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Sample records for extracellular potassium levels

  1. High potassium level

    Science.gov (United States)

    Hyperkalemia; Potassium - high; High blood potassium ... There are often no symptoms with a high level of potassium. When symptoms do occur, they may include: Nausea Slow, weak, or irregular pulse Sudden collapse, when the heartbeat gets too ...

  2. Extracellular potassium homeostasis: insights from hypokalemic periodic paralysis.

    Science.gov (United States)

    Cheng, Chih-Jen; Kuo, Elizabeth; Huang, Chou-Long

    2013-05-01

    Extracellular potassium makes up only about 2% of the total body's potassium store. The majority of the body potassium is distributed in the intracellular space, of which about 80% is in skeletal muscle. Movement of potassium in and out of skeletal muscle thus plays a pivotal role in extracellular potassium homeostasis. The exchange of potassium between the extracellular space and skeletal muscle is mediated by specific membrane transporters. These include potassium uptake by Na(+), K(+)-adenosine triphosphatase and release by inward-rectifier K(+) channels. These processes are regulated by circulating hormones, peptides, ions, and by physical activity of muscle as well as dietary potassium intake. Pharmaceutical agents, poisons, and disease conditions also affect the exchange and alter extracellular potassium concentration. Here, we review extracellular potassium homeostasis, focusing on factors and conditions that influence the balance of potassium movement in skeletal muscle. Recent findings that mutations of a skeletal muscle-specific inward-rectifier K(+) channel cause hypokalemic periodic paralysis provide interesting insights into the role of skeletal muscle in extracellular potassium homeostasis. These recent findings are reviewed. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Extracellular potassium inhibits Kv7.1 potassium channels by stabilizing an inactivated state

    DEFF Research Database (Denmark)

    Larsen, Anders Peter; Steffensen, Annette Buur; Grunnet, Morten;

    2011-01-01

    Kv7.1 (KCNQ1) channels are regulators of several physiological processes including vasodilatation, repolarization of cardiomyocytes, and control of secretory processes. A number of Kv7.1 pore mutants are sensitive to extracellular potassium. We hypothesized that extracellular potassium also...... modulates wild-type Kv7.1 channels. The Kv7.1 currents were measured in Xenopus laevis oocytes at different concentrations of extracellular potassium (1-50 mM). As extracellular potassium was elevated, Kv7.1 currents were reduced significantly more than expected from theoretical calculations based...... on the Goldman-Hodgkin-Katz flux equation. Potassium inhibited the steady-state current with an IC(50) of 6.0 ± 0.2 mM. Analysis of tail-currents showed that potassium increased the fraction of channels in the inactivated state. Similarly, the recovery from inactivation was slowed by potassium, suggesting...

  4. Low potassium level

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    ... or vomiting Using too much laxative, which can cause diarrhea Chronic kidney disease Diuretic medicines (water pills), used to treat heart failure and high blood pressure Eating disorders (such as bulimia ) Low magnesium level Sweating

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

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    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.

  6. Can Diuretics Decrease Your Potassium Level?

    Science.gov (United States)

    ... and Conditions High blood pressure (hypertension) Can diuretics decrease your potassium level? Answers from Sheldon G. Sheps, ... D. Yes, some diuretics — also called water pills — decrease potassium in the blood. Diuretics are commonly used ...

  7. Extracellular potassium dynamics in the hyperexcitable state of the neuronal ictal activity

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    Florence, Gerson; Pereira, Tiago; Kurths, Jürgen

    2012-12-01

    An enduring question in epilepsy research concerns with the mechanisms responsible for the neuronal hyperexcitability. This theme is under debate and different hypotheses have been put forward. One hypothesis relates to extracellular ionic variations, especially the increase of the extracellular potassium concentration ([K+]o). During the epileptiform bursting, an increase of [K+]o is observed which raises the cellular excitability. It remains unclear, however, how the extracellular potassium variation could affect the generation and persistence of epileptiform bursting within the ictal phase, that is, during the epileptic seizure. The neuronal mechanisms responsible for this cellular hyperexcitability are not yet fully understood, hindering the development of more efficient therapies to control epilepsy. Mathematical models with biological plausibility have provided considerable insights into the mechanisms underlying epileptiform pattern. This paper reviews experimental evidences and computational studies concerning effects of the extracellular potassium dynamics on the cellular excitability within the neuronal ictal activity.

  8. Plasma Potassium Levels in Healthy Prehypertension Subjects and the Role of A High Potassium Drink.

    Science.gov (United States)

    Farapti, Farapti; Sayogo, Savitri; Siregar, Parlindungan

    2017-02-24

    Most populations around the world consume less than the recommended levels of potassium. Long term low potassium intake could lead to decreased plasma potassium levels and induce hypokalemia. The increasing of plasma potassium levels 0,2-0,4 mmol/L by improving potassium intake decreased significantly blood pressure (BP). Assessing plasma potassium levels in healthy people related to potassium intake have not been studied. In this study, we analysed plasma potassium levels in prehypertension (PHT) subjects and to evaluate the effect of tender coconut water (TCW) as a high potassium drink on plasma potassium levels in PHT adults. Thirthy-two female aged 25-44 years were randomly allocated to 14 days on TCW or water in a parallel randomized clinical trial . The treatment (T) group received TCW 300 ml twice daily and the control (C) group received water 300 ml twice daily too. At baseline, plasma potassium levels was 3.71±0.41 mmol/L, and 22.58% were categorized as hypokalemia. After 14 days treatment, potassium plasma level between T and C groups were not significantly different (p=0,247). The change of plasma potassium levels in both groups showed tendency to increase but not statistically significant (p=0.166). In healthy prehypertension women, the low levels of potassium plasma may be caused by low potassium intake for long time and intervension with TCW 300 ml twice daily for 14 consecutive days has not proven yet to increase plasma potassium levels. It is necessary to give higher dose and longer time to increase potassium plasma in low potassium plasma level subjects.

  9. Biofouling-Resistant Impedimetric Sensor for Array High-Resolution Extracellular Potassium Monitoring in the Brain

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    Ruben Machado

    2016-10-01

    Full Text Available Extracellular potassium concentration, [K+]o, plays a fundamental role in the physiological functions of the brain. Studies investigating changes in [K+]o have predominantly relied upon glass capillary electrodes with K+-sensitive solution gradients for their measurements. However, such electrodes are unsuitable for taking spatio-temporal measurements and are limited by the surface area of their tips. We illustrate seizures invoked chemically and in optogenetically modified mice using blue light exposure while impedimetrically measuring the response. A sharp decrease of 1–2 mM in [K+]o before each spike has shown new physiological events not witnessed previously when measuring extracellular potassium concentrations during seizures in mice. We propose a novel approach that uses multichannel monolayer coated gold microelectrodes for in vivo spatio-temporal measurements of [K+]o in a mouse brain as an improvement to the conventional glass capillary electrode.

  10. Biofouling-Resistant Impedimetric Sensor for Array High-Resolution Extracellular Potassium Monitoring in the Brain

    Science.gov (United States)

    Machado, Ruben; Soltani, Nima; Dufour, Suzie; Salam, Muhammad Tariqus; Carlen, Peter L.; Genov, Roman; Thompson, Michael

    2016-01-01

    Extracellular potassium concentration, [K+]o, plays a fundamental role in the physiological functions of the brain. Studies investigating changes in [K+]o have predominantly relied upon glass capillary electrodes with K+-sensitive solution gradients for their measurements. However, such electrodes are unsuitable for taking spatio-temporal measurements and are limited by the surface area of their tips. We illustrate seizures invoked chemically and in optogenetically modified mice using blue light exposure while impedimetrically measuring the response. A sharp decrease of 1–2 mM in [K+]o before each spike has shown new physiological events not witnessed previously when measuring extracellular potassium concentrations during seizures in mice. We propose a novel approach that uses multichannel monolayer coated gold microelectrodes for in vivo spatio-temporal measurements of [K+]o in a mouse brain as an improvement to the conventional glass capillary electrode. PMID:27754393

  11. Imaging extracellular potassium dynamics in brain tissue using a potassium-sensitive nanosensor.

    Science.gov (United States)

    Wellbourne-Wood, Joel; Rimmele, Theresa S; Chatton, Jean-Yves

    2017-01-01

    Neuronal activity results in the release of [Formula: see text] into the extracellular space (ECS). Classically, measurements of extracellular [Formula: see text] ([Formula: see text]) are carried out using [Formula: see text]-sensitive microelectrodes, which provide a single point measurement with undefined spatial resolution. An imaging approach would enable the spatiotemporal mapping of [Formula: see text]. Here, we report on the design and characterization of a fluorescence imaging-based [Formula: see text]-sensitive nanosensor for the ECS based on dendrimer nanotechnology. Spectral characterization, sensitivity, and selectivity of the nanosensor were assessed by spectrofluorimetry, as well as in both wide-field and two-photon microscopy settings, demonstrating the nanosensor efficacy over the physiologically relevant ion concentration range. Spatial and temporal kinetics of the nanosensor responses were assessed using a localized iontophoretic [Formula: see text] application on a two-photon imaging setup. Using acute mouse brain slices, we demonstrate that the nanosensor is retained in the ECS for extended periods of time. In addition, we present a ratiometric version of the nanosensor, validate its sensitivity in brain tissue in response to elicited neuronal activity and correlate the responses to the extracellular field potential. Together, this study demonstrates the efficacy of the [Formula: see text]-sensitive nanosensor approach and validates the possibility of creating multimodal nanosensors.

  12. Dietary levels of potassium for broiler chickens

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    JE Oliveira

    2005-03-01

    Full Text Available Three experiments were conducted to determine the nutritional requirements of potassium (K for male Ross broiler chickens, from 8 to 21, 22 to 42 and 43 to 53 days of age. The following parameters were evaluated: body weight gain (BWG, feed intake (FI and feed conversion ratio (FCR. In each experiment, a completely randomized experimental design was used, with six treatments (K levels, and six, eight and eight numbers of replicates, and eight, five and four birds per pen, respectively. The experimental diets were basal diets deficient in K but supplemented with K carbonate to result in levels of 0.30, 0.44, 0.58, 0.72, 0.86 and 1.00% K. Estimated requirements for BWG were 0.628, 0.714 and 0.798% K, for the periods 8-21, 22-42 and 43-53 d, respectively.

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

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    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.

  14. Pharmacological blockade of gap junctions induces repetitive surging of extracellular potassium within the locust CNS.

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    Spong, Kristin E; Robertson, R Meldrum

    2013-10-01

    The maintenance of cellular ion homeostasis is crucial for optimal neural function and thus it is of great importance to understand its regulation. Glial cells are extensively coupled by gap junctions forming a network that is suggested to serve as a spatial buffer for potassium (K(+)) ions. We have investigated the role of glial spatial buffering in the regulation of extracellular K(+) concentration ([K(+)]o) within the locust metathoracic ganglion by pharmacologically inhibiting gap junctions. Using K(+)-sensitive microelectrodes, we measured [K(+)]o near the ventilatory neuropile while simultaneously recording the ventilatory rhythm as a model of neural circuit function. We found that blockade of gap junctions with either carbenoxolone (CBX), 18β-glycyrrhetinic acid (18β-GA) or meclofenamic acid (MFA) reliably induced repetitive [K(+)]o surges and caused a progressive impairment in the ability to maintain baseline [K(+)]o levels throughout the treatment period. We also show that a low dose of CBX that did not induce surging activity increased the vulnerability of locust neural tissue to spreading depression (SD) induced by Na(+)/K(+)-ATPase inhibition with ouabain. CBX pre-treatment increased the number of SD events induced by ouabain and hindered the recovery of [K(+)]o back to baseline levels between events. Our results suggest that glial spatial buffering through gap junctions plays an essential role in the regulation of [K(+)]o under normal conditions and also contributes to a component of [K(+)]o clearance following physiologically elevated levels of [K(+)]o.

  15. Serum Potassium Levels in Sigmoid Volvulus

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    Atamanalp, S. Selcuk; Keles, M. Sait; Aydinli, Bulent

    2009-01-01

    Objective: This study aimed to determine the serum potassium concentrations in patients with sigmoid volvulus (SV), which is a rare large bowel obstruction. Materials and Methods: The records of 86 patients with SV were reviewed retrospectively, while the records of 41 patients diagnosed with obstructive rectosigmoid cancer (ORC) were considered as the control group and as such, served as a source for comparison. Results: The analysis revealed a mean serum potassium concentration of 3.9 ± 0.6 mEq/L for the patients with SV, while the mean potassium concentration was 3.9 ± 0.5 mEq/L for the patients diagnosed with ORC (t:0.1, P>0.05). The number of hypokalemic and hyperkalemic patients identified in this study sample were 11 versus 5 patients and 1 versus 0 patients, respectively for the SV and ORC groups (x2 = 0.1 and 0.5, respectively with a P>0.05). Conclusions: No cause-and-effect relationship was observed between the serum potassium concentrations and SV. The serum potassium concentration is not pathognomonic for SV. PMID:25610090

  16. Maximum likelihood q-estimator reveals nonextensivity regulated by extracellular potassium in the mammalian neuromuscular junction

    CERN Document Server

    da Silva, A J; Santos, D O C; Lima, R F

    2013-01-01

    Recently, we demonstrated the existence of nonextensivity in neuromuscular transmission [Phys. Rev. E 84, 041925 (2011)]. In the present letter, we propose a general criterion based on the q-calculus foundations and nonextensive statistics to estimate the values for both scale factor and q-index using the maximum likelihood q-estimation method (MLqE). We next applied our theoretical findings to electrophysiological recordings from neuromuscular junction (NMJ) where spontaneous miniature end plate potentials (MEPP) were analyzed. These calculations were performed in both normal and high extracellular potassium concentration, [K+]o. This protocol was assumed to test the validity of the q-index in electrophysiological conditions closely resembling physiological stimuli. Surprisingly, the analysis showed a significant difference between the q-index in high and normal [K+]o, where the magnitude of nonextensivity was increased. Our letter provides a general way to obtain the best q-index from the q-Gaussian distrib...

  17. Effects of extracellular potassium on ventricular automaticity and evidence for a pacemaker current in mammalian ventricular myocardium.

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    Katzung, B G; Morgenstern, J A

    1977-01-01

    Automaticity was induced in isolated guinea pig and cat papillary muscles by application of depolarizing constant current pulses. Increasing extracellular potassium from 1 to 15 mM caused a shift of pacemaker-like activity to less negative diastolic potentials and a decrease in maximum phase 4 slope. Membrane resistance, estimated from the relation of applied current to maximum diastolic potential, decreased when extracellular potassium was increased. Voltage clamps of cat papillary muscle demonstrated that action potentials activate a time-dependent outward current which has a reversal potential of -79.1 mV (+/- 0.99 SE, n = 20) at an extracellular potassium concentration of 5 mM. The reversal potential of this current varies with extracellular K+ with a slope of 50-60 mV per 10-fold concentration change. The current is activated by voltage clamps or action potential plateaus in the range of -30 to +30 mV. It has a time constant of deactivation which increases from approximately 100 to over 400 msec as clamp potential is increased from -90 to -60 mV. It is proposed that this current is equivalent to Ix1 demonstrated in other cardiac tissues and is responsible, in combination with inward currents, for automaticity in ventricular fibers.

  18. High extracellular potassium ion concentration attenuates the blockade action of ketanserin on Kvl.3 channels expressed in xenopus oocytes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Background Ketanserin (KT), a selective serotonin (5-HT) 2-receptor antagonist, reduces peripheral blood pressure by blocking the activation of peripheral 5-HT receptors. In this study electrophysiological method was used to investigate the effect of KT and potassium ion on Kv1.3 potassium channels and explore the role of blocker KT in the alteration of channel kinetics contributing to the potassium ion imbalances. Methods Kvl.3 channels were expressed in xenopus oocytes, and currents were measured using the two-microelectrode voltage-clamp technique. Results KCI made a left shift of activation and an inactivation curve of Kv1.3 current and accelerated the activation and inactivation time constant. High extracellular [K+] attenuated the blockade effect of KT on Kv1.3 channels. In the presence of KT and KCI the activation and inactivation time constants were not influenced significantly no matter what was administered first. KT did not significantly inhibit Kv1.3 current induced by tetraethylammonium (TEA). Conclusions KT is a weak blocker of Kv1.3 channels at different concentrations of extracellular potassium and binds to the intracellular side of the channel pore. The inhibitor KT of ion channels is not fully effective in clinical use because of high [K+]o and other electrolyte disorders.

  19. Potassium

    Science.gov (United States)

    ... blackberries Root vegetables, such as carrots and potatoes Citrus fruits, such as oranges and grapefruit Your kidneys help to keep the right amount of potassium in your body. If you have chronic kidney disease, your kidneys may not remove extra potassium from ...

  20. Heart Rate and Extracellular Sodium and Potassium Modulation of Gap Junction Mediated Conduction in Guinea Pigs.

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    Entz, Michael; George, Sharon A; Zeitz, Michael J; Raisch, Tristan; Smyth, James W; Poelzing, Steven

    2016-01-01

    Recent studies suggested that cardiac conduction in murine hearts with narrow perinexi and 50% reduced connexin43 (Cx43) expression is more sensitive to relatively physiological changes of extracellular potassium ([K(+)]o) and sodium ([Na(+)]o). Determine whether similar [K(+)]o and [Na(+)]o changes alter conduction velocity (CV) sensitivity to pharmacologic gap junction (GJ) uncoupling in guinea pigs. [K(+)]o and [Na(+)]o were varied in Langendorff perfused guinea pig ventricles (Solution A: [K(+)]o = 4.56 and [Na(+)]o = 153.3 mM. Solution B: [K(+)]o = 6.95 and [Na(+)]o = 145.5 mM). Gap junctions were inhibited with carbenoxolone (CBX) (15 and 30 μM). Epicardial CV was quantified by optical mapping. Perinexal width was measured with transmission electron microscopy. Total and phosphorylated Cx43 were evaluated by western blotting. Solution composition did not alter CV under control conditions or with 15μM CBX. Decreasing the basic cycle length (BCL) of pacing from 300 to 160 ms decreased CV uniformly with both solutions. At 30 μM CBX, a change in solution did not alter CV either longitudinally or transversely at BCL = 300 ms. However, reducing BCL to 160 ms caused CV to decrease more in hearts perfused with Solution B than A. Solution composition did not alter perinexal width, nor did it change total or phosphorylated serine 368 Cx43 expression. These data suggest that the solution dependent CV changes were independent of altered perinexal width or GJ coupling. Action potential duration was always shorter in hearts perfused with Solution B than A, independent of pacing rate and/or CBX concentration. Increased heart rate and GJ uncoupling can unmask small CV differences caused by changing [K(+)]o and [Na(+)]o. These data suggest that modulating extracellular ionic composition may be a novel anti-arrhythmic target in diseases with abnormal GJ coupling, particularly when heart rate cannot be controlled.

  1. Heart Rate and Extracellular Sodium and Potassium Modulation of Gap Junction Mediated Conduction in Guinea Pigs

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    Michael eEntz

    2016-02-01

    Full Text Available Background: Recent studies suggested that cardiac conduction in murine hearts with narrow perinexi and 50% reduced connexin43 (Cx43 expression is more sensitive to relatively physiological changes of extracellular potassium ([K+]o and sodium ([Na+]o. Purpose: Determine whether similar [K+]o and [Na+]o changes alter conduction velocity (CV sensitivity to pharmacologic gap junction (GJ uncoupling in guinea pigs.Methods: [K+]o and [Na+]o were varied in Langendorff perfused guinea pig ventricles (Solution A: [K+]o=4.56 and [Na+]o=153.3 mM. Solution B: [K+]o=6.95 and [Na+]o=145.5 mM. Gap junctions were inhibited with carbenoxolone (CBX (15 and 30 μM. Epicardial CV was quantified by optical mapping. Perinexal width was measured with transmission electron microscopy. Total and phosphorylated Cx43 were evaluated by western blotting. Results: Solution composition did not alter CV under control conditions or with 15M CBX. Decreasing the basic cycle length (BCL of pacing from 300 to 160ms decreased CV uniformly with both solutions. At 30 M CBX, a change in solution did not alter CV either longitudinally or transversely at BCL=300ms. However, reducing BCL to 160ms caused CV to decrease more in hearts perfused with Solution B than A. Solution composition did not alter perinexal width, nor did it change total or phosphorylated serine 368 Cx43 expression. These data suggest that the solution dependent CV changes were independent of altered perinexal width or GJ coupling. Action potential duration was always shorter in hearts perfused with Solution B than A, independent of pacing rate and/or CBX concentration. Conclusions: Increased heart rate and GJ uncoupling can unmask small CV differences caused by changing [K+]o and [Na+]o. These data suggest that modulating extracellular ionic composition may be a novel anti-arrhythmic target in diseases with abnormal GJ coupling, particularly when heart rate cannot be controlled.

  2. Effects of acidification and increased extracellular potassium on dynamic muscle contractions in isolated rat muscles.

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    Overgaard, Kristian; Højfeldt, Grith Westergaard; Nielsen, Ole Bækgaard

    2010-12-15

    Since accumulation of both H(+) and extracellular K(+) have been implicated in the reduction in dynamic contractile function during intense exercise, we investigated the effects of acidification and high K(+) on muscle power and the force-velocity relation in non-fatigued rat soleus muscles. Contractions were elicited by supramaximal electrical stimulation at 60 Hz. Force-velocity (FV) curves were obtained by fitting data on force and shortening velocity at different loads to the Hill equation. Acidification of the muscles by incubation with up to 24 mm lactic acid produced no significant changes in maximal power (P(max)) at 30 °C. More pronounced acidification, obtained by increasing CO(2) levels in the equilibration gas from 5% to 53%, markedly decreased P(max) and maximal isometric force (F(max)), increased the curvature of the FV relation, but left maximal shortening velocity (V(max)) unchanged. Increase of extracellular K(+) from 4 to 10 mm caused a depression of 58% in P(max) and 52% in F(max), but had no significant effect on V(max) or curvature of the FV curve. When muscles at 10 mM K(+) were acidified by 20 mm lactic acid, P(max) and F(max) recovered completely to the initial control level at 4 mm K(+). CO(2) acidification also induced significant recovery of dynamic contractions, but not entirely to control levels. These results demonstrate that in non-fatigued muscles severe acidification can be detrimental to dynamic contractile function, but in muscles depolarised by exposure to high extracellular [K(+)], approaching the [K(+)] level seen during intense fatiguing exercise, acidification can have positive protective effects on dynamic muscle function.

  3. Potassium

    Science.gov (United States)

    ... high in potassium include bananas, cantaloupe, grapefruit, oranges, tomato or prune juice, honeydew melons, prunes, molasses and ... of a Heart Attack 10 Angina (Chest Pain) *Red Dress ™ DHHS, Go Red ™ AHA ; National Wear Red ...

  4. Changes in Acetylcholine Extracellular Levels during Cognitive Processes

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    Pepeu, Giancarlo; Giovannini, Maria Grazia

    2004-01-01

    Measuring the changes in neurotransmitter extracellular levels in discrete brain areas is considered a tool for identifying the neuronal systems involved in specific behavioral responses or cognitive processes. Acetylcholine (ACh) is the first neurotransmitter whose diffusion from the central nervous system was investigated and whose extracellular…

  5. Phasic oscillations of extracellular potassium (K(o in pregnant rat myometrium.

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    Roger C Young

    Full Text Available K-sensitive microelectrodes were used to measure K(+ within the extracellular space (K(o of pregnant rat myometrium. Contractile activity was monitored by measuring either force or bioelectrical signals. Single and double-barreled electrodes were used. Double-barreled electrodes allowed monitoring of electrical activity 15 microns from the site of K(o measurement. From double-barreled electrode experiments, the bioelectrical burst started first, and then K(o began to rise 0.6 ± 0.1 seconds later. This delay indicates that K(+ leaves the cells in response to local electrical activity rather than vice versa. Four control experiments were performed to assess the influence of electrical artifacts caused by tissue motion on K(o values. When observed, artifacts were negative and transient, and hence would result in an underestimation of K(o rises. Artifacts were minimized when tissue motion was minimized by fixing the tissue at both ends. At 37°C, 7 single barreled experiments and 45 contractions were analyzed. Resting K(o was within 1 mM of bath K(+ (5 mM at the beginning and end of the experiments. K(o rose during the contraction, fell after the completion of the contraction, and normalized before the next contraction began. Peak K(o values observed during force production were 18.8 ± 5.9 mM, a value high enough to modulate tissue-level electrical activity. K(o required 15.7 ± 2.8 seconds to normalize halfway (t50. Six experiments expressing 38 contractions were performed at 24°C. The contraction period was longer at 24°C. Values for peak K(o (26.2 ± 9.9 mM and t50 (29.8±16.2 sec were both larger than at 37°C (p<0.0003 for both. The direct relationships between peak K(o, t50 and the contraction period, suggest elevations in K(o may modulate contraction frequency. The myometrial interstitial space appears to be functionally important, and K(o metabolism may participate in cell-cell interactions.

  6. The effects of thioperamide on extracellular levels of glutamate and GABA in the rat prefrontal cortex.

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    Welty, Natalie; Shoblock, James R

    2009-12-01

    Histamine H3 receptors (H3R) are presynaptic heteroreceptors that negatively modulate the release of histamine and other neurotransmitters such as acetylcholine. Blocking H3 receptors with antagonists/inverse agonists has been shown to be procognitive and this effect has often been associated with increases in acetylcholine transmission. H3 receptors are abundantly expressed in the prefrontal cortex, an area associated with cognitive performance. While the procognitive effects of H3 receptor antagonists/inverse agonists may depend on alterations to acetylcholine or histamine release, other transmitters involved in cognitive processing such as glutamate and gamma-aminobutyric acid (GABA) may also be involved. The purpose of the present study was to examine the effects of thioperamide, an H3 receptor antagonist, on extracellular levels of glutamate and GABA in the prefrontal cortex. By means of in vivo microdialysis on freely moving Sprague Dawley rats, samples were collected and assayed via high-performance liquid chromatography coupled to electrochemical detection. Replacement of calcium with magnesium revealed that the release of GABA, but not glutamate, was calcium-dependent. Thioperamide (10-20 mg/kg) did not affect basal glutamate or GABA release. Perfusion with a high concentration of potassium (100 mM) increased GABA, but not glutamate, release and thioperamide (20 mg/kg) attenuated the effects of high potassium on GABA release. These data indicate that H3 receptors in the prefrontal cortex can enhance stimulated GABA release, but do not regulate basal levels of glutamate or GABA.

  7. Regional increase in extracellular potassium can be arrhythmogenic due to nonuniform muscle contraction in rat ventricular muscle

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    Hattori, Taiki; Murai, Naomi; Nagano, Tsuyoshi; Nishio, Taichi; Boyden, Penelope A.; Shindoh, Chiyohiko

    2012-01-01

    In the ischemic myocardium, extracellular potassium ([K+]o) increases to ≥20 mmol/l. To determine how lethal arrhythmias occur during ischemia, we investigated whether the increased spatial pattern of [K+]o, i.e., a regional or a global increase, affects the incidence of arrhythmias. Force, sarcomere length, membrane potential, and nonuniform intracellular Ca2+ ([Ca2+]i) were measured in rat ventricular trabeculae. A “regional” or “global” increase in [K+]o was produced by exposing a restricted region of muscle to a jet of 30 mmol/l KCl or by superfusing trabeculae with a solution containing 30 mmol/l KCl, respectively. The increase in [Ca2+]i (CaCW) during Ca2+ waves was measured (24°C, 3.0 mmol/l [Ca2+]o). A regional increase in [K+]o caused nonuniform [Ca2+]i and contraction. In the presence of isoproterenol, the regional increase in [K+]o induced sustained arrhythmias in 10 of 14 trabeculae, whereas the global increase did not induce such arrhythmias. During sustained arrhythmias, Ca2+ surged within the jet-exposed region. In the absence of isoproterenol, the regional increase in [K+]o increased CaCW, whereas the global increase decreased it. This increase in CaCW with the regional increase in [K+]o was not suppressed by 100 μmol/l streptomycin, whereas it was suppressed by 1) a combination of 10 μmol/l cilnidipine and 3 μmol/l SEA0400; 2) 20 mmol/l 2,3-butanedione monoxime; and 3) 10 μmol/l blebbistatin. A regional but not a global increase in [K+]o induces sustained arrhythmias, probably due to nonuniform excitation-contraction coupling. The same mechanism may underlie arrhythmias during ischemia. PMID:22447939

  8. Characterizing the persistent CA3 interneuronal spiking activity in elevated extracellular potassium in the young rat hippocampus.

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    Shin, Damian Seung-Ho; Yu, Wilson; Fawcett, Adrian; Carlen, Peter Louis

    2010-05-17

    Seizures coincide with an increase in extracellular potassium concentrations [K(+)](e) yet little information is available regarding this phenomenon on the firing pattern, frequency and neuronal properties of inhibitory neurons responsible for modulating network excitability. Therefore, we investigated the effects of elevating [K(+)](e) from 2.5 to 12.5mM on CA3 rat hippocampal interneurons in vitro using whole-cell patch-clamp recordings. We found that the majority of interneurons (21/25) in artificial cerebral spinal fluid (aCSF) exhibited spontaneous tonic spiking activity. As the [K(+)](e) increased to 12.5mM, interneurons exhibited a tonic, irregular, burst firing activity, or a combination of these. The input resistance decreased significantly to 59+/-18% at 7.5mM K(+) and did not further change at higher [K(+)](e) while the amount of K(+)-induced depolarization significantly increased from 5 to 12.5mM K(+) perfusion; a depolarization block occurred in 4 of the 12 interneurons at 12.5mM. Also, as [K(+)](e) increased, a transition from lower (1.3+/-0.6Hz) to higher dominant peak frequency (15.0+/-5.0Hz) was observed. We found that non-fast spiking (NFS) interneurons represented the majority of cells recorded and exhibited mostly tonic firing activity in raised K(+). Fast spiking (FS) interneurons predominately had a tonic firing pattern with very few exhibiting bursting activity in elevated K(+). In conclusion, we report that raised [K(+)](e) in amounts observed during seizures increases hippocampal CA3 interneuronal activity and suggests that a loss or impairment of inhibitory function may be present during these events.

  9. Potassium physiology.

    Science.gov (United States)

    Thier, S O

    1986-04-25

    Potassium is the most abundant exchangeable cation in the body. It exists predominantly in the intracellular fluid at concentrations of 140 to 150 meq/liter and in the extracellular fluid at concentrations of 3.5 to 5 meq/liter. The maintenance of the serum potassium concentration is a complex bodily function and results from the balance between intake, excretion, and distribution between intracellular and extracellular space. Ingested potassium is virtually completely absorbed from and minimally excreted through the intestine under nonpathologic circumstances. Renal excretion of potassium, which is the major chronic protective mechanism against abnormalities in potassium balance, depends on filtration, reabsorption, and a highly regulated distal nephron secretory process. Factors regulating potassium secretion include prior potassium intake, intracellular potassium, delivery of sodium chloride and poorly reabsorbable anions to the distal nephron, the urine flow rate, hormones such as aldosterone and beta-catecholamines, and the integrity of the renal tubular cell. The maintenance of distribution between the inside and outside of cells depends on the integrity of the cell membrane and its pumps, osmolality, pH, and the hormones insulin, aldosterone, beta 2-catecholamines, alpha-catecholamines, and prostaglandins. Both distribution across cell membranes and/or renal excretion of potassium may be altered by pharmacologic agents such as diuretics, alpha- and beta-catechol antagonists and agonists, depolarizing agents, and digitalis. Problems with hypokalemia and hyperkalemia can be analyzed on the basis of potassium physiology and pharmacology; proper treatment depends on an accurate analysis.

  10. Short-term mortality risk of serum potassium levels in hypertension

    DEFF Research Database (Denmark)

    Krogager, Maria Lukács; Torp-Pedersen, Christian; Mortensen, Rikke Nørmark;

    2016-01-01

    AIMS: Diuretics and renin-angiotensin-aldosterone system inhibitors are central in the treatment of hypertension, but may cause serum potassium abnormalities. We examined mortality in relation to serum potassium in hypertensive patients. METHODS AND RESULTS: From Danish National Registries, we...... identified 44 799 hypertensive patients, aged 30 years or older, who had a serum potassium measurement within 90 days from diagnosis between 1995 and 2012. All-cause mortality was analysed according to seven predefined potassium levels: 5.......0 mmol/L (hyperkalaemia). Outcome was 90-day mortality, estimated with multivariable Cox proportional hazard model, with the potassium interval of 4.1-4.4 mmol/L as reference. During 90-day follow-up, mortalities in the seven strata were 4.5, 2.7, 1.8, 1.5, 1.7, 2.7, and 3.6%, respectively. Adjusted risk...

  11. Serum Level and 24hr. Excretion Pattern of Potassium Following the Intake of Combined Oral Contraceptives

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    S. Kamyab

    1978-01-01

    Full Text Available Serum level and 24hr urinary excretion pattern of potassium have been studied in 104 healthy women, aged 18-44 years, using combined • oral contraceptives for a period of 3-48 months, and results h av e been compared with those obtained from 21 healthy controls of the same clinic. aged 19-40 years, using IUD. There was no sign ificant change observed in s erum potassium level, but 24hr urinary excretion pattern of potassium decreased significantly in 90% of the individuals equivalent to 2. &- 78 . 3% of the mean control, possibly due to a retention of potas sium in the cells.

  12. Influence of Herbal Complexes Containing Licorice on Potassium Levels: A Retrospective Study

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    WooSang Jung

    2014-01-01

    Full Text Available To observe the influence of these complexes on potassium levels in a clinical setting, we investigated the influence of herbal complexes containing licorice on potassium levels. We retrospectively examined the medical records of patients treated with herbal complexes containing licorice from January 1, 2010, to December 31, 2010. We recorded the changes in the levels of potassium, creatinine, and blood urea nitrogen and examined the differences between before and after herbal complexes intake using a paired t-test. In addition, we investigated the prevalence of hypokalemia among these patients and reviewed such patients. We identified 360 patients who did not show significant changes in the levels of potassium and creatinine (P=0.815, 0.289. We observed hypokalemia in 6 patients. However, in 5 patients, the hypokalemia did not appear to be related to the licorice. Thus, we could suggest that herbal complexes containing licorice do not significantly influence the potassium levels in routine clinical herbal therapies. However, we propose that follow-up examination for potassium levels is required to prevent any unpredictable side effects of administration of licorice in routine herbal medicine care.

  13. Observation of Landau levels in potassium-intercalated graphite under a zero magnetic field

    Science.gov (United States)

    Guo, Donghui; Kondo, Takahiro; Machida, Takahiro; Iwatake, Keigo; Okada, Susumu; Nakamura, Junji

    2012-01-01

    The charge carriers in graphene are massless Dirac fermions and exhibit a relativistic Landau-level quantization in a magnetic field. Recently, it has been reported that, without any external magnetic field, quantized energy levels have been also observed from strained graphene nanobubbles on a platinum surface, which were attributed to the Landau levels of massless Dirac fermions in graphene formed by a strain-induced pseudomagnetic field. Here we show the generation of the Landau levels of massless Dirac fermions on a partially potassium-intercalated graphite surface without applying external magnetic field. Landau levels of massless Dirac fermions indicate the graphene character in partially potassium-intercalated graphite. The generation of the Landau levels is ascribed to a vector potential induced by the perturbation of nearest-neighbour hopping, which may originate from a strain or a gradient of on-site potentials at the perimeters of potassium-free domains. PMID:22990864

  14. Observation of Landau levels in potassium-intercalated graphite under a zero magnetic field.

    Science.gov (United States)

    Guo, Donghui; Kondo, Takahiro; Machida, Takahiro; Iwatake, Keigo; Okada, Susumu; Nakamura, Junji

    2012-01-01

    The charge carriers in graphene are massless Dirac fermions and exhibit a relativistic Landau-level quantization in a magnetic field. Recently, it has been reported that, without any external magnetic field, quantized energy levels have been also observed from strained graphene nanobubbles on a platinum surface, which were attributed to the Landau levels of massless Dirac fermions in graphene formed by a strain-induced pseudomagnetic field. Here we show the generation of the Landau levels of massless Dirac fermions on a partially potassium-intercalated graphite surface without applying external magnetic field. Landau levels of massless Dirac fermions indicate the graphene character in partially potassium-intercalated graphite. The generation of the Landau levels is ascribed to a vector potential induced by the perturbation of nearest-neighbour hopping, which may originate from a strain or a gradient of on-site potentials at the perimeters of potassium-free domains.

  15. Serum Sodium and Potassium Levels in Cerebro-vascular Accident Patients.

    Science.gov (United States)

    Farahmand, Farahmand; Choobi Anzali, Babak; Heshmat, Ramin; Ghafouri, Hamed-Basir; Hamedanchi, Sepehr

    2013-05-01

    We aim to assess serum sodium and potassium levels in patients with different types of cerebro-vascular accidents (CVA) in comparison to control group. A comparative cross-sectional study conducted on patients admitted to the emergency department from January to August 2012. Control group consisted of patients admitted to emergency department due to common cold, urinary tract infection, low back pain, cluster, and tension headache or migraine. Serum sodium and potassium levels were measured via standard laboratory methods. There were 77 patients in control group and 78 in CVA group. Forty nine patients from the CVA group had ischemic CVA, 11 had hemorrhagic CVA and 18 suffered a transient ischemic attack (TIA). Serum sodium level in control group was significantly lower than in patients with TIA, ischemic CVA, and hemorrhagic CVA (P < 0.001). Serum potassium level in control group was higher than patients with TIA, ischemic CVA, and hemorrhagic CVA (P < 0.001). Patients with hemorrhagic CVA showed significantly lower serum potassium level than patients with TIA and ischemic CVA (P < 0.001). Correspondingly, it was observed that serum sodium to potassium ratio was higher in patients with TIA, ischemic CVA, and hemorrhagic CVA (P < 0.001). In patients with hemorrhagic CVA serum sodium to potassium ratio was higher when compared to patients with TIA and ischemic CVA (P < 0.001). This study shows that higher serum sodium and lower serum potassium level may be associated with higher incidence of CVA. Further studies are paramount to elucidate the role of serum electrolyte levels in vascular events.

  16. Effect of heparin and low-molecular weight heparin on serum potassium and sodium levels

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    Girish M Bengalorkar

    2011-01-01

    Full Text Available Introduction: To study the effects of heparin and low-molecular weight heparin (LMWH on potassium and sodium levels in patients with cardiovascular diseases (CVDs and stroke. Materials and Methods : Sixty patients were recruited with 30 patients each receiving heparin and enoxaparin. Patients with CVD and stroke receiving heparin and LMWH were compared for their demographic profile and laboratory data, and this was analyzed by descriptive statistics. Risk factors associated with the development of hyperkalemia were analyzed using multiple logistic regression model. Results : There was an increase in potassium levels and decrease in sodium levels compared with baseline in both the groups. The difference between the groups with respect to sodium and potassium levels was not statistically significant. On analysis, the risk factors for development of hyperkalemia were baseline potassium levels, serum creatinine, and creatinine clearance. The change in sodium and potassium levels on the fifth day of therapy was increased with LMWH compared with heparin, although not statistically significant. Conclusions : The clinician should anticipate hyperkalemia especially in patients with renal impairment receiving these drugs.

  17. Transient decrease in serum potassium level during ischemic attack of acute coronary syndrome: Paradoxical contribution of plasma glucose level and glycohemoglobin

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    Sekiyama Hiroshi

    2013-01-01

    Full Text Available Abstract Background Although a decrease in serum potassium level has been suggested to be a fairly common observation in acute coronary syndrome (ACS, there have so far been no definitive reports directly demonstrating the transient potassium decrease (the potassium dip during ischemic attack of ACS compared to stable phase in individual patients. To understand the pathophysiological significance of the potassium dip, we examined the changes in serum potassium level throughout ischemic attack and evaluated the clinical factors affecting it. Methods The degree of the potassium dip during ischemic attack (as indicated by ΔK, ΔK = K at discharge − K on admission was examined in 311 consecutive patients with ACS who required urgent hospitalization in our institution. Results Serum potassium level during ischemic attack was significantly decreased compared to that during stable phase (P  Conclusions We have clearly demonstrated that there is a transient decrease in serum potassium level during ischemic attack of ACS compared to stable phase. The degree of the potassium dip was tightly correlated with glucose level, which overwhelmed the diabetic condition, and it also indicates the disease severity. The present study therefore promotes awareness of the significance of monitoring potassium level in parallel with glucose level in patients with ACS.

  18. Smoking is associated with increased levels of extracellular peptidylarginine deiminase 2 (PAD2) in the lungs

    DEFF Research Database (Denmark)

    Damgaard, Dres; Friberg Bruun Nielsen, Michael; Quisgaard Gaunsbaek, Maria

    2015-01-01

    lavage (BAL) fluid from smokers, but intracellularly located PAD cannot be responsible for citrullination of extracellular self-antigens. We aimed to establish a link between smoking and extracellular PAD2 in the lungs. METHODS: BAL fluid samples were obtained from 13 smokers and 11 nonsmoking controls...... fluids from smokers as compared to non-smokers (p=0.018). The PAD2 content correlated with the overall CRP levels (p=0.009) and cell count (p=0.016). CONCLUSIONS: This first demonstration of increased levels of extracellular PAD2 in the lungs of smokers supports the hypothesis that smoking promotes...

  19. Testosterone and LH Seric Level Dynamics in Male Rats after Potassium Dichromate Intake (Two Generation Study

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    Jelena Rankov

    2010-05-01

    Full Text Available The aim of this study was the evaluation of potassium dichromate impact on biochemical biomarkers for testicular function (serum testosterone and LH level (two generations experiment. Males and females from F0 generation were exposed to potassium dichromate three months before mating. F1 generation was represented by male pups, resulted from F0 generation, exposed to potassium dichromate in utero, in suckling period (via milk and water and until sexual maturity. All the animals were divided in four groups: three experimental and one control, exposed to Cr VI trough drinking water, as follows E1: 25 ppm (LOAEL; E2: 50 ppm: E3: 75 ppm; control group received tap water without chromium content. The study was performed in compliance with national and international law regarding animal welfare and ethics in animal experiments. In male rats, from F0 and F1 generation, exposure to Cr VI determined: significant decrease of testosterone and significant increase of LH seric level in all experimental groups comparative to control one, indirectly, respectively, directly correlated to exposure level. Comparative to F0 generation, in F1 generation seric testosterone level was lower, significantly only in E1 and E3 groups, and LH seric level was significantly higher.

  20. Estimation of postmortem interval using vitreous potassium levels in cases of fatal road traffic collision

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    Suzanne N. Foster

    2016-11-01

    Full Text Available Aim of the study : To produce a formula that can accurately predict postmortem interval (PMI based on vitreous potassium levels using road traffic collision fatalities. Material and methods: Vitreous humour samples were taken from 78 individuals who had died following road traffic collisions between 2010 and 2015. Samples were obtained from both eyes and were sent for on-site analysis. Measurement of potassium was by an indirect ion-specific electrode Siemens diagnostics ADVIA 2400 chemistry system. Exact time of death was known from police reports, the time of postmortem was recorded and the postmortem interval was calculated. Linear regression was then used to analyse the relationship between the two. The impact of age was also assessed. Results: PMI was between 6 and 162 hours. As vitreous potassium increases, the PMI also increases; exhibiting a linear relationship. This is illustrated by a regression equation of PMI = 6.42[K+] – 40.94, R = 0.67 (p < 0.001. This produced a formula closely comparable with three other studies proposed in previous literature and produces estimates that may exceed one calendar day. When both age and medical intervention are accounted for there is an insignificant improvement in prediction. Conclusions : Validated methods have been used to produce a formula for prediction of PMI using vitreous potassium. Although this is specific to road traffic collisions, the methods are transferable and can be seen to be comparable with other recently published methods. Nonetheless, if greater levels of accuracy are required it is suggested that biomarkers delivering a higher level of precision should still be sought.

  1. Studies on the interaction of growth regulators with potassium ions in some physiological processes in the bean (Phaseolus vulguris L.. II. The effect of potassium on growth of bean leaves and on their potassium and hormone levels

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    Jadwiga Stopińska

    2014-02-01

    Full Text Available The subject of study was the effect of K on the growth of primary and trifoliate leaves of the bean and on their potassium and hormone levels. Bean seedlings were grown in Hoagland's water solution in which the potassium concentrations (K –NO3, were 1 and 3 mM. The increase in the amount of potassium in bean leaves. elicited by increased K concentration in the medium or by partial defoliation. was correlated with a stimulation of growth of these organs and an increase in their H2O content. These effects were connected with an increase in the amount of ABA and bound GA and decrease in the amount of auxins. The effect of potassium on the level of free gibberellins and cytokinins depended on the kind of leaves. In young, i.e. trifoliate leaves_ K was found to have a positive effect on the level of free GA, whereas in older. i.e. primary leaves, this effect concerned the level of cytokinins.

  2. 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.

  3. GLC determination of plasma drug levels after oral administration of clorazepate potassium salts.

    Science.gov (United States)

    Hoffman, D J; Chun, A H

    1975-10-01

    Plasma nordiazepam levels resulting from the oral administration of clorazepate potassium salts were determined by a sensitive GLC assay. Nordiazepam and the internal standard (diazepam) were selectively extracted into ether at pH 9.2, hydrolyzed to their respective benzophenones, and quantified by electron-capture detection. The assay was used in a comparative bioavailability study of single equimolar oral doses of monopotassium and dipotassium salts of clorazepate in dogs. Both clorazepate salts were rapidly absorbed and exhibited mean peak total drug levels after 1 hr. Clorazepate levels accounted for about 50% of the total drug levels present. No statistical difference in the plasma drug levels of clorazepate mono- and dipotassium salts and the metabolite was found in dogs.

  4. Effect of novel atypical antipsychotic, blonanserin, on extracellular neurotransmitter level in rat prefrontal cortex.

    Science.gov (United States)

    Ohoyama, Keiko; Yamamura, Satoshi; Hamaguchi, Tatsuya; Nakagawa, Masanori; Motomura, Eishi; Shiroyama, Takashi; Tanii, Hisashi; Okada, Motohiro

    2011-02-25

    To clarify the mechanisms of action of blonanserin, an atypical antipsychotic drug, we studied the effects of systemic administration of blonanserin and risperidone on extracellular levels of norepinephrine, dopamine, serotonin, GABA and glutamate in the medial prefrontal cortex using microdialysis, and neuronal firing in the ventral tegmental area, locus coeruleus, dorsal raphe nucleus and mediodorsal thalamic nucleus using radiotelemetry. The binding affinities of blonanserin to D(2) and 5-HT(2A) receptors in the rat brain were confirmed and found to be similar. Blonanserin transiently increased neuronal firing in locus coeruleus and ventral tegmental area but not in dorsal raphe nucleus or mediodorsal thalamic nucleus, whereas risperidone increased the firing in locus coeruleus, ventral tegmental area and dorsal raphe nucleus but not in mediodorsal thalamic nucleus. Blonanserin persistently increased frontal extracellular levels of norepinephrine and dopamine but not serotonin, GABA or glutamate, whereas risperidone persistently increased those of norepinephrine, dopamine and serotonin but not GABA or glutamate. These results suggest a pharmacological correlation between the stimulatory effects of these antipsychotics on frontal monoamine release and neuronal activity in monoaminergic nuclei. Inhibition of the α(2) adrenoceptor increased extracellular monoamine levels and enhanced blonanserin-induced increase in extracellular serotonin level. These results indicated that the combination of antagonism of D(2) and 5-HT(2A) receptors contribute to the rise in extracellular levels of norepinephrine and dopamine, and that α(2) adrenoceptors play important roles in frontal serotonin release. They also suggest that blonanserin-induced activation of monoaminergic transmission could be, at least partially, involved in atypical antipsychotic properties of blonanserin. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Evidences of Hfq associates with tryptophanase and affects extracellular indole levels

    Institute of Scientific and Technical Information of China (English)

    Yinghua Zhang; Guofan Hong

    2009-01-01

    In this study, we observed a novel property of Escherichia coil Hfq protein: it possibly influenced extracellular indole levels. The extracellular indole concentrations were increased in Hfq mutant cells and decreased in Hfq overexpression cells in a cell density-dependent manner. The decreased extracellular indole levels in Hfq overexpression cells caused the postpone-ment of entering into stationary phase, lndole was pro-duced by tryptophanase, the gene product of tnaA, which catalyzed tryptophan into indole, ammonia and pyruvate. Further studies showed that at cell density of 0.8 but not at 0.4, tryptophanase activities of total cell extracts were affected by Hfq mutation or overexpression. Protein pull-down assay and co-immunoprecipitation experiments revealed that Hfq associated with trypto-phanase under relatively higher extracellular indole levels, suggesting this was a feedback control of indole production. The association of Hfq and tryptophanase might be indirect because purified Hfq could not affect the values of Km and Vmax of purified tryptophanase.

  6. Evidences of Hfq associates with tryptophanase and affects extracellular indole levels.

    Science.gov (United States)

    Zhang, Yinghua; Hong, Guofan

    2009-08-01

    In this study, we observed a novel property of Escherichia coli Hfq protein: it possibly influenced extracellular indole levels. The extracellular indole concentrations were increased in Hfq mutant cells and decreased in Hfq overexpression cells in a cell density-dependent manner. The decreased extracellular indole levels in Hfq overexpression cells caused the postponement of entering into stationary phase. Indole was produced by tryptophanase, the gene product of tnaA, which catalyzed tryptophan into indole, ammonia and pyruvate. Further studies showed that at cell density of 0.8 but not at 0.4, tryptophanase activities of total cell extracts were affected by Hfq mutation or overexpression. Protein pull-down assay and co-immunoprecipitation experiments revealed that Hfq associated with tryptophanase under relatively higher extracellular indole levels, suggesting this was a feedback control of indole production. The association of Hfq and tryptophanase might be indirect because purified Hfq could not affect the values of Km and Vmax of purified tryptophanase.

  7. Orientations and proximities of the extracellular ends of transmembrane helices S0 and S4 in open and closed BK potassium channels.

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    Xiaowei Niu

    Full Text Available The large-conductance potassium channel (BK α subunit contains a transmembrane (TM helix S0 preceding the canonical TM helices S1 through S6. S0 lies between S4 and the TM2 helix of the regulatory β1 subunit. Pairs of Cys were substituted in the first helical turns in the membrane of BK α S0 and S4 and in β1 TM2. One such pair, W22C in S0 and W203C in S4, was 95% crosslinked endogenously. Under voltage-clamp conditions in outside-out patches, this crosslink was reduced by DTT and reoxidized by a membrane-impermeant bis-quaternary ammonium derivative of diamide. The rate constants for this reoxidation were not significantly different in the open and closed states of the channel. Thus, these two residues are approximately equally close in the two states. In addition, 90% crosslinking of a second pair, R20C in S0 and W203C in S4, had no effect on the V50 for opening. Taken together, these findings indicate that separation between residues at the extracellular ends of S0 and S4 is not required for voltage-sensor activation. On the contrary, even though W22C and W203C were equally likely to form a disulfide in the activated and deactivated states, relative immobilization by crosslinking of these two residues favored the activated state. Furthermore, the efficiency of recrosslinking of W22C and W203C on the cell surface was greater in the presence of the β1 subunit than in its absence, consistent with β1 acting through S0 to stabilize its immobilization relative to α S4.

  8. 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...

  9. Transcranial Direct-Current Stimulation Increases Extracellular Dopamine Levels in the Rat Striatum

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    Tomoko eTanaka

    2013-04-01

    Full Text Available Background: Transcranial direct-current stimulation is a non-invasive procedure that achieves polarity-dependent modulation of neuronal membrane potentials. It has recently been used as a functional intervention technique for the treatment of psychiatric and neurological diseases; however, its neuronal mechanisms have not been fully investigated in vivo. Objective/Hypothesis: To investigate whether the application of cathodal or anodal transcranial direct-current stimulation affects extracellular dopamine and serotonin levels in the rat striatum. Methods: Stimulation and in vivo microdialysis were carried out under urethane anesthesia, and microdialysis probes were slowly inserted into the striatum. After the collection of baseline fractions in the rat striatum, cathodal or anodal transcranial direct-current stimulation was applied continuously for 10 min with a current intensity of 800 µA from an electrode placed on the skin of the scalp. Dialysis samples were collected every 10 min until at least 400 min after the onset of stimulation.Results: Following the application of cathodal, but not anodal, transcranial direct-current stimulation for 10 min, extracellular dopamine levels increased for more than 400 min in the striatum. There were no significant changes in extracellular serotonin levels. Conclusion: These findings suggest that transcranial direct-current stimulation has a direct and/or indirect effect on the dopaminergic system in the rat basal ganglia.

  10. Critical ranges for leaf nitrogen and potassium levels in coffee fertigated at the production phase1

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    Gleice Aparecida de Assis

    Full Text Available With the aim of establishing critical ranges for the leaf nitrogen (N and potassium (K levels in fertigated coffee crops under production, an experiment was carried out in the experimental area of the Sector for Coffee Cultivation of the Department of Agriculture at the Federal University of Lavras, in Brazil. Treatments consisted of five levels of fertilizer applied through fertigation: 30%, 80%, 130%, 180% and 230% of the recommended amounts of N and K for rainfed coffee grown in Minas Gerais. A randomised block design with four replications was used. Critical ranges for nutrient concentrations in the leaves were established from the results of growth characteristics (plant height and stem diameter, leaf analyses and productivity. The results obtained were: a nitrogen (g kg-1: 32.39 to 32.40 for January/February; 33.60 to 33.61 for March/April; 27.39 to 27.42 for May/June; 24.23 to 24.24 for July/August; 26.06 to 26.09 for September/October and 26.50 to 26.51 for November/December; b potassium (g kg-1: 20.08 to 20.14 for January/February; 17.89 to 17.91 for March/April; 15.93 to 15.96 for May/June; 15.29 to 15.35 for July/August; 16.61 to 16.64 for September/October and 20.58 to 20.64 for November/December.

  11. Specific inhibition of kynurenate synthesis enhances extracellular dopamine levels in the rodent striatum

    Science.gov (United States)

    Amori, L; Wu, H.-Q.; Marinozzi, M; Pellicciari, R; Guidetti, P; Schwarcz, R

    2011-01-01

    Fluctuations in the endogenous levels of kynurenic acid (KYNA), a potent α7 nicotinic and NMDA receptor antagonist, affect extracellular dopamine (DA) concentrations in the rat brain. Moreover, reductions in KYNA levels increase the vulnerability of striatal neurons to NMDA receptor-mediated excitotoxic insults. We now assessed the role of a key KYNA-synthesizing enzyme, kynurenine aminotransferase II (KAT II), in these processes in the rodent striatum, using KAT II KO mice—which have reduced KYNA levels—and the selective KAT II inhibitor (S)-4-(ethylsulfonyl)benzoylalanine (S-ESBA) as tools. S-ESBA (applied by reverse dialysis) raised extracellular DA levels in the striatum of KYNA-deficient mice threefold and caused a much larger, 15-fold increase in wild-type mice. In the rat striatum, S-ESBA produced a 35% reduction in extracellular KYNA, which was accompanied by a 270% increase in extracellular DA. The latter effect was abolished by co-infusion of 100 nM KYNA. Intrastriatal S-ESBA pre-treatment augmented the size of a striatal quinolinate lesion by 370%, and this potentiation was prevented by co-infusion of KYNA. In separate animals, acute inhibition of KAT II reduced the de novo synthesis of KYNA during an early excitotoxic insult without enhancing the formation of the related neurotoxic metabolites 3-hydroxykynurenine and quinolinate. Taken together, these results provide further support for the concept that KAT II is a critical determinant of functionally relevant KYNA fluctuations in the rodent striatum. PMID:19138730

  12. The P2X7 receptor is an important regulator of extracellular ATP levels

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    Andrea eBrandao-Burch

    2012-03-01

    Full Text Available Controlled ATP release has been demonstrated from many neuronal and non-neuronal cell types. Once released, extracellular ATP acts on cells in a paracrine manner via purinergic receptors. Considerable evidence now suggests that extracellular nucleotides, signalling via P2 receptors, play important roles in bone homeostasis modulating both osteoblast and osteoclast function. In this study, we demonstrate that mouse osteoclasts and their precursors constitutively release ATP into their extracellular environment. Levels were highest at day 2 (precursor cells, possibly reflecting the high number of red blood cells and accessory cells present. Mature osteoclasts constitutively released ATP in the range 0.05-0.5pmol/ml/cell. Both osteoclasts and osteoblasts express mRNA and protein for the P2X7 receptor. We found that in osteoclasts, expression levels are 4-fold higher in mature cells relative to precursors, whilst in osteoblasts expression remains relatively constant during differentiation. Selective antagonists (0.1-100µM AZ10606120, A438079 and KN-62 were used to determine whether this release was mediated via P2X7 receptors. AZ10606120, A438079 and KN-62, at 0.1-10µM, decreased ATP release by mature osteoclasts by up to 70%, 60% and 80%, respectively. No differences in cell viability were observed. ATP release also occurs via vesicular exocytosis; inhibitors of this process (1-100µM NEM or brefeldin A had no effect on ATP release from osteoclasts. P2X7 receptor antagonists (0.1-10µM also decreased ATP release from primary rat osteoblasts by up to 80%. These data show that ATP release via the P2X7 receptor contributes to extracellular ATP levels in osteoclast and osteoblast cultures, suggesting an important additional role for this receptor in autocrine/paracrine purinergic signalling in bone.

  13. Quality in the pepper under different fertigation managements and levels of nitrogen and potassium

    Directory of Open Access Journals (Sweden)

    Francisco de Assis de Oliveira

    Full Text Available ABSTRACTThe rational use of nutrients is of fundamental importance for obtaining high productivity of high nutritional quality. This work was developed with the aim of evaluating the quality of pepper fruit grown under different fertigation managements and different levels of nitrogen and potassium. The experimental design was of randomised blocks in a 3 x 6 factorial scheme with four replications. The treatments resulted from the combination of three fertigation managements (M1-based on the rate of absorption; M2-monitoring the conductivity of the soil solution; M3-monitoring concentrations of N and K ions in the soil solution with six levels of N and K (N0K0, N50K50, N100K100, N150K150, N200K200 and N300K300 as a percentage of the recommended dosage for the crop under conventional fertigation (M1 or hydroponics (M2 and M3. Fruit quality was evaluated for the following characteristics: pH, soluble solids, titratable acidity, vitamin C content and the ratio of soluble solids to titratable acidity. The different fertigation managements only affected the levels of soluble solids (SS and titratable acidity (TA, reducing the SS and TA. The variables under study were adjusted for the levels of N and K using quadratic models.

  14. Seasonal variation of the {sup 137}Cs level and its relationship with potassium and carbon levels in conifer needles

    Energy Technology Data Exchange (ETDEWEB)

    Rantavaara, Aino, E-mail: aino.rantavaara@stuk.fi [Radiation and Nuclear Safety Authority (STUK), Research and Environmental Surveillance, P.O. Box 14, FI-00881 Helsinki (Finland); Vetikko, Virve, E-mail: virve.vetikko@stuk.fi [Radiation and Nuclear Safety Authority (STUK), Research and Environmental Surveillance, P.O. Box 14, FI-00881 Helsinki (Finland); Raitio, Hannu, E-mail: hannu.raitio@metla.fi [Finnish Forest Research Institute (Metla), P. O. Box 18 , FI-01301 Vantaa (Finland); Aro, Lasse, E-mail: lasse.aro@metla.fi [Finnish Forest Research Institute (Metla), Parkano Unit, Kaironiementie 15, FI-39700 Parkano (Finland)

    2012-12-15

    Seasonal variations in foliar {sup 137}Cs levels were examined in Norway spruce (Picea abies (L.) Karst.), and Scots pine (Pinus sylvestris L.) in western Finland. Our aim was to test the occurrence of seasonal variation in contents and concentrations of {sup 137}Cs, potassium and carbon in needles. The study focused on analysing levels of total {sup 137}Cs in the three youngest needle age classes and comparing them to the levels of potassium and carbon. Spruce and pine needles were collected from 50- and 65-year-old stands on 18 sampling occasions between April 1996 and February 1997. Phases of intensive growth, needle elongation and dormancy were apparent in the time series for the needle contents and activity concentration of {sup 137}Cs, both of which varied according to needle age class and tree species. The sequence of phases with a temporal fluctuation of needle contents, activity concentrations of {sup 137}Cs and concentrations of K and carbon varied occasionally, and the efficiency of their translocation revealed some differences in the dynamics of {sup 137}Cs, K and carbon in spruce and pine. The data clearly showed that the needles' K contents responded strongly to changes in K demand from other parts of the tree due to seasonal changes and that these responses were stronger than the associated retranslocations of {sup 137}Cs, particularly in Scots pine. During intensive growth, K was less mobile than {sup 137}Cs in the needles. The uptake of {sup 137}Cs by current-year needles is simultaneously affected by uptake from the soil via the roots and retranslocation from other internal sources, and both of these processes affect the observed transfer rates during the growth period. Our results provided information on the transfer rates and revealed differentiation of root uptake and retranslocation of {sup 137}Cs in needles. The study can support dynamic modelling of atmospheric {sup 137}Cs contamination in forests. -- Highlights: Black

  15. Effects of levels of potassium and nitrogen on yields and post-harvest conservation of onions in winter

    Directory of Open Access Journals (Sweden)

    Geraldo Milanez de Resende

    2014-08-01

    Full Text Available Potassium and nitrogen are the elements present in the highest percentage in the onion dry matter. The objective of this experiment was to evaluate yield and post-harvest conservation of Vale Ouro IPA-11 onion cultivar regarding to nitrogen and potassium levels. The experiment was carried out in Petrolina-PE, Brazil, from June to September 2009. The experimental design was a completely randomized block in a 4 x 3 factorial design, composed of four nitrogen levels (0, 60, 120 and 180 kg ha-1 and three potassium levels (0, 90 and 180 kg ha-1 with three replications. The highest yield of commercial bulbs was achieved at an estimated N level of 172.6 kg ha-1. The lowest yield of noncommercial bulbs was estimated at N level of 147.0 kg ha-1. Lower percentage of smaller bulbs (class 2 were obtained by increasing levels of N x K, with a quadratic effect at the dose of 90 kg ha-1 K2O and minimum production point with 127.6 kg N ha-1 (20.3%. Regarding larger caliber bulbs (class 4, linear effects were found both in the absence and for the level of 90 kg ha-1 of K2O as levels of N were increased. When the highest level of 180 kg ha-1 K2O was applied, the level of 92.8 kg ha-1 of N was estimated as the one that would promote the highest bulb yield of this class (35.4%, and 5.3% was found in the lack of potassium fertilization.

  16. Changes in plant medium composition after a spaceflight experiment: Potassium levels are of special interest

    Science.gov (United States)

    Levine, Howard G.; Krikorian, A. D.

    2008-09-01

    We present results on the analysis of 100 mL medium samples extracted from sterilized foam (Smithers-Oasis, Kent OH) used to support the growth of a representative dicotyledon ( Haplopappus gracilis) and a representative monocotyledon ( Hemerocallis cv Autumn Blaze) in NASA's Plant Growth Unit (PGU) during a 5-day Space Shuttle flight and ground experiments. At recovery, the media remaining within replicate ( n = 5) foam blocks (for both the spaceflight and ground experiments) were extracted under vacuum, filtered and subjected to elemental analyses. A unique aspect of this experiment was that all plants were either aseptically-generated tissue culture propagated plantlets or aseptic seedling clones. The design of the PGU facilitated the maintenance of asepsis throughout the mission (confirmed by post-flight microbial sampling) and thus any possible impact of microorganisms on medium composition was eliminated. Concentration levels of some elements remained the same, while some decreased and others increased. There was a significant two-fold difference between the final concentrations of potassium when the Earth-based and microgravity experiments were contrasted.

  17. Changes in extracellular levels of amygdala amino acids in genetically fast and slow kindling rat strains.

    Science.gov (United States)

    Shin, Rick S; Anisman, Hymie; Merali, Zul; McIntyre, Dan C

    2002-08-01

    A neurochemical basis for many of the epilepsies has long been suspected to result from an imbalance between excitatory and inhibitory neurotransmitter mechanisms. Data supporting changes in extrasynaptic amino acid levels during epileptogenesis, however, remain controversial. In the present study, we used in vivo microdialysis to measure the levels of extracellular GABA (gamma-aminobutyric acid) and glutamate during seizure development in rats with a genetic predisposition for (Fast), or against (Slow), amygdala kindling. Dialysates were collected from both amygdalae before, during, and up to 12 min after a threshold-triggered amygdala afterdischarge (AD). One hour later, samples were again collected from both amygdalae in response to a hippocampal threshold AD. Daily amygdala kindling commenced the next day but without dialysis. After the rats were fully kindled, the same protocol was again employed. Amino acid levels were not consistently increased above baseline with triggered seizures in either strain. Instead, before kindling, a focal seizure in the Slow rats was associated with a large decrease in GABA in the non-stimulated amygdala, while amino acid levels in the Fast rats remained near baseline in both amygdalae. Similar results were seen after kindling. By contrast, before and after kindling, hippocampal stimulation caused large decreases in all amino acid levels in both amygdalae in both strains. These data suggest that, in response to direct stimulation, extracellular amino acid concentrations remain stable in tissues associated with either greater natural (Fast) or induced (kindled Fast/Slow) excitability, but are lowered with indirect stimulation (hippocampus) and/or low excitability.

  18. Neuropeptide Y infusion into the shell region of the rat nucleus accumbens increases extracellular levels of dopamine

    DEFF Research Database (Denmark)

    Sørensen, Gunnar; Wegener, Gregers; Hasselstrøm, Jørgen;

    2009-01-01

    Increases in extracellular dopamine in the shell region of the nucleus accumbens are centrally involved in mediating reinforcement of addictive drugs. Neuropeptide Y (NPY) and its receptors are present in the nucleus accumbens and have been implicated in addiction mechanisms. This study further...... explored the potential role of NPY in addiction mechanisms using microdialysis to measure extracellular dopamine in vivo after infusion of NPY directly into the accumbal shell region of adult rats. NPY was found to dose-dependently increase extracellular dopamine levels, indicating that NPY could play...

  19. The association between fluid balance and mortality in patients with ARDS was modified by serum potassium levels: a retrospective study

    Directory of Open Access Journals (Sweden)

    Zhongheng Zhang

    2015-02-01

    Full Text Available Background and Objective. Acute respiratory distress syndrome (ARDS is characterized by pulmonary edema and may benefit from conservative fluid management. However, conflicting results exist in the literature. The study aimed to investigate the association between mean fluid balance and mortality outcome in ARDS patients who required invasive mechanical ventilation.Methods. The study was a secondary analysis of a prospectively collected dataset obtained from the NHLBI Biologic Specimen and Data Repository Information Coordinating Center. ARDS patients with invasive mechanical ventilation were eligible. Demographic and laboratory data were extracted from the dataset. Multivariable regression model was built by stepwise selection of covariates. A fractional polynomial approach was used to test the linearity of mean fluid balance in the model. The potential interactions of mean fluid balance with other variables were tested.Main Results. A total of 282 patients were eligible for the analysis, including 61 non-survivors with a mortality rate of 21.6%. After stepwise regression analysis, mean fluid balance remained to be an independent predictor of death (OR: 1.00057; 95% CI [1.00034–1.00080]. The two-term model obtained using fractional polynomial analysis was not superior to the linear model. There was significant interaction between mean fluid balance and serum potassium levels (p = 0.011. While the risk of death increased with increasing mean fluid balance at potassium levels of 1.9, 2.9 , 3.9 and 4.9 mmol/l, the risk decreased at potassium level of 5.9 mmol/l.Conclusion. The present study demonstrates that more positive fluid balance in the first 8 days is significantly associated with increased risk of death. However, the relationship between mean fluid balance and mortality can be modified by serum potassium levels. With hyperkalemia, more positive fluid balance is associated with reduced risk of death.

  20. Potassium sorbate residue levels and persistence in citrus fruit as detected by a simple colorimetric method

    Science.gov (United States)

    Postharvest applications of potassium sorbate (PS) to fresh citrus fruit control fungal decay pathogens, such as Penicillium digitatum, cause of green mold. Although PS effectiveness has been examined repeatedly, little is known about PS residues. A colorimetric method that employed extraction of th...

  1. 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 a......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...

  2. High Prolidase Levels may be a Marker of Irreversible Extracellular Matrix Changes in Controlled Acromegaly Patients?

    Science.gov (United States)

    Tabur, S; Sezen, H; Korkmaz, H; Ozkaya, M; Akarsu, E

    2016-02-01

    The present study aimed to evaluate the activity of prolidase in controlled acromegaly patients and its association with oxidative stress. 25 acromegalic patients in remission who were followed in our outpatient clinic and 31 healthy controls were enrolled in the study. Serum growth hormone (GH), insulin-like growth factor 1 (IGF-1), total antioxidative status (TAS), total oxidative stress (TOS), total free sulfhydryl (-SH), paraoxonase (PON), arylesterase (ARE), lipid hydroperoxide (LOOH) and prolidase activity levels were measured. Percent ratio of TOS to TAS level was accepted as oxidative stress index (OSI). Serum prolidase activity, TOS, OSI, and LOOH levels were significantly higher in acromegaly patients compared to the healthy control group (pacromegaly patients compared to the healthy control group (p=0.002). Prolidase activity were positively correlated with TOS, OSI, LOOH and negatively correlated with -SH in patients with acromegaly (r=0.471, pacromegaly patients. These results suggest that extracellular matrix changes continue eventhough the disease is controlled, and elevated oxidative stress is involved in the increased prolidase activity in acromegaly patients.

  3. Exposure to repeated immobilization stress inhibits cocaine-induced increase in dopamine extracellular levels in the rat ventral tegmental area.

    Science.gov (United States)

    Sotomayor-Zárate, Ramón; Abarca, Jorge; Araya, Katherine A; Renard, Georgina M; Andrés, María E; Gysling, Katia

    2015-11-01

    A higher vulnerability to drug abuse has been observed in human studies of individuals exposed to chronic or persistent stress, as well as in animal models of drug abuse. Here, we explored the effect of repeated immobilization stress on cocaine-induced increase in dopamine extracellular levels in VTA and its regulation by corticotropin-releasing factor (CRF) and GABA systems. Cocaine (10mg/Kg i.p.) induced an increase of VTA DA extracellular levels in control rats. However, this effect was not observed in repeated stress rats. Considering the evidence relating stress with CRF, we decided to perfuse CRF and CP-154526 (selective antagonist of CRF1 receptor) in the VTA of control and repeated stress rats, respectively. We observed that perfusion of 20μM CRF inhibited the increase of VTA DA extracellular levels induced by cocaine in control rats. Interestingly, we observed that in the presence of 10μM CP-154526, cocaine induced a significant increase of VTA DA extracellular levels in repeated stress rats. Regarding the role of VTA GABA neurotransmission, cocaine administration induced a significant increase in VTA GABA extracellular levels only in repeated stress rats. Consistently, cocaine was able to increase VTA DA extracellular levels in repeated stress rats when 100μM bicuculline, an antagonist of GABAA receptor, was perfused intra VTA. Thus, both CRF and GABA systems are involved in the lack of response to cocaine in the VTA of repeated stress rats. It is tempting to suggest that the loss of response in VTA dopaminergic neurons to cocaine, after repeated stress, is due to an interaction between CRF and GABA systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Effect of nitrogen narcosis on extracellular levels of dopamine and its metabolites in the rat striatum, using intracerebral microdialysis.

    Science.gov (United States)

    Barthelemy-Requin, M; Semelin, P; Risso, J J

    1994-12-19

    In man, nitrogen narcosis is characterized by euphoria, impaired cognitive function, neuromuscular incoordination and, ultimately, loss of consciousness. Because of the motor movement disorders, we chose to study the nigrostriatal system, whose major function is to regulate the extrapyramidal nervous system. The purpose of this investigation was to monitor changes in extracellular levels of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the striatum of conscious rats, using intracerebral microdialysis. Results show a 40% decrease in extracellular DA concentration, a 59% increase in extracellular DOPAC and an increase in HVA starting with exposure to the nitrogen mixture. Thirty minutes after the beginning of the exposure, a compensation phase took place. HVA returns to its initial basal value, and levels of DOPAC and DA returned towards normal but never reached their initial values. These results contrast with those observed during the High Pressure Neurological Syndrome (HPNS, 5.1 MPa of helium pressure) in which there is a significant increase in extracellular DA. Therefore, some of the symptoms of nitrogen narcosis may be linked with the decrease in the extracellular DA levels.

  5. Extracellular DNA amplicon sequencing reveals high levels of benthic eukaryotic diversity in the central Red Sea.

    Science.gov (United States)

    Pearman, John K; Irigoien, Xabier; Carvalho, Susana

    2016-04-01

    The present study aims to characterize the benthic eukaryotic biodiversity patterns at a coarse taxonomic level in three areas of the central Red Sea (a lagoon, an offshore area in Thuwal and a shallow coastal area near Jeddah) based on extracellular DNA. High-throughput amplicon sequencing targeting the V9 region of the 18S rRNA gene was undertaken for 32 sediment samples. High levels of alpha-diversity were detected with 16,089 operational taxonomic units (OTUs) being identified. The majority of the OTUs were assigned to Metazoa (29.2%), Alveolata (22.4%) and Stramenopiles (17.8%). Stramenopiles (Diatomea) and Alveolata (Ciliophora) were frequent in a lagoon and in shallower coastal stations, whereas metazoans (Arthropoda: Maxillopoda) were dominant in deeper offshore stations. Only 24.6% of total OTUs were shared among all areas. Beta-diversity was generally lower between the lagoon and Jeddah (nearshore) than between either of those and the offshore area, suggesting a nearshore-offshore biodiversity gradient. The current approach allowed for a broad-range of benthic eukaryotic biodiversity to be analysed with significantly less labour than would be required by other traditional taxonomic approaches. Our findings suggest that next generation sequencing techniques have the potential to provide a fast and standardised screening of benthic biodiversity at large spatial and temporal scales.

  6. LRRK2 affects vesicle trafficking, neurotransmitter extracellular level and membrane receptor localization.

    Directory of Open Access Journals (Sweden)

    Rossana Migheli

    Full Text Available The leucine-rich repeat kinase 2 (LRRK2 gene was found to play a role in the pathogenesis of both familial and sporadic Parkinson's disease (PD. LRRK2 encodes a large multi-domain protein that is expressed in different tissues. To date, the physiological and pathological functions of LRRK2 are not clearly defined. In this study we have explored the role of LRRK2 in controlling vesicle trafficking in different cellular or animal models and using various readouts. In neuronal cells, the presence of LRRK2(G2019S pathological mutant determines increased extracellular dopamine levels either under basal conditions or upon nicotine stimulation. Moreover, mutant LRRK2 affects the levels of dopamine receptor D1 on the membrane surface in neuronal cells or animal models. Ultrastructural analysis of PC12-derived cells expressing mutant LRRK2(G2019S shows an altered intracellular vesicle distribution. Taken together, our results point to the key role of LRRK2 to control vesicle trafficking in neuronal cells.

  7. LRRK2 Affects Vesicle Trafficking, Neurotransmitter Extracellular Level and Membrane Receptor Localization

    Science.gov (United States)

    Spissu, Ylenia; Sanna, Giovanna; Xiong, Yulan; Dawson, Ted M.; Dawson, Valina L.; Galioto, Manuela; Rocchitta, Gaia; Biosa, Alice; Serra, Pier Andrea; Carri, Maria Teresa; Crosio, Claudia; Iaccarino, Ciro

    2013-01-01

    The leucine-rich repeat kinase 2 (LRRK2) gene was found to play a role in the pathogenesis of both familial and sporadic Parkinson’s disease (PD). LRRK2 encodes a large multi-domain protein that is expressed in different tissues. To date, the physiological and pathological functions of LRRK2 are not clearly defined. In this study we have explored the role of LRRK2 in controlling vesicle trafficking in different cellular or animal models and using various readouts. In neuronal cells, the presence of LRRK2G2019S pathological mutant determines increased extracellular dopamine levels either under basal conditions or upon nicotine stimulation. Moreover, mutant LRRK2 affects the levels of dopamine receptor D1 on the membrane surface in neuronal cells or animal models. Ultrastructural analysis of PC12-derived cells expressing mutant LRRK2G2019S shows an altered intracellular vesicle distribution. Taken together, our results point to the key role of LRRK2 to control vesicle trafficking in neuronal cells. PMID:24167564

  8. Extracellular DNA amplicon sequencing reveals high levels of benthic eukaryotic diversity in the central Red Sea

    KAUST Repository

    Pearman, John K.

    2015-11-01

    The present study aims to characterize the benthic eukaryotic biodiversity patterns at a coarse taxonomic level in three areas of the central Red Sea (a lagoon, an offshore area in Thuwal and a shallow coastal area near Jeddah) based on extracellular DNA. High-throughput amplicon sequencing targeting the V9 region of the 18S rRNA gene was undertaken for 32 sediment samples. High levels of alpha-diversity were detected with 16,089 operational taxonomic units (OTUs) being identified. The majority of the OTUs were assigned to Metazoa (29.2%), Alveolata (22.4%) and Stramenopiles (17.8%). Stramenopiles (Diatomea) and Alveolata (Ciliophora) were frequent in a lagoon and in shallower coastal stations, whereas metazoans (Arthropoda: Maxillopoda) were dominant in deeper offshore stations. Only 24.6% of total OTUs were shared among all areas. Beta-diversity was generally lower between the lagoon and Jeddah (nearshore) than between either of those and the offshore area, suggesting a nearshore–offshore biodiversity gradient. The current approach allowed for a broad-range of benthic eukaryotic biodiversity to be analysed with significantly less labour than would be required by other traditional taxonomic approaches. Our findings suggest that next generation sequencing techniques have the potential to provide a fast and standardised screening of benthic biodiversity at large spatial and temporal scales.

  9. High levels of the extracellular matrix proteoglycan decorin are associated with inhibition of testicular function

    Science.gov (United States)

    Adam, Marion; Urbanski, Henryk F.; Garyfallou, Vasilios T.; Welsch, Ulrich; Köhn, Frank M.; Schwarzer, J. Ullrich; Strauss, Leena; Poutanen, Matti; Mayerhofer, Artur

    2011-01-01

    Decorin (DCN), a component of the extracellular matrix of the peritubular wall and the interstitial areas of the human testis, can interact with growth factor (GF) signaling, thereby blocking downstream actions of GFs. In the present study the expression and regulation of DCN using both human testes and two experimental animal models, namely the rhesus monkey and mouse, were examined. DCN protein was present in peritubular and interstitial areas of adult human and monkey testes, while it was almost undetectable in adult wild-type mice. Interestingly, the levels and sites of testicular DCN expression in the monkeys were inversely correlated with testicular maturation markers. A strong DCN expression associated with the abundant connective tissue of the interstitial areas in the postnatal through prepubertal phases was observed. In adult and old monkeys the DCN pattern was similar to the one in normal human testes, presenting strong expression at the peritubular region. In the testes of both infertile men and in a mouse model of inflammation associated infertility (aromatase-overexpressing transgenic mice), the fibrotic changes and increased numbers of Tumor necrosis factor (TNF)-α-producing immune cells were shown to be associated with increased production of DCN. Furthermore, studies with human testicular peritubular cells isolated from fibrotic testis indicated that TNF-α significantly increased DCN production. The data, thus, show that an increased DCN level is associated with impaired testicular function, supporting our hypothesis that DCN interferes with paracrine signaling of the testis in health and disease. PMID:22413766

  10. [Effects of the combination of angiotensin receptor blockers and thiazide diuretics on laboratory values (levels of serum potassium, sodium, and uric acid)].

    Science.gov (United States)

    Takahashi, Tatsuya; Teramachi, Hitomi; Tachi, Tomoya; Noguchi, Yoshihiro; Nagasawa, Hiroyuki; Mizui, Takashi; Goto, Chitoshi; Tsuchiya, Teruo

    2014-01-01

    The combination of angiotensin receptor blockers (ARB) and a thiazide diuretic (hereafter, ARB/diuretic) is expected to improve patient adherence and increase the therapeutic effects because of the lower number of pills that require to be administered. In addition, an ARB/diuretic combination alleviates hypokalemia that frequently develops in patients receiving thiazide diuretics. In this study, we used electronic medical records to investigate the laboratory values (serum levels of potassium, sodium, and uric acid) of 194 ambulatory and hospitalized patients at the Gifu Municipal Hospital who received ARB/diuretic combination therapy for the first time between February 2010 and September 2012. According to the grade of classification of low serum potassium and sodium levels, the serum potassium level in one patient was grade 3 and the serum sodium level in two patients was grade 3 after the initiation of ARB/diuretic combination therapy. After administration of ARB/diuretic combination therapy, two patients received potassium supplements because their serum potassium levels decreased below the reference value. Similarly, one patient received a sodium supplement because of a decrease in the sodium level below the reference value. Uric acid level increased above the reference value after administration of the ARB/diuretic combination therapy in one patient; thus, this patient received antihyperuricemic agents. Therefore, pharmacists must carefully monitor the serum levels of potassium, sodium, and uric acid, particularly in the first six months after the initiation of ARB/diuretic combination therapy.

  11. Acute dosing of latrepirdine (Dimebon™, a possible Alzheimer therapeutic, elevates extracellular amyloid-β levels in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Sano Mary

    2009-12-01

    Full Text Available Abstract Background Recent reports suggest that latrepirdine (Dimebon™, dimebolin, a retired Russian antihistamine, improves cognitive function in aged rodents and in patients with mild to moderate Alzheimer's disease (AD. However, the mechanism(s underlying this benefit remain elusive. AD is characterized by extracellular accumulation of the amyloid-β (Aβ peptide in the brain, and Aβ-lowering drugs are currently among the most popular anti-amyloid agents under development for the treatment of AD. In the current study, we assessed the effect of acute dosing of latrepirdine on levels of extracellular Aβ using in vitro and in vivo experimental systems. Results We evaluated extracellular levels of Aβ in three experimental systems, under basal conditions and after treatment with latrepirdine. Mouse N2a neuroblastoma cells overexpressing Swedish APP were incubated for 6 hr in the presence of either vehicle or vehicle + latrepirdine (500pM-5 μM. Synaptoneurosomes were isolated from TgCRND8 mutant APP-overexpressing transgenic mice and incubated for 0 to 10 min in the absence or presence of latrepirdine (1 μM or 10 μM. Drug-naïve Tg2576 Swedish mutant APP overexpressing transgenic mice received a single intraperitoneal injection of either vehicle or vehicle + latrepirdine (3.5 mg/kg. Picomolar to nanomolar concentrations of acutely administered latrepirdine increased the extracellular concentration of Aβ in the conditioned media from Swedish mutant APP-overexpressing N2a cells by up to 64% (p = 0.01, while a clinically relevant acute dose of latrepirdine administered i.p. led to an increase in the interstitial fluid of freely moving APP transgenic mice by up to 40% (p = 0.01. Reconstitution of membrane protein trafficking and processing is frequently inefficient, and, consistent with this interpretation, latrepirdine treatment of isolated TgCRND8 synaptoneurosomes involved higher concentrations of drug (1-10 μM and led to more modest

  12. Characterization of Intracellular and Extracellular Saxitoxin Levels in Both Field and Cultured Alexandrium spp. Samples from Sequim Bay, Washington

    Directory of Open Access Journals (Sweden)

    Vera L. Trainer

    2008-05-01

    Full Text Available Traditionally, harmful algal bloom studies have primarily focused on quantifying toxin levels contained within the phytoplankton cells of interest. In the case of paralytic shellfish poisoning toxins (PSTs, intracellular toxin levels and the effects of dietary consumption of toxic cells by planktivores have been well documented. However, little information is available regarding the levels of extracellular PSTs that may leak or be released into seawater from toxic cells during blooms. In order to fully evaluate the risks of harmful algal bloom toxins in the marine food web, it is necessary to understand all potential routes of exposure. In the present study, extracellular and intracellular PST levels were measured in field seawater samples (collected weekly from June to October 2004- 2007 and in Alexandrium spp. culture samples isolated from Sequim Bay, Washington. Measurable levels of intra- and extra-cellular toxins were detected in both field and culture samples via receptor binding assay (RBA and an enzyme-linked immunosorbent assay (ELISA. Characterization of the PST toxin profile in the Sequim Bay isolates by preMar. column oxidation and HPLC-fluorescence detection revealed that gonyautoxin 1 and 4 made up 65 ± 9.7 % of the total PSTs present. Collectively, these data confirm that extracellular PSTs are present during blooms of Alexandrium spp. in the Sequim Bay region.

  13. Effects of Altered Levels of Extracellular Superoxide Dismutase and Irradiation on Hippocampal Neurogenesis in Female Mice

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Yani [Department of Neurology and Neurological Sciences, Stanford University, Stanford, California (United States); Leu, David [Department of Neurology and Neurological Sciences, Stanford University, Stanford, California (United States); Palo Alto Institute of Research and Education, Palo Alto, California (United States); Chui, Jennifer [Department of Neurology and Neurological Sciences, Stanford University, Stanford, California (United States); Fike, John R. [Departments of Neurosurgery and Radiation Oncology, University of California, San Francisco, California (United States); Huang, Ting-Ting, E-mail: tthuang@stanford.edu [Department of Neurology and Neurological Sciences, Stanford University, Stanford, California (United States); VA Palo Alto Health Care System, Palo Alto, California (United States)

    2013-11-15

    Purpose: Altered levels of extracellular superoxide dismutase (EC-SOD) and cranial irradiation have been shown to affect hippocampal neurogenesis. However, previous studies were only conducted in male mice, and it was not clear if there was a difference between males and females. Therefore, female mice were studied and the results compared with those generated in male mice from an earlier study. Methods and Materials: Female wild-type, EC-SOD-null (KO), and EC-SOD bigenic mice with neuronal-specific expression of EC-SOD (OE) were subjected to a single dose of 5-Gy gamma rays to the head at 8 weeks of age. Progenitor cell proliferation, differentiation, and long-term survival of newborn neurons were determined. Results: Similar to results from male mice, EC-SOD deficiency and irradiation both resulted in significant reductions in mature newborn neurons in female mice. EC-SOD deficiency reduced long-term survival of newborn neurons whereas irradiation reduced progenitor cell proliferation. Overexpression of EC-SOD corrected the negative impacts from EC-SOD deficiency and irradiation and normalized the production of newborn neurons in OE mice. Expression of neurotrophic factors brain-derived neurotrophic factor and neurotrophin-3 were significantly reduced by irradiation in wild-type mice, but the levels were not changed in KO and OE mice even though both cohorts started out with a lower baseline level. Conclusion: In terms of hippocampal neurogenesis, EC-SOD deficiency and irradiation have the same overall effects in males and females at the age the studies were conducted.

  14. Deltorphin II enhances extracellular levels of dopamine in the nucleus accumbens via opioid receptor-independent mechanisms.

    NARCIS (Netherlands)

    Murakawa, K.; Hirose, N.; Takada, K.; Suzuki, T.; Nagase, H.; Cools, A.R.; Koshikawa, N.

    2004-01-01

    The effects of the delta2-opioid receptor agonist, deltorphin II, on extracellular levels of dopamine in the rat nucleus accumbens were investigated in awake animals by in vivo brain microdialysis. In agreement with previous studies, perfusion of deltorphin II (50.0 nmol) into the nucleus accumbens

  15. Effect of Different Levels of Potassium and Boron on Stress Physiology and Cell Wall Boron Content of Cotton Leaf

    OpenAIRE

    Wu, Xiu-Wen; HAO Yan-shu; Lei, Jing; JIANG Cun-cang

    2016-01-01

    To find out the effect of potassium(K) and boron(B) on cotton leaf cell membrane and B distribution and utilization, the membrane relative permeability, MDA, Pro, the content of free B, semi-bound B and bound B and the content of B in cell wall of cotton leaf were analyzed under different K levels with solution culture method in this study. The results showed that in normal K(20 mgK·L-1), B deficiency(0 mgB·L-1) hindered the normal growth and dry mass of shoots, in addition, the membrane rela...

  16. Effects of the 5-HT(4) receptor agonist RS67333 and paroxetine on hippocampal extracellular 5-HT levels

    DEFF Research Database (Denmark)

    Licht, Cecilie Löe; Knudsen, Gitte Moos; Sharp, Trevor

    2010-01-01

    The 5-HT(4) receptor modulates activity of serotonergic neurons and is a new potential target for antidepressant treatment. This microdialysis study evaluated the effect of the 5-HT(4) receptor agonist, RS67333, on extracellular serotonin (5-hydroxytryptamine, 5-HT) and 5-HIAA levels in rat ventral...... on extracellular 5-HT or 5-HIAA levels, while acute paroxetine (0.5mg/kg i.v.) increased 5-HT levels by 299+/-16% and decreased 5-HIAA levels by 25+/-4%. Administration of RS67333 80 min after paroxetine caused an additional transient increase in 5-HT levels (to 398+/-52% of baseline). Subchronic RS67333...... administration (1.5mg/kg i.p.) increased basal 5-HT levels by 73+/-15% and decreased 5-HIAA levels by 27+/-13%. In conclusion, the 5-HT(4) receptor agonist RS67333 augmented the acute effect of paroxetine on extracellular 5-HT levels in the ventral hippocampus, and after 3 days increased basal hippocampal 5-HT...

  17. Relations between slow extracellular potential changes, glial potassium buffering, and electrolyte and cellular volume changes during neuronal hyperactivity in cat brain.

    Science.gov (United States)

    Dietzel, I; Heinemann, U; Lux, H D

    1989-01-01

    The aim of this investigation is to estimate the contribution of spatial glial K+ buffer currents to extracellular K+ homeostasis during enhanced neuronal activity. Neuronal hyperactivity was induced by electrical stimulation of the cortical surface or the ventrobasal thalamic nuclei of cats (5-50 Hz, 0.1-0.2 ms, two to three times threshold stimulation intensity, 5-20 s). The accompanying slow field potential changes were recorded simultaneously across the grey matter with vertical assemblies of eight micropipettes glued 300 microns apart. Using the Poisson equation, the amplitudes of the underlying current sources and sinks were calculated. The current source densities depended on the depth of recording, frequency, strength, and duration of the stimulation. Current sinks, corresponding to a removal of 0.1-0.5 mmoles of monovalent cations per liter of brain tissue and second from the extracellular space, were observed in middle cortical layers, whereas sources appeared at superficial and deeper sites. These sinks and sources might represent K+ moved across glial membranes by spatial buffer currents. The consequences of glial buffer currents of this magnitude were investigated with model calculations. It turned out that measurements of electrolyte and volume changes of the extracellular space (Dietzel et al. Exp. Brain Res. 40:432-439, 1980; Exp. Brain Res. 46:73-84, 1982) could only partially be explained by spatial buffer currents of this magnitude. Comparison of the calculated values with intracellular measurements in neurons and glial cells (Coles et al. Ann. N.Y. Acad. Sci. 481:303-317, 1986; Ballanyi et al. J. Physiol. 382:159-174, 1987) suggests that spatial buffering combines with an approximately equimolar KCl transport and, depending on the preparation, also K+/Na+-exchange across glial membranes.

  18. The association between normal-range admission potassium levels in Israeli patients with acute coronary syndrome and early and late outcomes.

    Science.gov (United States)

    Shlomai, Gadi; Berkovitch, Anat; Pinchevski-Kadir, Shiran; Bornstein, Gil; Leibowitz, Avshalom; Goldenberg, Ilan; Grossman, Ehud

    2016-06-01

    Abnormal serum potassium levels are associated with an increased risk of ventricular arrhythmias and mortality in patients with acute myocardial infarction (AMI). The aim of the present study was to evaluate whether different levels of serum potassium, within the normal range, are associated with worse outcomes. The present study comprised 1277 patients with AMI and normal-range admission potassium levels (3.5-5.2 mEq/L), who were enrolled and prospectively followed up in the Acute Coronary Syndrome Israeli Survey between 2010 and 2013. Patients were divided into 4 quartiles based on admission potassium levels; "normal-low" (K ≥ 3.5 and K ≤ 3.9), "normal-moderate" (K > 3.9 and K ≤ 4.18), "normal-high" (K > 4.18 and K ≤ 4.45), and "normal-very high" (K > 4.45 and K ≤ 5.2). We analyzed the association between admission serum potassium levels and 7 days in-hospital complication rates, and 30-day and 1-year all-cause mortality rates. Patients with "normal-very high" potassium displayed increased frequency of baseline clinical risk factors and experienced a higher rate of acute kidney injury during hospitalization compared with the "normal-low" group (7.7% vs 2.4%; P = 0.002). However, the rate of in-hospital ventricular arrhythmias was similar across the range of admission potassium levels (overall P = 0.26), Multivariate analysis showed that compared with "low-normal" potassium values, patients with "normal-very high" potassium levels experienced increased risk for 30-days (adjusted hazard ratio 2.88, 95% confidence interval 1.05-7.87, P = 0.039) and 1-year all-cause mortality (adjusted hazard ratio 1.98, 95% confidence interval 1.05-3.75, P = 0.034). In patients admitted with AMI, admission serum potassium levels of 4.45 to 5.2 mEq/L are not associated with in-hospital ventricular arrhythmias, but are associated with increased short and long-term mortality.

  19. Effect of copper on extracellular levels of key pro-inflammatory molecules in hypothalamic GN11 and primary neurons.

    Science.gov (United States)

    Spisni, Enzo; Valerii, Maria Chiara; Manerba, Marcella; Strillacci, Antonio; Polazzi, Elisabetta; Mattia, Toni; Griffoni, Cristiana; Tomasi, Vittorio

    2009-07-01

    Copper dyshomeostasis is responsible for the neurological symptoms observed in the genetically inherited copper-dependent disorders (e.g., Menkes' and Wilson's diseases), but it has been also shown to have an important role in neurodegenerative diseases such as Alzheimer disease, prion diseases, Parkinson's disease and amyotrophic lateral sclerosis. It is widely accepted that increased extracellular copper levels contribute to neuronal pathogenic process by increasing the production of dangerous radical oxygen species, but the existence of other molecular mechanisms explaining copper neurotoxicity has not been investigated yet. By using a cellular model based on hypothalamic GN11 cultured neurons exposed to copper supplementation and by analysing the cell conditioned media, we try here to identify new molecular events explaining the association between extracellular copper accumulation and neuronal damages. We show here that increased extracellular copper levels produce a wide complex of alterations in the neuronal extracellular environment. In particular, copper affects the secretion of molecules involved in the protection of neurons against oxidative stress, such as cyclophilin A (CypA), or of molecules capable of shifting neuronal cells towards a pro-inflammatory state, such as IL-1alpha, IL-12, Rantes, neutrophil gelatinase-associated lipocalin (NGAL) and secreted protein acidic and rich in cysteine (SPARC). Copper pro-inflammatory properties have been confirmed by using primary neurons.

  20. Residual production of pineapple biomass under different levels of nitrogen and potassium in northwestern Paraná

    Directory of Open Access Journals (Sweden)

    Maria Elisa Vicentini

    2015-12-01

    Full Text Available Emphasis on studies that seek sustainable energy alternatives to oil has increased over the last few years. Ethanol derived from sugarcane remains a promising technology for biofuel production. Waste from pineapple culture remains is a potential alternative raw material for biofuel production. The goal of this study was to determine the potential of residual biomass production of a pineapple crop, subjected to fertilization by different levels of nitrogen and potassium. The experiment was conducted in Northwest Paraná, in a commercial area in Santa Isabel do Ivaí-PR. The climate in this area is subtropical humid according to the Köppen classification, and has a sandy dystrophic red acrisol.The experimental design was a 4 × 4 factorial, where factor A:N doses (0; 11; 22; and 33 g per plant and factor B:K2O doses (0; 11; 22; and 33 g per plant. The production of residual pineapple biomass responded differently to the N and K doses applied. Potassium fertilization had a positive linear correlation, up to the addition of 33 g plant-1 with a production of 5.88 Mg ha-1. A dose of 18.138 g plant-1 yielded in the maximum dry biomass production for nitrogen fertilization.

  1. Potassium Iodide

    Science.gov (United States)

    Potassium iodide is used to protect the thyroid gland from taking in radioactive iodine that may be released ... damage the thyroid gland. You should only take potassium iodide if there is a nuclear radiation emergency and ...

  2. Extracellular-purine metabolism in blood vessels (part I). Extracellular-purine level in blood of patients with abdominal aortic aneurysm.

    Science.gov (United States)

    Lecka, Joanna; Molski, Stanislaw; Komoszynski, Michal

    2010-09-01

    Adenosine and adenosine derivatives are the main regulators of purinoceptors (P1 and P2) mediated hemostasis and blood pressure. Since impaired hemostasis and high blood pressure lead to atherosclerosis and to the development of aneurysm, in this study we tested and compared the concentration of extracellular purines (e-purines) in the blood in of patients having abdominal aortic aneurysm with that from healthy volunteers. Whereas adenine nucleosides and nucleotides level in human blood plasma was analysed using reverse phase high performance liquid chromatography (HPLC), cholesterol concentration was estimated by an enzymatic assay. We did not find any correlation between e-purines concentration and the age of healthy volunteers. Furthermore, the sum level of e-purines (ATP, ADP, AMP, adenosine, and inosine) in the control group did not exceed 70 microM, while it was nearly two-fold higher in the blood of patients having abdominal aortic aneurysm, (123 microM). In a special case of people with Leriche Syndrome, a disease characterized by deep atherosclerotic changes, the e-purines level had further increased. Additionally, we also report typical atherosclerotic changes in the aorta using histological assays as well as total cholesterol rise. The significant rise in cholesterol concentration in the blood of the patients with abdominal aortas aneurysm, compared with the control groups, was not unique since 23% of the healthy people also exceeded the normal level of cholesterol. Therefore, our results strongly indicate that the estimation of e-purines concentration in the blood may serve as another indicator of atherosclerosis and warrant further consideration as a futuristic diagnostic tool.

  3. Morphine decreases extracellular levels of glutamate in the anterior cingulate cortex: an in vivo microdialysis study in freely moving rats

    Institute of Scientific and Technical Information of China (English)

    YueHAO; Jing-yuYANG; MingGUO; Chun-fuWU; Ming-fanWU

    2004-01-01

    AIM: The anterior cingulate cortex (ACC), an important region of prefrontal cortex for cognitive functions, has been implicated in drug abuse and addiction. In the present study, we intended to investigate the effect of morphine on the extracellular levels of glutamate in the ACC in freely moving rats. METHODS: In vivo microdialysis coupled to high performance liquid chromatography and electrochemical detection had been used for the

  4. Association of Levels of Antibodies from Patients with Inflammatory Bowel Disease with Extracellular Proteins of Food and Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Arancha Hevia

    2014-01-01

    Full Text Available Inflammatory bowel disease (IBD is an autoimmune disease characterized by a chronic inflammation of the gastrointestinal tract mucosa and is related to an abnormal immune response to commensal bacteria. Our aim of the present work has been to explore the levels of antibodies (IgG and IgA raised against extracellular proteins produced by LAB and its association with IBD. We analyzed, by Western-blot and ELISA, the presence of serum antibodies (IgA and IgG developed against extracellular protein fractions produced by different food bacteria from the genera Bifidobacterium and Lactobacillus. We used a sera collection consisting of healthy individuals (HC, n=50, Crohn's disease patients (CD, n=37, and ulcerative colitis patients (UC, n=15. Levels of IgA antibodies developed against a cell-wall hydrolase from Lactobacillus casei subsp. rhamnosus GG (CWH were significantly higher in the IBD group (P<0.002; n=52. The specificity of our measurements was confirmed by measuring IgA antibodies developed against the CWH peptide 365-VNTSNQTAAVSAS-377. IBD patients appeared to have different immune response to food bacteria. This paper sets the basis for developing systems for early detection of IBD, based on the association of high levels of antibodies developed against extracellular proteins from food and probiotic bacteria.

  5. Extracellular matrix protein fibulin-1 plasma levels are associated with increased cardiovascular risk in chronic kidney disease

    DEFF Research Database (Denmark)

    Scholze, Alexandra

    INTRODUCTION AND AIMS: Fibulin-1 is one of the 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 in patients with chronic kidney disease. METHODS: Plasma fibulin-1...... of plasma fibulin-1. CONCLUSIONS: Increased plasma fibulin-1 levels were associated with impaired kidney function and diabetes. Fibulin-1 levels were also associated with hemodynamic cardiovascular risk markers. We conclude, that fibulin-1 is involved in the pathogenesis of cardiovascular disease observed...

  6. Comparative effects of parathion and chlorpyrifos on extracellular endocannabinoid levels in rat hippocampus: Influence on cholinergic toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jing [Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK (United States); Parsons, Loren [Committee on Neurobiology of Affective Disorders, The Scripps Research Institute, La Jolla, CA (United States); Pope, Carey, E-mail: carey.pope@okstate.edu [Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK (United States)

    2013-11-01

    Parathion (PS) and chlorpyrifos (CPF) are organophosphorus insecticides (OPs) that elicit acute toxicity by inhibiting acetylcholinesterase (AChE). Endocannabinoids (eCBs, N-arachidonoylethanolamine, AEA; 2-arachidonoylglycerol, 2AG) can modulate neurotransmission by inhibiting neurotransmitter release. We proposed that differential inhibition of eCB-degrading enzymes (fatty acid amide hydrolase, FAAH, and monoacylglycerol lipase, MAGL) by PS and CPF leads to differences in extracellular eCB levels and toxicity. Microdialysis cannulae were implanted into hippocampus of adult male rats followed by treatment with vehicle (peanut oil, 2 ml/kg, sc), PS (27 mg/kg) or CPF (280 mg/kg) 6–7 days later. Signs of toxicity, AChE, FAAH and MAGL inhibition, and extracellular levels of AEA and 2AG were measured 2 and 4 days later. Signs were noted in PS-treated rats but not in controls or CPF-treated rats. Cholinesterase inhibition was extensive in hippocampus with PS (89–90%) and CPF (78–83%) exposure. FAAH activity was also markedly reduced (88–91%) by both OPs at both time-points. MAGL was inhibited by both OPs but to a lesser degree (35–50%). Increases in extracellular AEA levels were noted after either PS (about 2-fold) or CPF (about 3-fold) while lesser treatment-related 2-AG changes were noted. The cannabinoid CB1 receptor antagonist/inverse agonist AM251 (3 mg/kg, ip) had no influence on functional signs after CPF but markedly decreased toxicity in PS-treated rats. The results suggest that extracellular eCBs levels can be markedly elevated by both PS and CPF. CB1-mediated signaling appears to play a role in the acute toxicity of PS but the role of eCBs in CPF toxicity remains unclear. - Highlights: • Chlorpyrifos and parathion both extensively inhibited hippocampal cholinesterase. • Functional signs were only noted with parathion. • Chlorpyrifos and parathion increased hippocampal extracellular anandamide levels. • 2-Arachidonoylglycerol levels were

  7. EVALUATION OF TRACHEAL INTUBATING CONDITIONS AND SERUM POTASSIUM LEVELS WITH DIFFERENT DOSES OF SUCCINYLCHOLINE : A PROSPECTIVE RANDOMIZED COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    Shravan Kumar

    2015-08-01

    Full Text Available BACKGROUND: Utility of succinylcholine for rapid sequence induction is a common practice for more than last 50 years. The ED 95 dose of succinylcholine is 0.3mg/kg. Regularly 2 - 3 times ED 95 doses of non - depolarizing muscle relaxants are being used for tracheal intubation, but succinylcholine is being used traditionally in a dose of 1mg/kg which is more than 3.5 times ED 95. However, according to the available literature evidence doses as smal l as 0.4 mg /kg may also provide clinically acceptable intubating conditions with the possibility of earlier return of neuromuscular function which avoids critical hemoglobin desaturation in unanticipated difficult airway& CVCI situations. We did a study to evaluate the ease of tracheal intubation with low doses of succinylcholine in Indian population. AIM: To evaluate tracheal intubating conditions and serum potassium levels with different doses of succinylcholine. DESIGN: A prospective randomized double bli nd comparative study. METHODS: 80 patients belonging to ASA PS I&II were randomly divided into 4 groups A,B,C&D who received 0.5mg/kg,0.6mg/kg,0.7mg/kg& 1mg/kg of succinylcholine respectively. All the patients were pre - medicated with Tab. Alprazolam 0.25 mg PO previous night and fentanyl 1mcg/kg 5 min before induction, induced with sleep dose of thiopentone followed by administration of test drug. After 1 min , 3yrs experienced anesthesiologist attempted tracheal intubation& assessment of intubating conditions w ere done using Cooper& colleagues criteria. N - M effects were monitored preoperatively and up to 3 min after dug administration. Haemodynamic parameters& serum potassium were measured preoperatively , continued up to 5 min & 1 hour after drug administration res pectively. RESULTS: Clinical intubation cumulative scores in GROUP A were significantly different from other GROUPS ( B, C, D with ( p<0.05 on ANOVA. N - M monitoring has revealed significant twitch height depression in Group D

  8. Increased extracellular dopamine and 5-hydroxytryptamine levels contribute to enhanced subthalamic nucleus neural activity during exhausting exercise

    Directory of Open Access Journals (Sweden)

    Y Hu

    2015-09-01

    Full Text Available The purpose of the study was to explore the mechanism underlying the enhanced subthalamic nucleus (STN neural activity during exhausting exercise from the perspective of monoamine neurotransmitters and changes of their corresponding receptors. Rats were randomly divided into microdialysis and immunohistochemistry study groups. For microdialysis study, extracellular fluid of the STN was continuously collected with a microdialysis probe before, during and 90 min after one bout of exhausting exercise. Dopamine (DA and 5-hydroxytryptamine (5-HT levels were subsequently detected with high-performance liquid chromatography (HPLC. For immunohistochemistry study, the expression of DRD 2 and HT 2C receptors in the STN, before, immediately after and 90 min after exhaustion was detected through immunohistochemistry technique. Microdialysis study results showed that the extracellular DA and 5-HT neurotransmitters increased significantly throughout the procedure of exhausting exercise and the recovery period (P0.05. Our results suggest that the increased extracellular DA and 5-HT in the STN might be one important factor leading to the enhanced STN neural activity and the development of fatigue during exhausting exercise. This study may essentially offer useful evidence for better understanding of the mechanism of the central type of exercise-induced fatigue.

  9. Ascorbate reduces morphine-induced extracellular DOPAC level in the nucleus accumbens: A microdialysis study in rats.

    Science.gov (United States)

    Rajaei, Z; Alaei, H; Nasimi, A; Amini, H; Ahmadiani, A

    2005-08-16

    Most drugs of abuse increase dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) release in the shell of the nucleus accumbens. The effects of ascorbate, which is known to modulate dopamine neurotransmission, on the extracellular level of DOPAC in the nucleus accumbens of naive rats and of rats treated acutely with morphine were studied by using in vivo microdialysis and high performance liquid chromatography with electrochemical detection (HPLC-ECD). Acute morphine (20 mg/kg ip) treatment increased the level of DOPAC in the nucleus accumbens to approximately 170% of basal level. Acute treatment with ascorbate (500 mg/kg ip) alone did not alter nucleus accumbens' DOPAC level, but pretreatment with ascorbate (500 mg/kg ip) 30 min before morphine administration attenuated the effects of acute morphine on the level of DOPAC. These results suggest that ascorbate modulates the mesolimbic dopaminergic pathway.

  10. Trichomonas vaginalis NTPDase and ecto-5'-nucleotidase hydrolyze guanine nucleotides and increase extracellular guanosine levels under serum restriction.

    Science.gov (United States)

    Menezes, Camila Braz; Durgante, Juliano; de Oliveira, Rafael Rodrigues; Dos Santos, Victor Hugo Jacks Mendes; Rodrigues, Luiz Frederico; Garcia, Solange Cristina; Dos Santos, Odelta; Tasca, Tiana

    2016-05-01

    Trichomonas vaginalis is the aethiologic agent of trichomoniasis, the most common non-viral sexually transmitted disease in the world. The purinergic signaling pathway is mediated by extracellular nucleotides and nucleosides that are involved in many biological effects as neurotransmission, immunomodulation and inflammation. Extracellular nucleotides can be hydrolyzed by a family of enzymes known as ectonucleotidases including the ecto-nucleoside triphosphate diphosphohydrolases (E-NTPDases) family which hydrolyses nucleosides triphosphate and diphosphate as preferential substrates and ecto-5'-nucleotidase which catalyzes the conversion of monophosphates into nucleosides. In T. vaginalis the E-NTPDase and ecto-5'-nucleotidase activities upon adenine nucleotides have already been characterized in intact trophozoites but little is known concerning guanine nucleotides and nucleoside. These enzymes may exert a crucial role on nucleoside generation, providing the purine sources for the synthesis de novo of these essential nutrients, sustaining parasite growth and survival. In this study, we investigated the hydrolysis profile of guanine-related nucleotides and nucleoside in intact trophozoites from long-term-grown and fresh clinical isolates of T. vaginalis. Knowing that guanine nucleotides are also substrates for T. vaginalis ectoenzymes, we evaluated the profile of nucleotides consumption and guanosine uptake in trophozoites submitted to a serum limitation condition. Results show that guanine nucleotides (GTP, GDP, GMP) were substrates for T. vaginalis ectonucleotidases, with expected kinetic parameters for this enzyme family. Different T. vaginalis isolates (two from the ATCC and nine fresh clinical isolates) presented a heterogeneous hydrolysis profile. The serum culture condition increased E-NTPDase and ecto-5'-nucleotidase activities with high consumption of extracellular GTP generating enhanced GDP, GMP and guanosine levels as demonstrated by HPLC, with final

  11. Modulation of memory with septal injections of morphine and glucose: effects on extracellular glucose levels in the hippocampus.

    Science.gov (United States)

    McNay, Ewan C; Canal, Clinton E; Sherwin, Robert S; Gold, Paul E

    2006-02-28

    The concentration of glucose in the extracellular fluid (ECF) of the hippocampus decreases substantially during memory testing on a hippocampus-dependent memory task. Administration of exogenous glucose, which enhances task performance, prevents this decrease, suggesting a relationship between hippocampal glucose availability and memory performance. In the present experiment, spontaneous alternation performance and task-related changes in hippocampal ECF glucose were assessed in rats after intraseptal administration of morphine, which impairs memory on a spontaneous alternation task, and after co-administration of intraseptal glucose, which attenuates that impairment. Consistent with previous findings, spontaneous alternation testing resulted in a decrease in hippocampal ECF glucose levels in control rats. However, rats that received intraseptal morphine prior to testing showed memory impairments and an absence of the task-related decrease in hippocampal ECF glucose levels. Intraseptal co-administration of glucose with morphine attenuated the memory impairment, and ECF glucose levels in the hippocampus decreased in a manner comparable to that seen in control rats. These data suggest that fluctuations in hippocampal ECF glucose levels may be a marker of mnemonic processing and support the view that decreases in extracellular glucose during memory testing reflect increased glucose demand during memory processing.

  12. High-level extracellular production and characterization of Candida antarctica lipase B in Pichia pastoris.

    Science.gov (United States)

    Eom, Gyeong Tae; Lee, Seung Hwan; Song, Bong Keun; Chung, Keun-Wo; Kim, Young-Wun; Song, Jae Kwang

    2013-08-01

    The gene encoding lipase B from Candida antarctica (CalB) was expressed in Pichia pastoris after it was synthesized by the recursive PCR and cloned into the Pichia expression plasmid, pPICZαA. The CalB was successfully secreted in the recombinant P. pastoris strain X-33 with an apparent molecular weight of 34 kDa. For 140 h flask culture, the dry cell weight and the extracellular lipase activity reached at 5.4 g/l and 57.9 U/l toward p-nitrophenyl palmitate, respectively. When we performed the fed-batch fermentation using a methanol feeding strategy for 110 h, the dry cell weight and the extracellular lipase activity were increased to 135.7 g/l and 11,900 U/l; the CalB protein concentration was 1.18 g/l of culture supernatant. The characteristics of CalB recovered from the P. pastoris culture were compared with the commercial form of CalB produced in Aspergillus oryzae. The kinetic constants and specific activity, the effects of activity and stability on temperature and pH, the glycosylation extent, the degree of immobilization on macroporous resin and the yield of esterification reaction between oleic acid and n-butanol were almost identical to each other. Therefore, we successfully proved that the Pichia-based expression system for CalB in this study was industrially promising compared with one of the most efficient production systems.

  13. A Model to Determine the Level of Serum Aldosterone in the Workers Attributed to the Combined Effects of Sound Pressure Level, Exposure Time and Serum Potassium Level: A Field-Based Study

    Directory of Open Access Journals (Sweden)

    Parvin Nassiri

    2016-09-01

    Full Text Available Background Occupational exposure to excessive noise is one of the biggest work-related challenges in the world. This phenomenon causes the release of stress-related hormones, which in turn, negatively affects cardiovascular risk factors. Objectives The current study study aimed to determine the level of workers’ serum aldosterone in light of the combined effect of sound pressure level, exposure time and serum potassium level. Methods This cross-sectional, descriptive, analytical study was conducted on 45 workers of Gol-Gohar Mining and Industrial Company in the fall of 2014. The subjects were divided into three groups (one control and two case groups, each including 15 workers. Participants in the control group were selected from workers with administrative jobs (exposure to the background noise. On the other hand, participants in the case groups were selected from the concentrator and pelletizing factories exposed to excessive noise. Serum aldosterone and potassium levels of participants were assessed at three different time intervals: at the beginning of the shift and before exposure to noise (7:30 - 8:00 AM, during exposure to noise (10:00 - 10:30 AM, and during continuous exposure (1:30 - 2:00 PM. The obtained data were transferred into SPSS ver. 18. Repeated measures analysis of variance (ANOVA was used to develop the statistical model of workers’ aldosterone level in light of the combined effect of sound pressure level, exposure time, and serum potassium level. Results The results of the final statistical model to determine the level of serum aldosterone based on the combined effect of sound pressure level, exposure time and serum potassium level indicated that the sound pressure level had a significant influence on the human’s serum aldosterone level (P = 0.04. In addition, the effects of exposure time and serum potassium on aldosterone level were statistically significant with P-values of 0.008 and 0.001, respectively. Conclusions

  14. Postmortem vitreous chemistry--an evaluation of sodium, potassium and chloride levels in estimation of time since death (during the first 36 h after death).

    Science.gov (United States)

    Chandrakanth, H V; Kanchan, Tanuj; Balaraj, B M; Virupaksha, H S; Chandrashekar, T N

    2013-05-01

    Estimation of time since death is a paramount medico-legal issue in any postmortem examination. The present study is intended to study the correlation between postmortem interval and vitreous humor chemistry for sodium, potassium, and chlorides. The study is aimed to find male-female differences and differences between right and left eyes in vitreous chemistry. The vitreous humor samples were collected in 114 autopsies conducted in the study center and analyzed biochemically. All the cases where exact time of death was known and where the time since death ranged between 0 and 36 h were included in the study. Data obtained was analyzed statistically using spss version 11.0. The present research did not find a significant correlation between vitreous chemistry and postmortem interval. The differences in vitreous sodium, potassium, chloride levels and the sodium potassium ratio among males and females and between right and left eyes were not found to be statistically significant.

  15. The effects of LPM570065, a novel triple reuptake inhibitor, on extracellular serotonin, dopamine and norepinephrine levels in rats.

    Directory of Open Access Journals (Sweden)

    Renyu Zhang

    Full Text Available Triple reuptake inhibitors (TRIs are currently being developed as a new class of promising antidepressants that block serotonin (5-HT, dopamine (DA and norepinephrine (NE transporters, thereby increasing extracellular monoamine concentrations. The purpose of this study was to investigate the effects of LPM570065, a novel TRI and a desvenlafaxine prodrug, on extracellular 5-HT, DA and NE levels in the rat striatum after acute and chronic administration relative to desvenlafaxine, using High Performance Liquid Chromatography (HPLC and microdialysis. Acute administration was performed by providing rodents with oral solutions (0.06 mmol·kg(-1 p.o., oral suspensions (0.06 mmol·kg(-1 p.o. and intravenous solutions (0.04 mmol·kg(-1 i.v. of LPM570065 and desvenlafaxine. Oral suspensions (0.06 mmol·kg(-1·day(-1 of the two drugs were also administered for a 14-day chronic period. HPLC analysis revealed that LPM570065 rapidly penetrated the rat striatum, converted into desvenlafaxine and exhibited larger total exposure compared with the administration of desvenlafaxine. Microdialysis revealed that acute and chronic administration of oral suspension of LPM570065 increased the 5-HT, DA and NE levels more than the relative administration of desvenlafaxine. Unlike desvenlafaxine, acute administration of an intravenous LPM570065 solution did not induce the undesirable 90% decrease in extracellular 5-HT levels. In contrast to the fully dose-dependent elevation of 5-HT induced by desvenlafaxine, the acute administration of LPM570065 showed a capped increase in extracellular 5-HT levels when combined with WAY-100635. Additionally, forced swim test demonstrated that acute and chronic administration of LPM570065 reduced the immobility time more than the relative administration of desvenlafaxine. These data suggest that LPM570065 may have greater efficacy and/or a more rapid onset of antidepressant action than desvenlafaxine and also counterbalance the harmful

  16. Light Absorption and Carotenoid Synthesis of Pot Marigold (Calendula officinalis L. in Response to Phosphorous and Potassium Varying Levels

    Directory of Open Access Journals (Sweden)

    Mohammad SEDGHI

    2011-03-01

    Full Text Available In order to provide additional information on the effects of elemental deficiency on factors that affect plant production in medicinal plants, a factorial field experiment as randomized complete block design was conducted on Calendula officinalis. Treatments were four phosphorus levels (P2O5 including 0, 40, 80 and 120 Kg ha-1 and four potassium levels (K2O as 0, 50, 100 and 150 Kg ha-1. Results showed that applied treatments had significant effects on petal carotenoids and the highest amount of ? - carotene obtained at 80 and 150 Kg ha-1 P2O5 and K2O, respectively. Effect of K2O on light interception and light use efficiency was significant and the highest radiation use efficiency achieved by applying 150 Kg ha-1 K2O. The highest yield of grain and dry flowers was recorded in the mixture of 80 and 150 Kg ha-1 P2O5 and K2O, respectively. In conclusion, using of K2O had greater effects on studied traits than P2O5.

  17. Local Control of Extracellular Dopamine Levels in the Medial Nucleus Accumbens by a Glutamatergic Projection from the Infralimbic Cortex.

    Science.gov (United States)

    Quiroz, César; Orrú, Marco; Rea, William; Ciudad-Roberts, Andrés; Yepes, Gabriel; Britt, Jonathan P; Ferré, Sergi

    2016-01-20

    It is generally assumed that infralimbic cortex (ILC) and prelimbic cortex, two adjacent areas of the medial prefrontal cortex (mPFC) in rodents, provide selective excitatory glutamatergic inputs to the nucleus accumbens (NAc) shell and core, respectively. It is also generally believed that mPFC influences the extracellular levels of dopamine in the NAc primarily by an excitatory collateral to the ventral tegmental area (VTA). In the present study, we first established the existence of a selective functional connection between ILC and the posteromedial portions of the VTA (pmVTA) and the mNAc shell (pmNAc shell), by measuring striatal neuronal activation (immunohistochemical analysis of ERK1/2 phosphorylation) and glutamate release (in vivo microdialysis) upon ILC electrical stimulation. A novel optogenetic-microdialysis approach allowed the measurement of extracellular concentrations of glutamate and dopamine in the pmNAc shell upon local light-induced stimulation of glutamatergic terminals from ILC. Cortical electrical and local optogenetic stimulation produced significant increases in the extracellular concentrations of glutamate and dopamine in the pmNAc shell. Local blockade of glutamate release by perfusion of an adenosine A2A receptor antagonist in the pmNAc shell blocked the dopamine release induced by local optogenetic stimulation but only partially antagonized dopamine release induced by cortical electrical stimulation. The results demonstrate that ILC excitatory afferents directly modulate the extracellular concentration of dopamine in the pmNAc shell, but also support the involvement of an indirect mechanism of dopamine control, through a concomitant ILC-mediated activation of the pmVTA. Significance statement: We established the existence of a functional connection between the infralimbic cortex (ILC) and the posteromedial portions of the ventral tegmental area (pmVTA) and the medial nucleus acumbens shell (pmNAc shell). A novel optogenetic

  18. The astrocyte-derived alpha7 nicotinic receptor antagonist kynurenic acid controls extracellular glutamate levels in the prefrontal cortex.

    Science.gov (United States)

    Wu, Hui-Qiu; Pereira, Edna F R; Bruno, John P; Pellicciari, Roberto; Albuquerque, Edson X; Schwarcz, Robert

    2010-01-01

    The cognitive deficits seen in schizophrenia patients are likely related to abnormal glutamatergic and cholinergic neurotransmission in the prefrontal cortex. We hypothesized that these impairments may be secondary to increased levels of the astrocyte-derived metabolite kynurenic acid (KYNA), which inhibits alpha7 nicotinic acetylcholine receptors (alpha7AChR) and may thereby reduce glutamate release. Using in vivo microdialysis in unanesthetized rats, we show here that nanomolar concentrations of KYNA, infused directly or produced in situ from its bioprecursor kynurenine, significantly decrease extracellular glutamate levels in the prefrontal cortex. This effect was prevented by the systemic administration of galantamine (3 mg/kg) but not by donepezil (2 mg/kg), indicating that KYNA blocks the allosteric potentiating site of the alpha7AChR, which recognizes galantamine but not donepezil as an agonist. In separate rats, reduction of prefrontal KYNA formation by (S)-4-ethylsulfonyl benzoylalanine, a specific inhibitor of KYNA synthesis, caused a significant elevation in extracellular glutamate levels. Jointly, our results demonstrate that fluctuations in endogenous KYNA formation bidirectionally influence cortical glutamate concentrations. These findings suggest that selective attenuation of cerebral KYNA production, by increasing glutamatergic tone, might improve cognitive function in individuals with schizophrenia.

  19. Highly improved hydration level sensing properties of copper oxide films with sodium and potassium doping

    Science.gov (United States)

    Sahin, Bünyamin; Kaya, Tolga

    2016-01-01

    In this study, un-doped, Na-doped, and K-doped nanostructured CuO films were successfully synthesized by the successive ionic layer adsorption and reaction (SILAR) technique and then characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and current-voltage (I-V) measurements. Structural properties of the CuO films were affected from doping. The XRD pattern indicates the formation of polycrystalline CuO films with no secondary phases. Furthermore, doping affected the crystal structure of the samples. The optimum conductivity values for both Na and K were obtained at 4 M% doping concentrations. The comparative hydration level sensing properties of the un-doped, Na-doped, and K-doped CuO nanoparticles were also investigated. A significant enhancement in hydration level sensing properties was observed for both 4 M% Na and K-doped CuO films for all concentration levels. Detailed discussions were reported in the study regarding atomic radii, crystalline structure, and conductivity.

  20. Increased Obesity-Associated Circulating Levels of the Extracellular Matrix Proteins Osteopontin, Chitinase-3 Like-1 and Tenascin C Are Associated with Colon Cancer

    National Research Council Canada - National Science Library

    Catalán, Victoria; Gómez-Ambrosi, Javier; Rodríguez, Amaia; Ramírez, Beatriz; Izaguirre, Maitane; Hernández-Lizoain, José Luis; Baixauli, Jorge; Martí, Pablo; Valentí, Víctor; Moncada, Rafael; Silva, Camilo; Salvador, Javier; Frühbeck, Gema

    2016-01-01

    ...) remodeling being proposed as plausible mechanisms. The aim of this study was to investigate whether obesity can influence circulating levels of inflammation-related extracellular matrix proteins in patients with colon cancer (CC...

  1. Increasing extracellular matrix collagen level and MMP activity induces cyst development in polycystic kidney disease

    Directory of Open Access Journals (Sweden)

    Liu Bin

    2012-09-01

    Full Text Available Abstract Background Polycystic Kidney Disease (PKD kidneys exhibit increased extracellular matrix (ECM collagen expression and metalloproteinases (MMPs activity. We investigated the role of these increases on cystic disease progression in PKD kidneys. Methods We examined the role of type I collagen (collagen I and membrane bound type 1 MMP (MT1-MMP on cyst development using both in vitro 3 dimensional (3D collagen gel culture and in vivo PCK rat model of PKD. Results We found that collagen concentration is critical in controlling the morphogenesis of MDCK cells cultured in 3D gels. MDCK cells did not form 3D structures at collagen I concentrations lower than 1 mg/ml but began forming tubules when the concentration reaches 1 mg/ml. Significantly, these cells began to form cyst when collagen I concentration reached to 1.2 mg/ml, and the ratios of cyst to tubule structures increased as the collagen I concentration increased. These cells exclusively formed cyst structures at a collagen I concentration of 1.8 mg/ml or higher. Overexpression of MT1-MMP in MDCK cells significantly induced cyst growth in 3D collagen gel culture. Conversely, inhibition of MMPs activity with doxycycline, a FDA approved pan-MMPs inhibitor, dramatically slowed cyst growth. More importantly, the treatment of PCK rats with doxycycline significantly decreased renal tubule cell proliferation and markedly inhibited the cystic disease progression. Conclusions Our data suggest that increased collagen expression and MMP activity in PKD kidneys may induce cyst formation and expansion. Our findings also suggest that MMPs may serve as a therapeutic target for the treatment of human PKD.

  2. Effect of Different Levels of Potassium and Boron on Stress Physiology and Cell Wall Boron Content of Cotton Leaf

    Directory of Open Access Journals (Sweden)

    WU Xiu-wen

    2016-01-01

    Full Text Available To find out the effect of potassium(K and boron(B on cotton leaf cell membrane and B distribution and utilization, the membrane relative permeability, MDA, Pro, the content of free B, semi-bound B and bound B and the content of B in cell wall of cotton leaf were analyzed under different K levels with solution culture method in this study. The results showed that in normal K(20 mgK·L-1, B deficiency(0 mgB·L-1 hindered the normal growth and dry mass of shoots, in addition, the membrane relative permeability, the content of MDA and Pro significantly increased compared with the normal B(0.2 mgB·L-1, and the relative concentration of bound B, R value, cell wall material and the ratio of total cell wall B/leaf B increased by 10.32%, 21.28%, 31.35% and 31.35%, respectively. In contrast, under low K(2 mgK·L-1 supply, B deficiency produced a very significant decrease in the relative concentration of bound B and the ratio of total cell wall B/leaf B. The above results showed that under either K-deficient or K-sufficient condition, B deficiency damaged the cotton leaf cell membrane and cell membrane permeability. In normal B-supplied plants, lacking of B induced more B into the cytoplasm, but increased the proportion of B that combined with the pectic polysaccharides in cell wall. However, under K-deficient treatment, the proportion of B cross-linked pectic polysaccharides in cell wall decreased.

  3. Effects of Different Levels of Supplementary Nitrogen and Potassium in Nutrient Solution on Yield and Leaf N and K Concentrations of Tomato

    Directory of Open Access Journals (Sweden)

    N. Farzaneh

    2010-06-01

    Full Text Available The effects of different levels of nitrogen (100, 200, 300 and 400 mg/L and potassium (125, 250 and 375 mg/L on yield and leaf N and K concentrations of tomato were investigated in perlit culture using a factorial randomized design with three replications. The highest fruit yield was obtained with 200 mg/L N. Higher levels of nitrogen decreased tomato yield. With increasing nitrogen concentration in nutrient solution, N content of leaf increased significantly whereas leaf K concentration decreased. Different potassium levels had no significant effect on tomato yield. With increasing potassium levels of nutrient solution, concentration of leaf N decreased significantly whereas concentration of leaf K increased. The greatest and the least fruit yields were obtained from N200K250 and N400K375 treatments, respectively. The highest and the lowest concentrations of leaf N were observed in N400K125 and N100K375 treatments, respectively. The greatest and the least concentrations of leaf K were observed in N100K375 and N400K125 treatments, respectively.

  4. Extracellular citrulline levels in the nucleus accumbens during the acquisition and extinction of a classical conditioned reflex with pain reinforcement.

    Science.gov (United States)

    Savel'ev, S A; Saul'skaya, N B

    2007-03-01

    Studies on Sprague-Dawley rats using in vivo microdialysis and HPLC showed that the acquisition and performance of a classical conditioned reflex with pain reinforcement was accompanied by increases in the concentrations of citrulline (a side product of nitric oxide formation) and arginine (the substrate of NO synthase) in the intercellular space of the nucleus accumbens. During extinction of the reflex, there was a decrease in the elevation of extracellular citrulline in this brain structure, which correlated with the extent of extinction of the reflex. Recovery of the reflex led to increases in arginine and citrulline levels in the nucleus accumbens. These data suggest that there is an increase in nitric oxide production in the nucleus accumbens during the acquisition and performance of a classical conditioned reflex with pain reinforcement, which decreases as the reflex is extinguished and recovers with recovery of the reflex.

  5. Acute iboga alkaloid effects on extracellular serotonin (5-HT) levels in nucleus accumbens and striatum in rats.

    Science.gov (United States)

    Wei, D; Maisonneuve, I M; Kuehne, M E; Glick, S D

    1998-08-03

    The iboga alkaloid, ibogaine, its metabolite, noribogaine, and the congener, 18-methoxycoronaridine (18-MC) have all been claimed to have anti-addictive properties in animal models, but the mechanisms underlying these effects are unclear. Ibogaine and noribogaine were shown to have affinity for the serotonin transporter, and inhibition of serotonin reuptake has been proposed to be involved in their anti-addictive actions. It is not known yet if 18-MC also has this property. In vivo microdialysis and HPLC (microbore) were used to determine acute changes in extracellular serotonin levels in nucleus accumbens (NAC) and striatum (STR) after both i.p. (40 mg/kg for all drugs) and i.v. (1-10 mg/kg for ibogaine and noribogaine) drug administration in awake freely moving female Sprague-Dawley rats (250-275 g). After i.p. administration, ibogaine, noribogaine and 18-MC had very different effects on extracellular serotonin levels in both NAC and STR: ibogaine elicited large increases (up to 25-fold in NAC and 10- fold in STR), noribogaine produced moderate increases (up to 8-fold in NAC and 5-fold in STR), and 18-MC had no effect in either brain region. These and other data suggest that (1) the serotonergic system may not be an essential factor in the anti-addictive actions of these drugs; (2) ibogaine (or an unidentified metabolite) may release serotonin as well as inhibit its reuptake; (3) stimulation of the ascending serotonergic system may mediate ibogaine's hallucinogenic effect; and (4) 18-MC probably has no affinity for the serotonin transporter, and is unlikely to be a hallucinogen.

  6. POTENTIATION OF CAFFEINE-INDUCED CONTRACTURE BY RAISING EXTRACELLULAR POTASSIUM IN FROG SKELETAL MUSCLE%提高胞外钾引起的蛙骨骼肌咖啡因挛缩增强

    Institute of Scientific and Technical Information of China (English)

    陈克樱; 朱培闳

    1999-01-01

    用蛙胫前肌小束为材料, 研究了提高胞外钾[K+]O对咖啡因挛缩的作用.[K+]O从2 mmol/L提高到10或25 mmol/L, 由3 mmol/L咖啡因引起的挛缩明显增强.以PKC/PC (PKC和PC分别为在高钾和正常钾条件下的咖啡因挛缩)表示的咖啡因挛缩增强, 依赖[K+]O和高钾作用时间.随着10 mmol/L [K+]O作用时间延长, 直至10 min, 增强逐渐增加.但是, 25 mmol/L [K+]O作用1 min时增强达到最大, 然后下降到对照.PKC/PC变化时程不能用高钾引起的去极化解释, 而与由相似[K+]O引起的胞浆自由钙变化时程相符.提示, 至少在蛙骨骼肌, 高钾引起的咖啡因挛缩增强主要是由胞浆自由钙升高引起的.%The effect of raising extracellular potassium ([K+]O) on caffeine contracture was inves~tigated, using small bundles dissected from frog anterior tibialis muscle. Elevating [K+]O from the control of 2 mmol/L to 10 or 25 mmol/L significantly potentiated the contracture induced by 3 mmol/L caffeine. The potentiation represented by PKC/PC, where PKC and PC are the peak tension of the caffeine contracture evoked in high and normal [K+]O respectively, was dependent on [K+]O and the duration of conditioning high K+ exposure. With 10 mmol/L [K+]O, the potentiation was gradually increased by prolonging conditioning exposure up to 10 min. On the contrary, with 25 mmol/L [K+]O the potentiation reached a maximum within only 1 min, and then subsided to the control. These different time courses of PKC/PC could not be accounted for by high K+ induced depolarization, but were in general consistence with the time courses of the change in myoplasmic free calcium induced by corresponding high [K+]O[10]. It is suggested that, at least in frog skeletal muscle, the high [K+]O induced potentiation of caffeine contracture is mainly due to an increase of myoplasmic free calcium.

  7. A new classification paradigm of extracellular polymeric substances (EPS) in activated sludge: separation and characterization of exopolymers between floc level and microcolony level.

    Science.gov (United States)

    Wang, Bin-Bin; Chang, Qing; Peng, Dang-Cong; Hou, Yin-Ping; Li, Hui-Juan; Pei, Li-Ying

    2014-11-01

    Extracellular polymeric substances (EPS) play a crucial role in the formation of activated sludge flocs. However, until now, the EPS are rather classified by the method used for extraction than by a theoretical consideration of their function and composition. In this paper, a new classification paradigm of EPS was proposed, which offered a novel approach to identify the role of EPS in the formation of activated sludge flocs. The current study gave an exploration to distinguish the EPS in the floc level (extra-microcolony polymers, EMPS) and in the microcolony level (extra-cellular polymers, ECPS). It was found that cation exchange resin treatment is efficient to disintegrate the flocs for EMPS extraction, however, inefficient to disaggregate the microcolonies for ECPS harvesting. A two-steps extraction strategy (cation exchange resin treatment followed by ultrasonication-high speed centrifugation treatment) was suggested to separate these two types of EPS in activated sludge flocs and the physicochemical characteristics of EMPS and ECPS were compared. The protein/polysaccharide ratio of ECPS was higher than that of EMPS and the molecular weight of proteins in EMPS and ECPS were found to be different. The ECPS contained higher molecular weight proteins and more hydrophobic substances than the EMPS contained. The result of excitation-emission matrix fluorescence spectroscopy analysis also showed that the EMPS and the ECPS have different fluorescent expressions and the components of EMPS were more diverse than that of ECPS. All results reported herein demonstrated that two different types of exopolymers exist in the activated sludge flocs and the inter-particle forces for aggregation of activated sludge flocs are not identical between the floc level and the microcolony level. It suggested that cation bridging interactions are more crucial in floc level flocculation, while the entanglement and hydrophobic interactions are more important in microcolony level cohesion.

  8. Effect of Patiromer on Serum Potassium Level in Patients With Hyperkalemia and Diabetic Kidney Disease: The AMETHYST-DN Randomized Clinical Trial.

    Science.gov (United States)

    Bakris, George L; Pitt, Bertram; Weir, Matthew R; Freeman, Mason W; Mayo, Martha R; Garza, Dahlia; Stasiv, Yuri; Zawadzki, Rezi; Berman, Lance; Bushinsky, David A

    2015-07-14

    Hyperkalemia is a potentially life-threatening condition predominantly seen in patients treated with renin-angiotensin-aldosterone system (RAAS) inhibitors with stage 3 or greater chronic kidney disease (CKD) who may also have diabetes, heart failure, or both. To select starting doses for a phase 3 study and to evaluate the long-term safety and efficacy of a potassium-binding polymer, patiromer, in outpatients with hyperkalemia. Phase 2, multicenter, open-label, dose-ranging, randomized clinical trial (AMETHYST-DN), conducted at 48 sites in Europe from June 2011 to June 2013 evaluating patiromer in 306 outpatients with type 2 diabetes (estimated glomerular filtration rate, 15 to 5.0 mEq/L). All patients received RAAS inhibitors prior to and during study treatment. Patients were stratified by baseline serum potassium level into mild or moderate hyperkalemia groups and received 1 of 3 randomized starting doses of patiromer (4.2 g [n = 74], 8.4 g [n = 74], or 12.6 g [n = 74] twice daily [mild hyperkalemia] or 8.4 g [n = 26], 12.6 g [n = 28], or 16.8 g [n = 30] twice daily [moderate hyperkalemia]). Patiromer was titrated to achieve and maintain serum potassium level 5.0 mEq/L or lower. The primary efficacy end point was mean change in serum potassium level from baseline to week 4 or prior to initiation of dose titration. The primary safety end point was adverse events through 52 weeks. Secondary efficacy end points included mean change in serum potassium level through 52 weeks. A total of 306 patients were randomized. The least squares mean reduction from baseline in serum potassium level at week 4 or time of first dose titration in patients with mild hyperkalemia was 0.35 (95% CI, 0.22-0.48) mEq/L for the 4.2 g twice daily starting-dose group, 0.51 (95% CI, 0.38-0.64) mEq/L for the 8.4 g twice daily starting-dose group, and 0.55 (95% CI, 0.42-0.68) mEq/L for the 12.6 g twice daily starting-dose group. In those with moderate hyperkalemia, the

  9. Modulation of Extracellular ATP Content of Mast Cells and DRG Neurons by Irradiation: Studies on Underlying Mechanism of Low-Level-Laser Therapy

    Directory of Open Access Journals (Sweden)

    Lina Wang

    2015-01-01

    Full Text Available Low-level-laser therapy (LLLT is an effective complementary treatment, especially for anti-inflammation and wound healing in which dermis or mucus mast cells (MCs are involved. In periphery, MCs crosstalk with neurons via purinergic signals and participate in various physiological and pathophysiological processes. Whether extracellular ATP, an important purine in purinergic signaling, of MCs and neurons could be modulated by irradiation remains unknown. In this study, effects of red-laser irradiation on extracellular ATP content of MCs and dorsal root ganglia (DRG neurons were investigated and underlying mechanisms were explored in vitro. Our results show that irradiation led to elevation of extracellular ATP level in the human mast cell line HMC-1 in a dose-dependent manner, which was accompanied by elevation of intracellular ATP content, an indicator for ATP synthesis, together with [Ca2+]i elevation, a trigger signal for exocytotic ATP release. In contrast to MCs, irradiation attenuated the extracellular ATP content of neurons, which could be abolished by ARL 67156, a nonspecific ecto-ATPases inhibitor. Our results suggest that irradiation potentiates extracellular ATP of MCs by promoting ATP synthesis and release and attenuates extracellular ATP of neurons by upregulating ecto-ATPase activity. The opposite responses of these two cell types indicate complex mechanisms underlying LLLT.

  10. Oxidation Level of Vacuum-Packaged Shredded Meat Treated with Different Concentrations of Potassium Sorbate, Sodium Diacetate and Nisin

    Directory of Open Access Journals (Sweden)

    Juyang Zhao

    2013-01-01

    Full Text Available The preservatives have been common used in food product, drugs and cosmetics to prevent their aging and decay. Shredded meat has been frequently used in Chinese traditional dishes. However, there is little information available for the corrosion protection of preservatives in commercial shredded meat products. The effect of different concentrations of potassium sorbate, sodium diacetate and nisin on the inhibition of oxidation process of shredded meat was studied. Results showed that potassium sorbate (0.05 g/kg and nisin (0.2 g/kg showed the greatest antioxidation activity by determining the Aerobic Plate Count (APC, Thiobarbituric Acid-Reactive Substances (TBARS and Peroxide Value (PV. It could help to provide theoretical basis for developing convenience shredded meat products with long shelf life.

  11. Relationship between serum HER2 extracellular domain levels,tissue HER2 expression,and clinico-pathological parameters in early stage breast cancer

    Institute of Scientific and Technical Information of China (English)

    MA Li; YANG Hong-ying; HAN Xiao-hong; LI Jia; WANG Fang; ZHANG Chun-ling; YAO Jia-rui; SHI Yuan-kai

    2012-01-01

    Background Measurement of human epidermal growth factor receptor 2(HER2)protein in the serum of metastatic breast cancer patients has previously been reported,but there are no consistent data to support the clinical utility of serum HER2 extracellufar domain for patients with early stage breast cancer.We aimed to evaluate the correlation between serum extracellular domain levels and tissue HER2 expression,and analyzed their relationship with clinico-pathological parameters in patients with early stage disease.Methods A prospective study was conducted on 232 breast cancer patients with stage Ⅰ-Ⅲ?prior to treatment.Preoperative serum samples were measured by enzyme-linked immunosorbent assay.Tissue HER2 status was analyzed by immunohistochemistry and fluorescence in situ hybridization assays.Results The median serum extracellular domain concentration was 6.8 ng/ml.The best diagnostic cut-off value was 7.4 ng/ml,with 62.9% sensitivity and 85.3% specificity.High serum extracellular domain levels were reported in 89 patients(38.3%),and HER2-positive expression was observed in 77 patients(33.2%).Multivariate analysis showed that elevated serum extracellular domain correlated with postmenopausal status(P<0.001),high histological grade(P<0.001),negativity of both estrogen(P=0.012)and progesterone receptors(P<0.001),and high levels of carcinoembryonic antigen 153(P=0.048).Conclusions We recommend that 7.4 ng/ml should be used as the cut-off value when evaluating serum extracellular domain levels in early stage of breast cancer.Patients with high serum extracellular domain levels have a certain clinicopathological characteristics,may provide a basis for clinical practice.

  12. Alterations in brain extracellular dopamine and glycine levels following combined administration of the glycine transporter type-1 inhibitor Org-24461 and risperidone.

    Science.gov (United States)

    Nagy, Katalin; Marko, Bernadett; Zsilla, Gabriella; Matyus, Peter; Pallagi, Katalin; Szabo, Geza; Juranyi, Zsolt; Barkoczy, Jozsef; Levay, Gyorgy; Harsing, Laszlo G

    2010-12-01

    The most dominant hypotheses for the pathogenesis of schizophrenia have focused primarily upon hyperfunctional dopaminergic and hypofunctional glutamatergic neurotransmission in the central nervous system. The therapeutic efficacy of all atypical antipsychotics is explained in part by antagonism of the dopaminergic neurotransmission, mainly by blockade of D(2) dopamine receptors. N-methyl-D-aspartate (NMDA) receptor hypofunction in schizophrenia can be reversed by glycine transporter type-1 (GlyT-1) inhibitors, which regulate glycine concentrations at the vicinity of NMDA receptors. Combined drug administration with D(2) dopamine receptor blockade and activation of hypofunctional NMDA receptors may be needed for a more effective treatment of positive and negative symptoms and the accompanied cognitive deficit in schizophrenia. To investigate this type of combined drug administration, rats were treated with the atypical antipsychotic risperidone together with the GlyT-1 inhibitor Org-24461. Brain microdialysis was applied in the striatum of conscious rats and determinations of extracellular dopamine, DOPAC, HVA, glycine, glutamate, and serine concentrations were carried out using HPLC/electrochemistry. Risperidone increased extracellular concentrations of dopamine but failed to influence those of glycine or glutamate measured in microdialysis samples. Org-24461 injection reduced extracellular dopamine concentrations and elevated extracellular glycine levels but the concentrations of serine and glutamate were not changed. When risperidone and Org-24461 were added in combination, a decrease in extracellular dopamine concentrations was accompanied with sustained elevation of extracellular glycine levels. Interestingly, the extracellular concentrations of glutamate were also enhanced. Our data indicate that coadministration of an antipsychotic with a GlyT-1 inhibitor may normalize hypofunctional NMDA receptor-mediated glutamatergic neurotransmission with reduced

  13. Serum Potassium Levels Inversely Correlate with D-Dimer In Patients with Acute-Onset Atrial Fibrillation

    Energy Technology Data Exchange (ETDEWEB)

    Cervellin, Gianfranco, E-mail: gcervellin@ao.pr.it; Bonfanti, Laura; Picanza, Alessandra; Lippi, Giuseppe [1Academic Hospital of Parma (Italy)

    2015-03-15

    D-dimer values are frequently increased in patients with atrial fibrillation (AF) compared to subjects in sinus rhythm. Hypokalemia plays a role in several cardiovascular diseases, but little is known about the association with AF. D-dimer values are frequently increased in patients with atrial fibrillation (AF) compared with subjects in sinus rhythm. Hypokalemia plays a role in several cardiovascular diseases, but little is known about the association with AF. The aim of this study was to investigate correlations between D-dimer and serum potassium in acute-onset AF (AAF). To investigate the potential correlation between the values of serum potassium and D-dimer in patients with AAF, we retrospectively reviewed clinical and laboratory data of all emergency department visits for AAF in 2013. Among 271 consecutive AAF patients with D-dimer assessments, those with hypokalemia (n = 98) had significantly higher D-dimer values than normokalemic patients (139 versus 114 ng/mL, p = 0.004). The rate of patients with D-dimer values exceeding the diagnostic cut-off was higher in the group of patients with hypokalemia than in those with normal serum potassium (26.5% versus 16.2%; p = 0.029). An inverse and highly significant correlation was found between serum potassium and D-dimer (r = −0.21; p < 0.001), even after adjustments for age and sex (beta coefficient −94.8; p = 0.001). The relative risk for a positive D-dimer value attributed to hypokalemia was 1.64 (95% CI, 1.02 to 2.63; p = 0.040). The correlation remained statistically significant in patients free from antihypertensive drugs (r = −0.25; p = 0.018), but not in those taking angiotensin-receptor blockers, angiotensin-converting enzyme inhibitors, or diuretics. The inverse correlation between values of potassium and D-dimer in patients with AAF provides important and complementary information about the thromboembolic risk of these patients.

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

    NARCIS (Netherlands)

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

    2012-01-01

    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. 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

  16. Potassium Iodide (KI)

    Science.gov (United States)

    ... Health Matters Information on Specific Types of Emergencies Potassium Iodide (KI) Language: English Español (Spanish) Recommend on Facebook ... can I get KI (potassium iodide)? What is Potassium Iodide (KI)? KI (potassium iodide) is a salt of ...

  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. Extraction and Analysis of Extracellular Polymeric Substances (EPS): Comparison of Methods and EPS Levels in Salmonella pullorum SA 1685

    Science.gov (United States)

    The extracellular polymeric substances (EPS) production and composition for Salmonella pullorum SA 1685 exposed to artificial groundwater (AGW) has been examined utilizing three EPS extraction methods: lyophilization, ethanol, and sonication. Experiments were carried out to evaluate the robustness...

  19. Effectiveness of the aldosterone-sodium and -potassium feedback control system.

    Science.gov (United States)

    Young, D B; McCaa, R E; Pan, U J; Guyton, A C

    1976-09-01

    This study was conducted to determine the quantitative importance of the aldosterone feedback mechanism in controlling each one of three major factors that have often been associated with aldosterone, namely, extracellular fluid sodium concentration, extracellular fluid potassium concentration, and extracellular fluid volume. To do this, the ability of the body to control these three factors in the face of marked changes in daily sodium or potassium intake was studied under two conditions: 1) in the normal dog, and 2) in the dog in which the aldosterone feedback mechanism was prevented from functioning by removing the adrenal glands and then providing a continuous fixed level of supportive aldosterone and glucocorticoids during the low and high electrolyte intake periods. Under these conditions, removal of feedback control of aldosterone secretion decreased the effectiveness of plasma potassium control by nearly fivefold (39% vs. 8% change in plasma potassium concentration), fluid volume by sixfold (12% vs. 2% change in sodium space) and had no effect on control of plasma sodium concentration (2% change with and without feedback control of aldosterone secretion.)

  20. Changes in plasma potassium levels following massive transfusion in trauma%大量输血导致血钾变化的相关分析

    Institute of Scientific and Technical Information of China (English)

    伍玉容; 李朝金; 李玲; 郑强; 王逊

    2012-01-01

    Objective To explore the changes of plasma potassium levels and the impact factor of hyperkalemia following massive transfusion. Methods The clinical data of all non - crush trauma patients with massive transfusion treated in this hospital from March 2007 to December 2010 were retrospectively analyzed. Multivariate analysis was used to examine the effect of massive transfusion on plasma potassium level. Results There was no significant difference in plasma potassium level between study group and control group before and after blood transfusion and surgery ( P >0.05). Although the incidence of hyperkalemia in study group was higher than that in control group during 12 h postoperation ( P 0.05). Logistic regression identifed only preoperative high K + level ( P < 0.05 ) and postoperative lower pH ( P < 0. 05 ), but not massive transfusion, as independent risk factors for postoperative hyperkalemia. Conclusion Massive transfusion patients with non - crush trauma were at no higher risk of hyperkalemia than those who received no blood products, but we should detect the levels of plasma potassium dynamically following massive transfusion.%目的 探讨大量输血与血清钾变化的相关性.方法 回顾性分析2007年3月至2010年12月所有非挤压伤病人大量输血(观察组)和非输血患者(对照组)的临床资料,采用多因素分析方法分析输血前后血钾变化规律及影响因素.结果 手术和输血前、后两组血清钾水平无显著差异(P>0.05),但术后12 h内观察组的高钾血症发生率高于对照组(P<0.05),而12 h后两组高血钾的发生率无显著差异(P>0.05).Logistic回归分析显示术前高血钾(P<0.05)和术后低pH值(P<0.05)是导致术后高钾血症的主要原因,而与大量输血治疗无明显相关性(P> 0.05).结论 非挤压伤病人大量输血并不是导致高钾血症的发生的直接原因,但同样需要动态监测输血前后的血钾变化.

  1. Convulsant and Subconvulsant Doses of Norfloxacin in the Presence and Absence of Biphenylacetic Acid Alter Extracellular Hippocampal Glutamate but Not Gamma-Aminobutyric Acid Levels in Conscious Rats

    Science.gov (United States)

    Smolders, I.; Gousseau, C.; Marchand, S.; Couet, W.; Ebinger, G.; Michotte, Y.

    2002-01-01

    Fluoroquinolones are antibiotics with central excitatory side effects. These adverse effects presumably result from inhibition of γ-aminobutyric acid (GABA) binding to GABAA receptors. This GABA antagonistic effect is greatly potentiated by the active metabolite of fenbufen, biphenylacetic acid (BPAA). Nevertheless, it remains questionable whether GABA receptor antagonism alone can explain the convulsant activity potentials of these antimicrobial agents. The present study was undertaken to investigate the possible effects of norfloxacin, both in the absence and in the presence of BPAA, on the extracellular hippocampal levels of GABA and glutamate, the main central inhibitory and excitatory amino acid neurotransmitters, respectively. This in vivo microdialysis approach with conscious rats allows monitoring of behavioral alterations and concomitant transmitter modulation in the hippocampus. Peroral administration of 100 mg of BPAA per kg of body weight had no effect on behavior and did not significantly alter extracellular GABA or glutamate concentrations. Intravenous perfusion of 300 mg of norfloxacin per kg did not change the rat's behavior or the concomitant neurotransmitter levels in about half of the experiments, while the remaining animals exhibited severe seizures. These norfloxacin-induced convulsions did not affect extracellular hippocampal GABA levels but were accompanied by enhanced glutamate concentrations. Half of the rats receiving both 100 mg of BPAA per kg and 50 mg of norfloxacin per kg displayed lethal seizures, while the remaining animals showed no seizure-related behavior. In the latter subgroup, again no significant alterations in extracellular GABA levels were observed, but glutamate overflow remained significantly elevated for at least 3 h. In conclusion, norfloxacin exerts convulsant activity in rats, accompanied by elevations of extracellular hippocampal glutamate levels but not GABA levels, even in the presence of BPAA. PMID:11796360

  2. Potassium clavulanate

    Directory of Open Access Journals (Sweden)

    Kotaro Fujii

    2010-08-01

    Full Text Available The title salt, K+·C8H8NO5− [systematic name: potassium (2R,5R,Z-3-(2-hydroxyethylidene-7-oxo-4-oxa-1-azabicyclo[3.2.0]heptane-2-carboxylate], a widely used β-lactam antibiotic, is usually chemically unstable even in the solid state owing to its tendency to be hydrolysed. In the crystal structure, the potassium cations are arranged along the a axis, forming interactions to the carboxylate and hydroxy groups, resulting in one-dimensional ionic columns. These columns are arranged along the b axis, connected by O—H...O hydrogen bonds, forming a layer in the ab plane.

  3. Diagnostic accuracy of salivary creatinine, urea, and potassium levels to assess dialysis need in renal failure patients

    Science.gov (United States)

    Bagalad, Bhavana S.; Mohankumar, K. P.; Madhushankari, G. S.; Donoghue, Mandana; Kuberappa, Puneeth Horatti

    2017-01-01

    Background: The prevalence of chronic renal failure is increasing because of increase in chronic debilitating diseases and progressing age of population. These patients experience accumulation of metabolic byproducts and electrolyte imbalance, which has harmful effects on their health. Timely hemodialysis at regular intervals is a life-saving procedure for these patients. Salivary diagnostics is increasingly used as an alternative to the traditional methods. Thus, the aim of the present study was to determine the diagnostic efficacy of saliva in chronic renal failure patients. Materials and Methods: This case–control study included 82 individuals, of which 41 were chronic renal failure patients and 41 were age- and sex-matched controls. Blood and saliva were collected and centrifuged. Serum and supernatant saliva were used for biochemical analysis. Serum and salivary urea, creatinine, sodium, potassium, calcium, and phosphorus were evaluated and correlated in chronic renal failure patients using unpaired t-test, Pearson's correlation coefficient, diagnostic validity tests, and receiver operative curve. Results: When compared to serum; salivary urea, creatinine, sodium, and potassium showed diagnostic accuracy of 93%, 91%, 73%, and 89%, respectively, based on the findings of study. Conclusion: It can be concluded that salivary investigation is a dependable, noninvasive, noninfectious, simple, and quick method for screening the mineral and metabolite values of high-risk patients and monitoring the renal failure patients.

  4. Nitrogen, Phosphor, and Potassium Level in Soil and Oil Palm Tree at various Composition of plant species mixtures grown

    Science.gov (United States)

    Hanum, C.; Rauf, A.; Fazrin, D. A.; Habibi, A. R.

    2016-08-01

    In productive oil palm plantation areas, poor vegetation is generally caused by low light intensity. This condition causes excessive erosion and decreases soil fertility. One of the efforts for soil and water conservation at oil palm plantations is through increased vegetation diversity. The changes of soil and plant nitrogen, phosporus, and potassium content, observed by planting two types of herbs under oil palm tree, with different compositions. Vegetation composition was set as: Arachis glabrata 100%; Stenotaprum secundatum 100%; Arachis glabrata 50% + Stenotaprum secundatum 50%; Arachis glabrata 75% + Stenotaprum secundatum 25%; Arachis glabrata 25% + Stenotaprum secundatum 75%. The shoot and root fresh/dry weight, nutrient content (nitrogen, phosphor, and potassium) of each cutting were measured at the end of the experiment. Ten of treatment plant were harvested and divided shoots and roots after washing out of soil. Biomass samples were dried at 70 °C for 48 h and weighed. The total N and its proportional concentration (N%) were analyzed with the micro- Kjeldahl method. Potasium analyzing with flamephotometry, and phosphor and from samples was determined by analyzing with spectrophotometry method. The results showed the highest shoot growth of A.glabarata if planting was mixed with S. secundatum, but the result was different with S.secundatum being superior if planted with monoculture system. Combination of interrow cultivation is more recommended for soil conservation and nutrient maintenance in palm oil trees were A. Glabarata 75% + S.secundatum 25%.

  5. Neuropeptide Y infusion into the shell region of the rat nucleus accumbens increases extracellular levels of dopamine

    DEFF Research Database (Denmark)

    Sørensen, Gunnar; Wegener, Gregers; Hasselstrøm, Jørgen;

    2009-01-01

    Increases in extracellular dopamine in the shell region of the nucleus accumbens are centrally involved in mediating reinforcement of addictive drugs. Neuropeptide Y (NPY) and its receptors are present in the nucleus accumbens and have been implicated in addiction mechanisms. This study further...

  6. Measurement of indoor radon and thoron levels in dwellings and estimation of uranium, thorium and potassium in soil samples from central part of India

    Energy Technology Data Exchange (ETDEWEB)

    Kher, R.S. [Department of Physics, Government Science Postgraduate College, Bilaspur 495 006 (India)], E-mail: kherrs@hotmail.com; Khokhar, M.S.K. [Department of Rural Technology, Guru Ghasidas University, Bilaspur 495 009 (India); Rathore, V.B. [Department of Radiotherapy, Pt. J.N.M. Medical College, Raipur 492 001 (India); Ramachandran, T.V. [Environmental Assessment Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2008-08-15

    In the frame of nationwide survey project, measurement of indoor radon/thoron level has been carried out in 132 dwellings situated in 10 different towns/villages of centrally located states Madhya Pradesh and Chhattisgarh. LR 115 solid-state nuclear track detectors in plastic twin chamber dosimeter cups were used for the measurement. The measurements were carried out for a full year, divided into four quarters. The mean radon/thoron concentration at all the locations falls well below the range of active level recommended by International Commission on Radiological Protection. The results of uranium, thorium and potassium estimation in soil samples belonging to these areas are also reported. Positive correlation has not been observed between indoor radon/thoron concentration and uranium/thorium content of the soil. It is concluded that the diffusion of radon from soil to dwelling is greatly affected by flooring material.

  7. Diverse levels of an inwardly rectifying potassium conductance generate heterogeneous neuronal behavior in a population of dorsal cochlear nucleus pyramidal neurons.

    Science.gov (United States)

    Leao, Ricardo M; Li, Shuang; Doiron, Brent; Tzounopoulos, Thanos

    2012-06-01

    Homeostatic mechanisms maintain homogeneous neuronal behavior among neurons that exhibit substantial variability in the expression levels of their ionic conductances. In contrast, the mechanisms, which generate heterogeneous neuronal behavior across a neuronal population, remain poorly understood. We addressed this problem in the dorsal cochlear nucleus, where principal neurons exist in two qualitatively distinct states: spontaneously active or not spontaneously active. Our studies reveal that distinct activity states are generated by the differential levels of a Ba(2+)-sensitive, inwardly rectifying potassium conductance (K(ir)). Variability in K(ir) maximal conductance causes variations in the resting membrane potential (RMP). Low K(ir) conductance depolarizes RMP to voltages above the threshold for activating subthreshold-persistent sodium channels (Na(p)). Once Na(p) channels are activated, the RMP becomes unstable, and spontaneous firing is triggered. Our results provide a biophysical mechanism for generating neural heterogeneity, which may play a role in the encoding of sensory information.

  8. Thanatochemistry: Study of vitreous humor potassium

    Directory of Open Access Journals (Sweden)

    Nilesh Keshav Tumram

    2014-12-01

    Full Text Available This study has been carried out to determine the death interval from the biochemical parameter of vitreous potassium. In 308 medicolegal cases vitreous humor was taken and analyzed for potassium with known time of death. There was a linear rise in potassium concentration with increasing death interval. Regression equation was calculated for the same. The study indicates that potassium levels in vitreous for determining death interval are useful and can afford a good method of determining the death interval along with other traditional methods. Also the previously established formulae for estimating death interval from vitreous potassium were also studied.

  9. Levels of Circulating MMCN-151, a Degradation Product of Mimecan, Reflect Pathological Extracellular Matrix Remodeling in Apolipoprotein E Knockout Mice

    DEFF Research Database (Denmark)

    Barascuk, N; Vassiliadis, E; Zheng, Qiuju;

    2011-01-01

    Arterial extracellular matrix (ECM) remodeling by matrix metalloproteinases (MMPs) is one of the major hallmarks of atherosclerosis. Mimecan, also known as osteoglycin has been implicated in the integrity of the ECM. This study assessed the validity of an enzyme-linked immunosorbent assay (ELISA)......) developed to measure a specific MMP12-derived fragment of mimecan, MMCN-151, in apolipoprotein-E knockout (ApoE-KO) mice....

  10. Effect of background potassium channels on potassium homeostasis in healthy and epileptic hippocampus

    OpenAIRE

    Päsler, Dennis

    2015-01-01

    In the frequent neurological disease of epilepsy, focal extracellular potassium concentration in the brain increases to pathological values. The underlying mechanisms are not yet fully understood. Two-pore-domain potassium channels (K2P channels), postulated in the 1950s and cloned and investigated in the past years, came into scientific view. A contribution of these channels on keeping membrane’s resting potential of glial cells is proven. In the present study, the contribution of K2P channe...

  11. Morphine sensitization increases the extracellular level of glutamate in CA1 of rat hippocampus via μ-opioid receptor.

    Science.gov (United States)

    Farahmandfar, Maryam; Karimian, Seyed Morteza; Zarrindast, Mohammad-Reza; Kadivar, Mehdi; Afrouzi, Hossein; Naghdi, Nasser

    2011-04-25

    Repeated administration of abuse drugs such as morphine elicits a progressive enhancement of drug-induced behavioral responses, a phenomenon termed behavioral sensitization. These changes in behavior may reflect plastic changes requiring regulation of glutamatergic system in the brain. In this study, we investigated the effect of morphine sensitization on extracellular glutamate concentration in the hippocampus, a brain region rich in glutamatergic neurons. Sensitization was induced by subcutaneous (s.c.) injection of morphine, once daily for 3 days followed by 5 days free of the opioid treatment. The results showed that extracellular glutamate concentration in the CA1 was decreased following administration of morphine in non-sensitized rats. However, morphine-induced behavioral sensitization significantly increased the extracellular glutamate concentration in this area. The enhancement of glutamate in morphine sensitized rats was prevented by administration of naloxone 30 min before each of three daily doses of morphine. These results suggest an adaptation of the glutamatergic neuronal transmission in the hippocampus after morphine sensitization and it is postulated that opioid receptors may play an important role in this effect.

  12. Rapid fluctuations in extracellular brain glucose levels induced by natural arousing stimuli and intravenous cocaine: fueling the brain during neural activation

    Science.gov (United States)

    Lenoir, Magalie

    2012-01-01

    Glucose, a primary energetic substrate for neural activity, is continuously influenced by two opposing forces that tend to either decrease its extracellular levels due to enhanced utilization in neural cells or increase its levels due to entry from peripheral circulation via enhanced cerebral blood flow. How this balance is maintained under physiological conditions and changed during neural activation remains unclear. To clarify this issue, enzyme-based glucose sensors coupled with high-speed amperometry were used in freely moving rats to evaluate fluctuations in extracellular glucose levels induced by brief audio stimulus, tail pinch (TP), social interaction with another rat (SI), and intravenous cocaine (1 mg/kg). Measurements were performed in nucleus accumbens (NAcc) and substantia nigra pars reticulata (SNr), which drastically differ in neuronal activity. In NAcc, where most cells are powerfully excited after salient stimulation, glucose levels rapidly (latency 2–6 s) increased (30–70 μM or 6–14% over baseline) by all stimuli; the increase differed in magnitude and duration for each stimulus. In SNr, where most cells are transiently inhibited by salient stimuli, TP, SI, and cocaine induced a biphasic glucose response, with the initial decrease (−20–40 μM or 5–10% below baseline) followed by a reboundlike increase. The critical role of neuronal activity in mediating the initial glucose response was confirmed by monitoring glucose currents after local microinjections of glutamate (GLU) or procaine (PRO). While intra-NAcc injection of GLU transiently increased glucose levels in this structure, intra-SNr PRO injection resulted in rapid, transient decreases in SNr glucose. Therefore, extracellular glucose levels in the brain change very rapidly after physiological and pharmacological stimulation, the response is structure specific, and the pattern of neuronal activity appears to be a critical factor determining direction and magnitude of physiological

  13. Effects of drought stress and various levels of potassium fertilizer on yield and yield component of sunflower (Helianthus Annuus L. cultivar Armaviresky in Ardabil

    Directory of Open Access Journals (Sweden)

    Hossein Salati Momeni

    2016-06-01

    Full Text Available To study the effect of drought stress and various levels of potassium fertilizer on yield and yield component of sunflower (Helianthus Annuus L. cultivarArmaviresky in Ardabil a randomized complete block design experiment factorial the four replications in 1394. The amount of potassium factor of 3 K1= 0kg/h, K2= 50kg/h and K3= 100kg/h, respectively. And the second factor consisted of drought stress levels D1=70mm evaporation, D2=140mm evaporation and the D3 =210 mm evaporation. Was used in this experiment was Armawireski. Overall, it was concluded that water stress, yield in oil yield significantly reduced. In this experiment, the highest grain yield D1= 70mm treatments, respectively (5021kg/h (5631/4 kg/h and the lowest yield of treatments and treatments D3=210 mm K1=0 kg/h, respectively (2481/3 kg/h and (2996/9 kg/h. The results suggest that treatment D1=70 mm increased number of seeds per heah was.The higher leaf area during this stage of growth. Environmental stress by limiting the supply of assimilates for grain filling, the number of seeds per head is affected. So the highest seed weight, number of seeds per head and oil yield, respectively (74/51gr, (938/26 number and (2457 kg/h from D1=70mm treatment and lowest seed weight, number of seeds per head and oil yield, respectively (50/29 gr, (number 628/60 and (1631 kg g/h of treatment K1=0 kg/h, respectively. If the highest oil percent (%59/74 of treatment K3=100 kg/h, respectively.

  14. Decreased extracellular adenosine levels lead to loss of hypoxia-induced neuroprotection after repeated episodes of exposure to hypoxia.

    Directory of Open Access Journals (Sweden)

    Mei Cui

    Full Text Available Achieving a prolonged neuroprotective state following transient ischemic attacks (TIAs is likely to effectively reduce the brain damage and neurological dysfunction associated with recurrent stroke. HPC is a phenomenon in which advanced exposure to mild hypoxia reduces the stroke volume produced by a subsequent TIA. However, this neuroprotection is not long-lasting, with the effects reaching a peak after 3 days. Therefore, in this study, we investigated the use of multiple episodes of hypoxic exposure at different time intervals to induce longer-term protection in a mouse stroke model. C57BL/6 mice were subjected to different hypoxic preconditioning protocols: a single episode of HPC or five identical episodes at intervals of 3 days (E3d HPC or 6 days (E6d HPC. Three days after the last hypoxic exposure, temporary middle cerebral artery occlusion (MCAO was induced. The effects of these HPC protocols on hypoxia-inducible factor (HIF regulated gene mRNA expression were measured by quantitative PCR. Changes in extracellular adenosine concentrations, known to exert neuroprotective effects, were also measured using in vivo microdialysis and high pressure liquid chromatography (HPLC. Neuroprotection was provided by E6d HPC but not E3d HPC. HIF-regulated target gene expression increased significantly following all HPC protocols. However, E3d HPC significantly decreased extracellular adenosine and reduced cerebral blood flow in the ischemic region with upregulated expression of the adenosine transporter, equilibrative nucleoside transporter 1 (ENT1. An ENT1 inhibitor, propentofylline increased the cerebral blood flow and re-established neuroprotection in E3d HPC. Adenosine receptor specific antagonists showed that adenosine mainly through A1 receptor mediates HPC induced neuroprotection. Our data indicate that cooperation of HIF-regulated genes and extracellular adenosine is necessary for HPC-induced neuroprotection.

  15. Potassium accumulation as dynamic modulator of neurohypophysial excitability.

    Science.gov (United States)

    Foley, J; Nguyen, H; Bennett, C B; Muschol, M

    2010-08-11

    Activity-dependent modulation of excitable responses from neurohypophysial axons and their secretory swellings has long been recognized as an important regulator of arginine vasopressin and oxytocin release during patterned stimulation. Various activity-dependent mechanisms, including action potential broadening, potassium accumulation, and autocrine or paracrine feedback, have been proposed as underlying mechanisms. However, the relevance of any specific mechanism on net excitability in the intact preparation, during different levels of overall activation, and during realistic stimulation with trains of action potentials has remained largely undetermined. Using high-speed optical recordings and potentiometric dyes, we have quantified the dynamics of global excitability under physiologically more realistic conditions, that is in the intact neurohypophysis during trains of stimuli at varying frequencies and levels of overall activity. Net excitability facilitated during stimulation at low frequencies or at low activity. During persistent high-intensity or high-frequency stimulation, net excitability became severely depressed. Depression of excitable responses was strongly affected by manipulations of extracellular potassium levels, including changes to resting [K(+)](out), increases of interstitial spaces with hypertonic solutions and inhibition of Na(+)/K(+) ATPase activity. Application of the GABA(A) receptor blocker bicuculline or manipulations of Ca(2+) influx showed little effect. Numerical simulation of K(+) accumulation on action potentials of individual axons reproduced optically recorded population responses, including the overall depression of action potential (AP) amplitudes, modest AP broadening and the prominent loss of hyperpolarizing undershoots. Hence, extracellular potassium accumulation dominates activity-dependent depression of neurohypophysial excitability under elevated stimulation conditions. The intricate dependence on the short

  16. Increases in extracellular fluid glucose levels in the rat hippocampus following an anesthetic dose of pentobarbital or ketamine-xylazine: an in vivo microdialysis study.

    Science.gov (United States)

    Canal, Clinton E; McNay, Ewan C; Gold, Paul E

    2005-02-15

    Using in vivo microdialysis, we examined glucose levels in the extracellular fluid (ECF) of the hippocampus and in the blood prior to and during pentobarbital (45 mg/kg) or ketamine-xylazine (66 mg/kg, 7 mg/kg) anesthesia. Anesthesia with either pentobarbital or ketamine-xylazine significantly increased hippocampal ECF glucose levels (mean peak increases of +71% and +85%, respectively). In addition, there were substantial increases in blood glucose levels (mean peak increases of +24% and +30%, respectively). The increased levels of hippocampal ECF glucose during anesthesia complement past evidence for decreases in ECF glucose in the hippocampus observed while rats perform a memory task sensitive to hippocampal damage, providing further support for the view that ECF glucose levels in the hippocampus are dynamically coupled to local neural activity.

  17. Monitoring In Vivo Changes in Tonic Extracellular Dopamine Level by Charge-Balancing Multiple Waveform Fast-Scan Cyclic Voltammetry.

    Science.gov (United States)

    Oh, Yoonbae; Park, Cheonho; Kim, Do Hyoung; Shin, Hojin; Kang, Yu Min; DeWaele, Mark; Lee, Jeyeon; Min, Hoon-Ki; Blaha, Charles D; Bennet, Kevin E; Kim, In Young; Lee, Kendall H; Jang, Dong Pyo

    2016-11-15

    Dopamine (DA) modulates central neuronal activity through both phasic (second to second) and tonic (minutes to hours) terminal release. Conventional fast-scan cyclic voltammetry (FSCV), in combination with carbon fiber microelectrodes, has been used to measure phasic DA release in vivo by adopting a background subtraction procedure to remove background capacitive currents. However, measuring tonic changes in DA concentrations using conventional FSCV has been difficult because background capacitive currents are inherently unstable over long recording periods. To measure tonic changes in DA concentrations over several hours, we applied a novel charge-balancing multiple waveform FSCV (CBM-FSCV), combined with a dual background subtraction technique, to minimize temporal variations in background capacitive currents. Using this method, in vitro, charge variations from a reference time point were nearly zero for 48 h, whereas with conventional background subtraction, charge variations progressively increased. CBM-FSCV also demonstrated a high selectivity against 3,4-dihydroxyphenylacetic acid and ascorbic acid, two major chemical interferents in the brain, yielding a sensitivity of 85.40 ± 14.30 nA/μM and limit of detection of 5.8 ± 0.9 nM for DA while maintaining selectivity. Recorded in vivo by CBM-FSCV, pharmacological inhibition of DA reuptake (nomifensine) resulted in a 235 ± 60 nM increase in tonic extracellular DA concentrations, while inhibition of DA synthesis (α-methyl-dl-tyrosine) resulted in a 72.5 ± 4.8 nM decrease in DA concentrations over a 2 h period. This study showed that CBM-FSCV may serve as a unique voltammetric technique to monitor relatively slow changes in tonic extracellular DA concentrations in vivo over a prolonged time period.

  18. Physic nut seed productivity (Jatropha curcas L.), in rainy season, under different drip irrigation levels and potassium dosages; Produtividade de sementes de pinhao-manso (Jatropha curcas L.), da estacao chuvosa, submetido a diferentes laminas de irrigacao e adubacao potassica

    Energy Technology Data Exchange (ETDEWEB)

    Deus, Fabio Ponciano de; Faria, Manoel Alves de; Portela, Jaqueline Damyane [Universidade Federal de Lavras (DEG/UFLA), Lavras, MG (Brazil). Dept. de Engenharia], E-mail: fpdagricola@yahoo.com.br; Oliveira, Ednaldo Liberato de [Centro Federal de Educacao Tecnologica (CEFET), Januaria, MG (Brazil)

    2010-07-01

    The aim of this research was to value the Physic nut seed productivity, in rainy season, under different drip irrigation levels and potassium dosages, for 2008, 2009 and for the accumulated of theses years, in Lavras - MG, Brazil. The experimental design was the one of randomized blocks, in split plot design, with four replicates. The treatment levels were four water levels (plots) and four potassium dosages (subplots). The irrigation was applied based on the amount estimated by the water balance considering the class A pan evaporation (ECA) and rain depths - L{sub 0} (non irrigated), L{sub 40}, L{sub 80} and L{sub 120} (40, 80 and 120% of the balance respectively). The potassium dosages were K{sub 30}, K{sub 60}, K{sub 90} and K{sub 120} (30, 60, 90 and 120 kg.ha{sup -1} respectively). It was used the drip irrigation system. It was used the Sisvar 4.0 software, for analysis of variance and the Tukey test at 5% level of probability to compare the means. However, it was possible to observe in rainy season, that the irrigation has not changed the Physic nut seed productivity. The potassium level 120 kg.ha{sup -1} in all significant situations was the treatment with higher productivity. (author)

  19. Effect of salinity levels and lead and cadmium heavy metals on growth, photosynthetic pigments and sodium and potassium content in spinach

    Directory of Open Access Journals (Sweden)

    H. Ghorbani

    2016-06-01

    Full Text Available Heavy metals (HMs are hazardous environmental pollutants which by entering the food chain cause harm to humans, plants and other organisms. In order to study the effects of salinity and lead (Pb and cadmium (Cd HMs on spinach plant, a factorial, pot experiment, based on complete randomized blocks design, was carried out in 2013 in College of Agriculture, Shahrood University of Technology. Treatments consisted of three levels of salinity (0, 4 and 8 dS/m as factor A and HMs at four levels (control, Cd, Pb and Cd+Pb as Factor B. results revealed that salinity had no significant effect on fresh and dry weight of spinach; but HMs treatment caused significant changes in these traits. Minimum and maximum fresh and dry weights were obtained in the Cd and Cd+Pb treatments, respectively. Besides photosynthetic pigments of flavonoids and anthocyanin, salinity had significant effect only on chlorophyll a, chlorophyll b, cartenoid contents and reduced them at 8 dS/m level. Salinity treatment, without affecting potassium content, increased sodium and soluble carbohydrates in spinach leaves. Interaction between salinity and HMs was only significant for carbohydrate, chlorophyll a and chlorophyll b. The highest amount of carbohydrate was obtained in the Cd+Pb and 8 dS/m treatment and the highest amount of chlorophyll a and chlorophyll b was obtained in the no salinity (control and Pb treatment.

  20. Elevated extracellular calcium increases fibroblast growth factor-2 gene and protein expression levels via a cAMP/PKA dependent pathway in cementoblasts.

    Science.gov (United States)

    Kanaya, Sousuke; Nemoto, Eiji; Ebe, Yukari; Somerman, Martha J; Shimauchi, Hidetoshi

    2010-09-01

    Cementoblasts, tooth root lining cells, are responsible for laying down cementum on the root surface, a process that is indispensable for establishing a functional periodontal ligament. Cementoblasts share phenotypical features with osteoblasts. Elevated levels of extracellular Ca(2+) have been implicated in osteogenesis by stimulating the proliferation and differentiation of osteoblasts; however, the role of extracellular Ca(2+) signaling in cementogenesis has not been examined. Using RT-PCR, we found that elevated levels of extracellular Ca(2+) increase fibroblast growth factor (FGF)-2 gene expression with a peak at 6h. Pretreatment with a protein kinase A (PKA) inhibitor, H89, or an adenylate cyclase inhibitor, MDL-12,330A, inhibited Ca(2+)-stimulated Fgf-2 expression. In contrast, pretreatment with the protein kinase C (PKC) inhibitor GF-109203X or the phospholipase C (PLC) inhibitor U73122 did not affect the expression of Fgf-2 transcripts, suggesting that the increase in Fgf-2 expression was dependent on the PKA but not the PLC/PKC signaling pathway. Treatment with an activator of adenylate cyclase, forskolin, or a cell-permeable analog of cAMP, 8-Br-cAMP, enhanced Ca(2+)-stimulated Fgf-2 expression, but a single treatment with forskolin or 8-Br-cAMP did not, suggesting that cAMP generation is indispensable but not sufficient for Ca(2+)-stimulated FGF2 expression. Next, we examined the cation specificity of the putative receptor and showed that treatment with trivalent/divalent inorganic ions, Ca(2+), Gd(3+), Sr(2+), or Al(3+), caused a dose-dependent increase in Fgf-2 mRNA levels in a cAMP-dependent fashion, whereas Mg(2+) and the organic ions neomycin and spermine had no effect on Fgf-2 gene expression levels. These findings suggest that an extracellular Ca(2+)-sensing mechanism is present in cementoblasts and its activation leads to FGF-2 stimulation in a cAMP/PKA dependent fashion. Understanding the pathway regulating key genes involved in modulating the

  1. Potassium Aspartate Attenuates Brain Injury Induced by Controlled Cortical Impact in Rats Through Increasing Adenosine Triphosphate (ATP) Levels, Na+/K+-ATPase Activity and Reducing Brain Edema.

    Science.gov (United States)

    Gu, Yi; Zhang, Jie; Zhao, Yumei; Su, Yujin; Zhang, Yazhuo

    2016-12-13

    BACKGROUND Potassium aspartate (PA), as an electrolyte supplement, is widely used in clinical practice. In our previous study, we found PA had neuroprotective effects against apoptosis after cerebral ischemia/reperfusion in rats. In this study, we examine whether PA has protective effects on traumatic brain injury (TBI). MATERIAL AND METHODS TBI was induced by controlled cortical impact (CCI) in rats. Vehicle treatment (control) or PA treatment was administered intraperitoneally at 30 minutes after CCI. The modified neurological severity score (mNSS) and cortical lesion volume were examined. Brain edema and blood-brain barrier (BBB) integrity were measured, as well as brain ATP contents, lactic acid levels, and Na+/K+-ATPase activities. RESULTS We found that CCI induced cortical injury in rats. Acute PA treatment at the dose of 62.5 mg/kg and 125 mg/kg significantly improved neurological deficits (pATP (pATP levels, Na+/K+-ATPase activity, and reducing brain edema. It provides experimental evidence for the clinical application of PA.

  2. Increased Obesity-Associated Circulating Levels of the Extracellular Matrix Proteins Osteopontin, Chitinase-3 Like-1 and Tenascin C Are Associated with Colon Cancer.

    Science.gov (United States)

    Catalán, Victoria; Gómez-Ambrosi, Javier; Rodríguez, Amaia; Ramírez, Beatriz; Izaguirre, Maitane; Hernández-Lizoain, José Luis; Baixauli, Jorge; Martí, Pablo; Valentí, Víctor; Moncada, Rafael; Silva, Camilo; Salvador, Javier; Frühbeck, Gema

    2016-01-01

    Excess adipose tissue represents a major risk factor for the development of colon cancer with inflammation and extracellular matrix (ECM) remodeling being proposed as plausible mechanisms. The aim of this study was to investigate whether obesity can influence circulating levels of inflammation-related extracellular matrix proteins in patients with colon cancer (CC), promoting a microenvironment favorable for tumor growth. Serum samples obtained from 79 subjects [26 lean (LN) and 53 obese (OB)] were used in the study. Enrolled subjects were further subclassified according to the established diagnostic protocol for CC (44 without CC and 35 with CC). Anthropometric measurements as well as circulating metabolites and hormones were determined. Circulating concentrations of the ECM proteins osteopontin (OPN), chitinase-3-like protein 1 (YKL-40), tenascin C (TNC) and lipocalin-2 (LCN-2) were determined by ELISA. Significant differences in circulating OPN, YKL-40 and TNC concentrations between the experimental groups were observed, being significantly increased due to obesity (Pcolon cancer (Pobesity (Pobese patients with CC exhibit increased circulating levels of OPN, YKL-40 and TNC providing further evidence for the influence of obesity on CC development via ECM proteins, representing promising diagnostic biomarkers or target molecules for therapeutics.

  3. Cloning and high level expression of the biologically active extracellular domain of Macaca mulatta CD40 in Pichia pastoris.

    Science.gov (United States)

    Zhu, Shengyun; Wan, Lin; Yang, Hao; Cheng, Jingqiu; Lu, Xiaofeng

    2016-03-01

    The CD40-mediated immune response contributes to a wide variety of chronic inflammatory diseases. CD40 antagonists have potential as novel therapies for immune disorders. However, the CD40 pathway has not been well characterized in the rhesus monkey Macaca mulatta, which is a valuable animal model for human immune disease. An 834 bp transcript was cloned from peripheral blood mononuclear cells (PBMCs) of rhesus monkey using specific primers designed according to the predicted sequence of M. mulatta CD40 (mmCD40) in GenBank. Sequence analysis demonstrated that mmCD40 is highly homologous to human CD40 (hCD40), with an amino acid sequence identity of 94%. Genes encoding the extracellular domain of mmCD40 and the Fc fragment of the hIgG1 were inserted into a pPIC9K plasmid to produce mmCD40Ig by Pichia pastoris. Approximately 15-20 mg of the mmCD40Ig protein with ∼90% purity could be recovered from 1 L of culture. The purified mmCD40Ig protein can form dimers and can specifically bind CD40L-positive cells. Additionally, the mmCD40Ig protein can bind hCD40L protein in phosphate buffered saline and form a stable combination in a size-exclusion chromatography assay using a Superdex 200 column. Moreover, mmCD40Ig is as efficient as M. mulatta CTLA4Ig (mmCTLA4Ig) to suppress Con A-stimulated lymphocyte proliferation. Additionally, mmCD40Ig only showed mild immunosuppressive activity in a one-way mixed lymphocyte reaction (MLR) system. These results suggest that mmCD40Ig secreted by P. pastoris was productive and functional, and it could be used as a tool for pathogenesis and therapies for chronic inflammatory diseases in a M. mulatta model.

  4. Treatment of dentinal hypersensitivity using low-level laser therapy and 5% potassium nitrate: A randomized, controlled, three arm parallel clinical study

    Science.gov (United States)

    Pandey, Ruchi; Koppolu, Pradeep; Kalakonda, Butchibabu; Lakshmi, Bolla Vijaya; Mishra, Ashank; Reddy, Pathakota Krishnajaneya; Bollepalli, Appaiah Chowdary

    2017-01-01

    Aim: The present randomized study was aimed to compare the efficacy 5% potassium nitrate (KNO3) toothpaste, low-level laser therapy (LLLT), and LLLT with 5% KNO3 toothpaste in the treatment of dentinal hypersensitivity (DH). Materials and Methods: Total of 45 patients complaining of DH with visual analog scale (VAS) score being ≥2 were recruited and were divided into three groups. Group A was treated with 5% KNO3 toothpaste, Group B using LLLT along with the application of 5% KNO3 toothpaste, and Group C using LLLT alone. VAS scores were recorded at the baseline, 1st, 2nd, and 3rd weeks by the examiner who is blinded toward the treatment. The sensitivity response was evaluated using air spray and tactile sensation (explorer). Results: A greater reduction of DH was recorded at the end of 3 weeks in Group C and Group B when compared to Group A. Better results were noted in Group C at the end of the 1st week when compared to Group B. According to this study, there was no additional benefit of using toothpaste along with LLLT. Conclusion: A greater reduction of DH was recorded at the end of 3 weeks in Group C and Group B when compared to Group A. Better results were noted in Group C at the end of the 1st week when compared to Group B. According to this study, there was no additional benefit of using toothpaste along with LLLT. PMID:28251111

  5. The critical role of lipid rafts nanodomains in the cross-talk between calcium and reactive oxygen and nitrogen species in cerebellar granule neurons apoptosis by extracellular potassium deprivation

    Directory of Open Access Journals (Sweden)

    Carlos Gutierrez-Merino

    2016-01-01

    Full Text Available The apoptosis of cerebellar granule neurons (CGN induced by low-potassium in serum free medium in vitro has become a widely used model for neuronal apoptosis during in vivo brain development. In this review we shall summarize first the basic features of this model for neuronal apoptosis. Next, we shall focus on the L-type calcium channels (LTCC inactivation as the primary pro-apoptotic signal in low K+-induced CGN death. This apoptotic process can be split into two major and sequential cellular signaling phases: one reversible phase that offers a temporal window for therapeutic interventions to prevent neuronal death, and an irreversible later phase. Therefore, we shall comment next the critical role of reactive oxygen species (ROS production and major ROS sources triggering the entry of CGN in the irreversible stages of low K+-induced apoptosis. Then, we shall present the experimental evidences showing clustering of LTCC and ROS producing enzymes in plasma membrane lipid rafts of CGN matured in vitro, which have opened new perspectives for cell signaling in the early and reversible phase of this apoptosis. The role of lipid rafts nanodomains as fast response calcium/nitric oxide transducers of the switch of CGN to low K+ medium will be discussed next. The two major conclusions drawn from this review are: (1 deregulation of the pool of cytochrome b5 reductase associated to plasma membrane-lipid rafts, at least in part due to overexpression of cytochrome b5, can account for the critical superoxide anion overshot which triggers the entry in the irreversible phase of low K+ apoptosis of CGN, and (2 LTCC inactivation is rapidly transduced by lipid rafts nanodomains into a large drop of cytosolic calcium, a switch-off of nitric oxide production and subsequent inactivation of survival signaling pathways dependent on the activity of CaMKII, PKA and Akt/PKB kinases.

  6. Potassium carbonate poisoning

    Science.gov (United States)

    Potassium carbonate is a white powder used to make soap, glass, and other items. This article discusses poisoning from swallowing or breathing in potassium carbonate. This article is for information only. Do ...

  7. Potassium maldistribution revisited

    African Journals Online (AJOL)

    distributor of 15% potassium chloride has printed instructions ... maldistribution of concentrated 15% potassium chloride after injection into one-liter, flexible, ... rates should be controlled, preferably using an electronic infusion controller.

  8. Adenovirus-induced extracellular signal-regulated kinase phosphorylation during the late phase of infection enhances viral protein levels and virus progeny

    DEFF Research Database (Denmark)

    Schümann, Michael; Dobbelstein, Matthias

    2006-01-01

    during the late phase of infection. Pharmacologic inhibition of ERK phosphorylation reduced virus recovery by >100-fold. Blocking MEK/ERK signaling affected virus DNA replication and mRNA levels only weakly but strongly reduced the amount of viral proteins, independently of the kinases MNK1 and PKR....... Hence, adenovirus induces the oncogenic Raf/MEK/ERK signaling pathway to enhance viral progeny by sustaining the levels of viral proteins. Concerning therapy, our results suggest that the use of Raf/MEK/ERK inhibitors will interfere with the propagation of oncolytic adenoviruses.......The Raf/mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK signaling cascade enhances tumor cell proliferation in many cases. Here, we show that adenovirus type 5, a small DNA tumor virus used in experimental cancer therapy, strongly induces ERK phosphorylation...

  9. Expression patterns of two potassium channel genes in skeletal muscle cells of patients with familial hypokalemic periodic paralysis.

    Science.gov (United States)

    Kim, June-Bum; Lee, Gyung-Min; Kim, Sung-Jo; Yoon, Dong-Ho; Lee, Young-Hyuk

    2011-01-01

    Familial hypokalemic periodic paralysis is an autosomal-dominant disorder characterized by episodic attacks of muscle weakness with hypokalemia. The combination of sarcolemmal depolarization and hypokalemia has been attributed to abnormalities of the potassium conductance governing the membrane potential; however, the molecular mechanism that causes hypokalemia has not yet been determined. To test the hypothesis that the expression patterns of delayed rectifier potassium channel genes in the skeletal muscle cells of patients with familial hypokalemic periodic paralysis differ from those in normal cells. We examined both mRNA and protein levels of two major delayed rectifier potassium channel genes KCNQ3 and KCNQ5 in the skeletal muscle cells from three patients with familial hypokalemic periodic paralysis and three healthy controls. When normal cells were exposed to 50 mM potassium buffer, which was used to induce depolarization, the KCNQ3 protein level significantly increased in the membrane fraction but decreased in the cytosolic fraction, whereas the opposite was true in patient cells. Abnormal subcellular distribution of the KCNQ3 protein was observed in patient cells. Our results suggest that the altered expression of KCNQ3 in patient cells exposed to high extracellular potassium levels could possibly hinder normal function of the channel protein. These findings may provide an important clue to understanding the molecular mechanism of familial hypokalemic periodic paralysis.

  10. Expression patterns of two potassium channel genes in skeletal muscle cells of patients with familial hypokalemic periodic paralysis

    Directory of Open Access Journals (Sweden)

    June-Bum Kim

    2011-01-01

    Full Text Available Background: Familial hypokalemic periodic paralysis is an autosomal-dominant disorder characterized by episodic attacks of muscle weakness with hypokalemia. The combination of sarcolemmal depolarization and hypokalemia has been attributed to abnormalities of the potassium conductance governing the membrane potential; however, the molecular mechanism that causes hypokalemia has not yet been determined. Aim: To test the hypothesis that the expression patterns of delayed rectifier potassium channel genes in the skeletal muscle cells of patients with familial hypokalemic periodic paralysis differ from those in normal cells. Material and Methods: We examined both mRNA and protein levels of two major delayed rectifier potassium channel genes KCNQ3 and KCNQ5 in the skeletal muscle cells from three patients with familial hypokalemic periodic paralysis and three healthy controls. Results: When normal cells were exposed to 50 mM potassium buffer, which was used to induce depolarization, the KCNQ3 protein level significantly increased in the membrane fraction but decreased in the cytosolic fraction, whereas the opposite was true in patient cells. Conclusion: Abnormal subcellular distribution of the KCNQ3 protein was observed in patient cells. Our results suggest that the altered expression of KCNQ3 in patient cells exposed to high extracellular potassium levels could possibly hinder normal function of the channel protein. These findings may provide an important clue to understanding the molecular mechanism of familial hypokalemic periodic paralysis.

  11. Potassium changes associated with blood transfusion in pediatric patients.

    Science.gov (United States)

    Olson, Jordan; Talekar, Mala; Sachdev, Mansi; Castellani, William; De la Cruz, Nestor; Davis, Jerry; Liao, Jason; George, Melissa

    2013-06-01

    Storing packed red blood cells (pRBCs) increases the potassium concentration. This effect is characterized in citrate phosphate dextrose/citrate phosphate dextrose adenine units but not published for Adsol (AS-5) units. The change in whole-blood potassium concentration in pediatric patients during routine transfusion is also poorly characterized. In this study, pediatric patients undergoing transfusion had pre- and posttransfusion whole-blood potassium measurements. The pRBC unit transfused and the unit's segment were sampled, with potassium concentration measured. In addition, potassium concentration in AS-5 units was measured over 42 days of storage. Unit extracellular potassium increased in AS-5 units after day 7 at 0.83 mmol/L/d. The mean change in patient potassium concentration was 0.08 mmol/L (range, -0.5 to 0.5 mmol/L). No correlation with unit age or unit potassium concentration was identified with change in patient whole-blood potassium concentration. The lack of clinical effect on patient potassium does not support the use of "fresh" pRBC units with routine pediatric transfusion.

  12. Diagnosis of drowning by summation of sodium, potassium and chloride ion levels in pleural effusion: differentiating between freshwater and seawater drowning and application to bathtub deaths.

    Science.gov (United States)

    Yajima, Daisuke; Saito, Hisako; Sato, Kaoru; Hayakawa, Mutsumi; Iwase, Hirotaro

    2013-12-10

    Although electrolyte analysis of pleural effusion at autopsy is useful for the diagnosis of water aspiration (i.e., drowning), the method of comparing each level of sodium (Na(+)), potassium (K(+)), and chloride (Cl(-)) ions does not clearly differentiate between freshwater drowning, seawater drowning, and non-drowning. Therefore, here we introduce the summation of Na(+), K(+), and Cl(-) levels, that is SUM(Na+K+Cl), as a modified diagnostic indicator. In 21 autopsy cases of freshwater drowning, 32 cases of seawater drowning, and 43 non-drowning controls (with pleural effusion), mean SUM(Na+K+Cl) differed significantly between the groups (188.8±33.2, 403.5±107.9, and 239.3±21.7 mEq/L, respectively). We defined a SUM(Na+K+Cl) cut-off value of 282.7 mEq/L as strongly suggestive of seawater aspiration. When these values were applied to the two drowning groups, 15 cases (71%) of freshwater drowning and 29 cases (91%) of seawater drowning were diagnosed correctly. This new approach may be more valid than previous methods in cases found >2 days after death or those with substantial pleural effusion (>100 mL). For an additional 15 bathtub deaths, mean SUM(Na+K+Cl) was 198.8±40.0 mEq/L, and in 14 of these cases (93%) the relationship between cause of death and SUM(Na+K+Cl) could be explained using this method. Forensic pathologists should not depend exclusively on chemical findings and should consider also typical pathological indicators of drowning. This new method may be useful as a supplementary diagnostic tool when used alongside consideration of the pathological findings.

  13. Serum HER 2 extracellular domain level is correlated with tissue HER 2 status in metastatic gastric or gastro-oesophageal junction adenocarcinoma.

    Directory of Open Access Journals (Sweden)

    Shu-Qin Dai

    Full Text Available BACKGROUND: To explore the association between serum human epidermal growth factor receptor 2 (HER 2 extracellular domain (ECD levels and tissue HER 2 status in metastatic gastric cancer. PATIENTS AND METHODS: HER 2 status was retrospectively analyzed in 219 advanced gastric or gastroesophageal junction (GEJ patients. Serum HER 2 ECD was measured by chemiluminescent assay and tissue HER 2 was assessed by fluorescent in situ hybridisation (FISH and immunohistochemistry (IHC assay. RESULTS: Significant associations were found between serum HER 2 ECD levels and tissue HER 2 status. Twenty-four patients had HER 2 ECD levels >16.35 ng/mL, which has a sensitivity of 51.4% and a specificity of 97.3% to predict tissue HER 2 status. When the cut-off value was increased to 22 ng/mL, then all 12 patients with serum HER 2 ECD levels>22 ng/mL were tissue HER 2 positive, corresponding to a specificity of 100% and a sensitivity of 32.4%. High serum HER 2 ECD levels were strongly associated with the intestinal histological type (Lauren's classification, liver metastasis, multiple metastasis (>2 and increased LDH levels, but not with overall survival. CONCLUSIONS: The high specificity of the serum HER 2 ECD assay in predicting tissue HER 2 status suggests its potential as a surrogate marker of the HER 2 status in gastric cancer.

  14. Increased Obesity-Associated Circulating Levels of the Extracellular Matrix Proteins Osteopontin, Chitinase-3 Like-1 and Tenascin C Are Associated with Colon Cancer

    Science.gov (United States)

    Catalán, Victoria; Gómez-Ambrosi, Javier; Rodríguez, Amaia; Ramírez, Beatriz; Izaguirre, Maitane; Hernández-Lizoain, José Luis; Baixauli, Jorge; Martí, Pablo; Valentí, Víctor; Moncada, Rafael; Silva, Camilo; Salvador, Javier; Frühbeck, Gema

    2016-01-01

    Background Excess adipose tissue represents a major risk factor for the development of colon cancer with inflammation and extracellular matrix (ECM) remodeling being proposed as plausible mechanisms. The aim of this study was to investigate whether obesity can influence circulating levels of inflammation-related extracellular matrix proteins in patients with colon cancer (CC), promoting a microenvironment favorable for tumor growth. Methods Serum samples obtained from 79 subjects [26 lean (LN) and 53 obese (OB)] were used in the study. Enrolled subjects were further subclassified according to the established diagnostic protocol for CC (44 without CC and 35 with CC). Anthropometric measurements as well as circulating metabolites and hormones were determined. Circulating concentrations of the ECM proteins osteopontin (OPN), chitinase-3-like protein 1 (YKL-40), tenascin C (TNC) and lipocalin-2 (LCN-2) were determined by ELISA. Results Significant differences in circulating OPN, YKL-40 and TNC concentrations between the experimental groups were observed, being significantly increased due to obesity (P<0.01) and colon cancer (P<0.05). LCN-2 levels were affected by obesity (P<0.05), but no differences were detected regarding the presence or not of CC. A positive association (P<0.05) with different inflammatory markers was also detected. Conclusions To our knowledge, we herein show for the first time that obese patients with CC exhibit increased circulating levels of OPN, YKL-40 and TNC providing further evidence for the influence of obesity on CC development via ECM proteins, representing promising diagnostic biomarkers or target molecules for therapeutics. PMID:27612200

  15. Potassium Secondary Batteries.

    Science.gov (United States)

    Eftekhari, Ali; Jian, Zelang; Ji, Xiulei

    2017-02-08

    Potassium may exhibit advantages over lithium or sodium as a charge carrier in rechargeable batteries. Analogues of Prussian blue can provide millions of cyclic voltammetric cycles in aqueous electrolyte. Potassium intercalation chemistry has recently been demonstrated compatible with both graphite and nongraphitic carbons. In addition to potassium-ion batteries, potassium-O2 (or -air) and potassium-sulfur batteries are emerging. Additionally, aqueous potassium-ion batteries also exhibit high reversibility and long cycling life. Because of potentially low cost, availability of basic materials, and intriguing electrochemical behaviors, this new class of secondary batteries is attracting much attention. This mini-review summarizes the current status, opportunities, and future challenges of potassium secondary batteries.

  16. Potassium softens vascular endothelium and increases nitric oxide release

    OpenAIRE

    2009-01-01

    In the presence of aldosterone, plasma sodium in the high physiological range stiffens endothelial cells and reduces the release of nitric oxide. We now demonstrate effects of extracellular potassium on stiffness of individual cultured bovine aortic endothelial cells by using the tip of an atomic force microscope as a mechanical nanosensor. An acute increase of potassium in the physiological range swells and softens the endothelial cell and increases the release of nitric oxide. A high physio...

  17. Effects of time of administration and dietary iodine levels on potassium iodide (KI) blockade of thyroid irradiation by 131I from radioactive fallout.

    Science.gov (United States)

    Zanzonico, P B; Becker, D V

    2000-06-01

    Radioiodines, particularly 131I, may be released into the environment in breach-of-containment nuclear reactor accidents and localize in and irradiate the thyroid with an attendant risk of neoplastic growth and other adverse health effects. Pharmacologic thyroid blockade by oral potassium iodide (KI) (50-100 mg in adults) can substantially reduce thyroid uptake of and irradiation by internalized radioiodine. In the current analysis, computer modeling of iodine metabolism has been used to systematically elucidate the effects of two practically important but highly variable factors on the radioprotective effect of KI: the time of administration relative to exposure to radioiodine and the dietary level of iodine. In euthyroid adults receiving iodine-sufficient diets (250 microg d(-1) in the current analysis), KI administered up to 48 h before 131I exposure can almost completely block thyroid uptake and therefore greatly reduce the thyroid absorbed dose. However, KI administration 96 h or more before 131I exposure has no significant protective effect. In contrast, KI administration after exposure to radioiodine induces a smaller and rapidly decreasing blockade effect. KI administration 16 h or later after 131I exposure will have little effect on thyroid uptake and absorbed dose and therefore little or no protective effect. The 131I thyroid absorbed dose is two-fold greater with insufficient levels of dietary iodine, 2,900 cGy/37 MBq, than with sufficient levels of dietary iodine, 1,500 cGy/37 MBq. When KI is administered 48 h or less before 131I intake, the thyroid absorbed doses (in cGy/37 MBq) are comparably low with both sufficient and insufficient dietary iodine levels. When KI is administered after 131I intake, however, the protective effect of KI is less and decreases more rapidly with insufficient than with sufficient dietary iodine. For example, KI administration 2 and 8 h after 131I intake yields protective effects of 80 and 40%, respectively, with iodine

  18. Noise controlled synchronization in potassium coupled neural models

    DEFF Research Database (Denmark)

    Postnov, Dmitry E; Ryazanova, Ludmila S; Zhirin, Roman 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...... show that potassium induced depolarization underlies the formation of noise-induced patterns such as delayed firing and synchronization. These phenomena are associated with the appearance of new time scales in the distribution of interspike intervals that may be significant for the spatio...

  19. Alterations in potassium channel gene expression in atria of patients with persistent and paroxysmal atrial fibrillation : Differential regulation of protein and mRNA levels for K+ channels

    NARCIS (Netherlands)

    Brundel, BJJM; Van Gelder, IC; Henning, RH; Tuinenburg, AE; Wietses, M; Grandjean, JG; Wilde, AAM; Van Gilst, WH; Crijns, HJGM

    2001-01-01

    OBJECTIVES Our purpose was to determine whether patients with persistent atrial fibrillation (AF) and patients with paroxysmal AF show alterations in potassium channel expression. BACKGROUND Persistent AF is associated with a sustained shortening of the atrial action potential duration and atrial re

  20. Intractable hyperkalemia due to nicorandil induced potassium channel syndrome

    Directory of Open Access Journals (Sweden)

    Vivek Chowdhry

    2015-01-01

    Full Text Available Nicorandil is a commonly used antianginal agent, which has both nitrate-like and ATP-sensitive potassium (K ATP channel activator properties. Activation of potassium channels by nicorandil causes expulsion of potassium ions into the extracellular space leading to membrane hyperpolarization, closure of voltage-gated calcium channels and finally vasodilatation. However, on the other hand, being an activator of K ATP channel, it can expel K + ions out of the cells and can cause hyperkalemia. Here, we report a case of nicorandil induced hyperkalemia unresponsive to medical treatment in a patient with diabetic nephropathy.

  1. Proteome-level display by 2-dimensional chromatography of extracellular matrix-dependent modulation of the phenotype of bladder cancer cells

    Directory of Open Access Journals (Sweden)

    Singh Anil

    2006-06-01

    Full Text Available Abstract Background The extracellular matrix can have a profound effect upon the phenotype of cancer cells. Previous work has shown that growth of bladder cancer cells on a matrix derived from normal basement membrane suppresses many malignant features that are displayed when the cells are grown on a matrix that has been modified by malignant tumors. This work was undertaken to investigate proteome-level changes as determined by a new commercially available proteome display involving 2-dimensional chromatography for bladder cancer cells grown on different extracellular matrix preparations that modulate the expression of the malignant phenotype. Results Depending on the matrix, between 1300 and 2000 distinct peaks were detected by two-dimensional chromatographic fractionation of 2.1 – 4.4 mg of total cellular protein. The fractions eluting from the reversed-phase fractionation were suitable for mass spectrometric identification following only lyophilization and trypsin digestion and achieved approximately 10-fold higher sensitivity than was obtained with gel-based separations. Abundant proteins that were unique to cells grown on one of the matrices were identified by mass spectrometry. Following concentration, peaks of 0.03 AU provided unambiguous identification of protein components when 10% of the sample was analyzed, whereas peaks of 0.05 AU was approximately the lower limit of detection when the entire sample was separated on a gel and in-gel digestion was used. Although some fractions were homogeneous, others were not, and up to 3 proteins per fraction were identified. Strong evidence for post-translational modification of the unique proteins was noted. All 13 of the unique proteins from cells grown on Matrigel were related to MYC pathway. Conclusion The system provides a viable alternative to 2-dimensional gel electrophoresis for proteomic display of biological systems. The findings suggest the importance of MYC to the malignant phenotype

  2. Virus-induced dilated cardiomyopathy is characterized by increased levels of fibrotic extracellular matrix proteins and reduced amounts of energy-producing enzymes.

    Science.gov (United States)

    Nishtala, Krishnatej; Phong, Truong Q; Steil, Leif; Sauter, Martina; Salazar, Manuela G; Kandolf, Reinhard; Kroemer, Heyo K; Felix, Stephan B; Völker, Uwe; Klingel, Karin; Hammer, Elke

    2011-11-01

    The most relevant clinical phenotype resulting from chronic enteroviral myocarditis is dilated cardiomyopathy (DCM). Mice of the susceptible mouse strain A.BY/SnJ mimick well human DCM since they develop as a consequence of persistent infection and chronic inflammation a dilation of the heart ventricle several weeks after coxsackievirus B3 (CVB3) infection. Therefore, this model is well suited for the analysis of changes in the heart proteome associated with DCM. Here, we present a proteomic survey of the dilated hearts based on differential fluorescence gel electrophoresis and liquid chromatography-mass spectrometric centered methods in comparison to age-matched non-infected hearts. In total, 101 distinct proteins, which belong to categories immunity and defense, cell structure and associated proteins, energy metabolism and protein metabolism/modification differed in their levels in both groups. Levels of proteins involved in fatty acid metabolism and electron transport chain were found to be significantly reduced in infected mice suggesting a decrease in energy production in CVB3-induced DCM. Furthermore, proteins associated with muscle contraction (MLRV, MLRc2, MYH6, MyBPC3), were present in significantly altered amounts in infected mice. A significant increase in the level of extracellular matrix proteins in the dilated hearts indicates cardiac remodeling due to fibrosis.

  3. Potassium food supplement

    Science.gov (United States)

    Bourland, C. T.; Huber, C. S.; Rambaut, C.; Heidelbaugh, N. D.

    1973-01-01

    Potassium gluconate is considered best supplementary source for potassium. Gluconate consistently received highest taste rating and was indistinguishable from nonsupplemented samples. No unfavorable side effects were found during use, and none are reported in literature. Gluconate is normal intermediary metabolite that is readily adsorbed and produces no evidence of gastrointestinal ulcerations.

  4. Penicillin V Potassium Oral

    Science.gov (United States)

    V-Cillin K® ... Penicillin V potassium is an antibiotic used to treat certain infections caused by bacteria such as pneumonia, scarlet fever, ... Penicillin V potassium comes as a tablet and liquid to take by mouth. It is usually taken every 6 ...

  5. 不同施肥条件下甘蔗对钾的吸收利用研究%Potassium uptake and its utilization in sugarcane under the different fertilization levels

    Institute of Scientific and Technical Information of China (English)

    谭宏伟; 周柳强; 谢如林; 黄美福

    2011-01-01

    [目的]明确不同施肥条件下甘蔗对钾的吸收利用规律.[方法]以甘蔗品种新台糖22号为试材,进行第1年新植蔗、第2年宿根蔗不同施肥处理田间试验,各生育阶段分别测定各处理甘蔗对钾的吸收强度、对钾肥的利用率以及土壤中钾养分的盈余量,并用阴阳离子交换树脂监测施钾和不施钾处理耕作层土壤钾离子淋溶量.[结果]不同施肥条件下,甘蔗各生育阶段对钾的吸收强度存在较大差异;随着生长量的增加,钾养分在甘蔗植株体内的稀释效应明显,植株含钾量以苗期较高,成熟期较低;增施钾肥后甘蔗吸钾量明显增加,新植蔗、宿根蔗对钾肥的利用率分别为34.3%~40.6%、29.4%~31.7%;不同施肥条件下,新植蔗的土壤速效钾和缓效钾含量均有所降低,而宿根蔗中施钾处理的土壤速效钾和缓效钾含量则有所增加;施钾处理较不施钾处理耕作层土壤钾离子淋溶量明显增加;不同施肥条件下,新植蔗和宿根蔗土壤中钾养分平衡均表现为P2K2、N2P2K3处理有所盈余,N2P2K2、N2P2K1、N2P2处理有所亏损,但以N2P2处理亏损最大.[结论]不同施肥条件对甘蔗吸收利用钾素以及土壤中钾素的移动和平衡均有影响,实际生产中应注重氮、磷、钾合理配施,提高肥料利用率,为甘蔗高产优质栽培提供施肥指导.%[Objective]The present experiment was conducted to study the mechanism of potassium uptake and its utilization in sugarcane under the different fertilization levels. [Method]A field experiment was conducted on plant crop and first ratoon crop of sugarcane variety ROC22 to find out the uptake amount and utilization rate of potassium in plants and its surplus content in the soil at different growth stages under different treatments. The cation-anion exchange resin was used to monitor the amount of leaching potassium in the treatments with and without potassium fertilizer. [Result ]Great differences in

  6. High serum levels of extracellular vesicles expressing malignancy-related markers are released in patients with various types of hematological neoplastic disorders.

    Science.gov (United States)

    Caivano, Antonella; Laurenzana, Ilaria; De Luca, Luciana; La Rocca, Francesco; Simeon, Vittorio; Trino, Stefania; D'Auria, Fiorella; Traficante, Antonio; Maietti, Maddalena; Izzo, Tiziana; D'Arena, Giovanni; Mansueto, Giovanna; Pietrantuono, Giuseppe; Laurenti, Luca; Musto, Pellegrino; Del Vecchio, Luigi

    2015-12-01

    Many cell types release extracellular vesicles (EVs), including exosomes, microvesicles (MVs), and apoptotic bodies, which play a role in physiology and diseases. Presence and phenotype of circulating EVs in hematological malignancies (HMs) remain largely unexplored.The aim of this study was to characterize EVs in peripheral blood of HM patients compared to healthy subjects (controls). We isolated serum EVs from patients with chronic lymphocytic leukemia (CLL), non-Hodgkin's lymphoma (NHL), Waldenstrom's macroglobulinemia (WM), Hodgkin's lymphoma (HL), multiple myeloma (MM), acute myeloid leukemia (AML), myeloproliferative neoplasms (MPNs), myelodysplastic syndromes (MDS), and controls. EVs were isolated from serum of peripheral blood by ultracentrifuge steps and analyzed by flow cytometry to define count, size, and immunophenotype. MV levels were significantly elevated in WM, HL, MM, AML, and some MPNs and, though at a lesser degree, in CLL and NHL as compared to healthy controls. HL, MM, and MPNs generated a population of MVs characterized by lower size (below 0.3 μm) when compared to controls. MVs from patients specifically expressed tumor-related antigens, such as CD19 in B cell neoplasms, CD38 in MM, CD13 in myeloid tumors, and CD30 in HL. Both total and antigen-specific count of MVs significantly correlated with different HM clinical features such as Rai stage in CLL, International Prognostic Scoring System in WM, International Staging System in MM, and clinical stage in HL. MVs may represent a novel biomarker in HMs.

  7. A higher response of plasma neuropeptide Y, growth hormone, leptin levels and extracellular glycerol levels in subcutaneous abdominal adipose tissue to Acipimox during exercise in patients with bulimia nervosa: single-blind, randomized, microdialysis study

    Directory of Open Access Journals (Sweden)

    Smitka Kvido

    2011-11-01

    Full Text Available Abstract Background Neuropeptide Y (NPY is an important central orexigenic hormone predominantly produced by the hypothalamus, and recently found to be secreted in adipose tissue (AT. Acipimox (Aci inhibits lipolysis in AT and reduces plasma glycerol and free fatty acid (FFA levels. Exercise and Aci are enhancers of growth hormone (GH and NPY secretion and exercise may alter leptin levels. We expect to find abnormal neuropeptidergic response in plasma and AT in patients with bulimia nervosa (BN. We hypothesize that Aci influences these peptides via a FFA-independent mechanism and that Aci inhibits lipolysis through a cyclic adenosine monophosphate (cAMP-dependent pathway. Dysregulations of the AT-brain axis peptides might be involved in binge eating as is the case in BN. Methods The objective of this study was to determine the responses of plasma NPY, GH, leptin, FFA and glycerol levels to exercise in BN patients and healthy women (C given the anti-lipolytic drug Aci or placebo. The secondary objective of this study was to compare the responses of extracellular glycerol levels and plasma glycerol levels to exercise alone or together with Aci administration in BN patients and C women. Extracellular glycerol was measured in vivo in subcutaneous (sc abdominal AT using microdialysis. Eight BN and eight C women were recruited for this single-blind, randomized study. Aci or placebo was given 1 hour before the exercise (45 min, 2 W/kg of lean body mass [LBM]. NPY, GH, leptin, FFA, glycerol plasma and AT glycerol levels were measured using commercial kits. Results The primary outcome of this study was that the exercise with Aci administration resulted in plasma NPY and GH increase (after a 45-minute exercise and leptin (after a 90-minute post-exercise recovering phase increased more in BN patients. The secondary outcomes of this study were that the exercise with Aci administration induced a higher decrease of extracellular glycerol in BN patients

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

    DEFF Research Database (Denmark)

    Brazhe, Alexey; Maksimov, G. V.; Mosekilde, Erik;

    2011-01-01

    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......-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....

  9. Effects of Different Potassium Levels on Eggplant Solanine Content and Distribution%不同钾水平对茄子茄碱含量和分配的影响

    Institute of Scientific and Technical Information of China (English)

    王菲; 李银科; 叶学见; 王正银

    2015-01-01

    采用盆栽试验的方式,就不同钾水平对盆栽茄子生物量和茄碱含量、累积量及分配的影响进行研究,以期从植物营养角度控制茄子茄碱的形成和累积,达到改善茄子口感和风味品质的目的.结果表明,施用钾肥后茄子各器官以果实增产效果最为明显.施钾处理可使茄子果实中茄碱含量显著降低,果蒂、根、茎、花等器官的茄碱含量总体上也表现为降低.两个采收期茄子果实茄碱累积量均在施用钾肥后升高,以中量和高量钾处理影响最大,而果蒂、茎、花的茄碱累积量呈下降趋势.茄子果实中茄碱分配最多,其次为叶片,花瓣分配最少.两个采收期果蒂、花等器官茄碱分配系数随钾水平增加而降低.施用钾肥能降低果实茄碱含量,但对茄碱在果实中的累积和分配有增加趋势.%This experiment studies the effect of different potassium levels on eggplant biomass,solanine content,solanine accumulation and distribution,so as to understand from plant nutrition view point how to control by certain extent the solanine formation and accumulation in eggplant,and then to improve the taste and flavor quality. Pot experiment was conducted in this experiment. The results indicated that eggplant fruit weight increase was distinct after applying potassium fertilizer. The solanine content in eggplant fruit was reduced remarkably after applying potassium fertilizer,that in other organs were also reduced. During 2 harvesting times,the solanine accumulation in eggplant fruit increased after applying potassium fertilizer,especially with moderate and large quantity of potassium fertilization. But that in fruit base,stem and flower showed declining tendency. The largest solanine distribution was observed in eggplant fruit ,then followed by leaf,and the least was in flower. While, solanine distribution coefficient in fruit base, flower,etc. organs were decreased along with the increase of potassium level

  10. Thermal diffusion of potassium on the modified iron surface

    Energy Technology Data Exchange (ETDEWEB)

    Narkiewicz, U. [Institute of Chemical and Environment Engineering, Technical University of Szczecin, PuIaskiego 10, 70-322 Szczecin (Poland)]. E-mail: urszula.narkiewicz@ps.pl; Moszynski, D. [Institute of Chemical and Environment Engineering, Technical University of Szczecin, PuIaskiego 10, 70-322 Szczecin (Poland); BrosIawski, M. [Institute of Chemical and Environment Engineering, Technical University of Szczecin, PuIaskiego 10, 70-322 Szczecin (Poland)

    2005-10-31

    The diffusion of potassium on the polycrystalline iron surface modified by adsorbed oxygen and nitrogen has been studied by means of AES. The migration of potassium atoms has been observed independently on the constitution of the iron surface in the temperature range between 300 and 450 deg. C. The final concentration of potassium on the iron surface increases with temperature from 300 to 400 deg. C, irrespective of what atoms accompany potassium on the surface. At 450 deg. C, the final level of potassium concentration is decreased. The profiles of the concentration on the surface along the line crossing the source of potassium were also acquired. Applying the diffusion model of finite source, the diffusion coefficient of potassium for oxygen-covered and nitrogen-covered surfaces were evaluated.

  11. Efeito da fertirrega com azoto e potássio num olival sobre os teores de nitratos e de potássio do solo Effect of nitrogen and potassium fertigation in an olive grove on soil levels of nitrate and potassium

    Directory of Open Access Journals (Sweden)

    Mª Encarnação Marcelo

    2011-07-01

    os teores de potássio extraível não sofreram alterações significativas nas quatro camadas de solo estudadas.The use of drip irrigation systems allows the application of fertilizers through water providing the necessary nutrients to crops in times of greater consumption. In the case of the olive tree, it is increasingly common the use of this cultural technique, especially in young olive groves, but in most cases this fertilization is carried out empirically. In order to evaluate the effect of nitrogen and potassium applied by fertigation on yield, on foliar nutrient concentrations and on some soil parameters, a field experiment was established on an olive grove, cv. Cobrançosa, planted in 1990 in Safara, in the Portuguese region of Alentejo. Three levels of nitrogen (0, 50 and 100 kg ha-1 N and potassium (0, 42 and 84 kg ha-1 K were used, arranged into a factorial experiment with three replications. The trees were irrigated with a drip irrigation system. The management of irrigation was made using tensiometers, and all trees received the same amount of water. The nitrogen (UAN solution was applied through fertigation from March to September and the potassium (potassium sulphate from April to October. The present paper reports the results on nitrate and potassium concentrations at different soil depths (0-0.2 m, 0.2-0.4 m, 0.4-0.6 m and 0.6-0.8 m in the first two years. Nitrogen fertilization caused an increase in soil N-NO3- concentration between 0.2 and 0.8 m depth. This effect was more pronounced in the samples taken in the two deeper layers and when it was applied the highest level of nitrogen (100 kg ha-1 N. For the potassium, the effect of potassium fertilization occurred on exchangeable potassium only in 0-0.2 m and 0.2-0.4 m depths, whereas the levels of extractable potassium did not suffer significant changes in four soil layers studied.

  12. KV7 potassium channels

    DEFF Research Database (Denmark)

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

    2014-01-01

    identified as being crucial mediators of this process in a variety of smooth muscle. Recently, KV7 channels have been shown to be involved in the pathogenesis of hypertension, as well as being implicated in other smooth muscle disorders, providing a new and inviting target for smooth muscle disorders.......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...

  13. Calcium-activated potassium conductance noise in snail neurons.

    Science.gov (United States)

    Westerfield, M; Lux, H D

    1982-11-01

    Current fluctuations were measured in small, 3-6 micrometers-diameter patches of soma membrane in bursting neurons of the snail, Helix pomatia. The fluctuations dramatically increased in magnitude with depolarization of the membrane potential under voltage clamp conditions. Two components of conductance noise were identified in the power spectra calculated from the membrane currents. One component had a corner frequency which increased with depolarization. This component was blocked by intracellular injection of TEA and was relatively insensitive to extracellular calcium levels (as long as the total number of effective divalent cations remained constant). It was identified as fluctuations of the voltage-dependent component of delayed outward current. The second component of conductance noise had a corner frequency which decreased with depolarization. It was relatively unaffected by TEA injection and was reversibly blocked by substitution of extracellular calcium with magnesium, cobalt, or nickel. This second component of noise was identified as fluctuations of the calcium-dependent potassium current. The results suggest that the two components of delayed outward current are conducted through physically distinct channels.

  14. [Effect of angiotensin II receptor antagonist (losartan) on renal function, serum potassium and blood pressure in patients with advanced renal failure: differences between patients with a serum creatinine (SCr) level higher than 3 mg/dl and those with a lower SCr level].

    Science.gov (United States)

    Nakayama, Masaaki; Tanno, Yudo; Otsuka, Yasushi; Takahashi, Hajime; Ikeda, Masato; Katoh, Naohiko; Yokoyama, Keitaro; Yamamoto, Hiroyasu; Tokutome, Goro; Hosoya, Tatsuo

    2002-10-01

    The administration of angiotensin II receptor antagonist(AIIA) to patients with advanced chronic renal failure(CRF) is not actively recommended. This study was performed to verify the appropriateness of this situation and to determine if there are any substantial differences between patients with a serum creatinine(SCr) level higher than 3 mg/dl and those with a lower SCr level in terms of the clinical effects such as renal function, serum potassium level and systemic blood pressure(BP) after the administration of AIIA. Sixteen patients with advanced CRF who were admitted to the out-patient clinic in Jikei University Hospital(1998/1-1999/12) were enrolled(average age: 65 years, underlying renal disease: diabetic nephropathy 6, CGN 5, and other 1). They had never been administered AIIA before. The patients were classified into two groups in accordance with their level of SCr: group A(SCr lower than 3.0 mg/dl; n = 11), and Group B(SCr higher than 3.0 mg/dl; n = 5). Losartan(50 mg/day) administration was started in order to examine parameters such as the SCr, potassium, BP at the out-patient clinic, and urinary protein excretion at the 0, 1, 3, 6, 9, and 12 month time points. Although the 1/SCr values provided negative slopes with time in both groups, no significant difference was found between the two slopes. There were no changes in the serum potassium levels or urinary protein excretion during the study period in either group, and no statistical difference was found between the two groups. Although the serum potassium level exceeded 5.5 mEq/l in two patients each in both groups, the level was controlled by diet therapy with restricted potassium. BP was reduced significantly in both groups during the study period, and no statistical difference in BP reduction was observed between the two groups. In conclusion, the results indicate there were no differences in the effect on renal function, serum potassium levels or systemic BP between the patients with a SCr level

  15. Potassium in diet

    Science.gov (United States)

    ... pills) to treat high blood pressure or heart failure Take too many laxatives Have severe or prolonged vomiting and diarrhea Have certain kidney or adrenal gland disorders Too much potassium in the blood ...

  16. Detection of basal and potassium-evoked acetylcholine release from embryonic DRG explants.

    Science.gov (United States)

    Bernardini, Nadia; Tomassy, Giulio Srubek; Tata, Ada Maria; Augusti-Tocco, Gabriella; Biagioni, Stefano

    2004-03-01

    Spontaneous and potassium-induced acetylcholine release from embryonic (E12 and E18) chick dorsal root ganglia explants at 3 and 7 days in culture was investigated using a chemiluminescent procedure. A basal release ranging from 2.4 to 13.8 pm/ganglion/5 min was detected. Potassium application always induced a significant increase over the basal release. The acetylcholine levels measured in E12 explants were 6.3 and 38.4 pm/ganglion/5 min at 3 and 7 days in culture, respectively, while in E18 explant cultures they were 10.7 and 15.5 pm/ganglion/5 min. In experiments performed in the absence of extracellular Ca2+ ions, acetylcholine release, both basal and potassium-induced, was abolished and it was reduced by cholinergic antagonists. A morphometric analysis of explant fibre length suggested that acetylcholine release was directly correlated to neurite extension. Moreover, treatment of E12 dorsal root ganglion-dissociated cell cultures with carbachol as cholinergic receptor agonist was shown to induce a higher neurite outgrowth compared with untreated cultures. The concomitant treatment with carbachol and the antagonists at muscarinic receptors atropine and at nicotinic receptors mecamylamine counteracted the increase in fibre outgrowth. Although the present data have not established whether acetylcholine is released by neurones or glial cells, these observations provide the first evidence of a regulated release of acetylcholine in dorsal root ganglia.

  17. Potassium currents in type II vestibular hair cells isolated from the guinea-pig's crista ampullaris.

    Science.gov (United States)

    Griguer, C; Kros, C J; Sans, A; Lehouelleur, J

    1993-11-01

    Type II vestibular hair cells were isolated from cristae ampullares of guinea-pig and maintained in vitro for 2-3 h. Outward membrane currents were studied under whole-cell voltage-clamp conditions. Type II hair cells had resting potentials of about -45 mV. Depolarizing voltage steps from a holding potential of -80 or -90 mV induced time- and voltage-dependent outward currents which slowly decayed to a sustained level. Tail currents reversed at about -70 mV, indicating that the outward currents were mainly carried by potassium ions. The currents had an activation threshold around -50 mV. The transient component was completely removed by a depolarizing pre-pulse positive to -10 mV. While bath application of 4-aminopyridine (5 mM) reduced both components, extracellular tetraethylammonium (10 mM) or zero calcium preferentially diminished the sustained current. We conclude that at least two potassium conductances are present, a delayed rectifier with a relatively fast inactivation and a calcium-dependent potassium current. Depolarizing current injections induced an electrical resonance in the voltage responses, with a frequency of 25-100 Hz, larger currents causing higher frequencies.

  18. The relationship between serum potassium, potassium variability and in-hospital mortality in critically ill patients and a before-after analysis on the impact of computer-assisted potassium control

    NARCIS (Netherlands)

    Hessels, Lara; Hoekstra, Miriam; Mijzen, Lisa J.; Vogelzang, Mathijs; Dieperink, Wim; Lansink, Annemieke Oude; Nijsten, Maarten W.

    2015-01-01

    Introduction: The relationship between potassium regulation and outcome is not known. Our first aim in the present study was to determine the relationship between potassium level and variability in (ICU) stay and outcome. The second aim was to evaluate the impact of a computer-assisted potassium reg

  19. Serum, liver, and lung levels of the major extracellular matrix components at the early stage of BCG-induced granulomatosis depending on the infection route.

    Science.gov (United States)

    Kim, L B; Shkurupy, V A; Putyatina, A N

    2015-01-01

    Experiments on the model of mouse BCG-induced granulomatous showed that the content of glycosaminoglycans and proteoglycans in the extracellular matrix of the liver and lungs are changed at the early stages of inflammation (days 3 and 30 postinfection) before cell destruction in the organs begins. This is related to degradation of extracellular matrix structures. Their high content in the blood and interstitium probably contributes to the formation of granulomas, fibroblast proliferation and organ fibrosis. These processes depend on the infection route that determines different conditions for generalization of the inflammation process. Intravenous method of vaccine injection is preferable to use when designing the experiments simulating tuberculosis granulomatosis, especially for the analysis of its early stages.

  20. Variation in Extracellular Protease Production among Clinical Isolates of Staphylococcus aureus Due to Different Levels of Expression of the Protease Repressor sarA

    OpenAIRE

    Karlsson, Anna; Arvidson, Staffan

    2002-01-01

    Staphylococcus aureus produces four major extracellular proteases: staphylococcal serine protease (V8 protease; SspA), cysteine protease (SspB), metalloprotease (aureolysin; Aur), and staphopain (Scp). Several in vitro studies have suggested that these enzymes are important virulence factors. Here we analyzed the protease production of 92 S. aureus strains from infected human soft tissue. Twenty-one strains produced variable zones of proteolysis on casein agar plates, while the remaining 71 s...

  1. Crescimento, nutrição mineral e nível crítico foliar de K em mudas de umbuzeiro, em função da adubação potássica Growth, mineral nutrition and foliar critical level of K in umbuzeiro seedlings, in function of the potassium fertilization

    Directory of Open Access Journals (Sweden)

    Orlando Sílvio Caires Neves

    2007-06-01

    Full Text Available O umbuzeiro (Spondias tuberosa Arr. Cam. é uma frutífera originária da região nordeste do Brasil e se caracteriza pela alta tolerância à seca. O crescimento, a nutrição mineral e o nível crítico foliar de potássio em mudas de umbuzeiros crescidas num Latossolo Vermelho distroférrico, em função de doses de potássio, foram avaliados neste experimento. O delineamento experimental utilizado foi o de blocos casualizados com quatro repetições e seis doses de potássio (0, 30, 60, 120, 240 e 480 mg dm-3. A adubação potássica foi realizada parceladamente, em quatro aplicações, tendo como fontes o sulfato de potássio e o cloreto de potássio. Enquanto para atingir a máxima produção de folhas a dose de potássio foi de 137 mg dm-3, a máxima produção de raízes só aconteceu na dose de 229 mg dm-3. Os teores foliares de potássio nas mudas do umbuzeiro aumentaram com a adubação potássica. O nível crítico de potássio nas folhas das mudas do umbuzeiro variou de 3,40 a 6,04 g kg-1.The umbuzeiro (Spondias tuberosa Arr. Cam. is original of the Northeast of Brazil and it is characterized by tolerance to the drought. The growth, the mineral nutrition and the foliar critical level of potassium in umbuzeiro seedlings, grown in distroferric Red Latosol, in function of potassium doses, were evaluated in this experiment. The experimental design was randomized blocks with four replications and six doses of potassium (0, 30, 60, 120, 240 and 480, mg dm-3. The potassium fertilization was accomplished in four applications, and the used sources were potassium sulfate and the potassium chloride. The highest production of leaves occurred in the dose of 137 mg dm-3 of potassium and the highest production of roots at the dose of 229 mg dm-3 of potassium. The foliar contents of potassium in the umbuzeiro seedlings increased with the potassium fertilization. The critical level of potassium in the leaves of the umbuzeiro seedlings ranged from 3

  2. Construction of high level prokaryotic expression and purification system of PD-L1 extracellular domain by using Escherichia coli host cell machinery.

    Science.gov (United States)

    Kalim, Muhammad; Chen, Jie; Wang, Shenghao; Lin, Caiyao; Ullah, Saif; Liang, Keying; Ding, Qian; Chen, Shuqing; Zhan, Jinbiao

    2017-10-01

    Programmed cell death 1 ligand 1 (PD-L1) is a trans-membrane protein highly expressed on the membrane of cancer cell, which binds inhibitory receptor of PD-1 on the T cells and attenuates anti-tumor immune response.The strategy of blocking PD1 and PD-L1 interaction has been widely used for anti-cancer drug development. The DNA encoding extracellular domain of PD-L1 was cloned and expressed with the pET30(+) and Escherichia coli BL21(DE3) system. Cloning of PD-L1 extracellular domain was confirmed by PCR and enzymatic digestion. Sequence analysis of cloned targeted genes showed 100% homology of original sequence. The recombinant protein was expressed using 1mM/mL IPTG and purified by affinity chromatography on a column of Ni-NTA and confirmed by SDS-PAGE and western blot analysis. Results showed that our constructed pET30(+)/PDL1-ECD system efficiently produces desired recombinant protein with molecular weight of 38.1kDa. The prokaryotic expression system provides an easy method to express PD-L1 extracellular domain that further facilitate the role of PD-1/PD-L1 binding inhibition and helps in valuable drug and antibodies production. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  3. Analysis of the electrosensory pyramidal cell bursting model for weakly electric fish: model prediction under low levels of dendritic potassium conductance.

    Science.gov (United States)

    Shirahata, T

    2012-09-01

    Pyramidal cells in the electrosensory lateral line lobe (ELL) of weakly electric fish produce burst discharge. A Hodgkin-Huxley-type model, called ghostburster, consisting of two compartments (soma and dendrite) reproduces ELL pyramidal cell bursting observed in vitro. A previous study analyzed the ghostburster by treating Is and gDr,d as bifurcation parameters (Is: current injected into the somatic compartment and gDr,d: maximal conductance of the delayed rectifying potassium current in the dendritic compartment) and indicated that when both Is and gDr,d are set at particular values, the ghostburster shows a codimension-two bifurcation at which both saddle-node bifurcation of fixed points and saddle-node bifurcation of limit cycles occur simultaneously. In the present study, the ghostburster was investigated to clarify the bursting that occurred at gDr,d values smaller than that at the codimension-two bifurcation. Based on the number of spikes per burst, various burst patterns were observed depending on the (Is, gDr,d) values. Depending on the (Is, gDr,d) values, the burst trajectory in a phase space of the ghostburster showed either a high or a low degree of periodicity. Compared to the previous study, the present findings contribute to a more detailed understanding of ghostburster bursting.

  4. A novel potassium deficiency-induced stimulon in Anabaena torulosa

    Indian Academy of Sciences (India)

    Anuradha Alahari; Shree Kumar Apte

    2004-06-01

    Potassium deficiency enhanced the synthesis of fifteen proteins in the nitrogen-fixing cyanobacterium Anabaena 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 synthesis of a majority of the osmotic stress-induced proteins and of PDPs in these bacteria. These proteins contrast with the dinitrogenase reductase of A. torulosa and the glycine betaine-binding protein of E. coli, both of which were osmo-induced to a higher level in potassium-supplemented conditions. The data demonstrate the occurrence of novel potassium deficiency-induced stimulons and a wider role of K+ in regulation of gene expression and stress responses in bacteria.

  5. Low dialysate potassium concentration: an overrated risk factor for cardiac arrhythmia?

    Science.gov (United States)

    Abuelo, J Gary

    2015-01-01

    Serum potassium concentrations rise with dietary potassium intake between dialysis sessions and are often at hyperkalemic levels by the next session. Conversely, potassium concentrations fall during each hemodialysis, and sometimes reach hypokalemic levels by the end. Low potassium dialysate, which rapidly decreases serum potassium and often brings it to hypokalemic levels, is almost universally considered a risk factor for life-threatening arrhythmias. While there is little doubt about the threat of lethal arrhythmias due to hyperkalemia, convincing evidence for the danger of low potassium dialysate and rapid or excess potassium removal has not been forthcoming. The original report of more frequent ventricular ectopy in early dialysis that was improved by reducing potassium removal has received very little confirmation from subsequent studies. Furthermore, the occurrence of ventricular ectopy during dialysis does not appear to predict mortality. Studies relating sudden deaths to low potassium dialysate are countered by studies with more thorough adjustment for markers of poor health. Dialysate potassium concentrations affect the excursions of serum potassium levels above or below the normal range, and have the potential to influence dialysis safety. Controlled studies of different dialysate potassium concentration and their effect on mortality and cardiac arrests have not been done. Until these results become available, I propose interim guidelines for the setting of dialysate potassium levels that may better balance risks and benefits.

  6. Epicardial measurement of alterations in extracellular pH and electrolytes during ischemia and reperfusion in cardiac surgery.

    Science.gov (United States)

    Vogt, Sebastian; Troitzsch, Dirk; Moosdorf, Rainer

    2009-12-01

    Simultaneous measurements of extracellular pH, potassium (K(+)), and calcium (Ca(2+)) activity might be indicative of myocardium vitality or ischemia. Ten consecutive patients undergoing elective coronary artery bypass grafting were studied. Epicardial extracellular pH, potassium, and calcium were measured by a miniaturized disposable multi-sensor probe. Blood gases and electrolytes were derived with measurements of arterial and mixed venous blood samples at intervals during surgery. The mean epicardial baseline levels for pH in all patients were 8.04+/-0.22 arbitrary units (AU) for the right ventricle (RV) and 8.03+/-0.21 AU for the left ventricle (LV); for Ca(2+) 0.23+/-0.07 mmol/l (RV) and 0.20+/-0.10 mmol/l (LV); and for K(+) 4.54+/-1.51 mmol/l (RV) and 4.38+/-0.57 mmol/l (LV). Before ischemia, epicardial pH was moderately (ppH, venous K(+) and Ca(2+), but moderately correlated with arterial K(+) and Ca(2+) (pischemia and reperfusion with reproducible trends of extracellular pH, K(+), and Ca(2+), which results in electrolyte patterns applicable for detecting inadequate myocardial protection during cardiac surgery in patients.

  7. Nível crítico e resposta das culturas ao potássio em um Argissolo sob sistema plantio direto Critical level and crop yield response to potassium in a typic Hapludalf under no-tillage

    Directory of Open Access Journals (Sweden)

    Gustavo Brunetto

    2005-07-01

    Full Text Available O nível crítico de potássio usado para a recomendação de adubação em solos do Rio Grande do Sul e Santa Catarina com CTC a pH 7,0 entre 5,1 e 15,0 cmol c dm-3 é de 60 mg dm-3, embora tenha sido de 80 mg dm-3 até 2002. Este trabalho foi realizado com o objetivo de validar o nível crítico de potássio adotado, nas culturas da soja, do milho e do sorgo. O trabalho foi composto por dois experimentos, instalados na área experimental do Departamento de Solos da UFSM sobre um Argissolo Vermelho distrófico arênico. O primeiro experimento foi instalado em 1991 e realizado até 2002, ocasião em que foram aplicadas quatros doses de potássio (0, 60, 120 e 180 kg ha-1 de K2O, na parcela, a cada quatro anos, e reaplicados 60 kg ha-1 de K2O, nas subparcelas, em 0, 1, 2, ou 3 anos. O segundo experimento foi realizado de 1995 a 2002 e os tratamentos constaram de cinco doses de potássio (0, 50, 100, 150, 200 kg ha-1 ano-1 de K2O. Os resultados obtidos mostraram que o nível crítico de potássio extraído com Mehlich-1 no Argissolo estudado foi de 42 mg dm-3. Para estes solos, com a utilização do novo nível crítico estabelecido pela Comissão de Química e Fertilidade do Solo - RS/SC, foi possível atingir mais de 95 % do rendimento máximo das culturas.The critical potassium level for fertilizer recommendation for soils in the State of Rio Grande do Sul (RS and Santa Catarina (SC with CEC from 5.1 to 15 cmol c dm-3 is 60 mg dm-3. However, until 2002 concentrations of 80 mg dm-3 had been used. Two experiments were carried out on an experimental area of the Department of Soil Science of the Federal University of Santa Maria (RS-Brazil on a Sandy Typic Hapludalf under no-tillage. The objective of the study was to evaluate critical potassium levels for fertilizer recommendations for soybean, maize and sorghum. The first experiment was set up in 1991 and carried out until 2002. The main plot treatments were the application of 0, 60, 120, and 180

  8. Evaluation of random urine sodium and potassium compensated by creatinine as possible alternative markers for 24 hours urinary sodium and potassium excretion.

    Science.gov (United States)

    Koo, Hyunmin; Lee, Sang-Guk; Kim, Jeong-Ho

    2015-03-01

    Sodium and potassium intake was assessed on the basis of its respective excretion levels in 24 hr urine samples. However, owing to the inconvenience of collection, we evaluated random spot urine for alternative sodium and potassium excretion markers. We included 250 patients who submitted 24 hr- and spot urine for clinical tests. However, 22 patients who showed 24 hr urine creatinine excretion levels creatinine (r=0.34, Pcreatinine (r=0.47, Pcreatinine and potassium/creatinine ratios showed a significant correlation with 24 hr urine sodium and potassium excretion, respectively, further studies are required to develop a spot urine test for individualized monitoring of sodium and potassium excretion.

  9. 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.

  10. A systems-level approach to parental genomic imprinting: the imprinted gene network includes extracellular matrix genes and regulates cell cycle exit and differentiation.

    Science.gov (United States)

    Al Adhami, Hala; Evano, Brendan; Le Digarcher, Anne; Gueydan, Charlotte; Dubois, Emeric; Parrinello, Hugues; Dantec, Christelle; Bouschet, Tristan; Varrault, Annie; Journot, Laurent

    2015-03-01

    Genomic imprinting is an epigenetic mechanism that restrains the expression of ∼ 100 eutherian genes in a parent-of-origin-specific manner. The reason for this selective targeting of genes with seemingly disparate molecular functions is unclear. In the present work, we show that imprinted genes are coexpressed in a network that is regulated at the transition from proliferation to quiescence and differentiation during fibroblast cell cycle withdrawal, adipogenesis in vitro, and muscle regeneration in vivo. Imprinted gene regulation is not linked to alteration of DNA methylation or to perturbation of monoallelic, parent-of-origin-dependent expression. Overexpression and knockdown of imprinted gene expression alters the sensitivity of preadipocytes to contact inhibition and adipogenic differentiation. In silico and in cellulo experiments showed that the imprinted gene network includes biallelically expressed, nonimprinted genes. These control the extracellular matrix composition, cell adhesion, cell junction, and extracellular matrix-activated and growth factor-activated signaling. These observations show that imprinted genes share a common biological process that may account for their seemingly diverse roles in embryonic development, obesity, diabetes, muscle physiology, and neoplasm.

  11. Decellularized matrices as in vitro models of extracellular matrix in tumor tissues at different malignant levels: Mechanism of 5-fluorouracil resistance in colorectal tumor cells.

    Science.gov (United States)

    Hoshiba, Takashi; Tanaka, Masaru

    2016-11-01

    Chemoresistance is a major barrier for tumor chemotherapy. It is well-known that chemoresistance increases with tumor progression. Chemoresistance is altered by both genetic mutations and the alteration of extracellular microenvironment. Particularly, the extracellular matrix (ECM) is remodeled during tumor progression. Therefore, ECM remodeling is expected to cause the acquisition of chemoresistance in highly malignant tumor tissue. Here, we prepared cultured cell-derived decellularized matrices that mimic native ECM in tumor tissues at different stages of malignancy, and 5-fluorouracil (5-FU) resistance was compared among these matrices. 5-FU resistance of colorectal tumor cells increased on the matrices derived from highly malignant tumor HT-29 cells, although the resistance did not increase on the matrices derived from low malignant tumor SW480 cells and normal CCD-841-CoN cells. The resistance on HT-29 cell-derived matrices increased through the activation of Akt and the upregulation of ABCB1 and ABCC1 without cell growth promotion, suggesting that ECM remodeling plays important roles in the acquisition of chemoresistance during tumor progression. It is expected that our decellularized matrices, or "staged tumorigenesis-mimicking matrices", will become preferred cell culture substrates for in vitro analysis of comprehensive ECM roles in chemoresistance and the screening and pharmacokinetic analysis of anti-cancer drugs.

  12. High level extracellular production of a recombinant alkaline catalase in E. coli BL21 under ethanol stress and its application in hydrogen peroxide removal after cotton fabrics bleaching.

    Science.gov (United States)

    Yu, Zhenxiao; Zheng, Hongchen; Zhao, Xingya; Li, Shufang; Xu, Jianyong; Song, Hui

    2016-08-01

    The effects of induction parameters, osmolytes and ethanol stress on the productivity of the recombinant alkaline catalase (KatA) in Escherichia coli BL21 (pET26b-KatA) were investigated. The yield of soluble KatA was significantly enhanced by 2% ethanol stress. And a certain amount of Triton X-100 supplementation could markedly improved extracellular ratio of KatA. A total soluble catalase activity of 78,762U/mL with the extracellular ratio of 92.5% was achieved by fed-batch fermentation in a 10L fermentor, which was the highest yield so far. The purified KatA showed high stability at 50°C and pH 6-10. Application of KatA for elimination of H2O2 after cotton fabrics bleaching led to less consumption of water, steam and electric power by 25%, 12% and 16.7% respectively without productivity and quality losing of cotton fabrics. Thus, the recombinant KatA is a promising candidate for industrial production and applications.

  13. POTASSIUM MEASUREMENT: CAUSES OF ERRORS IN MEASUREMENT

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    Kavitha

    2014-07-01

    Full Text Available It is not a easy task to recognize the errors in potassium measurement in the lab. Falsely elevated potassium levels if goes unrecognized by the lab and clinician, it is difficult to treat masked hypokalemic state, which is again a medical emergency. Such cases require proper monitoring by the clinician, so that cases with such history of pseudohyperkalemia which cannot be easily identified in the laboratory should not go unrecognized by clinician. The aim of this article is to discuss the causes and mechanisms of spuriously elevated potassium and minimize the factors causing pseudohyperkalemia. Literature search performed on pubmed using terms “pseudohyperkalemia”, “spurious hyperkalemia”, “and masked hyperkalemia”, “reverse pseudohyperkalemia”, “factitious hyperkalemia”.

  14. Expression of the Genes Encoding the Trk and Kdp Potassium Transport Systems of Mycobacterium tuberculosis during Growth In Vitro

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    Moloko C. Cholo

    2015-01-01

    Full Text Available Two potassium (K+-uptake systems, Trk and Kdp, are operative in Mycobacterium tuberculosis (Mtb, but the environmental factors triggering their expression have not been determined. The current study has evaluated the expression of these genes in the Mtb wild-type and a trk-gene knockout strain at various stages of logarithmic growth in relation to extracellular K+ concentrations and pH. In both strains, mRNA levels of the K+-uptake encoding genes were relatively low compared to those of the housekeeping gene, sigA, at the early- and mid-log phases, increasing during late-log. Increased gene expression coincided with decreased K+ uptake in the context of a drop in extracellular pH and sustained high extracellular K+ concentrations. In an additional series of experiments, the pH of the growth medium was manipulated by the addition of 1N HCl/NaOH. Decreasing the pH resulted in reductions in both membrane potential and K+ uptake in the setting of significant induction of genes encoding both K+ transporters. These observations are consistent with induction of the genes encoding the active K+ transporters of Mtb as a strategy to compensate for loss of membrane potential-driven uptake of K+ at low extracellular pH. Induction of these genes may promote survival in the acidic environments of the intracellular vacuole and granuloma.

  15. The Effects of Boiling and Leaching on the Content of Potassium and Other Minerals in Potatoes

    Science.gov (United States)

    The white potato (Solanum tuberosum L.) is a valuable source of potassium in the human diet. While most consumers benefit from high levels of potassium in potato tubers, individuals with compromised kidney function must minimize their potassium intake. This study was undertaken to determine the ef...

  16. [Diet low in potassium].

    Science.gov (United States)

    Sáez Rodríguez, Loreto; Meizoso Ameneiro, Ana; Pérez Paz, Ma Jesús; Valiño Pazos, Cristina

    2011-11-01

    After confirming the high prevalence rates in our hemodialysis unit of the following nursing diagnoses: nutritional imbalances--both excesses and shortages, willingness to improve nutrition and fear related to the consequences of excessive intake of potassium and manifested by the inhibition in some people towards the enjoyment of food, we decided to plan an educational strategy which later resulted in a nursing intervention for these diagnoses, with the objective of providing adequate resources for the monitoring of balanced diets with a restriction of potassium. Inspired by dietary rations, as well as recognized dietary programs of learning by points, we decided to incorporate these ideas to design an educational tool to facilitate advice to our patients on how to follow diet plans as well as the choice of appropriate foods. The result was a set of cards incorporating nutritional information of various kinds, aimed at our patients covering different aspects of the diet appropriate food rations using household measurements, promoting good food preparation, appropriate dietary advice for different chronic diseases and a scoring system of foods according to their potassium content. Together they form a board game available during the hemodialysis sessions that also takes into consideration other issues of importance related to conditions such as cognitive stimulation, coping with the disease, improving the therapeutic performance or resources to increase patient motivation. Although initially it was only an educational exercise, the result has turned out to be both enjoyable and entertaining.

  17. The role of dietary potassium in hypertension and diabetes.

    Science.gov (United States)

    Ekmekcioglu, Cem; Elmadfa, Ibrahim; Meyer, Alexa L; Moeslinger, Thomas

    2016-03-01

    Potassium is an essential mineral which plays major roles for the resting membrane potential and the intracellular osmolarity. In addition, for several years, it has been known that potassium also affects endothelial and vascular smooth muscle functions and it has been repeatedly shown that an increase in potassium intake shifts blood pressure to a more preferable level. Meanwhile, the blood pressure lowering effects of potassium were presented in several intervention trials and summarized in a handful of meta-analyses. Furthermore, accumulating epidemiological evidence from, especially, the last decade relates low dietary potassium intake or serum potassium levels to an increased risk for insulin resistance or diabetes. However, intervention trials are required to confirm this association. So, in addition to reduction of sodium intake, increasing dietary potassium intake may positively affect blood pressure and possibly also glucose metabolism in many populations. This concise review not only summarizes the studies linking potassium to blood pressure and diabetes but also discusses potential mechanisms involved, like vascular smooth muscle relaxation and endothelium-dependent vasodilation or stimulation of insulin secretion in pancreatic β-cells, respectively.

  18. Potassium Channelopathies and Gastrointestinal Ulceration

    Science.gov (United States)

    Han, Jaeyong; Lee, Seung Hun; Giebisch, Gerhard; Wang, Tong

    2016-01-01

    Potassium channels and transporters maintain potassium homeostasis and play significant roles in several different biological actions via potassium ion regulation. In previous decades, the key revelations that potassium channels and transporters are involved in the production of gastric acid and the regulation of secretion in the stomach have been recognized. Drugs used to treat peptic ulceration are often potassium transporter inhibitors. It has also been reported that potassium channels are involved in ulcerative colitis. Direct toxicity to the intestines from nonsteroidal anti-inflammatory drugs has been associated with altered potassium channel activities. Several reports have indicated that the long-term use of the antianginal drug Nicorandil, an adenosine triphosphate-sensitive potassium channel opener, increases the chances of ulceration and perforation from the oral to anal regions throughout the gastrointestinal (GI) tract. Several of these drug features provide further insights into the role of potassium channels in the occurrence of ulceration in the GI tract. The purpose of this review is to investigate whether potassium channelopathies are involved in the mechanisms responsible for ulceration that occurs throughout the GI tract. PMID:27784845

  19. Potassium Channelopathies and Gastrointestinal Ulceration.

    Science.gov (United States)

    Han, Jaeyong; Lee, Seung Hun; Giebisch, Gerhard; Wang, Tong

    2016-11-15

    Potassium channels and transporters maintain potassium homeostasis and play significant roles in several different biological actions via potassium ion regulation. In previous decades, the key revelations that potassium channels and transporters are involved in the production of gastric acid and the regulation of secretion in the stomach have been recognized. Drugs used to treat peptic ulceration are often potassium transporter inhibitors. It has also been reported that potassium channels are involved in ulcerative colitis. Direct toxicity to the intestines from nonsteroidal anti-inflammatory drugs has been associated with altered potassium channel activities. Several reports have indicated that the long-term use of the antianginal drug Nicorandil, an adenosine triphosphate-sensitive potassium channel opener, increases the chances of ulceration and perforation from the oral to anal regions throughout the gastrointestinal (GI) tract. Several of these drug features provide further insights into the role of potassium channels in the occurrence of ulceration in the GI tract. The purpose of this review is to investigate whether potassium channelopathies are involved in the mechanisms responsible for ulceration that occurs throughout the GI tract.

  20. Effects of the 5-HT1B receptor antagonist NAS-181 on extracellular levels of acetylcholine, glutamate and GABA in the frontal cortex and ventral hippocampus of awake rats: a microdialysis study.

    Science.gov (United States)

    Hu, Xiao Jing; Wang, Fu-Hua; Stenfors, Carina; Ogren, Sven Ove; Kehr, Jan

    2007-09-01

    The purpose of this study was to investigate the effects of the 5-HT(1B) receptor antagonist NAS-181 ((R)-(+)-2-(3-morpholinomethyl-2H-chromen-8-yl) oxymethyl-morpholine methanesulfonate) on cholinergic, glutamatergic and GABA-ergic neurotransmission in the rat brain in vivo. Extracellular levels of acetylcholine, glutamate and GABA were monitored by microdialysis in the frontal cortex (FC) and ventral hippocampus (VHipp) in separate groups of freely moving rats. NAS-181 (1, 5 or 10 mg/kg, s.c.) caused a dose-dependent increase in ACh levels, reaching the maximal values of 500% (FC) and 230% (VHipp) of controls at 80 min post-injection. On the contrary, NAS-181 injected at doses of 10 or 20 mg/kg s.c. had no effect on basal extracellular levels of Glu and GABA in these areas. The present data suggest that ACh neurotransmission in the FC and VHipp, the brain structures strongly implicated in cognitive function, is under tonic inhibitory control of 5-HT(1B) heteroreceptors localized at the cholinergic terminals in these areas.

  1. Extracellular poly(ADP-ribose) is a neurotrophic signal that upregulates glial cell line-derived neurotrophic factor (GDNF) levels in vitro and in vivo.

    Science.gov (United States)

    Nakajima, Hidemitsu; Itakura, Masanori; Sato, Keishi; Nakamura, Sunao; Azuma, Yasu-Taka; Takeuchi, Tadayoshi

    2017-03-04

    Synthesis of poly(ADP-ribose) (PAR) is catalyzed by PAR polymerase-1 (PARP-1) in neurons. PARP1 plays a role in various types of brain damage in neurodegenerative disorders. In neurons, overactivation of PARP-1 during oxidative stress induces robust PAR formation, which depletes nicotinamide adenine dinucleotide levels and leads to cell death. However, the role of the newly-formed PAR in neurodegenerative disorders remains elusive. We hypothesized that the effects of PAR could occur in the extracellular space after it is leaked from damaged neurons. Here we report that extracellular PAR (EC-PAR) functions as a neuroprotective molecule by inducing the synthesis of glial cell line-derived neurotrophic factor (GDNF) in astrocytes during neuronal cell death, both in vitro and in vivo. In primary rat astrocytes, exogenous treatment with EC-PAR produced GDNF but not other neurotrophic factors. The effect was concentration-dependent and did not affect cell viability in rat C6 astrocytoma cells. Topical injection of EC-PAR into rat striatum upregulated GDNF levels in activated astrocytes and improved pathogenic rotation behavior in a unilateral 6-hydroxydopamine model of Parkinson disease in rats. These findings indicate that EC-PAR acts as a neurotrophic enhancer by upregulating GDNF levels. This effect protects the remaining neurons following oxidative stress-induced brain damage, such as that seen with Parkinson disease.

  2. 大量输血对外科手术患者血钾及血糖水平的影响%Effect of massive transfusion on serum potassium and blood glucose levels of patients with surgery

    Institute of Scientific and Technical Information of China (English)

    崔允霞

    2016-01-01

    Objective To investigate the effect of massive transfusion on serum potassium and blood glucose levels of patients with surgery.Methods From January 2012 to December 2014, 232 patients with severe trauma were randomly selected, of the 1232 patients, the 132 cases with massive transfusion as transfusion group, 100 cases with no blood transfusion as no transfusion group.The changes of serum potassium, blood glucose, serum sodium, serum pH value and other indicators of the two groups before surgery (T0), 1 h after operation (T1), 12 h after operation (T2) were compared.Results When it was T1, blood glucose levels of the two groups were significantly higher than when it was T0 and T2, the blood glucose level in transfusion group was higher than that in no transfusion group, the difference was statistically significant(P <0.05);When it was T0 and T1, serum pH value in transfusion group was significantly lower than that in no transfusion group, the difference was significant(P <0.05);The incidence rate of hyperkalemia of transfusion group after operation was 33.3%, which was significantly higher than that of no transfusion group (18%), the difference was significant (P < 0.05).Conclusions Massive blood transfusion after trauma is not easy to cause significant impact on blood potassium level, so the risk of hyperkalemia after operation is relatively low, but real-time signs monitoring is still needed to adopting intervention measures in time to improve safety of treatment.%目的 探讨大量输血对外科手术患者血钾及血糖水平的影响.方法 随机选取2012年1月至2014年12月严重创伤患者232例,其中大量输血者132例为输血组,未输血者100例为无输血组,比较两组术前(T0)、术后1 h(T1)、术后12 h(T2)血钾、血糖、血钠及血清pH值等指标变化.结果 T1时两组患者血糖水平均显著高于T0及T2时,其中输血组患者血糖值高于无输血组,差异有统计学意义(P <0.05);T0及T1时,输血组

  3. Produção de pepino de plantas enxertadas cultivadas em soluções nutritivas com diferentes teores de potássio Growth and yield of grafted cucumber plants cultivated in hydroponic solution with different potassium levels

    Directory of Open Access Journals (Sweden)

    Paulo César Costa

    2001-11-01

    Full Text Available O experimento foi conduzido em estufa tipo arco de 50 m² na Faculdade de Ciências Agronômicas da UNESP em Botucatu. Plantas de pepino (Cucumis sativus L. não enxertadas e enxertadas em abóbora (Cucurbita sp. foram cultivadas em sistema hidropônico para estudar o efeito de níveis de potássio (45; 90; 180 e 360 mg.L-1 de K na altura da planta e produção de número de frutos/m². A condução das plantas foi em vasos de 28 L de capacidade contendo 20% vermiculita + 80% casca de arroz + solução nutritiva fornecida a partir de galões individuais contendo 20 litros de solução. O delineamento experimental foi blocos casualizados, com oito tratamentos (fatorial 4 x 2 e três repetições. Não houve efeito da enxertia e das doses de K sobre a altura da planta, porém, os níveis de potássio independente da enxertia alteraram o início da floração. A enxertia potencializou a produção aumentando em 39% o número de frutos/m² quando fornecido na solução nutritiva 45 mg.L-1 de K e 144% com 360 mg.L-1 de K. O menor teor de potássio, 45 mg.L-1, foi suficiente para atingir alta produção.The trial was carried out at Faculdade de Ciências Agronômicas in Botucatu, Brazil. Cucumber plants (Cucumis sativus L. grafted on squash (Cucumis sp. were cultivated in hydroponic solution to study the effect of three potassium levels (45; 90; 180 and 360 mg.L-1 K on growth and yield of grafted and non grafted cucumber plants. There was no effect of plant height, but grafting and potassium level altered flowering outset. Grafted plants fertilized with 45 mg.L_1 K produced 39% more fruits than non grafted ones, and produced 144% more fruits when fertilized with 360 mg.L-1 K. The lowest K level studied (45 mg.L_1 K was enough to obtain high yield.

  4. Structural dynamics of potassium-channel gating revealed by single-molecule FRET.

    Science.gov (United States)

    Wang, Shizhen; Vafabakhsh, Reza; Borschel, William F; Ha, Taekjip; Nichols, Colin G

    2016-01-01

    Crystallography has provided invaluable insights regarding ion-channel selectivity and gating, but to advance understanding to a new level, dynamic views of channel structures within membranes are essential. We labeled tetrameric KirBac1.1 potassium channels with single donor and acceptor fluorophores at different sites and then examined structural dynamics within lipid membranes by single-molecule fluorescence resonance energy transfer (FRET). We found that the extracellular region is structurally rigid in both closed and open states, whereas the N-terminal slide helix undergoes marked conformational fluctuations. The cytoplasmic C-terminal domain fluctuates between two major structural states, both of which become less dynamic and move away from the pore axis and away from the membrane in closed channels. Our results reveal mobile and rigid conformations of functionally relevant KirBac1.1 channel motifs, implying similar dynamics for similar motifs in eukaryotic Kir channels and in cation channels in general.

  5. Structural dynamics of potassium channel gating revealed by single molecule FRET

    Science.gov (United States)

    Borschel, William F.; Ha, Taekjip; Nichols, Colin G.

    2016-01-01

    Crystallography has provided invaluable insights to ion channel selectivity and gating, but to advance understanding to a new level, dynamic views of channel structures within membranes are essential. We labeled tetrameric KirBac1.1 potassium channels with single donor and acceptor fluorophores at different sites, and examined structural dynamics within lipid membranes by single molecule FRET. We found that the extracellular region is structurally rigid in both closed and open states, whereas the N-terminal slide helix undergoes marked conformational fluctuations. The cytoplasmic C-terminal domain fluctuates between two major structural states both of which become less dynamic and move away from the pore axis and away from the membrane in closed channels. Our results reveal mobile and rigid conformations of functionally relevant KirBac1.1 channel motifs, implying similar dynamics for similar motifs in eukaryotic Kir channels and for cation channels in general. PMID:26641713

  6. Elevated tissue Cr levels, increased plasma oxidative markers, and global hypomethylation of blood DNA in male Sprague-Dawley rats exposed to potassium dichromate in drinking water.

    Science.gov (United States)

    Wang, Yu; Wu, Wei; Yao, Chunji; Lou, Jianlin; Chen, Riping; Jin, Lingzhi; Wu, Nanxiang; Gao, Ming; Song, Peng; Tan, Yufeng; Liu, Kecheng

    2016-09-01

    Hexavalent chromium [Cr (VI)] is prevalent in ground water in some areas, but evidence on the toxic effects of Cr (VI) via ingestion through drinking water remains insufficient. The aims of our study were to investigate the toxic effects of Cr (VI) through oral water ingestion on oxidative stress and DNA methylation. Thirty-two Sprague-Dawley rats were randomly divided into four groups, and exposed to porassium dichromate (K2 Cr2 O7 ; 0, 30, 100, and 300 mg/L) in drinking water for 4 weeks. Mean body weight gain, mean water consumption, clinical chemistry determinations, and oxidative stress levels in plasma were measured. Global DNA methylation changes and DNA methylation status at the promoter of p16 gene were also detected. After 4 weeks, mild anemic effects and increased plasma malondialdehyde (MDA) levels occurred in rats exposed to 100 mg/L or 300 mg/L of Cr (VI). Plasma glutathione peroxidase (GSH-Px) activity decreased in all exposed groups. Global DNA methylation levels were reduced in 100 mg/L and 300 mg/L exposure groups. However, DNA methylation status at the promoter of P16 gene remained unchanged in all K2 Cr2 O7- treated groups. The correlation analysis indicated that increased MDA levels were closely correlated to global DNA hypomethylation. Our results indicated that oral ingestion of Cr (VI) through drinking water caused not only oxidative stress in plasma, but also global DNA hypomethylation in blood cells from male rats, and a good correlation was found between increased MDA levels and reduced global DNA methylation. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1080-1090, 2016.

  7. Potassium oxalurate monohydrate

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available The title salt, poly[aqua-μ3-oxalurato-potassium(I], [K(C3H3N2O4(H2O]n, which was obtained from a water solution of oxaluric acid and KOH at room temperature, crystallizes as potassium and oxalurate ions along with a water molecule. The K+ cation lies on a crystallographic twofold rotation axis (site symmetry 2, Wyckoff position f, and the water and oxalurate molecules are located within different mirror planes (site symmetry m, Wyckoff position g. The K+ cation is eight-coordinated by six O atoms of six oxalurate ligands and two O atoms from two water molecules in a distorted square-antiprismatic geometry. All of the eight coordinated O atoms are in a monodentate bridging mode, with alternate bridged K...K distances of 3.5575 (12 and 3.3738 (12 Å. The oxalurate ligand shows a μ3-bridging coordination mode, which links the K+ cation into a three-dimensional network. The oxalurate ligands and the water molecules are involved in inter- and intramolecular N—H...O, and O—H...O hydrogen bonds, which stabilize the network.

  8. Respuesta fisiológica del cilantro a diferentes niveles de potasio y nitrógeno Physiological response of coriander to different levels of potassium and nitrogen

    Directory of Open Access Journals (Sweden)

    María Sara Mejía de Tafur

    2008-10-01

    Full Text Available Se realizó un experimento con el fin de evaluar la respuesta del cilantro cv. Unapal-Precoso a diferentes niveles de N y K. Se sembraron plantas en potes con 4 kg de arena de río, lavada, y se regaron con soluciones nutritivas (Testigo: solución completa de Hougland y Arnon; tratamientos restantes: concentraciones variables de N y K. Se utilizó un diseño completamente al azar con siete tratamientos y cinco repeticiones. Se realizaron cuatro muestreos cada nueve días hasta la cosecha final. Con la concentración alta de K se observó mayor acumulación de biomasa y menor pérdida de agua en poscosecha. El rango óptimo de concentración de N en la solución nutritiva se estimó entre 3.9 y 8.7 mM y el nivel crítico de deficiencia de K en 8.4 mM.To evaluate the response of coriander cv. Unapal-Precoso at different levels of N and K an experiment was carried out. Plants were sown in pots with 4 kg of river washed sand and irrigated with nutrient solutions (Control: solution of Hougland and Arnon, other treatments: different concentrations of N and K. A complete randomized design with seven treatments and five repetitions was used. Four sampling every nine days until the final harvest were taken. With the high concentration of K greater biomass accumulation and the lowest post-harvest loss of water was observed. The optimum range of N concentration in the nutrient solution was estimated between 3.9-8.7 mM and the critical level of K deficiency was 8.4 mM.

  9. Extracellular calcium sensing and extracellular calcium signaling

    Science.gov (United States)

    Brown, E. M.; MacLeod, R. J.; O'Malley, B. W. (Principal Investigator)

    2001-01-01

    The cloning of a G protein-coupled extracellular Ca(2+) (Ca(o)(2+))-sensing receptor (CaR) has elucidated the molecular basis for many of the previously recognized effects of Ca(o)(2+) on tissues that maintain systemic Ca(o)(2+) homeostasis, especially parathyroid chief cells and several cells in the kidney. The availability of the cloned CaR enabled the development of DNA and antibody probes for identifying the CaR's mRNA and protein, respectively, within these and other tissues. It also permitted the identification of human diseases resulting from inactivating or activating mutations of the CaR gene and the subsequent generation of mice with targeted disruption of the CaR gene. The characteristic alterations in parathyroid and renal function in these patients and in the mice with "knockout" of the CaR gene have provided valuable information on the CaR's physiological roles in these tissues participating in mineral ion homeostasis. Nevertheless, relatively little is known about how the CaR regulates other tissues involved in systemic Ca(o)(2+) homeostasis, particularly bone and intestine. Moreover, there is evidence that additional Ca(o)(2+) sensors may exist in bone cells that mediate some or even all of the known effects of Ca(o)(2+) on these cells. Even more remains to be learned about the CaR's function in the rapidly growing list of cells that express it but are uninvolved in systemic Ca(o)(2+) metabolism. Available data suggest that the receptor serves numerous roles outside of systemic mineral ion homeostasis, ranging from the regulation of hormonal secretion and the activities of various ion channels to the longer term control of gene expression, programmed cell death (apoptosis), and cellular proliferation. In some cases, the CaR on these "nonhomeostatic" cells responds to local changes in Ca(o)(2+) taking place within compartments of the extracellular fluid (ECF) that communicate with the outside environment (e.g., the gastrointestinal tract). In others

  10. Potassium supplementation and heart rate

    NARCIS (Netherlands)

    Gijsbers, L.; Molenberg, Famke; Bakker, S.J.L.; Geleijnse, J.M.

    2016-01-01

    Background and aims: Increasing the intake of potassium has been shown to lower blood pressure, but whether it also affects heart rate (HR) is largely unknown. We therefore assessed the effect of potassium supplementation on HR in a meta-analysis of randomized controlled trials. Methods and resul

  11. [Effects of different potassium fertilizer application periods on the yield and quality of Fuji apple].

    Science.gov (United States)

    Lu, Yong-li; Yang, Xian-long; Li, Ru; Li, Shui-li; Tong, Yan-an

    2015-04-01

    In order to ascertain the effects of potassium fertilizer application periods on apple production, we conducted a field experiment and analyzed the differences in apple yield, fruit quality, potassium fertilizer use efficiency, and nutrient concentrations in leaves and fruits among treatments with differences in timing of potassium application. The results indicated that, compared with no potassium-applied treatment (CK), all potassium fertilizer application treatments significantly increased the apple yield by 4.3%-33.2%, meanwhile, it also obviously improved the fruit quality. In comparison with the application of 100% potassium fertilizer as a base, the application of 50% or 100% of potassium fertilizer at the fruit enlargement stage (the remaining 50% applied as a base or after flowering) significantly increased the apple yield by 20.5% - 27.7% and improved the fruit quality. Compared with the application 100% potassium fertilizer at the stage of fruit enlargement, the evenly split application as base flowering stage and at the fruit enlargement: stage not only contributed to a higher yield, better quality and higher potassium use efficiency, but also maintained a relatively stable potassium concentration level in leaves. However, the split potassium fertilizer application at the flowering and fruit enlargement stages resulted in the significant decrease in concentration of calcium in fruit, which would be negative to fruit quality. In conclusion, our research suggested that evenly split application of potassium fertilizer as a base and at the fruit enlargement stage was the suitable period for apple production in Fuji apple orchards in this region.

  12. 硅钙镁磷钾肥不同用量对超级稻产量及磷钾吸收利用的影响%The Effects of Silicon, Calcium, Magnesium, Phosphorus and Potassium Fertilization Level on Yield and Phosphorus and Potassium Absorption of Super Rice

    Institute of Scientific and Technical Information of China (English)

    李敏; 叶舒娅; 刘枫; 郭熙盛; 黄义德

    2014-01-01

    In order to explore the application effect of silicon, calcium, magnesium, phosphorus and potassium fertilizer on super rice, a field plots experiment was conducted to investigate the effects of silicon, calcium, magnesium, phosphorus and potassium fertilizer on the yield and phosphorus and potassium absorption of rice and soil nutrient contents. The results showed that in comparison with farmer custom fertilizer (CF 1) and custom fertilizer with phosphorus and potassium halving (CF2), silicon, calcium, magnesium, phosphorus and potassium fertilizer could increase yield of super-rice, and the yield increased 1.87%-10.65% and 3.69%-12.63%, respectively. The yield was consistent between T100 and T125. Silicon, calcium, magnesium, phosphorus and potassium fertilizer could increase filled grain. With the increasing of the application, contents and uptake amounts of phosphorus and potassium in grain and straw increased. Silicon, calcium, magnesium, phosphorus and potassium fertilizer could increase soil available phosphorus, available potassium and pH value, but had no significant effects on soil total nitrogen, total phosphorus, organic matter and available nitrogen content. The feasible silicon, calcium, magnesium, phosphorus and potassium fertilization was 1500 kg/hm2 (T100) and the yield, phosphorus and potassium absorption and soil nutrient contents would be increased.%为了探讨硅钙镁磷钾肥在超级稻上施用效果,通过采用田间小区试验,研究了硅钙镁磷钾肥不同用量和习惯施肥磷钾减半(CF2)配合施用对水稻产量磷钾吸收利用及土壤养分含量的影响。结果表明,施用硅钙镁磷钾肥较习惯施肥能够有效提高超级稻产量,随着施用量的增加而增大,比习惯施肥(CF1)增产1.87%~10.65%,比习惯施肥磷钾减半(CF2)增产3.69%~12.63%,施用量1500 kg/hm2(T100)和1875 kg/hm2(T125)产量结果一致。施用硅钙镁磷钾肥通过提高每穗实粒数来提高水稻产量。

  13. Implementation and evaluation of a nurse-centered computerized potassium regulation protocol in the intensive care unit - a before and after analysis

    Directory of Open Access Journals (Sweden)

    van der Horst Iwan CC

    2010-01-01

    Full Text Available Abstract Background Potassium disorders can cause major complications and must be avoided in critically ill patients. Regulation of potassium in the intensive care unit (ICU requires potassium administration with frequent blood potassium measurements and subsequent adjustments of the amount of potassium administrated. The use of a potassium replacement protocol can improve potassium regulation. For safety and efficiency, computerized protocols appear to be superior over paper protocols. The aim of this study was to evaluate if a computerized potassium regulation protocol in the ICU improved potassium regulation. Methods In our surgical ICU (12 beds and cardiothoracic ICU (14 beds at a tertiary academic center, we implemented a nurse-centered computerized potassium protocol integrated with the pre-existent glucose control program called GRIP (Glucose Regulation in Intensive Care patients. Before implementation of the computerized protocol, potassium replacement was physician-driven. Potassium was delivered continuously either by central venous catheter or by gastric, duodenal or jejunal tube. After every potassium measurement, nurses received a recommendation for the potassium administration rate and the time to the next measurement. In this before-after study we evaluated potassium regulation with GRIP. The attitude of the nursing staff towards potassium regulation with computer support was measured with questionnaires. Results The patient cohort consisted of 775 patients before and 1435 after the implementation of computerized potassium control. The number of patients with hypokalemia (5.0 mmol/L were recorded, as well as the time course of potassium levels after ICU admission. The incidence of hypokalemia and hyperkalemia was calculated. Median potassium-levels were similar in both study periods, but the level of potassium control improved: the incidence of hypokalemia decreased from 2.4% to 1.7% (P Conclusions Computerized potassium control

  14. 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...

  15. Cardiac potassium channel subtypes

    DEFF Research Database (Denmark)

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

    2014-01-01

    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......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...

  16. Effects of acute and chronic administration of venlafaxine and desipramine on extracellular monoamine levels in the mouse prefrontal cortex and striatum.

    Science.gov (United States)

    Higashino, Kosuke; Ago, Yukio; Umehara, Masato; Kita, Yuki; Fujita, Kazumi; Takuma, Kazuhiro; Matsuda, Toshio

    2014-04-15

    Prefrontal catecholamine neurotransmission plays a key role in the therapeutic actions of drugs for attention-deficit/hyperactivity disorder (ADHD). We have recently shown that serotonin/noradrenaline reuptake inhibitors and the noradrenaline reuptake inhibitor desipramine attenuated horizontal hyperactivity in spontaneously hypertensive rats, an animal model of ADHD, and that these drugs are potential pharmacotherapeutics for ADHD. In this study, we used in vivo microdialysis to study the effects of acute and chronic (once daily for 3 weeks) administration of the serotonin/noradrenaline reuptake inhibitor venlafaxine and the noradrenaline reuptake inhibitor desipramine on noradrenaline, dopamine, and serotonin levels, and the expression of the neuronal activity marker c-Fos in the mouse prefrontal cortex and striatum. Both acute and chronic venlafaxine administration increased prefrontal noradrenaline, dopamine, and serotonin levels and striatal noradrenaline and serotonin levels. Both acute and chronic desipramine administration increased prefrontal noradrenaline and dopamine levels and striatal noradrenaline levels, with chronic administration yielding stronger increase. Chronic desipramine did not affect striatal dopamine and serotonin levels. Both acute and chronic venlafaxine administration increased the expression of c-Fos in the prefrontal cortex, whereas chronic, but not acute, desipramine administration increased the expression of c-Fos in the prefrontal cortex. Both acute and chronic venlafaxine administration increased the striatal c-Fos expression to some degree, whereas desipramine administration did not. These results suggest that acute and chronic venlafaxine and chronic desipramine administration maximally activate the prefrontal adrenergic and dopaminergic systems without affecting striatal dopaminergic systems in mice.

  17. Effects of somatostatin and oral potassium administration on terbutaline-induced hypokalemia.

    Science.gov (United States)

    Schnack, C; Podolsky, A; Watzke, H; Schernthaner, G; Burghuber, O C

    1989-01-01

    Terbutaline, a beta 2-adrenergic agonist, has been shown to cause hypokalemia and an increase of plasma glucose and serum insulin concentrations. We considered that terbutaline-induced hypokalemia may be due to the insulin-induced shift of potassium (K+) from the extracellular to the intracellular space. If so, then inhibition of insulin secretion by somatostatin would prevent terbutaline-induced hypokalemia. Further, we wondered whether oral potassium pretreatment could prevent terbutaline-induced hypokalemia. Therefore, 10 healthy volunteers (5 men, 5 women; mean age, 23 yr +/- 3 SD) received either sodium chloride (NaCl) or somatostatin intravenously together with 0.25 mg terbutaline subcutaneously in a double-blind crossover design. On a third test day, they received 39 mval of K+ powder orally before terbutaline injection in an open trial. Terbutaline caused a significant decrease of K+ (from 3.96 +/- 0.08 to 3.3 +/- 0.13 mmol/L +/- SEM; p less than 0.0005), accompanied by a significant increase in plasma glucose (from 83 +/- 3.6 to 101 +/- 4.4 mg/dl +/- SEM; p less than 0.01) and serum insulin concentrations (from 11.7 +/- 0.9 to 19.9 +/- 1.1 microU/ml +/- SEM; p less than 0.001), confirming earlier data. Somatostatin pretreatment inhibited the terbutaline-induced hypokalemia; the small fall of K+ (from 3.7 +/- 0.08 to 3.5 +/- 0.2 mmol/L) was no longer significant. Insulin secretion was completely blocked by somatostatin, leading to an even more pronounced increase of blood glucose. Hypokalemia after terbutaline injection was not prevented by oral potassium pretreatment. In summary, the present findings confirm that terbutaline-induced hypokalemia is associated with increased plasma glucose and insulin levels.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Disorders of body fluids, sodium and potassium in chronic renal failure.

    Science.gov (United States)

    Mitch, W E; Wilcox, C S

    1982-03-01

    A stable volume and composition of extracellular fluid are essential for normal functioning of the body. Since the kidney is primarily responsible for regulating extracellular fluid, loss of kidney function should have catastrophic consequences. Fortunately, even with loss of more than 90 percent of renal function, a remarkable capacity to regulate body fluid volumes and sodium and potassium persists. Nevertheless, this capacity is limited to chronic renal disease and this has important consequences for clinical management of these patients. How can sodium and potassium homeostasis be assessed? Methods for evaluating the steady-state regulation of sodium include measurement of body fluids and their distribution in different compartments and measurement of exchangeable and intracellular sodium. Short-term regulation of body sodium can be assessed from measurement of sodium balance during changes in dietary salt. Potassium is predominantly contained within cells and thus the assessment of its regulation requires special emphasis on measurement of steady-state body stores and potassium distribution across cell membranes. However, the methods used to make all of these measurements require assumptions that may not hold in the altered state of uremia. This raises problems in interpretation requiring critical analysis before conclusions can be made regarding sodium and potassium homeostasis in patients with chronic renal failure. This review focuses on abnormalities of body fluids, sodium and potassium in patients with creatinine clearances of less than 20 ml/min due to chronic renal failure and the impact of conservative therapy, dialysis and renal transplantation on these patients.

  19. Association of plasma potassium concentration with muscle tone, ECG, and levels of serum muscle enzymes in patients with hypokalemic periodic paralysis%低钾型周期性麻痹患者血钾浓度与肌力、心电图改变及肌酶水平的关系探讨

    Institute of Scientific and Technical Information of China (English)

    韩增灿

    2011-01-01

    Objective To explore the association of plasma potassium concentration with muscle tone, ECG, and levels of serum muscle enzymes in patients with hypokalemic periodic paralysis.Methods The muscle tone, ECG, levels of serum muscle enzymes, and plasma potassium concentration wore measured and then analyzed in 80 patients. Results Of 80 patients, 20 patients had mild hypokalemia, 34 had moderate hypokalemia, and 26 had severe hypokalemia. The relation between muscle tone and potassium was not stable ( P> 0.05 ). 68 patients ( 85% ) developed abnormal ECG changes; the occurrence of abnormal ECG increased with the decrease in potassium levels. 64 patients( 80% ) had an elevated levels of muscle enzymes; and the levels of muscle enzymes were negatively related with potassium concentration. Conclusions Understanding of the association of plasma potassium concentration with with muscle tone, ECG, and levels of serum muscle enzymes is very important in the diagnosis and treatment of hypokalemic periodic paralysis.%目的 探讨低钾性周期性麻痹(HOPP)患者血钾浓度与肌力、心电图及肌酶的关系.方法对80例HOPP患者进行血钾浓度、肌力、心电图及肌酶水平检测并分析.结果 80例HOPP患者中,轻度低钾组20例,中度低钾组34例,重度低钾组26例,3组中血钾浓度与肌力关系不恒定(P>0.05).80例HOPP患者中心电图异常68例,占85%.心电图异常随低血钾程度下降,出现率增高.80例HOPP患者中肌酶升高64例,占80%.血清肌酶水平均有不同程度增高,血钾浓度与肌酶水平呈负相关.结论 了解低钾程度与肌力、肌酶及心电图的关系,对HOPP的诊断、治疗具有重要意义.

  20. Effect of Nitrogen Phosphorus and Potassium Fertilization on Sago Growth

    OpenAIRE

    2014-01-01

    Fertilization is an important act of cultivation in an effort to provide plant nutrients to increase sago crop productivity. This research aimed to study the effect of nitrogen, phosphorus and potassium fertilizers towards the growth of sago palm. The study included three separate experiments i.e. experimental fertilization of nitrogen, phosphorus and potassium. The experiment was conducted by using a randomized block design (RBD) consisting of four levels of treatments and each treatment was...

  1. CB-1 receptors modulate the effect of the selective serotonin reuptake inhibitor, citalopram on extracellular serotonin levels in the rat prefrontal cortex

    NARCIS (Netherlands)

    Kleijn, Jelle; Cremers, Thomas I. F. H.; Hofland, Corry M.; Westerink, Ben H. C.

    2011-01-01

    A large percentage of depressed individuals use drugs of abuse, like cannabis. This study investigates the impact of cannabis on the pharmacological effects of the antidepressant citalopram. Using microdialysis in the prefrontal cortex of rats we monitored serotonin levels before and after cannabino

  2. CB-1 receptors modulate the effect of the selective serotonin reuptake inhibitor, citalopram on extracellular serotonin levels in the rat prefrontal cortex

    NARCIS (Netherlands)

    Kleijn, Jelle; Cremers, Thomas I. F. H.; Hofland, Corry M.; Westerink, Ben H. C.

    2011-01-01

    A large percentage of depressed individuals use drugs of abuse, like cannabis. This study investigates the impact of cannabis on the pharmacological effects of the antidepressant citalopram. Using microdialysis in the prefrontal cortex of rats we monitored serotonin levels before and after cannabino

  3. Glucose- and interleukin-1beta-induced beta-cell apoptosis requires Ca2+ influx and extracellular signal-regulated kinase (ERK) 1/2 activation and is prevented by a sulfonylurea receptor 1/inwardly rectifying K+ channel 6.2 (SUR/Kir6.2) selective potassium channel opener in human islets

    DEFF Research Database (Denmark)

    Maedler, Kathrin; Størling, Joachim; Sturis, Jeppe

    2004-01-01

    -regulated kinase (ERK) 1/2, an effect that was abrogated by 3 micromol/l NN414. Similarly, 1 micromol/l of the mitogen-activated protein kinase/ERK kinase 1/2 inhibitor PD098059 or 1 micromol/l of the l-type Ca(2+) channel blocker nimodipine prevented glucose- and IL-1beta-induced ERK activation, beta......Increasing evidence indicates that a progressive decrease in the functional beta-cell mass is the hallmark of both type 1 and type 2 diabetes. The underlying causes, beta-cell apoptosis and impaired secretory function, seem to be partly mediated by macrophage production of interleukin (IL)-1beta...... and/or high-glucose-induced beta-cell production of IL-1beta. Treatment of type 1 and type 2 diabetic patients with the potassium channel opener diazoxide partially restores insulin secretion. Therefore, we studied the effect of diazoxide and of the novel potassium channel opener NN414, selective...

  4. Role of water balance in the enhanced potassium excretion and hypokalaemia of rats with diabetes insipidus.

    Science.gov (United States)

    Fernández-Repollet, E; Martínez-Maldonado, M; Opava-Stitzer, S

    1980-08-01

    1. The role of water balance in the hypokalaemia of rats with diabetes insipidus (DI rats) was studied. 2. After a 3-day balance study DI rats had a lower muscle potassium content, and plasma [K+], and the urinary excretion of potassium in response to oral KCl loading was reduced when compared to normal rats. The hypokalaemia was found to be associated with elevated concentrations of potassium in renal medulla and papilla when compared to values in normal Long-Evans rats. 3. During a 9-day balance study urinary potassium excretion was higher than that of normal rats on days 1-3, but not different on days 4-9; this transient elevation was observed in DI rats on normal, high and low potassium diets. On a low potassium diet the urinary potassium excretion of DI rats fell to minimal levels, making unlikely the existence of a renal defect in potassium handling. 4. Muscle potassium content and plasma [K+] were normal after 9 days in metabolism cages. This spontaneous reversal of the hypokalaemia of DI rats was associated with increased water content of renal medulla and papilla, and decreased potassium concentration in these zones. 5. The effect of acute mild dehydration on potassium handling of DI rats was evaluated. Water deprivation for 1-8 hr was sufficient to raise the urinary potassium excretion of DI rats above that of DI rats drinking ad lib. Renal tissue [K+] was significantly increased after 8 hr of dehydration. Water deprivation also enhanced the response of DI rats to an oral KCl load. Two days of chronic dehydration in the form of water rationing also significantly enhanced the urinary potassium excretion of DI rats. 6. These data suggest that chronic mild dehydration may be responsible for the modest potassium deficiency observed in DI rats via alterations in renal tissue [K+] and consequently in urinary potassium excretion. Correction of dehydration during prolonged periods in metabolism cages may account for the spontaneous reversal of the hypokelaemic

  5. 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 of ...

  6. Downregulation of extracellular signal-regulated kinase 1/2 activity by calmodulin KII modulates p21Cip1 levels and survival of immortalized lymphocytes from Alzheimer's disease patients.

    Science.gov (United States)

    Esteras, Noemí; Alquézar, Carolina; Bermejo-Pareja, Félix; Bialopiotrowicz, Emilia; Wojda, Urszula; Martín-Requero, Angeles

    2013-04-01

    Previously, we reported a Ca(2+)/calmodulin (CaM)-dependent impairment of apoptosis induced by serum deprivation in Alzheimer's disease (AD) lymphoblasts. These cell lines showed downregulation of extracellular signal-regulated kinase (ERK)1/2 activity and elevated content of p21 compared with control cells. The aim of this study was to delineate the molecular mechanism underlying the distinct regulation of p21 content in AD cells. Quantitative reverse transcription polymerase chain reaction analysis demonstrated increased p21 messenger RNA (mRNA) levels in AD cells. The ERK1/2 inhibitor, PD98059, prevented death of control cells and enhanced p21 mRNA and protein levels. The CaM antagonist, calmidazolium, and the CaMKII inhibitor, KN-62, normalized the survival pattern of AD lymphoblasts by augmenting ERK1/2 activation and reducing p21 mRNA and protein levels. Upregulation of p21 transcription in AD cells appears to be the consequence of increased activity of forkhead box O3a (FOXO3a) as the result of diminished ERK1/2-mediated phosphorylation of this transcription factor, which in turn facilitates its nuclear accumulation. Murine double minute 2 (MDM2) protein levels were decreased in AD cells relative to control lymphoblasts, suggesting an impairment of FOXO3a degradation.

  7. 21 CFR 184.1635 - Potassium iodate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium iodate. 184.1635 Section 184.1635 Food... Specific Substances Affirmed as GRAS § 184.1635 Potassium iodate. (a) Potassium iodate (KIO3, CAS Reg. No. 7758-05-6) does not occur naturally but can be prepared by reacting iodine with potassium hydroxide....

  8. 21 CFR 172.375 - Potassium iodide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium iodide. 172.375 Section 172.375 Food and... Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be safely used in accordance with the following prescribed conditions: (a) Potassium iodide may be...

  9. 21 CFR 184.1634 - Potassium iodide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium iodide. 184.1634 Section 184.1634 Food... Specific Substances Affirmed as GRAS § 184.1634 Potassium iodide. (a) Potassium iodide (KI, CAS Reg. No. 7681-11-0) is the potassium salt of hydriodic acid. It occurs naturally in sea water and in...

  10. 21 CFR 184.1610 - Potassium alginate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium alginate. 184.1610 Section 184.1610 Food... Specific Substances Affirmed as GRAS § 184.1610 Potassium alginate. (a) Potassium alginate (CAS Reg. No... algae. Potassium alginate is prepared by the neutralization of purified alginic acid with appropriate...

  11. Low-level laser therapy stimulates tissue repair and reduces the extracellular matrix degradation in rats with induced arthritis in the temporomandibular joint.

    Science.gov (United States)

    Lemos, George Azevedo; Rissi, Renato; de Souza Pires, Ivan Luiz; de Oliveira, Letícia Prado; de Aro, Andrea Aparecida; Pimentel, Edson Rosa; Palomari, Evanisi Teresa

    2016-08-01

    The objective of this study was to characterize morphological and biochemistry action of low-level laser therapy (LLLT) on induced arthritis in the temporomandibular joint (TMJ) of rats. Twenty-four male Wistar rats were randomly divided into groups with 12 animals each: (AG) group with arthritis induced in the left TMJ and (LG) group with arthritis induced in the left TMJ and treated with LLLT (830 nm, 30 mW, 3 J/cm(2)). Right TMJs in the AG group were used as noninjected control group (CG). Arthritis was induced by intra-articular injection of 50 μl Complete Freund's Adjuvant (CFA) and LLLT began 1 week after arthritis induction. Histopathological analysis was performed using sections stained with hematoxylin-eosin, Toluidine Blue, and picrosirius. Biochemical analysis was determined by the total concentration of sulfated glycosaminoglycans (GAGs) and evaluation of matrix metalloproteinases (MMP-2 and MMP-9). Statistical analysis was performed using paired and unpaired t tests, with p arthritis.

  12. Tn5 insertion in the tonB gene promoter affects iron-related phenotypes and increases extracellular siderophore levels in Gluconacetobacter diazotrophicus.

    Science.gov (United States)

    de Paula Soares, Cleiton; Rodrigues, Elisete Pains; de Paula Ferreira, Jéssica; Simões Araújo, Jean Luiz; Rouws, Luc Felicianus Marie; Baldani, José Ivo; Vidal, Marcia Soares

    2015-03-01

    TonB-dependent receptors in concert with the TonB-ExbB-ExbD protein complex are responsible for the uptake of iron and substances such as vitamin B12 in several bacterial species. In this study, Tn5 mutagenesis of the sugarcane endophytic bacterium Gluconacetobacter diazotrophicus led to the isolation of a mutant with a single Tn5-insertion in the promoter region of a tonB gene ortholog. This mutant, named Gdiaa31, displayed a reduced growth rate and a lack of response to iron availability when compared to the wild-type strain PAL5(T). Several efforts to generate null-mutants for the tonB gene by insertional mutagenesis were without success. RT-qPCR analysis demonstrated reduced transcription of tonB in Gdiaa31 when compared to PAL5(T). tonB transcription was inhibited in the presence of Fe(3+) ions both in PAL5(T) and in Gdiaa31. In comparison with PAL5(T), Gdiaa31 also demonstrated decreased nitrogenase activity and biofilm formation capability, two iron-requiring physiological characteristics of G. diazotrophicus. Additionally, Gdiaa31 accumulated higher siderophore levels in culture supernatant. The genetic complementation of the Gdiaa31 strain with a plasmid that carried the tonB gene including its putative promoter region (pP(tonB)) restored nitrogenase activity and siderophore accumulation phenotypes. These results indicate that the TonB complex has a role in iron/siderophore transport and may be essential in the physiology of G. diazotrophicus.

  13. Effects of potassium deficiency on potassium, polyamines and amino acids in mouse tissues.

    Science.gov (United States)

    Cremades, A; Sanchez-Capelo, A; Monserrat, A; Monserrat, F; Peñafiel, R

    2003-03-01

    Sexual dimorphism in potassium content was found in plasma, kidney, heart and skeletal muscle of CD1 mice. We observed that feeding mice with a K(+)-deficient diet had an uneven and gender-dependent effect on organ weight and tissue potassium concentrations. Treatment produced a marked decrease in plasma, pancreas and skeletal muscle K(+) levels in both sexes, and a reduction in kidney, liver and heart potassium concentrations in females. Moreover, K(+) deficiency produced a 2-3-fold increase in the concentrations of cationic amino acids, such as arginine and lysine in both heart and skeletal muscle of the two sexes, a slight increase ( approximately 37%) in renal arginine in the male mice. The concentrations of these amino acids in plasma and other tissues in both sexes remained unaltered. Polyamine levels in heart, liver, skeletal muscle and pancreas from male and female mice were not affected by K(+) deficiency. However, in the male kidney potassium deficiency was accompanied by an increase of putrescine and spermidine concentration, and a reduction of putrescine excretion into the urine, even though renal K(+) concentration was not significantly affected and ornithine decarboxylase activity was dramatically decreased. The general lack of correlation between tissue potassium decrease and the increase in organic cations suggests that it is unlikely that the changes observed could be related with an attempt of the tissues to compensate for the reduction in cellular positive charge produced by the fall in K(+) content. The mechanisms by which these changes are produced are discussed, but their physiological implications remain to be determined.

  14. Specific and potassium components in the depolarization of the la afferents in the spinal cord of the cat.

    Science.gov (United States)

    Jiménez, I; Rudomin, P; Solodkin, M; Vyklicky, L

    1983-08-01

    In the cat spinal cord, primary afferent depolarization (PAD) of group Ia fibers of extensor muscles is produced by high-frequency stimulation (100 Hz) of group I muscle flexor afferents without significant increases in extracellular potassium. On the other hand, the PAD produced by stimulation of mixed and pure cutaneous nerves correlates well with increases in potassium ions. We conclude that the PAD produced by group I muscle afferents results from the activation of specific pathways making axo-axonic synapses with the Ia fiber terminals. The PAD of Ia fibers resulting from activation of cutaneous nerves involves instead unspecific accumulation of potassium ions.

  15. 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.

  16. Age-dependent variations in potassium sensitivity of A-currents in rat hippocampal neurons.

    Science.gov (United States)

    Klee, R; Eder, C; Ficker, E; Heinemann, U

    1997-09-01

    Hippocampal pyramidal neurons were either cultured from prenatal rats or acutely isolated from the brain of newborn and juvenile rats. The influence of lowering the concentration of the extracellular potassium concentration ([K+]o) on isolated fast transient outward K+ currents (I(A)) was studied in these neurons using the patch clamp technique in the whole cell configuration. With respect to the response of I(A) to lowering [K+]o, three types of cells were observed. The first subpopulation of neurons was characterized by a complete suppression of I(A) over the whole voltage range under potassium-free solutions (type A neurons). A second proportion of cells showed an increase of I(A) at test pulses below -0 mV and a decrease of I(A) at voltages above -0 mV (type B neurons). In a third group of neurons, amplitudes of I(A) increased at all potentials tested during omission of potassium ions from the extracellular superfusate (type C neurons). Whereas type A and type B neurons were preferentially found in freshly plated cultures and newborn rats, the majority of type C cells was detected in long-term cultures and in animals of older ages. Thus, hippocampal A-currents lose their sensitivity to extracellular potassium ions during early ontogenesis.

  17. Effects of AT1 receptor antagonism on kainate-induced seizures and concomitant changes in hippocampal extracellular noradrenaline, serotonin, and dopamine levels in Wistar-Kyoto and spontaneously hypertensive rats.

    Science.gov (United States)

    Tchekalarova, Jana; Loyens, Ellen; Smolders, Ilse

    2015-05-01

    In the management of epilepsy, AT1 receptor antagonists have been suggested as an additional treatment strategy. A hyperactive brain angiotensin (Ang) II system and upregulated AT1 receptors are implicated in the cerebrovascular alterations in a genetic form of hypertension. Uncontrolled hypertension could also, in turn, be a risk factor for a seizure threshold decrease and development of epileptogenesis. The present study aimed to assess the effects of the selective AT1 receptor antagonist ZD7155 on kainic acid (KA)-induced status epilepticus (SE) development and accompanying changes in the hippocampal extracellular (EC) neurotransmitter levels of noradrenaline (NAD), serotonin (5-HT), and dopamine (DA) in spontaneously hypertensive rats (SHRs) and their parent strain Wistar-Kyoto (WKY) rats, since monoamines are well-known neurotransmitters involved in mechanisms of both epilepsy and hypertension. Status epilepticus was evoked in freely moving rats by a repetitive intraperitoneal (i.p.) administration of KA in subconvulsant doses. In the treatment group, ZD7155 (5mg/kg i.p.) was coadministered with the first KA injection. Spontaneously hypertensive rats exhibited higher susceptibility to SE than WKY rats, but the AT1 receptor antagonist did not alter the development of SE in SHRs or in WKY rats. In vivo microdialysis demonstrated significant KA-induced increases of the hippocampal NAD and DA levels in SHRs and of NAD, 5-HT, and DA in WKY rats. Although SHRs developed more severe seizures while receiving a lower dose of KA compared to WKY rats, AT1 receptor antagonism completely prevented all KA-induced increases of hippocampal monoamine levels in both rat strains without affecting seizure development per se. These results suggest a lack of direct relationship between KA-induced seizure susceptibility and adaptive changes of hippocampal NAD, 5-HT, and DA levels in the effects of ZD7155 in WKY rats and SHRs.

  18. Use of Consumer Acceptability as a Tool to Determine the Level of Sodium Reduction: A Case Study on Beef Soup Substituted With Potassium Chloride and Soy-Sauce Odor.

    Science.gov (United States)

    Lee, Cho Long; Lee, Soh Min; Kim, Kwang-Ok

    2015-11-01

    In this study, consumer acceptability was considered as a tool of reducing sodium rather than just using it as a final examination of the successfulness of the substitution. This study consisted of 4 experimental steps. First, by gradually reducing the concentrations of NaCl, consumer rejection threshold (CRT) of NaCl in beef soup was examined. Then, the amount of KCl that can increase preference was examined in 2 low sodium beef soups, with sodium concentrations slightly above or below the CRT. Relative saltiness of various KCl and NaCl/KCl mixtures were also measured. Finally, consumers evaluated acceptability and intensities of sensory characteristics for 9 beef soup samples that differed with respect to NaCl content and/or KCl content with/without addition of salty-congruent odor (soy-sauce odor). The results showed that in the "above CRT" system, consumer acceptability as well as sensory profile of low sodium beef soup substituted using KCl had similar profile to the control although saltiness was not fully recovered, whereas in the "below CRT" system, consumer acceptability was not recovered using KCl solely as a substitute. Potential of using salty-congruent odor as a final touch to induce salty taste was observed; however, the results inferred the importance of having almost no artificialness in the odor and having harmony with the final product when using it as a strategy to substitute sodium. Overall, the results of the study implied the importance of considering consumer acceptability when approaching sodium reduction to better understand the potentials of the sodium substitutes and salty-congruent odor. Strategies attempting to reduce sodium contents in food have mainly substituted sodium to the level that provides equivalent salty taste and then examined consumer liking. However, these approaches may result in failure for consumer appeal. This study attempted to consider consumer acceptability as a tool of reducing sodium in beef soup substituted using

  19. Vascular potassium channels in NVC.

    Science.gov (United States)

    Yamada, K

    2016-01-01

    It has long been proposed that the external potassium ion ([K(+)]0) works as a potent vasodilator in the dynamic regulation of local cerebral blood flow. Astrocytes may play a central role for producing K(+) outflow possibly through calcium-activated potassium channels on the end feet, responding to a rise in the intracellular Ca(2+) concentration, which might well reflect local neuronal activity. A mild elevation of [K(+)]0 in the end feet/vascular smooth muscle space could activate Na(+)/K(+)-ATPase concomitant with inwardly rectifying potassium (Kir) channels in vascular smooth muscle cells, leading to a hyperpolarization of vascular smooth muscle and relaxation of smooth muscle actin-positive vessels. Also proposed notion is endothelial calcium-activated potassium channels and/or inwardly rectifying potassium channel-mediated hyperpolarization of vascular smooth muscle. A larger elevation of [K(+)]0, which may occur pathophysiologically in such as spreading depression or stroke, can trigger a depolarization of vascular smooth muscle cells and vasoconstriction instead.

  20. Local radiotherapy increases the level of autoantibodies to ribosomal P0 protein but not to heat shock proteins, extracellular matrix molecules and EGFR/ErbB2 receptors in prostate cancer patients.

    Science.gov (United States)

    Ingrosso, Gianluca; Fantini, Massimo; Nardi, Alessandra; Benvenuto, Monica; Sacchetti, Pamela; Masuelli, Laura; Ponti, Elisabetta; Frajese, Giovanni Vanni; Lista, Florigio; Schillaci, Orazio; Santoni, Riccardo; Modesti, Andrea; Bei, Roberto

    2013-03-01

    Prostate cancer is a common cancer among men in developed countries. Although hormonotherapy and radiotherapy (RT) represent valid therapies for prostate cancer treatment, novel immunological approaches have been explored. The development of clinical trials employing cancer vaccines has indicated that immune response to tumor antigens can be boosted and that vaccine administration can improve patient survival. Immune response to tumor antigens could also be enhanced after standard therapies. In the present study, we determined the occurrence of antibodies to extracellular matrix (ECM) molecules, heat shock protein (HSP), ribosomal P0 protein, EGFR, ErbB2 and prostate-specific antigen (PSA) in 35 prostate cancer patients prior to and following local RT and hormonotherapy. We demonstrated that immunity to P0, ECM molecules [collagens (C) CI, CIII, CV, fibronectin (FN) and laminin (LM)] and to HSP90 was associated with malignancy in untreated patients. None of the patient sera showed antibodies to EGFR, while 2 and 1 patients showed reactivity to ErbB2 and PSA, respectively. We also demonstrated that 8 months after therapy the IgG serum levels to CI, CIII, FN and HSP90 significantly decreased. Conversely, the level of P0 autoantibodies increased after therapy in 10 patients. Five of the 10 patients with increased levels of P0 autoantibodies were treated with RT plus hormonotherapy. Treatment of patients did not change the levels of antibodies against EGFR, ErbB2 and PSA. Our results indicated that the modification of antibody level to self molecules after standard treatment of prostate cancer patients is influenced by the type of antigen. Ribosomal P0 protein appears to be a high immunogenic antigen and its immunogenicity increases following RT. In addition, 10 patients with increased levels of autoantibodies to P0 showed PSA mean levels lower than the remaining 25 patients at 18 months. This study may contribute to a better understanding of the

  1. 冬虫夏草对肾衰患者细胞氨基酸代谢的影响%The Influence of Cordyceps Sinensis on the Extracellular and Intracellular Free Amino Acid Levels in Patients with CRF

    Institute of Scientific and Technical Information of China (English)

    朱淳; 左静南; 朱汉威

    2000-01-01

    Objective To study the Cordyceps Sinensis acting on the metabolism of intracellular and extracellular amino acids in patients with CRF. Methods We observed ten patients with CRF, compared the free amino acid concentrations in plasma, erthrocytes and skeletal muscle before and after Cordyceps Sinensis treatment by the amino acid automatic analytical instrument. Results After the CRF group took Cordyceps Sinensis, the Leu, Ile, Thr, Lys, Cys, Tyr concentrations in plasma and Tyr, Glu in erythrocytes approached the normal levels. In one sample of skeletal muscle, the Thr, Lys concentrations approached the normal, whereas both the intracellular and extracellular Val concentrations were still decreased remarkably as compared with the normal controls. Conclusion In patinets with CRF, Cordyceps Sinensis can improve the metabolic disorder notably, increase the dropped free amino acids in varying degrees, but couldn't correct completely the disturbance.%目的 研究冬虫夏草(虫草)对慢性肾功能衰竭(CRF)患者细胞内外氨基酸代谢的影响。 方法 采用LKB-4400型氨基酸自动分析仪测定10例CRF患者服用虫草前后的血浆、红细胞、骨骼肌细胞内的游离氨基酸浓度。结果 CRF患者服用虫草后血浆中亮氨酸、异亮氨酸、苏氨酸、赖氨酸、胱氨酸、酪氨酸浓度和红细胞中酪氨酸、谷氨酸浓度接近正常,1例骨骼肌标本苏氨酸、赖氨酸浓度接近正常;而细胞内外缬氨酸浓度仍显著降低。结论 虫草能显著改善CRF患者的氨基酸代谢紊乱,使下降的游离氨基酸水平均有不同程度的提高,但不能使其完全恢复正常。

  2. Activity-Dependent Plasticity of Astroglial Potassium and Glutamate Clearance

    Science.gov (United States)

    Cheung, Giselle; Sibille, Jérémie; Zapata, Jonathan; Rouach, Nathalie

    2015-01-01

    Recent evidence has shown that astrocytes play essential roles in synaptic transmission and plasticity. Nevertheless, how neuronal activity alters astroglial functional properties and whether such properties also display specific forms of plasticity still remain elusive. Here, we review research findings supporting this aspect of astrocytes, focusing on their roles in the clearance of extracellular potassium and glutamate, two neuroactive substances promptly released during excitatory synaptic transmission. Their subsequent removal, which is primarily carried out by glial potassium channels and glutamate transporters, is essential for proper functioning of the brain. Similar to neurons, different forms of short- and long-term plasticity in astroglial uptake have been reported. In addition, we also present novel findings showing robust potentiation of astrocytic inward currents in response to repetitive stimulations at mild frequencies, as low as 0.75 Hz, in acute hippocampal slices. Interestingly, neurotransmission was hardly affected at this frequency range, suggesting that astrocytes may be more sensitive to low frequency stimulation and may exhibit stronger plasticity than neurons to prevent hyperexcitability. Taken together, these important findings strongly indicate that astrocytes display both short- and long-term plasticity in their clearance of excess neuroactive substances from the extracellular space, thereby regulating neuronal activity and brain homeostasis. PMID:26346563

  3. Extracellular Matrix Proteins

    Directory of Open Access Journals (Sweden)

    Linda Christian Carrijo-Carvalho

    2012-01-01

    Full Text Available Lipocalin family members have been implicated in development, regeneration, and pathological processes, but their roles are unclear. Interestingly, these proteins are found abundant in the venom of the Lonomia obliqua caterpillar. Lipocalins are β-barrel proteins, which have three conserved motifs in their amino acid sequence. One of these motifs was shown to be a sequence signature involved in cell modulation. The aim of this study is to investigate the effects of a synthetic peptide comprising the lipocalin sequence motif in fibroblasts. This peptide suppressed caspase 3 activity and upregulated Bcl-2 and Ki-67, but did not interfere with GPCR calcium mobilization. Fibroblast responses also involved increased expression of proinflammatory mediators. Increase of extracellular matrix proteins, such as collagen, fibronectin, and tenascin, was observed. Increase in collagen content was also observed in vivo. Results indicate that modulation effects displayed by lipocalins through this sequence motif involve cell survival, extracellular matrix remodeling, and cytokine signaling. Such effects can be related to the lipocalin roles in disease, development, and tissue repair.

  4. Equatorial potassium currents in lenses.

    Science.gov (United States)

    Wind, B E; Walsh, S; Patterson, J W

    1988-02-01

    Earlier work with the vibrating probe demonstrated the existence of outward potassium currents at the equator and inward sodium currents at the optical poles of the lens. By adding microelectrodes to the system, it is possible to relate steady currents (J) to the potential difference (PD) measured with a microelectrode. By injecting an outward current (I), it is possible to determine resistances and also the PD at which the steady outward potassium current becomes zero (PDJ = 0). At this PD the concentration gradient for potassium efflux and the electrical gradient for potassium influx are balanced so that there is no net flow of potassium across the membranes associated with the production of J. The PDJ = 0 for 18 rat lenses was 86 mV and that for 12 frogs lenses was -95 mV. This agrees with the potassium equilibrium potential and provides strong evidence to support the view that the outward equatorial current, J, is a potassium current. With the injection of outward current, I, the PD becomes more negative, the outward equatorial current, J, decreases, and the inward current at the optical poles increases. This suggests that there are separate electrical loops for K+ and Na+ that are partially linked by the Na, K-pump. Using Ohm's law, it is possible to calculate the input resistance (R = delta PD/I), the resistance related to the production of J (RJ = delta PD/delta J), and the effect of the combined resistances (delta J/I). The driving force for J can be estimated (PDJ = 0-PD). The relationships among currents, voltages and resistance can be used to determine the characteristics of the membranes that are associated with the outward potassium current observed at the equator. The effects of graded deformation of the lens were determined. The effects were reversible. The sites of inward and outward currents were not altered. Following deformation, the equatorial current, J, increased, and the PD became less negative. The PDJ = 0 remains the same so the ratio of K

  5. Interaction between adsorbed hydrogen and potassium on a carbon nanocone containing material as studied by photoemission

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiaofeng [Nesna University College, 8700 Nesna (Norway); Raaen, Steinar, E-mail: sraaen@ntnu.no [Physics Department, Norwegian University of Science and Technology, 7491 Trondheim (Norway)

    2015-09-14

    Hydrogen adsorption on a potassium doped carbon nanocone containing material was studied by photoelectron spectroscopy and work function measurement. The valence band spectra indicate that there is charge transfer from potassium to carbon. Upon deposition on carbon potassium is in its ionic state for lower doping and shows both ionic and metallic behavior at higher doping. Adsorption of hydrogen facilitates diffusion of potassium on the carbon material as seen by changes in the K{sub 2p} core level spectrum. Variations in the measured sample work function indicate that hydrogen initially adsorb on the K dopants and subsequently adsorb on the carbon cone containing material.

  6. Topdressing fertilization with nitrogen and potassium levels in sweet-potatoAdubação de cobertura na batata-doce com doses combinadas de nitrogênio e potássio

    Directory of Open Access Journals (Sweden)

    José Salvador Simoneti Foloni

    2013-03-01

    Full Text Available Balanced fertilizations with N and K often increase the performance of crops, however, when there is absence of one of these nutrients in poor soils, can reduce crop response to fertilization with the other. The objective of this work was to evaluate the productivity of sweet-potato, the amount of sweetpotato without quality, and leaf nutrients analysis, of sweet-potato crop fertilized with N and K. The trial was conducted in farming for commercial production, in Presidente Prudente, São Paulo State, during February-June 2007, in a dystrophic Ultisol of medium texture. The experimental design was a randomized complete block design, with four replications, on factorial 4 x 4: levels of 0, 30, 60 and 120 kg N ha-1 (urea source combined with levels of 0, 30, 60 and 120 kg K2O ha-1 (KCl source, applied to 39 days after planting of the crop. The sweet-potato is responsive to topdressing application with nitrogen and potassium, however, the greatest increases in productivity occur when doses of N and K are combined. Fertilization with N and K not increase the amount of sweet-potato without quality marketing. The highest increase in productivity of sweet-potato is reached with topdressing combined with 100 kg N ha-1 plus 120 kg K2O ha-1. A adubação balanceada de N e K frequentemente aumenta o desempenho das lavouras, contudo, a falta de um desses nutrientes em solos deficientes pode levar a decréscimos na resposta ao outro. O objetivo deste trabalho foi avaliar a produtividade de batata-doce comercializável, a quantidade de raízes tuberosas para descarte e a diagnose foliar de lavoura de batata-doce adubada com N e K. O experimento foi realizado em lavoura comercial, em Presidente Prudente-SP, de fevereiro a junho de 2007, em um Argissolo Vermelho distroférrico de textura média. O delineamento experimental foi em blocos completos casualizados, com quatro repetições, no esquema fatorial 4 x 4, com 0, 30, 60 e 120 kg ha-1 de N (uréia, em

  7. Produção e qualidade do óleo essencial de menta em hidroponia com doses de potássio Production and quality of essential oil of mint under hydroponics with four potassium levels

    Directory of Open Access Journals (Sweden)

    Tânea Maria Bisognin Garlet

    2007-08-01

    Full Text Available Este trabalho objetivou avaliar a produção de fitomassa de folhas, o teor e a qualidade do óleo essencial de Mentha x gracilis Sole, cultivada em quatro doses de potássio nas soluções hidropônicas (276, 414, 552 e 690mg L-1, no sistema "NFT" (Técnica do Fluxo Laminar de Nutrientes. Empregou-se delineamento experimental inteiramente casualizado, com cinco repetições. Estacas de plantas matrizes foram enraizadas em espuma fenólica, por 20 dias, em berçário, e, após isso, foram transferidas para bancadas de produção final. A colheita ocorreu aos 49 dias após o transplante. As folhas foram retiradas e pesadas para determinação da fitomassa fresca e aproveitadas para extração do óleo em aparelho de Clevenger. As análises de constituição química do óleo foram realizadas em Cromatógrafo Gasoso acoplado a Espectrômetro de Massa. As concentrações de K alteraram a produção de fitomassa fresca de folhas, o teor e a qualidade do óleo essencial. A dose máxima de K proporcionou aumento no teor do óleo essencial, porém reduziu a acumulação de fitomassa de folhas, diminuindo o rendimento do óleo por planta e a quantidade de linalol, o principal constituinte desse quimiotipo. A concentração de K sugerida para obtenção de maior rendimento da M. x gracilis, em cultivo hidropônico, não deve ultrapassar 276mg L-1 na solução nutritiva.This research was aimed at evaluating the production of leaves' phytomass, the content and quality of Mentha x gracilis Sole essential oil with four potassium (K levels (276, 414, 552 e 690mg L-1 under hydroponics, on "NFT" system (Nutrient Film Technique. A completely randomized design was used with five replications. Stakes of matrix plants were rooted in phenolic foam for 20 days in a nursery, being then transferred to final production benches. Harvesting occurred at 49 days after transplanting. Leaves were separeted and weighted to determine fresch phytomass, and utilized for oil

  8. Frequently Asked Questions on Potassium Iodide (KI)

    Science.gov (United States)

    ... Bioterrorism and Drug Preparedness Frequently Asked Questions on Potassium Iodide (KI) Share Tweet Linkedin Pin it More sharing ... Drug Administration (FDA) issued a final Guidance on Potassium Iodide as a Thyroid Blocking Agent in Radiation Emergencies) ( ...

  9. Potassium ions in the cavity of a KcsA channel model.

    Science.gov (United States)

    Yao, Zhenwei; Qiao, Baofu; Olvera de la Cruz, Monica

    2013-12-01

    The high rate of ion flux and selectivity of potassium channels has been attributed to the conformation and dynamics of the ions in the filter which connects the channel cavity and the extracellular environment. The cavity serves as the reservoir for potassium ions diffusing from the intracellular medium. The cavity is believed to decrease the dielectric barrier for the ions to enter the filter. We study here the equilibrium and dynamic properties of potassium ions entering the water-filled cavity of a KcsA channel model. Atomistic molecular dynamics simulations that are supplemented by electrostatic calculations reveal the important role of water molecules and the partially charged protein helices at the bottom of the cavity in overcoming the energy barrier and stabilizing the potassium ion in the cavity. We further show that the average time for a potassium ion to enter the cavity is much shorter than the conduction rate of a potassium passing through the filter, and this time duration is insensitive over a wide range of the membrane potential. The conclusions drawn from the study of the channel model are applicable in generalized contexts, including the entry of ions in artificial ion channels and other confined geometries.

  10. 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....

  11. 21 CFR 184.1639 - Potassium lactate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium lactate. 184.1639 Section 184.1639 Food... Specific Substances Affirmed as GRAS § 184.1639 Potassium lactate. (a) Potassium lactate (C3H5O3K, CAS Reg. No. 996-31-6) is the potassium salt of lactic acid. It is a hydroscopic, white, odorless solid and...

  12. 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.

  13. Use of X-ray microanalysis for study of cation distribution in potassium deficient pumpkin roots

    Directory of Open Access Journals (Sweden)

    Natalia Burmistrova

    2014-01-01

    Full Text Available Ice slices of root tissues were investigated by X-ray microanalysis. It is shown that the cytoplasm of the meristematic and differentiated cells of potassium dificiest roots maintains a high potassium level. The vacuoles of various root cells loose more K and accumulate more Na and Mg than does the cytoplasm.

  14. 21 CFR 182.3640 - Potassium sorbate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium sorbate. 182.3640 Section 182.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Potassium sorbate. (a) Product. Potassium sorbate. (b) Conditions of use. This substance is...

  15. 21 CFR 582.1643 - Potassium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium sulfate. 582.1643 Section 582.1643 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1643 Potassium sulfate. (a) Product. Potassium sulfate. (b) Conditions of use....

  16. 21 CFR 172.730 - Potassium bromate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium bromate. 172.730 Section 172.730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Specific Usage Additives § 172.730 Potassium bromate. The food additive potassium bromate may be...

  17. 21 CFR 582.6625 - Potassium citrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is...

  18. 21 CFR 582.1625 - Potassium citrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use....

  19. 21 CFR 184.1643 - Potassium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 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... having a bitter, saline taste. It is prepared by the neutralization of sulfuric acid with...

  20. 21 CFR 582.3640 - Potassium sorbate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium sorbate. 582.3640 Section 582.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3640 Potassium sorbate. (a) Product. Potassium sorbate. (b) Conditions of use. This substance...

  1. 21 CFR 582.5634 - Potassium iodide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium iodide. 582.5634 Section 582.5634 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5634 Potassium iodide. (a) Product. Potassium iodide. (b) Tolerance. 0.01 percent....

  2. 21 CFR 582.7610 - Potassium alginate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium alginate. 582.7610 Section 582.7610 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium alginate. (a) Product. Potassium alginate. (b) Conditions of use. This substance is...

  3. 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...

  4. [Effects of fertilization on aquic brown soil potassium budget and crop potassium allocation].

    Science.gov (United States)

    Jiang, Zishao; Yu, Wantai; Zhang, Lu

    2006-12-01

    Through a consecutive 15 years field trial on the aquic brown soil in Shenyang suburb of Northeast China, this paper studied the soil potassium budget and crop potassium allocation under effects of different fertilization systems. The results indicated that applying nitrogen or nitrogen plus phosphorous without potassium application accelerated the deficit of soil potassium. The potassium concentration in soybean grain and stalk was higher under potassium application than with no potassium supply, while that in maize grain had no significant difference in different fertilization treatments. The reutilization of recycled nutrients in farming system could mitigate the deficit of soil potassium budget, and such reutilization assorted with appropriate amount of potassium fertilization could not only produce high crop yield, but also balance soil potassium budget.

  5. High-level inducible Smad4-reexpression in the cervical cancer cell line C4-II is associated with a gene expression profile that predicts a preferential role of Smad4 in extracellular matrix composition

    Directory of Open Access Journals (Sweden)

    Schwarz Elisabeth

    2007-11-01

    Full Text Available Abstract Background Smad4 is a tumour suppressor frequently inactivated in pancreatic and colorectal cancers. We have recently reported loss of Smad4 in every fourth carcinoma of the uterine cervix. Smad4 transmits signals from the TGF-β superfamily of cytokines and functions as a versatile transcriptional co-modulator. The prevailing view suggests that the tumour suppressor function of Smad4 primarily resides in its capability to mediate TGF-β growth inhibitory responses. However, accumulating evidence indicates, that the acquisition of TGF-β resistance and loss of Smad4 may be independent events in the carcinogenic process. Through inducible reexpression of Smad4 in cervical cancer cells we wished to shed more light on this issue and to identify target genes implicated in Smad4 dependent tumor suppression. Methods Smad4-deficient human C4-II cervical carcinoma cells were used to establish inducible Smad4 reexpression using the commercial Tet-on™ system (Clontech. The impact of Smad4 reexpression on cell growth was analysed in vitro and in vivo. Transcriptional responses were assessed through profiling on cDNA macroarrays (Clontech and validated through Northern blotting. Results Clones were obtained that express Smad4 at widely varying levels from approximately physiological to 50-fold overexpression. Smad4-mediated tumour suppression in vivo was apparent at physiological expression levels as well as in Smad4 overexpressing clones. Smad4 reexpression in a dose-dependent manner was associated with transcriptional induction of the extracellular matrix-associated genes, BigH3, fibronectin and PAI-1, in response to TGF-β. Smad4-dependent regulation of these secreted Smad4 targets is not restricted to cervical carcinoma cells and was confirmed in pancreatic carcinoma cells reexpressing Smad4 after retroviral transduction and in a stable Smad4 knockdown model. On the other hand, the classical cell cycle-associated TGF-β target genes, c-myc, p

  6. New nonabsorbable potassium-exchange resins in hyperkalaemia

    NARCIS (Netherlands)

    Roscioni, Sara S.; Lambers Heerspink, Hiddo

    2015-01-01

    New data suggest that treatment with patiromer or sodium zirconium cyclosilicate for up to 8 weeks reduces plasma potassium levels in hyperkalaemic patients. If proven safe and effective for long-term use, these therapies might be administered together with intensive renin-angiotensin-aldosterone bl

  7. Activity-Dependent Changes in Extracellular Ca2+ and K+ Reveal Pacemakers in the Spinal Locomotor-Related Network

    OpenAIRE

    Brocard, Frédéric; Shevtsova, Natalia A.; Bouhadfane, Mouloud; Tazerart, Sabrina; Heinemann, Uwe; Rybak, Ilya A.; Vinay, Laurent

    2013-01-01

    Changes in the extracellular ionic concentrations occur as a natural consequence of firing activity in large populations of neurons. The extent to which these changes alter the properties of individual neurons and the operation of neuronal networks remains unknown. Here, we show that the locomotor-like activity in the isolated neonatal rodent spinal cord reduces the extracellular calcium ([Ca2+]o) to 0.9 mM and increases the extracellular potassium ([K+]o) to 6 mM. Such changes in [Ca2+]o and...

  8. A novel optical intracellular imaging approach for potassium dynamics in astrocytes.

    Directory of Open Access Journals (Sweden)

    Theresa S Rimmele

    Full Text Available Astrocytes fulfill a central role in regulating K+ and glutamate, both released by neurons into the extracellular space during activity. Glial glutamate uptake is a secondary active process that involves the influx of three Na+ ions and one proton and the efflux of one K+ ion. Thus, intracellular K+ concentration ([K+]i is potentially influenced both by extracellular K+ concentration ([K+]o fluctuations and glutamate transport in astrocytes. We evaluated the impact of these K+ ion movements on [K+]i in primary mouse astrocytes by microspectrofluorimetry. We established a new noninvasive and reliable approach to monitor and quantify [K+]i using the recently developed K+ sensitive fluorescent indicator Asante Potassium Green-1 (APG-1. An in situ calibration procedure enabled us to estimate the resting [K+]i at 133±1 mM. We first investigated the dependency of [K+]i levels on [K+]o. We found that [K+]i followed [K+]o changes nearly proportionally in the range 3-10 mM, which is consistent with previously reported microelectrode measurements of intracellular K+ concentration changes in astrocytes. We then found that glutamate superfusion caused a reversible drop of [K+]i that depended on the glutamate concentration with an apparent EC50 of 11.1±1.4 µM, corresponding to the affinity of astrocyte glutamate transporters. The amplitude of the [K+]i drop was found to be 2.3±0.1 mM for 200 µM glutamate applications. Overall, this study shows that the fluorescent K+ indicator APG-1 is a powerful new tool for addressing important questions regarding fine [K+]i regulation with excellent spatial resolution.

  9. A novel optical intracellular imaging approach for potassium dynamics in astrocytes.

    Science.gov (United States)

    Rimmele, Theresa S; Chatton, Jean-Yves

    2014-01-01

    Astrocytes fulfill a central role in regulating K+ and glutamate, both released by neurons into the extracellular space during activity. Glial glutamate uptake is a secondary active process that involves the influx of three Na+ ions and one proton and the efflux of one K+ ion. Thus, intracellular K+ concentration ([K+]i) is potentially influenced both by extracellular K+ concentration ([K+]o) fluctuations and glutamate transport in astrocytes. We evaluated the impact of these K+ ion movements on [K+]i in primary mouse astrocytes by microspectrofluorimetry. We established a new noninvasive and reliable approach to monitor and quantify [K+]i using the recently developed K+ sensitive fluorescent indicator Asante Potassium Green-1 (APG-1). An in situ calibration procedure enabled us to estimate the resting [K+]i at 133±1 mM. We first investigated the dependency of [K+]i levels on [K+]o. We found that [K+]i followed [K+]o changes nearly proportionally in the range 3-10 mM, which is consistent with previously reported microelectrode measurements of intracellular K+ concentration changes in astrocytes. We then found that glutamate superfusion caused a reversible drop of [K+]i that depended on the glutamate concentration with an apparent EC50 of 11.1±1.4 µM, corresponding to the affinity of astrocyte glutamate transporters. The amplitude of the [K+]i drop was found to be 2.3±0.1 mM for 200 µM glutamate applications. Overall, this study shows that the fluorescent K+ indicator APG-1 is a powerful new tool for addressing important questions regarding fine [K+]i regulation with excellent spatial resolution.

  10. 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.

  11. 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.

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

    Science.gov (United States)

    Stone, Michael S.; Martyn, Lisa; Weaver, Connie M.

    2016-01-01

    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. PMID:27455317

  13. The relation of potassium and sodium intakes to diet cost among U.S. adults.

    Science.gov (United States)

    Drewnowski, A; Rehm, C D; Maillot, M; Monsivais, P

    2015-01-01

    The 2010 Dietary Guidelines recommended that Americans increase potassium and decrease sodium intakes to reduce the burden of hypertension. One reason why so few Americans meet the recommended potassium or sodium goals may be perceived or actual food costs. This study explored the monetary costs associated with potassium and sodium intakes using national food prices and a representative sample of US adults. Dietary intake data from the 2001-2002 National Health and Nutrition Examination Survey were merged with a national food prices database. In a population of 4744 adults, the association between the energy-adjusted sodium and potassium intakes, and the sodium-to-potassium ratio (Na:K) and energy-adjusted diet cost was evaluated. Diets that were more potassium-rich or had lower Na:K ratios were associated with higher diet costs, while sodium intakes were not related to cost. The difference in diet cost between extreme quintiles of potassium intakes was $1.49 (95% confidence interval: 1.29, 1.69). A food-level analysis showed that beans, potatoes, coffee, milk, bananas, citrus juices and carrots are frequently consumed and low-cost sources of potassium. Based on existing dietary data and current American eating habits, a potassium-dense diet was associated with higher diet costs, while sodium was not. Price interventions may be an effective approach to improve potassium intakes and reduce the Na:K ratio of the diet. The present methods helped identify some alternative low-cost foods that were effective in increasing potassium intakes. The identification and promotion of lower-cost foods to help individuals meet targeted dietary recommendations could accompany future dietary guidelines.

  14. Impaired astrocytic gap junction coupling and potassium buffering in a mouse model of tuberous sclerosis complex.

    Science.gov (United States)

    Xu, Lin; Zeng, Ling-Hui; Wong, Michael

    2009-05-01

    Abnormalities in astrocytes occur in the brains of patients with Tuberous Sclerosis Complex (TSC) and may contribute to the pathogenesis of neurological dysfunction in this disease. Here, we report that knock-out mice with Tsc1 gene inactivation in glia (Tsc1(GFAP)CKO mice) exhibit decreased expression of the astrocytic connexin protein, Cx43, and an associated impairment in gap junction coupling between astrocytes. Correspondingly, hippocampal slices from Tsc1(GFAP)CKO mice have increased extracellular potassium concentration in response to stimulation. This impaired potassium buffering can be attributed to abnormal gap junction coupling, as a gap junction inhibitor elicits an additional increase in potassium concentration in control, but not Tsc1(GFAP)CKO slices. Furthermore, treatment with a mammalian target of rapamycin inhibitor reverses the deficient Cx43 expression and impaired potassium buffering. These findings suggest that Tsc1 inactivation in astrocytes causes defects in astrocytic gap junction coupling and potassium clearance, which may contribute to epilepsy in Tsc1(GFAP)CKO mice.

  15. A receptor that is highly specific for extracellular ATP in developing chick skeletal muscle in vitro.

    OpenAIRE

    Thomas, S A; Zawisa, M. J.; X. Lin; Hume, R. I.

    1991-01-01

    1. Extracellular adenosine 5'-triphosphate (ATP) activated an early excitatory conductance followed by a late potassium conductance in developing chick skeletal muscle. A series of ATP analogues were tested for their ability to activate these two conductances. All compounds tested were either agonists for both responses or for neither. Furthermore, the potency of agonists was similar for the two responses. 2. The order of potency for agonists was ATP approximately adenosine 5'-O-(3-thiotripho...

  16. 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)

  17. Extracellular vesicles for drug delivery

    NARCIS (Netherlands)

    Vader, Pieter; Mol, Emma A; Pasterkamp, Gerard; Schiffelers, Raymond M

    Extracellular vesicles (EVs) are cell-derived membrane vesicles, and represent an endogenous mechanism for intercellular communication. Since the discovery that EVs are capable of functionally transferring biological information, the potential use of EVs as drug delivery vehicles has gained

  18. De novo characterization of the alligator weed (Alternanthera philoxeroides) transcriptome illuminates gene expression under potassium deprivation

    Indian Academy of Sciences (India)

    Liqin Li; Li Xu; Xiyao Wang; Gang Pan; Liming Lu

    2015-03-01

    As one of the three macronutrients, potassium participates in many physiological processes in plant life cycle. Recently, potassium-dependent transcriptome analysis has been reported in Arabidopsis, rice and soybean. Alligator weed is well known, particularly for its strong ability to accumulate potassium. However, the molecular mechanism that underlies potassium starvation responses has not yet been described. In this study, we used Illumina (Solexa) sequencing technology to analyse the root transcriptome information of alligator weed under low potassium stress. Further analysis suggested that 9253 differentially expressed genes (DEGs) were upregulated, and 2138 DEGs were downregulated after seven days of potassium deficiency. These factors included 121 transcription factors, 108 kinases, 136 transporters and 178 genes that were related to stress. Twelve transcription factors were randomly selected for further analysis. The expression level of each transcription factor was confirmed by quantitative RT-PCR, and the results of this secondary analysis were consistent with the results of Solexa sequencing. Enrichment analysis indicated that 10,993 DEGs were assigned to 54 gene ontology terms and 123 KEGG pathways. Approximately 24% of DEGs belong to the metabolic, ribosome and biosynthesis of secondary metabolite KEGG pathways. Our results provide a comprehensive analysis of the gene regulatory network of alligator weed under low potassium stress, and afford a valuable resource for genetic and genomic research on plant potassium deficiency.

  19. 21 CFR 184.1625 - Potassium citrate.

    Science.gov (United States)

    2010-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 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,...

  20. [Rare, severe hypersensitivity reaction to potassium iodide].

    Science.gov (United States)

    Korsholm, Anne Sofie; Ebbehøj, Eva; Richelsen, Bjørn

    2014-07-07

    The literature reports a large variety of adverse reactions to potassium iodide. A severe hypersensitivity reaction to potassium iodide in a 51-year-old woman with Graves' thyrotoxicosis is described. Following administration the patient developed sialadenitis, conjunctivitis, stomatitis and acneiform iododerma that responded dramatically to withdrawal of the potassium iodide and administration with corticosteroids. Awareness of these adverse reactions may prevent prolonged hospitalization and unnecessary tests and treatments.

  1. RADIOACTIVITY AND PHYSIOLOGICAL ACTION OF POTASSIUM.

    Science.gov (United States)

    Loeb, R F

    1920-11-20

    1. The non-radioactive cesium ion can replace the potassium ion almost quantitatively in solutions required for the development of the egg of the sea urchin into swimming blastulae. 2. Thorium chloride and uranium acetate cannot replace the potassium chloride in the solutions required for the development of the egg. 3. Thorium chloride and uranium acetate do not antagonize the action of the potassium contained in sea water upon the development of eggs.

  2. Extracellular DNA: the tip of root defenses?

    Science.gov (United States)

    Hawes, Martha C; Curlango-Rivera, Gilberto; Wen, Fushi; White, Gerard J; Vanetten, Hans D; Xiong, Zhongguo

    2011-06-01

    This review discusses how extracellular DNA (exDNA) might function in plant defense, and at what level(s) of innate immunity this process might operate. A new role for extracellular factors in mammalian defense has been described in a series of studies. These studies reveal that cells including neutrophils, eosinophils, and mast cells produce 'extracellular traps' (ETs) consisting of histone-linked exDNA. When pathogens are attracted to such ETs, they are trapped and killed. When the exDNA component of ETs is degraded, trapping is impaired and resistance against invasion is reduced. Conversely, mutation of microbial genes encoding exDNases that degrade exDNA results in loss of virulence. This discovery that exDNases are virulence factors opens new avenues for disease control. In plants, exDNA is required for defense of the root tip. Innate immunity-related proteins are among a group of >100 proteins secreted from the root cap and root border cell populations. Direct tests revealed that exDNA also is rapidly synthesized and exported from the root tip. When this exDNA is degraded by the endonuclease DNase 1, root tip resistance to fungal infection is lost; when the polymeric structure is degraded more slowly, by the exonuclease BAL31, loss of resistance to fungal infection is delayed accordingly. The results suggest that root border cells may function in a manner analogous to that which occurs in mammalian cells.

  3. Researches toward potassium channels on tumor progressions.

    Science.gov (United States)

    Shen, Zheng; Yang, Qian; You, Qidong

    2009-01-01

    As trans-membrane proteins located in cytoplasm and organelle membrane, potassium (K(+)) channels are generally divided into four super-families: voltage-gated K(+) channels (K(v)), Ca(2+)-activated K(+) channels (K(Ca)), inwardly rectifying K(+) channels (K(ir)) and two-pore domain K(+) channels (K(2P)). Since dysfunctions of K(+) channels would induce many diseases, various studies toward their functions in physiologic and pathologic process have been extensively launched. This review focuses on the recent advances of K(+) channels in tumor progression, including the brief introduction of K(+) channels, the role of K(+) channels in tumor cells, the possible mechanism of action at cellular level, and the possible application of K(+) channel modulators in cancer chemotherapy.

  4. Inward-rectifying potassium channelopathies: new insights into disorders of sodium and potassium homeostasis.

    Science.gov (United States)

    Cheng, Chih-Jen; Sung, Chih-Chien; Huang, Chou-Long; Lin, Shih-Hua

    2015-03-01

    Inward-rectifying potassium (Kir) channels allow more inward than outward potassium flux when channels are open in mammalian cells. At physiological resting membrane potentials, however, they predominantly mediate outward potassium flux and play important roles in regulating the resting membrane potential in diverse cell types and potassium secretion in the kidneys. Mutations of Kir channels cause human hereditary diseases collectively called Kir channelopathies, many of which are characterized by disorders of sodium and potassium homeostasis. Studies on these genetic Kir channelopathies have shed light on novel pathophysiological mechanisms, including renal sodium and potassium handling, potassium shifting in skeletal muscles, and aldosterone production in the adrenal glands. Here, we review several recent advances in Kir channels and their clinical implications in sodium and potassium homeostasis.

  5. Genetic Control of Potassium Channels.

    Science.gov (United States)

    Amin, Ahmad S; Wilde, Arthur A M

    2016-06-01

    Approximately 80 genes in the human genome code for pore-forming subunits of potassium (K(+)) channels. Rare variants (mutations) in K(+) channel-encoding genes may cause heritable arrhythmia syndromes. Not all rare variants in K(+) channel-encoding genes are necessarily disease-causing mutations. Common variants in K(+) channel-encoding genes are increasingly recognized as modifiers of phenotype in heritable arrhythmia syndromes and in the general population. Although difficult, distinguishing pathogenic variants from benign variants is of utmost importance to avoid false designations of genetic variants as disease-causing mutations.

  6. Acute coronary syndromes. Challenging accepted post-MI serum potassium targets.

    Science.gov (United States)

    van Diepen, Sean; Granger, Christopher B

    2012-02-28

    On the basis of high-quality observational data, Goyal et al. have found that serum potassium levels <3.5 mmol/l or ≥4.5 mmol/l are associated with increased in-hospital mortality in patients with acute myocardial infarction. We discuss whether target potassium levels in clinical practice and guidelines should be changed to 3.5–4.5 mmol/l.

  7. Effect of losartan potassium combined with Yishenhuashi on the levels of plasma protein, IL-1, IL-6 and IL-13 in the patients with chronic glomerulonephritis%氯沙坦钾联合益肾化湿颗粒对慢性肾炎患者血浆蛋白浓度和IL-1、IL-6、IL-13水平的影响

    Institute of Scientific and Technical Information of China (English)

    倪志刚

    2016-01-01

    Objective: To evaluate the effect of losartan potassium combined with yishenhuashi on the levels of urine protein, IL-1, IL-6 and IL-13 in the patients with chronic glomerulonephritis.Methods: Fifty-nine cases of patients with chronic glomerulonephritis were retrospectively analyzed and divided into a control group (29 cases, treated with losartan potassium 50 mg/d qd) and an observation group (30 cases, treated with losartan potassium combined with yishenhuashi 10 g bid) and the treatment was lasted for 12 weeks. The changes of the concentrations of plasma and urine proteins and the levels of IL-1, IL-6 and IL-13 were observed before and after treatment, meanwhile the incidence of adverse reactions was recorded.Results: After treatment, the levels of urine protein were lower and the levels of plasma protein, IL-6 and IL-13 were higher in the observation group than in the control group (P0.05)。结论:氯沙坦钾联合益肾化湿颗粒治疗慢性肾炎的疗效更好,能有效增加血浆蛋白含量,减少尿蛋白,降低血清IL-1、IL-6、IL-13的水平,不良反应较少。

  8. Regulation of Synaptic Transmission by Ambient Extracellular Glutamate

    OpenAIRE

    Featherstone, David E.; Scott A. Shippy

    2007-01-01

    Many neuroscientists assume that ambient extracellular glutamate concentrations in the nervous system are biologically negligible under nonpathological conditions. This assumption is false. Hundreds of studies over several decades suggest that ambient extracellular glutamate levels in the intact mammalian brain are ~0.5 to ~5 μM. This has important implications. Glutamate receptors are desensitized by glutamate concentrations significantly lower than needed for receptor activation; 0.5 to 5 μ...

  9. Astrocytic Dysfunction in Epileptogenesis: Consequences of Altered Potassium and Glutamate Homeostasis?

    Science.gov (United States)

    David, Yaron; Cacheaux, Luisa P; Ivens, Sebastian; Lapilover, Ezequiel; Heinemann, Uwe; Kaufer, Daniela; Friedman, Alon

    2010-01-01

    Focal epilepsy often develops following traumatic, ischemic or infectious brain injury. While the electrical activity of the epileptic brain is well characterized, the mechanisms underlying epileptogenesis are poorly understood. We have recently shown that in the rat neocortex, long-lasting breakdown of the blood-brain barrier (BBB) or direct exposure of the neocortex to serum-derived albumin leads to rapid up-regulation of the astrocytic marker, glial fibrillary acidic protein (GFAP), followed by delayed (within 4–7 days) development of an epileptic focus. We investigated the role of astrocytes in epileptogenesis in the BBB-breakdown and albumin models of epileptogenesis. We found similar, robust changes in astrocytic gene expression in the neocortex within hours following treatment with deoxycholic acid (BBB breakdown) or albumin. These changes predict reduced clearance capacity for both extracellular glutamate and potassium. Electrophysiological recordings in-vitro confirmed the reduced clearance of activity-dependent accumulation of both potassium and glutamate 24 h following exposure to albumin. We used a NEURON model to simulate the consequences of reduced astrocytic uptake of potassium and glutamate on excitatory postsynaptic potentials (EPSPs). The model predicted that the accumulation of glutamate is associated with frequency-dependent (>100 Hz) decreased facilitation of EPSPs, while potassium accumulation leads to frequency-dependant (10–50 Hz) and N-methyl-D-aspartic acid (NMDA)-dependent synaptic facilitation. In-vitro electrophysiological recordings during epileptogenesis confirmed frequency-dependant synaptic facilitation leading to seizure-like activity. Our data indicate a transcription-mediated astrocytic transformation early during epileptogenesis. We suggest that the resulting reduction in the clearance of extracellular potassium underlies frequency-dependent neuronal hyper-excitability and network synchronization. PMID:19710312

  10. Insertion of tetracysteine motifs into dopamine transporter extracellular domains.

    Directory of Open Access Journals (Sweden)

    Deanna M Navaroli

    Full Text Available The neuronal dopamine transporter (DAT is a major determinant of extracellular dopamine (DA levels and is the primary target for a variety of addictive and therapeutic psychoactive drugs. DAT is acutely regulated by protein kinase C (PKC activation and amphetamine exposure, both of which modulate DAT surface expression by endocytic trafficking. In order to use live imaging approaches to study DAT endocytosis, methods are needed to exclusively label the DAT surface pool. The use of membrane impermeant, sulfonated biarsenic dyes holds potential as one such approach, and requires introduction of an extracellular tetracysteine motif (tetraCys; CCPGCC to facilitate dye binding. In the current study, we took advantage of intrinsic proline-glycine (Pro-Gly dipeptides encoded in predicted DAT extracellular domains to introduce tetraCys motifs into DAT extracellular loops 2, 3, and 4. [(3H]DA uptake studies, surface biotinylation and fluorescence microscopy in PC12 cells indicate that tetraCys insertion into the DAT second extracellular loop results in a functional transporter that maintains PKC-mediated downregulation. Introduction of tetraCys into extracellular loops 3 and 4 yielded DATs with severely compromised function that failed to mature and traffic to the cell surface. This is the first demonstration of successful introduction of a tetracysteine motif into a DAT extracellular domain, and may hold promise for use of biarsenic dyes in live DAT imaging studies.

  11. Power Consideration for Pulsed Discharges in Potassium Seeded Argon

    Institute of Scientific and Technical Information of China (English)

    XIA Sheng-Guo; HE Jun-Jia; LIU Ke-Fu

    2007-01-01

    Minimization of energy consumed in plasma generation is critical for applications, in which a large volume of plasmas is needed. We suggest that a high electron density atmospheric pressure plasmas can be generated by pulsed discharges in potassium seeded argon at an elevated temperature with a very small power input. The ionization efficiency and power budget of pulsed discharges in such plasmas are analytically studied. The results show that ionization efficiency of argon, especially at small reduced electric field E/N (the ratio of the electric field to the gas number density), is improved effectively in the presence of small amount of potassium additives. Power input of pulsed discharge to sustain a prescribed average level of ionization in potassium seeded argon is three orders of magnitude lower than that in pure argon. Further, unlike in pure argon, it is found that very short high-voltage pulses with very high repetition rates are unnecessary in potassium seeded argon. A pulse with 100ns of pulse duration, 5kHz of repetition rate, and 2Td (1 Td = 1 ×10-21 Vm2) of E/N is enough to sustain an electron density of 10l9m-3 in 1 atm 1500 K Ar+0.1% K mixture, with a very small power input of about 0.08 × 104 W/m3.

  12. Characterization of verdete rock as a potential source of potassium

    Directory of Open Access Journals (Sweden)

    Wedisson Oliveira Santos

    2015-08-01

    Full Text Available Potassium is a nutrient found at low levels in Brazilian soils, requiring large inputs of fertilizers to achieve satisfactory crop yields. Brazil has high external dependence and limited reserves of soluble K mineral, which is traditionally exploited for the production of fertilizers. On the other hand, it is common the occurrence in the country of potassium-rich silicate minerals which are not commercially exploited. This study aimed to characterize mineralogically and chemically samples of verdete rock separated into size fractions and evaluate its potential as potassium fertilizer. The mineral composition of verdete rock is based on glauconite, quartz and feldspar. The total K2O content in verdete rock ranged from 5.18 to 9.0 dag/kg. The K content extracted in water or 2% citric acid was 2.4% below the total of K, indicating low reactivity of verdete rock and limitations for direct use as K source. The processes of physical fractionation and sedimentation in water are inefficient to promote the concentration of K in the different verdete rock fractions. The total K content in some samples are considerable and may enable the use of this rock as raw material for production of more reactive potassium fertilizers.

  13. Macronutrients in watermelon plants fertilized with potassium and cattle manure

    Directory of Open Access Journals (Sweden)

    José A. M. do Nascimento

    Full Text Available ABSTRACT Potassium is the nutrient required in greatest quantity by watermelon, especially during the production phase. Therefore, the aim of this experiment was to evaluate the effect of potassium and cattle manure doses on the nutritional composition of ‘Crimson Sweet’ watermelon plants. The treatments were arranged in a randomized block design with three replicates and 21 plants per plot using a 3 × 5 + 1 factorial scheme, referring to three manure doses (0; 1,100 and 2,520 g hole-1, in order to increment the level of soil organic matter from 0.67 present in the soil to 3.0 and 6.0%, five potassium doses (0, 7.5, 15, 22.5 and 30 kg ha-1 in the form of potassium chloride and one additional treatment (without organic and mineral fertilization. At the beginning of fruiting, leaves were collected to evaluate the nutritional status of the plants in macronutrients. According to the results, cattle manure stimulates the absorption of macronutrients by watermelon; in soil with 3.0% of organic matter, the best results corresponded to the K2O dose of 15 kg ha-1 and, for 6.0%, between 11 and 13 kg ha-1.

  14. Potassium Isotopic Compositions of NIST Potassium Standards and 40Ar/39Ar Mineral Standards

    Science.gov (United States)

    Morgan, Leah; Tappa, Mike; Ellam, Rob; Mark, Darren; Higgins, John; Simon, Justin I.

    2013-01-01

    Knowledge of the isotopic ratios of standards, spikes, and reference materials is fundamental to the accuracy of many geochronological methods. For example, the 238U/235U ratio relevant to U-Pb geochronology was recently re-determined [1] and shown to differ significantly from the previously accepted value employed during age determinations. These underlying values are fundamental to accurate age calculations in many isotopic systems, and uncertainty in these values can represent a significant (and often unrecognized) portion of the uncertainty budget for determined ages. The potassium isotopic composition of mineral standards, or neutron flux monitors, is a critical, but often overlooked component in the calculation of K-Ar and 40Ar/39Ar ages. It is currently assumed that all terrestrial materials have abundances indistinguishable from that of NIST SRM 985 [2]; this is apparently a reasonable assumption at the 0.25per mille level (1s) [3]. The 40Ar/39Ar method further relies on the assumption that standards and samples (including primary and secondary standards) have indistinguishable 40K/39K values. We will present data establishing the potassium isotopic compositions of NIST isotopic K SRM 985, elemental K SRM 999b, and 40Ar/39Ar biotite mineral standard GA1550 (sample MD-2). Stable isotopic compositions (41K/39K) were measured by the peak shoulder method with high resolution MC-ICP-MS (Thermo Scientific NEPTUNE Plus), using the accepted value of NIST isotopic SRM 985 [2] for fractionation [4] corrections [5]. 40K abundances were measured by TIMS (Thermo Scientific TRITON), using 41K/39K values from ICP-MS measurements (or, for SRM 985, values from [2]) for internal fractionation corrections. Collectively these data represent an important step towards a metrologically traceable calibration of 40K concentrations in primary 40Ar/39Ar mineral standards and improve uncertainties by ca. an order of magnitude in the potassium isotopic compositions of standards.

  15. Natural mineral bottled waters available on the Polish market as a source of minerals for the consumers. Part 2: The intake of sodium and potassium.

    Science.gov (United States)

    Gątarska, Anna; Ciborska, Joanna; Tońska, Elżbieta

    Natural mineral waters are purchased and consumed according to consumer preferences and possible recommendations. The choice of appropriate water should take into account not only the general level of mineralization but also the content of individual components, including electrolytes such as sodium and potassium. Sodium is necessary to ensure the proper physiological functions of the body. It is defined as a health risk factor only when its excessive intake occurs. Potassium acts antagonistically towards sodium and calcium ions, contributes to a reduction of the volume of extracellular fluids and at the same time reduces muscle tension and permeability of cell membranes. The demand for sodium and potassium is of particular importance in people expending significant physical effort, where an increased electrolyte supply is recommended. The aim of the study was to estimate the content of sodium and potassium in natural mineral waters available in the Polish market and to evaluate the intake of those components with the commercially available mineral waters by different groups of consumers at the assumed volume of their consumption. The research material consisted of natural mineral waters of forty various brands available on the Polish market. The examined products were either produced in Poland or originated in other European countries. Among the products under examination, about 30% of the waters were imported from Lithuania, Latvia, the Czech Republic, France, Italy and Germany. A sample for analyses consisted of two package units of the examined water from different production lots. Samples for research were collected at random. The study was conducted with the same samples in in which calcium and magnesium content was determined, which was the subject of the first part of the study. The content of sodium and potassium was determined using the emission technique (acetylene-air flame), with the use of atomic absorption spectrometer – ICE 3000 SERIES – THERMO

  16. Balancing Sodium and Potassium: Estimates of Intake in a New Zealand Adult Population Sample

    Directory of Open Access Journals (Sweden)

    Rachael McLean

    2015-10-01

    Full Text Available Dietary intakes of sodium and potassium are important determinants of blood pressure. We assessed sodium and potassium intake in a cross-sectional survey which included a random sample of New Zealand Adults aged 18 to 64 years from two New Zealand cities: Dunedin and Wellington. Participants completed a short questionnaire, had height, weight and blood pressure measured, and collected a 24 h urine sample. Mean 24 h sodium excretion was 3386 mg/day (95% CI 3221, 3551: 3865 mg/day for men and for 2934 mg/day women. Mean 24 h potassium excretion was 2738 mg/day (95% CI 2623, 2855: 3031 mg/day for men and 2436 mg/day for women. Mean sodium:potassium ratio was 1.32 (95% CI 1.26, 1.39; 1.39 for men and 1.26 for women. Sodium intake was higher among younger people, men, those with a higher BMI and higher potassium excretion. Potassium excretion was higher among older people, men and those with a higher sodium excretion. New Zealand adults have high sodium intakes and low potassium intakes compared to recommended levels. This is likely to adversely affect population blood pressure levels as well as incidence of cardiovascular disease. A comprehensive public health programme to reduce dietary sodium intake and increase intake of fruit and vegetables is warranted.

  17. EXTRACELLULAR VESICLES: CLASSIFICATION, FUNCTIONS AND CLINICAL RELEVANCE

    Directory of Open Access Journals (Sweden)

    A. V. Oberemko

    2014-12-01

    Full Text Available This review presents a generalized definition of vesicles as bilayer extracellular organelles of all celular forms of life: not only eu-, but also prokaryotic. The structure and composition of extracellular vesicles, history of research, nomenclature, their impact on life processes in health and disease are discussed. Moreover, vesicles may be useful as clinical instruments for biomarkers, and they are promising as biotechnological drug. However, many questions in this area are still unresolved and need to be addressed in the future. The most interesting from the point of view of practical health care represents a direction to study the effect of exosomes and microvesicles in the development and progression of a particular disease, the possibility of adjusting the pathological process by means of extracellular vesicles of a particular type, acting as an active ingredient. Relevant is the further elucidation of the role and importance of exosomes to the surrounding cells, tissues and organs at the molecular level, the prospects for the use of non-cellular vesicles as biomarkers of disease.

  18. METHODS OF AVAILABLE POTASSIUM ASSESSMENT IN ...

    African Journals Online (AJOL)

    AGROSEARCH UIL

    Soil potassium (K+) exists in solution, exchangeable, and non-exchangeable ... evaluating K availability under intensive cropping; as those soils considered sufficient in ... response to potassium, soil test methods should have a high correlation with .... loamy sand to sandy loam in texture with kaolinite being the dominant.

  19. Thanatochemistry: Study of synovial fluid potassium

    African Journals Online (AJOL)

    Nilesh Keshav Tumram

    2014-03-28

    Mar 28, 2014 ... sion equations, but these may be useless when dealing with eye trauma, ocular disorders or in muti- lated remains. .... potassium concentration which rises more rapidly in the first .... postmortem interval based on differential behaviour of vitreous ... course of potassium ion activity in cadaveric synovial fluid.

  20. 低钾血症与内分泌性疾病的探讨%Study on the Low Potassium and Endocrine Diseases

    Institute of Scientific and Technical Information of China (English)

    刘红艳; 谷伟军(审校)

    2016-01-01

    Low potassium is one of the most common electrolyte disorder in clinic. Causes of low potassium levels are inadequate intake, excessive discharge or changes in the distribution of internal and external potassium. Among them, causes by endocrine disorders of hypokalemia in patients with clinical mainly include primary aldosteronism increase in disorder, and secondary aldosteronism hyperplasia, Cushing's syndrome (CS), pheochromocytoma, congenital adrenal cortical hyperplasia (CAH), Liddle's syndrome, syndrome of renal tubular acidosis and hypokalemia periodic paralysis, Bartter,and Gitelman comprehensive syndrome etc.. The main causes of the disease of the endocrine disease include renal loss of potassium and the transfer of extracellular potassium ions into the cell. This paper mainly introduces the related endocrine diseases of these two factors.%低钾血症是临床上最常见的电解质紊乱之一。引起低钾血症的原因有摄入不足、排出过多或者细胞内外钾分布的变化。其中,由内分泌性疾病导致的低钾血症临床上主要有原发性醛固酮增多症、继发性醛固酮增多症、库欣综合征(Cushing综合征)、嗜铬细胞瘤、先天性肾上腺皮质增生症(congenital adrenal hyperplasia,CAH)、Liddle综合征、肾小管酸中毒、低钾周期性麻痹、Bartter综合征、Gitelman综合征等。内分泌性疾病导致低钾血症的原因主要有肾性失钾以及细胞外钾离子转移到细胞内,本文主要介绍这两种原因导致低钾血症的相关内分泌疾病。

  1. ATP and potassium ions: a deadly combination for astrocytes

    Science.gov (United States)

    Jackson, David G.; Wang, Junjie; Keane, Robert W.; Scemes, Eliana; Dahl, Gerhard

    2014-04-01

    The ATP release channel Pannexin1 (Panx1) is self-regulated, i.e. the permeant ATP inhibits the channel from the extracellular space. The affinity of the ATP binding site is lower than that of the purinergic P2X7 receptor allowing a transient activation of Panx1 by ATP through P2X7R. Here we show that the inhibition of Panx1 by ATP is abrogated by increased extracellular potassium ion concentration ([K+]o) in a dose-dependent manner. Since increased [K+]o is also a stimulus for Panx1 channels, it can be expected that a combination of ATP and increased [K+]o would be deadly for cells. Indeed, astrocytes did not survive exposure to these combined stimuli. The death mechanism, although involving P2X7R, does not appear to strictly follow a pyroptotic pathway. Instead, caspase-3 was activated, a process inhibited by Panx1 inhibitors. These data suggest that Panx1 plays an early role in the cell death signaling pathway involving ATP and K+ ions. Additionally, Panx1 may play a second role once cells are committed to apoptosis, since Panx1 is also a substrate of caspase-3.

  2. Aminoglycosides block the Kv3.1 potassium channel and reduce the ability of inferior colliculus neurons to fire at high frequencies.

    Science.gov (United States)

    Liu, Si-Qiong J; Kaczmarek, Leonard K

    2005-03-01

    The Kv3.1 potassium channel is expressed at high levels in auditory nuclei and contributes to the ability of auditory neurons to fire at high frequencies. We have tested the effects of streptomycin, an agent that produces progressive hearing loss, on the firing properties of inferior colliculus neurons and on Kv3.1 currents in transfected cells. We found that in inferior colliculus neurons, intracellular streptomycin decreased the current density of a high threshold, noninactivating outward current and reduced the rate of repolarization of action potentials and the ability of these neurons to fire at high frequencies. Furthermore, potassium current in CHO cells transfected with the Kv3.1 gene was reduced by 50% when cells were cultured in the presence of streptomycin or when streptomycin was introduced intracellularly in the pipette solution. In the presence of intracellular streptomycin, the activation rate of Kv3.1 current increased and inhibition by extracellular TEA become voltage-dependent. The data indicate that streptomycin inhibits Kv3.1 currents by inducing a conformational change in the Kv3.1 channel. The hearing loss caused by aminoglycoside antibiotics may be partially mediated by their inhibition of Kv3.1 current in auditory neurons.

  3. Potassium in hypertension and cardiovascular disease.

    Science.gov (United States)

    Castro, Hector; Raij, Leopoldo

    2013-05-01

    The increased prevalence of hypertension and cardiovascular disease in industrialized societies undoubtedly is associated with the modern high-sodium/low-potassium diet. Extensive experimental and clinical data strongly link potassium intake to cardiovascular outcome. Most studies suggest that the sodium-to-potassium intake ratio is a better predictor of cardiovascular outcome than either nutrient individually. A high-sodium/low-potassium environment results in significant abnormalities in central hemodynamics, leading to potential target organ damage. Altered renal sodium handling, impaired endothelium-dependent vasodilatation, and increased oxidative stress are important mediators of this effect. It remains of paramount importance to reinforce consumption of a low-sodium/high-potassium diet as a critical strategy for prevention and treatment of hypertension and cardiovascular disease.

  4. Serum potassium changes with e.C.T.

    Science.gov (United States)

    Shukla, G D; Srivastava, S L; Kaur, A; Varma, D D; Doshi, L D

    1982-04-01

    Serum potassium changes with direct E.C.T. and with modified E.C.T., given under three anaesthetic (thiopentone, diazepam and propanidid) and relaxant (suxamethonium) combinations were studied in 25 patients. Ten patients each, undergoing minor surgical procedures, acted as controls for these three combinations. Modified E.C.T. caused a rise in scram potassium, which, being highest at 3 minutes, was sustained well beyond 10 minutes. Direct E.C.T. caused maximum rise within one minute which, however, came down rapidly. The rise following modified E.C.T. was one and half times more compared to that occurring in controls given only drugs but not E.C.T., in all the three anaesthetic-relaxant combinations. The rise from pre-induction level was maximum following diazepam and minimum with propanidid, thiopentone falling in between. The rise from pre-relaxant level, on the other hand, was maximum with thiopentone and minimum with propanidid.

  5. Outward potassium current oscillations in macrophage polykaryons: extracellular calcium entry and calcium-induced calcium release

    Directory of Open Access Journals (Sweden)

    Saraiva R.M.

    1997-01-01

    Full Text Available Outward current oscillations associated with transient membrane hyperpolarizations were induced in murine macrophage polykaryons by membrane depolarization in the absence of external Na+. Oscillations corresponded to a cyclic activation of Ca2+-dependent K+ currents (IKCa probably correlated with variations in intracellular Ca2+ concentration. Addition of external Na+ (8 mM immediately abolished the outward current oscillations, suggesting that the absence of the cation is necessary not only for their induction but also for their maintenance. Oscillations were completely blocked by nisoldipine. Ruthenium red and ryanodine reduced the number of outward current cycles in each episode, whereas quercetin prolonged the hyperpolarization 2- to 15-fold. Neither low molecular weight heparin nor the absence of a Na+ gradient across the membrane had any influence on oscillations. The evidence suggests that Ca2+ entry through a pathway sensitive to Ca2+ channel blockers is elicited by membrane depolarization in Na+-free medium and is essential to initiate oscillations, which are also dependent on the cyclic release of Ca2+ from intracellular Ca2+-sensitive stores; Ca2+ ATPase acts by reducing intracellular Ca2+, thus allowing slow deactivation of IKCa. Evidence is presented that neither a Na+/Ca2+ antiporter nor Ca2+ release from IP3-sensitive Ca2+ stores participate directly in the mechanism of oscillation

  6. 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.

  7. Enhanced inhibition of Listeria monocytogenes in Frankfurter sausage by the addition of potassium lactate and sodium diacetate mixtures

    NARCIS (Netherlands)

    Stekelenburg, F.K.

    2003-01-01

    Frankfurter-type sausages were prepared with potassium lactate, sodium diacetate and various levels of a mixture of potassium lactate and sodium diacetate. The development of Lactobacillus sake and Listeria monocytogenes and the sensory quality were compared with a reference product without any of t

  8. Enhanced inhibition of Listeria monocytogenes in Frankfurter sausage by the addition of potassium lactate and sodium diacetate mixtures

    NARCIS (Netherlands)

    Stekelenburg, F.K.

    2003-01-01

    Frankfurter-type sausages were prepared with potassium lactate, sodium diacetate and various levels of a mixture of potassium lactate and sodium diacetate. The development of Lactobacillus sake and Listeria monocytogenes and the sensory quality were compared with a reference product without any of

  9. Comparison of potassium and sodium binding in vivo and in agarose samples using TQTPPI pulse sequence

    Science.gov (United States)

    Schepkin, Victor D.; Neubauer, Andreas; Nagel, Armin M.; Budinger, Thomas F.

    2017-04-01

    Potassium and sodium specific binding in vivo were explored at 21.1 T by triple quantum (TQ) magnetic resonance (MR) signals without filtration to achieve high sensitivities and precise quantifications. The pulse sequence used time proportional phase increments (TPPI). During simultaneous phase-time increments, it provided total single quantum (SQ) and TQ MR signals in the second dimension at single and triple quantum frequencies, respectively. The detection of both TQ and SQ signals was performed at identical experimental conditions and the resulting TQ signal equals 60 ± 3% of the SQ signal when all ions experience sufficient time for binding. In a rat head in vivo the TQ percentage relative to SQ for potassium is 41.5 ± 3% and for sodium is 16.1 ± 1%. These percentages were compared to the matching values in an agarose tissue model with MR relaxation times similar to those of mammalian brain tissue. The sodium TQ signal in agarose samples decreased in the presence of potassium, suggesting a competitive binding of potassium relative to sodium ions for the same binding sites. The TQTPPI signals correspond to almost two times more effective binding of potassium than sodium. In vivo, up to ∼69% of total potassium and ∼27% of total sodium can be regarded as bound or experiencing an association time in the range of several milliseconds. Experimental data analyses show that more than half of the in vivo total sodium TQ signal could be from extracellular space, which is an important factor for quantification of intracellular MR signals.

  10. Composição química de tubérculos de batata para processamento, cultivados sob diferentes doses e fontes de potássio Chemical composition of potato tubers for processing, grown in different levels and sources of potassium

    Directory of Open Access Journals (Sweden)

    Diomar Augusto de Quadros

    2009-06-01

    Full Text Available A batata é considerada um dos poucos alimentos capazes de nutrir a crescente população mundial por ser fonte de energia e conter elevado teor de proteínas, vitaminas e minerais. Porém os teores desses compostos sofrem influência de diversos fatores como: cultivar utilizada, condições edafoclimáticas, safra, colheita e armazenamento. Assim, o presente trabalho teve como objetivo determinar a composição química de batatas (cvs. Atlantic, Asterix, Innovator e Shepody, cultivadas em quatro doses (0, 120, 360 e 1080 kg K2O.ha-1 e duas fontes de potássio (KCl e K2SO4. As amostras foram provenientes do município de Fazenda Rio Grande/PR, cultivadas na safra das águas. Foram realizadas as seguintes determinações: vitamina C, umidade, proteínas, lipídios, cinzas, carboidratos, energia, amido e potássio. A cv. Atlantic apresentou os maiores teores médios de cinzas (0,93% e potássio (528,80 mg.100 g-1; a cv. Asterix, a maior umidade (81,47%; a cv. Innovator, os maiores teores de proteínas (2,25%, lipídios (0,06%, carboidratos (17,72%, energia (80,40 kcal.100 g-1 e amido (16,45%; e a cv. Shepody obteve a maior quantidade de vitamina C (31,01 mg.100 g-1. Pode-se concluir que a composição química das batatas é dependente da cultivar e da adubação potássica (dose e fonte empregada.Potato is considered one of the few foods able to nourish the growing world population for being a source of energy and containing high levels of proteins, vitamins, and minerals. However, these compounds suffer influence of several factors such as the use of cultivars, soil and climate characteristics, crop, harvest, and storage. Hence, the present paper aims to determine the potato chemical composition (cvs. Atlantic, Asterix, Innovator and Shepody, grown under four different levels (0, 120, 360 and 1080 kg K2O.ha-1 and two different sources of potassium (KCl e K2SO4. Samples of crop water production were collected from a farm in the city of Fazenda

  11. Two outward potassium current types are expressed during the neural differentiation of neural stem cells**

    Institute of Scientific and Technical Information of China (English)

    Ruiying Bai; Guowei Gao; Ying Xing; Hong Xue

    2013-01-01

    The electrophysiological properties of potassium ion channels are regarded as a basic index for determining the functional differentiation of neural stem cells. In this study, neural stem cells from the hippocampus of newborn rats were induced to differentiate with neurotrophic growth factor, and the electrophysiological properties of the voltage-gated potassium ion channels were observed. Immunofluorescence staining showed that the rapidly proliferating neural stem cells formed spheres in vitro that expressed high levels of nestin. The differentiated neurons were shown to express neuron-specific enolase. Flow cytometric analysis revealed that the neural stem cells were actively dividing and the percentage of cells in the S + G2/M phase was high. However, the ratio of cells in the S + G2/M phase decreased obviously as differentiation proceeded. Whole-cellpatch-clamp re-cordings revealed apparent changes in potassium ion currents as the neurons differentiated. The potassium ion currents consisted of one transient outward potassium ion current and one delayed rectifier potassium ion current, which were blocked by 4-aminopyridine and tetraethylammonium, respectively. The experimental findings indicate that neural stem cells from newborn rat hippo-campus could be cultured and induced to differentiate into functional neurons under defined condi-tions in vitro. The differentiated neurons expressed two types of outward potassium ion currents similar to those of mature neurons in vivo.

  12. Effect of Application Potassium Nitrate and Azosprillume on Growth and Yield of Pollinates

    Directory of Open Access Journals (Sweden)

    Hadi Ghasemi

    2017-02-01

    Full Text Available One of the most important ornamental plant in Iran and all of the world is pollinates. In this research we studded effect of two types of fertilizer on the characters quantity and quality of pollinates. We used Bio fertilizer and chemical fertilizer. The bio fertilizer was Azosprillum and the chemical fertilizer was potassium nitrate. A factorial experiment was conducted based on a Randomized Complete Block Design with three replications. The result show that characters of related of leaf, total weight of bulbs, originally bulbs weight, number of side bulblets, number of bulbs and amount of potassium were significant in Potassium nitrate treatment. Also, in Azosprillum treatment characters originally bulbs diameter, steam diameter and amount of potassium were significant. In interaction of Potassium nitrate and Azosprillum characters such as: Leaf fresh weight, leaf area meter, originally bulbs diameter, originally bulbs weight, number of side bulblets, number of bulbs and amount of potassium were significant. Potassium nitrate was more effect with level of 150 k/ha on often characters, especially on percent flowering and number of bulbs was increased rang 20 numbers. On the other hand, Azosprillum was little effect on characters of vegetative and reproductive.

  13. Extracellular vesicles for drug delivery

    NARCIS (Netherlands)

    Vader, Pieter; Mol, Emma A; Pasterkamp, Gerard; Schiffelers, Raymond M

    2016-01-01

    Extracellular vesicles (EVs) are cell-derived membrane vesicles, and represent an endogenous mechanism for intercellular communication. Since the discovery that EVs are capable of functionally transferring biological information, the potential use of EVs as drug delivery vehicles has gained consider

  14. Effectiveness of Foliar Application of Potassium on Flowering and Fruiting of Cocoa

    OpenAIRE

    Rudy Erwiyono; Achmad Sucahyo; Suyono; Sugeng Winarso

    2006-01-01

    An experiment of foliar application of potassium on cocoa has been carried out in Kaliwining Experimental Station, Indonesian Coffee and Cocoa Research Institute in Jember to study its effectiveness on the flowering and fruiting of cocoa. The experiment was arranged according to factorial design of 2 factors with environmental design of randomized complete blocks. The first factor was soil application of potassium fertilization in two levels, i.e. without fertilizer and with K-fertilizer as K...

  15. 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.

  16. 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.

  17. Endocytic regulation of voltage-dependent potassium channels in the heart.

    Science.gov (United States)

    Ishii, Kuniaki; Norota, Ikuo; Obara, Yutaro

    2012-01-01

    Understanding the regulation of cardiac ion channels is critical for the prevention of arrhythmia caused by abnormal excitability. Ion channels can be regulated by a change in function (qualitative) and a change in number (quantitative). Functional changes have been extensively investigated for many ion channels including cardiac voltage-dependent potassium channels. By contrast, the regulation of ion channel numbers has not been widely examined, particularly with respect to acute modulation of ion channels. This article briefly summarizes stimulus-induced endocytic regulation of major voltage-dependent potassium channels in the heart. The stimuli known to cause their endocytosis include receptor activation, drugs, and low extracellular [K(+)], following which the potassium channels undergo either clathrin-mediated or caveolin-mediated endocytosis. Receptor-mediated endocytic regulation has been demonstrated for Kv1.2, Kv1.5, KCNQ1 (Kv7.1), and Kv4.3, while drug-induced endocytosis has been demonstrated for Kv1.5 and hERG. Low [K(+)](o)-induced endocytosis might be unique for hERG channels, whose electrophysiological characteristics are known to be under strong influence of [K(+)](o). Although the precise mechanisms have not been elucidated, it is obvious that major cardiac voltage-dependent potassium channels are modulated by endocytosis, which leads to changes in cardiac excitability.

  18. Regenerating mammalian nerve fibres: changes in action potential waveform and firing characteristics following blockage of potassium conductance.

    Science.gov (United States)

    Kocsis, J D; Waxman, S G; Hildebrand, C; Ruiz, J A

    1982-12-22

    Extracellular application of potassium channel blocking agents is known to increase the amplitude and duration of the compound action potential in non-myelinated and demyelinated axons, but not in mature mammalian myelinated fibres. In the present study we used intra-axonal and whole nerve recording techniques to study the effects of the potassium channel blocking agent 4-aminopyridine (4-AP) on regenerating rat nerve fibres. Our results indicate that early regenerating (premyelinated) axons show considerable broadening of the action potential after 4-AP application and late regenerating (myelinated) axons give rise to burst activity following a single stimulus after 4-AP application. 4-AP did not affect spike waveform or firing properties of normal mature sciatic nerve fibres. These results demonstrate the importance of potassium conductance in stabilizing firing properties of myelinated regenerating axons.

  19. A compartmental model predicts that dietary potassium affects lithium dynamics in rats.

    Science.gov (United States)

    Everts, H B; Jang, H; Boston, R C; Canolty, N L

    1996-05-01

    Lithium is the treatment of choice for manic depression, but therapy often results in nephrogenic diabetes insipidus and lithium intoxication. To investigate the effects of dietary potassium on potential side effects of lithium therapy, a mathematical model was built using the modeling program SAAM (Simulation, Analysis, And Modeling). Experimental data modeled were from adult male Sprague-Dawley rats fed diets with or without lithium and one of three levels of potassium for 17 d. A five-compartment model of lithium dynamics was built that was consistent with data from rats fed a lithium-containing diet adequate in potassium. This model was then compared with data from rats fed the other two lithium-containing diets. The model predicts that both the fractional transfer coefficient and rate of transport of lithium to the serum compartment from the kidney compartment are lower in rats fed the potassium-adequate diet than in those fed the potassium-deficient diet, and even lower in those fed the potassium-supplemented diet. In addition, fractional transfer coefficients into the serum compartment from the sampled and simulated tissue compartments changed differently with time depending on the amount of dietary potassium. The model also predicts that there would be less accumulation of lithium in the kidney, sampled tissue and simulated tissue compartments with supplemental dietary potassium. The model suggests that potassium supplementation, after a 7-d delay, protects against nephrogenic diabetes insipidus and the potentially toxic accumulation of lithium by decreasing the reabsorption of lithium from the kidneys and increasing lithium efflux from the tissues.

  20. Serum potassium concentrations: Importance of normokalaemia.

    Science.gov (United States)

    Heras, Manuel; Fernández-Reyes, María José

    2017-06-21

    Abnormalities in potassium concentrations are associated with morbidity and mortality. In recent years it has been considered that small variations in serum potassium concentrations within normal intervals may also be associated with mortality. Strategies for achieving normokalaemia include dietary measures, limiting the use of potassium retaining drugs, and use of conventional cation exchange resins (calcium/sodium polystyrene sulfonate) and/or the new non-absorbed cation exchange polymer (patiromer). Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  1. Produtividade e armazenamento de cebola (Allium cepa L. submetida a doses de nitrogênio e potássio via fertirrigação em cultivo de verão Yield and storage of onion (Allium cepa L. submitted to nitrogen and potassium levels through fertirrigation in summer planting

    Directory of Open Access Journals (Sweden)

    Geraldo Milanez de Resende

    2009-10-01

    Full Text Available O experimento foi conduzido no período de agosto de 2001 a março de 2002, com o objetivo de avaliar a influência de doses de nitrogênio (N e potássio (K aplicadas via fertirrigação sobre o rendimento e armazenamento da cebola. Utilizou-se a cultivar Alfa Tropical, no delineamento experimental de blocos ao acaso, em esquema fatorial 4 x 3, compreendendo quatro doses de nitrogênio (0, 60, 120 e 180 kg/ha e três doses de potássio (0, 90 e 180 kg/ha de K2O, com três repetições. A produtividade comercial apresentou efeito linear quando se aplicou 90,0 kg/ha de K2O e efeitos quadráticos na ausência da adubação potássica com máxima produtividade na dose de 96,5 kg/ha e mínima produtividade na dose de 136,5 kg/ha de nitrogênio na dose de 180,0 kg/ha de K2O. O incremento das doses de N reduziu a produtividade não comercial (refugos de forma linear. A massa fresca dos bulbos evidenciou efeitos lineares com o incremento das doses de N. Não se constataram efeitos significativos aos 40 dias, após cura, para perda de massa, evidenciando-se efeito significativo apenas aos 80 dias, após cura, com a aplicação de N e K.This study was carried out from August 2001 to March 2002 to evaluate the influence of nitrogen (N and potassium (K levels through fertirrigation on yield and post-harvest storage of onion bulbs. Cultivar Alfa Tropical was used in a randomized complete block design, in a 4 x 3 factorial arrangement, with four nitrogen levels (0, 60, 120, and 180 kg/ha and three potassium levels (0, 90, and 180 kg/ha K2O with three replications. The commercial yield showed linear effect in the doses of 90 kg/ha K2O and quadratic effect in the absence of potassium fertilization, with maximum yield with the level of 96.5 kg/ha nitrogen and minimum yield with the level of 136.5 kg/ha nitrogen with the dose of 180 kg/ha K2O. The increment of the levels of N reduced the non-commercial yield (culls in a linear way. Linear effects were observed

  2. Intensity scaling of an optically pumped potassium laser

    Science.gov (United States)

    Hurd, Edward J.; Holtgrave, Jeremy C.; Perram, Glen P.

    2015-12-01

    A pulsed, optically pumped potassium laser has been demonstrated with output intensity exceeding 7 MW/cm2. By using a surrogate pump, heat pipe gain cell, and helium pressure of 2500 Torr, the intensity of Diode Pumped Alkali Lasers (DPAL) has been increased by a factor of 38. Bottlenecking due to slow fine structure mixing can be avoided without hydrocarbon buffer gases with as many as 375 lasing photons obtained per potassium atom following a 7.4 ns pump pulse. A slope efficiency of 9.4% is achieved and primarily limited by a mismatch between pumped and cavity mode volumes. Laser performance is well described by a three-level, longitudinally averaged model without ionization.

  3. Serum potassium concentration in hyperglycemia of diabetes mellitus with long-term dialysis.

    Science.gov (United States)

    Tzamaloukas, A H; Avasthi, P S

    1987-05-01

    Severe hyperkalemia (serum potassium level >6 mmol per liter [mEq per liter]), often with electrocardiographic disturbances, was noted at presentation in 30% of 73 hyperglycemic episodes (serum glucose concentration >25 mmol per liter [455 mg per dl]) observed in 15 in-hospital patients with insulin-dependent diabetes mellitus who were receiving long-term hemodialysis or peritoneal dialysis. Serum glucose concentration and total carbon dioxide content correlated significantly with the presenting serum potassium concentration. Treatment with parenteral insulin alone resulted in a decrease of the serum glucose value from 41 +/- 14 (standard deviation) to 11 +/- 5 mmol per liter (P decrease in potassium concentration during treatment. Insulin alone resulted in correction of hyperkalemia in all instances. Posttreatment hypokalemia was noted in only two instances, each associated with both ketoacidosis and low-normal serum potassium concentration at hyperglycemia. Giving insulin is the only treatment usually needed for the hyperkalemia of hyperglycemia in patients on ongoing dialysis.

  4. 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

  5. Extracellular enzyme kinetics scale with resource availability

    Science.gov (United States)

    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 assimi...

  6. 21 CFR 181.34 - Sodium nitrite and potassium nitrite.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium nitrite and potassium nitrite. 181.34...-Sanctioned Food Ingredients § 181.34 Sodium nitrite and potassium nitrite. Sodium nitrite and potassium... fixatives and preservative agents, with or without sodium or potassium nitrate, in the curing of red...

  7. Neutrophil Extracellular Traps and Microcrystals

    Science.gov (United States)

    2017-01-01

    Neutrophil extracellular traps represent a fascinating mechanism by which PMNs entrap extracellular microbes. The primary purpose of this innate immune mechanism is thought to localize the infection at an early stage. Interestingly, the ability of different microcrystals to induce NET formation has been recently described. Microcrystals are insoluble crystals with a size of 1–100 micrometers that have different composition and shape. Microcrystals have it in common that they irritate phagocytes including PMNs and typically trigger an inflammatory response. This review is the first to summarize observations with regard to PMN activation and NET release induced by microcrystals. Gout-causing monosodium urate crystals, pseudogout-causing calcium pyrophosphate dehydrate crystals, cholesterol crystals associated with atherosclerosis, silicosis-causing silica crystals, and adjuvant alum crystals are discussed. PMID:28373994

  8. Neutrophil Extracellular Traps and Microcrystals.

    Science.gov (United States)

    Rada, Balázs

    2017-01-01

    Neutrophil extracellular traps represent a fascinating mechanism by which PMNs entrap extracellular microbes. The primary purpose of this innate immune mechanism is thought to localize the infection at an early stage. Interestingly, the ability of different microcrystals to induce NET formation has been recently described. Microcrystals are insoluble crystals with a size of 1-100 micrometers that have different composition and shape. Microcrystals have it in common that they irritate phagocytes including PMNs and typically trigger an inflammatory response. This review is the first to summarize observations with regard to PMN activation and NET release induced by microcrystals. Gout-causing monosodium urate crystals, pseudogout-causing calcium pyrophosphate dehydrate crystals, cholesterol crystals associated with atherosclerosis, silicosis-causing silica crystals, and adjuvant alum crystals are discussed.

  9. Neutrophil Extracellular Traps and Microcrystals

    Directory of Open Access Journals (Sweden)

    Balázs Rada

    2017-01-01

    Full Text Available Neutrophil extracellular traps represent a fascinating mechanism by which PMNs entrap extracellular microbes. The primary purpose of this innate immune mechanism is thought to localize the infection at an early stage. Interestingly, the ability of different microcrystals to induce NET formation has been recently described. Microcrystals are insoluble crystals with a size of 1–100 micrometers that have different composition and shape. Microcrystals have it in common that they irritate phagocytes including PMNs and typically trigger an inflammatory response. This review is the first to summarize observations with regard to PMN activation and NET release induced by microcrystals. Gout-causing monosodium urate crystals, pseudogout-causing calcium pyrophosphate dehydrate crystals, cholesterol crystals associated with atherosclerosis, silicosis-causing silica crystals, and adjuvant alum crystals are discussed.

  10. [Evaluation of potassium iodide in Polish dietary salt].

    Science.gov (United States)

    Andrzejewska, E; Rokicka, B; Gajda, J; Jarecka, J; Oraczewska, A; Karłowski, K

    1996-01-01

    The consequences of iodine deficiency occurring still in Poland include serious health disorders in the population, such as psycho- somatic retardation, hypothyroidism, endemic goitre, even cretinism. Administration of iodized edible salt with daily diet is an effective method for prevention of iodine deficiency. The condition of success is the proper level of potassium iodide in this salt and adequate distribution of iodized salt in various regions of the country. Successful iodine prophylaxis should be based on iodination of edible salt in amounts of 30 +/- 10 mg of KJ/kg. The permission given in the period from February to May 1994 by the General Sanitary Inspector for the production and marketing of edible salt iodized in proportions of 30 +/- 10 mg KJ/kg opened the possibility of starting its production in salt mines. The purpose of the presently reported work was to assess, in cooperation with the Province Sanitary Epidemiological Stations, the adequacy of iodination of the Polish edible salt produced in the years 1994-1995. The study was carried out according to the Polish Standard "Salt (Sodium Chloride) /PN-80/C-84081.35. Potassium iodide determination by photo colorimetric method." In 1995 the number of edible salt samples analyzed was 2484, and this number included 2129 samples of iodized salt. Potassium iodide content agreeing with the above permission was found in 122 samples, that is in 57.4% of iodized salt samples. In 603 samples (28.3%) of iodized salt this content was below that given in the permissions. In 1994 this study was carried out taking 2172 samples of edible salt, including 1586 samples of iodized salt. The content of potassium iodide agreeing with the permissions (30 +/- 10 mg/kg) was found in 342 samples (28, 1%), but 272 (22.4%) samples of iodized salt produced by salt mines contained lower amounts of potassium iodide than the amount indicated in the permissions, but still within the limits set down in the Polish Standard (20 +/- 5 mg

  11. Connexin 43 impacts on mitochondrial potassium uptake

    Directory of Open Access Journals (Sweden)

    Kerstin eBoengler

    2013-06-01

    Full Text Available In cardiomyocytes, connexin 43 (Cx43 forms gap junctions and unopposed hemichannels at the plasma membrane, but the protein is also present at the inner membrane of subsarcolemmal mitochondria. Both inhibition and genetic ablation of Cx43 reduce ADP-stimulated complex 1 respiration. Since mitochondrial potassium influx impacts on oxygen consumption, we investigated whether or not inhibition or ablation of mitochondrial Cx43 alters mitochondrial potassium uptake.Subsarcolemmal mitochondria were isolated from rat left ventricular (LV myocardium and loaded with the potassium-sensitive dye PBFI. Intramitochondrial potassium was replaced by TEA (tetraethylammonium. Mitochondria were incubated under control conditions or treated with 250 µM Gap19, a peptide that specifically inhibits Cx43-dependent hemichannels at plasma membranes. Subsequently, 140 mM KCl was added and the slope of the increase in PBFI fluorescence over time was calculated. The slope of the PBFI fluorescence of the control mitochondria was set to 100%. In the presence of Gap19, the mitochondrial potassium influx was reduced from 100±11.6 % in control mitochondria to 65.5±10.7 % (n=6, p<0.05. In addition to the pharmacological inhibition of Cx43, potassium influx was studied in mitochondria isolated from conditional Cx43 knockout mice. Here, the ablation of Cx43 was achieved by the injection of 4-hydroxytamoxifen (Cx43Cre-ER(T/fl + 4-OHT. The mitochondria of the Cx43Cre-ER(T/fl + 4-OHT mice contained 3±1% Cx43 (n=6 of that in control mitochondria (100±11%, n=8, p<0.05. The ablation of Cx43 (n=5 reduced the velocity of the potassium influx from 100±11.2 % in control mitochondria (n=9 to 66.6±5.5 % (p<0.05.Taken together, our data indicate that both pharmacological inhibition and genetic ablation of Cx43 reduce mitochondrial potassium influx.

  12. The Ketogenic Diet and Potassium Channel Function

    Science.gov (United States)

    2014-10-01

    The overall objective of this Discovery Award is to explore the hypothesis the ketogenic diet regulates neuronal excitability by influencing...potassium channel activity via the auxiliary potassium channel subunit Kv Beta 2. To test this hypothesis we have examining the impact of the ketogenic diet on...vitro bursting activity (seizures) which is reversed by treatment with the ketogenic diet (KD). Conversely, the latency to the first in vitro burst

  13. 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.

  14. Muscarinic agonists and potassium currents in guinea-pig myenteric neurones.

    Science.gov (United States)

    Galligan, J J; North, R A; Tokimasa, T

    1989-01-01

    1. Intracellular electrophysiological recordings were obtained from single neurones of the guinea-pig myenteric plexus in vitro. Using single electrode voltage clamp techniques, four distinct potassium currents were described and the effects of muscarinic agonists on these currents were studied. 2. A calcium-dependent potassium current (gKCa) was present in AH neurones at rest, and was much increased following a brief depolarization (50 ms, to 0 mV). Muscarinic agonists reduced both the resting current and the current evoked by depolarization. Pirenzepine competitively antagonized the suppression by muscarine of the calcium-dependent potassium current (or after-hyperpolarization) following an action potential. The dissociation equilibrium constant for pirenzepine was about 10 nM. 3. The conductance of AH neurones increased two to three fold when they were hyperpolarized negative to -90 mV. This inward rectification was blocked by extracellular caesium (2 mM) or rubidium (2 mM), but not by tetraethylammonium (TEA, 40 mM), 4-aminopyridine (100 microM) or cobalt (2 mM). The inward rectification was unaffected by muscarinic agonists. 4. When AH neurones were depolarized from very negative holding potentials (less than -80 mV) a brief outward current was recorded with a duration of about 200 ms. This transient or A current was completely blocked by 4-aminopyridine (100 microM) but was not affected by tetrodotoxin (300 nM), TEA (40 mM) or cobalt (2 mM). Muscarinic agonists did not affect the A current. 5. In S neurones, and in AH neurones in calcium-free solutions, the potassium conductance (in TEA and caesium) behaved according to constant field assumptions. This background conductance was suppressed by muscarinic agonists. 6. It is concluded that the depolarization by muscarinic agonists of myenteric AH neurones is due to a suppression of both a calcium-dependent potassium conductance and a background potassium conductance. Muscarinic depolarization of S neurones

  15. 低钾型周期性瘫痪患者运动诱发试验中肌力和肌电图改变与血钾的关系%Correlation between muscle strength and electromyography with blood potassium level after exercise test in patients with hypokalemic periodic paralysis

    Institute of Scientific and Technical Information of China (English)

    刘明生; 崔丽英; 冯新红; 管宇宙

    2011-01-01

    Objective To assess the correlations between muscle strength and amplitude of compound muscle action potential(CMAP)with blood potassium level in hypokalemic periodic paralysis after long exercise test(ET).Methods ET of abductor digiti minimi(ADM)was performed on 78 patients with hypokalemic periodic paralysis.Ulnar and median CMAP amplitude,blood potassium level,muscle strength of ADM,palmar interossei muscle and abductor pollicis brevis were measured before and 120 minutes after exercise.The correlations of muscle strength,CMAP amplitude and blood potassium level were analyzed.Results Ulnar CMAP amplitude was(4.6 ±2.7)mV after ET and(9.6 ±3.2)mV before ET(t =16.047,P =0.000)in 78 patients with hypokalemic periodic paralysis,respectively.Median CMAP amplitude was(10.9 ± 4.2)mV after ET and(11.2 ± 3.9)mV before ET(t =0.673,P =0.822),respectively.After ET,muscle strength of ADM decreased in 76 patients,score on MRC was less than Ⅲ in ADM but V in palmar interossei muscle and abductor pollicis brevis in 41 patients,the blood potassium level was tested in 10 of them,which was(3.8 ±0.3)mmol/L before ET and(3.9 ±0.4)mmol/L after ET(t =0.395,P =0.702).Conclusion In patients with hypokalemic periodic paralysis,blood potassium level is not the key factor affecting muscle strength and CMAP amplitude after ET.%目的 通过长时运动诱发试验,观察低钾型周期性瘫痪患者肌力和肌电图的变化与血钾之间的关系.方法 收集确诊为低钾型周期性瘫痪患者78例,对小指展肌进行运动诱发试验测定,以拇短展肌作为对照,观察120 min,测定运动诱发前后尺神经/小指展肌和正中神经/拇短展肌复合肌肉动作电位(compound muscle action potential,CMAP)波幅变化,同时观察患者小指外展和小指内收肌力以及拇短展肌肌力的变化,部分患者测定运动前后血钾水平.分析运动后不同肌肉的肌力、CMAP波幅与血钾之间的关系.结果 在小指外展运动后,78例患者

  16. 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.

  17. Analysis of relationship between serum potassium concentration of hypokalemic periodic paralysed patients and muscle strength, electrocardiogram, and the levels of muscle enzymes%低钾型周期性瘫痪患者血钾浓度与肌力、心电图、肌酶水平关系分析

    Institute of Scientific and Technical Information of China (English)

    林琇

    2015-01-01

    目的:探讨低钾型周期性瘫痪患者血钾浓度与肌力、心电图及肌酶水平的关系。方法选取来我院就诊的HOPP患者134例并分为A组(轻度低钾组,n=23),B组(中度低钾组,n=49),C组(重度低钾组, n=62)。结果三组上肢肌力及下肢肌力、血清肌酶升高率及血清肌酶水平差异有统计学意义(P<0.05)。治疗后心电图P-R间期、QRS时限、Q-T间期低于治疗前(P<0.05)。C组血清肌酶升高率、血清肌酶水平均高于A组及B组,B组高于A组(P<0.05),血钾浓度与CK值呈现明显负相关(P<0.05)。结论对HOPP患者血钾浓度降低的程度及其与肌力、心电图及肌酶水平之间的关系进行了解在疾病的诊断、治疗效果及预后的评估方面具有重要的作用。%Objective To study the relationship between serum potassium concentration of hypokalemic periodic paralysed patients and muscle strength, electrocardiogram, and the levels of muscle enzymes. Methods 134 patients with HOPP who were selected in our hospital were divided into group A(mild hypokalemia group, n=23), group B (moderate hypokalemia, n=49), and group C(serious hypokalemia group, n=62). Results The differences of upper extremity muscle strength, lower extremity muscle strength, the rising rate of muscle enzymes, and the levels of muscle enzymes between the three groups had statistical significance(P <0.05). The P-R interval, QRS duration, and P-T interval of electrocardiogram after treatment were lower than which of before treatment(P<0.05). The rising rate of muscle enzymes and the levels of muscle enzymes in group C were all higher than which in group A and group B, while which in group B was higher than which in group A(P<0.05). Serum potassium concentration and CK were statistical negative correlation.(P < 0.05). Conclusion The understanding of the relationship between the degree of serum potassium concentration reduction of patients with

  18. From mechanotransduction to extracellular matrix gene expression in fibroblasts.

    Science.gov (United States)

    Chiquet, Matthias; Gelman, Laurent; Lutz, Roman; Maier, Silke

    2009-05-01

    Tissue mechanics provide an important context for tissue growth, maintenance and function. On the level of organs, external mechanical forces largely influence the control of tissue homeostasis by endo- and paracrine factors. On the cellular level, it is well known that most normal cell types depend on physical interactions with their extracellular matrix in order to respond efficiently to growth factors. Fibroblasts and other adherent cells sense changes in physical parameters in their extracellular matrix environment, transduce mechanical into chemical information, and integrate these signals with growth factor derived stimuli to achieve specific changes in gene expression. For connective tissue cells, production of the extracellular matrix is a prominent response to changes in mechanical load. We will review the evidence that integrin-containing cell-matrix adhesion contacts are essential for force transmission from the extracellular matrix to the cytoskeleton, and describe novel experiments indicating that mechanotransduction in fibroblasts depends on focal adhesion adaptor proteins that might function as molecular springs. We will stress the importance of the contractile actin cytoskeleton in balancing external with internal forces, and describe new results linking force-controlled actin dynamics directly to the expression of specific genes, among them the extracellular matrix protein tenascin-C. As assembly lines for diverse signaling pathways, matrix adhesion contacts are now recognized as the major sites of crosstalk between mechanical and chemical stimuli, with important consequences for cell growth and differentiation.

  19. Analgesic effect of intrathecal bumetanide is accompanied by changes in spinal sodium-potassium-chloride co-transporter 1 and potassium-chloride co-transporter 2 expression in a rat model of incisional pain

    Institute of Scientific and Technical Information of China (English)

    Yanbing He; Shiyuan Xu; Junjie Huang; Qingjuan Gong

    2014-01-01

    Accumulating evidence has demonstrated that the sodium-potassium-chloride co-transporter 1 and potassium-chloride co-transporter 2 have a role in the modulation of pain transmission at the spinal level through chloride regulation in the pain pathway and by effecting neuronal excitability and pain sensitization. The present study aimed to investigate the analgesic effect of the speciifc sodium-potassium-chloride co-transporter 1 inhibitor bumetanide, and the change in spinal sodium-potassium-chloride co-transporter 1 and potassium-chloride co-transporter 2 expression in a rat model of incisional pain. Results showed that intrathecal bumetanide could decrease cumulative pain scores, and could increase thermal and mechanical pain thresholds in a rat model of incisional pain. Sodium-potassium-chloride co-transporter 1 expression in-creased in neurons from dorsal root ganglion and the deep laminae of the ipsilateral dorsal horn following incision. By contrast, potassium-chloride co-transporter 2 expression decreased in neurons of the deep laminae from the ipsilateral dorsal horn. These ifndings suggest that spinal sodium-potassium-chloride co-transporter 1 expression was up-regulated and spinal potassi-um-chloride co-transporter 2 expression was down-regulated following incision. Intrathecal bumetanide has analgesic effects on incisional pain through inhibition of sodium-potassi-um-chloride co-transporter 1.

  20. A case study involving allergic reactions to sulfur-containing compounds including, sulfite, taurine, acesulfame potassium and sulfonamides.

    Science.gov (United States)

    Stohs, Sidney J; Miller, Mark J S

    2014-01-01

    A case study is reported whereby an individual with known sulfite and sulfonamide allergies develops hypersensitivity to taurine above a threshold level as well as to the non-nutritive sweetener acesulfame potassium, compounds that are not normally associated with allergic reactions. Sulfites, sulfonamides, taurine and acesulfame potassium all contain a SO3 moiety. Challenge tests provide evidence for the hypersensitivities to taurine and acesulfame potassium. The subject is also allergic to thiuram mix and thimerosal, sulfur containing compounds, as well as to various food products. This may be the first case where hypersensitivities to taurine and acesulfame potassium have been documented and reported. Several mechanistic explanations are provided for the untoward reactions to taurine and acesulfame potassium. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Scorpion Potassium Channel-blocking Defensin Highlights a Functional Link with Neurotoxin.

    Science.gov (United States)

    Meng, Lanxia; Xie, Zili; Zhang, Qian; Li, Yang; Yang, Fan; Chen, Zongyun; Li, Wenxin; Cao, Zhijian; Wu, Yingliang

    2016-03-25

    The structural similarity between defensins and scorpion neurotoxins suggests that they might have evolved from a common ancestor. However, there is no direct experimental evidence demonstrating a functional link between scorpion neurotoxins and defensins. The scorpion defensin BmKDfsin4 from Mesobuthus martensiiKarsch contains 37 amino acid residues and a conserved cystine-stabilized α/β structural fold. The recombinant BmKDfsin4, a classical defensin, has been found to have inhibitory activity against Gram-positive bacteria such as Staphylococcus aureus, Bacillus subtilis, and Micrococcus luteusas well as methicillin-resistant Staphylococcus aureus Interestingly, electrophysiological experiments showed that BmKDfsin4,like scorpion potassium channel neurotoxins, could effectively inhibit Kv1.1, Kv1.2, and Kv1.3 channel currents, and its IC50value for the Kv1.3 channel was 510.2 nm Similar to the structure-function relationships of classical scorpion potassium channel-blocking toxins, basic residues (Lys-13 and Arg-19) of BmKDfsin4 play critical roles in peptide-Kv1.3 channel interactions. Furthermore, mutagenesis and electrophysiological experiments demonstrated that the channel extracellular pore region is the binding site of BmKDfsin4, indicating that BmKDfsin4 adopts the same mechanism for blocking potassium channel currents as classical scorpion toxins. Taken together, our work identifies scorpion BmKDfsin4 as the first invertebrate defensin to block potassium channels. These findings not only demonstrate that defensins from invertebrate animals are a novel type of potassium channel blockers but also provide evidence of a functional link between defensins and neurotoxins.

  2. Defining the extracellular matrix using proteomics

    Science.gov (United States)

    Byron, Adam; Humphries, Jonathan D; Humphries, Martin J

    2013-01-01

    The cell microenvironment has a profound influence on the behaviour, growth and survival of cells. The extracellular matrix (ECM) provides not only mechanical and structural support to cells and tissues but also binds soluble ligands and transmembrane receptors to provide spatial coordination of signalling processes. The ability of cells to sense the chemical, mechanical and topographical features of the ECM enables them to integrate complex, multiparametric information into a coherent response to the surrounding microenvironment. Consequently, dysregulation or mutation of ECM components results in a broad range of pathological conditions. Characterization of the composition of ECM derived from various cells has begun to reveal insights into ECM structure and function, and mechanisms of disease. Proteomic methodologies permit the global analysis of subcellular systems, but extracellular and transmembrane proteins present analytical difficulties to proteomic strategies owing to the particular biochemical properties of these molecules. Here, we review advances in proteomic approaches that have been applied to furthering our understanding of the ECM microenvironment. We survey recent studies that have addressed challenges in the analysis of ECM and discuss major outcomes in the context of health and disease. In addition, we summarize efforts to progress towards a systems-level understanding of ECM biology. PMID:23419153

  3. Enzymatic Production of Extracellular Reactive Oxygen Species by Marine Microorganisms

    Science.gov (United States)

    Diaz, J. M.; Andeer, P. F.; Hansel, C. M.

    2014-12-01

    Reactive oxygen species (ROS) serve as intermediates in a myriad of biogeochemically important processes, including cell signaling pathways, cellular oxidative stress responses, and the transformation of both nutrient and toxic metals such as iron and mercury. Abiotic reactions involving the photo-oxidation of organic matter were once considered the only important sources of ROS in the environment. However, the recent discovery of substantial biological ROS production in marine systems has fundamentally shifted this paradigm. Within the last few decades, marine phytoplankton, including diatoms of the genus Thalassiosira, were discovered to produce ample extracellular quantities of the ROS superoxide. Even more recently, we discovered widespread production of extracellular superoxide by phylogenetically and ecologically diverse heterotrophic bacteria at environmentally significant levels (up to 20 amol cell-1 hr-1), which has introduced the revolutionary potential for substantial "dark" cycling of ROS. Despite the profound biogeochemical importance of extracellular biogenic ROS, the cellular mechanisms underlying the production of this ROS have remained elusive. Through the development of a gel-based assay to identify extracellular ROS-producing proteins, we have recently found that enzymes typically involved in antioxidant activity also produce superoxide when molecular oxygen is the only available electron acceptor. For example, large (~3600 amino acids) heme peroxidases are involved in extracellular superoxide production by a bacterium within the widespread Roseobacter clade. In Thalassiosira spp., extracellular superoxide is produced by flavoproteins such as glutathione reductase and ferredoxin NADP+ reductase. Thus, extracellular ROS production may occur via secreted and/or cell surface enzymes that modulate between producing and degrading ROS depending on prevailing geochemical and/or ecological conditions.

  4. The effect of foliar feeding of potassium salts and urea in spinach on gas exchange, leaf yield and quality

    Directory of Open Access Journals (Sweden)

    Edward Borowski

    2012-12-01

    Full Text Available In a pot experiment conducted in a phytotron, the effectiveness of foliar feeding of different potassium salts, with and without the addition of 0.5% CO(NH22, in spinach (Spinacia oleracea L. was investigated. Potassium was applied 3 times in the form of 1% solutions KCl, KNO3, K2SO4 and C6H5K3O7•H2O, compared to water as the control treatment. The obtained results show that foliar feeding of potassium salts in spinach is an efficient method of supplementing the level of K+ in plants during vegetation. Plants fed with KNO3 had the highest content of potassium in leaves, and those fertilized with K2SO4, C6H5K3O7 × H2O and KCl had an only slightly lower potassium content. The application of potassium salts resulted in more intensive gas exchange in leaves (stomatal conductance, photosynthesis, transpiration and, as a consequence of that, increased leaf yield. Potassium nitrate and citrate influenced most effectively the abovementioned processes. The treatment of spinach with potassium salts resulted in an increased content of protein, chlorophyll, carotenoids, nitrates and iron as well as a decreased content of vitamin C and calcium in leaves.

  5. 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.

  6. Potassium dependent rescue of a myopathy with core-like structures in mouse.

    Science.gov (United States)

    Hanson, M Gartz; Wilde, Jonathan J; Moreno, Rosa L; Minic, Angela D; Niswander, Lee

    2015-01-07

    Myopathies decrease muscle functionality. Mutations in ryanodine receptor 1 (RyR1) are often associated with myopathies with microscopic core-like structures in the muscle fiber. In this study, we identify a mouse RyR1 model in which heterozygous animals display clinical and pathological hallmarks of myopathy with core-like structures. The RyR1 mutation decreases sensitivity to activated calcium release and myoplasmic calcium levels, subsequently affecting mitochondrial calcium and ATP production. Mutant muscle shows a persistent potassium leak and disrupted expression of regulators of potassium homeostasis. Inhibition of KATP channels or increasing interstitial potassium by diet or FDA-approved drugs can reverse the muscle weakness, fatigue-like physiology and pathology. We identify regulators of potassium homeostasis as biomarkers of disease that may reveal therapeutic targets in human patients with myopathy of central core disease (CCD). Altogether, our results suggest that amelioration of potassium leaks through potassium homeostasis mechanisms may minimize muscle damage of myopathies due to certain RyR1 mutations.

  7. Serum Potassium Profile and Associated Factors in Incident Peritoneal Dialysis Patients

    Directory of Open Access Journals (Sweden)

    Ying Liu

    2016-08-01

    Full Text Available Background/Aims: Abnormal potassium profiles are common in peritoneal dialysis (PD patients. We studied the factors associated with serum potassium profiles in incident PD patients. Methods: Patients were enrolled from two hospital-facilitated PD centers from May 2013 to May 2016 and January 2009 to December 2015. A total of 319 incident PD patients were examined for factors associated with serum potassium profile. Average serum potassium levels were obtained for analysis during the first 3 months after PD initiation. Clinically factors and parameters associated with PD were assessed by logistic regression. Results: There were 168 men and 151 women (mean age, 50.8 years. Blood urea nitrogen (BUN, creatinine (Cr, and intact parathyroid hormone levels were significantly increased in patients in the higher serum potassium group. There were no significant risk factors for hypokalemia, including sex, age, diabetes, blood examination parameters, medication use, or PD-related parameters by multivariate logistic regression analysis. BUN (adjusted odds ratio [OR] 1.02, 95% CI 1.01-1.03, p = 0.001 and Cr (adjusted OR 1.08, 95% CI 1.01-1.16, p = 0.029 levels were significant risk factors for hyperkalemia by multivariate logistic regression analysis. Conclusion: Hyperkalemia and blood BUN and Cr levels were significantly associated in incident PD patients.

  8. Development of potassium ion conducting hollow glass fibers. [potassium sulfur battery

    Science.gov (United States)

    Tsang, F. Y.

    1974-01-01

    Potassium ion conducting glasses, chemically resistant to potassium, potassium sulfide and sulfur, were made and their possible utility as the membrane material for a potassium/sulfur battery was evaluated. At least one satisfactory candidate was found. It possesses an electrical resistance which makes it usable as a membrane in the form of a fine hollow fiber. It's chemical and electrochemical resistances are excellent. The other aspects of the possible potassium sulfur battery utilizing such fine hollow fibers, including the header (or tube sheet) and a cathode current collector were studied. Several cathode materials were found to be satisfactory. None of the tube sheet materials studied possessed all the desired properties. Multi-fiber cells had very limited life-time due to physical failure of fibers at the fiber/tube sheet junctions.

  9. Filtration recovery of extracellular DNA from environmental water samples

    Science.gov (United States)

    qPCR methods are able to analyze DNA from microbes within hours of collecting water samples, providing the promptest notification and public awareness possible when unsafe pathogenic levels are reached. Health risk, however, may be overestimated by the presence of extracellular ...

  10. Regulation of pituitary hormones and cell proliferation by components of the extracellular matrix

    Directory of Open Access Journals (Sweden)

    M. Paez-Pereda

    2005-10-01

    Full Text Available The extracellular matrix is a three-dimensional network of proteins, glycosaminoglycans and other macromolecules. It has a structural support function as well as a role in cell adhesion, migration, proliferation, differentiation, and survival. The extracellular matrix conveys signals through membrane receptors called integrins and plays an important role in pituitary physiology and tumorigenesis. There is a differential expression of extracellular matrix components and integrins during the pituitary development in the embryo and during tumorigenesis in the adult. Different extracellular matrix components regulate adrenocorticotropin at the level of the proopiomelanocortin gene transcription. The extracellular matrix also controls the proliferation of adrenocorticotropin-secreting tumor cells. On the other hand, laminin regulates the production of prolactin. Laminin has a dynamic pattern of expression during prolactinoma development with lower levels in the early pituitary hyperplasia and a strong reduction in fully grown prolactinomas. Therefore, the expression of extracellular matrix components plays a role in pituitary tumorigenesis. On the other hand, the remodeling of the extracellular matrix affects pituitary cell proliferation. Matrix metalloproteinase activity is very high in all types of human pituitary adenomas. Matrix metalloproteinase secreted by pituitary cells can release growth factors from the extracellular matrix that, in turn, control pituitary cell proliferation and hormone secretion. In summary, the differential expression of extracellular matrix components, integrins and matrix metalloproteinase contributes to the control of pituitary hormone production and cell proliferation during tumorigenesis.

  11. Differential response of root morphology to potassium deficient stress among rice genotypes varying in potassium efficiency

    Institute of Scientific and Technical Information of China (English)

    Yan-bo JIA; Xiao-e YANG; Ying FENG; Ghulam JILANI

    2008-01-01

    Disparity in the root morphology of six rice (Oryza sativa L.) genotypes varying in potassium (K) efficiency was studied with three K levels: 5 mg/L (low),10 mg/L (moderate) and 40 mg/L (adequate) in hydroponic culture.Morphological parameters included root length,surface area,volume and count of lateral roots,as well as fine (diameter0.2 mm) roots.The results indicate that the root growth of all genotypes was reduced under low K,but moderate K deficiency increased the root length of the efficient genotypes.At deficient and moderate K levels,all the efficient rice genotypes developed more fine roots (diameter<0.2 mm) than the inefficient ones.Both fine root count and root surface area were found to be the best parameters to portray K stress in rice.In accordance with the root morphology,higher K concentrations were noted in shoots of the efficient genotypes when grown at moderate and deficient K levels,indicating that root morphology parameters are involved in root uptake for K and in the translocation of K up to shoots.K deficiency affected not only the root morphology,but also the root ultra-structure.The roots of high-efficient genotypes had stronger tolerance to K deficient stress for root membrane damage,and could maintain the developed root architecture to adapt to the low K growth medium.

  12. 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.

  13. New mutations of SCN4A cause a potassium-sensitive normokalemic periodic paralysis.

    Science.gov (United States)

    Vicart, S; Sternberg, D; Fournier, E; Ochsner, F; Laforet, P; Kuntzer, T; Eymard, B; Hainque, B; Fontaine, B

    2004-12-14

    Periodic paralysis is classified into hypokalemic (hypoPP) and hyperkalemic (hyperPP) periodic paralysis according to variations of blood potassium levels during attacks. To describe new mutations in the muscle sodium channel gene SCN4A that cause periodic paralysis. A thorough clinical, electrophysiologic, and molecular study was performed of four unrelated families who presented with periodic paralysis. The nine affected members had episodes of muscle weakness reminiscent of both hyperPP and hypoPP. A provocative test with potassium chloride was positive in two patients. However, repeated and carefully performed tests of blood potassium levels during attacks resulted in normal potassium levels. Remarkably, two patients experienced hypokalemic episodes of paralysis related to peculiar provocative factors (corticosteroids and thyrotoxicosis). Similarly to hyperPP, electromyography in nine patients revealed increased compound muscle action potentials after short exercise and a delayed decline during rest after long exercise as well as myotonic discharges in one patient. With use of molecular genetic analysis of the gene SCN4A, three new mutations were found affecting codon 675. They resulted in an amino acid substitution of a highly conserved arginine (R) to either a glycine (G), a glutamine (Q), or a tryptophan (W). Interestingly, hypoPP is caused by both mutations affecting nearby codons as well as the change of an arginine into another amino acid. A potassium-sensitive and normokalemic type of periodic paralysis caused by new SCN4A mutations at codon 675 is reported.

  14. Characteristics of Potassium-Enriched, Flue-Cured Tobacco Genotype in Potassium Absorption,Accumulation,and In-Ward Potassium Currents of Root Cortex

    Institute of Scientific and Technical Information of China (English)

    YNAG Tie-zhao; LU Li-ming; XIA Wei; FAN Jin-hua

    2007-01-01

    This study was to investigate the main traits of potassium-enriched,flue-cured tobacco genotypes related to potassium absorption,accumulation,and in-ward potassium currents of the root cortex.Hydroponic methods,K+-depletion methods,and patch-clamp,whole-cell recordings were conducted to study the accumulation of dry matter and potassium in different organs,and to measure potassium absorption and dynamic and in-ward potassium currents in potassium-enriched,fluecured tobacco genotypes.The average dry weights of leaves and whole plant of potassium-enriched,flue-cured tobacco genotype ND202 were 10.20,and 14.85g,respectively,higher than JYH(8.50 and 13.11g,respectively)and NC2326(8.39 and 12.72g,respectively),when potassium concentration in the solution ranged from 0.1 to 50mmol L-1.Potassium accumulation in the leaves of ND202 was 18.6% higher than JYH and 34% higher than NC2326 when potassium concentration in the solution was superior to 0.5mmol L-1.The Vmax(the maximum velocity)of ND202 was 118.11μmol FW g-1h-1,obviously higher than that of JYH(58.87 μmol FW g-1 h-1)and NC2326(64.40μmol FW g-1 h-1).In the in-ward potassium currents,the absolute value of current density(pA/pF)of ND202 was 60,higher than that of JYH(50)and NC2326(40).Potassium concentration in leaves,Vmax and in-ward potassium currents,could be used to screen potassium-enriched,flue-cured tobacco genotypes.

  15. p38 Activation Is Required Upstream of Potassium Current Enhancement and Caspase Cleavage in Thiol Oxidant-Induced Neuronal Apoptosis

    Science.gov (United States)

    McLaughlin, BethAnn; Pal, Sumon; Tran, Minhnga P.; Parsons, Andrew A.; Barone, Frank C.; Erhardt, Joseph A.; Aizenman, Elias

    2013-01-01

    Oxidant-induced neuronal apoptosis has been shown to involve potassium and zinc dysregulation, energetic dysfunction, activation of stress-related kinases, and caspase cleavage. The temporal ordering and interdependence of these events was investigated in primary neuronal cultures exposed to the sulfhydryl oxidizing agent 2,2′-dithiodipyridine (DTDP), a compound that induces the intracellular release of zinc. We previously observed that tetraethylammonium (TEA), high extracellular potassium, or cysteine protease inhibitors block apoptosis induced by DTDP. We now report that both p38 and extracellular signal-regulated kinase phosphorylation are evident in neuronal cultures within 2 hr of a brief exposure to 100 μm DTDP. However, only p38 inhibition is capable of blocking oxidant-induced toxicity. Cyclohexamide or actinomycin D does not attenuate DTDP-induced cell death, suggesting that posttranslational modification of existing targets, rather than transcriptional activation, is responsible for the deleterious effects of p38. Indeed, an early robust increase in TEA-sensitive potassium channel currents induced by DTDP is attenuated by p38 inhibition but not by caspase inhibition. Moreover, we found that activation of p38 is required for caspase 3 and 9 cleavage, suggesting that potassium currents enhancement is required for caspase activation. Finally, we observed that DTDP toxicity could be blocked with niacinamide or benzamide, inhibitors of poly (ADP-ribose) synthetase. Based on these findings, we conclude that oxidation of sulfhydryl groups on intracellular targets results in intracellular zinc release, p38 phosphorylation, enhancement of potassium currents, caspase cleavage, energetic dysfunction, and translationally independent apoptotic cell death. PMID:11331359

  16. Potassium and Phosphorus effects on disease severity of charcoal rot of soybean

    Science.gov (United States)

    The effects of potassium (K) and phosphorus (P) fertilizers on charcoal rot of soybean [Glycine max (L.) Merr.] are unknown. Therefore, the severity of charcoal rot was studied at five levels of K (0, 37, 75, 111 and 149 kg K ha-1) and a level that was equal to the recommended fertilizer applicatio...

  17. 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.

  18. Potassium channels in pulmonary arterial hypertension.

    Science.gov (United States)

    Boucherat, Olivier; Chabot, Sophie; Antigny, Fabrice; Perros, Frédéric; Provencher, Steeve; Bonnet, Sébastien

    2015-10-01

    Pulmonary arterial hypertension (PAH) is a devastating cardiopulmonary disorder with various origins. All forms of PAH share a common pulmonary arteriopathy characterised by vasoconstriction, remodelling of the pre-capillary pulmonary vessel wall, and in situ thrombosis. Although the pathogenesis of PAH is recognised as a complex and multifactorial process, there is growing evidence that potassium channels dysfunction in pulmonary artery smooth muscle cells is a hallmark of PAH. Besides regulating many physiological functions, reduced potassium channels expression and/or activity have significant effects on PAH establishment and progression. This review describes the molecular mechanisms and physiological consequences of potassium channel modulation. Special emphasis is placed on KCNA5 (Kv1.5) and KCNK3 (TASK1), which are considered to play a central role in determining pulmonary vascular tone and may represent attractive therapeutic targets in the treatment of PAH.

  19. Effects of Impellor Speed and Aeration Rate on Mycelial Biomass and Extracellular Polysaccharide Production,Reducing Sugar Consumption and Dissolved Oxygen Levels in Fermentor-grown Cultures of Phellinus baumii%不同搅拌转速和通气量对桑黄深层发酵培养的影响

    Institute of Scientific and Technical Information of China (English)

    雷萍; 吴亚召; 张文隽; 陈旭; 吕德平; 安军民

    2014-01-01

    The effects of impellor speed and aeration rate on mycelial biomass and extracellular polysaccharide production,reducing sugar consumption and dissolved oxygen levels during growth of Phellinus baumii in a 20-L fermentor were determined.Highest biomass (12.65 g/L)and extracellular polysaccharide(2.99 g/L) yields,and the most rapid decrease in dissolved oxygen levels,were recorded when the impellor speed was set at 150 r/min.Mycelial pellets were globose and compact,and the proportion of hyphal filaments was low. Highest yields of mycelial biomass (12.69 g/L)and extracellular polysaccharide(3.0 g/L),and the most rapid decrease in dissolved oxygen levels,were recorded when the aeration rate was set at 1∶0.65 vvm (air volume/culture volume/min).At this setting,the fungal mycelium grew well and formed compact pellets of uniform size.%探讨在20 L搅拌式发酵罐中,转速和通气量对桑黄菌丝生物量、胞外多糖产率、溶氧以及菌丝形态的影响。结果表明,实验范围内,转速为150 r/min时,桑黄菌丝体生物量最大(12.65 g/L),胞外多糖得率最高(2.99 g/L),相对溶氧下降最快,菌球小球状、较紧密、丝状体比例小;通气量为1∶0.65 vvm,桑黄菌丝体生物量最大(12.69 g/L),胞外多糖得率最高(3.00 g/L),相对溶氧下降最快,菌球大小均匀、紧密、生长良好。

  20. The stoichiometry and biophysical properties of the Kv4 potassium channel complex with K+ channel-interacting protein (KChIP) subunits are variable, depending on the relative expression level.

    Science.gov (United States)

    Kitazawa, Masahiro; Kubo, Yoshihiro; Nakajo, Koichi

    2014-06-20

    Kv4 is a voltage-gated K(+) channel, which underlies somatodendritic subthreshold A-type current (ISA) and cardiac transient outward K(+) (Ito) current. Various ion channel properties of Kv4 are known to be modulated by its auxiliary subunits, such as K(+) channel-interacting protein (KChIP) or dipeptidyl peptidase-like protein. KChIP is a cytoplasmic protein and increases the current amplitude, decelerates the inactivation, and accelerates the recovery from inactivation of Kv4. Crystal structure analysis demonstrated that Kv4 and KChIP form an octameric complex with four Kv4 subunits and four KChIP subunits. However, it remains unknown whether the Kv4·KChIP complex can have a different stoichiometry other than 4:4. In this study, we expressed Kv4.2 and KChIP4 with various ratios in Xenopus oocytes and observed that the biophysical properties of Kv4.2 gradually changed with the increase in co-expressed KChIP4. The tandem repeat constructs of Kv4.2 and KChIP4 revealed that the 4:4 (Kv4.2/KChIP4) channel shows faster recovery than the 4:2 channel, suggesting that the biophysical properties of Kv4.2 change, depending on the number of bound KChIP4s. Subunit counting by single-molecule imaging revealed that the bound number of KChIP4 in each Kv4.2·KChIP4 complex was dependent on the expression level of KChIP4. Taken together, we conclude that the stoichiometry of Kv4·KChIP complex is variable, and the biophysical properties of Kv4 change depending on the number of bound KChIP subunits.

  1. The Stoichiometry and Biophysical Properties of the Kv4 Potassium Channel Complex with K+ Channel-interacting Protein (KChIP) Subunits Are Variable, Depending on the Relative Expression Level*

    Science.gov (United States)

    Kitazawa, Masahiro; Kubo, Yoshihiro; Nakajo, Koichi

    2014-01-01

    Kv4 is a voltage-gated K+ channel, which underlies somatodendritic subthreshold A-type current (ISA) and cardiac transient outward K+ (Ito) current. Various ion channel properties of Kv4 are known to be modulated by its auxiliary subunits, such as K+ channel-interacting protein (KChIP) or dipeptidyl peptidase-like protein. KChIP is a cytoplasmic protein and increases the current amplitude, decelerates the inactivation, and accelerates the recovery from inactivation of Kv4. Crystal structure analysis demonstrated that Kv4 and KChIP form an octameric complex with four Kv4 subunits and four KChIP subunits. However, it remains unknown whether the Kv4·KChIP complex can have a different stoichiometry other than 4:4. In this study, we expressed Kv4.2 and KChIP4 with various ratios in Xenopus oocytes and observed that the biophysical properties of Kv4.2 gradually changed with the increase in co-expressed KChIP4. The tandem repeat constructs of Kv4.2 and KChIP4 revealed that the 4:4 (Kv4.2/KChIP4) channel shows faster recovery than the 4:2 channel, suggesting that the biophysical properties of Kv4.2 change, depending on the number of bound KChIP4s. Subunit counting by single-molecule imaging revealed that the bound number of KChIP4 in each Kv4.2·KChIP4 complex was dependent on the expression level of KChIP4. Taken together, we conclude that the stoichiometry of Kv4·KChIP complex is variable, and the biophysical properties of Kv4 change depending on the number of bound KChIP subunits. PMID:24811166

  2. 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

    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 to norepineph......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......). 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...... chloride. We conclude that norepinephrine and ANG II use different mechanisms for contraction and that extracellular chloride is essential for contraction in afferent arterioles after activation of voltage-dependent calcium channels. We suggest that a chloride influx pathway is activated concomitantly...

  3. Regulation of adenosine triphosphate-sensitive potassium channels suppresses the toxic effects of amyloid-beta peptide (25-35)

    Institute of Scientific and Technical Information of China (English)

    Min Kong; Maowen Ba; Hui Liang; Peng Shao; Tianxia Yu; Ying Wang

    2013-01-01

    In this study, we treated PC12 cells with 0-20 μM amyloid-β peptide (25-35) for 24 hours to induce cytotoxicity, and found that 5-20 μM amyloid-β peptide (25-35) decreased PC12 cell viability, but adenosine triphosphate-sensitive potassium channel activator diazoxide suppressed the decrease reactive oxygen species levels. These protective effects were reversed by the selective mitochondrial adenosine triphosphate-sensitive potassium channel blocker 5-hydroxydecanoate. An inducible nitric oxide synthase inhibitor, Nω-nitro-L-arginine, also protected PC12 cells from intracellular reactive oxygen species levels. However, the H2O2-degrading enzyme catalase could that the increases in both mitochondrial membrane potential and reactive oxygen species levels adenosine triphosphate-sensitive potassium channels and nitric oxide. Regulation of adenosine triphosphate-sensitive potassium channels suppresses PC12 cell cytotoxicity induced by amyloid-β

  4. Correction factors for estimating potassium concentrations in samples with in vitro hemolysis: a detriment to patient safety.

    Science.gov (United States)

    Mansour, Mai M H; Azzazy, Hassan M E; Kazmierczak, Steven C

    2009-06-01

    Correction factors have been proposed for estimating true potassium concentrations in blood samples with evidence of in vitro hemolysis. We used 2 different models of true (ie, nonsimulated) in vitro hemolysis to evaluate the clinical utility of correction factors for estimating potassium concentrations in samples with evidence of in vitro hemolysis. Potassium correction factors were derived using 2 different models. In model 1, potassium and plasma hemoglobin were measured with the Hitachi 747 analyzer in 132 paired blood samples, with each pair consisting of 1 sample with evidence of hemolysis and 1 without, collected during the same phlebotomy procedure. The change in measured potassium concentration was plotted versus the change in plasma hemoglobin concentration for each pair of samples. In model 2, the potassium levels of 142 784 blood samples and the corresponding hemolytic index values were measured with the Beckman LX20 analyzer. Potassium concentrations at the 10th, 25th, 50th, 75th, and 90th percentiles were calculated for each hemolysis index category. From our 2 models, we derived correction factors expressing an increase in potassium concentration of 0.51 and 0.40 mEq/L for every increase in plasma hemoglobin concentration of 0.1 g/dL. These correction factors are much higher than those reported in studies that simulated in vitro hemolysis by freeze-thaw lysis or osmotic disruption of whole blood. Use of correction factors for estimating the true potassium concentration in samples with evidence of in vitro hemolysis is not recommended. Derivation of correction factors by using samples with nonsimulated in vitro hemolysis suggests that the actual increase in potassium in hemolyzed samples is much higher than that reported in previous studies that produced hemolysis with artificial means.

  5. A potassium Faraday anomalous dispersion optical filter

    Science.gov (United States)

    Yin, B.; Shay, T. M.

    1992-01-01

    The characteristics of a potassium Faraday anomalous dispersion optical filter operating on the blue and near infrared transitions are calculated. The results show that the filter can be designed to provide high transmission, very narrow pass bandwidth, and low equivalent noise bandwidth. The Faraday anomalous dispersion optical filter (FADOF) provides a narrow pass bandwidth (about GHz) optical filter for laser communications, remote sensing, and lidar. The general theoretical model for the FADOF has been established in our previous paper. In this paper, we have identified the optimum operational conditions for a potassium FADOF operating on the blue and infrared transitions. The signal transmission, bandwidth, and equivalent noise bandwidth (ENBW) are also calculated.

  6. Direct determination of calcium, sodium and potassium in fermented milk products

    Directory of Open Access Journals (Sweden)

    Kravić Snežana Ž.

    2012-01-01

    Full Text Available The aim of this study was the investigation of the possibilities of direct determination of calcium, sodium and potassium in the commercial and kombucha-based fermented milk products by flame photometry. Two procedures were used for sample preparation: simple dilution with water (direct method and extraction with mineral acid. Calcium, sodium and potassium levels determined after mentioned sample preparation methods were compared. The results showed that the differences between the values obtained for the different sample treatment were within the experimental error at the 95% confidence level. Compared to the method based on extraction with mineral acid, the direct method is efficient, faster, simpler, cheaper, and operates according to the principles of Green Chemistry. Consequently, the proposed method for the direct determination of calcium, sodium and potassium could be applied for the rapid routine analysis of the mineral content in the fermented dairy products. [Projekat Ministarstva nauke Republike Srbije, br. III 46009

  7. 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.

  8. Extracellular Molecules Involved in Cancer Cell Invasion

    Energy Technology Data Exchange (ETDEWEB)

    Stivarou, Theodora; Patsavoudi, Evangelia, E-mail: epatsavoudi@pasteur.gr [Department of Biochemistry, Hellenic Pasteur Institute, Athens 11521 (Greece); Technological Educational Institute of Athens, Egaleo, Athens 12210 (Greece)

    2015-01-26

    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.

  9. 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.

  10. How Potassium Can Help Control High Blood Pressure

    Science.gov (United States)

    ... natural sources of potassium. For example, a medium banana has about 420 mg of potassium and half ... high blood pressure. Learn more Get a fact sheet on following a heart-healthy diet: English | Spanish ...

  11. Increased intra- and extracellular granzyme expression in patients with tuberculosis.

    Science.gov (United States)

    Garcia-Laorden, M Isabel; Blok, Dana C; Kager, Liesbeth M; Hoogendijk, Arie J; van Mierlo, Gerard J; Lede, Ivar O; Rahman, Wahid; Afroz, Rumana; Ghose, Aniruddha; Visser, Caroline E; Md Zahed, Abu Shahed; Husain, Md Anwar; Alam, Khan Mashrequl; Chandra Barua, Pravat; Hassan, Mahtabuddin; Hossain, Ahmed; Tayab, Md Abu; Day, Nick; Dondorp, Arjen M; de Vos, Alex F; van der Poll, Tom

    2015-09-01

    Tuberculosis (TB) is an important cause of morbidity and mortality worldwide. Granzymes (gzms) are proteases mainly found in cytotoxic lymphocytes, but also extracellularly. While the role of gzms in target cell death has been widely characterized, considerable evidence points towards broader roles related to infectious and inflammatory responses. To investigate the expression of the gzms in TB, intracellular gzms A, B and K were measured by flow cytometry in lymphocyte populations from peripheral blood mononuclear cells from 18 TB patients and 12 healthy donors from Bangladesh, and extracellular levels of gzmA and B were measured in serum from 58 TB patients and 31 healthy controls. TB patients showed increased expression of gzmA in CD8(+) T, CD4(+) T and CD56(+) T, but not NK, cells, and of gzmB in CD8(+) T cells, when compared to controls. GzmK expression was not altered in TB patients in any lymphocyte subset. The extracellular levels of gzmA and, to a lesser extent, of gzmB, were increased in TB patients, but did not correlate with intracellular gzm expression in lymphocyte subsets. Our results reveal enhanced intra- and extracellular expression of gzmA and B in patients with pulmonary TB, suggesting that gzms are part of the host response to tuberculosis.

  12. Potassium ferrate treatment of RFETS` contaminated groundwater

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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 {sup +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.

  13. Dendritic potassium channels in hippocampal pyramidal neurons.

    Science.gov (United States)

    Johnston, D; Hoffman, D A; Magee, J C; Poolos, N P; Watanabe, S; Colbert, C M; Migliore, M

    2000-05-15

    Potassium channels located in the dendrites of hippocampal CA1 pyramidal neurons control the shape and amplitude of back-propagating action potentials, the amplitude of excitatory postsynaptic potentials and dendritic excitability. Non-uniform gradients in the distribution of potassium channels in the dendrites make the dendritic electrical properties markedly different from those found in the soma. For example, the influence of a fast, calcium-dependent potassium current on action potential repolarization is progressively reduced in the first 150 micrometer of the apical dendrites, so that action potentials recorded farther than 200 micrometer from the soma have no fast after-hyperpolarization and are wider than those in the soma. The peak amplitude of back-propagating action potentials is also progressively reduced in the dendrites because of the increasing density of a transient potassium channel with distance from the soma. The activation of this channel can be reduced by the activity of a number of protein kinases as well as by prior depolarization. The depolarization from excitatory postsynaptic potentials (EPSPs) can inactivate these A-type K+ channels and thus lead to an increase in the amplitude of dendritic action potentials, provided the EPSP and the action potentials occur within the appropriate time window. This time window could be in the order of 15 ms and may play a role in long-term potentiation induced by pairing EPSPs and back-propagating action potentials.

  14. Tradescantia-micronucleus test on potassium dichromate

    OpenAIRE

    Rafael Villalobos; Sandra Gómez; Ana Rosa Flores; Adriana Cisneros

    1986-01-01

    Cuttings with inflorescences of Tradescantia clone 4430 were allowed to absorb severa1 different concentrations of potassium dichromate during 6 hours and analysed 30 hours Jater. The frequencies of micronuclei (MCNs) in tetrads were more than twice those of the control. The relationship concentration-frequency was asymptotic.

  15. Genetics Home Reference: potassium-aggravated myotonia

    Science.gov (United States)

    ... structure and function of sodium channels. The altered channels cannot properly regulate ion flow, increasing the movement of sodium ions into ... area? Other Names for This Condition PAM sodium channel ... and Rare Diseases Information Center (1 link) Potassium aggravated myotonia Additional ...

  16. Hg0 absorption in potassium persulfate solution

    Institute of Scientific and Technical Information of China (English)

    YE Qun-feng; WANG Cheng-yun; WANG Da-hui; SUN Guan; XU Xin-hua

    2006-01-01

    The aqueous phase oxidation of gaseous elemental mercury (Hg0) by potassium persulfate (KPS) catalyzed by Ag+was investigated using a glass bubble column reactor. Concentration of gaseous mercury and potassium persulfate were measured by cold vapor atom absorption (CVAA) and ion chromatograph (IC), respectively. The effects of pH value, concentration of potassium persulfate and silver nitrate (SN), temperature, Hg0 concentration in the reactor inlet and tertiary butanol (TBA), free radical scavenger, on the removal efficiency of Hg0 were studied. The results showed that the removal efficiency of Hg0 increased with increasing concentration of potassium persulfate and silver nitrate, while temperature and TBA were negatively effective. Furthermore, the removal efficiency of Hg0 was much better in neutral solution than in both acidic and alkaline solution. But the influence of pH was almost eliminated by adding AgNO3. High Hg0 concentration has positive effect. The possible reaction mechanism of gaseous mercury was also discussed.

  17. 75 FR 23298 - Potassium Permanganate From China

    Science.gov (United States)

    2010-05-03

    ... from China (49 FR 3897). Following first five-year reviews by Commerce and the Commission, effective... permanganate from China (64 FR 66166). Following second five-year reviews by Commerce and the Commission... potassium permanganate from China (70 FR 35630). The Commission is now conducting a third review...

  18. Calcium, magnesium, and potassium in food

    Science.gov (United States)

    The biochemical and physiological functions and consequences of deficient intakes, which show the nutritional importance of calcium, magnesium and potassium for humans, are reviewed. The dietary recommendations and food sources for these essential mineral elements for humans are presented. Factors t...

  19. Organogels Derived from Potassium 8-Nitroquinolinecarboxylate

    Institute of Scientific and Technical Information of China (English)

    HU,Hai-Yu; YANG,Yong; XIANG,Jun-Feng; CHEN,Chuan-Feng

    2007-01-01

    A new class of organogels derived from potassium 8-nitroquinoline-2-carboxylate was selectively formed in (V∶ V= 1∶ 1) THF/MeOH, and their superstructures were characterized by atomic force microscopy, scanning electron microscopy and transmission electron microscopy.

  20. Spectrophotometric Determination of Losartan Potassium in Tablets

    Directory of Open Access Journals (Sweden)

    Arianne Diane A. Aniñon

    2014-06-01

    Full Text Available In the quality control of pharmaceutical products, it is of utmost importance that validated analytical methods are used to ensure the credibility of the results generated. At the time of the study, official monographs from the United States Pharmacopeia and National Formulary (USP-NF for the quantification of Losartan potassium in tablets were unavailable, denoting the need for a validated analytical procedure for the analysis of the drug. The study adapted direct and first-derivative UV spectrophotometry methods proposed by Bonfilio and others (2010 for the assay of Losartan potassium in Losartan 50 mg. capsules, then modified and validated the said procedures for the assay of Losartan potassium in Losartan 100 mg. tablets following the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH guidelines on method validation for accuracy, precision, specificity, linearity, limit of detection, and limit of quantitation. Results demonstrated that all the performance characteristics of both methods were highly satisfactory and confirmed the possible application of the methods in routine analysis of Losartan potassium tablets.

  1. 21 CFR 582.3616 - Potassium bisulfite.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium bisulfite. 582.3616 Section 582.3616 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 Chemical Preservatives §...

  2. 21 CFR 582.3637 - Potassium metabisulfite.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium metabisulfite. 582.3637 Section 582.3637 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 Chemical Preservatives §...

  3. 21 CFR 182.3637 - Potassium metabisulfite.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium metabisulfite. 182.3637 Section 182.3637 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives §...

  4. 21 CFR 182.3616 - Potassium bisulfite.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium bisulfite. 182.3616 Section 182.3616 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives §...

  5. Carbenoxolone inhibits Pannexin1 channels through interactions in the first extracellular loop.

    Science.gov (United States)

    Michalski, Kevin; Kawate, Toshimitsu

    2016-02-01

    Pannexin1 (Panx1) is an ATP release channel important for controlling immune responses and synaptic strength. Various stimuli including C-terminal cleavage, a high concentration of extracellular potassium, and voltage have been demonstrated to activate Panx1. However, it remains unclear how Panx1 senses and integrates such diverse stimuli to form an open channel. To provide a clue on the mechanism underlying Panx1 channel gating, we investigated the action mechanism of carbenoxolone (CBX), the most commonly used small molecule for attenuating Panx1 function triggered by a wide range of stimuli. Using a chimeric approach, we discovered that CBX reverses its action polarity and potentiates the voltage-gated channel activity of Panx1 when W74 in the first extracellular loop is mutated to a nonaromatic residue. A systematic mutagenesis study revealed that conserved residues in this loop also play important roles in CBX function, potentially by mediating CBX binding. We extended our experiments to other Panx1 inhibitors such as probenecid and ATP, which also potentiate the voltage-gated channel activity of a Panx1 mutant at position 74. Notably, probenecid alone can activate this mutant at a resting membrane potential. These data suggest that CBX and other inhibitors, including probenecid, attenuate Panx1 channel activity through modulation of the first extracellular loop. Our experiments are the first step toward identifying a previously unknown mode of CBX action, which provide insight into the role of the first extracellular loop in Panx1 channel gating.

  6. Potassium-oxygen interactions on a Ru(001) surface

    Energy Technology Data Exchange (ETDEWEB)

    Hrbek, J.; Shek, M.L.; Xu, G.Q. (Brookhaven National Lab., Upton, NY (United States)); Sham, T.K. (Univ. of Western Ontario, London, Ontario (Canada))

    1992-10-01

    The interaction of potassium with oxygen has been examined using synchrotron-based photoemission and NEXAFS, thermal desorption, work function measurements, and isotope exchange. Potassium coverages on Ru(001) surface ranging from monolayer to multilayer were investigated. Oxygen coadsorbed with potassium at 80 K forms a potassium-dioxygen complex, where both peroxide and superoxide ions were identified. The complex has high thermal stability on the Ru(001) surface, decomposing and desorbing at T > 900 K. 52 refs., 14 figs., 2 tabs.

  7. Effects of salt intake and potassium supplementation on renalase expression in the kidneys of Dahl salt-sensitive rats.

    Science.gov (United States)

    Zheng, Wen-Ling; Wang, Jing; Mu, Jian-Jun; Liu, Fu-Qiang; Yuan, Zu-Yi; Wang, Yang; Wang, Dan; Ren, Ke-Yu; Guo, Tong-Shuai; Xiao, Hong-Yu

    2016-02-01

    Renalase is currently the only known amine oxidase in the blood that can metabolize catecholamines and regulate sympathetic activity. High salt intake is associated with high blood pressure (BP), possibly through the modulation of renalase expression and secretion, whereas potassium can reverse the high salt-mediated increase in blood pressure. However, whether potassium could also modulate BP through renalase is unclear. In this study, we aim to investigate how salt intake and potassium supplementation affect the level of renalase in rats. Eighteen salt-sensitive (SS) and 18 SS-13BN rats were divided into six groups, receiving normal salt (0.3% NaCl), high salt (8% NaCl) and high salt/potassium (8% NaCl and 8% KCl) dietary intervention for four weeks. At the end of experiments, blood and kidneys were collected for analysis. mRNA level of renalase was measured by quantitative real-time PCR and protein level was determined by Western blot. We found that mRNA and protein levels of renalase in the kidneys of SS and SS-13BN rats were significantly decreased (P high salt intervention, whereas dopamine in plasma was increased (P high salt/potassium, compared with that of the high salt SS group. Taken together, the salt-induced increase and potassium-induced decrease in BP could be mediated through renalase. More studies are needed to confirm our findings and understand the underlying mechanisms.

  8. New type of potassium deposit: Modal analysis and preparation of potassium carbonate

    Institute of Scientific and Technical Information of China (English)

    MA; Hongwen; FENG; Wuwei; MIAO; Shiding; WANG; Yingbin; TI

    2005-01-01

    A kind of dolomitic mudstone newly found in North China has high amounts of K2O up to 10wB% in average, and potassium reserve is at superior scale. Mineral assemblage of the potassium ore indicates a specific and complicated geological environment under which the potassium deposit formed. Modal analysis of the potassium host rock shows that the principal minerals in the ore include microcline, dolomite, and clay minerals such as illite, illite/smectite mixed layer, and kaolinite, attributable to a new type of insoluble potassium deposits in ore genesis. The experiments in this research demonstrated that with sodium carbonate as flux agent, the potassium ore could be decomposed with a proportion as high as 99.4% by calcinations at moderate temperature for no more than 1.5―2.0 h; more than 70% of K2O in the calcined materials were leached into the liquor, and by acidification reaction of the filter liquor, a large amount of impurities such as Fe3+, Ti4+, Mn2+, Mg2+, and Ca2+ were removed with precipitation of alumino-silicious colloid residue, which makes it possible to prepare potassium carbonate of electronic grade from the filter liquor, whereas the alumino-silicious residue could be utilized to make mineral polymer, a new type of inorganic construction structural materials. The current research shows that industrial exploitation and comprehensive utilization of this new type of insoluble potassium resource are feasible both in economic benefits and environmental kindness with the fairly clean production process as sketched in this paper.

  9. 40 CFR 721.5970 - Phosphated polyarylphenol ethoxylate, potassium salt.

    Science.gov (United States)

    2010-07-01

    ..., potassium salt. 721.5970 Section 721.5970 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5970 Phosphated polyarylphenol ethoxylate, potassium salt. (a) Chemical... as phosphated polyarylphenol ethoxylate, potassium salt (PMN P-93-1222) is subject to reporting under...

  10. 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...

  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. Reduction of potassium content of green bean pods and chard by culinary processing. Tools for chronic kidney disease.

    Science.gov (United States)

    Martínez-Pineda, Montserrat; Yagüe-Ruiz, Cristina; Caverni-Muñoz, Alberto; Vercet-Tormo, Antonio

    2016-01-01

    In order to prevent a possible hyperkalemia, chronic renal patients, especially in advanced stages, must follow a low potassium diet. So dietary guidelines for chronic kidney disease recommend limiting the consumption of many vegetables, as well as to apply laborious culinary techniques to maximize the reduction of potassium. The aim of this work is to analyze potassium content from several vegetable, fresh products, frozen and preserved, as well as check and compare the effectiveness in potassium reduction of different culinary processes, some of them recommended in dietary guidelines such as soaking or double cooking. Sample potassium content was analyzed by triplicate using flamephotometry. The results showed significant reductions in potassium content in all culinary processes studied. The degree of loss varied depending on the type of vegetable and processing applied. Frozen products achieved greater reductions than the fresh ones, obtaining in some cases losses greater than 90%. In addition, it was observed how in many cases the single application of a normal cooking reached potassium reductions to acceptable levels for its inclusion in renal patient diet. The results shown in this study are very positive because they provide tools for professionals who deal with this kind of patients. They allow them to adapt more easily to the needs and preferences of their patients and increase dietary variety. Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  13. Time to Consider Use of the Sodium-to-Potassium Ratio for Practical Sodium Reduction and Potassium Increase.

    Science.gov (United States)

    Iwahori, Toshiyuki; Miura, Katsuyuki; Ueshima, Hirotsugu

    2017-07-05

    Pathogenetic studies have demonstrated that the interdependency of sodium and potassium affects blood pressure. Emerging evidences on the sodium-to-potassium ratio show benefits for a reduction in sodium and an increase in potassium compared to sodium and potassium separately. As presently there is no known review, this article examined the practical use of the sodium-to-potassium ratio in daily practice. Epidemiological studies suggest that the urinary sodium-to-potassium ratio may be a superior metric as compared to separate sodium and potassium values for determining the relation to blood pressure and cardiovascular disease risks. Higher correlations and better agreements are seen for the casual urine sodium-to-potassium ratio than for casual urine sodium or potassium alone when compared with the 24-h urine values. Repeated measurements of the casual urine provide reliable estimates of the 7-day 24-h urine value with less bias for the sodium-to-potassium ratio as compared to the common formulas used for estimating the single 24-h urine from the casual urine for sodium and potassium separately. Self-monitoring devices for the urinary sodium-to-potassium ratio measurement makes it possible to provide prompt onsite feedback. Although these devices have been evaluated with a view to support an individual approach for sodium reduction and potassium increase, there has yet to be an accepted recommended guideline for the sodium-to-potassium ratio. This review concludes with a look at the practical use of the sodium-to-potassium ratio for assistance in practical sodium reduction and potassium increase.

  14. Extracellular DNA in oral microbial biofilms.

    Science.gov (United States)

    Jakubovics, Nicholas S; Burgess, J Grant

    2015-07-01

    The extracellular matrix of microbial biofilms is critical for surface adhesion and nutrient homeostasis. Evidence is accumulating that extracellular DNA plays a number of important roles in biofilm integrity and formation on hard and soft tissues in the oral cavity. Here, we summarise recent developments in the field and consider the potential of targeting DNA for oral biofilm control.

  15. Systemic Administration of Substance P Recovers Beta Amyloid-Induced Cognitive Deficits in Rat: Involvement of Kv Potassium Channels

    OpenAIRE

    Patrizia Campolongo; Patrizia Ratano; Maria Teresa Ciotti; Fulvio Florenzano; Stefania Lucia Nori; Roberta Marolda; Maura Palmery; Anna Maria Rinaldi; Cristina Zona; Roberta Possenti; Pietro Calissano; Cinzia Severini

    2013-01-01

    Reduced levels of Substance P (SP), an endogenous neuropeptide endowed with neuroprotective and anti-apoptotic properties, have been found in brain and spinal fluid of Alzheimer's disease (AD) patients. Potassium (K(+)) channel dysfunction is implicated in AD development and the amyloid-β (Aβ)-induced up-regulation of voltage-gated potassium channel subunits could be considered a significant step in Aβ brain toxicity. The aim of this study was to evaluate whether SP could reduce, in vivo, Aβ-...

  16. Removal of potassium chloride by nanofiltration from ion-exchanged solution containing potassium clavulanate.

    Science.gov (United States)

    Kim, Hyun Han; Kim, Jae Hyung; Chang, Yong Keun

    2010-01-01

    In this study, nanofiltration with NF200 membrane was employed to remove KCl from ion-exchanged solutions containing potassium clavulanate. The pore radius of NF200 membrane was estimated to be around 0.39 nm. The effects of operating pressure on separation performance were investigated in a range of 100-400 psig. The influences of cross-flow velocity (0.14-0.70 cm/s), temperature (4-25 degrees C), and feed composition were also investigated. In all experiments, clavulanate rejection showed high levels from 0.91 to 0.99, while chloride rejection ranged from 0.06 to 0.54. In a case at an operating pressure of 50 psig and 25 degrees C, as much as 94% of clavulanate was retained while 94% of chloride was removed, indicating that NF200 membrane was a suitable choice for selectively removing KCl. NF200 membrane also showed a stable performance in the operational stability test with an ion-exchanged solution obtained by treating actual fermentation broth.

  17. Analysis of Clinical Characteristics of Cushing's Syndrome in Patients with Different Serumal Potassium Levels and Its Complications%不同血钾水平库欣综合症患者的临床特点及并发症分析

    Institute of Scientific and Technical Information of China (English)

    王旭红; 张之农; 刘元志; 杨伟光; 林杨

    2015-01-01

    目的:分析不同血钾水平的库欣综合症患者的临床特点及并发症发生趋势。方法筛选2013年12月-2015年1月该院收治的库欣综合症患者156例,作为研究对象。根据患者血钾水平将其分为正常组与低血钾组,正常组62例,低血钾组94例,比较两组患者的临床特点,分析两组患者并发症发生特点。结果与正常组比较低血钾组患者男性构成比高于女性,同时低血钾组男性患者病程、血压、血脂与正常组比较,差异有统计学意义(P<0.05);低血钾组紫纹、瘀斑、碱中毒和下肢水肿发生率明显高于正常组;低血钾组并发症发生率明显高于正常组,并且以心律失常最为常见。结论库欣综合症合并低血钾者常见于男性患者,患者表现为病程短、代谢异常加重、体征突出等,库欣综合症发生心脑血管并发症发生率较高,而低血钾患者发生率更高。%Objective To analyze the clinical characteristics of Cushing's syndrome in patients with different serumal potassium levels and its complications. Methods 156 patients with Cushing's syndrome admitted to our hospital from December 2013 to Jan-uary 2015 were selected as the research object and divided into normal group (n=62) and hypokalemia group (n=94) according to potassium levels. The clinical characteristics and complications of the two groups were analyzed. Results Constituent ratio of male patients in the hypokalemia group was higher than that in the normal group, and there were statistically significant differences be-tween the duration of disease, blood pressure, blood lipid of the male patients in the hypokalemia group and those in the normal group (P<0.05). The incidences of purple striae, ecchymosis, alkalosis, lower extremity edema, and the complications (arrhythmias and so on) rate of the hypokalemia group were obviously higher than those of the normal group. Conclusion Hypokalemia is more common in male

  18. Physicochemical action of potassium-magnesium citrate in nephrolithiasis

    Science.gov (United States)

    Pak, C. Y.; Koenig, K.; Khan, R.; Haynes, S.; Padalino, P.

    1992-01-01

    Effect of potassium-magnesium citrate on urinary biochemistry and crystallization of stone-forming salts was compared with that of potassium citrate at same dose of potassium in five normal subjects and five patients with calcium nephrolithiasis. Compared to the placebo phase, urinary pH rose significantly from 6.06 +/- 0.27 to 6.48 +/- 0.36 (mean +/- SD, p less than 0.0167) during treatment with potassium citrate (50 mEq/day for 7 days) and to 6.68 +/- 0.31 during therapy with potassium-magnesium citrate (containing 49 mEq K, 24.5 mEq Mg, and 73.5 mEq citrate per day). Urinary pH was significantly higher during potassium-magnesium citrate than during potassium citrate therapy. Thus, the amount of undissociated uric acid declined from 118 +/- 61 mg/day during the placebo phase to 68 +/- 54 mg/day during potassium citrate treatment and, more prominently, to 41 +/- 46 mg/day during potassium-magnesium citrate therapy. Urinary magnesium rose significantly from 102 +/- 25 to 146 +/- 37 mg/day during potassium-magnesium citrate therapy but not during potassium citrate therapy. Urinary citrate rose more prominently during potassium-magnesium citrate therapy (to 1027 +/- 478 mg/day from 638 +/- 252 mg/day) than during potassium citrate treatment (to 932 +/- 297 mg/day). Consequently, urinary saturation (activity product) of calcium oxalate declined significantly (from 1.49 x 10(-8) to 1.03 x 10(-8) M2) during potassium-magnesium citrate therapy and marginally (to 1.14 x 10(-8) M2) during potassium citrate therapy.(ABSTRACT TRUNCATED AT 250 WORDS).

  19. TbIRK is a signature sequence free potassium channel from Trypanosoma brucei locating to acidocalcisomes.

    Science.gov (United States)

    Steinmann, Michael E; Schmidt, Remo S; Bütikofer, Peter; Mäser, Pascal; Sigel, Erwin

    2017-04-06

    Potassium channels from prokaryotes and eukaryotes are usually recognized by a typical amino acid sequence TXTGY(F)G representing the ionic selectivity filter. Using a screening approach with ion channel family profiles but without the above motif, we identified a gene in Trypanosoma brucei that exhibits homology to inward rectifying potassium channels. We report here cloning of this ion channel named TbIRK. The protein is localized to acidocalcisomes in procyclic and in bloodstream form parasites. Functional properties of this channel were established after expression in Xenopus oocytes. Currents recorded in potassium medium show inward rectification and little time dependence. Surprisingly, this channel retains selectivity for potassium ions over sodium ions >7, in spite of the lack of the classical selectivity filter. The sequence GGYVG was predicted in silico to replace this filter motif. Point mutations of the corresponding glycine residues confirmed this at the functional level. The channel is inhibited by caesium ions but remains unaffected by barium ions up to 10 mM. TbIRK is to our knowledge the first potassium channel in T. brucei that localizes to the acidocalcisomes, organelles involved in the storage of phosphates and the response to osmotic stress that occurs during the life cycle of trypanosomes.

  20. Sodium and Potassium Currents Influence Wallerian Degeneration of Injured Drosophila Axons

    Science.gov (United States)

    Mishra, Bibhudatta; Carson, Ross; Hume, Richard I.

    2013-01-01

    Axons degenerate after injury and in neuropathies and disease via a self-destruction program whose mechanism is poorly understood. Axons that have lost connection to their cell bodies have altered electrical and synaptic activities, but whether such changes play a role in the axonal degeneration process is not clear. We have used a Drosophila model to study the Wallerian degeneration of motoneuron axons and their neuromuscular junction synapses. We found that degeneration of the distal nerve stump after a nerve crush is greatly delayed when there is increased potassium channel activity (by overexpression of two different potassium channels, Kir2.1 and dORKΔ-C) or decreased voltage-gated sodium channel activity (using mutations in the para sodium channel). Conversely, degeneration is accelerated when potassium channel activity is decreased (by expressing a dominant-negative mutation of Shaker). Despite the effect of altering voltage-gated sodium and potassium channel activity, recordings made after nerve crush demonstrated that the distal stump does not fire action potentials. Rather, a variety of lines of evidence suggest that the sodium and potassium channels manifest their effects upon degeneration through changes in the resting membrane potential, which in turn regulates the level of intracellular free calcium within the isolated distal axon. PMID:24285879

  1. Nitrate and potassium concentration in fertigated soil cultivated with wine vines

    Directory of Open Access Journals (Sweden)

    Alexsandro Oliveira da Silva

    2016-06-01

    Full Text Available ABSTRACT In the semiarid region of Brazil the use of irrigation systems for applying fertilizers in horticulture is the primary means for incorporating nutrients in the soil. However, this technique still requires its use in wine vines to be assessed. In view of this, this study aimed to assess nitrate and potassium concentrations in soil fertigated with nitrogen and potassium fertilizers in 3 wine grape growing cycles. A field experiment was conducted with 'Syrah' wine grapes, in Petrolina, Pernambuco, Brazil; it assessed five nitrogen doses (0, 15, 30, 60 and 120 kg ha-1 and five K2O doses (0, 15, 30, 60 and 120 kg ha-1 applied by drip irrigation system with two emitters per plant, with a flow rate of 4 L h-1. The experimental design used was the factorial split-plot, making up 13 combinations arranged in 4 randomized blocks. Soil solution samples were collected weekly with the aid of porous cup extractors for all treatments and at depths of 0.4 and 0.6 m by determining nitrate and potassium concentrations and electrical conductivity. Increased levels of both nutrients in the irrigation water increased the availability of nitrate and potassium in the soil solution. The highest nitrate and potassium concentrations were found in the second growing cycle at both depths studied.

  2. Potassium Influence NRA、HPA and PODA on Leaves of Fiber Flax

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effecf of potassium fertilizer on Nitrate Reductase Activity (NRA), Hydrogen Peroxide Activity (HPA) ,Peroxidase Activity (PODA) in the fiber flax was studied on campus of NEAU in 1995 and 1996. The result showed that the changing of NRA,HPA and PODA was same in the period from the quick growth to blossom period in the different treamets. NAR and HPA was the highest in the quick growth period then cut down gradually,and PODA was just right contrary. The other side,it was obviously different to NRA, HPA and PODA in the different Potassium levels. NRA and HPA presented the highest enzyme activity in the trea ment of K2O 22.5kg · ha-1. PODA in creased gradually with the increase of Potassium. PODA was the high est in the treament of K2O 67.5kg · ha-1. But all of the Potassium treatments was higher than CK whatever NRA,HPA and PODA. Potassium may enhanced the primary stem yield and fiber percentage and lead to fiber yield rising.

  3. Doses and application seasons of potassium on soybean crop in succession the cover crops

    Directory of Open Access Journals (Sweden)

    Amilton Ferreira Silva

    2014-02-01

    Full Text Available Potassium (K is the second nutrient that is required in larger amounts by soybean crop. With the use of high doses of that nutrient and increase of no-tillage areas in last years, some changes occurred in ways of this nutrient application, as well as the introduction of cover crops in the system for straw formation. Due those facts, the aim with this work was to study doses and times of potassium application for soybean sowed as succession for cover crops in no-tillage system, in a clayey Distrofic Red Latosol, in cerrado region. The experimental design was a randomized block with treatments arranged in 3x3x5 factorial scheme, with the following factors, cover crops: Pearl millet (Pennisetum glaucum and Proso millet (Panicum miliaceum and a control (fallow area, rates of K2O (0, 50 e 100 kg ha-1 and K2O application forms (100% in the cover crops; 100% at sowing of soybean; 100% in topdressing in soybean; 50% at sowing cover crops + 50% at soybean sowing; 50% at soybean sowing + 50% in topdressing in the soybean with four replicates. The Pennisetum glaucum as soybean predecessor crop yields higher dry matter content than the Panicum miliaceum in a short period of time. In clay soil with high content of potassium there was no response to the applied potassium levels. Full doses of potassium maintenance fertilization can be applied in the predecessor cover crop, at sowing or topdressing in soybean crop.

  4. Sodium, potassium and chloride status in Australian foods and diets using neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fardy, J.J.; McOrist, G.D.; Farrar, Y.J.; Bowles, C.J. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1993-12-31

    A study of the status of essential, toxic and trace elements in the foods and diets of Australian has been in progress for six years. Results for sodium, potassium and chloride levels are reported here. The average daily dietary intake of sodium and chloride exceeded the range of values recommended by the National Health and Medical Research Council for most population groups with grain and dairy products the main contributor to these high intakes. In contrast, the average daily intakes of potassium fell well within the recommended values for all age groups with intakes for adult females close to the recommended minimum figure. 9 refs., 1 tab., 2 figs.

  5. Extracellular matrix components direct porcine muscle stem cell behavior

    Energy Technology Data Exchange (ETDEWEB)

    Wilschut, Karlijn J. [Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM, Utrecht (Netherlands); Haagsman, Henk P. [Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL, Utrecht (Netherlands); Roelen, Bernard A.J., E-mail: b.a.j.roelen@uu.nl [Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM, Utrecht (Netherlands)

    2010-02-01

    In muscle tissue, extracellular matrix proteins, together with the vasculature system, muscle-residence cells and muscle fibers, create the niche for muscle stem cells. The niche is important in controlling proliferation and directing differentiation of muscle stem cells to sustain muscle tissue. Mimicking the extracellular muscle environment improves tools exploring the behavior of primary muscle cells. Optimizing cell culture conditions to maintain muscle commitment is important in stem cell-based studies concerning toxicology screening, ex vivo skeletal muscle tissue engineering and in the enhancement of clinical efficiency. We used the muscle extracellular matrix proteins collagen type I, fibronectin, laminin, and also gelatin and Matrigel as surface coatings of tissue culture plastic to resemble the muscle extracellular matrix. Several important factors that determine myogenic commitment of the primary muscle cells were characterized by quantitative real-time RT-PCR and immunofluorescence. Adhesion of high PAX7 expressing satellite cells was improved if the cells were cultured on fibronectin or laminin coatings. Cells cultured on Matrigel and laminin coatings showed dominant integrin expression levels and exhibited an activated Wnt pathway. Under these conditions both stem cell proliferation and myogenic differentiation capacity were superior if compared to cells cultured on collagen type I, fibronectin and gelatin. In conclusion, Matrigel and laminin are the preferred coatings to sustain the proliferation and myogenic differentiation capacity of the primary porcine muscle stem cells, when cells are removed from their natural environment for in vitro culture.

  6. Urinary potassium excretion and risk of developing hypertension: the prevention of renal and vascular end-stage disease study.

    Science.gov (United States)

    Kieneker, Lyanne M; Gansevoort, Ron T; Mukamal, Kenneth J; de Boer, Rudolf A; Navis, Gerjan; Bakker, Stephan J L; Joosten, Michel M

    2014-10-01

    Previous prospective cohort studies on the association between potassium intake and risk of hypertension have almost exclusively relied on self-reported dietary data, whereas repeated 24-hour urine excretions, as estimate of dietary uptake, may provide a more objective and quantitative estimate of this association. Risk of hypertension (defined as blood pressure ≥140/90 mm Hg or initiation of blood pressure-lowering drugs) was prospectively studied in 5511 normotensive subjects aged 28 to 75 years not using blood pressure-lowering drugs at baseline of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study. Potassium excretion was measured in two 24-hour urine specimens at baseline (1997-1998) and midway during follow-up (2001-2003). Baseline median potassium excretion was 70 mmol/24 h (interquartile range, 57-85 mmol/24 h), which corresponds to a dietary potassium intake of ≈91 mmol/24 h. During a median follow-up of 7.6 years (interquartile range, 5.0-9.3 years), 1172 subjects developed hypertension. The lowest sex-specific tertile of potassium excretion (men: hypertension after multivariable adjustment (hazard ratio, 1.20; 95% confidence interval, 1.05-1.37), compared with the upper 2 tertiles (Pnonlinearity=0.008). The proportion of hypertension attributable to low potassium excretion was 6.2% (95% confidence interval, 1.7%-10.9%). No association was found between the sodium to potassium excretion ratio and risk of hypertension after multivariable adjustment. Low urinary potassium excretion was associated with an increased risk of developing hypertension. Dietary strategies to increase potassium intake to the recommended level of 90 mmol/d may have the potential to reduce the incidence of hypertension.

  7. Electrochemical intercalation of potassium into graphite in KF melt

    Energy Technology Data Exchange (ETDEWEB)

    Liu Dongren [College of Chemistry and Chemical Engineering, Central South University, South Lushan Road, Changsha 410083, Hunan (China); Department of Chemical and Environmental engineering, Jiaozuo University, JiaoZuo 454003, Henan (China); Yang Zhanhong, E-mail: zhyang@mail.csu.edu.c [College of Chemistry and Chemical Engineering, Central South University, South Lushan Road, Changsha 410083, Hunan (China); Li Wangxing; Qiu Shilin; Luo Yingtao [Zhengzhou Research Institute of Chalco, Zhengzhou 450041, Henan (China)

    2010-01-01

    Electrochemical intercalation of potassium into graphite in molten potassium fluoride at 1163 K was investigated by means of cyclic voltammetry, galvanostatic electrolysis and open-circuit potential measurements. It was found that potassium intercalated into graphite solely between graphite layers. In addition, the intercalation compound formed in graphite bulk in molten KF was quite unstable and decomposed very fast. X-ray diffraction measurements indicate that a very dilute potassium-graphite intercalation compound was formed in graphite matrix in the fluoride melt. Analysis with scanning electron microscope and transmission electron microscope shows that graphite was exfoliated to sheets and tubes due to lattice expansion caused by intercalation of potassium in molten KF.

  8. 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.

  9. Potassium as a key modulator of tropical woody vegetation structure and function

    Science.gov (United States)

    Lloyd, Jonathan

    2015-04-01

    Sampling a range of tropical vegetation types across Africa, Australia and South America we find - other things being equal - lower soil and plant potassium concentrations in savanna as opposed to forest species. There is also a trend- similarly observed in cross-continental comparisons, for foliar [K] to increase with declining precipitation. Moreover, when considered in a multivariate context with mean annual precipitation and soil plant available water storage capacity as covariates, soil exchangeable K turns to be an excellent predictor of stand-level canopy areas across vegetation types, providing drastically improved predictions as compared to models considering just precipitation or soil water storage potential alone This underlying basis of an important role for potassium as a modulator of tropical vegetation structure and function will be considered in terms of its role in plant water relations as well as in relation to recent key findings implicating potassium to have an important role in many root-shoot signalling pathways.

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

    Institute of Scientific and Technical Information of China (English)

    Mahmood AHMAD; Muhammad IQBAL; Ghulam MURTAZA

    2009-01-01

    Two different salts of diclofenac, diclofenac sodium and dielofenae 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. AUC0-∞, 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.

  11. Extracellular superoxide dismutase is present in secretory vesicles of human neutrophils and released upon stimulation

    DEFF Research Database (Denmark)

    Iversen, Marie B; Gottfredsen, Randi H; Larsen, Ulrike G

    2016-01-01

    Extracellular superoxide dismutase (EC-SOD) is an antioxidant enzyme present in the extracellular matrix (ECM), where it provides protection against oxidative degradation of matrix constituents including type I collagen and hyaluronan. The enzyme is known to associate with macrophages and polymor......Extracellular superoxide dismutase (EC-SOD) is an antioxidant enzyme present in the extracellular matrix (ECM), where it provides protection against oxidative degradation of matrix constituents including type I collagen and hyaluronan. The enzyme is known to associate with macrophages......), the protein was released into the extracellular space and found to associate with DNA released from stimulated cells. The functional consequences were evaluated by the use of neutrophils isolated from wild-type and EC-SOD KO mice, and showed that EC-SOD release significantly reduce the level of superoxide...

  12. Effect of potassium humate on early growth of Gobustan wheat variety

    African Journals Online (AJOL)

    Yomi

    2012-01-16

    Jan 16, 2012 ... In order to study the effect of potassium humate on germination and seedling growth of Gobustan wheat variety ... acid reduces the amount of fertilizer consumption, and makes plant ... so clear and dramatic that in some cases increases the size of the ... Duncan's Multiple Rang test at 5% level. RESULTS ...

  13. Determination of Potassium in Feldspars by Beta Counting Using a GM Multicounter System

    DEFF Research Database (Denmark)

    Bøtter-Jensen, Lars; Mejdahl, V.

    1985-01-01

    A gas flow multicounter system developed at Riso National Laboratory for low-level beta counting applications was adopted for measuring potassium in feldspars extracted from archaeological and geological materials, in connection with TL dating work. A guard counter reduces the background by using...

  14. Study of Microwave Multiphoton Transition of Rydberg Potassium Atom by Using B-Spline

    Institute of Scientific and Technical Information of China (English)

    JIN Cheng; ZHOU Xiao-Xin; ZHAO Song-Feng

    2005-01-01

    The B-spline expansion technique and time-dependent two-level approach are applied to study the interaction between the microwave field and potassium atoms in a static electric field. We obtain theoretical multiphoton resonance spectra that can be compared with the experimental data. We also obtain the time evolution of the final state in different microwave fields.

  15. Estimating 24-h urinary sodium/potassium ratio from casual ('spot') urinary sodium/potassium ratio: the INTERSALT Study.

    Science.gov (United States)

    Iwahori, Toshiyuki; Miura, Katsuyuki; Ueshima, Hirotsugu; Chan, Queenie; Dyer, Alan R; Elliott, Paul; Stamler, Jeremiah

    2016-12-30

    Association between casual and 24-h urinary sodium-to-potassium (Na/K) ratio is well recognized, although it has not been validated in diverse demographic groups. Our aim was to assess utility across and within populations of casual urine to estimate 24-h urinary Na/K ratio using data from the INTERSALT Study. The INTERSALT Study collected cross-sectional standardized data on casual urinary sodium and potassium and also on timed 24-h urinary sodium and potassium for 10 065 individuals from 52 population samples in 32 countries (1985-87). Pearson correlation coefficients and agreement were computed for Na/K ratio of casual urine against 24-h urinary Na/K ratio both at population and individual levels. Pearson correlation coefficients relating means of 24-h urine and casual urine Na/K ratio were r = 0.96 and r = 0.69 in analyses across populations and individuals, respectively. Correlations of casual urine Na/creatinine and K/creatinine ratios with 24-h urinary Na and K excretion, respectively, were lower than correlation of casual and 24-h urinary Na/K ratio in analyses across populations and individuals. The bias estimate with the Bland-Altman method, defined as the difference between Na/K ratio of 24-h urine and casual urine, was approximately 0.4 across both populations and individuals. Spread around, the mean bias was higher for individuals than populations. With appropriate bias correction, casual urine Na/K ratio may be a useful, low-burden alternative method to 24-h urine for estimation of population urinary Na/K ratio. It may also be applicable for assessment of the urinary Na/K ratio of individuals, with use of repeated measurements to reduce measurement error and increase precision. © The Author 2016. Published by Oxford University Press on behalf of the International Epidemiological Association.

  16. Potassium and Its Discontents: New Insight, New Treatments.

    Science.gov (United States)

    Ellison, David H; Terker, Andrew S; Gamba, Gerardo

    2016-04-01

    Hyperkalemia is common in patients with impaired kidney function or who take drugs that inhibit the renin-angiotensin-aldosterone axis. During the past decade, substantial advances in understanding how the body controls potassium excretion have been made, which may lead to improved standard of care for these patients. Renal potassium disposition is primarily handled by a short segment of the nephron, comprising part of the distal convoluted tubule and the connecting tubule, and regulation results from the interplay between aldosterone and plasma potassium. When dietary potassium intake and plasma potassium are low, the electroneutral sodium chloride cotransporter is activated, leading to salt retention. This effect limits sodium delivery to potassium secretory segments, limiting potassium losses. In contrast, when dietary potassium intake is high, aldosterone is stimulated. Simultaneously, potassium inhibits the sodium chloride cotransporter. Because more sodium is then delivered to potassium secretory segments, primed by aldosterone, kaliuresis results. When these processes are disrupted, hyperkalemia results. Recently, new agents capable of removing potassium from the body and treating hyperkalemia have been tested in clinical trials. This development suggests that more effective and safer approaches to the prevention and treatment of hyperkalemia may be on the horizon.

  17. Sodium retention by insulin may depend on decreased plasma potassium.

    Science.gov (United States)

    Friedberg, C E; Koomans, H A; Bijlsma, J A; Rabelink, T J; Dorhout Mees, E J

    1991-02-01

    Evidence is accumulating that insulin is a hypertensive factor in humans. The involved mechanism may be its sodium-retaining effect. We examined whether insulin causes sodium retention through a direct action on the kidney, as is generally assumed, or indirectly through hypokalemia. Insulin was infused (euglycemic clamp technique) with and without potassium infusion to prevent hypokalemia in six healthy subjects. Without potassium infusion, insulin caused a marked decrease in plasma potassium (-0.75 mmol/L), and decreased urinary sodium and potassium excretions by, approximately 38% and 65%, respectively. Simultaneous potassium infusion largely prevented the decrease in plasma potassium, as well as the decrease in urinary sodium and potassium excretions. These data suggest that the acute antinatriuretic effect of insulin may be largely mediated in an indirect way, ie, through hypokalemia.

  18. Variações dos níveis séricos de sódio, potássio e glicose de cães em choque séptico Sodium, potassium and glucose serum levels changes in dogs with endotoxic shock

    Directory of Open Access Journals (Sweden)

    Leonardo Pinto Brandão

    1999-12-01

    Full Text Available Foram avaliados os níveis séricos de sódio, potássio e glicose em trinta e cinco cães, machos e fêmeas, que se apresentaram em estado de choque séptico decorrente da gastrenterite hemorrágica, antes e após terapia sintomática (Ringer com lactato de sódio e glicose, com a finalidade de se determinar a melhora clínica obtida. Observou-se que 74,2% dos animais apresentavam hipocalemia, 57,1% hipoglicemia e 60% discreta hiponatremia, quando da primeira colheita. Após 2 horas da instituição da terapia sintomática, observou-se que a hipopotassemia ainda persistia, porém a hipoglicemia fora suficientemente corrigida (apenas 5,8% mantiveram-se hipoglicêmicos. Conclui-se que a terapia sintomática é efetiva para a correção dos valores glicêmicos, porém não é capaz de repor a deficiência de potássio apresentada por estes animais, devendo ser então acrescida deste íon.In order to evaluate sodium, potassium and glucose serum levels changes in dogs with septic shock, thirty-five young dogs of both sexes presenting hemorragic gastroenteritis and signs of septic shock were studied. Hypokalemia was observed in 74.2%, hypoglicemia in 57.1% and mild hyponatremia in 60% of the animals. Two hours after therapy (Ringer’s sodium lactate solution and glucose, glucose serum levels increased, but hypokalemia was still present. This study revealed that the therapy was effective to increase the glucose serum levels but, it was not able to correct the hypocalemia, and therefore, this ion have to be add in order to obtain success in the treatment of this condition.

  19. How far can sodium substitute for potassium in red beet?

    Science.gov (United States)

    Subbarao, G. V.; Wheeler, R. M.; Stutte, G. W.; Levine, L. H.; Sager, J. C. (Principal Investigator)

    1999-01-01

    Sodium (Na) movement between plants and humans is one of the more critical aspects of bioregenerative systems of life support, which NASA is studying for the establishment of long-term bases on the Lunar or Martian surface. This study was conducted to determine the extent to which Na can replace potassium (K) in red beet (Beta vulgaris L. ssp vulgaris) without adversely affecting metabolic functions such as water relations, photosynthetic rates, and thus growth. Two cultivars, Ruby Queen and Klein Bol, were grown for 42 days at 1200 micromoles mol-1 CO2 in a growth chamber using a re-circulating nutrient film technique with 0%, 75%, 95%, and 98% Na substitution for K in a modified half-strength Hoagland solution. Total biomass of Ruby Queen was greatest at 95% Na substitution and equal at 0% and 98% Na substitution. For Klein Bol, there was a 75% reduction in total biomass at 98% Na substitution. Nearly 95% of the total plant K was replaced with Na at 98% Na substitution in both cultivars. Potassium concentrations in leaves decreased from 120 g kg-1 dwt in 0% Na substitution to 3.5 g kg-1 dwt at 98% Na substitution. Leaf chlorophyll concentration, photosynthetic rate, and osmotic potential were not affected in either cultivar by Na substitution for K. Leaf glycinebetaine levels were doubled at 75% Na substitution in Klein Bol, but decreased at higher levels of Na substitution. For Ruby Queen, glycinebetaine levels in leaf increased with the first increase of Na levels and were maintained at the higher Na levels. These results indicate that in some cultivars of red beet, 95% of the normal tissue K can be replaced by Na without a reduction in growth.

  20. A common theme in extracellular fluids of beetles: extracellular superoxide dismutases crucial for balancing ROS in response to microbial challenge

    Science.gov (United States)

    Gretscher, René R.; Streicher, Priska E.; Strauß, Anja S.; Wielsch, Natalie; Stock, Magdalena; Wang, Ding; Boland, Wilhelm; Burse, Antje

    2016-01-01

    Extracellular Cu/Zn superoxide dismutases (SODs) are critical for balancing the level of reactive oxygen species in the extracellular matrix of eukaryotes. In the present study we have detected constitutive SOD activity in the haemolymph and defensive secretions of different leaf beetle species. Exemplarily, we have chosen the mustard leaf beetle, Phaedon cochleariae, as representative model organism to investigate the role of extracellular SODs in antimicrobial defence. Qualitative and quantitative proteome analyses resulted in the identification of two extracellular Cu/Zn SODs in the haemolymph and one in the defensive secretions of juvenile P. cochleariae. Furthermore, quantitative expression studies indicated fat body tissue and defensive glands as the main synthesis sites of these SODs. Silencing of the two SODs revealed one of them, PcSOD3.1, as the only relevant enzyme facilitating SOD activity in haemolymph and defensive secretions in vivo. Upon challenge with the entomopathogenic fungus, Metarhizium anisopliae, PcSOD3.1-deficient larvae exhibited a significantly higher mortality compared to other SOD-silenced groups. Hence, our results serve as a basis for further research on SOD regulated host-pathogen interactions. In defensive secretions PcSOD3.1-silencing affected neither deterrent production nor activity against fungal growth. Instead, we propose another antifungal mechanism based on MRJP/yellow proteins in the defensive exudates. PMID:27068683

  1. 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.

  2. 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.

  3. Structural and spectroscopic characterization of potassium fluoroborohydrides.

    Science.gov (United States)

    Heyn, Richard H; Saldan, Ivan; Sørby, Magnus H; Frommen, Christoph; Arstad, Bjørnar; Bougza, Aud M; Fjellvåg, Helmer; Hauback, Bjørn C

    2013-07-21

    Mechanochemical reactions between KBH4 and KBF4 result in the formation of potassium fluoroborohydrides K(BH(x)F(4-x)) (x = 0-4), as determined by (11)B and (19)F solid state NMR. The materials maintain the cubic KBH4 structure. Thermogravimetric (TG) data for a ball-milled sample with KBH4 : KBF4 = 3 : 1 are consistent with only desorption of hydrogen.

  4. Formulation and optimization of potassium iodide tablets

    OpenAIRE

    Al-Achi, Antoine; Patel, Binit

    2014-01-01

    The use of potassium iodide (KI) as a protective agent against accidental radioactive exposure is well established. In this study, we aimed to prepare a KI tablet formulation using a direct compression method. We utilized Design of Experiment (DoE)/mixture design to define the best formulation with predetermined physical qualities as to its dissolution, hardness, assay, disintegration, and angle of repose. Based on the results from the DoE, the formulation had the following components (%w/w):...

  5. Anharmonic properties of potassium halide crystals

    OpenAIRE

    RAJU, Krishna Murti

    2011-01-01

    An effort has been made to obtain the anharmonic properties of potassium halides starting from primary physical parameters viz. nearest neighbor distance and hardness parameters assuming long- and short- range potentials at elevated temperatures. The elastic energy density for a deformed crystal can be expanded as power series of strains for obtaining coefficients of quadratic, cubic and quartic terms which are known as the second, third and fourth order elastic constants respectively...

  6. [About the history chemistry and potassium iodide].

    Science.gov (United States)

    Fournier, Josette

    2008-07-01

    Louis Melsen was born at Louvain, he spent four years in Paris, working in Dumas's laboratory. Four letters from Melsens to Chevreul, since 1951 to 1880, are commented on. Two letters relate to Van Helmont and common interest of the two scientists in history of sciences. The others recall Melsens's proposal that potassium iodide can cure and prevent lead and mercury poisoning, and Chevreul's researches about colours seeing.

  7. Effect of potassium and hypomagnesemia on insulin in the bovine

    Energy Technology Data Exchange (ETDEWEB)

    Lentz, D.E.; Madsen, F.C.; Miller, J.K.; Hansard, S.L.

    1976-01-01

    Grass tetany in cattle has been associated with the consumption of early spring forages high in potassium (K) and low in magnesium (Mg). Alterations in serum Mg and K may affect intermediary carbohydrate metabolism, resulting in hypoglycemia and ketosis that often accompany grass tetany. We investigated these interrelationships by infusing potassium chloride (KCl) intravenously in normal (plasma Mg greater than 2.1 mg/100 ml) and Mg-deficient (plasma Mg less than .7 mg/100 ml) 9-month-old Holstein bull calves and intraruminally into nonpregnant, nonlactating Holstein cows. Plasma levels of both K and immunoreactive insulin (IRI) were elevated (P less than .01) by 1.14, 2, and 3 percent KCl (51, 64, and 135 mg K/kg) in calves and by 550 g KCl (440 mg K/kg body weight) in cows. Plasma K was lower (P less than .01) and IRI higher (P less than .01) in Mg-deficient calves than in normal calves during 2 percent KCl infusion. These results suggest that prolonged elevation of K and insulin in ruminants could lead to a series of metabolic disturbances that may play an important role in the etiology of grass tetany.

  8. Laser cooling and trapping of potassium at magic wavelengths

    CERN Document Server

    Safronova, M S; Clark, Charles W

    2013-01-01

    We carry out a systematic study of the static and dynamic polarizabilities of the potassium atom using a first-principles high-precision relativistic all-order method in which all single, double, and partial triple excitations of the Dirac-Fock wave functions are included to all orders of perturbation theory. Recommended values are provided for a large number of electric-dipole matrix elements. Static polarizabilities of the 4s, 4p_j, 5s, 5p_j, and 3d_j states are compared with other theory and experiment where available. We use the results of the polarizability calculations to identify magic wavelengths for the 4s-np transitions for $n = 4, 5$, i.e. those wavelengths for which the two levels have the same ac Stark shifts. These facilitate state-insensitive optical cooling and trapping. The magic wavelengths for the $4s-5p$ transitions are of particular interest for attaining a quantum gas of potassium at high phase-space density. We find 20 such wavelengths in the technically interest region of 1050-1130 nm....

  9. Formulation and optimization of potassium iodide tablets.

    Science.gov (United States)

    Al-Achi, Antoine; Patel, Binit

    2015-01-01

    The use of potassium iodide (KI) as a protective agent against accidental radioactive exposure is well established. In this study, we aimed to prepare a KI tablet formulation using a direct compression method. We utilized Design of Experiment (DoE)/mixture design to define the best formulation with predetermined physical qualities as to its dissolution, hardness, assay, disintegration, and angle of repose. Based on the results from the DoE, the formulation had the following components (%w/w): Avicel 48.70%, silicon dioxide 0.27%, stearic acid (1.00%), magnesium stearate 2.45%, and dicalcium phosphate 18.69%, in addition to potassium iodide 28.89% (130 mg/tablet). This formulation was scaled-up using two tablet presses, a single-punch press and a rotary mini tablet press. The final scaled-up formulation was subjected to a variety of quality control tests, including photo-stability testing. The results indicate that potassium iodide tablets prepared by a rotary mini tablet press had good pharmaceutical characteristics and a shelf-life of 25 days when stored at room temperature protected from light.

  10. 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.

  11. 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.

  12. Use of potassium-42 in the study of kidney functioning; Emploi du patassium-12 pour l'etude du fonctionnement renal

    Energy Technology Data Exchange (ETDEWEB)

    Morel, F.; Guinnebault, M. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    Following an intravenous injection of potassium-42 as indicator, an analysis of the specific activity vs. time curve in arterial plasma, in venous plasma efferent from the kidney, in urine and in various regions of the kidney of rabbits reveals that: 1) The turnover rate of potassium in the cortex cells (proximal and distal convoluted tubes) is very large, being limited only by renal blood flow. 2) The turnover rate of potassium in deep regions (Henle loops and collector tubules) is much smaller. 3) Potassium in the urine comes from cells of the convoluted tubes and not from cells of Henle loops, collector ducts, or glomerular filtrate. 4) Any potassium filtered at the level of the glomerules would be entirely reabsorbed at the level of the proximal tube, while total potassium in the urine results from a process of excretion by cells of the distal tube. These results are comparable with the assumption that the movement of potassium between interstitial medium and convoluted tube cells results from entirely passive processes. (author) [French] Apres injection intraveineuse au lapin de radiopotassium comme indicateur, l'analyse des courbes de la radioactivite specifique du potassium, mesuree en fonction du temps dans le plasma arteriel, dans le plasma veineux efferent du rein, dans l'urine et dans diverses regions du rein, lui-meme, permet de montrer: 1)que la vitesse de renouvellement du potassium contenu dans les cellules du cortex (tubes contournes proximaux et distaux), apparait tres grande et semble limitee par le debit sanguin renal. 2) que le vitesse de renouvellement du potassium contenu dans les regions profondes (anses de Henle et tubes collecteurs) est beaucoup plus faible. 3) que le potassium de l'urine a pour precurseur le potassium des cellules des tubes contournes et non celui des cellules des anses de Henle ou des canaux collecteurs, ni celui du filtrat glomerulaire. 4) que le potassium filtre au niveau des glomerules serait entierement

  13. 肝细胞癌患者血清细胞外基质蛋白1表达水平与术后复发及预后的关系%The prognostic significance of preoperative serum levels of extracellular matrix protein 1 in patients with hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    陈浩; 李建生; 荚卫东; 许戈良; 马金良; 任维华; 王伟

    2012-01-01

    Objective To evaluate the prtognostic significance of preoperative serum extracellular matrix protein 1 ( ECM1 ) levels in patients with hepatocellular carcinoma (HCC).Methods Preoperative serum levels of ECM1 were detected by enzyme-linked immunosorbent assay (ELISA) in 117 HCC patients and 53 healthy volunteers.Corrrlations to the clinicopathological characteristics and patients survival were analyzed.Results ECM1 were detected in all the samples of 117 HCC patients and 53 healthy volunteers,the median serum ECM1 level in HCC patients was significantly higher than that in healthy volunteers ( 166.39 vs 108.06 pg/ml,Z =- 7.805,P < 0.001 ).Median serum ECM 1 levels were significantly higher in patients with invasive phenotypes,such as larger tumor size (Z =- 3.454,P =0.001 ),multiple nodule ( Z =- 2.201,P =0.028 ),vascular invasion ( Z =- 4.685,P < 0.001 ),and advanced TN M stage ( Z =-4.610,P < 0.001 ).Patients with lower serum ECM1 level (≤ 180 pg/ml ) have significantly better overall and disease free survival than those with higher levels ( > 180 pg/ml).By Cox proportional-hazard model multivariate analysis,high serum ECM1 level ( > 180 pg/ml) was an independent factor for OS and DFS in HCC patients.Conclusions Serum ECM1 levels are significantly correhted to the invasive phenotypes and survival rate.Serum ECM1 level could be used as a predictive marker for HCC recurrence and prognostic factor of HCC patients after surgery.%目的 探讨细胞外基质蛋白-1(extracellular matrix protein 1,ECM1)在肝细胞癌(hepatocellular carcinoma,HCC)患者术前血清中的表达水平与肝癌临床病理特征及生存预后间的关系.方法 应用酶联免疫吸附法测定HCC患者及健康体检者血清中ECM1表达水平,分析血清ECM1表达水平与临床病理特征及生存预后间的关系.结果 117例HCC患者及53例正常对照血清ECM1中位表达浓度分别为166.39、108.06 pg/ml,差异有统计学意义(Z=-7.805,P <0.001).

  14. Extracellular Ca2+ is a danger signal activating the NLRP3 inflammasome through G protein-coupled calcium sensing receptors

    DEFF Research Database (Denmark)

    Rossol, Manuela; Pierer, Matthias; Raulien, Nora;

    2012-01-01

    Activation of the NLRP3 inflammasome enables monocytes and macrophages to release high levels of interleukin-1ß during inflammatory responses. Concentrations of extracellular calcium can increase at sites of infection, inflammation or cell activation. Here we show that increased extracellular cal......, and this effect was inhibited in GPRC6A(-/-) mice. Our results demonstrate that G-protein-coupled receptors can activate the inflammasome, and indicate that increased extracellular calcium has a role as a danger signal and amplifier of inflammation....

  15. Kinetics of Nitrogen and Potassium Uptake by Various Rice Cultivars at Differnt Nitrogen Lvels from Purple Soil

    Institute of Scientific and Technical Information of China (English)

    WANGZHENGYIN; XUWEIHONG; 等

    1998-01-01

    A pot experiment was conducted to study the effect of nitrogen fertilizer on nitrogen and potassium uptake by four rice cultivars.Results showed that the quadratic parabola relationship between biomass of rice and nitrogen levels was observed ,with the maximum biomass at the nitrogen level of 150 mg kg-1.The rate of nitrogen and potassium uptake by the four rice cultivars depended on growth stage and rice cultivar with the maximum rate of N in Shanyou-63 and maximum rate of K in Kaiyou-5(hybrid rice),respectively,The kinetics of nitrogen and potasssium uptake by rice plant could be quantitatively described by the following equations:y=a+blogt,y=ab+t1/2 and y=ae-bt,The b value in the equations was correlated significantly to the rates of nitrogen and potassium uptake (-↑NR and -↑KR,r=0.901**-0.990**),suggesting that the b value could be used to distinguish the index of nitrogen and potassium uptake capacity of rice .The maximum values of nitrogen uptake by plant(b value)and apparent recovery of fertilizer nitrogen were observed in Shanyou-63,and the minimum value in Eryou-6078,However,the capacity of potassium uptake (b value)by kaiyou-5 ranked first and that by Shanyou-63 second.There was a significant linear relationship between nitrogen level and nitrogen uptake by rice,but a quadratic parabola relationship was found between nitrogen level and patassium uptake by rice.The application of nitrogen fertilzier decreased the ratios of potassium to nitrogen uptake by rice plant.The greatest reduction in the ratio was observed at hiht nitrogen level,and the least reduction was foun in Kaiyou-5 and Shanyou-63 due to their greater ability to absorb potassium.

  16. 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.

  17. The extracellular matrix in breast cancer.

    Science.gov (United States)

    Insua-Rodríguez, Jacob; Oskarsson, Thordur

    2016-02-01

    The extracellular matrix (ECM) is increasingly recognized as an important regulator in breast cancer. ECM in breast cancer development features numerous changes in composition and organization when compared to the mammary gland under homeostasis. Matrix proteins that are induced in breast cancer include fibrillar collagens, fibronectin, specific laminins and proteoglycans as well as matricellular proteins. Growing evidence suggests that many of these induced ECM proteins play a major functional role in breast cancer progression and metastasis. A number of the induced ECM proteins have moreover been shown to be essential components of metastatic niches, promoting stem/progenitor signaling pathways and metastatic growth. ECM remodeling enzymes are also markedly increased, leading to major changes in the matrix structure and biomechanical properties. Importantly, several ECM components and ECM remodeling enzymes are specifically induced in breast cancer or during tissue regeneration while healthy tissues under homeostasis express exceedingly low levels. This may indicate that ECM and ECM-associated functions may represent promising drug targets against breast cancer, providing important specificity that could be utilized when developing therapies. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. and extracellular laccase isoenzymes from Pleurotus ostreatus ...

    African Journals Online (AJOL)

    ZMG

    Colonia Vicentina, Delegación Iztapalapa, 09340 México D.F., México. ... In this study, extracellular laccase enzymes produced by Pleurotus ostreatus was identified in .... the intracellular forms), through the modified zymography method of.

  19. Alternative methods for characterization of extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Fatemeh eMomen-Heravi

    2012-09-01

    Full Text Available Extracellular vesicles are nano-sized vesicles released by all cells in vitro as well as in vivo. Their role has been implicated mainly in cell-cell communication, but also in disease biomarkers and more recently in gene delivery. They represent a snapshot of the cell status at the moment of release and carry bioreactive macromolecules such as nucleic acids, proteins and lipids. A major limitation in this emerging new field is the availability/awareness of techniques to isolate and properly characterize Extracellular vesicles. The lack of gold standards makes comparing different studies very difficult and may potentially hinder some Extracellular vesicles -specific evidence. Characterization of Extracellular vesicles has also recently seen many advances with the use of Nanoparticle Tracking Analysis (NTA, flow cytometry, cryo-EM instruments and proteomic technologies. In this review, we discuss the latest developments in translational technologies involving characterization methods including the facts in their support and the challenges they face.

  20. Patterns of sodium and potassium excretion and blood pressure in the African Diaspora.

    Science.gov (United States)

    Tayo, B O; Luke, A; McKenzie, C A; Kramer, H; Cao, G; Durazo-Arvizu, R; Forrester, T; Adeyemo, A A; Cooper, R S

    2012-05-01

    Habitual levels of dietary sodium and potassium are correlated with age-related increases in blood pressure (BP) and likely have a role in this phenomenon. Although extensive published evidence exists from randomized trials, relatively few large-scale community surveys with multiple 24-h urine collections have been reported. We obtained three 24-h samples from 2704 individuals from Nigeria, Jamaica and the United States to evaluate patterns of intake and within-person relationships with BP. The average (±s.d.) age and weight of the participants across all the three sites were 39.9±8.6 years and 76.1±21.2 kg, respectively, and 55% of the total participants were females. Sodium excretion increased across the East-West gradient (for example, 123.9±54.6, 134.1±48.8, 176.6±71.0 (±s.d.) mmol, Nigeria, Jamaica and US, respectively), whereas potassium was essentially unchanged (for example, 46.3±22.9, 40.7±16.1, 44.7±16.4 (±s.d.) mmol, respectively). In multivariate analyses both sodium (positively) and potassium (negatively) were strongly correlated with BP (P<0.001); quantitatively the association was stronger, and more consistent in each site individually, for potassium. The within-population day-to-day variation was also greater for sodium than for potassium. Among each population group, a significant correlation was observed between sodium and urine volume, supporting the prior finding of sodium as a determinant of fluid intake in free-living individuals. These data confirm the consistency with the possible role of dietary electrolytes as hypertension risk factors, reinforcing the relevance of potassium in these populations.

  1. Potassium inhibits dietary salt-induced transforming growth factor-beta production.

    Science.gov (United States)

    Ying, Wei-Zhong; Aaron, Kristal; Wang, Pei-Xuan; Sanders, Paul W

    2009-11-01

    Human and animal studies demonstrate an untoward effect of excess dietary NaCl (salt) intake on cardiovascular function and life span. The endothelium in particular augments the production of transforming growth factor (TGF)-beta, a fibrogenic growth factor, in response to excess dietary salt intake. This study explored the initiating mechanism that regulates salt-induced endothelial cell production of TGF-beta. Male Sprague-Dawley rats were given diets containing different amounts of NaCl and potassium for 4 days. A bioassay for TGF-beta demonstrated increased (35.2%) amounts of active TGF-beta in the medium of aortic ring segments from rats on the high-salt diet compared with rats maintained on a 0.3% NaCl diet. Inhibition of the large-conductance, calcium-activated potassium channel inhibited dietary salt-induced vascular production of TGF-beta but did not affect production of TGF-beta by ring segments from rats on the low-salt diet. Immunohistochemical and Western analyses demonstrated the alpha subunit of the calcium-activated potassium channel in endothelial cells. Increasing medium [K+] inhibited production of dietary salt-induced vascular production levels of total and active TGF-beta but did not alter TGF-beta production by aortic rings from rats on the 0.3% NaCl diet. Increasing dietary potassium content decreased urinary active TGF-beta in animals receiving the high-salt diet but did not change urinary active TGF-beta in animals receiving the low-salt diet. The findings demonstrated an interesting interaction between the dietary intake of potassium and excess NaCl and further showed the fundamental role of the endothelial calcium-activated potassium channel in the vascular response to excess salt intake.

  2. 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...

  3. Collisional transfer of population and orientation in sodium potassium

    Science.gov (United States)

    Wolfe, Christopher Matthew

    Collisional spectral satellite lines have been identified in recent optical-optical double resonance (OODR) excitation spectra of the NaK molecule. These satellite lines represent both a transfer of population, and a partial preservation of angular momentum orientation, to a rotational level adjacent to the one directly excited by the pump laser beam. A rate equation model was used to study the intensities of these satellite lines as a function of argon pressure and heat pipe oven temperature, in order to separate the collisional effects of argon and potassium atoms (being the most populous species in the vapor by an order of magnitude over the third most populous). Using a fit of this rate equation model to the data, it was found that collisions between NaK and potassium are more likely to transfer population and destroy orientation than argon collisions, and also more likely to transfer population to rotational levels higher in energy than the one being pumped (i.e. a propensity for positive Delta J collisions). Also, collisions between NaK and argon atoms show a propensity toward even-numbered changes in J. In addition to the above study, an analysis of collisional line broadening and velocity-changes in J-changing collisions was performed, showing potassium has a higher line broadening rate coefficient, as well as a smaller velocity change in J-changing collisions, than argon. A program was also written in Fortran 90/95 which solves the density matrix equations of motion in steady state for a coupled system of 3 (or 4) energy levels with their constituent degenerate magnetic sublevels. The solution to these equations yields the populations of each sublevel in steady state, as well as the laser-induced coherences between each sublevel (which are needed to model the polarization spectroscopy lineshape precisely). Development of an appropriate theoretical model for collisional transfer will yield a more rigorous study of the problem than the empirical rate

  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. The extracellular RNA complement of Escherichia coli.

    Science.gov (United States)

    Ghosal, Anubrata; Upadhyaya, Bimal Babu; Fritz, Joëlle V; Heintz-Buschart, Anna; Desai, Mahesh S; Yusuf, Dilmurat; Huang, David; Baumuratov, Aidos; Wang, Kai; Galas, David; Wilmes, Paul

    2015-01-21

    The secretion of biomolecules into the extracellular milieu is a common and well-conserved phenomenon in biology. In bacteria, secreted biomolecules are not only involved in intra-species communication but they also play roles in inter-kingdom exchanges and pathogenicity. To date, released products, such as small molecules, DNA, peptides, and proteins, have been well studied in bacteria. However, the bacterial extracellular RNA complement has so far not been comprehensively characterized. Here, we have analyzed, using a combination of physical characterization and high-throughput sequencing, the extracellular RNA complement of both outer membrane vesicle (OMV)-associated and OMV-free RNA of the enteric Gram-negative model bacterium Escherichia coli K-12 substrain MG1655 and have compared it to its intracellular RNA complement. Our results demonstrate that a large part of the extracellular RNA complement is in the size range between 15 and 40 nucleotides and is derived from specific intracellular RNAs. Furthermore, RNA is associated with OMVs and the relative abundances of RNA biotypes in the intracellular, OMV and OMV-free fractions are distinct. Apart from rRNA fragments, a significant portion of the extracellular RNA complement is composed of specific cleavage products of functionally important structural noncoding RNAs, including tRNAs, 4.5S RNA, 6S RNA, and tmRNA. In addition, the extracellular RNA pool includes RNA biotypes from cryptic prophages, intergenic, and coding regions, of which some are so far uncharacterised, for example, transcripts mapping to the fimA-fimL and ves-spy intergenic regions. Our study provides the first detailed characterization of the extracellular RNA complement of the enteric model bacterium E. coli. Analogous to findings in eukaryotes, our results suggest the selective export of specific RNA biotypes by E. coli, which in turn indicates a potential role for extracellular bacterial RNAs in intercellular communication. © 2015 The

  6. 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

    aerosol (mass based distribution mode:1.3 μm) compared to that of the KCl aerosol (mass based distribution mode: 0.12 μm). The relative activities of exposed catalysts indicate that promotion with WO3 accelerates the deactivation, likely due to theenhanced Brønsted acidity which appears to promote...... the transport of potassium. Using a newly developed experimental protocol consisting of two-layer pellets of SCR catalysts, where one side is impregnated with KCl or K2SO4, the potassium transport in such systems, which is assumed to take place through reactionand diffusion over acid sites, was investigated...

  7. 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.

  8. Influence of NaCl, urea, potassium and pH on HSP72 expression in MDCK cells.

    Science.gov (United States)

    Neuhofer, W; Müller, E; Grünbein, R; Thurau, K; Beck, F X

    1999-12-01

    The renal inner medulla is characterised by elevated extracellular concentrations of NaCl, urea, potassium and hydrogen ions, an environment that may affect cell viability negatively. High amounts of HSP72, a stress protein allowing cells to resist harmful situations, are also observed in this region. The present study examined HSP72 induction by various medullary stress factors, individually or in combination, in MDCK cells, a renal epithelial cell line expressing characteristics of the medullary collecting duct. MDCK cells were incubated for 3 days in media containing elevated concentrations of NaCl, urea, potassium and hydrogen ions individually or in combination. HSP72 mRNA and protein expression were determined by Northern and Western blot analyses, respectively. HSP72 expression was enhanced moderately by addition of 50 mM NaCl to normal medium at pH 7.4 but enhanced strongly when added at pH 6.5. The latter degree of HSP72 induction was comparable to that observed when 150 mM NaCl was added at pH 7.4. In normal medium (pH 7.4) containing 300 mM urea, MDCK HSP72 expression was not different from controls. In contrast, urea-induced HSP72 expression was clearly evident when medium pH was lowered to 6.5. Potassium at 20 or 40 mM induced HSP72 only slightly. These results indicate that expression of HSP72 in renal epithelial cells is regulated synergistically by NaCl, urea and pH. Since HSP72 is only slightly induced by increased potassium, this probably reflects the changes in medium osmolality rather than a specific effect of potassium. The high medullary HSP72 content observed even in diuresis may be due to co-operative effects of medullary solutes on HSP72 expression.

  9. Extracellular Ligninolytic Enzymes in Bjerkandera adusta and Lentinus squarrosulus.

    Science.gov (United States)

    Tripathi, Astha; Upadhyay, R C; Singh, Surendra

    2012-09-01

    Extracellular ligninolytic enzyme activities were determined in two white-rot fungi, Bjerkandera adusta and Lentinus squarrosulus. To investigate the activity of extracellular enzymes, cultures were incubated over a period of 20 days in nutrient rich medium (NRM) and nutrient poor medium under static and shaking conditions. Enzymatic activity was varied with media and their incubation conditions. The highest level of Aryl alcohol oxidase (AAO) was detected under shaking condition of both medium while Manganese peroxidase (MnP) activity was best in NRM under both conditions. AAO is the main oxidases enzyme in B. adusta while laccase plays important role in L. squarrosulus. MnP is the main peroxidase enzyme in both varieties.

  10. Basic Components of Connective Tissues and Extracellular Matrix

    DEFF Research Database (Denmark)

    Halper, Jaroslava; Kjær, Michael

    2014-01-01

    of the extracellular matrix in soft tissues. Some of these are reviewed in this chapter. Besides their basic structure, biochemistry and physiology, their roles in disorders of soft tissues are discussed only briefly as most chapters in this volume deal with relevant individual compounds. Fibronectin with its...... network. Laminins contribute to the structure of the extracellular matrix (ECM) and modulate cellular functions such as adhesion, differentiation, migration, stability of phenotype, and resistance towards apoptosis. Though the primary role of fibrinogen is in clot formation, after conversion to fibrin...... and TGFβ activity was observed in fibrotic skin disorders such as keloids and scleroderma. Cartilage oligomeric matrix protein (COMP) or thrombospondin-5 is primarily present in the cartilage. High levels of COMP are present in fibrotic scars and systemic sclerosis of the skin, and in tendon, especially...

  11. Lower serum potassium associated with increased mortality in dialysis patients: A nationwide prospective observational cohort study in Korea

    Science.gov (United States)

    Lee, Sunhwa; Kang, Eunjeong; Yoo, Kyung Don; Choi, Yunhee; Kim, Dong Ki; Joo, Kwon Wook; Yang, Seung Hee; Kim, Yong-Lim; Kang, Shin-Wook; Yang, Chul Woo; Kim, Nam Ho; Kim, Yon Su; Lee, Hajeong

    2017-01-01

    Background Abnormal serum potassium concentration has been suggested as a risk factor for mortality in patients undergoing dialysis patients. We investigated the impact of serum potassium levels on survival according to dialysis modality. Methods A nationwide, prospective, observational cohort study for end stage renal disease patients has been ongoing in Korea since August 2008. Our analysis included patients whose records contained data regarding serum potassium levels. The relationship between serum potassium and mortality was analyzed using competing risk regression. Results A total of 3,230 patients undergoing hemodialysis (HD, 64.3%) or peritoneal dialysis (PD, 35.7%) were included. The serum potassium level was significantly lower (P < 0.001) in PD (median, 4.5 mmol/L; interquartile range, 4.0–4.9 mmol/L) than in HD patients (median, 4.9 mmol/L; interquartile range, 4.5–5.4 mmol/L). During 4.4 ± 1.7 years of follow-up, 751 patients (23.3%) died, mainly from cardiovascular events (n = 179) and infection (n = 120). In overall, lower serum potassium level less than 4.5 mmol/L was an independent risk factor for mortality after adjusting for age, comorbidities, and nutritional status (sub-distribution hazard ratio, 1.30; 95% confidence interval 1.10–1.53; P = 0.002). HD patients showed a U-shaped survival pattern, suggesting that both lower and higher potassium levels were deleterious, although insignificant. However, in PD patients, only lower serum potassium level (<4.5 mmol/L) was an independent predictor of mortality (sub-distribution hazard ratio, 1.35; 95% confidence interval 1.00–1.80; P = 0.048). Conclusion Lower serum potassium levels (<4.5 mmol/L) occur more commonly in PD than in HD patients. It represents an independent predictor of survival in overall dialysis, especially in PD patients. Therefore, management of dialysis patients should focus especially on reducing the risk of hypokalemia, not only that of hyperkalemia. PMID:28264031

  12. The role of ERK-1/2 in the N/OFQ-induced inhibition of delayed rectifier potassium currents

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei [Laboratory of Neural Electrophysiology, Department of Physiology, Harbin Medical University, Harbin 150081 (China); Cui, Qingbo [Department of Pediatric Surgery, The 2nd Hospital of Harbin Medical University, Harbin 150081 (China); Li, Yurong [Laboratory of Neural Electrophysiology, Department of Physiology, Harbin Medical University, Harbin 150081 (China); Li, Baoxin [Institute of Pharmacology, Harbin Medical University, Harbin 150081 (China); Yang, Xu; Cui, Lanwei; Jin, Hongbo [Laboratory of Neural Electrophysiology, Department of Physiology, Harbin Medical University, Harbin 150081 (China); Qu, Lihui, E-mail: lihui_qu@yahoo.com.cn [Laboratory of Neural Electrophysiology, Department of Physiology, Harbin Medical University, Harbin 150081 (China)

    2010-04-16

    Nociceptin/orphanin FQ (N/OFQ) is an endogenous opioid-like heptadecapeptide involved in many neurocognitive functions, including learning and memory. Our previous report showed that N/OFQ inhibits the delayed rectifier potassium current (I{sub K}), and this effect is associated with protein kinase C (PKC) activation. Therefore, we wanted to determine if extracellular signal-regulated kinase-1/2 (ERK-1/2) signaling is regulated by N/OFQ and associated with the effect of N/OFQ on the I{sub K}. In the current study, we tested if N/OFQ and two PKC activators [phorbol 12,13-dibutyrate (PDBu) and ingenol 3,20-dibenzoate (IDB)] affected the phosphorylation level of ERK-1/2 and its nuclear substrate, ETS-like transcription factor-1 (Elk-1), using western blots. In addition, we tested if ERK-1/2 affected the N/OFQ-induced inhibition of the I{sub K} by using whole-cell patch-clamp recordings in acutely dissociated rat parietal cortical neurons. We found that N/OFQ, PDBu, and IDB increased the amount of phosphorylated ERK-1/2 and Elk-1; U0126, a specific inhibitor for ERK-1/2, attenuated the inhibitory effect of N/OFQ on the I{sub K}. These data suggest that the ERK-1/2 pathway, at least in part, mediates the inhibitory effect of N/OFQ on the I{sub K} in acutely dissociated rat cerebral parietal cortical neurons.

  13. The role of ERK-1/2 in the N/OFQ-induced inhibition of delayed rectifier potassium currents.

    Science.gov (United States)

    Wang, Wei; Cui, Qingbo; Li, Yurong; Li, Baoxin; Yang, Xu; Cui, Lanwei; Jin, Hongbo; Qu, Lihui

    2010-04-16

    Nociceptin/orphanin FQ (N/OFQ) is an endogenous opioid-like heptadecapeptide involved in many neurocognitive functions, including learning and memory. Our previous report showed that N/OFQ inhibits the delayed rectifier potassium current (I(K)), and this effect is associated with protein kinase C (PKC) activation. Therefore, we wanted to determine if extracellular signal-regulated kinase-1/2 (ERK-1/2) signaling is regulated by N/OFQ and associated with the effect of N/OFQ on the I(K). In the current study, we tested if N/OFQ and two PKC activators [phorbol 12,13-dibutyrate (PDBu) and ingenol 3,20-dibenzoate (IDB)] affected the phosphorylation level of ERK-1/2 and its nuclear substrate, ETS-like transcription factor-1 (Elk-1), using western blots. In addition, we tested if ERK-1/2 affected the N/OFQ-induced inhibition of the I(K) by using whole-cell patch-clamp recordings in acutely dissociated rat parietal cortical neurons. We found that N/OFQ, PDBu, and IDB increased the amount of phosphorylated ERK-1/2 and Elk-1; U0126, a specific inhibitor for ERK-1/2, attenuated the inhibitory effect of N/OFQ on the I(K). These data suggest that the ERK-1/2 pathway, at least in part, mediates the inhibitory effect of N/OFQ on the I(K) in acutely dissociated rat cerebral parietal cortical neurons.

  14. Decolorization of dyes and textile wastewater by potassium permanganate.

    Science.gov (United States)

    Xu, Xiang-Rong; Li, Hua-Bin; Wang, Wen-Hua; Gu, Ji-Dong

    2005-05-01

    Decolorization of 10 types of dye solutions by potassium permanganate was studied. Effects of reaction conditions on the decolorization efficiency were examined in batch experiments. The pH value had a significant effect on the decolorization efficiency. When pH value decolorization efficiency was very high. When pH value >4.0, the dye solutions were almost not decolorized. Concentration of potassium permanganate and temperature also showed significant effects on the decolorization efficiency. The decolorization rate of dye solutions by potassium permanganate was rapid, and most of dye solutions can be decolorized effectively. The results of total organic carbon indicated that dye solutions were degraded incompletely by potassium permanganate. The results of treatment of textile wastewater by potassium permanganate indicated that the oxidation with potassium permanganate might be used as a pre-treatment process before biological treatment.

  15. Potassium and magnesium distribution, ECG changes, and ventricular ectopic beats during beta 2-adrenergic stimulation with terbutaline in healthy subjects

    DEFF Research Database (Denmark)

    Tveskov, C; Djurhuus, M S; Klitgaard, N A

    1994-01-01

    OBJECTIVE: To study the effect of intravenous (i.v.) terbutaline on potassium (K) and magnesium (Mg) distribution, ECG changes, and prevalence of ventricular ectopic beats in healthy subjects. DESIGN: Randomized double-blind, placebo-controlled crossover. Subjects received either placebo or terbu......OBJECTIVE: To study the effect of intravenous (i.v.) terbutaline on potassium (K) and magnesium (Mg) distribution, ECG changes, and prevalence of ventricular ectopic beats in healthy subjects. DESIGN: Randomized double-blind, placebo-controlled crossover. Subjects received either placebo......-potassium pump number. Urinary excretion of potassium and magnesium. ECG changes (T-wave and QTC interval) and the number of ventricular ectopic beats. MAIN RESULTS: Terbutaline produced an immediate decrease in serum potassium level from 4.17 (4.04 to 4.30) mmol/L to a nadir of 3.32 (3.06 to 3.58) mmol/L (p ... of sodium-potassium pumps. Furthermore, terbutaline induced changes in ECG with a highly significant lengthening of the QTc interval but with an unchanged number of ventricular ectopic beats in healthy subjects....

  16. Assessment of Sodium and Potassium Intake by 24 h Urinary Excretion in a Healthy Mexican Cohort.

    Science.gov (United States)

    Vallejo, Maite; Colín-Ramírez, Eloisa; Rivera Mancía, Susana; Cartas Rosado, Raúl; Madero, Magdalena; Infante Vázquez, Oscar; Vargas-Barrón, Jesús

    2017-02-01

    A high dietary sodium intake and a low potassium intake are associated with adverse cardiovascular health. Data on these nutrients consumption in Mexico is limited. The aim of this study was to assess sodium and potassium intake by 24 h urinary excretion in a clinically healthy Mexican population. We additionally explored their association with blood pressure. 711 clinically healthy participants aged 20-50 years old recruited in the Tlalpan 2020 cohort from September 2014-December 2015, were included in this cross-sectional analysis. All participants provided a 24 h urine sample and underwent anthropometric, biochemical, and blood pressure evaluations. Univariate and multivariate linear regression analyses were used to assess the association of urinary sodium, potassium, and Na/K ratio with blood pressure. Mean (95% confidence interval [CI]) urinary sodium and potassium in the overall population was 3150.1 (3054.2-3246.0) mg/d and 1909.5 (1859.3-1959.6) mg/d, respectively. Overall, only 121 (17%) met the WHO recommendation for sodium intake (<2000 mg/d) and 16 (2.3%) met the goal for potassium intake (≥3510 mg/d). Urinary sodium (β coefficient 1.3, 95% CI: 0.7, 1.8, p <0.001) and potassium (β coefficient 2.1, 95% CI: 1.0, 3.2, p <0.001) were found to be associated with systolic blood pressure in the univariate analysis but not in the multivariate analysis. Sodium intake was higher and potassium intake was lower than the WHO recommendations in this healthy Mexican population. Sodium and potassium intakes were not associated with blood pressure at the mean levels of intake observed in this population, after adjusting for key variables. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

  17. Potassium emission absorption system. Topical report 12

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, L.E.

    1995-04-01

    The Potassium Emission Absorption System is one of the advanced optical diagnostics developed at Mississippi State University to provide support for the demonstration of prototype-scale coal-fired combustion magnetohydrodynamic (MHD) electrical power generation. Intended for application in the upstream of an MHD flow, the system directly measures gas temperature and neutral potassium atom number density through spectroscopic emission absorption techniques. From these measurements the electron density can be inferred from a statistical equilibrium calculation and the electron conductivity in the MHD channel found by use of an electron mobility model. The instrument has been utilized for field test measurements on MHD facilities for almost a decade and has been proven to provide useful measurements as designed for MHD nozzle, channel, and diffuser test sections. The theory of the measurements, a system description, its capabilities, and field test measurement results are reported here. During the development and application of the instrument several technical issues arose which when addressed advanced the state of the art in emission absorption measurement. Studies of these issues are also reported here and include: two-wavelength measurements for particle-laden flows, potassium D-line far wing absorption coefficient, bias in emission absorption measurements arising from dirty windows and misalignments, non-coincident multiwavelength emission absorption sampling errors, and lineshape fitting for boundary layer flow profile information. Although developed for NLHD application, the instrument could be applied to any high temperature flow with a resonance line in the 300 to 800 nm range, for instance other types of flames, rocket plumes or low temperature plasmas.

  18. Launching a salt substitute to reduce blood pressure at the population level: a cluster randomized stepped wedge trial in Peru

    National Research Council Canada - National Science Library

    Bernabe-Ortiz, Antonio; Diez-Canseco, Francisco; Gilman, Robert H; Cárdenas, María K; Sacksteder, Katherine A; Miranda, J Jaime

    2014-01-01

    .... This study aims to estimate the impact of a population-level intervention based on sodium reduction and potassium increase - in practice, introducing a low-sodium, high-potassium salt substitute...

  19. Potassium accumulation and translocation among rice genotypes in relation to internal potassium use efficiency (IKUE)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Abiotic stresses including potassium deficiency are limiting factors for increasing rice yield. Nine rice genotypes (Oryza Sativa L., indica) differing in sensitivity to low K stress selected from 200 volume-solution screening were used in this study to examine accumulation and translocation of K.

  20. Effect of operating conditions and potassium content on Fischer-Tropsch liquid products produced by potassium-promoted iron catalysts

    Institute of Scientific and Technical Information of China (English)

    Francisco E. M. Farias; Fernando G. Sales; Fabiano A. N. Fernandes

    2008-01-01

    The dependencies of Fischer-Tropsch synthesis liquid hydrocarbon product distribution on operating pressure and temperature have been studied over three potassium-promoted iron catalysts with increasing potassium molar content. The study followed an experimental planning and the results were analyzed based on surface response methodology. The effects of different operating conditions and potassium contents on the liquid product distribution were compared based on number average carbon number and dispersion. Results showed that high pressures (25 to 30 atm) favored the production of waxes that could be converted into liquid fuels through hydrocracking, while greater direct selectivity towards diesel was favored by low pressure (20 atm) using catalysts with low potassium to iron molar ratios. The liquid product distribution produced using an iron catalyst with high potassium content presented higher number-average number of carbons when compared to the distribution obtained using an iron catalyst with low potassium content.

  1. Response of extracellular zinc in the ventral hippocampus against novelty stress.

    Science.gov (United States)

    Takeda, Atsushi; Sakurada, Naomi; Kanno, Shingo; Minami, Akira; Oku, Naoto

    2006-10-01

    An extensive neuronal activity takes place in the hippocampus during exploratory behavior. However, the role of hippocampal zinc in exploratory behavior is poorly understood. To analyze the response of extracellular zinc in the hippocampus against novelty stress, rats were placed for 50 min in a novel environment once a day for 8 days. Extracellular glutamate in the hippocampus was increased during exploratory behavior on day 1, whereas extracellular zinc was decreased. The same phenomenon was observed during exploratory behavior on day 2 and extracellular zinc had returned to the basal level during exploratory behavior on day 8. To examine the significance of the decrease in extracellular zinc in exploratory activity, exploratory behavior was observed during perfusion with 1 mm CaEDTA, a membrane-impermeable zinc chelator. Locomotor activity in the novel environment was decreased by perfusion with CaEDTA. The decrease in extracellular zinc and the increase in extracellular glutamate in exploratory period were abolished by perfusion with CaEDTA. These results suggest that zinc uptake by hippocampal cells is linked to exploratory activity and is required for the activation of the glutamatergic neurotransmitter system. The zinc uptake may be involved in the response to painless psychological stress or in the cognitive processes.

  2. Nitrogênio, fósforo e potássio na nutrição e no crescimento de mudas de laranjeiravalência, enxertadas sobre limoeiro cravo Effect of nitrogen, phosphorus, and potassium levels on nutrition and production of seedlings of 'Valencia' sweet orange grafted on 'cravo' lemon rootstock

    Directory of Open Access Journals (Sweden)

    Renato de Mello Prado

    2009-12-01

    (Citrus limonia Osbeck, in response to Nitrogen, Phosphorus, and Potassium levels. The experimental design was entirely randomized, in factorial scheme 3³ + 1, being 3 factors (Nitrogen, Phosphorus, and Potassium -NPK, 3 levels and a control (without fertilization with 3 replications. The experimental unit constituted of a 'Valencia' sweet orange grafted on 'Cravo' lemon rootstock in a plastic bag with 2,5 kg of substratum. The treatments consisted of half, one, and two times the standard recommended dose for production of orange seedlings (4,590, 920, and 4,380 mg bag-1 of N, P, and K, respectively. Fertilization with N and K was carried out by three weekly fertirrigations, and the P was added to the substratum of Pinus spp. bark and vermiculite before sowing. After 424 days, the plants were subdivided in roots and aerial parts for determination of dry matter, height, leaf area, diameter of stem, and nutrient content. Fertilization with N, P, and K provided for greater development and greater accumulation of these macronutrients in the aerial part and root of the 'Valencia' sweet orange grafted on 'Cravo' lemon rootstock. There was adequate development of the plants with half the recommended dose of N, P, and K according to literature, approximately of 918, 184, and 876 mg dm-3 of N, P, and K, respectively. Satisfactory development was obtained with half the recommended dose of N, P and K, in general. Slightly greater development occurred in the recommended dose of 4,590, 920, and 4,380 mg bag-1 or 918, 184, and 876 mg dm-3 of substratum, respectively.

  3. Vertebrate extracellular preovulatory and postovulatory egg coats.

    Science.gov (United States)

    Menkhorst, Ellen; Selwood, Lynne

    2008-11-01

    Extracellular egg coats deposited by maternal or embryonic tissues surround all vertebrate conceptuses during early development. In oviparous species, the time of hatching from extracellular coats can be considered equivalent to the time of birth in viviparous species. Extracellular coats must be lost during gestation for implantation and placentation to occur in some viviparous species. In the most recent classification of vertebrate extracellular coats, Boyd and Hamilton (Cleavage, early development and implantation of the egg. In: Parkes AS (ed.), Marshall's Physiology of Reproduction, vol. 2, 3rd ed. London: Longmans, Green & Co; 1961:1-126) defined the coat synthesized by the oocyte during oogenesis as primary and the coat deposited by follicle cells surrounding the oocyte as secondary. Tertiary egg coats are those synthesized and deposited around the primary or secondary coat by the maternal reproductive tract. This classification is difficult to reconcile with recent data collected using modern molecular biological techniques that can accurately establish the site of coat precursor synthesis and secretion. We propose that a modification to the classification by Boyd and Hamilton is required. Vertebrate egg coats should be classed as belonging to the following two broad groups: the preovulatory coat, which is deposited during oogenesis by the oocyte or follicle cells, and the postovulatory coats, which are deposited after fertilization by the reproductive tract or conceptus. This review discusses the origin and classification of vertebrate extracellular preovulatory and postovulatory coats and illustrates what is known about coat homology between the vertebrate groups.

  4. STUDY OF SODIUM, POTASSIUM, AND CALCIUM SALTS INFLUENCE ON PROTEIN STABILITY BY DIFFERENTIAL SCANNING CALORIMETRY

    Directory of Open Access Journals (Sweden)

    E. K. Tunieva

    2016-01-01

    Full Text Available Abstract Study of protein stability depending on the various technological factors allows to directionally adjust the physicochemical properties of raw meat and the quality of finished meat products. The paper investigates the possibility of using the DSC to study the influence of monovalent and divalent salts on protein thermal stability. In order to determine the effect of sodium chloride and its substitutes, potassium and calcium salts, on the thermal stability of proteins, the studies were carried out with grinded pork longissimus muscle samples salted with sodium chloride at level of 2.0% and with salt compositions containing reduced by 50% level of sodium chloride (a mixture of sodium and potassium chlorides; a mixture of sodium, potassium, and calcium chlorides using the differential scanning calorimeter DSC Q 2000 in the temperature range of 5 °C to 100 °C and the temperature change rate of 1 K/min. It was found that the addition of potassium chloride instead of 50% of sodium chloride had no significant effect on actin and myosin resistance to thermal denaturation. Meat salting using the mixture of sodium, potassium, and calcium chlorides resulted in decrease of myofibrillar proteins stability indicating the destabilizing effect of calcium on actin and myosin. A negative correlation between the magnitude of the ionic strength and the temperature of myosin and actin denaturation has been found. The correlation coefficients were minus 0.99 and minus 0.95 for myosin and actin respectively. Reduction of denaturation temperature for myofibrillar proteins in the presence of calcium chloride opens perspectives to study the possibility of heat treatment at lower temperatures for meat products with reduced sodium content.

  5. Extracellular Alkalinization as a Defense Response in Potato Cells

    Science.gov (United States)

    Moroz, Natalia; Fritch, Karen R.; Marcec, Matthew J.; Tripathi, Diwaker; Smertenko, Andrei; Tanaka, Kiwamu

    2017-01-01

    A quantitative and robust bioassay to assess plant defense response is important for studies of disease resistance and also for the early identification of disease during pre- or non-symptomatic phases. An increase in extracellular pH is known to be an early defense response in plants. In this study, we demonstrate extracellular alkalinization as a defense response in potatoes. Using potato suspension cell cultures, we observed an alkalinization response against various pathogen- and plant-derived elicitors in a dose- and time-dependent manner. We also assessed the defense response against a variety of potato pathogens, such as protists (Phytophthora infestans and Spongospora subterranea) and fungi (Verticillium dahliae and Colletotrichum coccodes). Our results show that extracellular pH increases within 30 min in proportion to the number of pathogen spores added. Consistently with the alkalinization effect, the higher transcription level of several defense-related genes and production of reactive oxygen species was observed. Our results demonstrate that the alkalinization response is an effective marker to study early stages of defense response in potatoes. PMID:28174578

  6. Extracellular Proteins: Novel Key Components of Metal Resistance in Cyanobacteria?

    Science.gov (United States)

    Giner-Lamia, Joaquín; Pereira, Sara B; Bovea-Marco, Miquel; Futschik, Matthias E; Tamagnini, Paula; Oliveira, Paulo

    2016-01-01

    Metals are essential for all living organisms and required for fundamental biochemical processes. However, when in excess, metals can turn into highly-toxic agents able to disrupt cell membranes, alter enzymatic activities, and damage DNA. Metal concentrations are therefore tightly controlled inside cells, particularly in cyanobacteria. Cyanobacteria are ecologically relevant prokaryotes that perform oxygenic photosynthesis and can be found in many different marine and freshwater ecosystems, including environments contaminated with heavy metals. As their photosynthetic machinery imposes high demands for metals, homeostasis of these micronutrients has been widely studied in cyanobacteria. So far, most studies have focused on how cells are capable of controlling their internal metal pools, with a strong bias toward the analysis of intracellular processes. Ultrastructure, modulation of physiology, dynamic changes in transcription and protein levels have been studied, but what takes place in the extracellular environment when cells are exposed to an unbalanced metal availability remains largely unknown. The interest in studying the subset of proteins present in the extracellular space has only recently begun and the identification and functional analysis of the cyanobacterial exoproteomes are just emerging. Remarkably, metal-related proteins such as the copper-chaperone CopM or the iron-binding protein FutA2 have already been identified outside the cell. With this perspective, we aim to raise the awareness that metal-resistance mechanisms are not yet fully known and hope to motivate future studies assessing the role of extracellular proteins on bacterial metal homeostasis, with a special focus on cyanobacteria.

  7. Assessment of Cation Exchange Membrane Method and Estimation of Potassium Critical Values

    Institute of Scientific and Technical Information of China (English)

    SHENJIANBO; J.J.SCHOENAU; 等

    1996-01-01

    Soil and tissue analyses are usually used in identifying potassium(K) deficiencies and predicting K fertilizer requirements of crops.The critical levels of both soil and fresh leaf tissue at seventh leaf stage were developed and assessed for canola,chickpea and sunflower grown on two saskatchewan,soils,with six rates of K fertilizer supply.in a growth chamber experiment.The available potassium in soils was detemined by two methods:1)resin strip extraction,and 2)NH4OAC extraction.The potassium in fresh leaves was determined at seventh leaf stage by a simple procedure using a common garlic press and injector to extract the plant sap and testing the sap with a handheld ion selection electrode meter,The results showed significant relationships between the resin strip extractable K and NH4OAC extractable K,and between the plant uptake of total K and the supple of available K in the soils determined by the two methods.Good relationships were also found between the potassium in fresh leaves and the plant uptake of totak K for canola,chickpea and sunflower.The resin strip extraction for K was calibrated using common NH4OAC extraction,and recommended for routine analyses because of its simplicity and sensitivity.

  8. Functional characterization of a potassium transporter geneNrHAK1 in Nicotiana rustica

    Institute of Scientific and Technical Information of China (English)

    Zhao-kui GUO; Qian YANG; Xiu-qing WAN; Pei-qiang YAN

    2008-01-01

    The purpose of this study is to investigate the function of a novel potassium transporter gene(NrHAK1) isolated from Nicotiana rustica roots using yeast complement and real-time PCR technique. The complementary DNA (cDNA) of NrHAK1, 2 488 bp long, contains an open reading frame (ORF) of 2334 bp encoding a protein of 777 amino acids (87.6 kDa) with 12 predicted transmembrane domains. The NrHAK1 protein shows a high sequence similarity to those of high-affinity potassium transporters in Mesembryanthemum, Phytolacca acinosa, Arabidopsis thaliana, and so on. We found that the NrHAK1 gene could complement the yeast-mutant defect in K+ uptake. Among several tissues surveyed, the expression level of NrHAK1 was most abundant in the root tip and was up-regulated when exposed to potassium starvation. Moreover, the transcript accumulation was significantly reduced by adding 5 mmol/L NH4 to the solution. These results suggest that NrHAK1 plays an important role in potassium absorption in N. Rustica.

  9. Potassium currents in isolated CA1 neurons of the rat after kindling epileptogenesis.

    Science.gov (United States)

    Vreugdenhil, M; Wadman, W J

    1995-06-01

    Daily tetanic stimulation of the Schaffer collaterals generates an epileptogenic focus in area CA1 of the rat hippocampus, ultimately leading to generalized tonic-clonic convulsions (kindling). Potassium currents were measured under voltage-clamp conditions in pyramidal neurons, acutely dissociated from the focus of fully kindled rats, one day and six weeks after the last generalized seizure. Their amplitude, kinetics, voltage dependence and calcium dependence were compared with controls. With Ca2+ influx blocked by 0.5 mM Ni2+, the sustained current (delayed rectifier) and the transient current (A-current) were not different after kindling. Calcium influx evoked an additional fast transient current component. This transient calcium-dependent current component was increased by 154%, but only immediately after the seizure. A second, slow calcium-dependent potassium current component was dependent on the intracellular calcium level, set by the pipette as well as on calcium influx. The peak amplitude of this slow calcium-dependent current was under optimal calcium conditions not different after kindling, but we found indications that either calcium homeostasis or the calcium sensitivity of the potassium channels was affected by the kindling process. In contrast to the previously described enhancement of calcium current, kindling epileptogenesis did not change the total potassium current amplitude. The minor changes that were observed can be related either to changes in calcium current or to changes in intracellular calcium homeostasis.

  10. DEVELOPMENT AND IN VITRO EVALUATION OF BUCCOADHESIVE TABLETS OF LOSARTAN POTASSIUM

    Directory of Open Access Journals (Sweden)

    Raviteja Achanta

    2012-09-01

    Full Text Available Buccoadhesion, or the attachment of a natural or synthetic polymer to a biological substrate, is a practical method of drug immobilization or localization and an important new aspect of controlled drug delivery. The unique environment of the oral (buccal cavity offers its potential as a site for drug delivery. Because of the rich blood supply and direct access to systemic circulation. The Buccal route is suitable for drugs, which are susceptible to acid hydrolysis in the stomach or which are extensively metabolized in the liver (first pass effect. Oral controlled release (CR systems continue to be most popular once amongst all the drug delivery systems. Mucoadhesive delivery systems offer several advantages over other oral CR systems by virtue of prolongation of residence time of drug in buccal mucosa, and targeting and localization of the dosage form at a specific site. Also, these mucoadhesive systems are known to provide intimate contact between dosage form and the absorptive mucosa, resulting thereby in high drug flux through the absorptive tissue. Losartan potassium is an angiotensin II receptor (type AT1 antagonist. Administration of conventional tablets of Losartan potassium has been reported to exhibit fluctuations in the plasma drug levels, resulting either in manifestation of side effects or reduction in drug concentration at the receptor site. Losartan Potassium is having less bioavailability (25-35%. In order to increase the bioavailability to avoid the hepatic metabolism, the buccal tablets of Losartan potassium were prepared.

  11. Investigation of dispersion and clustering in bubbles of ion implanted potassium in refractory metals

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.

    1989-01-01

    Potassium is a well known dopant for refractory metals. Being insoluble and of large atomic size it forms stable trapping sites for mobile defects at high temperature in the form of fine bubbles. Because of its insolubility it is difficult to introduce potassium into refractory metals, such as in lamp filaments. Ion implantation offers an excellent research tool as it permits the injection of insoluble element into the surface layer. This method was used to produce a uniform dispersion of potassium at a very fine level into tungsten and rhenium. Clustering and bubble formation were studied as a function of annealing time (up to 20 hours) and temperature (up to 2300 C). The methods of investigation were transmission electron microscopy and microchemical analysis. Orientation relationships between host metal and potassium precipitates inside bubbles were analyzed from superimposed electron diffraction patterns. In tungsten, the orientation relationship and the morphology of the bubbles are identical to those published for powder-metallurgically doped material. The bubbles are trapping sites for grain boundaries and dislocations as explained by the Zener drag-force model.

  12. Modeling extracellular field potentials and the frequency-filtering properties of extracellular space

    CERN Document Server

    Bedard, C; Destexhe, A; Bédard, Claude; Kroeger, Helmut; Destexhe, Alain

    2003-01-01

    Extracellular local field potentials (LFP) are usually modeled as arising from a set of current sources embedded in a homogeneous extracellular medium. Although this formalism can successfully model several properties of LFPs, it does not account for their frequency-dependent attenuation with distance, a property essential to correctly model extracellular spikes. Here we derive expressions for the extracellular potential that include this frequency-dependent attenuation. We first show that, if the extracellular conductivity is non-homogeneous, there is induction of non-homogeneous charge densities which may result in a low-pass filter. We next derive a simplified model consisting of a punctual (or spherical) current source with spherically-symmetric conductivity/permittivity gradients around the source. We analyze the effect of different radial profiles of conductivity and permittivity on the frequency-filtering behavior of this model. We show that this simple model generally displays low-pass filtering behav...

  13. Connecting extracellular metabolomic measurements to intracellular flux states in yeast

    Directory of Open Access Journals (Sweden)

    Herrgård Markus J

    2009-03-01

    Full Text Available Abstract Background Metabolomics has emerged as a powerful tool in the quantitative identification of physiological and disease-induced biological states. Extracellular metabolome or metabolic profiling data, in particular, can provide an insightful view of intracellular physiological states in a noninvasive manner. Results We used an updated genome-scale metabolic network model of Saccharomyces cerevisiae, iMM904, to investigate how changes in the extracellular metabolome can be used to study systemic changes in intracellular metabolic states. The iMM904 metabolic network was reconstructed based on an existing genome-scale network, iND750, and includes 904 genes and 1,412 reactions. The network model was first validated by comparing 2,888 in silico single-gene deletion strain growth phenotype predictions to published experimental data. Extracellular metabolome data measured in response to environmental and genetic perturbations of ammonium assimilation pathways was then integrated with the iMM904 network in the form of relative overflow secretion constraints and a flux sampling approach was used to characterize candidate flux distributions allowed by these constraints. Predicted intracellular flux changes were consistent with published measurements on intracellular metabolite levels and fluxes. Patterns of predicted intracellular flux changes could also be used to correctly identify the regions of the metabolic network that were perturbed. Conclusion Our results indicate that integrating quantitative extracellular metabolomic profiles in a constraint-based framework enables inferring changes in intracellular metabolic flux states. Similar methods could potentially be applied towards analyzing biofluid metabolome variations related to human physiological and disease states.

  14. COMPORTAMENTO FISIOLÓGICO IN VITRO DE BANANEIRA (Musa sp., AAA e AAB cvs. NANICA E PRATA ANÃ: INFLUÊNCIA DE DIFERENTES NÍVEIS DE POTÁSSIO PYSIOLOGICAL BEHAVIOR OF BANANA (Musa sp., AAA and AAB cvs. 'NANICA' AND 'PRATA ANÃ' IN VITRO CONDITION: INFLUENCE OF DIFFERENT LEVELS OF POTASSIUM

    Directory of Open Access Journals (Sweden)

    Humberto Actis Zaidan

    1999-01-01

    Full Text Available Nas abordagens biotecnológicas de propagação de plantas, os meios de cultura devem ter uma composição química adequada à essa finalidade permitindo a otimização da produção. Como a bananeira (Musa sp. é exigente em potássio, a busca do nível adequado desse macronutriente envolve não somente o comprometimento com o nível dos outros nutrientes (balanço iônico, mas também a relação entre eles. Para acompanhar os efeitos fisiológicos dos vários teores de K, explantes caulinares dos cvs. "Nanica" e "Prata Anã" foram cultivados em meio MS modificado, em presença de BAP (2,5 mg/L, sacarose, vitaminas e agar, em seis diferentes concentrações de K: 5, 10, 15, 20, 25 e 30 mM, sendo 20 mM a concentração de K no MS básico. Foram feitas análises de massa de matéria seca (MMS, K na parte aérea, raiz e plântulas inteiras, e determinado o número de plântulas, aos 90 dias de idade. Após início de cultivo todos os parâmetros foram analisados segundo um delineamento inteiramente casualizado. As plântulas que se desenvolveram em baixas concentrações de K apresentaram sintomas visuais de deficiência de K, como clorose e necrose nas folhas mais velhas. Os cultivares apresentaram diferenças quantitativas entre si, relacionados à concentração de K presente no meio de cultura, seja em relação aos valores de MMS, ou quanto ao número de plântulas formadas. Em ambos os cultivares, foi observada uma relação direta entre o desenvolvimento de plântulas e as concentrações de K com otimização ao redor de 15 a 20 mM de K.The chemical composition of culture growth media to micropropagate plants should be devised to allow the best quality and high production of plant material. One of the challenges is to optimize the ionic balance involving mineral nutrients. As banana (Musa sp. requires high levels of potassium, the optimum level was investigated. Shoot apexes of two banana cultivars 'Nanica' and 'Prata Anã' were

  15. Extracellular proteolysis in the adult murine brain.

    Science.gov (United States)

    Sappino, A P; Madani, R; Huarte, J; Belin, D; Kiss, J Z; Wohlwend, A; Vassalli, J D

    1993-08-01

    Plasminogen activators are important mediators of extracellular metabolism. In the nervous system, plasminogen activators are thought to be involved in the remodeling events required for cell migration during development and regeneration. We have now explored the expression of the plasminogen activator/plasmin system in the adult murine central nervous system. Tissue-type plasminogen activator is synthesized by neurons of most brain regions, while prominent tissue-type plasminogen activator-catalyzed proteolysis is restricted to discrete areas, in particular within the hippocampus and hypothalamus. Our observations indicate that tissue-type plasminogen activator-catalyzed proteolysis in neural tissues is not limited to ontogeny, but may also contribute to adult central nervous system physiology, for instance by influencing neuronal plasticity and synaptic reorganization. The identification of an extracellular proteolytic system active in the adult central nervous system may also help gain insights into the pathogeny of neurodegenerative disorders associated with extracellular protein deposition.

  16. Serum levels of extracellular matrix protein 1 and TIMP-2 in patients with hepatocellular carcinoma and its clinical significance%ECM-1和TIMP-2在肝细胞癌患者血清中的表达及其临床意义

    Institute of Scientific and Technical Information of China (English)

    孙其恺; 王伟; 吕阳; 刘国岩; 荚卫东; 许戈良; 马金良; 余继海; 陈浩

    2013-01-01

    目的 通过检测肝细胞癌患者血清中ECM-1和TIMP-2的表达水平,分析ECM-1和TIMP-2与临床病理参数之间的关系及临床意义.方法 应用酶联免疫吸附法测定59例肝癌患者血清ECM-1和TIMP-2水平.结果 59例肝癌患者血清ECM-1和TIMP-2平均水平分别为145.08 +22.13 pg/ml、30.77±13.89 ng/ml;两者水平均与肿瘤包膜、TNM分级、血管侵犯、肿瘤结节有关(P<0.005),而ECM-1与肿瘤分化程度有关(P<0.005);ECM-1和TIMP-2水平呈显著负相关(r=-0.469,P=0.000).结论 ECM-1与TIMP-2的表达可能与肝癌侵袭转移密切相关,可作为患者术后复发与转移的预测指标.%Objective To investigate the serum levels of extracellular matrix protein 1 ( ECM-1) , tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in patients with hepatocellular carcinoma (HCC). Methods Serum levels of ECM-1 and TIMP-2 were detected by enzyme-linked immunosorbent assay in 59 patients with HCC. Results The serum ECM-1 and TIMP-9 levels were 145. 08 ±22. 13 pg/ml and 30. 77 ± 13. 89 ng/ml, respectively. And they were significantly associated with tumor capsula, TNM stage, vascular invasion and tumor nodes (P<0. 005). Furthermore, ECM-1 levels were associated with tumor differentiation, which also were positively correlated with TIMP-2 (r = - 0. 469, P=0. 000). Conclusions Expression of ECM-1 and TIMP-2 may be closely related to the invasion and metastasis of HCC, which can be used as a predictor of recurrence and metastasis for postoperative patients.

  17. The stability of potassium iodate in crude table salt.

    Science.gov (United States)

    ARROYAVE, G; PINEDA, O; SCRIMSHAW, N S

    1956-01-01

    An experiment carried out by the authors confirms that the addition, under commercial conditions, of potassium iodate to crude sea salt is a reliable method for the iodization of salt, a fact of particular significance to countries in which iodization by potassium iodide is unsatisfactory owing to adverse environmental conditions.

  18. Potassium cycling and losses in grassland systems : a review

    NARCIS (Netherlands)

    Kayser, M; Isselstein, J

    Cycling of potassium in grassland systems has received relatively little attention in research and practice in recent years. Balanced nutrient systems require consideration of nutrients other than nitrogen (N). Potassium (K) is needed in large amounts and is closely related to N nutrition. In

  19. Urinary potassium excretion and risk of cardiovascular events

    NARCIS (Netherlands)

    Kieneker, L.M.; Gansevoort, R.T.; Boer, de R.; Brouwers, Frank P.; Feskens, E.J.M.; Geleijnse, J.M.; Navis, G.; Bakker, Stephan L.J.; Joosten, M.M.

    2016-01-01

    Background: Observational studies on dietary potassium and risk of cardiovascular disease (CVD) have reported weak-to-modest inverse associations. Long-term prospective studies with multiple 24-h urinary samples for accurate estimation of habitual potassium intake, however, are scarce.

  20. 40 CFR 721.10021 - Magnesium potassium titanium oxide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Magnesium potassium titanium oxide... Specific Chemical Substances § 721.10021 Magnesium potassium titanium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as magnesium...

  1. Process for preparation of potassium-38. [DOE patent application

    Science.gov (United States)

    Lambrecht, R.M.; Wolf, A.P.

    A solution of potassium-38 suitable for use as a radiopharmaceutical and a method for its production. Argon is irradiated with protons having energies above the threshold for the /sup 40/Ar(p,3n)/sup 38/K reaction. The resulting potassium-38 is dissolved in a sterile water and any contaminating chlorine-38 is removed.

  2. Crystal structure of the sodium-potassium pump

    DEFF Research Database (Denmark)

    Morth, J Preben; Pedersen, Bjørn Panyella; Toustrup-Jensen, Mads S;

    2007-01-01

    The Na+,K+-ATPase generates electrochemical gradients for sodium and potassium that are vital to animal cells, exchanging three sodium ions for two potassium ions across the plasma membrane during each cycle of ATP hydrolysis. Here we present the X-ray crystal structure at 3.5 A resolution of the...

  3. Differences in serum potassium concentrations between Chinese, Indians and Malays.

    Science.gov (United States)

    Hawkins, Robert C

    2010-01-01

    It has been suggested that potassium concentrations may vary between different geographical regions, possibly reflecting ethnic differences in potassium status. This study compared the serum potassium concentrations of three Asian ethnicities in a single geographical location. Details of simultaneous serum potassium, creatinine, cholesterol, triglyceride and serum index measurements for samples from polyclinics and health screening were extracted for multivariable linear regression. Haemolysed and duplicate patient samples were excluded. Separate analysis was performed based on measurement platform (Roche or Beckman-Coulter) and patient location. Eighty-five thousand nine hundred and ninety-seven records met the inclusion criteria. When controlled for age, gender, serum creatinine, cholesterol and triglyceride, the average serum potassium concentration in Indians was 0.13-0.16 mmol/L higher than in Malays, who in turn had average serum potassium concentrations 0.05-0.06 mmol/L higher than Chinese when controlled for age, gender, serum creatinine, cholesterol and triglyceride concentrations. For patients undergoing health screening, the average serum potassium concentration in Indians and Malays was 0.12 mmol/L higher than in Chinese. Chinese individuals have lower average serum potassium concentrations than Indians and Malays. This may have clinical implications in relation to the high occurrence of thyrotoxic hypokalaemic paralysis and the aetiology of sudden unexplained death syndrome (SUDS) in Asians.

  4. A novel role for extracellular signal-regulated kinase in maintaining long-term memory-relevant excitability changes.

    Science.gov (United States)

    Cohen-Matsliah, Sivan Ida; Brosh, Inbar; Rosenblum, Kobi; Barkai, Edi

    2007-11-14

    Pyramidal neurons in the piriform cortex from olfactory-discrimination-trained rats show enhanced intrinsic neuronal excitability that lasts for several days after learning. Such enhanced intrinsic excitability is mediated by long-term reduction in the postburst afterhyperpolarization (AHP), which is generated by repetitive spike firing. AHP reduction is attributable to decreased conductance of a calcium-dependent potassium current, the sI(AHP). We have previously shown that such learning-induced AHP reduction is maintained by PKC activation. However, the molecular machinery underlying such long-lasting modulation of intrinsic excitability is yet to be fully described. Here we examine whether the extracellular signal-regulated kinase I/II (ERKI/II) pathway, which is known to be crucial in learning, memory, and synaptic plasticity processes, is instrumental for the long-term maintenance of learning-induced AHP reduction. PD98059 or UO126, which selectively block MEK, the upstream kinase of ERK, increased the AHP in neurons from trained rats but not in neurons from naive and pseudo-trained rats. Consequently, the differences in AHP amplitude and neuronal adaptation between neurons from trained rats and controls were abolished. This effect was not mediated by modulation of basic membrane properties. In accordance with its effect on neuronal excitability, the level of activated ERK in the membranal fraction was significantly higher in piriform cortex samples taken from trained rats. In addition, the PKC activator OAG (1-oleoyl-20acety-sn-glycerol), which was shown to reduce the AHP in neurons from control rats, had no effect on these neurons in the presence of PD98059. Our data show that ERK has a key role in maintaining long-lasting learning-induced enhancement of neuronal excitability.

  5. Study on the Effect of Calcium and Potassium Spray on Date Bunch Fading Disorder

    Directory of Open Access Journals (Sweden)

    Hosein Shekofteh

    2017-02-01

    weight, fruit length, fruit diameter, stone weight, stone diameter, and bunch fading percentage at 1℅ level. The highest wet fruit weight, fruit length, fruit diameter, stone weight, and stone diameter were attained in the treatment containing combined application of calcium nitrate and potassium sulfate. Furthermore, the lowest amounts of these traits were obtained in control. The lowest and highest percentage of date bunch fading belonged to the combined treatment of calcium nitrate and potassium sulfate, and control, respectively. In general, application of calcium nitrate and potassium sulfate with each other improved fruit traits and reduced bunch fading percentage. Calcium mobility in the plant takes place mainly in the xylem, together with water. Therefore, calcium uptake is directly related to plant transpiration rate. Conditions of high humidity, cold and low transpiration rates may result in calcium deficiency. Salinity might also cause calcium deficiency because it decreases water uptake by the plant. Since calcium mobility in plants is limited, calcium deficiency appears in younger leaves and in fruits, because they have a very low transpiration rate. Therefore, it is necessary to have a constant supply of calcium for continued growth. Calcium deficiency is usually caused by low calcium availability or water stress which results in low transpiration rates. Calcium is an essential plant nutrient with many roles including participation in metabolic processes of other nutrients uptake, promotion of proper plant cell elongation, and improvement of cell wall structure – calcium is an essential part of plant cell wall. It forms calcium pectate compounds which give stability to cell walls and bind cells together. It also helps protecting the plant against heat stress - calcium improves stomata function and participates in induction of heat shock proteins. In addition, it helps protecting the plant against diseases - numerous fungi and bacteria secret enzymes

  6. The Molecular Basis of Polyunsaturated Fatty Acid Interactions with the Shaker Voltage-Gated Potassium Channel.

    Directory of Open Access Journals (Sweden)

    Samira Yazdi

    2016-01-01

    Full Text Available Voltage-gated potassium (KV channels are membrane proteins that respond to changes in membrane potential by enabling K+ ion flux across the membrane. Polyunsaturated fatty acids (PUFAs induce channel opening by modulating the voltage-sensitivity, which can provide effective treatment against refractory epilepsy by means of a ketogenic diet. While PUFAs have been reported to influence the gating mechanism by electrostatic interactions to the voltage-sensor domain (VSD, the exact PUFA-protein interactions are still elusive. In this study, we report on the interactions between the Shaker KV channel in open and closed states and a PUFA-enriched lipid bilayer using microsecond molecular dynamics simulations. We determined a putative PUFA binding site in the open state of the channel located at the protein-lipid interface in the vicinity of the extracellular halves of the S3 and S4 helices of the VSD. In particular, the lipophilic PUFA tail covered a wide range of non-specific hydrophobic interactions in the hydrophobic central core of the protein-lipid interface, while the carboxylic head group displayed more specific interactions to polar/charged residues at the extracellular regions of the S3 and S4 helices, encompassing the S3-S4 linker. Moreover, by studying the interactions between saturated fatty acids (SFA and the Shaker KV channel, our study confirmed an increased conformational flexibility in the polyunsaturated carbon tails compared to saturated carbon chains, which may explain the specificity of PUFA action on channel proteins.

  7. Impact of potassium doping on the electronic structure of tetracene and pentacene: An electron energy-loss study

    Energy Technology Data Exchange (ETDEWEB)

    Roth, Friedrich, E-mail: Friedrich.Roth@cfel.de [Center for Free-Electron Laser Science / DESY, Notkestraße 85, D-22607 Hamburg (Germany); Knupfer, Martin, E-mail: M.Knupfer@ifw-dresden.de [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany)

    2015-10-21

    We report the doping induced changes of the electronic structure of tetracene and pentacene probed by electron energy-loss spectroscopy in transmission. A comparison between the dynamic response of undoped and potassium-intercalated tetracene and pentacene emphasizes the appearance of a new excitation feature in the former gap upon potassium addition. Interestingly, the momentum dependency of this new excitation shows a negative dispersion. Moreover, the analysis of the C 1s and K 2p core-level excitation results in a significantly lower doping level compared to potassium doped picene, a recently discovered superconductor. Therefore, the present electronic structure investigations open a new pathway to better understand the exceptional differences between acenes and phenacene and their divergent behavior upon alkali doping.

  8. Adjusted nutrition of tomato with potassium and zinc in drought stress conditions induced by polyethylene glycol 6000 in hydroponic culture

    Directory of Open Access Journals (Sweden)

    F. S. Sadoogh

    2014-07-01

    Full Text Available In drought stress conditions, besides the inhibition of water uptake, the plant nutrients availability and uptake are also limited. Proper nutrition is known as a management procedure for plant production under different environmental-stress conditions. Generally, the combined effects of drought and deficiency of potassium and zinc on plant water content and some physiological parameters reduce yield quantity and quality. This investigation was conducted to assess the interactive effect of different levels of potassium as KNO3 (0.6, 3 and 6 mM and zinc as ZnSO4 (0, 1 and 2 μM, under drought stress conditions induced with PEG 6000 (0, 55 and 110 g/L PEG 6000 on some water status indices and physiological parameters of tomato in hydroponic culture. The results showed that interaction of drought, potassium and zinc on shoot and root dry weight, leaf chlorophyll and proline content and percentage of root ion leakage was significant. Both potassium and zinc improved water status of the plants; however the effect of zinc on leaf water potential was not significant. Drought stress increased the chlorophyll content and decreased the sulfhydryl groups. Application of a high level of potassium in the nutrient solution increased root ion leakage.

  9. Potassium sorbate-A new aqueous copper corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Abelev, Esta [Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Starosvetsky, David [Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Ein-Eli, Yair [Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel)]. E-mail: eineli@tx.technion.ac.il

    2007-01-01

    This work presents the novel nature of 2,4-hexadienoic acid potassium salt (potassium sorbate (KCH{sub 3}CH=CHCH=CHCO{sub 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.

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

    DEFF Research Database (Denmark)

    Findsen, Anders; Pedersen, Thomas Holm; Nielsen, Ole Bækgaard

    Many insect species enter a comatose state when their body temperature is lowered to a critical limit (critical thermal minimum) but the physiological and cellular processes that underlie chill coma are still unresolved. Several studies have demonstrated that transition into chill-coma involves...

  11. Increasing plasma [K+] by intravenous potassium infusion reduces NCC phosphorylation and drives kaliuresis and natriuresis.

    Science.gov (United States)

    Rengarajan, Srinivas; Lee, Donna H; Oh, Young Taek; Delpire, Eric; Youn, Jang H; McDonough, Alicia A

    2014-05-01

    Dietary potassium loading results in rapid kaliuresis, natriuresis, and diuresis associated with reduced phosphorylation (p) of the distal tubule Na(+)-Cl(-) cotransporter (NCC). Decreased NCC-p inhibits NCC-mediated Na(+) reabsorption and shifts Na(+) downstream for reabsorption by epithelial Na(+) channels (ENaC), which can drive K(+) secretion. Whether the signal is initiated by ingesting potassium or a rise in plasma K(+) concentration ([K(+)]) is not understood. We tested the hypothesis, in male rats, that an increase in plasma [K(+)] is sufficient to reduce NCC-p and drive kaliuresis. After an overnight fast, a single 3-h 2% potassium (2%K) containing meal increased plasma [K(+)] from 4.0 ± 0.1 to 5.2 ± 0.2 mM; increased urinary K(+), Na(+), and volume excretion; decreased NCC-p by 60%; and marginally reduced cortical Na(+)-K(+)-2Cl(-) cotransporter (NKCC) phosphorylation 25% (P = 0.055). When plasma [K(+)] was increased by tail vein infusion of KCl to 5.5 ± 0.1 mM over 3 h, significant kaliuresis and natriuresis ensued, NCC-p decreased by 60%, and STE20/SPS1-related proline alanine-rich kinase (SPAK) phosphorylation was marginally reduced 35% (P = 0.052). The following were unchanged at 3 h by either the potassium-rich meal or KCl infusion: Na(+)/H(+) exchanger 3 (NHE3), NHE3-p, NKCC, ENaC subunits, and renal outer medullary K(+) channel. In summary, raising plasma [K(+)] by intravenous infusion to a level equivalent to that observed after a single potassium-rich meal triggers renal kaliuretic and natriuretic responses, independent of K(+) ingestion, likely driven by decreased NCC-p and activity sufficient to shift sodium reabsorption downstream to where Na(+) reabsorption and flow drive K(+) secretion.

  12. Gut sensing of potassium intake and its role in potassium homeostasis.

    Science.gov (United States)

    Youn, Jang H

    2013-05-01

    Extracellular K(+) homeostasis has been explained by feedback mechanisms in which changes in extracellular K(+) concentration drive renal K(+) excretion directly or indirectly via stimulating aldosterone secretion. However, this cannot explain meal-induced kaliuresis, which often occurs without increases in plasma K(+) or aldosterone concentrations. Recent studies have produced evidence supporting a feedforward control in which gut sensing of dietary K(+) increases renal K(+) excretion (and extrarenal K(+) uptake) independent of plasma K(+) concentrations, namely, a gut factor. This review focuses on these new findings and discusses the role of gut factor in acute and chronic regulation of extracellular K(+) as well as in the beneficial effects of high K(+) intake on the cardiovascular system.

  13. Potassium dihydrogen phosphate and potassium tantalate niobate pyroelectric materials and far-infrared detectors

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, H. B. [Lawrence Berkeley Lab., CA (United States); [California Univ., Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

    1993-10-01

    This thesis discusses characterization of two ferroelectric materials and the fabrication of bolometers. Potassium tantalate niobate (KTN) and potassium dihydrogen phosphate (KDP) are chosen because they can be optimized for operation near 100K. Chap. 2 reviews the physics underlying pyroelectric materials and its subclass of ferroelectric materials. Aspects of pyroelectric detection are discussed in Chap. 3 including measurement circuit, noise sources, and effects of materials properties on pyroelectric response. Chap. 4 discusses materials selection and specific characteristics of KTN and KDP; Chap. 5 describes materials preparation; and Chap. 6 presents detector configuration and a thermal analysis of the pyroelectric detector. Electrical techniques used to characterize the materials and devices and results are discussed in Chap. 7 followed by conclusions on feasibility of KDP and KTN pyroelectric detectors in Chap. 8.

  14. Electrocaloric properties of potassium tantalate niobate crystals

    Science.gov (United States)

    Maiwa, Hiroshi

    2016-10-01

    The electrocaloric properties of potassium tantalate niobate (KTN) crystals were investigated by indirect estimation and direct measurement of temperature-electric field (T-E) hysteresis loops. The measured T-E loops showed a similar shape to strain-electric field (s-E) loops. The adiabatic temperature change ΔT due to the electrocaloric effect was estimated from the polarization change of this sample to be 0.49 K under a field of 20 kV/cm. The measured temperature change ΔT in these samples upon the release of the electric field from 20 kV/cm to zero was 0.42 K. The temperature dependences of the electromechanical and electrocaloric properties were measured. The maximum performance appeared at approximately the phase transition temperature of KTN crystal and the properties were relatively moderate-temperature-dependent.

  15. High pressure studies of potassium perchlorate

    Science.gov (United States)

    Pravica, Michael; Wang, Yonggang; Sneed, Daniel; Reiser, Sharissa; White, Melanie

    2016-09-01

    Two experiments are reported on KClO4 at extreme conditions. A static high pressure Raman study was first conducted to 18.9 GPa. Evidence for at least two new phases was observed: one between 2.4 and 7.7 GPa (possibly sluggish), and the second near 11.7 GPa. Then, the X-ray induced decomposition rate of potassium perchlorate (KClO4 → hν KCl + 2O2) was studied up to 15.2 GPa. The time-dependent growth of KCl and O2 was monitored. The decomposition rate slowed at higher pressures. We present the first direct evidence for O2 crystallization at higher pressures, demonstrating that O2 molecules aggregate at high pressure.

  16. Protein Complexes in Urine Interfere with Extracellular Vesicle Biomarker Studies

    OpenAIRE

    Magda Wachalska; Danijela Koppers-Lalic; Monique van Eijndhoven; Michiel Pegtel; Geldof, Albert A.; Lipinska, Andrea D.; R. Jeroen van Moorselaar; Irene V. Bijnsdorp

    2016-01-01

    Urine exosomes (extracellular vesicles; EVs) contain (micro)RNA (miRNA) and protein biomarkers that are useful for the non-invasive diagnosis of various urological diseases. However, the urinary Tamm-Horsfall protein (THP) complex, which forms at reduced temperatures, may affect EV isolation and may also lead to contamination by other molecules including microRNAs (miRNAs). There‐ fore, we compared the levels of three miRNAs within the purified EV fraction and THP- protein-network. Urine was ...

  17. Minireview: potassium channels and aldosterone dysregulation: is primary aldosteronism a potassium channelopathy?

    Science.gov (United States)

    Gomez-Sanchez, Celso E; Oki, Kenji

    2014-01-01

    Primary aldosteronism is the most common form of secondary hypertension and has significant cardiovascular consequences. Aldosterone-producing adenomas (APAs) are responsible for half the cases of primary aldosteronism, and about half have mutations of the G protein-activated inward rectifying potassium channel Kir3.4. Under basal conditions, the adrenal zona glomerulosa cells are hyperpolarized with negative resting potentials determined by membrane permeability to K(+) mediated through various K(+) channels, including the leak K(+) channels TASK-1, TASK-3, and Twik-Related Potassium Channel 1, and G protein inward rectifying potassium channel Kir3.4. Angiotensin II decreases the activity of the leak K(+) channels and Kir3.4 channel and decreases the expression of the Kir3.4 channel, resulting in membrane depolarization, increased intracellular calcium, calcium-calmodulin pathway activation, and increased expression of cytochrome P450 aldosterone synthase (CYP11B2), the last enzyme for aldosterone production. Somatic mutations of the selectivity filter of the Kir3.4 channel in APA results in loss of selectivity for K(+) and entry of sodium, resulting in membrane depolarization, calcium mobilization, increased CYP11B2 expression, and hyperaldosteronism. Germ cell mutations cause familial hyperaldosteronism type 3, which is associated with adrenal zona glomerulosa hyperplasia, rather than adenoma. Less commonly, somatic mutations of the sodium-potassium ATPase, calcium ATPase, or the calcium channel calcium channel voltage-dependent L type alpha 1D have been found in some APAs. The regulation of aldosterone secretion is exerted to a significant degree by activation of membrane K(+) and calcium channels or pumps, so it is not surprising that the known causes of disorders of aldosterone secretion in APA have been channelopathies, which activate mechanisms that increase aldosterone synthesis.

  18. Extracellular matrix and tissue engineering applications

    NARCIS (Netherlands)

    Fernandes, Hugo; Moroni, Lorenzo; Blitterswijk, van Clemens; Boer, de Jan

    2009-01-01

    The extracellular matrix is a key component during regeneration and maintenance of tissues and organs, and it therefore plays a critical role in successful tissue engineering as well. Tissue engineers should recognise that engineering technology can be deduced from natural repair processes. Due to a