muscle microsomes are increased by the process of potassium adaptation. We conclude that skeletal muscle is an important participant in potassium adaptation and acts to temporarily buffer acute increases in the extracellular concentration of potassium

  5. Modeling the concentration-dependent permeation modes of the KcsA potassium ion channel.

    Science.gov (United States)

    Nelson, Peter Hugo

    2003-12-01

    The potassium channel from Streptomyces lividans (KcsA) is an integral membrane protein with sequence similarity to all known potassium channels, particularly in the selectivity filter region. A recently proposed model for ion channels containing either n or (n-1) single-file ions in their selectivity filters [P. H. Nelson, J. Chem. Phys. 177, 11396 (2002)] is applied to published KcsA channel K+ permeation data that exhibit a high-affinity process at low concentrations and a low-affinity process at high concentrations [M. LeMasurier et al., J. Gen. Physiol. 118, 303 (2001)]. The kinetic model is shown to provide a reasonable first-order explanation for both the high- and low-concentration permeation modes observed experimentally. The low-concentration mode ([K+]200 mM) has a 200-mV dissociation constant of 1100 mM and a conductance of 500 pS. Based on the permeation model, and x-ray analysis [J. H. Morais-Cabral et al., Nature (London) 414, 37 (2001)], it is suggested that the experimentally observed K+ permeation modes correspond to an n=3 mechanism at high concentrations and an n=2 mechanism at low concentrations. The ratio of the electrical dissociation distances for the high- and low-concentration modes is 3:2, also consistent with the proposed n=3 and n=2 modes. Model predictions for K+ channels that exhibit asymmetric current-voltage (I-V) curves are presented, and further validation of the kinetic model via molecular simulation and experiment is discussed. The qualitatively distinct I-V characteristics exhibited experimentally by Tl+, NH+4, and Rb+ ions at 100 mM concentration can also be explained using the model, but more extensive experimental tests are required for quantitative validation of the model predictions.

  6. Potassium-selective microelectrode revealed difference in threshold potassium concentration for cortical spreading depression in female and male rat brain

    Czech Academy of Sciences Publication Activity Database

    Adámek, S.; Vyskočil, František

    2011-01-01

    Roč. 1370, - (2011), s. 215-219 ISSN 0006-8993 R&D Projects: GA AV ČR(CZ) IAA500110905 Institutional research plan: CEZ:AV0Z50110509 Keywords : rat cortex * potassium in brain Subject RIV: ED - Physiology Impact factor: 2.728, year: 2011

  7. Determination of thorium, uranium and potassium elemental concentrations in surface soils in Cyprus

    International Nuclear Information System (INIS)

    Tzortzis, Michalis; Tsertos, Haralabos

    2004-01-01

    A comprehensive study was conducted to determine thorium, uranium and potassium elemental concentrations in surface soils throughout the accessible area of Cyprus using high-resolution γ-ray spectrometry. A total of 115 soil samples was collected from all over the bedrock surface of the island based on the different lithological units of the study area. The soil samples were air-dried, sieved through a fine mesh, sealed in 1000-ml plastic Marinelli beakers, and measured in the laboratory in terms of their gamma radioactivity for a counting time of 18 h each. From the measured γ-ray spectra, elemental concentrations were determined for thorium (range from 2.5x10 -3 to 9.8 μg g -1 ), uranium (from 8.1x10 -4 to 3.2 μg g -1 ) and potassium (from 1.3x10 -4 to 1.9%). The arithmetic mean values (A.M.±S.D.) calculated from all samples are: (1.2±1.7) μg g -1 , (0.6±0.7) μg g -1 and (0.4±0.3)%, for thorium, uranium and potassium, respectively, which are by a factor of three-six lower than the world average values of 7.4 μg g -1 (Th), 2.8 μg g -1 (U) and 1.3% (K) derived from all data available worldwide. The best-fitting relation between the concentrations of Th and K versus U and also of K versus Th, is essentially of linear type with a correlation coefficient of 0.93, 0.84 and 0.90, respectively. The Th/U, K/U and K/Th ratios (slopes) extracted are equal to 2.0, 2.8x10 3 and 1.4x10 3 , respectively

  8. [The relationship between PMI and concentration of potassium ion and sodium ion in swine aqueous humor after death].

    Science.gov (United States)

    Han, Ju; Yu, Guang-biao; Dong, Ye-qiang; Fang, Chao; Jing, Hua-lan; Luo, Si-min

    2010-04-01

    To explored the relationship between the concentration of potassium ion as well as sodium ion in the aqueous humor and post-mortem interval (PMI). The concentrations of potassium ion and sodium ion in the aqueous humor of swine within 48 h after death at 4 degrees C and 28 degrees C were detected using Z-500 atomic absorption spectrophotometer. The concentrations of potassium ion and sodium ion in aqueous humor of isolated swine eyeballs within 48 h after death when the environmental temperature was 4 degrees C were significantly related to PMI. The relationship between PMI and the concentration of potassium ion was PMI = -0.178[K+]2 + 49.978 (R2 = 0.995). The relationship between PMI and the rate of sodium ion and potassium ion was PMI = 120.987/[Na+/K+]-28.834 (R2 = 0.905). The concentration of potassium in aqueous humor of isolated swine eyeballs may be one of the reference indicators to estimate PMI of the corpses at lower temperatures.

  9. Increased concentrations of potassium in heartwood of trees in response to groundwater contamination

    Science.gov (United States)

    Vroblesky, Don A.; Yanosky, Thomas M.; Siegel, Frederic R.

    1992-03-01

    The wood of tuliptrees ( Liriodendron tulipifera L.) growing above groundwater contamination from a hazardous-waste landfill in Maryland contained elevated concentrations of potassium (K). The groundwater contamination also contained elevated concentrations of dissolved K, as well as arsenic (As), cadmium (Cd), chloride (Cl), iron (Fe), manganese (Mn), zinc (Zn), and organic solvents. The dissolved K is derived from disposed smoke munitions. The excess K in the tuliptrees is concentrated in the heartwood, the part of the xylem most depleted in K in trees growing outside of the contamination. These data show that the uptake and translocation of K by tuliptrees can be strongly influenced by the availability of K in groundwater contamination and suggest the utility of this species as an areal indicator of groundwater contamination.

  10. Increased concentrations of potassium in heartwood of trees in response to groundwater contamination

    Science.gov (United States)

    Vroblesky, D.A.; Yanosky, T.M.; Siegel, F.R.

    1992-01-01

    The wood of tuliptrees (Liriodendron tulipifera L.) growing above groundwater contamination from a hazardous-waste landfill in Maryland contained elevated concentrations of potassium (K). The groundwater contamination also contained elevated concentrations of dissolved K, as well as arsenic (As), cadmium (Cd), chloride (Cl), iron (Fe), manganese (Mn), zinc (Zn), and organic solvents. The dissolved K is derived from disposed smoke munitions. The excess K in the tuliptrees is concentrated in the heartwood, the part of the xylem most depleted in K in trees growing outside of the contamination. These data show that the uptake and translocation of K by tuliptrees can be strongly influenced by the availability of K in groundwater contamination and suggest the utility of this species as an areal indicator of groundwater contamination. ?? 1992 Springer-Verlag New York Inc.

  11. Brain intra- and extracellular sodium concentration in multiple sclerosis: a 7 T MRI study.

    Science.gov (United States)

    Petracca, Maria; Vancea, Roxana O; Fleysher, Lazar; Jonkman, Laura E; Oesingmann, Niels; Inglese, Matilde

    2016-03-01

    Intra-axonal accumulation of sodium ions is one of the key mechanisms of delayed neuro-axonal degeneration that contributes to disability accrual in multiple sclerosis. In vivo sodium magnetic resonance imaging studies have demonstrated an increase of brain total sodium concentration in patients with multiple sclerosis, especially in patients with greater disability. However, total sodium concentration is a weighted average of intra- and extra-cellular sodium concentration whose changes reflect different tissue pathophysiological processes. The in vivo, non-invasive measurement of intracellular sodium concentration is quite challenging and the few applications in patients with neurological diseases are limited to case reports and qualitative assessments. In the present study we provide first evidence of the feasibility of triple quantum filtered (23)Na magnetic resonance imaging at 7 T, and provide in vivo quantification of global and regional brain intra- and extra-cellular sodium concentration in 19 relapsing-remitting multiple sclerosis patients and 17 heathy controls. Global grey matter and white matter total sodium concentration (respectively P brain regional level, clusters of increased total sodium concentration and intracellular sodium concentration and decreased intracellular sodium volume fraction were found in several cortical, subcortical and white matter regions when patients were compared with healthy controls (P Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Hemodynamic Behavior During Hemodialysis: Effects of Dialysate Concentrations of Bicarbonate and Potassium

    Directory of Open Access Journals (Sweden)

    Bruno C. Silva

    2014-11-01

    Full Text Available Background/Aims: Ultrafiltration that occurs during hemodialysis (HD promotes profound alterations in a relatively short period of time. The dialysate content of bicarbonate (DBic and potassium (DK may have impact over intradialytic hemodynamics, which goes beyond ultrafiltration, and its impact was evaluated in a prospective cohort. Methods: 30 patients under HD were submitted to hemodynamic assessment (HA at the beginning and at the end of HD sessions, through a non-invasive method. Serum minus dialysate potassium concentration was expressed as K-Gap. Cardiac index (CI and peripheral arterial resistance (PAR variation (post-HD minus pre-HD were expressed as ΔCI and ΔPAR. Dialysate content of sodium and calcium were expressed as DNa and DCa, respectively. Results: Mean DNa, DK and DBic were, respectively, 136.4 ± 1.1, 2.1 ± 0.6 and 38.2 ± 2.1 mEq/L. In 15 patients, DCa was >1.5 mmol/L and in the other 15 patients ≤ 1.5 mmol/L. The K-Gap ranged from 1.4 to 5.1 mEq/l (median 3.0 mEq/L. There was a reduction in post-HD CI and systolic blood pressure (ΔCI = -0.72l/min/m2 and -11.3±15.1mmHg, respectively, p5, pConclusion: We confirmed that Na and Ca dialysate content exerts and important role on hemodynamic during HD. In addition, our findings pointed out that higher dialysate concentrations of bicarbonate and potassium promote lower cardiac performance at the end of hemodialysis session.

  13. Sources Contributing to the Average Extracellular Concentration of Dopamine in the Nucleus Accumbens

    OpenAIRE

    Owesson-White, CA; Roitman, MF; Sombers, LA; Belle, AM; Keithley, RB; Peele, JL; Carelli, RM; Wightman, RM

    2012-01-01

    Mesolimbic dopamine neurons fire in both tonic and phasic modes resulting in detectable extracellular levels of dopamine in the nucleus accumbens (NAc). In the past, different techniques have targeted dopamine levels in the NAc to establish a basal concentration. In this study we used in vivo fast scan cyclic voltammetry (FSCV) in the NAc of awake, freely moving rats. The experiments were primarily designed to capture changes in dopamine due to phasic firing – that is, the measurement of dopa...

  14. Noise Controlled Synchronization in Potassium Coupled Neural Models

    DEFF Research Database (Denmark)

    Postnov, D. E.; Ryazanova, L. S.; Zhirin, R. A.

    2007-01-01

    The paper applies biologically plausible models to investigate how noise input to small ensembles of neurons, coupled via the extracellular potassium concentration, can influence their firing patterns. Using the noise intensity and the volume of the extracellular space as control parameters, we......-temporal oscillations in neuronal ensembles....

  15. On the Sodium Concentration Diffusion with Three-Dimensional Extracellular Stimulation

    Directory of Open Access Journals (Sweden)

    Luisa Consiglieri

    2011-01-01

    Full Text Available We deal with the transmembrane sodium diffusion in a nerve. We study a mathematical model of a nerve fibre in response to an imposed extracellular stimulus. The presented model is constituted by a diffusion-drift vectorial equation in a bidomain, that is, two parabolic equations defined in each of the intra- and extra-regions. This system of partial differential equations can be understood as a reduced three-dimensional Poisson-Nernst-Planck model of the sodium concentration. The representation of the membrane includes a jump boundary condition describing the mechanisms involved in the excitation-contraction couple. Our first novelty comes from this general dynamical boundary condition. The second one is the three-dimensional behaviour of the extracellular stimulus. An analytical solution to the mathematical model is proposed depending on the morphology of the excitation.

  16. Correlation between Creatinine Clearance and Transtubular Potassium Concentration Gradient in old people and chronic renal disease patients

    International Nuclear Information System (INIS)

    Musso, C.; Imperiali, N.; Algranati, L.; Miguel, R.D.; Liakopoulos, V.; Stefanidis, I.

    2007-01-01

    Senescence and chronic kidney disease (CKD) reduce progressively glomerular filtration rate (GFR) which usually results in an increase in potassium renal secretion. To evaluate whether the transtubular potassium concentration gradient (TTKG) is more accurate parameter for evaluating the renal secretion of this cation than using fractional excretion of potassium as its urinary secretion marker, we studied 55 subjects, 43 of them were healthy elderly volunteers and 12 were CKD patients. Exclusion criteria were: abnormal plasma potassium level or presence of any disease or drug that could induce alteration of balance of this electrolyte levels. All the subjects were on a diet with potassium content around 50 mmol/day. The curves, which demonstrate the relationship between creatinine clearance and TTKG and the grade of correlation between these two parameters were analyzed in both groups. We found that the transtubular potassium concentration gradient had a significant negative correlation with the creatinine clearance level in the healthy elderly group, while there was no correlation in the CKD group. (author)

  17. Influence of dissolved oxygen concentration on the toxicity of potassium cyanide to rainbow trout. [Salmo gairdneri

    Energy Technology Data Exchange (ETDEWEB)

    Downing, K M

    1954-01-01

    The present work was undertaken to see if similar results were obtained when fish were tested in a continuous flow of water in which the concentrations of oxygen and cyanide were kept constant. Periods of survival were measured this way to minimize distortion of results by accumulation of metabolic waste, depletion of oxygen or depletion of poison. Results are summarized as follows: rainbow trout survival in potassium cyanide increased with increase in dissolved oxygen; increase in survival times did not decline as oxygen saturation was approached; and medium survival times of 3.3 minutes or less were normally distributed while those of greater than 13 minutes were log normally distributed. 6 references, 1 figure.

  18. Effect of donepezil hydrochloride (E2020) on extracellular acetylcholine concentration in the cerebral cortex of rats.

    Science.gov (United States)

    Kosasa, T; Kuriya, Y; Yamanishi, Y

    1999-10-01

    Donepezil hydrochloride (donepezil), a potent and selective acetylcholinesterase inhibitor, has been developed for the treatment of Alzheimer's disease. We studied the effect of oral administration of this drug on the extracellular acetylcholine (ACh) concentration in the cerebral cortex of rats using microdialysis. We also observed fasciculation, a peripheral cholinergic sign induced by activation of neuromuscular transmission, after oral administration of the drug as an index of peripheral cholinergic activation. Other cholinesterase inhibitors, tacrine, ENA-713 and TAK-147, were used as reference drugs. Donepezil significantly and dose-dependently increased the extracellular ACh concentration in the rat cerebral cortex within the dose range of 2.5-10 mg/kg. Tacrine, ENA-713 and TAK-147 also elevated the extracellular concentration of ACh. The minimum effective doses of donepezil, tacrine, ENA-713 and TAK-147 were (< or = 2.5, 10, 10 and < or = 10 mg/kg, respectively. Donepezil produced fasciculation at doses of 2.5 mg/kg and above, with a dose-dependent increase in incidence and intensity. The reference compounds also induced fasciculation in a dose-dependent manner. The threshold doses of tacrine, ENA-713 and TAK-147 for fasciculation were 5, 2.5 and 2.5 mg/kg, respectively. The values of the ratio of the minimum effective dose for the ACh-increasing action to that for the fasciculation-producing action were: donepezil, < or = 1; tacrine, 2; ENA-713, 4; TAK-147, < or = 4. These results indicate that orally administered donepezil has a potent and selective activity on the central cholinergic system.

  19. Excretion of 137 Cs and bio energetic processes in Carp Cyprinus Carpio L. in the time of his acclimation to different concentrations of potassium in the water

    International Nuclear Information System (INIS)

    Romanenko, V.D.; Solomatina, V.D.; Fomovskij, M.A.; Nasvit, O.I.

    1995-01-01

    The result of the investigation on the peculiarities of 137 Cs release acclimatized to different potassium concentration in water are reported. The differences in characteristics of ion exchange and bioenergetic processes between fishes acclimated to different potassium concentrations were mainly eliminated to the 28-th day of acclimation period. The dynamics of radiocesium release is characterized by slow and just components. No differences in 137 Cs release rate were observed in experiments with different water potassium concentrations

  20. Effects of focal brain cooling on extracellular concentrations of neurotransmitters in patients with epilepsy.

    Science.gov (United States)

    Nomura, Sadahiro; Inoue, Takao; Imoto, Hirochika; Suehiro, Eiichi; Maruta, Yuichi; Hirayama, Yuya; Suzuki, Michiyasu

    2017-04-01

    Brain hypothermia controls epileptic discharge and reduces extracellular concentrations of glutamate (Glu), an excitatory neurotransmitter. We aimed to determine the effects of focal brain cooling (FBC) on levels of γ-aminobutyric acid (GABA), which is a major inhibitory neurotransmitter. The relationship between Glu or GABA concentrations and the severity of epileptic symptoms was also analyzed. Patients with intractable epilepsy underwent FBC at lesionectomized (n = 11) or hippocampectomized (n = 8) regions at 15°C for 30 min using custom-made cooling devices. Concentrations of Glu (n = 18) and GABA (n = 12) were measured in extracellular fluid obtained through microdialysis using high-performance liquid chromatography (HPLC). The reduction rate of neurotransmitter levels and its relationship with electrocorticography (ECoG) signal changes in response to FBC were measured. We found no relationship between the concentrations of Glu or GABA and seizure severity. There was a significant decrease in the concentration of Glu to 66.3% of control levels during the cooling period (p = 0.001). This rate of reduction correlated with ECoG power (r 2 = 0.68). Cortical and hippocampal GABA levels significantly (p = 0.02) and nonsignificantly decreased to 47.7% and 32.4% of control levels, respectively. However, the rate of this reduction did not correlate with ECoG (r 2 = 0.11). Although the decrease in hippocampal GABA levels was not significant due to wide variations in its concentration, the levels of cortical GABA and Glu were decreased following FBC. FBC suppresses epileptic discharge and the release of both excitatory and inhibitory neurotransmitters. The reduction in Glu levels further contributes to the reduction in epileptic discharge. However, the reduction in the levels of GABA has no impact on ECoG. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  1. A standardized method to determine the concentration of extracellular vesicles using tunable resistive pulse sensing

    Directory of Open Access Journals (Sweden)

    Robert Vogel

    2016-09-01

    Full Text Available Background: Understanding the pathogenic role of extracellular vesicles (EVs in disease and their potential diagnostic and therapeutic utility is extremely reliant on in-depth quantification, measurement and identification of EV sub-populations. Quantification of EVs has presented several challenges, predominantly due to the small size of vesicles such as exosomes and the availability of various technologies to measure nanosized particles, each technology having its own limitations. Materials and Methods: A standardized methodology to measure the concentration of extracellular vesicles (EVs has been developed and tested. The method is based on measuring the EV concentration as a function of a defined size range. Blood plasma EVs are isolated and purified using size exclusion columns (qEV and consecutively measured with tunable resistive pulse sensing (TRPS. Six independent research groups measured liposome and EV samples with the aim to evaluate the developed methodology. Each group measured identical samples using up to 5 nanopores with 3 repeat measurements per pore. Descriptive statistics and unsupervised multivariate data analysis with principal component analysis (PCA were used to evaluate reproducibility across the groups and to explore and visualise possible patterns and outliers in EV and liposome data sets. Results: PCA revealed good reproducibility within and between laboratories, with few minor outlying samples. Measured mean liposome (not filtered with qEV and EV (filtered with qEV concentrations had coefficients of variance of 23.9% and 52.5%, respectively. The increased variance of the EV concentration measurements could be attributed to the use of qEVs and the polydisperse nature of EVs. Conclusion: The results of this study demonstrate the feasibility of this standardized methodology to facilitate comparable and reproducible EV concentration measurements.

  2. Growth and gas exchange in white pitaya under different concentrations of potassium and calcium

    Directory of Open Access Journals (Sweden)

    João Paulo Cajazeira

    Full Text Available ABSTRACT Agriculture in Brazil has improved at a fast pace in recent years, given the growing demand for quality and the need for new products. In this respect, white pitaya [Hylocereus undatus (Haw. Britton & Rose] has become a feasible alternative for Northeast farmers. The limiting factors include a small amount of data on plant mineral nutrition and crop growth (phenology. Therefore, this study goal was to evaluate the effect of different concentrations of potassium (K and calcium (Ca on crop development and gas exchange in white pitaya grown in the coastal region of the state of Ceará, in Brazil. Sixteen treatments with three repetitions were organized in a completely randomized block design and a 4 × 4 factorial arrangement. Treatments consisted of various concentrations of K (0; 125; 250 and 375 mg dm-3 and Ca (0, 53, 106, and 159 mg dm-3. Biometric characteristics and gas exchange were determined after 270 and 240 days of treatment, respectively. For morphometric characteristics, the most significant nutrient combination was 250 mg dm-3 of K and 159 mg dm-3 of Ca. Net photosynthesis was higher at the dose of 125 mg dm-3 of K and 0 mg dm-3 of Ca. Our results indicate that, for the environmental conditions under which the test was conducted, an optimum nutrient combination for the analyzed variables was 250 mg dm-3 K and 159 mg dm-3 Ca.

  3. Mechanisms of astrocytic K(+) clearance and swelling under high extracellular K(+) concentrations.

    Science.gov (United States)

    Murakami, Shingo; Kurachi, Yoshihisa

    2016-03-01

    In response to the elevation of extracellular K(+) concentration ([K(+)]out), astrocytes clear excessive K(+) to maintain conditions necessary for neural activity. K(+) clearance in astrocytes occurs via two processes: K(+) uptake and K(+) spatial buffering. High [K(+)]out also induces swelling in astrocytes, leading to edema and cell death in the brain. Despite the importance of astrocytic K(+) clearance and swelling, the underlying mechanisms remain unclear. Here, we report results from a simulation analysis of astrocytic K(+) clearance and swelling. Astrocyte models were constructed by incorporating various mechanisms such as intra/extracellular ion concentrations of Na(+), K(+), and Cl(-), cell volume, and models of Na,K-ATPase, Na-K-Cl cotransporter (NKCC), K-Cl cotransporter, inwardly-rectifying K(+) (KIR) channel, passive Cl(-) current, and aquaporin channel. The simulated response of astrocyte models under the uniform distribution of high [K(+)]out revealed significant contributions of NKCC and Na,K-ATPase to increases of intracellular K(+) and Cl(-) concentrations, and swelling. Moreover, we found that, under the non-uniform distribution of high [K(+)]out, KIR channels localized at synaptic clefts absorbed excess K(+) by depolarizing the equivalent potential of K(+) (E K) above membrane potential, while K(+) released through perivascular KIR channels was enhanced by hyperpolarizing E K and depolarizing membrane potential. Further analysis of simulated drug effects revealed that astrocyte swelling was modulated by blocking each of the ion channels and transporters. Our simulation analysis revealed controversial mechanisms of astrocytic K(+) clearance and swelling resulting from complex interactions among ion channels and transporters.

  4. Effect of ethanol at clinically relevant concentrations on atrial inward rectifier potassium current sensitive to acetylcholine.

    Science.gov (United States)

    Bébarová, Markéta; Matejovič, Peter; Pásek, Michal; Hořáková, Zuzana; Hošek, Jan; Šimurdová, Milena; Šimurda, Jiří

    2016-10-01

    Alcohol intoxication tends to induce arrhythmias, most often the atrial fibrillation. To elucidate arrhythmogenic mechanisms related to alcohol consumption, the effect of ethanol on main components of the ionic membrane current is investigated step by step. Considering limited knowledge, we aimed to examine the effect of clinically relevant concentrations of ethanol (0.8-80 mM) on acetylcholine-sensitive inward rectifier potassium current I K(Ach). Experiments were performed by the whole-cell patch clamp technique at 23 ± 1 °C on isolated rat and guinea-pig atrial myocytes, and on expressed human Kir3.1/3.4 channels. Ethanol induced changes of I K(Ach) in the whole range of concentrations applied; the effect was not voltage dependent. The constitutively active component of I K(Ach) was significantly increased by ethanol with the maximum effect (an increase by ∼100 %) between 8 and 20 mM. The changes were comparable in rat and guinea-pig atrial myocytes and also in expressed human Kir3.1/3.4 channels (i.e., structural correlate of I K(Ach)). In the case of the acetylcholine-induced component of I K(Ach), a dual ethanol effect was apparent with a striking heterogeneity of changes in individual cells. The effect correlated with the current magnitude in control: the current was increased by eth-anol in the cells showing small current in control and vice versa. The average effect peaked at 20 mM ethanol (an increase of the current by ∼20 %). Observed changes of action potential duration agreed well with the voltage clamp data. Ethanol significantly affected both components of I K(Ach) even in concentrations corresponding to light alcohol consumption.

  5. Nicotine at clinically relevant concentrations affects atrial inward rectifier potassium current sensitive to acetylcholine.

    Science.gov (United States)

    Bébarová, Markéta; Matejovič, Peter; Švecová, Olga; Kula, Roman; Šimurdová, Milena; Šimurda, Jiří

    2017-05-01

    Nicotine abuse is associated with variety of diseases including arrhythmias, most often atrial fibrillation (AF). Altered inward rectifier potassium currents including acetylcholine-sensitive current I K(Ach) are known to be related to AF pathogenesis. Since relevant data are missing, we aimed to investigate I K(Ach) changes at clinically relevant concentrations of nicotine. Experiments were performed by the whole cell patch clamp technique at 23 ± 1 °C on isolated rat atrial myocytes. Nicotine was applied at following concentrations: 4, 40 and 400 nM; ethanol at 20 mM (∼0.09%). Nicotine at 40 and 400 nM significantly activated constitutively active component of I K(Ach) with the maximum effect at 40 nM (an increase by ∼100%); similar effect was observed at -110 and -50 mV. Changes at 4 nM nicotine were negligible on average. Coapplication of 40 nM nicotine and 20 mM ethanol (which is also known to activate this current) did not show cumulative effect. In the case of acetylcholine-induced component of I K(Ach) , a dual effect of nicotine and its correlation with the current magnitude in control were apparent: the current was increased by nicotine in the cells showing small current in control and vice versa. The effect of 40 and 400 nM nicotine on acetylcholine-induced component of I K(Ach) was significantly different at -110 and -50 mV. We conclude that nicotine at clinically relevant concentrations significantly increased constitutively active component of I K(Ach) and showed a dual effect on its acetylcholine-induced component, similarly as ethanol. Synchronous application of nicotine and ethanol did not cause additive effect.

  6. Low Concentrations of Vitamin C Reduce the Synthesis of Extracellular Polymers and Destabilize Bacterial Biofilms

    KAUST Repository

    Pandit, Santosh

    2017-12-26

    Extracellular polymeric substances (EPS) produced by bacteria form a matrix supporting the complex three-dimensional architecture of biofilms. This EPS matrix is primarily composed of polysaccharides, proteins and extracellular DNA. In addition to supporting the community structure, the EPS matrix protects bacterial biofilms from the environment. Specifically, it shields the bacterial cells inside the biofilm, by preventing antimicrobial agents from getting in contact with them, thereby reducing their killing effect. New strategies for disrupting the formation of the EPS matrix can therefore lead to a more efficient use of existing antimicrobials. Here we examined the mechanism of the known effect of vitamin C (sodium ascorbate) on enhancing the activity of various antibacterial agents. Our quantitative proteomics analysis shows that non-lethal concentrations of vitamin C inhibit bacterial quorum sensing and other regulatory mechanisms underpinning biofilm development. As a result, the EPS biosynthesis in reduced, and especially the polysaccharide component of the matrix is depleted. Once the EPS content is reduced beyond a critical point, bacterial cells get fully exposed to the medium. At this stage, the cells are more susceptible to killing, either by vitamin C-induced oxidative stress as reported here, or by other antimicrobials or treatments.

  7. Decreasing extracellular Na+ concentration triggers inositol polyphosphate production and Ca2+ mobilization

    International Nuclear Information System (INIS)

    Smith, J.B.; Dwyer, S.D.; Smith, L.

    1989-01-01

    Removing extracellular Na+ (Na+o) evoked a large increase in cytosolic free Ca2+ concentration ([Ca2+]i in human skin fibroblasts. Decreasing [Na+]o from 120 to 14 mM caused the half-maximal peak increase in [Ca2+]i. Removing Na+o strongly stimulated 45 Ca2+ efflux and decreased total cell Ca2+ by about 40%. Bradykinin caused changes in [Ca2+]i, total Ca2+, and 45 Ca2+ fluxes similar to those evoked by removing Na+o. Prior stimulation of the cells with bradykinin prevented Na+o removal from increasing [Ca2+]i and vice versa. Na+o removal rapidly increased [ 3 H]inositol polyphosphate production. Loading the cells with Na+ had no effect on the increase in 45 Ca2+ efflux produced by Na+o removal. Therefore, decreasing [Na+]o probably stimulates a receptor(s) which is sensitive to extracellular, not intracellular, Na+. Removing Na+o also mobilized intracellular Ca2+ in smooth muscle and endothelial cells cultured from human umbilical and dog coronary arteries, respectively

  8. Low Concentrations of Vitamin C Reduce the Synthesis of Extracellular Polymers and Destabilize Bacterial Biofilms

    KAUST Repository

    Pandit, Santosh; Ravikumar, Vaishnavi; Abdel-Haleem, Alyaa M.; Derouiche, Abderahmane; Mokkapati, V. R. S. S.; Sihlbom, Carina; Mineta, Katsuhiko; Gojobori, Takashi; Gao, Xin; Westerlund, Fredrik; Mijakovic, Ivan

    2017-01-01

    Extracellular polymeric substances (EPS) produced by bacteria form a matrix supporting the complex three-dimensional architecture of biofilms. This EPS matrix is primarily composed of polysaccharides, proteins and extracellular DNA. In addition to supporting the community structure, the EPS matrix protects bacterial biofilms from the environment. Specifically, it shields the bacterial cells inside the biofilm, by preventing antimicrobial agents from getting in contact with them, thereby reducing their killing effect. New strategies for disrupting the formation of the EPS matrix can therefore lead to a more efficient use of existing antimicrobials. Here we examined the mechanism of the known effect of vitamin C (sodium ascorbate) on enhancing the activity of various antibacterial agents. Our quantitative proteomics analysis shows that non-lethal concentrations of vitamin C inhibit bacterial quorum sensing and other regulatory mechanisms underpinning biofilm development. As a result, the EPS biosynthesis in reduced, and especially the polysaccharide component of the matrix is depleted. Once the EPS content is reduced beyond a critical point, bacterial cells get fully exposed to the medium. At this stage, the cells are more susceptible to killing, either by vitamin C-induced oxidative stress as reported here, or by other antimicrobials or treatments.

  9. The modulation of TRPM7 currents by nafamostat mesilate depends directly upon extracellular concentrations of divalent cations

    Directory of Open Access Journals (Sweden)

    Chen Xuanmao

    2010-12-01

    Full Text Available Abstract Concentrations of extracellular divalent cations (Ca2+ and Mg2+ fall substantially during intensive synaptic transmission as well as during some pathophysiological conditions such as epilepsy and brain ischemia. Here we report that a synthetic serine protease inhibitor, nafamostat mesylate (NM, and several of its analogues, block recombinant TRPM7 currents expressed in HEK293T cells in inverse relationship to the concentration of extracellular divalent cations. Lowering extracellular Ca2+ and Mg2+ also evokes a divalent-sensitive non-selective cation current that is mediated by TRPM7 expression in hippocampal neurons. In cultured hippocampal neurons, NM blocked these TRPM7-mediated currents with an apparent affinity of 27 μM, as well as the paradoxical Ca2+ influx associated with lowering extracellular Ca2+. Unexpectedly, pre-exposure to NM strongly potentiated TRPM7 currents. In the presence of physiological concentrations of extracellular divalent cations, NM activates TRPM7. The stimulating effects of NM on TRPM7 currents are also inversely related to extracellular Ca2+ and Mg2+. DAPI and HSB but not netropsin, blocked and stimulated TRPM7. In contrast, mono-cationic, the metabolites of NM, p-GBA and AN, as well as protease inhibitor leupeptin and gabexate failed to substantially modulate TRPM7. NM thus provides a molecular template for the design of putative modulators of TRPM7.

  10. Inflammaging and Frailty Status Do Not Result in an Increased Extracellular Vesicle Concentration in Circulation

    Directory of Open Access Journals (Sweden)

    Ainhoa Alberro

    2016-07-01

    Full Text Available In the last decades extracellular vesicles (EVs have emerged as key players for intercellular communication. In the case of inflammation, several studies have reported that EV levels are increased in circulation during inflammatory episodes. Based on this, we investigated whether aging results in elevated EV number, as a basal proinflammatory status termed “inflammaging” has been described in aged individuals. Moreover, we also hypothesized that frailty and dependence conditions of the elderly could affect EV concentration in plasma. Results showed that inflammaging, frailty or dependence status do not result in EV increase, at least in the total number of EVs in circulation. These results open a new perspective for investigating the role of EVs in human aging and in the inflammaging process.

  11. Inflammaging and Frailty Status Do Not Result in an Increased Extracellular Vesicle Concentration in Circulation.

    Science.gov (United States)

    Alberro, Ainhoa; Sáenz-Cuesta, Matías; Muñoz-Culla, Maider; Mateo-Abad, Maider; Gonzalez, Esperanza; Carrasco-Garcia, Estefania; Araúzo-Bravo, Marcos J; Matheu, Ander; Vergara, Itziar; Otaegui, David

    2016-07-20

    In the last decades extracellular vesicles (EVs) have emerged as key players for intercellular communication. In the case of inflammation, several studies have reported that EV levels are increased in circulation during inflammatory episodes. Based on this, we investigated whether aging results in elevated EV number, as a basal proinflammatory status termed "inflammaging" has been described in aged individuals. Moreover, we also hypothesized that frailty and dependence conditions of the elderly could affect EV concentration in plasma. Results showed that inflammaging, frailty or dependence status do not result in EV increase, at least in the total number of EVs in circulation. These results open a new perspective for investigating the role of EVs in human aging and in the inflammaging process.

  12. Carbon dioxide absorbents containing potassium hydroxide produce much larger concentrations of compound A from sevoflurane in clinical practice.

    Science.gov (United States)

    Yamakage, M; Yamada, S; Chen, X; Iwasaki, S; Tsujiguchi, N; Namiki, A

    2000-07-01

    We investigated the concentrations of degraded sevoflurane Compound A during low-flow anesthesia with four carbon dioxide (CO(2)) absorbents. The concentrations of Compound A, obtained from the inspiratory limb of the circle system, were measured by using a gas chromatograph. In the groups administered 2 L/min fresh gas flow with 1% sevoflurane, when the conventional CO(2) absorbents, Wakolime(TM) (Wako, Tokyo, Japan) and Drägersorb(TM) (Dräger, Lübeck, Germany), were used, the concentrations of Compound A increased steadily from a baseline to 14.3 ppm (mean) and 13.2 ppm, respectively, at 2 h after exposure to sevoflurane. In contrast, when the other novel types of absorbents containing decreased or no potassium hydroxide/sodium hydroxide, Medisorb(TM) (Datex-Ohmeda, Louisville, CO) and Amsorb(TM) (Armstrong, Coleraine, Northern Ireland), were used, Compound A remained at baseline (potassium hydroxide/sodium hydroxide produce much larger concentrations of Compound A from sevoflurane in clinical practice. An absorbent containing neither potassium hydroxide nor sodium hydroxide produces the smallest concentrations of Compound A.

  13. A novel technique using potassium permanganate and reflectance confocal microscopy to image biofilm extracellular polymeric matrix reveals non-eDNA networks in Pseudomonas aeruginosa biofilms.

    Science.gov (United States)

    Swearingen, Matthew C; Mehta, Ajeet; Mehta, Amar; Nistico, Laura; Hill, Preston J; Falzarano, Anthony R; Wozniak, Daniel J; Hall-Stoodley, Luanne; Stoodley, Paul

    2016-02-01

    Biofilms are etiologically important in the development of chronic medical and dental infections. The biofilm extracellular polymeric substance (EPS) determines biofilm structure and allows bacteria in biofilms to adapt to changes in mechanical loads such as fluid shear. However, EPS components are difficult to visualize microscopically because of their low density and molecular complexity. Here, we tested potassium permanganate, KMnO4, for use as a non-specific EPS contrast-enhancing stain using confocal laser scanning microscopy in reflectance mode. We demonstrate that KMnO4 reacted with EPS components of various strains of Pseudomonas, Staphylococcus and Streptococcus, yielding brown MnO2 precipitate deposition on the EPS, which was quantifiable using data from the laser reflection detector. Furthermore, the MnO2 signal could be quantified in combination with fluorescent nucleic acid staining. COMSTAT image analysis indicated that KMnO4 staining increased the estimated biovolume over that determined by nucleic acid staining alone for all strains tested, and revealed non-eDNA EPS networks in Pseudomonas aeruginosa biofilm. In vitro and in vivo testing indicated that KMnO4 reacted with poly-N-acetylglucosamine and Pseudomonas Pel polysaccharide, but did not react strongly with DNA or alginate. KMnO4 staining may have application as a research tool and for diagnostic potential for biofilms in clinical samples. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Inhibitory effect of extracellular purine nucleotide and nucleoside concentrations on T cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Weiler, Monica [Department of Medicine III and Transfusion Medicine, University Hospital Grosshadern, Ludwig-Maximilians-University, Munich (Germany); Schmetzer, Helga [Helmholtz Center Munich (Germany); German Research Center for Environmental Health, Munich (Germany); Braeu, Marion; Buhmann, Raymund [Helmholtz Center Munich (Germany); German Research Center for Environmental Health, Munich (Germany); Department of Medicine III and Transfusion Medicine, University Hospital Grosshadern, Ludwig-Maximilians-University, Munich (Germany)

    2016-11-15

    The release of nucleic acids and derivatives after tissue-injury may affect cellular immune-response. We studied the impact of extracellular ribo-, desoxyribonucleotides and nucleosides on T-cell immunity. Peripheral-blood-mononuclear-cells (PBMCs) or isolated CD3{sup +}T-cells obtained from 6 healthy donors were stimulated via CD3/CD28 Dynabeads or dendritic cells (DCs) in the presence or absence of pyrimidine-, purine-nucleotides and -nucleosides (range 2–200 µM). Addition of deoxy-, guanosine-triphosphate (dGTP, GTP) and guanosine resulted concentration dependent in a complete, adenosine-triphosphate (ATP) in a partial inhibition of the induced T-cell-proliferation. Deoxyadenosine-triphosphate (dATP), adenosine and the pyrimidine-ribo- and -deoxyribonucleotides displayed no inhibitory capacity. Inhibitory effects of dGTP and GTP, but not of guanosine and ATP were culture-media-dependent and could be almost abrogated by use of the serum-free lymphocyte-culture-media X-Vivo15 instead of RPMI1640 with standard-supplementation. In contrast to RPMI1640, X-Vivo15 resulted in a significant down-regulation of the cell-surface-located ectonucleotidases CD39 (Ecto-Apyrase) and CD73 (Ecto-5′-Nucleotidase), critical for the extracellular nucleotides-hydrolysis to nucleosides, explaining the loss of inhibition mediated by dGTP and GTP, but not Guanosine. In line with previous findings ATP was found to exert immunosuppressive effects on T-cell-proliferation. Purine-nucleotides, dGTP and GTP displayed a higher inhibitory capacity, but seem to be strictly dependent on the microenvironmental conditions modulating the responsiveness of the respective T-lymphocytes. Further evaluation of experimental and respective clinical settings should anticipate these findings.

  15. Inhibitory effect of extracellular purine nucleotide and nucleoside concentrations on T cell proliferation

    International Nuclear Information System (INIS)

    Weiler, Monica; Schmetzer, Helga; Braeu, Marion; Buhmann, Raymund

    2016-01-01

    The release of nucleic acids and derivatives after tissue-injury may affect cellular immune-response. We studied the impact of extracellular ribo-, desoxyribonucleotides and nucleosides on T-cell immunity. Peripheral-blood-mononuclear-cells (PBMCs) or isolated CD3 + T-cells obtained from 6 healthy donors were stimulated via CD3/CD28 Dynabeads or dendritic cells (DCs) in the presence or absence of pyrimidine-, purine-nucleotides and -nucleosides (range 2–200 µM). Addition of deoxy-, guanosine-triphosphate (dGTP, GTP) and guanosine resulted concentration dependent in a complete, adenosine-triphosphate (ATP) in a partial inhibition of the induced T-cell-proliferation. Deoxyadenosine-triphosphate (dATP), adenosine and the pyrimidine-ribo- and -deoxyribonucleotides displayed no inhibitory capacity. Inhibitory effects of dGTP and GTP, but not of guanosine and ATP were culture-media-dependent and could be almost abrogated by use of the serum-free lymphocyte-culture-media X-Vivo15 instead of RPMI1640 with standard-supplementation. In contrast to RPMI1640, X-Vivo15 resulted in a significant down-regulation of the cell-surface-located ectonucleotidases CD39 (Ecto-Apyrase) and CD73 (Ecto-5′-Nucleotidase), critical for the extracellular nucleotides-hydrolysis to nucleosides, explaining the loss of inhibition mediated by dGTP and GTP, but not Guanosine. In line with previous findings ATP was found to exert immunosuppressive effects on T-cell-proliferation. Purine-nucleotides, dGTP and GTP displayed a higher inhibitory capacity, but seem to be strictly dependent on the microenvironmental conditions modulating the responsiveness of the respective T-lymphocytes. Further evaluation of experimental and respective clinical settings should anticipate these findings.

  16. Heavy metal toxicities in vegetable crops. VI. The effect of potassium and calcium concentration in the nutrient solution on manganese toxicities in vegetable crops

    Energy Technology Data Exchange (ETDEWEB)

    Osawa, T; Ikeda, H

    1977-01-01

    Eight species of vegetable crops were grown in solution culture in order to investigate the effect of potassium and calcium concentration in the nutrient solution on manganese toxicities in vegetable crops. Manganese was supplied at levels of 0.5, 30, and 100 ppm. At each manganese level potassium or calcium was supplied at rates of 2, 6, and 18 me/l. The pH of the nutrient solution was adjusted to 5. Manganese excess induced interveinal chlorosis on upper leaves in bean, eggplant, pepper, and spinach, and marginal chlorosis on lower leaves in cabbage, lettuce, and celery. In Welsh onions chlorosis was induced on lower leaves. Increasing the supply of potassium and calcium reduced the severity of manganese-induced chlorosis. This beneficial effect was generally more marked with calcium than with potassium. Increasing the supply of potassium and calcium was effective in alleviating the growth reduction of vegetable crops due to manganese excess. This effect also was more marked with calcium than with potassium. With increasing manganese level in the nutrient solution the manganese concentration in leaves of vegetable crops increased. Increasing the supply of potassium and calcium inhibited excessive accumulation of manganese in leaves. The influence of calcium was stronger than that of potassium. In any of the vegetable crops tested, regardless of potassium and calcium treatments, manganese concentration in leaves was closely related to manganese toxicities; the more the accumulation of manganese in leaves increased, the more the severity of manganese-induced chlorosis and growth reduction increased.

  17. Pathogenic Candida species differ in the ability to grow at limiting potassium concentrations

    Czech Academy of Sciences Publication Activity Database

    Hušeková, Barbora; Elicharová, Hana; Sychrová, Hana

    2016-01-01

    Roč. 62, č. 5 (2016), s. 394-401 ISSN 0008-4166 R&D Projects: GA ČR(CZ) GAP302/12/1151; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:67985823 Keywords : Candida * potassium homeostasis * morphology Subject RIV: EE - Microbiology, Virology Impact factor: 1.462, year: 2016

  18. The biphasic effect of extracellular glucose concentration on carbachol-induced fluid secretion from mouse submandibular glands.

    Science.gov (United States)

    Terachi, Momomi; Hirono, Chikara; Kitagawa, Michinori; Sugita, Makoto

    2018-06-01

    Cholinergic agonists evoke elevations of the cytoplasmic free-calcium concentration ([Ca 2+ ] i ) to stimulate fluid secretion in salivary glands. Salivary flow rates are significantly reduced in diabetic patients. However, it remains elusive how salivary secretion is impaired in diabetes. Here, we used an ex vivo submandibular gland perfusion technique to characterize the dependency of salivary flow rates on extracellular glucose concentration and activities of glucose transporters expressed in the glands. The cholinergic agonist carbachol (CCh) induced sustained fluid secretion, the rates of which were modulated by the extracellular glucose concentration in a biphasic manner. Both lowering the extracellular glucose concentration to less than 2.5 mM and elevating it to higher than 5 mM resulted in decreased CCh-induced fluid secretion. The CCh-induced salivary flow was suppressed by phlorizin, an inhibitor of the sodium-glucose cotransporter 1 (SGLT1) located basolaterally in submandibular acinar cells, which is altered at the protein expression level in diabetic animal models. Our data suggest that SGLT1-mediated glucose uptake in acinar cells is required to maintain the fluid secretion by sustaining Cl - secretion in real-time. High extracellular glucose levels may suppress the CCh-induced secretion of salivary fluid by altering the activities of ion channels and transporters downstream of [Ca 2+ ] i signals. © 2018 Eur J Oral Sci.

  19. A standardized method to determine the concentration of extracellular vesicles using tunable resistive pulse sensing

    NARCIS (Netherlands)

    Vogel, Robert; Coumans, Frank A. W.; Maltesen, Raluca G.; Böing, Anita N.; Bonnington, Katherine E.; Broekman, Marike L.; Broom, Murray F.; Buzás, Edit I.; Christiansen, Gunna; Hajji, Najat; Kristensen, Søren R.; Kuehn, Meta J.; Lund, Sigrid M.; Maas, Sybren L. N.; Nieuwland, Rienk; Osteikoetxea, Xabier; Schnoor, Rosalie; Scicluna, Benjamin J.; Shambrook, Mitch; de Vrij, Jeroen; Mann, Stephen I.; Hill, Andrew F.; Pedersen, Shona

    2016-01-01

    Background: Understanding the pathogenic role of extracellular vesicles (EVs) in disease and their potential diagnostic and therapeutic utility is extremely reliant on in-depth quantification, measurement and identification of EV sub-populations. Quantification of EVs has presented several

  20. Preparation of Potassium Dichromate Crystals from the Chromite Concentrate by Microwave Assisted Leaching

    Directory of Open Access Journals (Sweden)

    Hua Liu

    2017-10-01

    Full Text Available In the present investigation, the oxidizing roasting process of chromite with sodium carbonate to prepare potassium dichromate crystals was studied in the microwave field with air, by heating the chromite and sodium carbonate. The chromite and sodium carbonate heated separately at 1000 °C in the microwave oven (frequency: 2.45 GHz; power 1.5 kW in order to study the microwave absorption properties. The dielectric constant and dielectric loss factor of the chromite and sodium carbonate examined. Then, chromite with sodium carbonate taken in (1:2 ratio and heated at 750 °C. Thus obtained samples were characterized using various techniques includes Powder-XRD (XRD, Scanning Electron Microscopy (SEM, and X-ray fluorescence (XRF. The XRD pattern reveals the existence of Fe3O4, Fe2O3, NaAlO2, and Na2CrO4. The iron and aluminum were leached out as Fe2O3 and Al(OH3 respectively. The resulting sample treated with the KCl to prepare potassium dichromate crystals. Finally, potassium dichromate crystals formed.

  1. Increased ratio of peritoneal effusion-to-serum potassium concentration in a dog with gastric perforation.

    Science.gov (United States)

    Ben Oz, Jennifer; Aroch, Itamar; Segev, Gilad

    2016-11-01

    To describe the clinical and laboratory findings of a dog with gastric perforation, resulting in a markedly increased peritoneal effusion-to-serum potassium ratio. A 6-year-old mixed breed neutered male dog presented with a right femoral fracture after being hit by car. The fracture was repaired surgically. Four days postoperatively, the dog developed peritoneal effusion, confirmed with ultrasonography. Peritoneal effusion analysis and serum biochemistry, performed concurrently, showed blood-to-effusion glucose difference >1.1 mmol/L [>20 mg/dL], suggesting the effusion was septic. The effusion-to-serum creatinine ratio was mildly increased (1.36) and the effusion-to-serum potassium ratio was markedly increased (>2.67). Combined, these findings were suggestive of a septic uroabdomen. A positive contrast retrograde urethrocystography did not reveal urine leakage from the lower urinary tract. An exploratory laparotomy revealed a gastric perforation in the pyloric area and an intact urinary tract. Gastric perforation should be considered a differential diagnosis in dogs with an increased peritoneal effusion to serum potassium ratio. © Veterinary Emergency and Critical Care Society 2016.

  2. A method for the determination of potassium concentration in organic tissue samples

    International Nuclear Information System (INIS)

    Maciel, A.C.A.

    1976-12-01

    An original method has been developed to detect small variations of potassium in several samples of organic tissue. These variations are relative to elements that are biologically representative, such as carbon, oxygen, and nitrogen. The samples are irradiated with a beam of protons from a Van de Graaff accelerator (4MV). Vacancies are created in the K-shell of potassium, and x-rays are emitted when these vacancies are filled with outer electrons. These X-rays and the protons elastically scattered by the nuclei of carbon, nitrogen and oxygen are detected and their energy spectra are analysed by computer programs especially elaborated for this purpose. A technique for routine preparation of samples in the laboratory was developed including the production of aluminum support layers, and the preparation of organic tissue samples with a low temperature microtome. The unique features of this method are that it does not destroy the tissue, permitting further analysis with the microscope, and the normalization of the amount of potassium using other elements (C,O,N) instead of the total mass of the sample. (Author) [pt

  3. Modulation of sibutramine-induced increases in extracellular noradrenaline concentration in rat frontal cortex and hypothalamus by α2-adrenoceptors

    Science.gov (United States)

    Wortley, K E; Heal, D J; Stanford, S C

    1999-01-01

    The effects of sibutramine (0.25–10 mg kg−1 i.p.) on extracellular noradrenaline concentration in the frontal cortex and hypothalamus of freely-moving rats were investigated using microdialysis. The role of presynaptic α2-adrenoceptors in modulating the effects of sibutramine in these brain areas was also determined.Sibutramine induced an increase in extracellular noradrenaline concentration, the magnitude of which paralleled dose, in both brain areas. In the cortex, this increase was gradual and sustained, whereas in the hypothalamus it was more rapid and of shorter duration.In both the cortex and hypothalamus, pretreatment of rats with the α2-adrenoceptor antagonist RX821002 (3 mg kg−1 i.p.) potentiated increases in the accumulation of extracellular noradrenaline induced by sibutramine (10 mg kg−1 i.p.), by 7 and 10 fold respectively. RX821002 also reduced the latency of sibutramine to reach its maximum effect in the cortex, but not in the hypothalamus.Infusion of RX821002 (1 μM) via the probe increased the accumulation of extracellular noradrenaline induced by sibutramine (10 mg kg−1 i.p.) in both brain areas. In the hypothalamus, the effects of RX821002 on the accumulation of noradrenaline induced by sibutramine were 2 fold greater than those in the cortex.These findings support evidence that sibutramine inhibits the reuptake of noradrenaline in vivo, but that the accumulation of extracellular noradrenaline is limited by noradrenergic activation of presynaptic α2-adrenoceptors. Furthermore, the data suggest that terminal α2-adrenoceptors in the hypothalamus exert a greater inhibitory effect over the control of extracellular noradrenaline accumulation than do those in the cortex. PMID:10516646

  4. Effect of different cycling frequencies during incremental exercise on the venous plasma potassium concentration in humans.

    Science.gov (United States)

    Zoladz, J A; Duda, K; Majerczak, J; Thor, P

    2002-01-01

    rate of 120 rev.min(-1) causes significantly higher [K+]v changes than when cycling at 60 rev.min(-1), b) the increase of venous plasma potassium concentration during dynamic incremental exercise is linearly related to the metabolic cost of work expressed by the percentage of VO2max (increase as reported previously by Vollestad et al. J. Physiol. 475: 359-368, 1994), c) there is a tendency towards upward up shift in the [K+]v and % VO2max relation during cycling at 120 rev.min(-1) when compared to cycling at 60 rev.min(-1).

  5. The production and use of citric acid for the removal of potassium from the iron ore concentrate of the Sishen Iron Ore Mine, South Africa

    Directory of Open Access Journals (Sweden)

    Peter J. Williams

    2010-04-01

    Full Text Available The depletion of the richer iron ore worldwide has made it necessary to process lower quality iron ore. Certain substances, such as potassium, contained within the lower quality iron ore, have a detrimental effect on the smelting process during steel manufacturing. Therefore, international steel-making companies charge penalties when purchasing iron ore concentrates containing high concentrations of potassium. To date, lower quality iron ore has been blended with high quality iron ore in an attempt to alleviate the potassium concentrations in the export iron ore; however, the ratio of low quality iron ore to high quality iron ore is increasing, thereby becoming an escalating problem within the economic functioning of the Sishen Iron Ore Mine. It has, therefore, become necessary to develop an economically viable and environmentally friendly process to reduce the high potassium concentrations contained in the iron ore concentrate of the Sishen Iron Ore Mine. In this study, we compared solid substrate and submerged fermentation using Aspergillus niger for the production of citric acid, which is used for the chemical leaching of potassium from the iron ore concentrate. It was found that submerged fermentation proved to be more economical and efficient, producing a maximum citric acid concentration of 102.3 g/L in 96 h of fermentation. ‘Heap leaching’ simulation experiments were found to be uneconomical, due to the required addition of fungal growth medium every 5 days as a result of growth factor depletion within this time; however, this process removed 17.65% of the potassium from the iron ore concentrate. By contrast, chemical leaching of potassium from the iron ore concentrate proved to be most efficient when using a 1 mol citric acid leaching solution at 60 ºC, removing 23.53% of the potassium contained within the iron ore concentrate. Therefore, the most economical and efficient process for the removal of potassium from the iron

  6. Potassium maldistribution revisited

    African Journals Online (AJOL)

    Background:This study investigated maldistribution of concentrated 15% potassium chloride after injection into .... and latter experiments referred to for example as “Control 1” ..... be further investigated as a reliable, simple method of potassium.

  7. Influence of antihypertensive therapy, sodium intake and the concentration of potassium in plasma on concentration of aldosterone and plasma renin activity

    Directory of Open Access Journals (Sweden)

    Lalić Tijana

    2013-01-01

    Full Text Available Introduction: Primary aldosteronism (PA is a group of disorders which are characterized by inadequate and non-suppressible production of aldosterone. The prevalence of PA is increasing in hypertensive population. The golden standard of screening for primary aldosteronism, determination of aldosterone/plasma renin activity (ARR, is influenced by numerous exogenous and endogenous factors. Testing cannot always be conducted under optimal conditions. Objective: To determine influence of antihypertensive drugs and concentrations of potassium and sodium in blood and urine on values of aldosterone and plasma renin activity. Methods: In this retrospective study, we analyzed medical reports of patients admitted to Department of thyroid gland disease in the period from 2009 to 2011, with increased risk for primary aldosteronism. Body weight and height, sodium and potassium in serum and urine, plasma aldosterone concentrations and plasma renin activity, data on medicines and comorbidity were analyzed in all patients. In processing data, statistical methods descriptive analysis, Student T test and univariate linear regression were applied. Result: Of 137 patients, there were more patients with resistant hypertension (53,28% than with adrenal tumors (46,72%. Most patients used calcium channel blockers. Treatment with alpha blockers and calcium channel blockers does not influence ARR. Beta blockers and ACE inhibitors can influence ARR and diuretics and vasodilatators have definite influence. Diabetes mellitus can have higher risk of false negative results. Urine sodium excretion is significantly correlated with plasma aldosteron and serum potassium. Plasma aldosteron and PRA are significantly correlated with concentrations of electrolites in urine. Conclusion: Increased prevalence of primary aldosteronism necessitates need for accurate and better diagnostics.

  8. The concentration of extracellular superoxide dismutase in plasma is maintained by LRP-mediated endocytosis

    DEFF Research Database (Denmark)

    Petersen, Steen V; Thøgersen, Ida B; Valnickova, Zuzana

    2010-01-01

    In this study, we show that human extracellular superoxide dismutase (EC-SOD) binds to low-density lipoprotein receptor-related protein (LRP). This interaction is most likely responsible for the removal of EC-SOD from the blood circulation via LRP expressed in liver tissue. The receptor recognition...

  9. A Novel Reconfigurable Logic Unit Based on the DNA-Templated Potassium-Concentration-Dependent Supramolecular Assembly.

    Science.gov (United States)

    Yang, Chunrong; Zou, Dan; Chen, Jianchi; Zhang, Linyan; Miao, Jiarong; Huang, Dan; Du, Yuanyuan; Yang, Shu; Yang, Qianfan; Tang, Yalin

    2018-03-15

    Plenty of molecular circuits with specific functions have been developed; however, logic units with reconfigurability, which could simplify the circuits and speed up the information process, are rarely reported. In this work, we designed a novel reconfigurable logic unit based on a DNA-templated, potassium-concentration-dependent, supramolecular assembly, which could respond to the input stimuli of H + and K + . By inputting different concentrations of K + , the logic unit could implement three significant functions, including a half adder, a half subtractor, and a 2-to-4 decoder. Considering its reconfigurable ability and good performance, the novel prototypes developed here may serve as a promising proof of principle in molecular computers. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Uranium, Thorium and Potassium concentrations and volumetric heat production rates at the eastern border of the Parana basin

    International Nuclear Information System (INIS)

    Andrade, Telma C.Q.; Ribeiro, Fernando B.

    1997-01-01

    Uranium, thorium and potassium concentrations were measured and volumetric heat production rates were calculated for rocks from the exposed basement at the eastern-southeastern border of the Parana Basin between 23 deg S and 32 deg S. Heat generating element concentration data available in the literature were also used when possible, for volumetric heat production calculations. The uranium concentrations vary from below determination limit (0.51 ppm) and 16 ppm whereas the thorium concentrations vary from below the determination limit (1.26 ppm) and 68 ppm, and K concentrations vary between 0.08% and 5.6%. Volumetric heat production rates vary between 0.07 μW/m 3 to 6.2 μW/m 3 , and the obtained results show a variable heat generation rate with high heat producing bodies scattered along this Parana Basin border. The higher observed values concentrate in the Ribeira fold belt at about 23 deg S and between 30 deg S and 32 deg S in the Down Feliciano fold belt. Isolated high heat production rates can also be observed between 26 deg S and 28 deg S. (author). 11 refs., 3 tabs

  11. The increases in potassium concentrations are greater with succinylcholine than with rocuronium-sugammadex in outpatient surgery: a randomized, multicentre trial.

    Science.gov (United States)

    Sabo, Daniel; Jahr, Jonathan; Pavlin, Janet; Philip, Beverly; Shimode, Noriko; Rowe, Everton; Woo, Tiffany; Soto, Roy

    2014-05-01

    Succinylcholine provides rapid onset of neuromuscular blockade and short duration of action, but its administration may be associated with hyperkalemia. Rocuronium is not known to increase potassium concentration, has fast onset of activity, and can be rapidly reversed by sugammadex. This study evaluated changes in plasma potassium concentrations in patients randomized either to rocuronium followed by sugammadex reversal or to succinylcholine in ambulatory surgery. In this multicentre randomized active-controlled study, adult patients undergoing short surgical procedures in an outpatient setting received either rocuronium 0.6 mg·kg(-1) for intubation with sugammadex 4.0 mg·kg(-1) for reversal (n = 70) or succinylcholine 1.0 mg·kg(-1) with spontaneous recovery (n = 80). Blood potassium concentrations were assessed at baseline (before study drug administration) and at intervals up to 15 min after rocuronium, sugammadex, and succinylcholine. At the primary endpoint, five minutes post-administration, the changes in potassium concentrations from baseline were significantly smaller in patients treated with rocuronium than in those given succinylcholine [mean (SD): -0.06 (0.32) vs 0.30 (0.34) mmol·L(-1), respectively; P rocuronium (P rocuronium baseline. No adverse effects related to hyperkalemia were observed. Succinylcholine was associated with a modest increase in potassium concentration; these changes were not seen after rocuronium or sugammadex ( NCT00751179).

  12. From the Cover: Selective Enhancement of Domoic Acid Toxicity in Primary Cultures of Cerebellar Granule Cells by Lowering Extracellular Na+ Concentration.

    Science.gov (United States)

    Pérez-Gómez, Anabel; Cabrera-García, David; Warm, Davide; Marini, Ann M; Salas Puig, Javier; Fernández-Sánchez, Maria Teresa; Novelli, Antonello

    2018-01-01

    Domoic acid (DOM) is an excitatory amino acid analog of kainic acid (KA) that acts through glutamic acid (GLU) receptors, inducing a fast and potent neurotoxic response. Here, we present evidence for an enhancement of excitotoxicity following exposure of cultured cerebellar granule cells to DOM in the presence of lower than physiological Na+ concentrations. The concentration of DOM that reduced by 50% neuronal survival was approximately 3 µM in Na+-free conditions and 16 µM in presence of a physiological concentration of extracellular Na+. The enhanced neurotoxic effect of DOM was fully prevented by AMPA/KA receptor antagonist, while N-methyl-D-aspartate-receptor-mediated neurotoxicity did not seem to be involved, as the absence of extracellular Na+ failed to potentiate GLU excitotoxicity under the same experimental conditions. Lowering of extracellular Na+ concentration to 60 mM eliminated extracellular recording of spontaneous electrophysiological activity from cultured neurons grown on a multi electrode array and prevented DOM stimulation of the electrical activity. Although changes in the extracellular Na+ concentration did not alter the magnitude of the rapid increase in intracellular Ca2+ levels associated to DOM exposure, they did change significantly the contribution of voltage-sensitive calcium channels (VScaCs) and the recovery time to baseline. The prevention of Ca2+ influx via VSCaCs by nifedipine failed to prevent DOM toxicity at any extracellular Na+ concentration, while the reduction of extracellular Ca2+ concentration ameliorated DOM toxicity only in the absence of extracellular Na+, enhancing it in physiological conditions. Our data suggest a crucial role for extracellular Na+ concentration in determining excitotoxicity by DOM. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  13. Frequency distribution of Radium-226, Thorium-228 and Potassium-40 concentration in ploughed soils

    International Nuclear Information System (INIS)

    Drichko, V.F.; Krisyuk, B.E.; Travnikova, I.G.; Lisachenko, E.P.; Dubenskaya, M.A.

    1977-01-01

    The results of studying Ra-226, Th-228 and K-40 concentration distribution laws in podsol, chernozem and saline soils are considered. Radionuclide concentrations were determined by gamma-spectrometric method in the samples chosen from arable soil layer according to the generally accepted agrotechnical procedure. Measuring procedure is described. The results show that frequency distributions of radionuclide concentrations transform from asymmetric form in normal coordinates into symmetric form in logarithmic coordinates. The usage of the lognormal law to describe frequency concentration distributions is substantiated. The values of concentration distribution parameters are given. The analysis of the data obtained permits to establish that Ra-226 and Th-228 concentrations in soils distribute lognormally and K-40 concentrations - normally and lognormally. According to the degree of decreasing mean concentrations of Ra-226 and Th-228, soils lie in line: chernozems=chernozem salterns > podsols; and according to the degree of decreasing mean quadratic deviation - in line: podsols>chernozems=salterns. It is necessary to determine the value of mean quadratic deviation and distribution type for full characteristics of the studied soil radioactivity

  14. In vivo sodium, potassium, and sperm concentrations in the rat epididymis.

    Science.gov (United States)

    Turner, T T; Hartmann, P K; Howards, S S

    1977-02-01

    In vivo samples of epididymal fluids were obtained through the use of micropuncture techniques. Microsamples from four areas of the rat epididymis were analyzed for Na+ and K+ concentrations and for sperm density. Na+ values declined significantly from caput to corpus epididymidis (P less than 0.01), while K+ and sperm concentrations increased significantly (P less than 0.01). A large water loss from the epididymal lumen was calculated, as well as net losses of both cations. Water losses may be explained on the basis of an active Na+ pump; however, the effect of the absolute values of epididymal Na+ and K+ concentrations on sperm motility and fertility remains unresolved.

  15. [Serial change of perilymphatic potassium ion concentration in the scala tympani after introducing KCl-solution into the guinea pigs' tympanic cavity].

    Science.gov (United States)

    Ikeno, K

    1990-09-01

    Characteristic nystagmus similar to the Meniere's attack could be observed after introducing KCl solution into the tympanic cavity of guinea pigs. To confirm the fact that this nystagmus was provoked by the high perilymphatic potassium ion concentration, the K+ activity of perilymph was recorded serially through the K+ specific microelectrode inserted into the scala tympani. The rapid increment of K+ activity reached maximum at 120 minutes after introducing KCl solution, and then it decreased gradually to a half of the maximum activity. However, such change of perilymphatic potassium ion concentration was not observed by introducing sucrose solution as control.

  16. Role of potassium and nitrogen on sugar concentration of sugar beet

    African Journals Online (AJOL)

    Sugar is obtained from root of sugar beet (Beta vulgaris L.) in addition to other sources. Three important economic parameters are often considered and these are root yield, sugar concentration in root juice and total sugar yield. All the three are affected by cropping period and use of fertilisers. Existing literature suggests the ...

  17. Mercury separation from concentrated potassium iodide/iodine leachate using Self-Assembled Mesoporous Mercaptan Support (SAMMS) technology

    International Nuclear Information System (INIS)

    Mattigod, S.V.; Feng, X.; Fryxell, G.E.

    1997-10-01

    A study was conducted to demonstrate the effectiveness of a novel adsorber, the Self-Assembled Mesoporous Mercaptan Support (SAMMS) material to remove mercury (Hg) from potassium iodide/iodine (KI/I 2 ) waste streams. This study included investigations of the SAMMS material''s binding kinetics, loading capacity, and selectivity for Hg adsorption from surrogate and actual KI/I 2 waste solutions. The kinetics data showed that binding of Hg by the adsorber material occurs very rapidly, with 82% to 95% adsorption occurring within the first 5 min. No significant differences in the rate of adsorption were noted between pH values of 5 and 9 and at Hg concentrations of ∼100 mg/1. Within the same range of pH values, an approximate four-fold increase in initial Hg concentration resulted in a two-fold increase in the rate of adsorption. In all cases studied, equilibrium adsorption occured within 4 h. The loading capacity experiments in KI/I 2 surrogate solutions indicated Hg adsorption densities between 26 to 270 mg/g. The loading density increased with increasing solid: solution ratio and decreasing iodide concentrations. Values of distribution coefficients (1.3x10 5 to >2.6x10 8 ml/g) indicated that material adsorbs Hg with very high specificity from KI/I 2 surrogate solutions. Reduction studies showed that compared to metallic iron (Fe), sodium dithionite can very rapidly reduce iodine as the triiodide species into the iodide form. Adsorption studies conducted with actual KI/I 2 leachates confirmed the highly specific Hg adsorption properties (K d >6x10 7 to>1x10 8 ml//g) of the adsorber material. Following treatment, the Hg concentrations in actual leachates were below instrumental detection limits (i.e., < 0.00005 mg/l), indicating that the KI solutions can be recycled

  18. Effect of low potassium concentration on cadmium induced epileptiform activity of leech retzius neurons

    Directory of Open Access Journals (Sweden)

    Milićević Nebojša

    2016-01-01

    Full Text Available Epilepsies have a large significance and require detailed investigation of cellular mechanisms that lead to this disorder. Environmental, especially industrial, toxins are having increasingly more prominent role in these investigations. The aim of our research was to investigate the significance of Cd2+ in generation of epileptiform electrical activity of neurons, and the role of Na+/K+ pump in mechanisms that lead to cessation of this activity. Experiments were performed on Retzius nerve cells of the leech Haemopis sanguisuga. Intracellularly placed microelectrodes were used to measure membrane potential changes upon administration of Cd2+ (100 µmol/l, and the same concentration of Cd2+ in low K+ (1 mmol/l solution. In our experiments Cd2+ led to generation of rhythmic repetitive oscillatory activity. This activity closely resembles paroxysmal depolarizing shifts (PDS which represent the cellular basis of epilepsy. Cd2+ induced epileptiform activity had the following characteristics: frequency of 3.9±0.8 PDS/minute, PDS duration of 4.0±0.3 s, and PDS amplitude of 8.1±0.7 mV. Cd2+ induces effects similar to those of Ni2+ and Co2+, but in 30 times smaller concentration. Application of Cd2+ in low K+ solution led to a significant reduction of PDS frequency (by 2.34±0.55 PDS/minute, p<0.05, Student's t-test, highly significant increase in PDS duration (by 2.84±0.23 s, p<0.01, Student's t-test and highly significant reduction in PDS amplitude (by 1.91±0.33 mV, p=0.01, Student's t-test. Our results show that Cd2+ is a potent initiator of epileptiform activity, and that Na+/K+ pump significantly affects this activity and has a potentially important role in mechanisms that lead to its cessation.

  19. Extracellular concentration of homocysteine in human cell lines is influenced by specific inhibitors of cyst(e)ine transport.

    Science.gov (United States)

    Hultberg, Björn

    2004-04-01

    Despite the growing evidence that plasma homocysteine is a cardiovascular risk factor, the mechanism behind the vascular injuries is still unknown. Studies of the cellular uptake systems for homocysteine are scarce, but membrane transporters of cyst(e)ine seem to be involved. In the present study the cellular uptake of extracellular homocysteine in HeLa and hepatoma cell lines is investigated by using several different transport inhibitors for cellular uptake of cyst(e)ine. It is shown that systems A and Xc- are the main transport systems for homocysteine uptake in HeLa cells. It is also confirmed that the magnitude of homocysteine uptake in hepatoma cells is lower than in HeLa cells. However, in the presence of high amounts of extracellular homocysteine both cell types exhibited a high elimination of homocysteine, which was inhibited by the presence of inhibitors of systems A or Xc-. It is possible that there is normally a high turnover of homocysteine in cell cultures, which is not detected by occasional determinations of homocysteine concentrations. The complex pattern of homocysteine production, release, uptake and distribution between different cells in the body is important to examine further in order to possibly be able to modulate the elimination of homocysteine from circulation and thereby lower the risk of cardiovascular disease.

  20. A new adsorption-elution technique for the concentration of aquatic extracellular antibiotic resistance genes from large volumes of water.

    Science.gov (United States)

    Wang, Da-Ning; Liu, Lu; Qiu, Zhi-Gang; Shen, Zhi-Qiang; Guo, Xuan; Yang, Dong; Li, Jing; Liu, Wei-Li; Jin, Min; Li, Jun-Wen

    2016-04-01

    Extracellular antibiotic resistance genes (eARGs) that help in the transmission and spread of antibiotic-resistant bacteria are emerging environmental contaminants in water, and there is therefore a growing need to assess environmental levels and associated risks of eARGs. However, as they are present in low amounts, it is difficult to detect eARGs in water directly with PCR techniques. Here, we prepared a new type of nucleic acid adsorption particle (NAAP) with high capacity and developed an optimal adsorption-elution method to concentrate eARGs from large volumes of water. With this technique, we were able to achieve an eARG recovery rate of above 95% from 10 L of water samples. Moreover, combining this new method with quantitative real-time PCR (qPCR), the sensitivity of the eARG detection was 10(4) times that of single qPCR, with the detection limit lowered to 100 gene copies (GCs)/L. Our analyses showed that the eARG load, virus load and certain water characteristics such as pH, chemical oxygen demand (CODMn), and turbidity affected the eARGs recovery rate. However, high eARGs recovery rates always remained within the standard limits for natural surface water quality, while eARG levels in water were lower than the detection limits of single qPCR assays. The recovery rates were not affected by water temperature and heterotrophic plate counts (HPC). The eARGs whatever located in the plasmids or the short-length linear DNAs can be recovered from the water. Furthermore, the recovery rate was high even in the presence of high concentrations of plasmids in different natural water (Haihe river, well water, raw water for drinking water, Jinhe river, Tuanbo lake and the Yunqiao reservoir). By this technology, eARGs concentrations were found ranging from (2.70 ± 0.73) × 10(2) to (4.58 ± 0.47) × 10(4) GCs/L for the extracellular ampicillin resistance gene and (5.43 ± 0.41) × 10(2) to (2.14 ± 0.23) × 10(4) GCs/L for the extracellular gentamicin

  1. Dependence of the concentrations of "1"3"7Cs and potassium in extracted soil solutions on soil humidity before centrifugation

    International Nuclear Information System (INIS)

    Prorok, V.V.; Datsenko, O.Yi.; Bulavyin, L.A.; Zlens'kij, S.Je.; Melnichenko, L.Yu.; Rozuvan, S.G.; Poperenko, L.V.; White, P.J.

    2017-01-01

    Concentrations of 137Cs and potassium in solutions extracted by centrifugation from soils selected at some experimental sites in the 10-km Exclusion Zone of Chornobyl Nuclear Plant were determined. The results showed that for the majority of investigated soils, the concentration of 137Cs in soil solution depends on the humidity of the soil before centrifugation. It is possible to explain the dependence of the concentration of 137Cs in the soil solution on soil humidity from the dependence of the concentrations of molecules of different molecular-gravimetric fractions in soil solution on soil humidity. Considerable amount of 137Cs in soil solution is associated with these molecules, that is why the concentration of 137Cs in the extracted soil solution changes with the humidity of soil. These dependences differ between soils. For the majority of investigated soils the concentration of 137Cs in the extracted soil solution increases with increasing humidity of the soil. By contrast, soil humidity had no effect on the potassium concentration in the extracted soil solution for any soil investigated. It is concluded, that potassium is practically not associated with molecules of different molecular-gravimetric fractions in the extracted soil solutions

  2. Comparison of changes in the extracellular concentration of noradrenaline in rat frontal cortex induced by sibutramine or d-amphetamine: modulation by α2-adrenoceptors

    Science.gov (United States)

    Wortley, K E; Hughes, Z A; Heal, D J; Stanford, S C

    1999-01-01

    The effects of sibutramine (0.25–10 mg kg−1, i.p.) on extracellular noradrenaline concentration in the frontal cortex of halothane-anaesthetized rats were compared with those of d-amphetamine (1–3 mg kg−1, i.p.) using in vivo microdialysis. The role of presynaptic α2-adrenoceptors in modulating the effects of these drugs on extracellular noradrenaline concentration were also investigated by pretreating rats with the selective α2-adrenoceptor antagonist, RX821002.Sibutramine induced a gradual and sustained increase in extracellular noradrenaline concentration. The dose-response relationship was described by a bell-shaped curve with a maximum effect at 0.5 mg kg−1. In contrast, d-amphetamine induced a rapid increase in extracellular noradrenaline concentration, the magnitude of which paralleled drug dose.Pretreatment with the α2-adrenoceptor antagonist, RX821002 (dose 3 mg kg−1, i.p.) increased by 5 fold the accumulation of extracellular noradrenaline caused by sibutramine (10 mg kg−1) and reduced the latency of sibutramine to reach its maximum effect from 144–56 min.RX821002-pretreatment increased by only 2.5 fold the increase in extracellular noradrenaline concentration caused by d-amphetamine alone (10 mg kg−1) and had no effect on the latency to reach maximum.These findings support evidence that sibutramine acts as a noradrenaline uptake inhibitor in vivo and that the effects of this drug are blunted by indirect activation of presynaptic α2-adreno-ceptors. In contrast, the rapid increase in extracellular noradrenaline concentration induced by d-amphetamine is consistent with this being mainly due to an increase in Ca2+-independent release of noradrenaline. PMID:10482917

  3. Plasma concentrations of extracellular matrix protein fibulin-1 are related to cardiovascular risk markers in chronic kidney disease and diabetes

    DEFF Research Database (Denmark)

    Scholze, Alexandra; Bladbjerg, Else-Marie; Sidelmann, Johannes J

    2013-01-01

    ABSTRACT: BACKGROUND: Fibulin-1 is one of a few extracellular matrix proteins present in blood in high concentrations. We aimed to define the relationship between plasma fibulin-1 levels and risk markers of cardiovascular disease. METHODS: Plasma fibulin-1 was determined in subjects with chronic...... to determine central hemodynamic and arterial stiffness indices. RESULTS: We observed a positive correlation of fibulin-1 levels with age (r = 0.38; p = 0.033), glycated hemoglobin (r = 0.80; p = 0.003), creatinine (r = 0.35; p = 0.045), and fibrinogen (r = 0.39; p = 0.027). Glomerular filtration rate...... and fibulin-1 were inversely correlated (r = -0.57; p = 0.022). There was a positive correlation between fibulin-1 and central pulse pressure (r = 0.44; p = 0.011) and central augmentation pressure (r = 0.55; p = 0.001). In a multivariable regression model, diabetes, creatinine, fibrinogen and central...

  4. Study of the correlation between the concentration of potassium in an extract of Aferontany and its biological effect on an isolated heart

    International Nuclear Information System (INIS)

    MANOELA, F.P.

    2005-01-01

    The objective of the present work is to determine the elemental quality of the extract of the malagasy medicinal plant, named Aferontany (Mollugo Nudicaulis), in particular the content of potassium in order to measure its contribution to cause heart hazardous. Decoction was used for plant extraction purposes. Total Refection X ray fluorescence analytical method was employed for the quantitative analysis. Organ isolated test method was applied to evaluate the impact of potassium in the extract on heart. The analytical results showed that Aferontany plant contains potassium (K), calcium (Ca), iron (Fe), titanium (Ti), zinc (Zn), manganese (Mn), rubidium (Rb), barium (Ba), strontium (Sr), copper (Cu) and lead (Pb).Their concentration varies with the collecting sites, the conservation duration, the age and the type of plant used organ. The potassium content of the plant is high and varies between 0.016 and 0.064%. The obtained results showed that the elemental concentrations in the decoction increase with the amount of used plant, the temperature and the duration. The concentration value of strontium is lower than 14 μg/L (MDL). The toxic elements concentrations measured in the decoction are low and in the order of 160 μg/L, 6.45 μg/L for the barium and the lead respectively (1g of decocted plant for 100 mL of water). The same decoction contains 5.59 mg/L of calcium, 346 μg/L of manganese 4.05 mg/L of Iron and 130 μg/L of copper. When using the ordinary posology, these elements do not present theoretically any problem on heart function. Besides, the decoction has 520 mg/L of potassium. This high content of potassium may cause heart problem. According to the experimentation carried out on the frog heart, cardiac stopping may occur if the potassium concentration value is in the order of 1100 mg/L. Therefore, The plant decoction would have mortal effect in the case of over uptake. Nevertheless, the intoxication is reversible [fr

  5. Low Concentrations of Vitamin C Reduce the Synthesis of Extracellular Polymers and Destabilize Bacterial Biofilms

    DEFF Research Database (Denmark)

    Pandit, Santosh; Ravikumar, Vaishnavi; Abdel-Haleem, Alyaa M.

    2017-01-01

    to a more efficient use of existing antimicrobials. Here we examined the mechanism of the known effect of vitamin C (sodium ascorbate) on enhancing the activity of various antibacterial agents. Our quantitative proteomics analysis shows that non-lethal concentrations of vitamin C inhibit bacterial quorum....... At this stage, the cells are more susceptible to killing, either by vitamin C-induced oxidative stress as reported here, or by other antimicrobials or treatments....

  6. Effect of donepezil hydrochloride (E2020) on basal concentration of extracellular acetylcholine in the hippocampus of rats.

    Science.gov (United States)

    Kosasa, T; Kuriya, Y; Matsui, K; Yamanishi, Y

    1999-09-10

    The effects of oral administration of the centrally acting acetylcholinesterase (AChE) inhibitors, donepezil hydrochloride (donepezil: E2020: (+/-)-2-[(1-benzylpiperidin-4-yl)methyl]-5,6-dimethoxy-indan-1-one monohydrochloride), tacrine (9-amino-1,2,3,4-tetrahydroacridine hydrochloride) and ENA-713 (rivastigmine: (S)-N-ethyl-3-[(1-dimethyl-amino)ethyl]-N-methyl-phenylcarbamate hydrogentartrate), which have been developed for the treatment of Alzheimer's disease, on the extracellular acetylcholine concentration in the hippocampus of rats were evaluated by using a microdialysis technique without adding cholinesterase inhibitor to the perfusion solution. We also compared the inhibition of brain AChE and the brain concentrations of these drugs. Donepezil at 2.5 mg/kg and tacrine at 5 mg/kg showed significant effects for more than 6 h. At these doses, the maximum increases were observed at about 1.5 h after administration of donepezil, and at about 2 h with tacrine, and were 499% and 422% of the pre-level, respectively. ENA-713 produced significant effects at doses of 0.625, 1.25 and 2.5 mg/kg, which lasted for about 1, 2 and 4 h, respectively. The maximum increases produced by these doses at about 0.5 h after administration were 190, 346 and 458% of the pre-level, respectively. The time courses of brain AChE inhibition with donepezil at 2.5 mg/kg, tacrine at 10 mg/kg and ENA-713 at 2.5 mg/kg were mirror images of the extracellular acetylcholine-increasing action at the same doses. The time courses of the brain concentrations of drugs after oral administration of donepezil at 2.5 mg/kg and tacrine at 10 mg/kg were consistent with those of brain AChE inhibition at the same doses, and there was a linear relation between these parameters. Brain concentration of ENA-713 at 2.5 mg/kg was below the limit of quantification at all time points measured. These results suggest that oral administration of donepezil, tacrine and ENA-713 increases acetylcholine concentration in the

  7. Potassium in milk and milk products

    International Nuclear Information System (INIS)

    Sombrito, E.Z.; Nuguid, Z.F.S.; Tangonan, M.C.

    1989-01-01

    The amount of potassium in imported processed milk was determined by gamma spectral analysis. The results show that the potassium content of diluted infant formula milk is closest to the reported mean concentration of potassium in human milk while other milk types have potassium values similar to the potassium content of cow milk. (Auth.). 2 figs., 5 refs

  8. Extracting the basal extracellular dopamine concentrations from the evoked responses: re-analysis of the dopamine kinetics.

    Science.gov (United States)

    Chen, Kevin C; Budygin, Evgeny A

    2007-08-15

    Fast-scan cyclic voltammetry in conjunction with carbon fiber microelectrode has been used to study dopamine (DA) release and uptake mechanisms in rat brains because of the smaller size of the electrode and the subsecond resolution. Current voltammetry data were analyzed by a DA kinetic model assuming a zero baseline, which is in conflict with existing microdialysis findings and a recent claim of the striatal extracellular DA concentration at micromolar levels. This work applied a new analysis approach based on a modified DA kinetic model to analyze the kinetics of electrically evoked DA overflow in the caudate-putamen of anesthetized rats. The DA uptake parameters were fitted from the electrical stimulation phase, and subsequently used to calculate theoretical DA uptake rates. Comparison of the theoretical uptake rates with experimental clearance rates allows for the study of the tonic DA release process following electrical stimulations. Analyses of DA voltammetry data suggest that the locally averaged basal level of extracellular DA in the rat striatum might be confined between 95 and 220 nM. The disparate time scales in the clearance kinetics of endogenous and exogenous DA were investigated. Long-distance diffusion could only partially explain the slow clearance time course of exogenous DA. Model simulations and parameter analyses on evoked DA responses indicate that suppression of the nonevoked DA release process immediately following electrical stimulation cannot completely account for the rapid clearance of the electrically evoked DA. Inconsistency in the measured uptake strengths in the literature studying endogenous and exogenous DA remains to be investigated in the future.

  9. Graphene oxide significantly inhibits cell growth at sublethal concentrations by causing extracellular iron deficiency.

    Science.gov (United States)

    Yu, Qilin; Zhang, Bing; Li, Jianrong; Du, Tingting; Yi, Xiao; Li, Mingchun; Chen, Wei; Alvarez, Pedro J J

    Graphene oxide (GO)-based materials are increasingly being used in medical materials and consumer products. However, their sublethal effects on biological systems are poorly understood. Here, we report that GO (at 10 to 160 mg/L) induced significant inhibitory effects on the growth of different unicellular organisms, including eukaryotes (i.e. Saccharomyces cerevisiae, Candida albicans, and Komagataella pastoris) and prokaryotes (Pseudomonas fluorescens). Growth inhibition could not be explained by commonly reported cytotoxicity mechanisms such as plasma membrane damage or oxidative stress. Based on transcriptomic analysis and measurement of extra- and intracellular iron concentrations, we show that the inhibitory effect of GO was mainly attributable to iron deficiency caused by binding to the O-functional groups of GO, which sequestered iron and disrupted iron-related physiological and metabolic processes. This inhibitory mechanism was corroborated with supplementary experiments, where adding bathophenanthroline disulfonate-an iron chelating agent-to the culture medium exerted similar inhibition, whereas removing surface O-functional groups of GO decreased iron sequestration and significantly alleviated the inhibitory effect. These findings highlight a potential indirect detrimental effect of nanomaterials (i.e. scavenging of critical nutrients), and encourage research on potential biomedical applications of GO-based materials to sequester iron and enhance treatment of iron-dependent diseases such as cancer and some pathogenic infections.

  10. The Effect of Potassium Concentration in Nutrient Solution on Lycopene, Vitamin C and Qualitative Characteristics of Cherry Tomato in Saline Conditions

    Directory of Open Access Journals (Sweden)

    E. Shabani Sangtarashani

    2013-06-01

    Full Text Available Potassium (K has a special place in improving the quality of agricultural products. To evaluate the effect of K concentration in nutrient solution on lycopene content, vitamin C and qualitative characteristics of cherry tomato in NaCl salinity conditions, an experiment was carried out as a completely randomized design with five treatments and three replications at university of Tabriz, Tabriz, Iran, in 2010. Treatments consisted of four concentrations of K (0.2, 2, 7 and 14 mM in nutrient solution with 60 mM NaCl concentration. A nutrient solution treatment without salinity was considered as control. The experiment was conducted in greenhouse, in a hydroponic system. The results indicated that increasing of K concentration increased lycopene content in fruit. Lycopene content in control treatment showed significant difference (P<0.01 in comparison with salinity treatments. With increasing the K concentration (except at 14 mM concentration, vitamin C content was increased, but indicated no statistically significant difference. Vitamin C content in saline conditions was more than control treatment, but showed no significant difference. Adding potassium concentration in nutrient solution improved yield and enhanced quality parameters such as percentage of dry matter, soluble solids and electrical conductivity of fruit extract. Since in saline conditions, the qualitative characteristics of tomato at 7 mM concentration were in the best situation, therefore using this concentration is recommended.

  11. [Ion channels that are sensitive to the extracellular concentration of protons: their structure, function, pharmacology and pathophysiology].

    Science.gov (United States)

    Mercado, F; Vega, R; Soto, E

    Acid sensing ion channels (ASIC) members of the ENaC degenerine channel family, have been shown to participate in various sensorial pathways including nociception, also they have been shown to participate in synaptic transmission, learning and memory processes and in the physiopathology of the ischemic stroke. The proton concentration in the organism is strictly regulated by distinct buffer systems. Drastic changes of pH are generated only by pathological conditions as is the ischemia; however, some physiological processes may produce local changes in the extracellular pH. Recently, a new family of proton receptors known as ASIC has been cloned. These are ionic channels inactivated at physiological pH (7.4) and activated with a pH fall (increase in H+ concentration). ASICs are permeable to sodium ions and in a lesser degree to calcium ions, activation of these channels leads to an increase in cell excitability. The ASICs are distributed widely in the central and peripheral nervous system, and in specialized epithelia. In the past few years they have become a focus of interest due to its role in nociception, taste perception, long term potentation and the physiopathology of ischemic stroke. In this review we address the most relevant molecular, physiological and pharmacological aspects of the ASICs, its participation in some pathological process, and the perspectives of basic and clinic investigation in this arising research field.

  12. Ceftriaxone attenuates ethanol drinking and restores extracellular glutamate concentration through normalization of GLT-1 in nucleus accumbens of male alcohol-preferring rats.

    Science.gov (United States)

    Das, Sujan C; Yamamoto, Bryan K; Hristov, Alexandar M; Sari, Youssef

    2015-10-01

    Alteration of glutamatergic-neurotransmission is a hallmark of alcohol dependence. We have previously reported that chronic ethanol-drinking downregulated glutamate transporter 1 (GLT-1) in nucleus accumbens (NAc) in male P rats in a manner that was reversed by ceftriaxone treatment. However, the effect of ceftriaxone on extracellular glutamate concentrations in NAc after chronic ethanol-drinking has not yet been studied. In the present study, male P rats were treated with ceftriaxone (100 mg/kg/day, i.p.) for five consecutive days following five-weeks of free choice ethanol (15% and 30%) drinking. In vivo microdialysis was performed to measure the extracellular glutamate concentrations in NAc and the effect of blockade of GLT-1 with dihydrokainic acid (DHK) on extracellular glutamate in NAc of ceftriaxone-treated rats was determined. Ceftriaxone treatment attenuated ethanol intake as well as ethanol preference. Extracellular glutamate was significantly higher in NAc after five-weeks of ethanol drinking in saline-treated compared to water control rats. Ceftriaxone treatment blocked the increase extracellular glutamate produced by ethanol intake. Blockade of GLT-1 by DHK reversed the effects of ceftriaxone on glutamate and implicated the role of GLT-1 in the normalization of extracellular glutamate by ceftriaxone. In addition, GLT-1 protein was decreased in ethanol exposed animals and ceftriaxone treatment reversed this deficit. Ceftriaxone treatment also increased glutamine synthetase activity in NAc but not in PFC as compared to ethanol drinking saline-treated rats. Our present study demonstrates that ceftriaxone treatment prevents ethanol drinking in part through normalization of extracellular glutamate concentrations in NAc of male P rats via GLT-1. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Why do insects enter and recover from chill coma? Low temperature and high extracellular potassium compromises muscle function in Locusta migratoria

    DEFF Research Database (Denmark)

    Findsen, Anders; Pedersen, Thomas Holm; Petersen, Asbjørn G

    2014-01-01

    When exposed to low temperatures, many insect species enter a reversible comatose state (chill coma), which is driven by a failure of neuromuscular function. Chill coma and chill coma recovery have been associated with a loss and recovery of ion-homeostasis (particularly extracellular [K......+]) and accordingly onset of chill coma has been hypothesised to result from depolarization of membrane potential caused by loss of ion-homeostasis. Here we examined whether onset of chill coma is associated with a disturbance in ion balance by examining the correlation between disruption of ion homeostasis and onset...... of chill coma in locusts exposed to cold at varying rates of cooling. Chill coma onset temperature changed maximally 1°C under different cooling rates and marked disturbances of ion homeostasis were not observed at any of the cooling rates. In a second set of experiments we used isolated tibial muscle...

  14. Removal of Anabaena spiroides by potassium permanganate pre-oxidation: effect on photosynthetic capacity and molecular weight distribution.

    Science.gov (United States)

    Qiao, Junlian; Zhang, Xiaodong; Lv, Liping

    2017-11-01

    Bench scale tests were conducted to investigate the effect of potassium permanganate pre-oxidation on the photosynthetic activity and molecular weight distribution of Anabaena spiroides. Different concentrations of potassium permanganate were added into the suspension of Anabaena spiroides, one of the dominant algae in water bloom, and after pre-oxidation of permanganate for 1 h, the results show that the removal rate significantly increases by 33.99~36.35% compared to direct coagulation. Then, the algal characteristics, including photosynthetic ability, the changes in extracellular organic matter three-dimensional fluorescence, and the distribution of molecular weight were conducted and the results show that along with increasing concentration of potassium permanganate, the photosynthetic ability of algae decreases, more extracellular organic matter is secreted, and large molecular weight matter (humic-like and fulvic-like substances) are generated. Therefore, this study demonstrates that potassium permanganate could be used in addressing the algae-rich water.

  15. The effects of venous cannulation technique and cardioplegia type on plasma potassium concentration and arterial blood pressure during cardiopulmonary bypass.

    LENUS (Irish Health Repository)

    Coleman, E T

    2012-02-03

    The cannulation method and cardioplegia solution used during cardiopulmonary bypass (CPB) may both influence plasma potassium concentrations ([K+]) and mean arterial blood pressure (MAP). Bi-caval or right atrial cannulation methods are routinely used in conjunction with crystalloid or blood cardioplegia. We investigated the influence of cannulation method and cardioplegia solutions on plasma [K+] and MAP during cardiopulmonary bypass. Sixty consecutive patients undergoing elective coronary artery bypass grafting (CABG) using CPB were studied. They were randomly divided into three groups of 20 patients. Patients in Group A underwent bi-caval venous cannulation and received crystalloid cardioplegia. Group B patients underwent right atrial cannulation and received crystalloid cardioplegia. Group C patients underwent right atrial cannulation and received blood cardioplegia. In each case. cardioplegia was administered antegrade via the aortic root. Plasma [K+], MAP. and hemoglobin concentration (Hb) were measured over an 8-min period following cardioplegia administration (pilot studies indicated pressure changes occuring post cardioplegia administration up to this time). The combination of bi-caval cannulation and crystalloid cardioplegia (Group A) was associated with the least increase in plasma [K+] and no decrease in MAP. The maximum [K+] for this Group was 4.2 mmol\\/L (4.6% increase). The minimum mean pressure was 57 mmHg (13.6% increase). Both right atrial cannulation groups (B and C) showed a large rise in plasma [K+] and a decrease in MAP. Group B maximum [K+] was 5.2 mmol\\/L (27.5% increase). Group C was also 5.2 mmol\\/L (26.0% increase). Group C showed the largest pressure decrease, the minimum mean pressure was 45 mmHg (21.3% decrease). The Group B minimum mean pressure was 45 mmHg (8.7% decrease). Our results show that patients undergoing CPB operations who are deemed to be at increased risk of suffering adverse effects from hypotensive episodes may

  16. Raffinose Induces Biofilm Formation by Streptococcus mutans in Low Concentrations of Sucrose by Increasing Production of Extracellular DNA and Fructan.

    Science.gov (United States)

    Nagasawa, Ryo; Sato, Tsutomu; Senpuku, Hidenobu

    2017-08-01

    Streptococcus mutans is the primary etiological agent of dental caries and causes tooth decay by forming a firmly attached biofilm on tooth surfaces. Biofilm formation is induced by the presence of sucrose, which is a substrate for the synthesis of extracellular polysaccharides but not in the presence of oligosaccharides. Nonetheless, in this study, we found that raffinose, which is an oligosaccharide with an intestinal regulatory function and antiallergic effect, induced biofilm formation by S. mutans in a mixed culture with sucrose, which was at concentrations less than those required to induce biofilm formation directly. We analyzed the possible mechanism behind the small requirement for sucrose for biofilm formation in the presence of raffinose. Our results suggested that sucrose contributed to an increase in bacterial cell surface hydrophobicity and biofilm formation. Next, we examined how the effects of raffinose interacted with the effects of sucrose for biofilm formation. We showed that the presence of raffinose induced fructan synthesis by fructosyltransferase and aggregated extracellular DNA (eDNA, which is probably genomic DNA released from dead cells) into the biofilm. eDNA seemed to be important for biofilm formation, because the degradation of DNA by DNase I resulted in a significant reduction in biofilm formation. When assessing the role of fructan in biofilm formation, we found that fructan enhanced eDNA-dependent cell aggregation. Therefore, our results show that raffinose and sucrose have cooperative effects and that this induction of biofilm formation depends on supportive elements that mainly consist of eDNA and fructan. IMPORTANCE The sucrose-dependent mechanism of biofilm formation in Streptococcus mutans has been studied extensively. Nonetheless, the effects of carbohydrates other than sucrose are inadequately understood. Our findings concerning raffinose advance the understanding of the mechanism underlying the joint effects of sucrose and

  17. Release of ATP from Marginal Cells in the Cochlea of Neonatal Rats Can Be Induced by Changes in Extracellular and Intracellular Ion Concentrations

    Science.gov (United States)

    Peng, Yating; Chen, Jie; He, Shan; Yang, Jun; Wu, Hao

    2012-01-01

    Background Adenosine triphosphate (ATP) plays an important role in the cochlea. However, the source of ATP and the mechanism by which it is released remain unclear. This study investigates the presence and release mechanism of ATP in vitro cultured marginal cells isolated from the stria vascularis of the cochlea in neonatal rats. Methods Sprague-Dawley rats aged 1–3 days old were used for isolation, in vitro culture, and purification of marginal cells. Cultured marginal cells were verified by flow cytometry. Vesicles containing ATP in these cells were identified by fluorescence staining. The bioluminescence assay was used for determination of ATP concentration in the extracellular fluid released by marginal cells. Assays for ATP concentration were performed when the ATP metabolism of cells was influenced, and ionic concentrations in intracellular and extracellular fluid were found to change. Results Evaluation of cultured marginal cells with flow cytometry revealed the percentage of fluorescently-labeled cells as 92.9% and 81.9%, for cytokeratin and vimentin, respectively. Quinacrine staining under fluorescence microscopy revealed numerous green, star-like spots in the cytoplasm of these cells. The release of ATP from marginal cells was influenced by changes in the concentration of intracellular and extracellular ions, namely extracellular K+ and intra- and extracellular Ca2+. Furthermore, changes in the concentration of intracellular Ca2+ induced by the inhibition of the phospholipase signaling pathway also influence the release of ATP from marginal cells. Conclusion We confirmed the presence and release of ATP from marginal cells of the stria vascularis. This is the first study to demonstrate that the release of ATP from such cells is associated with the state of the calcium pump, K+ channel, and activity of enzymes related to the phosphoinositide signaling pathway, such as adenylate cyclase, phospholipase C, and phospholipase A2. PMID:23071731

  18. Baseline extracellular potassium level as an indicator of the rate of increase of the same on further storage in CPDA-1 whole blood units: a potential approach to complement FIFO system for prioritisation of blood bags for release from blood-banks.

    Science.gov (United States)

    Baliarsingh, S; Jaiswal, M

    2014-02-01

    Potassium levels in stored blood bags increases as they age. Hyperkalemia in transfused blood has undesirable cardiac effects. Within a 19-month period, baseline and weekly samples from 15 CPDA-1 whole blood bags were collected till 28 days of storage and analysed for potassium, sodium, uric acid, albumin and whole blood haemoglobin. One unit increase in baseline (0 day) potassium in extracellular fluid of blood units was associated with the following increases in potassium levels on later days of storage: around two unit increase at 1 week (r2 = 0·50, P values. For CPDA-1 blood bags (i) low baseline potassium blood bags might be preferred for transfusion in cases demanding a low potassium load and (ii) coordinating the ‘first-in-first-out’ (FIFO) policy with ‘early release of blood-bags with high initial potassium’ might be helpful in improving the release of suitable blood units from blood-banks.

  19. Optimum potassium chloride concentration to reduce hydration capacity of clay formations; Concentracao otima de cloreto de potassio para reduzir a capacidade de hidratacao das formacoes argilosas

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Jose Carlos Vieira [PETROBRAS, Salvador, BA (Brazil). Centro de Recursos Humanos Norte-Nordeste. Setor de Programas de Perfuracao; Oliveira, Manoel Martins de [PETROBRAS, BA (Brazil). Distrito de Perfuracao. Div. de Tecnicas de Perfuracao

    1988-12-31

    An experimental method for ascertaining the optimal concentration of potassium chloride for reducing the hydration and dispersion capacity of clayey formations sensitive to water-based fluids is described. Under this method, filtering time for disperse systems prepared from clayey formation samples is measured. A discussion is offered on theoretical aspects of hydration, expansion, and dispersion of clayey rocks in response to the variations in stress equilibrium states produced by these phenomena when a hole (well) is opened in the rock. The state of the art of this technological branch is also described. (author) 10 refs., 5 figs., 4 tabs.

  20. Comparison of sodium, potassium, calcium, magnesium, zinc, copper and iron concentrations of elements in 24-h urine and spot urine in hypertensive patients with healthy renal function.

    Science.gov (United States)

    Zhang, Tianjing; Chang, Xiaoyu; Liu, Wanlu; Li, Xiaoxia; Wang, Faxuan; Huang, Liping; Liao, Sha; Liu, Xiuying; Zhang, Yuhong; Zhao, Yi

    2017-12-01

    Sodium, potassium, calcium, magnesium, zinc, copper and iron are associated with the sequela of hypertension. The most reliable method for testing those elements is by collecting 24-h urine samples. However, this is cumbersome and collection of spot urine is more convenient in some circumstance. The aim of this study was to compare the concentrations of different elements in 24-h urine and spot urine. Data was collected from a sub-study of China Salt Substitute and Stroke Study. 240 participants were recruited randomly from 12 villages in two counties in Ningxia, China. Both spot and 24-h urine specimens were collected from each patient. Routine urine test was conducted, and concentration of elements was measured using microwave digestion and Inductively Coupled Plasma-Optical Emission Spectrometry. Partial correlation analysis and Spearman correlation analysis were used to investigate the concentration of different elements and the relationship between 24- h urine and spot urine. A partial correlation in sodium, potassium, calcium, magnesium and iron was found between paired 24-h urine and spot urine samples except copper and zinc: 0.430, 0.426, 0.550, 0.221 and 0.191 respectively. Spot urine can replace 24-h urine for estimating some of the elements in hypertensive patients with normal renal function. Copyright © 2017 Elsevier GmbH. All rights reserved.

  1. Identification of an evolutionarily conserved extracellular threonine residue critical for surface expression and its potential coupling of adjacent voltage-sensing and gating domains in voltage-gated potassium channels.

    Science.gov (United States)

    Mckeown, Lynn; Burnham, Matthew P; Hodson, Charlotte; Jones, Owen T

    2008-10-31

    The dynamic expression of voltage-gated potassium channels (Kvs) at the cell surface is a fundamental factor controlling membrane excitability. In exploring possible mechanisms controlling Kv surface expression, we identified a region in the extracellular linker between the first and second of the six (S1-S6) transmembrane-spanning domains of the Kv1.4 channel, which we hypothesized to be critical for its biogenesis. Using immunofluorescence microscopy, flow cytometry, patch clamp electrophysiology, and mutagenesis, we identified a single threonine residue at position 330 within the Kv1.4 S1-S2 linker that is absolutely required for cell surface expression. Mutation of Thr-330 to an alanine, aspartate, or lysine prevented surface expression. However, surface expression occurred upon co-expression of mutant and wild type Kv1.4 subunits or mutation of Thr-330 to a serine. Mutation of the corresponding residue (Thr-211) in Kv3.1 to alanine also caused intracellular retention, suggesting that the conserved threonine plays a generalized role in surface expression. In support of this idea, sequence comparisons showed conservation of the critical threonine in all Kv families and in organisms across the evolutionary spectrum. Based upon the Kv1.2 crystal structure, further mutagenesis, and the partial restoration of surface expression in an electrostatic T330K bridging mutant, we suggest that Thr-330 hydrogen bonds to equally conserved outer pore residues, which may include a glutamate at position 502 that is also critical for surface expression. We propose that Thr-330 serves to interlock the voltage-sensing and gating domains of adjacent monomers, thereby yielding a structure competent for the surface expression of functional tetramers.

  2. Increase of extracellular glutamate concentration increases its oxidation and diminishes glucose oxidation in isolated mouse hippocampus: reversible by TFB-TBOA.

    Science.gov (United States)

    Torres, Felipe Vasconcelos; Hansen, Fernanda; Locks-Coelho, Lucas Doridio

    2013-08-01

    Glutamate concentration at the synaptic level must be kept low in order to prevent excitotoxicity. Astrocytes play a key role in brain energetics, and also astrocytic glutamate transporters are responsible for the vast majority of glutamate uptake in CNS. Experiments with primary astrocytic cultures suggest that increased influx of glutamate cotransported with sodium at astrocytes favors its flux to the tricarboxylic acid cycle instead of the glutamate-glutamine cycle. Although metabolic coupling can be considered an emergent field of research with important recent discoveries, some basic aspects of glutamate metabolism still have not been characterized in brain tissue. Therefore, the aim of this study was to investigate whether the presence of extracellular glutamate is able to modulate the use of glutamate and glucose as energetic substrates. For this purpose, isolated hippocampi of mice were incubated with radiolabeled substrates, and CO2 radioactivity and extracellular lactate were measured. Our results point to a diminished oxidation of glucose with increasing extracellular glutamate concentration, glutamate presumably being the fuel, and might suggest that oxidation of glutamate could buffer excitotoxic conditions by high glutamate concentrations. In addition, these findings were reversed when glutamate uptake by astrocytes was impaired by the presence of (3S)-3-[[3-[[4-(trifluoromethyl)benzoyl]amino]phenyl]methoxy]-L-aspartic acid (TFB-TBOA). Taken together, our findings argue against the lactate shuttle theory, because glutamate did not cause any detectable increase in extracellular lactate content (or, presumably, in glycolysis), because the glutamate is being used as fuel instead of going to glutamine and back to neurons. Copyright © 2013 Wiley Periodicals, Inc.

  3. Variation in bacterial ATP concentration during rapid changes in extracellular pH and implications for the activity of attached bacteria.

    Science.gov (United States)

    Albert, Lynal S; Brown, Derick G

    2015-08-01

    In this study we investigated the relationship between a rapid change in extracellular pH and the alteration of bacterial ATP concentration. This relationship is a key component of a hypothesis indicating that bacterial bioenergetics - the creation of ATP from ADP via a proton gradient across the cytoplasmic membrane - can be altered by the physiochemical charge-regulation effect, which results in a pH shift at the bacteria's surface upon adhesion to another surface. The bacterial ATP concentration was measured during a rapid change in extracellular pH from a baseline pH of 7.2 to pH values between 3.5 and 10.5. Experiments were conducted with four neutrophilic bacterial strains, including the Gram-negative Escherichia coli and Pseudomonas putida and the Gram-positive Bacillus subtilis and Staphylococcus epidermidis. A change in bulk pH produced an immediate response in bacterial ATP, demonstrating a direct link between changes in extracellular pH and cellular bioenergetics. In general, the shifts in ATP were similar across the four bacterial strains, with results following an exponential relationship between the extracellular pH and cellular ATP concentration. One exception occurred with S. epidermidis, where there was no variation in cellular ATP at acidic pH values, and this finding is consistent with this species' ability to thrive under acidic conditions. These results provide insight into obtaining a desired bioenergetic response in bacteria through (i) the application of chemical treatments to vary the local pH and (ii) the selection and design of surfaces resulting in local pH modification of attached bacteria via the charge-regulation effect. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Proton concentrations can be a major contributor to the modification of osteoclast and osteoblast differentiation, working independently of extracellular bicarbonate ions.

    Science.gov (United States)

    Kato, Kohtaro; Matsushita, Misao

    2014-01-01

    We established a system to separately analyze the role of protons and bicarbonate ions in vitro in which the pH of the medium was controlled by HEPES at various concentrations of sodium bicarbonate (NaHCO3) in the absence of carbon dioxide (CO2). Using this system, we demonstrated that acidosis promoted osteoclast formation independently of extracellular NaHCO3 in a short-term culture. Protons and bicarbonate ions acted on osteoclast differentiation with opposite effects, the former positively and the latter negatively. The HEPES-based system maintained pH in the absence of extracellular NaHCO3 without CO2. Therefore, we could demonstrate that osteoblast differentiation was promoted at higher pH in a long-term culture system without NaHCO3 in which ALP activity and nodule mineralization were enhanced. This finding indicates that protons negatively control osteoblast differentiation independently of extracellular bicarbonate ions. However, the difference in the concentration of NaHCO3 did not have any influence on nodule mineralization. The opposite effects of protons, the promotion of osteoclast formation and the inhibition of osteoblast differentiation, were suppressed in the presence of 5 mM N-acetyl cysteine, a reagent activating the scavenging of reactive oxygen species (ROS), implying that ROS act on both systems, the promotion of large osteoclast formation and the deterioration of osteoblast formation under acidosis.

  5. Effects of potassium concentration on firing patterns of low-calcium epileptiform activity in anesthetized rat hippocampus: inducing of persistent spike activity.

    Science.gov (United States)

    Feng, Zhouyan; Durand, Dominique M

    2006-04-01

    It has been shown that a low-calcium high-potassium solution can generate ictal-like epileptiform activity in vitro and in vivo. Moreover, during status epileptiform activity, the concentration of [K+]o increases, and the concentration of [Ca2+]o decreases in brain tissue. Therefore we tested the hypothesis that long-lasting persistent spike activity, similar to one of the patterns of status epilepticus, could be generated by a high-potassium, low-calcium solution in the hippocampus in vivo. Artificial cerebrospinal fluid was perfused over the surface of the exposed left dorsal hippocampus of anesthetized rats. A stimulating electrode and a recording probe were placed in the CA1 region. By elevating K+ concentration from 6 to 12 mM in the perfusate solution, the typical firing pattern of low-calcium ictal bursts was transformed into persistent spike activity in the CA1 region with synaptic transmission being suppressed by calcium chelator EGTA. The activity was characterized by double spikes repeated at a frequency approximately 4 Hz that could last for >1 h. The analysis of multiple unit activity showed that both elevating [K+]o and lowering [Ca2+]o decreased the inhibition period after the response of paired-pulse stimulation, indicating a suppression of the after-hyperpolarization (AHP) activity. These results suggest that persistent status epilepticus-like spike activity can be induced by nonsynaptic mechanisms when synaptic transmission is blocked. The unique double-spike pattern of this activity is presumably caused by higher K+ concentration augmenting the frequency of typical low-calcium nonsynaptic burst activity.

  6. Potassium supplements for oral diarrhoea regimens.

    Science.gov (United States)

    Clements, M L; Levine, M M; Black, R E; Hughes, T P; Rust, J; Tome, F C

    1980-10-18

    A study is proposed for supplementing potassium loss from diarrhea in rehydration therapies with fresh fruit and other naturally potassium-rich foods. Bananas contain .1 mol of potassium per gm. Freshly squeezed lemon or orange juices were tested for potassium and sodium content and found to have very low potassium concentration. Therefore, the banana was chosen for an upcoming study that will determine if infants and children suffering from diarrhea can ingest the amounts of the fruit necessary to elevate the potassium level sufficiently. Bananas as the potassium source are thought to be well-accepted in developing areas.

  7. The Effects of Arbuscular Mycorrhiza Fungi on Dry Matter and Concentrations of Nitrogen, Phosphorus and Potassium in Berseem Clover, by Cadmium stress

    Directory of Open Access Journals (Sweden)

    hashem aram

    2016-02-01

    Zanjan, after the complete analysis of soil and obtaining the chemical and physical properties in the laboratory. 6 kg of soil was weighed for each pot and then the soil was contaminated. Cadmium sulfate was used in this experiment. The mycorrhizal fungi weighed 150 grams and was mixed with the soil. After mixing the soil with mycorrhizal fungi, the soil was put in pots and then it was cultivated with clover. In this study, clover seeds weighed 0/5 grams and were disinfected with 10% hydrogen peroxide solution and were added to each pot. Distilled water was used for irrigation. After the completion of growth of plants (about 70 day, plant aerial parts and roots were harvested and before measuring, they were washed with distilled water and then were dried in the oven for 72 hours. Plant aerial parts were harvested. Data were analyzed by SAS (version 9 and MSTATC (version 2.10 software, and obtained variance analysis tables. Mean comparison of different treatments was conducted by Duncan test. Charts were obtained by excel software. Results and Discussion: The results showed that the effects of arbuscular mycorrhizal fungi were significant on all traits measured (P< 0.01. With increasing cadmium concentration in soil, dry matter of 37% and 39%, nitrogen concentration of 35% and 28%, Potassium 9/27% and 37%, and phosphorus concentration of 37% and 39%, reduced in root and aerial, respectively. Also the results showed that arbuscular mycorrhizal fungi increased dry matter amount by 42% and 26%, nitrogen concentration by 40.3% and 30%, phosphorus concentration by 6% and 15.4%, potassium concentrations by 54% and 91.2% in root and aerial, respectively. Interaction between cadmium levels and mycorrhizal fungi in statistics was significant on dry matter aerial, nitrogen concentration in aerial and root, and potassium concentrations in plant root (P< 0.01. Conclusion: The results showed that mycorrhizal fungi were significant on all traits measured in one percent level. Cadmium

  8. The inhibitory effects of potassium chloride versus potassium silicate application on 137Cs uptake by rice

    International Nuclear Information System (INIS)

    Fujimura, Shigeto; Yoshioka, Kunio; Ota, Takeshi; Ishikawa, Tetsuya; Sato, Makoto; Satou, Mutsuto

    2016-01-01

    After the accident at the Fukushima Dai-ichi Nuclear Power Plant owned by the Tokyo Electric Power Company on 11 March 2011, potassium fertilizer was applied to agricultural fields in the southern Tohoku and northern Kanto regions of Japan to reduce the uptake of radiocesium by crops. In this study, we examined the effects of two types of potassium fertilizers, potassium chloride (a readily available potassium fertilizer) and potassium silicate (a slow-release potassium fertilizer), as well as a split application of potassium, on the accumulation of 137 Cs by rice plants in two pot experiments. The 137 Cs concentrations in the brown rice and in the above-ground plants were significantly lower after potassium chloride application than after potassium silicate application. The potassium ion (K + ) concentrations in soil solutions sampled 9 and 21 d after transplanting were significantly higher for the potassium chloride application than for the potassium silicate application. The K + concentrations in soil solutions observed in the application of potassium silicate were similar to those in the treatment when no potassium was applied. This finding indicates that the application of potassium silicate did not sufficiently increase the available K + for rice plants in the soil, which led to a greater uptake of 137 Cs after the potassium silicate application than after the application of potassium chloride. The 137 Cs concentration in brown rice was higher in the split application of potassium fertilizer with the second application at the full heading stage than that without split application and the split application with the second application before heading. - Highlights: • Potassium application reduced 137 Cs uptake by rice grown in pot experiments. • Readily available K fertilizer more effectively decreased brown rice 137 Cs concentration. • Potassium should be applied before heading to reduce brown rice 137 Cs concentration.

  9. Hormones of thyroid gland in sera of rats treated with different dose of concentrated potassium iodine solutions

    Directory of Open Access Journals (Sweden)

    Marković Ljiljana

    2010-01-01

    Full Text Available Introduction Potassium iodine (KI is used as a drug therapy for treating numerous diseases such as small-vessel vasculitis, erythema nodosum, vasculitis nodularis, Sweet's syndrome, tuberculosis and granulomatosis, and for iodized salt. At the same time, KI can be harmful. Iodine intake may increase the frequency of thyroiditis in humans, and may induce the occurrence of experimental thyroiditis (ET in animals. Investigations on an experimental model for the examination of thyroiditis in Wistar rats have clearly showed morphological changes in the rat thyroid evoked by KI administration. Objective The purpose of this study was to compare the effects of low and high doses of KI on the thyroid gland of Wistar rats and determine the effect on hormone status (T4, T3 and TSH in this rat strain. Methods Two groups of rats from the Wistar strain were treated with a low iodine dose (225 μg/g BW and with a high iodine dose (675 μg/g BW of KI solutions. Untreated nonimmunized animals served as controls. The solution was administrated daily intraperitoneally during the period of 26 consecutive days. Results Monitoring hormone status (TSH, T3 and T4 and morphological changes it was found that therapeutic doses of KI applied in treatment induced the occurrence of experimental thyroiditis (chronic destructive Hashimoto's thyroiditis in humans and cell necrosis in animals not carrying a genetic susceptibility. Significant inflammatory changes were observed in rats treated with a high iodine dose. Conclusion The early iodine induced cell necrosis and inflammation in the nonimmunized animals without genetic susceptibility is a new experimental model of thyroiditis. .

  10. Caffeine Alters Blood Potassium and Catecholamine Concentrations but not the Perception of Pain and Fatigue with a 1 km Cycling Sprint

    Directory of Open Access Journals (Sweden)

    Dean M. Cordingley

    2016-07-01

    Full Text Available Background: Caffeine has been used by some athletes to improve short-term high-intensity exercise performance; however, the literature is equivocal. Objectives: The objective of this study was to investigate the effects of caffeine on plasma potassium and catecholamine concentrations, pain and fatigue perception, to determine whether potassium ion handling and altered perception related to the central nervous system are associated with enhanced performance during a 1 km cycling time trial.  Methods: Thirteen well trained men with a mean age of 27 ± 6 yrs (body mass: 76.4 ± 6.4 kg, height: 180 ± 7 cm, and max: 57.5 ± 4.6 ml·kg-1·min-1 were recruited.  Participants were randomized to a caffeine (5 mg·kg-1 or a placebo condition using a double blind, cross over design.  Results: Caffeine had no significant effects on the 1 km time-trial performance indicators of time (82.1 ± 2.4 vs. 81.9 ± 3.9s, peak (633.0 ± 83.6 vs. 638.7 ± 110.1 watts or average power (466.0 ± 37.3 vs. 467.5 ± 59.9 watts; caffeine and placebo conditions respectively.  In addition, caffeine had no significant effect on oxygen consumption ( (4.11 ± 0.24 vs 4.06 ± 0.29 L,the perception of pain (5.6 ± 2.4 vs. 5.5 ± 2.6 or fatigue (7.1 ± 1.8 vs.7.1 ± 1.8: caffeine and placebo conditions respectively.  There was a significantly greater increase in post-exercise blood lactate (p<0.05 and catecholamines (p<0.05 as well as a lower pre-exercise blood potassium concentration (p<0.05 in the caffeine condition. Conclusions: The results suggest that caffeine can enhance certain metabolic parameters, but these changes were unable to augment short-distance (1km, high-intensity cycling performance. Keywords: ergogenic, anaerobic exercise, performance, oxygen consumption

  11. The variation of calcium, magnesium, sodium, potassium and bicarbonate concentration, pH and conductivity in groundwater of Karachi region

    International Nuclear Information System (INIS)

    Zubair, A.; Ali, S.I.

    2002-01-01

    Groundwater in Karachi is influenced mainly by the evaporation / crystallization process as expressed by the Na/(Na+Ca) weight concentration ratio. The high coefficient of determined between conductivity and total dissolved ions concentration in meq/sup -1/ revealed that major ions affect the conductivity of groundwater. It was also found that groundwater quality with respect to cations is not significantly influenced by geology, particularly in the Urban are of the city, where the 90% of the population resides. The relationship between conductivity and bicarbonate concentration shows that supersaturation of groundwater with carbon dioxide is responsible for general depression of pH. (author)

  12. Nitrogen and potassium concentrations in the nutrients solution for melon plants growing in coconut fiber without drainage.

    Science.gov (United States)

    Gratieri, Luiz Augusto; Cecílio Filho, Arthur Bernardes; Barbosa, José Carlos; Pavani, Luiz Carlos

    2013-01-01

    With the objective of evaluating the effects of N and K concentrations for melon plants, an experiment was carried out from July 1, 2011 to January 3, 2012 in Muzambinho city, Minas Gerais State, Brazil. The "Bonus no. 2" was cultivated at the spacing of 1.1 × 0.4. The experimental design was a randomized complete block with three replications in a 4 × 4 factorial scheme with four N concentrations (8, 12, 16, and 20 mmol L(-1)) and four K concentrations (4, 6, 8, and 10 mmol L(-1)). The experimental plot constituted of eight plants. It was observed that the leaf levels of N and K, of N-NO₃ and of K, and the electrical conductivity (CE) of the substrate increased with the increment of N and K in the nutrients' solution. Substratum pH, in general, was reduced with increments in N concentration and increased with increasing K concentrations in the nutrients' solution. Leaf area increased with increments in N concentration in the nutrients solution. Fertigation with solutions stronger in N (20 mmol L(-1)) and K (10 mmol L(-1)) resulted in higher masses for the first (968 g) and the second (951 g) fruits and crop yield (4,425 gm(-2)).

  13. Nitrogen and Potassium Concentrations in the Nutrients Solution for Melon Plants Growing in Coconut Fiber without Drainage

    Directory of Open Access Journals (Sweden)

    Luiz Augusto Gratieri

    2013-01-01

    Full Text Available With the objective of evaluating the effects of N and K concentrations for melon plants, an experiment was carried out from July 1, 2011 to January 3, 2012 in Muzambinho city, Minas Gerais State, Brazil. The “Bonus no. 2” was cultivated at the spacing of 1.1 × 0.4. The experimental design was a randomized complete block with three replications in a 4 × 4 factorial scheme with four N concentrations (8, 12, 16, and 20 mmol L−1 and four K concentrations (4, 6, 8, and 10 mmol L−1. The experimental plot constituted of eight plants. It was observed that the leaf levels of N and K, of N-NO3 and of K, and the electrical conductivity (CE of the substrate increased with the increment of N and K in the nutrients' solution. Substratum pH, in general, was reduced with increments in N concentration and increased with increasing K concentrations in the nutrients' solution. Leaf area increased with increments in N concentration in the nutrients solution. Fertigation with solutions stronger in N (20 mmol L−1 and K (10 mmol L−1 resulted in higher masses for the first (968 g and the second (951 g fruits and crop yield (4,425 gm−2.

  14. Determinants of renal potassium excretion in critically ill patients : The role of insulin therapy

    NARCIS (Netherlands)

    Hoekstra, Miriam; Yeh, Lu; Oude Lansink, Annemieke; Vogelzang, Mathijs; Stegeman, Coen A.; Rodgers, Michael G. G.; van der Horst, Iwan C. C.; Wietasch, Gotz; Zijlstra, Felix; Nijsten, Maarten W. N.

    Objectives: Insulin administration lowers plasma potassium concentration by augmenting intracellular uptake of potassium. The effect of insulin administration on renal potassium excretion is unclear. Some studies suggest that insulin has an antikaliuretic effect although plasma potassium levels were

  15. Genetic parameters of calcium, phosphorus, magnesium, and potassium serum concentrations during the first 8 days after calving in Holstein cows.

    Science.gov (United States)

    Tsiamadis, V; Banos, G; Panousis, N; Kritsepi-Konstantinou, M; Arsenos, G; Valergakis, G E

    2016-07-01

    Calcium, Mg, P, and K are of great importance for the health and productivity of dairy cows after calving. So far genetic studies have focused on clinical hypocalcemia, leaving the genetic parameters of these macroelements unstudied. Our objective was to estimate the genetic parameters of Ca, Mg, P, and K serum concentrations and their changes during the first 8d after calving. The study was conducted in 9 herds located in northern Greece, with 1,021 Holstein cows enrolled from November 2010 until November 2012. No herd used any kind of preventive measures for hypocalcemia. Pedigree information for all cows was available. A total of 35 cows were diagnosed and treated for periparturient paresis and, therefore, excluded from the study. The remaining 986 cows were included in genetic analysis. The distribution of cows across parities was 459 (parity 1), 234 (parity 2), 158 (parity 3), and 135 (parity ≥4). A sample of blood was taken from each cow on d1, 2, 4, and 8 after calving and serum concentrations of Ca, P, Mg, and K were measured in each sample. A final data set of 15,390 biochemical records was created consisting of 3,903 Ca, 3,902 P, 3,903Mg, and 3,682K measurements. Moreover, changes of these concentrations between d1 and 4 as well as 1 and 8 after calving were calculated and treated as different traits. Random regression models were used to analyze the data. Results showed that daily heritabilities of Ca, P, and Mg concentrations traits were moderate to high (0.20-0.43), whereas those of K were low to moderate (0.12-0.23). Regarding concentration changes, only Mg change between d1 and 8 after calving had a significant heritability of 0.18. Genetic correlations between Ca, P, Mg, and K concentrations and their concentration changes from d1 to 4 and 1 to 8 after calving were not significantly different from zero. Most phenotypic correlations among Ca, P, Mg, and K concentrations were positive and low (0.09-0.16), whereas the correlation between P and Mg was

  16. Potassium-transporting proteins in skeletal muscle: cellular location and fiber-type differences

    DEFF Research Database (Denmark)

    Kristensen, Michael; Juel, Carsten

    2010-01-01

    Potassium (K+) displacement in skeletal muscle may be an important factor in the development of muscle fatigue during intense exercise. It has been shown in vitro that an increase in the extracellular K+ concentration ([K+]e) to values higher than approx. 10 mm significantly reduce force developm......Potassium (K+) displacement in skeletal muscle may be an important factor in the development of muscle fatigue during intense exercise. It has been shown in vitro that an increase in the extracellular K+ concentration ([K+]e) to values higher than approx. 10 mm significantly reduce force......, but is suggested primarily to participate in K+ release to the interstitium. Because there is restricted diffusion of K+ to the interstitium, K+ released to the T-tubules during AP propagation will be removed primarily by reuptake mediated by transport proteins located in the T-tubule membrane. The most important...

  17. Inhibition of Brain Swelling after Ischemia-Reperfusion by β-Adrenergic Antagonists: Correlation with Increased K+ and Decreased Ca2+ Concentrations in Extracellular Fluid

    Directory of Open Access Journals (Sweden)

    Dan Song

    2014-01-01

    Full Text Available Infarct size and brain edema following ischemia/reperfusion are reduced by inhibitors of the Na+, K+, 2Cl−, and water cotransporter NKCC1 and by β1-adrenoceptor antagonists. NKCC1 is a secondary active transporter, mainly localized in astrocytes, driven by transmembrane Na+/K+ gradients generated by the Na+,K+-ATPase. The astrocytic Na+,K+-ATPase is stimulated by small increases in extracellular K+ concentration and by the β-adrenergic agonist isoproterenol. Larger K+ increases, as occurring during ischemia, also stimulate NKCC1, creating cell swelling. This study showed no edema after 3 hr medial cerebral artery occlusion but pronounced edema after 8 hr reperfusion. The edema was abolished by inhibitors of specifically β1-adrenergic pathways, indicating failure of K+-mediated, but not β1-adrenoceptor-mediated, stimulation of Na+,K+-ATPase/NKCC1 transport during reoxygenation. Ninety percent reduction of extracellular Ca2+ concentration occurs in ischemia. Ca2+ omission abolished K+ uptake in normoxic cultures of astrocytes after addition of 5 mM KCl. A large decrease in ouabain potency on K+ uptake in cultured astrocytes was also demonstrated in Ca2+-depleted media, and endogenous ouabains are needed for astrocytic K+ uptake. Thus, among the ionic changes induced by ischemia, the decrease in extracellular Ca2+ causes failure of the high-K+-stimulated Na+,K+-ATPase/NKCC1 ion/water uptake, making β1-adrenergic activation the only stimulus and its inhibition effective against edema.

  18. Calcium, potassium, iron, copper and zinc concentrations in the white and gray matter of the cerebellum and corpus callosum in brain of four genetic mouse strains

    Energy Technology Data Exchange (ETDEWEB)

    Sergeant, C. [CNRS-Universite de Bordeaux I, UMR 5084, Chimie Nucleaire Analytique et Bio environnementale, Le Haut Vigneau, BP120, 33175 Bordeaux-Gradignan (France)]. E-mail: sergeant@cenbg.in2p3.fr; Vesvres, M.H. [CNRS-Universite de Bordeaux I, UMR 5084, Chimie Nucleaire Analytique et Bio environnementale, Le Haut Vigneau, BP120, 33175 Bordeaux-Gradignan (France); Deves, G. [CNRS-Universite de Bordeaux I, UMR 5084, Chimie Nucleaire Analytique et Bio environnementale, Le Haut Vigneau, BP120, 33175 Bordeaux-Gradignan (France); Guillou, F. [INRA-CNRS-Universite de Tours-Haras nationaux, UMR 6175, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly (France)

    2005-04-01

    In the central nervous system, metallic cations are involved in oligodendrocyte maturation and myelinogenesis. Moreover, the metallic cations have been associated with pathogenesis, particularly multiple sclerosis and malignant gliomas. The brain is vulnerable to either a deficit or an excess of available trace elements. Relationship between trace metals and myelinogenesis is important in understanding a severe human pathology : the multiple sclerosis, which remains without efficient treatment. One approach to understand this disease has used mutant or transgenic mice presenting myelin deficiency or excess. But to date, the concentration of trace metals and mineral elements in white and gray matter areas in wild type brain is unknown. The aim of this study is to establish the reference concentrations of trace metals (iron, copper and zinc) and minerals (potassium and calcium) in the white and gray matter of the mouse cerebellum and corpus callosum. The brains of four different genetic mouse strains (C57Black6/SJL, C57Black6/D2, SJL and C3H) were analyzed. The freeze-dried samples were prepared to allow PIXE (Proton-induced X-ray emission) and RBS (Rutherford backscattering spectrometry) analyses with the nuclear microprobe in Bordeaux. The results obtained give the first reference values. Furthermore, one species out of the fours testes exhibited differences in calcium, iron and zinc concentrations in the white matter.

  19. Calcium, potassium, iron, copper and zinc concentrations in the white and gray matter of the cerebellum and corpus callosum in brain of four genetic mouse strains

    International Nuclear Information System (INIS)

    Sergeant, C.; Vesvres, M.H.; Deves, G.; Guillou, F.

    2005-01-01

    In the central nervous system, metallic cations are involved in oligodendrocyte maturation and myelinogenesis. Moreover, the metallic cations have been associated with pathogenesis, particularly multiple sclerosis and malignant gliomas. The brain is vulnerable to either a deficit or an excess of available trace elements. Relationship between trace metals and myelinogenesis is important in understanding a severe human pathology : the multiple sclerosis, which remains without efficient treatment. One approach to understand this disease has used mutant or transgenic mice presenting myelin deficiency or excess. But to date, the concentration of trace metals and mineral elements in white and gray matter areas in wild type brain is unknown. The aim of this study is to establish the reference concentrations of trace metals (iron, copper and zinc) and minerals (potassium and calcium) in the white and gray matter of the mouse cerebellum and corpus callosum. The brains of four different genetic mouse strains (C57Black6/SJL, C57Black6/D2, SJL and C3H) were analyzed. The freeze-dried samples were prepared to allow PIXE (Proton-induced X-ray emission) and RBS (Rutherford backscattering spectrometry) analyses with the nuclear microprobe in Bordeaux. The results obtained give the first reference values. Furthermore, one species out of the fours testes exhibited differences in calcium, iron and zinc concentrations in the white matter

  20. Second trimester amniotic fluid glucose, uric acid, phosphate, potassium, and sodium concentrations in relation to maternal pre-pregnancy BMI and birth weight centiles.

    Science.gov (United States)

    Fotiou, Maria; Michaelidou, Alexandra Maria; Athanasiadis, Apostolos P; Menexes, Georgios; Symeonidou, Maria; Koulourida, Vasiliki; Ganidou, Maria; Theodoridis, Theodoros D; Tarlatzis, Basil C

    2015-05-01

    To study the evolution profile of amniotic fluid (AF) glucose, uric acid, phosphate, potassium, and sodium, in the second trimester of pregnancy, and explore the possible relations between the concentration of these components and maternal, as well as neonatal characteristics. AF of 52 pregnant women was analyzed using an automatic multichannel analyzer. Maternal age, pre-pregnancy Body Mass Index (BMI), inter-pregnancy intervals, and smoking status were derived from questionnaires. Information on pregnancy and delivery was collected from medical records. Uric acid increased (r = 0.423, p pregnancy (r = -0.590, p pregnancy BMI was significantly correlated with AF uric acid concentration (r = 0.460, p sodium (r = 0.254, p = 0.070) levels. Multiple linear regression indicated that mid-trimester AF uric acid and phosphate levels were significantly related to birth weight centiles (R(2)( )= 0.345, p pregnancy BMI is significantly correlated with AF uric acid concentration, and (c) in appropriate for gestational age infants, AF phosphate and uric acid levels may serve as potential biomarkers of birth weight centiles. Further studies on AF composition may help to unravel the biochemical pathways underlying fetal development and could offer insight on the potential impact of maternal nutritional management on fetal growth regulation.

  1. Enhancement of delayed-rectifier potassium conductance by low concentrations of local anaesthetics in spinal sensory neurones

    Science.gov (United States)

    Olschewski, Andrea; Wolff, Matthias; Bräu, Michael E; Hempelmann, Gunter; Vogel, Werner; Safronov, Boris V

    2002-01-01

    Combining the patch-clamp recordings in slice preparation with the ‘entire soma isolation' method we studied action of several local anaesthetics on delayed-rectifier K+ currents in spinal dorsal horn neurones.Bupivacaine, lidocaine and mepivacaine at low concentrations (1–100 μM) enhanced delayed-rectifier K+ current in intact neurones within the spinal cord slice, while exhibiting a partial blocking effect at higher concentrations (>100 μM). In isolated somata 0.1–10 μM bupivacaine enhanced delayed-rectifier K+ current by shifting its steady-state activation characteristic and the voltage-dependence of the activation time constant to more negative potentials by 10–20 mV.Detailed analysis has revealed that bupivacaine also increased the maximum delayed-rectifier K+ conductance by changing the open probability, rather than the unitary conductance, of the channel.It is concluded that local anaesthetics show a dual effect on delayed-rectifier K+ currents by potentiating them at low concentrations and partially suppressing at high concentrations. The phenomenon observed demonstrated the complex action of local anaesthetics during spinal and epidural anaesthesia, which is not restricted to a suppression of Na+ conductance only. PMID:12055132

  2. On the concept of resting potential--pumping ratio of the Na⁺/K⁺ pump and concentration ratios of potassium ions outside and inside the cell to sodium ions inside and outside the cell.

    Science.gov (United States)

    Xu, Ning

    2013-01-01

    In animal cells, the resting potential is established by the concentration gradients of sodium and potassium ions and the different permeabilities of the cell membrane to them. The large concentration gradients of sodium and potassium ions are maintained by the Na⁺/K⁺ pump. Under physiological conditions, the pump transports three sodium ions out of and two potassium ions into the cell per ATP hydrolyzed. However, unlike other primary or secondary active transporters, the Na⁺/K⁺ pump does not work at the equilibrium state, so the pumping ratio is not a thermodynamic property of the pump. In this article, I propose a dipole-charging model of the Na⁺/K⁺ pump to prove that the three Na⁺ to two K⁺ pumping ratio of the Na⁺/K⁺ pump is determined by the ratio of the ionic mobilities of potassium to sodium ions, which is to ensure the time constant τ and the τ-dependent processes, such as the normal working state of the Na⁺/K⁺ pump and the propagation of an action potential. Further, the concentration ratios of potassium ions outside and inside the cell to sodium ions inside and outside the cell are 0.3027 and 0.9788, respectively, and the sum of the potassium and sodium equilibrium potentials is -30.3 mV. A comparative study on these constants is made for some marine, freshwater and terrestrial animals. These findings suggest that the pumping ratio of the Na⁺/K⁺ pump and the ion concentration ratios play a role in the evolution of animal cells.

  3. Effects of potassium iodide in concentrations of TSH, tT3 and tT4 in serum of subjects with sporotrichosis.

    Science.gov (United States)

    Ramírez Soto, Max Carlos

    2014-08-01

    The saturated potassium iodide solution (SSKI) as treatment for sporotrichosis may cause hypothyroidism by suppressing the synthesis of thyroid hormones (tT3 and tT4 ) and the iodine excess could lead to thyrotoxicosis. Evaluating the changes in serum levels of TSH, tT3 and tT4 in euthyroid patients with sporotrichosis treated with SSKI. For the selection of euthyroid patients, TSH, tT3 and tT4 concentrations were measured for those adults and children diagnosed with sporotrichosis. Each paediatric patient was administered SSKI orally in increasing doses of 2-20 drops/3 times/day and 4-40 drops/3 times/day in adults. Serum concentrations of TSH, tT3 and tT4 were measured 20 days after started the treatment and 15 days posttreatment. Eight euthyroid patients aged between 2 to 65 years old were included. After 20 days of treatment, two suffered subclinical hypothyroidism, one developed subclinical hyperthyroidism, and one hyperthyroxinaemia euthyroid. At 15 days posttreatment only four patients were evaluated and all serum levels of TSH, tT3 and tT4 were normal. Some euthyroid patients with sporotrichosis can develop hyperthyroidism or subclinical iodine-induced hypothyroidism, during the administration of 3 or 6 g SSKI/day. © 2014 Blackwell Verlag GmbH.

  4. Extracellular Signal-Regulated Kinase 5 is Required for Low-Concentration H2O2-Induced Angiogenesis of Human Umbilical Vein Endothelial Cells.

    Science.gov (United States)

    Jiang, Shan; Zhang, Dongxin; Huang, Hong; Lei, Yonghong; Han, Yan; Han, Weidong

    2017-01-01

    Background . The aim of this study was to assess the effects of low concentrations of H 2 O 2 on angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro and explore the underlying mechanisms. Methods . HUVECs were cultured and stimulated with different concentrations of H 2 O 2 . Flow cytometric analysis was used to select an optimal concentration of H 2 O 2 for the following experiments. Cell proliferation, migration, and tubule formation were evaluated by Cell Counting Kit-8 (CCK-8) assays, scratch wound assays, and Matrigel tubule formation assays, respectively. For gain and loss of function studies, constitutively active MEK5 (CA-MEK5) and ERK5 shRNA lentiviruses were used to activate or knock down extracellular signal-regulated kinase 5 (ERK5). Results . We found that low concentrations of H 2 O 2 promoted HUVECs proliferation, migration, and tubule formation. ERK5 in HUVECs was significantly activated by H 2 O 2 . Enhanced ERK5 activity significantly amplified the proangiogenic effects of H 2 O 2 ; in contrast, ERK5 knock-down abrogated the effects of H 2 O 2 . Conclusions . Our results confirmed that low concentrations of H 2 O 2 promoted HUVECs angiogenesis in vitro, and ERK5 is an essential mediator of this process. Therefore, ERK5 may be a potential therapeutic target for promoting angiogenesis and improving graft survival.

  5. Potassium test

    Science.gov (United States)

    ... hyperkalemia ) may be due to: Addison disease (rare) Blood transfusion Certain medicines Crushed tissue injury Hyperkalemic periodic paralysis ... released. This may cause a falsely high result. Alternative Names Hypokalemia test; K+ Images Blood test References Mount DB. Disorders of potassium balance. ...

  6. Potassium Iodide

    Science.gov (United States)

    ... certain other liquids including low-fat white or chocolate milk, flat soda, orange juice, raspberry syrup, or ... Potassium iodide may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away: swollen glands metallic taste in the ...

  7. Potassium distribution in sugar cane

    International Nuclear Information System (INIS)

    Medina, N.H.

    2014-01-01

    In this work the distribution of potassium in sugarcane has been studied during its growth in two different conditions. In the first one the sugarcane soil was prepared with natural fertilizers, using sugarcane bagasse and, in another plantation the soil was prepared with commercial fertilizer NPK with a proportion of 10-10-10. For the measurement of potassium concentration in each part of the plant, gamma ray spectrometry techniques have been used to measure gamma-rays emitted from the radioisotope 40 K present in the sugarcane samples. The concentration of potassium in roots, stems and leaves were measured periodically. The results for sugarcane cultivated in soil with natural fertilizer show a higher concentration of potassium at the beginning of plant development and over time there is an oscillatory behavior in this concentration in each part of the plant, reaching a lower concentration in the adult plant. The results for the plant grown in soil with NPK fertilizer, indicate that the potassium concentration is higher in the stem at the beginning of cultivation and remained practically constant over time in various parts of the plant, with higher values in the leaves and stem than at the root. On the other hand, the results obtained using fertilizer NPK shows a lower potassium concentration, since the fertilizer provoked a much higher growth rate. (author)

  8. Low Potassium (Hypokalemia)

    Science.gov (United States)

    Symptoms Low potassium (hypokalemia) By Mayo Clinic Staff Low potassium (hypokalemia) refers to a lower than normal potassium level ... 2 millimoles per liter (mmol/L). A very low potassium level (less than 2.5 mmol/L) ...

  9. The inhibitory effects of potassium chloride versus potassium silicate application on (137)Cs uptake by rice.

    Science.gov (United States)

    Fujimura, Shigeto; Yoshioka, Kunio; Ota, Takeshi; Ishikawa, Tetsuya; Sato, Makoto; Satou, Mutsuto

    2016-03-01

    After the accident at the Fukushima Dai-ichi Nuclear Power Plant owned by the Tokyo Electric Power Company on 11 March 2011, potassium fertilizer was applied to agricultural fields in the southern Tohoku and northern Kanto regions of Japan to reduce the uptake of radiocesium by crops. In this study, we examined the effects of two types of potassium fertilizers, potassium chloride (a readily available potassium fertilizer) and potassium silicate (a slow-release potassium fertilizer), as well as a split application of potassium, on the accumulation of (137)Cs by rice plants in two pot experiments. The (137)Cs concentrations in the brown rice and in the above-ground plants were significantly lower after potassium chloride application than after potassium silicate application. The potassium ion (K(+)) concentrations in soil solutions sampled 9 and 21 d after transplanting were significantly higher for the potassium chloride application than for the potassium silicate application. The K(+) concentrations in soil solutions observed in the application of potassium silicate were similar to those in the treatment when no potassium was applied. This finding indicates that the application of potassium silicate did not sufficiently increase the available K(+) for rice plants in the soil, which led to a greater uptake of (137)Cs after the potassium silicate application than after the application of potassium chloride. The (137)Cs concentration in brown rice was higher in the split application of potassium fertilizer with the second application at the full heading stage than that without split application and the split application with the second application before heading. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. EFFECT OF ETHANOL AND ACETALDEHYDE AT CLINICALLY RELEVANT CONCENTRATIONS ON ATRIAL INWARD RECTIFIER POTASSIUM CURRENT I-K1 SEPARATE AND COMBINED EFFECT

    Czech Academy of Sciences Publication Activity Database

    Hořáková, Z.; Matejovič, P.; Pásek, Michal; Hošek, J.; Šimurdová, M.; Šimurda, J.; Bébarová, M.

    2016-01-01

    Roč. 67, č. 3 (2016), s. 339-351 ISSN 0867-5910 Institutional support: RVO:61388998 Keywords : arrhythmias * cardiomyocyte * inward rectifier potassium current * ethanol * mathematical model Subject RIV: BO - Biophysics Impact factor: 2.883, year: 2016

  11. Long-term lithium treatment increases intracellular and extracellular brain-derived neurotrophic factor (BDNF) in cortical and hippocampal neurons at subtherapeutic concentrations.

    Science.gov (United States)

    De-Paula, Vanessa J; Gattaz, Wagner F; Forlenza, Orestes V

    2016-12-01

    The putative neuroprotective effects of lithium treatment rely on the fact that it modulates several homeostatic mechanisms involved in the neurotrophic response, autophagy, oxidative stress, inflammation, and mitochondrial function. Lithium is a well-established therapeutic option for the acute and long-term management of bipolar disorder and major depression. The aim of this study was to evaluate the effects of subtherapeutic and therapeutic concentrations of chronic lithium treatment on brain-derived neurotrophic factor (BDNF) synthesis and secretion. Primary cultures of cortical and hippocampal neurons were treated with different subtherapeutic (0.02 and 0.2 mM) and therapeutic (2 mM) concentrations of chronic lithium treatment in cortical and hippocampal cell culture. Lithium treatment increased the intracellular protein expression of cortical neurons (10% at 0.02 mM) and hippocampal neurons (28% and 14% at 0.02 mM and 0.2 mM, respectively). Extracellular BDNF of cortical neurons increased 30% and 428% at 0.02 and 0.2 mM, respectively and in hippocampal neurons increased 44% at 0.02 mM. The present study indicates that chronic, low-dose lithium treatment up-regulates BDNF production in primary neuronal cell culture. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. VISIBE AND INFRARED SPECTRAL CHARACTERISATION OF CHINESE CABBAGE (BRASSICA RAPA L. SUBSPECIES CHINENSIS, GROWN UNDER DIFFERENT NITROGEN, POTASSIUM AND PHOSPHORUS CONCENTRATIONS

    Directory of Open Access Journals (Sweden)

    B. B. Mokoatsi

    2017-11-01

    Full Text Available There is a need to intensify research efforts on improving productivity of indigenous vegetables in South Africa. One research avenue is operationalizing remote sensing techniques to monitor crop health status. This study aimed at characterising the spectral properties of Chinese cabbage (Brassica Rapa L. subspecies Chinensis grown under varying fertilizer treatments: nitrogen (0 kg/ha, 75 kg/ha, 125 kg/ha, 175 kg/ha and 225 kg/ha, phosphorus (0 kg/ha, 9.4 kg/ha, 15.6, 21.9 kg/ha and 28.1 kg/ha and potassium (0 kg/ha, 9.4  kg/ha, 15.6 kg/ha, 21.9 kg/ha and 28.1 kg/ha. Visible and infrared spectral measurements were taken from a total of 60 samples inside the laboratory. Contiguous spectral regions were plotted to show spectral profiles of the different fertilizer treatments and then classified using gradient boosting and random forest classifiers. ANOVA revealed the potential of spectral reflectance data in discriminating different fertiliser treatments from crops. There was also a significant difference between the capabilities of the two classifiers. Gradient boost model (GBM yielded higher classification accuracies than random forest (RF. The important variables identified by each model improved the classification accuracy. Overall, the results indicate a potential for the use of spectroscopy in monitoring food quality parameters, thereby reducing the cost of traditional methods. Further research into advanced statistical analysis techniques is needed to improve the accuracy with which fertiliser concentrations in crops could be quantified. The random forest model particularly requires improvements.

  13. Electrolyte Balance of the Inner Ear Investigated by Neutron Activation Analysis of the Sodium and Potassium Content

    International Nuclear Information System (INIS)

    Ördögh, Mary; Miriszlai, E.

    1967-01-01

    Even the few experimental data that have been obtained from investigations of the inner ear are an important contribution to our biochemical knowledge of the sense organs. The apparent discrepancies between some experimental results have prompted comparative studies on the sodium and potassium concentrations in the inner-ear fluids, the liquor cerebrospinalis, the mammalian and human serum. The results of these studies are expected to give a good approximation of the intracellular and extracellular electrolyte concentrations and to yield important information on the physiological and pathological conditions of the inner ear as well as on the mechanism of hearing. The experimental material is obtained from guinea pigs by penetration through the round window (fenestra rotunda). The sodium and potassium content is determined by neutron activation analysis. Potassium is precipitated from the irradiated samples by sodium tetraphenyl borate reagent, so that the sodium activity retained by the filtrate can be directly counted. Since a single precipitation of potassium does not yield end products free from sodium contamination, the precipitate is dissolved in acetone and precipitated again with sodium tetraphenyl borate. The product of the second precipitation is radiochemically pure. In simultaneous experiments, potassium was separated from the much higher sodium activity by isotopic exchange. The irradiated sample is added to an experimentally determined inactive potassium tetraphenyl borate precipitate that adsorbs the total potassium activity present without adsorbing any sodium. The separation of potassium by isotopic exchange has the advantage of yielding in a single step a sufficiently pure product without any sodium contamination. For comparison, sodium and potassium were also determined by flame photometry. (author)

  14. The concentration of the coolant 7Li in Kozloduy Nuclear Power Plant operating with potassium hydroxide as an alkalizing reagent (possible impact on the occurrence of axial offset anomaly)

    International Nuclear Information System (INIS)

    Dobrevski, I.D.; Minkova, K.F.; Ivanova, R.A.

    2003-01-01

    The phenomenon of axial offset anomaly (AOA) has occurred in a number of PWRs operating with extended fuel cycles and high boiling duty cores. Up to now AOA has been observed in PWRs operating with lithium hydroxide and the alkalizing reagent used for pH adjustment in boric acid water solutions. Since AOA is connected with the LiBO 2 precipitation in porous corrosion product deposits on the fuel cladding surfaces, we could presume that the replacement of lithium hydroxide with potassium hydroxide will avoid AOA. Nowadays there is a lack of observed AOA in VVER, i.e., a lack of formation of lithium metaborate (LiBO 2 ) deposits on the fuel element surfaces by coolant alkalization with potassium hydroxide. Nevertheless, the concentrations of 7 Li appear in the coolant, as a product of the neutron reaction with boron: 10 B (n,α) → 7 Li (n, α). As a consequence the possibility it is not excluded of LiBO 2 formation in VVERs with potassium hydroxide water chemistry. The aim of this study is to inform the reader about the development of the concentration of the coolant lithium concentration during the fuel cycles of VVERs and to discuss the possibility of LiBO 2 formation under VVER operation conditions. (orig.)

  15. Effect of the MK 801 and (-) nicotine intracerebral administration on Glu and Gaba extracellular concentration in the pedunculopontine nucleus from rats

    International Nuclear Information System (INIS)

    Blanco Lezcano, Lisette; Lorigados Pedre, Lourdes del Carmen; Gonzalez Fraguela, Maria Elena and others

    2011-01-01

    Although the pharmacological manipulation of the glutamatergic and cholinergic systems have been studied in animal models of Parkinson's Disease (PD), only some authors have done work on this topic at the pedunculopontine nucleus (PPN). The present work studied the changes in glutamate (Glu) and δ-aminobutyric acid (GABA) extracellular concentrations (EC) in the PPN from hemiparkinsonian rats by 6hydroxydopamine injection. The rats were locally perfused by MK-801 (10 μ mol/l) or (-) nicotine (10 mm) solutions by cerebral microdialysis. The biochemical studies were carried out through high performance liquid chromatography coupled to fluorescence detection. Mk-801 infusion induced a significant decrease of Glu (p< 0.01) and GABA (p< 0.01) EC in PPN. On the other hand (-) nicotine infusion induced a significant increase of Glu (p< 0.001) and GABA (p< 0.001) EC in PPN from hemiparkinsonian rats. The local blockade of NMDA receptors by MK-801 infusion facilitates the interaction between Glu and their metabotropic receptors that take part in presynaptic inhibition mechanisms and interfere with neurotransmitters release. Meanwhile, the nicotine infusion sums the effects of nicotinic receptor activation with the glutamatergic and gabaergic neurotransmission changes produced in the PPN in the parkinsonian condition. The cholinergic and glutamergic drug infusion in PPN impose a new adjustment to the neurotransmission at this level that is added to the neurochemical changes associated to dopaminergic denervation.

  16. Electrolyte Concentrations of Intra- and Extracellular Compartments in Some Internal Diseases; Concentration des Electrolytes dans les Compartiments Intra- et Extracellulares, dans Certaines Maladies Internes; ВНУТРИКЛЕТОЧНАЯ И ВНЕКЛЕТОЧНАЯ КОНЦЕНТРАЦИЯ ЭЛЕКТРОЛИТОВ ПРИ НЕКОТОРЫХ ВНУТРЕННИХ ЗАБОЛЕВАНИЯХ; Concentraciones de Electrolitos en Comp Artimientos Intra y Extracelulares en Algunas Enfermedades Internas

    Energy Technology Data Exchange (ETDEWEB)

    Itahara, K.; Ito, K.; Tominaga, T.; Jimbo, T.; Sato, T. [Tohoku University, Sendai (Japan)

    1963-03-15

    It was reported by the authors, at the Third Japanese Conference on Radioisotopes, held in 1959, that they had measured the total body water (D{sub 2}O space), extracellular fluid volume (mannitol space) and total exchangeable sodium and potassium in oedematous and hypertensive patients. In the present paper, they report their studies of the sodium and potassium concentrations in extra- and intracellular fluids, using Na{sup 24} and K{sup 42}, in patients with essential hypertension, primary aldosteronism and periodic paralysis. The Na{sub e} (expressed as mEq/kg body weight) in ten hypertensive patients was 45.2 (normal 39.5) on an average, and the average value of Ke in 14 of these cases was 32,5 (normal 42.7). The ratio of intracellular concentration K/Na was 1.8 (normal 2.9) and the ratio of intra- and extracellular potassium concentrations was 26.6 (normal 28.4) on an average. It was therefore considered that in these, patients potassium was excreted from the urine by an increase in K- clearance and its content was thus decreased in the total body. In two cases Of primary aldosteronism, one case with paralytic attacks had an increased value (37.2) of this potassium concentration ratio and the other case without paralytic attack had a normal value (29.5). In another two patients with non-familial periodic paralysis, this concentration ratio of extra- and intracellular potassium was 42.8 and 48.7 respectively, during the induced attack, while potassium excretion in the urine was not increased. It was demonstrated that transmineralization had developed from extra- into intracellular fluids. When a complete or incomplete paralysis was induced by glucose and insulin in five out of eight patients with a paralytic history, this concentration ratio was over 38.0 during each attack. It was also disclosed that an increase in this value was correlated with the severity of the paralysis. The pathogenesis of paralysis therefore seems to be due to the difference in intra

  17. Effect of Intravenous Small-Volume Hypertonic Sodium Bicarbonate, Sodium Chloride, and Glucose Solutions in Decreasing Plasma Potassium Concentration in Hyperkalemic Neonatal Calves with Diarrhea.

    Science.gov (United States)

    Trefz, F M; Constable, P D; Lorenz, I

    2017-05-01

    Hyperkalemia is a frequently observed electrolyte imbalance in dehydrated neonatal diarrheic calves that can result in skeletal muscle weakness and life-threatening cardiac conduction abnormalities and arrhythmias. Intravenous administration of a small-volume hypertonic NaHCO 3 solution is clinically more effective in decreasing the plasma potassium concentration (cK) in hyperkalemic diarrheic calves than hypertonic NaCl or glucose solutions. Twenty-two neonatal diarrheic calves with cK >5.8 mmol/L. Prospective randomized clinical trial. Calves randomly received either 8.4% NaHCO 3 (6.4 mL/kg BW; n = 7), 7.5% NaCl (5 mL/kg BW; n = 8), or 46.2% glucose (5 mL/kg BW; n = 7) IV over 5 minutes and were subsequently allowed to suckle 2 L of an electrolyte solution. Infusions with NaHCO 3 and NaCl provided an identical sodium load of 6.4 mmol/kg BW. Hypertonic NaHCO 3 infusions produced an immediate and sustained decrease in plasma cK. Hypertonic glucose infusions resulted in marked hyperglycemia and hyperinsulinemia, but cK remained unchanged for 20 minutes. Between 30 and 120 minutes after initiation of treatment, the most marked decrements in cK from baseline occurred in group NaHCO 3 , which were significantly (P < .05) larger during this period of time than in calves in group NaCl, but not group glucose. After 120 minutes, the mean decrease in cK from baseline was -26 ± 10%, -9 ± 8%, and -22 ± 6% in groups NaHCO 3 , NaCl, and glucose, respectively. Small-volume hypertonic NaHCO 3 infusions appear to have clinical advantages for the rapid resuscitation of hyperkalemic diarrheic calves, compared to hypertonic NaCl or glucose solutions. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  18. Chronic potassium depletion increases adrenal progesterone production that is necessary for efficient renal retention of potassium.

    Science.gov (United States)

    Elabida, Boutaïna; Edwards, Aurélie; Salhi, Amel; Azroyan, Anie; Fodstad, Heidi; Meneton, Pierre; Doucet, Alain; Bloch-Faure, May; Crambert, Gilles

    2011-08-01

    Modern dietary habits are characterized by high-sodium and low-potassium intakes, each of which was correlated with a higher risk for hypertension. In this study, we examined whether long-term variations in the intake of sodium and potassium induce lasting changes in the plasma concentration of circulating steroids by developing a mathematical model of steroidogenesis in mice. One finding of this model was that mice increase their plasma progesterone levels specifically in response to potassium depletion. This prediction was confirmed by measurements in both male mice and men. Further investigation showed that progesterone regulates renal potassium handling both in males and females under potassium restriction, independent of its role in reproduction. The increase in progesterone production by male mice was time dependent and correlated with decreased urinary potassium content. The progesterone-dependent ability to efficiently retain potassium was because of an RU486 (a progesterone receptor antagonist)-sensitive stimulation of the colonic hydrogen, potassium-ATPase (known as the non-gastric or hydrogen, potassium-ATPase type 2) in the kidney. Thus, in males, a specific progesterone concentration profile induced by chronic potassium restriction regulates potassium balance.

  19. Determination of the sodium, aluminium, potassium, manganese, magnesium, bromine, cadmium and chlorine concentration values in the whole blood samples of human cancer using neutron activation analysis facility of the second Egyptian research reactor

    Directory of Open Access Journals (Sweden)

    N. F. Soliman

    2010-06-01

    Full Text Available Neutron activation analysis (NAA using the Second Egyptian Research Reactor (ETRR-2 has been utilized to analyze whole blood samples. The National Cancer Institute of Egypt provided us with 18 blood samples (11 breast, 2 prostate, 2 colon, 1 pancreatic, 1 ovarian and a random sample of normal person to estimate the concentration values of Sodium, Aluminium, Potassium, Manganese, Magnesium, Bromine, Chlorine. The pneumatic irradiation rabbit system (PIRS built in the vertical thermal column of the ETRR-2 reactor is used for short time irradiation at constant power. Elemental concentrations were estimated from measurements of the gamma-ray spectra of the product short lived isotopes in the samples. The calculated thermal to epithermal neutron flux ratio was found to be 196 at irradiation position. The tabulated concentrations were calculated by using k0-neutron activation analysis (k0NAA standardization method.

  20. Extracellular adenosine 5'-triphosphate concentrations changes in rat spinal cord associated with the activation of urinary bladder afferents. A microdialysis study.

    Science.gov (United States)

    Rocha, Jeová Nina

    2016-01-01

    To determine adenosine 5'-triphosphate levels in the interstice of spinal cord L6-S1 segment, under basal conditions or during mechanical and chemical activation of urinary bladder afferents. A microdialysis probe was transversally implanted in the dorsal half of spinal cord L6-S1 segment in female rats. Microdialysate was collected at 15 minutes intervals during 135 minutes, in anesthetized animals. Adenosine 5'-triphosphate concentrations were determined with a bioluminescent assay. In one group of animals (n=7) microdialysate samples were obtained with an empty bladder during a 10-minutes bladder distension to 20 or 40cmH2O with either saline, saline with acetic acid or saline with capsaicin. In another group of animals (n=6) bladder distention was performed and the microdialysis solution contained the ectonucleotidase inhibitor ARL 67156. Basal extracellular adenosine triphosphate levels were 110.9±35.34fmol/15 minutes, (mean±SEM, n=13), and bladder distention was associated with a significant increase in adenosine 5'-triphosphate levels which was not observed after bladder distention with saline solution containing capsaicin (10µM). Microdialysis with solution containing ARL 67156 (1mM) was associated with significantly higher extracellular adenosine 5'-triphosphate levels and no further increase in adenosine 5'-triphosphate was observed during bladder distension. Adenosine 5'-triphosphate was present in the interstice of L6-S1 spinal cord segments, was degraded by ectonucleotidase, and its concentration increased following the activation of bladder mechanosensitive but not of the chemosensitive afferents fibers. Adenosine 5'-triphosphate may originate either from the central endings of bladder mechanosensitive primary afferent neurons, or most likely from intrinsic spinal neurons, or glial cells and its release appears to be modulated by capsaicin activated bladder primary afferent or by adenosine 5'-triphosphate itself. Determinar as concentra

  1. Extracellular KCl effect on organic bound tritium in human cells

    International Nuclear Information System (INIS)

    Gonen, Rafi; Uzi, German; Priel, Esther; Alfassi, Zeev B.

    2008-01-01

    Tritium atoms can replace hydrogen atoms in organic compounds, forming Organic Bound Tritium. Therefore, exposure of the body to tritium may lead to binding of tritium in tissue molecules, retaining it in the body longer than HTO, and causing higher doses. Ignoring this effect when evaluating inner exposures, may lead to under-estimation of tritium exposures. It was published, that tritium bound to some organic molecules has the potential to accumulate in organisms at higher levels as in the surrounding media. In order to investigate this effect and to identify physiological factors, OBT production in human malignant MG-63 osteoblast cells was studied. The purpose of the present work was to investigate the influence of the ionic extracellular potassium concentration on the amount of tritium in cells. Potassium is known as an ionic compound present in the body, which has the potential to cause cells swelling. Therefore, cells were exposed to isotonic and hypotonic media, supplemented with different concentrations of KCl, and the tritium accumulations were determined after incubation with HTO. An increase in the total Organic Bound Tritium production was observed, as well as an increase of the intracellular HTO content when increasing the KCl concentration. (author)

  2. Phosphatidic acid accumulation and catecholamine release in adrenal chromaffin cells: stimulation by high potassium and by nicotine, and effect of a diacylglycerol kinase inhibitor R 59 022.

    Science.gov (United States)

    Owen, P J; Jones, J A; Boarder, M R

    1991-09-01

    Using primary cultures of bovine adrenal chromaffin cells labelled with 32Pi, we show that stimulation with bradykinin, nicotine, or a depolarising concentration of potassium stimulates the accumulation of [32P]phosphatidic acid. The effects of nicotine and potassium are smaller than the effect of bradykinin, and are dependent entirely on extracellular calcium. The diacylglycerol kinase inhibitor R 59 022 attenuates the formation of phosphatidic acid by nicotine and depolarising concentrations of potassium. This inhibitor also blocks the nicotine and potassium stimulation of noradrenaline release from chromaffin cells. Using 45Ca2+ influx studies, we show that the nicotine-evoked calcium influx is also attenuated by R 59 022. These observations contrast with those in another report in which we showed that bradykinin stimulation of either [32P]phosphatidic acid accumulation or noradrenaline release is not affected by R 59 022. It is likely that the calcium influx produced by nicotine and depolarising potassium is blocked by R 59 022 by a mechanism that is independent of its ability to block diacylglycerol kinase. The nicotine- and potassium-stimulated [32P]phosphatidic acid accumulation is a consequence of this calcium influx and presumably reflects calcium activation of either phospholipase C or phospholipase D.

  3. Effects of Long-term Fertilization on Potassium Fixation Capacity in Brown Soil

    Science.gov (United States)

    Li, Na; Guo, Chunlei; Wang, Yue; Gao, Tianyi; Yang, Jinfeng; Han, Xiaori

    2018-01-01

    This study concentrated on the research of features of fixation. The objective of this study was to provide theoretical foundation of rational application of potassium fertilizer along with improving fertilizer availability ratio. A 32 years long-term experiment was conducted to evaluate the effects of fertilizer application on potassium changes and the factors affecting K fixation on brown soil by simulation in laboratory. When the concentration of exogenous potassium was in range of 400∼4000 mg·kg-1, potassium fixation capacity increased along with the rise of concentration of exogenous potassium, whereas K fixation rate reduced; Compared with no-potassium fertilizer, application of potassium fertilizer and organic fertilizer reduced soil potassium fixation capacity. Potassium rate and fixation-release of potassium character in soil should be taken into comprehensive consideration for rational fertilization to maintain or improve soil fertility for increasing potassium fertilizers efficiency in agriculture.

  4. Penicillin V Potassium

    Science.gov (United States)

    Penicillin V potassium is used to treat certain infections caused by bacteria such as pneumonia and other ... heart valves and other symptoms) from coming back. Penicillin V potassium is in a class of medications ...

  5. Patients with HBV-related acute-on-chronic liver failure have increased concentrations of extracellular histones aggravating cellular damage and systemic inflammation.

    Science.gov (United States)

    Li, X; Gou, C; Yao, L; Lei, Z; Gu, T; Ren, F; Wen, T

    2017-01-01

    Acute-on-chronic liver failure (ACLF) is the most common type of liver failure and associated with grave consequences. Systemic inflammation has been linked to its pathogenesis and outcome, but the identifiable triggers are absent. Recently, extracellular histones, especially H4, have been recognized as important mediators of cell damage in various inflammatory conditions. This study aimed to investigate whether extracellular histones have clinical implications in patients with hepatitis B virus (HBV)-related ACLF. One hundred and twelve patients with HBV-related ACLF, 90 patients with chronic hepatitis B, 88 patients with HBV-related liver cirrhosis and 40 healthy volunteers were entered into this study. Plasma histone H4 levels, cytokine profile and clinical data were obtained. Besides, patient's sera were incubated overnight with human L02 hepatocytes or monocytic U937 cells in the presence or absence of antihistone H4 antibody, and cellular damage and cytokine production were evaluated. We found that plasma histone H4 levels were greatly increased in patients with ACLF as compared with chronic hepatitis B, liver cirrhosis and healthy control subjects and were significantly associated with disease severity, systemic inflammation and outcome. Notably, ACLF patients' sera incubation decreased cultured L02 cell integrity and induced profound cytokine production in the supernatant of U937 cells. Antihistone H4 antibody treatment abrogated these adverse effects, thus confirming a cause-effect relationship between extracellular histones and organ injury/dysfunction. The data support the hypothesis that the increased extracellular histone levels in ACLF patients may aggravate disease severity by inducing cellular injury and systemic inflammation. Histone-targeted therapies may have potentially interventional value in clinical practice. © 2016 John Wiley & Sons Ltd.

  6. KV7 potassium channels

    DEFF Research Database (Denmark)

    Stott, Jennifer B; Jepps, Thomas Andrew; Greenwood, Iain A

    2014-01-01

    Potassium channels are key regulators of smooth muscle tone, with increases in activity resulting in hyperpolarisation of the cell membrane, which acts to oppose vasoconstriction. Several potassium channels exist within smooth muscle, but the KV7 family of voltage-gated potassium channels have been...

  7. Potassium fluorotitanate preparation

    International Nuclear Information System (INIS)

    Perillo, Patricia; Ares, Osvaldo; Botbol, Jose.

    1989-01-01

    In order to determine the best conditions for potassium fluotitanate preparation as intermediate step in the electrolytic production of metalic titanium, the effects of a number of experimental variables have been studied. This method is a process of sintering titanium dioxide with potassium fluosilicate and potassium chloride, followed by leaching with boiling water and further crystallization by cooling the solution. An overall yield of 90% has been attained under the following conditions: working temperature: 750 deg C; heating time for sintering: 3 hours; molar ratio: titanium dioxide: potassium fluosilicate: potassium chloride: 1 : 2 : 0.4; number of leachings: 6. (Author) [es

  8. Influence of drainage and nutrient-solution nitrogen and potassium concentrations on the agronomic behavior of bell-pepper plants cultivated in a substrate.

    Science.gov (United States)

    Wamser, Anderson Fernando; Cecilio Filho, Arthur Bernardes; Nowaki, Rodrigo Hiyoshi Dalmazzo; Mendoza-Cortez, Juan Waldir; Urrestarazu, Miguel

    2017-01-01

    The interactive effects of N (6, 9, 12 and 15 mmol L-1) and K (3, 5, 7, and 9 mmol L-1) concentrations in nutrient solutions were evaluated on bell pepper grown in a coconut-coir substrate and fertilized without drainage. An additional treatment with drainage was evaluated using N and K concentrations of 12 and 7 mmol L-1, respectively. The hybrid Eppo cultivar of yellow bell pepper was cultivated for 252 days beginning 9 November 2012. Electrical conductivity (EC), the N and K concentrations in the substrate solution, marketable fruit yield, total dry weight and macronutrient concentrations in shoots were periodically evaluated. Fruit production was lower in the system without drainage, regardless of the N and K concentrations, compared to the recommended 10-20% drainage of the volume of nutrient solution applied. Higher K concentrations in the nutrient solution did not affect plant production in the system without drainage for the substrate with an initial K concentration of 331.3 mg L-1. Fruit yield was higher without drainage at a nutrient-solution N concentration of 10.7 mmol L-1. The upper EC limit of the substrate solution in the system without drainage was exceeded 181 days after planting. Either lower nutrient concentrations in the nutrient solution or a drainage system could thus control the EC in the substrate solution.

  9. Firing patterns and synchronization in nonsynaptic epileptiform activity: the effect of gap junctions modulated by potassium accumulation

    International Nuclear Information System (INIS)

    Santos, D O C; Dickman, R; Rodrigues, A M; De Almeida, A C G

    2009-01-01

    Several lines of evidence point to the modification of firing patterns and of synchronization due to gap junctions (GJs) as having a role in the establishment of epileptiform activity (EA). However, previous studies consider GJs as ohmic resistors, ignoring the effects of intense variations in ionic concentration known to occur during seizures. In addition to GJs, extracellular potassium is regarded as a further important factor involved in seizure initiation and sustainment. To analyze how these two mechanisms act together to shape firing and synchronization, we use a detailed computational model for in vitro high-K + and low-Ca 2+ nonsynaptic EA. The model permits us to explore the modulation of electrotonic interactions under ionic concentration changes caused by electrodiffusion in the extracellular space, altered by tortuosity. In addition, we investigate the special case of null GJ current. Increased electrotonic interaction alters bursts and action potential frequencies, favoring synchronization. The particularities of pattern changes depend on the tortuosity and array size. Extracellular potassium accumulation alone modifies firing and synchronization when the GJ coupling is null

  10. A Comparison of Concentrations of Sodium and Related Nutrients (Potassium, Total Dietary Fiber, Total and Saturated Fat, and Total Sugar) in Private-Label and National Brands of Popular, Sodium-Contributing, Commercially Packaged Foods in the United States.

    Science.gov (United States)

    Ahuja, Jaspreet K C; Pehrsson, Pamela R; Cogswell, Mary

    2017-05-01

    Private-label brands account for about one in four foods sold in US supermarkets. They provide value to consumers due to their low cost. We know of no US studies comparing the nutrition content of private-label products with corresponding national brand products. The objective was to compare concentrations of sodium and related nutrients (potassium, total dietary fiber, total and saturated fat, and total sugar) in popular sodium-contributing, commercially packaged foods by brand type (national or private-label brand). During 2010 to 2014, the Nutrient Data Laboratory of the US Department of Agriculture obtained 1,706 samples of private-label and national brand products from up to 12 locations nationwide and chemically analyzed 937 composites for sodium and related nutrients. The samples came from 61 sodium-contributing, commercially packaged food products for which both private-label and national brands were among the top 75% to 80% of brands for US unit sales. In this post hoc comparative analysis, the authors assigned a variable brand type (national or private label) to each composite and determined mean nutrient contents by brand type overall and by food product and type. The authors tested for significant differences (Pfoods sampled, differences between brand types were not statistically significant for any of the nutrients studied. However, differences in both directions exist for a few individual food products and food categories. Concentrations of sodium and related nutrients (potassium, total dietary fiber, total and saturated fat, and total sugar) do not differ systematically between private-label and national brands, suggesting that brand type is not a consideration for nutritional quality of foods in the United States. The study data provide public health officials with baseline nutrient content by brand type to help focus US sodium-reduction efforts. Published by Elsevier Inc.

  11. Handling of potassium

    International Nuclear Information System (INIS)

    Schwarz, N.; Komurka, M.

    1983-03-01

    As a result for the Fast Breeder Development extensive experience is available worldwide with respect to Sodium technology. Due to the extension of the research program to topping cycles with Potassium as the working medium, test facilities with Potassium have been designed and operated in the Institute of Reactor Safety. The different chemical properties of Sodium and Potassium give rise in new safety concepts and operating procedures. The handling problems of Potassium are described in the light of theoretical properties and own experiences. Selected literature on main safety and operating problems complete this report. (Author) [de

  12. Simultaneous determination of free calcium, magnesium, sodium and potassium ion concentrations in simulated milk ultrafiltrate and reconstituted skim milk using the Donnan Membrane Technique

    NARCIS (Netherlands)

    Gao, R.; Temminghoff, E.J.M.; Leeuwen, van H.P.; Valenberg, van H.J.F.; Eisner, M.D.; Boekel, van M.A.J.S.

    2009-01-01

    This study focused on determination of free Ca2+, Mg2+, Na+ and K+ concentrations in a series of CaCl2 solutions, simulated milk ultrafiltrate and reconstituted skim milk using a recently developed Donnan Membrane Technique (DMT). A calcium ion selective electrode was used to compare the DMT

  13. A note on the manipulation of sodium and potassium concentrations in the rumen of reindeer and the possible effect on digestibility

    Directory of Open Access Journals (Sweden)

    Hans Staaland

    1987-06-01

    Full Text Available Rumen Na+ and K+ concentrations in reindeer were manipulated by introducing 4 M KC1 or 4 M NaCl into the reindeer rumen. A positive correlation was found between salivary and ruminal concentrations of Na+ and K+. Decreased ruminal Na+ concentrations seemed to decrease dry matter digestibility in nylon bags incubated in the rumen.Om manipulering av natrium og kalium konsentrasjoner i vomma hos rein og om de mulige effekter på fordøyeligheten.Abstract in Norwegian / Sammendrag: Na+ og K+ konsentrasjoner i vomma hos rein ble regulert ved å gi reinen 4 M KC1 eller 4 M NaCl direkte i vomma. Det ble funnet en positiv korrelasjon mellom spytt og vomkonsentrasjoner av Na+ og K+. Redusert Na+ konsentrasjon i vomma synes å redusere tørrstoff-fordøyelighet i nylonposer plassert i vomma.Poron pötsin natrium- ja kaliumkonsentraation kokeellisesta mu-uttamisesta ja tämän mahdollisesta vaikutuksesta sulavuuteen.Abstract in Finnish / Yhteenveto: Poron potsin natrium- ja kaliumkonsentraatioita muutettiin antamalla 4 M KC1 tai 4 M NaCl suo-raan potsiin. Syljen ja potsin Na ja K -konsentraatioiden vålillå todettiin positiivinen korrelaatio. Alentunut Na -konsentraatio potsisså nåyttåå våhentåvån kuiva-aineen sulavuutta potsiin sijoitetuissa nailonpusseissa.

  14. Effects of solution concentration and capping agents on the properties of potassium titanyl phosphate noparticles synthesized using a co-precipitation method

    Science.gov (United States)

    Gharibshahian, E.; Jafar Tafershi, M.; Fazli, M.

    2018-05-01

    In this study, KTiOPO4 (KTP) nanoparticles were synthesized using a co-precipitation method. The effects of the solution concentration (M) and capping agents, such as PVA, oxalic acid, glycine, triethanolamine, and L-alanine, on the structural, microstructural, and optical properties of the products were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy. Decreasing the solution concentration decreased the crystallite size from 53.07 nm (for M = 2) to 39.42 nm (for M = 0.5). After applying different capping agents to the sample at the optimum concentration (M = 0.5), the crystallite size decreased again and grains as small as 10.61 nm were obtained. XRD and FTIR analyses indicated the formation of KTP nanoparticles with an orthorhombic structure in all of the samples. The optical band gap increased as the crystallite size decreased. Different morphological patterns such as spherical, needle shaped, polyhedron, and tablet forms were observed in the nanoparticles, which were correlated with the effects of the capping agents employed.

  15. Potassium and Your CKD Diet

    Science.gov (United States)

    ... vegetable in your diet, leach them before using. Leaching is a process by which some potassium can be pulled out ... out of my favorite high-potassium vegetables? The process of leaching will help pull potassium out of some high- ...

  16. Effect of concentrating and exposing the bioluminescent bacteria to the non-luminescent allo-bacterial extracellular products on their luminescence

    Digital Repository Service at National Institute of Oceanography (India)

    Ravindran, J.; Priya, G.G.; Kannapiran, E.

    of cell-cell physical contact will be high. In this study, the physical proximity was artificially enhanced between cells and the effect on luminescence in the concentrated cells in the normal culture medium and in the presence of other non-bacterial cell...

  17. Statistical analysis of the potassium concentration obtained through; Analise estatistica da concentracao de potassio obtida por aerolevantamentos geofisicos em diferentes formacoes geologicas na regiao de Santa Maria, RS

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Joao Eduardo da Silva [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Dept. de Estatistica]. E-mail: jesp61@gmail.com; Silva, Jose Luiz Silverio da; Pires, Carlos Alberto da Fonseca [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Lab. de Hidrogeologia; Strieder, Adelir Jose [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Lab. de Modelagem Geologica e Ambiental

    2007-07-01

    The present work was developed in outcrops of Santa Maria region, southern Brazil, Rio Grande do Sul State. Statistic evaluations were applied in different rock types. The possibility to distinguish different geologic units, sedimentary and volcanic (acid and basic types) by means of the statistic analyses from the use of airborne gamma-ray spectrometry integrating potash radiation emissions data with geological and geochemistry data is discussed. This Project was carried out at 1973 by Geological Survey of Brazil/Companhia de Pesquisas de Recursos Minerais. The Camaqua Project evaluated the behavior of potash concentrations generating XYZ Geosof 1997 format, one grid, thematic map and digital thematic map files from this total area. Using these data base, the integration of statistics analyses in sedimentary formations which belong to the Depressao Central do Rio Grande do Sul and/or to volcanic rocks from Planalto da Serra Geral at the border of Parana Basin was tested. Univariate statistics model was used: the media, the standard media error, and the trust limits were estimated. The Tukey's Test was used in order to compare mean values. The results allowed to create criteria to distinguish geological formations based on their potash content. The back-calibration technique was employed to transform K radiation to percentage. Inside this context it was possible to define characteristic values from radioactive potash emissions and their trust ranges in relation to geologic formations. The potash variable when evaluated in relation to geographic Universal Transverse Mercator coordinates system showed a spatial relation following one polynomial model of second order, with one determination coefficient. The statistica 7.1 software Generalist Linear Models produced by Statistics Department of Federal University of Santa Maria/Brazil was used. (author)

  18. Correlations in distribution and concentration of calcium, copper and iron with zinc in isolated extracellular deposits associated with age-related macular degeneration

    Science.gov (United States)

    Flinn, Jane M; Kakalec, Peter; Tappero, Ryan; Jones, Blair F.; Lengyel, Imre

    2014-01-01

    Zinc (Zn) is abundantly enriched in sub-retinal pigment epithelial (RPE) deposits, the hallmarks of age-related macular degeneration (AMD), and is thought to play a role in the formation of these deposits. However, it is not known whether Zn is the only metal relevant for sub-RPE deposit formation. Because of their involvement in the pathogenesis of AMD, we determined the concentration and distribution of calcium (Ca), iron (Fe) and copper (Cu) and compared these with Zn in isolated and sectioned macular (MSD), equatorial (PHD) and far peripheral (FPD) sub-RPE deposits from an 86 year old donor eye with post mortem diagnosis of early AMD. The sections were mounted on Zn free microscopy slides and analyzed by microprobe synchrotron X-ray fluorescence (μSXRF). Metal concentrations were determined using spiked sectioned sheep brain matrix standards, prepared the same way as the samples. The heterogeneity of metal distributions was examined using pixel by pixel comparison. The orders of metal concentrations were Ca ⋙ Zn > Fe in all three types of deposits but Cu levels were not distinguishable from background values. Zinc and Ca were consistently present in all deposits but reached highest concentration in MSD. Iron was present in some but not all deposits and was especially enriched in FPD. Correlation analysis indicated considerable variation in metal distribution within and between sub-RPE deposits. The results suggest that Zn and Ca are the most likely contributors to deposit formation especially in MSD, the characteristic risk factor for the development of AMD in the human eye.

  19. Potassium Blood Test

    Science.gov (United States)

    ... K. Brunner & Suddarth's Handbook of Laboratory and Diagnostic Tests. 2 nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Potassium, Serum; 426–27 p. Lab ...

  20. High potassium level

    Science.gov (United States)

    ... level is very high, or if you have danger signs, such as changes in an ECG . Emergency ... Seifter JL. Potassium disorders. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine . 25th ed. Philadelphia, PA: ...

  1. Low potassium level

    Science.gov (United States)

    ... treat and prevent low level of potassium. These foods include: Avocados Baked potato Bananas Bran Carrots Cooked lean beef Milk Oranges Peanut butter Peas and beans Salmon Seaweed Spinach Tomatoes Wheat germ

  2. A neuronal lactate uptake inhibitor slows recovery of extracellular ion concentration changes in the hippocampal CA3 region by affecting energy metabolism.

    Science.gov (United States)

    Angamo, Eskedar Ayele; Rösner, Joerg; Liotta, Agustin; Kovács, Richard; Heinemann, Uwe

    2016-11-01

    Astrocyte-derived lactate supports pathologically enhanced neuronal metabolism, but its role under physiological conditions is still a matter of debate. Here, we determined the contribution of astrocytic neuronal lactate shuttle for maintenance of ion homeostasis and energy metabolism. We tested for the effects of α-cyano-4-hydroxycinnamic acid (4-CIN), which could interfere with energy metabolism by blocking monocarboxylate-transporter 2 (MCT2)-mediated neuronal lactate uptake, on evoked potentials, stimulus-induced changes in K + , Na + , Ca 2+ , and oxygen concentrations as well as on changes in flavin adenine dinucleotide (FAD) autofluorescence in the hippocampal area CA3. MCT2 blockade by 4-CIN reduced synaptically evoked but not antidromic population spikes. This effect was dependent on the activation of K ATP channels indicating reduced neuronal ATP synthesis. By contrast, lactate receptor activation by 3,5-dihydroxybenzoic acid (3,5-DHBA) resulted in increased antidromic and orthodromic population spikes suggesting that 4-CIN effects are not mediated by lactate accumulation and subsequent activation of lactate receptors. Recovery kinetics of all ion transients were prolonged and baseline K + concentration became elevated by blockade of lactate uptake. Lactate contributed to oxidative metabolism as both baseline respiration and stimulus-induced changes in Po 2 were decreased, while FAD fluorescence increased likely due to a reduced conversion of FAD into FADH 2 These data suggest that lactate shuttle contributes to regulation of ion homeostatsis and synaptic signaling even in the presence of ample glucose. Copyright © 2016 the American Physiological Society.

  3. Distribuição da concentração de potássio no solo em lisímetros cultivados com amendoim Distribution of the potassium concentration in soil with lysimeters cultivated with peanut

    Directory of Open Access Journals (Sweden)

    Jarbas H Miranda

    2010-04-01

    tensiometers. It was concluded that low incident solar radiation in the two environments with plastic coverings negatively affected peanut's yield; the period that the peanut demands larger amount of potassium happens from 30 to 55 days after sowing; peanut plants did not present nutritional deficiency with a smaller leaching of K+ for the deepest layers of soil; in the lysimeters with plastic covering of 100 and 150 micras occurred a larger concentration of K+ in the soil surface.

  4. Adaptation of Bacillus subtilis to Life at Extreme Potassium Limitation.

    Science.gov (United States)

    Gundlach, Jan; Herzberg, Christina; Hertel, Dietrich; Thürmer, Andrea; Daniel, Rolf; Link, Hannes; Stülke, Jörg

    2017-07-05

    Potassium is the most abundant metal ion in every living cell. This ion is essential due to its requirement for the activity of the ribosome and many enzymes but also because of its role in buffering the negative charge of nucleic acids. As the external concentrations of potassium are usually low, efficient uptake and intracellular enrichment of the ion is necessary. The Gram-positive bacterium Bacillus subtilis possesses three transporters for potassium, KtrAB, KtrCD, and the recently discovered KimA. In the absence of the high-affinity transporters KtrAB and KimA, the bacteria were unable to grow at low potassium concentrations. However, we observed the appearance of suppressor mutants that were able to overcome the potassium limitation. All these suppressor mutations affected amino acid metabolism, particularly arginine biosynthesis. In the mutants, the intracellular levels of ornithine, citrulline, and arginine were strongly increased, suggesting that these amino acids can partially substitute for potassium. This was confirmed by the observation that the supplementation with positively charged amino acids allows growth of B. subtilis even at the extreme potassium limitation that the bacteria experience if no potassium is added to the medium. In addition, a second class of suppressor mutations allowed growth at extreme potassium limitation. These mutations result in increased expression of KtrAB, the potassium transporter with the highest affinity and therefore allow the acquisition and accumulation of the smallest amounts of potassium ions from the environment. IMPORTANCE Potassium is essential for every living cell as it is required for the activity for many enzymes and for maintaining the intracellular pH by buffering the negative charge of the nucleic acids. We have studied the adaptation of the soil bacterium Bacillus subtilis to life at low potassium concentrations. If the major high-affinity transporters are missing, the bacteria are unable to grow

  5. Spectroscopic Characterization of Extracellular Polymeric Substances from Escherichia coli and Serratia marcescens: Suppression using Sub-Inhibitory Concentrations of Bismuth Thiols

    Energy Technology Data Exchange (ETDEWEB)

    Badireddy, Appala R.; Korpol, Bhoom Reddy; Chellam, Shankararaman; Gassman, Paul L.; Engelhard, Mark H.; Lea, Alan S.; Rosso, Kevin M.

    2008-10-21

    Free and capsular EPS produced by Escherichia coli and Serratia marcescens were characterized in detail using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES). Total EPS production decreased upon treatment with sub-inhibitory concentrations of lipophilic bismuth thiols (bismuth dimercaptopropanol, BisBAL; bismuth ethanedithiol, BisEDT; and bismuth pyrithione, BisPYR), BisBAL being most effective. Bismuth thiols also influenced acetylation and carboxylation of polysaccharides in EPS from S. marcescens. Extensive homology between EPS samples in the presence and absence of bismuth was observed with proteins, polysaccharides, and nucleic acids varying predominantly only in the total amount expressed. Second derivative analysis of the amide I region of FTIR spectra revealed decreases in protein secondary structures in the presence of bismuth thiols. Hence, anti-fouling properties of bismuth thiols appear to originate in their ability to suppress O-acetylation and protein secondary structures in addition to total EPS secretion.

  6. Potassium sorbate-A new aqueous copper corrosion inhibitor

    International Nuclear Information System (INIS)

    Abelev, Esta; Starosvetsky, David; Ein-Eli, Yair

    2007-01-01

    This work presents the novel nature of 2,4-hexadienoic acid potassium salt (potassium sorbate (KCH 3 CH=CHCH=CHCO 2 )) as an effective copper aqueous corrosion inhibitor. The influence of pH and potassium sorbate concentration on copper corrosion in aerated sulfate and chloride solutions is reported. Degree of copper protection was found to increase with an increase in potassium sorbate concentration; an optimum concentration of this inhibitor in sulfate solutions was found to be 10 g/L. Copper is highly resistant to corrosion attacks by chloride ions in the presence of potassium sorbate. X-ray photoelectron spectroscopy (XPS) studies suggest that copper protection is achieved via the formation of a mixed layer of cuprous oxide, cupric hydroxide and copper(II)-sorbate at the metal surface

  7. 腹膜透析和血液透析对尿毒症患者血钾的影响%Effects of peritoneal dialysis and hemodialysis on blood potassium concentrations in patients with uremia

    Institute of Scientific and Technical Information of China (English)

    林明增; 范佳妮; 陈霄峰; 陈文芬

    2014-01-01

    目的:探讨血液透析与腹膜透析对尿毒症患者血钾的影响。方法对97例血液透析及45例腹膜透析均治疗3个月以上的患者进行血钾、血钠、血氯测定和比较,并调查当月患者的尿量及住院情况。结果腹膜透析组的低钾、低钠、低氯血症发生率分别为20.0%、15.6%、37.8%,而血液透析组分别为2.1%、4.1%、16.5%,两组差异有统计学意义(P<0.05)。血液透析组的高钾血症发生率为28.9%,而腹膜透析组为11.1%,两组差异有统计学意义(P<0.05)。血液透析组患者的血钾、血氯分别为(5.076±1.093)、(99.660±3.889)mmol/L ,腹膜透析组分别为(4.435±0.99)、(96.910±3.646)mmol/L ,两组差异均有统计学意义(均P<0.05)。尿量>500ml者腹膜透析组占55.6%,血液透析组占6.2%,两组差异有统计学意义(P<0.05)。两组患者住院率的差异无统计学意义(P>0.05)。结论腹膜透析组低钾血症发生率高,血液透析组的高钾血症发生率高,需要对不同透析方式的患者饮食状况进行相应的指导,不能忽视患者在使用一些药物时对血钾异常可能产生的影响。%Objective To investigate the effects of peritoneal dialysis and hemodialysis on blood potassium concentration in patients with uremia. Methods The levels of serum potassium, sodium and chloride were measured in 45 uremic patients un-dergoing peritoneal dialysis and 97 patients undergoing hemodialysis for more than three months. In addition, the urine output and hospitalization of patients were also documented. Results The incidence rate of hypokalemia, hyponatremia and low chlo-rine in peritoneal dialysis group was 20.0%, 15.6%and 37.8%;and in peritoneal dialysis group was 2.1%, 4.1%, 16.5%respec-tively (P500ml in peritoneal dialysis and hemodialysis groups accounted for 55.6% and 6.2%, respectively (P<0.05). These was no difference in hospitalization between two

  8. Extracellular DNA metabolism in Haloferax volcanii

    Directory of Open Access Journals (Sweden)

    Scott eChimileski

    2014-02-01

    Full Text Available Extracellular DNA is found in all environments and is a dynamic component of the micro-bial ecosystem. Microbial cells produce and interact with extracellular DNA through many endogenous mechanisms. Extracellular DNA is processed and internalized for use as genetic information and as a major source of macronutrients, and plays several key roles within prokaryotic biofilms. Hypersaline sites contain some of the highest extracellular DNA con-centrations measured in nature–a potential rich source of carbon, nitrogen and phosphorus for halophilic microorganisms. We conducted DNA growth studies for the halophilic archaeon Haloferax volcanii DS2 and show that this model Halobacteriales strain is capable of using exogenous double-stranded DNA as a nutrient. Further experiments with varying medium composition, DNA concentration and DNA types revealed that DNA is utilized primarily as a phosphorus source, that growth on DNA is concentration-dependent and that DNA isolated from different sources is metabolized selectively, with a bias against highly divergent methylated DNA sources. Additionally, fluorescence microscopy experiments showed that labeled DNA colocalized with Haloferax volcanii cells. The gene Hvo_1477 was also identified using a comparative genomic approach as a factor likely to be involved in extracellular DNA processing at the cell surface, and deletion of Hvo_1477 created an H. volcanii strain deficient in its ability to grow on extracellular DNA. Widespread distribution of Hvo_1477 homologs in archaea suggests metabolism of extracellular DNA may be of broad ecological and physiological relevance in this domain of life.

  9. Regulation of extrarenal potassium homeostasis by adrenal hormones in rats.

    Science.gov (United States)

    Bia, M J; Tyler, K A; DeFronzo, R A

    1982-06-01

    The effect of chronic (7-10 days) adrenal insufficiency on extrarenal potassium tolerance was examined by infusing potassium into rats after acute nephrectomy. The increment in plasma potassium concentration was significantly higher in glucocorticoid-replaced adrenalectomized rats versus controls (max delta PK 3.59 +/-0.11 vs. 2.93 +/- 0.08 meq/liter; P less than 0.001). The impairment in extrarenal potassium tolerance in adrenalectomized rats could not be attributed to acidemia, hypotension, changes in plasma insulin or glucose concentration, or potassium retention prior to study. Acute replacement with aldosterone resulted in significant improvement in the rise in plasma potassium after KCl (max delta PK 3.18 +/- 0.06 meq/liter; P less than 0.005 compared with aldosterone-deficient adrenalectomized rats but higher than in controls, P less than 0.02). If given on a chronic basis, aldosterone replacement led to a complete correction of the defect (max delta PK = 2.89 +/- 0.08 meq/liter). Acute epinephrine replacement in adrenalectomized rats also returned potassium tolerance to normal (max delta PK = 3.02 +/- 0.10 meq/liter). The results demonstrate that extrarenal potassium tolerance is impaired in chronic adrenal insufficiency and suggest that both aldosterone and epinephrine deficiency may contribute to the defect, since replacement with either hormone returns potassium tolerance toward normal. Accordingly, both aldosterone and epinephrine have important extrarenal mechanisms of action.

  10. Plasma extracellular superoxide dismutase concentration, allelic variations in the SOD3 gene and risk of myocardial infarction and all-cause mortality in people with type 1 and type 2 diabetes.

    Science.gov (United States)

    Mohammedi, Kamel; Bellili-Muñoz, Naïma; Marklund, Stefan L; Driss, Fathi; Le Nagard, Hervé; Patente, Thiago A; Fumeron, Frédéric; Roussel, Ronan; Hadjadj, Samy; Marre, Michel; Velho, Gilberto

    2015-01-15

    Oxidative stress is involved in development of diabetes complications. Extracellular superoxide dismutase (EC-SOD, SOD3) is a major extracellular antioxidant enzyme and is highly expressed in arterial walls. Advanced oxidation protein products (AOPP) and 8-iso-prostaglandin (isoprostane) are markers of oxidative stress. We investigated association of SOD3 gene variants, plasma concentrations of EC-SOD, AOPP and isoprostane with myocardial infarction and mortality in diabetic patients. We studied three cohorts designed to evaluate the vascular complications of diabetes: the GENEDIAB study (469 participants with type 1 diabetes at baseline; follow-up data for 259 participants), the GENESIS study (603 participants with type 1 diabetes at baseline; follow-up data for 525 participants) and the DIABHYCAR study (3137 participants with type 2 diabetes at baseline and follow-up). Duration of follow-up was 9, 5, and 5 years, respectively. Main outcome measures were incidence of myocardial infarction, and cardiovascular and total mortality during follow-up. Six single nucleotide polymorphisms in the SOD3 locus were genotyped in the three cohorts. Plasma concentrations of EC-SOD, AOPP, and isoprostane were measured in baseline samples of GENEDIAB participants. In GENEDIAB/GENESIS pooled cohorts, the minor T-allele of rs2284659 variant was inversely associated with the prevalence at baseline (Odds Ratio 0.48, 95% CI 0.29-0.78, p = 0.004) and the incidence during follow-up of myocardial infarction (Hazard Ratio 0.58, 95% CI 0.40-0.83, p = 0.003) and with cardiovascular (HR 0.33, 95% CI 0.08-0.74, p = 0.004) and all-cause mortality (HR 0.44, 95% CI 0.21-0.73, p = 0.0006). The protective allele was associated with higher plasma EC-SOD and lower plasma AOPP concentrations in GENEDIAB. It was also inversely associated with incidence of myocardial infarction (HR 0.75, 95% CI 0.59-0.94, p = 0.01) and all-cause mortality (HR 0.87, 95% CI 0.79-0.97, p = 0

  11. Comparative effect of Prunus persica L. BATSCH-water extract and tacrine (9-amino-1,2,3,4-tetrahydroacridine hydrochloride) on concentration of extracellular acetylcholine in the rat hippocampus.

    Science.gov (United States)

    Kim, Yeon-Kye; Koo, Byung-Soo; Gong, Dae-Jong; Lee, Young-Choon; Ko, Jeong-Heon; Kim, Cheorl-Ho

    2003-08-01

    Prunus persica L. BATSCH seed-water extract (PPE) has been used in the treatment of the degenerative disorders, such as hypermenorrhea and dysmenorrhea, in Taiwan, China, Japan and Korea. In this study, the effects of oral administration of PPE on the extracellular acetylcholine concentration in the hippocampus of rats were evaluated, and compared to that of tacrine (9-amino-1,2,3,4-tetrahydroacridine hydrochloride), a well-known and centrally acting acetylcholinesterase (AChE) inhibitor, which had been developed for the treatment of Alzheimer's disease. We measured the inhibition of brain AChE. PPE at 2.5g/kg and tacrine at 5mg/kg showed significant effects for more than 6h. At these doses, the maximum increases were observed at about 1.5h after administration of PPE, and at about 2h with tacrine, and were 454 and 412% of the pre-level, respectively. The results suggest that oral administration of PPE and tacrine increases acetylcholine concentration in the synaptic cleft of the hippocampus mostly through AChE inhibition, and that PPE has a potent and long-lasting effect on the central cholinergic system.

  12. Transport and concentration controls for chloride, strontium, potassium and lead in Uvas Creek, a small cobble-bed stream in Santa Clara County, California, U.S.A. 1. Conceptual model

    Science.gov (United States)

    Kennedy, V.C.; Jackman, A.P.; Zand, S.M.; Zellweger, G.W.; Avanzino, R.J.

    1984-01-01

    Stream sediments adsorb certain solutes from streams, thereby significantly changing the solute composition; but little is known about the details and rates of these adsorptive processes. To investigate such processes, a 24-hr. injection of a solution containing chloride, strontium, potassium, sodium and lead was made at the head of a 640-m reach of Uvas Creek in west-central Santa Clara County, California. Uvas Creek is a cobble-bed pool-and-riffle stream draining the eastern slopes of the Santa Cruz Mountains. By September 12, 1973, after a long dry season, Uvas Creek had a low (0.0215 m3s-1 average) flow which varied diurnally, from 0.018 to 0.025 m3s-1. Because stream discharge varied while the injection rate was constant, the concentration of tracers (injected solutes), after mixing in the stream, varied inversely with discharge. Chloride, a nonreactive solute, served as a tracer of water movement. Analysis of extensive chloride concentration data at five sites below the injection point during and after the injection demonstrated that there was considerable underflow of water through the stream gravels; however, the extent of underflow varied greatly within the study reach. Pre-injection water, displaced by tracer-laden water percolating through the gravels, diluted tracers in the stream channel, giving the mistaken impression of groundwater inflow at some points. Accurate measurement of total discharge in such streams requires prolonged tracer injection unless a reach can be found where underflow is negligible. Strontium and potassium were adsorbed by the bed sediments to a moderate extent and lead was strongly adsorbed. A high proportion of these metals could be removed by adsorption from percolating underflow because of extensive and intimate contact with bed sediments. After channel clearing following injection cutoff, 51% of the added strontium and 96% of the lead remained in the study reach, whereas only 19% of the chloride remained. Packets of sized

  13. Potassium sensing histidine kinase in Bacillus subtilis.

    Science.gov (United States)

    López, Daniel; Gontang, Erin A; Kolter, Roberto

    2010-01-01

    The soil-dwelling organism Bacillus subtilis is able to form multicellular aggregates known as biofilms. It was recently reported that the process of biofilm formation is activated in response to the presence of various, structurally diverse small-molecule natural products. All of these small-molecule natural products made pores in the membrane of the bacterium, causing the leakage of potassium cations from the cytoplasm of the cell. The potassium cation leakage was sensed by the membrane histidine kinase KinC, triggering the genetic pathway to the production of the extracellular matrix that holds cells within the biofilm. This chapter presents the methodology used to characterize the leakage of cytoplasmic potassium as the signal that induces biofilm formation in B. subtilis via activation of KinC. Development of novel techniques to monitor activation of gene expression in microbial populations led us to discover the differentiation of a subpopulation of cells specialized to produce the matrix that holds all cells together within the biofilm. This phenomenon of cell differentiation was previously missed by conventional techniques used to monitor transcriptional gene expression. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. Errors in potassium balance

    International Nuclear Information System (INIS)

    Forbes, G.B.; Lantigua, R.; Amatruda, J.M.; Lockwood, D.H.

    1981-01-01

    Six overweight adult subjects given a low calorie diet containing adequate amounts of nitrogen but subnormal amounts of potassium (K) were observed on the Clinical Research Center for periods of 29 to 40 days. Metabolic balance of potassium was measured together with frequent assays of total body K by 40 K counting. Metabolic K balance underestimated body K losses by 11 to 87% (average 43%): the intersubject variability is such as to preclude the use of a single correction value for unmeasured losses in K balance studies

  15. The Trk Potassium Transporter Is Required for RsmB-Mediated Activation of Virulence in the Phytopathogen Pectobacterium wasabiae.

    Science.gov (United States)

    Valente, Rita S; Xavier, Karina B

    2016-01-15

    Pectobacterium wasabiae (previously known as Erwinia carotovora) is an important plant pathogen that regulates the production of plant cell wall-degrading enzymes through an N-acyl homoserine lactone-based quorum sensing system and through the GacS/GacA two-component system (also known as ExpS/ExpA). At high cell density, activation of GacS/GacA induces the expression of RsmB, a noncoding RNA that is essential for the activation of virulence in this bacterium. A genetic screen to identify regulators of RsmB revealed that mutants defective in components of a putative Trk potassium transporter (trkH and trkA) had decreased rsmB expression. Further analysis of these mutants showed that changes in potassium concentration influenced rsmB expression and consequent tissue damage in potato tubers and that this regulation required an intact Trk system. Regulation of rsmB expression by potassium via the Trk system occurred even in the absence of the GacS/GacA system, demonstrating that these systems act independently and are both required for full activation of RsmB and for the downstream induction of virulence in potato infection assays. Overall, our results identified potassium as an essential environmental factor regulating the Rsm system, and the consequent induction of virulence, in the plant pathogen P. wasabiae. Crop losses from bacterial diseases caused by pectolytic bacteria are a major problem in agriculture. By studying the regulatory pathways involved in controlling the expression of plant cell wall-degrading enzymes in Pectobacterium wasabiae, we showed that the Trk potassium transport system plays an important role in the regulation of these pathways. The data presented further identify potassium as an important environmental factor in the regulation of virulence in this plant pathogen. We showed that a reduction in virulence can be achieved by increasing the extracellular concentration of potassium. Therefore, this work highlights how elucidation of the

  16. Transmission spectra study of sulfate substituted potassium dihydrogen phosphate

    KAUST Repository

    LI, LIANG; Zhang, Jianqin; Sun, Xun; Zhang, Qiang; Zhao, Xian; Zhang, Xixiang

    2013-01-01

    Potassium dihydrogen phosphate (KDP) crystals with different amounts of sulfate concentration were grown and the transmittance spectrum was studied. A crystal with high sulfate replacement density exhibits heavy absorption property

  17. Inhibition of large conductance calcium-dependent potassium ...

    African Journals Online (AJOL)

    conductance, calcium and voltage- dependent potassium (BKCa) channels thereby promoting vasoconstriction. Our results show that the Rho-kinase inhibitor, Y-27632, induced concentration-dependent relaxation in rat mesenteric artery.

  18. Integrated process using non-stoichiometric sulfides or oxides of potassium for making less active metals and hydrocarbons

    International Nuclear Information System (INIS)

    Swanson, R.

    1984-01-01

    Disclosed is a combinative integrated chemical process using inorganic reactants and yielding, if desired, organic products. The process involves first the production of elemental potassium by the thermal or thermal-reduced pressure decomposition of potassium oxide or potassium sulfide and distillation of the potassium. This elemental potassium is then used to reduce ores or ore concentrates of copper, zinc, lead, magnesium, cadmium, iron, arsenic, antimony or silver to yield one or more of these less active metals in elemental form. Process potassium can also be used to produce hydrogen by reaction with water or potassium hydroxide. This hydrogen is reacted with potassium to produce potassium hydride. Heating the latter with carbon produces potassium acetylide which forms acetylene when treated with water. Acetylene is hydrogenated to ethene or ethane with process hydrogen. Using Wurtz-Fittig reaction conditions, the ethane can be upgraded to a mixture of hydrocarbons boiling in the fuel range

  19. Impacts of limestone and nitrogen top dressing application on the potassium content in the soil profile and marandu-grass leaf concentration Impactos da aplicação de calcário e nitrogênio em cobertura no teor de potássio no perfil do solo e na concentração foliar do capim-marandu

    Directory of Open Access Journals (Sweden)

    Geraldo Balieiro Neto

    2009-07-01

    Full Text Available The objective of this experiment was to evaluate the effects of nitrogen doses (0, 100, 200, 300, and 400 kg ha-1 year-1, with or without dolomitic lime covering application, on the potassium (K soil content at depths varying form 0 to 5, 5 to 10, and 10 to 20 cm, and the potassium concentration in the plant. The experiment was carried out in a rhodic ferralsol with a slightly rolling relief, in a 5 × 2 factorial arrangement, in a complete randomized block design, with four replications. Nitrogenated fertilization caused a linear increase in the potassium concentration in the plant and also in the mineral content in the 0-5 cm soil layer. An effect of competitive inhibition occurred between the potassium and calcium absorption, and potassium and magnesium absorption. Although a significant fraction of potassium returned to the soil surface layer through the forage residue due to the increase in dry matter production caused by nitrogenated fertilization, the increase in the potassium concentration in the plant due to the doses of nitrogen demonstrated the importance of considering the potassium supply to the plant, when the forage mass is intensified through nitrogenated fertilization.Objetivou-se avaliar os efeitos de nitrogênio (0, 100, 200, 300 e 400 kg/ha.ano, com ou sem aplicação de calcário dolomítico em cobertura, sobre o teor de potássio (K do solo nas profundidades de 0 a 5; 5 a 10; e 10 a 20 cm e a concentração de potássio na planta. O experimento foi realizado em Latossolo Vermelho distroférrico de relevo suavemente ondulado, disposto em esquema fatorial 5 × 2, em blocos casualizados, com quatro repetições. A adubação nitrogenada promoveu aumento linear na concentração de potássio na planta e no teor desse mineral na camada de 0 a 5 cm do solo. Ocorreu efeito de inibição competitiva entre a absorção de potássio e cálcio e entre potássio e magnésio. Embora uma fração significativa de potássio retorne

  20. Commensal Bacteria-Induced Inflammasome Activation in Mouse and Human Macrophages Is Dependent on Potassium Efflux but Does Not Require Phagocytosis or Bacterial Viability.

    Directory of Open Access Journals (Sweden)

    Kejie Chen

    Full Text Available Gut commensal bacteria contribute to the pathogenesis of inflammatory bowel disease, in part by activating the inflammasome and inducing secretion of interleukin-1ß (IL-1ß. Although much has been learned about inflammasome activation by bacterial pathogens, little is known about how commensals carry out this process. Accordingly, we investigated the mechanism of inflammasome activation by representative commensal bacteria, the Gram-positive Bifidobacterium longum subspecies infantis and the Gram-negative Bacteroides fragilis. B. infantis and B. fragilis induced IL-1ß secretion by primary mouse bone marrow-derived macrophages after overnight incubation. IL-1ß secretion also occurred in response to heat-killed bacteria and was only partly reduced when phagocytosis was inhibited with cytochalasin D. Similar results were obtained with a wild-type immortalized mouse macrophage cell line but neither B. infantis nor B. fragilis induced IL-1ß secretion in a mouse macrophage line lacking the nucleotide-binding/leucine-rich repeat pyrin domain containing 3 (NLRP3 inflammasome. IL-1ß secretion in response to B. infantis and B. fragilis was significantly reduced when the wild-type macrophage line was treated with inhibitors of potassium efflux, either increased extracellular potassium concentrations or the channel blocker ruthenium red. Both live and heat-killed B. infantis and B. fragilis also induced IL-1ß secretion by human macrophages (differentiated THP-1 cells or primary monocyte-derived macrophages after 4 hours of infection, and the secretion was inhibited by raised extracellular potassium and ruthenium red but not by cytochalasin D. Taken together, our findings indicate that the commensal bacteria B. infantis and B. fragilis activate the NLRP3 inflammasome in both mouse and human macrophages by a mechanism that involves potassium efflux and that does not require bacterial viability or phagocytosis.

  1. MR imaging of intracellular and extracellular deoxyhemoglobin

    International Nuclear Information System (INIS)

    Janick, P.A.; Grossman, R.I.; Asakura, T.

    1989-01-01

    MR imaging was performed on varying concentrations of intracellular and extracellular deoxyhemoglobin as well as varying proportions of deoxyhemoglobin and oxyhemoglobin in vitro at 1.5T with use of standard spin-echo and gradient-refocused spin sequences. This study indicates that susceptibility-induced T2 shortening occurs over a broad range of intracellular deoxyhemoglobin concentrations (maximal at hematocrits between 20% and 45%), reflecting diffusional effects at the cellular level. T2* gradient-echo imaging enhances the observed hypointensity in images of intracellular deoxyhemoglobin. The characteristic MR appearance of acute hemotomas can be modeled by the behavior of intracellular and extracellular deoxyhemoglobin and oxyhemoglobin

  2. Potassium toxicity at low serum potassium levels with refeeding syndrome.

    Science.gov (United States)

    Vemula, Praveen; Abela, Oliver G; Narisetty, Keerthy; Rhine, David; Abela, George S

    2015-01-01

    Refeeding syndrome is a life-threatening condition occurring in severely malnourished patients after initiating feeding. Severe hypophosphatemia with reduced adenosine triphosphate production has been implicated, but little data are available regarding electrolyte abnormalities. In this case, we report electrocardiographic changes consistent with hyperkalemia during potassium replacement after a serum level increase from 1.9 to 2.9 mEq/L. This was reversed by lowering serum potassium back to 2.0 mEq/L. In conclusion, the patient with prolonged malnutrition became adapted to low potassium levels and developed potassium toxicity with replacement. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Concentração de nitrogênio, fósforo e potásiio na parte aérea do feijoeiro em resposta à irrigação, fertirrigação e micronutrientes Concentration of nitrogen, phosphorus and potassium in drybean shoots in response to irrigation, fertirrigation and micronutrients

    Directory of Open Access Journals (Sweden)

    Eder João Pozzebon

    1996-08-01

    Full Text Available Este experimento teve como objetivo avaliar a concentração de nitrogênio, fósforo e potássio na parte aérea do feijoeiro em resposta à irrigação, fertirrigação com nitrogênio parcelado e aplicação de micronutrientes via semente. O experimento foi conduzido a campo em solo Podzólico Vermelho-Amarelo, de textura média, em Santa Maria, RS. Os tratamentos consistiram de combinações do uso de irrigação por aspersão, micronutrientes via semente e modo de aplicação de nitrogênio em cobertura. Os tratamentos com adubação de cobertura convencional receberam o nitrogênio (85kg N ha-1 na forma de uréia granulada aos 12 dias após a emergência. Na fertirrigação usou-se o parcelamento do nitrogênio aos 12, 24 e 30 dias após a emergência. Os micronutrientes foram aplicados numa dosagem de 3,5 g kg ha-1 de sementes de uma formulação de 38% de zinco, 9% de molibdênio, 2% de boro e 0,5% de cobalto. As concentrações de nitrogênio, fósforo e potássio foram determinadas nas folhas, talos e sementes aos 49 e 71 dias após a emergência. A irrigação promoveu maior concentração de nitrogênio, fósforo e potássio nas folhas aos 49 dias após a emergência. Aos 71 dias após a emergência, ocorreram menores concentrações de nitrogênio e fósforo nas folhas e talos para os tratamentos irrigados e nas sementes houve maior concentração de nitrogênio, fósforo e potássio para os tratamentos não irrigados. Não houve efeito do parcelamento do nitrogênio via fertirrigação e aplicação de micronutrientes às sementes sobre a concentração de nitrogênio, fósforo e potássio na parte aérea das plantas.The objective of this study was to evaluate the concentration of nitrogen, phosphorus and potassium in drybean shoots in response to irrigation, fertirrigation with nitrogen and seed micronutrient application. The experiment was conducted on a loam Podzolic soil, in Santa Maria, RS. Treatments with conventional

  4. Behaviour of potassium hexabromoruthenate (4) in solutions

    International Nuclear Information System (INIS)

    Rudnitskaya, O.V.; Miroshnichenko, I.V.; Pichkov, V.N.

    1989-01-01

    Behaviour of potassium hexabromoruthenate in HBr, H 2 O-acetone, dimethylformamide, dimetnylsulfoxide (DMSO) solutions is investigated by means of absorption and ESR specroscopy. Complex is shown to be labile, interacts easily with solvents forming ruthenium complexes in more low oxidation degrees. Hexabromoruthenate-ion is formed in concentrated HBr, while in DMSO the formation of ruthenium (3) and (2) bromide-dimethylsulfoxide complexes occurs gradually, final product is trans-[Ru(DMSO) 4 Br 2

  5. The role of glutathione in DNA damage by potassium bromate in vitro.

    Science.gov (United States)

    Parsons, J L; Chipman, J K

    2000-07-01

    We have investigated the role of reduced glutathione (GSH) in the genetic toxicity of the rodent renal carcinogen potassium bromate (KBrO(3)). A statistically significant increase in the concentration of 8-oxodeoxyguanosine (8-oxodG) relative to deoxyguanosine was measured following incubation of calf thymus DNA with KBrO(3) and GSH or N-acetylcysteine (NACys). This was dependent on these thiols and was associated with the loss of GSH and production of oxidized glutathione. A short-lived (potassium chlorate (KClO(3)) or potassium iodate (KIO(3)) were used instead of KBrO(3), though GSH depletion also occurred with KIO(3), but not with KClO(3). Other reductants and thiols in combination with KBrO(3) did not cause a significant increase in DNA oxidation. DNA strand breakage was also induced by KBrO(3) in human white blood cells (5 mM) and rat kidney epithelial cells (NRK-52E, 1.5 mM). This was associated with an apparent small depletion of thiols in NRK-52E cells at 15 min and with an elevation of 8-oxodG at a delayed time of 24 h. Depletion of intra-cellular GSH by diethylmaleate in human lymphocytes decreased the amount of strand breakage induced by KBrO(3). Extracellular GSH, however, protected against DNA strand breakage by KBrO(3), possibly due to the inability of the reactive product to enter the cell. In contrast, membrane-permeant NACys enhanced KBrO(3)-induced DNA strand breakage in these cells. DNA damage by KBrO(3) is therefore largely dependent on access to intracellular GSH.

  6. Studies in photo chromic behavior of some potassium hexacyanoferrate (2)-dye systems

    International Nuclear Information System (INIS)

    Taneja, Hanshu; Paliwala, Mukesh; Kumara Anil; Singh Sadhana; Ameta, Suresh C.; Ameta, Rameshwar

    2009-01-01

    The photo chromic behavior of potassium hexacyanoferrate (2)-fuchsin basic and potassium hexacyanoferrate (2)-malachite green systems was investigated in detail. The effect of variation of various parameters, like ph, light intensity, concentration of dyes, and concentration of potassium hexacyanoferrate(2), on the rates of forward and backward reactions of these systems has been observed. Based on experimental data, a tentative mechanism has also been proposed. (author)

  7. 21 CFR 184.1619 - Potassium carbonate.

    Science.gov (United States)

    2010-04-01

    ... solution of potassium hydroxide with excess carbon dioxide to produce potassium carbonate; (3) By treating a solution of potassium hydroxide with carbon dioxide to produce potassium bicarbonate, which is... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium carbonate. 184.1619 Section 184.1619 Food...

  8. The effect of potassium nutrition on sup 137 Cs uptake in two upland species

    Energy Technology Data Exchange (ETDEWEB)

    Jones, H E; Harrison, A F; Poskitt, J M; Roberts, J D; Clint, G [Institute for Terrestrial Ecology, Grange-over-Sands (UK)

    1991-01-01

    Agrostis capillaris (Agrostis) and Calluna vulgaris (Calluna), two species with differing phenologies and widespread presence in upland areas of Britain where high Chernobyl fallout occurred, were grown in pot culture with varying concentrations of potassium in the rooting medium. Tissue content of potassium increased with increasing supply in both species. Roots, excised from these plants, were placed in a solution of {sup 137}Cs-labelled caesium chloride for 15 min to determine uptake potential. There were clear negative relationships between the rate of uptake of {sup 137}Cs by both species and (a) the concentration of potassium supplied and (b) plant issue potassium concentrations. With Agrotis, there was an approximately ten-fold difference in {sup 137}Cs uptake between potassium-deficient and optimum plants; with Calluna, it was approximately eight-fold. These results demonstrate the suppression of {sup 137}Cs uptake into plants by potassium supply. (author).

  9. Dietary reference values for potassium

    DEFF Research Database (Denmark)

    Sjödin, Anders Mikael

    2016-01-01

    Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derives dietary reference values (DRVs) for potassium. The Panel decides to set DRVs on the basis of the relationships between potassium intake and blood pressure and stroke...

  10. Can Diuretics Decrease Your Potassium Level?

    Science.gov (United States)

    ... of low potassium? Can diuretics decrease your potassium level? Answers from Sheldon G. Sheps, M.D. Yes, ... your urine. This can lead to low potassium levels in your blood (hypokalemia). Signs and symptoms of ...

  11. Potassium iodide stockpiling

    International Nuclear Information System (INIS)

    Krimm, R.W.

    1983-01-01

    After examination by the Federal Emergency Management Agency (FEMA) and other federal agencies of federal policy on the use and distribution of potassium iodide (KI) as a thyroid-blocking agent for use in off-site preparedness around commercial nuclear powerplants, FEMA believes the present shelf life of KI is too short, that the minimum ordering quantities are an obstacle to efficient procurement, and that the packaging format offered by the drug industry does not meet the wishes of state and local government officials. FEMA has asked assistance from the Food and Drug Administration in making it possible for those states wishing to satisfy appropriate requirements to do so at the minimum cost to the public. Given an appropriate packaging and drug form, there appears to be no reason for the federal government to have further involvement in the stockpiling of KI

  12. Potassium-argon technology

    International Nuclear Information System (INIS)

    Cassignol, Charles; Cornette, Yves; David, Benjamin; Gillot, P.-Y.

    1978-04-01

    The main features of the method of processing rocks and minerals and measuring the extracted argon, for the purpose of potassium-argon dating are described. It differs in several respects from the conventional one, as described, f.i., in Dalrymple and Lanphere's monography. Principally it was established that the continual purification of the gases in the mass spectrometer cell during the measurement, stops the peaks of current drift, and renders them representative of the introduced argon. This allows on the one hand to improve the reliability and accuracy of measurements, on the other hand to get rid of the isotopic dilution method, with 38 A as a spike. Moreover the reliability of the radiogenic argon is improved by taking into account the mislinearness of the M.S. response. All this results in a higher performance of the K/Ar dating method, especially in the recent ages range. The technological side of the problem was only dealt with [fr

  13. Cardiac potassium channel subtypes

    DEFF Research Database (Denmark)

    Schmitt, Nicole; Grunnet, Morten; Olesen, Søren-Peter

    2014-01-01

    About 10 distinct potassium channels in the heart are involved in shaping the action potential. Some of the K(+) channels are primarily responsible for early repolarization, whereas others drive late repolarization and still others are open throughout the cardiac cycle. Three main K(+) channels...... drive the late repolarization of the ventricle with some redundancy, and in atria this repolarization reserve is supplemented by the fairly atrial-specific KV1.5, Kir3, KCa, and K2P channels. The role of the latter two subtypes in atria is currently being clarified, and several findings indicate...... that they could constitute targets for new pharmacological treatment of atrial fibrillation. The interplay between the different K(+) channel subtypes in both atria and ventricle is dynamic, and a significant up- and downregulation occurs in disease states such as atrial fibrillation or heart failure...

  14. Excitation block in a nerve fibre model owing to potassium-dependent changes in myelin resistance.

    Science.gov (United States)

    Brazhe, A R; Maksimov, G V; Mosekilde, E; Sosnovtseva, O V

    2011-02-06

    The myelinated nerve fibre is formed by an axon and Schwann cells or oligodendrocytes that sheath the axon by winding around it in tight myelin layers. Repetitive stimulation of a fibre is known to result in accumulation of extracellular potassium ions, especially between the axon and the myelin. Uptake of potassium leads to Schwann cell swelling and myelin restructuring that impacts the electrical properties of the myelin. In order to further understand the dynamic interaction that takes place between the myelin and the axon, we have modelled submyelin potassium accumulation and related changes in myelin resistance during prolonged high-frequency stimulation. We predict that potassium-mediated decrease in myelin resistance leads to a functional excitation block with various patterns of altered spike trains. The patterns are found to depend on stimulation frequency and amplitude and to range from no block (less than 100 Hz) to a complete block (greater than 500 Hz). The transitional patterns include intermittent periodic block with interleaved spiking and non-spiking intervals of different relative duration as well as an unstable regime with chaotic switching between the spiking and non-spiking states. Intermittent conduction blocks are accompanied by oscillations of extracellular potassium. The mechanism of conductance block based on myelin restructuring complements the already known and modelled block via hyperpolarization mediated by the axonal sodium pump and potassium depolarization.

  15. Sterically screened halogenocyclobutanones. I. Transformations of cyclopropyl-substituted 2,2-dichlorocyclobutanones under the influence of potassium hydroxide

    International Nuclear Information System (INIS)

    Donskaya, N.A.; Bessmertnykh, A.G.; Drobysh, V.A.; Shabarov, Yu.S.

    1987-01-01

    The reaction of 2,2-dichloro-3-cyclopropylcyclobutanones with potassium hydroxide was studied. The direction of the reaction depends on the concentration of the potassium hydroxide; with a 2% solution of potassium hydroxide 4,4-dichlorobutyric acids are formed with yields of up to 80%, and with a 15% solution of potassium hydroxide 5-hydroxydihydro-2-furanones are formed with yields of up to 80%. Proposals are made about the mechanism of formation of 5-hydroxydihydro-2-furanones

  16. Potassium Silicate Foliar Fertilizer Grade from Geothermal Sludge and Pyrophyllite

    Directory of Open Access Journals (Sweden)

    Muljani Srie

    2016-01-01

    Full Text Available Potassium silicate fertilizer grade were successfully produced by direct fusion of silica (SiO2 and potasium (KOH and K2CO3 in furnaces at temperatures up to melting point of mixture. The geothermal sludge (98% SiO2 and the pyrophyllite (95% SiO2 were used as silica sources. The purposes of the study was to synthesise potassium silicate fertilizer grade having solids concentrations in the range of 31-37% K2O, and silica in the range of 48-54% SiO2. The weight ratio of silicon dioxide/potasium solid being 1:1 to 5:1. Silica from geothermal sludge is amorphous, whereas pyrophylite is crystalline phase. The results showed that the amount of raw materials needed to get the appropriate molar ratio of potassium silicate fertilizer grade are different, as well as the fusion temperature of the furnace. Potassium silicate prepared from potassium hydroxide and geothermal sludge produced a low molar ratio (2.5: 1 to 3: 1. The potassium required quite small (4:1 in weight ratio, and on a fusion temperature of about 900 °C. Meanwhile, the potassium silicate prepared from pyrophyllite produced a high molar ratio (1.4 - 9.4 and on a fusion temperature of about 1350 °C, so that potassium needed large enough to meet the required molar ratio for the fertilizer grade. The product potassium silicate solid is amorphous with a little trace of crystalline.

  17. Parathyroid hormone impairs extrarenal potassium tolerance in the rat

    International Nuclear Information System (INIS)

    Sugarman, A.; Kahn, T.

    1988-01-01

    The effect of parathyroid hormone (PTH) on the extrarenal disposition of an acute potassium load was examined in acutely nephrectomized rats infused with KCl alone or in combination with PTH, with serial monitoring of plasma potassium every 10 min. The rise in plasma potassium concentration (ΔPK) in the PTH group was higher than control. PTH was then administered along with KCl to two groups of nephrectomized and acutely thyroparathyroidectomized (TPTX) rats in doses of 1 and 0.25 U · kg -1 · min -1 for 90 min. ΔPK with PTH in both groups was higher than TPTX control. The two higher doses of PTH resulted in a decrease in mean arterial pressure from their respective controls. A similar reduction in arterial pressure in three groups of nephrectomized rats by administration of hydralazine or nitroprusside or by acute blood loss did not change ΔPK subsequent to potassium infusion from that in control rats. Furthermore, the lowest dose of PTH did not lower arterial pressure from its respective control. Therefore, hypotension is not a cause for the PTH-induced potassium intolerance. Serum levels of insulin, aldosterone, catecholamines, calcium, plasma HCO 3 concentration, and pH were not different in PTH-infused vs. respective control rats. These data suggest that PTH impairs extrarenal potassium disposal in the rat. The effect of PTH may relate to enhanced calcium entry into cells

  18. Intracellular mediators of potassium-induced aldosterone secretion

    International Nuclear Information System (INIS)

    Ganguly, A.; Chiou, S.; Davis, J.S.

    1990-01-01

    We have investigated the intracellular messengers of potassium in eliciting aldosterone secretion in calf adrenal glomerulosa cells since there were unresolved issues relating to the role of phosphoinositides, cAMP and protein kinases. We observed no evidence of hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP 2 ) in 3 H-inositol labeled alf adrenal cells or increase of cAMP in response to potassium. Addition of calcium channel blocker, nitrendipine after stimulating adrenal glomerulosa cells with potassium, markedly inhibited aldosterone secretion. A calmodulin inhibitor (W-7) produced greater reduction of aldosterone secretion than an inhibitor of protein kinase C (H-7). These results suggest that a rise in cytosolic free calcium concentration through voltage-dependent calcium channel and calmodulin are the critical determinants of aldosterone secretion stimulated by potassium

  19. Influence of Potassium on Sapric Peat under Different Environmental Conditions

    Science.gov (United States)

    Tajuddin, Syafik Akmal Mohd; Rahman, Junita Abdul; Rahim, Nor Haakmal Abd; Saphira Radin Mohamed, Radin Maya; Saeed Abduh Algheethi, Adel Ali, Dr

    2018-04-01

    Potassium is mainly present in soil in the natural form known as the K-bearing mineral. Potassium is also available in fertilizer as a supplement to plants and can be categorized as macronutrient. The application of potassium improves the texture and structure of the soil beside to improves plant growth. The main objective of this study was to determine the concentration of potassium in sapric peat under different conditions. Physical model was used as a mechanism for the analysis of the experimental data using a soil column as an equipment to produce water leaching. In this investigation, there were four outlets in the soil column which were prepared from the top of the column to the bottom with the purpose of identifying the concentration of potassium for each soil level. The water leaching of each outlet was tested using atomic absorption spectroscopy (AAS). The results obtained showed that the highest concentrations of potassium for flush condition at outlet 4 was 13.58 ppm. Similarly, sapric under rainwater condition recorded the highest value of 13.32 and 12.34 ppm respectively at outlet 4 for wet and dry condition. However, the difference in Sapric, rainwater and fertilizer category showed that the highest value for the wet condition was achieved at outlet 2 with 13.99 ppm while highest value of 14.82 ppm was obtained for the dry condition at the outlet 3. It was concluded that the outlets in the soil column gave a detailed analysis of the concentration of potassium in the soil which was influenced by the environmental conditions.

  20. Potassium channels in brain mitochondria.

    Science.gov (United States)

    Bednarczyk, Piotr

    2009-01-01

    Potassium channels are the most widely distributed class of ion channels. These channels are transmembrane proteins known to play important roles in both normal and pathophysiological functions in all cell types. Various potassium channels are recognised as potential therapeutic targets in the treatment of Parkinson's disease, Alzheimer's disease, brain/spinal cord ischaemia and sepsis. In addition to their importance as therapeutic targets, certain potassium channels are known for their beneficial roles in anaesthesia, cardioprotection and neuroprotection. Some types of potassium channels present in the plasma membrane of various cells have been found in the inner mitochondrial membrane as well. Potassium channels have been proposed to regulate mitochondrial membrane potential, respiration, matrix volume and Ca(+) ion homeostasis. It has been proposed that mitochondrial potassium channels mediate ischaemic preconditioning in various tissues. However, the specificity of a pharmacological agents and the mechanisms underlying their effects on ischaemic preconditioning remain controversial. The following potassium channels from various tissues have been identified in the inner mitochondrial membrane: ATP-regulated (mitoK(ATP)) channel, large conductance Ca(2+)-regulated (mitoBK(Ca)) channel, intermediate conductance Ca(2+)-regulated (mitoIK(Ca)) channel, voltage-gated (mitoKv1.3 type) channel, and twin-pore domain (mitoTASK-3) channel. It has been shown that increased potassium flux into brain mitochondria induced by either the mitoK(ATP) channel or mitoBK(Ca) channel affects the beneficial effects on neuronal cell survival under pathological conditions. Recently, differential distribution of mitoBK(Ca) channels has been observed in neuronal mitochondria. These findings may suggest a neuroprotective role for the mitoBK(Ca) channel in specific brain structures. This minireview summarises current data on brain mitochondrial potassium channels and the efforts to identify

  1. Oral potassium supplementation in surgical patients.

    Science.gov (United States)

    Hainsworth, Alison J; Gatenby, Piers A

    2008-08-01

    Hospital inpatients are frequently hypokalaemic. Low plasma potassium levels may cause life threatening complications, such as cardiac arrhythmias. Potassium supplementation may be administered parenterally or enterally. Oral potassium supplements have been associated with oesophageal ulceration, strictures and gastritis. An alternative to potassium salt tablets or solution is dietary modification with potassium rich food stuffs, which has been proven to be a safe and effective method for potassium supplementation. The potassium content of one medium banana is equivalent to a 12 mmol potassium salt tablet. Potassium supplementation by dietary modification has been shown to be equally efficacious to oral potassium salt supplementation and is preferred by the majority of patients. Subsequently, it is our practice to replace potassium using dietary modification, particularly in surgical patients having undergone oesophagogastrectomy or in those with peptic ulcer disease.

  2. The Limitation Amount of Available Potassium for Wheat in a Loess Soil

    Directory of Open Access Journals (Sweden)

    M. Vafakhah

    2014-04-01

    Full Text Available The objective of this study was determining the most limiting plant growth factor in the wheat root zone dominated by illite in clay fraction and a high specific surface with ample ammonium acetate extractible potassium. A completely randomized block design with 4 replicates was used in Seyed Miran Research Farm (Gorgan during 2009-2010 growing season. Treatments were mineral fertilizers (to achieve different levels of yields, gypsum (1000 Kg/ha calcium, calcium chloride (1000 Kg ha-1 Ca, urea (93 Kg ha-1 N and potassium chloride (105 Kg ha-1 K combined, gypsum (1000 Kg ha-1 Ca and potassium chloride (105 Kg ha-1 K combined, calcium chloride (1000 Kg ha-1 Ca and potassium chloride (105 Kg ha-1 K combined and control. Wheat cultivar (N-80-19 was planted in experimental site at 2009/12/9. The results showed that potassium is the most limiting plant growth factor in the site of the experiment. Electric diffuse double layer is expected to be truncated with a high specific surface soil in this area minimizing the soil solution-diffuse double layer interface for rapid potassium diffusion. The highest yield grain and straw with urea and potassium chloride showed a greater effect on plant and soil potassium concentrations. A greater potassium diffusion rate may be achieved as a result of greater concentration gradients between the exchange sites and soil solution by potassium fertilization and more potassium excess. Ammonium from urea diminished potassium fixation with illite and increased potassium root uptake.

  3. Effects of potassium on kesterite solar cells: Similarities, differences and synergies with sodium

    Directory of Open Access Journals (Sweden)

    S. G. Haass

    2018-01-01

    Full Text Available Addition of alkali dopants is essential for achieving high-efficiency conversion efficiency of thin film solar cells based on chalcogenide semiconductors like Cu(In,GaSe2 (CIGS and Cu2ZnSn(S,Se4 (CZTSSe also called kesterite. Whereas the treatment with potassium allows boosting the performance of CIGS solar cells as compared to the conventional sodium doping, it is debated if similar effects can be expected for kesterite solar cells. Here the influence of potassium is investigated by introducing the dopant during the solution processing of kesterite absorbers. It is confirmed that the presence of potassium leads to an enhanced grain growth and a ten-fold lower potassium concentration is sufficient for obtaining grain size similar to sodium-containing absorbers. Potassium is located predominantly at grain boundaries and it suppresses incorporation of sodium into the absorber layer. The potassium doping increases the apparent carrier concentration to ∼2×1016 cm-3 for a potassium concentration of 0.2 at%. The potassium-doped solar cells yield conversion efficiency close to 10%, on par with only sodium-doped samples. Co-doping with potassium and sodium has not revealed any beneficial synergetic effects and it is concluded that both dopants exhibit similar effects on the kesterite solar cell performance.

  4. 21 CFR 184.1631 - Potassium hydroxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium hydroxide. 184.1631 Section 184.1631 Food... Specific Substances Affirmed as GRAS § 184.1631 Potassium hydroxide. (a) Potassium hydroxide (KOH, CAS Reg... pellets, flakes, sticks, lumps, and powders. Potassium hydroxide is obtained commercially from the...

  5. 21 CFR 184.1643 - Potassium sulfate.

    Science.gov (United States)

    2010-04-01

    ... hydroxide or potassium carbonate. (b) The ingredient meets the specifications of the “Food Chemicals Codex... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium sulfate. 184.1643 Section 184.1643 Food... Specific Substances Affirmed as GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg...

  6. 21 CFR 184.1622 - Potassium chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium chloride. 184.1622 Section 184.1622 Food... Specific Substances Affirmed as GRAS § 184.1622 Potassium chloride. (a) Potassium chloride (KCl, CAS Reg... levels not to exceed current good manufacturing practice. Potassium chloride may be used in infant...

  7. Extracellular enzyme kinetics scale with resource availability

    Science.gov (United States)

    Sinsabaugh, Robert L.; Belnap, Jayne; Findlay, Stuart G.; Follstad Shah, Jennifer J.; Hill, Brian H.; Kuehn, Kevin A.; Kuske, Cheryl; Litvak, Marcy E.; Martinez, Noelle G.; Moorhead, Daryl L.; Warnock, Daniel D.

    2014-01-01

    Microbial community metabolism relies on external digestion, mediated by extracellular enzymes that break down complex organic matter into molecules small enough for cells to assimilate. We analyzed the kinetics of 40 extracellular enzymes that mediate the degradation and assimilation of carbon, nitrogen and phosphorus by diverse aquatic and terrestrial microbial communities (1160 cases). Regression analyses were conducted by habitat (aquatic and terrestrial), enzyme class (hydrolases and oxidoreductases) and assay methodology (low affinity and high affinity substrates) to relate potential reaction rates to substrate availability. Across enzyme classes and habitats, the scaling relationships between apparent Vmax and apparent Km followed similar power laws with exponents of 0.44 to 0.67. These exponents, called elasticities, were not statistically distinct from a central value of 0.50, which occurs when the Km of an enzyme equals substrate concentration, a condition optimal for maintenance of steady state. We also conducted an ecosystem scale analysis of ten extracellular hydrolase activities in relation to soil and sediment organic carbon (2,000–5,000 cases/enzyme) that yielded elasticities near 1.0 (0.9 ± 0.2, n = 36). At the metabolomic scale, the elasticity of extracellular enzymatic reactions is the proportionality constant that connects the C:N:P stoichiometries of organic matter and ecoenzymatic activities. At the ecosystem scale, the elasticity of extracellular enzymatic reactions shows that organic matter ultimately limits effective enzyme binding sites. Our findings suggest that one mechanism by which microbial communities maintain homeostasis is regulating extracellular enzyme expression to optimize the short-term responsiveness of substrate acquisition. The analyses also show that, like elemental stoichiometry, the fundamental attributes of enzymatic reactions can be extrapolated from biochemical to community and ecosystem scales.

  8. Extracellular Gd-CA

    DEFF Research Database (Denmark)

    Thomsen, Henrik S; Marckmann, Peter

    2008-01-01

    Until recently it was believed that extracellular gadolinium-based contrast agents were safe for both the kidneys and all other organs within the dose range up to 0.3 mmol/kg body weight. However, in 2006, it was demonstrated that some gadolinium-based contrast agents may trig the development...... gadolinium-based agent (3-7% versus 0-1% per injection) in patients with reduced renal function. Prevalence after exposure to two gadodiamide injections is as high as 36% in patients with chronic kidney disease (CKD) stage 5. No report of NSF after the most stable agents has been reported in the peer...

  9. Mechanism of inhibition of mouse Slo3 (KCa 5.1) potassium channels by quinine, quinidine and barium.

    Science.gov (United States)

    Wrighton, David C; Muench, Stephen P; Lippiat, Jonathan D

    2015-09-01

    The Slo3 (KCa 5.1) channel is a major component of mammalian KSper (sperm potassium conductance) channels and inhibition of these channels by quinine and barium alters sperm motility. The aim of this investigation was to determine the mechanism by which these drugs inhibit Slo3 channels. Mouse (m) Slo3 (KCa 5.1) channels or mutant forms were expressed in Xenopus oocytes and currents recorded with 2-electrode voltage-clamp. Gain-of-function mSlo3 mutations were used to explore the state-dependence of the inhibition. The interaction between quinidine and mSlo3 channels was modelled by in silico docking. Several drugs known to block KSper also affected mSlo3 channels with similar levels of inhibition. The inhibition induced by extracellular barium was prevented by increasing the extracellular potassium concentration. R196Q and F304Y mutations in the mSlo3 voltage sensor and pore, respectively, both increased channel activity. The F304Y mutation did not alter the effects of barium, but increased the potency of inhibition by both quinine and quinidine approximately 10-fold; this effect was not observed with the R196Q mutation. Block of mSlo3 channels by quinine, quinidine and barium is not state-dependent. Barium inhibits mSlo3 outside the cell by interacting with the selectivity filter, whereas quinine and quinidine act from the inside, by binding in a hydrophobic pocket formed by the S6 segment of each subunit. Furthermore, we propose that the Slo3 channel activation gate lies deep within the pore between F304 in the S6 segment and the selectivity filter. © 2015 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of The British Pharmacological Society.

  10. Modeling the growth boundary of Listeria monocytogenes in ready-to-eat cooked meat products as a function of the product salt, moisture, potassium lactate, and sodium diacetate concentrations.

    Science.gov (United States)

    Legan, J D; Seman, D L; Milkowski, A L; Hirschey, J A; Vandeven, M H

    2004-10-01

    A central composite response surface design was used to determine the time to growth of Listeria monocytogenes as a function of four continuous variables: added sodium chloride (0.8 to 3.6%), sodium diacetate (0 to 0.2%), potassium lactate syrup (60% [wt/wt]; 0.25 to 9.25%), and finished-product moisture (45.5 to 83.5%) in ready-to-eat cured meat products. The design was repeated for ready-to-eat uncured meat products giving a fifth categorical variable for cure status. Products were stored at 4 degrees C. The results were modeled using a generalized regression approach. All five main effects, six two-factor interactions, and two quadratic terms were statistically significant. The model was used to show the boundary between growth and no-growth conditions at 4 degrees C using contour plots of time to growth. It was validated using independent challenge studies of cured and uncured products. Generally, the model predicted well, particularly for cured products, where it will be useful for establishing conditions that prevent the growth of L. monocytogenes. For uncured products, there was good agreement overall between predicted and observed times to growth, but the model is less thoroughly validated than for cured products. The model should initially only be used for screening of formulations likely to prevent growth of Listeria monocytogenes in uncured products, with recommendations subject to confirmation by challenge studies.

  11. Induction of Barley Silicon Transporter HvLsi1 and HvLsi2, increased silicon concentration in the shoot and regulated Starch and ABA Homeostasis under Osmotic stress and Concomitant Potassium Deficiency

    Directory of Open Access Journals (Sweden)

    Seyed A. Hosseini

    2017-08-01

    Full Text Available Drought is one of the major stress factors reducing cereal production worldwide. There is ample evidence that the mineral nutrient status of plants plays a critical role in increasing plant tolerance to different biotic and abiotic stresses. In this regard, the important role of various nutrients e.g., potassium (K or silicon (Si in the mitigation of different stress factors, such as drought, heat or frost has been well documented. Si application has been reported to ameliorate plant nutrient deficiency. Here, we used K and Si either solely or in combination to investigate whether an additive positive effect on barley growth can be achieved under osmotic stress and which mechanisms contribute to a better tolerance to osmotic stress. To achieve this goal, barley plants were subjected to polyethylene glycol (PEG-induced osmotic stress under low or high K supply and two Si regimes. The results showed that barley silicon transporters HvLsi1 and HvLsi2 regulate the accumulation of Si in the shoot only when plant suffered from K deficiency. Si, in turn, increased the starch level under both osmotic stress and K deficiency and modulated the glycolytic and TCA pathways. Hormone profiling revealed that the beneficial effect of Si is most likely mediated also by ABA homeostasis and active cytokinin isopentenyl adenine (iP. We conclude that Si may effectively improve stress tolerance under K deficient condition in particular when additional stress like osmotic stress interferes.

  12. 21 CFR 184.1625 - Potassium citrate.

    Science.gov (United States)

    2010-04-01

    ... acid with potassium hydroxide or potassium carbonate. It occurs as transparent crystals or a white... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS...

  13. Acid-permanganate oxidation of potassium tetraphenylboron

    International Nuclear Information System (INIS)

    Smith, J.R.

    1993-02-01

    Scoping experiments have been performed which show that potassium tetraphenylboron (KTPB) is rapidly oxidized by permanganate in acidic solutions at room temperature. The main Products are CO 2 , highly oxidized organic compounds related to tartaric and tartronic acids, boric acid, and potassium phosphate (when phosphoric acid is used as the source of acid). One liter of 0.6M NaMnO 4 /2.5M H 3 PO 4 solution will destroy up to 8 grams of KTPB. The residual benzene concentration has been measured to be less than the RCRA limit of 0.5 ppm. Approximately 30% of the organic material is released as CO 2 (trace CO) and 0.16% as benzene vapor. The reaction is well behaved, no foaming or spattering. Tests were performed from .15M to near 1M permanganate. The phosphoric acid concentration was maintained at a concentration at least three times that of the permanganate since an excess of acid was desired and this is the ratio that these two reagents are consumed in the oxidation

  14. [Effects of allitridum on rapidly delayed rectifier potassium current in HEK293 cell line].

    Science.gov (United States)

    Zhang, Jiancheng; Lin, Kun; Wei, Zhixiong; Chen, Qian; Liu, Li; Zhao, Xiaojing; Zhao, Ying; Xu, Bin; Chen, Xi; Li, Yang

    2015-08-01

    To study the effect of allitridum on rapidly delayed rectifier potassium current (IKr) in HEK293 cell line. HEK293 cells were transiently transfected with HERG channel cDNA plasmid pcDNA3.1 via Lipofectamine. Allitridum was added to the extracellular solution by partial perfusion after giga seal at the final concentration of 30 µmol/L. Whole-cell patch clamp technique was used to record the HERG currents and gating kinetics before and after allitridum exposure at room temperature. The amplitude and density of IHERG were both suppressed by allitridum in a voltage-dependent manner. In the presence of allitridum, the peak current of IHERG was reduced from 73.5∓4.3 pA/pF to 42.1∓3.6 pA/pF at the test potential of +50 mV (P<0.01). Allitridum also concentration-dependently decreased the density of the IHERG. The IC50 of allitridum was 34.74 µmol/L with a Hill coefficient of 1.01. Allitridum at 30 µmol/L caused a significant positive shift of the steady-state activation curve of IHERG and a markedly negative shift of the steady-state inactivation of IHERG, and significantly shortened the slow time constants of IHERG deactivation. Allitridum can potently block IHERG in HEK293 cells, which might be the electrophysiological basis for its anti-arrhythmic action.

  15. ROLE OF POTASSIUM IN THE OXIDATIVE METABOLISM OF MICROCOCCUS SODONENSIS1

    Science.gov (United States)

    Perry, Jerome J.; Evans, James B.

    1961-01-01

    Perry, Jerome J. (The University of Chicago, Chicago, Ill.), and James B. Evans. Role of potassium in the oxidative metabolism of Micrococcus sodonensis. J. Bacteriol. 82:551–555. 1961.—An absolute potassium requirement has been established for the growth of Micrococcus sodonensis with lactate or pyruvate as substrate. Potassium at 0.67 × 10−2m concentration was necessary for maximal growth. Resting cell and cell-free preparations from cells grown on minimal levels of potassium were stimulated by potassium but, due to residual or bound cation, did not show an absolute requirement. Rubidium and cesium replaced potassium in these cells although cesium is much less effective. PMID:14485577

  16. Determination of potassium in several plants and study of potassium transfer to different beverages, including tequila, by measurement of 40K

    International Nuclear Information System (INIS)

    Navarrete, J.M.; Muller, G.; Cabrera, L.; Martinez, T.

    2006-01-01

    Measurement of 40 K was used for determination of potassium concentrations in leaves of agave and maguey cactus leaves, and coffee beans of various origins. The procedure was also used to study potassium transfer to tequila (alcoholic drink made of agave cactus), and the cactus and coffee infusions using 40 K as a natural radioactive tracer. Counting of 40 K in Marinelli containers with the aid of a low background NaI(Tl) scintillation detection system for 12-24 hours was employed. The method appeared to be simple and suitable for determination of potassium concentrations in large samples, which eliminates homogeneity problems. (author)

  17. Potassium-phosphorus relationships in cotton (gossypium hirsutum L.) as affected by potassium nutrition

    International Nuclear Information System (INIS)

    Makhdum, M.I.; Ashraf, M.

    2007-01-01

    Field studies were undertaken to determine the interrelationship between potassium (K+) concentration in various organs of plant and phosphorus (P) content as influenced by K-nutrition in cotton. The experiment was conducted on Miani soil series silt loam and classified as Calcaric Cambisols, fine silty, mixed Hyperthermic Fluventic Haplocambids. The treatments consisted .of (a) four cotton (Gossypium hirsutum L.) cultivars (CI.M-448, CIM-IIOO, Karishma, S-12); and (b) four potassium fertilizer doses (0, 62.5, 125.0, 250.0 kg K ha-l). The design of experiment was split plot (main: cultivars, sub-plot: K-doses). The plant samples were collected at five stages of growth, i.e., first flower bud., first flower, peak flowering, first boll split and maturity. The various parts of plants were analyzed for phosphorus and potassium concentration at various stages of growth. Phosphorus concentration in leaves, stems, burs, seed and lint decreased with concurrent increase in K-doses. Crop maintained 0.22% phosphorus concentration in leaf tissues at first flower bud and dropped to 0.11% at maturity. Cultivars differed greatly amongst themselves in terms of maintaining P content in their different parts. Averaged across K-doses, cv. CIM-448 maintained the highest P content in all parts than other cultivars. There was a negative and significant correlation co-efficient between K and P concentration in various parts of the plant. The study demonstrated antagonistic interaction between K+ and P in cotton plant under irrigated conditions. (author)

  18. Salinity effect on seedling growth, water, sodium and potassium ...

    African Journals Online (AJOL)

    Mature leaves exhibited good adaptative behavior toward salinity stress by increasing succulence due to absorption of large quantities of water and K+ in leaves. Potassium uptake in leaves was not found to be affected by NaCl concentration. As a consequence, monovalent cations adsorption resulted in an increase in the ...

  19. Transmission spectra study of sulfate substituted potassium dihydrogen phosphate

    KAUST Repository

    LI, LIANG

    2013-04-18

    Potassium dihydrogen phosphate (KDP) crystals with different amounts of sulfate concentration were grown and the transmittance spectrum was studied. A crystal with high sulfate replacement density exhibits heavy absorption property in the ultraviolet region which confirms and agrees well with former results. © 2013 Astro Ltd.

  20. Acute toxicity of potassium permanganate to fingerlings of the ...

    African Journals Online (AJOL)

    Laboratory static bioassays were conducted to determine the 96-h LC50 and the lethal levels of concentrations of the aquaculture therapeutant, potassium permanganate (KMnO4) on fingerlings (mean weight, 6.24 ± 0.15 g and mean length, 4.25 ± 0.07 cm) of the African catfish, Clarias gariepinus. A total number of one ...

  1. Activation of retinal glial (Müller cells by extracellular ATP induces pronounced increases in extracellular H+ flux.

    Directory of Open Access Journals (Sweden)

    Boriana K Tchernookova

    Full Text Available Small alterations in extracellular acidity are potentially important modulators of neuronal signaling within the vertebrate retina. Here we report a novel extracellular acidification mechanism mediated by glial cells in the retina. Using self-referencing H+-selective microelectrodes to measure extracellular H+ fluxes, we show that activation of retinal Müller (glial cells of the tiger salamander by micromolar concentrations of extracellular ATP induces a pronounced extracellular H+ flux independent of bicarbonate transport. ADP, UTP and the non-hydrolyzable analog ATPγs at micromolar concentrations were also potent stimulators of extracellular H+ fluxes, but adenosine was not. The extracellular H+ fluxes induced by ATP were mimicked by the P2Y1 agonist MRS 2365 and were significantly reduced by the P2 receptor blockers suramin and PPADS, suggesting activation of P2Y receptors. Bath-applied ATP induced an intracellular rise in calcium in Müller cells; both the calcium rise and the extracellular H+ fluxes were significantly attenuated when calcium re-loading into the endoplasmic reticulum was inhibited by thapsigargin and when the PLC-IP3 signaling pathway was disrupted with 2-APB and U73122. The anion transport inhibitor DIDS also markedly reduced the ATP-induced increase in H+ flux while SITS had no effect. ATP-induced H+ fluxes were also observed from Müller cells isolated from human, rat, monkey, skate and lamprey retinae, suggesting a highly evolutionarily conserved mechanism of potential general importance. Extracellular ATP also induced significant increases in extracellular H+ flux at the level of both the outer and inner plexiform layers in retinal slices of tiger salamander which was significantly reduced by suramin and PPADS. We suggest that the novel H+ flux mediated by ATP-activation of Müller cells and of other glia as well may be a key mechanism modulating neuronal signaling in the vertebrate retina and throughout the brain.

  2. Produção do melão rendilhado em função da concentração de potássio na solução nutritiva e do número de frutos por planta Net melon yield as affected by potassium concentration in nutrient solution and number of fruits per plant

    Directory of Open Access Journals (Sweden)

    Caciana C. Costa

    2004-03-01

    Full Text Available O experimento foi conduzido em hidroponia (NFT, de junho a novembro de 2001, na UNESP, em Jaboticabal. A cultivar Bônus nº 2 foi cultivada sob blocos casualizados, em esquema de parcelas subdivididas, com seis repetições. Foram avaliados o número de frutos por planta (2; 3; 4 e fixação livre e a concentração de potássio na solução nutritiva (66; 115,5; 165 e 247,5 mg L-1 de K. Nas colheitas ocorridas entre 105 e 133 dias após o transplantio (DAT, foram obtidos 2,0; 2,5; 2,7 e 2,3 frutos por planta, enquanto que aos 85 DAT, o número de frutos fixados tinha sido, respectivamente, 2; 3; 4 e 6,2 frutos por planta. O incremento da concentração de potássio na solução nutritiva aumentou, inicialmente, o número de frutos fixados, e contribuiu, posteriormente, para a redução do abortamento dos frutos. Também, promoveu aumento no peso médio do segundo fruto. A produção e o peso médio dos frutos não foram influenciados pelo emprego de soluções nutritivas com concentração de potássio acima de 66 mg L-1. Entretanto, o número de frutos por planta afetou a produção e o peso médio dos frutos, promovendo respectivamente, aumento e redução à medida que maior foi o número de frutos por planta.The experiment was carried out using hidroponic solution (NFT from June to November-2001, in Jaboticabal, São Paulo State, Brazil. The 'Bonus nº 2' was cultivated in randomized blocks design, with split-plot scheme and six replications. Fruit number per plant (2; 3; 4 and free and potassium concentration in the nutrient solution (66; 115.5; 165 e 247.5 mg L-1 were the studied factors. At harvests [105 to 133 days after transplant (DAT], 2.0; 2.5; 2.7 and 2.3 fruits per plant were obtained, whereas at 85 DAT, 2; 3; 4 and 6.2 fruits had been set, respectively. Increasing potassium concentration in the nutrient solution improved initially fruit set and contributed later to reduce the fruit aborting in plants. Also the potassium promoted

  3. Potassium Permanganate as an Alternative for Gold Mining Wastewater Treatment

    Science.gov (United States)

    Ordiales, M.; Fernández, D.; Verdeja, L. F.; Sancho, J.

    2015-09-01

    The feasibility of using potassium permanganate as a reagent for cyanide oxidation in wastewater was experimentally studied. Both artificial and production wastewater from two different gold mines were tested. The experiments had three goals: determine the optimum reagent concentration and reaction time required to achieve total cyanide removal, obtain knowledge of the reaction kinetics, and improve the management of the amount of reagent. The results indicate that potassium permanganate is an effective and reliable oxidizing agent for the removal of cyanide from gold mining wastewater.

  4. Evaluating the effect of potassium on cellulose pyrolysis reaction kinetics

    International Nuclear Information System (INIS)

    Trendewicz, Anna; Evans, Robert; Dutta, Abhijit; Sykes, Robert; Carpenter, Daniel; Braun, Robert

    2015-01-01

    This paper proposes modifications to an existing cellulose pyrolysis mechanism in order to include the effect of potassium on product yields and composition. The changes in activation energies and pre-exponential factors due to potassium were evaluated based on the experimental data collected from pyrolysis of cellulose samples treated with different levels of potassium (0–1% mass fraction). The experiments were performed in a pyrolysis reactor coupled to a molecular beam mass spectrometer (MBMS). Principal component analysis (PCA) performed on the collected data revealed that cellulose pyrolysis products could be divided into two groups: anhydrosugars and other fragmentation products (hydroxyacetaldehyde, 5-hydroxymethylfurfural, acetyl compounds). Multivariate curve resolution (MCR) was used to extract the time resolved concentration score profiles of principal components. Kinetic tests revealed that potassium apparently inhibits the formation of anhydrosugars and catalyzes char formation. Therefore, the oil yield predicted at 500 ° C decreased from 87.9% from cellulose to 54.0% from cellulose with 0.5% mass fraction potassium treatment. The decrease in oil yield was accompanied by increased yield of char and gases produced via a catalyzed dehydration reaction. The predicted char and gas yield from cellulose were 3.7% and 8.4%, respectively. Introducing 0.5% mass fraction potassium treatment resulted in an increase of char yield to 12.1% and gas yield to 33.9%. The validation of the cellulose pyrolysis mechanism with experimental data from a fluidized-bed reactor, after this correction for potassium, showed good agreement with our results, with differences in product yields of up to 5%

  5. Potassium isotope abundances in Australasian tektites and microtektites.

    Science.gov (United States)

    Herzog, G. F.; O'D. Alexander, C. M.; Berger, E. L.; Delaney, J. S.; Glass, B. P.

    2008-10-01

    We report electron microprobe determinations of the elemental compositions of 11 Australasian layered tektites and 28 Australasian microtektites; and ion microprobe determinations of the 41K/39K ratios of all 11 tektites and 13 of the microtektites. The elemental compositions agree well with literature values, although the average potassium concentrations measured here for microtektites, 1.1 1.6 wt%, are lower than published average values, 1.9 2.9 wt%. The potassium isotope abundances of the Australasian layered tektites vary little. The average value of δ41K, 0.02 ± 0.12‰ (1σ mean), is indistinguishable from the terrestrial value (= 0 by definition) as represented by our standard, thereby confirming four earlier tektite analyses of Humayun and Koeberl (2004). In agreement with those authors, we conclude that evaporation has significantly altered neither the isotopic nor the elemental composition of Australasian layered tektites for elements less volatile than potassium. Although the average 41K/39K ratio of the microtektites, 1.1 ± 1.7‰ (1σ mean), is also statistically indistinguishable from the value for the standard, the individual ratios vary over a very large range, from -10.6 ± 1.4‰ to +13.8 ± 1.5‰ and at least three of them are significantly different from zero. We interpret these larger variations in terms of the evaporation of isotopically light potassium; condensation of potassium in the vapor plume; partial or complete stirring and quenching of the melts; and the possible uptake of potassium from seawater. That the average 41K/39K ratio of the microtektites equals the terrestrial value suggests that the microtektite-forming system was compositionally closed with respect to potassium and less volatile elements. The possibility remains open that 41K/39K ratios of microtektites vary systematically with location in the strewn field.

  6. Measurement of whole body cellular and collagen nitrogen, potassium, and other elements by neutron activation and whole body counting

    International Nuclear Information System (INIS)

    James, H.M.; Fabricius, P.J.; Dykes, P.W.

    1987-01-01

    Whole body nitrogen can be measured by neutron activation analysis with an acceptable radiation dose; it is an index of body protein which, in normal subjects, is 65% cellular protein and 35% extracellular connective collagen. Whole body potassium can be measured by whole body counting without irradiating the subject; it is an index of body cell mass. We measured whole body nitrogen, potassium, extracellular water, intracellular water, and fat-folds. The differences between 37 malnourished patients and five normal subjects suggested that the patients had 9 kg less cell mass than normal, but no difference in extracellular mass. Measurements were made on eight patients before and after 14 days of total parenteral nutrition; balance of nitrogen intake and excretion also was measured. The changes were consistent with mean increases of 3 kg of cellular mass and 3 kg of fat with no change of extracellular mass. The accuracy and sensitivity of the whole body measurements need further confirmation for use in patients with changing body composition. Where tissue wasting is largely from the cellular compartment, potassium could be a more sensitive index of wasting than nitrogen. Multielement analysis of nitrogen, potassium, chlorine, and carbon will probably be valuable in elucidating body composition in malnutrition

  7. Effects of administration of potassium- and sodiumchlorides on faecal excretions and salivary and alimentary concentrations of, Na, K, 134Cs, Ca, Mg and P in reindeer fed a lichen diet

    Directory of Open Access Journals (Sweden)

    Hans Staaland

    1998-02-01

    Full Text Available A comparison of the effects of administration of 350 mmol d-1 of KC1 or NaCl on faecal excretions, salivary concentrations and concentrations and pools of Na, K, 134Cs, Ca, Mg, P, and water in the alimentary tract of reindeer was carried out using three groups of three 10 months old reindeer fed a lichen diet. One group was used as a control group with no mineral supplementation. The level of K supplementation mimicked K intakes from summer pastures. NaCl was given at a rate which would mimic intake from salt licks by domestic ruminants of similar body size. Treatment with KC1 increased the salivary and alimentary concentrations and the alimentary pool sizes of K and faecal excretion of K increased. A decrease in l34Cs concentrations in all parts of the gastrointestinal tract indicated greater absorption of 134Cs during the KC1 treatment than in NaCl treated and control animals. Increased intake of Na or K had no significant effect on the digestibility of the lichen diet, but urine production increased. Little effects on pools or concentrations of Ca, Mg and P were observed. NaCl treatment increased urinary and faecal excretion of Na, but did not affect the metabolism of any of the other studied minerals.

  8. Modulation of Kir4.1 and Kir4.1-Kir5.1 channels by extracellular cations

    DEFF Research Database (Denmark)

    Søe, Rikke; Andreasen, Mogens; Klærke, Dan Arne

    2009-01-01

    This work demonstrates that extracellular Na(+) modulates the cloned inwardly rectifying K(+) channels Kir4.1 and Kir4.1-Kir5.1. Whole-cell patch clamp studies on astrocytes have previously indicated that inward potassium currents are regulated by external Na(+). We expressed Kir4.1 and Kir4.1-Kir5.......1 in Xenopus oocytes to disclose if Kir4.1 and/or Kir4.1-Kir5.1 at the molecular level are responsible for the observed effect of [Na(+)](o) and to investigate the regulatory mechanism of external cations further. Our results showed that Na(+) has a biphasic modulatory effect on both Kir4.1 and Kir4.1-Kir5.......1 currents. Depending on the Na(+)-concentration and applied voltage, the inward Kir4.1/Kir4.1-Kir5.1 currents are either enhanced or reduced by extracellular Na(+). The Na(+) activation was voltage-independent, whereas the Na(+)-induced reduction of the Kir4.1 and Kir4.1-Kir5.1 currents was both...

  9. Lack of genotoxicity of potassium iodate in the alkaline comet assay and in the cytokinesis-block micronucleus test. Comparison to potassium bromate.

    Science.gov (United States)

    Poul, J M; Huet, S; Godard, T; Sanders, P

    2004-02-01

    Iodine could be added to the diet of human population in the form of iodide or iodate but iodate had not been adequately tested for genotoxicity and carcinogenicity. In the present study, genotoxic effects of potassium iodate were evaluated in vitro using the alkaline comet assay and the cytokinesis-block micronucleus assay on CHO cells and compared to halogenate salt analogues potassium bromate and chlorate and also to their respective reduced forms (potassium iodide, bromide and chloride). The results showed that the comet assay failed to detect the presence of DNA damage after a treatment of cells by potassium iodate for concentrations up to 10 mM. This absence of primary DNA damage was confirmed in the cytokinesis-block micronucleus assay. In the same way, results showed that potassium chlorate as well as potassium iodide, bromide and chloride did not induced DNA damage in the alkaline comet assay for doses up to 10 mM. By contrast, potassium bromate exposure led to an increase in both DNA damage and frequency of micronucleated cells. The repair of bromate-induced DNA damage was incomplete 24 h after the end of treatment. These results seem to indicate that potassium bromate would induce DNA damage by several mechanisms besides oxidative stress.

  10. Gamma-spectrometric correction in radiometric determination of potassium

    International Nuclear Information System (INIS)

    Gejsler, M.

    1979-01-01

    The method is described of determination of potassium in mixed fertilizers in production conditions on a chemical enterprise in the GDR. Potassium content was determined according to the value of measured radiation from potassium-40. For measurement probes were used with radiation counters. While changing raw material, coming to the enterprise has been established that in raw phosphate, supplied from Morocco, there is low enough concentration of the natural radioactive isotopes of the uranium-radium series. In this connection, the two-cannel gamma-spectroscopy method has been developed taking into account influence of the background from these isotopes. Principles are explained of the method used and descriptions are given of the instruments used and sources of errors are listed. Relative standard deviation of the potassiun determination by this method equals nearly to 5% [ru

  11. Potassium acceptor doping of ZnO crystals

    Directory of Open Access Journals (Sweden)

    Narendra S. Parmar

    2015-05-01

    Full Text Available ZnO bulk single crystals were doped with potassium by diffusion at 950°C. Positron annihilation spectroscopy confirms the filling of zinc vacancies and a different trapping center for positrons. Secondary ion mass spectroscopy measurements show the diffusion of potassium up to 10 μm with concentration ∼1 × 1016 cm−3. IR measurements show a local vibrational mode (LVM at 3226 cm−1, at a temperature of 9 K, in a potassium doped sample that was subsequently hydrogenated. The LVM is attributed to an O–H bond-stretching mode adjacent to a potassium acceptor. When deuterium substitutes for hydrogen, a peak is observed at 2378 cm−1. The O-H peak is much broader than the O-D peak, perhaps due to an unusually low vibrational lifetime. The isotopic frequency ratio is similar to values found in other hydrogen complexes. Potassium doping increases the resistivity up to 3 orders of magnitude at room temperature. The doped sample has a donor level at 0.30 eV.

  12. Potassium acceptor doping of ZnO crystals

    Science.gov (United States)

    Parmar, Narendra S.; Corolewski, Caleb D.; McCluskey, Matthew D.; Lynn, K. G.

    2015-05-01

    ZnO bulk single crystals were doped with potassium by diffusion at 950°C. Positron annihilation spectroscopy confirms the filling of zinc vacancies and a different trapping center for positrons. Secondary ion mass spectroscopy measurements show the diffusion of potassium up to 10 μm with concentration ˜1 × 1016 cm-3. IR measurements show a local vibrational mode (LVM) at 3226 cm-1, at a temperature of 9 K, in a potassium doped sample that was subsequently hydrogenated. The LVM is attributed to an O-H bond-stretching mode adjacent to a potassium acceptor. When deuterium substitutes for hydrogen, a peak is observed at 2378 cm-1. The O-H peak is much broader than the O-D peak, perhaps due to an unusually low vibrational lifetime. The isotopic frequency ratio is similar to values found in other hydrogen complexes. Potassium doping increases the resistivity up to 3 orders of magnitude at room temperature. The doped sample has a donor level at 0.30 eV.

  13. Potassium acceptor doping of ZnO crystals

    Energy Technology Data Exchange (ETDEWEB)

    Parmar, Narendra S., E-mail: nparmar@wsu.edu; Lynn, K. G. [Center for Materials Research, Washington State University, Pullman, Washington 99164-2711 (United States); Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814 (United States); Corolewski, Caleb D.; McCluskey, Matthew D. [Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814 (United States)

    2015-05-15

    ZnO bulk single crystals were doped with potassium by diffusion at 950°C. Positron annihilation spectroscopy confirms the filling of zinc vacancies and a different trapping center for positrons. Secondary ion mass spectroscopy measurements show the diffusion of potassium up to 10 μm with concentration ∼1 × 10{sup 16} cm{sup −3}. IR measurements show a local vibrational mode (LVM) at 3226 cm{sup −1}, at a temperature of 9 K, in a potassium doped sample that was subsequently hydrogenated. The LVM is attributed to an O–H bond-stretching mode adjacent to a potassium acceptor. When deuterium substitutes for hydrogen, a peak is observed at 2378 cm{sup −1}. The O-H peak is much broader than the O-D peak, perhaps due to an unusually low vibrational lifetime. The isotopic frequency ratio is similar to values found in other hydrogen complexes. Potassium doping increases the resistivity up to 3 orders of magnitude at room temperature. The doped sample has a donor level at 0.30 eV.

  14. Potassium evaluation in blood of Brazilian athletes using NAA

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, L.; Zamboni, C.B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Nunes, L.A.S.; Lourenco, T.F.; Macedo, D. Vaz de [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

    2010-07-01

    Full text: According to nutrition sources an athlete needs per day at least one gram of potassium for keeping the correct mineral balance in the organism. Its deficiency or even instantaneous low concentration in blood can diminish the athlete performance originating nervous irritability, muscular weakness, and mental disorientation and in more several causes cardiac arrhythmias. In this study the K levels in blood were determined in athletes submitted to constant load exercise at treadmill at LABEX (Laboratorio de Bioquimica do Exercicio - UNICAMP, Brazil) using Neutron Activation Analyses (NAA). The blood samples were collected from male athletes, age 18 to 26 years, before and after the physical training. Immediately after the collection an amount of 10 micro liters of whole blood was transferred to the filter paper and dried for a few minutes using an infrared lamp. To determine the concentration of potassium each sample was irradiated in the nuclear reactor (IEA-R1, 2-4MW, pool type) at IPEN and was gamma counted using an HPGe Spectrometer of High Energy Resolution. The concentrations of the selected element, 1525keV related to the potassium activated {sup 42}K, were calculated using in -house software. The potassium levels were evaluated before and after the physical exercise and the data were compared with the normal range. (author)

  15. Potassium evaluation in blood of Brazilian athletes using NAA

    International Nuclear Information System (INIS)

    Kovacs, L.; Zamboni, C.B.; Nunes, L.A.S.; Lourenco, T.F.; Macedo, D. Vaz de

    2010-01-01

    Full text: According to nutrition sources an athlete needs per day at least one gram of potassium for keeping the correct mineral balance in the organism. Its deficiency or even instantaneous low concentration in blood can diminish the athlete performance originating nervous irritability, muscular weakness, and mental disorientation and in more several causes cardiac arrhythmias. In this study the K levels in blood were determined in athletes submitted to constant load exercise at treadmill at LABEX (Laboratorio de Bioquimica do Exercicio - UNICAMP, Brazil) using Neutron Activation Analyses (NAA). The blood samples were collected from male athletes, age 18 to 26 years, before and after the physical training. Immediately after the collection an amount of 10 micro liters of whole blood was transferred to the filter paper and dried for a few minutes using an infrared lamp. To determine the concentration of potassium each sample was irradiated in the nuclear reactor (IEA-R1, 2-4MW, pool type) at IPEN and was gamma counted using an HPGe Spectrometer of High Energy Resolution. The concentrations of the selected element, 1525keV related to the potassium activated 42 K, were calculated using in -house software. The potassium levels were evaluated before and after the physical exercise and the data were compared with the normal range. (author)

  16. Genetics Home Reference: potassium-aggravated myotonia

    Science.gov (United States)

    ... aggravated by eating potassium-rich foods such as bananas and potatoes. Stiffness occurs in skeletal muscles throughout the body. Potassium-aggravated myotonia ranges in severity from mild episodes ...

  17. The heart and potassium: a banana republic.

    Science.gov (United States)

    Khan, Ehsan; Spiers, Christine; Khan, Maria

    2013-03-01

    The importance of potassium in maintaining stable cardiac function is a clinically understood phenomenon. Physiologically the importance of potassium in cardiac function is described by the large number of different kinds of potassium ions channels found in the heart compared to channels and membrane transport mechanisms for other ions such as sodium and calcium. Potassium is important in physiological homeostatic control of cardiac function, but is also of relevance to the diseased state, as potassium-related effects may stabilize or destabilize cardiac function. This article aims to provide a detailed understanding of potassium-mediated cardiac function. This will help the clinical practitioner evaluate how modulation of potassium ion channels by disease and pharmacological manipulation affect the cardiac patient, thus aiding in decision making when faced with clinical problems related to potassium.

  18. Qualitative Carbohydrate Analysis using Alkaline Potassium ...

    Indian Academy of Sciences (India)

    IAS Admin

    CLASSROOM. 285. RESONANCE | March 2016. Qualitative Carbohydrate Analysis using Alkaline. Potassium Ferricyanide. Keywords. Alkaline potassium ferricyanide, qualitative ... Carbohydrates form a distinct class of organic compounds often .... Laboratory Techniques: A contemporary Approach, W B Saunders Com-.

  19. Extracellular matrix structure.

    Science.gov (United States)

    Theocharis, Achilleas D; Skandalis, Spyros S; Gialeli, Chrysostomi; Karamanos, Nikos K

    2016-02-01

    Extracellular matrix (ECM) is a non-cellular three-dimensional macromolecular network composed of collagens, proteoglycans/glycosaminoglycans, elastin, fibronectin, laminins, and several other glycoproteins. Matrix components bind each other as well as cell adhesion receptors forming a complex network into which cells reside in all tissues and organs. Cell surface receptors transduce signals into cells from ECM, which regulate diverse cellular functions, such as survival, growth, migration, and differentiation, and are vital for maintaining normal homeostasis. ECM is a highly dynamic structural network that continuously undergoes remodeling mediated by several matrix-degrading enzymes during normal and pathological conditions. Deregulation of ECM composition and structure is associated with the development and progression of several pathologic conditions. This article emphasizes in the complex ECM structure as to provide a better understanding of its dynamic structural and functional multipotency. Where relevant, the implication of the various families of ECM macromolecules in health and disease is also presented. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Status of potassium permanganate - 2008

    Science.gov (United States)

    This is a brief overview of the Technical Sections completed and being worked on for the New Animal Drug Application (NADA) for potassium permanganate will be presented. Initial Label Claim (Columnaris on catfish/HSB): 1) Human Food Safety - Complete for all fin fish (June 1999). A hazard charac...

  1. Efficacy and safety of topical application of 15% and 10% potassium hydroxide for the treatment of Molluscum contagiosum.

    Science.gov (United States)

    Teixidó, Concepció; Díez, Olga; Marsal, Josep R; Giner-Soriano, Maria; Pera, Helena; Martinez, Mireia; Galindo-Ortego, Gisela; Schoenenberger, Joan A; Real, Jordi; Cruz, Ines; Morros, Rosa

    2018-02-26

    Molluscum contagiosum is the most common skin infection in children. One topical treatment used for Molluscum contagiosum is potassium hydroxide. The objective of this study was to compare the efficacy of potassium hydroxide topical treatment at different concentrations with that of placebo in terms of complete clearing of Molluscum contagiosum lesions and to assess the safety and tolerance of potassium hydroxide topical treatment. This was a double-blind randomized clinical trial of three treatments (potassium hydroxide 10%, potassium hydroxide 15%, placebo) applied once daily up to complete clearing of lesions (maximum duration 60 days) in 53 children aged 2-6 years in primary health care pediatric offices in Catalonia, Spain. In the intention-to-treat analysis, potassium hydroxide 10% (58.8%, P = .03) and potassium hydroxide 15% (64.3%, P = .02) had efficacy superior to that of placebo (18.8%). The number of Molluscum contagiosum lesions was significantly reduced with potassium hydroxide 10% and 15%. The main efficacy outcome was achieved in 58.8% of children in the potassium hydroxide 10% group (P = .03 vs placebo) and in 64.3% of children in the potassium hydroxide 15% group (P = .02 vs placebo). Potassium hydroxide 10% and 15% were not significantly different in efficacy from each other. Potassium hydroxide 10% and placebo were better tolerated than potassium hydroxide 15%. No adverse events were reported during the study period. Potassium hydroxide 10% and 15% demonstrated high rates of efficacy in clearing Molluscum contagiosum lesions, with potassium hydroxide 10% being better tolerated. © 2018 Wiley Periodicals, Inc.

  2. Increased serum potassium affects renal outcomes

    DEFF Research Database (Denmark)

    Miao, Y; Dobre, D; Heerspink, H J Lambers

    2011-01-01

    To assess the effect of an angiotensin receptor blocker (ARB) on serum potassium and the effect of a serum potassium change on renal outcomes in patients with type 2 diabetes and nephropathy.......To assess the effect of an angiotensin receptor blocker (ARB) on serum potassium and the effect of a serum potassium change on renal outcomes in patients with type 2 diabetes and nephropathy....

  3. Intracellular and non-neuronal targets of voltage-gated potassium channel complex antibodies

    OpenAIRE

    Lang, Bethan; Makuch, Mateusz; Moloney, Teresa; Dettmann, Inga; Mindorf, Swantje; Probst, Christian; Stoecker, Winfried; Buckley, Camilla; Newton, Charles R; Leite, M Isabel; Maddison, Paul; Komorowski, Lars; Adcock, Jane; Vincent, Angela; Waters, Patrick

    2017-01-01

    Objectives Autoantibodies against the extracellular domains of the voltage-gated potassium channel (VGKC) complex proteins, leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-2 (CASPR2), are found in patients with limbic encephalitis, faciobrachial dystonic seizures, Morvan's syndrome and neuromyotonia. However, in routine testing, VGKC complex antibodies without LGI1 or CASPR2 reactivities (double-negative) are more common than LGI1 or CASPR2 specificities. Therefore, ...

  4. Obtaining of potassium dicyan-argentate

    International Nuclear Information System (INIS)

    Sattarova, M.A.; Solojenkin, P.M.

    1997-01-01

    This work is devoted to obtaining of potassium dicyan-argentate. By means of exchange reaction between silver nitrate and potassium cyanide the potassium dicyan-argentate was synthesized. The analysis of obtained samples was carried out by means of titration and potentiometry.

  5. 21 CFR 172.160 - Potassium nitrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium nitrate. 172.160 Section 172.160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used as a curing...

  6. 21 CFR 582.1631 - Potassium hydroxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

  7. 21 CFR 582.5622 - Potassium chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium chloride. 582.5622 Section 582.5622 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5622 Potassium chloride. (a) Product. Potassium chloride. (b) Conditions of use. This...

  8. Chloride is essential for contraction of afferent arterioles after agonists and potassium

    DEFF Research Database (Denmark)

    Jensen, B L; Ellekvist, Peter; Skøtt, O

    1997-01-01

    to norepinephrine, angiotensin II (ANG II), and potassium were measured after chloride depletion and compared with controls. Chloride depletion did not change arteriolar diameters, but the response to norepinephrine was markedly reduced when chloride was substituted with gluconate (n = 6) or isethionate (n = 6......). Reintroduction of chloride fully restored the sensitivity to norepinephrine. Contractions after ANG II and potassium were totally abolished in the absence of chloride (n = 6). In additional experiments (n = 7), the arteriolar contraction to 100 mM potassium was abolished only 1 min after removal of extracellular......A depolarizing chloride efflux has been suggested to activate voltage-dependent calcium channels in renal afferent arteriolar smooth muscle cells in response to vasoconstrictors. To test this proposal, rabbit afferent arterioles were microperfused, and the contractile dose responses...

  9. Soil transport parameters of potassium under a tropical saline soil condition using STANMOD

    Science.gov (United States)

    Suzanye da Silva Santos, Rafaelly; Honorio de Miranda, Jarbas; Previatello da Silva, Livia

    2015-04-01

    Environmental responsibility and concerning about the final destination of solutes in soil, so more studies allow a better understanding about the solutes behaviour in soil. Potassium is a macronutrient that is required in high concentrations, been an extremely important nutrient for all agricultural crops. It plays essential roles in physiological processes vital for plant growth, from protein synthesis to maintenance of plant water balance, and is available to plants dissolved in soil water while exchangeable K is loosely held on the exchange sites on the surface of clay particles. K will tend to be adsorbed onto the surface of negatively charged soil particles. Potassium uptake is vital for plant growth but in saline soils sodium competes with potassium for uptake across the plasma membrane of plant cells. This can result in high Na+:K+ ratios that reduce plant growth and eventually become toxic. This study aimed to obtain soil transport parameters of potassium in saline soil, such as: pore water velocity in soil (v), retardation factor (R), dispersivity (λ) and dispersion coefficient (D), in a disturbed sandy soil with different concentrations of potassium chlorate solution (KCl), which is one of the most common form of potassium fertilizer. The experiment was carried out using soil samples collected in a depth of 0 to 20 cm, applying potassium chlorate solution containing 28.6, 100, 200 and 500 mg L-1 of K. To obtain transport parameters, the data were adjusted with the software STANMOD. At low concentrations, interaction between potassium and soil occur more efficiently. It was observed that only the breakthrough curve prepared with solution of 500 mg L-1 reached the applied concentration, and the solution of 28.6 mg L-1 overestimated the parameters values. The STANMOD proved to be efficient in obtaining potassium transport parameters; KCl solution to be applied should be greater than 500 mg L-1; solutions with low concentrations tend to overestimate

  10. Preparation of potassium-reduced tantalum powders

    International Nuclear Information System (INIS)

    Kolosov, V.N.; Miroshnichenko, M.N.; Orlov, V.M.; Prokhorova, T.Yu.

    2005-01-01

    Characteristics of tantalum powders prepared by reduction of molten potassium heptafluorotantalate with liquid potassium are studied in a temperature range of 750 - 850 deg C using potassium chloride as a flux at a ratio of K 2 TaF 7 : KCl = 1, 2, and 3. The use of potassium as a reducing agent facilitates washing of tantalum powders for impurity salt removal, reduces sodium content and leakage currents in the anodes. As compared to sodium process, the potassium reduction results in a high yield of sponge material, a decrease in the specific surface area and yield of tantalum powder suitable for manufacture of capacitor anodes [ru

  11. Structurally diverse natural products that cause potassium leakage trigger multicellularity in Bacillus subtilis.

    Science.gov (United States)

    López, Daniel; Fischbach, Michael A; Chu, Frances; Losick, Richard; Kolter, Roberto

    2009-01-06

    We report a previously undescribed quorum-sensing mechanism for triggering multicellularity in Bacillus subtilis. B. subtilis forms communities of cells known as biofilms in response to an unknown signal. We discovered that biofilm formation is stimulated by a variety of small molecules produced by bacteria--including the B. subtilis nonribosomal peptide surfactin--that share the ability to induce potassium leakage. Natural products that do not cause potassium leakage failed to induce multicellularity. Small-molecule-induced multicellularity was prevented by the addition of potassium, but not sodium or lithium. Evidence is presented that potassium leakage stimulates the activity of a membrane protein kinase, KinC, which governs the expression of genes involved in biofilm formation. We propose that KinC responds to lowered intracellular potassium concentration and that this is a quorum-sensing mechanism that enables B. subtilis to respond to related and unrelated bacteria.

  12. Data on electrical properties of nickel modified potassium polytitanates compacted powders.

    Science.gov (United States)

    Goffman, V G; Gorokhovsky, A V; Gorshkov, N V; Fedorov, F S; Tretychenko, E V; Sevrugin, A V

    2015-09-01

    Potassium polytitanates are new promising type of ferroelectric ceramic materials with high ionic conductivity, highly polarizable structure and extremely high permittivity. Its structure is formed by [TiO6] octahedral units to layers with mobile potassium and hydroxonium ions in-between. The treatment in solutions containing nickel ions allows forming heterostructured materials which consist of potassium polytitanate particles intercalated by Ni(2+) ions and/or decorated by nickel oxides NiO x . This modification route is fully dependant on solution pH, i.e. in acidic solutions the intercalation process prevails, in alkaline solutions potassium polytitanate is mostly decorated by the oxides. Therefore, electronic structure and electrical properties can be regulated depending on modification conditions, pH and ions concentration. Here we report the data on electric properties of potassium titanate modified in nickel sulfate solutions at different pH.

  13. Data on electrical properties of nickel modified potassium polytitanates compacted powders

    Directory of Open Access Journals (Sweden)

    V.G. Goffman

    2015-09-01

    Full Text Available Potassium polytitanates are new promising type of ferroelectric ceramic materials with high ionic conductivity, highly polarizable structure and extremely high permittivity. Its structure is formed by [TiO6] octahedral units to layers with mobile potassium and hydroxonium ions in-between. The treatment in solutions containing nickel ions allows forming heterostructured materials which consist of potassium polytitanate particles intercalated by Ni2+ ions and/or decorated by nickel oxides NiOx. This modification route is fully dependant on solution pH, i.e. in acidic solutions the intercalation process prevails, in alkaline solutions potassium polytitanate is mostly decorated by the oxides. Therefore, electronic structure and electrical properties can be regulated depending on modification conditions, pH and ions concentration. Here we report the data on electric properties of potassium titanate modified in nickel sulfate solutions at different pH.

  14. Dermal extracellular lipid in birds.

    Science.gov (United States)

    Stromberg, M W; Hinsman, E J; Hullinger, R L

    1990-01-01

    A light and electron microscopic study of the skin of domestic chickens, seagulls, and antarctic penguins revealed abundant extracellular dermal lipid and intracellular epidermal lipid. Dermal lipid appeared ultrastructurally as extracellular droplets varying from less than 1 micron to more than 25 microns in diameter. The droplets were often irregularly contoured, sometimes round, and of relatively low electron density. Processes of fibrocytes were often seen in contact with extracellular lipid droplets. Sometimes a portion of such a droplet was missing, and this missing part appeared to have been "digested away" by the cell process. In places where cells or cell processes are in contact with fact droplets, there are sometimes extracellular membranous whorls or fragments which have been associated with the presence of fatty acids. Occasionally (in the comb) free fat particles were seen in intimate contact with extravasated erythrocytes. Fat droplets were seen in the lumen of small dermal blood and lymph vessels. We suggest that the dermal extracellular lipid originates in the adipocyte layer and following hydrolysis the free fatty acids diffuse into the epidermis. Here they become the raw material for forming the abundant neutral lipid contained in many of the epidermal cells of both birds and dolphins. The heretofore unreported presence and apparently normal utilization of abundant extracellular lipid in birds, as well as the presence of relatively large droplets of neutral lipid in dermal vessels, pose questions which require a thorough reappraisal of present concepts of the ways in which fat is distributed and utilized in the body.

  15. Elevated extracellular pH during early shell formation in the blue mussel Mytilus edulis

    Science.gov (United States)

    Ramesh, K.; Melzner, F.; Himmerkus, N.; Hu, M.; Bleich, M.

    2016-02-01

    Marine calcifiers are amongst the most vulnerable organisms to ocean acidification (OA). However, limited studies investigate the mechanisms underlying their hindered performance under OA stress. Working with larval stages of the blue mussel, Mytilus edulis, we use microsensors to study the pH and calcium conditions necessary for shell deposition. Using 45-48 hour, D-veliger stages, we discover alkaline conditions with respect to ambient seawater pH by 0.28 pH units and higher calcium concentrations (by 0.54mM) in the extra pallial space beneath the growing shell that likely promotes the rapid synthesis of the first shell. We further use enzyme assays in combination with immuno-stainings of sodium-potassium ATPase (NKA) and proton ATPase (VHA) to provide information on the major ion regulatory pathways that enable transport of calcium carbonate required for shell formation and pH homeostasis. We also use the juvenile stages of M. edulis to understand how extracellular pH regulation close to the shell formation site will be influenced by OA stress. This allows us to describe the pH dependency of early shell formation and to begin to develop a model of the ion regulatory network that facilitates biomineralisation in the organism. The results are discussed in the context of environmental change and consequences for mollusc developmental success.

  16. Potassium Capture by Kaolin, Part 1: KOH

    DEFF Research Database (Denmark)

    Wang, Guoliang; Jensen, Peter Arendt; Wu, Hao

    2018-01-01

    -capture level. The effect of reaction temperature,K-concentration in the flue gas, and, thereby, molar ratio of K/(Al+Si) in reactants, gas residence time, and solid particle size on K-capture reaction was systematically investigated. Corresponding equilibrium calculations were conducted with FactSage 7.......0. The experimental results showed that kaolin reached almost full conversion to K-aluminosilicates under suspension-fired conditions at 1100–1450 °C for a residence time of 1.2 s and a particle size of D50 = 5.47 μm. The amount of potassium captured by kaolin generally followed the equilibrium at temperatures above...

  17. High dose potassium-nitrate chemical dosimeter

    International Nuclear Information System (INIS)

    Dorda de Cancio, E.M.; Munoz, S.S.

    1982-01-01

    This dosimeter is used to control 10 kGY-order doses (1 Mrad). Nitrate suffers a radiolitic reduction phenomena, which is related to the given dose. The method to use potassium nitrate as dosimeter is described, as well as effects of the temperature of irradiation, pH, nitrate concentration and post-irradiation stability. Nitrate powder was irradiated at a Semi-Industrial Plant, at Centro Atomico Ezeiza, and also in a Gammacell-220 irradiator. The dose rates used were 2,60 and 1,80 KGY/hour, and the given doses varied between 1,0 and 150 KGY. The uncertainty was +-3% in all the range. (author) [es

  18. Comparative study of sodium and potassium in different types of gallstones and in serum of subjects with gallstones and controls

    International Nuclear Information System (INIS)

    Channa, N.A.; Ghanghro, A.B.; Soomro, A.M.

    2008-01-01

    The study comprises evaluation of sodium and potassium in the pathogenesis of human gallstones as well as measurement of the concentration of these elements in gallstones and in sera of 109 gallstone subjects and 100 controls (age and sex matched with no personal or family history of gallstone disease). It was observed that serum concentrations for both sodium and potassium were comparable (p<0.05) between gallstone subjects and control subjects. In gallstones the concentration of sodium was significantly higher as compared to potassium (p<0.5). Normal sodium to potassium ratio was seen in serum of gallstone subject, whereas, low sodium to potassium ratio was seen in gallstone carriers. Amongst the different types of gallstones, significantly high (p<0.05) concentrations of sodium and potassium were seen in calcium bilirubinate gallstones. The levels for these mineral elements were also raised in serum of pure calcium carbonate gallstone subjects. The results demonstrate that the higher concentration of sodium and potassium in gallstones may involve in both calcium bilirubinate gallstones and in serum of calcium carbonate gallstone subjects, which indicate their association with calcium in the precipitation of calcium bilirubinate and calcium carbonate in bile. Furthermore, low sodium to potassium ratio in gallstones indicates low ratio in bile of gallstone subjects. (author)

  19. Comparative Study of Sodium and Potassium in Different Types of Gallstones and in Serum of Subjects with Gallstones and Controls

    Directory of Open Access Journals (Sweden)

    Ali Mohammad Soomro

    2008-06-01

    Full Text Available The study comprises evaluation of sodium and potassium in the pathogenesis of human gallstones as well as measurement of the concentration of these elements in gallstones and in sera of 109 gallstone subjects and 100 controls (age and sex matched with no personal or family history of gallstone disease. It was observed that serum concentrations for both sodium and potassium were comparable (p>0.05 between gallstone subjects and control subjects. In gallstones the concentration of sodium was significantly higher as compared to potassium (p<0.05. Normal sodium to potassium ratio was seen in serum of gallstone subjects, whereas, low sodium to potassium ratio was seen in gallstone carriers. Amongst the different types of gallstones, significantly high (p<0.05 concentrations of sodium and potassium were seen in calcium bilirubinate gallstones. The levels for these mineral elements were also raised in serum of pure calcium carbonate gallstone subjects.The results demonstrate that the higher concentration of sodium and potassium in gallstones may involve in both calcium bilirubinate gallstones and in serum of calcium carbonate gallstone subjects, which indicate their association with calcium in the precipitation of calcium bilirubinate and calcium carbonate in bile. Furthermore, low sodium to potassium ratio in gallstones indicates low ratio in bile of gallstone subjects.

  20. Effect of potassium ferrate on disintegration of waste activated sludge (WAS).

    Science.gov (United States)

    Ye, Fenxia; Ji, Haizhuang; Ye, Yangfang

    2012-06-15

    The activated sludge process of wastewater treatment results in the generation of a considerable amount of excess activated sludge. Increased attention has been given to minimization of waste activated sludge recently. This paper investigated the effect of potassium ferrate oxidation pretreatment on the disintegration of the waste activated sludge at various dosages of potassium ferrate. The results show that potassium ferrate pretreatment disintegrated the sludge particle, resulting in the reduction of total solid content by 31%. The solubility (SCOD/TCOD) of the sludge increased with the increase of potassium ferrate dosage. Under 0.81 g/g SS dosage of potassium ferrate, SCOD/TCOD reached 0.32. Total nitrogen (TN) and total phosphorous (TP) concentrations in the solution all increased significantly after potassium ferrate pretreatment. The sludge particles reduced from 116 to 87 μm. The settleability of the sludge (SVI) was enhanced by 17%, which was due to the re-flocculation by the by-product, Fe(III), during potassium ferrate oxidation and the decrease of the viscosity. From the result of the present investigations, it can be concluded that potassium ferrate oxidation is a feasible method for disintegration of excess activated sludge. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Sodium and potassium urinary excretion levels of preschool children: Individual, daily, and seasonal differences.

    Science.gov (United States)

    Yasutake, Kenichiro; Nagafuchi, Mikako; Izu, Ryoji; Kajiyama, Tomomi; Imai, Katsumi; Murata, Yusuke; Ohe, Kenji; Enjoji, Munechika; Tsuchihashi, Takuya

    2017-06-01

    In this study, the authors measured sodium and potassium concentrations in spot urine samples of preschool children on multiple days, and evaluated individual, daily, and seasonal effects. A total of 104 healthy preschool children aged 4 to 5 years were studied. Urine samples were collected from the first urine of the day after waking for three consecutive days (Monday-Wednesday) four times a year (spring, summer, autumn, winter). The authors estimated the daily urine volume as 500 mL and daily creatinine excretion as 300 mg, and used these to calculate daily sodium and potassium excretion levels. Daily sodium and potassium excretion levels and sodium to potassium ratios were highly variable. The coefficient variant in the children's excretion levels were also high within and between individuals. Sodium excretion levels and sodium to potassium ratios were higher on Monday (weekend sodium intakes) than Tuesday. Season had no effect on sodium or potassium excretion levels, but the sodium to potassium ratio was higher in summer than in winter. In conclusion, levels of urinary sodium excretion are comparatively high and those of potassium are low in preschool students, with high variability within and between individuals. ©2017 Wiley Periodicals, Inc.

  2. Potassium Intake, Bioavailability, Hypertension, and Glucose Control

    Directory of Open Access Journals (Sweden)

    Michael S. Stone

    2016-07-01

    Full Text Available Potassium is an essential nutrient. It is the most abundant cation in intracellular fluid where it plays a key role in maintaining cell function. The gradient of potassium across the cell membrane determines cellular membrane potential, which is maintained in large part by the ubiquitous ion channel the sodium-potassium (Na+-K+ ATPase pump. Approximately 90% of potassium consumed (60–100 mEq is lost in the urine, with the other 10% excreted in the stool, and a very small amount lost in sweat. Little is known about the bioavailability of potassium, especially from dietary sources. Less is understood on how bioavailability may affect health outcomes. Hypertension (HTN is the leading cause of cardiovascular disease (CVD and a major financial burden ($50.6 billion to the US public health system, and has a significant impact on all-cause morbidity and mortality worldwide. The relationship between increased potassium supplementation and a decrease in HTN is relatively well understood, but the effect of increased potassium intake from dietary sources on blood pressure overall is less clear. In addition, treatment options for hypertensive individuals (e.g., thiazide diuretics may further compound chronic disease risk via impairments in potassium utilization and glucose control. Understanding potassium bioavailability from various sources may help to reveal how specific compounds and tissues influence potassium movement, and further the understanding of its role in health.

  3. Does short-term potassium fertilization improve recovery from drought stress in laurel?

    Science.gov (United States)

    Oddo, Elisabetta; Inzerillo, Simone; Grisafi, Francesca; Sajeva, Maurizio; Salleo, Sebastiano; Nardini, Andrea

    2014-08-01

    Xylem hydraulic conductance varies in response to changes in sap solute content, and in particular of potassium (K(+)) ion concentration. This phenomenon, known as the 'ionic effect', is enhanced in embolized stems, where it can compensate for cavitation-induced loss of hydraulic conductance. Previous studies have shown that in well-watered laurel plants (Laurus nobilis L.), potassium concentration of the xylem sap and plant hydraulic conductance increased 24 h after fertilization with KCl. The aim of this work was to test whether water-stressed laurel plants, grown under low potassium availability, could recover earlier from stress when irrigated with a KCl solution instead of potassium-free water. Two-year-old potted laurel seedlings were subjected to water stress by suspending irrigation until leaf conductance to water vapour (g(L)) dropped to ∼30% of its initial value and leaf water potential (ψ(L)) reached the turgor loss point (ψ(TLP)). Plants were then irrigated either with water or with 25 mM KCl and monitored for water status, gas exchange and plant hydraulics recovery at 3, 6 and 24 h after irrigation. No significant differences were found between the two experimental groups in terms of ψ(L), g(L), plant transpiration, plant hydraulic conductance or leaf-specific shoot hydraulic conductivity. Analysis of xylem sap potassium concentration showed that there were no significant differences between treatments, and potassium levels were similar to those of potassium-starved but well-watered plants. In conclusion, potassium uptake from the soil solution and/or potassium release to the xylem appeared to be impaired in water-stressed plants, at least up to 24 h after relief from water stress, so that fertilization after the onset of stress did not result in any short-term advantage for recovery from drought. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Change of heavy metal speciation, mobility, bioavailability, and ecological risk during potassium ferrate treatment of waste-activated sludge.

    Science.gov (United States)

    Yu, Ming; Zhang, Jian; Tian, Yu

    2018-05-01

    The effects of potassium ferrate treatment on the heavy metal concentrations, speciation, mobility, bioavailability, and environmental risk in waste-activated sludge (WAS) at various dosages of potassium ferrate and different treatment times were investigated. Results showed that the total concentrations of all metals (except Cd) were decreased slightly after treatment and the order of metal concentrations in WAS and treated waste-activated sludge (TWAS) was Mg > Zn > Cu > Cr > Pb > Ni > Cd. Most heavy metals in WAS remained in TWAS after potassium ferrate treatment with metal residual rates over 67.8% in TWAS. The distribution of metal speciation in WAS was affected by potassium ferrate treatment. The bioavailability and the mobility of heavy metals (except Mg) in TWAS were mitigated, compared to those in WAS. Meanwhile, the environmental risk of heavy metals (except Pb and Cu) was alleviated after potassium ferrate treatment.

  5. Unique chloride-sensing properties of WNK4 permit the distal nephron to modulate potassium homeostasis.

    Science.gov (United States)

    Terker, Andrew S; Zhang, Chong; Erspamer, Kayla J; Gamba, Gerardo; Yang, Chao-Ling; Ellison, David H

    2016-01-01

    Dietary potassium deficiency activates thiazide-sensitive sodium chloride cotransport along the distal nephron. This may explain, in part, the hypertension and cardiovascular mortality observed in individuals who consume a low-potassium diet. Recent data suggest that plasma potassium affects the distal nephron directly by influencing intracellular chloride, an inhibitor of the with-no-lysine kinase (WNK)-Ste20p-related proline- and alanine-rich kinase (SPAK) pathway. As previous studies used extreme dietary manipulations, we sought to determine whether the relationship between potassium and NaCl cotransporter (NCC) is physiologically relevant and clarify the mechanisms involved. We report that modest changes in both dietary and plasma potassium affect NCC in vivo. Kinase assay studies showed that chloride inhibits WNK4 kinase activity at lower concentrations than it inhibits activity of WNK1 or WNK3. Also, chloride inhibited WNK4 within the range of distal cell chloride concentration. Mutation of a previously identified WNK chloride-binding motif converted WNK4 effects on SPAK from inhibitory to stimulatory in mammalian cells. Disruption of this motif in WNKs 1, 3, and 4 had different effects on NCC, consistent with the three WNKs having different chloride sensitivities. Thus, potassium effects on NCC are graded within the physiological range, which explains how unique chloride-sensing properties of WNK4 enable it to mediate effects of potassium on NCC in vivo. Copyright © 2015 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  6. Impact of reduced atmospheric CO2 and varied potassium supply on carbohydrate and potassium distribution in grapevine and grape berries (Vitis vinifera L.).

    Science.gov (United States)

    Coetzee, Zelmari A; Walker, Rob R; Deloire, Alain J; Barril, Célia; Clarke, Simon J; Rogiers, Suzy Y

    2017-11-01

    To assess the robustness of the apparent sugar-potassium relationship during ripening of grape berries, a controlled-environment study was conducted on Shiraz vines involving ambient and reduced (by 34%) atmospheric CO 2 concentrations, and standard and increased (by 67%) soil potassium applications from prior to the onset of ripening. The leaf net photoassimilation rate was decreased by 35% in the reduced CO 2 treatment. The reduction in CO 2 delayed the onset of ripening, but at harvest the sugar content of the berry pericarp was similar to that of plants grown in ambient conditions. The potassium content of the berry pericarp in the reduced CO 2 treatment was however higher than for the ambient CO 2 . Berry potassium, sugar and water content were strongly correlated, regardless of treatments, alluding to a ternary link during ripening. Root starch content was lower under reduced CO 2 conditions, and therefore likely acted as a source of carbohydrates during berry ripening. Root carbohydrate reserve replenishment could also have been moderated under reduced CO 2 at the expense of berry ripening. Given that root potassium concentration was less in the vines grown in the low CO 2 atmosphere, these results point toward whole-plant fine-tuning of carbohydrate and potassium partitioning aimed at optimising fruit ripening. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. Formulation and evaluation of sublingual tablets of losartan potassium

    Directory of Open Access Journals (Sweden)

    Nikunj J. Aghera

    2012-05-01

    Full Text Available Objective: Sublingual tablets of Losartan Potassium were prepared to improve its bioavailability, to avoid pre-systemic metabolism in the gastrointestinal tract and hepatic first pass elimination. Methods: The Sublingual tablets were prepared by direct compression procedure using different concentration of Starch 1500 and microcrystalline cellulose. Compatibility studies of drug and polymer were performed by FTIR spectroscopy and DSC. Preformulation property of API was evaluated. Postcompressional parameters such disintegration time, wetting time, water absorption ratio, in vitro drug release and in vivo bioavailability study of optimized formulation were determined. Results: FTIR spectroscopy and DSC study revealed that there was no possible interaction between drug and polymers. The precompression parameters were in acceptable range of pharmacopoeial specification. The disintegration time of optimized formulation (F3 was upto 48 sec. The in vitro release of Losartan Potassium was upto 15 min. The percentage relative bioavailability of Losartan Potassium from optimized sublingual tablets was found to be 144.7 %. Conclusions: Sublingual tablets of Losartan Potassium were successfully prepared with improved bioavailability.

  8. Effect of osmolarity on potassium transport in isolated cerebral microvessels

    International Nuclear Information System (INIS)

    Lin, J.D.

    1988-01-01

    Potassium transport in microvessels isolated from rat brain by a technique involving density gradient centrifugation was studied in HEPES buffer solutions of varying osmolarity from 200 to 420 mosmols, containing different concentration of sodium chloride, choline chloride, or sodium nitrate. The flux of 86 Rb into and out of the endothelial cells was estimated. Potassium influx was very sensitive to the osmolarity of the medium. Ouabain-insensitive K-component was reduced in hypotonic medium and was increased in medium made hypertonic with sodium chloride or mannitol. Choline chloride replacement caused a large reduction in K influx. Potassium influx was significant decrease when nitrate is substituted for chloride ion in isotonic and hypertonic media, whereas a slight decrease was found in hypotonic medium. The decrease of K influx in the ion-replacement medium is due to a decrement of the ouabain-insensitive component. Potassium efflux was unchanged in hypotonic medium but was somewhat reduced in hypertonic medium. The marked effect of medium osmolarity of K fluxes suggests that these fluxes may be responsible for the volume regulatory K movements. The possible mechanism of changes of K flux under anisotonic media is also discussed

  9. Evaluation of human muscle in vivo by potassium radiometric measuring

    International Nuclear Information System (INIS)

    Sousa, Wanderson de P.

    2000-01-01

    Potassium is an essential element to the human metabolism and is present in all living cells, mainly in the striated muscular fibers. K-40 is one of the natural potassium isotopes with mass percentage of 0,0118% . This isotope emits beta particle and gamma rays with 1460 keV. The energy of K-40 photon and its uniform distribution within the human body allows its in vivo measurement. The objective of this study is to optimize this technique and evaluate the possibility of its medical application in order to quantify muscle increase during recovering procedures. Subjects of both sexes measured until this moment were divided into two groups. Subjects of Group 1 do not exercise routinely and subjects of Group 2 does. In Group 1 the average potassium mass, muscle mass and potassium concentration were (101±16)g of K, (20±3)kg of muscle and (1,3±0,3)g of K/kg of body mass, respectively, while in Group 2 average values were (125±38)g of K, (25±8)kg of muscle and (1,7±0,2)g of K/kg of body mass. The comparison between average values shows a clear difference, which allows to correlate a higher K mass with routine body activity. The technique has shown enough sensitivity for this application. (author)

  10. Potassium availability in soils - forms and spatial distribution

    International Nuclear Information System (INIS)

    Afari-Sefa, Victor; Kwakye, Peter K.; Nyamiah, Mercy; Okae-Anti, Daniel; Imoro, A. Ziblim

    2004-10-01

    Potassium forms the third most important plant nutrient limiting plant growth and consequently reducing crop yields. This study was conducted on soil potassium availability, distribution and relationship with other soil properties. Seventeen top soil samples (0-15 cm) were collected from four agro-ecological zones of the Central and Western Regions of Ghana. Water soluble, exchangeable and non-exchangeable forms of K were determined. The exchangeable K was extracted with 1 N-bar NH 4 OAc, 0.1 N-bar HNO 3 , 0.01 M-bar CaCl 2 , Bray No. 1 and 1 N-bar boiling HNO 3 . The non-exchangeable K was extracted with 1 N-bar boiling HNO 3 . Potassium was determined using flame photometer. The results showed that potassium is available in the soil in different forms and amounts. Soils from the forest-savanna transition and coastal savanna zones had relatively higher soil solution K concentration than soils from the moist rainforest and semi-deciduous forest zones. Also, soils of the semi-deciduous forest and forest savanna transition as well as the coastal savanna zones contained 2-3 times exchangeable K of the soils of the moist rainforest. The results also showed that the pH, texture as well as the land use affected K availability in the soils. (author)

  11. Potassium incorporation in fruits of South American tropical species

    International Nuclear Information System (INIS)

    Cid, Alberto S.; Anjos, Roberto M.; Macario, Kita D.; Veiga, Rodrigo; Lacerda, Thiago; Velasco, Hugo; Rizzoto, Marcos; Valladares, Daniel; Zamboni, Cibelle B.; Medeiros, Ilca M.A.

    2010-01-01

    Full text: This work proposes the use of a new mathematical model liable for describing the temporal evolution of potassium concentration in fruits of tropical species. Studies of the potassium incorporation are important for two main reasons: a) from the physiological point of view, this flux characterizes the dynamics of the demand of this essential macro nutrient during the gestation period of the fruit; and b) from a radioecological perspective, potassium is a chemical analogue of cesium, particularly of 137 Cs, one of the most important contaminant deposited after accidental releases of radionuclides into the environment. Therefore, describing the potassium incorporation, we can obtain crucial information on how this radionuclide can enter to the human food chain trough fruits. Nutrients accumulation by fruits has been extensively studied for different trees. These investigations have been addressed to evaluate the nutritional status at different stages of the fruit development, estimating the amount of the soil nutrient removal and then to know the better time to program the control and supply of fertilizers. The fruit quality and its aptitude to the conservation are closely related with de nutrient content and the equilibrium between them. The rate of the weight increment in fruit is not uniform. The dry mass accumulation is small in the initial period, later a more expressive increment is observed and, finally during the maturation period, a lower dry mass accumulation was observed. The lengths in days of each one of these grown phases depend of the fruit type. A sigmoid grown model appears to be a very good approximation. The nutrient accumulations follow characteristics patterns along these fruit grown phases. When food-chain model are used to describe the radionuclide key transfer processes for dose assessment, the steady state radionuclide concentration is assumed in each compartment. In many cases that could be a strict simplification of the reality

  12. Potassium incorporation in fruits of South American tropical species

    Energy Technology Data Exchange (ETDEWEB)

    Cid, Alberto S.; Anjos, Roberto M.; Macario, Kita D.; Veiga, Rodrigo; Lacerda, Thiago [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Velasco, Hugo; Rizzoto, Marcos; Valladares, Daniel [Univesidad Nacional de San Luis (Argentina); Zamboni, Cibelle B.; Medeiros, Ilca M.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    Full text: This work proposes the use of a new mathematical model liable for describing the temporal evolution of potassium concentration in fruits of tropical species. Studies of the potassium incorporation are important for two main reasons: a) from the physiological point of view, this flux characterizes the dynamics of the demand of this essential macro nutrient during the gestation period of the fruit; and b) from a radioecological perspective, potassium is a chemical analogue of cesium, particularly of {sup 137}Cs, one of the most important contaminant deposited after accidental releases of radionuclides into the environment. Therefore, describing the potassium incorporation, we can obtain crucial information on how this radionuclide can enter to the human food chain trough fruits. Nutrients accumulation by fruits has been extensively studied for different trees. These investigations have been addressed to evaluate the nutritional status at different stages of the fruit development, estimating the amount of the soil nutrient removal and then to know the better time to program the control and supply of fertilizers. The fruit quality and its aptitude to the conservation are closely related with de nutrient content and the equilibrium between them. The rate of the weight increment in fruit is not uniform. The dry mass accumulation is small in the initial period, later a more expressive increment is observed and, finally during the maturation period, a lower dry mass accumulation was observed. The lengths in days of each one of these grown phases depend of the fruit type. A sigmoid grown model appears to be a very good approximation. The nutrient accumulations follow characteristics patterns along these fruit grown phases. When food-chain model are used to describe the radionuclide key transfer processes for dose assessment, the steady state radionuclide concentration is assumed in each compartment. In many cases that could be a strict simplification of the

  13. Interaction of Low Doses of Ionizing Radiation, Potassium Dichromate and Cadmium Chloride in Artemia franciscana Biotest

    Directory of Open Access Journals (Sweden)

    K. Beňová

    2007-01-01

    Full Text Available The influence of cadmium chloride (at concentrations of 100 and 200 mg l-1 and potassium dichromate (at a concentration of 50 mg l-1 along with the effect of gamma radiation 60Co (at a dose of 10 and 50 Gy on lethality to Artemia franciscana was investigated. Four different interactions were studied, namely, those of potassium dichromate and gamma radiation, cadmium chloride and gamma radiation, and combinations of potassium dichromate and cadmium chloride in interaction with gamma radiation. A significant (α = 0.05 decrease was observed in lethality due to exposure to radiation (10 Gy in comparison with action of only potassium dichromate and cadmium chloride or their combination without exposure to gamma rays. These results support the theory of hormesis.

  14. Potassium

    Science.gov (United States)

    ... confusion listlessness tingling, prickling, burning, tight, or pulling sensation of arms, hands, legs, or feet heaviness or weakness of legs cold, pale, gray skin stomach pain unusual stomach bulging ...

  15. Atrial Na,K-ATPase increase and potassium dysregulation accentuate the risk of postoperative atrial fibrillation

    DEFF Research Database (Denmark)

    Tran, Cao Thach; Schmidt, Thomas Andersen; Christensen, John Brochorst

    2009-01-01

    BACKGROUND: Postoperative atrial fibrillation is a common complication to cardiac surgery. Na,K-ATPase is of major importance for the resting membrane potential and action potential. The purpose of the present study was to evaluate the importance of Na,K-ATPase concentrations in human atrial...... biopsies and plasma potassium concentrations for the development of atrial fibrillation. METHODS: Atrial myocardial biopsies were obtained from 67 patients undergoing open chest cardiac surgery. Na,K-ATPase was quantified using vanadate-facilitated 3H-ouabain binding. Plasma potassium concentration....../g wet weight (n = 33), p = 0.03]. Also with multivariable analysis, 3H-ouabain-binding site concentration was significantly associated with the development of atrial fibrillation. High increase in plasma potassium concentration during the perioperative period and surgery was associated...

  16. Operating experience with potassium systems

    International Nuclear Information System (INIS)

    Schwarz, N.F.

    1984-04-01

    In an international cooperation R and D work for the realization of potassium topping cycles to increase the conversion efficiency of thermal power stations is going on. Feasibility studies show that the realization of such a process can be achieved under economic considerations with existing materials and today's technology. Nevertheless, it has to be shown that the assumptions with respect to material behaviour and component reliability are based on sound technical premises. Therefore, in continuation of design studies, a hardware programme has been initiated in the Austrian Research Centre Seibersdorf. First results with respect to component and material behaviour are described. (Author) [de

  17. Combined effects of gamma radiation and potassium dichromate on morphological changes in guppy kidneys

    International Nuclear Information System (INIS)

    Benova, K.; Almasiova, V.; Dvorak, P.; Halan, M.

    2008-01-01

    Our experiment was conducted to investigate the effect of ionizing radiation and potassium dichromate on morphological changes in the kidneys of Poecilia reticulata. Fish were irradiated with gamma rays at a dose of 20 Gy and exposed to potassium dichromate in concentration of 50 mg · dm -3 . The combined effects resulted in marked morphological changes in urinary tubules. The brush border on the apical part of the cells was discontinuous, cytoplasm showed vacuolisation and the integrity of vessels was disturbed. (authors)

  18. The Effects of Changing Membrane Compositions and Internal Electrolytes on the Respon of Potassium Ion Sensor

    OpenAIRE

    Ulianas, Alizar; Heng, Lee Yook

    2015-01-01

    A study on the changing of membrane compositions and internal solution towards the response potassium ion sensor was carried out. Potassium ion sensor based on photocured cross linking poly(n-butyl acrylate) membranes with varying composition of valinomycin (val), sodium tetrakis [3.5-bis(trifluoro-methyl) phenyl] borat (NaTFPB), types ion of internal solution were investigated. Effects of varying composition of val, NaTFPB, types and concentration of internal solution were observed on potass...

  19. Crystal structure of the sodium-potassium pump (Na+,K+-ATPase) with bound potassium and ouabain

    OpenAIRE

    Ogawa, Haruo; Shinoda, Takehiro; Cornelius, Flemming; Toyoshima, Chikashi

    2009-01-01

    The sodium-potassium pump (Na+,K+-ATPase) is responsible for establishing Na+ and K+ concentration gradients across the plasma membrane and therefore plays an essential role in, for instance, generating action potentials. Cardiac glycosides, prescribed for congestive heart failure for more than 2 centuries, are efficient inhibitors of this ATPase. Here we describe a crystal structure of Na+,K+-ATPase with bound ouabain, a representative cardiac glycoside, at 2.8 Å resolution in a state analog...

  20. Radiation Doses to Hanford Workers from Natural Potassium-40

    Energy Technology Data Exchange (ETDEWEB)

    Strom, Daniel J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lynch, Timothy P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weier, Dennis R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2009-02-01

    The chemical element potassium is an essential mineral in people and is subject to homeostatic regulation. Natural potassium comprises three isotopes, 39K, 40K, and 41K. Potassium-40 is radioactive, with a half life of 1.248 billion years. In most transitions, it emits a β particle with a maximum energy of 0.560 MeV, and sometimes a gamma photon of 1.461 MeV. Because it is ubiquitous, 40K produces radiation dose to all human beings. This report contains the results of new measurements of 40K in 248 adult females and 2,037 adult males performed at the Department of Energy Hanford Site in 2006 and 2007. Potassium concentrations diminish with age, are generally lower in women than in men, and decrease with body mass index (BMI). The average annual effective dose from 40K in the body is 0.149 mSv y-1 for men and 0.123 mSv y-1 women respectively. Averaged over both men and women, the average effective dose per year is 0.136 mSv y-1. Calculated effective doses range from 0.069 to 0.243 mSv y-1 for adult males, and 0.067 to 0.203 mSv y-1 for adult females, a roughly three-fold variation for each gender. The need for dosimetric phantoms with a greater variety of BMI values should be investigated. From our data, it cannot be determined whether the potassium concentration in muscle in people with large BMI values differs from that in people with small BMI values. Similarly, it would be important to know the potassium concentration in other soft tissues, since much of the radiation dose is due to beta radiation, in which the source and target tissues are the same. These uncertainties should be evaluated to determine their consequences for dosimetry.

  1. Concentração de potássio na solução nutritiva e a qualidade e número de frutos de melão por planta em hidroponia Potassium concentration in nutrient solution and quality and number of fruits of melon, cultivated in hidroponic

    Directory of Open Access Journals (Sweden)

    Caciana Cavalcanti Costa

    2004-06-01

    Full Text Available O experimento foi conduzido em hidroponia (NFT no período de junho a novembro de 2001, na FCAV-UNESP em Jaboticabal-SP, situada a 21º15’ 22" Sul, 48º18’58" Oeste, e altitude de 575 metros. O híbrido Bônus n0 2 foi cultivado em blocos casualizados, em esquema de parcelas subdivididas, com seis repetições. Os elementos avaliados foram número de frutos por planta (2, 3, 4 e fixação livre e concentração de potássio na solução nutritiva (66; 115,5; 165 e 247,5mg L-1. O experimento teve como objetivo avaliar a concentração de potássio na solução nutritiva e número de frutos por planta sobre a qualidade dos frutos do meloeiro. Concentrações maiores do que 66mg L-1 de potássio na solução nutritiva não promoveram incrementos nas características de qualidade dos frutos do meloeiro como: teor de sólidos solúveis médio de todos os frutos da planta, do segundo fruto, da acidez total titulável média de todos os frutos da planta, do primeiro fruto, do segundo fruto, do índice de maturação, da espessura da polpa e do índice de formato dos frutos. Frutos oriundos de plantas de melão com dois frutos apresentaram maior teor de sólidos solúveis e acidez total titulável, independente da concentração de potássio na solução nutritiva. O maior número de frutos por planta reduziu a espessura do mesocarpo dos frutos.The experiment was carried out in Jaboticabal-SP. The hybrid Bonus n0 2 was cropped in randomized blocks design, in split-plot scheme and six replications. Fruit number per plant (2, 3, 4 e free fruit set and potassium concentration in the nutrient solution (66, 115.5, 165 and 247.5mg L-1 were the studied factors. The increase of potassium concentration in the nutrient solution did not promote increase melon fruit quality characteristics such as: average soluble solid content from all plant fruits or that of the second fruit; average total tritratable acidity from all plant fruits and that of the first or

  2. Potassium adsorption ratios as an indicator for the fate of agricultural potassium in groundwater

    NARCIS (Netherlands)

    Griffioen, J.

    2001-01-01

    Fertilization of agricultural land in groundwater infiltration areas often causes deterioration of groundwater quality. In addition to nitrogen and phosphorous, potassium deserves attention. The fate of potassium in the subsurface is controlled mainly by cation-exchange. Use of the Potassium

  3. Effects of allocryptopine on outward potassium current and slow delayed rectifier potassium current in rabbit myocardium.

    Science.gov (United States)

    Fu, Yi-Cheng; Zhang, Yu; Tian, Liu-Yang; Li, Nan; Chen, Xi; Cai, Zhong-Qi; Zhu, Chao; Li, Yang

    2016-05-01

    Allocryptopine (ALL) is an effective alkaloid of Corydalis decumbens (Thunb.) Pers. Papaveraceae and has proved to be anti-arrhythmic. The purpose of our study is to investigate the effects of ALL on transmural repolarizing ionic ingredients of outward potassium current (I to) and slow delayed rectifier potassium current (I Ks). The monophasic action potential (MAP) technique was used to record the MAP duration of the epicardium (Epi), myocardium (M) and endocardium (Endo) of the rabbit heart and the whole cell patch clamp was used to record I to and I Ks in cardiomyocytes of Epi, M and Endo layers that were isolated from rabbit ventricles. The effects of ALL on MAP of Epi, M and Endo layers were disequilibrium. ALL could effectively reduce the transmural dispersion of repolarization (TDR) in rabbit transmural ventricular wall. ALL decreased the current densities of I to and I Ks in a voltage and concentration dependent way and narrowed the repolarizing differences among three layers. The analysis of gating kinetics showed ALL accelerated the channel activation of I to in M layers and partly inhibit the channel openings of I to in Epi, M and Endo cells. On the other hand, ALL mainly slowed channel deactivation of I Ks channel in Epi and Endo layers without affecting its activation. Our study gives partially explanation about the mechanisms of transmural inhibition of I to and I Ks channels by ALL in rabbit myocardium. These findings provide novel perspective regarding the anti-arrhythmogenesis application of ALL in clinical settings.

  4. Effect of different concentrations of potassium and magnesium on ...

    African Journals Online (AJOL)

    use

    2011-11-21

    Nov 21, 2011 ... Plant physiology, Subject of nutrition and absorption. Tehran University press. (In Farsi). Fritz O, Sieverding E, Inechin K, Mazder P, Boller T, Wiemken A (2003). Impact of land use intensity on the species diversity of Arbuscular mycorrhizal fungi in agro-ecosystems of central Europe. Appl. Environ. Microbiol.

  5. Investigation of iodine liberation process in redox titration of potassium iodate with sodium thiosulfate

    Energy Technology Data Exchange (ETDEWEB)

    Asakai, Toshiaki, E-mail: t-asakai@aist.go.jp [National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 3-9, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563 (Japan); Hioki, Akiharu [National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 3-9, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563 (Japan)

    2011-03-09

    Potassium iodate is often used as a reference material to standardize a sodium thiosulfate solution which is a familiar titrant for redox titrations. In the standardization, iodine (triiodide) liberated by potassium iodate in an acidic potassium iodide solution is titrated with a sodium thiosulfate solution. The iodine liberation process is significantly affected by the amount of acid, that of potassium iodide added, the waiting time for the liberation, and light; therefore, the process plays a key role for the accuracy of the titration results. Constant-voltage biamperometry with a modified dual platinum-chip electrode was utilized to monitor the amount of liberated iodine under several liberation conditions. Coulometric titration was utilized to determine the concentration of a sodium thiosulfate solution on an absolute basis. Potassium iodate was assayed by gravimetric titration with the sodium thiosulfate solution under several iodine liberation conditions. The liberation process was discussed from the changes in the apparent assay of potassium iodate. The information of the appropriate titration procedure obtained in the present study is useful for any analysts utilizing potassium iodate to standardize a thiosulfate solution.

  6. Investigation of iodine liberation process in redox titration of potassium iodate with sodium thiosulfate

    International Nuclear Information System (INIS)

    Asakai, Toshiaki; Hioki, Akiharu

    2011-01-01

    Potassium iodate is often used as a reference material to standardize a sodium thiosulfate solution which is a familiar titrant for redox titrations. In the standardization, iodine (triiodide) liberated by potassium iodate in an acidic potassium iodide solution is titrated with a sodium thiosulfate solution. The iodine liberation process is significantly affected by the amount of acid, that of potassium iodide added, the waiting time for the liberation, and light; therefore, the process plays a key role for the accuracy of the titration results. Constant-voltage biamperometry with a modified dual platinum-chip electrode was utilized to monitor the amount of liberated iodine under several liberation conditions. Coulometric titration was utilized to determine the concentration of a sodium thiosulfate solution on an absolute basis. Potassium iodate was assayed by gravimetric titration with the sodium thiosulfate solution under several iodine liberation conditions. The liberation process was discussed from the changes in the apparent assay of potassium iodate. The information of the appropriate titration procedure obtained in the present study is useful for any analysts utilizing potassium iodate to standardize a thiosulfate solution.

  7. Vanadium, rubidium and potassium in Octopus vulgaris (Mollusca: Cephalopoda

    Directory of Open Access Journals (Sweden)

    Sónia Seixas

    2005-06-01

    Full Text Available The levels of vanadium, rubidium and potassium were determined in Octopus vulgaris caught during commercial fishing activities at three locations (Cascais, Santa Luzia and Viana do Castelo in Portugal in autumn and spring. We determined the concentration of these elements in digestive gland, branchial heart, gills, mantle and arms in males and females. At least five males and five females were assessed for each season/location combination. Elemental concentrations were determined by Particle Induced X-ray Emission (PIXE. Vanadium was detectable only in digestive gland and branchial heart samples. Its concentration was not correlated with total weight, total length or mantle length. There were no differences in concentrations of V, Rb and K between sexes. There were significant differences in vanadium concentrations in branchial hearts in autumn between samples from Viana do Castelo and those from the other two sites. We found a significant positive relationship between the concentration of vanadium and those of potassium and rubidium in branchial hearts. Branchial hearts appear to play an important role in decontamination of V.

  8. 21 CFR 582.1613 - Potassium bicarbonate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium bicarbonate. 582.1613 Section 582.1613 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Purpose Food Additives § 582.1613 Potassium bicarbonate. (a)...

  9. Potassium doped MWCNTs for hydrogen storage enhancement

    International Nuclear Information System (INIS)

    Adabi Qomi, S.; Gashtasebi, M.; Khoshnevisan, B.

    2012-01-01

    Here we have used potassium doped MWCNTs for enhancement of hydrogen storage process. XRD and SEM images have confirmed the doping of potassium. For studying the storage process a hydrogenic battery set up has been used. In the battery the working electrode has been made of the silver foam deposited by the doped MWCNTs electrophoretically.

  10. 75 FR 23298 - Potassium Permanganate From China

    Science.gov (United States)

    2010-05-03

    ... Permanganate From China AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the antidumping duty order on potassium permanganate from China. SUMMARY: The... on potassium permanganate from China would be likely to lead to continuation or recurrence of...

  11. 75 FR 51112 - Potassium Permanganate From China

    Science.gov (United States)

    2010-08-18

    ... Permanganate From China AGENCY: United States International Trade Commission. ACTION: Scheduling of an expedited five-year review concerning the antidumping duty order on potassium permanganate from China... of the antidumping duty order on potassium permanganate from China would be likely to lead to...

  12. 21 CFR 172.375 - Potassium iodide.

    Science.gov (United States)

    2010-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be...

  13. Ammonium nitrate-potassium nitrate system

    Energy Technology Data Exchange (ETDEWEB)

    Cady, H.H.

    1981-01-01

    A portion of the binary phase diagram for the system ammonium nitrate-potassium nitrate has been determined from -55/sup 0/C to 185/sup 0/C. Results are presented for the ammonium-nitrate-rich end of the system up to 30 wt% potassium nitrate.

  14. 21 CFR 184.1610 - Potassium alginate.

    Science.gov (United States)

    2010-04-01

    ...: Category of food Maximum level of use in food (as served) (percent) Functional use Confections and...) of this chapter 0.25 Do. All other food categories 0.01 Do. (d) Prior sanctions for potassium... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium alginate. 184.1610 Section 184.1610 Food...

  15. Effect of nitrogen and potassium fertilization on radiocesium absorption in soybean

    International Nuclear Information System (INIS)

    Nihei, Naoto; Hirose, Atsushi; Tanoi, Keitaro; Nakanishi, Tomoko M.

    2015-01-01

    Radioactive materials that were released during the nuclear accident contaminated the soil and agricultural products. It has become clear that potassium fertilization is effective for the reduction of radiocesium concentrations in agricultural crops. However, apart from reports about potassium, few reports have examined how nitrogen, which has a large effect on crop growth, contributes to the radiocesium absorption. Focusing on this point, we studied the effect of nitrogen and potassium fertilizer on the radiocesium absorption in soybean seedlings. The concentration of radiocesium in the seed of soybean was higher in nitrogen-fertilized plants than in plants grown without fertilizer. The radiocesium concentration in the aboveground biomass increased as the amount of nitrogen fertilization increased. But the concentrations of radiocesium were higher in potassium-fertilized plants at high-N than in plants without added nitrogen and potassium. Further study is required to clarify the factors that incur an increase in radiocesium concentration in response to nitrogen fertilization. Special care is required to start farming soybean on fallow fields evacuated after the accident or on fields where rice has been grown before, which tend to have higher available nitrogen than the regularly cultivated fields. (author)

  16. Leaching of potassium in a lysimeter experiment

    International Nuclear Information System (INIS)

    Gerzabek, M.H.

    1996-11-01

    Leaching of potassium was studied in the lysimeter plant in Seibersdorf/Austria (Pannonian climate). Averaged over three years, gravitational water amounted to 15.7% of the sum of precipitation (mean 485 mm) and irrigation (mean 138 mm). Differences between the four soils with respect to drainage were explained by the specific percentage of the soil skeleton. The average yearly potassium leaching ranged from 3.64 kg K/ha·yr (Dystric-Cambisol) to 22.7 kg K/ha·yr (drained Gleysol). Correlation between gravitational water volume and potassium leaching were only significant for one out of four soil types. No correlation was observed between extractable potassium in the soil profiles and potassium leaching. (author)

  17. Observations of the dynamics of ionic potassium-38 in brain

    International Nuclear Information System (INIS)

    Duncan, C.C.; Lambrecht, R.M.; Bennett, G.W.; Rescigno, A.; Ment, L.R.

    1984-01-01

    Short time course potassium dynamics in brain were investigated in the cat. 38 K (T1/2 . 7.6m) was prepared on the BNL 60'' cyclotron by the 40 Ar(p, 3n) 38 K reaction. Positron decay in brain was measured by the limited angle of view positron camera (LAPC). Radioactivity corrected for physical decay following intravenous bolus injection of 38 K showed an initial peak followed by a washout phase with a subsequent monotonic increase. The slope of the washout phase was linearly related to PaCO2 and the subsequent monotonic increase paralleled the arterial concentration of the tracer. No significant changes in 38 K radioactivity were determined following coma producing levels of phenobarbital or seizure producing doses of potassium penicillin as compared to control

  18. Secretory proteins of the pulmonary extracellular lining

    International Nuclear Information System (INIS)

    Gupta, R.P.; Patton, S.E.; Eddy, M.; Smits, H.L.; Jetten, A.M.; Nettesheim, P.; Hook, G.E.R.

    1986-01-01

    The objective of this investigation was to identify proteins in the pulmonary extracellular lining (EL) that are secreted by cells of the pulmonary epithelium. Pulmonary lavage effluents from the lungs of rabbits were centrifuged to remove all cells and particulate materials. Serum proteins were removed by repeatedly passing concentrated lavage effluent fluid through an affinity column containing IgG fraction of goat anti-rabbit (whole serum) antiserum bound to Sepharose-4B. Nonserum proteins accounted for 21.3 +/- 10.3% of the total soluble proteins in pulmonary lavage effluents. Serum free lavage effluents (SFL) contained 25 identifiable proteins as determined by using SDS-PAGE under reducing conditions. Of these proteins approximately 73% was accounted for by a single protein with MW of 66 kd. The secretory nature of the proteins present in SFL was investigated by studying the incorporation of 35 S-methionine into proteins released by lung slices and trachea followed by SDS-PAGE and autoradiography. Many, but not all proteins present in SFL were identified as proteins secreted by pulmonary tissues. The major secretory proteins appeared to have MWs of 59, 53, 48, 43, 24, 14, and 6 kd under reducing conditions. These data demonstrate the presence of several proteins in the pulmonary extracellular lining that appear to be secreted by the pulmonary epithelium

  19. Extracellular histones induce erythrocyte fragility and anemia.

    Science.gov (United States)

    Kordbacheh, Farzaneh; O'Meara, Connor H; Coupland, Lucy A; Lelliott, Patrick M; Parish, Christopher R

    2017-12-28

    Extracellular histones have been shown to play an important pathogenic role in many diseases, primarily through their cytotoxicity toward nucleated cells and their ability to promote platelet activation with resultant thrombosis and thrombocytopenia. In contrast, little is known about the effect of extracellular histones on erythrocyte function. We demonstrate in this study that histones promote erythrocyte aggregation, sedimentation, and using a novel in vitro shear stress model, we show that histones induce erythrocyte fragility and lysis in a concentration-dependent manner. Furthermore, histones impair erythrocyte deformability based on reduced passage of erythrocytes through an artificial spleen. These in vitro results were mirrored in vivo with the injection of histones inducing anemia within minutes of administration, with a concomitant increase in splenic hemoglobin content. Thrombocytopenia and leukopenia were also observed. These findings suggest that histones binding to erythrocytes may contribute to the elevated erythrocyte sedimentation rates observed in inflammatory conditions. Furthermore, histone-induced increases in red blood cell lysis and splenic clearance may be a significant factor in the unexplained anemias seen in critically ill patients. © 2017 by The American Society of Hematology.

  20. Extracellular vesicles: Exosomes, microvesicles, and friends

    NARCIS (Netherlands)

    Raposo, G.; Stoorvogel, W.|info:eu-repo/dai/nl/074352385

    2013-01-01

    Cells release into the extracellular environment diverse types of membrane vesicles of endosomal and plasma membrane origin called exosomes and microvesicles, respectively. These extracellular vesicles (EVs) represent an important mode of intercellular communication by serving as vehicles for

  1. The reference range of serum magnesium substance concentration ...

    African Journals Online (AJOL)

    Background: Magnesium is the second most abundant intracellular cation, with only a small proportion of the body's content being in the extracellular fluid. It is required for the active transport of other cations such as calcium, sodium and potassium across the membrane by active transport system. It is also needed for many ...

  2. Interacting influence of potassium and polychlorinated biphenyl on cortisol and aldosterone biosynthesis

    International Nuclear Information System (INIS)

    Li, L.-A.; Lin, Tsu-Chun Emma

    2007-01-01

    Giving human adrenocortical H295R cells 14 mM KCl for 24 h significantly induced not only aldosterone biosynthesis but also cortisol biosynthesis. Pre-treating the cells with polychlorinated biphenyl 126 (PCB126) further increased potassium-induced aldosterone and cortisol productions in a dose-dependent manner, but all examined concentrations of PCB126 had little effect on the yields of precursor steroids progesterone and 17-OH-progesterone. Subsequent examinations revealed that CYP11B1 and CYP11B2 genes, responsible for the respective final steps of the cortisol and aldosterone biosynthetic pathways, exhibited increased responsiveness to PCB126 under high potassium. While 10 -5 M PCB126 was needed to induce a significant increase in the basal mRNA abundance of either gene, PCB126 could enhance potassium-induced mRNA expression of CYP11B1 at 10 -7 M and CYP11B2 at 10 -9 M. Actually, potassium and PCB126 synergistically upregulated mRNA expression of both genes. Potassium raised the transcriptional rates of CYP11B1 and CYP11B2 probably through a conserved Ad5 cis-element, whereas PCB126 appeared to regulate these two genes at the post-transcriptional level. Positive potassium-PCB126 synergism was also detected in CYP11B2 enzyme activity estimated by aldosterone/progesterone ratio. In contrast, potassium and PCB126 increased CYP11B1 enzyme activity or cortisol/17-OH-progesterone ratio additively. Moreover, potassium improved the time effect of PCB126 on gene expression and enzyme activity of CYP11B2, but not the PCB126 time response of CYP11B1. These data demonstrated that potassium differentially enhanced the potency of PCB126 to induce CYP11B1- and CYP11B2-mediated steroidogenesis

  3. Corrosion phenomena in sodium-potassium coolant resulting from solute interaction in multicomponent solution

    Science.gov (United States)

    Krasin, V. P.; Soyustova, S. I.

    2018-03-01

    The solubility of Fe, Cr, Ni, V, Mn and Mo in sodium-potassium melt has been calculated using the mathematical framework of pseudo-regular solution model. The calculation results are compared with available published experimental data on mass transfer of components of austenitic stainless steel in sodium-potassium loop under non-isothermal conditions. It is shown that the parameters of pair interaction of oxygen with transition metal can be used to predict the corrosion behavior of structural materials in sodium-potassium melt in the presence of oxygen impurity. The results of calculation of threshold concentration of oxygen of ternary oxide formation of sodium with transitional metals (Fe, Cr, Ni, V, Mn, Mo) are given in conditions when pure solid metal comes in contact with sodium-potassium melt.

  4. Study Of Calcium And Potassium Different Nature Strength Gel Kappa-Carrageenan

    Directory of Open Access Journals (Sweden)

    Петро Васильович Гурський

    2015-07-01

    Full Text Available The influence of certain organic and mineral salts of potassium and calcium for strength gel kappa-carrageenan. The influence of the mass concentration of individual calcium for strength gels with different content kappa-carrageenan. Grounded mass concentration of some calcium salts for use in the composition of the jelly for sweet and savory dishes based on kappa-carrageenan

  5. Effect of potassium and potting-bag size on foliar biomass and ...

    African Journals Online (AJOL)

    Foliar fresh mass was significantly increased by the interaction between K concentration and potting-bag size. Growers may use a 5.3 mmol L−1 K concentration and a 5 L potting bag for optimum production of rose geranium under soil-less cultivation. Keywords: C:G ratio, enzyme activation, oil quality, potassium, rose ...

  6. TWIK-1 two-pore domain potassium channels change ion selectivity and conduct inward leak sodium currents in hypokalemia.

    Science.gov (United States)

    Ma, Liqun; Zhang, Xuexin; Chen, Haijun

    2011-06-07

    Background potassium (K+) channels, which are normally selectively permeable to K+, maintain the cardiac resting membrane potential at around -80 mV. In subphysiological extracellular K+ concentrations ([K+]o), which occur in pathological hypokalemia, the resting membrane potential of human cardiomyocytes can depolarize to around -50 mV, whereas rat and mouse cardiomyocytes become hyperpolarized, consistent with the Nernst equation for K+. This paradoxical depolarization of cardiomyocytes in subphysiological [K+]o, which may contribute to cardiac arrhythmias, is thought to involve an inward leak sodium (Na+) current. Here, we show that human cardiac TWIK-1 (also known as K2P1) two-pore domain K+ channels change ion selectivity, becoming permeable to external Na+, and conduct inward leak Na+ currents in subphysiological [K+]o. A specific threonine residue (Thr118) within the pore selectivity sequence TxGYG was required for this altered ion selectivity. Mouse cardiomyocyte-derived HL-1 cells exhibited paradoxical depolarization with ectopic expression of TWIK-1 channels, whereas TWIK-1 knockdown in human spherical primary cardiac myocytes eliminated paradoxical depolarization. These findings indicate that ion selectivity of TWIK-1 K+ channels changes during pathological hypokalemia, elucidate a molecular basis for inward leak Na+ currents that could trigger or contribute to cardiac paradoxical depolarization in lowered [K+]o, and identify a mechanism for regulating cardiac excitability.

  7. Structural and functional analysis of the putative pH sensor in the Kir1.1 (ROMK) potassium channel.

    Science.gov (United States)

    Rapedius, Markus; Haider, Shozeb; Browne, Katharine F; Shang, Lijun; Sansom, Mark S P; Baukrowitz, Thomas; Tucker, Stephen J

    2006-06-01

    The pH-sensitive renal potassium channel Kir1.1 is important for K+ homeostasis. Disruption of the pH-sensing mechanism causes type II Bartter syndrome. The pH sensor is thought to be an anomalously titrated lysine residue (K80) that interacts with two arginine residues as part of an 'RKR triad'. We show that a Kir1.1 orthologue from Fugu rubripes lacks this lysine and yet is still highly pH sensitive, indicating that K80 is not the H+ sensor. Instead, K80 functionally interacts with A177 on transmembrane domain 2 at the 'helix-bundle crossing' and controls the ability of pH-dependent conformational changes to induce pore closure. Although not required for pH inhibition, K80 is indispensable for the coupling of pH gating to the extracellular K+ concentration, explaining its conservation in most Kir1.1 orthologues. Furthermore, we demonstrate that instead of interacting with K80, the RKR arginine residues form highly conserved inter- and intra-subunit interactions that are important for Kir channel gating and influence pH sensitivity indirectly.

  8. Extracellular secretion of recombinant proteins

    Science.gov (United States)

    Linger, Jeffrey G.; Darzins, Aldis

    2014-07-22

    Nucleic acids encoding secretion signals, expression vectors containing the nucleic acids, and host cells containing the expression vectors are disclosed. Also disclosed are polypeptides that contain the secretion signals and methods of producing polypeptides, including methods of directing the extracellular secretion of the polypeptides. Exemplary embodiments include cellulase proteins fused to secretion signals, methods to produce and isolate these polypeptides, and methods to degrade lignocellulosic biomass.

  9. G-protein-coupled inward rectifier potassium channels involved in corticostriatal presynaptic modulation.

    Science.gov (United States)

    Meneses, David; Mateos, Verónica; Islas, Gustavo; Barral, Jaime

    2015-09-01

    Presynaptic modulation has been associated mainly with calcium channels but recent data suggests that inward rectifier potassium channels (K(IR)) also play a role. In this work we set to characterize the role of presynaptic K(IR) channels in corticostriatal synaptic transmission. We elicited synaptic potentials in striatum by stimulating cortical areas and then determined the synaptic responses of corticostriatal synapsis by using paired pulse ratio (PPR) in the presence and absence of several potassium channel blockers. Unspecific potassium channels blockers Ba(2+) and Cs(+) reduced the PPR, suggesting that these channels are presynaptically located. Further pharmacological characterization showed that application of tertiapin-Q, a specific K(IR)3 channel family blocker, also induced a reduction of PPR, suggesting that K(IR)3 channels are present at corticostriatal terminals. In contrast, exposure to Lq2, a specific K(IR)1.1 inward rectifier potassium channel, did not induce any change in PPR suggesting the absence of these channels in the presynaptic corticostriatal terminals. Our results indicate that K(IR)3 channels are functionally expressed at the corticostriatal synapses, since blockage of these channels result in PPR decrease. Our results also help to explain how synaptic activity may become sensitive to extracellular signals mediated by G-protein coupled receptors. A vast repertoire of receptors may influence neurotransmitter release in an indirect manner through regulation of K(IR)3 channels. © 2015 Wiley Periodicals, Inc.

  10. Inward-rectifying potassium (Kir) channels regulate pacemaker activity in spinal nociceptive circuits during early life

    Science.gov (United States)

    Li, Jie; Blankenship, Meredith L.; Baccei, Mark L.

    2013-01-01

    Pacemaker neurons in neonatal spinal nociceptive circuits generate intrinsic burst-firing and are distinguished by a lower “leak” membrane conductance compared to adjacent, non-bursting neurons. However, little is known about which subtypes of leak channels regulate the level of pacemaker activity within the developing rat superficial dorsal horn (SDH). Here we demonstrate that a hallmark feature of lamina I pacemaker neurons is a reduced conductance through inward-rectifying potassium (Kir) channels at physiological membrane potentials. Differences in the strength of inward rectification between pacemakers and non-pacemakers indicate the presence of functionally distinct Kir currents in these two populations at room temperature. However, Kir currents in both groups showed high sensitivity to block by extracellular Ba2+ (IC50 ~ 10 µM), which suggests the presence of ‘classical’ Kir (Kir2.x) channels in the neonatal SDH. The reduced Kir conductance within pacemakers is unlikely to be explained by an absence of particular Kir2.x isoforms, as immunohistochemical analysis revealed the expression of Kir2.1, Kir2.2 and Kir2.3 within spontaneously bursting neurons. Importantly, Ba2+ application unmasked rhythmic burst-firing in ~42% of non-bursting lamina I neurons, suggesting that pacemaker activity is a latent property of a sizeable population of SDH cells during early life. In addition, the prevalence of spontaneous burst-firing within lamina I was enhanced in the presence of high internal concentrations of free Mg2+, consistent with its documented ability to block Kir channels from the intracellular side. Collectively, the results indicate that Kir channels are key modulators of pacemaker activity in newborn central pain networks. PMID:23426663

  11. Selective effects of potassium elevations on glutamate signaling and action potential conduction in hippocampus.

    Science.gov (United States)

    Meeks, Julian P; Mennerick, Steven

    2004-01-07

    High-frequency synaptic transmission is depressed by moderate rises in the extracellular potassium concentration ([K+]o). Previous reports have indicated that depression of action potential signaling may underlie the synaptic depression. Here, we investigated the specific contribution of K+-induced action potential changes to synaptic depression. We found that glutamatergic transmission in the hippocampal area CA1 was significantly depressed by 8-10 mM [K+]o, but that GABAergic transmission remained intact. Riluzole, a drug that slows recovery from inactivation of voltage-gated sodium channels (NaChs), interacts with subthreshold [K+]o to depress afferent volleys and EPSCs strongly. Thus, elevated [K+]o likely depresses synapses by slowing NaCh recovery from inactivation. It is unclear from previous studies whether [K+]o-induced action potential depression is caused by changes in initiation, reliability, or waveform. We investigated these possibilities explicitly. [K+]o-induced afferent volley depression was independent of stimulus strength, suggesting that changes in action potential initiation do not explain [K+]o-induced depression. Measurements of action potentials from single axons revealed that 8 mM [K+]o increased conduction failures in a subpopulation of fibers and depressed action potential amplitude in all fibers. Together, these changes quantitatively account for the afferent volley depression. We estimate that conduction failure explains more than half of the synaptic depression observed at 8 mM [K+]o, with the remaining depression likely explained by waveform changes. These mechanisms of selective sensitivity of glutamate release to [K+]o accumulation represent a unique neuromodulatory mechanism and a brake on runaway excitation.

  12. Performance and mechanism of sludge dewaterability enhanced by potassium ferrate pretreatment and calcium chloride addition

    Directory of Open Access Journals (Sweden)

    Yali Liu

    2017-06-01

    Full Text Available The potential benefits and mechanisms of potassium ferrate pretreatment and calcium chloride addition on sludge dewaterability were investigated in this study. The capillary suction time (CST was used to evaluate sludge dewaterability. Results indicated that potassium ferrate of 0.1 g/g total solids (TS and calcium chloride of 0.4 g/g TS were optimal parameters, and corresponding CST reached 43.7 s. Soluble organics in extracellular polymeric substances (EPS were determined by three-dimensional excitation-emission matrix fluorescence spectroscopy, which was used to explain the mechanism of sludge dewaterability. The fluorescence intensities of protein-like and humic-like substances in EPS had a negative relationship with the CST. Scanning electron microscopy images indicated that calcium chloride neutralized the surface charge of particles, making the soluble protein-like substances agglomerate and form bigger flocs, consequently enhancing sludge dewaterability.

  13. VKCDB: Voltage-gated potassium channel database

    Directory of Open Access Journals (Sweden)

    Gallin Warren J

    2004-01-01

    Full Text Available Abstract Background The family of voltage-gated potassium channels comprises a functionally diverse group of membrane proteins. They help maintain and regulate the potassium ion-based component of the membrane potential and are thus central to many critical physiological processes. VKCDB (Voltage-gated potassium [K] Channel DataBase is a database of structural and functional data on these channels. It is designed as a resource for research on the molecular basis of voltage-gated potassium channel function. Description Voltage-gated potassium channel sequences were identified by using BLASTP to search GENBANK and SWISSPROT. Annotations for all voltage-gated potassium channels were selectively parsed and integrated into VKCDB. Electrophysiological and pharmacological data for the channels were collected from published journal articles. Transmembrane domain predictions by TMHMM and PHD are included for each VKCDB entry. Multiple sequence alignments of conserved domains of channels of the four Kv families and the KCNQ family are also included. Currently VKCDB contains 346 channel entries. It can be browsed and searched using a set of functionally relevant categories. Protein sequences can also be searched using a local BLAST engine. Conclusions VKCDB is a resource for comparative studies of voltage-gated potassium channels. The methods used to construct VKCDB are general; they can be used to create specialized databases for other protein families. VKCDB is accessible at http://vkcdb.biology.ualberta.ca.

  14. Potassium as an index of fruit content in baby food products. Part I. Banana-containing and apricot-containing products.

    Science.gov (United States)

    Harvey, R A; Theuer, R C

    1991-01-01

    Percentage ingredient labeling has been proposed for baby foods. We determined whether or not the potassium content of baby foods could be used to verify the quantity of fruit when the characterizing ingredients were apricots or bananas, fruits rich in potassium. Official values for potassium in fruit (USDA Handbook No. 8-9) did not agree well with actual analyses. The potassium levels of products of known composition were accurately predicted from analyses of the actual ingredients used to make the foods. For banana-containing monofruit products of variable or unknown composition, potassium analysis led to fruit level estimates consistent with either the known composition or the label declaration. For products of unknown composition made with apricot concentrate, however, potassium analysis led to fruit level estimates lower than the probable fruit content. The quantity of fruit in baby foods made with potassium-rich fruits can be estimated from the potassium content if the potassium value for the fruit is representative of the actual ingredients used to make the product. If potassium analysis is to be used to verify compliance with percentage ingredient labeling, there must be statutory specification of the single-strength fruit level for fruit reconstituted from concentrate.

  15. Cole–Cole Parameter Characterization of Urea and Potassium for Improving Dialysis Treatment Assessment

    DEFF Research Database (Denmark)

    Jensen, Peter Damsgaard; Meaney, Paul M.; Epstien, Neil R.

    2012-01-01

    In this letter, we investigate the characteristics of the dielectric properties of urea and ions such as potassium and sodium, which are the principal molecules studied during dialysis treatment. The method involves measuring the electrical properties of varying concentrations of the constituent...... solutions over a broad frequency range and estimating the associated Cole–Cole parameters. We utilized concentrations above those expected in vivo to achieve a more accurate characterization. In these studies, we found that the conductivity was essentially constant with respect to urea concentration but had...... a strong, nearly linear correlation with potassium. In addition, the alpha factor had a distinct, monotonically varying relationship for both urea and potassium with significantly different initial slopes. Utilizing these two curves, simple inversion algorithms are possible to compute the solute...

  16. Comparison of bioavailability and pharmacokinetics of diclofenac sodium and diclofenac potassium in normal and dehydrated rabbits.

    Science.gov (United States)

    Ahmad, Mahmood; Iqbal, Muhammad; Murtaza, Ghulam

    2009-01-01

    Two different salts of diclofenac, diclofenac sodium and diclofenac potassium, in tablet dosage form were tested for their bioavailability and disposition kinetics in a group of eighteen rabbits in normal and experimentally induced dehydrated conditions with a wash out period of 7 days between both stages of study. Biochemical and physiological parameters were also measured in both normal and dehydrated states. Diclofenac levels in plasma were determined using a validated reversed phase HPLC method. Primary kinetic parameters i.e. AUC(0-infinity), Cmax, Tmax and other disposition kinetics were obtained with non-compartmental procedure. Biochemical parameters i.e. packed cell volume, plasma glucose and total lipid concentration in dehydrated rabbits increased significantly. Plasma concentration of diclofenac sodium and diclofenac potassium decreased significantly in water deprived rabbits. In comparison, diclofenac potassium in normal and dehydrated state of the same group of rabbits showed a significantly increased plasma concentration when compared with diclofenac sodium.

  17. Thermodynamic properties of potassium chloride aqueous solutions

    Science.gov (United States)

    Zezin, Denis; Driesner, Thomas

    2017-04-01

    Potassium chloride is a ubiquitous salt in natural fluids, being the second most abundant dissolved salt in many geological aqueous solutions after sodium chloride. It is a simple solute and strong electrolyte easily dissociating in water, however the thermodynamic properties of KCl aqueous solutions were never correlated with sufficient accuracy for a wide range of physicochemical conditions. In this communication we propose a set of parameters for a Pitzer-type model which allows calculation of all necessary thermodynamic properties of KCl solution, namely excess Gibbs free energy and derived activity coefficient, apparent molar enthalpy, heat capacity and volume, as well as osmotic coefficient and activity of water in solutions. The system KCl-water is one of the best studied aqueous systems containing electrolytes. Although extensive experimental data were collected for thermodynamic properties of these solutions over the years, the accurate volumetric data became available only recently, thus making possible a complete thermodynamic formulation including a pressure dependence of excess Gibbs free energy and derived properties of the KCl-water liquids. Our proposed model is intended for calculation of major thermodynamic properties of KCl aqueous solutions at temperatures ranging from freezing point of a solution to 623 K, pressures ranging from saturated water vapor up to 150 MPa, and concentrations up to the salt saturation. This parameterized model will be further implemented in geochemical software packages and can facilitate the calculation of aqueous equilibrium for reactive transport codes.

  18. On the fusibility of potassium heptafluorotantalate

    International Nuclear Information System (INIS)

    Agulyanskij, A.I.; Bessonova, V.A.

    1983-01-01

    Phase transformations of potassium heptafluorotantalate near the liquidus temperature have been studied. Thermograms and polytherm of the electric condUctivity of potassium heptafluorotantalate, thermogram of the mechanical mixture 0.5 K 2 TaF 7 +0.5 KF and thermogram of K 3 TaF 8 crystallization are plotted. The phase diagram of the K 2 TaF 7 -KF system is presented. In the temperature range 746 to 778 deg, i.e. above K 2 TaF 7 melting point, the melt is shown to remain heterogeneous. A portion of the phase diagram rich in potassium heptafluorotantalate is qualified as an ordinary eutectics

  19. X-ray absorption in atomic potassium

    International Nuclear Information System (INIS)

    Gomilsek, Jana Padeznik; Kodre, Alojz; Arcon, Iztok; Nemanic, Vincenc

    2008-01-01

    A new high-temperature absorption cell for potassium vapor is described. X-ray absorption coefficient of atomic potassium is determined in the energy interval of 600 eV above the K edge where thresholds for simultaneous excitations of 1s and outer electrons, down to [1s2p] excitation, appear. The result represents also the atomic absorption background for XAFS (X-ray absorption fine structure) structure analysis. The K ionization energy in the potassium vapor is determined and compared with theoretical data and with the value for the metal

  20. Nutrient concentrations in potato stem, petiole and leaflet in response to potassium fertilizer Teores de nutrientes no caule, pecíolo e limbo da batateira em função da adubação potássica

    Directory of Open Access Journals (Sweden)

    Roberto dos Anjos Reis Jr.

    2000-06-01

    Full Text Available Chemical composition of potato stem, petiole and leaflet were evaluated in response to the application of K fertilizer. Potassium was applied at six different rates (0, 60, 120, 240, 480 and 960 kg ha-1 of K2O, as K2SO4 and was placed in the furrow during planting. Two plants per plot were sampled 48 days after plant emergence to evaluate N, P, K, Ca, Mg, S, Cu, Mn and Zn concentrations in stems, petioles and leaflets of the youngest fully expanded leaf. It is recommended using potato petioles to evaluate the N, P, K, Ca, Mg and Cu status and using potato leaflet to evaluate the S, Mn and Zn status. The stem was not a good indicator of S nutritional status. Petiole N, P and Cu concentrations associated with the maximum tuber yield (30.5 t ha-1, with 353.4 kg ha-1 of K2O were 25.9 g kg-1, 1.4 g kg-1 and 9.7 mg kg-1, respectively, while, the leaflet S, Mn and Zn concentrations associated with the maximum tuber yield were 4.0 g kg-1, 155.2 mg kg-1 and 59.4 mg kg-1, respectively. This information should be used to build data banks of adequate nutrient concentration at different portions of potato plant and like this, to aid the nutrient diagnosis in potato crops.Para avaliar a composição mineral em órgãos da batateira em função da adubação potássica, foi realizado experimento com doses de potássio (0, 60, 120, 240, 480 e 960 kg ha-1 de K2O delineado em blocos casualizados com quatro repetições. Duas plantas por parcela foram amostradas aos 48 dias após emergência das plantas para avaliar teores de N, P, K, Ca, Mg, S, Cu, Mn e Zn no caule, pecíolo e limbo da folha recém madura. Recomenda-se utilizar o pecíolo da batateira para avaliar o status de N, P, K, Ca, Mg e Cu e utilizar o limbo da batateira para avaliar o status de S, Mn e Zn. O caule não foi um bom indicador do estado nutricional em relação ao S. A aplicação de 353,4 kg ha-1 de K2O proporcionou a máxima produtividade de tubérculos (30,5 t ha-1 e teores de N, P e Cu no

  1. Hyperpolarization moves S4 sensors inward to open MVP, a methanococcal voltage-gated potassium channel.

    Science.gov (United States)

    Sesti, Federico; Rajan, Sindhu; Gonzalez-Colaso, Rosana; Nikolaeva, Natalia; Goldstein, Steve A N

    2003-04-01

    MVP, a Methanococcus jannaschii voltage-gated potassium channel, was cloned and shown to operate in eukaryotic and prokaryotic cells. Like pacemaker channels, MVP opens on hyperpolarization using S4 voltage sensors like those in classical channels activated by depolarization. The MVP S4 span resembles classical sensors in sequence, charge, topology and movement, traveling inward on hyperpolarization and outward on depolarization (via canaliculi in the protein that bring the extracellular and internal solutions into proximity across a short barrier). Thus, MVP opens with sensors inward indicating a reversal of S4 position and pore state compared to classical channels. Homologous channels in mammals and plants are expected to function similarly.

  2. A pharmacokinetic analysis of diclofenac potassium soft-gelatin capsule in patients after bunionectomy.

    Science.gov (United States)

    Kowalski, Mark; Stoker, Douglas G; Bon, Charles; Moore, Keith A; Boesing, Stephen E

    2010-01-01

    The clinical utility of diclofenac potassium, a nonsteroidal anti-inflammatory drug, may be lessened by inconsistent gastrointestinal absorption. Diclofenac potassium liquid filled soft-gelatin capsule (DPSGC) is an investigational formulation that uses ProSorb dispersion technology to facilitate rapid and consistent gastrointestinal absorption. In this study, the pharmacokinetic (PK) properties of DPSGC are investigated and compared with a commercially available oral diclofenac potassium tablet in patients after primary unilateral first metatarsal bunionectomy. In an open-label, randomized study, 53 patients received ProSorb-D 12.5 mg (the liquid equivalent of DPSGC), DPSGC 25 mg, DPSGC 50 mg, or immediate-release diclofenac potassium 50-mg tablet administered every 8 hours for a 24-hour inpatient period followed by 7 days of outpatient dosing. Diclofenac steady-state PK was evaluated over an 8-hour sampling period 4 days after surgery. Delayed and/or multiple peaks in the diclofenac plasma concentration-time course profiles occurred more frequently with the commercially available oral diclofenac potassium 50-mg tablet than with the other DPSGC formulations. PK data for ProSorb-D 12.5-mg liquid, DPSGC 25 mg, DPSGC 50 mg, and diclofenac potassium 50-mg tablet revealed mean peak plasma concentrations (Cmax) of 302, 749, 1006, and 902 ng/mL, respectively, whereas area under the plasma concentration curve values were 316, 595, 1029, and 1166 ng-hour/mL, respectively. Mean times to Cmax (tmax) were 0.49, 0.63, 0.95, and 1.26 h, respectively. When compared with absorption characteristics of diclofenac potassium 50-mg tablet, DPSGC was more rapidly and consistently absorbed after bunionectomy. These characteristics should be advantageous when rapid pain relief is desired.

  3. Electrical Transport Ability of Nanostructured Potassium-Doped Titanium Oxide Film

    Science.gov (United States)

    Lee, So-Yoon; Matsuno, Ryosuke; Ishihara, Kazuhiko; Takai, Madoka

    2011-02-01

    Potassium-doped nanostructured titanium oxide films were fabricated using a wet corrosion process with various KOH solutions. The doped condition of potassium in TiO2 was confirmed by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Nanotubular were synthesized at a dopant concentration of 0.27%, these structures disappeared. To investigate the electrical properties of K-doped TiO2, pseudo metal-oxide-semiconductor field-effect transistor (MOSFET) samples were fabricated. The samples exhibited a distinct electrical behavior and p-type characteristics. The electrical behavior was governed by the volume of the dopant when the dopant concentration was 0.18%.

  4. Evaluation of the effects of occupational noise exposure on serum aldosterone and potassium among industrial workers

    Directory of Open Access Journals (Sweden)

    Sajad Zare

    2016-01-01

    Full Text Available The existing literature indicates that occupational exposure to noise may have adverse effects on workers′ health. The aim of this study was to evaluate the possible effects of exposure to different sound pressure levels (SPLs on serum aldosterone and potassium concentration among Iranian blue collar workers in Golgohar Mining and Industrial Company in Sirjan, Kerman Province, Iran. This case-control study was performed on 45 workers of Golgohar Mining and Industrial Company. The subjects consisted of 30 workers from manufacturing departments and 15 office employees of the mining company. The controls, mainly with administrative jobs were exposed to 72 dBA SPL. Cases, in two separate groups, were exposed to noise levels of 88 dBA and 103 dBA, respectively. Noise intensity was measured at the desired locations. Noise measurements were performed according to the International Organization for Standardization (ISO 9612. To measure the serum aldosterone and potassium concentrations, a 5 mL blood sample was taken from each worker at the specified time intervals and aldosterone concentration was determined using enzyme-linked immunosorbent assay (ELISA test in the laboratory. Repeated measurement and Spearman′s correlation coefficient analysis were used with α = 0.05. Exposure to the different levels of sound pressure resulted in different aldosterone concentrations and meanwhile an increase in the SPL did not affect the concentration of potassium. From 10:00 AM to 10:30 AM, as SPL increased, aldosterone concentrations did not increase significantly but from 13:30 PM to 14:00 PM, raised SPL led to a significant increase in aldosterone concentration. However, there was no correlation between the concentration of potassium and different factors. This study indicated that increases in SPLs affect aldosterone concentration but at the same time do not have significant effects on serum potassium level.

  5. Effect of palytoxin on the sodium–potassium pump: model and simulation

    International Nuclear Information System (INIS)

    Rodrigues, Antônio M; Infantosi, Antonio F C; Almeida, Antônio-Carlos G

    2008-01-01

    We propose a reaction model for the palytoxin–sodium–potassium (PTX–Na + /K + ) pump complex. The model, which is similar to the Albers–Post model for Na + /K + -ATPase, is used to elucidate the effect of PTX on Na + /K + -ATPase during the enzyme interactions with Na + and/or K + ions. Conformational substates and reactions for the pump are incorporated into the Albers–Post model to represent enzymes with or without bound PTX. A mathematical model based on the reaction scheme is used in simulations modeling experimental studies of PTX-induced ionic currents. Our simulations suggest that (i) extracellular Na + as well as K + promotes PTX-induced channel blockage; (ii) extracellular K + accelerates PTX unbinding; and (iii) K + occlusion in the PTX–pump complex is essential for describing the PTX-induced current dynamics

  6. Potassium citrate prevents increased osteoclastogenesis resulting from acidic conditions: Implication for the treatment of postmenopausal bone loss.

    Directory of Open Access Journals (Sweden)

    Donatella Granchi

    Full Text Available The extracellular acidic milieu in bones results in activation of osteoclasts (OC and inhibition of osteoblasts (OB causing a net loss of calcium from the skeleton and the deterioration of bone microarchitecture. Alkalinization through supplementation with potassium citrate (K citrate has been proposed to limit the osteopenia progression, even though its pharmacological activity in bone microenvironment is not well defined. We evaluated if K citrate was able to prevent the adverse effects that acidic milieu induces on bone cells. OC and OB were maintained in neutral (pH 7.4 versus acidic (pH 6.9 culture medium, and treated with different K citrate concentrations. We evaluated the OC differentiation at seven days, by counting of multinucleated cells expressing tartrate-resistant acid phosphatase, and the activity of mature OC at 14 days, by quantifying of collagen degradation. To evaluate the effects on OB, we analyzed proliferation, mineralization, and expression of bone-related genes. We found that the low pH increased OC differentiation and activity and decreased OB function. The osteoclastogenesis was also promoted by RANKL concentrations ineffective at pH 7.4. Non-cytotoxic K citrate concentrations were not sufficient to steadily neutralize the acidic medium, but a inhibited the osteoclastogenesis, the collagen degradation, and the expression of genes involved in RANKL-mediated OC differentiation, b enhanced OB proliferation and alkaline phosphatase expression, whereas it did not affect the in vitro mineralization, and c were effective also in OC cultures resistant to alendronate, i.e. the positive control of osteoclastogenesis inhibition. In conclusion, K citrate prevents the increase in OC activity induced by the acidic microenvironment, and the effect does not depend exclusively on its alkalizing capacity. These data provide the biological basis for the use of K citrate in preventing the osteopenia progression resulting from low

  7. Effect of potassium on micromorphological and chemical ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... study the effect of potassium on yield and internal leaf tissues composition of cotton ... Nitrogen (N) and phosphorus (P) were applied at 150 mg N/kg soil and 75 mg ..... Copper enzymes in isolated chloroplasts: Polyphenol.

  8. Crystal structure transformation in potassium acrylate

    Science.gov (United States)

    Pai Verneker, V. R.; Vasanthakumari, R.

    1983-10-01

    Potassium acrylate undergoes a reversible phase transformation around 335°K with an activation energy of 133 kcal/mole. Differential scanning calorimetry and high temperature X-ray powder diffraction techniques have been used to probe this phenomenon.

  9. Thanatochemistry: Study of vitreous humor potassium

    African Journals Online (AJOL)

    Nilesh Keshav Tumram

    2014-02-18

    Feb 18, 2014 ... particularly vitreous potassium has received most attention. It is known that ... respect to different age and sex at different death intervals. The details regarding the ... Analyser by the Ion selective method. The reagents used ...

  10. Photoconductivity and dielectric studies of potassium pentaborate

    Indian Academy of Sciences (India)

    Single crystal of potassium pentaborate (KB5) has been grown by solution growth ... equipped with the Gunn Oscillator guided with rectangular wave-guide. ... its dielectric behaviour with the change of frequency has also been investigated.

  11. Overnight soaking or boiling of "Matooke" to reduce potassium content for patients with chronic kidney disease: does it really work?

    Science.gov (United States)

    Asiimwe, J; Sembajwe, L F; Senoga, A; Bakiika, E; Muwonge, H; Kalyesubula, R

    2013-09-01

    There is an increase in number of patients with chronic kidney disease (CKD) in Uganda's health facilities looking for different options of preparing matooke (bananas), their staple food. To establish and evaluate an effective method of removing potassium from bananas (matooke). Bananas were sampled from 5 markets in Kampala, Uganda. Deionized water was used to soak the bananas and the potassium concentration was determined using an atomic absorption spectrophotometer in both the bananas and water after soaking for varying time intervals. We also determined the potassium concentrations in the bananas and the water after boiling the bananas at 200 degrees Celsius at intervals of 10 minutes (for 60 minutes). The potassium concentration did not appear to change on soaking alone without boiling. However, on boiling, the concentration in the bananas decreased from about 1.4 ppm to approx. 1 ppm after 60 min; yet the concentration of potassium released into deionized water increased steadily from 0.0 ppm to about 1.2 ppm after 60 min of boiling. This study demonstrates that boiling the bananas is a more effective way of removing the potassium from bananas than simply soaking them.

  12. Drug utilization review of potassium chloride injection formulations available in a private hospital in kuching, sarawak, malaysia.

    Science.gov (United States)

    Melissa, Mohammad Hirman; Azmi, Sarriff

    2013-07-01

    The concentrated potassium chloride injection is a high-alert medication and replacing it with a pre-mixed formulation can reduce the risks associated with its use. The aim of this study was to determine the clinical characteristics of patients receiving different potassium chloride formulations available at a private institution. The study also assessed the effectiveness and safety of pre-mixed formulations in the correction of hypokalaemia. This was a retrospective observational study consisting of 296 cases using concentrated and pre-mixed potassium chloride injections in 2011 in a private hospital in Kuching, Sarawak, Malaysia. There were 135 (45.6%) cases that received concentrated potassium chloride, and 161 (54.4%) cases that received pre-mixed formulations. The patients' clinical characteristics that were significantly related to the utilization of the different formulations were diagnosis (P < 0.001), potassium serum blood concentration (P < 0.05), and fluid overload risk (P < 0.05). The difference observed for the cases that achieved or maintained normokalaemia was statistically insignificant (P = 0.172). Infusion-related adverse effects were seen more in pre-mixes compared to concentrated formulations (6.8% versus 2.2%, P < 0.05). This study provides insight into the utilization of potassium chloride injections at this specific institution. The results support current recommendations to use pre-mixed formulations whenever possible.

  13. Extracellular Vesicles in Hematological Disorders

    Directory of Open Access Journals (Sweden)

    Anat Aharon

    2014-10-01

    Full Text Available Extracellular vesicles (EVs, comprised of exosomes, microparticles, apoptotic bodies, and other microvesicles, are shed from a variety of cells upon cell activation or apoptosis. EVs promote clot formation, mediate pro-inflammatory processes, transfer proteins and miRNA to cells, and induce cell signaling that regulates cell differentiation, proliferation, migration, invasion, and apoptosis. This paper will review the contribution of EVs in hematological disorders, including hemoglobinopathies (sickle cell disease, thalassemia, paroxysmal nocturnal hemoglobinuria, and hematological malignancies (lymphomas, myelomas, and acute and chronic leukemias.

  14. Blood extracellular DNA after irradiation

    International Nuclear Information System (INIS)

    Vladimirov, V.G.; Tishchenko, L.I.; Surkova, E.A.; Vasil'eva, I.N.

    1993-01-01

    It has been shown that blood extracellular DNA of irradiated rats largely consists of the low-molecular DNA and its oligomers. Molecular masses of oligomers are multiple to molecular mass of monomer fragment with nucleosome size. The low-molecular DNA has linear form. The average content of GC-pairs in low-molecular DNA is higher than in total rat's DNA (48.5% against 41.5%). The low-molecular DNA is a part of complex containing RNA, acidic proteins and lipids. It is assumed that the formation of low-molecular DNA is a result of Ca/Mg - dependent nuclear endonuclease action

  15. Suicidal Ingestion of Potassium Permanganate Crystals: A Rare Encounter

    OpenAIRE

    Karthik, Ravikanti; Veerendranath, Hari Prasad Kanakapura; Wali, Siddraj; Mohan, Murali N T; Kumar, Praveen A. C.; Trimurty, Gaganam

    2014-01-01

    Potassium permanganate poisoning is not common. Although Symptoms of potassium permanganate ingestion are gastrointestinal and Complications due to ingestion of potassium permanganate include cardiovascular depression, hepatic and renal damage, upper airway obstruction, bleeding tendency and methemoglobinemia. Gastric damage due to potassium permanganate has rarely been reported previously. We are reporting a 34-year old female patient who presented to our Emergency Department after suicidal ...

  16. The Ketogenic Diet and Potassium Channel Function

    Science.gov (United States)

    2015-11-01

    1 AWARD NUMBER: W81XWH-13-1-0463 TITLE: The Ketogenic Diet and Potassium Channel Function PRINCIPAL INVESTIGATOR: Dr. Geoffrey Murphy...NUMBER The Ketogenic Diet and Potassium Channel Function 5b. GRANT NUMBER W81XWH-13-1-0463 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Geoffrey Murphy...The overall objective of this Discovery Award was to explore the hypothesis the ketogenic diet (KD) regulates neuronal excitability by influencing

  17. Digoxin affects potassium homeostasis during exercise in patients with heart failure.

    Science.gov (United States)

    Schmidt, T A; Bundgaard, H; Olesen, H L; Secher, N H; Kjeldsen, K

    1995-04-01

    The aim was to evaluate whether digitalisation of heart failure patients affects extrarenal potassium handling during and following exercise, and to assess digoxin receptor occupancy in human skeletal muscle in vivo. In a paired study of before versus after digitalisation, 10 patients with congestive heart failure underwent identical exercise sessions consisting of three bouts of increasing work rates, 41-93 W, on a cycle ergometer. The final bouts were followed by exercise to exhaustion. The femoral vessels and brachial artery were catheterised. Arterial blood pressure, heart rate, leg blood flow, cardiac output, plasma potassium, haemoglobin, pH, and skeletal muscle receptor occupancy with digoxin in biopsies were determined. Occupancy of skeletal muscle Na/K-ATPase with digoxin was 9% (P digitalisation femoral venous plasma potassium increased by 0.2-0.3 mmol.litre-1 (P digitalisation the femoral venoarterial difference in plasma potassium increased by 50-100% (P digitalisation on plasma potassium were not the outcome of changes in haemodynamics, because cardiac output and leg blood flow increased by up to 13% and 19% (P < 0.05), nor was it the outcome of changes in haemoconcentration or pH. Extrarenal potassium handling is altered as a result of digoxin treatment. This is likely to reflect a reduced capacity of skeletal muscle Na/K-ATPase for active potassium uptake because of inhibition by digoxin, adding to the reduction of skeletal muscle Na/K-ATPase concentration induced by heart failure per se. In heart failure patients, improved haemodynamics induced by digoxin may, however, increase the capacity for physical conditioning. Thus the impairment of extrarenal potassium homeostasis by heart failure and digoxin treatment may be counterbalanced by training.

  18. Potassium chloride production by microcline chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Orosco, Pablo, E-mail: porosco@unsl.edu.ar [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina); Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, San Luis (Argentina); Ruiz, María del Carmen [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina)

    2015-08-10

    Highlights: • Use of chlorination for the KCl production. • The reagents used were microcline, hydromagnesite and chlorine. • Isothermal and non-isothermal assays were performed in Cl{sub 2}–N{sub 2} mixture. • The chlorination generated KCl at 700 °C. • The chlorination products promote KCl formation. - Abstract: The potassium chloride is one of the most important fertilizers used in agriculture. The current demand of this salt makes interesting the study of potassium chloride production from unconventional potassium resources. In this work the potassium chloride production by chlorination of microcline was investigated. The starting reagents were microcline, hydromagnesite and chlorine. Non-isothermal and isothermal chlorination assays were carried out in a thermogravimetric device adapted to work in corrosive atmospheres. The temperature effect on potassium extraction and the phase transformations produced during chlorination of microcline were studied. The reagents and reaction products were analyzed by X-ray fluorescence (XRF) and X-ray diffraction (XRD). The experimental results indicated that by chlorination of microcline an important extraction of potassium in the temperature range from 800 to 900 °C was produced. Moreover, at 800 °C the forsterite, enstatite and magnesium aluminate spinel phases were generated.

  19. Asthma caused by potassium aluminium tetrafluoride: a case series

    OpenAIRE

    LA?TOVKOV?, Andrea; KLUS??KOV?, Pavlina; FENCLOV?, Zdenka; BONNETERRE, Vincent; PELCLOV?, Daniela

    2015-01-01

    The objective of this study is to describe a case-series of potassium aluminium tetrafluoride (KAlF4)-induced occupational asthma (OA) and/or occupational rhinitis (OR). The study involves five patients from a heat-exchanger production line who were examined (including specific inhalation challenge tests) for suspected OA and/or OR caused by a flux containing almost 100% KAlF4 ? with fluorides? workplace air concentrations ranging between 1.7 and 2.8?mg/m3. No subject had a previous history o...

  20. Extracellular nucleotide signaling in plants

    Energy Technology Data Exchange (ETDEWEB)

    Stacey, Gary [Univ. of Missouri, Columbia, MO (United States)

    2016-09-08

    Over the life of this funded project, our research group identified and characterized two key receptor proteins in plants; one mediating the innate immunity response to chitin and the other elucidating the key receptor for extracellular ATP. In the case of chitin recognition, we recently described the quaternary structure of this receptor, shedding light on how the receptor functions. Perhaps more importantly, we demonstrated that all plants have the ability to recognize both chitin oligomers and lipochitooligosacchardes, fundamentally changing how the community views the evolution of these systems and strategies that might be used, for example, to extend symbiotic nitrogen fixation to non-legumes. Our discovery of DORN1 opens a new chapter in plant physiology documenting conclusively that eATP is an important extracellular signal in plants, as it is in animals. At this point, we cannot predict just how far reaching this discovery may prove to be but we are convinced that eATP signaling is fundamental to plant growth and development and, hence, we believe that the future will be very exciting for the study of DORN1 and its overall function in plants.

  1. Transverse thermal magnetoresistance of potassium

    International Nuclear Information System (INIS)

    Newrock, R.S.; Maxfield, B.W.

    1976-01-01

    Results are presented of extensive thermal magnetoresistance measurements on single-crystal and polycrystalline specimens of potassium having residual resistance ratios (RRR) ranging from 1100 to 5300. Measurements were made between 2 and 9 0 K for magnetic fields up to 1.8 T. The observed thermal magnetoresistance cannot be understood on the basis of either semiclassical theories or from the electrical magnetoresistance and the Wiedemann-Franz law. A number of relationships are observed between the thermal and electrical magnetoresistances, many of which are not immediately obvious when comparing direct experimental observations. The thermal magnetoresistance W(T,H) is given reasonably well by W(T,H)T = W(T,0)T + AH + BH 2 , where both A and B are temperature-dependent coefficients. Results show that A = A 0 + A 1 T 3 , while B(T) cannot be expressed as any simple power law. A 0 is dependent on the RRR, while A 1 is independent of the RRR. Two relationships are found between corresponding coefficients in the electrical and thermal magnetoresistance: (i) the Wiedmann--Franz law relates A 0 to the Kohler slope of the electrical magnetoresistance and (ii) the temperature-dependent portions of the electrical and thermal Kohler slopes are both proportional to the electron--phonon scattering contribution to the corresponding zero-field resistance. The latter provides evidence that inelastic scattering is very important in determining the temperature-dependent linear magnetoresistances. Part, but by no means all, of the quadratic thermal resistance is accounted for by lattice thermal conduction. It is concluded that at least a portion of the anomalous electrical and thermal magnetoresistances is due to intrinsic causes and not inhomogeneities or other macroscopic defects

  2. Extracellular hyperosmolality and body temperature during physical exercise in dogs

    Science.gov (United States)

    Kozlowski, S.; Greenleaf, J. E.; Turlejska, E.; Nazar, K.

    1980-01-01

    The purpose of this study was to test the hypothesis that thermoregulation during exercise can be affected by extracellular fluid hyperosmolality without changing the plasma Na(+) concentration. The effects of preexercise venous infusions of hypertonic mannitol and NaCl solutions on rectal temperature responses were compared in dogs running at moderate intensity for 60 min on a treadmill. Plasma Na(+) concentration was increased by 12 meq after NaCl infusion, and decreased by 9 meq after mannitol infusion. Both infusions increased plasma by 15 mosmol/kg. After both infusions, rectal temperature was essentially constant during 60 min rest. However, compared with the noninfusion exercise increase in osmolality of 1.3 C, rectal temperature increased by 1.9 C after both postinfusion exercise experiments. It was concluded that inducing extracellular hyperosmolality, without elevating plasma, can induce excessive increases in rectal temperature during exericse but not at rest.

  3. Stabilize lead and cadmium in contaminated soils using hydroxyapatite and potassium chloride.

    Science.gov (United States)

    Wang, Li; Li, Yonghua; Li, Hairong; Liao, Xiaoyong; Wei, Binggan; Ye, Bixiong; Zhang, Fengying; Yang, Linsheng; Wang, Wuyi; Krafft, Thomas

    2014-12-01

    Combination of hydroxyapatite (HAP) and potassium chloride (KCl) was used to stabilize lead and cadmium in contaminated mining soils. Pot experiments of chilli (Capsicum annuum) and rape (Brassica rapachinensis) were used to evaluate the stabilization efficiency. The results were the following: (1) the optimal combination decreased the leachable lead by 83.3 and 97.27 %, and decreased leachable cadmium by 57.82 and 35.96% for soil HF1 and soil HF2, respectively; (2) the total lead and cadmium concentrations in both plants decreased 69 and 44 %, respectively; (3) The total lead and cadmium concentrations in the edible parts of both vegetables also decreased significantly. This study reflected that potassium chloride can improve the stabilization efficiency of hydroxyapatite, and the combination of hydroxyapatite and potassium chloride can be effectively used to remediate lead and cadmium contaminated mining soil.

  4. Permeability of solutes through cellophanes grafted with vinyl monomers. II. Diffusion of potassium chloride through cellophanes grafted with acrylic acid

    International Nuclear Information System (INIS)

    Takigami, S.; Maeda, Y.; Nakamura, Y.

    1979-01-01

    The permeability behavior of potassium chloride through cellophane grafted with acrylic acid by a γ-irradiation method was studied by the theoretical equation derived from the phenomenological equation and compared with the results of Donnan membrane equilibrium. It was shown that the permeation of potassium chloride through the grafted cellophanes exhibited behavior typical of a polyionic membrane for grafts of more than 55% but depended on the permeability of both cellophane and graft regions for lower percents of grafting. It was found that the dominant factor affecting the permeation of potassium chloride was an effective concentration of fixed charge in the membrane. 5 figures, 2 tables

  5. Kidney in potassium depletion. II. K+ handling by the isolated perfused rat kidney

    International Nuclear Information System (INIS)

    Hayashi, M.; Katz, A.I.

    1987-01-01

    In a companion paper the authors reported a large increment in Na + -K + -ATPase activity and [ 3 H]ouabain binding the inner stripe of outer medullary collecting tubules from K-depleted rats. To test the hypothesis that the increased number of Na + -K + pumps in these animals may be involved in potassium reabsorption they examined the effect of ouabain on K excretion by isolated, perfused kidneys from rats fed a K-free diet for 3 wk. Kidneys from K-depleted rats retain potassium avidly, both the fractional (FE/sub K/) and absolute K excretion being approximately fivefold lower than in control kidneys. Ouabain (5 mM) increased FE/sub K/ in kidneys from each K-depleted rat; similar results were obtained when kidneys were perfused with low and high potassium concentrations. In contrast, ouabain produced a variable effect in control kidneys, that depended on the perfusate potassium concentration. In K-depleted rats amiloride did not significantly alter K excretion and did not block the ouabain-induced kaliuresis, suggesting that the latter is not due to enhanced secretion secondary to increased distal fluid delivery. These results provide evidence for ouabain-sensitive potassium reabsorption in kidneys of chronically K-depleted rats, and suggest an explanation for the increased Na + -K + -ATPase observed in such animals

  6. Determination of microamounts of potassium in sodium iodide by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Ogasawara, Ken; Ohta, Masatoshi; Abe, Kenzo

    1980-01-01

    Microdetermination of potassium in sodium iodide was developed by the standard addition method. Twenty grams of sample were dissolved in 50 ml of water in a quartz beaker. To the solution, 30 ml of concentrated hydrochloric acid and 30 ml of 30% hydrogen peroxide were added, and evaporated to dryness. By this process sodium iodide was converted into sodium chloride. The cake thus obtained was dissolved in water and diluted to exactly 200 ml. To 25 ml aliquots of the solution, the standard potassium and cesium chloride solutions were added and diluted to 50 ml with water; the concentration of potassium was 0 -- 1 mg/l and that of cesium 4 mM. These solutions were introduced into an air-propane flame and the absorbances were measured at 769.9 nm. During the conversion reaction, hydrochloric acid was completely decomposed, and remained hydrogen peroxide had no influence for absorbance, and other backgrounds were negligible. The linear calibration curve was obtained in the range 0 -- 2 mg of potassium per liter. Potassium in sodium iodide was determined by this method within the coefficient of variation of +-(20 -- 3)% in the range (1.7 -- 32.5) ppm. (author)

  7. Effect of polacrilin potassium as disintegrant on bioavailability of diclofenac potassium in tablets : a technical note.

    Science.gov (United States)

    Bele, Mrudula H; Derle, Diliprao V

    2012-09-01

    Polacrilin potassium is an ion exchange resin used in oral pharmaceutical formulations as a tablet disintegrant. It is a weakly acidic cation exchange resin. Chemically, it is a partial potassium salt of a copolymer of methacrylic acid with divinyl benzene. It ionizes to an anionic polymer chain and potassium cations. It was hypothesized that polacrilin potassium may be able to improve the permeability of anionic drugs according to the Donnan membrane phenomenon. The effect of polacrilin potassium on the permeability of diclofenac potassium, used as a model anionic drug, was tested in vitro using diffusion cells and in vivo by monitoring serum levels in rats. The amount of drug permeated across a dialysis membrane in vitro was significantly more in the presence of polacrilin potassium. Significant improvement was found in the extent of drug absorption in vivo. It could be concluded that polacrilin potassium may be used as a high-functionality excipient for improving the bioavailability of anionic drugs having poor gastrointestinal permeability.

  8. Analysis of extracellular RNA by digital PCR

    Directory of Open Access Journals (Sweden)

    Kenji eTakahashi

    2014-06-01

    Full Text Available The transfer of extracellular RNA is emerging as an important mechanism for intracellular communication. The ability for the transfer of functionally active RNA molecules from one cell to another within vesicles such as exosomes enables a cell to modulate cellular signaling and biological processes within recipient cells. The study of extracellular RNA requires sensitive methods for the detection of these molecules. In this methods article, we will describe protocols for the detection of such extracellular RNA using sensitive detection technologies such as digital PCR. These protocols should be valuable to researchers interested in the role and contribution of extracellular RNA to tumor cell biology.

  9. Extracellular Molecules Involved in Cancer Cell Invasion

    International Nuclear Information System (INIS)

    Stivarou, Theodora; Patsavoudi, Evangelia

    2015-01-01

    Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion

  10. Extracellular Molecules Involved in Cancer Cell Invasion

    Directory of Open Access Journals (Sweden)

    Theodora Stivarou

    2015-01-01

    Full Text Available Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion.

  11. Ocular Injury due to Potassium Permanganate Granules

    Directory of Open Access Journals (Sweden)

    Chareenun Chirapapaisan

    2018-02-01

    Full Text Available Purpose: We report a rare case of ocular injury due to potassium permanganate (KMnO4 granules in a child. Methods: This is a retrospective case report. Results: A 2-year-old boy was transferred to our emergency room with severe pain in his right eye, inflamed eyelids, and brownish stains on his fingers. Chemical injury was suspected. Copious eye irrigation was immediately performed. Diffuse brownish splotches were then observed at the inferior bulbar conjunctiva. Otherwise, systemic organs were intact. Complete eye exam under general anesthesia revealed a 5-mm epithelial defect at the central cornea, along with generalized conjunctival injection and limbal ischemia, inferiorly. Multiple semi-dissolved granules of KMnO4 trapped in the inferior fornix were identified. The chemical particles were gradually washed out and removed; however, the brownish stains remained. The patient received preservative-free steroid, antibiotic eye drops, and lubricants as regular management for mild to moderate degree of ocular burn. Pseudomembrane developed early and transformed into symblepharon within a few days after the injury. Membrane adhesion was lysed, and more aggressive medications were then substituted. Commercial amniotic membrane (PROKERA® was also applied to promote wound healing and to prevent recurrence of symblepharon. The ocular surface was eventually restored, and corneal transparency was preserved. Conclusion: Ocular injury with the granular form of KMnO4 is rare. Its toxicity is comparable to concentrated KMnO4 solution. However, the dissolved particles that had been absorbed in the stained conjunctiva were continuously released and damaged the ocular surface more than we primarily anticipated. Awareness of this condition and prompt management yield a good treatment outcome.

  12. Electrical properties of the potassium polytitanate compacts

    International Nuclear Information System (INIS)

    Goffman, V.G.; Gorokhovsky, A.V.; Kompan, M.M.; Tretyachenko, E.V.; Telegina, O.S.; Kovnev, A.V.; Fedorov, F.S.

    2014-01-01

    Highlights: • Quasi-static permittivity of potassium polytitanates compacts achieves 10 4 –10 5 . • Observed Maxwell–Wagner polarization attributes to layered structure of polytitanates. • The conductivity varies from 5 × 10 −2 to 10 −6 –10 −7 Sm/m in a wide range of temperatures. - Abstract: Titanates of alkali metals are widely applied materials as they are relatively low in cost and might be easily synthesized. They are utilized as adsorbents, catalysts, solid state electrolytes, superconductors. Here we report our results on electrical properties of the compacted amorphous potassium polytitanates powders. The electrical properties of the compacts were studied by means of complex impedance spectroscopy in a wide range of frequencies at different temperatures using two-electrode configuration. The frequency dependences of conductivity for the investigated potassium polytitanates compacts varies in the range from 5 × 10 −2 Sm/m (high frequencies, ion conductivity) up to 10 −6 –10 −7 Sm/m (low frequencies, electron conductivity) for a wide range of temperatures (19–150 °C). According to the results, at low frequencies quasi-static permittivity of the stabilized PPT compacts achieves high values of 10 4 –10 5 . This might be explained by Maxwell–Wagner polarization attributed to the layered structure of the potassium polytitanates particles containing potassium and hydronium ions together with crystallization water in the interlayer and is very promising for solid state electrolyte applications for moderate temperatures

  13. The International Society for Extracellular Vesicles launches the first massive open online course on extracellular vesicles

    OpenAIRE

    L?sser, Cecilia; Th?ry, Clotilde; Buz?s, Edit I.; Mathivanan, Suresh; Zhao, Weian; Gho, Yong Song; L?tvall, Jan

    2016-01-01

    The International Society for Extracellular Vesicles (ISEV) has organised its first educational online course for students and beginners in the field of extracellular vesicles (EVs). This course, “Basics of Extracellular Vesicles,” uses recorded lectures from experts in the field and will be open for an unlimited number of participants. The course is divided into 5 modules and can be accessed at www.coursera.org/learn/extracellular-vesicles. The first module is an introduction to the field co...

  14. Interaction between the cardiac rapidly (IKr) and slowly (IKs) activating delayed rectifier potassium channels revealed by low K+-induced hERG endocytic degradation.

    Science.gov (United States)

    Guo, Jun; Wang, Tingzhong; Yang, Tonghua; Xu, Jianmin; Li, Wentao; Fridman, Michael D; Fisher, John T; Zhang, Shetuan

    2011-10-07

    Cardiac repolarization is controlled by the rapidly (I(Kr)) and slowly (I(Ks)) activating delayed rectifier potassium channels. The human ether-a-go-go-related gene (hERG) encodes I(Kr), whereas KCNQ1 and KCNE1 together encode I(Ks). Decreases in I(Kr) or I(Ks) cause long QT syndrome (LQTS), a cardiac disorder with a high risk of sudden death. A reduction in extracellular K(+) concentration ([K(+)](o)) induces LQTS and selectively causes endocytic degradation of mature hERG channels from the plasma membrane. In the present study, we investigated whether I(Ks) compensates for the reduced I(Kr) under low K(+) conditions. Our data show that when hERG and KCNQ1 were expressed separately in human embryonic kidney (HEK) cells, exposure to 0 mM K(+) for 6 h completely eliminated the mature hERG channel expression but had no effect on KCNQ1. When hERG and KCNQ1 were co-expressed, KCNQ1 significantly delayed 0 mM K(+)-induced hERG reduction. Also, hERG degradation led to a significant reduction in KCNQ1 in 0 mM K(+) conditions. An interaction between hERG and KCNQ1 was identified in hERG+KCNQ1-expressing HEK cells. Furthermore, KCNQ1 preferentially co-immunoprecipitated with mature hERG channels that are localized in the plasma membrane. Biophysical and pharmacological analyses indicate that although hERG and KCNQ1 closely interact with each other, they form distinct hERG and KCNQ1 channels. These data extend our understanding of delayed rectifier potassium channel trafficking and regulation, as well as the pathology of LQTS.

  15. Thermoluminescence properties of the Cu-doped lithium potassium borate glass

    International Nuclear Information System (INIS)

    Aboud, Haydar; Wagiran, H.; Hussin, R.; Ali, Hassan; Alajerami, Yasser; Saeed, M.A.

    2014-01-01

    Characteristics of lithium potassium borate glasses with various copper concentrations are reported. The glasses were prepared by the melt quenching method and irradiated with photons to doses in the 0.5–4.0 Gy range. Glowing curves, dose response curves, reproducibility of the response, dose threshold, thermal fading and optical bleaching were studied

  16. Potassium sorbate reduces production of ethanol and 2 esters in corn silage

    DEFF Research Database (Denmark)

    Hafner, Sasha; Franco, Roberta B; Kung, Limin

    2014-01-01

    concentrations within silage were measured after ensiling and sample storage using a headspace gas chromatography method. The high dose of potassium sorbate was the only treatment that inhibited the production of multiple VOC. Compared with the control response, it reduced ethanol by 58%, ethyl acetate by 46...

  17. Solution enthalpy of potassium iodide in furfural and its mixtures with dimethylsulfoxide

    International Nuclear Information System (INIS)

    Vlasenko, K.K.; Belov, A.A.; Vorob'ev, A.F.

    1986-01-01

    Solution enthalpy of potassium iodide in furfural-dimethylsulfoxide mixtures at 298.15 K and furfural concentration 17.3-100% are determined experimentally. K + and I - ion solvate shell composition, which in the general case doesn't correspond to the mixed solvent composition, is calculated

  18. Effect of soaking of seeds in potassium silicate and uniconazole on ...

    African Journals Online (AJOL)

    ... by low concentration of uniconazole treatment as compared to the control and other treatments. The growth of tomato seedlings was efficiently regulated by uniconazole 50 mg L-1 (12 h soaking) treatment. Key words: Chlorophyll fluorescence, plant growth retardants, plug plants, potassium silicate, seed treatment, silicon, ...

  19. Synthesis and thermal behavior of double copper and potassium pyrophosphate

    International Nuclear Information System (INIS)

    Ciopec, Mihaela; Muntean, Cornelia; Negrea, Adina; Lupa, Lavinia; Negrea, Petru; Barvinschi, Paul

    2009-01-01

    This paper presents the synthesis and thermal behavior of double copper and potassium pyrophosphate, which can be used as a PK fertilizer containing copper as micronutrient. In order to find the conditions for the synthesis of this compound from copper sulphate and potassium pyrophosphate, various Cu 2+ :P 2 O 7 4- molar ratios (0:1-2:1), various molar concentrations of the solutions (0.075; 0.1; 0.15 and 0.2 mol L -1 ) and various temperatures (25, 50, 75 and 100 o C) have been used. The solid product synthesized in optimum conditions for the separation of micronutrient copper from the reaction mass (Cu 2+ :P 2 O 7 4- molar ratio 1:1, concentration 0.1 mol L -1 ) was subjected to a complex study: chemical analysis, thermal analysis, energy dispersive X-ray spectroscopy, scanning electron microscopy and X-ray diffractometry. During heating up to 1000 o C, K 2 Cu 3 (P 2 O 7 ) 2 .3H 2 O loses the crystallization water; several transformations of the phosphates also take place: the decomposition of pyrophosphates to ortho-phosphates; the transformation of ortho-phosphates; the polymerization of a fraction of ortho-phosphates to amorphous phosphates with longer chains; the reorganization of ortho-phosphates and poly-phosphates to pyrophosphates and their crystallization. The decomposition mechanism was confirmed when using the X-ray diffraction patterns of the compound, thermally treated at several temperatures.

  20. Potassium permanganate ingestion as a suicide attempt

    Directory of Open Access Journals (Sweden)

    Sebnem Eren Cevik

    2012-02-01

    Full Text Available Potassium permanganate is a highly corrosive, water-soluble oxidizing antiseptic. A 68- year-old female patient was admitted to our Emergency Department after ingestion of 3 tablets of 250 mg potassium permanganate as a suicide attempt. The physical exam revealed brown stained lesions in the oropharynx. Emergency endoscopy was performed by the gastroenterologist after the third hour of ingestion. Emergency endoscopy revealed multiple superficial (Grade I-II lesions on the esophagus and cardia, which were considered secondary to the caustic substance. The mainstay in the treatment of potassium permanganate is supportive and the immediate priority is to secure the airway. Emergency endoscopy is an important tool used to evaluate the location and severity of injury to the esophagus, stomach and duodenum after caustic ingestion. Patients with signs and symptoms of intentional ingestion should undergo endoscopy within 12 to 24 h to define the extent of the disease.

  1. Potassium cardioplegia: early assessment by radionuclide ventriculography

    International Nuclear Information System (INIS)

    Ellis, R.J.; Born, M.; Feit, T.; Ebert, P.A.

    1978-01-01

    Left ventricular function was evaluated by single pass /sup 99m/Tc radionuclide ventriculography when potassium cardioplegia was combined with hypothermia. In 35 patients undergoing myocardial revascularization (3 CABG/patient) in which potassium cardioplegia at 4 0 C was used, no patient developed a myocardial infarction either by electrocardiogram or /sup 99m/Tc pyrophosphate imaging in the postoperative period. In 22 patients, aortic cross-clamp time was greater than 60 min, and the ejection fraction by the single pass radionuclide technique was 50% preoperatively and 53% postoperatively (NS). Wall motion in the single RAO view was not worse postoperatively. No patient required any inotropic agents in the immediate postoperative period. It appears that no significant ventricular impairment occurred in the immediate postoperative period (48 to 72 hours) when potassium cardioplegia combined with hypothermia was used for a 60-minute period

  2. Potassium permanganate ingestion as a suicide attempt

    Directory of Open Access Journals (Sweden)

    Tuba Cimilli Ozturk

    2012-01-01

    Full Text Available Potassium permanganate is a highly corrosive, water-soluble oxidizing antiseptic. A 68- year-old female patient was admitted to our Emergency Department after ingestion of 3 tablets of 250 mg potassium permanganate as a suicide attempt. The physical exam revealed brown stained lesions in the oropharynx. Emergency endoscopy was performed by the gastroenterologist after the third hour of ingestion. Emergency endoscopy revealed multiple superficial (Grade I-II lesions on the esophagus and cardia, which were considered secondary to the caustic substance. The mainstay in the treatment of potassium permanganate is supportive and the immediate priority is to secure the airway. Emergency endoscopy is an important tool used to evaluate the location and severity of injury to the esophagus, stomach and duodenum after caustic ingestion. Patients with signs and symptoms of intentional ingestion should undergo endoscopy within 12 to 24 h to define the extent of the disease.

  3. Suicidal ingestion of potassium permanganate crystals: a rare encounter.

    Science.gov (United States)

    Karthik, Ravikanti; Veerendranath, Hari Prasad Kanakapura; Wali, Siddraj; Mohan, Murali N T; Kumar, Praveen A C; Trimurty, Gaganam

    2014-01-01

    Potassium permanganate poisoning is not common. Although Symptoms of potassium permanganate ingestion are gastrointestinal and Complications due to ingestion of potassium permanganate include cardiovascular depression, hepatic and renal damage, upper airway obstruction, bleeding tendency and methemoglobinemia. Gastric damage due to potassium permanganate has rarely been reported previously. We are reporting a 34-year old female patient who presented to our Emergency Department after suicidal ingestion of potassium permanganate crystals. After treatment, the patient was discharged home on the 8(th) day after admission. So we conclude that Emergency endoscopy has a significant role in diagnosis and management of potassium permanganate ingestion.

  4. Determination of uranium, thorium and potassium contents of rock samples in Yemen

    International Nuclear Information System (INIS)

    Abdulrahman Abdul-Hadi; Wedad Al-Qadhi; Enayat El-Zeen

    2011-01-01

    Uranium, thorium and potassium contents in 16 different rock samples from various sites in Republic of Yemen were determined using three different techniques of analysis: γ-spectrometry, Instrumental neutron activation analyses (INAA) and X-ray fluorescence (XRF). The concentration range for thorium, uranium and potassium were found to be from 9,810 ± 272 to 3.6 ± 1.3 ppm, 1,072 ± 40 to 1.2 ± 0.7 ppm and 11 ± 1 to 0.26 ± 0.05%, respectively. (author)

  5. Determination of the water insoluble residuum in potassium salts using gamma logging

    International Nuclear Information System (INIS)

    Mishin, G.T.; Gavrilova, L.I.

    1976-01-01

    For potassium salts the relationship has been established between the concentration of heavy radioelements (the uranium-radium and thorium series) and the content of the water-insoluble, residue which is mainly represented by the clay-iodine fraction. A method is described for determining the content of the insoluble residue with the aid of PRKS-2 equipment. The results are given of experimental investigations aimed at studying the content of the insoluble residue in salts along the section of rising production wells. The results of the determination of the insoluble residue in potassium salts define their quality with an accuracy sufficient for industrial purposes

  6. Corrosion of a hot potassium carbonate CO/sub 2/ removal plant

    International Nuclear Information System (INIS)

    Johnson, J.J.

    1987-01-01

    After ten years of successful operation, a hot potassium carbonate CO/sub 2/ removal plant experienced severe corrosion to the 2'' (50 mm) thick carbon steel absorber process vessel over a fourteen month period. This corrosive attack resulted in complete penetration on three separate occasions. Although the cause of this corrosion is still uncertain, it appears to be the result of decreasing strength of the vanadium pentoxide inhibitor, due to increasing concentrations of hydrogen sulfide in the feed gas. After extensive research, Chevron believes that stainless steel metallurgy or replacement of the hot potassium carbonate process are the only reliable long-term solutions

  7. Comparison of Chemical Extraction Methods for Determination of Soil Potassium in Different Soil Types

    Science.gov (United States)

    Zebec, V.; Rastija, D.; Lončarić, Z.; Bensa, A.; Popović, B.; Ivezić, V.

    2017-12-01

    Determining potassium supply of soil plays an important role in intensive crop production, since it is the basis for balancing nutrients and issuing fertilizer recommendations for achieving high and stable yields within economic feasibility. The aim of this study was to compare the different extraction methods of soil potassium from arable horizon of different types of soils with ammonium lactate method (KAL), which is frequently used as analytical method for determining the accessibility of nutrients and it is a common method used for issuing fertilizer recommendations in many Europe countries. In addition to the ammonium lactate method (KAL, pH 3.75), potassium was extracted with ammonium acetate (KAA, pH 7), ammonium acetate ethylenediaminetetraacetic acid (KAAEDTA, pH 4.6), Bray (KBRAY, pH 2.6) and with barium chloride (K_{BaCl_2 }, pH 8.1). The analyzed soils were extremely heterogeneous with a wide range of determined values. Soil pH reaction ( {pH_{H_2 O} } ) ranged from 4.77 to 8.75, organic matter content ranged from 1.87 to 4.94% and clay content from 8.03 to 37.07%. In relation to KAL method as the standard method, K_{BaCl_2 } method extracts 12.9% more on average of soil potassium, while in relation to standard method, on average KAA extracts 5.3%, KAAEDTA 10.3%, and KBRAY 27.5% less of potassium. Comparison of analyzed extraction methods of potassium from the soil is of high precision, and most reliable comparison was KAL method with KAAEDTA, followed by a: KAA, K_{BaCl_2 } and KBRAY method. Extremely significant statistical correlation between different extractive methods for determining potassium in the soil indicates that any of the methods can be used to accurately predict the concentration of potassium in the soil, and that carried out research can be used to create prediction model for concentration of potassium based on different methods of extraction.

  8. Palytoxin and the sodium/potassium pump—phosphorylation and potassium interaction

    International Nuclear Information System (INIS)

    Rodrigues, Antônio M; De Almeida, Antônio-Carlos G; Infantosi, Antonio F C

    2009-01-01

    We proposed a reaction model for investigating interactions between K + and the palytoxin–sodium–potassium (PTX–Na + /K + ) pump complex under conditions where enzyme phosphorylation may occur. The model is composed of (i) the Albers–Post model for Na + /K + –ATPase, describing Na + and K + pumping; (ii) the reaction model proposed for Na + /K + –ATPase interactions with its ligands (Na + , K + , ATP, ADP and P) and with PTX. A mathematical model derived for representing the reactions was used to simulate experimental studies of the PTX-induced current, in different concentrations for the pump ligands. The simulations allow interpretation of the simultaneous action of Na + /K + –ATPase phosphorylation and K + on the PTX-induced channels. The results suggest that (i) phosphorylation increases the PTX toxic effect, increasing its affinity and reducing the K + occlusion rate, and (ii) K + causes channel blockage, increases the toxin dissociation rate and impedes the induced channel phosphorylation, implying reduction of the PTX toxic effect

  9. Effect of potassium application on root uptake of radiocesium in rice

    International Nuclear Information System (INIS)

    Saito, Takashi; Ohkoshi, Satoru; Fujimura, Shigeto

    2013-01-01

    After the Fukushima Daiichi Nuclear Power Plant accident that occurred in March 2011, the concentration of radiocesium in brown rice that has been produced in some area has exceeded the provisional regulation value. In order to decrease the concentration of radiocesium in brown rice, we investigated the effect of the application of potassium fertilizer in rice paddy fields on the root uptake of radiocesium. The observed concentration ratio of "1"3"4Cs to "1"3"7Cs was 0.81 at the time of sample collection, and the mean concentrations of radiocesium in the soils at depths of 0-5, 5-10, and 10-15 cm were 5879 Bq kg"-"1 DW, 3223 Bq kg"-"1 DW and 1835 Bq kg"-"1 DW, respectively. The results showed that the vertical distribution of radiocesium was not uniform, although the rice paddy fields had been plowed. The concentration of radiocesium at a depth of 0-5 cm in soil collected from the 5 different rice paddy fields was in the range of 2465-7823Bq kg"-"1 DW, showing an approximately 3-fold variation between the upper and lower limits of the range. The concentration of radiocesium in brown rice cultivated in 5 different fields, was in the range of 52-485 Bq kg"-"1. The concentration of radiocesium in brown rice was found to be not correlated with that in the soil, and the soil-to-brown rice transfer factor was found to lie in the range of 0.0075-0.11. However, the radiocesium in brown rice decreased with an increase in exchangeable potassium in the soil. The concentration of radiocesium in brown rice also decreased from 370 to 138 Bq kg"-"1 upon the application of a top dressing of potassium fertilizer. Thus, the application of potassium fertilizer is shown to reduce the concentration of radiocesium in brown rice. (author)

  10. Increased level of extracellular ATP at tumor sites: in vivo imaging with plasma membrane luciferase.

    Directory of Open Access Journals (Sweden)

    Patrizia Pellegatti

    2008-07-01

    Full Text Available There is growing awareness that tumour cells build up a "self-advantageous" microenvironment that reduces effectiveness of anti-tumour immune response. While many different immunosuppressive mechanisms are likely to come into play, recent evidence suggests that extracellular adenosine acting at A2A receptors may have a major role in down-modulating the immune response as cancerous tissues contain elevated levels of adenosine and adenosine break-down products. While there is no doubt that all cells possess plasma membrane adenosine transporters that mediate adenosine uptake and may also allow its release, it is now clear that most of extracellularly-generated adenosine originates from the catabolism of extracellular ATP.Measurement of extracellular ATP is generally performed in cell supernatants by HPLC or soluble luciferin-luciferase assay, thus it generally turns out to be laborious and inaccurate. We have engineered a chimeric plasma membrane-targeted luciferase that allows in vivo real-time imaging of extracellular ATP. With this novel probe we have measured the ATP concentration within the tumour microenvironment of several experimentally-induced tumours.Our results show that ATP in the tumour interstitium is in the hundreds micromolar range, while it is basically undetectable in healthy tissues. Here we show that a chimeric plasma membrane-targeted luciferase allows in vivo detection of high extracellular ATP concentration at tumour sites. On the contrary, tumour-free tissues show undetectable extracellular ATP levels. Extracellular ATP may be crucial for the tumour not only as a stimulus for growth but also as a source of an immunosuppressive agent such as adenosine. Our approach offers a new tool for the investigation of the biochemical composition of tumour milieu and for development of novel therapies based on the modulation of extracellular purine-based signalling.

  11. Towards traceable size determination of extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Zoltán Varga

    2014-02-01

    Full Text Available Background: Extracellular vesicles (EVs have clinical importance due to their roles in a wide range of biological processes. The detection and characterization of EVs are challenging because of their small size, low refractive index, and heterogeneity. Methods: In this manuscript, the size distribution of an erythrocyte-derived EV sample is determined using state-of-the-art techniques such as nanoparticle tracking analysis, resistive pulse sensing, and electron microscopy, and novel techniques in the field, such as small-angle X-ray scattering (SAXS and size exclusion chromatography coupled with dynamic light scattering detection. Results: The mode values of the size distributions of the studied erythrocyte EVs reported by the different methods show only small deviations around 130 nm, but there are differences in the widths of the size distributions. Conclusion: SAXS is a promising technique with respect to traceability, as this technique was already applied for traceable size determination of solid nanoparticles in suspension. To reach the traceable measurement of EVs, monodisperse and highly concentrated samples are required.

  12. An Electrochemical Sensor Based on Nanostructured Hollandite-type Manganese Oxide for Detection of Potassium Ions

    Directory of Open Access Journals (Sweden)

    Alex S. Lima

    2009-08-01

    Full Text Available The participation of cations in redox reactions of manganese oxides provides an opportunity for development of chemical sensors for non-electroactive ions. A sensor based on a nanostructured hollandite-type manganese oxide was investigated for voltammetric detection of potassium ions. The detection is based on the measurement of anodic current generated by oxidation of Mn(III to Mn(IV at the surface of the electrode and the subsequent extraction of the potassium ions into the hollandite structure. In this work, an amperometric procedure at an operating potential of 0.80 V (versus SCE is exploited for amperometric monitoring. The current signals are linearly proportional to potassium ion concentration in the range 4.97 × 10−5 to 9.05 × 10−4 mol L−1, with a correlation coefficient of 0.9997.

  13. Oxidation kinetics of crystal violet by potassium permanganate in acidic medium

    Science.gov (United States)

    Khan, Sameera Razi; Ashfaq, Maria; Mubashir; Masood, Summyia

    2016-05-01

    The oxidation kinetics of crystal violet (a triphenylmethane dye) by potassium permanganate was focused in an acidic medium by the spectrophotometric method at 584 nm. The oxidation reaction of crystal violet by potassium permanganate is carried out in an acidic medium at different temperatures ranging within 298-318 K. The kinetic study was carried out to investigate the effect of the concentration, ionic strength and temperature. The reaction followed first order kinetics with respect to potassium permanganate and crystal violet and the overall rate of the reaction was found to be second order. Thermodynamic activation parameters like the activation energy ( E a), enthalpy change (Δ H*), free energy change (Δ G*), and entropy change (Δ S*) have also been evaluated.

  14. Pharmacokinetics of diclofenac potassium after oral administration of sachets and tablets

    Directory of Open Access Journals (Sweden)

    A Martso

    2008-01-01

    Results. There is evidence that patients tolerate both its sachets and tablets equally well, as confirmed by subjective and objective observations. There are neither marked side effects nor considerable changes in laboratory tests and in the values of vital functions. Diclofenac potassium as early-action tablets (50 and 100 mg exerts a very good analgesic effect in treating migraine since the plasma concentration of the drug peaks on an average of an hour of administration (range 0,33-2 hours and the analgesic effect developed following 60-90 min. Conclusion. By comparing the rate of absorption, it may be concluded that diclofenac potassium as sachets will produce a much rapider analgesic effect. Thus, the high solubility of diclofenac potassium and its very good absorbability (as sachets in particular make the drug a superior analgesic that has a rapid analgesic activity.

  15. Alcohol and the calcium-dependent potassium transport of human erythrocytes

    International Nuclear Information System (INIS)

    Harris, R.A.; Caldwell, K.K.

    1985-01-01

    In vitro exposure of human red blood cells to ethanol (100 and 400 mM) was found to increase the initial rate of calcium-dependent potassium efflux through the red cell membrane. This effect of ethanol was apparently not due to an elevation of the intracellular free calcium but rather to a direct action of the drug on the transport process as, (1) intracellular calcium concentrations were tightly buffered with EGTA, (2) ethanol did not alter the efflux of 45 Ca from the cells, and (3) dantrolene, which has been proposed to counteract the effect of ethanol on intracellular calcium levels in the erythrocyte, did not inhibit the stimulatory action of ethanol. The efflux of potassium from erythrocytes obtained from chronic alcoholics was not different from that of erythrocytes from non-alcoholic individuals. The relationship of these findings to neuronal potassium transport is discussed

  16. The effect of intra- and extracellular GSH depletion on aerobic radiosensitization in three cell lines

    International Nuclear Information System (INIS)

    Clark, E.P.; Epp, E.R.; Morse-Gaudio, M.; Biaglow, J.E.

    1985-01-01

    The effect of changes in the intra- and extracellular glutathione (GSH) concentrations on aerobic radiosensitization was studied in thee cell lines: CHO, V79 and A549. Intracellular GSH was metabolically depleted after the inhibition of GSH synthesis by buthionine sulfoximine (BSO) treatment of attached cell cultures. Extracellular GSH was controlled through the replacement of growth medium with a thiol-free salt solution and, where desired, by the exogenous addition of GSH. Each of the cell lines examined exhibited an enhanced aerobic radioresponse when the intracellular GSH was extensively depleted (GSH < 5% of control after 1.0 mM BSO/24 hr treatment) and the extracellular GSH concentration was zero. However, this enhanced radiosensitivity was eliminated by the addition of exogenous GSH, albeit at a high concentration (5 mM). Most interesting and as yet unexplained is the observation that GSH appears to affect restoration of the control radioresponse without increasing the intracellular GSH concentration

  17. Potassium humate inhibits complement activation and the production of inflammatory cytokines in vitro

    Energy Technology Data Exchange (ETDEWEB)

    van Rensburg, C.E.J.; Naude, P.J. [University of Pretoria, Pretoria (South Africa)

    2009-08-15

    The effects of brown coal derived potassium humate on lymphocyte proliferation, cytokine production and complement activation were investigated in vitro. Potassium humate increased lymphocyte proliferation of phytohaemaglutinin A (PHA) and pokeweed mitogen (PWM) stimulated mononuclear lymphocytes (MNL) in vitro from concentrations of 20 to 80 {mu} g/ml, in a dose dependant manner. On the other hand potassium humate, at 40 {mu} g/ml, significantly inhibited the release of TNF-alpha, IL-1 beta, IL-6 and IL-10 by PHA stimulated MNL. Regarding complement activation it was found that potassium humate inhibits the activation of both the alternative and classical pathways without affecting the stability of the red blood cell membranes. These results indicate that the anti-inflammatory potential of potassium humate could be partially due to the inhibition of pro-inflammatory cytokines responsible for the initiation of these reactions as well as inhibition of complement activation. The increased lymphocyte proliferation observed, might be due to increased IL-2 production as previously been documented.

  18. Delayed rectifier potassium channels are involved in SO2 derivative-induced hippocampal neuronal injury.

    Science.gov (United States)

    Li, Guangke; Sang, Nan

    2009-01-01

    Recent studies implicate the possible neurotoxicity of SO(2), however, its mechanisms remain unclear. In the present study, we investigated SO(2) derivative-induced effect on delayed rectifier potassium channels (I(K)) and cellular death/apoptosis in primary cultured hippocampal neurons. The results demonstrate that SO(2) derivatives (NaHSO(3) and Na(2)SO(3), 3:1M/M) effectively augmented I(K) and promoted the activation of delayed rectifier potassium channels. Also, SO(2) derivatives increased neuronal death percentage and contributed to the formation of DNA ladder in concentration-dependent manners. Interestingly, the neuronal death and DNA ladder formation, caused by SO(2) derivatives, could be attenuated by the delayed rectifier potassium channel blocker (tetraethylammonium, TEA), but not by the transient outward potassium channel blocker (4-aminopyridine, 4-AP). It implies that stimulating delayed rectifier potassium channels were involved in SO(2) derivative-caused hippocampal neuronal insults, and blocking these channels might be one of the possibly clinical treatment for SO(2)-caused neuronal dysfunction.

  19. 21 CFR 862.1600 - Potassium test system.

    Science.gov (United States)

    2010-04-01

    ... potassium in serum, plasma, and urine. Measurements obtained by this device are used to monitor electrolyte balance in the diagnosis and treatment of diseases conditions characterized by low or high blood potassium levels. (b) Classification. Class II. ...

  20. The existence of the potassium dioxodifluorobromate

    International Nuclear Information System (INIS)

    Tantot, Georges; Bougon, Roland

    1975-01-01

    The reaction of liquid bromine pentafluoride with potassium bromate allows the formation of an oxyfluorinated complex ion of bromine V: the dioxodifluorobromate ion BrO 2 F 2 - . From Raman spectroscopy data this ion has a structure related to those of the chlorine and iodine corresponding ions [fr

  1. 21 CFR 184.1613 - Potassium bicarbonate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium bicarbonate. 184.1613 Section 184.1613 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS §...

  2. Resonant second harmonic generation in potassium vapor

    International Nuclear Information System (INIS)

    Kim, D.; Mullin, C.S.; Shen, Y.R.; Lawrence Berkeley Lab., CA

    1995-06-01

    Picosecond pulses are used to study resonant second harmonic generation in potassium vapor. Although the process is both microscopically and macroscopically forbidden, it can readily be observed. The results can be quantitatively understood by a multiphoton-ionization-initiated, dc-field-induced, coherent transient model

  3. Computational study on potassium picrate crystal

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Xue-Hai; Lu, Ya-Lin; Ma, Xiu-Fang; Xiao, He-Ming [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, 210094 (China)

    2006-08-15

    DFT calculation at the B3LYP level was performed on crystalline potassium picrate. The frontier bands are slightly fluctuant. The energy gap between the highest occupied crystal orbital (HOCO) and the lowest unoccupied crystal orbital (LUCO) is 0.121 a.u. (3.29 eV). The carbon atoms that are connected with the nitro groups make up the narrow lower energy bands, with small contributions from nitro oxygen and phenol oxygen. The higher energy bands consist of orbitals from the nitro groups and carbon atom. The potassium bears almost 1 a.u. positive charge. The potassium forms ionic bonding with the phenol oxygen and the nitro oxygen at the same time. The crystal lattice energy is predicted to be -574.40 kJ/mol at the B3LYP level determined with the effective core pseudopotential HAYWSC-31G basis set for potassium and 6-31G** basis set for other atoms. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  4. Altered potassium homeostasis in Crohn's disease

    International Nuclear Information System (INIS)

    Schober, O.; Hundeshagen, H.; Bosaller, C.; Lehr, L.

    1983-01-01

    The total body potassium (TBK), serum potassium, and the number of red blood cell ouabain-binding sites was studied in 94 patients with Crohn's diease. TBK was measured by counting the endogenous 40 K in a whole body counter. TBK was 87%+-13% in 94 patients was Crohn's disease, while in control subjects, it was 97%+-12% (n=24). This significant reduction in TBK was accompanied by normal serum potassium levels (4.4+-0.5 mM). TBK was significantly correlated with the Crohn's disease activity index (r=0.79, n=113, P 3 H-ouabain showed a significant increse in the number of Na-K pumps in Crohn's disease (396+-65, n=27) compared with the control group. 290+-45 (n=24). These results support the suggestion that changes in TBK may regulate the synthesis of Na-K pump molecules. The total body potassium depletion and the need for a preoperative nutritional support in Crohn's disease are discussed. (orig.)

  5. Nutritional potassium requirement for laying Japanese quails

    Directory of Open Access Journals (Sweden)

    Fernando Guilherme Perazzo Costa

    2011-12-01

    Full Text Available The objective of this study was to evaluate the potassium requirement for laying Japanese quails. Two hundred and forty quails were distributed in a randomized block design, with five treatments and six replicates, with eight birds each. The treatments consisted of a basal diet deficient in potassium (K (2.50 g/kg, supplemented with potassium carbonate, to replace the inert, to reach levels of 2.50, 3.50, 4.50, 5.50 and 6.50 (g/kg of K in the diet. There was a quadratic effect of K levels on feed intake, egg production, egg mass and feed conversion per egg mass and per egg dozen, estimating the requirements of 4.26, 4.41, 4.38, 4.43 and 4.48 (g/kg of K diet, respectively. There was no significant effect on the levels of K in the diet on egg weight, albumen weight, percentage of yolk or shell and yolk color. However, yolk and shell weights reduced and the albumen percentage increased linearly with increasing levels of K in the diet. Despite the reduction of shell weight, the increased levels of K did not influence the specific gravity and shell thickness. The use of 4.41 g/kg of potassium is recommended in the diet for laying Japanese quails.

  6. Rheological properties of potassium barium borate glasses

    NARCIS (Netherlands)

    Szwejda, K.A.; Vogel, D.L.; Stevels, J.M.

    1973-01-01

    Several series of potassium barium borate glasses have been investigated as to their rheological properties. It has been found, that all these glasses show deviations from ‘Newtonian’ behaviour below temperatures corresponding to viscosities of 1010 poises. The activation energies of viscous flow

  7. Potassium ferrate treatment of RFETS' contaminated groundwater

    International Nuclear Information System (INIS)

    1995-01-01

    The potassium ferrate treatment study of Rocky Flats Environmental Technology Site (RFETS) groundwater was performed under the Sitewide Treatability Studies Program (STSP). This study was undertaken to determine the effectiveness of potassium ferrate in a water treatment system to remove the contaminants of concern (COCS) from groundwater at the RFETS. Potassium ferrate is a simple salt where the iron is in the plus six valence state. It is the iron at the plus six valence state (Fe +6 ) that makes it an unique water treatment chemical, especially in waters where the pH is greater than seven. In basic solutions where the solubility of the oxides/hydroxides of many of the COCs is low, solids are formed as the pH is raised. By using ferrate these solids are agglomerated so they can be effectively removed by sedimentation in conventional water treatment equipment. The objective of this study was to determine the quality of water after treatment with potassium ferrate and to determine if the Colorado Water Quality Control Commission (CWQCC) discharge limits for the COCs listed in Table 1.0-1 could be met. Radionuclides in the groundwater were of special concern

  8. Acute Renal Failure following Accidental Potassium Bromate ...

    African Journals Online (AJOL)

    Accidental poisoning is common in children. Potassium bromate is a commonly used additive and raising agent in many edibles particularly bread, a staple food worldwide, yet its accidental poisoning has hitherto, not been documented in Nigeria. We report an unusual case of acute renal failure following accidental ...

  9. Potassium Dichromate as a Reference Substance for Embryonic Tests of Toxicity in the Common Carp (Cyprinus carpio L.

    Directory of Open Access Journals (Sweden)

    R. Krejčí

    2006-01-01

    Full Text Available Potassium dichromate (K2Cr2O7 has already been used as a reference substance in tests of toxicity with aquatic animals. The aim of this study was to determine and compare values of LC50 for potassium dichromate during the whole period of embryonic development (i.e., 120 h and 48 h after hatching of embryos in the common carp (Cyprinus carpio L.. Fish eggs and embryos were exposed to 5 different concentrations of potassium dichromate (i.e., 372, 409, 450, 495, 545 mg l-1 during two experiments. Such characteristics as the cumulative mortality, the start and the end of hatching, the number of deformities, body length, and body mass of surviving individuals were studied during the tests. The highest mortality was found in the hatched embryos. Mortality and frequency of deformities increased with the growing concentration of potassium dichromate. The value of 120 LC50 for potassium dichromate was 464.91 ± 23.83 mg l-1 and the value of 48 LC50 was 458.94 ± 4.14 mg l-1 (mean ± SD. No statistically significant difference between values 120 LC50 a 48 LC50 was found. This is why reduction of the exposure period to only 48 h after hatching seems a reasonable method to study the control of susceptibility using potassium dichromate in embryonic tests of toxicity.

  10. Comparative study of 5% and 2.5% potassium hydroxide solution for molluscum contagiosum in children.

    Science.gov (United States)

    Uçmak, Derya; Akkurt, Meltem Zeynep; Kacar, Seval Dogruk; Sula, Bilal; Arica, Mustafa

    2014-03-01

    Molluscum contagiosum (MC) is a pediatric viral infection that is fairly contagious. Although various treatment methods are available, the presence of facial lesions limits options of therapy. We aimed to test an alternative treatment consisting of application of two different concentrations of potassium hydroxide (of KOH 5% solution and of KOH 2.5% solution) aqueous solution. In this study we evaluated the effectiveness and side-effects of daily applications of potassium hydroxide (KOH) aqueous solution at 2.5% and 5% concentrations, twice daily in 29 children with MC. Out of a total of 29 patients with molluscum contagiosum included in the study, 13 patients in the 2.5% KOH group and 12 patients in the KOH 5% group completed the study. Families were instructed to apply potassium hydroxide twice a day. The assessment of response and side-effects were performed on days 0, 15, 30, 45 and 60 (visits were numbered 1, 2, 3, 4 and 5, respectively) and one month after. We had a total of 11 (44%) patients who completely recovered after the fifth visit. While eight (66.7%) of these 11 patients were in the 5% treatment group, three (23.1%) patients were in the 2.5% treatment group, and there was a statistically meaningful difference (p Potassium hydroxide solution at a concentration of 5% was more effective than 2.5% in our patients. The treatment was well-tolerated on the face with the advantage of administration of lower concentrations. This study suggests potassium hydroxide may be a more preferable mode of treatment for molluscum contagiosum lesions on the face.

  11. Electrical properties of the potassium polytitanate compacts

    Energy Technology Data Exchange (ETDEWEB)

    Goffman, V.G.; Gorokhovsky, A.V. [NanoTechProm Ltd., Saratov (Russian Federation); Saratov State Technical University, Saratov (Russian Federation); Kompan, M.M. [Physico-Technical Institute of the Russian Academy of Science, St. Petersburg (Russian Federation); Tretyachenko, E.V.; Telegina, O.S.; Kovnev, A.V. [NanoTechProm Ltd., Saratov (Russian Federation); Saratov State Technical University, Saratov (Russian Federation); Fedorov, F.S., E-mail: fedorov_fs@daad-alumni.de [NanoTechProm Ltd., Saratov (Russian Federation); Saratov State Technical University, Saratov (Russian Federation)

    2014-12-05

    Highlights: • Quasi-static permittivity of potassium polytitanates compacts achieves 10{sup 4}–10{sup 5}. • Observed Maxwell–Wagner polarization attributes to layered structure of polytitanates. • The conductivity varies from 5 × 10{sup −2} to 10{sup −6}–10{sup −7} Sm/m in a wide range of temperatures. - Abstract: Titanates of alkali metals are widely applied materials as they are relatively low in cost and might be easily synthesized. They are utilized as adsorbents, catalysts, solid state electrolytes, superconductors. Here we report our results on electrical properties of the compacted amorphous potassium polytitanates powders. The electrical properties of the compacts were studied by means of complex impedance spectroscopy in a wide range of frequencies at different temperatures using two-electrode configuration. The frequency dependences of conductivity for the investigated potassium polytitanates compacts varies in the range from 5 × 10{sup −2} Sm/m (high frequencies, ion conductivity) up to 10{sup −6}–10{sup −7} Sm/m (low frequencies, electron conductivity) for a wide range of temperatures (19–150 °C). According to the results, at low frequencies quasi-static permittivity of the stabilized PPT compacts achieves high values of 10{sup 4}–10{sup 5}. This might be explained by Maxwell–Wagner polarization attributed to the layered structure of the potassium polytitanates particles containing potassium and hydronium ions together with crystallization water in the interlayer and is very promising for solid state electrolyte applications for moderate temperatures.

  12. Binding of matrix metalloproteinase inhibitors to extracellular matrix: 3D-QSAR analysis.

    Science.gov (United States)

    Zhang, Yufen; Lukacova, Viera; Bartus, Vladimir; Nie, Xiaoping; Sun, Guorong; Manivannan, Ethirajan; Ghorpade, Sandeep R; Jin, Xiaomin; Manyem, Shankar; Sibi, Mukund P; Cook, Gregory R; Balaz, Stefan

    2008-10-01

    Binding to the extracellular matrix, one of the most abundant human protein complexes, significantly affects drug disposition. Specifically, the interactions with extracellular matrix determine the free concentrations of small molecules acting in tissues, including signaling peptides, inhibitors of tissue remodeling enzymes such as matrix metalloproteinases, and other drug candidates. The nature of extracellular matrix binding was elucidated for 63 matrix metalloproteinase inhibitors, for which the association constants to an extracellular matrix mimic were reported here. The data did not correlate with lipophilicity as a common determinant of structure-nonspecific, orientation-averaged binding. A hypothetical structure of the binding site of the solidified extracellular matrix surrogate was analyzed using the Comparative Molecular Field Analysis, which needed to be applied in our multi-mode variant. This fact indicates that the compounds bind to extracellular matrix in multiple modes, which cannot be considered as completely orientation-averaged and exhibit structural dependence. The novel comparative molecular field analysis models, exhibiting satisfactory descriptive and predictive abilities, are suitable for prediction of the extracellular matrix binding for the untested chemicals, which are within applicability domains. The results contribute to a better prediction of the pharmacokinetic parameters such as the distribution volume and the tissue-blood partition coefficients, in addition to a more imminent benefit for the development of more effective matrix metalloproteinase inhibitors.

  13. Intercellular Resistance to BRAF Inhibition Can Be Mediated by Extracellular Vesicle–Associated PDGFRβ

    Directory of Open Access Journals (Sweden)

    Laura J. Vella

    2017-11-01

    Full Text Available Treatment of BRAF mutant melanoma with kinase inhibitors has been associated with rapid tumor regression; however, this clinical benefit is short-lived, and most patients relapse. A number of studies suggest that the extracellular environment promotes BRAF inhibitor resistance and tumor progression. Extracellular vesicles, such as exosomes, are functional mediators in the extracellular environment. They are small vesicles known to carry a concentrated group of functional cargo and serve as intercellular communicators not only locally but also systemically. Increasingly, it is reported that extracellular vesicles facilitate the development of drug resistance in cancer; however, their role in BRAF inhibitor resistance in melanoma is unclear. Here we investigated if extracellular vesicles from BRAF inhibitor–resistant melanoma could influence drug sensitivity in recipient melanoma cells. We demonstrate that the resistance driver, PDGFRβ, can be transferred to recipient melanoma cells via extracellular vesicles, resulting in a dose-dependent activation of PI3K/AKT signaling and escape from MAPK pathway BRAF inhibition. These data suggest that the BRAF inhibitor–sensitive phenotype of metastatic melanoma can be altered by delivery of PDGFRβ by extracellular vesicles derived from neighboring drug-resistant melanoma cells.

  14. Extracellular matrix of collagen modulates arrhythmogenic activity of pulmonary veins through p38 MAPK activation.

    Science.gov (United States)

    Lu, Yen-Yu; Chen, Yao-Chang; Kao, Yu-Hsun; Chen, Shih-Ann; Chen, Yi-Jen

    2013-06-01

    Atrial fibrillation (AF) is the most common sustained arrhythmia. Cardiac fibrosis with enhanced extracellular collagen plays a critical role in the pathophysiology of AF through structural and electrical remodeling. Pulmonary veins (PVs) are important foci for AF genesis. The purpose of this study was to evaluate whether collagen can directly modulate PV arrhythmogenesis. Action potentials and ionic currents were investigated in isolated male New Zealand rabbit PV cardiomyocytes with and without collagen incubation (10μg/ml, 5-7h) using the whole-cell patch-clamp technique. Compared to control PV cardiomyocytes (n=25), collagen-treated PV cardiomyocytes (n=22) had a faster beating rate (3.2±04 vs. 1.9±0.2Hz, pcollagen-treated PV cardiomyocytes showed a larger transient outward potassium current, small-conductance Ca(2+)-activated K(+) current, inward rectifier potassium current, pacemaker current, and late sodium current than control PV cardiomyocytes, but amplitudes of the sodium current, sustained outward potassium current, and L-type calcium current were similar. Collagen increased the p38 MAPK phosphorylation in PV cardiomyocytes as compared to control. The change of the spontaneous activity and action potential morphology were ameliorated by SB203580 (the p38 MAPK catalytic activity inhibitor), indicating that collagen can directly increase PV cardiomyocyte arrhythmogenesis through p38 MAPK activation, which may contribute to the pathogenesis of AF. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. 21 CFR 181.33 - Sodium nitrate and potassium nitrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium nitrate and potassium nitrate. 181.33...-Sanctioned Food Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and potassium nitrate are subject to prior sanctions issued by the U.S. Department of Agriculture for use as sources of...

  16. A novel potassium deficiency-induced stimulon in Anabaena torulosa

    Indian Academy of Sciences (India)

    Unknown

    torulosa and of nine proteins in Escherichia coli. These were termed potassium deficiency-induced proteins or. PDPs and constitute hitherto unknown potassium deficiency–induced stimulons. Potassium deficiency also enhanced the synthesis of certain osmotic stress-induced proteins. Addition of K+ repressed the ...

  17. 21 CFR 520.1696d - Penicillin V potassium tablets.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin V potassium tablets. 520.1696d Section... Penicillin V potassium tablets. (a) Specifications. Each tablet contains penicillin V potassium equivalent to 125 milligrams (200,000 units) or 250 milligrams (400,000 units) of penicillin V. (b) Sponsors. See...

  18. Relationship between potassium intake and radiocesium retention in the reindeer

    International Nuclear Information System (INIS)

    Holleman, D.F.; Luick, J.R.

    1975-01-01

    The effect of dietary potassium on radiocesium retention was studied in reindeer fed winter diets of lichens. Potassium added to the diet markedly decreased radiocesium retention; this suggests that seasonal changes in cesium retention observed earlier in reindeer might be caused largely by nutritional factors. Data indicate that a 20-fold increase in dietary potassium results in a 2-fold decrease in radiocesium retention

  19. Formulation, Characterization and Physicochemical Evaluation of Potassium Citrate Effervescent Tablets

    Directory of Open Access Journals (Sweden)

    Fatemeh Fattahi

    2013-02-01

    Full Text Available Purpose: The aim of this study was to design and formulation of potassium citrate effervescent tablet for reduction of calcium oxalate and urate kidney stones in patients suffering from kidney stones. Methods: In this study, 13 formulations were prepared from potassium citrate and effervescent base in different concentration. The flowability of powders and granules was studied. Then effervescent tablets were prepared by direct compression, fusion and wet granulation methods. The prepared tablets were evaluated for hardness, friability, effervescent time, pH, content uniformity. To amend taste of formulations, different flavoring agents were used and then panel test was done by using Latin Square method by 30 volunteers. Results: Formulations obtained from direct compression and fusion methods had good flow but low hardness. Wet granulation improves flowability and other physicochemical properties such as acceptable hardness, effervescence time ≤3 minutes, pH<6, friability < 1%, water percentage < 0.5% and accurate content uniformity. In panel test, both of combination flavors; (orange - lemon and (strawberry - raspberry had good acceptability. Conclusion: The prepared tablets by wet granulation method using PVP solution had more tablet hardness. It is a reproducible process and suitable to produce granules that are compressed into effervescent tablets due to larger agglomerates.

  20. Optimization and evaluation of alkaline potassium permanganate pretreatment of corncob.

    Science.gov (United States)

    Ma, Lijuan; Cui, Youzhi; Cai, Rui; Liu, Xueqiang; Zhang, Cuiying; Xiao, Dongguang

    2015-03-01

    Alkaline potassium permanganate solution (APP) was applied to the pretreatment of corncob with a simple and effective optimization of APP concentration, reaction time, temperature and solid to liquid ratio (SLR). The optimized pretreatment conditions were at 2% (w/v) potassium permanganate with SLR of 1:10 treating for 6h at 50°C. This simple one-step treatment resulted in significant 94.56% of the cellulose and 81.47% of the hemicellulose recoveries and 46.79% of the lignin removal of corncob. The reducing sugar in the hydrolysate from APP-pretreated corncob was 8.39g/L after 12h enzymatic hydrolysis, which was 1.44 and 1.29 folds higher than those from raw and acid pretreated corncobs. Physical characteristics, crystallinity and structure of the pretreated corncob were analyzed and assessed by SEM, XRD and FTIR. The APP pretreatment process was novel and enhanced enzymatic hydrolysis of lignocellulose by affecting composition and structural features. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Bacterial binding to extracellular proteins - in vitro adhesion

    DEFF Research Database (Denmark)

    Schou, C.; Fiehn, N.-E.

    1999-01-01

    Viridans streptococci, bacterial adherence, extracellular matrix proteins, surface receptors, endocarditis......Viridans streptococci, bacterial adherence, extracellular matrix proteins, surface receptors, endocarditis...

  2. Preliminary Evaluation of Potassium Extraction from Bamboo Ash

    Directory of Open Access Journals (Sweden)

    Samadhi Tjokorde W.

    2018-01-01

    Full Text Available Bamboo is a potentially economical fuel crop that has not been utilized at a substantial extent for energy generation in Indonesia. As a thermal conversion waste, bamboo ash is particularly interesting due to its high potassium content. This paper discusses the determination of several key parameters of a simple batchwise extraction process to recover potassium in the form of weak solution from bamboo ash. To produce the ash, black bamboo (Gigantochloa atroviolaceae is charred in a fixed bed combustor. The bamboo char is ground and ashed at 500 °C in an electric furnace. The ash yield is 3.3 %-mass relative to as-received ash, with an ash K2O content of 12.9 %-mass. The ash is ground until passing 100-mesh standard sieve, and extracted by deionized water on a 2-stage laboratory-scale batchwise extractor battery. Process variables include extractror battery configuration (counter-current and co-current, temperature (nominal setting at 45-80 °C, and contact period of 1-6 hours. The concentration of extracted K2O increases asymptotically with temperature and contact time. Counter-current extraction yields more than twice the extract K2O concentration compared to cross-current extraction. The optimum conditions for the counter-current extraction is identified as a temperature of 78 °C and contact time of 4 hours, resulting in a 0.70 %-mass K2O solution concentration. Spot sampling of commercial liquid fertilizer products in Indonesia indicates an equivalent K2O content of 0.08-13.6 %-mass, suggesting the potential of the bamboo ash extract as an intermediate for fertilizer product.

  3. Presence of Cytotoxic Extracellular Histones in Machine Perfusate of Donation After Circulatory Death Kidneys.

    Science.gov (United States)

    van Smaalen, Tim C; Beurskens, Daniëlle M H; Hoogland, E R Pieter; Winkens, Bjorn; Christiaans, Maarten H L; Reutelingsperger, Chris P; van Heurn, L W Ernest; Nicolaes, Gerry A F

    2017-04-01

    Extracellular histones are cytotoxic molecules that are related to cell stress and death. They have been shown to play a crucial role in multiple pathophysiologic processes like sepsis, inflammation, vascular dysfunction, and thrombosis. Their role in organ donation and graft function and survival is still unknown. The aim of this study was to assess whether an association exists between the presence of extracellular histones in machine perfusates and deceased donor kidney viability. Machine perfusates of 390 donations after circulatory death kidneys were analyzed for histone concentration, and corresponding graft function and survival were assessed. Extracellular histone concentrations were significantly higher in perfusates of kidneys with posttransplant graft dysfunction (primary nonfunction and delayed graft function) and were an independent risk factor for delayed graft function (odds ratio, 2.152; 95% confidence interval [95% CI], 1.199-3.863) and 1 year graft failure (hazard ratio, 1.386; 95% CI, 1.037-1.853), but not for primary nonfunction (odds ratio, 1.342; 95% CI, 0.900-2.002). One year graft survival was 12% higher in the group with low histone concentrations (P = 0.008) as compared with the group that contained higher histone concentrations. This study warrants future studies to probe for a possible role of cytotoxic extracellular histones in organ viability and suggests that quantitation of extracellular histones might contribute to assessment of posttransplant graft function and survival.

  4. A new model for the estimation of time of death from vitreous potassium levels corrected for age and temperature.

    Science.gov (United States)

    Zilg, B; Bernard, S; Alkass, K; Berg, S; Druid, H

    2015-09-01

    Analysis of potassium concentration in the vitreous fluid of the eye is frequently used by forensic pathologists to estimate the postmortem interval (PMI), particularly when other methods commonly used in the early phase of an investigation can no longer be applied. The postmortem rise in vitreous potassium has been recognized for several decades and is readily explained by a diffusion of potassium from surrounding cells into the vitreous fluid. However, there is no consensus regarding the mathematical equation that best describes this increase. The existing models assume a linear increase, but different slopes and starting points have been proposed. In this study, vitreous potassium levels, and a number of factors that may influence these levels, were examined in 462 cases with known postmortem intervals that ranged from 2h to 17 days. We found that the postmortem rise in potassium followed a non-linear curve and that decedent age and ambient temperature influenced the variability by 16% and 5%, respectively. A long duration of agony and a high alcohol level at the time of death contributed less than 1% variability, and evaluation of additional possible factors revealed no detectable impact on the rise of vitreous potassium. Two equations were subsequently generated, one that represents the best fit of the potassium concentrations alone, and a second that represents potassium concentrations with correction for decedent age and/or ambient temperature. The former was associated with narrow confidence intervals in the early postmortem phase, but the intervals gradually increased with longer PMIs. For the latter equation, the confidence intervals were reduced at all PMIs. Therefore, the model that best describes the observed postmortem rise in vitreous potassium levels includes potassium concentration, decedent age, and ambient temperature. Furthermore, the precision of these equations, particularly for long PMIs, is expected to gradually improve by adjusting the

  5. Detection of extracellular enzymatic activity in microorganisms ...

    African Journals Online (AJOL)

    Detection of extracellular enzymatic activity in microorganisms isolated from waste vegetable oil contaminated soil using plate methodologies. Eugenia G. Ortiz Lechuga, Isela Quintero Zapata, Katiushka Arévalo Niño ...

  6. Purification and characterization of extracellular amylolytic enzyme ...

    African Journals Online (AJOL)

    DOSS

    2012-10-16

    Oct 16, 2012 ... Available online at http://www.academicjournals.org/AJB ... characterization of extracellular amylases from four ... Somogyi-Nelson's method (Nelson, 1944; Somogyi, 1952). ... The mycelia dry weight of currently studied four.

  7. Neutrophil Extracellular Traps in Ulcerative Colitis

    DEFF Research Database (Denmark)

    Bjerg Bennike, Tue; Carlsen, Thomas Gelsing; Ellingsen, Torkell

    2015-01-01

    microscopy and confocal microscopy. RESULTS: We identified and quantified 5711 different proteins with proteomics. The abundance of the proteins calprotectin and lactotransferrin in the tissue correlated with the degree of tissue inflammation as determined by histology. However, fecal calprotectin did...... not correlate. Forty-six proteins were measured with a statistically significant differences in abundances between the UC colon tissue and controls. Eleven of the proteins with increased abundances in the UC biopsies were associated with neutrophils and neutrophil extracellular traps. The findings were...... validated by microscopy, where an increased abundance of neutrophils and the presence of neutrophil extracellular traps by extracellular DNA present in the UC colon tissue were confirmed. CONCLUSIONS: Neutrophils, induced neutrophil extracellular traps, and several proteins that play a part in innate...

  8. Effect of micronized zeolite addition to lamb concentrate feeds on ...

    African Journals Online (AJOL)

    OEM

    2016-09-21

    Sep 21, 2016 ... URL: http://www.sasas.co.za .... sodium, potassium and chlorine concentrations were determined on the serum samples, while glucose ..... study and feed formulation, appropriate animal selection and helped to data collection ...

  9. Association of Bordetella dermonecrotic toxin with the extracellular matrix

    Directory of Open Access Journals (Sweden)

    Miyake Masami

    2010-09-01

    Full Text Available Abstract Background Bordetella dermonecrotic toxin (DNT causes the turbinate atrophy in swine atrophic rhinitis, caused by a Bordetella bronchiseptica infection of pigs, by inhibiting osteoblastic differentiation. The toxin is not actively secreted from the bacteria, and is presumed to be present in only small amounts in infected areas. How such small amounts can affect target tissues is unknown. Results Fluorescence microscopy revealed that DNT associated with a fibrillar structure developed on cultured cells. A cellular component cross-linked with DNT conjugated with a cross-linker was identified as fibronectin by mass spectrometry. Colocalization of the fibronectin network on the cells with DNT was also observed by fluorescence microscope. Several lines of evidence suggested that DNT interacts with fibronectin not directly, but through another cellular component that remains to be identified. The colocalization was observed in not only DNT-sensitive cells but also insensitive cells, indicating that the fibronectin network neither serves as a receptor for the toxin nor is involved in the intoxicating procedures. The fibronectin network-associated toxin was easily liberated when the concentration of toxin in the local environment decreased, and was still active. Conclusions Components in the extracellular matrix are known to regulate activities of various growth factors by binding and liberating them in response to alterations in the extracellular environment. Similarly, the fibronectin-based extracellular matrix may function as a temporary storage system for DNT, enabling small amounts of the toxin to efficiently affect target tissues or cells.

  10. Effects of calcium, potassium, rubidium and various fertilizers on radiocaesium transfers in field and experimental conditions

    International Nuclear Information System (INIS)

    Mitchell, N.G.; Coughtrey, P.J.; Kirton, J.A.

    1990-01-01

    To provide a basis for estimating the effectiveness of various treatments in reducing radiocaesium transfer to vegetation and grazing animals in upland ecosystems, studies have been undertaken to determine interactions between radiocaesium transfer and that of analogous elements (e.g. Rb, K) and the effects of various inorganic fertilizers (lime, NPK at different rates). Laboratory results demonstrated Rb and K (at equivalent ionic concentrations) tended to reduce radiocaesium concentrations in vegetation. These effects were highly dependent on the particular combination of plant species and soil conditions. Field investigations showed that potassium reduced radiocaesium concentrations in vegetation only very slightly. Though statistically significant, this effect was insufficient a basis to recommend the use of potassium treatments to ameliorate the effects of deposited radiocaesium. Studies at sites with a known history of land management prior to, or after, the Chernobyl accident show the effect of liming, ancient drainage, and application of organic and inorganic fertilizers. (author)

  11. Concentrations of ions in blood or athletes using NAA

    International Nuclear Information System (INIS)

    Kovacs, Luciana; Zamboni, Cibele B.; Loureno, Thiago F.; Nunes, Lazaro A.S.; Macedo, Denise V.

    2011-01-01

    Sodium (Na), chlorine (Cl) and potassium (K) are widely distributed in the body and are the mainly of body fluids electrolytes. K is the major intracellular ion. Na and Cl are the major extracellular ions. Therefore, Na and Cl can be regarded as the most important osmotically active electrolytes. The concentrations of these ions in body fluids are very tightly controlled. These electrolytes play central roles in electrolytic balances and current, in osmotic control, in the transport of organic metabolites by cells, and stabilization of poly electrolytes in cells. In this study Na, Cl and K levels were investigated in blood of athletes submitted to physical exercise at Laboratorio de Bioquimica do Exercicio (LABEX/UNICAMP - Brazil) using Neutron Activation Analyses (NAA) technique. The blood samples were collected from six male athletes, ranging from 18 to 26 years old, before and after the physical training. These results were compared with the rest condition (before start the physical exercise), as well as with the control group (subjects of same age but not involved with physical activities), for checking the performance of the athletes during and after the exercise. The nuclear procedure adopted as NAA, it can be an alternative procedure to perform biochemistry analyses in blood, mainly when the biological material is scarce. (author)

  12. Effects of cisplatin on potassium currents in CT26 cells

    Directory of Open Access Journals (Sweden)

    Naveen Sharma

    2016-01-01

    Conclusion: Potassium currents were detected in CT26 cells and the currents were reduced by the application of tetraethylammonium (TEA chloride, iberiotoxin, a big conductance calcium-activated potassium channel blocker and barium. The potassium currents were enhanced to 192< by the application of cisplatin (0.5 mM. Moreover, the increase of potassium currents by cisplatin was further inhibited by the application of TEA confirming the action of cisplatin on potassium channels. In addition, relative current induced by cisplatin in CT26 cells was bit larger than in normal IEC-6 cells.

  13. Sources of extracellular tau and its signaling.

    Science.gov (United States)

    Avila, Jesús; Simón, Diana; Díaz-Hernández, Miguel; Pintor, Jesús; Hernández, Félix

    2014-01-01

    The pathology associated with tau protein, tauopathy, has been recently analyzed in different disorders, leading to the suggestion that intracellular and extracellular tau may itself be the principal agent in the transmission and spreading of tauopathies. Tau pathology is based on an increase in the amount of tau, an increase in phosphorylated tau, and/or an increase in aggregated tau. Indeed, phosphorylated tau protein is the main component of tau aggregates, such as the neurofibrillary tangles present in the brain of Alzheimer's disease patients. It has been suggested that intracellular tau could be toxic to neurons in its phosphorylated and/or aggregated form. However, extracellular tau could also damage neurons and since neuronal death is widespread in Alzheimer's disease, mainly among cholinergic neurons, these cells may represent a possible source of extracellular tau. However, other sources of extracellular tau have been proposed that are independent of cell death. In addition, several ways have been proposed for cells to interact with, transmit, and spread extracellular tau, and to transduce signals mediated by this tau. In this work, we will discuss the role of extracellular tau in the spreading of the tau pathology.

  14. Transcriptome of extracellular vesicles released by hepatocytes.

    Directory of Open Access Journals (Sweden)

    Felix Royo

    Full Text Available The discovery that the cells communicate through emission of vesicles has opened new opportunities for better understanding of physiological and pathological mechanisms. This discovery also provides a novel source for non-invasive disease biomarker research. Our group has previously reported that hepatocytes release extracellular vesicles with protein content reflecting the cell-type of origin. Here, we show that the extracellular vesicles released by hepatocytes also carry RNA. We report the messenger RNA composition of extracellular vesicles released in two non-tumoral hepatic models: primary culture of rat hepatocytes and a progenitor cell line obtained from a mouse foetal liver. We describe different subpopulations of extracellular vesicles with different densities and protein and RNA content. We also show that the RNA cargo of extracellular vesicles released by primary hepatocytes can be transferred to rat liver stellate-like cells and promote their activation. Finally, we provide in vitro and in vivo evidence that liver-damaging drugs galactosamine, acetaminophen, and diclofenac modify the RNA content of these vesicles. To summarize, we show that the extracellular vesicles secreted by hepatocytes contain various RNAs. These vesicles, likely to be involved in the activation of stellate cells, might become a new source for non-invasive identification of the liver toxicity markers.

  15. Quantitative laser-induced breakdown spectroscopy of potassium for in-situ geochronology on Mars

    Energy Technology Data Exchange (ETDEWEB)

    Stipe, Christopher B., E-mail: stipec@seattleu.edu [Department of Mechanical Engineering, Seattle University, Seattle, WA 98122 (United States); Guevara, Edward; Brown, Jonathan [Department of Mechanical Engineering, Seattle University, Seattle, WA 98122 (United States); Rossman, George R. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)

    2012-04-15

    Laser-induced breakdown spectroscopy is explored for the development of an in-situ K-Ar geochronology instrument for Mars. Potassium concentrations in standard basaltic glasses and equivalent rock samples in their natural form are quantified using the potassium doublet at 766.49 and 769.90 nm. Measurement precision varies from 0.5 to 5.5 (% RSD) over the 3.63% to 0.025% potassium by weight for the standard samples, and little additional precision is achieved above 20 laser shots at 5 locations. For the glass standards, the quantification limits are 920 and 66 ppm for non-weighted and weighted calibration methods, respectively. For the basaltic rocks, the quantification limits are 2650 and 328 ppm for the non-weighted and weighted calibration methods, respectively. The heterogeneity of the rock samples leads to larger variations in potassium signal; however, normalizing the potassium peak by base area at 25 locations on the rock improved calibration accuracy. Including only errors in LIBS measurements, estimated age errors for the glasses range from approximately {+-} 30 Ma for 3000 Ma samples to {+-} 2 Ma for 100 Ma samples. For the basaltic rocks, the age errors are approximately {+-} 120 Ma for 3000 Ma samples and {+-} 8 Ma for 100 Ma samples. - Highlights: Black-Right-Pointing-Pointer Measurement of basaltic glasses and rocks by laser-induced breakdown spectroscopy. Black-Right-Pointing-Pointer Quantification of potassium for K-Ar dating. Black-Right-Pointing-Pointer Development of an instrument for in-situ geochronology on Mars. Black-Right-Pointing-Pointer Detection limit is 35 ppm, relative standard deviations range from 0.5% to 5.5%. Black-Right-Pointing-Pointer Estimated errors for the glass standards range from {+-} 30 Ma for 3000 Ma and {+-} 2 Ma for 100 Ma; estimated errors for the basaltic rocks range from {+-} 120 Ma for 3000 Ma and {+-} 8 Ma for 100 Ma.

  16. Increased Urinary Extracellular Vesicle Sodium Transporters in Cushing's Syndrome with Hypertension.

    Science.gov (United States)

    Salih, Mahdi; Bovée, Dominique M; van der Lubbe, Nils; Danser, Alexander H J; Zietse, Robert; Feelders, Richard A; Hoorn, Ewout J

    2018-05-02

    Increased renal sodium reabsorption contributes to hypertension in Cushing's syndrome (CS). Renal sodium transporters can be analyzed non-invasively in urinary extracellular vesicles (uEVs). To analyze renal sodium transporters in uEVs of patients with CS and hypertension. Observational study. University hospital. uEVs were isolated by ultracentrifugation and analyzed by immunoblotting in 10 CS patients and 7 age-matched healthy subjects. In 7 CS patients uEVs were analyzed before and after treatment. uEV protein abundance. The 10 CS patients were divided in those with suppressed and non-suppressed renin-angiotensin-aldosterone system (RAAS, n = 5/group). CS patients with suppressed RAAS had similar blood pressure but significantly lower serum potassium than CS patients with non-suppressed RAAS. Compared to healthy subjects, only those with suppressed RAAS had higher phosphorylated Na+-K+-Cl- cotransporter type 2 (pNKCC2) and higher total and phosphorylated Na+-Cl- cotransporter (NCC) in uEVs. Serum potassium but not urinary free cortisol correlated with pNKCC2, pNCC, and NCC in uEVs. Treatment of CS reversed the increases in pNKCC2, NCC, and pNCC. CS increases renal sodium transporter abundance in uEVs especially in patients with hypertension and suppressed RAAS. As potassium has recently been identified as an important driver of NCC activity, low serum potassium may also contribute to increased renal sodium reabsorption and hypertension in CS. These results may also be relevant for hypertension induced by exogenous glucocorticoids.

  17. Neutrophil extracellular trap formation in supragingival biofilms.

    Science.gov (United States)

    Hirschfeld, Josefine; Dommisch, Henrik; Skora, Philipp; Horvath, Gabor; Latz, Eicke; Hoerauf, Achim; Waller, Tobias; Kawai, Toshihisa; Jepsen, Søren; Deschner, James; Bekeredjian-Ding, Isabelle

    2015-01-01

    Oral biofilms are the causative agents of the highly prevalent oral diseases periodontitis and caries. Additionally, the host immune response is thought to play a critical role in disease onset. Neutrophils are known to be a key host response factor to bacterial challenge on host surfaces. Release of neutrophil extracellular traps (NETs) as a novel antimicrobial defense strategy has gained increasing attention in the past years. Here, we investigated the influx of neutrophils into the dental plaque and the ability of oral bacteria to trigger intra-biofilm release of NETs and intracellular proteins. Supragingival biofilms and whole saliva were sampled from systemically healthy subjects participating in an experimental gingivitis study. Biofilms were analysed by immunofluorescence followed by confocal and fluorescence microscopy. Moreover, concentrations of cytokines and immune-associated proteins in biofilm suspensions and saliva were assessed by ELISA. Neutrophils obtained from blood were stimulated with twelve bacterial species isolated from cultured biofilms or with lipopolysaccharide to monitor NET formation. Neutrophils, NETs, neutrophil-associated proteins (myeloperoxidase, elastase-2, cathepsin G, cathelicidin LL-37), interleukin-8, interleukin-1β and tumor necrosis factor were detected within plaque samples and saliva. All tested bacterial species as well as the polymicrobial samples isolated from the plaque of each donor induced release of NETs and interleukin-8. The degree of NET formation varied among different subjects and did not correlate with plaque scores or clinical signs of local inflammation. Our findings indicate that neutrophils are attracted towards dental biofilms, in which they become incorporated and where they are stimulated by microbes to release NETs and immunostimulatory proteins. Thus, neutrophils and NETs may be involved in host biofilm control, although their specific role needs to be further elucidated. Moreover, inter

  18. Urocortin2 prolongs action potential duration and modulates potassium currents in guinea pig myocytes and HEK293 cells.

    Science.gov (United States)

    Yang, Li-Zhen; Zhu, Yi-Chun

    2015-07-05

    We previously reported that activation of corticotropin releasing factor receptor type 2 by urocortin2 up-regulates both L-type Ca(2+) channels and intracellular Ca(2+) concentration in ventricular myocytes and plays an important role in cardiac contractility and arrhythmogenesis. This study goal was to further test the hypothesis that urocortin2 may modulate action potentials as well as rapidly and slowly activating delayed rectifier potassium currents. With whole cell patch-clamp techniques, action potentials and slowly activating delayed rectifier potassium currents were recorded in isolated guinea pig ventricular myocytes, respectively. And rapidly activating delayed rectifier potassium currents were tested in hERG-HEK293 cells. Urocortin2 produced a time- and concentration-dependent prolongation of action potential duration. The EC50 values of action potential duration and action potential duration at 90% of repolarization were 14.73 and 24.3nM respectively. The prolongation of action potential duration of urocortin2 was almost completely or partly abolished by H-89 (protein kinase A inhibitor) or KB-R7943 (Na(+)/Ca(2+) exchange inhibitor) pretreatment respectively. And urocortin2 caused reduction of rapidly activating delayed rectifier potassium currents in hERG-HEK293 cells. In addition, urocortin2 slowed the rate of slowly activating delayed rectifier potassium channel activation, and rightward shifted the threshold of slowly activating delayed rectifier potassium currents to more positive potentials. Urocortin2 prolonged action potential duration via activation of protein kinase A and Na(+)/ Ca(2+) exchange in isolated guinea pig ventricular myocytes in a time- and concentration- dependent manner. In hERG-HEK293 cells, urocortin2 reduced rapidly activating delayed rectifier potassium current density which may contribute to action potential duration prolongation. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Scanning Tunneling Spectroscopy of Potassium on Graphene

    Science.gov (United States)

    Cormode, Daniel; Leroy, Brian; Yankowitz, Matthew

    2012-02-01

    We investigate the effect of charged impurities on the electronic properties of large single crystal CVD grown graphene using scanning tunneling microscopy. Mono- and multilayer crystals were prepared by transferring graphene from copper onto exfoliated boron nitride flakes on 300 nm SiO2 substrates. The boron nitride provides an ultra flat surface for the graphene. Potassium atoms are controllably deposited on the graphene at low temperature by heating a nearby getter source. Scanning tunneling spectroscopy and transport measurements were performed in ultra high vacuum at 4.5 K. Transport measurements demonstrate the shifting of the Dirac point as the samples are doped, while STM measurements demonstrate the size, arrangement and local electronic influence of the potassium atoms.

  20. Potassium tetracyanidoaurate(III monohydrate: a redetermination

    Directory of Open Access Journals (Sweden)

    Nobuyuki Matsushita

    2017-03-01

    Full Text Available The structure of the title metal complex salt, K[Au(CN4]·H2O, has been redetermined using X-ray diffraction data at 173 K in order to improve the precision. The previous determination was based on neutron diffraction data [Bertinotti & Bertinotti (1970. Acta Cryst. B26, 422–428]. The title compound crystallizes in the space group P212121 with one potassium cation, one [Au(CN4]− anion and one water molecule in the asymmetric unit. The AuIII atom lies on a general position and has an almost square-planar coordination sphere defined by four cyanide ligands. Interactions between the potassium cation and N atoms of the complex anion, as well as O—H...N hydrogen bonds, lead to the formation of a three-dimensional framework structure.

  1. High-speed centrifugation induces aggregation of extracellular vesicles.

    Science.gov (United States)

    Linares, Romain; Tan, Sisareuth; Gounou, Céline; Arraud, Nicolas; Brisson, Alain R

    2015-01-01

    Plasma and other body fluids contain cell-derived extracellular vesicles (EVs), which participate in physiopathological processes and have potential biomedical applications. In order to isolate, concentrate and purify EVs, high-speed centrifugation is often used. We show here, using electron microscopy, receptor-specific gold labelling and flow cytometry, that high-speed centrifugation induces the formation of EV aggregates composed of a mixture of EVs of various phenotypes and morphologies. The presence of aggregates made of EVs of different phenotypes may lead to erroneous interpretation concerning the existence of EVs harbouring surface antigens from different cell origins.

  2. High-speed centrifugation induces aggregation of extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Romain Linares

    2015-12-01

    Full Text Available Plasma and other body fluids contain cell-derived extracellular vesicles (EVs, which participate in physiopathological processes and have potential biomedical applications. In order to isolate, concentrate and purify EVs, high-speed centrifugation is often used. We show here, using electron microscopy, receptor-specific gold labelling and flow cytometry, that high-speed centrifugation induces the formation of EV aggregates composed of a mixture of EVs of various phenotypes and morphologies. The presence of aggregates made of EVs of different phenotypes may lead to erroneous interpretation concerning the existence of EVs harbouring surface antigens from different cell origins.

  3. The order of draw of blood specimens into additive containing tubes not affect potassium and calcium measurements.

    Science.gov (United States)

    Majid, A; Heaney, D C; Padmanabhan, N; Spooner, R

    1996-12-01

    The effect of order of draw when taking blood into tubes containing additive was investigated in 47 medical inpatients; 12 of these patients acted as a control group. The samples were analysed in the order in which they were withdrawn. The results of potassium and calcium concentrations did not differ significantly between groups. Manufacturers recommend a specific order of draw when taking blood using vacuum based blood collection systems, which are routinely used in many hospitals. The results of this study, however, show that order of draw has no effect on calcium or potassium concentrations.

  4. Kinetics studies of oxidation of niacinamide by alkaline potassium permanganate

    Directory of Open Access Journals (Sweden)

    Sandipsingh Gour

    2012-04-01

    Full Text Available The oxidation of niacinamide in alkaline media is carried out using potassium permanganate as a oxiding agent. The reaction was monitored using UV-Visible spectrophotometer at 525 nm. It was found to be zero order with respect to oxidant,, fractional order with respect to hydrogen ion concentration and first order with respect to substrate. The thermodynamic parameters(were determinied . The average (?G# was found to be 87.60 KJ/mol. The values ?S# was found to be -0.2132 KJ/mole and energy of activation was found to be 23.95 KJ/mole. A suitable mechanism is proposed based on the experimental conditions.

  5. Dissolution rate effect upon lyolumenescence of irradiated potassium chloride

    International Nuclear Information System (INIS)

    Leshchinskij, B.L.; Dzelme, Yu.R.; Tiliks, Yu.E.; Bugaenko, L.T.

    1985-01-01

    The paper is aimed at studying dissolution rate effect and concentration of electron acceptor upon lyoluminescence (LL) that occurs during dissolution of solids with radiation defects. For investigation gamma-irradiated potassium chloride monocrystalline disks were used. As a solvent 3x10sup(-6) M solution of C(RH) hodamine in 2.7 KCl aqueous solution is used. It is shown that LL occurs as a result of recombination of radiation defects with the solution and between themselves in two different regions of subsurface layer of the solid. Investigated dependences of LL intensty on dissolution rate are the efficient method of studying the structure of solids-aqueous solution interface and LL mechanism

  6. Potassium iodide capsule treatment of feline sporotrichosis.

    Science.gov (United States)

    Reis, Erica G; Gremião, Isabella D F; Kitada, Amanda A B; Rocha, Raphael F D B; Castro, Verônica S P; Barros, Mônica B L; Menezes, Rodrigo C; Pereira, Sandro A; Schubach, Tânia M P

    2012-06-01

    Sporotrichosis is a mycosis caused by Sporothrix schenckii. The most affected animal is the cat; it has played an important role in the zoonotic transmission of this disease, especially in Rio de Janeiro, Brazil, since 1998. In order to evaluate the treatment of feline sporotrichosis with potassium iodide, an observational cohort was conducted in 48 cats with sporotrichosis at Instituto de Pesquisa Clínica Evandro Chagas, Fiocruz. All cats received potassium iodide capsules, 2.5 mg/kg to 20 mg/kg q24h. The cure rate was 47.9%, treatment failure was 37.5%, treatment abandonment was 10.4% and death was 4.2%. Clinical adverse effects were observed in 52.1% of the cases. Thirteen cats had a mild increase in hepatic transaminase levels during the treatment, six of them presented clinical signs suggestive of hepatotoxicity. Compared to previous studies with itraconazole and iodide in saturated solution, potassium iodide capsules are an alternative for feline sporotrichosis treatment.

  7. Potassium Permanganate Poisoning: A Nonfatal Outcome

    Directory of Open Access Journals (Sweden)

    Suzan M. Eteiwi

    2015-07-01

    Full Text Available Acute poisoning by potassium permanganate is a rare condition with high morbidity and mortality. Diagnosis of the condition relies on a history of exposure or ingestion and a high degree of clinical suspicion. Oxygen desaturation and the presence of methemoglobin are also helpful indicators. Since no specific antidote is available, treatment is mainly supportive. Few cases have been reported in the literature following potassium permanganate ingestion, whether intentional or accidental, and most of the patients in these cases had unfavorable outcomes, which was not the case in our patient. Our patient, a 73-year-old male, purchased potassium permanganate over the counter mistaking it for magnesium salt, which he frequently used as a laxative. Several hours after he ingested it, he was admitted to the endocrine department at King Hussein Medical Center, Jordan, with acute rapidly evolving shortness of breath. During hospitalization, his liver function tests deteriorated. Since he was diagnosed early and managed promptly he had a favorable outcome.

  8. A novel potassium channel in photosynthetic cyanobacteria.

    Directory of Open Access Journals (Sweden)

    Manuela Zanetti

    Full Text Available Elucidation of the structure-function relationship of a small number of prokaryotic ion channels characterized so far greatly contributed to our knowledge on basic mechanisms of ion conduction. We identified a new potassium channel (SynK in the genome of the cyanobacterium Synechocystis sp. PCC6803, a photosynthetic model organism. SynK, when expressed in a K(+-uptake-system deficient E. coli strain, was able to recover growth of these organisms. The protein functions as a potassium selective ion channel when expressed in Chinese hamster ovary cells. The location of SynK in cyanobacteria in both thylakoid and plasmamembranes was revealed by immunogold electron microscopy and Western blotting of isolated membrane fractions. SynK seems to be conserved during evolution, giving rise to a TPK (two-pore K(+ channel family member which is shown here to be located in the thylakoid membrane of Arabidopsis. Our work characterizes a novel cyanobacterial potassium channel and indicates the molecular nature of the first higher plant thylakoid cation channel, opening the way to functional studies.

  9. Cesium immobilization into potassium magnesium phosphate matrix

    International Nuclear Information System (INIS)

    Sayenko, S.Y.; Shkuropatenko, V.A.; Bereznyak, O.P.; Hodyreva, Y.S.; Tarasov, R.V.; Virych, V.D.; Ulybkina, E.A.; Pylypenko, O.V.; Kholomeev, G.O.; Zykova, A.V.; Wagh, Arun S.

    2017-01-01

    The possibility of isomorphous substitution of potassium ions by cesium ions in the structure of potassium magnesium phosphate KMgPO 4 centred dot 6H 2 O (PMP) was shown. It was established, that the Cs included into the PMP matrix does not transfer to the environment during high temperatures heating process (1176 deg C, 3 hours). Analysis of the IR absorption spectrum of the PMP sample has demonstrated that an increase in the amount of additive of the cesium chloride resulted in the shift of the main bands in the spectrum to the low-frequency region with average shift value 10 cm -1 , which indicates the strengthening of bonds in the crystal lattice of matter. The calculated degree of substitution of potassium by cesium during energy release process in the PMP matrix at the level of vitrified high level wastes is about 4%, i. e. the PMP matrix should correspond to the formula K 0.96 Cs 0.04 MgPO 4 centred dot 6H 2 O.

  10. On the Mechanism of Polyuria in Potassium Depletion

    Science.gov (United States)

    Berl, Tomas; Linas, Stuart L.; Aisenbrey, Gary A.; Anderson, Robert J.

    1977-01-01

    The association of potassium (K) depletion with polyuria and a concentrating defect is established, but the extent to which these defects could be secondary to an effect of low K on water intake has not been systematically investigated. To determine whether hypokalemia has a primary effect to increase thirst and whether any resultant polyuria and polydipsia contribute to the concentrating defect, we studied three groups of rats kept in metabolic cages for 15 days. The groups were set up as follows: group 1, normal diets and ad lib. fluids (n = 12); group 2, K-deficient diet on ad lib. fluids (n = 12); and group 3, K-deficient diet and fluid intake matched to group 1 (n = 14). Daily urine flow and urinary osmolality of groups 1 and 3 were not significantly different throughout the study. In contrast, as of day 6, group 2 rats consistently had a higher fluid intake (P polyuria. After 15 days of a K-deficient diet, the impaired maximal urinary concentration in hypokalemia, however, was not related to increased water intake, since fluid restriction did not abolish the renal concentrating defect. PMID:893666

  11. Assessment of sodium status in large ruminants by measuring the sodium-to-potassium ratio in muzzle secretions.

    Science.gov (United States)

    Singh, S P; Rani, D

    1999-09-01

    To develop a simple diagnostic test to assess sodium status in large ruminants on the basis of the sodium-to-potassium ratio (Na:K) and to determine its relevance. 7 buffalo heifers and 21 lactating, pregnant, and nonpregnant dairy cows and heifers. Buffalo heifers were subjected in 2 experiments to variable dietary sodium intake or sodium depletion and changes in sodium and potassium concentrations; Na:K was simultaneously monitored in various body fluids to study its value for indicating sodium status. Validity of the muzzle secretion test was assessed. Muzzle secretion and urinary Na:K and sodium concentration, but not serum electrolyte concentrations, reflected the sodium status of buffalo heifers in response to the widely variable intake of sodium (0.03 to 0.16% of dry matter [DM]). Progressive sodium depletion during an 11-day period, using saliva deprivation caused reciprocal changes in sodium and potassium concentrations in saliva and muzzle secretion, but not in urine. Decreasing urine sodium concentration was associated with decreasing urine potassium concentration. Saliva, urine, and muzzle secretion Na:K closely reflected the degree of sodium deficit. Buffaloes or dairy cows maintained on optimal sodium intake had muzzle secretion and urine Na:K > 0.30. Muzzle secretion or urine Na:K muzzle secretion Na:K, and to a large extent urine Na:K, may be used as a convenient diagnostic tool to assess sodium status in large ruminants. It has accuracy similar to that of saliva Na:K.

  12. Development of analytical method used for the estimation of potassium amide in liquid ammonia at HWP (Tuticorin)

    International Nuclear Information System (INIS)

    Ramanathan, A.V.

    2007-01-01

    Potassium amide in liquid ammonia is used as a homogeneous catalyst in mono-thermal ammonia-hydrogen isotopic chemical exchange process employed for the manufacture of heavy water. Estimation of concentration of potassium amide in liquid ammonia is vital for checking whether it is sufficient for catalysis in isotopic exchange towers or for purification in purifiers in the Heavy Water Plants. This estimation was carried out earlier by the conventional method involving evaporation of ammonia, decomposition of potassium amide with water and titration of liberated ammonia with sulphuric acid. This method has been replaced by a newly developed method involving direct titration of potassium amide in ammonia with ammonium bromide. This new method is based on the principle that ammonium bromide and potassium amide act as acid and base respectively in the non-aqueous solvent medium, liquid ammonia. This method has not only proved to be an alternative method of estimation of potassium amide in liquid ammonia but also has been serving as a developed analytical method, because it is faster (with fewer steps), more accurate, safer (as it excludes the use of corrosive sulphuric acid needed for the conventional method) and more convenient (as it doesn't need specially designed apparatus and inert gas like dry nitrogen used in the conventional method). (author)

  13. Tunable Diode Laser Atomic Absorption Spectroscopy for Detection of Potassium under Optically Thick Conditions.

    Science.gov (United States)

    Qu, Zhechao; Steinvall, Erik; Ghorbani, Ramin; Schmidt, Florian M

    2016-04-05

    Potassium (K) is an important element related to ash and fine-particle formation in biomass combustion processes. In situ measurements of gaseous atomic potassium, K(g), using robust optical absorption techniques can provide valuable insight into the K chemistry. However, for typical parts per billion K(g) concentrations in biomass flames and reactor gases, the product of atomic line strength and absorption path length can give rise to such high absorbance that the sample becomes opaque around the transition line center. We present a tunable diode laser atomic absorption spectroscopy (TDLAAS) methodology that enables accurate, calibration-free species quantification even under optically thick conditions, given that Beer-Lambert's law is valid. Analyte concentration and collisional line shape broadening are simultaneously determined by a least-squares fit of simulated to measured absorption profiles. Method validation measurements of K(g) concentrations in saturated potassium hydroxide vapor in the temperature range 950-1200 K showed excellent agreement with equilibrium calculations, and a dynamic range from 40 pptv cm to 40 ppmv cm. The applicability of the compact TDLAAS sensor is demonstrated by real-time detection of K(g) concentrations close to biomass pellets during atmospheric combustion in a laboratory reactor.

  14. Race, Serum Potassium, and Associations With ESRD and Mortality.

    Science.gov (United States)

    Chen, Yan; Sang, Yingying; Ballew, Shoshana H; Tin, Adrienne; Chang, Alex R; Matsushita, Kunihiro; Coresh, Josef; Kalantar-Zadeh, Kamyar; Molnar, Miklos Z; Grams, Morgan E

    2017-08-01

    Recent studies suggest that potassium levels may differ by race. The basis for these differences and whether associations between potassium levels and adverse outcomes differ by race are unknown. Observational study. Associations between race and potassium level and the interaction of race and potassium level with outcomes were investigated in the Racial and Cardiovascular Risk Anomalies in Chronic Kidney Disease (RCAV) Study, a cohort of US veterans (N=2,662,462). Associations between African ancestry and potassium level were investigated in African Americans in the Atherosclerosis Risk in Communities (ARIC) Study (N=3,450). Race (African American vs non-African American and percent African ancestry) for cross-sectional analysis; serum potassium level for longitudinal analysis. Potassium level for cross-sectional analysis; mortality and end-stage renal disease for longitudinal analysis. The RCAV cohort was 18% African American (N=470,985). Potassium levels on average were 0.162mmol/L lower in African Americans compared with non-African Americans, with differences persisting after adjustment for demographics, comorbid conditions, and potassium-altering medication use. In the ARIC Study, higher African ancestry was related to lower potassium levels (-0.027mmol/L per each 10% African ancestry). In both race groups, higher and lower potassium levels were associated with mortality. Compared to potassium level of 4.2mmol/L, mortality risk associated with lower potassium levels was lower in African Americans versus non-African Americans, whereas mortality risk associated with higher levels was slightly greater. Risk relationships between potassium and end-stage renal disease were weaker, with no difference by race. No data for potassium intake. African Americans had slightly lower serum potassium levels than non-African Americans. Consistent associations between potassium levels and percent African ancestry may suggest a genetic component to these differences. Higher and

  15. Assessment of extracellular dehydration using saliva osmolality.

    Science.gov (United States)

    Ely, Brett R; Cheuvront, Samuel N; Kenefick, Robert W; Spitz, Marissa G; Heavens, Kristen R; Walsh, Neil P; Sawka, Michael N

    2014-01-01

    When substantial solute losses accompany body water an isotonic hypovolemia (extracellular dehydration) results. The potential for using blood or urine to assess extracellular dehydration is generally poor, but saliva is not a simple ultra-filtrate of plasma and the autonomic regulation of salivary gland function suggests the possibility that saliva osmolality (Sosm) may afford detection of extracellular dehydration via the influence of volume-mediated factors. This study aimed to evaluate the assessment of extracellular dehydration using Sosm. In addition, two common saliva collection methods and their effects on Sosm were compared. Blood, urine, and saliva samples were collected in 24 healthy volunteers during paired euhydration and dehydration trials. Furosemide administration and 12 h fluid restriction were used to produce extracellular dehydration. Expectoration and salivette collection methods were compared in a separate group of eight euhydrated volunteers. All comparisons were made using paired t-tests. The diagnostic potential of body fluids was additionally evaluated. Dehydration (3.1 ± 0.5% loss of body mass) decreased PV (-0.49 ± 0.12 L; -15.12 ± 3.94% change), but Sosm changes were marginal ( 0.05). Extracelluar dehydration was not detectable using plasma, urine, or saliva measures. Salivette and expectoration sampling methods produced similar, consistent results for Sosm, suggesting no methodological influence on Sosm.

  16. Extracellular histones in tissue injury and inflammation.

    Science.gov (United States)

    Allam, Ramanjaneyulu; Kumar, Santhosh V R; Darisipudi, Murthy N; Anders, Hans-Joachim

    2014-05-01

    Neutrophil NETosis is an important element of host defense as it catapults chromatin out of the cell to trap bacteria, which then are killed, e.g., by the chromatin's histone component. Also, during sterile inflammation TNF-alpha and other mediators trigger NETosis, which elicits cytotoxic effects on host cells. The same mechanism should apply to other forms of regulated necrosis including pyroptosis, necroptosis, ferroptosis, and cyclophilin D-mediated regulated necrosis. Beyond these toxic effects, extracellular histones also trigger thrombus formation and innate immunity by activating Toll-like receptors and the NLRP3 inflammasome. Thereby, extracellular histones contribute to the microvascular complications of sepsis, major trauma, small vessel vasculitis as well as acute liver, kidney, brain, and lung injury. Finally, histones prevent the degradation of extracellular DNA, which promotes autoimmunization, anti-nuclear antibody formation, and autoimmunity in susceptible individuals. Here, we review the current evidence on the pathogenic role of extracellular histones in disease and discuss how to target extracellular histones to improve disease outcomes.

  17. Proapoptotic Role of Potassium Ions in Liver Cells

    Directory of Open Access Journals (Sweden)

    Zhenglin Xia

    2016-01-01

    Full Text Available Potassium channels are transmembrane proteins that selectively promote the infiltration of potassium ions. The significance of these channels for tumor biology has become obvious. However, the effects of potassium ions on the tumor or normal cells have seldom been studied. To address this problem, we studied the biological effects of L02 and HepG2 cells with ectogenous potassium ions. Cell proliferation, cell cycle, and apoptosis rate were analyzed. Our results indicated that potassium ions inhibited proliferation of L02 and HepG2 cells and promoted their apoptosis. Potassium ions induced apoptosis through regulating Bcl-2 family members and depolarized the mitochondrial membrane, especially for HepG2 cell. These biological effects were associated with channel protein HERG. By facilitating expression of channel protein HERG, potassium ions may prevent it from being shunted to procancerous pathways by inducing apoptosis. These results demonstrated that potassium ions may be a key regulator of liver cell function. Thus, our findings suggest that potassium ions could inhibit tumorigenesis through inducing apoptosis of hepatoma cells by upregulating potassium ions transport channel proteins HERG and VDAC1.

  18. Study on the Effect of Calcium and Potassium Spray on Date Bunch Fading Disorder

    Directory of Open Access Journals (Sweden)

    Hosein Shekofteh

    2017-09-01

    Full Text Available Introduction: Date bunch fading disorder has been one of the most important problems, which caused economic damage to date plantation area of Iran. It has been first reported on Mozafti cultivar in Kahnuj area, Kerman province. It has often been observed on soft and mid ripening cultivars such as Mozafti, Mordaseng and Kalote. Furthermore, it usually appears on Mozafti cultivar when fruits change from Khalal to Rutab stage. The most important symptoms of this disorder are sudden wilting of fruits and necrotic strips on the upper surface of the main bunch stalk. Incidence and development of these symptoms increase by high temperature, low relative humidity, and hot and dry wind. Several research studies have been carried out on this disorder so far, but the only research about the effect of nutrition on disorder was performed by Rosta (2003. The aim of the present study was to investigate the effect of calcium and potassium spray on date bunch fading and some traits of date fruit in Rigan region, Kerman province. Materials and Methods: The experiment was conducted based on randomized complete block designs with three replicates in Rigan located in east south of Kerman province, Iran, in 2012. Treatments were: T1: control, T2: spray of calcium nitrate at the concentration of 5 ppm, T3: spray of potassium sulfate at the concentration of 5 ppm, and T4: combined spray of calcium nitrate and potassium sulfate at the concentration of 5 ppm. Treatments were applied at Kimri, Hobabok and Khalal stages. Sampling was performed from 3 date palms (3 bunches from each date palm were selected randomly at the second date harvest. Totally, the traits of 200 fruits were measured in each date palm. The traits measured in the present study were: fruit length, fruit diameter, fruit weight, stone weight, stone diameter, and bunch fading percentage. Results and Discussions: According to the data of variance analysis, treatments had a significant effect on wet fruit

  19. Growth and Extracellular Carbonic Anhydrase Activity of Zooxanthellae Symbiodinium sp. in Response of Zinc Enrichment

    Directory of Open Access Journals (Sweden)

    WIDIASTUTI KARIM

    2011-12-01

    Full Text Available Coral reef communities contain a wide variety of mutualistic associations none more important than the relationship between corals and their symbiotic dinoflagellates of the genus Symbiodinium sp., commonly referred to as zooxanthellae. The function of Zinc (Zn as cofactor of several enzyme systems such as extracellular carbonic anhydrase (extracellular CA which catalyzes the interconversion of HCO3- and CO2. Concentrations of dissolved Zn in oligothropic waters are often very low therefore may limit the growth of zooxanthellae and their ability to fix CO2 from seawater via the carbonic anhydrase. The aim of this research is to investigate the effect of various concentrations of Zn on the growth and extracellular CA activity in zooxanthellae. Cell density was monitored daily by enumeration with hemocytometer-type chamber (0.1 mm. Extracellular CA was measured in homogenized intact whole cell by a pH drift assay. Results revealed that Zn status strongly influences the growth rate and extracelullar CA activity in zooxanthellae. The specific growth rate and cell density increased two-fold whilst extracelullar CA activity increased 10.5 times higher than that in control with increasing concentrations of Zn from 0 to 80 nM, but decreased when Zn was over 80 nM. Under a concentration of 80 nM was not Zn limited culture, consequently the growth rate of zooxanthellae not dependent on CO2 concentration yet offset by extracelullar CA activity.

  20. Growth and Extracellular Carbonic Anhydrase Activity of Zooxanthellae Symbiodinium sp. in Response of Zinc Enrichment

    Directory of Open Access Journals (Sweden)

    WIDIASTUTI KARIM

    2011-12-01

    Full Text Available Coral reef communities contain a wide variety of mutualistic associations none more important than the relationship between corals and their symbiotic dinoflagellates of the genus Symbiodinium sp., commonly referred to as zooxanthellae. The function of Zinc (Zn as cofactor of several enzyme systems such as extracellular carbonic anhydrase (extracellular CA which catalyzes the interconversion of HCO3− and CO2. Concentrations of dissolved Zn in oligothropic waters are often very low therefore may limit the growth of zooxanthellae and their ability to fix CO2 from seawater via the carbonic anhydrase. The aim of this research is to investigate the effect of various concentrations of Zn on the growth and extracellular CA activity in zooxanthellae. Cell density was monitored daily by enumeration with hemocytometer-type chamber (0.1 mm. Extracellular CA was measured in homogenized intact whole cell by a pH drift assay. Results revealed that Zn status strongly influences the growth rate and extracelullar CA activity in zooxanthellae. The specific growth rate and cell density increased two-fold whilst extracelullar CA activity increased 10.5 times higher than that in control with increasing concentrations of Zn from 0 to 80 nM, but decreased when Zn was over 80 nM. Under a concentration of 80 nM was not Zn limited culture, consequently the growth rate of zooxanthellae not dependent on CO2 concentration yet offset by extracelullar CA activity.

  1. Mechanism of potassium ion uptake by the Na+/K+-ATPase

    Science.gov (United States)

    Castillo, Juan P.; Rui, Huan; Basilio, Daniel; Das, Avisek; Roux, Benoît; Latorre, Ramon; Bezanilla, Francisco; Holmgren, Miguel

    2015-07-01

    The Na+/K+-ATPase restores sodium (Na+) and potassium (K+) electrochemical gradients dissipated by action potentials and ion-coupled transport processes. As ions are transported, they become transiently trapped between intracellular and extracellular gates. Once the external gate opens, three Na+ ions are released, followed by the binding and occlusion of two K+ ions. While the mechanisms of Na+ release have been well characterized by the study of transient Na+ currents, smaller and faster transient currents mediated by external K+ have been more difficult to study. Here we show that external K+ ions travelling to their binding sites sense only a small fraction of the electric field as they rapidly and simultaneously become occluded. Consistent with these results, molecular dynamics simulations of a pump model show a wide water-filled access channel connecting the binding site to the external solution. These results suggest a mechanism of K+ gating different from that of Na+ occlusion.

  2. A Pilot Study Exploring the Plasma Potassium Variation in Dogs Undergoing Steroid Therapy and Its Clinical Importance.

    Science.gov (United States)

    Baltar, Marina; Costa, Alexandra; Carreira, L Miguel

    2016-06-01

    In most situations in veterinary medicine, glucocorticoids are the drugs of choice used, that is, to reduce the inflammatory response or limit an inappropriate immune response. Their use in long-term therapy may cause side effects that may weaken the patient. The aim of the study was to evaluate possible variations in the plasma potassium concentrations and their clinical relevance in dogs undergoing steroid therapy with methylprednisolone in anti-inflammatory doses. The study used a sample of 21 dogs (n = 21) presented for consultation, with a clinical condition requiring a corticosteroid therapeutic protocol with an anti-inflammatory dose of methylprednisolone. All the individuals were submitted to a corticosteroid therapeutic protocol administered orally during 18 days. During this period, 3 time points were considered: T0 (the day the prescription was first given), T1 (3 days later), and T2 (8 days later). Blood samples were collected from a peripheral vein to measure plasma potassium concentrations in T0, T1, and T2. Corticosteroid therapy on an outpatient basis statistically significantly decreased plasma potassium levels, especially between T1 and T2 (P = .03). The plasma potassium levels decreased in 12.5% of the males, compared with a decrease of 23.1% in the females. No statistically significant relationships were observe between the decreased plasma potassium levels and age, clinical condition, and patient׳s body weight. However, we found a statistically significant association between decreased plasma potassium levels and sex. The study results may justify the need for the systematic prescription of potassium supplements in patients undergoing steroid therapy, similar to what already occurs in human medicine. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Reduction of Cs-137 levels in plants and fungi after potassium fertilization in a Swedish forest

    International Nuclear Information System (INIS)

    Nikolova, I.

    1998-01-01

    The uptake of 137 Cs in plants in forest ecosystems are much higher than in agricultural ecosystems. One reason could be that the concentrations of mineral nutrients usually are at much lower levels in forest soils compared to soil from arable land. On the other hand there are often rather weak correlation between the concentrations of exchangeable potassium in forest soils and the levels of 137 Cs in, e. g., dwarf-shrubs. The variations of the potassium levels are rather small in forest soils. This deficit can be offset by fertilization with potassium. The aim of the present study was to investigate the effects of potassium fertilization on the uptake of 137 Cs in a rather nutrient poor forest ecosystem - a rocky area with a rather shallow soil layer with high organic content. The potassium was spread in May 1992 by using normal agricultural equipment in efforts to get to 200 kg of potassium chloride per hectare. Three plots about 200 m 2 each were selected on the fertilized area and used for sampling of blueberry, lingonberry and heather. One sampling was performed before the spreading and then at least once a year up to 1997. During the mushroom season, the fruit bodies of the commonest species of fungi were collected within the 3 plots. A closely located rocky area was selected as the control area. The 137 Cs levels in blueberry and lingonberry only showed a minor decrease during the 1992 vegetation period. In contrast, heather showed a marked decrease of about 50 % already the first year. In mushrooms (Lactarius rufus and Rozites caperatus) the decrease was even more pronounced. In 1997, 5 vegetation periods after the fertilization, the Cs-137 levels in blueberry, lingonberry and heather were 633, 926 and 3,22 Bq/kg, respectively, amounting to 23%, 53%, and 24% of the control levels (2767, 1741 and 13,2 Bq/kg, respectively). Even fruit bodies of the fungi showed 137 Cs levels around 30 to 50 % of that in the control area. Thus, potassium fertilization appears

  4. Shaping Synapses by the Neural Extracellular Matrix

    Directory of Open Access Journals (Sweden)

    Maura Ferrer-Ferrer

    2018-05-01

    Full Text Available Accumulating data support the importance of interactions between pre- and postsynaptic neuronal elements with astroglial processes and extracellular matrix (ECM for formation and plasticity of chemical synapses, and thus validate the concept of a tetrapartite synapse. Here we outline the major mechanisms driving: (i synaptogenesis by secreted extracellular scaffolding molecules, like thrombospondins (TSPs, neuronal pentraxins (NPs and cerebellins, which respectively promote presynaptic, postsynaptic differentiation or both; (ii maturation of synapses via reelin and integrin ligands-mediated signaling; and (iii regulation of synaptic plasticity by ECM-dependent control of induction and consolidation of new synaptic configurations. Particularly, we focused on potential importance of activity-dependent concerted activation of multiple extracellular proteases, such as ADAMTS4/5/15, MMP9 and neurotrypsin, for permissive and instructive events in synaptic remodeling through localized degradation of perisynaptic ECM and generation of proteolytic fragments as inducers of synaptic plasticity.

  5. Oxidation of volatile organic vapours in air by solid potassium permanganate.

    Science.gov (United States)

    Mahmoodlu, Mojtaba Ghareh; Hartog, Niels; Majid Hassanizadeh, S; Raoof, Amir

    2013-06-01

    Volatile organic compounds (VOCs) may frequently contaminate groundwater and pose threat to human health when migrating into the unsaturated soil zone and upward to the indoor air. The kinetic of chemical oxidation has been investigated widely for dissolved VOCs in the saturated zone. But, so far there have been few studies on the use of in situ chemical oxidation (ISCO) of vapour phase contaminants. In this study, batch experiments were carried out to evaluate the oxidation of trichloroethylene (TCE), ethanol, and toluene vapours by solid potassium permanganate. Results revealed that solid potassium permanganate is able to transform the vapour of these compounds into harmless oxidation products. The degradation rates for TCE and ethanol were higher than for toluene. The degradation process was modelled using a kinetic model, linear in the gas concentration of VOC [ML(-3)] and relative surface area of potassium permanganate grains (surface area of potassium permanganate divided by gas volume) [L(-1)]. The second-order reaction rate constants for TCE, ethanol, and toluene were found to be equal to 2.0×10(-6) cm s(-1), 1.7×10(-7) cm s(-1), and 7.0×10(-8) cm s(-1), respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Response of maize hybrids to varying potassium application in pakistan

    International Nuclear Information System (INIS)

    Haji, M.A.A.; Malik, A.U.; Ahmad, R.

    2009-01-01

    A field experiment was conducted in 2005 and 2006 to evaluate the growth, grain yield, N, P, K concentration in stalk, and quality parameters of three maize hybrids (Pioneer-30D55, Pioneer-3062 and Pioneer-3012) at different levels of potassium (0, 100, 150, 200, and 250 kg ha/sup -1/). Pioneer-30D55 surpassed other two hybrids in growth rate, grain yield (6.01 t ha /sup -1/), N (0.728%), P (0.078%), K (1.79%) concentration in stalk, crude starch (72.97%), protein (8.15%) and oil (4.46%) contents in grains. K application in all treatments significantly increased growth rate, grain yield, N, P, K concentration in stalk, and improved crude starch, protein and oil contents in grains over control. Maximum growth rate, grain yield (6.05 t ha-1), N (0.751% ), P (0.082%), K (1.86%) concentration in stalk, were recorded, when 200 kg K ha/sup -1/ was applied, and beyond this limit, tended to decline its growth rate, grain yield (6.02 t ha/sup -1/), N (0.743%), P (0.071%) and K (1.76%) concentration in stalk when 250 kg K ha-1 was applied, but continued to increase crude starch (72.65%), protein (8.31%) and oil (4.53%) contents in grains. Interactive effects of maize hybrids and potash application levels on growth, yield and N, P, K concentration in stalk, crude starch, oil, and protein contents in grains were, however, non significant. It was concluded that Pioneer-30D55 performed best with 200 kg K ha/sup -1/ when previous soil K status was 124.5 ppm. However, grain quality parameters were the best at 250 kg K ha/sup -1/ application. (author)

  7. Extraction atomic absorption determination of Cu, Ca, Mg and In in potassium chloride

    International Nuclear Information System (INIS)

    Telegin, G.F.; Chaplygin, V.I.

    1980-01-01

    Determination of microadmixtures of Cu, Ca, Mg, and In in potassium chloride by means of extraction separation of hydroxyquinolines of the elements determined by isoamyl alcohol from the sample basis is described. In is extracted in 10 min at pH 1.5-2.5% (100%). The extract is sprayed in the acetylene-air flame. Lower limits of the concentrations determined are 10 -5 -10 -7 %

  8. Calibration of a Micronal flame photometer model B-260. Intercomparison of the analytical results for potassium

    International Nuclear Information System (INIS)

    Alencar, Lucia Maria Laboissiere; Dalston, Regina Celia Reboucas.

    1983-01-01

    In its environmental monitoring program, NUCLEBRAS analyzes systematically environmental samples in order to determine the total alpha and beta activities. In most of these samples, 40 K is present in measurable quantities and can therefore be used for measuring beta activity since it is almost a 100% beta emitter. A method using a flame photometer for measuring the potassium concentration in water is presented. 5 refs., 28 figs., 25 tabs

  9. Extracellular matrix organization in various regions of rat brain grey matter.

    Science.gov (United States)

    Brückner, G; Härtig, W; Kacza, J; Seeger, J; Welt, K; Brauer, K

    1996-05-01

    Previous studies revealed the concentration of extracellular matrix proteoglycans in the so-called perineuronal nets on the one hand and in certain zones of the neuropil on the other. This nonhomogeneous distribution suggested a non-random chemical and spatial heterogeneity of the extracellular space. In the present investigation, regions dominated by one of both distribution patterns, i.e. piriform and parietal cortex, reticular thalamic nucleus, medial septum/diagonal band complex and cerebellar nuclei, were selected for correlative light and electron microscopic analysis. The labelling was performed by the use of the N-acetylgalactosamine-binding plant lectin Wisteria floribunda agglutinin visualized by peroxidase staining and additionally by photoconversion of red carbocyanine fluorescence labelling for electron microscopy. The intense labelling of the neuropil of a superficial piriform region, presumably identical with sublayer Ia, was confined to a fine meshwork spreading over the extracellular space between non-myelinated axons, dendrites and glial profiles. In the reticular thalamic nucleus the neuronal cell bodies were embedded in zones of labelled neuropil. In contrast to these patterns, the labelled extracellular matrix in different cortical layers and in the other subcortical regions was concentrated in perineuronal nets as large accumulations at surface areas of the neuronal perikarya and dendrites and the attached presynaptic boutons. Astrocytic processes usually were separated from the neuronal surface by the interposed extracellular material. Despite a great variability, the width of the extracellular space containing the labelled matrix components in all perineuronal nets appeared to be considerably larger than that in the labelled zones of neuropil and the non-labelled microenvironment of other neurons. Our results support the view that differences expressed in topographical and spatial peculiarities of the extracellular matrix constituents are

  10. Characteristic of Extracellular Zn2+ Influx in the Middle-Aged Dentate Gyrus and Its Involvement in Attenuation of LTP.

    Science.gov (United States)

    Takeda, Atsushi; Koike, Yuta; Osaw, Misa; Tamano, Haruna

    2018-03-01

    An increased influx of extracellular Zn 2+ into neurons is a cause of cognitive decline. The influx of extracellular Zn 2+ into dentate granule cells was compared between young and middle-aged rats because of vulnerability of the dentate gyrus to aging. The influx of extracellular Zn 2+ into dentate granule cells was increased in middle-aged rats after injection of AMPA and high K + into the dentate gyrus, but not in young rats. Simultaneously, high K + -induced attenuation of LTP was observed in middle-aged rats, but not in young rats. The attenuation was rescued by co-injection of CaEDTA, an extracellular Zn 2+ chelator. Intracellular Zn 2+ in dentate granule cells was also increased in middle-aged slices with high K + , in which the increase in extracellular Zn 2+ was the same as young slices with high K + , suggesting that ability of extracellular Zn 2+ influx into dentate granule cells is greater in middle-aged rats. Furthermore, extracellular zinc concentration in the hippocampus was increased age-dependently. The present study suggests that the influx of extracellular Zn 2+ into dentate granule cells is more readily increased in middle-aged rats and that its increase is a cause of age-related attenuation of LTP in the dentate gyrus.

  11. Possible potassium chlorate nephrotoxicity associated with chronic matchstick ingestion*

    OpenAIRE

    Thurlow, John S.; Little, Dustin J.; Baker, Thomas P.; Yuan, Christina M.

    2013-01-01

    We present a case of a 48-year-old active duty male soldier with a history of chronic exposure to potassium chlorate, later diagnosed with chronic interstitial nephritis. He reported regular matchstick consumption to prevent chigger (Trombicula autumnalis) bites, amounting to ?5.8 g of potassium chlorate over 3 years. Potassium chlorate can cause anuric renal failure within days of a toxic dose. Its slow excretion and mechanism of action suggest that renal toxicity may result from lower-dose ...

  12. Inwardly rectifying potassium channels influence Drosophila wing morphogenesis by regulating Dpp release.

    Science.gov (United States)

    Dahal, Giri Raj; Pradhan, Sarala Joshi; Bates, Emily Anne

    2017-08-01

    Loss of embryonic ion channel function leads to morphological defects, but the underlying reason for these defects remains elusive. Here, we show that inwardly rectifying potassium (Irk) channels regulate release of the Drosophila bone morphogenetic protein Dpp in the developing fly wing and that this is necessary for developmental signaling. Inhibition of Irk channels decreases the incidence of distinct Dpp-GFP release events above baseline fluorescence while leading to a broader distribution of Dpp-GFP. Work by others in different cell types has shown that Irk channels regulate peptide release by modulating membrane potential and calcium levels. We found calcium transients in the developing wing, and inhibition of Irk channels reduces the duration and amplitude of calcium transients. Depolarization with high extracellular potassium evokes Dpp release. Taken together, our data implicate Irk channels as a requirement for regulated release of Dpp, highlighting the importance of the temporal pattern of Dpp presentation for morphogenesis of the wing. © 2017. Published by The Company of Biologists Ltd.

  13. Disulfide mapping the voltage-sensing mechanism of a voltage-dependent potassium channel.

    Science.gov (United States)

    Nozaki, Tomohiro; Ozawa, Shin-Ichiro; Harada, Hitomi; Kimura, Tomomi; Osawa, Masanori; Shimada, Ichio

    2016-11-17

    Voltage-dependent potassium (Kv) channels allow for the selective permeability of potassium ions in a membrane potential dependent manner, playing crucial roles in neurotransmission and muscle contraction. Kv channel is a tetramer, in which each subunit possesses a voltage-sensing domain (VSD) and a pore domain (PD). Although several lines of evidence indicated that membrane depolarization is sensed as the movement of helix S4 of the VSD, the detailed voltage-sensing mechanism remained elusive, due to the difficulty of structural analyses at resting potential. In this study, we conducted a comprehensive disulfide locking analysis of the VSD using 36 double Cys mutants, in order to identify the proximal residue pairs of the VSD in the presence or absence of a membrane potential. An intramolecular SS-bond was formed between 6 Cys pairs under both polarized and depolarized environment, and one pair only under depolarized environment. The multiple conformations captured by the SS-bond can be divided by two states, up and down, where S4 lies on the extracellular and intracellular sides of the membrane, respectively, with axial rotation of 180°. The transition between these two states is caused by the S4 translocation of 12 Å, enabling allosteric regulation of the gating at the PD.

  14. Intracellular and extracellular radiosensitization of Serratia marcescens by bipyridinium compounds

    International Nuclear Information System (INIS)

    Anderson, R.F.; Patel, K.B.

    1979-01-01

    The one-electron reduced form of the bipyridinium compounds benzylviologen and methylviologen have been found to diffuse across the cytoplasmic membrane of Serratia marcescens cells. Subsequent reoxidation of the viologens to the dicationic form traps the compound inside the cells. Cells at a density of 4 x 10 9 ml -1 took up approximately half of the compound when incubated with an initial extracellular concentration of 200μM of either reduced viologen. The degree of radiosensitization in anoxia afforded by the compounds parallels the rise in internal concentration and reaches a maximum enhancement ratio of 2.0 +- 0.1 for both compounds. This level in sensitization is similar to that found when the compounds are external to the cell. No additivity in sensitization is found when the viologens are both internal and external to the cells at the time of irradiation suggesting that the same target site is sensitized. This site is probably some membrane-associated structure

  15. Synthesis of Analcime Crystals and Simultaneous Potassium Extraction from Natrolite Syenite

    Directory of Open Access Journals (Sweden)

    Jian Chen

    2017-01-01

    Full Text Available Analcime single crystals were successfully synthesized from natrolite syenite powder (K2O 10.89% and 92.6% of potassium was extracted simultaneously by means of soda roasting followed by alkali-hydrothermal method. Effects of NaOH concentration, reaction temperature, and holding period on the analcime formation and potassium extraction were investigated systemically. The results indicated that NaOH concentration plays an important role in determining the chemical composition of zeolites and size distribution; by turning the NaOH concentrations, three different pure zeolites (i.e., the phillipsite-Na, the analcime, and the sodalite were prepared. Besides, a higher temperature could accelerate the dissolution of K+ ions and enhance the crystallinity degree of zeolite. The reactions involved in the analcime synthesis can be summarized as follows: sodium aluminum silicate dissolution → precipitation and dissolution of metastable zeolite-P → analcime nucleation → analcime growth. The extraction ratio of K+ is associated with the types of synthesized zeolites, among which analcime is the most effective to promote potassium leaching out from zeolite lattice position. The optimal condition for analcime crystallization and K+ leaching is found to be as follows: 175°C for 4 h in 0.5 mol/L NaOH solution.

  16. Hydrogen and helium adsorption on potassium

    International Nuclear Information System (INIS)

    Garcia, R.; Mulders, N.; Hess, G.

    1995-01-01

    A previous quartz microbalance study of adsorption of helium on sodium indicates that the inert layer is surprisingly small. Similar experiments with hydrogen on sodium show layer by layer growth below a temperature of 7K. These results motivated the authors to extend the experiments to lower temperatures. A suitable apparatus, capable of reaching 0.45 K, while still enabling them to do in situ alkali evaporation, has been constructed. The authors will report on the results of microbalance adsorption experiments of helium and hydrogen on potassium

  17. Sound velocity in potassium hydroxide aqueous solution

    International Nuclear Information System (INIS)

    Tsapuryan, Kh.D.; Aleksandrov, A.A.; Kochetkov, A.I.

    1992-01-01

    Measurements of ultrasonic velocities in potassium hydroxide aqueous solutions are carried out within the frames of studies on improvement of water chemistry in NPP cooling systems. Method of echo pulses superposition with acoustic path length of 41.447 mm is used for measurements. The measurements are performed at 2.6 MHz frequency. Complex temperature dependence of ultrasonic velocity is determined. Ultrasonic velocity dependence on pressure is close to linear one. The formula for calculation of thermodynamic properties of the studied solutions on the basis of experimental data obtained is proposed

  18. Natural potassium as a teaching material

    International Nuclear Information System (INIS)

    Akatsu, Eiko

    1993-07-01

    An experience of an educational experiment is presented with results and discussion. It was performed in the introductory course of nuclear energy in the Nuclear Education Center of Japan Atomic Energy Research Institute. Purpose of the experiment is understanding disintegration rate (Bq, radioactivity or λN) through measurement of low radioactivity of natural potassium. It was accomplished through calculation of the radioactivity of a measuring known sample and counting efficiency during measurement. The students in the training course had great variety and most students did not have preliminary knowledge. But they said in the questionnaire having almost understood the experiment; and some students enjoyed it. (author)

  19. Poisoning of vanadia based SCR catalysts by potassium:influence of catalyst composition and potassium mobility

    DEFF Research Database (Denmark)

    Olsen, Brian Kjærgaard; Kügler, Frauke; Jensen, Anker Degn

    2016-01-01

    exposure temperatures slowdown the deactivation. K2SO4 causes a lower rate of deactivation compared to KCl. This may be related to a faster transfer of potassium from the solid KCl matrix to the catalyst, however, it cannot be ruled out toalso be caused by a significantly larger particle size of the K2SO4...

  20. Modeling removal of accumulated potassium from T-tubules by inward rectifier potassium channels

    NARCIS (Netherlands)

    Wallinga, W.; Vliek, M.; Wienk, E.D.; Alberink, M.J.; Ypey, D.L.; Ypey, D.L.

    1996-01-01

    The membrane models of Cannon et al. (1993) and Alberink et al. (1995) for mammalian skeletal muscle fibers are based upon Hodgkin-Huxley descriptions of sodium, potassium delayed rectifier and leak conductances and the capacitive current taking into account fast inactivation of sodium channels. Now

  1. Possible potassium chlorate nephrotoxicity associated with chronic matchstick ingestion.

    Science.gov (United States)

    Thurlow, John S; Little, Dustin J; Baker, Thomas P; Yuan, Christina M

    2013-06-01

    We present a case of a 48-year-old active duty male soldier with a history of chronic exposure to potassium chlorate, later diagnosed with chronic interstitial nephritis. He reported regular matchstick consumption to prevent chigger (Trombicula autumnalis) bites, amounting to ∼5.8 g of potassium chlorate over 3 years. Potassium chlorate can cause anuric renal failure within days of a toxic dose. Its slow excretion and mechanism of action suggest that renal toxicity may result from lower-dose chronic exposure. This case represents possible sequelae of chronic potassium chlorate ingestion.

  2. Possible potassium chlorate nephrotoxicity associated with chronic matchstick ingestion*

    Science.gov (United States)

    Thurlow, John S.; Little, Dustin J.; Baker, Thomas P.; Yuan, Christina M.

    2013-01-01

    We present a case of a 48-year-old active duty male soldier with a history of chronic exposure to potassium chlorate, later diagnosed with chronic interstitial nephritis. He reported regular matchstick consumption to prevent chigger (Trombicula autumnalis) bites, amounting to ∼5.8 g of potassium chlorate over 3 years. Potassium chlorate can cause anuric renal failure within days of a toxic dose. Its slow excretion and mechanism of action suggest that renal toxicity may result from lower-dose chronic exposure. This case represents possible sequelae of chronic potassium chlorate ingestion. PMID:26064493

  3. Role of hemolysis in potassium release by iodinated contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, K.; Nakamura, T.; Shimizu, Y. [Department of Radiology, Kyoto City Hospital (Japan)

    1999-09-01

    It has been demonstrated that an iodinated contrast medium (CM) causes release of potassium into blood vessel lumina, resulting in an increase in serum potassium. The purpose of the present study was to assess whether this potassium release is due to hemolysis. Fresh human blood was mixed in vitro with CM at a ratio of 10:2. Potassium release rates were determined, and serum haptoglobin and free hemoglobin were measured after 30 min of exposure to CM. To compare the potassium release curve between CM exposure and true hemolysis induced by distilled water, fresh human blood was also mixed with distilled water. The level of serum haptoglobin decreased due to hemodilution. Changes in haptoglobin were not correlated with potassium release rates. The serum free hemoglobin level did not increase significantly, and there was no correlation between changes in the free hemoglobin level and the rate of potassium release. Hemolysis caused by water occurred instantaneously, whereas potassium release caused by CM was a slow response, which was linearly correlated with exposure time. Potassium release from blood cannot be explained by hemolysis. (orig.) With 4 figs., 4 tabs., 3 refs.

  4. Behaviour of 29Si NMR and infrared spectra of aqueous sodium and potassium silica solutions as a function of (SiO2/M2+O) ratio

    International Nuclear Information System (INIS)

    Couty, R.; Fernandez, L.

    1996-01-01

    Sodium and potassium solutions of silica with silica concentration of 1,4 mo/kg and R ms = SiO 2 /M + 2 O ratios of 4.56 to 1.6 were obtained by depolymerization of amorphous silica gel in sodium and potassium hydroxide. Solutions have been characterized by 29 Si NMR and infrared spectroscopy. The results indicated that Na + and K + exhibit the same behaviour during the depolymerization of silica. (authors). 11 refs., 4 figs., 2 tabs

  5. Decrease of extracellular taurine in the rat dorsal hippocampus after central nervous administration of vasopressin

    DEFF Research Database (Denmark)

    Brust, P; Christensen, Thomas; Diemer, Nils Henrik

    1992-01-01

    of the composition of the extracellular fluid. The concentrations of 16 amino acids were measured by HPLC in the perfusate samples. The level of taurine declined 20% in the right hippocampus during perfusion with vasopressin, whereas o-phosphoethanolamine decreased in both sides, the left 20% and the right 24...

  6. Endolymphatic potassium of the chicken vestibule during embryonic development.

    Science.gov (United States)

    Masetto, Sergio; Zucca, Giampiero; Bottà, Luisa; Valli, Paolo

    2005-08-01

    The endolymph fills the lumen of the inner ear membranous labyrinth. Its ionic composition is unique in vertebrates as an extracellular fluid for its high-K(+)/low-Na(+) concentration. The endolymph is actively secreted by specialized cells located in the vestibular and cochlear epithelia. We have investigated the early phases of endolymph secretion by measuring the endolymphatic K(+) concentration in the chicken vestibular system during pre-hatching development. Measurements were done by inserting K(+)-selective microelectrodes in chicken embryo ampullae dissected at different developmental stages from embryonic day 9 up to embryonic day 21 (day of hatching). We found that the K(+) concentration is low (<10mM/L) up to embryonic day 11, afterward it increases steeply to reach a plateau level of about 140 mM/L at embryonic day 19--21. We have developed a short-term in vitro model of endolymph secretion by culturing vestibular ampullae dissected from embryonic day 11 chicken embryos for a few days. The preparation reproduced a double compartment system where the luminal K(+) concentration increased along with the days of culturing. This model could be important for (1) investigating the development of cellular mechanisms contributing to endolymph homeostasis and (2) testing compounds that influence those mechanisms.

  7. Kinetics of caesium and potassium absorption by roots of three grass pastures and competitive effects of potassium on caesium uptake in Cynodon sp.

    Science.gov (United States)

    Ayub, J. Juri; Valverde, L. Rubio; Garcia-Sanchez, M. J.; Fernandez, J. A.; Velasco, R. H.

    2008-08-01

    Caesium uptake by plant roots has been normally associated with the uptake of potassium as the potassium transport systems present in plants have also the capacity to transport caesium. Three grass species (Eragrostis curvula, Cynodon sp and Distichlis spicata) growing in seminatural grassland of central Argentina were selected to study their capability to incorporate Cs+ (and K+) using electrophysiological techniques. Although the 137Cs soil inventory ranged between 328-730 Bq m-2 in this region, no 137Cs activity was detected in these plants. However, all the species, submitted previously to K+ starvation, showed the uptake of both Cs+ and K+ when micromolar concentrations of these cations were present in the medium. The uptake showed saturation kinetics for both cations that could be fitted to the Michelis-Menten model. KM values were smaller for K+ than for Cs+, indicating a higher affinity for the first cation. The presence of increasing K+ concentrations in the assay medium inhibited Cs+ uptake in Cynodon sp., as expected if both cations are transported by the same transport systems. This effect is due to the competition of both ions for the union sites of the high affinity potassium transporters. In field situation, where soil concentration of Cs+ is smaller than K+ concentration, is then expectable that caesium activity in plants is not detectable. Nevertheless, the studied plants would have the capacity to incorporate caesium if its availability in soil solution increases. In addition, studies of Cs/K interaction can help us to understand the variability in transfer factors.

  8. Kinetics of caesium and potassium absorption by roots of three grass pastures and competitive effects of potassium on caesium uptake in Cynodon sp

    International Nuclear Information System (INIS)

    Ayub, J. Juri; Velasco, R. H.; Valverde, L. Rubio; Garcia-Sanchez, M. J.; Fernandez, J. A.

    2008-01-01

    Caesium uptake by plant roots has been normally associated with the uptake of potassium as the potassium transport systems present in plants have also the capacity to transport caesium. Three grass species (Eragrostis curvula, Cynodon sp and Distichlis spicata) growing in seminatural grassland of central Argentina were selected to study their capability to incorporate Cs + (and K + ) using electrophysiological techniques. Although the 137 Cs soil inventory ranged between 328-730 Bq m -2 in this region, no 137 Cs activity was detected in these plants. However, all the species, submitted previously to K + starvation, showed the uptake of both Cs + and K + when micromolar concentrations of these cations were present in the medium. The uptake showed saturation kinetics for both cations that could be fitted to the Michelis-Menten model. K M values were smaller for K + than for Cs + , indicating a higher affinity for the first cation. The presence of increasing K + concentrations in the assay medium inhibited Cs + uptake in Cynodon sp., as expected if both cations are transported by the same transport systems. This effect is due to the competition of both ions for the union sites of the high affinity potassium transporters. In field situation, where soil concentration of Cs + is smaller than K + concentration, is then expectable that caesium activity in plants is not detectable. Nevertheless, the studied plants would have the capacity to incorporate caesium if its availability in soil solution increases. In addition, studies of Cs/K interaction can help us to understand the variability in transfer factors

  9. Protein self-assembly and lipid binding in the folding of the potassium channel KcsA

    NARCIS (Netherlands)

    Barrera, F.N.; Renard, M.L.; Poveda, J.A.; de Kruijff, B.; Killian, J.A.; González-Ros, J.M.

    2008-01-01

    Moderate concentrations of the alcohol 2,2,2-trifluoroethanol (TFE) cause the coupled unfolding and dissociation into subunits of the homotetrameric potassium channel KcsA, in a process that is partially irreversible when the protein is solubilized in plain dodecyl â-D-maltoside (DDM) micelles

  10. Action of tributyltin (TBT) on the lipid content and potassium retention in the organotins degradating fungus Cunninghamella elegans.

    Science.gov (United States)

    Bernat, Przemysław; Słaba, Mirosława; Długoński, Jerzy

    2009-09-01

    The purpose of the presented paper was to study the effect of high concentrations of tributyltin (TBT) on the potassium retention and fatty acid (FA) composition of the fungus Cunninghamella elegans recognized as a very efficient TBT degrader. An increase in TBT had a strong influence on the potassium concentration in the fungus. In growth medium without TBT, the potassium content of the fungal cells was 5.8 mg K(+) g dry weight(-1). The maximum concentration of K(+) was 15.06 mg g(-1) dry weight at 30 mg l(-1) of TBT. The major FAs that characterized the tested strain were C16:0, C18:1, C18:2, C18:3 and C18:0. TBT in the concentration range 5-30 mg l(-1) strongly influenced the FA composition. In the presence of the organotin, the degree of saturation increased. It suggests that the observed changes promote an increase in the lipid ordering of the membrane by reducing its permeability and inhibiting potassium ion efflux.

  11. Toxic effects of chlorinated organic compounds and potassium dichromate on growth rate and photosynthesis of marine phytoplankton

    DEFF Research Database (Denmark)

    Kusk, Kresten Ole; Nyholm, Niels

    1992-01-01

    The toxic effects of potassium dichromate (K2Cr2O7), 3,4-dichloroaniline (DCA) and 2,4-dichlorophenol (DCP) on the photosynthesis of natural marine phytoplankton and five species of marine microalgae were investigated. Effect concentrations corresponding to a 50 % depression of photosynthesis (6h...

  12. Pharmacological activation of rapid delayed rectifier potassium current suppresses bradycardia-induced triggered activity in the isolated guinea pig heart

    DEFF Research Database (Denmark)

    Hansen, Rie Schultz; Olesen, Søren-Peter; Grunnet, Morten

    2007-01-01

    arrhythmias. We present here data that support that NS3623 affects native I(Kr) and report the effects that activating this potassium current have in the intact guinea pig heart. In Langendorff-perfused hearts, the compound showed a concentration-dependent shortening of action potential duration, which...

  13. Optimization of extracellular catalase production from Aspergillus ...

    African Journals Online (AJOL)

    The studies of the effect of each variable and the establishment of a correlation between the response of enzyme activity and variables revealed that the link is a multiple linear regression form. The optimization was carried out through a simplex algorithm. The amount of extracellular catalase produced by the strain in the ...

  14. Managing Brain Extracellular K(+) during Neuronal Activity

    DEFF Research Database (Denmark)

    Larsen, Brian Roland; Stoica, Anca; MacAulay, Nanna

    2016-01-01

    characteristics required to fulfill their distinct physiological roles in clearance of K(+) from the extracellular space in the face of neuronal activity. Understanding the nature, impact and effects of the various Na(+)/K(+)-ATPase isoform combinations in K(+) management in the central nervous system might...... understanding of the pathological events occurring during disease....

  15. Extracellular vesicles: fundamentals and clinical relevance

    Directory of Open Access Journals (Sweden)

    Wael Nassar

    2015-01-01

    Full Text Available All types of cells of eukaryotic organisms produce and release small nanovesicles into their extracellular environment. Early studies have described these vesicles as ′garbage bags′ only to remove obsolete cellular molecules. Valadi and colleagues, in 2007, were the first to discover the capability of circulating extracellular vesicles (EVs to horizontally transfer functioning gene information between cells. These extracellular vesicles express components responsible for angiogenesis promotion, stromal remodeling, chemoresistance, genetic exchange, and signaling pathway activation through growth factor/receptor transfer. EVs represent an important mode of intercellular communication by serving as vehicles for transfer between cells of membrane and cytosolic proteins, lipids, signaling proteins, and RNAs. They contribute to physiology and pathology, and they have a myriad of potential clinical applications in health and disease. Moreover, vesicles can pass the blood-brain barrier and may perhaps even be considered as naturally occurring liposomes. These cell-derived EVs not only represent a central mediator of the disease microenvironment, but their presence in the peripheral circulation may serve as a surrogate for disease biopsies, enabling real-time diagnosis and disease monitoring. In this review, we′ll be addressing the characteristics of different types of extracellular EVs, as well as their clinical relevance and potential as diagnostic markers, and also define therapeutic options.

  16. Extracellular space diffusion and extrasynaptic transmission

    Czech Academy of Sciences Publication Activity Database

    Vargová, Lýdia; Syková, Eva

    2008-01-01

    Roč. 57, Suppl.3 (2008), S89-S99 ISSN 0862-8408 R&D Projects: GA MŠk 1M0538; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50390512 Keywords : Diffusion * Extracellular volume * Tortuosity Subject RIV: FH - Neurology Impact factor: 1.653, year: 2008

  17. Integrins and extracellular matrix in mechanotransduction

    Directory of Open Access Journals (Sweden)

    Ramage L

    2011-12-01

    Full Text Available Lindsay RamageQueen’s Medical Research Institute, University of Edinburgh, Edinburgh, UKAbstract: Integrins are a family of cell surface receptors which mediate cell–matrix and cell–cell adhesions. Among other functions they provide an important mechanical link between the cells external and intracellular environments while the adhesions that they form also have critical roles in cellular signal-transduction. Cell–matrix contacts occur at zones in the cell surface where adhesion receptors cluster and when activated the receptors bind to ligands in the extracellular matrix. The extracellular matrix surrounds the cells of tissues and forms the structural support of tissue which is particularly important in connective tissues. Cells attach to the extracellular matrix through specific cell-surface receptors and molecules including integrins and transmembrane proteoglycans. Integrins work alongside other proteins such as cadherins, immunoglobulin superfamily cell adhesion molecules, selectins, and syndecans to mediate cell–cell and cell–matrix interactions and communication. Activation of adhesion receptors triggers the formation of matrix contacts in which bound matrix components, adhesion receptors, and associated intracellular cytoskeletal and signaling molecules form large functional, localized multiprotein complexes. Cell–matrix contacts are important in a variety of different cell and tissue properties including embryonic development, inflammatory responses, wound healing, and adult tissue homeostasis. This review summarizes the roles and functions of integrins and extracellular matrix proteins in mechanotransduction.Keywords: ligand binding, α subunit, ß subunit, focal adhesion, cell differentiation, mechanical loading, cell–matrix interaction

  18. Interaction of acetamiprid with extracellular polymeric substances ...

    African Journals Online (AJOL)

    Extracellular polymeric substances (EPS) are important components of activated sludge and it plays an important role in removing pollutants. The interaction between EPS and organic pollutants is still little known. In the present study, the interaction of soluble/bound EPS with acetamiprid, a neonicotinoid insecticide, was ...

  19. Optimization of extracellular catalase production from Aspergillus ...

    African Journals Online (AJOL)

    aghomotsegin

    extracellular catalase produced by the strain in the optimized medium was about four times higher than ... celial and unicellular fungi in synthetic media (Kurakov et .... covering the appropriate range and the broad calibration kit ... This optimization allowed us to define new cultural con- ..... Ann. New York Academy Sci.

  20. Production of extracellular aspartic protease in submerged ...

    African Journals Online (AJOL)

    Fungal milk-clotting enzymes have gained value as bovine Chymosin substitutes in the cheese industry. In this work, the effects of culture conditions on the production of extracellular milk clotting enzymes from Mucor mucedo DSM 809 in submerged fermentation were studied. The maximum activity was observed after 48 h ...